Tech

4月 092019
 

Natural language understanding (NLU) is a subfield of natural language processing (NLP) that enables machine reading comprehension. While both understand human language, NLU goes beyond the structural understanding of language to interpret intent, resolve context and word ambiguity, and even generate human language on its own. NLU is designed for communicating with non-programmers – to understand their intent and act on it. NLU algorithms tackle the extremely complex problem of semantic interpretation – that is, understanding the intended meaning of spoken or written language, with all the subtleties, of human error, such as mispronunciations or fragmented sentences.

How does it work?

After your data has been analyzed by NLP to identify parts of speech, etc., NLU utilizes context to discern meaning of fragmented and run-on sentences to execute intent. For example, imagine a voice command to Siri or Alexa:

Siri / Alexa play me a …. um song by ... um …. oh I don’t know …. that band I like …. the one you played yesterday …. The Beach Boys … no the bass player … Dick something …

What are the chances of Siri / Alexa playing a song by Dick Dale? That’s where NLU comes in.

NLU reduces the human speech (or text) into a structured ontology – a data model comprising of a formal explicit definition of the semantics (meaning) and pragmatics (purpose or goal). The algorithms pull out such things as intent, timing, location and sentiment.

The above example might break down into:

Play song [intent] / yesterday [timing] / Beach Boys [artist] / bass player [artist] / Dick [artist]

By piecing together this information you might just get the song you want!

NLU has many important implications for businesses and consumers alike. Here are some common applications:

    Conversational interfaces – BOTs that can enhance the customer experience and deliver efficiency.
    Virtual assistants – natural language powered, allowing for easy engagement using natural dialogue.
    Call steering – allowing customers to explain, in their own words, why they are calling rather than going through predefined menus.
    Smart listener – allowing users to optimize speech output applications.
    Information summarization – algorithms that can ‘read’ long documents and summarize the meaning and/or sentiment.
    Pre-processing for machine learning (ML) – the information extracted can then be fed into a machine learning recommendation engine or predictive model. For example, NLU and ML are used to sift through novels to predict which would make hit movies at the box office!

Imagine the power of an algorithm that can understand the meaning and nuance of human language in many contexts, from medicine to law to the classroom. As the volumes of unstructured information continue to grow exponentially, we will benefit from computers’ tireless ability to help us make sense of it all.

Further Resources:
Natural Language Processing: What it is and why it matters

White paper: Text Analytics for Executives: What Can Text Analytics Do for Your Organization?

SAS® Text Analytics for Business Applications: Concept Rules for Information Extraction Models, by Teresa Jade, Biljana Belamaric Wilsey, and Michael Wallis

Unstructured Data Analysis: Entity Resolution and Regular Expressions in SAS®, by Matthew Windham

So, you’ve figured out NLP but what’s NLU? was published on SAS Users.

4月 082019
 


As word spreads that SAS integrates with open source technologies, people are beginning to explore how to connect, interact with, and use SAS in new ways. More and more users are examining the possibilities and with this comes questions like: How do I code A, integrate B, and accomplish C?

Documentation is plentiful but is undergoing a makeover. People aren’t sure where to go for help – and that's why we're launching the SAS Developers Community, where you can gather to ask questions and get answers.

The community will mirror the activities in existing SAS Communities: Q&A, library articles, tips, technical discussions, etc. We migrated some content from other boards. For example, we moved the content from the Coding on SAS Viya board to the new community. Additionally, we scoured other boards for content that may be better aligned with developers and moved it. We also created some original content. Any good community needs participation by all, so read on and get the 411 on the new Developers Community.

Who is the target audience?

Developers – data scientists, application developers, analysts, programmers and administrators – who need to access SAS resources and/or run SAS procedures. This audience may or may not have SAS programming skills but need to access and analyze data using SAS.

What can developers expect to find?

The Developers Community provides a forum for collaboration, Q&A, and knowledge and resource sharing. The focus will be on developers using open source languages and technology. The community will create synergy between communities.sas.com, developer.sas.com, and github.com/sassoftware. SAS employees and external users will post how-to articles and other items of interest in the library section of the community. This community will not replace the SAS Programming Communities, rather, it will fill a void for non-SAS programmers who have a need/desire to interact with SAS.

When will the community launch?

The Developers Community is live! The site is public, and we've moved existing artifacts to the community. I am attending SAS Global Forum and will be available to answer questions about the new community from our booth in the Quad. Come by and see me!

Where will the community live?

The Developers Community exists on communities.sas.com, under the Developers Category.

Why do we need a community for developers?

Developers need a centralized place to share ideas, ask and answer questions, and discover resources. Currently developers lack a forum to work through things such as authentication, coding, API use, and integration issues. The community will encourage communication, engagement and leadership. Also, the Developers Community will be tightly integrated with the SAS Developers web site and SAS GitHub resources.

How do we go about creating the community?

After seeding the SAS Developer Community with existing discussions, we'll build out a group of SAS developer experts to help monitor the community. The true magic will happen as questions are asked, discussions transpire, and ideas are shared. But we need to your help too. Here is your call to action.

Share the community with your networks, buddies and even family members who may get something out of chatting it up about how to develop in SAS. The livelihood of the community hinges on user interaction. Our current and future users will thank you for it. And you may make a friend while you're at it.

Launching the Developers Community in SAS Communities was published on SAS Users.

4月 082019
 
The catch phrase “everything happens somewhere” is increasingly common these days.  That “somewhere” translates into a location on the Earth; a latitude and longitude.  When one of these “somewhere’s” is combined with many other “somewhere’s”, you quickly have a robust spatial data set that becomes actionable with the right analytic tools.

Opportunities for Spatial Analytics are increasing

In today’s modern world, GPS-enabled devices are ubiquitous, and their use continues to increase daily.  Cell phones, cars, fitness trackers, and cameras are all able to locate and track our position.  As a result, the location analytics market is expected to grow to over USD 16 Billion by 2021, up 17.6% from 2016 [1].

Waldo Tobler, an American-Swiss geographer and cartographer, developed his First Law of Geography based on this concept of everything happening somewhere.  He stated, “Everything is related to everything else, but near things are more related than distant things”[2].  As analytic professionals, we are accustomed to working with these correlations using scatterplots, heatmaps, or clustering models.  But what happens when we add a geographic map into the analysis?

Maps offer the ability to unlock a new level of insight into our data that traditional graphs do not offer: personal connection.  As humans, we naturally relate to our surroundings on a spatial level.   It helps build our perspective and frame of reference through which we view and navigate the world.  We feel a sense of loss when a physical landmark from our childhood – a building, tree, park, or route we used to walk to school – is destroyed or changed from the memories we have of it.  In this sense, we are connected, spatially and emotionally, to our surroundings.

We inherently understand how data relates to the world around us, at some level, just by viewing it on a map.  Whether it is a body of water or a mountain affecting a driving route or maybe a trendy area of a city causing housing prices to increase faster than the local average, a map connects us with these facts intuitively.  We come to these basic conclusions based solely on our experiences in the world and knowledge of the physical landmarks in the map.

One of the best examples of this is the 1854 Cholera outbreak in London.  Dr. John Snow was one of the first to use a map for understanding the origin of an epidemiological outbreak.  He created a map of the affected London neighborhood by plotting the location of all known Cholera deaths.  In addition to the deaths, he also plotted the location of 13 community wells that served as the public water supply.  Using this data, he was able to see a clustering of deaths around a single pump.  Armed with this information, Dr. Snow was able to convince local officials to remove the handle from the Broad Street pump.  Once removed, new cases of Cholera quickly began to diminish.  This helped prove his theory the outbreak’s origin was not air-borne as commonly believed during that time, but rather of a water-borne origin. [3]

1854 London Cholera deaths: Tabular data vs. Coordinate map [3]

Let’s look at how Dr. Snow’s map helped mitigate the outbreak and prove his theory.  The image above compares the data of the recorded deaths and community wells in tabular form to a Coordinate map.  It is obvious from the coordinate map that there is a clustering of points.  Town officials and those familiar with the neighborhood could easily get a sense of where the outbreak was concentrated.  The map told a better story by connecting their personal experience of the area to the locations of the deaths and ultimately to the wells.  Something a data table or traditional graph could not do.

Maps of London Cholera deaths with modern analytic overlays [3]

Today, with the computing power and modern analytic methods available to us, we can take the analysis even further.  The examples above show the same coordinate map with added Voronoi polygon and cluster analysis overlays.  The concentration around the Broad Street pump becomes even clearer, showing why Geographic Maps are an important tool to have in your analytic toolbox.

SAS Global Forum 2019 is being held April 28-May 1, 2019 in Dallas, Texas.  If you are planning to go to this year’s event, be sure to attend one of our presentations on the latest mapping features included in SAS Visual Analytics and BASE SAS.  While you’re there, don’t forget to stop by the SAS Mapping booth located in the QUAD to say ‘Hi!’ and let us help with your spatial data needs.  See you in Dallas!

Introduction to Esri Integration in SAS Visual Analytics

  • Monday, April 29, 4:30-5:30p, Room: Level 1, D162

There’s a Map for That! What’s New and Coming Soon in SAS Mapping Technologies

  • Tuesday April 30, 4:00-4:30p, Room: Level 1, D162

Creating Great Maps in ODS Graphics Using the SGMAP Procedure

  • Wednesday May 01, 11:30a-12:30p, Room: Level 1, D162

[1] https://www.marketsandmarkets.com/Market-Reports/location-analytics-market-177193456.html

[2] https://en.wikipedia.org/wiki/Tobler%27s_first_law_of_geography

[3] https://www1.udel.edu/johnmack/frec682/cholera/

How the 1854 Cholera outbreak showed us the importance of spatial analysis was published on SAS Users.

4月 052019
 

Recently, you may have heard about the release of the new SAS Analytics Cloud. The platform allows fast access to data-science applications in the cloud! Running on the SAS Cloud and using the latest container technology, Analytics Cloud eliminates the need to install, update, or maintain software or related infrastructure.

SAS Machine Learning on SAS Analytics Cloud is designed for SAS and open source data scientists to gain on-demand programmatic access to SAS Viya. All the algorithms provided by SAS Visual Data Mining and Machine Learning (VDMML), SAS Visual Statistics and SAS Visual Analytics are available through the offering. Developers and data scientists access SAS through a programming interface using either the SAS or Python programming languages.

A free trial for Analytics Cloud is available, and registration is simple. The trial environment allows users to manage and collaborate with others, share data, and create runtime models to analyze their data. The system is pre-loaded with sample data for learning, and allows users to upload their own data. My colleague Joe Furbee explains how to register for the trial and takes you on a tour of the system in his article, Zero to SAS in 60 Seconds- SAS Machine Learning on SAS Analytics Cloud.

Luckily, I had the privilege of being the technical writer for the documentation for SAS Analytics Cloud, and through this met two of my now close friends at SAS.

Alyssa Andrews (pictured left) and Mariah Bragg (pictured right) are both Software Developers at SAS, but worked on the UI for SAS Analytics Cloud. Mariah works in the Research and Development (R&D) division of SAS while Alyssa works in the Information Technology (IT) division. As you can see this project ended up being an interesting mix of SAS teams!

As Mariah told me the history, I learned that SAS Analytics Cloud “was a collaborative project between IT and R&D. The IT team presented the container technology idea to Dr. Goodnight but went to R&D because they wanted this idea run like an R&D project.”

As we prepared for the release of SAS Analytics Cloud to the public, I asked Mariah and Alyssa about their experience working on the UI for SAS Analytics Cloud, and about all the work that they had completed to bring this powerful platform to life!


What is SAS Analytics Cloud for you? How do you believe it will help SAS users?

Alyssa: For me, it is SAS getting to do Software as a Service. So now you can click on our SAS Software and it can magically run without having to add the complexity of shipping a technical support agent to the customers site to install a bunch of complex software.

Mariah: I agree. This will be a great opportunity for SAS to unify and have all our SAS products on cloud.

Alyssa: Now, you can trial and then pay for SAS products on the fly without having to go through any complexities.

What did you do on the project as UI Developers?

Alyssa: I was lent out to the SAS Analytics Cloud team from another team and given a tour-of-duty because I had a background in Django (a high-level Python Web design tool) which is another type of API framework you can build a UI on top of. Then I met Mariah, who came from an Angular background, and we decided to build the project on Angular. So, I would say Mariah was the lead developer and I was learning from her. She did more of the connecting to the API backend and building the store part out, and I did more of the tweaks and the overlays.

What is something you are proud of creating for SAS Analytics Cloud?

Mariah: I’m really proud to be a part of something that uses Angular. I think I was one of the first people to start using Angular at SAS and I am so excited that we have something out there that is using this new technology. I am also really proud of how our team works together, and I’m really proud of how we architectured the application. We went through multiple redesigns, but they were very manageable, and we really built and designed such that we could pull out components and modify parts without much stress.

Alyssa: That we implemented good design practices. It is a lot more work on the front-end, but it helps so much not to have just snowflake code (a term used by developers to describe code that isn’t reusable or extremely unique to where it becomes a problem later on and adds weight to the program) floating. Each piece of code is there for a reason, it’s very modular.

What are your hopes for the future of SAS Analytics Cloud?

Alyssa: I hope that it continues to grow and that we add even more applications to this new container technology, so that SAS can move even more into the cloud arena. I hope it brings success. It is a really cool platform, so I can’t wait to hear about users and their success with it.

Mariah:
I agree with Alyssa. I also hope it is successful so that we keep moving into the Cloud with SAS.

Learning more

As a Developmental Editor with SAS Press, it was a new and engaging experience to get to work with such an innovative technology like SAS Analytics Cloud. I was happy I got to work with such an exciting team and I also look forward to what is next for SAS Analytics Cloud.

And as a SAS Press team member, I hope you check out the new way to trial SAS Machine Learning with SAS Analytics Cloud. And while you are learning SAS, check out some of our great books that can help you get started with SAS Studio, like Ron Cody’s Biostatistics by Example Using SAS® Studio and also explore Geoff Der and Brian Everitt’s Essential Statistics Using SAS® University Edition.

Already experienced but want to know more about how to integrate R and Python into SAS? Check out Kevin D. Smith’s blogs on R and Python with SAS Viya. Also take a moment to investigate our new books on using open source R and Python with SAS Viya: SAS Viya: The R Perspective by Yue Qi, Kevin D. Smith, and XingXing Meng and SAS Viya: The Phyton Perspective by Kevin D. Smith and XingXing Meng.

These great books can set you on the right path to learning SAS before you begin your jump into SAS Analytics Cloud, the new way to experience SAS.

SAS® Analytics Cloud—an interview with the women involved was published on SAS Users.

4月 052019
 

You are a data scientist, in your office, doing data scientist-y things when, your manager's, manager's, manager makes an impossible request. She wants you take a raw data set from the stem cell research team, scrub the data, create and score models, and be ready to rescore when new data comes is available. And she wants it in a week. WHAT?! Your company doesn't own an analytics software license, and a spreadsheet is not going to work on this data with millions of records. Even if you received funding, how could you ever create and maintain an environment under your tight deadline? Take a deep breath, conjure your inner data scientist acumen, and realize SAS has the answer.

SAS Machine Learning on SAS Analytics Cloud provides on-demand programming access to machine learning algorithms in the cloud. No downloads, no install, no infrastructure, no maintenance. This solution provides a multithreaded, multiuser environment for concurrent access to data in memory. The solution is designed for data scientists (and others) coding in SAS or Python and allows them on-demand programmatic access to SAS Viya. You can find more details on Analytic Cloud in the fact sheet. You can even try it for free! The rest of this article will walk you through the features of this new SAS offering and outline how it can help you complete the task bestowed upon you.

Register and get started

Literally, to sign up for the trial, all you need are a SAS Profile, an email address, and a PC. You will be coding in SAS in less than a minute. From the SAS Cloud Analytics page, select the Get Free Trial button. This takes you to the SAS Profile login page (note you can create your SAS Profile here if you do not have one).

SAS Profile log in or creation

Agree to the Terms and Conditions on the License Agreement page and select the Continue button:

Trial License Agreement

You will receive an email containing a URL much like the following:

email confirmation with trial URL

Logging in

Select the link or paste it into your browser (Google Chrome 64-bit recommended) and you will see the log in screen. Enter your SAS Profile credentials and click the Sign In button.

Sign In screen

The Home screen (Applications) appears.

Home Page

We'll discuss the Data and Team pages in further detail later on in this article. You have two options for applications: SAS Studio (for SAS programming) and JupyterLab (for Python programming). This article focuses on SAS Studio. A follow up article will cover the JupyterLab use case. Select the SAS Studio button, a new tab opens to SAS Studio, and we're ready to start coding.

SAS Studio

You are familiar with the SAS language, but you need to brush up a little. Have no fear, support documentation is easily accessible. Also, the SAS Data Mining and Machine Learning Community is a great place to discover additional resources and ask questions. Finally, embedded in SAS Studio are code snippets. You decide to explore the latter.

Code snippets

In SAS Studio select the Snippets twisty in the left pane. Navigate to the SAS Viya Machine Learning section. Here you find code samples you will use to prep and analyze your data. When opening a snippet, you see code and detailed comments on what the code will accomplish. You will use these snippets as a guide when you load and prep your data and preform your analysis. Below is an image of the Prepare and Explore Data snippet. Notice each code step has accompanying comments.

You read through each snippet in the Machine Learning section. The command and structure of the code comes back to you pretty quickly and you're now ready to try it all out on your own data.

Uploading data

Now that you have an idea of what code you need to write, you need to load the data from the research department. You accomplish this by selecting the Server Files and Folders twisty and navigate to the Folder Shortcuts section. In this instance you want to upload your file into the shared/data directory (I'll explain why I chose this location in a moment). Use the Upload button to upload the research data file.

Upload file to the data directory

You're not alone

Files uploaded to shared/data are now visible by others logged into the environment. Wait, did I forget to mention this is a multi-user environment?! Well, yes, it is. You can invite others to collaborate on the project. To add and manage users, return to the Home screen (leaving SAS Studio open). Select the Team section in the left pane. The Team page lists users and displays an Invite button, used to send an invitation for system access to others.

Teams page

To invite others, click the button and enter the email address of the new user. This generates and sends an invitation in an email. The new user accepts the invite and now has access to the system. Using the URL provided in the email the new user logs in using their own SAS Profile credentials. The default role for new users is ‘User.’ A user with admin privileges can change the role to ‘Admin. In the free trial, you are permitted to have a total of five users.

Shared data

You may have guessed by now the Data section lists directories and files located in the shared directory in SAS Studio.

Data page

You also notice here you have 5 GB of storage space. This includes shared and non-shared files.

I love this. How do I get more?

Now you know your way around the system and are ready to start coding. Return to SAS Studio, open a new program, and commence your analysis of the stem cell data. When you successfully deliver the project and impress your management chain, you can mention how the SAS Analytics Cloud solution made it all possible (and simple). You now have a case for the departmental procurement of the solution opening your organization up to add more users, access more storage, and gain more power to run advanced machine learning algorithms on your data.

Your turn

In this article I've outlined how to easily register for the SAS Machine Learning trial and start coding in the matter of a minute. Try it out yourself. Register, load your data, get coding, and solve your problem.

Related Resources

For more details on the development of SAS Analytics Cloud, check out Missy Hannah's interview with two UI developers on the project.

Zero to SAS in 60 Seconds- SAS Machine Learning on SAS Analytics Cloud was published on SAS Users.

4月 052019
 

When working with files like SAS programs, images, documents, logs, etc., we are used to accessing them in operating system directories. In Viya, many of these files are not stored on the file-system. In this blog, we will look at where and how files are stored in Viya, and how to manage them.

In Viya, external files are stored in the Infrastructure Data server and accessed using the file micro-service. The file service manages a wide variety of file types including, images, html files, text files, csv files, SAS programs, media files, pdfs, office documents and logs. The file service is not a complete file system, but rather a method of accessing individual files stored in the infrastructure data server identified via their URI (a unique identifier).

Some files may also be accessible in Viya folders. The file service stores resources like images, SAS programs, etc. in the Infrastructure Data server, but they are accessible from Viya folders in the Content Area of Environment Manager or in SAS Drive.

The screenshot below shows the properties of an image file that was uploaded to a Viya folder using SAS Drive. You can see the filename, the URI (including the ID) and the location in the folder structure.

For files that are surfaced in folders, we can manage the files (view, copy, move, delete etc.) using SAS Environment Manager Content area, SAS Drive or the Folders command line interface. To learn more, watch this video from the SAS Technical Insights and Expertise Series.

However, many system generated files are managed by the file service and stored in the infrastructure data server, but are not accessible from the folders interfaces. A good example of system generated files that an administrator may need to manage are logs.

Many times when processing in Viya, logs are created and stored in the infrastructure data server. For example, when CAS table state management jobs, data plans, file imports, model or scoring processes are executed, a log is generated and stored by the file service.
How do we manage these files? While the files generated are mostly small in size, a large active Viya system with a long history will need management of the log and other files stored in the infrastructure data server.

One way we can access these files is using the REST API of the file service.

You can use your favorite tool to access the REST API. In this blog, I will use the GEL pyviyatools, initially the basic callrestapi tool. For more details on the pyviyatools, read this blog or go directly to the SAS GitHub site.

To get a list of all files are stored in the infrastructure data server send a GET request to the /files/files endpoint of the files service.

/./callrestapi.py -m get -e /files/files -o simple/

Partial output shows the image file referenced above and what could be a system generated log file.
=====Item 0 =======
contentType = image/jpeg
createdBy = geladm
creationTimeStamp = 2019-01-24T14:40:15.085Z
description = None
encoding = UTF-8
id = 6d2995b3-0fa6-4090-a338-1fbfe51fb26b
modifiedBy = geladm
modifiedTimeStamp = 2019-01-25T17:59:28.500Z
name = company_logo.JPG
properties = {}
size = 327848
version = 2

=====Item 164 =======
contentType = text/plain
createdBy = sasadm
creationTimeStamp = 2019-01-31T12:35:00.902Z
description = None
encoding = UTF-8
id = e4d4c83d-8677-433a-a8d3-b03bf00a5768
modifiedBy = sasadm
modifiedTimeStamp = 2019-01-31T12:35:09.342Z
name = 2019-01-31T12:35.823Z-results.log
parentUri = /jobExecution/jobs/380d3a0c-1c31-4ada-bf8d-4db66e786669
properties = {}
size = 2377
version = 2

To see the content of a file, use a GET request, the id of the file and the content endpoint. The content of the log file is displayed in the call below.

/./callrestapi.py -m get -e /files/files/01eb020f-468a-49df-a05a-34c6f834bfb6/content/

This will display the file contents. The output shows the log from a CAS table state management job.

———-JOB INFORMATION———-

Job Created: 2019-01-31T12:35.823Z
Job ID: 380d3a0c-1c31-4ada-bf8d-4db66e786669
Heartbeat interval: PT0.3S
Job expires after: PT168H
Running as: sasadm
Log file: /files/files/e4d4c83d-8677-433a-a8d3-b03bf00a5768 [ 2019-01-31T12:35.823Z-results.log ]
Arguments:

Options:
{
“enabled” : true,
“type” : “LOAD”,
“settings” : {
“refresh” : false,
“refreshMode” : “newer”,
“refreshAccessThreshold” : 0,
“varChars” : false,
“getNames” : true,
“allowTruncation” : true,
“charMultiplier” : 2,
“stripBlanks” : false,
“guessRows” : 200,
“scope” : “global”,
“encoding” : “utf-8”,
“delimiter” : “,”,
“successJobId” : “”
},
“selectors” : [ {
“serverName” : “cas-shared-default”,
“inputCaslib” : “hrdl”,
“outputCaslib” : “hrdl”,
“filter” : “or(endsWith(tableReference.sourceTableName,’.sashdat’), endsWith(tableReference.sourceTableName,’.SASHDAT’),\nendsWith(tableReference.sourceTableName,’.sas7bdat’),\nendsWith(tableReference.sourceTableName,’.csv’)\n)”,
“settings” : { }
} ]
}

————————————————–

Created session cas-shared-default: d4d1235a-6219-4649-940c-e67526be31ed (CAS Manager:Thu Jan 31 07:35:01 2019)
Using session d4d1235a-6219-4649-940c-e67526be31ed
Server: cas-shared-default
Input caslib: hrdl
Output caslib: hrdl
Effective Settings:

———-LOAD STARTING———-

— loaded –> unloaded – HR_SUMMARY unloaded – HR_SUMMARY_NEW unloaded – HRDATA unloaded – PERFORMANCE_LOOKUP <– performance_lookup.sas7bdat
Access denied.
———-LOAD COMPLETE———-

———-CLEANUP STARTING———-

Session deleted: cas-shared-default: d4d1235a-6219-4649-940c-e67526be31ed
———-CLEANUP COMPLETE———-

Final Job State: completed
Log file:/files/files/e4d4c83d-8677-433a-a8d3-b03bf00a5768

I started my journey into the file service to discover how an administrator could manage the log files. In reviewing the files and their contents using the REST API, I discovered that there was no easy way to uniquely identify a log file. The table below shows the attributes of some of log files from the GEL Shared Viya environment.

As this post has illustrated, file service REST API can be used to list and view the files. It can also be used for other file management activities. To help administrators manage files that are not visible via a user interface, a couple of new tools have been added to the pyiyatools.

listfiles.py provides an easy interface to query what files are currently stored in the infrastructure data server. You can sort files by size or modified date, and query based on date modified, user who last modified the file, parentUri or filename. The output provides the size of each file so that you can check the space being used to store files. Use this tool to view files managed by the file service and stored in the infrastructure data server. You can use lisfiles.py -h to see the parameters.

For example, if I want to see all potential log files older than 6 days old created by the /jobexecution service, I would use:

/./listfiles.py -n log -p /jobExecution -d 6 -o csv/

The output is a list of files in csv format:

id ,name ,contentType ,documentType ,createdBy ,modifiedTimeStamp ,size ,parentUri

“f9b11468-4417-4944-8619-e9ea9cd3fab8″,”2019-01-25T13:35.904Z-results.log”,”text/plain”,”None”,”sasadm”,”2019-01-25T13:35:09.490Z”,”2459″,”/jobExecution/jobs/37536453-fe2f-41c2-ba63-ce72737e482c”

“dffdcc97-3fb0-47c1-a47d-e6c8f24f8077″,”2019-01-25T12:35.869Z-results.log”,”text/plain”,”None”,”sasadm”,”2019-01-25T12:35:08.739Z”,”2459″,”/jobExecution/jobs/99708443-2449-40b7-acc3-c313c5dbca23″

“5fa889b6-93fb-4496-98ba-e0c055ca5999″,”2019-01-25T11:35.675Z-results.log”,”text/plain”,”None”,”sasadm”,”2019-01-25T11:35:09.118Z”,”2459″,”/jobExecution/jobs/eb182f88-4853-41f4-be24-225176991e8a”

“87988659-3c2d-4602-b61a-8042b34022ac”,”2019-01-25T10:35.657Z-results.log”,”text/plain”,”None”,”sasadm”,”2019-01-25T10:35:09.881Z”,”2459″,”/jobExecution/jobs/73fffe47-a7ef-4c1d-b7bf-83ef0b86319e”

archivefiles.py allows you to read files from the file service and save them to a directory on the file system. Optionally, the tool will also delete files from the file service to free up space. For example, if I want to archive all the files I listed above, I would use:

/./archivefiles.py -n log -d 6 -p /job -fp /tmp/

This tool will create a timestamp directory under /tmp and save a copy of each file in the directory.

If you want to archive and delete, add the -x option.

IMPORTANT: Use the archive tool carefully. We recommend that you run a Viya Backup prior to running the tool to delete files.

Now you know where your files are and you have some help with managing them. For the full details of how you can manage files using the file service REST API you can view the file service REST API documentation on developer.sas.com. If you would like to suggest any changes to the existing tools, please enter a suggestion on GitHub.

Where are my Viya files? was published on SAS Users.

4月 032019
 

Structuring a highly unstructured data source

Human language is astoundingly complex and diverse. We express ourselves in infinite ways. It can be very difficult to model and extract meaning from both written and spoken language. Usually the most meaningful analysis uses a number of techniques.

While supervised and unsupervised learning, and specifically deep learning, are widely used for modeling human language, there’s also a need for syntactic and semantic understanding and domain expertise. Natural Language Processing (NLP) is important because it can help to resolve ambiguity and add useful numeric structure to the data for many downstream applications, such as speech recognition or text analytics. Machine learning runs outputs from NLP through data mining and machine learning algorithms to automatically extract key features and relational concepts. Human input from linguistic rules adds to the process, enabling contextual comprehension.

Text analytics provides structure to unstructured data so it can be easily analyzed. In this blog, I would like to focus on two widely used text analytics techniques: information extraction and entity resolution.

Information Extraction

Information Extraction (IE) automatically extracts structured information from an unstructured or semi-structured text data type -- for example, a text file, to create new structured text data. IE works at the sub-document level, in contrast with techniques such as categorization, that work at the document or record level. Therefore, the results of IE can further feed into other analyses, like predictive modeling or topic identification, as features for those processes. IE can also be used to create a new database of information. One example is the recording of key information about terrorist attacks from a group of news articles on terrorism. Any given IE task has a defined template, which is a (or a set of) case frame(s) to hold the information contained in a single document. For the terrorism example, a template would have slots corresponding to the perpetrator, victim, and weapon of the terroristic act, and the date on which the event happened. An IE system for this problem is required to “understand” an attack article only enough to find data corresponding to the slots in this template. Such a database can then be used and analyzed through queries and reports about the data.

In their new book, SAS® Text Analytics for Business Applications: Concept Rules for Information Extraction Models, authors Teresa Jade, Biljana Belamaric Wilsey, and Michael Wallis, give some great examples of uses of IE:

"One good use case for IE is for creating a faceted search system. Faceted search allows users to narrow down search results by classifying results by using multiple dimensions, called facets, simultaneously. For example, faceted search may be used when analysts try to determine why and where immigrants may perish. The analysts might want to correlate geographical information with information that describes the causes of the deaths in order to determine what actions to take."

Another good example of using IE in predictive models is analysts at a bank who want to determine why customers close their accounts. They have an active churn model that works fairly well at identifying potential churn, but less well at determining what causes the churn. An IE model could be built to identify different bank policies and offerings, and then track mentions of each during any customer interaction. If a particular policy could be linked to certain churn behavior, then the policy could be modified to reduce the number of lost customers.

Reporting information found as a result of IE can provide deeper insight into trends and uncover details that were buried in the unstructured data. An example of this is an analysis of call center notes at an appliance manufacturing company. The results of IE show a pattern of customer-initiated calls about repairs and breakdowns of a type of refrigerator, and the results highlight particular problems with the doors. This information shows up as a pattern of increasing calls. Because the content of the calls is being analyzed, the company can return to its design team, which can find and remedy the root problem.

Entity Resolution and regular expressions

Entity Resolution is the technique of recognizing when two observations relate to the same entity (thing, person, company), despite having been described differently. And conversely, recognizing when two observations do not relate to the same entity, despite having been described similarly. For example, you are listed in one data base as S Roberts, Sian Roberts, S.Roberts. All refer to the same person but would be treated as different people in an analysis unless they are resolved (combined to one person).

Entity resolution can be performed as part of a data pre-processing step or as text analysis. Basically one helps resolve multiple entries (cleans the data) and the other resolves reference to a single entity to extract meaning, for example, pronoun resolution - when “it” refers to a particular company mentioned earlier in the text. Here is another example:

Assume each numbered item is a separate observation in the input data set:
1. SAS Institute is a great company. Our company has a recreation center and health care center for employees.
2. Our company has won many awards.
3. SAS Institute was founded in 1976.

The scoring output matches are below; note that the document ID associated with each match aligns with the number before the input document where the match was found.

Unstructured data clean-up

In the following section we focus on the pre-processing clean-up of the data. Unstructured data is the most voluminous form of data in the world, and analysts rarely receive it in perfect condition for processing. In other words, textual data needs to be cleaned, transformed, and enhanced before value can be derived from it.

A regular expression is a pattern that the regular expression engine attempts to match in input. In SAS programming, regular expressions are seen as strings of letters and special characters that are recognized by certain built-in SAS functions for the purpose of searching and matching. Combined with other built-in SAS functions and procedures, such as entity resolution, you can realize tremendous capabilities. Matthew Windham, author of Unstructured Data Analysis: Entity Resolution and Regular Expressions in SAS®, gives some great examples of how you might use these techniques to clean your text data in his book. Here we share one of them:

"As you are probably familiar with, data is rarely provided to analysts in a form that is immediately useful. It is frequently necessary to clean, transform, and enhance source data before it can be used—especially textual data."

Extract, Transform, and Load (ETL) ETL is a general set of processes for extracting data from its source, modifying it to fit your end needs, and loading it into a target location that enables you to best use it (e.g., database, data store, data warehouse). We’re going to begin with a fairly basic example to get us started. Suppose we already have a SAS data set of customer addresses that contains some data quality issues. The method of recording the data is unknown to us, but visual inspection has revealed numerous occurrences of duplicative records. In this example, it is clearly the same individual with slightly different representations of the address and encoding for gender. But how do we fix such problems automatically for all of the records?

First Name Last Name DOB Gender Street City State Zip Robert Smith 2/5/1967 M 123 Fourth Street Fairfax, VA 22030 Robert Smith 2/5/1967 Male 123 Fourth St. Fairfax va 22030

Using regular expressions, we can algorithmically standardize abbreviations, remove punctuation, and do much more to ensure that each record is directly comparable. In this case, regular expressions enable us to perform more effective record keeping, which ultimately impacts downstream analysis and reporting. We can easily leverage regular expressions to ensure that each record adheres to institutional standards. We can make each occurrence of Gender either “M/F” or “Male/Female,” make every instance of the Street variable use “Street” or “St.” in the address line, make each City variable include or exclude the comma, and abbreviate State as either all caps or all lowercase. This example is quite simple, but it reveals the power of applying some basic data standardization techniques to data sets. By enforcing these standards across the entire data set, we are then able to properly identify duplicative references within the data set. In addition to making our analysis and reporting less error-prone, we can reduce data storage space and duplicative business activities associated with each record (for example, fewer customer catalogs will be mailed out, thus saving money).

Your unstructured text data is growing daily, and data without analytics is opportunity yet to be realized. Discover the value in your data with text analytics capabilities from SAS. The SAS Platform fosters collaboration by providing a toolbox where best practice pipelines and methods can be shared. SAS also seamlessly integrates with existing systems and open source technology.

Further Resources:
Natural Language Processing: What it is and why it matters

White paper: Text Analytics for Executives: What Can Text Analytics Do for Your Organization?

SAS® Text Analytics for Business Applications: Concept Rules for Information Extraction Models, by Teresa Jade, Biljana Belamaric Wilsey, and Michael Wallis

Unstructured Data Analysis: Entity Resolution and Regular Expressions in SAS®, by Matthew Windham

Text analytics explained was published on SAS Users.

4月 012019
 

dividing by zero with SAS

Whether you are a strong believer in the power of dividing by zero, agnostic, undecided, a supporter, denier or anything in between and beyond, this blog post will bring all to a common denominator.

History of injustice

For how many years have you been told that you cannot divide by zero, that dividing by zero is not possible, not allowed, prohibited? Let me guess: it’s your age minus 7 (± 2).

But have you ever been bothered by that unfair restriction? Think about it: all other numbers get to be divisors. All of them, including positive, negative, rational, even irrational and imaginary. Why such an injustice and inequality before the Law of Math?

We have our favorites like π, and prime members (I mean numbers), but zero is the bottom of the barrel, the lowest of the low, a pariah, an outcast, an untouchable when it comes to dividing by. It does not even have a sign in front of it. Well, it’s legal to have, but it’s meaningless.

And that’s not all. Besides not being allowed in a denominator, zeros are literally discriminated against beyond belief. How else could you characterize the fact that zeros are declared as pathological liars as their innocent value is equated to FALSE in logical expressions, while all other more privileged numbers represent TRUE, even the negative and irrational ones!

Extraordinary qualities of zeros

Despite their literal zero value, their informational value and qualities are not less than, and in many cases significantly surpass those of their siblings. In a sense, zero is a proverbial center of the universe, as all the other numbers dislocated around it as planets around the sun. It is not coincidental that zeros are denoted as circles, which makes them forerunners and likely ancestors of the glorified π.

Speaking of π, what is all the buzz around it? It’s irrational. It’s inferior to 0: it takes 2 π’s to just draw a single zero (remember O=2πR?). Besides, zeros are not just well rounded, they are perfectly rounded.

Privacy protection experts and GDPR enthusiasts love zeros. While other small numbers are required to be suppressed in published demographical reports, zeros may be shown prominently and proudly as they disclose no one’s personally identifiable information (PII).

No number rivals zero. Zeros are perfect numerators and equalizers. If you divide zero by any non-zero member of the digital community, the result will always be zero. Always, regardless of the status of that member. And yes, zeros are perfect common denominators, despite being prohibited from that role for centuries.

Zeros are the most digitally neutral and infinitely tolerant creatures. What other number has tolerated for so long such abuse and discrimination!

Enough is enough!

Dividing by zero opens new horizons

Can you imagine what new opportunities will arise if we break that centuries-old tradition and allow dividing by zero? What new horizons will open! What new breakthroughs and discoveries can be made!

With no more prejudice and prohibition of the division by zero, we can prove virtually anything we wish. For example, here is a short 5-step mathematical proof of “4=5”:

1)   4 – 4 = 10 – 10
2)   22 – 22 = 5·(2 – 2)
3)   (2 + 2)·(2 – 2) = 5·(2 – 2) /* here we divide both parts by (2 – 2), that is by 0 */
4)   (2 + 2) = 5
5)   4 = 5

Let’s make the next logical step. If dividing by zero can make any wish a reality, then producing a number of our choosing by dividing a given number by zero scientifically proves that division by zero is not only legitimate, but also feasible and practical.

As you will see below, division by zero is not that easy, but with the power of SAS, the power to know and the powers of curiosity, imagination and perseverance nothing is impossible.

Division by zero - SAS implementation

Consider the following use case. Say you think of a “secret” number, write it on a piece of paper and put in a “secret” box. Now, you take any number and divide it by zero. If the produced result – the quotient – is equal to your secret number, wouldn’t it effectively demonstrate the practicality and magic power of dividing by zero?

Here is how you can do it in SAS. A relatively “simple”, yet powerful SAS macro %DIV_BY_0 takes a single number as a numerator parameter, divides it by zero and returns the result equal to the one that is “hidden” in your “secret” box. It is the ultimate, pure artificial intelligence, beyond your wildest imagination.

All you need to do is to run this code:

 
data MY_SECRET_BOX;        /* you can use any dataset name here */
   MY_SECRET_NUMBER = 777; /* you can use any variable name here and assign any number to it */
run;
 
%macro DIV_BY_0(numerator);
 
   %if %sysevalf(&numerator=0) %then %do; %put 0:0=1; %return; %end;
   %else %let putn=&sysmacroname; 
   %let %sysfunc(putn(%substr(&putn,%length(&putn)),words.))=
   %sysevalf((&numerator/%sysfunc(constant(pi)))**&sysrc);  
   %let a=com; %let null=; %let nu11=%length(null); 
   %let com=*= This is going to be an awesome blast! ;
   %let %substr(&a,&zero,&zero)=*Close your eyes and open your mind, then;
   %let imagine = "large number like 71698486658278467069846772 Bytes divided by 0";
   %let O=%scan(%quote(&c),&zero+&nu11); 
   %let l=%scan(%quote(&c),&zero);
   %let _=%substr(%scan(&imagine,&zero+&nu11),&zero,&nu11);
   %let %substr(&a,&zero,&zero)%scan(&&&a,&nu11+&nu11-&zero)=%scan(&&&a,-&zero,!b)_;
   %do i=&zero %to %length(%scan(&imagine,&nu11)) %by &zero+&zero;
   %let null=&null%sysfunc(&_(%substr(%scan(&imagine,&nu11),&i,&zero+&zero))); %end;
   %if &zero %then %let _0=%scan(&null,&zero+&zero); %else;
   %if &nu11 %then %let _O=%scan(&null,&zero);
   %if %qsysfunc(&O(_&can)) %then %if %sysfunc(&_0(&zero)) %then %put; %else %put;
   %put &numerator:0=%sysfunc(&_O(&zero,&zero));
   %if %sysfunc(&l(&zero)) %then;
 
%mend DIV_BY_0;
 
%DIV_BY_0(55); /* parameter may be of any numeric value */

When you run this code, it will produce in the SAS LOG your secret number:

55:0=777

How is that possible without the magic of dividing by zero? Note that the %DIV_BY_0 macro has no knowledge of your dataset name, nor the variable name holding your secret number value to say nothing about your secret number itself.

That essentially proves that dividing by zero can practically solve any imaginary problem and make any wish or dream come true. Don’t you agree?

There is one limitation though. We had to make this sacrifice for the sake of numeric social justice. If you invoke the macro with the parameter of 0 value, it will return 0:0=1 – not your secret number - to make it consistent with the rest of non-zero numbers (no more exceptions!): “any number, except zero, divided by itself is 1”.

Challenge

Can you crack this code and explain how it does it? I encourage you to check it out and make sure it works as intended. Please share your thoughts and emotions in the Comments section below.

Disclosure

This SAS code contains no cookies, no artificial sweeteners, no saturated fats, no psychotropic drugs, no illicit substances or other ingredients detrimental to your health and integrity, and no political or religious statements. It does not collect, distribute or sell your personal data, in full compliance with FERPA, HIPPA, GDPR and other privacy laws and regulations. It is provided “as is” without warranty and is free to use on any legal SAS installation. The whole purpose of this blog post and the accompanied SAS programming implementation is to entertain you while highlighting the power of SAS and human intelligence, and to fool around in the spirit of the date of this publication.

Dividing by zero with SAS was published on SAS Users.

3月 272019
 

SAS Visual Analytics supports region maps for Country, US states, and provinces out-of-the-box.  These work well for small scale maps covering the world, a continent, or a single country.  However, other regions are often needed.  Beginning in version 8.3, VA supports custom polygons to display regions such as sales territories, counties, or zip codes.

Region (choropleth) maps use a fill color to show relationships between the regions based upon a response value from your data.  Using custom polygons in VA follows the same steps outlined in previous posts for predefined or custom coordinate geography items, with just a few additional steps.  Here’s the basic flow:

  • Identify your data
  • Import polygon shapefile into SAS dataset
  • Import the shape dataset into VA
  • Create a Custom polygon provider
  • Create the geography item
  • Create and customize the map

Before we begin

VA supports two sources for creating custom polygons: Esri shapefiles and Esri Feature Services.  The goal for this post is to show how to create custom polygons using an Esri shapefile.

Typically, when working with custom polygons, you will have two datasets: the first defines the custom regions (shape data) and the second contains the data you wish to map (business data).  The shape data is derived from an Esri shapefile or feature service.  The business data can be in a shapefile or any format supported by VA (.sas7bdat, .csv, .xls, etc). It contains the information you want to analyze distributed across the regions defined by the shape data.

It is recommended that you verify the imported shape data before using it in your final map.  This will confirm the data is valid and make debugging an issue easier should you encounter any errors.  To verify, use the same dataset for both the shape and business data.  The example below will use this approach.

Access to a GIS application such as Esri’s ArcGIS or QGIS is recommended.  There are two areas where they can help you prepare to use custom polygons in your VA map:

  • Creating a shapefile to define polygons specific to your business need or application
  • Viewing the attribute table of existing shapefiles to determine its unique identifier column

For this example, we will be creating a map of registered Neighborhood Associations in Boise, Idaho. To follow along, download the data from the City of Boise open data site: Boise Neighborhood Associations

1. Identify your data

Shape data

The shape data defining the custom regions needs to be in an Esri shapefile format. These files can be created in a GIS application or obtained from a wide variety of online sources such as: the US Census Bureau (http://www.census.gov); local and state municipalities; state agencies such as the Department of Transportation; and university GIS departments.  Most municipalities now have Open Data portals that provide a wealth of reliable data for public use.  These sources are maintained by dedicated staff and are updated regularly.

Business data

The business data can be specific to your company’s operation or customer base.  Or it can be broad and general using census or demographic information.  It answers the question of What you want to analyze on the map.  The business data must contain a column that aligns with your shape data.  For example: If you want to map the age distribution and spending habits of your target customers across zip codes, then your business data must have a column for zip codes that allows it to be joined to a zip code region in the shape data.

2. Import polygon data into a SAS dataset

VA 8.3 does not support the native shapefile format. To use a shapefile in VA, you must first import it into SAS.  Included with Viya3.4, the %shpimprt macro will convert a shapefile into a SAS dataset and load it into CAS.  You can find the documentation for it here: %shpimprt documentation.

Alternatively, the shapefile can be manually imported with these basic steps:

  • Import the shapefile into SAS
  • Add a sequence column to the dataset
  • Reduce the density of the dataset
  • Limit the dataset based on the density value

Additional details and sample code for each of these steps can be found in the text file linked here: Manual shapefile import steps.

3. Import the shape dataset into VA

Next, we must import the dataset into VA, if using the manual shapefile import process.  To do this, locate the data pane on the left of VA.  From the ‘Open Data Source’ window, select Import > Local File.  Navigate to the location of the SAS dataset created from Step 2 and click the Open button.

Adjust the target location as needed, based on your VA installation, and make note of the location selected.  This path will be required to configure the custom polygon provider. Review and adjust the other options as needed.  Click the blue ‘Import Item’ button at the top of the window to start the import process.  A message will appear indicating the import status. Upon successful import, click the 'OK' button to open the dataset.

Since we are using the same dataset for the shape and business data, we need to make a copy of the category variable that will be used for our map. Right click on ‘ASSOCIATIO’ and select ‘Duplicate’.  Next, let’s change the names of both variables to better distinguish them from one another:

  • Change ‘ASSOCIATIO’ to ‘Business data’
  • Change ‘ASSOCIATIO (1)’ to ‘Shape data’

4. Create the geography item

We are now ready to start creating the geography item.  With Custom polygons, an additional step is required beyond what was described in previous posts with predefined and custom coordinates geography items.  We must define a Custom Polygon provider so VA knows how to locate and display the Boise Neighborhood Associations.  This is needed only once and is part of the geography item setup you are familiar with.

Our goal is to map the regions of the Boise Neighborhood Associations, so we will use ‘Shape data’ for our geography item.  Locate it in the VA data panel and change its Classification type to ‘Geography’.  From the ‘Geography data type’ dropdown, select ‘Custom polygonal shapes’. Several new fields will be displayed.  In the ‘Custom polygon provider’ dropdown, click the ‘Define new polygon provider’ button.

A ‘New Polygon Provider’ window will appear.  All fields shown are required.  The Advanced section has additional options, but they are not needed for this example.

Configure the fields based on the following:

  • Name / Label – Enter ‘Boise Neighborhoods’ for both (these values do not have to be the same)
  • Type – The default CAS Table is the correct option for this example.
  • Server / Library – These values must match those used for the data upload in Step 3.
  • Table – Select the name of the table uploaded in Step 3 (Boise_Neighborhoods)
  • ID Column – The unique identifier column of the dataset. Used to join the shape and business data together. (Select OBJECTID)
  • Sequence Column – This column is created during the import process from Step 2. Needed by VA to display the custom regions. (Select SEQUENCE)

The custom polygon provider is now configured.  All that is needed to finish the geography item setup, is to identify the Region ID.  This is the crucial step that will join the shape data to the business data.  The Region ID column must match the ID Column chosen when the custom polygon provider was setup.  Since we are using the same dataset in this example, that value is the same: OBJECTID.

In cases where different datasets are used for the shape and business data, the name of Region ID and ID Column may be different.  The column labels are not important, but their content must match for the join to occur.

Notice that once you select the correct RegionID value, the preview window will display the custom regions from the imported shape data.  The Latitude and Longitude columns are not required in this example.  Click the ‘OK’ button, to finish the setup.

5. Create and customize the map

You are now ready to create your map.  Drag the Boise Neighborhoods geography item to the report canvas.  Let’s enhance the appearance of our map by making a few style changes:

  • Set a Color role to shade the Neighborhood Association regions (Roles > Color > Business data)
  • Position the legend on the left of the map (Options > Legend)
  • Adjust the transparency of the fill color to 45% (Options > Map Transparency)
  • Change the map service to Esri World Street Map (Options > Map service)

Final map with custom polygons.

Congratulations!  You have just created your first custom region map.  In this post we discussed how to use the Custom Polygon provider to define your own regions using an Esri shapefile.  Compared to the Predefined and Custom Coordinate options, custom polygons give you additional flexibility and control over how your spatial data is analyzed.

Creating custom region maps with SAS Visual Analytics was published on SAS Users.

3月 272019
 

PAYG financial services: coming to a bank near you

You walk into your neighborhood bank to see about a mortgage. You and your spouse have your eye on the perfect 3BR, 2BA brick ranch near your child's school, and it won't be on the market long. An hour later, you burst through the front door with a bottle of champagne: "We're qualified!"

Also celebrating is your bank's branch manager. She was skeptical when headquarters analysts equipped branches for "Cloud-based application using SAS" , saying it would speed up loan applications. But your quick, frictionless transaction proved them right.The bank's accountants are happy too. The new pay-as-you-go mode of using SAS software in the cloud means big savings.

The above scenario is possible now through serverless functions, which enable your SAS Viya applications to take input from end users, score the loan application, and return results.

The rest of this post gets into the nitty gritty of serverless functions and SAS Viya, detailing what happens in a bank's computers after a customer applies for a loan. The qualification process starts by running a previously built scoring model to generate a score. You will see how the combination of REST APIs in SAS Viya, analytic models and the restaf library make the task of building the serverless function relatively simple.

The blog titled "SAS REST APIs: a sample application" demonstrated building a SAS Viya application using REST APIs, SAS Visual Analytics and SAS Operational Research. This is typical web applications with application server and SAS Viya running on premise.

If you are one of many users using(or considering) a cloud provider, serverless functions is an useful alternate way to deliver your applications to your users. This eliminates the need to manage the application server associated with your application. Additionally you get zero administration and auto-scaling among other benefits. Many SAS applications that respond quickly to user requests are ideal candidates to be deployed as serverless functions.

The example in this article is available on SAS software’s GitHub site in the viya-apps-serverless-score repository.  If you want to see the end application for frame of reference, see the Using the serverless functions section at the bottom of this article.

Let’s begin with a bit of background on serverless computing and then dig into the details of the application and functions.

Serverless computing explained

The benefits of serverless functions as touted by AWS serverless, Azure and serverless.com:

AWS Lambda

AWS Lambda lets you run code without provisioning or managing servers. You pay only for the compute time you consume– there is no charge when your code is not running. With Lambda, you can run code for virtually any type of application or backend service – all with zero administration. Just upload your code and Lambda takes care of everything required to run and scale your code with high availability. You can set up your code to automatically trigger from other AWS services or call it directly from any web or mobile app.

What is serverless computing?

According to Azure serverless computing is the abstraction of servers, infrastructure, and operating systems. When you build serverless apps you don’t need to provision and manage any servers, so you can take your mind off infrastructure concerns. Serverless computing is driven by the reaction to events and triggers happening in near-real-time—in the cloud. As a fully managed service, server management and capacity planning are invisible to the developer and billing is based just on resources consumed or the actual time your code is running.

Four core benefits of serverless computing from serverless.com:

  1. Zero administration – Deploy code without provisioning anything beforehand or managing anything afterward. There is no concept of a fleet, an instance, or even an operating system. No more bothering the Ops department.
  2. Auto-scaling – Let your service providers manage the scaling challenges. No need to fire alerts or write scripts to scale up and down. Handle quick bursts of traffic and weekend lulls the same way — with peace of mind.
  3. Pay-per-use – Function-as-a-service compute and managed services charged based on usage rather than pre-provisioned capacity. You can have complete resource utilization without paying a cent for idle time. The results? 90% cost-savings over a cloud VM, and the satisfaction of knowing that you never pay for resources you don’t use.
  4. Increased velocity – Shorten the loop between having an idea and deploying to production. Because there’s less to provision up front and less to manage after deployment, smaller teams can ship more features. It’s easier than ever to make your idea live.

OK, so there is a server involved in serverless computing. The beauty in this technology is that once you deploy your code, you don't have to worry about the underlying infrastructure. You just know that the app should work and you only incur costs when the app is running.

Basic flow

Serverless functions are loaded and executed based on the occurrence of one of the triggers/events supported by the cloud vendor. In this example the API Gateway triggers the serverless functions when an http call invokes the function. The API Gateway calls the handler for the function and passes in the user data. On return from the handler the response is sent to the client. This article focuses on the code inside the Serverless Function box in the picture below.

Figure 1: Request Workflow

This example utilizes two key functions:

  1. app – This function serves up an html application for user to enter the data. This is an example of a web application as a serverless function.
  2. score – This function takes user input from the web app, executes scoring on a Viya Server and returns the results.

Serverless.yml

The serverless.yml defines the serverless functions and the handlers, used to execute and other system related information. We will focus only on the application specific information.

The code snippet below shows the definition of the path and handler for the two functions in the serverles.yml file.

functions:
  app: 
    handler: src/app.app
    events:
      - http:
          path: app
          method: get
          cors: 
            origin: '*'
          request:
            parameters:
              paths:
                id: true  
 
  score:
    handler: src/score.score
    events:
      - http:
          path: score
          method: post
          cors: 
            origin: '*'

The functions(app & score) in the yaml define:

  1. event - http event will trigger this function
  2. path - this is path to the function - similar to what you define in Express or hapijs
  3. method - http standard GET, PUT etc...
  4. others - refer to the cloud vendor's documentation for other available options.

The serverless.yml file also sets application related information using environment variables. In this particular use case we define how to access SAS Viya and which scoring model to use.

environment:
#
# Information for logging into SAS Viya
#
  VIYA_SERVER: http://example.viya.server.com
  CLIENTID: raf
  CLIENTSECRET: raf
  USER:rafuser
  PASSWORD: rafpass
 
#
# astore to be used for scoring
#
  caslib: casuser
  name: GRADIENT_BOOSTING___BAD_2

A note on securing your password

In this example we store the userid and password in environment variables. This is to the keep the focus on the internals of serverless functions for SAS Viya. Locally you can use "serverless variables" to secure the information during development. However, for production deployment, refer to your provider's recommendations and the user community for best practices.

Sounds like a followup blog in the future 🙂

Anatomy of the serverless function

Figure 2 shows the flow inside the serverless function for this example. This pattern will repeat itself in your serverless functions.

Figure 2: Serverless Function Flow

Serverless function score

The code below is the handler for the score function. The rest of this section will discuss each of the key features of the handler.

//
// See src/score.js for the full code
//
module.exports.score = async function (event, context ) {
 
   let store      =  restaf.initStore(); /* initialize restaf     */
   let inParms = parseEvent(event);  /* get user input        */
   let payload = getLogonPayload(); /* get logon information */
 
   return store.logon(payload)               /* logon to SAS Viya */
        .then (()    > scoreMain( store, inParms )) /* score     */
        .then(result > setPayload(result)) /* return results     */
        .catch(err   > setError(err))	      /* else return errors */
}

Step 1: Parse the input

The event parameter contains the input from the caller (web application, another serverless function, etc).
The content of the event parameter is whatever the designer of the serverless function desires. In this particular case, a sample event data is shown below.

{
    "input": {
        "JOB"    : "J1",
        "CLAGE"  : 100,
        "CLNO"   : 20,
        "DEBTINC": 20,
        "DELINQ" : 2,
        "DEROG"  : 0,
        "MORTDUE": 4000,
        "NINQ"   : 1,
        "YOJ"    : 10,
        "LOAN"   : 10000,
        "VALUE"  : 1000000
    }
}

The parseEvent function validates the incoming information.

module.exports = function parseEvent(event)
    let input = null;
    let body = {};
    let rstore = {
        caslib:  process.env.ASTORE_CASLIB,
        name  : process.env.ASTORE_NAME
    }
    if ( event.body !=  null ) {
        body = ( typeof event.body === 'string') ? JSON.parse(event.body) : Object.assign({}, event.body);
       if ( body.hasOwnProperty('input') === true ) {
          input = body.input;
    }
    return { rstore: rstore, input: input }
}

Step 2: Logon to SAS Viya

The server.yml defines the SAS Viya logon information. Note there are other secure ways to manage sensitive information like passwords. You should refer to your provider’s documentation.

module.exports = function getLogonPayload() {
    let p = {
        authType    : 'password',
        host        : `${process.env.VIYA_SERVER}`,
        user        : process.env['USER'],
        password    : process.env['PASSWORD'],
        clientID    : process.env['CLIENTID'],
        clientSecret: (process.env.hasOwnProperty('CLIENTSECRET')) ? process.env[ 'CLIENTSECRET' ] : ''
        };
    return p;
 }

The line restaf.logon(payload) in function in the handler code logs on to the SAS Viya Server using this information.

Step 3 and Step 4: Create Payload and make REST API calls

On successful logon the server is called to do the scoring. This particular example uses the sccasl.runcasl method to run CAS Language (CASL) statements and return the scores. Creating the score has two steps:

  1. upload user input: The user input is converted to a csv and uploaded to a CAS table
  2. Submit CASL statements to SAS Viya (CAS) to do the scoring

The code in src/scoreMain in the repository accomplishes both these steps.

Each of these steps use a CAS action:

    • table.upload – to upload the user data into a CAS Table. The input data is converted into a comma-delimited file(csv) and then uploaded. The REST call using restaf looks like this:
    let csv = makecsv(input); /* create a csv */
    let JSON_Parameters = {
        casout: {
            caslib : 'casuser', /* a valid caslib */
            name   : 'INPUTDATA', /* name of output file on cas server */
            replace: true
        },
 
        importOptions: {
            fileType: 'csv' /* type of the file being uploaded */
        }
    };
 
    let payload = {
        headers: { 'JSON-Parameters': JSON_Parameters },
        data   : csv,
        action : 'table.upload'
    };
 
    let result = await store.runAction(session, payload);
    • sccasl.runcasl – execute CASL statements to do the scoring
 // Setup casl statements 	 	 
 let caslStatements = `	 	 
 loadactionset "astore";	 	 
 action table.loadTable /	 	 
 caslib = "${rstore.caslib}" 	 	 
 path = "${rstore.name}.sashdat"	 	 
 casout = { caslib = "${rstore.caslib}" name = "${rstore.name}" replace=TRUE};	 	 
 
 action astore.score /	 	 
 table = { caslib= 'casuser' name = 'INPUTDATA' } 	 	 
 rstore = { caslib= "${rstore.caslib}" name = '${rstore.name}' }	 	 
 out = { caslib = 'casuser' name = 'OUTPUTDATA' replace= TRUE};	 	 
 action table.fetch r = result/	 	 
 format = TRUE	 	 
 table = { caslib = 'casuser' name = 'OUTPUTDATA' } ;	 	 
 send_response(result);	 	 
 `;	 	 
 // execute cas actions	 	 
 payload = {	 	 
 action: 'sccasl.runcasl',	 	 
 data : { code: caslStatements}	 	 
 }	 	 
 result = await store.runAction(session, payload);

Step 5: Create response

AWS serverless functions must return data and error(s) in a certain form. The two functions setPayload.js and setError.js accomplish this.

module.exports = function setPayload (body) {
    return {
        "statusCode": 200,
        "headers"   : {
            'Access-Control-Allow-Origin'     : '*',
            'Access-Control-Allow-Credentials': true
          },
        "isBase64Encoded": false,
        "body"           : JSON.stringify(body)
    }
  }

Using the serverless functions

When the serverless function is deployed you will get a link for each of the functions. In our case we receive the request shown below (with xxxx replaced with appropriate information).

GET - https://xxxx.amazonaws.com/demo/app

The first link serves up the web application. The user enters some values and the app calls the score serverless function to get the results.
Alternatively, you can write your own application and make an http POST call to the score function using a link such as:

POST - https://xxxx.amazonaws.com/demo/score

To invoke the web application, you will visit the link

https://xxxx.amazonaws.com/demo/app

with your browser. You should see a display shown in Figure 3:

Figure 3: Application Input Screen

Entering values into the two fields and pressing Submit calls the second serverless function, score, and results in a pie chart as seen in Figure 4:

Figure 4: Score Report Screen

Please see the loan.html file in the GitHub repository for details on the application. Displayed below is the relevant part of the Javascript in the loan.html. The score-function-url is the url for the score function. The payload was described earlier in this article. The http call is made using axios.

async function runScore(inputValues ){
 
    let payload = {
        astore: {
            caslib: 'Public',
            name: 'GRADIENT_BOOSTING___BAD_2'
        },
        input: inputValues
    }
    let config = {
        url: {score-function-url}
        method: 'POST',
        data: payload
    }
    let r = await axios(config);
    return r.data.score;
 
}

Porting to other cloud providers

The cloud provider dependent information is handled in the following functions: score.js, parseEvent.js, setPayload.js and setError.js. The rest of the code is host agnostic. In writing your own functions the recommendation is to follow the same pattern as much as possible. The generic code is then available in its own repository for reuse with other providers and applications.

Go try it yourself

I have shown you how to deliver your SAS Viya applications as serverless functions. To access more examples please see the GitHub restaf-demos repository.

Supporting Resources

Serverless functions and SAS Viya - a good match was published on SAS Users.