Sentiment Analysis In R

Stefan Feuerriegel and Nicolas Pröllochs have a new package in CRAN:

Our package “SentimentAnalysis” performs a sentiment analysis of textual contents in R. This implementation utilizes various existing dictionaries, such as QDAP or Loughran-McDonald. Furthermore, it can also create customized dictionaries. The latter uses LASSO regularization as a statistical approach to select relevant terms based on an exogenous response variable.

I’m not sure how it stacks up to external services, but it’s another option available to us.

Using OtterTune To Tune Databases

Dana Van Aken, Geoff Gordon, and Any Pavlo show off OtterTune, which uses machine learning techniques to tune database management systems like MySQL and Postgres:

OtterTune, a new tool that’s being developed by students and researchers in the Carnegie Mellon Database Group, can automatically find good settings for a DBMS’s configuration knobs. The goal is to make it easier for anyone to deploy a DBMS, even those without any expertise in database administration.

OtterTune differs from other DBMS configuration tools because it leverages knowledge gained from tuning previous DBMS deployments to tune new ones. This significantly reduces the amount of time and resources needed to tune a new DBMS deployment. To do this, OtterTune maintains a repository of tuning data collected from previous tuning sessions. It uses this data to build machine learning (ML) models that capture how the DBMS responds to different configurations. OtterTune uses these models to guide experimentation for new applications, recommending settings that improve a target objective (for example, reducing latency or improving throughput).

In this post, we discuss each of the components in OtterTune’s ML pipeline, and show how they interact with each other to tune a DBMS’s configuration. Then, we evaluate OtterTune’s tuning efficacy on MySQL and Postgres by comparing the performance of its best configuration with configurations selected by database administrators (DBAs) and other automatic tuning tools.

This is potentially a very interesting technology and is not the only one of its kind—we’ve seen Microsoft enter this space as well for SQL Server index and tuning recommendations.

Genetic Algorithms

Melanie Mitchell provides an introduction to how genetic algorithms work:

Many computational problems require a computer program to be adaptive—to continue to perform well in a changing environment. This is typified by problems in robot control in which a robot has to perform a task in a variable environment, or computer interfaces that need to adapt to the idiosyncrasies of an individual user. Other problems require computers to be innovative—to construct something truly new and original, such as a new algorithm for accomplishing a computational task, or even a new scientific discovery. Finally, many computational problems require complex solutions that are difficult to program by hand. A striking example is the problem of creating artificial intelligence. Early on, AI practitioners believed that it would be straightforward to encode the rules that would confer intelligence in a program; expert systems are a good example. Nowadays, many AI researchers believe that the “rules” underlying intelligence are too complex for scientists to encode in a “top-down” fashion, and that the best route to artificial intelligence is through a “bottom-up” paradigm. In such a paradigm, human programmers encode simple rules, and complex behaviors such as intelligence emerge from these simple rules. Connectionism (i.e., the study of computer programs inspired by neural systems) is one example of this philosophy (Smolensky, 1988); evolutionary computation is another.

For fun and completely inappropriate implementations of genetic algorithms in T-SQL, William Talada and Gail Shaw have us covered.

Machine Learning At Build 2017

Adnan Masood looks at some of the new machine learning offerings in Azure:

Language Understanding Intelligent Service (LUIS) is one of the marquee offerings in cognitive services which contains an entire suite of NLU / NLP capabilities, teaching applications to understand entities, utterances, and genera; commands from user input. Other language services include Bing Spell Check API which detect and correct spelling mistakes, Web Language Model API which helps building knowledge graphs using predictive language models Text Analytics API to perform topic modeling and do sentiment analysis, as well as Translator Text API to perform automatic text translation. The Linguistic Analysis API is a new addition which parses and provide context around language concepts.

In the knowledge spectrum, the Recommendations API to help predict and recommend items, Knowledge Exploration Service to enable interactive search experiences over structured data via natural language inputs, Entity Linking Intelligence Service for NER / disambiguation, Academic Knowledge API (academic content in the Microsoft Academic Graph search), QnA Maker API, and the newly minted custom Decision Service which provides a contextual decision-making API with reinforcement learning features. Search APIs include Autosuggest, news, web, image, video and customized searches.

There are some nice products available on the Azure platform and Adnan does a good job of outlining them.

ML Algorithm Cheat Sheet

Hui Li has a quick cheat sheet on which algorithms might be useful in a particular situation:

A typical question asked by a beginner, when facing a wide variety of machine learning algorithms, is “which algorithm should I use?” The answer to the question varies depending on many factors, including:

  • The size, quality, and nature of data.
  • The available computational time.
  • The urgency of the task.
  • What you want to do with the data.

Even an experienced data scientist cannot tell which algorithm will perform the best before trying different algorithms. We are not advocating a one and done approach, but we do hope to provide some guidance on which algorithms to try first depending on some clear factors.

Hui then goes into detail on each. h/t Vincent Granville

SQL Server ML Services

SQL Server R Services is now SQL Server Machine Learning Services and supports Python.  First, Nagesh Pabbisetty and Sumit Kumar talk about Python support:

The addition of Python builds on the foundation laid for R Services in SQL Server 2016 and extends that mechanism to include Python support for in-database analytics and machine learning. We are renaming R Services to Machine Learning Services, and R and Python are two options under this feature.

The Python integration in SQL Server provides several advantages:

  • Elimination of data movement: You no longer need to move data from the database to your Python application or model. Instead, you can build Python applications in the database. This eliminates barriers of security, compliance, governance, integrity, and a host of similar issues related to moving vast amounts of data around. This new capability brings Python to the data and runs code inside secure SQL Server using the proven extensibility mechanism built in SQL Server 2016.

  • Easy deployment: Once you have the Python model ready, deploying it in production is now as easy as embedding it in a T-SQL script, and then any SQL client application can take advantage of Python-based models and intelligence by a simple stored procedure call.

  • Enterprise-grade performance and scale: You can use SQL Server’s advanced capabilities like in-memory table and column store indexes with the high-performance scalable APIs in RevoScalePy package. RevoScalePy is modeled after RevoScaleR package in SQL Server R Services. Using these with the latest innovations in the open source Python world allows you to bring unparalleled selection, performance, and scale to your SQL Python applications.

  • Rich extensibility: You can install and run any of the latest open source Python packages in SQL Server to build deep learning and AI applications on huge amounts of data in SQL Server. Installing a Python package in SQL Server is as simple as installing a Python package on your local machine.

  • Wide availability at no additional costs: Python integration is available in all editions of SQL Server 2017, including the Express edition.

Nagesh Pabbisetty also announces Microsoft R Server 9.1:

We took the first step with Microsoft R Server 9.0, and this follow on release includes significant innovations such as:

  • New machine learning enhancements and inclusion of pre-trained cognitive models such as sentiment analysis & image featurizers

  • SQL Server Machine Learning Services with integrated Python in Preview

  • Enterprise grade operationalization with real-time scoring and dynamic scaling of VMs

  • Deep customer & ISV partnerships to deliver the right solutions to customers

  • A panoply of sources to help you get started with ease

And Joseph Sirosh indicates that AI is where the money is:

So today it’s my pleasure to announce the first RDBMS with built-in AIa production-quality Community Technology Preview (CTP 2.0) of SQL Server 2017. In this preview release, we are introducing in-database support for a rich library of machine learning functions, and now for the first time Python support (in addition to R). SQL Server can also leverage NVIDIA GPU-accelerated computing through the Python/R interface to power even the most intensive deep-learning jobs on images, text, and other unstructured data. Developers can implement NVIDIA GPU-accelerated analytics and very sophisticated AI directly in the database server as stored procedures and gain orders of magnitude higher throughput. In addition, developers can use all the rich features of the database management system for concurrency, high-availability, encryption, security, and compliance to build and deploy robust enterprise-grade AI applications.

There’s a lot to digest here.

Using h2o.ai On HDInsight

Xiaoyong Zhu shows how to set up h2o.ai on Azure HDInsight:

H2O Flow is an interactive web-based computational user interface where you can combine code execution, text, mathematics, plots and rich media into a single document, much like Jupyter Notebooks. With H2O Flow, you can capture, rerun, annotate, present, and share your workflow. H2O Flow allows you to use H2O interactively to import files, build models, and iteratively improve them. Based on your models, you can make predictions and add rich text to create vignettes of your work – all within Flow’s browser-based environment. In this blog, we will only focus on its visualization part.

H2O FLOW web service lives in the Spark driver and is routed through the HDInsight gateway, so it can only be accessed when the spark application/Notebook is running

You can click the available link in the Jupyter Notebook, or you can directly access this URL:

https://yourclustername-h2o.apps.azurehdinsight.net/flow/index.html

Setup is pretty easy.

Linear Support Vector Machines

Ananda Das explains how linear Support Vector Machines work in classifying spam messages:

Linear SVM assumes that the two classes are linearly separable that is a hyper-plane can separate out the two classes and the data points from the two classes do not get mixed up. Of course this is not an ideal assumption and how we will discuss it later how linear SVM works out the case of non-linear separability. But for a reader with some experience here I pose a question which is like this Linear SVM creates a discriminant function but so does LDA. Yet, both are different classifiers. Why ? (Hint: LDA is based on Bayes Theorem while Linear SVM is based on the concept of margin. In case of LDA, one has to make an assumption on the distribution of the data per class. For a newbie, please ignore the question. We will discuss this point in details in some other post.)

This is a pretty math-heavy post, so get your coffee first. h/t R-Bloggers.

Understanding Neural Nets

David Smith links to a video which explains how neural networks do their thing:

In R, you can train a simple neural network with just a single hidden layer with the nnet package, which comes pre-installed with every R distribution. It’s a great place to start if you’re new to neural networks, but the deep learning applications call for more complex neural networks. R has several packages to check out here, including MXNetdarchdeepnet, and h2o: see this post for a comparison. The tensorflow package can also be used to implement various kinds of neural networks.

R makes it pretty easy to run one, though it then becomes important to understand regularization as a part of model tuning.

TensorFlow With YARN

Wangda Tan and Vinod Kumar Vavilapalli show how to control TensorFlow jobs with YARN:

YARN has been used successfully to run all sorts of data applications. These applications can all coexist on a shared infrastructure managed through YARN’s centralized scheduling.

With TensorFlow, one can get started with deep learning without much knowledge about advanced math models and optimization algorithms.

If you have GPU-equipped hardware, and you want to run TensorFlow, going through the process of setting up hardware, installing the bits, and optionally also dealing with faults, scaling the app up and down etc. becomes cumbersome really fast. Instead, integrating TensorFlow to YARN allows us to seamlessly manage resources across machine learning / deep learning workloads and other YARN workloads like MapReduce, Spark, Hive, etc.

Read on for more details, including a demo video.

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