Kotlin for Data Science

From building data pipelines to productionizing machine learning models, Kotlin can be a great choice for working with data:

• Kotlin is concise, readable and easy to learn.
• Static typing and null safety help create reliable, maintainable code that is easy to troubleshoot.
• Being a JVM language, Kotlin gives you great performance and an ability to leverage an entire ecosystem of tried and true Java libraries.

Interactive editors

Notebooks such as Jupyter Notebook and Apache Zeppelin provide convenient tools for data visualization and exploratory research. Kotlin integrates with these tools to help you explore data, share your findings with colleagues, or build up your data science and machine learning skills.

Jupyter Kotlin kernel

The Jupyter Notebook is an open-source web application that allows you to create and share documents (aka "notebooks") that can contain code, visualizations, and markdown text. Kotlin-jupyter is an open source project that brings Kotlin support to Jupyter Notebook.

Check out Kotlin kernel's GitHub repo for installation instructions, documentation, and examples.

Zeppelin Kotlin interpreter

Apache Zeppelin is a popular web-based solution for interactive data analytics. It provides strong support for the Apache Spark cluster computing system, which is particularly useful for data engineering. Starting from version 0.9.0, Apache Zeppelin comes with bundled Kotlin interpreter.

Libraries

The ecosystem of libraries for data-related tasks created by the Kotlin community is rapidly expanding. Here are some libraries that you may find useful:

Kotlin libraries

• kotlin-statistics is a library providing extension functions for exploratory and production statistics. It supports basic numeric list/sequence/array functions (from sum to skewness), slicing operators (such as countBy, simpleRegressionBy), binning operations, discrete PDF sampling, naive bayes classifier, clustering, linear regression, and much more.

• kmath is a library inspired by NumPy. This library supports algebraic structures and operations, array-like structures, math expressions, histograms, streaming operations, a wrapper around commons-math and koma, and more.

• krangl is a library inspired by R's dplyr and Python's pandas. This library provides functionality for data manipulation using a functional-style API; it also includes functions for filtering, transforming, aggregating, and reshaping tabular data.

• lets-plot is a plotting library for statistical data written in Kotlin. Lets-Plot is multiplatform and can be used not only with JVM, but also with JS and Python.

• kravis is another library for the visualization of tabular data inspired by R's ggplot.

Java libraries

Since Kotlin provides first-class interop with Java, you can also use Java libraries for data science in your Kotlin code. Here are some examples of such libraries:

• DeepLearning4J - a deep learning library for Java

• ND4J - an efficient matrix math library for JVM

• Dex - a Java-based data visualization tool

• Smile - a comprehensive machine learning, natural language processing, linear algebra, graph, interpolation, and visualization system. Besides Java API, Smile also provides a functional Kotlin API along with Scala and Clojure API.
  • Smile-NLP-kt - a Kotlin rewrite of the Scala implicits for the natural language processing part of Smile in the format of extension functions and interfaces.

• Apache Commons Math - a general math, statistics, and machine learning library for Java

• OptaPlanner - a solver utility for optimization planning problems

• Charts - a scientific JavaFX charting library in development

• CoreNLP - a natural language processing toolkit

• Apache Mahout - a distributed framework for regression, clustering and recommendation

• Weka - a collection of machine learning algorithms for data mining tasks

If this list doesn’t cover your needs, you can find more options in the Kotlin Data Science Resources digest from Thomas Nield.