Book Image

Scientific Computing with Scala

By : Vytautas Jancauskas
Book Image

Scientific Computing with Scala

By: Vytautas Jancauskas

Overview of this book

Scala is a statically typed, Java Virtual Machine (JVM)-based language with strong support for functional programming. There exist libraries for Scala that cover a range of common scientific computing tasks – from linear algebra and numerical algorithms to convenient and safe parallelization to powerful plotting facilities. Learning to use these to perform common scientific tasks will allow you to write programs that are both fast and easy to write and maintain. We will start by discussing the advantages of using Scala over other scientific computing platforms. You will discover Scala packages that provide the functionality you have come to expect when writing scientific software. We will explore using Scala's Breeze library for linear algebra, optimization, and signal processing. We will then proceed to the Saddle library for data analysis. If you have experience in R or with Python's popular pandas library you will learn how to translate those skills to Saddle. If you are new to data analysis, you will learn basic concepts of Saddle as well. Well will explore the numerical computing environment called ScalaLab. It comes bundled with a lot of scientific software readily available. We will use it for interactive computing, data analysis, and visualization. In the following chapters, we will explore using Scala's powerful parallel collections for safe and convenient parallel programming. Topics such as the Akka concurrency framework will be covered. Finally, you will learn about multivariate data visualization and how to produce professional-looking plots in Scala easily. After reading the book, you should have more than enough information on how to start using Scala as your scientific computing platform
Table of Contents (16 chapters)
Scientific Computing with Scala
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

Data storage and retrieval


It is possible to store ScalaLab arrays as text files. It is also possible to read these files. The file format is very simple. This also lets you create text containing data using any tool you want and load it into ScalaLab as data, as long as you follow the file format that is used, of course. There are two functions for doing this. They are called readAscii and saveAscii. The signatures of those functions are given here:

saveAscii(d: Array[Double], fileName: String): Unit
saveAscii(dd: Array[Array[Double]], fileName: String, sepChar: Char= ' '): Unit
readD1Ascii( fileName: String): Array[Double]
readD2Ascii(fileName: String): Array[Array[Double]]

The save function takes an array of doubles and a filename. The data will be stored into the file specified. The other version of the save function takes a 2-dimensional array and saves it to a specified file. You can also supply a separator symbol to be used. The default separator is the space. Let's see how this works...