Book Image

Modern R Programming Cookbook

By : Jaynal Abedin
Book Image

Modern R Programming Cookbook

By: Jaynal Abedin

Overview of this book

R is a powerful tool for statistics, graphics, and statistical programming. It is used by tens of thousands of people daily to perform serious statistical analyses. It is a free, open source system whose implementation is the collective accomplishment of many intelligent, hard-working people. There are more than 2,000 available add-ons, and R is a serious rival to all commercial statistical packages. The objective of this book is to show how to work with different programming aspects of R. The emerging R developers and data science could have very good programming knowledge but might have limited understanding about R syntax and semantics. Our book will be a platform develop practical solution out of real world problem in scalable fashion and with very good understanding. You will work with various versions of R libraries that are essential for scalable data science solutions. You will learn to work with Input / Output issues when working with relatively larger dataset. At the end of this book readers will also learn how to work with databases from within R and also what and how meta programming helps in developing applications.
Table of Contents (10 chapters)

Handling exceptions and error messages

Whenever you are creating a function, there could be a conditional statement or even some mathematical operation that might not be executable for all situations. For example, if you are transforming a numeric vector into logarithms, then a negative value will give an error. In this recipe, you will learn how to handle exceptions and errors and/or warnings while you write your own customized functions. There are several functions in R to handle exceptions/errors/warnings as follows:

  • warning(): This function can generate a warning message
  • stop(): This function can generate an error message
  • supressWarnings(expr): This function evaluates the expression inside the function and then ignores warnings if there are any
  • tryCatch(): This function (tryCatch() or try()) evaluates the code inside the parenthesis and then assigns an exception handler