R for Data Science Cookbook

The debugging function

As a programmer, debugging is the most common task faced on a daily basis. The simplest debugging method is to insert a print statement at every desired location; however, this method is rather inefficient. Here, we will illustrate how to use some R debugging tools to help accelerate the debugging process.

Getting ready

Make sure that you know how a function and works and how to create a new function.

How to do it...

Perform the following steps to debug an R function:

1. First, we create a debugfunc function with x and y as argument, but we only return x:

   >debugfunc<- function(x, y){
   + x <- y + 2
   + x
   + }
   >debug(2)
   

2. We then pass only 2 to dubugfunc:

   >debugfunc(2)
   Error in debugfunc(2) : argument "y" is missing, with no default
   

3. Next, ...