Probably the most helpful and simple debugging technique is to use cat() to print to the R console. There are two main reasons why you should do this:
- The first is to put in little messages to yourself—for example, cat("This branch of code executed").
- The second is to print the properties of R objects if you are having problems relating to data structure, size, or type. The cat(str(x)) phrase is particularly useful, and will print a little summary of any kind of R object, whether it is a list, a dataframe, a numeric vector, or anything else.
The other useful method is a standard method of debugging in R, browser(), which can be put anywhere in your code. As soon as it is executed, it halts the application and enters debug mode ...
