Introduction to Debugging in R

Debugging helps identify and fix errors in your code. In this lesson, you'll learn different debugging techniques in R.

Understanding Errors and Warnings

Errors stop code execution, while warnings indicate potential issues.

log(-1) # Warning: NaNs produced

Using print() for Debugging

The print() function helps inspect variables at different stages.

x <- 5
print(x)

Using traceback()

The traceback() function shows the sequence of function calls before an error.

f <- function() stop('Error')
f()
traceback()

Using debug()

The debug() function allows step-by-step execution of a function.

my_function <- function(x) {
  y <- x + 1
  return(y)
}
debug(my_function)
my_function(5)

Using browser()

The browser() function pauses execution, allowing inspection of variables.

my_function <- function(x) {
  browser()
  y <- x + 1
  return(y)
}
my_function(5)

Using tryCatch()

The tryCatch() function helps handle errors gracefully.

result <- tryCatch({
  log(-1)
}, warning = function(w) 'Warning occurred',
   error = function(e) 'Error occurred')
print(result)

Using try()

The try() function prevents script termination due to an error.

result <- try(log(-1), silent = TRUE)
print(result)

Summary

In this lesson, you learned:

• How to identify and fix errors.
• How to use debugging tools like traceback(), debug(), and browser().
• How to handle errors gracefully using tryCatch() and try().