# Catching errors when using tolower

##### Posted on May 29, 2012

When I’m working in R with text data parsed from online opinion forums and social webs (e.g. twitter), I need to do some cleaning and pre-processing such as removing punctuation marks, striping extra white spaces, or converting text to lower case.

More often than not, when using the tolower() function I encounter myself with a really annoying error that is a truly pain in the butt.

Consider the following example. Let’s say we have the text from a tweet in an object called some_text. When we print the object in the console, we get a warning message (in red) like this: So, how can we solve this error? Meet the tryCatch function! This function will help us to catch possible errors. We’ll make a new function combining tryCatch() and tolower() so we can identify any undesirable text  without returning any ugly message and without stopping our programs.

Here’s my tryTolower() function

### Let’s test it

Suppose you have a character vector with five elements

Published in categories how-to  Tagged with error  exception  handling  text  tolower  trycatch