title: Identifying character variables and changing them to numeric in R
body: <p>I have a dataset with nearly 30,000 rows and 1935 variables(columns). Among these many are character variables (around 350). Now I can change data type of an individual column using <code>as.numeric</code> on it, but it is painful to search for columns which are character type and then apply this individually on them. I have tried writing a function using a loop but since the data size is huge, laptop is crashing.
  Please help.</p>