How should I check if I have for example a letters or combination of letters and numbers or spaces in a column that type is a "character" ? I would like to know in which rows do I have it in my dataframe ? I would like to make a subset of it and look at it before I convert character column to numeric one and then values like "BBB" or "12ba" will become NA. I want to have only values like " 123", 321" in a particular column.
Any ideas will be much appreciated,