读取R中的csv文件，将货币列作为数字

I'm trying to read into R a csv file that contains information on political contributions. From what I understand, the columns by default are imported as factors, but I need the the amount column ('CTRIB_AMT' in the dataset) to be imported as a numeric column so I can run a variety of functions that wouldn't work for factors. The column is formatted as a currency with a "$" as prefix.I'm trying to read into R a csv file that conta