[R] Data Import to R

[Jeff Newmiller]

If your data uses a special marker such as "--" or "n/a" to indicate not available then once you have identified those markers (using any method, though Don's procedure below is what I use) then you can specify them with the na.strings parameter to read.csv. (See the help for read.table for many other parameters you can also give to read.csv.) Once those special values are specified, then you should get numeric columns just fine.
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Sent from my phone. Please excuse my brevity.

On November 14, 2014 11:11:20 AM PST, "MacQueen, Don" <macqueen1 at llnl.gov> wrote:
>Petr is almost certainly correct. A further suggestion:
>
>Continue to import using stringsAsFactors = FALSE
>
>On one of the columns that should be numeric, use as.numeric(), find
>the
>NA's in the result of that, and then look at those rows of the data.
>There
>will be something there that is non-numeric. By any chance, does your
>data
>use a comma instead of a decimal point (see the "dec" argument to
>read.table)?