[R] how todefine an variable/column in a dataframe as numeric mode

jim holtman jholtman at gmail.com
Mon Feb 23 15:09:06 CET 2009

First of all when read in you can define the class of each column.  It
sounds like you have a non-numeric in that column.  If you are not
using factors, then putting 'as.is=TRUE' will make sure that they are
read in as characters.  If you want to convert a column to numeric, do
the following:

df$col <- as.numeric(as.character(df$col))

On Mon, Feb 23, 2009 at 8:35 AM, Mao Jianfeng <jianfeng.mao at gmail.com> wrote:
> Hello dear R-users,
> I have a tricky problem of data manipulation with R. Although it seems
> very easy, I can not solve it by myselves.
> The problem is a variable in my dataset is usually be readed as
> "factor" (variable mode), however I want it be a "numeric" one. I want
> to know how can I define an variable/column in a dataframe as numeric
> mode, after I imported a large dataset using read.delim() from a txt
> file.
> Thanks a lot in advance.
> Mao J-F
> State Key Lab of Systematics and Evolutionary Botany
> Institute of Botany
> Chinese Academy of Sciences
> Beijing, China
>        [[alternative HTML version deleted]]
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Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?

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