R help - Feb 2009 - how todefine an variable/column in a dataframe as numeric mode

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]]

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]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>


-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?