Thanks Gabor, but in my case not every value ist actually encoded within 
the character string.  Vor example, I have an answer category, which is 
"more than one Mio. $".  (not in the column "income"...). 

I have the feeling, that there must be an another, straightforward way 
or function for transformation of levels / categories, but I just cannot 
make it work.

- greg

> Try this.  It matches the first numeric string on
> each line applying as.numeric to it and then using
> c to simplify the resulting list to a numeric vector.
>
>   
>> x <- c("from 1000$ to 2000$", "from 2000$  to 3000$", "more than 3000$",
>>     
> + "from 1000$ to 2000$", "from 1000$ to 2000$")
>
>   
>> library(gsubfn)
>> strapply(x, "([0-9]+).*", as.numeric, simplify = c)
>>     
> [1] 1000 2000 3000 1000 1000
>
> See the gsubfn home page for more:
> http://gsubfn.googlecode.com
>
> On Sun, Jun 28, 2009 at 4:25 AM, Gregor Povh<gregorpovh@yahoo.de> wrote:
>   
>> Dear R users,
>>
>> apologies for this quite simple question.  I've tried serverall approaches,
>> however, could not generate the desired result.
>>
>> I have a large data frame, which has several cathegories encoded as
>> character strings, for example.
>>
>> Name, income, gender, ...
>> ...  "from 1000$ to 2000$"  ...
>> ...  "from 2000$  to 3000$" ...
>> ...  "more than 3000$"        ...
>> ...  "from 1000$ to 2000$"  ...
>> ...  "from 1000$ to 2000$"  ...
>>
>>
>> How can I transform this column into numeric values for the categories, for
>> example in somethins like this:
>> ... 1000 ...
>> ... 2000 ...
>> ... 3000 ...
>> ... 1000 ...
>> ... 1000 ...
>>
>> ______________________________________________
>> R-help@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.
>>
>>     
>
>   


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