[R] data frame manipulation with conditions

[ilai]

Ahh, I see it now.
For some reason your original post popped up on the list again, could
be just my mail server, sorry.
Looks like Uwe gave you the same solution (in two lines for better
clarity) right away. Depending on your level of "noobiness", my advice
would have been to ignore everything after that. Although if the other
approaches worked better for you, cheers.
Again sorry for this double thread.


On Fri, Feb 24, 2012 at 12:31 PM, Arnaud Gaboury
<arnaud.gaboury at a2ct2.com> wrote:
> TY Elai for your answer. One solution has been given earlier in this list by Sarah Goslee and William Dunlap.
>
> Arnaud Gaboury
>
> A2CT2 Ltd.
>
>
> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of ilai
> Sent: vendredi 24 février 2012 20:14
> To: A2CT2 Trading
> Cc: r-help at r-project.org
> Subject: Re: [R] data frame manipulation with conditions
>
> On Fri, Feb 24, 2012 at 8:11 AM, A2CT2 Trading <trading at a2ct2.com> wrote:
>> Dear list,
>>
>> n00b question, but still can't find any easy answer.
>>
>> Here is a df:
>>
>>> df<-data.frame(cbind(x=c("AA","BB","CC","AA"),y=1:4))
>
> # No, your y is a factor
>  str(df)
> 'data.frame':   4 obs. of  2 variables:
>  $ x: Factor w/ 3 levels "AA","BB","CC": 1 2 3 1  $ y: Factor w/ 4 levels "1","2","3","4": 1 2 3 4
>
> # You want to remove the cbind
>> df<-data.frame(x=c("AA","BB","CC","AA"),y=1:4)
>> str(df)
> 'data.frame':   4 obs. of  2 variables:
>  $ x: Factor w/ 3 levels "AA","BB","CC": 1 2 3 1  $ y: int  1 2 3 4
>
>> I want to modify this df this way :
>>  if df$x=="AA" then df$y=df$y*10
>>  if df$x=="BB" then df$y=df$y*25
>>
>> and so on with other conditions.
>>
>
>  df$y<- df$y * c(10,25,.5)[df$x]
> [1] 10.0 50.0  1.5 40.0
>  # 1*10 2*25 3*.5 4*10
>
> HTH
>
> Elai
>
>> TY for any help.
>>
>> Trading
>>
>> A2CT2 Ltd.
>>
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>
> ______________________________________________
> R-help at r-project.org mailing list
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>