[R] Replacing NAs with 0 for variables with the same ending

[Uli Kleinwechter]

That's it, thanks a lot to all of you!

Uli


Henrique Dallazuanna schrieb:
> In grep use: grep("x$", names(data)).
>
> '$' matchs 'x' in the end of string
>
> On Fri, Jan 15, 2010 at 11:14 AM, Uli Kleinwechter
> <u.kleinwechter at uni-hohenheim.de> wrote:
>   
>> Jim Lemon schrieb:
>>     
>>> On 01/15/2010 07:10 PM, Uli Kleinwechter wrote:
>>>       
>>>> Dear all,
>>>>
>>>> I'm looking for a way to replace NA's with 0 for a number of variables
>>>> which share the same ending and which constitute a subset of a data
>>>> frame.
>>>>
>>>> Say, for example, there is
>>>>
>>>>         
>>>>> data<- data.frame(ax=c(1,2,3,NA,0) , bx=c(3,5,NA,5,1) ,
>>>>>           
>>>> ay=c(5,NA,2,NA,0) , by=c(4,2,NA,2,1))
>>>>         
>>>>> data
>>>>>           
>>>>    ax bx ay by
>>>> 1  1  3  5  4
>>>> 2  2  5 NA  2
>>>> 3  3 NA  2 NA
>>>> 4 NA  5 NA  2
>>>> 5  0  1  0  1
>>>>
>>>> I wish to apply something like  //
>>>> //
>>>> />  data[is.na(data)]<- 0/
>>>> //
>>>> but not to the entire data frame, rather only to the variables ending
>>>> with x.
>>>>
>>>>         
>>> Hi Uli,
>>> How about:
>>>
>>> data[,grep("x",names(data))][is.na(data[,grep("x",names(data))])]<-0
>>>
>>> Jim
>>>
>>>       
>> Hi Jim,
>>
>> thanks a lot. I'm just afraid that grep matches any occurence of "x" in
>> the variable name. So variables which would contain "x" at any position,
>> not necessarily only at the last one would be selected, as well. To
>> refine my example (sorry for having been so imprecise before...):
>>
>>     
>>> data<- data.frame(ax=c(1,2,3,NA,0) , bx=c(3,5,NA,5,1)
>>>       
>> ,ay=c(5,NA,2,NA,0) , xy=c(4,2,NA,2,1))
>>     
>>> data
>>>       
>>  ax bx ay xy
>> 1  1  3  5  4
>> 2  2  5 NA  2
>> 3  3 NA  2 NA
>> 4 NA  5 NA  2
>> 5  0  1  0  1
>>
>> The task, again, would be to replace NA's with 0 in "ax" and "bx", but
>> not in "ay" and "xy"
>>
>> Best,
>>
>> Uli
>>
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>>
>>     
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