[R] Loop in variable names

[Eik Vettorazzi]

Hi Stella,
in your coding 'cut' is a string, not a data object.

something like
 cut <- paste("P",i, sep="")
 table(StoreData$CompanyID, !is.na(StoreData[,cut]))

should work.

hth.

Am 09.02.2011 19:02, schrieb Rita Carreira:
> 
> 
> Hello!
> I would like to do some tables for several variables and I would like to write a loop that does the table for each variable. I should also point out that my data set has several missing observations and sometimes the observations that are missing are not the same for all my variables.
> 
> What I would like to do:
> 
> table(StoreData$CompanyID, 
>         !is.na(StoreData$P2))
> table(StoreData$CompanyID, 
>         !is.na(StoreData$P5))
> 
> If I run the above code, I get:
> 
>> table(StoreData$CompanyID, 
> +         !is.na(StoreData$P2))
>    
>     FALSE TRUE
>   2   940    0
>   3     0  323
>   4   288    0
>   5   306    0
> 
>> table(StoreData$CompanyID, 
> +         !is.na(StoreData$P5))
>    
>     FALSE TRUE
>   2   940    0
>   3     0  323
>   4   288    0
>   5   306    0
> 
> 
> Here's the loop that I wrote, which does not work:
> 
> angus <- c(2,5)
> 
> for(i in angus) {
>   cut <- paste("StoreData$P",i, sep="")
>   table(StoreData$CompanyID, !is.na(cut)) 
>   }
> 
> When I run the above, I get the following error message:
> 
> Error in table(StoreData$CompanyID, !is.na(cut)) : 
>   all arguments must have the same length
>> source(.trPaths[5], echo=TRUE, max.deparse.length=150)
> 
> Any help is greatly appreciated!
> Stella
> 
> 
> 
>  		 	   		  
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> 
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-- 
Eik Vettorazzi
Institut für Medizinische Biometrie und Epidemiologie
Universitätsklinikum Hamburg-Eppendorf

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20246 Hamburg

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