Loop in variable names

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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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Try:

for(i in angus) {
 cut <- StoreData[[paste("P", i)]]
 table(StoreData$CompanyID, !is.na(cut))
 }