[R] If help

[jim holtman]

Try this, assuming your data is consistent:

> x <- read.table(textConnection('"NoReduction"              "NoReduction"
+  "Reduction"                "Reduction"
+  "NoReduction"              "NoReduction"
+  "NoReduction"              "NoReduction"
+  "Reduction"                "Reduction"
+  "Reduction"                "Reduction"
+  "Reduction"                "Reduction"
+  "NoReduction"              "Reduction"
+  "Reduction"                "NoReduction"
+  "NoReduction"              "NoReduction"
+  "NoReduction"              "NoReduction"
+  "NoReduction"              "NoReduction"'), as.is=TRUE)
>
> mapping <- c("NoReduction NoReduction" = 1,
+         "NoReduction Reduction" = -1,
+         "Reduction NoReduction" = 2,
+         "Reduction Reduction" = 0)
>
> x$change <- mapping[paste(x[,1], x[,2])]
> x
            V1          V2 change
1  NoReduction NoReduction      1
2    Reduction   Reduction      0
3  NoReduction NoReduction      1
4  NoReduction NoReduction      1
5    Reduction   Reduction      0
6    Reduction   Reduction      0
7    Reduction   Reduction      0
8  NoReduction   Reduction     -1
9    Reduction NoReduction      2
10 NoReduction NoReduction      1
11 NoReduction NoReduction      1
12 NoReduction NoReduction      1


On Tue, Jul 20, 2010 at 1:14 PM, Heiman, Thomas J. <theiman at mitre.org> wrote:
> Hi Y'all,
>
> I have some data in a table with 2 columns. There are two values: "Reduction" and "No Reduction. "  I am trying to make a new variable change which recode the combinations from column 1 and 2 into a single number.  Here is a snippet from the table:
>
> [1,] "NoReduction"              "NoReduction"
>  [2,] "Reduction"                "Reduction"
>  [3,] "NoReduction"              "NoReduction"
>  [4,] "NoReduction"              "NoReduction"
>  [5,] "Reduction"                "Reduction"
>  [6,] "Reduction"                "Reduction"
>  [7,] "Reduction"                "Reduction"
>  [8,] "NoReduction"              "NoReduction"
>  [9,] "NoReduction"              "NoReduction"
> [10,] "NoReduction"              "NoReduction"
>
> This is the code that I have written so far..
>
> for (i in 1:nrow(change20082009))
> if(change20082009[i,1]=='No Reduction' & change20082009[i,2]=='No Reduction') "){change20082009[i,3] <- 1} else
> if(change20082009[i,1]=='No Reduction' & change20082009[i,2]=='Reduction'){change20082009[i,3] <- -1} else
> if(change20082009[i,1]=='Reduction'    & change20082009[i,2]=='No Reduction') {change20082009[i,3] <- 2} else
> if(change20082009[i,1]=='Reduction'    & change20082009[i,2]=='Reduction') {change20082009[i,3] <- 0}
> )
>
> I can't seem to get the code above to work..Any suggestions (I am sure it is really basic)? Is there a better way to do this?
>
> Sincerely,
>
> tom
>
>
>        [[alternative HTML version deleted]]
>
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-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?