[R] question about creating data frame

[jim holtman]

try this:


> x <- read.table(text = '"Not A" "A"
+ "Mathematics" 80 15
+ "Physics" 32 24
+ "Biology" 18 29', skip = 1, as.is = TRUE)
>
> # create the result
> result <- do.call(rbind, lapply(1:nrow(x), function(.row){
+     data.frame(course = x$V1[.row]
+         , A = c(rep(1, x$V2[.row]), rep(0, x$V3[.row]))
+         )
+ }))
>
> result
         course A
1   Mathematics 1
2   Mathematics 1
3   Mathematics 1
4   Mathematics 1
5   Mathematics 1
6   Mathematics 1
7   Mathematics 1
8   Mathematics 1
9   Mathematics 1
10  Mathematics 1
11  Mathematics 1
12  Mathematics 1
13  Mathematics 1
........
190     Biology 0
191     Biology 0
192     Biology 0
193     Biology 0
194     Biology 0
195     Biology 0
196     Biology 0
197     Biology 0
198     Biology 0



On Tue, May 15, 2012 at 2:47 PM, T Bal <studenttbal at gmail.com> wrote:
> Hello,
>
> My data is "study.txt":
>
> "Not A" "A"
> "Mathematics" 80 15
> "Physics" 32 24
> "Biology" 18 29
>
>
> I want to transform this data into with column names 'course' and 'A':
>
>                   course                       A
>             1   Mathematics              1
>             2   Mathematics              1
>             ..  ......                             ..
>            80  Mathematics              1
>            81  Mathematics              0
>            ...       ............                 ...
>            95  Mathematics              0
>            96  Physics                      1
>             ... ............                     ...
>           127 Physics                      1
>           128 Physics                      0
>           ...    ............                     ...
>           151  Physics                     0
>
>        etc.
>
>  How should I do it? So this data frame will consist from 198 rows.
>
> Thank you very much.
>
> kind regards,
> T. Bal
>
>        [[alternative HTML version deleted]]
>
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-- 
Jim Holtman
Data Munger Guru

What is the problem that you are trying to solve?
Tell me what you want to do, not how you want to do it.