Hi:
Here's a way using the reshape2 package.
library('reshape2')
rsub <- subset(rtest, concept %in% c('8.2.D', '8.3.A', '8.3.B'))
# want year ahead of concept in the variable list
rsub <- rsub[, c(1:4, 9, 5:8)]
cast(rsub, id + test + subject + grade + year ~ concept, value_var = 'per_corr')
# Using per_corr as value column. Use the value argument to cast to
override this choice
# id test subject grade year 8.2.D 8.3.A 8.3.B
# 1 1 83 Mathema 8 2011 100 50 100
# 2 2 83 Mathema 8 2011 100 100 50
HTH,
Dennis
On Thu, Oct 20, 2011 at 11:55 AM, James Holland <holland.ag...@gmail.com> wrote:
> Hello,
>
> I have a dataset with student performance on a math test. There are
> multiple cases for each student (identified by id) and the concept as a
> variable.
>
>> rtest
>
> id test subject grade concept correct tested per_corr
> year
> 1 1 83 Mathema 8 8.2.D 1 1 100
> 2011
> 2 1 83 Mathema 8 8.3.A 1 2 50
> 2011
> 3 1 83 Mathema 8 8.3.B 2 2 100
> 2011
> 4 1 83 Mathema 8 8.4 2 2 100
> 2011
> 5 1 83 Mathema 8 8.5.A 1 2 50
> 2011
> 6 1 83 Mathema 8 8.5.B 0 2 0
> 2011
> 7 2 83 Mathema 8 8.2.D 1 1 100
> 2011
> 8 2 83 Mathema 8 8.3.A 2 2 100
> 2011
> 9 2 83 Mathema 8 8.3.B 1 2 50
> 2011
> 10 2 83 Mathema 8 8.4 2 2 100
> 2011
> 11 2 83 Mathema 8 8.5.A 1 2 50
> 2011
> 12 2 83 Mathema 8 8.5.B 0 2 0
> 2011
>
>
> I would like to make a variable for each concept (e.g. 8.2D, 8.3.A, 8.3B)
> and then put that percentage correct currently under per_corr for that
> variable.
>
> Such as
>
> id test subject grade 8.2D 8.3.A 8.3.B
> year
> 1 1 83 Mathema 8 100 50 100
> 2011
> 2 2 83 Mathema 8 100 100 50
> 2011
>
>
>
>
> Does anybody have an effcient way of doing this?
>
> What trips me up is handling the variables such as test and subject.
>
> Thank you,
>
> James
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
