On May 17, 2013, at 01:59 , David Winsemius wrote:
>
> On May 16, 2013, at 1:46 PM, Hermann Norpois wrote:
>
>> Hello,
>>
>> I fail to tranfer data from a dataframe to a matrix.
>>
>> jam is from a dataframe (and belongs still to the class dataframe) and
>> should look like m (see below).
>>
>>> jam
>> vec1 vec3 d1 d2
>> 1 172 173 223 356
>>> dput (jam)
>> structure(list(vec1 = 172L, vec3 = 173L, d1 = 223L, d2 = 356L), .Names =
>> c("vec1",
>> "vec3", "d1", "d2"), row.names = 1L, class = "data.frame")
>>> m #THIS IS THE AIM
>> [,1] [,2]
>> [1,] 172 223
>> [2,] 173 356
>>
>>> dput (m)
>> structure(c(172, 173, 223, 356), .Dim = c(2L, 2L))
>>
>> How can I transform jam to m?
>
> jam <- structure(list(vec1 = 172L, vec3 = 173L, d1 = 223L, d2 = 356L), .Names
> =
> c("vec1",
> "vec3", "d1", "d2"), row.names = 1L, class = "data.frame")
> jm <- data.matrix(jam)
> dim(jm) <- c(2,2) # re-dimension a matrix with column-major order
> jm
>
> [,1] [,2]
> [1,] 172 223
> [2,] 173 356
also
> matrix(unlist(jam),2)
[,1] [,2]
[1,] 172 223
[2,] 173 356
--
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Email: pd....@cbs.dk Priv: pda...@gmail.com
______________________________________________
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.
