[R] quetion about matrix compute

Chel Hee Lee chl948 at mail.usask.ca
Sat Jan 31 18:47:35 CET 2015


Here is another implementation:

 > b
[1] 1 2 3 4 5
 > c
[1] 1 2 1 3 5 4
 > outer(c,b, "==")*1
      [,1] [,2] [,3] [,4] [,5]
[1,]    1    0    0    0    0
[2,]    0    1    0    0    0
[3,]    1    0    0    0    0
[4,]    0    0    1    0    0
[5,]    0    0    0    0    1
[6,]    0    0    0    1    0

I hope this helps.

Chel Hee Lee

On 1/30/2015 11:52 AM, JS Huang wrote:
> Hi,
>
>    Here is my implementation.  Hope this helps.
>
>> b
> [1] 1 2 3 4 5
>> c
> [1] 1 2 1 3 5 4
>> sapply(b,function(x)ifelse(x==c,1,0))
>       [,1] [,2] [,3] [,4] [,5]
> [1,]    1    0    0    0    0
> [2,]    0    1    0    0    0
> [3,]    1    0    0    0    0
> [4,]    0    0    1    0    0
> [5,]    0    0    0    0    1
> [6,]    0    0    0    1    0
>
>
>
> --
> View this message in context: http://r.789695.n4.nabble.com/quetion-about-matrix-compute-tp4702505p4702532.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.
>



More information about the R-help mailing list