# [R] help with one matrix

Jose Claudio Faria joseclaudio.faria at terra.com.br
Sun Sep 11 12:13:49 CEST 2005

```Gabor Grothendieck wrote:

> On 9/10/05, Jose Claudio Faria <joseclaudio.faria at terra.com.br> wrote:
>
>>Dear R-list,
>>
>>Could anybody tell me how to make one matrix as the below:
>>
>>     [,1] [,2] [,3] [,4] [,5] [,6]
>>[1,]    -    2    3    4    5    6
>>[2,]    2    -    2    3    4    5
>>[3,]    3    2    -    2    3    4
>>[4,]    4    3    2    -    2    3
>>[5,]    5    4    3    2    -    2
>>[6,]    6    5    4    3    2    -
>>
>
>
> Assuming that - means NA
>
> dd <- diag(NA, 6)
> abs(col(dd) - row(dd)) + 1 + dd
>
> or
>
> abs(outer(1:6, 1:6, "-")) + 1 + diag(NA,6)
>
> or
>
> f <- function(x,y) ifelse(x==y, NA, abs(x-y)+1)
> outer(1:6, 1:6, f)

Hi,

You are always solving (and teaching) my R doubts: thanks Gabor, very much!
Because I need one, I've been trying to make a more flexible function for
multiple comparison test of means (Tukey, SNK and Duncan). The matrix above is
necessary for SNK and Duncan tests. So, when running I will to sent it for you
for suggestions.

Best,
--
Jose Claudio Faria
Brasil/Bahia/UESC/DCET