[R] comparing matrices

[David Winsemius]

On Apr 26, 2009, at 1:02 PM, Esmail wrote:

> I'm trying to compare two matrices made up of bits.
>
> doing a simple comparison of
>
>        matA == matB

 > identical( matrix((1:4), ncol=2), matrix((1:4), nrow=2))
[1] TRUE
 > identical( matrix((1:4), ncol=2), matrix((2:5), nrow=2))
[1] FALSE

>
>
> yields this sort of output.
>
>      [,1] [,2]  [,3]  [,4]  [,5]  [,6]
> [1,] FALSE TRUE FALSE  TRUE  TRUE FALSE
> [2,]  TRUE TRUE  TRUE  TRUE  TRUE  TRUE
> [3,] FALSE TRUE FALSE FALSE FALSE  TRUE
> [4,] FALSE TRUE  TRUE FALSE FALSE FALSE
> [5,]  TRUE TRUE  TRUE  TRUE FALSE FALSE
> [6,]  TRUE TRUE  TRUE  TRUE FALSE FALSE
>
> I really would like just one comprehensive value to say TRUE or FALSE.
>
> This is the hack (rather ugly I think) I put together that works,
> but there has to be a nicer way, no?
>
>    res=pop[1:ROWS,] == keep[1:ROWS,]
>
>
>    if ((ROWS*COL) == sum(res))
>     {
>       cat('they are equal\n')
>     }else
>       cat('they are NOT equal\n')

That code is meaningless to us without a definition (in R) of ROWS,   
COL, keep, and pop
>
>
> Thanks!
>
> Esmail
>
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David Winsemius, MD
Heritage Laboratories
West Hartford, CT