Hello,
Thanks for the data examples. But you should give them in a form that's
easy for us to copy and paste into an R session. Using ?dput, for
instance. The examples below are the last two pairs of matrices in your
post, the ones with different signs. fun1() checks rows and fun2() columns.
x1 <- structure(c(1, -1, 1, -1, 1, 1, 1, -1, -1), .Dim = c(3L, 3L))
y1 <- structure(c(1, -1, -1, -1, 1, -1, 1, -1, 1), .Dim = c(3L, 3L))
x2 <- structure(c(1, -1, 1, -1, 1, 1, 1, -1, -1), .Dim = c(3L, 3L))
y2 <- structure(c(1, -1, 1, 1, -1, -1, 1, -1, -1), .Dim = c(3L, 3L))
fun1 <- function(x, y){
all(sapply(seq_len(nrow(x)), function(i)
identical(x[i,], y[i,]) || identical(x[i,], -y[i,])))
}
fun2 <- function(x, y){
all(sapply(seq_len(nrow(x)), function(i)
identical(x[,i], y[,i]) || identical(x[,i], -y[,i])))
}
fun1(x1, y1) # TRUE
fun2(x1, y1) # FALSE
fun1(x2, y2) # FALSE
fun2(x2, y2) # TRUE
Hope this helps,
Rui Barradas
Em 11-11-2012 08:06, Haris Rhrlp escreveu:
> Dear R users,
>
> i have this problem with matrices i want to check between two matrices if
> they are isomorphic i will give an example for what excactly i want
> 1 -1 1 -1 1 1
> -1 1 -1 1 -1 -1
> 1 1 -1 1 1 -1
> this two matrices are isomorphic beacause if i change the first 2 columns the
> matrices are identical
>
> 1 -1 1 -1 1 -1
> -1 1 -1 1 -1 1
> 1 1 -1 1 -1 1
> this two matrices are isomorphic because if i change the first 2 rows the
> matrices are identical
> 1 -1 1 1 -1 1
> -1 1 -1 -1 1 -1
> 1 1 -1 -1 -1 1
> this two matrices are isomorphic because in the third line if i change the
> signs the two matrices are identical
> 1 -1 1 1 1 1
> -1 1 -1 -1 -1 -1
> 1 1 -1 1 -1 -1
> this two matrices are isomorphic because in the second column if i change the
> signs the two matrices are identical
>
>
> and all the above together
>
> rA <- apply(BB2[,,1,(j-1)],1,paste,collapse=" ")
> rB <- apply(BB2[,,i,(j-1)],1,paste,collapse=" ")
> cA <- apply(BB2[,,1,(j-1)],2,paste,collapse=" ")
> cB <- apply(BB2[,,i,(j-1)],2,paste,collapse=" ")
> iso <- all(sort(rA) == sort(rB)) | all(sort(cA) == sort(cB))
>
> this is only for the change or rows and columns but i want to change the
> signs too.
>
> [[alternative HTML version deleted]]
>
>
>
> ______________________________________________
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
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