[R] Help wit matrices

[Lanre Okusanya]

Hello all,

I am working with a 1000x1000 matrix, and I would like to return a
1000x1000 matrix that tells me which value in the matrix is greater
than a theshold value (1 or 0 indicator).
i have tried
  mat2<-as.matrix(as.numeric(mat1>0.25))
but that returns a 1:100000 matrix.
I have also tried for loops, but they are grossly inefficient.

THanks for all your help in advance.

Lanre