ONKELINX, Thierry wrote: > Have a look at all.equal > > matA <- matrix(1:4, ncol = 2) > matB <- matA > all.equal(matA, matB) > matB[1,1] <- -10 > all.equal(matA, matB) Hi Thierry, Thanks, all.equal does indicate if it's all equal so that works great! Much nicer than my hack - thanks, Esmail