How to check if all rows of a matrix are equal [duplicate]

Question

What's the most efficient way of checking if all rows of a matrix are numerically equal? Preferably looking for something without a for loop.

Answer 1

Find difference between consecutive elements across columns with diff(..,1) and then detect if all such differences are zeros with nnz(..)==0, giving us a easy-peasy-chessy one-liner and pretty efficient solution -

isallrowsequal = nnz(diff(A,1))==0                      %// A is input matrix