compress m
i1 : m = matrix {{1,2,0,0},{0,0,1,0}} o1 = | 1 2 0 0 | | 0 0 1 0 | 2 4 o1 : Matrix ZZ <-- ZZ
i2 : compress m o2 = | 1 2 0 | | 0 0 1 | 2 3 o2 : Matrix ZZ <-- ZZ
The object compress is a method function.