Why is my own echelon function printing incorrect matrix

I am trying to create an echelon function, however, I am having trouble debugging my error. It works for almost all matrices but for the following matrix it gives an incorrect result: A=[1 2 3 ; 1 2 4 ; 1 2 4] echelon(A) function x = echelon(A) [m,n]= (size(A)); % m= rows , %n= columns j=1; i=1; while( i It gives the following incorrect result:     1 2 3 0 0 1 0 0 1   Also for the following matrix:     A=[1 2 3 ; 1 2 5]   gives the following incorrect result:   1 2 3 0 0 2