public Matrix abs(){
  Matrix result=new Matrix(m,n);
  for (int i=0; i < result.A.length; i++) {
    for (int j=0; j < result.A[i].length; j++)     result.A[i][j]=Math.abs(A[i][j]);
  }
  return result;
}

public Matrix abs ( ) { Matrix result = new Matrix ( m , n ) ; for ( int i = 0 ; i < result . A . length ; i ++ ) { for ( int j = 0 ; j < result . A [ i ] . length ; j ++ ) result . A [ i ] [ j ] = Math . abs ( A [ i ] [ j ] ) ; } return result ; }
returns a new matrix object , where each value is set to the absolute value
