question: 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 ; }
target:  returns a new Matrix object, where each value is set to the absolute value