question: public void logEquals ( ) { for ( int i = 0 ; i < A . length ; i ++ ) for ( int j = 0 ; j < A [ i ] . length ; j ++ ) A [ i ] [ j ] = Math . log ( A [ i ] [ j ] ) ; }
target:  X.logEquals() calculates the natural logarithem of each element of the matrix. The result is stored in this matrix object again.