php examples that run in command line and on web datatypes.php operators.php loop.php foreach.php while.php do_while.php ifelse.php function.php math.php array.php array2.php crossprod.php test_matrix.php uses matrix.php test_deriv.php uses deriv.php pde22_eq.php uses matrix.php deriv.php readfile.php date_time.php comment.php copy source code from /afs/umbc.edu/users/s/q/squire/pub/www/