function mmult( x, y ) {
		var i;
		var j;
		var k;
		var s;
		var z;

		z = new Float64Array( m * m );
		for ( i = 0; i < m; i++ ) {
			for ( j = 0; j < m; j++ ) {
				s = 0;
				for ( k = 0; k < m; k++ ) {
					s += x[ (i*m) + k ] * y[ (k*m) + j ];
					z[ (i*m) + j ] = s;
				}
			}
		}
		return z;
	}
Multiply matrices x and y.

@private
@param {Float64Array} x - first input matrix
@param {Float64Array} y - second input matrix
@returns {Float64Array} matrix product