transpose method
Transposes this matrix.
Implementation
Matrix3 transpose() {
final e = elements;
double t;
t = e[ 1 ]; e[ 1 ] = e[ 3 ]; e[ 3 ] = t;
t = e[ 2 ]; e[ 2 ] = e[ 6 ]; e[ 6 ] = t;
t = e[ 5 ]; e[ 5 ] = e[ 7 ]; e[ 7 ] = t;
return this;
}