@Fast_System: Yes you are really false. If you use
vec_set(my.pan,you.pan);
then the Engine do following:

vector1[0] = vector2[0]; // pan or x or red
vector1[1] = vector2[1]; // tilt or y or green
vector1[2] = vector2[2]; // roll or z or blue

The pan / tilt / roll or red / green / blue are notting other than a Vector (Vector = array that contains 3 values)

EDIT: have a look in the manual before you writing someting false.