it's the temp.x(my.x,my.y,my.z-100)

I don't exactly know what you mean with the code,
but you can use both:

.....vector(my.x,my.y,my.z-100).....
or ....temp....

you have to set temp[0] <== x, temp[1] <== y and temp[2] <==z to the values you want


when you type temp.x(my.x,my.y,my.z-100)
the compiler will start searching for a function x of the object temp, and give it the arguments my.x,my.y and my.z-100.... which doesn't exist.

I hope this helps