How to code motor commands?

Hi. In what file will I find motor commands for ArduCopter?

I have looked in (AP_MotorsMatrix.cpp) and other files but don’t see where the motor commands are.

I am coming from MultiWii development. Multiwii has a file (Output.cpp) where all motor commands are such as…
motor[0]= rcCommand[THROTTLE] -rcCommand[PITCH]+rcCommand[ROLL];
motor[1]= rcCommand[THROTTLE];+rcCommand[PITCH]-rcCommand[ROLL];
motor[2]= rcCommand[THROTTLE] +rcCommand[PITCH];
servo[0]= 1500 -rcCommand[YAW];

Where can I find such motor commands for ArduCopter? Thanks in advance.