Troubleshoot controlling motors with raspberry pi model B+

With raspberry pi b+ I have connected a motor driver ic board and want to control using matlab. I am using the following commands but no use the motor is not rotating. I am new to matlab so help me friends..

configureDigitalPin(mypi,16,'output')
configureDigitalPin(mypi,20,'output')
configureDigitalPin(mypi,21,'output')
writeDigitalPin(mypi,16,1)
writeDigitalPin(mypi,20,1)
writeDigitalPin(mypi,21,0)

This is the commands for the gpio for raspberry pi that i found in mathworks website.