Charts/Data on FRC Motor and Joystick Bias

Does anybody have any charts/data depicting the motor bias for the FRC motors and joysticks? And on that note does anybody know on what X and Y axises are needed to make the charts linear?

Is this the type of chart you are looking for? It displays motor speed with respect to PWM command. http://www.chiefdelphi.com/forums/attachment.php?attachmentid=3100