[omalleyj]

What problem are you trying to solve? Are you trying to prevent spinning your wheels on acceleration? Preventing stress on the drivetrain when reversing direction quickly? Or just generally going for more control and less 'twitchiness'?

Eddie12390 has the right idea, but you need to manage each situation of input. For instance what will happen if you are going full speed and get a joystick input of full forward (-1.0). If you exactly cut and paste that code without at least limiting it you will be out of range for the motor input.

But his concept is sound for the problem as stated: take some percentage between where you are now and where you want to be and apply it. Just make sure you account for all situations.