How do I tween or ease a global variable?

I can tween objects that have the tween behaviour no problem but what do I do if I need to tween a global variable?

Thanks

Explain?

If I understood, he wants to change a variable value not in a linear way, he wants to do it using an ease.

I have a global variable. Lets say Speed=0

I want to have it increase to 100 on a nice smooth easing curve. ie, its starts off slow, increases and then slows down toward the end. Like a tween but with a global.

I’m not sure how c3 does the tweening, but you can do it with an expression. First you have a variable t that will increase with a constant rate from 0 to 1. In the following it does it over 2 seconds. Then to do the ease/out you can use the cosp() expression. But there are other ways.

Var global=0

Var t=0

Every tick

— set t to min(1, t+dt/2)

— set global to cosp(0, 100, t)

Thank you both!