I need to plot a curve as y = f(t), where t is the time, in the following way.
y= 0 at t=-5
- first interval t=-5 to t=0: y slightly increasing
-second interval t=0 to t=5: y slightly increasing
-third interval t=5 to t= 10: y increasing at an increasing rate
-forth interval t=10 to t=15: y increasing at a decreasing rate
-fifth interval (smaller) t=15 to t=18: y unchanged
-sixth interval(smaller) t=18 to t=21: y decreasing at an increasing rate
-seventh interval (smaller) t=21 to t=24: y decreasing at a decreasing rate

I am unable to get the exact required shape.
Please note that the t values for intervals are just to explain the shape so they can be different. I think this can better be done by using trigonometric function. Any help in this regard!