propagate a predefined python surface over time I created in Python a script that models a circular wave on a plane

cf blend file with script python at the link:

https://drive.google.com/open?id=1CaVfRsN_fSqrb2ogYf-WeEMR1hy9S2EQ

What I have to do is to propagate this wave as a function of time (with the frame scrolling in the timeline) what I can not do in python although having introduced a variable frame
because after:

added at the beginning of the script the frame variable

and

seeing modified the line 29 in writing:

29>  return u,v,2*math.sin(math.pow(uu+vv,0.5)+function_affine(frame))

this script doesn't work !

So,my question:

What additional lines do I have to introduce in the script to play the animation or the propagation of the circular wave on this plane according to the frame of the timeline?

thanks
Here is the blend file with the modified script. Basically, you have to:


create a few shape keys, with incremented angle given to sin function
uncheck the Relative box for basis shapekey
make the interpolation type linear
set the value of evaluation time for the end frame one less than the maximum evaluation time