I have a curve I'm trying to fit with cspline and interp (see the attached calculation). Unfortunately, my y axis data oscilates so I had to write my function in terms of the x axis and use csort to make everything work. I was able to get a function M(phi) which works, but what I really need is phi(M) of an integral I need to perform on phi.
So, what I need to do is rewrite my function in the opposite terms (I'm not sure what the math terminology would be here). Any suggestions? What is the proper term for what I'm trying to do?
Thanks.