Welcome to the forum!
If you want sine loading vs. theta, you could use bearing loading. Downside of that is it would assume 0 force at 0 and 180-deg (horizontal in your case), and chop off the unused portions. Essentially from your pic, your force F might start at 3/4F at the far edges of your applied area, instead of ramping from zero at the edge to F at the middle/bottom.
Values input for non-uniform distribution are only coefficients (but with units), cannot be equation based or linked. Having not done it personally, I'd think you could put your CSYS at the lowest part of your curve, then use x and y^2 to plot a parabolic curve as an approximation.
Thank you Justin.
I didn´t use the bearing load distribution because i dont have a cilindrical face in the assemble, the faces are concave. But the idea of using a parabolic distribution worked just fine.
you cannot enter functions into the boxes, just values
also even though you have selected an axis, i do not believe that changes the equation to cylindrical for non uniform pressure distribution