[petsc-users] Time Stepping Terminology

[Gideon Simpson]

I was looking around to see if there was any built in routine for implicit midpoint time stepping in petsc.  By this I mean equation (1i) of https://en.wikipedia.org/wiki/Midpoint_method.  

I noticed the TSTHETA solver, and I see that the documentation says:

-ts_type theta -ts_theta_theta 0.5 corresponds to the implicit midpoint rule

But I wanted to verify that it agrees with what I interpret to be implicit midpoint.  

Also, is the distinction with the ts_theta_endpoint  flag as to whether it is the weighting of the argument to the f(t,y) function or the weighting of the f(t,y) evaluated at the different points?

-gideon