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
