#include "petscconvest.h" PetscErrorCode PetscConvEstGetConvRate(PetscConvEst ce, PetscReal alpha[])Not collective
Note: The convergence rate alpha is defined by
|| u_\Delta - u_exact || < C \Delta^alphawhere u_\Delta is the discrete solution, and Delta is a measure of the discretization size. We usually use h for the spatial resolution and \Delta t for the temporal resolution.
We solve a series of problems using increasing resolution (refined meshes or decreased timesteps), calculate an error based upon the exact solution in the DS, and then fit the result to our model above using linear regression.
-snes_convergence_estimate : Execute convergence estimation inside SNESSolve() and print out the rate | - - -ts_convergence_estimate : Execute convergence estimation inside TSSolve() and print out the rate |