KSPComputeConvergenceRate#
Compute the convergence rate for the iteration
Synopsis#
#include "petscksp.h"
#include "petscmat.h"
PetscErrorCode KSPComputeConvergenceRate(KSP ksp, PetscReal *cr, PetscReal *rRsq, PetscReal *ce, PetscReal *eRsq)
Not collective
Input Parameter#
ksp - The
KSP
Output Parameters#
cr - The residual contraction rate
rRsq - The coefficient of determination, R^2, indicating the linearity of the data
ce - The error contraction rate
eRsq - The coefficient of determination, R^2, indicating the linearity of the data
Note#
Suppose that the residual is reduced linearly, \(r_k = c^k r_0\), which means \(log r_k = log r_0 + k log c\). After linear regression, the slope is \(\log c\). The coefficient of determination is given by \(1 - \frac{\sum_i (y_i - f(x_i))^2}{\sum_i (y_i - \bar y)}\),
References#
**** -***
//en.wikipedia.org/wiki/Coefficient_of_determination
See Also#
Level#
advanced
Location#
src/ksp/ksp/interface/itfunc.c
Index of all KSP routines
Table of Contents for all manual pages
Index of all manual pages