#include "petscvec.h" PetscErrorCode VecStrideMax(Vec v,PetscInt start,PetscInt *idex,PetscReal *nrm)Collective on Vec
v | - the vector | |
start | - starting point of the subvector (defined by a stride) |
index | - the location where the maximum occurred (pass NULL if not required) | |
nrm | - the maximum value in the subvector |
If xa is the array representing the vector x, then this computes the max of the array (xa[start],xa[start+stride],xa[start+2*stride], ....)
This is useful for computing, say the maximum of the pressure variable when the pressure is stored (interlaced) with other variables, e.g., density, etc. This will only work if the desire subvector is a stride subvector.