#include "petscvec.h" PetscErrorCode VecStepMax(Vec X, Vec DX, PetscReal *step)Collective on Vec
| X | - vector with no negative entries | |
| DX | - a step direction, can have negative, positive or zero entries |
| step | - largest value such that x[i] + step*DX[i] >= 0 for all i |