#include "petsclog.h" PetscErrorCode PetscLogSetThreshold(PetscLogDouble newThresh, PetscLogDouble *oldThresh)Logically Collective over PETSC_COMM_WORLD
| newThresh | - the threshold to use | 
| oldThresh | - the previously set threshold value | 
| -log_view :filename.xml:ascii_xml | - Prints an XML summary of flop and timing information to the file | 
      PetscInitialize(...);
      PetscLogNestedBegin();
      PetscLogSetThreshold(0.1,&oldthresh);
       ... code ...
      PetscLogView(viewer);
      PetscFinalize();