PetscOptionsReal

Gets a PetscReal value for a particular option in the database.

Synopsis

#include <petscoptions.h>
PetscErrorCode PetscOptionsReal(const char opt[], const char text[], const char man[], PetscReal currentvalue, PetscReal *value, PetscBool *set)

Logically Collective on the communicator passed in PetscOptionsBegin()

Input Parameters

• opt - option name

• text - short string that describes the option

• man - manual page with additional information on option

• currentvalue - the current value; caller is responsible for setting this value correctly. Normally this is done with either

                 PetscOptionsReal(..., obj->value,&obj->value,...) or
                 value = defaultvalue
                 PetscOptionsReal(..., value,&value,&set);
                 if (set) {

Output Parameters

• value - the value to return

• set - PETSC_TRUE if found, else PETSC_FALSE

Notes

If the user does not supply the option at all value is NOT changed. Thus you should ALWAYS initialize value if you access it without first checking that set is PETSC_TRUE.

The currentvalue passed into this routine does not get transferred to the output value variable automatically.

Must be used between a PetscOptionsBegin() and a PetscOptionsEnd()

See Also

PetscOptionsGetReal(), PetscOptionsHasName(), PetscOptionsGetString(), PetscOptionsGetInt(), PetscOptionsGetIntArray(), PetscOptionsGetRealArray(), PetscOptionsGetBool(), PetscOptionsInt(), PetscOptionsString(), PetscOptionsReal(), PetscOptionsBool(), PetscOptionsName(), PetscOptionsBegin(), PetscOptionsEnd(), PetscOptionsHeadBegin(), PetscOptionsStringArray(), PetscOptionsRealArray(), PetscOptionsScalar(), PetscOptionsBoolGroupBegin(), PetscOptionsBoolGroup(), PetscOptionsBoolGroupEnd(), PetscOptionsFList(), PetscOptionsEList(), PetscOptionsBoundedReal(), PetscOptionsRangeReal()

Level

beginner

Location

include/petscoptions.h

Examples

src/snes/tutorials/ex46.c
src/ksp/ksp/tutorials/ex36.cxx
src/dm/impls/plex/tutorials/ex13.c
src/ksp/ksp/tutorials/ex29.c
src/ksp/ksp/tutorials/ex56.c
src/snes/tutorials/ex31.c
src/ksp/ksp/tutorials/ex73.c
src/ksp/ksp/tutorials/ex74.c
src/dm/impls/plex/tutorials/ex9.c
src/ksp/ksp/tutorials/ex35.cxx

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