PetscOptionsScalar#

Gets the PetscScalar value for a particular option in the database. Logically Collective on the communicator passed in PetscOptionsBegin()

Synopsis#

#include "petscsys.h"
PetscErrorCode PetscOptionsScalar(const char opt[],const char text[],const char man[],PetscScalar currentvalue,PetscScalar *value,PetscBool  *set)

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

                 PetscOptionsScalar(..., obj->value,&obj->value,...) or
                 value = defaultvalue
                 PetscOptionsScalar(..., value,&value,&flg);
                 if (flg) {

Output Parameters#

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 if the set flag is true.

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

Must be 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()

Level#

beginner

Location#

src/sys/objects/aoptions.c

Examples#

src/ksp/ksp/tutorials/ex32.c
src/ts/tutorials/ex35.cxx
src/ts/tutorials/ex52.c


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