PetscOptionsGetScalar#
Gets the scalar value for a particular option in the database.
Synopsis#
#include "petscsys.h"   
PetscErrorCode PetscOptionsGetScalar(PetscOptions options, const char pre[], const char name[], PetscScalar *dvalue, PetscBool *set)
Not Collective
Input Parameters#
- options - options database, use - NULLfor default global database
- pre - string to prepend to each name or - NULL
- name - the option one is seeking 
Output Parameters#
- dvalue - the scalar value to return 
- set - - PETSC_TRUEif found, else- PETSC_FALSE
Example Usage#
A complex number 2+3i must be specified with NO spaces
Note#
If the user does not supply the option dvalue is NOT changed. Thus
you should ALWAYS initialize dvalue if you access it without first checking if the set flag is true.
See Also#
PetscOptionsGetInt(), PetscOptionsHasName(),
PetscOptionsGetString(), PetscOptionsGetIntArray(), PetscOptionsGetRealArray(), PetscOptionsBool(),
PetscOptionsName(), PetscOptionsBegin(), PetscOptionsEnd(), PetscOptionsHeadBegin(),
PetscOptionsStringArray(), PetscOptionsRealArray(), PetscOptionsScalar(),
PetscOptionsBoolGroupBegin(), PetscOptionsBoolGroup(), PetscOptionsBoolGroupEnd(),
PetscOptionsFList(), PetscOptionsEList()
Level#
beginner
Location#
Examples#
src/dm/impls/stag/tutorials/ex1.c
src/ksp/ksp/tutorials/ex25.c
src/snes/tutorials/ex58.c
src/ts/tutorials/ex45.c
src/dm/impls/stag/tutorials/ex4.c
src/ts/tutorials/ex21.c
src/ksp/ksp/tutorials/ex49.c
Index of all Sys routines
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Index of all manual pages