petsc-3.12.5 2020-03-29
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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 NULL for default global database
pre - string to prepend to each name or NULL
name - the option one is seeking

Output Parameter

dvalue - the double value to return
set - PETSC_TRUE if found, else PETSC_FALSE

Usage

A complex number 2+3i must be specified with NO spaces

Notes

If the user does not supply the option dvalue is NOT changed. Thus you should ALWAYS initialize the ivalue if you access it without first checking if the set flag is true.

See Also

PetscOptionsGetInt(), PetscOptionsHasName(),
PetscOptionsGetString(), PetscOptionsGetIntArray(), PetscOptionsGetRealArray(), PetscOptionsBool(), PetscOptionsName(), PetscOptionsBegin(), PetscOptionsEnd(), PetscOptionsHead(), PetscOptionsStringArray(),PetscOptionsRealArray(), PetscOptionsScalar(), PetscOptionsBoolGroupBegin(), PetscOptionsBoolGroup(), PetscOptionsBoolGroupEnd(), PetscOptionsFList(), PetscOptionsEList()

Level

beginner

Location

src/sys/objects/options.c

Examples

src/ksp/ksp/examples/tutorials/ex25.c.html
src/ksp/ksp/examples/tutorials/ex49.c.html
src/snes/examples/tutorials/ex58.c.html
src/ts/examples/tutorials/ex21.c.html

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