petsc-3.13.6 2020-09-29

PetscOptionsReal

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

Synopsis

#include "petscsys.h"
PetscErrorCode  PetscOptionsReal(PetscOptionItems *PetscOptionsObject,const char opt[],const char text[],const char man[],PetscReal currentvalue,PetscReal *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

                PetscOptionsReal(..., obj->value,&obj->value,...) or

                value = defaultvalue

                PetscOptionsReal(..., value,&value,&flg);

                if (flg) {

Output Parameter

	value	- the value to return
	flg	- 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 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()

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

Level

beginner

Location

src/sys/objects/aoptions.c

Examples

src/dm/impls/plex/tutorials/ex9.c.html
src/ksp/ksp/tutorials/ex29.c.html
src/ksp/ksp/tutorials/ex56.c.html
src/ksp/ksp/tutorials/ex73.c.html
src/ksp/ksp/tutorials/ex74.c.html
src/snes/tutorials/ex12.c.html
src/snes/tutorials/ex15.c.html
src/snes/tutorials/ex46.c.html
src/snes/tutorials/ex48.c.html
src/snes/tutorials/ex56.c.html
src/snes/tutorials/ex62.c.html

Index of all Sys routines
Table of Contents for all manual pages
Index of all manual pages