# PetscOptionsGetReal

Gets the double precision value for a particular option in the database.

### Synopsis

    #include "petsc.h"
    PetscErrorCode PETSC_DLLEXPORT PetscOptionsGetReal(const char pre[],const char name[],PetscReal *dvalue,PetscTruth *flg)

Not Collective

### Input Parameters

| pre | - string to prepend to each name or PETSC_NULL
| name | - the option one is seeking

### Output Parameter

| dvalue | - the double value to return
| flg | - PETSC_TRUE if found, PETSC_FALSE if not found

### C++ variants

| PetscOptionsGetReal(const char b[],PetscReal *i,PetscTruth *f) |  | -> |  | PetscOptionsGetReal(PETSC_NULL,b,i,f)

### See Also

PetscOptionsGetInt(), PetscOptionsHasName(),
PetscOptionsGetString(), PetscOptionsGetIntArray(), PetscOptionsGetRealArray(),PetscOptionsTruth(), PetscOptionsName(), PetscOptionsBegin(), PetscOptionsEnd(), PetscOptionsHead(), PetscOptionsStringArray(),PetscOptionsRealArray(), PetscOptionsScalar(), PetscOptionsTruthGroupBegin(), PetscOptionsTruthGroup(), PetscOptionsTruthGroupEnd(), PetscOptionsList(), PetscOptionsEList()

Level:beginner
Location:src/sys/src/objects/options.c
Index of all Sys routines
Table of Contents for all manual pages
Index of all manual pages

### Examples

src/ksp/examples/tutorials/ex11.c.html
src/ksp/examples/tutorials/ex11f.F.html
src/snes/examples/tutorials/ex3.c.html
src/snes/examples/tutorials/ex5.c.html
src/snes/examples/tutorials/ex5s.c.html
src/snes/examples/tutorials/ex14.c.html
src/snes/examples/tutorials/ex18.c.html
src/snes/examples/tutorials/ex19.c.html
src/snes/examples/tutorials/ex20.c.html
src/snes/examples/tutorials/ex26.c.html
src/snes/examples/tutorials/ex27.c.html