PetscOptionsReal#

Gets a PetscReal value for a particular option in the database.

Synopsis#

#include <petscoptions.h>
PetscErrorCode PetscOptionsReal(const char opt[], const char text[], const char man[], PetscReal currentvalue, PetscReal *value, PetscBool *set)

Logically Collective on the communicator passed in PetscOptionsBegin()

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,&set);
                 if (set) {

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 that set is PETSC_TRUE.

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

Must be used 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(), PetscOptionsBoundedReal(), PetscOptionsRangeReal()

Level#

beginner

Location#

include/petscoptions.h

Examples#

src/snes/tutorials/ex56.c
src/snes/tutorials/ex15.c
src/tao/pde_constrained/tutorials/elliptic.c
src/tao/tutorials/ex4.c
src/tao/pde_constrained/tutorials/parabolic.c
src/dm/impls/plex/tutorials/ex9.c
src/snes/tutorials/ex77.c
src/tao/constrained/tutorials/tomographyADMM.c
src/dm/impls/plex/tutorials/ex13.c
src/tao/pde_constrained/tutorials/hyperbolic.c

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