Markers System

The marker system is a sub-system of the Adaptivity system in MOOSE. The Marker objects serve to set the refinement flag to one of four states as defined by the C++ Enum MarkerValue. MOOSE will call the computeElementMarker method, which returns a MarkerValue. This value is then applied to an elemental AuxVariable. The automatic mesh refinement engine will then use this field to refine and coarsen the mesh in a consistent manner, as detailed in the Adaptivity system.

Marker Values

The four possible MarkerValue states are defined in Marker.h as follows:

  enum MarkerValue
{
DONT_MARK = -1,
COARSEN,
DO_NOTHING,
REFINE
};
(moose/framework/include/markers/Marker.h)

The purpose of each value of the MarkerValue is define in the following table.

StateDescription
DONT_MARKDo not apply any refinement flag to the element.
COARSENMarks an element to be coarsened, if possible.
DO_NOTHINGDoes not change the marker flag from the current state.
REFINEMarks and element to be refined, if possible.

Example Syntax


[./Markers]
[./box]
type = BoxMarker
bottom_left = '0.3 0.3 0'
top_right = '0.6 0.6 0'
inside = refine
outside = do_nothing
[../]
[./combo]
type = ComboMarker
markers = 'box box2'
[../]
[./box2]
type = BoxMarker
bottom_left = '0.5 0.5 0'
top_right = '0.8 0.8 0'
inside = refine
outside = coarsen
[../]
[../]
[]
(moose/test/tests/markers/combo_marker/combo_marker_test.i)
• BoxMarkerMarks the region inside and outside of a 'box' domain for refinement or coarsening.
• ComboMarkerA marker that converts many markers into a single marker by considering the maximum value of the listed markers (i.e., refinement takes precedent).
• ErrorFractionMarkerMarks elements for refinement or coarsening based on the fraction of the min/max error from the supplied indicator.
• ErrorToleranceMarkerCoarsen or refine elements based on an absolute tolerance allowed from the supplied indicator.
• OrientedBoxMarkerMarks inside and outside a box that can have arbitrary orientation and center point.
• UniformMarkerUniformly mark all elements for refinement or coarsening.
• ValueRangeMarkerMark elements for adaptivity based on the supplied upper and lower bounds and the specified variable.
• ValueThresholdMarkerThe the refinement state based on a threshold value compared to the specified variable.