petsc-master 2020-11-25
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DMPlexComputeOrthogonalQuality

Compute cell-wise orthogonal quality mesh statistic. Optionally tags all cells with orthogonal quality below given tolerance.

Synopsis

#include "petscdmplex.h"   
PetscErrorCode DMPlexComputeOrthogonalQuality(DM dm, PetscFV fv, PetscReal atol, Vec *OrthQual, DMLabel *OrthQualLabel)
Collective

Input Parameters

dm - The DMPlex object
fv - Optional PetscFV object for pre-computed cell/face centroid information
atol - [0, 1] Absolute tolerance for tagging cells.

Output Parameters

OrthQual - Vec containing orthogonal quality per cell
OrthQualLabel - DMLabel tagging cells below atol with DM_ADAPT_REFINE

Options Database Keys

-dm_plex_orthogonal_quality_label_view - view OrthQualLabel if label is requested. Currently only PETSCVIEWERASCII is supported.
-dm_plex_orthogonal_quality_vec_view - view OrthQual vector.

Notes

Orthogonal quality is given by the following formula

\min \left[ \frac{A_i \cdot f_i}{\|A_i\| \|f_i\|} , \frac{A_i \cdot c_i}{\|A_i\| \|c_i\|} \right]

Where A_i is the i'th face-normal vector, f_i is the vector from the cell centroid to the i'th face centroid, and c_i is the vector from the current cells centroid to the centroid of its i'th neighbor (which shares a face with the current cell). This computes the vector similarity between each cell face and its corresponding neighbor centroid by calculating the cosine of the angle between these vectors.

Orthogonal quality ranges from 1 (best) to 0 (worst).

This routine is mainly useful for FVM, however is not restricted to only FVM. The PetscFV object is optionally used to check for pre-computed FVM cell data, but if it is not passed in then this data will be computed.

Cells are tagged if they have an orthogonal quality less than or equal to the absolute tolerance.

See Also

DMPlexCheckCellShape(), DMCreateLabel()

Level

intermediate

Location

src/dm/impls/plex/plex.c

Examples

src/dm/impls/plex/tutorials/ex9.c.html

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