quality provides a collection of mesh quality measurements. Together with commands in cmo/addatt a good summary of mesh metrics can be reported or used for further mesh optimization. For quality measurments to characterize tet elements by various types, see Quality Measures.
quality / [quality_type] / [quality_type_options]
The following are definitions for valid quality-type commands and their quality_type_options.
quality
with no arguments writes to screen and outx3dgen or lagrit.out logfile reports on the min, max, and counts of aspect ratios and volumes. The aspect ratios are displayed with 7 bins (log scale) with counts of values between .01 and 1. The element volumes are displayed with 5 bins with counts of values between the min and max volumes.
quality/aspect / [y]
computes the ratio of the radius of the circumsphere to the radius of the inscribed sphere of a tetrahedron. The ratio is multiplied by 3 so that a value of 1 indicates a regular tetrahedron. The display is a binned count of the number of elements whose aspect ratio falls in each of 7 bins (log scale between .01 and 1). y option creates aratio mesh element attribute containing the value of the aspect ratio for each element. Valid element types are tet and tri, hex, and quad (where the length of the hex or quad diagonals are used).
quality/edge_ratio / [y]
computes the ratio (shortest element edge/longest element edge) and displays a binned count of the min/max edge ratio in each of 7 bins (log scale between .01 and 1). y option creates eratio mesh element attribute containing the value of the min/max edge ratio for each element.
quality/edge_min / [y]
displays a binned count of the minimum edge lengths displayed log scale between .01 and 1. The binned values are normalized by dividing with the max value. The min and max of the mininum edge length for each element are also reported. y option creates edgemin mesh element attribute containing the value of the min edge length of each element.
quality/edge_max / [y]
displays a binned count of the maximum edge lengths displayed log scale between .01 and 1. The binned values are normalized by dividing with the max value. The min and max of the maximum edge length for each element are also reported. y option creates edgemax mesh element attribute containing the value of the max edge length of each element.
quality/angle / gt OR lt / value /
finds the max and min dihedral angles between adjacent faces (or 2D edges) of an element in radians. If the compare option is used, it displays a count of the number of elements with a dihedral angle that is greater than or less than the supplied value. See also cmo/addatt/cmo/ang_ commands for dihedral angle and solid angle calculations.
quality/pcc
creates an element based attribute called neg_coup_coeff which is a “negative coupling coefficient” indicator. A value of 1 means the coupling coefficient is OK. Anything less than 1 means it is negative. This is useful when viewing a mesh to find where the negative coupling coefficients occur.
quality/quad
generates some quality measures for quads and displays them after binning them into seven bins. For details on the quad quality measures see cmo/addatt/ quad_quality.
quality/taylor/ fieldname / value /
creates and displays a count of the number of element-edge pairs with a taylor error estimate value whose absolute value is greater than the supplied value. This creates the attribute quality_taylor with length in attribute quality_taylor_len.
quality/volume allows any combination of the quality_type_options for example:
quality/volume/ number_of_bins / itetclr / lt | gt | eq | ne | xvalue / eltset,get,ename
quality/volume / [number_of_bins] / [ itetclr ]
number_of_bins is an integer value controlling the number of bins in which to distribute the volume values for display. if number_of_bins is 0, then binning of distributed volumes is skipped, and only min and max volumes are reported. number_of_bins must be the 2nd argument to quality if used.
itetclr is a keyword that will give volume information according to the values in the itetclr attribute. Number_of_bins applies to each tetclr value. For each itetclr value, the volume of elements will be totaled.
quality/volume / gt OR lt OR eq OR ne / value
will report volumes based on compare operator and given xvalue, for instance quality/volume/lt 0.0/ will report total number of elements with volumes less than 0.0 It may be used in combination of other volume options. if used with itetclr keyword, values will be reported by itetclr value
quality/volume / eltset, get, eset_name
eltset,get,ename will report volumes on elements in defined eltset can be used in combination with previous options with operations done only on the chosen eltset. itetclr will still report for each of the values in itetclr.
quality/aspect
display summary of aspect ratio distribution in 7 bins
quality/aspect/ y
create attribute aratio and display summary of aspect the aratio distribution
quality/angle/gt/179/
return count of elements with a dihedral angle > 179
quality/taylor/boron/1.e-10/
run taylor error estimate and return count of element edge pairs with absolute error greater than 1.e-10
quality/volume
quality/volume/ 2
The first call will display summary of volumes with 5 bins, the second command will show summary with 2 bins
quality/volume/itetclr
quality/volume /itetclr/lt .03
quality/volume/itetclr/eltset,get,e2
All three commands will loop through itetclr (material values) and report a total volume for each itetclr value. The second command will report element volumes lt .03 by the itetclr values. The third command will report element volumes by itetclr values, but only for elements in the set e2
quality
quality/ aspect / y
quality/ edge_max / y
cmo/addatt /cmotri /area_normal/ xyz/ anorm
cmo/addatt /cmotri /scalar /xnorm ynorm znorm / anorm
cmo/printatt /cmotri / aratio minmax
cmo/printatt /cmotri / edgemax minmax
cmo/printatt /cmotri / znorm minmax
Example calls using quality and cmo/addatt commands to show mesh quality statistics.
quality
The default with no arguments will calculate and display element volumes and aspect ratios for the current mesh object.
Output for the quality command with no arguments:
quality
epsilonl, epsilonaspect: 1.4360051E-10 2.9612012E-30
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elements with aspect ratio < .01: 0
elements with aspect ratio b/w .01 and .02: 0
elements with aspect ratio b/w .02 and .05: 0
elements with aspect ratio b/w .05 and .1 : 0
elements with aspect ratio b/w .1 and .2 : 12020
elements with aspect ratio b/w .2 and .5 : 625891
elements with aspect ratio b/w .5 and 1. : 157053
min aspect ratio = 0.1053E+00 max aspect ratio = 0.7229E+00
epsilonvol: 1.1335396E-05
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element volumes b/w 0.1667E+02 and 0.3318E+02: 612924
element volumes b/w 0.3318E+02 and 0.6605E+02: 54612
element volumes b/w 0.6605E+02 and 0.1315E+03: 18204
element volumes b/w 0.1315E+03 and 0.2617E+03: 45510
element volumes b/w 0.2617E+03 and 0.5210E+03: 63714
element volumes b/w 0.2617E+03 and 0.5210E+03: 63714
min volume = 1.6666667E+01 max volume = 5.2100000E+02
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794964 total elements evaluated.