QUALITY
quality provides a collection of mesh quality measures
 
 FORMAT: quality /[quality_type] / [quality_type options]
Where quality-type can be aspect, pcc, volume, angle, quad, or taylor. Quality-type options depend on the quality-type.
quality (no arguments)
writes to screen and outx3dgen logfile giving volume and aspect ratio distribution information. Aspect ratios and element volumes are binned into 5 bins then totaled, min and max values are also reported.
quality/aspect/[y]
displays a count of the number of elements whose aspect ratio falls in each of 7 bins .  If y is specified create an attribute named aratio that will contain the value of the aspect ratio of each element.
quality/edge_ratio/[y]
displays a count of the edge length minimum/edge length maximum in each of 7 bins. If y is specified create an attribute named eratio that will contain the value of the min/max edge ratio of each element.
quality/edge_min/[y]
displays a count of the minimum edge length in each of 7 bins. If y is specified create an attribute named edgemin that will contain the value of the min edge length of each element.
quality/edge_max/[y]
displays a count of the maximum edge length in each of 7 bins. If y is specified create an attribute named edgemax that will contain the value of the max edge length of each element.
quality/angle/gt|lt/value]/
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/mo/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  element attribute and is useful when viewing a mesh with GMV to find the negative coupling coefficients.
quality/quad generates some quality measures for quads and displays them after binning them into seven bins. Please see cmo / addatt // quad_quality for details on the quality measures used.
quality/taylor/fieldname/value/
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.
quality/volume
quality/volume can appear with or without any of the following options:
quality/volume / number_of_bins
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.
quality/volume/itetclr
 output element volume distributions with 5 bins. loop through itetclr values and report total volume for each material
quality/volume/number_of_bins/itetclr
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/lt|gt|eq|ne/xvalue
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,ename
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 .

Any combination of quality_type options may occur with the volume quality_type, for example:
quality/volume/number_of_bins/itetclr/lt| gt | eq | ne | xvalue/eltset,get,ename.
 

EXAMPLES:
quality display volume and aspect ratio
quality/aspect display aspect ratiodistribution in 7 bins
quality/aspect/y display aspect ratio distribution and add attribute named aratio
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 value
quality/volume output element volume distribution with 5 bins
quality/volume / 2 output element volume distribution with 2 bins
quality/volume/itetclr loop through itetclr values and report total volume for each material
quality/volume/lt .03 count and report element volumes lt .03
quality/volume /itetclr/lt .03 count and report element volumes lt .03 by itetclr value
quality/volume/eltset,get,e2 report on element volumes only for those in the set e2
quality/volume/itetclr/eltset,get,e2 report on element volumes only for those in the set e2, loop through each of the itetclr values, report total volume by material for elements in set e2

Detect and characterize tetrahedra as type : sliver, cap, needle, wedge