LaGriT/documentation/lagrit_manual/commands/quality.txt

.. _quality:

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> **_QUALITY_**

>

>> quality provides a collection of mesh quality measures

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&nbsp_place_holder;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 .&nbsp_place_holder; 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_*
](cmo/cmo_addatt.html) 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.&nbsp_place_holder; A value of 1
means the coupling coefficient is OK.&nbsp_place_holder; Anything less than 1
means it is negative.&nbsp_place_holder; This is&nbsp_place_holder;
**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`](cmo/cmo_addatt.html#quad) 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**   
&nbsp_place_holder;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.&nbsp_place_holder; 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.   
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EXAMPLES:

**quality**/&nbsp_place_holder;
display volume and aspect ratio

**quality**/**aspect**/&nbsp_place_holder;
display aspect ratiodistribution in 7 bins

**quality**/**aspect**/**y**/&nbsp_place_holder;
display aspect ratio distribution and add attribute named aratio

**quality**/**angle**/**gt**/179/&nbsp_place_holder;
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](../QUALITY_sliver_cap_needle_wedge.html)