div

   'div'  |
          <line> [<division>]|
          <set>  [<division>]|
                 ['mult'|'div' <factor-div> <factor-bias>]|
                 ['auto' <node-dist> <angle> <elem-ratio>]

This keyword is used to define the division of line(s). The div keyword also works on a set of lines (see qadd). The division controls the number of nodes created when the geometry is meshed (see elty and mesh). For example,

div all 4

attaches the division of 4 to all lines. With the keyword mult or div in combination with a value, it is possible to multiply or divide already assigned divisions:

div all mult 2.

Or in case you need a starting-point for the individual divisions you can use the option auto with the optional parameters node-dist and angle. Node-dist is the maximum allowed distance between nodes and angle is the maximum allowed angle defined by three sequential nodes. If one parameter is not fulfilled then the division is halved until the requirements are fulfilled. Default values are defined in the file cgx.h and can be listed with

div

without parameters

div all auto

uses the defaults. But they can be overruled

div all auto 2. 10. 0.5

will use a maximum element lenght of 2., the angle between successive nodes is less than 10 degree and the minimum element is only half of the maximum-length. Some rules must be fulfilled before a geometry is meshable. For linear elements (ie. qu4 or he8), the sum of all divisions of each surface must be even. In case of quadratic elements (ie. qu8 or he20) this sum must be divisible by 4 without residue. Opposite edges of a given surface might have different divisions. For example on the left side of a given surface the division is 8 and on the right side it is only 4. But only two opposite surfaces of a body can use this feature. These surfaces are called top and bottom surfaces. All other surfaces of this body must have unique divisions on opposite edges.