geom_apply_formula.m File Reference

Description

GEOM_APPLY_FORMULA Apply formula to geometry.

[ SOUT, STAT ] = GEOM_APPLY_FORMULA( SIN, FORMULA, IS_WARN ) Applies a FORMULA string to geometry objects in the fea or geometry struct SIN. Returns the modified fea/geometry struct in SOUT, and zero status/return code STAT if all operations have been applied sucessfully, or else a positive integer corresponding to the number of failed geometry object combinations. The IS_WARN flag (default false) enables throwing warnings if the geometry objects cannot be combined.

The FORMULA is a string containing combinations of geometry object tags (operands defined by words with characteres [A-Za-z0-9_]), parentheses to define precedence, and geometry operators, +* = Join, - = Subtract, and &| = Intersect. Without defining precedence with parentheses operations perform from left to right.

Examples

   1) Join two touching blocks, CJ1 = B1 + B2.

   geom.objects = {gobj_block(), gobj_block(1, 2, 0, 1, 0, 1, 'B2')};
   geom = geom_apply_formula( geom, 'B1 + B2' );
   plotgeom(geom)

   2) Join and subtract rectangles with precedence, CJ1 = R3 + (R1 - R2) = R1 - R2 + R3.

   geom.objects = {gobj_rectangle(), ...
                   gobj_rectangle(1/3, 1, 1/3, 2/3, 'R2'), ...
                   gobj_rectangle(2/3, 1, 1/3, 2/3, 'R3')};
   geom = geom_apply_formula( geom, 'R3 + (R1 - R2)' );
   plotgeom(geom)

   3) Intersection between unit circle and rectangle, CI1 = C1 & R1.

   geom.objects = {gobj_circle(), gobj_rectangle()};
   geom = geom_apply_formula( geom, 'C1 & R1' );
   plotgeom(geom)