el_areas

(./FEM/el_areas.m)

Function Synopsis

[ret_struct,ineg]=el_areas(fem_grid_struct)

Help text

 EL_AREAS - compute triangular finite element areas

         EL_AREAS(FEM_GRID_STRUCT) computes the areas for the 
         elements of the FEM domain described in the 
         structure FEM_GRID_STRUCT.  The function must
         return a new structure, which is identical to the 
         input structure with the element areas attached.
         The element areas are contained in the field .ar,
         so that the new structure now includes:

         .ar   - element areas                    [ne x 1 double]  
         

         EL_AREAS optionally returns an index of element
         numbers whose areas are negative (if any).
         Negative element areas indicate clockwise elemental
         node numbering, instead of the conventional counter-
         clockwise numbering.

  INPUT : fem_grid_struct - (from LOADGRID, see FEM_GRID_STRUCT)       
           
 OUTPUT : new_struct (REQ) - new structure with areas
          ineg       (OPT) - index of negative area elements

   CALL : >>new_struct=el_areas(fem_grid_struct);
    or 
          >>[new_struct,ineg]=el_areas(fem_grid_struct);

 Written by : Brian O. Blanton 
 Summer 1997

Cross-Reference Information

is_valid_struct./FEM/is_valid_struct.m

interp_scalar  ./FEM/interp_scalar.m
loadgrid       ./FEM/loadgrid.m