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**Contents**

In the two-dimensional case, it corresponds to (according to the MODULEF approach):

- generating meshes from point, line, contour, course mesh, etc., data, using the appropriate algorithms;
- modifying existing meshes and combining them to form the final mesh, step by step, to which a
D.S. of type
**NOPO**is associated. This D.S. is then stored in a sequential access file.

In order to achieve the above steps, we need to:

- locate all the
*primal*sub-sets in the domain by eliminating all sub-sets which can be derived by symmetry, translation, etc., or more generally, by geometric transformation; - record, furthermore, the primal sub-sets linked to physical type constraints;
- search for the module which is the most suitable for each of these sub-sets;
- determine the nature of the data which each of these modules use;
- construct the data from the points and lines present;
- activate the desired mesh generator(s);
- perform the symmetries, translations, rotations, etc., of the primal sub-sets;
- "glue" these meshes together, two by two;
- repeat the two previous steps until the entire domain is covered;
- perform some local or global transformations (refinement, regularization, etc.);
- define the non-vertex nodes, if necessary, and remove the vertices from the nodal list;
- renumber, if necessary, the elements and/or nodes;
- store the result on file (and plot it to verify and ensure the quality of the mesh).

For each primal sub-set, we select the module which is most suitable:

- for a deformed quadrilateral or triangle, modules
**TRICOO**and**QUACOO**(algebraic methods ) generates quadrangles, which can be split into triangles, and triangles; - for an arbitrary domain, modules
**TRIFRO**and**TRIHER**(advancing-front method and Voronoi's method ) generates triangles; - similarly,
**COLIB2**(multi-block method ), in the 2D version, produces the same result from a partitioning of a course mesh of the domain. - when the elements to be created are few or identical, module
**CONOPO**(manual method ) could be used; -
**CONOPO**is suitable to mesh lines into segments; -
**MAOBJE**is used to treat catalogued objects.