I.4.1.1 “Keys”

The “keys” of Results correspond to the entities to which “values” are associated. For example, a key may be:

• The index of an element.
• The index of a node.
• A pair of integers corresponding to the indices of an element and of a node (for Results given at corners of elements).
• A pair of integers corresponding to the indices of an element and of a layer (for example, for layered Results corresponding to laminated properties).
• ...

So, at C++ level, each key is characterized by four integers:

• A 32bits integer corresponding to the element index,
• A 32bits integer corresponding to the node index,
• A 32bits integer corresponding to the layer index,
• An 8bits char corresponding to the sub-layer index (rarely used).

At ruby level, one can work with either the C++ integer ids, or their string correspondent. The correspondence between string and integers are given in Tables I.4.2, I.4.3, I.4.4 and I.4.5. The data given in these Tables can be completed by additional data peculiar to the different supported solvers. (See Part III for more information.)

In Table I.4.4, the last layers IDs cannot be attributed to Result keys. The elements corresponds to groups of layers and are used to perform extraction operations:

• “Beam Points” is used to extract on layers “Point A”, “Point B”,...
• “Shell Layers” is used to extract on layers “NONE”, “Z1” and “Z2”.
• “All Plies ” is used to extract on all layers with positive Ids (i.e. laminate plies).
• “All Layers ” extracts on all layers.

Note that the notion of “key” is also closely related to the “ResKeyList” ruby class which is simply a list of key objects (see Chapter I.5).