Concept of data and data structure


A finite elements project contains a great quantity of information, i.e. a significant volume of data. These data are saved in a database, managed by specific tools.

Data and data structure

The Flux database makes a logical distinction between data structure (or data type) and data themselves (see blocks below).


The principal terms, used in this document to make a distinction between data and data structure, are presented in the table below.

Term Definition
Entity-type an entity-type is a logical data structure defined by a name and a certain number of fields (attributes, relations, cases)
Entity an entity is an object corresponding to an entity-type characterized by an identifier (number/name) and fields (attributes, relations, case)

Caution on the vocabulary: the terms “entity” and “occurrence of entity” can be also used instead of “entity-type” and “entity”.


For points:

  • the entity-type Point is a data structure of the database, that contains:
  • an identifier (a number)
  • cases: parameterized or propagated point
  • attributes: color, visibility
  • the entities (Point[1], Point[2], …) are the objects ( data ) of Flux project

In practice

From a practical point of view:

  • during the creation of a new project the file (F3D_STR.SBD), which describes the data structure, is read by the program
  • during the project saving the data structures and the data of the project are stored in the project directory (*.FLU).

Software version / compatibility

A new software version often corresponds to a development of the data structures.

The logical distinction between data structure and data makes it possible to ensure compatibility between an old Flux project and the more recent Flux version: during the old project opening, with a new software version the database is automatically updated .