Generalities
===========




What is a table?
------------------------

A table is a computer data structure that stores a set of integer, real, complex, or character string values.

A table is comparable to a database EXCEL (version 5), that is to say that it can be seen as a list of columns (the term "column" is here to make the comparison with a list EXCEL; this does not mean that a table is always printed in columns (see § :ref:`8 <RefHeading__35501385>` Printing a table)) facing each other. Each column has a field name, which we call a parameter, and contains similar data such as I, R, C, K8, K16, K16, K24, or K32.

Example 1: T1


.. csv-table::

    "**NUME_ORDRE**", "**INST**", "****", "****", "**G**" NOEUD
    "1", "10. ", "N1", "5."
    "1", "10. ", "N2", "6."
    "1", "10. ", "N3", "7."
    "1", "10. ", "N4", "8."
    "2", "20. ", "N1", "9."
    "2", "20. ", "N2", "9."
    "2", "20. ", "N3", "8."
    "2", "20. ", "N4", "8."
    "3", "30. ", "N1", "7."
    "3", "30. ", "N2", "6."
    "3", "30. ", "N3", "5."
    "3", "30. ", "N4", "4."


Example 2: T2


.. csv-table::

    "**ACTION**", "**NUME_ORDRE**", "****", "**INST**", "**NOEUD**", "**DX**", "**DY**", "**MAILLE**", "****", "****", "****", "**SIXX**"
    "INTITULE 1", "1", "10. ", "N1", "3. ", "5. ", "", ""
    "INTITULE 1", "1", "10. ", "N2", "6. ", "7. ", "", ""
    "INTITULE 1", "1", "10. ", "N3", "8. ", "9. ", "", ""
    "INTITULE 1", "2", "20. ", "N1", "11. ", "12. ", "", ""
    "INTITULE 1", "2", "20. ", "N2", "15. ", "13. ", "", ""
    "INTITULE 1", "2", "20. ", "N3", "19. ", "18. ", "", ""
    "INTITULE 2", "2", "20. ", "", "", "", "MA1 ", "-12."
    "INTITULE 2", "2", "20. ", "", "", "", "MA2 ", "-14."





Some properties of tables
------------------------------


* A table has a limited number of columns (or parameters). These parameters are chosen by the developers of the commands that create tables. The name of a parameter is a string that is up to 16 characters in length.


* On the other hand, the number of rows in a table is often "dynamic": it generally depends on the user's choices: counting nodes, calculation times,...


* The values contained in a column of a table are all of the same type FORTRAN: real, complex, integer or text. SD Aster names or JEVEUX object names can be stored in "text" form in a table; for example function names.


* A table is said to be "full" when all its rows contain values for all the parameters in the table. Table t1 above is full. A table that is not full is said to be "hollow" (table t 2 above).


* The rows in a table are naturally ordered by the order in which they were inserted into the table (routine TBAJLI).


* The columns of a table are naturally ordered by the order in which their parameters are declared (routine TBAJPA).


* A table has at least one row. On a line, there may be empty cells: the associated parameter is not affected (table t2 above).