Notes for use
=======================

The functions associated with the interspectral matrix are accessible to the user using the RECU_FONCTION [:external:ref:`U4.32.03 <U4.32.03>`] command using the INTE_SPEC keyword.


File syntax
------------------

The information read on the file is composed of three parts:


* a mandatory chapter head keyword: INTERSPECTRE.


* the keyword DIM, matrix dimension.


* 'n' subfiles defining 'n' complex functions. Each subfile starts with the FONCTION_C keyword and ends with FINSF.


* The file must end with FIN.


Descriptor
-----------


Keyword describing the characteristics of the matrix
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


.. code-block:: text

    ♦ DIM = sun

Integer allows you to define the dimension of the matrix.

**Note:**

*The '=' sign is mandatory.*


Keyword describing a function_C
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

**Prior note:**

*'n', the number of functions to be defined is equal to:*

*n = (dim* (dim+1)) /2, since the matrix under consideration is* *' HERMITIENNE ' .*

The n functions are defined by their indices I and J in the matrix. Only the upper triangular part of the matrix is defined, (indices (1,1); (1,2); (2,2); (1,3); (1,3);... (n, n)).


.. code-block:: text

    ♦ FONCTION_C


.. code-block:: text

    ♦ I = integer subscript row of the function in the matrix.


.. code-block:: text

    ♦ J = integer subscript column of the function in the matrix.


.. code-block:: text

    ♦ NB_POIN = integer number of points in FONCTION


.. code-block:: text

    ♦ VALEUR = 3* NB_POINréels must be present. The values are read line by line.

On each line are defined in the following order:


* the value of the parameter, the real part of the result, the imaginary part of the result (FORMAT = 'REEL_IMAG'),

or


* the value of the parameter, the module of the result, the phase of the result (FORMAT =' MODULE_PHASE ')

**Note:**

*For the format* MODULE_PHASE *, the phase is given in degrees.*