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1.3.2 Introduction of a curve

There are two options to describe a curve which the mesh approximates:

• program a FORTRAN function, called FFRONT  of the following form:
  FUNCTION FFRONT(I,X,Y)

  where

  I

  is the reference number of the line (portion of the contour) described, and

  X,Y

  are the space variables.

  A typical example of function FFRONT is given below:

        FUNCTION FFRONT(I,X,Y)
        IF ( I .EQ. 1) THEN  
           FFRONT = function(X,Y) 
        ELSE IF ( I .EQ. nnn ) 
           FFRONT = ... 
        ELSE IF ... 
           ...
        END IF 
        END
  

• make use of the function parser :

  A typical example of a function parser, for example the description of the line with reference 1 by a function, is the following:

  COURBE01(X,Y) = X*X + (Y-1)*(Y-1) - .125
  

The first case corresponds to writing a FORTRAN function and linking it at execution. In the second case, the curves are given in a data file, thus avoiding performing a link.