Name:          DGAUSN  


Purpose:       DGAUSN computes the partial derivatives of that Gaussian

Files:         dgaussn.dc2,gaussn.shl

Author:        Peter Roelfsema


   Call:

       CALL DGAUSN(X,PAR,DERIV,NPAR)          ( entry point in GAUSSN )

   Input parameters:
                X     -R   -running coordinate.
                PAR   -R   -array  defined  as  follows:  PAR(0:NPAR*3)  that
                    contains the parameters for the Gaussian in the following
                    order:

                            PAR(0)        -zerolevel
                       PAR(1)  -PAR(3)    -int, pos.  of peak, fwhm cmp.  1
                             .                     .
                     PAR(1+3*n)-PAR(3+3*n)-int, pos.  of peak, fwhm cmp.  n-1
                                     etc
                NPAR  -I   -number of components.
   Output parameters:
                DERIV -R   -array defined as  follows:  DERIV(0:NPAR*3)  that
                    contains the partial derivatives in the following order:
                               DERIV(0)       -part.  deriv of zerolevel
                         DERIV(1)-DERIV(3)    -part.  derivs.  of cmp.  1
                                .                     .
                     DERIV(1+3*n)-DERIV(3+3*n)-part.  derivs.  of cmp.  n-1
                                          etc


   Use:
                  DGAUSN gives the partial derivatives for the gaussian.
                  Note  that  the Gaussian components are defined in terms of
                  their Intensity, centre coordinate and Full Width  at  Half
                  Maximum ( i.e.  not in terms of amplitude and sigma ! ).


   Update History:
      8- 7-85-PRR.-original document
     16- 6-86-PRR.-converted for VAX8600
     26- 2-92-PRR.-converted to new GIPSY