OUMODP ( pnum, ival, rval, ifail )
==================================

  Output modeller parameter

Receives:
  KI_cod_slmp              *pnum           --- parameter code

Returns:
  int                      *ival           --- integer value of parameter
  double                   *rval           --- real value of parameter
  KI_cod_error             *ifail          --- failure indicator


Description:

  Outputs the value of a modeller parameter.

  'pnum' specifies which parameter is to be returned:
  different parameters may be integer or real values and are returned in the
  appropriate return argument. At present all parameters returned from this
  routine are reals.

  The valid values of 'pnum' and the corresponding parameters are:

  'pnum'    return   significance

  SLMPLP    'rval'   Absolute (linear) precision of modeller as a real value
                     greater than zero. Lengths and distances differing by no
                     more than this value are treated as equal.

  SLMPAP    'rval'   Angular precision of modeller as a real value greater
                     than zero. Angles, and values calculated from normalised
                     vectors, that differ by no more than this value are
                     treated as equal.