intex8c.c

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#include "stack-c.h"

/*--------------------------------------------------------
 * An example of an hand written interface 
 * passing a Scilab function as input of function ex8c
 *
 * call in Scilab:-->ex8c(x1,x2,a_function)
 *     x1<->1    (double array)
 *     x2<->2    (double array) 
 *     a_function <-> 3    (a scilab function).
 *     a_function is the function "myfunction" defined 
 *     in ex8c.sce. It has mlhs=2 inputs and mrhs=3 outputs.
 *
 *--------------------------------------------------------*/

int intex8c(fname) 
     char *fname;
{
  int ibegin;
  static int l1, m1, n1, m2, n2, l2,mlhs,mrhs,lf, l4,l5,i;
  static int minlhs=1, minrhs=3, maxlhs=3, maxrhs=3;
  
  CheckRhs(minrhs,maxrhs) ;
  CheckLhs(minlhs,maxlhs) ;

  /* Getting x1 and x2 at l1 and l2 . x1 is m1 x n1 and x2 is m2 x n2 */
  GetRhsVar(1, "d", &m1, &n1, &l1);
  GetRhsVar(2, "d", &m2, &n2, &l2);
  /* Getting the Scilab function:
     It is the 3rd input parameter of ex8c and it is a function ("f") */
  GetRhsVar(3, "f", &mlhs, &mrhs, &lf);
  /*   It is at lf and has mlhs outputs and mrhs inputs */

  if ( mrhs != 2 ) 
    {
      Scierror(999,"%s: Third argument has an invalid rhs\r\n",fname);
      return 0;
    }

  /* 
   *  To call a_function it is required that its input arguments are
   *  stored in the last positions of the variables stack. NOTE that when 
   *  called, the function destroys its input variables and replaces them by 
   *  the output variables. so in this  case we need to make a copy of
   *  them.
   *  Remark: if the calling sequence of ex8c had been ex8c(a_function,x1,x2)
   *  the following two copies would be un-necessary.
   */

  CreateVar(3+1, "d", &m1, &n1, &l4);
  for (i =0 ; i < m1*n1 ; i++) *stk(l4+i) = *stk(l1+i);

  CreateVar(3+mrhs, "d", &m2, &n2, &l5);
  for (i =0 ; i < m1*n1 ; i++) *stk(l5+i) = *stk(l2+i);

  /* 
   *  Here a_function  takes  variables 4 and 5 as inputs and generates output
   *  variables at positions 4 to 4-1+mlhs
   *  ibegin must be the index of the first input variable of a_function
   */
  
  ibegin=3+1;

  /* execute the function */

  SciFunction(&ibegin,&lf,&mlhs,&mrhs);
  /* check if an error has occured while running a_function */
  if (Err > 0 ) return 0;
  
  /* output variables: 4 and 5 (created by a_function) and possibly 6
   * if a_function has 3 output parameters
   */

  LhsVar(1) = 4;
  LhsVar(2) = 5;
  if ( mlhs == 3) LhsVar(3) = 6;
  return 0;
}

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