# usecases/c/UsesCase_MEDinterp_3.c

    /*  This file is part of MED.
     *
     *  COPYRIGHT (C) 1999 - 2012  EDF R&D, CEA/DEN
     *  MED is free software: you can redistribute it and/or modify
     *  it under the terms of the GNU Lesser General Public License as published by
     *  the Free Software Foundation, either version 3 of the License, or
     *  (at your option) any later version.
     *
     *  MED is distributed in the hope that it will be useful,
     *  but WITHOUT ANY WARRANTY; without even the implied warranty of
     *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     *  GNU Lesser General Public License for more details.
     *
     *  You should have received a copy of the GNU Lesser General Public License
     *  along with MED.  If not, see <http://www.gnu.org/licenses/>.
     */

    /*
     * Interp use case 1 : read an interpolation family with a generic access by an iterator.
     * In this example, the interpolation family can be used with
     * the TEMPERATURE field of UsesCase_MEDfield_10 use case
     */

    #include <med.h>
    #define MESGERR 1
    #include <med_utils.h>

    #include <string.h>

    int main (int argc, char **argv) {
      med_idt fid;
      char              interpname[MED_NAME_SIZE+1]="";
      med_int           ninterp                    =0;
      int               it                         =0;
      med_geometry_type geotype                    =MED_NONE;
      med_bool          cellnodes                  =MED_FALSE;
      med_int           nbasisfunc              =0;
      med_int           nvariable               =0;
      med_int           maxdegree                  =0;
      med_int           nmaxcoefficient            =0;
      int               basisfuncit                =0;
      int               powerit                    =0;
      med_int           ncoefficient            =0;
      med_int*          power                      =NULL;
      med_float*        coefficient                =NULL;
      int               coefficientit              =0;
      int ret=-1;

      /* file creation */
      fid = MEDfileOpen("UsesCase_MEDinterp_1.med",MED_ACC_RDONLY);
      if (fid < 0) {
        MESSAGE("ERROR : file creation ...");
        goto ERROR;
      }

      /* how many interpolation family in the file ? */
      if ((ninterp = MEDnInterp(fid)) < 0) {
        MESSAGE("ERROR : read number of interpolation ...");
        goto ERROR;
      }

      /* read each interpolation family */
      /* with an access by an iterator */
      for (it=1; it<= ninterp; it++) {

        if (MEDinterpInfo(fid,it,interpname,&geotype,&cellnodes,&nbasisfunc,
                          &nvariable,&maxdegree,&nmaxcoefficient) < 0) {
          MESSAGE("ERROR : interpolation function information ...");
          goto ERROR;
        }

        /* read each basis function */
        for ( basisfuncit=1; basisfuncit<= nbasisfunc; ++basisfuncit) {
          if ((ncoefficient = MEDinterpBaseFunctionCoefSize(fid,interpname,basisfuncit) ) <0 ) {
            MESSAGE("ERROR : read number of coefficient in the base function ...");
            goto ERROR;
          }

          coefficient = (med_float*) calloc(sizeof(med_float),ncoefficient);
          power       = (med_int*)   calloc(sizeof(med_int),nvariable*ncoefficient);

          if (MEDinterpBaseFunctionRd(fid,interpname,basisfuncit,&ncoefficient,power,coefficient) < 0) {
            MESSAGE("ERROR : read base function ...");
            free(coefficient); free(power);
            goto ERROR;
          }

          free(coefficient);
          free(power);
        }

      }

      ret=0;
     ERROR:

      /* close file */
      if (MEDfileClose(fid) < 0) {
        MESSAGE("ERROR : close file ...");
        ret=-1;
      }

      return ret;
    }