# usecases/c/UsesCase_MEDfield_15.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/>.
     */

    /*
     * Field use case 15 : write a field in a MED file with
     * values defined on struct elements
     */

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

    #include <string.h>

    int main (int argc, char **argv) {
      med_idt fid=0,mfid=0;
      const char meshname[MED_NAME_SIZE+1] = "COMPUT_MESH";
      const char fieldname[MED_NAME_SIZE+1] = "SPEED";
      const med_int ncomponent = 3;
      /*                                              123456789012345612345678901234561234567890123456 */
      const char componentname[3*MED_SNAME_SIZE+1] = "Vx              Vy              Vz";
      const char componentunit[3*MED_SNAME_SIZE+1] = "m/s             m/s             m/s";
      med_geometry_type geotype=MED_NONE;
      const med_int npart = 3;
      char structelementname[MED_NAME_SIZE+1]="";
      const med_float part_speed1[3*3] = { 1.1, 2.2, 3.3,
                                     4.4, 5.5, 6.6,
                                     7.7, 8.8, 9.9 };
      int ret=-1;

      /* File creation to write the field */
      fid = MEDfileOpen("UsesCase_MEDfield_15.med",MED_ACC_CREAT);
      if (fid < 0) {
        MESSAGE("ERROR : file creation ...");
        goto ERROR;
      }

      /* Create mesh link */
      if (MEDlinkWr(fid,meshname,"./UsesCase_MEDstructElement_1.med") < 0) {
        MESSAGE("ERROR : create mesh link ...");
        goto ERROR;
      }

      /*
       * Read struct element geometric type
       */
      if (( mfid=MEDfileObjectsMount(fid,  "UsesCase_MEDstructElement_1.med",MED_ELSTRUCT)) < 0 ) {
        MESSAGE("ERROR : file mounting ...");
        goto ERROR;
      }

      strcpy(structelementname,MED_PARTICLE_NAME);
      geotype = MEDstructElementGeotype(fid,structelementname);

      /*
       * Speed field  creation for particles :
       * - 3 component
       * - component unit : m/s
       * - mesh is the 3D computation mesh of UsesCase_MEDstructElement_1 use case.
       * - computation step unit in 'ms'
       */
      if (MEDfieldCr(fid, fieldname, MED_FLOAT64,
                     ncomponent, componentname, componentunit,
                     "ms", meshname) < 0) {
        MESSAGE("ERROR : create field");
        goto ERROR;
      }

      if (MEDfieldValueWithProfileWr(fid, fieldname, MED_NO_DT, MED_NO_IT, MED_UNDEF_DT, MED_STRUCT_ELEMENT, geotype,
                                     MED_COMPACT_PFLMODE, MED_NO_PROFILE, MED_NO_LOCALIZATION,
                                     MED_FULL_INTERLACE, MED_ALL_CONSTITUENT,
                                     npart, (unsigned char*) part_speed1) < 0) {
        MESSAGE("ERROR : write field values on MED_PARTICLE ");
        goto ERROR;
      }

      if ( MEDfileObjectsUnmount(fid, mfid, MED_ELSTRUCT) < 0 ) {
        MESSAGE("ERROR : file unmounting ...");
        goto ERROR;
      }

      ret=0;
     ERROR:

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

      return ret;
    }