exgnv.c

一个用来实现偏微分方程中网格的计算库

/*
 * Copyright (c) 2005 Sandia Corporation. Under the terms of Contract
 * DE-AC04-94AL85000 with Sandia Corporation, the U.S. Governement
 * retains certain rights in this software.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * 
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 * 
 *     * Redistributions in binary form must reproduce the above
 *       copyright notice, this list of conditions and the following
 *       disclaimer in the documentation and/or other materials provided
 *       with the distribution.  
 * 
 *     * Neither the name of Sandia Corporation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 */
/*****************************************************************************
*
* exgnv - ex_get_nodal_var
*
* entry conditions - 
*   input parameters:
*       int     exoid                   exodus file id
*       int     time_step               whole time step number
*       int     nodeal_var_index        index of desired nodal variable
*       int     num_nodes               number of nodal points
*
* exit conditions - 
*       float*  nodal_var_vals          array of nodal variable values
*
* revision history - 
*
*  $Id: exgnv.c 2928 2008-07-11 17:45:07Z friedmud $
*
*****************************************************************************/

#include "exodusII.h"
#include "exodusII_int.h"

/*
 * reads the values of a single nodal variable for a single time step from 
 * the database; assume the first time step and nodal variable index is 1
 */

int ex_get_nodal_var (int   exoid,
                      int   time_step,
                      int   nodal_var_index,
                      int   num_nodes, 
                      void *nodal_var_vals)
{
  int varid;
  int status;
  size_t start[3], count[3];
  char errmsg[MAX_ERR_LENGTH];

  exerrval = 0; /* clear error code */

  /* inquire previously defined variable */

  if (ex_large_model(exoid) == 0) {
    /* read values of the nodal variable */
    if ((status = nc_inq_varid(exoid, VAR_NOD_VAR, &varid)) != NC_NOERR) {
      exerrval = status;
      sprintf(errmsg,
              "Warning: could not find nodal variables in file id %d",
              exoid);
      ex_err("ex_get_nodal_var",errmsg,exerrval);
      return (EX_WARN);
    }

    start[0] = --time_step;
    start[1] = --nodal_var_index;
    start[2] = 0;

    count[0] = 1;
    count[1] = 1;
    count[2] = num_nodes;

  } else {
    /* read values of the nodal variable  -- stored as separate variables... */
    /* Get the varid.... */
    if ((status = nc_inq_varid(exoid, VAR_NOD_VAR_NEW(nodal_var_index), &varid)) != NC_NOERR) {
      exerrval = status;
      sprintf(errmsg,
              "Warning: could not find nodal variable %d in file id %d",
              nodal_var_index, exoid);
      ex_err("ex_get_nodal_var",errmsg,exerrval);
      return (EX_WARN);
    }

    start[0] = --time_step;
    start[1] = 0;

    count[0] = 1;
    count[1] = num_nodes;
  }

  if (ex_comp_ws(exoid) == 4) {
    status = nc_get_vara_float(exoid, varid, start, count, nodal_var_vals);
  } else {
    status = nc_get_vara_double(exoid, varid, start, count, nodal_var_vals);
  }

  if (status != NC_NOERR) {
      exerrval = status;
      sprintf(errmsg,
              "Error: failed to get nodal variables in file id %d",
              exoid);
      ex_err("ex_get_nodal_var",errmsg,exerrval);
      return (EX_FATAL);
    }
  return (EX_NOERR);
}