li6.txt

这是机械工业张德丰《MATLAB与外部程序接口编程》随书源码

# include <stdio.h>
# include <string.h> /* For strcmp( ) */
# include <stdlib.h> /* For EXIT_FAILURE, EXIT_SUCCESS */
# include <mat.h>
# define BUFSIZE 256
int main( )
 {
  MATFile *pmat;
  mxArray *pa1, *pa2, *pa3;
  double data[9] = { 1.0, 4.0, 7.0, 2.0, 5.0, 8.0, 3.0, 6.0, 9.0 };
  const char *file = "mattest.mat";
  char str[BUFSIZE];
  int status; 
  printf("Creating file %s...\n\n", file);
  pmat = matOpen(file, "w");
  if (pmat = = NULL)
 {
    printf("Error creating file %s\n", file);
    printf("(Do you have write permission in this directory?)\n");
    return(EXIT_FAILURE);
  }
  pa1 = mxCreateDoubleMatrix(3,3,mxREAL);
  if (pa1 = = NULL) 
{
      printf("%s : Out of memory on line %d\n", __FILE__, __LINE__); 
      printf("Unable to create mxArray.\n");
      return(EXIT_FAILURE);
  }
  pa2 = mxCreateDoubleMatrix(3,3,mxREAL);
  if (pa2 = = NULL) 
{
      printf("%s : Out of memory on line %d\n", __FILE__, __LINE__);
      printf("Unable to create mxArray.\n");
      return(EXIT_FAILURE);
  }
  memcpy((void *) (mxGetPr(pa2)), (void *)data, sizeof(data));
  pa3 = mxCreateString("MATLAB: the language of technical computing");
  if (pa3 == NULL) 
{
      printf("%s :  Out of memory on line %d\n", __FILE__, __LINE__);
      printf("Unable to create string mxArray.\n");
      return(EXIT_FAILURE);
  }
  status = matPutVariable(pmat, "LocalDouble", pa1);
  if (status != 0) 
{
      printf("%s :  Error using matPutVariable on line %d\n", __FILE__, __LINE__);
      return(EXIT_FAILURE);
  }  
  status = matPutVariableAsGlobal(pmat, "GlobalDouble", pa2);
  if (status != 0)
  {
      printf("Error using matPutVariableAsGlobal\n");
      return(EXIT_FAILURE);
   } 
  status = matPutVariable(pmat, "LocalString", pa3);
  if (status != 0)
  {
      printf("%s :  Error using matPutVariable on line %d\n", __FILE__, __LINE__);
      return(EXIT_FAILURE);
   } 
    /*
   * Ooops! we need to copy data before writing the array.  (Well,
   * ok, this was really intentional.) This demonstrates that
   * matPutVariable will overwrite an existing array in a MAT-file.
   */
  memcpy((void *)(mxGetPr(pa1)), (void *)data, sizeof(data));
  status = matPutVariable(pmat, "LocalDouble", pa1);
  if (status != 0) 
{
      printf("%s :  Error using matPutVariable on line %d\n", __FILE__, __LINE__);
      return(EXIT_FAILURE);
  } 
  /* clean up */
  mxDestroyArray(pa1);
  mxDestroyArray(pa2);
  mxDestroyArray(pa3);
  if (matClose(pmat) != 0) 
{
    printf("Error closing file %s\n",file);
    return(EXIT_FAILURE);
  }
  /*
   * Re-open file and verify its contents with matGetVariable
   */
  pmat = matOpen(file, "r");
  if (pmat = = NULL)
  {
    printf("Error reopening file %s\n", file);
    return(EXIT_FAILURE);
   }
   /*
   * Read in each array we just wrote
   */
  pa1 = matGetVariable(pmat, "LocalDouble");
  if (pa1 = = NULL)
  {
    printf("Error reading existing matrix LocalDouble\n");
    return(EXIT_FAILURE);
   }
  if (mxGetNumberOfDimensions(pa1) != 2) 
{
    printf("Error saving matrix: result does not have two dimensions\n");
    return(EXIT_FAILURE);
  }
  pa2 = matGetVariable(pmat, "GlobalDouble");
  if (pa2 = = NULL) 
{
    printf("Error reading existing matrix GlobalDouble\n");
    return(EXIT_FAILURE);
  }
  if (!(mxIsFromGlobalWS(pa2)))
  {
    printf("Error saving global matrix: result is not global\n");
    return(EXIT_FAILURE);
  }
  pa3 = matGetVariable(pmat, "LocalString");
  if (pa3 = = NULL) 
{
    printf("Error reading existing matrix LocalString\n");
    return(EXIT_FAILURE);
  }
  status = mxGetString(pa3, str, sizeof(str));
  if(status != 0)
  {
      printf("Not enough space. String is truncated.");
      return(EXIT_FAILURE);
  }
  if (strcmp(str, "MATLAB: the language of technical computing"))
  {
    printf("Error saving string: result has incorrect contents\n");
    return(EXIT_FAILURE);
   }
  /* clean up before exit */
  mxDestroyArray(pa1);
  mxDestroyArray(pa2);
  mxDestroyArray(pa3);
  if (matClose(pmat) != 0) 
{
    printf("Error closing file %s\n",file);
    return(EXIT_FAILURE);
   }
  printf("Done\n");
  return(EXIT_SUCCESS);
}