proj/example/apps/scalesegments.c

#include "drms.h"
#include "drms_names.h"
#include "jsoc_main.h"
                         /* Default parameter values */
ModuleArgs_t module_args[] = {
  {ARG_FLOAT, "alpha", "", "multiplicative scaling"},
  {ARG_FLOAT, "beta", "",  "additive offset: data -> (alpha * data) + beta"},
  {ARG_END}
};
                        /* Module name presented to DRMS */
char *module_name = "scalesegments";
char *version_id = "1.8";

/* This module updates records in recordsets specified on the command line
   by rescaling all array segments and recomputing the array statistics. */

int DoIt () {
  char keyname[10];
  int i, j, status, dostat;
  arraylen_t n;
  arraylen_t k;
  arraylen_t count;
  char *rsname;
  DRMS_RecordSet_t *oldrs, *newrs;
  DRMS_Array_t *array;
  DRMS_Segment_t *oldseg, *newseg;
  HIterator_t newit, oldit;
  double alpha, beta, *data, sum;
                /* Read scaling parameters from command line */
  alpha = cmdparams_get_double (&cmdparams, "alpha", &status);
  beta = cmdparams_get_double (&cmdparams, "beta", &status);

  i = 1;
  while ((rsname = cmdparams_getarg (&cmdparams, i++))) {
    /* Query DRMS for record set. */
    oldrs = drms_open_records(drms_env, rsname, &status);    

    if (oldrs) {
                            /* Create new record set */
      newrs = drms_create_records (drms_env, oldrs->n,
                   oldrs->records[0]->seriesinfo->seriesname,
                   DRMS_PERMANENT, &status);
      if (status) {
    fprintf (stderr, "Create records failed.\n");
    return status;
      }
                          /* Allocate new record set */
      if (oldrs->n > 0 ) {  
                      /* Loop over records in record set */
    for (j=0; j<oldrs->n; j++) {
                       /* Initialize container iterators */
      hiter_new(&oldit, &((oldrs->records[j])->segments)); 
      hiter_new(&newit, &((newrs->records[j])->segments)); 
                         /* Loop over segments in record */
      while ((oldseg = (DRMS_Segment_t *)hiter_getnext (&oldit)) ) {
        newseg = (DRMS_Segment_t *)hiter_getnext (&oldit);
                    /* Check if we should do image stats */
        sprintf(keyname, "datamean[%d]", newseg->info->segnum);
        if (drms_keyword_lookup (oldrs->records[j], keyname, 1)) dostat = 1;
        else dostat = 0;
                   /* Read old segment, converting to double */
        array = drms_segment_read (oldseg, DRMS_TYPE_DOUBLE, &status);
        if (status) {
          printf("ERROR: drms_segment_read failed with status %d\n", status);
          return status;
        }
                         /* Get number of array elements */
        n = drms_array_count (array);
                   /* Scale array and and compute new statistics */
        data = array->data;
        count = 0;
        sum = 0.0;
        for (k=0; k<n; k++) {
          if (data[k] != DRMS_MISSING_DOUBLE) {
        count++;
        data[k] = alpha*data[k] + beta;
        if (dostat) sum += data[k];
          }
        }
                       /* Set stat keyword in new record */
        if (dostat) {
          sprintf (keyname, "datamean[%d]", newseg->info->segnum);
          drms_setkey_double (newrs->records[j], keyname, sum/count);
        }
                    /* Write array to new record segment */
        status = drms_segment_write (newseg, array,0);
        if (status) {
          fprintf (stderr,"ERROR: drms_segment_write failed with error "
              "code %d.\n",status);
          return status;
        }
        drms_free_array(array);
      }
    }
    drms_close_records (oldrs, DRMS_FREE_RECORD);
    drms_close_records (newrs, DRMS_INSERT_RECORD);
      }
    }
    else printf ("drms_open_records failed with error code %d.\n", status);
  }
  return 0;
}

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