netcdf-c/ncdap_test/test_varm3.c

/* varm_test */
/* acm 9/15/09 */
/* ansley.b.manke@noaa.gov */
/* test nc_get_varm_float with calls similar to Ferret calls */
/* local file is correct results with stride: every second value */
/* remote url; incorrect results with stride 

linked with:
 cc varm_test.c -g -o varm_test /home/nstout/ansley/local/lib/libnetcdf.a -L/usr/lib64 -lc -lm -lcurl

netcdf.a from the daily snapshot
netcdf-4.1-beta2-snapshot2009091100
*/

#include <config.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "netcdf.h"

#undef STANDALONE

#define URL "http://test.opendap.org/opendap/data/nc/coads_climatology.nc"

#define VAR "SST"

static float expected_stride1[12] = {
29.430857,
29.403780,
29.325428,
29.578333,
29.660833,
29.378437,
29.151943,
29.109715,
29.114864,
29.550285,
29.542500,
29.500286
};

static float expected_stride2[6] = {
29.430857,
29.325428,
29.660833,
29.151943,
29.114864,
29.542500
};

static float expected_stride3[3] = {
29.430857,
29.378437,
29.542500
};

int
main()
{

    int ncid;
    int varid;
    int i,fail;
    int err;
    size_t start[5], count[5];
    ptrdiff_t stride[5], imap[5];

    int idim, ndim;  
    float dat[20];

    printf("*** Test: varm on URL: %s\n",URL);

    err = nc_open(URL, NC_NOWRITE, &ncid); 
    err = nc_inq_varid(ncid, VAR, &varid);
    for (idim=0; idim<4; idim++) {
        start[idim] = 0;
        count[idim] = 1;
        stride[idim] = 1;
        imap[idim] = 1;
    }
    ndim=3;


    printf("*** Testing: stride case 1\n");
    start[1] = 44;
    start[2] = 66;
    count[0] = 12;

#ifdef STANDALONE
    printf("start = ");
    for(i=0;i<ndim;i++) printf(" %d",(int)start[i]);
    printf("\n");
    printf("count = ");
    for(i=0;i<ndim;i++) printf(" %d",(int)count[i]);
    printf("\n");
    printf("stride = ");
    for(i=0;i<ndim;i++) printf(" %d",(int)stride[i]);
    printf("\n");
    printf("map = ");
    for(i=0;i<ndim;i++) printf(" %d",(int)imap[i]);
    printf("\n");

    err = nc_get_vars_float (ncid, varid, start, count, stride,
			     (float*) dat);
    printf("vars: %s =",VAR);
    for(i=0;i<12;i++) printf(" %f",dat[i]);
    printf("\n");
#endif

    err = nc_get_varm_float (ncid, varid, start, count, stride, imap,
			     (float*) dat);
    if(err) goto ncfail;
#ifdef STANDALONE
    printf("varm: %s =",VAR);
    for(i=0;i<12;i++) printf(" %f",dat[i]);
    printf("\n");
#endif
    fail=0;
    for(i=0;i<12;i++) {
	float delta = (dat[i] - expected_stride1[i]);
	if(delta > 0.0005 || delta < -0.0005) {
	    fprintf(stderr,"*** Failure: unexpected value: delta=%g dat[%d]=%g expected[%d]=%g\n",
		    delta, i, dat[i], i, expected_stride1[i]);
	     fail = 1;
	}
    }
    printf("*** %s: stride case 1\n",(fail?"Fail":"Pass"));

    printf("*** Testing: stride case 2\n");
    /* case with strides #1 where len % stride == 0 */
    start[1] = 44;
    start[2] = 66;
    count[0] =  6;
    stride[0] = 2;

#ifdef STANDALONE
    printf("start = ");
    for(i=0;i<ndim;i++) printf(" %d",(int)start[i]);
    printf("\n");
    printf("count = ");
    for(i=0;i<ndim;i++) printf(" %d",(int)count[i]);
    printf("\n");
    printf("stride = ");
    for(i=0;i<ndim;i++) printf(" %d",(int)stride[i]);
    printf("\n");
    printf("map = ");
    for(i=0;i<ndim;i++) printf(" %d",(int)imap[i]);
    printf("\n");

    err = nc_get_vars_float(ncid, varid, start, count, stride, 
                             (float*) dat);
    printf("strided.vars: %s =",VAR);
    for(i=0;i<6;i++) printf(" %f",dat[i]);
    printf("\n");
#endif
    err = nc_get_varm_float(ncid, varid, start, count, stride, imap,
                             (float*) dat);
#ifdef STANDALONE
    printf("strided.varm: %s =",VAR);
    for(i=0;i<6;i++) printf(" %f",dat[i]);
    printf("\n");
#endif
    fail=0;
    for(i=0;i<6;i++) {
	float delta = (dat[i] - expected_stride2[i]);
	if(delta > 0.0005 || delta < -0.0005) {
	    fprintf(stderr,"*** Failure: unexpected value: delta=%g dat[%d]=%g expected[%d]=%g\n",
		    delta, i, dat[i], i, expected_stride2[i]);
	    fail=1;
	}
    }
    printf("*** %s: stride case 2\n",(fail?"Fail":"Pass"));

    /* case with strides #2: len % stride != 0 */
    printf("*** Testing: stride case 3\n");
    start[1] = 44;
    start[2] = 66;
    count[0] =  3;
    stride[0] = 5;

#ifdef STANDALONE
    printf("start = ");
    for(i=0;i<ndim;i++) printf(" %d",(int)start[i]);
    printf("\n");
    printf("count = ");
    for(i=0;i<ndim;i++) printf(" %d",(int)count[i]);
    printf("\n");
    printf("stride = ");
    for(i=0;i<ndim;i++) printf(" %d",(int)stride[i]);
    printf("\n");
    printf("map = ");
    for(i=0;i<ndim;i++) printf(" %d",(int)imap[i]);
    printf("\n");

    err = nc_get_vars_float(ncid, varid, start, count, stride, 
                             (float*) dat);
    printf("strided.vars: %s =",VAR);
    for(i=0;i<3;i++) printf(" %f",dat[i]);
    printf("\n");
#endif
    err = nc_get_varm_float(ncid, varid, start, count, stride, imap,
                             (float*) dat);
#ifdef STANDALONE
    printf("strided.varm: %s =",VAR);
    for(i=0;i<3;i++) printf(" %f",dat[i]);
    printf("\n");
#endif
    fail=0;
    for(i=0;i<3;i++) {
	float delta = (dat[i] - expected_stride3[i]);
	if(delta > 0.0005 || delta < -0.0005) {
	    fprintf(stderr,"*** Failure: stride case 2: unexpected value: delta=%g dat[%d]=%g expected[%d]=%g\n",
		    delta, i, dat[i], i, expected_stride3[i]);
	    fail=1;
	}
    }
    printf("*** %s: stride case 3\n",(fail?"Fail":"Pass"));

    return 0;

ncfail:
    printf("*** nc function failure: %d %s\n",err,nc_strerror(err));
    return 1;
}