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NOTICE: This version of the NSF Unidata web site (archive.unidata.ucar.edu) is no longer being updated.
Current content can be found at unidata.ucar.edu.
To learn about what's going on, see About the Archive Site.
Here's a simple nccat routine that Chuck Denham
(cdenham@xxxxxxxxxxxxxxxxxx) wrote that I use
all the time.
--
Rich Signell | rsignell@xxxxxxxxxxxxxxxxxx
U.S. Geological Survey | (508) 457-2229 | FAX (508) 457-2310
Quissett Campus | "What you don't know CAN hurt you,
Woods Hole, MA 02543-1598 | only you won't know it. "
/*
* nccat: Concatenate two netCDF files.
*
* The NetCDF files must be identical in variable
* names and dimensions. Each variable must have
* a leftmost NC_UNLIMITED record dimension.
*
* Copyright (C) 1991 Charles R. Denham, Zydeco.
*
*/
# include <stdio.h>
# include <stdlib.h>
# include <string.h>
# include "netcdf.h"
void usage();
int
main (
int argc,
char * argv[]
)
{
char dimname[MAX_NC_NAME];
char varname[MAX_NC_NAME];
int cdfid[2];
int varid[2];
int recdim[2], rec[2];
int dim[MAX_NC_DIMS];
int incoord[MAX_NC_DIMS], outcoord[MAX_NC_DIMS];
int incount[MAX_NC_DIMS], outcount[MAX_NC_DIMS];
int ndims, nvars, natts, ngatts;
int len, size, nrecords;
int instart, outstart;
nc_type datatype[2];
char * value;
int status;
int i, j, n;
/* Usage message if too few arguments. */
if (argc < 3) {
usage();
return (0);
}
/* Open the files. */
cdfid[0] = -1;
cdfid[1] = -1;
if (!strcmp(argv[1], argv[2])) {
printf("Cannot concatenate a file to itself.\n");
}
else if ((cdfid[0] = ncopen(argv[1], NC_WRITE)) == -1) {
printf("ncopen failure.\n");
return (-1);
}
else if ((cdfid[1] = ncopen(argv[2], NC_NOWRITE)) == -1) {
printf("ncopen failure.\n");
return (-1);
}
/* Inquire. */
else if ((status = ncinquire(cdfid[0],
&ndims, &nvars, &ngatts, &recdim[0])) == -1)
{
printf("ncinquire failure.\n");
return (-1);
}
else if ((status = ncinquire(cdfid[1],
&ndims, &nvars, &ngatts, &recdim[1])) == -1)
{
printf("ncinquire failure.\n");
return (-1);
}
/* Check for a dimension of NC_UNLIMITED. */
else if (recdim[0] == -1) {
printf("No NC_UNLIMITED dimension exists.\n");
}
else if (recdim[1] == -1) {
printf("No NC_UNLIMITED dimension exists.\n");
}
/* Transfer the variables. */
else {
ncdiminq(cdfid[0], recdim[0], dimname, &size);
outstart = size;
instart = 0;
ncdiminq(cdfid[1], recdim[1], dimname, &size);
nrecords = size;
printf("Records to transfer: %d\n", nrecords);
printf("Records in result: %d\n", (nrecords + outstart));
printf("Variables to process: %d\n", nvars);
for (i = 0; i < nvars; i++) {
/* Input hyperslab. */
varid[1] = i;
ncvarinq(cdfid[1], varid[1], varname,
&datatype[1], &ndims, dim, &natts);
status = -1;
for (j = 0; j < ndims; j++) {
ncdiminq(cdfid[1], dim[j], dimname, &size);
incoord[j] = 0;
incount[j] = size;
if (dim[j] == recdim[1]) {
rec[1] = j;
incount[j] = 1;
status = 0;
}
}
/* Output hyperslab. */
if (!status) {
varid[0] = ncvarid(cdfid[0], varname);
if ((status = ncvarinq(cdfid[0], varid[0],
varname,
&datatype[0], &ndims, dim,
&natts)) != -1) {
status = -1;
for (j = 0; j < ndims; j++) {
ncdiminq(cdfid[0], dim[j],
dimname, &size);
outcoord[j] = 0;
outcount[j] = size;
if (dim[j] == recdim[0])
{
rec[0] = j;
outcoord[j] = outstart;
outcount[j] = 1;
status = 0;
}
}
}
}
if (status) {
printf("No record dimension: %s\n", varname);
}
else if (datatype[0] != datatype[1]) {
printf("Incompatible data types: %s\n",
varname);
status = -1;
}
/* Allocate a transfer buffer. */
if (!status) {
n = 1;
for (j = 0; j < ndims; j++ ) {
n *= incount[j];
}
len = nctypelen(datatype[1]);
value = (char *) malloc(len * n);
/* Read/write with ncvarget/put. */
printf("\t%s; %d to go ...\n", varname,
(nvars-i-1));
fflush(stdout);
for (j = 0; j < nrecords; j++) {
ncvarget(cdfid[1], varid[1], incoord,
incount, value);
ncvarput(cdfid[0], varid[0], outcoord,
outcount, value);
/* Prepare for next record. */
incoord[rec[1]]++;
outcoord[rec[0]]++;
}
/* Deallocate the transfer buffer. */
free(value);
}
}
}
/* Close the files. */
for (i = 0; i < 2; i++) {
if (cdfid[i] != -1) {
if ((status = ncclose(cdfid[i])) == -1) {
printf("ncclose failure.\n");
return (-1);
}
}
}
return (0);
}
/* usage: Usage message for the program. */
void
usage()
{
printf("%% Usage:\n");
printf("%% \tnccat infile1 infile2\n");
printf("%% \t\tinfile1: NetCDF filename for input and output.\n");
printf("%% \t\tinfile2: NetCDF filename for input.\n");
printf("%% Purpose:\n");
printf("%% \tConcatenate NetCDF record viables.\n");
printf("%% \tThe NetCDF files must be identical in variable\n");
printf("%% \tnames and dimensions. Each variable must have a\n");
printf("%% \tleftmost NC_UNLIMITED record dimension.\n");
printf("%% Example:\n");
printf("%% \tnccat foo.cdf bar.cdf\n");
}
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