[fitsbits] exceeding buffer limit?

[Louis Giglio]

You've opened the file twice and used the same "fitsfile" structure each time:

> 	fits_create_file(&fptr, filename, &status);
                         ^^^^^
> 	sprintf(filename, "snapshot%05d", snapshot_count/snapshot_period);
> 	fits_open_file(&fptr, filename, READWRITE, &status);
                       ^^^^^

Later on you only close one of them, although I suspect because "fptr" is
clobbered the second time the file is opened that you'll get a different error
message (or a core dump) if you call fits_close_file() again.  I think
removing the call to fits_open_file() will fix the problem.

Why are you opening the file twice anyway?  Perhaps I'm just missing something
obvious.

Cheers,
Louis


On 22 Jul 2002, Atakan Gurkan wrote:

> Date: 22 Jul 2002 18:33:27 -0700
> From: Atakan Gurkan <hatokan at yahoo.com>
> To: fitsbits at donar.cv.nrao.edu
> Newsgroups: sci.astro.fits
> Subject: [fitsbits] exceeding buffer limit?
> 
> Hi,
> I am using FITS format to take snapshots for a program.However, I can
> only write 40 files. This is suspicious because NIOBUF is 40, but I am
> closing the files each time I finish writing them. My subroutine that
> deals with snapshots looks like this:
> 
> void take_snapshot(struct star *s, struct cluster c, struct code_par
> cp){
> 	static int snapshot_count = 0;
> 	int snapshot_period = 3;
> 
> 	fitsfile *fptr;
> 	int status;
> 	long firstrow, firstelem;
> 	int tfields;       /* table will have n columns */
> 	long nrows;	
> 
> 	char extname[] = "CLUSTER_STARS";          /* extension name */
> 	char filename[128];
> 	char *ttype[] = { "Mass"};
> 	char *tform[] = { "1D"};
> 	char *tunit[] = { "Nbody"};
> 	
> 	double *mass;
> 
> 	unsigned long i, N;
> 
> 
> 	snapshot_count++;
> 	if ( (snapshot_count%snapshot_period) ){
> 		return;
> 	}
> 
> 	printf("taking snapshot %05d\n", snapshot_count/snapshot_period);
> 	N = c.NSTAR;
> 	mass = malloc((N+2)*sizeof(double));
> 
> 	for(i=0; i<=N+1; i++){
> 		mass[i] = s[i].m;
> 	
> 	}
> 
> 	status = 0;
> 	tfields = 4;
> 	nrows = N+2;
> 	sprintf(filename, "!snapshot%05d", snapshot_count/snapshot_period);
> 
> 	fits_create_file(&fptr, filename, &status);
> 	sprintf(filename, "snapshot%05d", snapshot_count/snapshot_period);
> 	fits_open_file(&fptr, filename, READWRITE, &status);
> 
> 	fits_create_tbl(fptr, BINARY_TBL, nrows, tfields, ttype, tform,
>                 tunit, extname, &status);
> 	fits_update_key(fptr, TLONG, "NSTAR", &(N), 
> 			"No of Stars", &status);
> 
> 	firstrow  = 1;  /* first row in table to write   */
> 	firstelem = 1;  /* first element in row  (ignored in ASCII tables) */
> 
> 	fits_write_col(fptr, TDOUBLE, 1, firstrow, firstelem, nrows, mass,
>                    &status);
> 	
>         free(mass);
> 	fits_close_file(fptr, &status);
> 
> 	printerror(status);
> }
> 
> I removed a few lines to make it shorter.
> printerror() is from cookbook.c
> 
> it dies with the message:
> FITSIO status = 115: NULL input pointer
> failed to create new file (already exists?):
> snapshot00040
> 
> I would really appreciate if someone could provide some insight.
> Thank you,
> 
> Atakan Gurkan

Louis Giglio
Science Systems and Applications, Inc.
NASA/GSFC Code 923
Greenbelt, MD 20771
(301) 614-6698
giglio at hades.gsfc.nasa.gov