diff options
Diffstat (limited to 'src/libcf/cf_modify_hist_times.c')
| -rw-r--r-- | src/libcf/cf_modify_hist_times.c | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/src/libcf/cf_modify_hist_times.c b/src/libcf/cf_modify_hist_times.c new file mode 100644 index 0000000..ba1b5d0 --- /dev/null +++ b/src/libcf/cf_modify_hist_times.c @@ -0,0 +1,83 @@ +/***************************************************************************** + * Johns Hopkins University + * Center For Astrophysical Sciences + * FUSE + ***************************************************************************** + * + * Synopsis: cf_modify_hist_times (fitsfile *infits, long nevents, + * float *time, GTI *gti); + * + * Description: For histogram data, set photon-arrival times to the midpoint + * of the longest good-time interval. + * + * Arguments: fitsfile *infits Input FITS file pointer + * long nevents Number of photon events + * float *time Time array for photon list + * GIT *gti Good time interval(s) + * + * Calls: + * + * Returns: TRUE if time array is changed. + * FALSE if time array is not changed. + * + * History: 06/02/04 1.1 wvd Initial coding + * 06/07/04 1.2 wvd Use standard return values. + * 02/17/05 1.3 wvd Initalize jmax to 0. + * + ****************************************************************************/ + +#include <string.h> +#include <stdio.h> +#include <stdlib.h> +#include "calfuse.h" + +int +cf_modify_hist_times (fitsfile *infits, long nevents, float *time, GTI *gti) +{ + char CF_PRGM_ID[] = "cf_modify_hist_times"; + char CF_VER_NUM[] = "1.3"; + + int errflg=0, status=0; + long j, jmax=0; + float exptime, gti_time, max_time, photon_time, rawtime; + + cf_error_init(CF_PRGM_ID, CF_VER_NUM, stderr); + cf_timestamp(CF_PRGM_ID, CF_VER_NUM, "Begin Processing"); + + /* If data were not taken in HIST mode, exit now. */ + if ((errflg = cf_proc_check(infits, CF_PRGM_ID))) return errflg; + + /* Read header keywords. */ + FITS_read_key(infits, TFLOAT, "EXPTIME", &exptime, NULL, &status); + FITS_read_key(infits, TFLOAT, "RAWTIME", &rawtime, NULL, &status); + + /* + * If the entire exposure was rejected by the screening routines, + * we don't bother changing photon-arrival times. If no time was + * lost to screening, the default arrival times are OK. Exit now. + */ + if (exptime < 1. || exptime > rawtime - 1.) { + cf_proc_update(infits, CF_PRGM_ID, "COMPLETE"); + cf_timestamp(CF_PRGM_ID, CF_VER_NUM, "Done processing"); + return -1; + } + + /* Determine which is the longest good-time interval. */ + max_time = 0.; + for (j = 0; j < gti->ntimes; j++) { + if ((gti_time = gti->stop[j] - gti->start[j]) > max_time) { + max_time = gti_time; + jmax = j; + } + } + + /* Set all photon-arrival times to midpoint of longest GTI. */ + photon_time = (gti->start[jmax] + gti->stop[jmax]) / 2.; + for (j = 0; j < nevents; j++) + time[j] = photon_time; + cf_verbose(1, "Setting photon-arrival times to %.1f", photon_time); + + cf_proc_update(infits, CF_PRGM_ID, "COMPLETE"); + cf_timestamp(CF_PRGM_ID, CF_VER_NUM, "Done processing"); + return status; +} |