Initial commit

1 files changed, 147 insertions, 0 deletions

diff --git a/pkg/tbtables/cfitsio/iter_a.c b/pkg/tbtables/cfitsio/iter_a.c
new file mode 100644
index 00000000..19ea1d1c
--- /dev/null
+++ b/pkg/tbtables/cfitsio/iter_a.c
@@ -0,0 +1,147 @@
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "fitsio.h"
+
+/*
+  This program illustrates how to use the CFITSIO iterator function.
+  It reads and modifies the input 'iter_a.fit' file by computing a
+  value for the 'rate' column as a function of the values in the other
+  'counts' and 'time' columns.
+*/
+main()
+{
+    extern flux_rate(); /* external work function is passed to the iterator */
+    fitsfile *fptr;
+    iteratorCol cols[3];  /* structure used by the iterator function */
+    int n_cols;
+    long rows_per_loop, offset;
+
+    int status, nkeys, keypos, hdutype, ii, jj;
+    char filename[]  = "iter_a.fit";     /* name of rate FITS file */
+
+    status = 0; 
+
+    fits_open_file(&fptr, filename, READWRITE, &status); /* open file */
+
+    /* move to the desired binary table extension */
+    if (fits_movnam_hdu(fptr, BINARY_TBL, "RATE", 0, &status) )
+        fits_report_error(stderr, status);    /* print out error messages */
+
+    n_cols  = 3;   /* number of columns */
+
+    /* define input column structure members for the iterator function */
+    fits_iter_set_by_name(&cols[0], fptr, "COUNTS", TLONG,  InputCol);
+    fits_iter_set_by_name(&cols[1], fptr, "TIME",   TFLOAT, InputCol);
+    fits_iter_set_by_name(&cols[2], fptr, "RATE",   TFLOAT, OutputCol);
+
+    rows_per_loop = 0;  /* use default optimum number of rows */
+    offset = 0;         /* process all the rows */
+
+    /* apply the rate function to each row of the table */
+    printf("Calling iterator function...%d\n", status);
+
+    fits_iterate_data(n_cols, cols, offset, rows_per_loop,
+                      flux_rate, 0L, &status);
+
+    fits_close_file(fptr, &status);      /* all done */
+
+    if (status)
+        fits_report_error(stderr, status);  /* print out error messages */
+
+    return(status);
+}
+/*--------------------------------------------------------------------------*/
+int flux_rate(long totalrows, long offset, long firstrow, long nrows,
+             int ncols, iteratorCol *cols, void *user_strct ) 
+
+/*
+   Sample iterator function that calculates the output flux 'rate' column
+   by dividing the input 'counts' by the 'time' column.
+   It also applies a constant deadtime correction factor if the 'deadtime'
+   keyword exists.  Finally, this creates or updates the 'LIVETIME'
+   keyword with the sum of all the individual integration times.
+*/
+{
+    int ii, status = 0;
+
+    /* declare variables static to preserve their values between calls */
+    static long *counts;
+    static float *interval;
+    static float *rate;
+    static float deadtime, livetime; /* must preserve values between calls */
+
+    /*--------------------------------------------------------*/
+    /*  Initialization procedures: execute on the first call  */
+    /*--------------------------------------------------------*/
+    if (firstrow == 1)
+    {
+       if (ncols != 3)
+           return(-1);  /* number of columns incorrect */
+
+       if (fits_iter_get_datatype(&cols[0]) != TLONG  ||
+           fits_iter_get_datatype(&cols[1]) != TFLOAT ||
+           fits_iter_get_datatype(&cols[2]) != TFLOAT )
+           return(-2);  /* bad data type */
+
+       /* assign the input pointers to the appropriate arrays and null ptrs*/
+       counts       = (long *)  fits_iter_get_array(&cols[0]);
+       interval     = (float *) fits_iter_get_array(&cols[1]);
+       rate         = (float *) fits_iter_get_array(&cols[2]);
+
+       livetime = 0;  /* initialize the total integration time */
+
+       /* try to get the deadtime keyword value */
+       fits_read_key(cols[0].fptr, TFLOAT, "DEADTIME", &deadtime, '\0',
+                     &status);
+       if (status)
+       {
+           deadtime = 1.0;  /* default deadtime if keyword doesn't exist */
+       }
+       else if (deadtime < 0. || deadtime > 1.0)
+       {
+           return(-1);    /* bad deadtime value */
+       }
+
+       printf("deadtime = %f\n", deadtime);
+    }
+
+    /*--------------------------------------------*/
+    /*  Main loop: process all the rows of data */
+    /*--------------------------------------------*/
+
+    /*  NOTE: 1st element of array is the null pixel value!  */
+    /*  Loop from 1 to nrows, not 0 to nrows - 1.  */
+
+    /* this version tests for null values */
+    rate[0] = DOUBLENULLVALUE;   /* define the value that represents null */
+
+    for (ii = 1; ii <= nrows; ii++)
+    {
+       if (counts[ii] == counts[0])   /*  undefined counts value? */
+       {
+           rate[ii] = DOUBLENULLVALUE;
+       }
+       else if (interval[ii] > 0.)
+       {
+           rate[ii] = counts[ii] / interval[ii] / deadtime;
+           livetime += interval[ii];  /* accumulate total integration time */
+       }
+       else
+           return(-2);  /* bad integration time */
+    }
+
+    /*-------------------------------------------------------*/
+    /*  Clean up procedures:  after processing all the rows  */
+    /*-------------------------------------------------------*/
+
+    if (firstrow + nrows - 1 == totalrows)
+    {
+        /*  update the LIVETIME keyword value */
+
+        fits_update_key(cols[0].fptr, TFLOAT, "LIVETIME", &livetime, 
+                 "total integration time", &status);
+        printf("livetime = %f\n", livetime);
+   }
+    return(0);  /* return successful status */
+}