From 9222a66e76b7e63325e078a7c60dd465108337b0 Mon Sep 17 00:00:00 2001
From: Ken MacDonald <kmacdonald@stsci.edu>
Date: Fri, 26 Jan 2024 10:18:56 -0500
Subject: [PATCH] Updating median rate check for segment variance computation
 for a 2 group ramp.

---
 src/stcal/ramp_fitting/src/slope_fitter.c | 46 ++++++++++++++++++-----
 1 file changed, 37 insertions(+), 9 deletions(-)

diff --git a/src/stcal/ramp_fitting/src/slope_fitter.c b/src/stcal/ramp_fitting/src/slope_fitter.c
index a748108df..e224c08e9 100644
--- a/src/stcal/ramp_fitting/src/slope_fitter.c
+++ b/src/stcal/ramp_fitting/src/slope_fitter.c
@@ -675,14 +675,16 @@ print_delim_char(char c, int len) {
 static inline int
 is_pix_in_list(struct pixel_ramp * pr)
 {
-    // [(37, 737), (11, 964), (19, 283), (3, 1702), (39, 522)]
-    // const int len = 5;
-    // npy_intp rows[len] = { 37,  11,  19,    3,  39};
-    // npy_intp cols[len] = {737, 964, 283, 1702, 522};
-
+#if 0
+    // nrs_verify_nrs1...
+    // [(13, 1446), (279, 1077), (285, 576), (289, 1758), (297, 1447)]
+    const int len = 5;
+    npy_intp rows[len] = {  13,  279,  285,   289,  297};
+    npy_intp cols[len] = {1446, 1077,  576,  1758, 1447};
+#endif
     const int len = 1;
-    npy_intp rows[len] = { 19};
-    npy_intp cols[len] = {283};
+    npy_intp rows[len] = {  13};
+    npy_intp cols[len] = {1446};
     int k;
 
     for (k=0; k<len; ++k) {
@@ -2266,6 +2268,13 @@ ramp_fit_pixel(
         ret = 1;
         goto END;
     }
+#if 0
+    if (is_pix_in_list(pr)) {
+        print_delim();
+        dbg_ols_print("Pixel (%ld, %ld)\n", pr->row, pr->col);
+        dbg_ols_print("Median Rate = %.10f\n", pr->median_rate);
+    }
+#endif
 
     /* Clean up any thing from the last pixel ramp */
     clean_segment_list(pr->nints, pr->segs);
@@ -2437,6 +2446,13 @@ ramp_fit_pixel_integration_fit_slope(
         pr->rateints[integ].slope = slope_i_num * var_err;
         pr->rateints[integ].var_err = sqrt(var_err);
     }
+#if 0
+    if (is_pix_in_list(pr)) {
+        dbg_ols_print("invvar_e = %.10f\n", invvar_e);
+        dbg_ols_print("var_err = %.10f\n", var_err);
+        dbg_ols_print("[%ld] var_err = %.10f\n", pr->rateints[integ].var_err);
+    }
+#endif
 
     // DBG_INTEG_INFO;  /* XXX */
 
@@ -2576,8 +2592,10 @@ ramp_fit_pixel_integration_fit_slope_seg_len2(
     seg->slope = data_diff / rd->group_time;
 
     /* Segment Poisson variance */
-    pden = (rd->group_time * pr->gain);
-    seg->var_p = pr->median_rate / pden;
+    if (pr->median_rate > 0.) {
+        pden = (rd->group_time * pr->gain);
+        seg->var_p = pr->median_rate / pden;
+    }
 
     /* Segment read noise variance */
     rnum = pr->rnoise / rd->group_time;
@@ -2589,6 +2607,16 @@ ramp_fit_pixel_integration_fit_slope_seg_len2(
     /* Segment total variance */
     // seg->var_e = 2. * pr->rnoise * pr->rnoise;  /* XXX Is this right? */
     seg->var_e = seg->var_p + seg->var_r;
+#if 0
+    if (is_pix_in_list(pr)) {
+        tmp = sqrt2 * pr->rnoise;
+        dbg_ols_print("rnoise     = %.10f\n", pr->rnoise);
+        dbg_ols_print("seg->var_s = %.10f\n", tmp);
+        dbg_ols_print("seg->var_p = %.10f\n", seg->var_p);
+        dbg_ols_print("seg->var_r = %.10f\n", seg->var_r);
+        dbg_ols_print("seg->var_e = %.10f\n", seg->var_e);
+    }
+#endif
 
     if (rd->save_opt) {
         seg->sigslope = sqrt2 * pr->rnoise;