diff options
| author | Thomas White <taw@physics.org> | 2020-03-09 14:23:49 +0100 |
|---|---|---|
| committer | Thomas White <taw@physics.org> | 2020-03-09 14:23:49 +0100 |
| commit | d4873dff09b3cf314fce0019d76e3a4ca64d7221 (patch) | |
| tree | 8b6c7c45c4c03bc6e777a874fb83d6656310a180 | |
| parent | 118835f8b3fc5ded5c4d6958678db54365f45d2f (diff) | |
integrate_rings_once: Handle case where reflection is negative by < 1 photon
| -rw-r--r-- | libcrystfel/src/integration.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/libcrystfel/src/integration.c b/libcrystfel/src/integration.c index c922f703..3d8258c1 100644 --- a/libcrystfel/src/integration.c +++ b/libcrystfel/src/integration.c @@ -1487,6 +1487,11 @@ static int integrate_rings_once(Reflection *refl, struct image *image, * appropriate size */ if ( intensity < -aduph ) { sig2_poisson = -aduph*intensity; + } else if ( intensity < 0.0 ) { + /* If the intensity is negative (by less than one + * photon), assume the reflection is very weak and + * therefore has a Poisson error of one photon. */ + sig2_poisson = aduph; } sigma = sqrt(sig2_poisson + bx->m*sig2_bg); |