ligo-skymap.md

@@ -7,6 +7,8 @@ $ ligo-skymap-from-samples --outdir skymap --enable-multiresolution PROD0_poster
 $ summarypages --webdir ./webpage --samples PROD0_posterior_samples.hdf5 --gw --multi_process 20
 ```
 
+## Comparing the skymaps
+
 Below is the skymap produced by `pesummary`:
 
 ![Screen_Shot_2020-03-06_at_09.05.52](uploads/358cb145e143fca1e02c7c4e6385c9ac/Screen_Shot_2020-03-06_at_09.05.52.png)
@@ -17,6 +19,53 @@ Below is the skymap produced by `ligo.skymap`
 
 The differences between the 50% and 90% credible intervals is small and likely caused by a different random seed. `pesummary` now takes a random seed as a command line argument. See commit: 2ba972f0
 
+## Comparing the fits files
+
+Here we compare the metadata stored in the fits files produced by `ligo.skymap` and `pesummary`. We use the script below:
+
+```python
+from astropy.table import Table
+
+LIGO_SKYMAP = "/home/charlie.hoy/projects/pesummary_review/ligo.skymap_consistency/skymap/skymap.fits"
+PESUMMARY = "/home/charlie.hoy/projects/pesummary_review/ligo.skymap_consistency/webpage/samples/1583428865_PROD0_posterior_samples_skymap.fits"
+
+ligo_skymap = Table.read(LIGO_SKYMAP, format='fits')
+pesummary_skymap = Table.read(PESUMMARY, format='fits')
+
+not_included = []
+for meta, value in ligo_skymap.meta.items():
+    if meta in pesummary_skymap.meta.keys():
+        if pesummary_skymap.meta[meta] != value:
+            print(
+                "The field {} is not the same between the two fits files. PESummary "
+                "reports {} and ligo.skymap reports {}".format(
+                    meta, pesummary_skymap.meta[meta], value
+                )
+            )
+    else:
+        not_included.append(meta)
+
+if len(not_included):
+    print("--------------------")
+    print(
+        "Parameters not included in this analysis because fields not stored in "
+        "PESummary: {}".format(", ".join(not_included))
+    )
+    print("--------------------")
+```
+
+with output:
+
+```bash
+$ python check_fits_files.py
+The field DATE is not the same between the two fits files. PESummary reports 2020-03-05T19:14:43.236422 and ligo.skymap reports 2020-03-06T03:01:08.421209
+The field CREATOR is not the same between the two fits files. PESummary reports pesummary and ligo.skymap reports ligo-skymap-from-samples
+--------------------
+Parameters not included in this analysis because fields not stored in PESummary: DATE-OBS, MJD-OBS, VCSVERS, VCSREV, DATE-BLD, HISTORY
+--------------------
+```
+
+
 # Review comments
 
 # Related MRs