Minor errors (and fixes) from ASKAP processing

[mattwhiting]

Here are a couple of errors that had cropped up in debugging some ASKAP processing. One was

Traceback (most recent call last):
File "/group/askap/acesops/ACES-r48219/UserScripts/col52r/ASKAP_continuum_validation.py", line 153, in
AKcat.set_specs(AK)
File "/group/askap/acesops/ACES-r48219/UserScripts/col52r/catalogue.py", line 344, in set_specs
self.img_peak_rms = rms_map.data[self.img_peak_pos][0]
IndexError: index 0 is out of bounds for axis 0 with size 0

and another, similar one was

Traceback (most recent call last):
File "/group/askap/acesops/ACES-r48219/UserScripts/col52r/ASKAP_continuum_validation.py", line 153, in
AKcat.set_specs(AK)
File "/group/askap/acesops/ACES-r48219/UserScripts/col52r/catalogue.py", line 339, in set_specs
self.img_peak = np.max(img_data[~np.isnan(img_data)])
File "/pawsey/cle60up05/python/2.7.14/numpy/1.13.3/lib/python2.7/site-packages/numpy-1.13.3-py2.7-linux-x86_64.egg/numpy/core/fromnumeric.py", line 2272, in amax
out=out, **kwargs)
File "/pawsey/cle60up05/python/2.7.14/numpy/1.13.3/lib/python2.7/site-packages/numpy-1.13.3-py2.7-linux-x86_64.egg/numpy/core/_methods.py", line 26, in _amax
return umr_maximum(a, axis, None, out, keepdims)
ValueError: zero-size array to reduction operation maximum which has no identity

These are related to, I think, spurious values, but simple tests will allow you to proceed. I have checked in the following changes to the ASKAP subversion repo, but you may want to do the same here (and there may be more - this was enough to get things going):

Index: catalogue.py
===================================================================
--- catalogue.py	(revision 48353)
+++ catalogue.py	(working copy)
@@ -341,7 +341,10 @@
         self.img_rms = int(np.median(rms_map.data[self.rms_bounds])*1e6) #uJy
         self.img_peak_bounds = np.max(img_data[self.rms_bounds])
         self.img_peak_pos = np.where(img_data == self.img_peak_bounds)
-        self.img_peak_rms = rms_map.data[self.img_peak_pos][0]
+        if len(rms_map.data[self.img_peak_pos])>0:
+            self.img_peak_rms = rms_map.data[self.img_peak_pos][0]
+        else:
+            self.img_peak_rms = 0.
         self.dynamic_range = self.img_peak_bounds/self.img_peak_rms
         self.blends = len(np.where(self.df[self.island_col].value_counts() > 1)[0])
         self.img_flux = np.sum(img_data[~np.isnan(img_data)]) / (1.133*((img.bmaj * img.bmin) / (img.raPS * img.decPS))) #divide by beam area

for the first instance, and

Index: catalogue.py
===================================================================
--- catalogue.py	(revision 48353)
+++ catalogue.py	(working copy)
@@ -336,12 +336,18 @@
         img_data = img.fits.data
         if self.finder == 'aegean':
             img_data = img_data[0][0]
-        self.img_peak = np.max(img_data[~np.isnan(img_data)])
+        if len(img_data)>0:
+            self.img_peak = np.max(img_data[~np.isnan(img_data)])
+        else:
+            self.img_peak = 0.
         self.rms_bounds = rms_map.data > 0
         self.img_rms = int(np.median(rms_map.data[self.rms_bounds])*1e6) #uJy

for the second.