Final scan plot failing for cascades

[mlincett]

Sometimes the final plot fails for cascades (today's example run00136692.evt000006590287.HESE).

<class 'ValueError'>
arange: cannot compute length
<traceback object at 0x7fd6224d18c0>

[mlincett]

A couple for tracebacks (two unrelated failing modes) thank to @clagunas :

File "/cvmfs/icecube.opensciencegrid.org/users/followup/metaprojects/combo-realtime/trunk/build/lib/icecube/skymap_scanner/create_plot_zoomed.py", line 643, in loop_over_plots
  create_plot_zoomed(eventID, state_dict, outdir, syst, ra, dec, radius, log_func, upload_func, final_channels)
 File "/cvmfs/icecube.opensciencegrid.org/users/followup/metaprojects/combo-realtime/trunk/build/lib/icecube/skymap_scanner/create_plot_zoomed.py", line 384, in create_plot_zoomed
  healpy.graticule(dpar=2, dmer=2, force=True) 
 File "/cvmfs/icecube.opensciencegrid.org/py3-v4.1.0/RHEL_7_x86_64/lib/python3.7/site-packages/healpy/visufunc.py", line 1387, in graticule
  ax.graticule(dpar=dpar, dmer=dmer, coord=coord, local=local, **kwds)
 File "/cvmfs/icecube.opensciencegrid.org/py3-v4.1.0/RHEL_7_x86_64/lib/python3.7/site-packages/healpy/projaxes.py", line 549, in graticule
  phi_list = np.around(np.arange(mmin, mmax + 0.5 * dmer, dmer) / dmer) * dmer
ValueError: arange: cannot compute length

File "/cvmfs/icecube.opensciencegrid.org/users/followup/metaprojects/combo-realtime/trunk/build/lib/icecube/skymap_scanner/create_plot_zoomed.py", line 643, in loop_over_plots
    create_plot_zoomed(eventID, state_dict, syst, ra, dec, radius, log_func, upload_func, final_channels)
  File "/cvmfs/icecube.opensciencegrid.org/users/followup/metaprojects/combo-realtime/trunk/build/lib/icecube/skymap_scanner/create_plot_zoomed.py", line 522, in create_plot_zoomed
    new_pixels = fixpixnumber(nside, pixels)
  File "/cvmfs/icecube.opensciencegrid.org/users/followup/metaprojects/combo-realtime/trunk/build/lib/icecube/skymap_scanner/create_plot_zoomed.py", line 518, in fixpixnumber
    pix_fixed = healpy.ang2pix(nside, th_fixed, phi_o)
  File "/cvmfs/icecube.opensciencegrid.org/py3-v4.1.0/RHEL_7_x86_64/lib/python3.7/site-packages/healpy/pixelfunc.py", line 481, in ang2pix
    return pixlib._ang2pix_ring(nside, theta, phi)
MemoryError: Unable to allocate array with shape (12582912,) and data type int64

[ric-evans]

@tianluyuan @mlincett do we know if this is still happening?

[mlincett]

I think this can be moved to skymap-scanner-tools and we will take it from there. Probably some refactoring of the plotting routines is in order anyway.