python-casacore has implicit dependency on casadata

[dmehring]

We'd like not to have to install casadata, which is a fairly large package. However, opening an image will fail without the Observatories table which is part of casadata. Can code be modified to eliminate the casadata dependency? I believe any image will reproduce the error, but if not I can make mine available.

from casacore.images import image as cimage
casa_image = cimage('demo_simulated.im')

2023-10-11 15:05:01        WARN        MeasIERS::findTab (file
/code/measures/Measures/MeasIERS.cc, line 389)        Requested data table
Observatories cannot be found in the searched directories:
2023-10-11 15:05:01        WARN        MeasIERS::findTab (file
/code/measures/Measures/MeasIERS.cc, line
389)+        /usr/share/casacore/data/ephemerides/
2023-10-11 15:05:01        WARN        MeasIERS::findTab (file
/code/measures/Measures/MeasIERS.cc, line
389)+        /usr/share/casacore/data/geodetic/
2023-10-11 15:05:01        SEVERE        MeasTable::doInitObservatories() (file
/code/measures/Measures/MeasTable.cc, line 2867)Cannot read table of
Observatories
---------------------------------------------------------------------------
RuntimeError                              Traceback (most recent call last)
Cell In[7], line 1
----> 1 casa_image = cimage('demo_simulated.im')

File
~/projects/xradio/xenv/lib/python3.10/site-packages/casacore/images/image.py:159,
in image.__init__(self, imagename, axis, maskname, images, values,
coordsys, overwrite, ashdf5, mask, shape, tileshape)
    157         six.print_("Probably could not import casacore.util")
    158         pass
--> 159     Image.__init__(self, imagename, maskname, imgs)
    160 else:
    161     # Create an image from an array
    162     # The values can be a masked array
    163     #  use the mask if no explicit mask is given
    164     if isinstance(values, nma.MaskedArray):

RuntimeError: demo_simulated.im cannot be opened as image (expression):
2023-10-11 15:05:01        SEVERE        MeasTable::doInitObservatories() (file
/code/measures/Measures/MeasTable.cc, line 2867)        Cannot read table of
Observatories

[tammojan]

I could reproduce the error, and got the following stack trace (boost and python stuff omitted). Just from this stacktrace, it looks like this may need changes in casacore.

gdb --args python3 -c 'from casacore.images import image; image("test_image.im")'

#0  0x00007f091af104a1 in __cxa_throw () from /lib/x86_64-linux-gnu/libstdc++.so.6
#1  0x00007f091a12c002 in void casacore::LogIO::postThenThrow<casacore::AipsError>(casacore::AipsError const&) ()
   from /usr/local/lib/python3.10/dist-packages/casacore/images/../../python_casacore.libs/libcasa_casa-aa1f7f3c.so.7
#2  0x00007f091a12bb4a in casacore::operator<<(casacore::LogIO&, casacore::LogIO::Command) ()
   from /usr/local/lib/python3.10/dist-packages/casacore/images/../../python_casacore.libs/libcasa_casa-aa1f7f3c.so.7
#3  0x00007f091c839471 in casacore::MeasTable::doInitObservatories() ()
   from /usr/local/lib/python3.10/dist-packages/casacore/images/../../python_casacore.libs/libcasa_measures-3aaf8b1f.so.7
#4  0x00007f091f9afee8 in __pthread_once_slow (once_control=0x7f091c968760 <casacore::MeasTable::theirObsInitOnceFlag>, init_routine=0x7f091af3cd50 <__once_proxy>)
    at ./nptl/pthread_once.c:116
#5  0x00007f091c83026d in casacore::MeasTable::Observatory(casacore::MPosition&, casacore::String const&) ()
   from /usr/local/lib/python3.10/dist-packages/casacore/images/../../python_casacore.libs/libcasa_measures-3aaf8b1f.so.7
#6  0x00007f091e249aa6 in casacore::ObsInfo::setTelescope(casacore::String const&) ()
   from /usr/local/lib/python3.10/dist-packages/casacore/images/../../python_casacore.libs/libcasa_coordinates-53a1c604.so.7
#7  0x00007f091e24c2fc in casacore::ObsInfo::fromRecord(casacore::String&, casacore::RecordInterface const&) ()
   from /usr/local/lib/python3.10/dist-packages/casacore/images/../../python_casacore.libs/libcasa_coordinates-53a1c604.so.7
#8  0x00007f091e1ef33e in casacore::CoordinateSystem::restore(casacore::RecordInterface const&, casacore::String const&) ()
   from /usr/local/lib/python3.10/dist-packages/casacore/images/../../python_casacore.libs/libcasa_coordinates-53a1c604.so.7
#9  0x00007f091e76e92c in casacore::PagedImage<float>::restoreAll(casacore::TableRecord const&) ()
   from /usr/local/lib/python3.10/dist-packages/casacore/images/../../python_casacore.libs/libcasa_images-a6905fae.so.7
#10 0x00007f091e76eb60 in casacore::PagedImage<float>::PagedImage(casacore::Table&, casacore::MaskSpecifier, unsigned int) ()
   from /usr/local/lib/python3.10/dist-packages/casacore/images/../../python_casacore.libs/libcasa_images-a6905fae.so.7
#11 0x00007f091e7e3884 in casacore::ImageOpener::openPagedImage(casacore::String const&, casacore::MaskSpecifier const&) ()
   from /usr/local/lib/python3.10/dist-packages/casacore/images/../../python_casacore.libs/libcasa_images-a6905fae.so.7
#12 0x00007f091e7e3ef3 in casacore::ImageOpener::openImage(casacore::String const&, casacore::MaskSpecifier const&) ()
   from /usr/local/lib/python3.10/dist-packages/casacore/images/../../python_casacore.libs/libcasa_images-a6905fae.so.7
#13 0x00007f091e83a3f3 in casacore::ImageProxy::openImageOrExpr(casacore::String const&, casacore::MaskSpecifier const&, casacore::Block<casacore::LatticeExprNode> const&) ()
   from /usr/local/lib/python3.10/dist-packages/casacore/images/../../python_casacore.libs/libcasa_images-a6905fae.so.7
#14 0x00007f091e83f588 in casacore::ImageProxy::openImage(casacore::String const&, casacore::String const&, std::vector<casacore::ImageProxy, std::allocator<casacore::ImageProxy> > const&) () from /usr/local/lib/python3.10/dist-packages/casacore/images/../../python_casacore.libs/libcasa_images-a6905fae.so.7
#15 0x00007f091e83f821 in casacore::ImageProxy::ImageProxy(casacore::String const&, casacore::String const&, std::vector<casacore::ImageProxy, std::allocator<casacore::ImageProxy> > const&) () from /usr/local/lib/python3.10/dist-packages/casacore/images/../../python_casacore.libs/libcasa_images-a6905fae.so.7
#16 0x00007f091f3db125 in boost::python::objects::value_holder<casacore::ImageProxy>::value_holder<boost::python::objects::reference_to_value<casacore::String>, boost::python::objects::reference_to_value<casacore::String>, boost::python::objects::reference_to_value<std::vector<casacore::ImageProxy, std::allocator<casacore::ImageProxy> > > > (a2=..., a1=...,
    a0=..., self=0x7f091f69c900, this=0x7f0917c61c58) at /opt/boost/include/boost/python/object/forward.hpp:74

[dmehring]

Yes, the messages come from the casacore measures code. So, maybe this ticket is more appropriate for casacore, but I don't have a sample C++ program for it :), although I'm guessing one of the casacore test programs that opens an image could be used to reproduce the error.

[tammojan]

Good point. Let's continue the issue in casacore/casacore#1321

[maneesh29s]

Is this issue fixed?
Does python-casacore 3.6.1 does not depend on casadata?