Missed python module definition and setup.py script

[ipa-nhg]

Related to #293

[Chamango90]

The import is not required. An empty __init__.py file is sufficient.

[ipa-nhg]

you are right, it is within the same package. The init file can be empty

[gavanderhoorn]

Suggestion: can we please rebase as much as possible, instead of merging in kinetic-devel all the time? Let's try to keep the commit history sane.

[ipa-nhg]

@gavanderhoorn yes! sorry, I clicked the button "update branch" of the PR to verify the commit with Travis. But you are right, it is horrible for the history of the repo...

[gavanderhoorn]

No need to apologise.

Let's just keep it in mind.

[Chamango90]

Reviewed and accepted

[gavanderhoorn]

Thanks @ipa-nhg for fixing this.

[pidipidi]

I cannot still find a python module, ur_kin_py when I run test_analytical_ik.py. Here is the message,

"ImportError: No module named ur_kin_py"

I am not an expert for the python wrapper, but I could not find any setup for ur_kin_py.cpp in CMakeList.

[cambel]

@pidipidi Yeah I found the same error, after trying many things I manage to made it work.

Here is what I did:
First, make sure you have installed Boost.Numpy, if not you can install it from source:

sudo apt-get install build-essential python-setuptools libatlas-dev libatlas3gf-base

git clone https://github.com/ndarray/Boost.NumPy
cd Boost.NumPy
cmake .
make
make install

Then in the CMakeLists.txt file, you have to add the following

find_package(PythonLibs 2.7 REQUIRED)
... 
###########
## Build ##
###########
...
PYTHON_ADD_MODULE(ur_kin_py src/ur_kin_py.cpp)
target_link_libraries(ur_kin_py ur3_kin boost_python boost_numpy ${PYTHON_LIBRARIES} ${Boost_LIBRARIES} )

set_target_properties(ur_kin_py PROPERTIES 
                      LIBRARY_OUTPUT_DIRECTORY ${CATKIN_DEVEL_PREFIX}/${CATKIN_PACKAGE_PYTHON_DESTINATION})
...
#############
## Install ##
#############
install(TARGETS ur_kin_py
  ARCHIVE DESTINATION ${CATKIN_PACKAGE_PYTHON_DESTINATION}
  LIBRARY DESTINATION ${CATKIN_PACKAGE_PYTHON_DESTINATION}
)
...

Note that I link the library just with the ur3_kin, if you need a different robot, you can change it.

Then you can test with the test_analytical_ik.py but you have to also fix the import line on this file:
from ur_kinematics.ur_kin_py import forward, inverse
then it should work fine.

Finally, if you encounter the problem of libboost_numpy.so: cannot open shared object file just update your LD_LIBRARY_PATH with the location of your library, in my case /usr/local/lib64

Hope it helps!