Expose data.dhg in python

[ddliu365]

I just happen to use computeCentrodialMomentumTimeVariation to compute angular momentum derivative and I can find data.hg, but the data.dhg is missing in python.

The install procedure follows the website. https://stack-of-tasks.github.io/pinocchio/download.html

I do find a issue which is relevant to this #760, but I didn't see you add dhg in the code.

[jcarpent]

Done through #994. Thanks for the report.

[ddliu365]

Thanks for your timely reply.

Do I need to build from source? Or should I repeat the same procedure in this website to install from binary?

I am using Mac and linux

[ddliu365]

I download the dependencies, revised the code by following your code, recompile it and install it.

The error still appears:

('Simulator: Linear momentum:', [0.0, 0.0, 0.0])
('Simulator: Angular momentum w.r.t CoM:', [0.0, 0.0, 0.0])
Traceback (most recent call last):
  File "data_collecting_biped.py", line 341, in <module>
    print('Simulator: Linear momentum time derivative:', vec2list(bipd.pinocchio_robot.data.dhg.linear))
AttributeError: 'Data' object has no attribute 'dhg'
numActiveThreads = 0
stopping threads
Thread with taskId 0 exiting
Thread TERMINATED
destroy semaphore
semaphore destroyed
destroy main semaphore
main semaphore destroyed
finished
numActiveThreads = 0
btShutDownExampleBrowser stopping threads
Thread with taskId 0 exiting
Thread TERMINATED
destroy semaphore
semaphore destroyed
destroy main semaphore
main semaphore destroyed

[ddliu365]

Did I miss something? I only add the following in the data.hpp

        .ADD_DATA_PROPERTY_READONLY(Force,dhg,
                                    "Centroidal momentum time derivative(expressed in the frame centered at the CoM and aligned with world frame).")

[jcarpent]

A simple

brew uninstall pinocchio
brew install pinocchio --HEAD

should work.

[ddliu365]

For linux, without brew, how to do that

[gabrielebndn]

@ddliugit, since the change is not released, the only way to have it now it to build it from source on the branch devel. You can find instructions here

[ddliu365]

I did that, but it doesn’t work. Should I use different cmake flag

[gabrielebndn]

I do not think it has anything to do with the CMake flags.

1. If you were using APT binaries before, make sure to remove them:

   sudo apt remove robotpkg-py27-pinocchio

2. If you have made changes to your repo, clean it:

   git fetch --all
   git reset --hard origin/devel
   rm -rf build*

   (assuming the main Pinocchio remote is called origin). This will completely clean your repo of any change you have made to the repo and it will make your folder identical to devel. Then, you can proceed with a new installation. While installing, pay attention to the installation path: sudo apt-get installs in /opt/openrobots. You can control where you install when doing

   cmake .. -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=/your/installation/path

   You can install in /opt/openrobots, but this is not recommended, as it may lead to nasty conflicts with APT. Choose another path: we recommend /usr/local, but you may pick another one if you prefer. Then, you will have to configure your environment variables as

   export ROBOTPKG_BASE=/your/installation/path
   export PATH=$ROBOTPKG_BASE/bin:$ROBOTPKG_BASE/sbin:$PATH
   export LD_LIBRARY_PATH=$ROBOTPKG_BASE/lib:$ROBOTPKG_BASE/lib/plugin:$ROBOTPKG_BASE/lib64:$LD_LIBRARY_PATH
   export PYTHONPATH=$ROBOTPKG_BASE/lib/python2.7/site-packages:$ROBOTPKG_BASE/lib/python2.7/dist-packages:$PYTHONPATH
   export PKG_CONFIG_PATH=$ROBOTPKG_BASE/lib/pkgconfig/:$PKG_CONFIG_PATH
   export ROS_PACKAGE_PATH=$ROBOTPKG_BASE/share:$ROBOTPKG_BASE/stacks:$ROS_PACKAGE_PATH
   export CMAKE_PREFIX_PATH=$ROBOTPKG_BASE:$CMAKE_PREFIX_PATH

[ddliu365]

Thanks. I think it is caused by binary problem. First I followed robotpkg installation. I will do remove thing.