PlotMsg for C++

This repository brings PlotMsg to C++ by utilising the native PlotMsg library backend in Python. This is achieved by implementing a publisher and subscriber model between C++ and Python, and a stateful model in the Jupyter notebook ecosystem that captures the incoming message. It supports asynchronous refresh within the notebook whenever a new message is published from your C++ files, and automatically display them within the notebook. This library also support non-notebook usage where it uses PlotMsg's native figure display from within your browser.

Requirements

• zeromq (messaging protocol)

• protobuf (serialisation of message)

Using the library in your C++ project

You can include the project it as you normally. The following shows a snippet to quickly visualise your code using PlotMsg without much setup

Quick and dirty out-of-tree build in cmake

In your CMakeLists.txt:

cmake_minimum_required(...)

...

# Add as out-of-tree build (with absolute path & binary directory)
add_subdirectory(
        /home/soraxas/git-repo/plotmsg
        plotmsg
)
find_package( plotmsg REQUIRED )

...

# link the library to your target
target_link_libraries( ${MY_TARGET} plotmsg )

Example Usage

Say you have something like this in your ${MY_TARGET}

#include "plotmsg/main.hpp"
#include "plotmsg/template/core.hpp"

int main(int argc, char const *argv[]) {
  PlotMsg::Figure fig;
  std::vector<double> x{1, 2, 3, 4, 5, 6, 7};
  std::vector<double> y{1, 2, 3, 2, 3, 4, 5};

  auto trace = PlotMsg::TraceTemplate::scatter(x, y);
  trace["mode"] = "lines";

  fig.add_trace(trace);

  fig.send();
}

Run

cmake -Bbuild
make -C build

to build your C++ project.

You can then, for example, start the python subscriber with

ipython

import sys; sys.path.insert(0, "built_python_pkg")

from plotmsg_dash import PlotMsgPlotly

sub = PlotMsgPlotly()
sub.initialise()
sub.spin()

Afterwards, the ipython kernel is listening at the default tcp://127.0.0.1:5557 socket and, when you execute your compiled C++ binary, it will send the fig message using the same socket.

Example Project

./demo_project is an example of a simple project that utilises plotmsg. You can test it out with

cd demo_project
cmake -Bbuild
make -C build

# start subscriber in the background (1)
python py_sub_example.py &

# publish figure from c++
./build/test

# killall background jobs (py script in (1) that is running in bg )
kill $(jobs -p)

git clone https://github.com/protocolbuffers/protobuf.git
cd protobuf
git submodule update --init --recursive
./autogen.sh

./configure --prefix=/usr
make
make check
sudo make install
sudo ldconfig # refresh shared library cache.

cmake .. -DCMAKE_INSTALL_PREFIX=$HOME/zmq_cmake
make
make install