Multi-Language and Shared Objects
Multilanguage Interops: Caesar SDKs and APIs
The Caesar framework is not limited to direct Julia use. The following Github projects provide access to features of Caesar in their language:
21Q1, a new multilanguage interface is under development and will replace and consolidate the previous methods listed below.
Julia Web interface:
ZMQ Interface
- C/C++:
- Python:
Please contact info@navability.io for more information.
ZMQ Messaging Interface
Caesar.jl has a ZMQ messaging interface (interested can see code here) that allows users to interact with the solver code base in a variety of ways. The messaging interface is not meant to replace static .so
library file compilation–see below–-but rather provide a more versatile and flexible development strategy.
The current known interface implementations to Caesar.jl are:
- C/C++ GraffCPP,
- Python GraffSDK.py (needs to be updated),
Starting the Caesar ZMQ Navigation Server
Start the Caesar.ZmqCaesar
server in a Julia session with a few process cores and full optimization:
julia -p4 -O3
Then run the following commands, and note these steps have also been scripted here:
#import the required modules
using Caesar, Caesar.ZmqCaesar
# create empty factor graph and config objects
fg = initfg()
config = Dict{String, String}()
zmqConfig = ZmqServer(fg, config, true, "tcp://*:5555");
# Start the server over ZMQ
start(zmqConfig)
# give the server a minute to start up ...
The current tests are a good place to see some examples of the current interfacing functions. Feel free to change the ZMQ interface for to any of the ZMQ supported modes of data transport, such as Interprocess Communication (IPC) vs. TCP.
TODO: expand the ZMQ documentation
ROS Integration
Yes, but not yet. See:
Static, Shared Object .so
Compilation
The plan for the Caesar.jl
& the mm-iSAM is to use PackageCompiler.jl to generate linkable .o
or .so
files; or maybe even full executables.
Please add your comments to this issue discussion.
Alternative Methods
Interfacing from languages like Python may also be achieved using PyCall.jl although little work has been done in the Caesar.jl framework to explore this path. Julia is itself interactive/dynamic and has plenty of line-by-line and Integrated Development Environment support – consider trying Julia for your application.