Getting Started

Caesar.jl is one of the packages within the JuliaRobotics community, and adheres to the code-of-conduct.

Local Dependencies

The following system packages are used by Caesar.jl:

# required packages
sudo apt-get install hdf5-tools

# optional packages
sudo apt-get install graphviz imagemagick

Install "Just the ZMQ/ROS Runtime Solver" (Linux)

Work in progress (see issue #278).

The "I Know Julia" Installation (TL;DR)

Install Inference Tools

Add Caesar to your Julia packages, you can install the metadata registered package 'Caesar' in Julia 1.0 with:

julia> ] # to enable package manager
(v1.0) pkg> add Caesar

Unit tests can further be performed for the upstream packages as follows – NOTE first time runs are slow since each new function call or package must first be precompiled.

# the multimodal incremental smoothing and mapping solver
(v1.0) pkg> test IncrementalInference
# robotics related variables and factors to work with IncrementalInference -- can be used standalone SLAM system
(v1.0) pkg> test RoME
# umbrella framework with interaction tools and more -- allows stand alone and server based solving
(v1.0) pkg> test Caesar

Install Visualization Tools

RoMEPlotting.jl (2D) and Arena.jl (3D) as optional visualization packages:

(v1.0) pkg> add RoMEPlotting

# separately
(v1.0) pkg> add Arena#master

Note currently requires Arena#master branch (2019Q2).

The "I want a Development Environment from Scratch" Install

Local Installation of Julia

Although Julia (or JuliaPro) can be installed on a Linux computer using the apt package manager, we are striving for a fully local installation environment which is highly reproducible on a variety of platforms.

The easiest method is–-via the terminal–-to download the desired version of Julia as a binary, extract, setup a symbolic link, and run:

cd ~
mkdir -p julia-software
cd julia-software
tar -xvf julia-1.2.0-linux-x86_64.tar.gz
cd /usr/bin
sudo ln -s ~/julia-software/julia-1.2.0/bin/julia julia

Note Feel free to modify this setup as you see fit.

This should allow any terminal or process on the computer to run the Julia REPL by type julia and testing with:

println("hello world")
# Should print "hello world"

Maybe a script, or command:

user@...$ echo "println(\"hello again\")" > myscript.jl
user@...$ julia myscript.jl
hello again
user@...$ rm myscript.jl

user@...$ julia -e "println(\"one more time.\")"
one more time.
user@...$ julia -e "println(\"...testing...\")"

Note: When searching for Julia related help online, use the phrase 'julialang' instead of just 'julia'.

For example, search for 'julialang workflow tips' or 'julialang performance tips'.

Note see FAQ - Why are first runs slow?, because of just of Just-In-Time/Pre compiling and caching.

Setup Juno IDE Environment

Juno IDE allows for interactive development of Julia code by extending the Atom text editor with a few packages. Download and install Atom as instructed on the website, or via command line:

cd ~/Downloads
dpkg -i atom-amd64.deb

After installing and running Atom, you can choose to either install uber-juno package in one go or install the three associated packages individually. In Atom, open the command pallette by pressing Ctrl + Shft + p and typing settings. Go to the install tab, search for and install either


or the individual packages directly:


Note Some situations have required the user separately installing the Atom.jl Julia package via command line (if Juno does not automatically install Atom.jl for you). Atom.jl can then be installed with Julia's package manager and add Atom:

] # activate Pkg manager
(v1.0) pkg> add Atom

There are a variety of useful packages in Atom, such as minimap and minimap-git.

To install the Julia packages related to Caesar.jl–-which are independent of the Atom packages installed above–-please follow instructions below.

Julia Packages

The philosophy around Julia packages are discussed at length in the Julia core documentation, where each Julia package relates to a git repository likely found on To install a Julia package, simply open a julia REPL (equally the julia REPL in Atom/Juno) and type:

] # activate Pkg manager
(v1.0) pkg> add Caesar

These are registered packages maintained by JuliaLang/METADATA.jl. Unregistered latest packages can also be installed with using only the Pkg.develop function:

# Just using Caesar URL as an example --  Caesar is already registered with METADATA
using Pkg

Unless you change the default environment variable JULIA_PKG_DIR, all packages (git repos) are cloned/installed to ~/.julia. You can work with the packages as regular git repositories there.

Install Visualization Utils (e.g. Arena.jl)

Visualizations were removed from Caesar and moved to a new package Arena.jl instead. Please follow instructions on the Visualizations page for a variety of 3D utilities.

Arena.jl can be installed with the following steps:

add Arena

of the latest development version:

(v1.0) pkg> add Arena#master

RoMEPlotting.jl for 2D plots

Previous versions of libraries required the following Linux system packages be installed:

sudo apt-get install libfontconfig1
sudo apt-get install gettext
sudo apt-get install libcairo2
sudo apt-get install libpango1.0-0  # or libpango1.0-1

The RoMEPlotting.jl package must be installed up to latest master branch (development branch) owing to an upstream issue with Pango fonts on Julia 1.0 with Gadfly.jl plotting. Once this issue is resolved, the next RoMEPlotting stable version can be tagged and be available as a standard stable release.

Please install the latest RoMEPlotting using Package manager as follows:

$ julia # latest v1.0.x
julia> ] # to get package manager
(v1.0) pkg> add RoMEPlotting#master

Alternatively, the dev command –- i.e. (v1.0) pkg> dev RoMEPlotting –- will clone the RoMEPlotting.jl git repository to your local .julia/dev/RoMEPlotting folder.

Last updated February 2019

Contributing, Issues, or Comments

Please feel free to open issues with Caesar.jl or even Fork and Pull Request as required. General conversations or comments can be made in the Caesar Gist.