Skip to content

Setup Julia

Install Julia

Install Julia with the juliaup installer.

curl -fsSL https://install.julialang.org | sh -s -- -y

winget install julia -s msstore

Alternatively, download and install Julia official binaries.

Post-install configurations

Auto-activate local projects

Set environment variable JULIA_PROJECT=@. to let Julia automatically load the closest upstream Project.toml and activate the environment.

~/.profile
export JULIA_PROJECT=@.

Info

IJulia.jl, the Julia kernel for Jupyter notebooks, sets JULIA_PROJECT=@. by default. Thus, Jupyter notebooks load their local Julia environments automatically.

Warning

Loading local environments unconditionally is unsafe for untrusted sources, as shown in Nefarious.jl.
That is why Julia does not run julia --project=@. by default.

Fully utilize CPU threads

Set environment variable JULIA_NUM_THREADS=auto to let Julia use all CPU threads.

~/.profile
export JULIA_NUM_THREADS=auto

Run Python packages

To run Python packages in Julia (like matplotlib for PythonPlot.jl and jupyter for IJulia.jl)

  1. Install micromamba, the minimal Python package manager.
  2. Create a conda environment, for example, micromamba create -n juliapy matplotlib.
  3. Set up the following environment variables
~/.profile
export CONDA_JL_HOME="${HOME}/micromamba/envs/juliapy"
export JULIA_CONDAPKG_ENV=$CONDA_JL_HOME
export JULIA_CONDAPKG_BACKEND="Current"

Load packages at REPL startup

Add the following lines to ~/.julia/config/startup.jl after Revise.jl and OhMyREPL.jl are installed

~/.julia/config/startup.jl
using Pkg: Pkg
if isinteractive()
    using OhMyREPL
    @info "Using OhMyREPL"
    using Revise
    @info "Using Revise"
    catch e
        @warn "Error initializing" exception=(e, catch_backtrace())
        @info "Try to install OhMyREPL and Revise"
        Pkg.add(["OhMyREPL", "Revise"])
    end
end

For IJulia (Jupyter notebooks) to use Revise, add the following lines to ~.julia/config/startup_ijulia.jl

~/.julia/config/startup_ijulia.jl
try
    @eval using Revise
catch e
    @warn "Error initializing Revise" exception=(e, catch_backtrace())
end

Or run the following commands (heredoc in Linux) to create these two files at once

mkdir -p ~/.julia/config/ && cat >  ~/.julia/config/startup.jl << END
using Pkg: Pkg
if isinteractive()
    using OhMyREPL
    @info "Using OhMyREPL"
    using Revise
    @info "Using Revise"
    catch e
        @warn "Error initializing" exception=(e, catch_backtrace())
        @info "Try to install OhMyREPL and Revise"
        Pkg.add(["OhMyREPL", "Revise"])
    end
end
END

mkdir -p ~/.julia/config/ && cat >  ~/.julia/config/startup_ijulia.jl << END
try
    @eval using Revise
catch e
    @warn "Error initializing Revise" exception=(e, catch_backtrace())
end
END