Julia

• Author: Fu Yin

• Update: Dec 17, 2022

• Reading: 30 min

---

Installation

• (not recommend) Download dmg package from official website with MacBook，click install, and then add the env variable in ~/.zshrc as following:

  # >>> Julia >>>
  export PATH="/Applications/Julia-1.6.app/Contents/Resources/julia/bin/:$PATH"
  # <<< Julia <<<
  

• (recommend) Using jill.py to download julia and manage multiple versions. Use pip install jill firstly, then:

  # install julia with version 1.8
  jill install 1.8 		
  
  # check all versions you have installed
  jill list  			
  
  # set the default version to 1.6
  jill switch 1.6 		
  

Do you know how to uninstall julia?

• If you install the pkg package into Applications, you can delete ~/.Julia folder and the env variable.

• If you use jill to install multiple versions of julia, just want to delete one version. Remove the symlinks in symlink_dir, e.g., ~/.local/bin/julia-1.6.

Wether to delete ~/.julia folder?

• All Julia packages are installed in ~/.julia/packages/ in version-agnostic manner; whether a specific package version is used depends on the environment you’re using. For instance, ~/.julia/environments/v1.6/Manifest.toml specifies all julia package versions. There isn’t ~/.julia/packages/v1.6 stuff. Thus you don’t need to worry about this at all.

• If you want to cleanup some spaces, you can try pkg> gc in Pkg mode. Or if you insist, another way is to manually remove ~/.julia/packages folder and then pkg> instantiate to rebuild it.

reference：https://github.com/johnnychen94/jill.py/issues/96

Startup.jl

The startup.jl is initialization file of julia REPL. Open the ~/.julia/config/startup.jl file, and then add the following info for example:

if VERSION >= v"1.4"
    try
        using OhMyREPL
    catch e
        @warn "error while using OhMyREPL" e
    end
end

3 Modes in REPL

Open the julia firstly, and then

• type ] will into the pkg managment mode.

• type ; will into the shell mode.

• type ? will into help mode.

• type delete will return the last mode.

Run Scripts

• Open the terminal, and then run julia name.jl.

• In Julia REPL, type include("name.jl")

VScode IDE for Julia

• Install julia extensions, and set the interpreter that you want to use.

• The shift + return will run the code in REPL, and control + return will open the REPL in VScode.

Package

$ julia

# check the default info of julia
versioninfo()

# using pkg
using XXX 			


# install the local pkg
$ ]
dev folder_name

# check all pkgs installed
$ ]
status or st

# install pkg with the specifical version
$ ]
add XXX@1.6.2 		

# remove pkg
$ ]
rm XXX 			

# update pkg
$ ]
update XXX  

# test pkg
$ ]
test XXX 			

geophysics package:

Name	Purpose	Way
Revise	…
PkgServerClient	Set mirror servers for China region
Plots
OhMyREPL
BenchmarkTools
``

scientific computation-related package:

Name	Purpose	Way
SeisIO	Seismic data processing	pkg
SeisNoise	Ambient noise cc	Pkg
FwiFlow	CO2 simulation
``