Getting Started With Julia¶

(Back to Overview)

Getting Help¶

If you get stuck, these are good places to look:

  1. The Julia Discourse (https://discourse.julialang.org/) has a lot of examples, and a decent number of HPC-centric examples and solutions.
  2. For faster feedback, try the Julia Slack (https://julialang.org/community/)

Getting involved with the community:

  1. Monthly HPC Call (https://julialang.org/community/working-groups/). We are also working (slowly) on dedicated HPC pages: https://juliaparallel.org/
  2. BoFs at SC, JuliaCon (https://juliacon.org/2023/)

How to get Julia:¶

Fast (but often outdated):

  1. Debian/Ubuntu: apt-get install julia
  2. macOS: brew install --cask julia

Bleeding edge:

  1. Juliaup: https://github.com/JuliaLang/juliaup (Juliaup also provides as version multi-plexer)
  2. Manual install: https://julialang.org/downloads/
  3. Spack: https://spack.io/ (but often requires expert-level knowledge)

Interact with Julia using:¶

Option 1: The REPL: julia¶

repl

Option 2: Your favorite editor/CLI¶

vim hello.jl
julia hello.jl

Option 3: IJulia + Jupyter:¶

# Install IJulia
import Pkg
Pkg.add("IJulia")

# Install the Jupyter kernel
using IJulia
installkernel("Julia")

... then start your favorite Jupyter instance

Option 4: Dedicated IDE¶

  • Juno https://junolab.org/
  • VScode https://code.visualstudio.com/docs/languages/julia

ide

First Steps¶

Let's start with Hello World

In [11]:
println("Hello World")

Hello World

Julia is unicode:

In [2]:
println("Hey 😸")

Hey 😸

But not just unicode strings -- Julia code is unicode:

In [3]:
😸 = 12
Out[3]:
12

In Jupyter you can generate unicode symbols by typing \:<description>: + <tab>. Eg. \:smile_cat: + <tab> to generate 😸

In [4]:
😸^2
Out[4]:
144

Package Management¶

Two ways to manage packages:

  1. You can use the Pkg module from within Julia.
  2. From the Julia REPL you can type ] to enter the Package Manager's CLI

Eg. to add the CSV package using the Pkg module run:

import Pkg
Pkg.add("CSV")
In [5]:
import Pkg
Pkg.add("CSV")

   Resolving package versions...
    Updating `~/.julia/environments/v1.7/Project.toml`
  [336ed68f] + CSV v0.10.2
    Updating `~/.julia/environments/v1.7/Manifest.toml`
  [336ed68f] + CSV v0.10.2
  [944b1d66] + CodecZlib v0.7.0
  [91c51154] + SentinelArrays v1.3.12
  [3bb67fe8] + TranscodingStreams v0.9.6
  [ea10d353] + WeakRefStrings v1.4.2

When you're in the REPL you can type ] to enter the Package Manager's CLI (note that the promt turns blue and has the format (environment name) pkg>). Eg. to add the CSV package using the Package Manager's CLI in the REPL, type: add CSV in the Package manager

repl

(hit ESC to go back to normal mode)

Environments¶

Environments are a good way of managing dependencies

In [1]:
cd(mktempdir())
pwd() # print current directory
Out[1]:
"/tmp/jl_cjAB0j"

This creates an empty temporary folder

In [2]:
readdir()
Out[2]:
String[]

Let's use this directory as a Julia environment

In [3]:
import Pkg
In [4]:
Pkg.activate(".")

  Activating new project at `/tmp/jl_cjAB0j`
In [5]:
Pkg.add("CSV")

    Updating registry at `~/.julia/registries/General.toml`
   Resolving package versions...
   Installed PooledArrays ─ v1.4.1
   Installed Parsers ────── v2.2.4
   Installed CSV ────────── v0.10.4
    Updating `/tmp/jl_cjAB0j/Project.toml`
  [336ed68f] + CSV v0.10.4
    Updating `/tmp/jl_cjAB0j/Manifest.toml`
  [336ed68f] + CSV v0.10.4
  [944b1d66] + CodecZlib v0.7.0
  [34da2185] + Compat v3.42.0
  [9a962f9c] + DataAPI v1.9.0
  [e2d170a0] + DataValueInterfaces v1.0.0
  [48062228] + FilePathsBase v0.9.18
  [842dd82b] + InlineStrings v1.1.2
  [82899510] + IteratorInterfaceExtensions v1.0.0
  [bac558e1] + OrderedCollections v1.4.1
  [69de0a69] + Parsers v2.2.4
  [2dfb63ee] + PooledArrays v1.4.1
  [91c51154] + SentinelArrays v1.3.12
  [3783bdb8] + TableTraits v1.0.1
  [bd369af6] + Tables v1.7.0
  [3bb67fe8] + TranscodingStreams v0.9.6
  [ea10d353] + WeakRefStrings v1.4.2
  [0dad84c5] + ArgTools
  [56f22d72] + Artifacts
  [2a0f44e3] + Base64
  [ade2ca70] + Dates
  [8bb1440f] + DelimitedFiles
  [8ba89e20] + Distributed
  [f43a241f] + Downloads
  [9fa8497b] + Future
  [b77e0a4c] + InteractiveUtils
  [b27032c2] + LibCURL
  [76f85450] + LibGit2
  [8f399da3] + Libdl
  [37e2e46d] + LinearAlgebra
  [56ddb016] + Logging
  [d6f4376e] + Markdown
  [a63ad114] + Mmap
  [ca575930] + NetworkOptions
  [44cfe95a] + Pkg
  [de0858da] + Printf
  [3fa0cd96] + REPL
  [9a3f8284] + Random
  [ea8e919c] + SHA
  [9e88b42a] + Serialization
  [1a1011a3] + SharedArrays
  [6462fe0b] + Sockets
  [2f01184e] + SparseArrays
  [10745b16] + Statistics
  [fa267f1f] + TOML
  [a4e569a6] + Tar
  [8dfed614] + Test
  [cf7118a7] + UUIDs
  [4ec0a83e] + Unicode
  [e66e0078] + CompilerSupportLibraries_jll
  [deac9b47] + LibCURL_jll
  [29816b5a] + LibSSH2_jll
  [c8ffd9c3] + MbedTLS_jll
  [14a3606d] + MozillaCACerts_jll
  [4536629a] + OpenBLAS_jll
  [83775a58] + Zlib_jll
  [8e850b90] + libblastrampoline_jll
  [8e850ede] + nghttp2_jll
  [3f19e933] + p7zip_jll
Precompiling project...
  ✓ PooledArrays
  ✓ Parsers
  ✓ InlineStrings
  ✓ WeakRefStrings
  ✓ CSV
  5 dependencies successfully precompiled in 9 seconds (17 already precompiled)
  1 dependency precompiled but a different version is currently loaded. Restart julia to access the new version

This adds two files to the environment's root directory, which can then reproduce the your environment on another computer:

In [6]:
readdir()
Out[6]:
2-element Vector{String}:
 "Manifest.toml"
 "Project.toml"

Let's see how the environment is defined:

In [9]:
println(read("Project.toml", String))

[deps]
CSV = "336ed68f-0bac-5ca0-87d4-7b16caf5d00b"
In [13]:
println(read("Manifest.toml", String))

# This file is machine-generated - editing it directly is not advised

julia_version = "1.7.2"
manifest_format = "2.0"

[[deps.ArgTools]]
uuid = "0dad84c5-d112-42e6-8d28-ef12dabb789f"

[[deps.Artifacts]]
uuid = "56f22d72-fd6d-98f1-02f0-08ddc0907c33"

[[deps.Base64]]
uuid = "2a0f44e3-6c83-55bd-87e4-b1978d98bd5f"

[[deps.CSV]]
deps = ["CodecZlib", "Dates", "FilePathsBase", "InlineStrings", "Mmap", "Parsers", "PooledArrays", "SentinelArrays", "Tables", "Unicode", "WeakRefStrings"]
git-tree-sha1 = "873fb188a4b9d76549b81465b1f75c82aaf59238"
uuid = "336ed68f-0bac-5ca0-87d4-7b16caf5d00b"
version = "0.10.4"

[[deps.CodecZlib]]
deps = ["TranscodingStreams", "Zlib_jll"]
git-tree-sha1 = "ded953804d019afa9a3f98981d99b33e3db7b6da"
uuid = "944b1d66-785c-5afd-91f1-9de20f533193"
version = "0.7.0"

[[deps.Compat]]
deps = ["Base64", "Dates", "DelimitedFiles", "Distributed", "InteractiveUtils", "LibGit2", "Libdl", "LinearAlgebra", "Markdown", "Mmap", "Pkg", "Printf", "REPL", "Random", "SHA", "Serialization", "SharedArrays", "Sockets", "SparseArrays", "Statistics", "Test", "UUIDs", "Unicode"]
git-tree-sha1 = "96b0bc6c52df76506efc8a441c6cf1adcb1babc4"
uuid = "34da2185-b29b-5c13-b0c7-acf172513d20"
version = "3.42.0"

[[deps.CompilerSupportLibraries_jll]]
deps = ["Artifacts", "Libdl"]
uuid = "e66e0078-7015-5450-92f7-15fbd957f2ae"

[[deps.DataAPI]]
git-tree-sha1 = "cc70b17275652eb47bc9e5f81635981f13cea5c8"
uuid = "9a962f9c-6df0-11e9-0e5d-c546b8b5ee8a"
version = "1.9.0"

[[deps.DataValueInterfaces]]
git-tree-sha1 = "bfc1187b79289637fa0ef6d4436ebdfe6905cbd6"
uuid = "e2d170a0-9d28-54be-80f0-106bbe20a464"
version = "1.0.0"

[[deps.Dates]]
deps = ["Printf"]
uuid = "ade2ca70-3891-5945-98fb-dc099432e06a"

[[deps.DelimitedFiles]]
deps = ["Mmap"]
uuid = "8bb1440f-4735-579b-a4ab-409b98df4dab"

[[deps.Distributed]]
deps = ["Random", "Serialization", "Sockets"]
uuid = "8ba89e20-285c-5b6f-9357-94700520ee1b"

[[deps.Downloads]]
deps = ["ArgTools", "LibCURL", "NetworkOptions"]
uuid = "f43a241f-c20a-4ad4-852c-f6b1247861c6"

[[deps.FilePathsBase]]
deps = ["Compat", "Dates", "Mmap", "Printf", "Test", "UUIDs"]
git-tree-sha1 = "129b104185df66e408edd6625d480b7f9e9823a0"
uuid = "48062228-2e41-5def-b9a4-89aafe57970f"
version = "0.9.18"

[[deps.Future]]
deps = ["Random"]
uuid = "9fa8497b-333b-5362-9e8d-4d0656e87820"

[[deps.InlineStrings]]
deps = ["Parsers"]
git-tree-sha1 = "61feba885fac3a407465726d0c330b3055df897f"
uuid = "842dd82b-1e85-43dc-bf29-5d0ee9dffc48"
version = "1.1.2"

[[deps.InteractiveUtils]]
deps = ["Markdown"]
uuid = "b77e0a4c-d291-57a0-90e8-8db25a27a240"

[[deps.IteratorInterfaceExtensions]]
git-tree-sha1 = "a3f24677c21f5bbe9d2a714f95dcd58337fb2856"
uuid = "82899510-4779-5014-852e-03e436cf321d"
version = "1.0.0"

[[deps.LibCURL]]
deps = ["LibCURL_jll", "MozillaCACerts_jll"]
uuid = "b27032c2-a3e7-50c8-80cd-2d36dbcbfd21"

[[deps.LibCURL_jll]]
deps = ["Artifacts", "LibSSH2_jll", "Libdl", "MbedTLS_jll", "Zlib_jll", "nghttp2_jll"]
uuid = "deac9b47-8bc7-5906-a0fe-35ac56dc84c0"

[[deps.LibGit2]]
deps = ["Base64", "NetworkOptions", "Printf", "SHA"]
uuid = "76f85450-5226-5b5a-8eaa-529ad045b433"

[[deps.LibSSH2_jll]]
deps = ["Artifacts", "Libdl", "MbedTLS_jll"]
uuid = "29816b5a-b9ab-546f-933c-edad1886dfa8"

[[deps.Libdl]]
uuid = "8f399da3-3557-5675-b5ff-fb832c97cbdb"

[[deps.LinearAlgebra]]
deps = ["Libdl", "libblastrampoline_jll"]
uuid = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"

[[deps.Logging]]
uuid = "56ddb016-857b-54e1-b83d-db4d58db5568"

[[deps.Markdown]]
deps = ["Base64"]
uuid = "d6f4376e-aef5-505a-96c1-9c027394607a"

[[deps.MbedTLS_jll]]
deps = ["Artifacts", "Libdl"]
uuid = "c8ffd9c3-330d-5841-b78e-0817d7145fa1"

[[deps.Mmap]]
uuid = "a63ad114-7e13-5084-954f-fe012c677804"

[[deps.MozillaCACerts_jll]]
uuid = "14a3606d-f60d-562e-9121-12d972cd8159"

[[deps.NetworkOptions]]
uuid = "ca575930-c2e3-43a9-ace4-1e988b2c1908"

[[deps.OpenBLAS_jll]]
deps = ["Artifacts", "CompilerSupportLibraries_jll", "Libdl"]
uuid = "4536629a-c528-5b80-bd46-f80d51c5b363"

[[deps.OrderedCollections]]
git-tree-sha1 = "85f8e6578bf1f9ee0d11e7bb1b1456435479d47c"
uuid = "bac558e1-5e72-5ebc-8fee-abe8a469f55d"
version = "1.4.1"

[[deps.Parsers]]
deps = ["Dates"]
git-tree-sha1 = "621f4f3b4977325b9128d5fae7a8b4829a0c2222"
uuid = "69de0a69-1ddd-5017-9359-2bf0b02dc9f0"
version = "2.2.4"

[[deps.Pkg]]
deps = ["Artifacts", "Dates", "Downloads", "LibGit2", "Libdl", "Logging", "Markdown", "Printf", "REPL", "Random", "SHA", "Serialization", "TOML", "Tar", "UUIDs", "p7zip_jll"]
uuid = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"

[[deps.PooledArrays]]
deps = ["DataAPI", "Future"]
git-tree-sha1 = "28ef6c7ce353f0b35d0df0d5930e0d072c1f5b9b"
uuid = "2dfb63ee-cc39-5dd5-95bd-886bf059d720"
version = "1.4.1"

[[deps.Printf]]
deps = ["Unicode"]
uuid = "de0858da-6303-5e67-8744-51eddeeeb8d7"

[[deps.REPL]]
deps = ["InteractiveUtils", "Markdown", "Sockets", "Unicode"]
uuid = "3fa0cd96-eef1-5676-8a61-b3b8758bbffb"

[[deps.Random]]
deps = ["SHA", "Serialization"]
uuid = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"

[[deps.SHA]]
uuid = "ea8e919c-243c-51af-8825-aaa63cd721ce"

[[deps.SentinelArrays]]
deps = ["Dates", "Random"]
git-tree-sha1 = "6a2f7d70512d205ca8c7ee31bfa9f142fe74310c"
uuid = "91c51154-3ec4-41a3-a24f-3f23e20d615c"
version = "1.3.12"

[[deps.Serialization]]
uuid = "9e88b42a-f829-5b0c-bbe9-9e923198166b"

[[deps.SharedArrays]]
deps = ["Distributed", "Mmap", "Random", "Serialization"]
uuid = "1a1011a3-84de-559e-8e89-a11a2f7dc383"

[[deps.Sockets]]
uuid = "6462fe0b-24de-5631-8697-dd941f90decc"

[[deps.SparseArrays]]
deps = ["LinearAlgebra", "Random"]
uuid = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"

[[deps.Statistics]]
deps = ["LinearAlgebra", "SparseArrays"]
uuid = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"

[[deps.TOML]]
deps = ["Dates"]
uuid = "fa267f1f-6049-4f14-aa54-33bafae1ed76"

[[deps.TableTraits]]
deps = ["IteratorInterfaceExtensions"]
git-tree-sha1 = "c06b2f539df1c6efa794486abfb6ed2022561a39"
uuid = "3783bdb8-4a98-5b6b-af9a-565f29a5fe9c"
version = "1.0.1"

[[deps.Tables]]
deps = ["DataAPI", "DataValueInterfaces", "IteratorInterfaceExtensions", "LinearAlgebra", "OrderedCollections", "TableTraits", "Test"]
git-tree-sha1 = "5ce79ce186cc678bbb5c5681ca3379d1ddae11a1"
uuid = "bd369af6-aec1-5ad0-b16a-f7cc5008161c"
version = "1.7.0"

[[deps.Tar]]
deps = ["ArgTools", "SHA"]
uuid = "a4e569a6-e804-4fa4-b0f3-eef7a1d5b13e"

[[deps.Test]]
deps = ["InteractiveUtils", "Logging", "Random", "Serialization"]
uuid = "8dfed614-e22c-5e08-85e1-65c5234f0b40"

[[deps.TranscodingStreams]]
deps = ["Random", "Test"]
git-tree-sha1 = "216b95ea110b5972db65aa90f88d8d89dcb8851c"
uuid = "3bb67fe8-82b1-5028-8e26-92a6c54297fa"
version = "0.9.6"

[[deps.UUIDs]]
deps = ["Random", "SHA"]
uuid = "cf7118a7-6976-5b1a-9a39-7adc72f591a4"

[[deps.Unicode]]
uuid = "4ec0a83e-493e-50e2-b9ac-8f72acf5a8f5"

[[deps.WeakRefStrings]]
deps = ["DataAPI", "InlineStrings", "Parsers"]
git-tree-sha1 = "b1be2855ed9ed8eac54e5caff2afcdb442d52c23"
uuid = "ea10d353-3f73-51f8-a26c-33c1cb351aa5"
version = "1.4.2"

[[deps.Zlib_jll]]
deps = ["Libdl"]
uuid = "83775a58-1f1d-513f-b197-d71354ab007a"

[[deps.libblastrampoline_jll]]
deps = ["Artifacts", "Libdl", "OpenBLAS_jll"]
uuid = "8e850b90-86db-534c-a0d3-1478176c7d93"

[[deps.nghttp2_jll]]
deps = ["Artifacts", "Libdl"]
uuid = "8e850ede-7688-5339-a07c-302acd2aaf8d"

[[deps.p7zip_jll]]
deps = ["Artifacts", "Libdl"]
uuid = "3f19e933-33d8-53b3-aaab-bd5110c3b7a0"