Advanced usage

For advanced users it is suggested to install git, bash and vscode or vscodium in addition to Julia. vscode and vscodium both have a very good plugin for Julia support, see https://www.julia-vscode.org. For Windows users, you can find some installation instructions here: Julia on Windows .

Whe using vscode, I do NOT use the Julia terminal provided by vscode, but the normal bash terminal which is also available in vscode by selecting Terminal->New Terminal From this terminal I start Julia with julia --project or a different command as explained below. This makes it easier to understand what happens and is also faster when you need to restart.

For Ubuntu Linux I use the following ppa to install vscode and to keep it up-to-date: https://www.ubuntuupdates.org/ppa/vscode .

Creating a custom system image

To reduce the startup time it is suggested to use a custom system image that contains all the packages you use on a daily base in compiled form.

For end users, follow the instructions on KiteSimulators . Package developers can follow these instructions:

1. Go to the website https://github.com/ufechner7/KiteModels.jl and click on the Fork button at the top right.
2. clone the new repository which is owned by you with a command similar to this one: git clone https://github.com/aenarete/KiteModels.jl Your own git user name must appear in the URL, otherwise you will not be able to push your changes.

From a bash prompt you can create one using the following commands, assuming you created a folder "test" as explained on the Quickstart page:

cd KiteModels.jl
julia --project

using Pkg
Pkg.instantiate()
Pkg.precompile()

If you enter shell mode by pressing ";" and type the command treeyou should see the following files:

shell> tree
.
├── bin
│   ├── create_sys_image
│   ├── create_sys_image2
│   ├── run_julia
│   └── run_julia2
├── data
│   ├── settings.yaml
│   └── system.yaml
├── docs
│   ├── data
│   ├── make.jl
│   ├── Project.toml
│   └── src
│       ├── 4-point-kite.png
│       ├── advanced.md
│       ├── assets
│       │   └── logo.png
│       ├── examples_4p.md
│       ├── examples.md
│       ├── functions.md
│       ├── index.md
│       ├── initial_state_4p.png
│       ├── initial_state.png
│       ├── kite.png
│       ├── kite_power_tools.png
│       ├── kps4_hires.png
│       ├── kps4.png
│       ├── parameters.md
│       ├── quickstart.md
│       └── types.md
├── examples
│   ├── compare_kps3_kps4.jl
│   ├── plot2d.jl
│   ├── reel_out.jl
│   ├── simulate_ii.jl
│   └── simulate.jl
├── LICENSE
├── Manifest-1.7.toml.default
├── Manifest-1.8.toml.default
├── Manifest.toml
├── Project.toml
├── README.md
├── src
│   ├── init.jl
│   ├── KiteModels.jl
│   ├── KPS3.jl
│   └── KPS4.jl
└── test
    ├── bench3.jl
    ├── bench4.jl
    ├── create_sys_image2.jl
    ├── create_sys_image.jl
    ├── plot2d.jl
    ├── plot_initial_state.jl
    ├── plot_kps3.jl
    ├── plot_kps4.jl
    ├── runtests.jl
    ├── test_for_precompile.jl
    ├── test_kps3.jl
    ├── test_kps4.jl
    ├── test_staticarrays.jl
    ├── test_steady_state.jl
    ├── test_sundials.jl
    └── update_packages.jl

9 directories, 55 files

Now leave Julia with the command exit() and then type:

cd bin
./create_sys_image --update

This will take about 6 min on a i7-10510U CPU. You should now see a new file in the bin folder:

~/repos/test/bin$ ls -lah kps*
-rwxrwxr-x 1 ufechner ufechner 344M apr 18 18:23 kps-image-1.7.so

You can launch julia such that it makes use of this system image with the commands:

cd ..
./bin/run_julia

If you now run any of the examples the time-to-first-plot (TTFP) should be less than 25s:

julia> @time include("examples/simulate.jl")
lift, drag  [N]: 597.61, 129.33
Average number of callbacks per time step: 481.845
 23.901076 seconds (63.42 M allocations: 12.686 GiB, 5.67% gc time, 70.62% compilation time)

julia> 

A second run of this command needs about 5.5 s which means the startup time (load and compilation time of the package and the libraries) has been reduced to about 18.4s.

Without a system image the first time execution of the script "simulate.jl" on the same computer is about 71 seconds while the time for the second execution is the same (5.5s). So now about 47s of time are saved after each restart.

Outlook

The next steps:

• reduce memory allocations
• add export as FMI for co-simulation component