GeometricIntegrators.jl

Geometric integrators (Euler, symplectic-Euler, velocity-Verlet, position-Verlet and leapfrog) in Julia

You can use this module of GeometricIntegrators with Julia-1.6 and Julia-1.7.

Its homepage is https://github.com/t-nissie/GeometricIntegrators.jl .

GeometricIntegrators.jl is under continuous integration at Travis CI:

Coverrage report:

Setup

There are no dependencies, just install with

julia> using Pkg; Pkg.add(PackageSpec(url="https://github.com/t-nissie/GeometricIntegrators.jl", rev="master"));

You may also need to install Winston package.

julia> using Pkg; Pkg.add("Winston")

Example

In-line example

An example is in the end of src/GeometricIntegrators.jl. If you are using Julia-1.4 and Winston (https://github.com/nolta/Winston.jl),

$ cd src/
$ julia GeometricIntegrators.jl

gives you an example plot of GeometricIntegrators.eps.

Harmonic oscillator

test/harmonic_oscillator.jl is an example of one-dimensional harmonic oscillator. Execute harmonic_oscillator.jl, then you will get harmonic_oscillator_??.eps.

$ cd test/
$ julia --project harmonic_oscillator.jl

Two body problem

test/twobody.jl is an example of two body problem. Execute twobody.jl, then you will get twobody_??.eps as shown in Fig. 1.

 $ cd test/
 $ julia --project twobody.jl

FIG. 1. Trajectories of two bodies with masses M=2 and m=1.

Test

Test as a user

Clone, test, then remove this package:

julia> using Pkg; Pkg.add(PackageSpec(url="https://github.com/t-nissie/GeometricIntegrators.jl", rev="master")); Pkg.test("GeometricIntegrators"); Pkg.rm("GeometricIntegrators")

Test as a developer

From Pkg REPL-mode:

$ julia --project
julia> ]
(GeometricIntegrators) pkg> test

From command line:

$ julia --project -e 'using Pkg; Pkg.test()'

Usage

Prepare arrays of functions qdot and pdot.