GitHub

Installation & Getting Started

Installation

using Pkg
Pkg.add(url="https://github.com/subhk/QGYBJplus.jl")

Or develop locally:

git clone https://github.com/subhk/QGYBJplus.jl
cd QGYBJ+.jl
julia --project=. -e 'using Pkg; Pkg.instantiate(); Pkg.precompile()'

MPI Support

MPI parallel packages (MPI.jl, PencilArrays.jl, PencilFFTs.jl) are included as dependencies and installed automatically.

To run MPI simulations, you need a system MPI library:

  • macOS: brew install open-mpi
  • Ubuntu: apt install libopenmpi-dev

Quick Example

using QGYBJplus

config = create_simple_config(
    Lx=500e3, Ly=500e3, Lz=4000.0,  # Domain (REQUIRED)
    nx=64, ny=64, nz=32,
    dt=0.001, total_time=1.0
)

result = run_simple_simulation(config)
println("KE: ", flow_kinetic_energy(result.state.u, result.state.v))

Core Types

QGParams

params = default_params(
    Lx=500e3, Ly=500e3, Lz=4000.0,  # REQUIRED
    nx=64, ny=64, nz=32,
    f₀=1.0, N²=1.0,
    ybj_plus=true
)

Unicode: type f\_0<tab> → f₀, \nu<tab> → ν

Grid & State

grid = init_grid(params)     # Coordinates, wavenumbers
state = init_state(grid)     # Fields: q, B, psi, A, u, v
plans = plan_transforms!(grid)  # FFT plans

Code Structure

src/
├── parameters.jl      # QGParams
├── grid.jl            # Grid struct
├── elliptic.jl        # q→ψ, B→A inversions
├── timestep.jl        # Leapfrog
├── timestep_imex.jl   # IMEX-CN (faster)
├── simulation.jl      # High-level API
└── parallel_mpi.jl    # MPI support

What's Next?