Airy Waves

AiryState

Holds the discrete frequency-direction components of the sea state. This is the "data" layer.

generate_interpolable_sea(state::AiryState, x, y, z, t; vars=[:η, :ϕ, :u, :v, :w], interp=:linear)

Computes the sea fields on the provided regular grids and returns a NamedTuple of interpolation functions for each requested variable. Each interpolant is a callable taking (x, y, z, t) and returning the interpolated value.

Arguments

• state: an AiryState produced by AiryState(...) or constructed manually.
• x, y, z, t: regular 1D coordinate vectors used to compute the fields.
• vars: which fields to compute, default [:η, :ϕ, :u, :v, :w].
• interp: interpolation kernel, :linear (default), :cubic, or :nearest.

Examples

using WaveSpec

# (1) Construct an AiryState (example uses a regular monochromatic wave)
spec = WaveSpec.ContinuousSpectrums.RegularWave(1.0, 5.0)                      # H=1 m, T=5 s
ds = WaveSpec.SpectralSpreading.DiscreteSpectralSpreading(spec)                # discrete spectrum
spread = WaveSpec.AngularSpreading.DiscreteAngularSpreading(0.0)              # unidirectional
as = WaveSpec.AiryWaves.AiryState(ds, spread, 50.0)                          # water depth 50 m

# (2) Choose evaluation grid
x = range(0.0, stop=10.0, length=11)
y = [0.0]
z = [0.0]
t = 0.0:0.1:10.0

# (3) Get interpolants (linear by default)
itps = WaveSpec.AiryWaves.generate_interpolable_sea(as, collect(x), collect(y), collect(z), collect(t); vars=[:η])

# (4) Evaluate η at an arbitrary point (not necessarily on the grid)
η_val = itps[:η](1.23, 0.0, 0.0, 2.57)

generate_sea(state::AiryState, x, y, z, t)

The main evaluation engine. Computes η, ϕ, u, v, w for a 4D grids (x, y, z, t). Everything is computed on-the-fly to minimize memory footprint. The trick to compute the series is to expand all items to 6 dimensional tensors with dimensional structure T = (x, y, z, t, ω, θ) and then contract the last 2 dimensions (ω and θ) to sum the series components.