Tidal Models

Tidal Models#

Tidal models store the harmonic constants (amplitude and phase) on a computational grid. A model is loaded once at startup and then passed to evaluate_tide() for interpolation at arbitrary coordinates.

Three grid types are available, each templated on the value precision:

  • Cartesian - regular latitude/longitude grids (e.g. individual FES constituent NetCDF files).

  • LGP1 - unstructured triangular meshes with first-order (P1) elements.

  • LGP2 - unstructured triangular meshes with second-order (P2) elements, the native format of the FES2022 ocean-tide model.

The Complex128 variants use double-precision complex numbers (complex128); Complex64 variants use single-precision (complex64).

Axis#

class pyfes.core.Axis#

A coordinate axis a variable that specifies one of the coordinates of a variable’s values.

end(self: pyfes.core.Axis) → float#

Return the last value of the axis.

find_index(self: pyfes.core.Axis, value: SupportsFloat, bounded: bool = True) → int#

Find the index of the axis point closest to the given value.

Parameters:

  • value – The value to find the index for.

  • bounded – If true, the index will be bounded by the axis domain.

Returns:

The index of the axis point closest to the given value.

find_indices(self: pyfes.core.Axis, values: SupportsFloat) → tuple[int, int] | None#

Find the indices of the axis points closest to the given values.

Parameters:

values – The values to find the indices for.

Returns:

The indices of the axis points closest to the given values.

property is_ascending#

Return true if the axis is ascending.

property is_periodic#

Return true if the axis is periodic

max_value(self: pyfes.core.Axis) → float#

Return the maximum value of the axis.

min_value(self: pyfes.core.Axis) → float#

Return the minimum value of the axis.

property start#

Return the first value of the axis.

property step#

Return the step of the axis.

Cartesian#

class pyfes.core.tidal_model.CartesianComplex128#

A tidal model that uses a Cartesian grid to store the wave models.

lat(self: pyfes.core.tidal_model.CartesianComplex128) → pyfes.core.Axis#

Get the latitude axis.

Returns:

The latitude axis.

lon(self: pyfes.core.tidal_model.CartesianComplex128) → pyfes.core.Axis#

Get the longitude axis.

Returns:

The longitude axis.

resample(self: pyfes.core.tidal_model.CartesianComplex128, origin_lon: pyfes.core.Axis, origin_lat: pyfes.core.Axis, wave: Annotated[numpy.typing.ArrayLike, numpy.complex128, '[m, 1]'], row_major: bool = True, num_threads: SupportsInt = 0) → Annotated[numpy.typing.NDArray[numpy.complex128], '[m, 1]']#

Resample a tidal constituent wave to this model’s grid using bilinear interpolation.

Parameters:

  • origin_lon – The longitude axis of the original grid.

  • origin_lat – The latitude axis of the original grid.

  • wave – The wave to resample.

  • row_major – Whether the input wave is stored in longitude-major order.

  • num_threads – The number of threads to use. If 0, the number of threads is determined by the number of cores.

Returns:

A vector containing the resampled wave on this model’s grid.

class pyfes.core.tidal_model.CartesianComplex64#

A tidal model that uses a Cartesian grid to store the wave models.

lat(self: pyfes.core.tidal_model.CartesianComplex64) → pyfes.core.Axis#

Get the latitude axis.

Returns:

The latitude axis.

lon(self: pyfes.core.tidal_model.CartesianComplex64) → pyfes.core.Axis#

Get the longitude axis.

Returns:

The longitude axis.

resample(self: pyfes.core.tidal_model.CartesianComplex64, origin_lon: pyfes.core.Axis, origin_lat: pyfes.core.Axis, wave: Annotated[numpy.typing.ArrayLike, numpy.complex64, '[m, 1]'], row_major: bool = True, num_threads: SupportsInt = 0) → Annotated[numpy.typing.NDArray[numpy.complex64], '[m, 1]']#

Resample a tidal constituent wave to this model’s grid using bilinear interpolation.

Parameters:

  • origin_lon – The longitude axis of the original grid.

  • origin_lat – The latitude axis of the original grid.

  • wave – The wave to resample.

  • row_major – Whether the input wave is stored in longitude-major order.

  • num_threads – The number of threads to use. If 0, the number of threads is determined by the number of cores.

Returns:

A vector containing the resampled wave on this model’s grid.

LGP1#

class pyfes.core.tidal_model.LGP1Complex128#

Handle the wave models loaded from finite elements using LGP1 discretization.

index(self: pyfes.core.tidal_model.LGP1Complex128) → pyfes.core.mesh.Index#

Get the index of the finite elements.

Returns:

The index of the finite elements.

selected_indices(self: pyfes.core.tidal_model.LGP1Complex128) → Annotated[numpy.typing.NDArray[numpy.int64], '[m, 1]']#

Retrieve the indices for wave model values that intersect the specified bounding box.

Returns:

A vector containing the selected indices. If no bounding box is set, an empty vector is returned.

class pyfes.core.tidal_model.LGP1Complex64#

Handle the wave models loaded from finite elements using LGP1 discretization.

index(self: pyfes.core.tidal_model.LGP1Complex64) → pyfes.core.mesh.Index#

Get the index of the finite elements.

Returns:

The index of the finite elements.

selected_indices(self: pyfes.core.tidal_model.LGP1Complex64) → Annotated[numpy.typing.NDArray[numpy.int64], '[m, 1]']#

Retrieve the indices for wave model values that intersect the specified bounding box.

Returns:

A vector containing the selected indices. If no bounding box is set, an empty vector is returned.

LGP2#

class pyfes.core.tidal_model.LGP2Complex128#

Handle the wave models loaded from finite elements using LGP2 discretization.

index(self: pyfes.core.tidal_model.LGP2Complex128) → pyfes.core.mesh.Index#

Get the index of the finite elements.

Returns:

The index of the finite elements.

selected_indices(self: pyfes.core.tidal_model.LGP2Complex128) → Annotated[numpy.typing.NDArray[numpy.int64], '[m, 1]']#

Retrieve the indices for wave model values that intersect the specified bounding box.

Returns:

A vector containing the selected indices. If no bounding box is set, an empty vector is returned.

class pyfes.core.tidal_model.LGP2Complex64#

Handle the wave models loaded from finite elements using LGP2 discretization.

index(self: pyfes.core.tidal_model.LGP2Complex64) → pyfes.core.mesh.Index#

Get the index of the finite elements.

Returns:

The index of the finite elements.

selected_indices(self: pyfes.core.tidal_model.LGP2Complex64) → Annotated[numpy.typing.NDArray[numpy.int64], '[m, 1]']#

Retrieve the indices for wave model values that intersect the specified bounding box.

Returns:

A vector containing the selected indices. If no bounding box is set, an empty vector is returned.

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