Class SimpleCoordinateTransform

xarray/tests/test_coordinate_transform.py:13–43

Simple uniform scale transform in a 2D space (x/y coordinates).

class SimpleCoordinateTransform(CoordinateTransform):
    """Simple uniform scale transform in a 2D space (x/y coordinates)."""

    def __init__(self, shape: tuple[int, int], scale: float, dtype: Any = None):
        super().__init__(("x", "y"), {"x": shape[1], "y": shape[0]}, dtype=dtype)

        self.scale = scale

        # array dimensions in reverse order (y = rows, x = cols)
        self.xy_dims = tuple(self.dims)
        self.dims = (self.dims[1], self.dims[0])

    def forward(self, dim_positions: dict[str, Any]) -> dict[Hashable, Any]:
        assert set(dim_positions) == set(self.dims)
        return {
            name: dim_positions[dim] * self.scale
            for name, dim in zip(self.coord_names, self.xy_dims, strict=False)
        }

    def reverse(self, coord_labels: dict[Hashable, Any]) -> dict[str, Any]:
        return {dim: coord_labels[dim] / self.scale for dim in self.xy_dims}

    def equals(
        self, other: CoordinateTransform, exclude: frozenset[Hashable] | None = None
    ) -> bool:
        if not isinstance(other, SimpleCoordinateTransform):
            return False
        return self.scale == other.scale

    def __repr__(self) -> str:
        return f"Scale({self.scale})"


def test_abstract_coordinate_transform() -> None: