"""DEM class and functions."""
from __future__ import annotations
import pathlib
import warnings
from typing import Any, Literal
import rasterio as rio
from affine import Affine
from geoutils import SatelliteImage
from geoutils.raster import RasterType
from pyproj import CRS
from pyproj.crs import CompoundCRS, VerticalCRS
from xdem._typing import MArrayf, NDArrayf
from xdem.vcrs import (
_build_ccrs_from_crs_and_vcrs,
_grid_from_user_input,
_parse_vcrs_name_from_product,
_transform_zz,
_vcrs_from_crs,
_vcrs_from_user_input,
)
dem_attrs = ["_vcrs", "_vcrs_name", "_vcrs_grid"]
[docs]class DEM(SatelliteImage): # type: ignore
"""
The digital elevation model.
The DEM has a single main attribute in addition to that inherited from :class:`geoutils.Raster`:
vcrs: :class:`pyproj.VerticalCRS`
Vertical coordinate reference system of the DEM.
Other derivative attributes are:
vcrs_name: :class:`str`
Name of vertical CRS of the DEM.
vcrs_grid: :class:`str`
Grid path to the vertical CRS of the DEM.
ccrs: :class:`pyproj.CompoundCRS`
Compound vertical and horizontal CRS of the DEM.
The attributes inherited from :class:`geoutils.Raster` are:
data: :class:`np.ndarray`
Data array of the DEM, with dimensions corresponding to (count, height, width).
transform: :class:`affine.Affine`
Geotransform of the DEM.
crs: :class:`pyproj.crs.CRS`
Coordinate reference system of the DEM.
nodata: :class:`int` or :class:`float`
Nodata value of the DEM.
All other attributes are derivatives of those attributes, or read from the file on disk.
See the API for more details.
"""
[docs] def __init__(
self,
filename_or_dataset: str | RasterType | rio.io.DatasetReader | rio.io.MemoryFile,
vcrs: Literal["Ellipsoid"]
| Literal["EGM08"]
| Literal["EGM96"]
| VerticalCRS
| str
| pathlib.Path
| int
| None = None,
silent: bool = True,
**kwargs: Any,
) -> None:
"""
Instantiate a digital elevation model.
The vertical reference of the DEM can be defined by passing the `vcrs` argument.
Otherwise, a vertical reference is tentatively parsed from the DEM product name.
Inherits all attributes from the :class:`geoutils.Raster` and :class:`geoutils.SatelliteImage` classes.
:param filename_or_dataset: The filename of the dataset.
:param vcrs: Vertical coordinate reference system either as a name ("WGS84", "EGM08", "EGM96"),
an EPSG code or pyproj.crs.VerticalCRS, or a path to a PROJ grid file (https://github.com/OSGeo/PROJ-data).
:param silent: Whether to display vertical reference parsing.
"""
self.data: NDArrayf
self._vcrs: VerticalCRS | Literal["Ellipsoid"] | None = None
self._vcrs_name: str | None = None
self._vcrs_grid: str | None = None
# If DEM is passed, simply point back to DEM
if isinstance(filename_or_dataset, DEM):
for key in filename_or_dataset.__dict__:
setattr(self, key, filename_or_dataset.__dict__[key])
return
# Else rely on parent SatelliteImage class options (including raised errors)
else:
with warnings.catch_warnings():
warnings.filterwarnings("ignore", message="Parse metadata from file not implemented")
super().__init__(filename_or_dataset, silent=silent, **kwargs)
# Ensure DEM has only one band: self.indexes can be None when data is not loaded through the Raster class
if self.indexes is not None and len(self.indexes) > 1:
raise ValueError("DEM rasters should be composed of one band only")
# If the CRS in the raster metadata has a 3rd dimension, could set it as a vertical reference
vcrs_from_crs = _vcrs_from_crs(CRS(self.crs))
if vcrs_from_crs is not None:
# If something was also provided by the user, user takes precedence
# (we leave vcrs as it was for input)
if vcrs is not None:
# Raise a warning if the two are not the same
vcrs_user = _vcrs_from_user_input(vcrs)
if not vcrs_from_crs == vcrs_user:
warnings.warn(
"The CRS in the raster metadata already has a vertical component, "
"the user-input '{}' will override it.".format(vcrs)
)
# Otherwise, use the one from the raster 3D CRS
else:
vcrs = vcrs_from_crs
# If no vertical CRS was provided by the user or defined in the CRS
if vcrs is None:
vcrs = _parse_vcrs_name_from_product(self.product)
# If a vertical reference was parsed or provided by user
if vcrs is not None:
self.set_vcrs(vcrs)
def copy(self, new_array: NDArrayf | None = None) -> DEM:
"""
Copy the DEM, possibly updating the data array.
:param new_array: New data array.
:return: Copied DEM.
"""
new_dem = super().copy(new_array=new_array) # type: ignore
# The rest of attributes are immutable, including pyproj.CRS
for attrs in dem_attrs:
setattr(new_dem, attrs, getattr(self, attrs))
return new_dem # type: ignore
[docs] @classmethod
def from_array(
cls: type[DEM],
data: NDArrayf | MArrayf,
transform: tuple[float, ...] | Affine,
crs: CRS | int | None,
nodata: int | float | None = None,
vcrs: Literal["Ellipsoid"]
| Literal["EGM08"]
| Literal["EGM96"]
| str
| pathlib.Path
| VerticalCRS
| int
| None = None,
) -> DEM:
"""Create a DEM from a numpy array and the georeferencing information.
:param data: Input array.
:param transform: Affine 2D transform. Either a tuple(x_res, 0.0, top_left_x,
0.0, y_res, top_left_y) or an affine.Affine object.
:param crs: Coordinate reference system. Either a rasterio CRS,
or an EPSG integer.
:param nodata: Nodata value.
:param vcrs: Vertical coordinate reference system.
:returns: DEM created from the provided array and georeferencing.
"""
# We first apply the from_array of the parent class
rast = SatelliteImage.from_array(data=data, transform=transform, crs=crs, nodata=nodata)
# Then add the vcrs to the class call (that builds on top of the parent class)
return cls(filename_or_dataset=rast, vcrs=vcrs)
@property
def vcrs(self) -> VerticalCRS | Literal["Ellipsoid"] | None:
"""Vertical coordinate reference system of the DEM."""
return self._vcrs
@property
def vcrs_grid(self) -> str | None:
"""Grid path of vertical coordinate reference system of the DEM."""
return self._vcrs_grid
@property
def vcrs_name(self) -> str | None:
"""Name of vertical coordinate reference system of the DEM."""
if self.vcrs is not None:
# If it is the ellipsoid
if isinstance(self.vcrs, str):
# Need to call CRS() here to make it work with rasterio.CRS...
vcrs_name = f"Ellipsoid (No vertical CRS). Datum: {CRS(self.crs).ellipsoid.name}."
# Otherwise, return the vertical reference name
else:
vcrs_name = self.vcrs.name
else:
vcrs_name = None
return vcrs_name
[docs] def set_vcrs(
self,
new_vcrs: Literal["Ellipsoid"] | Literal["EGM08"] | Literal["EGM96"] | str | pathlib.Path | VerticalCRS | int,
) -> None:
"""
Set the vertical coordinate reference system of the DEM.
:param new_vcrs: Vertical coordinate reference system either as a name ("Ellipsoid", "EGM08", "EGM96"),
an EPSG code or pyproj.crs.VerticalCRS, or a path to a PROJ grid file (https://github.com/OSGeo/PROJ-data).
"""
# Get vertical CRS and set it and the grid
self._vcrs = _vcrs_from_user_input(vcrs_input=new_vcrs)
self._vcrs_grid = _grid_from_user_input(vcrs_input=new_vcrs)
@property
def ccrs(self) -> CompoundCRS | CRS | None:
"""Compound horizontal and vertical coordinate reference system of the DEM."""
if self.vcrs is not None:
ccrs = _build_ccrs_from_crs_and_vcrs(crs=self.crs, vcrs=self.vcrs)
return ccrs
else:
return None
[docs] def to_vcrs(
self,
dst_vcrs: Literal["Ellipsoid", "EGM08", "EGM96"] | str | pathlib.Path | VerticalCRS | int,
src_vcrs: Literal["Ellipsoid", "EGM08", "EGM96"] | str | pathlib.Path | VerticalCRS | int | None = None,
) -> None:
"""
Convert the DEM to another vertical coordinate reference system.
:param dst_vcrs: Destination vertical CRS. Either as a name ("WGS84", "EGM08", "EGM96"),
an EPSG code or pyproj.crs.VerticalCRS, or a path to a PROJ grid file (https://github.com/OSGeo/PROJ-data)
:param src_vcrs: Force a source vertical CRS (uses metadata by default). Same formats as for `dst_vcrs`.
:return:
"""
if self.vcrs is None and src_vcrs is None:
raise ValueError(
"The current DEM has no vertical reference, define one with .set_vref() "
"or by passing `src_vcrs` to perform a conversion."
)
# Initial Compound CRS (only exists if vertical CRS is not None, as checked above)
if src_vcrs is not None:
# Warn if a vertical CRS already existed for that DEM
if self.vcrs is not None:
warnings.warn(
category=UserWarning,
message="Overriding the vertical CRS of the DEM with the one provided in `src_vcrs`.",
)
src_ccrs = _build_ccrs_from_crs_and_vcrs(self.crs, vcrs=src_vcrs)
else:
src_ccrs = self.ccrs
# New destination Compound CRS
dst_ccrs = _build_ccrs_from_crs_and_vcrs(self.crs, vcrs=_vcrs_from_user_input(vcrs_input=dst_vcrs))
# If both compound CCRS are equal, do not run any transform
if src_ccrs.equals(dst_ccrs):
warnings.warn(
message="Source and destination vertical CRS are the same, skipping vertical transformation.",
category=UserWarning,
)
return None
# Transform elevation with new vertical CRS
zz = self.data
xx, yy = self.coords(offset="center")
zz_trans = _transform_zz(crs_from=src_ccrs, crs_to=dst_ccrs, xx=xx, yy=yy, zz=zz)
# Update DEM
self._data = zz_trans.astype(self.dtypes[0]) # type: ignore
# Update vcrs (which will update ccrs if called)
self.set_vcrs(new_vcrs=dst_vcrs)
