def test_wgs84_invariance(self):
lats = [-10, 0, 10]
lons = [-170, 0, 100]
wgs84_epsg = WGS84_LATLON_EPSG
xs, ys = utils.reproject_latlons(lats, lons, epsg=wgs84_epsg)
assert lats == ys
assert lons == xs
def test_only_one_projection_format_can_be_provided(self):
with pytest.raises(ValueError):
lats = [-10, 0, 10]
lons = [-170, 0, 100]
xs, ys = utils.reproject_latlons(
lats, lons, epsg=WGS84_LATLON_EPSG, wkt=WGS84_LATLON_WKT
)
def test_utm_conversion(self):
lats = [10.5]
lons = [120.8]
epsg = 32651
xs, ys = utils.reproject_latlons(lats, lons, epsg=epsg)
x = 259212
y = 1161538
assert np.allclose(x, xs)
assert np.allclose(y, ys)
def location_paths(self, lats, lons):
"""File corresponding to each location.
Args:
lats, lons: Lists of locations.
Returns:
List of filenames, same length as locations.
"""
lats = np.asarray(lats)
lons = np.asarray(lons)
# Convert to filename projection.
xs, ys = utils.reproject_latlons(lats, lons, epsg=self.filename_epsg)
# Find corresponding tile.
filenames = self._location_to_tile_corner(xs, ys,
self.filename_tile_size)
paths = [self._tile_lookup.get(f) for f in filenames]
return paths
def location_paths(self, lats, lons):
"""File corresponding to each location.
Args:
lats, lons: Lists of locations.
Returns:
List of filenames, same length as locations.
"""
lats = np.asarray(lats)
lons = np.asarray(lons)
# Convert to filename projection.
xs, ys, = utils.reproject_latlons(lats, lons, epsg=self.filename_epsg)
# Use to look up.
filenames = self.__class__._location_to_tile_name(
xs, ys, self.filename_tile_size, self.ns_fixed_width,
self.ew_fixed_width)
paths = [self._tile_lookup.get(f) for f in filenames]
return paths
def _get_elevation_from_path(lats, lons, path, interpolation):
"""Read values at locations in a raster.
Args:
lats, lons: Arrays of latitudes/longitudes.
path: GDAL supported raster location.
interpolation: method name string.
Returns:
z_all: List of elevations, same length as lats/lons.
"""
z_all = []
interpolation = INTERPOLATION_METHODS.get(interpolation)
lons = np.asarray(lons)
lats = np.asarray(lats)
try:
with rasterio.open(path) as f:
if f.crs is None:
msg = "Dataset has no coordinate reference system."
msg += f" Check the file '{path}' is a geo raster."
msg += " Otherwise you'll have to add the crs manually with a tool like gdaltranslate."
raise InputError(msg)
try:
if f.crs.is_epsg_code:
xs, ys = utils.reproject_latlons(lats,
lons,
epsg=f.crs.to_epsg())
else:
xs, ys = utils.reproject_latlons(lats,
lons,
wkt=f.crs.to_wkt())
except ValueError:
raise InputError(
"Unable to transform latlons to dataset projection.")
# Check bounds.
oob_indices = _validate_points_lie_within_raster(
xs, ys, lats, lons, f.bounds, f.res)
rows, cols = tuple(f.index(xs, ys, op=_noop))
# Offset by 0.5 to convert from center coords (provided by
# f.index) to ul coords (expected by f.read).
rows = np.array(rows) - 0.5
cols = np.array(cols) - 0.5
# Because of floating point precision, indices may slightly exceed
# array bounds. Because we've checked the locations are within the
# file bounds, it's safe to clip to the array shape.
rows = rows.clip(0, f.height - 1)
cols = cols.clip(0, f.width - 1)
# Read the locations, using a 1x1 window. The `masked` kwarg makes
# rasterio replace NODATA values with np.nan. The `boundless` kwarg
# forces the windowed elevation to be a 1x1 array, even when it all
# values are NODATA.
for i, (row, col) in enumerate(zip(rows, cols)):
if i in oob_indices:
z_all.append(None)
continue
window = rasterio.windows.Window(col, row, 1, 1)
z_array = f.read(
indexes=1,
window=window,
resampling=interpolation,
out_dtype=float,
boundless=True,
masked=True,
)
z = np.ma.filled(z_array, np.nan)[0][0]
z_all.append(z)
# Depending on the file format, when rasterio finds an invalid projection
# of file, it might load it with a None crs, or it might throw an error.
except rasterio.RasterioIOError as e:
if "not recognized as a supported file format" in str(e):
msg = f"Dataset file '{path}' not recognised as a geo raster."
msg += " Check that the file has projection information with gdalsrsinfo,"
msg += " and that the file is not corrupt."
raise InputError(msg)
raise e
return z_all
def test_no_projection_provided(self):
with pytest.raises(ValueError):
lats = [10.5]
lons = [120.8]
xs, ys = utils.reproject_latlons(lats, lons)
def test_bad_epsg(self):
with pytest.raises(ValueError):
lats = [10.5]
lons = [120.8]
epsg = 0
xs, ys = utils.reproject_latlons(lats, lons, epsg=epsg)
def test_cache_gets_populated(self):
lats = [10.5]
lons = [120.8]
assert NAD83_WKT not in utils._TRANSFORMER_CACHE
utils.reproject_latlons(lats, lons, wkt=NAD83_WKT)
assert NAD83_WKT in utils._TRANSFORMER_CACHE
