def _location_to_tile_corner(cls, xs, ys, tile_size=1):
"""Convert locations to SRTM tile corner.
For example, (-120.5, 40.1) becomes (-120, 40). The lower left corner
of the tile is used. Decimals are used to preserve precsion for
fractional tile sizes.
Args:
xs, ys: Lists of x and y coordinates.
tile_size: Which value to round the tiles to. Int or Decimal.
Returns:
tile_names: List of (Decimal, Decimal) northing, easting tuples.
"""
northings = [utils.decimal_base_floor(y, tile_size) for y in ys]
eastings = [utils.decimal_base_floor(y, tile_size) for y in xs]
return list(zip(northings, eastings))
def test_fractional_base(self):
assert utils.decimal_base_floor(5.6, Decimal("0.25")) == Decimal("5.5")
def test_other_base(self):
assert utils.decimal_base_floor(290.9, 50) == 250
def test_negative_value(self):
assert utils.decimal_base_floor(-5.1, 5) == -10
def test_base_1_default(self):
values = [-1, 0, 1, -0.6, -0.4, 0.4, 0.6, 99.91]
for x in values:
assert np.floor(x) == utils.decimal_base_floor(x)
assert np.floor(x) == utils.decimal_base_floor(x, 1)
