def test_viewshed_invalid_y_view():
OBSERVER_X = 0
OBSERVER_Y = ys[-1] + 1
with pytest.raises(Exception) as e_info: # NOQA
viewshed(raster=empty_agg,
x=OBSERVER_X,
y=OBSERVER_Y,
observer_elev=10)
def test_viewshed_invalid_x_view():
OBSERVER_X = xs[0] - 1
OBSERVER_Y = 0
with pytest.raises(Exception) as e_info: # NOQA
viewshed(raster=empty_agg,
x=OBSERVER_X,
y=OBSERVER_Y,
observer_elev=10)
def test_viewshed():
x = 0
y = 5
v = viewshed(raster=raster, x=x, y=y)
assert v.shape[0] == raster.values.shape[0]
assert v.shape[1] == raster.values.shape[1]
assert isinstance(v, xa.DataArray)
assert isinstance(v.values, np.ndarray)
assert type(v.values[0, 0]) == np.float64
def test_viewshed_output_properties():
for obs_elev in OBS_ELEVS:
OBSERVER_X = xs[0]
OBSERVER_Y = ys[0]
v = viewshed(raster=empty_agg,
x=OBSERVER_X,
y=OBSERVER_Y,
observer_elev=obs_elev)
assert v.shape[0] == empty_agg.shape[0]
assert v.shape[1] == empty_agg.shape[1]
assert isinstance(v, xa.DataArray)
assert isinstance(v.values, np.ndarray)
assert type(v.values[0, 0]) == np.float64
def test_viewshed_invalid_y():
x = 0
y = 20e8
with pytest.raises(Exception) as e_info:
viewshed(raster=raster, x=x, y=y)
assert e_info
def test_viewshed():
# check if a matrix is symmetric
def check_symmetric(matrix, rtol=1e-05, atol=1e-08):
return np.allclose(matrix, matrix.T, rtol=rtol, atol=atol)
def get_matrices(y, x, height, width):
# indexing 0 1 ... height-1 and 0 1 ... width-1
height = height - 1
width = width - 1
# find first matrix's diagonal
tmp = min(y, x)
f_top_y, f_left_x = y - tmp, x - tmp
tmp = min(height - y, width - x)
f_bottom_y, f_right_x = y + tmp, x + tmp
# find second matrix's antidiagonal
tmp = min(y, width - x)
s_top_y, s_right_x = y - tmp, x + tmp
tmp = min(height - y, x)
s_bottom_y, s_left_x = y + tmp, x - tmp
return (f_top_y, f_left_x, f_bottom_y + 1, f_right_x + 1), \
(s_top_y, s_left_x, s_bottom_y + 1, s_right_x + 1)
# test on 3 scenarios:
# empty image.
# image with all 0s, except 1 cell with a negative value.
# image with all 0s, except 1 cell with a positive value.
# for each scenario:
# if not empty image,
# observer is located at the same position as the non zero value.
# observer elevation can be: negative, zero, or positive.
# assertion:
# angle at viewpoint is always 180.
# when the observer is above the terrain, all cells are visible.
# the symmetric property of observer's visibility.
for obs_elev in OBS_ELEVS:
for elev_at_vp in TERRAIN_ELEV_AT_VP:
for col_id, x in enumerate(xs):
for row_id, y in enumerate(ys):
empty_agg.values[row_id, col_id] = elev_at_vp
v = viewshed(raster=empty_agg,
x=x,
y=y,
observer_elev=obs_elev)
# angle at viewpoint is always 180
assert v[row_id, col_id] == 180
if obs_elev + elev_at_vp >= 0 and \
obs_elev >= abs(elev_at_vp):
# all cells are visible
assert (v.values > -1).all()
b1, b2 = get_matrices(row_id, col_id, H, W)
m1 = v.values[b1[0]:b1[2], b1[1]:b1[3]]
m2 = v.values[b2[0]:b2[2], b2[1]:b2[3]]
assert check_symmetric(m1)
assert check_symmetric(m2[::-1])
# empty image for next uses
empty_agg.values[row_id, col_id] = 0