def _compute_distance(self, row):
pt0 = row['prev_pt']
pt1 = row['geometry']
if type(pt0) != Point:
return 0.0
if pt0 == pt1:
return 0.0
if self.is_latlon():
dist_meters = measure_distance_spherical(pt0, pt1)
else: # The following distance will be in CRS units that might not be meters!
dist_meters = measure_distance_euclidean(pt0, pt1)
return dist_meters
def get_closest_centroid(self, pt, max_dist=100000000):
(i, j) = self.get_grid_position(pt)
shortest_dist = self.cell_size * 100
nearest_centroid = None
for k in range(max(i - 1, 0), min(i + 2, self.n_cols)):
for m in range(max(j - 1, 0), min(j + 2, self.n_rows)):
if not self.cells[k][m]: # no centroid in this cell yet
continue
dist = measure_distance_euclidean(pt, self.cells[k][m].centroid)
if dist <= max_dist and dist < shortest_dist:
nearest_centroid = (k, m)
shortest_dist = dist
return nearest_centroid
def _compute_speed(self, row):
pt0 = row['prev_pt']
pt1 = row['geometry']
if type(pt0) != Point:
return 0.0
if type(pt1) != Point:
raise ValueError('Invalid trajectory! Got {} instead of point!'.format(pt1))
if pt0 == pt1:
return 0.0
if self.is_latlon():
dist_meters = measure_distance_spherical(pt0, pt1)
else: # The following distance will be in CRS units that might not be meters!
dist_meters = measure_distance_euclidean(pt0, pt1)
return dist_meters / row['delta_t'].total_seconds()
def test_euclidean_distance(self):
assert (measure_distance_euclidean(Point(0, 0), Point(0, 1))) == 1
def test_measure_distance_euclidean_throws_type_error(self):
with pytest.raises(TypeError):
measure_distance_euclidean((0, 0), (0, 1))