def min_dist(p, positions):
'''
Calculate minimize distance from point p to point set poisition
:param p: [$lon, $lat]
:param positions: [[$lon, $lat]]
:return: precision, recall
'''
d = cal_distance(p, positions[0])
for i in range(1, len(positions)):
tmp = cal_distance(p, positions[i])
d = tmp if tmp < d else d
return d
def plot_trajectories(signal_set):
'''
Plot all trajectories in signal set according to time.
:param signal_set: A list of trajactory.
:return:
'''
plt.close() # clf() # 清图 cla() # 清坐标轴 close() # 关窗口
fig = plt.figure()
# plt.show()
ax = fig.add_subplot(1, 1, 1)
plt.grid(True) # 添加网格
plt.ion() # interactive mode on
for i in range(len(signal_set)):
signal = signal_set[i]
max_time = max(signal.dates)
min_time = min(signal.dates)
max_time_str = datetime_tostr(max_time, '%H:%M')
min_time_str = datetime_tostr(min_time, '%H:%M')
day = datetime_tostr(min_time, '%m/%d')
delta_time = (max_time - min_time).total_seconds() / 60
for j in range(len(signal)-1):
lon1, lon2 = signal['lon'][j:(j+2)]
lat1, lat2 = signal_set[i]['lat'][j:(j+2)]
dist = cal_distance([lon1, lat1], [lon2, lat2])
plt.title('[Trace %d %s(%.2f min)]%s to %s. T=%d, D=%.2fm.'
% (i, day, delta_time, min_time_str, max_time_str, j, dist))
ax.plot(signal['lon'][j:(j+2)], signal_set[i]['lat'][j:(j+2)], 'C' + str(i % 10))
if j == 0:
ax.scatter([lon1, lon2], [lat1, lat2], s=10, color='red')
else:
# TODO: make the forward points to be black
ax.scatter(signal.lon[:j], signal.lat[:j], color='black', s=10)
ax.scatter([lon2], [lat2], s=10, color='red')
plt.pause(0.5)
plt.pause(1)
def dtw_boundary(self):
'''
Get a rough upper boundary
:return:
'''
min_dist = 0
node = [0, 0]
# for i in range(max(self.m, self.n)-1):
# nxt = [node[0] + 1, node[1] + 1]
# if nxt[0] >= self.m:
# nxt[0] = self.m - 1
# if nxt[1] >= self.n:
# nxt[1] = self.n - 1
# max_dist += cal_distance(self.ts1[nxt[0]], self.ts2[nxt[1]])
# node = nxt
while node != [self.m - 1, self.n - 1]:
value = np.inf
for dir in self.directions:
tmp = [node[0] + dir[0], node[1] + dir[1]]
if not self.is_in_bound(tmp[0], tmp[1]):
continue
tmp_value = cal_distance(self.ts1[tmp[0]], self.ts2[tmp[1]])
if tmp_value < value:
nxt = tmp
value = tmp_value
min_dist += value
node = nxt
return min_dist
def dtw(self):
mat = np.ones((self.m, self.n)) + np.inf
mat_ind = {}
start_nodes = [(0, 0)]
mat[start_nodes[0]] = 0
layer_cnt = 0
end_node = (self.m - 1, self.n - 1)
print('m = %d, n = %d' % (self.m, self.n))
while len(start_nodes) != 0:
next_nodes = []
for node in start_nodes:
for dir in self.directions:
succ = (node[0] + dir[0], node[1] + dir[1])
if 0 <= succ[0] < self.m and 0 <= succ[1] < self.n:
new_dist = mat[node] + cal_distance(
self.ts1[succ[0]], self.ts2[succ[1]])
if succ in mat_ind.keys():
if new_dist < mat[succ]:
mat_ind[succ] = [node]
mat[succ] = new_dist
elif new_dist == mat[succ]:
mat_ind[succ].append(node)
else:
mat_ind[succ] = [node]
mat[succ] = new_dist
if succ not in next_nodes:
next_nodes.append(succ)
start_nodes = next_nodes
layer_cnt += 1
print('Layer %d is finished' % layer_cnt)
print('Minimum distance = %f' % mat[end_node])
return mat, mat_ind
def get_median_dist(self, mat_ind=None):
if mat_ind is None:
_, mat_ind = self.shortest_path_dtw()
nts1, nts2 = self.get_new_ts(mat_ind)
dist = []
for t in range(len(nts1)):
dist.append(cal_distance(nts1[t], nts2[t]))
return np.median(dist)
def get_average_dist(self, mat_ind=None):
if mat_ind is None:
_, mat_ind = self.shortest_path_dtw()
nts1, nts2 = self.get_new_ts(mat_ind)
dist = 0
for t in range(len(nts1)):
dist += cal_distance(nts1[t], nts2[t])
return dist / len(nts1)
def deal_pingpong(obs, tol=10):
'''
Deal with one of the ping pong problem:
1. p1 -> p2 -> p1 => Replace by p1.
2. p1 -> p2 -> p1 -> p2=> Replace by mean(p1, p2).
:param obs: A DataFrame with ['dates', 'lon', 'lat']
:param tol: If dist(p1, p1') < tol, take p1 and p1' as the same point. Unit: Meter(m).
:return: A dealed obs DataFrame.
'''
obs = obs.reset_index(drop=True)
i = 2
stored = [[obs.lon[0], obs.lat[0]], [obs.lon[1], obs.lat[1]], 0, 1]
res = obs
while i < len(obs):
pos = [obs.lon[i], obs.lat[i]]
if cal_distance(stored[0], pos) < tol:
if i + 1 < len(obs):
if cal_distance(stored[1],
[obs.lon[i + 1], obs.lat[i + 1]]) < tol:
res = res.drop([stored[2], stored[3], i + 1])
res.lon[i] = (stored[0][0] + stored[1][0]) / 2
res.lat[i] = (stored[0][1] + stored[1][1]) / 2
stored = [pos, pos, i, i]
i = i + 2
else:
res = res.drop([stored[2], stored[3]])
stored = [pos, [obs.lon[i + 1], obs.lat[i + 1]], i, i + 1]
i = i + 2
else:
res = res.drop([stored[2], stored[3]])
i = i + 1
else:
stored[0] = stored[1]
stored[1] = pos
i = i + 1
res = res.reset_index(drop=True)
return res
def fill_with_dist(self, num):
'''
Fill the observation with distance.
:param num: The num of final observation.
:return: A new observation.
'''
total_dist = self.get_total_dist()
each_dist = total_dist / (num - 1)
dist = 0
obs = self.obs
lon = [obs.lon[0]]
lat = [obs.lat[0]]
dates = [obs.dates[0]]
for i in range(1, len(obs)):
p1 = [obs.lon[i - 1], obs.lat[i - 1]]
p2 = [obs.lon[i], obs.lat[i]]
d_have = cal_distance(p1, p2)
d_need = each_dist - dist
while d_have >= d_need:
p_need = d_need / d_have
p1 = [(1 - p_need) * p1[0] + p_need * p2[0],
(1 - p_need) * p1[1] + p_need * p2[1]]
lon.append(p1[0])
lat.append(p1[1])
dates.append(obs.dates[i - 1] +
(obs.dates[i] - obs.dates[i - 1]) * p_need)
dist = 0
d_have = cal_distance(p1, p2)
d_need = each_dist - dist
dist += d_have
return pd.DataFrame({'lon': lon, 'lat': lat, 'dates': dates})
def density_clustering(points, eps=600):
'''
Density Clustering of DBSCAN in sklearn
:param points: [[lon, lat]]
:return: labels of all points.
If label == -1: Means the point is a single point.
If label >= 0: Means the point is in the group label.
'''
n = len(points)
dist_mat = np.zeros((n, n))
for i in range(n):
for j in range(i + 1, n):
dist = cal_distance(points[i], points[j])
dist_mat[i, j] = dist_mat[j, i] = dist
labels = DBSCAN(eps=eps, metric='precomputed',
min_samples=2).fit_predict(dist_mat)
return labels
def cal_multi_distance(self, ind):
'''
ind is a tuple
:param ind:
e.x:
ind = (1, 2, 4)
Calculate distance between ts0_1, ts1_2, ts2_4.
:return:
'''
ind = list(ind)
combs = list(combinations(range(len(ind)), 2))
dist = 0
for comb in combs:
ts1_ind = comb[0]
ts2_ind = comb[1]
ts1_t = ind[ts1_ind]
ts2_t = ind[ts2_ind]
dist += cal_distance(self.tses[ts1_ind][ts1_t],
self.tses[ts2_ind][ts2_t])
return dist / len(combs)
def emission_score(self, road: Vertex, lon, lat):
dist = cal_distance([road.lon, road.lat], [lon, lat]) / 1000
# return exp(- dist**2) if dist < 2 else 0
return 2 + exp(-dist**2) #if dist < 2 else 0
def trajectories_tojson(signal_set, user_id, save_path, is_json=None):
'''
Save the json file.
:param signal_set: A list of trajectory DataFrame.
:param user_id: String.
:param save_path: The path to save json.
:param is_json: Whether to save as json. If True, json; if False, js.
:return:
{
user_id: String,
trajectories: [{lon: float, lat: float, start_time, end_time}]
}
'''
res = {'user_id': user_id}
trajectories = []
mean_lon = []
mean_lat = []
for i in range(len(signal_set)):
signal = signal_set[i]
# ind = [limit_time(t, 7, 10) or limit_time(t, 17, 20) for t in signal.dates]
# signal = signal[ind]
signal = signal.reset_index(drop=True)
if len(signal) < 5:
continue
max_time = max(signal.dates)
min_time = min(signal.dates)
start_time = datetime_tostr(min_time, '%H:%M')
end_time = datetime_tostr(max_time, '%H:%M')
day = datetime_tostr(min_time, '%m/%d')
delta_time = (max_time - min_time).total_seconds() / 60 # min
N = len(signal)
dist = cal_distance([signal.lon[0], signal.lat[0]], [signal.lon[N-1], signal.lat[N-1]]) # m
if delta_time == 0:
continue
rough_speed = dist / delta_time / 60 # m/s
trajectory = {'lon': signal.lon.tolist(),
'lat': signal.lat.tolist(),
'start': '[%d-S]%s(%.1fmin)%s' % (i, day, delta_time, start_time),
'end': '[%d-E]%s(%.1fm)%s' % (i, day, dist, end_time),
'start_time': start_time,
'end_time': end_time,
'day': day,
'delta_time': '%.1f' % delta_time,
'speed': '%.2f' % rough_speed,
'dist': '%.1f' % dist,
'dates': signal.dates.apply(datetime_tostr).tolist()}
trajectories.append(trajectory)
mean_lon.append(np.mean(signal.lon))
mean_lat.append(np.mean(signal.lat))
res['trajectories'] = trajectories
res['lon'] = np.mean(mean_lon)
res['lat'] = np.mean(mean_lat)
if is_json:
save_json(res, save_path)
else:
save_js(res, save_path)
links = get_link()
cells = get_cellSheet()
cells = cells[0:10]
start = time.time()
tree = KDTree(np.array(links[['blon', 'clat']]), leaf_size=1000)
end = time.time()
this_link = []
dists = []
for i in range(len(cells)):
cell = cells[i:(i + 1)]
query = cell[['lon', 'lat']].as_matrix()[0]
_, ind = tree.query(query)
ind = ind[0][0]
dist = cal_distance(query, links.loc[ind:ind, ['blon', 'clat']].values[0])
dists.append(dist)
this_link.append(links[ind:(ind + 1)].values[0])
if i % 1 == 0: print(i)
this_link = np.array(this_link).T
cells['link'] = this_link[0]
cells['link_lon'] = this_link[1]
cells['link_lat'] = this_link[2]
cells['link_dist'] = dists
print(cells.head(10))
#cells.to_csv('../../res/cells_process.csv', index=False)
print('prepare time', end - start)
def dist_trajectories(ts1, ts2):
assert len(ts2) == len(ts1)
dist = 0
for i in range(len(ts1)):
dist += cal_distance(ts1[i], ts2[i])
return dist / len(ts1)
def get_total_dist(self):
dist = 0
for i in range(1, len(self.obs)):
dist += cal_distance([self.obs.lon[i - 1], self.obs.lat[i - 1]],
[self.obs.lon[i], self.obs.lat[i]])
return dist
def get_dist_matrix(self, ts1, ts2):
dist_mat = np.zeros((self.m, self.n))
for i in range(self.m):
for j in range(self.n):
dist_mat[i, j] = cal_distance(ts1[i], ts2[j])
return dist_mat