【Python文本处理】基于运动路线记录GPX的文件解析，及对经纬度坐标的数学模型运动速度求解
解析
GPX文件格式
GPX文件本身其实就是坐标、海拔、时间、心率等综合性的xml文件
如图：
海拔：ele
时间：time
心率：heartrate
功率：power
踏频：cadence
距离：distance
一般不用距离distance 但可以根据距离求瞬时速度（前提是时间间隔均匀 最小精度不低于1s） 不过如果距离和坐标之差相差太远 则不太好确定 Strava等软件通过这个来计算瞬时速度和距离 但不用于计算赛段速度（赛段时间）
某一时刻的数据就看trkpt部分
以trkpt 为始 到 /trkpt 为止
比如：
<trkpt lat="30.3940883" lon="112.2400167">
<ele>34</ele>
<time>2023-05-12T12:26:13Z</time>
<extensions>
<heartrate>167</heartrate>
<distance>26698</distance>
</extensions>
</trkpt>
代码实现
首先借助time库 求出每个时刻的参数 并且转换为"%Y-%m-%d %H:%M:%S"格式
而后对海拔 经纬度进行获取
最后获取关键词
import time
keywords_list=["heartrate","cadence","power","distance"]
def read_gpx(gpx):
first_time=0
first_str_time=""
trkpt_flag=0
j=0
num_list=[0]
time_list=[None]
ele_list=[None]
lat_list=[None]
lon_list=[None]
key_list=[]
gpx_dict={}
key_dict={}
for i in keywords_list:
key_list.append([None])
for i in range(len(gpx)):
try:
ti=str((gpx[i].split("<time>")[1]).split("</time>")[0])
now_time = time.mktime(time.strptime(ti, "%Y-%m-%dT%H:%M:%SZ"))
first_time=now_time
first_str_time=time.strftime("%Y-%m-%d %H:%M:%S",time.localtime(first_time))
break
except:
pass
time_list[0]=first_str_time
for i in range(len(gpx)):
if gpx[i].count('<trkpt'):
trkpt_flag=1
j=j+1
num_list.append(j)
time_list.append(j)
ele_list.append(j)
lat_list.append(j)
lon_list.append(j)
for k in range(len(keywords_list)):
key_list[k].append(j)
if trkpt_flag==1:
try:
ti=str((gpx[i].split("<time>")[1]).split("</time>")[0])
now_time = time.mktime(time.strptime(ti, "%Y-%m-%dT%H:%M:%SZ"))
now_str_time=time.strftime("%Y-%m-%d %H:%M:%S",time.localtime(now_time))
time_list[j]=now_str_time
except:
pass
if gpx[i].count('<trkpt'):
lat_list[j]=float(gpx[i].split('"')[1])
lon_list[j]=float(gpx[i].split('"')[3])
try:
ele_list[j]=float(str((gpx[i].split("<ele>")[1]).split("</ele>")[0]))
except:
pass
for k in range(len(keywords_list)):
try:
dat=str((gpx[i].split("<"+keywords_list[k]+">")[1]).split("</"+keywords_list[k]+">")[0])
key_list[k][j]=float(dat)
except:
pass
if gpx[i].count('</trkpt>'):
trkpt_flag=0
if gpx[i].count('</trkseg>'):
break
gpx_dict["num"]=num_list
gpx_dict["time"]=time_list
gpx_dict["lat"]=lat_list
gpx_dict["lon"]=lon_list
gpx_dict["ele"]=ele_list
for k in range(len(keywords_list)):
key_dict[keywords_list[k]]=key_list[k]
gpx_dict["key"]=key_dict
return gpx_dict
最后保存为字典集合
输出结果：
{'num': [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184], 'time': ['2023-06-01 09:58:22', '2023-06-01 09:58:41', '2023-06-01 09:58:42', '2023-06-01 09:58:43', '2023-06-01 09:58:44', '2023-06-01 09:58:45', '2023-06-01 09:58:46', '2023-06-01 09:58:47', '2023-06-01 09:58:48', '2023-06-01 09:58:49', '2023-06-01 09:58:50', '2023-06-01 09:58:51', '2023-06-01 09:58:52', '2023-06-01 09:58:53', '2023-06-01 09:58:54', '2023-06-01 09:58:55', '2023-06-01 09:58:56', '2023-06-01 09:58:57', '2023-06-01 09:58:58', '2023-06-01 09:58:59', '2023-06-01 09:59:00', '2023-06-01 09:59:01', '2023-06-01 09:59:02', '2023-06-01 09:59:03', '2023-06-01 09:59:04', '2023-06-01 09:59:05', '2023-06-01 09:59:06', '2023-06-01 09:59:07', '2023-06-01 09:59:08', '2023-06-01 09:59:09', '2023-06-01 09:59:10', '2023-06-01 09:59:11', '2023-06-01 09:59:12', '2023-06-01 09:59:13', '2023-06-01 09:59:14', '2023-06-01 09:59:15', '2023-06-01 09:59:16', '2023-06-01 09:59:17', '2023-06-01 09:59:18', '2023-06-01 09:59:19', '2023-06-01 09:59:20', '2023-06-01 09:59:21', '2023-06-01 09:59:22', '2023-06-01 09:59:23', '2023-06-01 09:59:24', '2023-06-01 09:59:25', '2023-06-01 09:59:26', '2023-06-01 09:59:27', '2023-06-01 09:59:28', '2023-06-01 09:59:29', '2023-06-01 09:59:30', '2023-06-01 09:59:31', '2023-06-01 09:59:32', '2023-06-01 09:59:33', '2023-06-01 09:59:34', '2023-06-01 09:59:35', '2023-06-01 09:59:36', '2023-06-01 09:59:37', '2023-06-01 09:59:38', '2023-06-01 09:59:39', '2023-06-01 09:59:40', '2023-06-01 09:59:41', '2023-06-01 09:59:42', '2023-06-01 09:59:43', '2023-06-01 09:59:44', '2023-06-01 09:59:45', '2023-06-01 09:59:46', '2023-06-01 09:59:47', '2023-06-01 09:59:48', '2023-06-01 09:59:49', '2023-06-01 09:59:50', '2023-06-01 09:59:51', '2023-06-01 09:59:52', '2023-06-01 09:59:53', '2023-06-01 09:59:54', '2023-06-01 09:59:55', '2023-06-01 09:59:56', '2023-06-01 09:59:57', '2023-06-01 09:59:58', '2023-06-01 09:59:59', '2023-06-01 10:00:00', '2023-06-01 10:00:01', '2023-06-01 10:00:02', '2023-06-01 10:00:03', '2023-06-01 10:00:04', '2023-06-01 10:00:05', '2023-06-01 10:00:06', '2023-06-01 10:00:07', '2023-06-01 10:00:08', '2023-06-01 10:00:09', '2023-06-01 10:00:10', '2023-06-01 10:00:11', '2023-06-01 10:00:12', '2023-06-01 10:00:13', '2023-06-01 10:00:14', '2023-06-01 10:00:15', '2023-06-01 10:00:16', '2023-06-01 10:00:17', '2023-06-01 10:00:18', '2023-06-01 10:00:19', '2023-06-01 10:00:20', '2023-06-01 10:00:21', '2023-06-01 10:00:22', '2023-06-01 10:00:23', '2023-06-01 10:00:24', '2023-06-01 10:00:25', '2023-06-01 10:00:26', '2023-06-01 10:00:27', '2023-06-01 10:00:28', '2023-06-01 10:00:29', '2023-06-01 10:00:30', '2023-06-01 10:00:31', '2023-06-01 10:00:32', '2023-06-01 10:00:33', '2023-06-01 10:00:34', '2023-06-01 10:00:35', '2023-06-01 10:00:36', '2023-06-01 10:00:37', '2023-06-01 10:00:38', '2023-06-01 10:00:39', '2023-06-01 10:00:40', '2023-06-01 10:00:41', '2023-06-01 10:00:42', '2023-06-01 10:00:43', '2023-06-01 10:00:44', '2023-06-01 10:00:45', '2023-06-01 10:00:46', '2023-06-01 10:00:47', '2023-06-01 10:00:48', '2023-06-01 10:00:49', '2023-06-01 10:00:50', '2023-06-01 10:00:51', '2023-06-01 10:00:52', '2023-06-01 10:00:53', '2023-06-01 10:00:54', '2023-06-01 10:00:55', '2023-06-01 10:00:56', '2023-06-01 10:00:57', '2023-06-01 10:00:58', '2023-06-01 10:00:59', '2023-06-01 10:01:00', '2023-06-01 10:01:01', '2023-06-01 10:01:02', '2023-06-01 10:01:03', '2023-06-01 10:01:04', '2023-06-01 10:01:05', '2023-06-01 10:01:06', '2023-06-01 10:01:07', '2023-06-01 10:01:08', '2023-06-01 10:01:09', '2023-06-01 10:01:10', '2023-06-01 10:01:11', '2023-06-01 10:01:12', '2023-06-01 10:01:13', '2023-06-01 10:01:14', '2023-06-01 10:01:15', '2023-06-01 10:01:16', '2023-06-01 10:01:17', '2023-06-01 10:01:18', '2023-06-01 10:01:19', '2023-06-01 10:01:20', '2023-06-01 10:01:21', '2023-06-01 10:01:22', '2023-06-01 10:01:23', '2023-06-01 10:01:24', '2023-06-01 10:01:25', '2023-06-01 10:01:26', '2023-06-01 10:01:27', '2023-06-01 10:01:28', '2023-06-01 10:01:29', '2023-06-01 10:01:30', '2023-06-01 10:01:31', '2023-06-01 10:01:32', '2023-06-01 10:01:33', '2023-06-01 10:01:34', '2023-06-01 10:01:54', '2023-06-01 10:01:55', '2023-06-01 10:01:56', '2023-06-01 10:01:57', '2023-06-01 10:02:13', '2023-06-01 10:02:14', '2023-06-01 10:02:15', '2023-06-01 10:02:16', '2023-06-01 10:02:17', '2023-06-01 10:02:18'], 'lat': [None, 30.452805, 30.4528125, 30.4528189, 30.4528247, 30.4528287, 30.4528306, 30.4528274, 30.4528185, 30.4528061, 30.4527819, 30.4527605, 30.4527407, 30.4527255, 30.4527165, 30.4527105, 30.4527043, 30.4527002, 30.4526961, 30.4526878, 30.4526799, 30.4526724, 30.4526653, 30.4526585, 30.4526511, 30.4526432, 30.4526382, 30.4526364, 30.4526347, 30.4526313, 30.4526268, 30.4526225, 30.4526161, 30.4526085, 30.4526009, 30.4525931, 30.452585, 30.4525761, 30.4525672, 30.4525573, 30.4525471, 30.4525388, 30.4525315, 30.4525241, 30.4525176, 30.4525106, 30.4525042, 30.4524992, 30.4524957, 30.4524939, 30.4524964, 30.4525027, 30.4525095, 30.4525144, 30.4525146, 30.4525092, 30.4525001, 30.452491, 30.4524821, 30.4524735, 30.4524656, 30.4524585, 30.4524522, 30.4524467, 30.4524397, 30.4524306, 30.4524212, 30.4524128, 30.4524072, 30.4524037, 30.4523976, 30.452387, 30.4523743, 30.4523626, 30.4523544, 30.4523475, 30.4523411, 30.4523334, 30.4523246, 30.4523151, 30.4523058, 30.4522994, 30.4522931, 30.452284, 30.4522709, 30.4522573, 30.4522449, 30.4522331, 30.4522227, 30.4522135, 30.4522036, 30.4521941, 30.4521846, 30.4521749, 30.452165, 30.4521557, 30.4521475, 30.4521407, 30.452135, 30.4521298, 30.4521242, 30.4521187, 30.4521134, 30.4521077, 30.452099, 30.4520891, 30.4520801, 30.4520722, 30.4520656, 30.4520581, 30.4520494, 30.4520406, 30.4520326, 30.4520258, 30.4520207, 30.4520166, 30.4520156, 30.4520157, 30.4520148, 30.4520109, 30.4520021, 30.4519891, 30.451975, 30.4519647, 30.4519547, 30.4519429, 30.4519314, 30.4519224, 30.4519173, 30.4519121, 30.451905, 30.4518969, 30.4518886, 30.4518795, 30.45187, 30.4518607, 30.4518506, 30.451841, 30.451832, 30.4518227, 30.4518112, 30.4517992, 30.451789, 30.4517806, 30.4517714, 30.4517642, 30.4517577, 30.4517519, 30.4517441, 30.4517381, 30.4517355, 30.4517277, 30.4517154, 30.451696, 30.4516821, 30.4516804, 30.4516841, 30.4516871, 30.4516861, 30.4516817, 30.4516731, 30.4516592, 30.4516392, 30.4516241, 30.4515869, 30.4515576, 30.4515302, 30.4515145, 30.4514761, 30.4514449, 30.4514142, 30.4513832, 30.451353, 30.4513262, 30.4513047, 30.4512268, 30.4512039, 30.4511808, 30.4511591, 30.4510384, 30.4510348, 30.4510312, 30.4510243, 30.4510148, 30.4509683], 'lon': [None, 114.42341, 114.4234075, 114.4234007, 114.4233901, 114.4233757, 114.4233531, 114.4233333, 114.4233105, 114.4232842, 114.4232355, 114.4231986, 114.4231621, 114.4231234, 114.42308, 114.4230341, 114.4229862, 114.4229577, 114.4229293, 114.4228785, 114.4228315, 114.4227793, 114.4227282, 114.4226775, 114.4226272, 114.422577, 114.4225274, 114.4224779, 114.4224276, 114.4223772, 114.4223269, 114.4222768, 114.4222261, 114.4221743, 114.422121, 114.4220673, 114.4220143, 114.4219619, 114.4219094, 114.4218565, 114.4218039, 114.4217506, 114.421697, 114.4216435, 114.4215901, 114.4215373, 114.4214851, 114.4214326, 114.4213798, 114.4213273, 114.421277, 114.4212281, 114.4211797, 114.4211314, 114.4210826, 114.4210331, 114.4209821, 114.4209311, 114.4208804, 114.4208289, 114.420777, 114.4207252, 114.4206734, 114.4206211, 114.4205688, 114.4205168, 114.420465, 114.4204133, 114.4203623, 114.4203093, 114.4202557, 114.4202033, 114.4201521, 114.4201022, 114.4200552, 114.4200083, 114.419961, 114.4199125, 114.4198619, 114.4198099, 114.4197569, 114.4197042, 114.4196513, 114.4195989, 114.4195456, 114.4194927, 114.4194397, 114.4193878, 114.4193369, 114.419286, 114.4192341, 114.4191815, 114.419129, 114.4190763, 114.4190232, 114.4189688, 114.418915, 114.418861, 114.4188058, 114.4187511, 114.418697, 114.4186434, 114.4185905, 114.4185378, 114.4184854, 114.4184328, 114.4183798, 114.4183267, 114.4182727, 114.4182176, 114.4181623, 114.4181082, 114.4180579, 114.4180111, 114.4179664, 114.4179228, 114.4178808, 114.41784, 114.4177991, 114.4177536, 114.4177059, 114.4176574, 114.4176081, 114.4175565, 114.4175062, 114.4174569, 114.4174089, 114.4173598, 114.4173088, 114.4172565, 114.4172029, 114.4171484, 114.4170935, 114.4170372, 114.4169823, 114.4169284, 114.4168755, 114.4168227, 114.4167703, 114.416719, 114.4166684, 114.4166182, 114.4165688, 114.41652, 114.4164722, 114.4164238, 114.4163759, 114.4163279, 114.4162817, 114.4162345, 114.4161873, 114.416144, 114.4161079, 114.4160834, 114.4160621, 114.4160486, 114.4160213, 114.4159636, 114.4159197, 114.4158811, 114.415848, 114.4158204, 114.4157996, 114.4157916, 114.4157787, 114.4157734, 114.4157721, 114.4157722, 114.4157734, 114.4157742, 114.4157747, 114.4157775, 114.4157841, 114.4157923, 114.415801, 114.415851, 114.4158589, 114.4158646, 114.4158705, 114.4158796, 114.4158809, 114.4158822, 114.4158852, 114.4158888, 114.4159033], 'ele': [None, 19.0, 19.0, 19.0, 19.0, 19.0, 19.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 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118.0, 118.0, 118.0, 117.0, 118.0, 118.0, 118.0, 118.0, 117.0, 117.0, 117.0, 112.0, 112.0, 112.0, 112.0, 113.0, 113.0, 113.0, 112.0, 112.0, 112.0], 'cadence': [None, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184], 'power': [None, 1, 2, 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788.0, 790.0, 803.0, 806.0, 808.0, 809.0, 820.0, 820.0, 820.0, 820.0, 821.0, 821.0]}}
速度求解
速度＝位移/时间
所以最先要做的就是算出两个经纬度坐标点的距离（弧长）
数学模型
首先 地球的平均半径为6371393米
近视地球为一个球体 则经纬度坐标就是一个球坐标方程
球坐标和直角坐标转换用到这两个方程组：
其中 φ为经度 90°-θ为纬度（这里有个坑需要注意）：
标准球坐标为：
可以看到 θ是90°-纬度
所以如果带入经纬度的话 就是：
（theta是经度 phi是纬度）
df['r'] = 6371393+df['ele']# radius of the Earth in meters
df['theta'] = np.deg2rad(df['lon'])
df['phi'] = np.deg2rad(df['lat'])
df['x'] = df['r']*np.cos(df['theta'])*np.cos(df['phi'])
df['y'] = df['r']*np.sin(df['theta'])*np.cos(df['phi'])
df['z'] = df['r']*np.sin(df['phi'])
df['x2'] = df['x'].shift()
df['y2'] = df['y'].shift()
df['z2'] = df['z'].shift()
df['distance'] = np.sqrt((df['x2']-df['x'])**2 + (df['y2']-df['y'])**2 + (df['z2']-df['z'])**2)
df['central_angle'] = np.arccos((df['x']*df['x2'] + df['y']*df['y2'] + df['z']*df['z2'])/df['r']**2)
df['arclength'] = df['central_angle']*df['r']
df['elapsed_time'] = (df.index.to_series().diff() / pd.Timedelta(seconds=1))
df['speed'] = df['arclength'] / df['elapsed_time']*3.6 # km/h
df = df[columns + ['speed']]
通过三角函数计算出两个坐标点的弧长，则可以算出该时间段的速度
但物理里面学过：
若要精确计算速度 则应该求两个连续弧长/两个经过的时间
但也可以不这么麻烦：
弧长公式在球坐标中更容易求得 而且如果转成直角坐标 则可能把角度弄错（我第一次就把90°-θ踩坑了 导致我的弧长求反三角函数时 居然大于1）
计算经纬度坐标距离的原理就是就算球面两点间的距离，经纬度表示法实际是用角度描述的坐标。纬度上下一共180度，经度360度。
假设地球是标准的球形，计算距离就等于计算一个截面圆的弧长。计算弧长的话需要先求出两点相对于球芯的夹角。然后根据半径就可以求出弧长了，也就是距离。
假设A点纬度lat1，精度lng1.B点纬度lat2， 经度lng2， 地球半径为R
求这个夹角之前，先把坐标转换为直角空间坐标系的点，并让地心为坐标中心点，即
A（Rcos(lat1)cos(lng1), Rcos(lat1)sin(lng1), Rsin(lat1)）
B（Rcos(lat2)cos(lng2), Rcos(lat2)sin(lng2), Rsin(lat2)）
然后算夹角，这里用向量的夹角计算方法,可以求出夹角余弦值，那么夹角COS为
COS = (向量A*向量B) / (向量A的模 * 向量B的模)
令A为（x,y,z）,B(a,b,c)
COS = (xa+yb+zc)/[√(x2+y2+z2)*√(a2+b2+c2)]
把经纬度的坐标代进去
COS = cos(lat2) * cos(lat1) * cos(lng1-lng2) + sin(lat2)*sin(lat1)
得到夹角的余弦值可得角度，然后就可以算出弧长了，即得距离(arccos 为反余弦函数，这里反余弦的结果得到的是弧度)
d = 2PI*R * (arccos(COS) / 2 * PI)
d = R * arccos(COS)
最终
d = R * arccos( cos(lat2) * cos(lat1) * cos(lng2-lng1) + sin(lat2)*sin(lat1))
代码：
df['arclength'] = df['r'] * np.arccos(np.cos(df['phi']) * np.cos(df['phi2']) * np.cos(df['theta2']-df['theta']) + np.sin(df['phi'])*np.sin(df['phi2']))
加上物理中求速度的公式 运动速度求解就成了：
其中elapsed_time_list为经过的时间列表
try:
speed_list.append((df['arclength'][i]+df['arclength'][i+1])/ (elapsed_time_list[i]+elapsed_time_list[i+1])) # km/h
except:
speed_list.append(df['arclength'][i]/ elapsed_time_list[i]) # m/s
如果还想更加精确 则再延伸两个时间段 并且求出来的速度按权重去求平均值 这里就需要经验值了
代码实现
这里用到了numpy和pandas做数学计算
同时也要引入状态机考虑如果时间戳相同的结果（一般GPX是一秒钟更新一次 所以也没啥影响）
def calculate_speed(time_list,lat_list,lon_list,ele_list):
if len(time_list)==len(lat_list) and len(time_list)==len(lon_list) and len(time_list)==len(ele_list):
pass
else:
return
df = pd.DataFrame({'time': time_list, 'lat': lat_list, 'lon': lon_list, 'ele': ele_list})
columns = df.columns.tolist()
df['r'] = 6371393+df['ele'] # radius of the Earth in meters
df['theta'] = np.deg2rad(df['lon'])
df['phi'] = np.deg2rad(df['lat'])
df['theta2']=df['theta'].shift()
df['phi2']=df['phi'].shift()
df['arclength'] = df['r'] * np.arccos(np.cos(df['phi']) * np.cos(df['phi2']) * np.cos(df['theta2']-df['theta']) + np.sin(df['phi'])*np.sin(df['phi2']))
elapsed_time_list=[]
stamp_list=[]
speed_list=[]
stamp_same_list=[]
same_flag=0
enable_flag=0
exit_same_list=[]
for i in range(len(time_list)):
try:
stamp_list.append(time.mktime(time.strptime(time_list[i], "%Y-%m-%d %H:%M:%S")))
enable_flag=1
if i>0 and enable_flag==1:
if stamp_list[i]>stamp_list[i-1]:
elapsed_time_list.append(stamp_list[i]-stamp_list[i-1])
if same_flag==1:
same_flag=0
exit_same_list.append(i)
else:
if same_flag==0:
stamp_same_list.append(i)
same_flag=1
elapsed_time_list.append(0.0)
else:
elapsed_time_list.append(None)
except:
if enable_flag==0:
elapsed_time_list.append(None)
else:
if same_flag==0:
stamp_same_list.append(i)
same_flag=1
elapsed_time_list.append(0.0)
if len(stamp_same_list)>len(exit_same_list):
exit_same_list.append(0)
j=0
displacement=0.0
displacement_time=0.0
end_displacement=0.0
same_flag=0
end_elapsed_time=0.0
stamp_same_in_1st_flag=0
if len(stamp_same_list)==0:
for i in range(len(elapsed_time_list)):
try:
try:
speed_list.append((df['arclength'][i]+df['arclength'][i+1])/ (elapsed_time_list[i]+elapsed_time_list[i+1])) # km/h
except:
speed_list.append(df['arclength'][i]/ elapsed_time_list[i]) # m/s
except:
speed_list.append(None)
else:
for i in range(len(elapsed_time_list)):
try:
if i>0:
try:
if i==stamp_same_list[j]-1:
same_flag=1
if stamp_same_list[0]==1 and stamp_same_in_1st_flag==0:
stamp_same_in_1st_flag=1
same_flag=1
except:
pass
if same_flag==0:
try:
speed_list.append((df['arclength'][i]+df['arclength'][i+1])/ (elapsed_time_list[i]+elapsed_time_list[i+1])) # m/s
except:
speed_list.append(df['arclength'][i]/ elapsed_time_list[i]) # m/s
else:
try:
displacement=displacement+df['arclength'][i]
except:
displacement=displacement+0.0
try:
displacement_time=displacement_time+elapsed_time_list[i]
except:
displacement_time=displacement_time+0.0
if j==len(stamp_same_list)-1 and exit_same_list[j]==0:
if end_elapsed_time==0.0:
end_elapsed_time=elapsed_time_list[i]
end_displacement=end_displacement+df['arclength'][i]
if end_elapsed_time>0.0:
speed_list.append(end_displacement/end_elapsed_time)
else:
speed_list.append(end_displacement/1.0)
else:
speed_list.append(None)
if i==exit_same_list[j]:
avg_speed=displacement/displacement_time
for k in range(stamp_same_list[j]-1,i+1):
speed_list[k]=avg_speed
j=j+1
try:
if elapsed_time_list[j]-end_elapsed_time[j-1]<=1:
pass
else:
same_flag=0
displacement=0.0
displacement_time=0.0
except:
same_flag=0
displacement=0.0
displacement_time=0.0
else:
speed_list.append(None)
except:
speed_list.append(None)
df['elapsed_time'] = elapsed_time_list
df['speed'] = speed_list # m/s
df['speed'] = 3.6*df['speed'] # km/h
df = df[columns + ['arclength']+['speed']]
return df
输出结果：
time lat ... arclength speed
0 2023-06-01 09:58:22 NaN ... NaN NaN
1 2023-06-01 09:58:41 30.452805 ... NaN NaN
2 2023-06-01 09:58:42 30.452813 ... 0.870153 3.309064
3 2023-06-01 09:58:43 30.452819 ... 0.968216 3.904454
4 2023-06-01 09:58:44 30.452825 ... 1.200925 4.775849
5 2023-06-01 09:58:45 30.452829 ... 1.452325 6.533599
6 2023-06-01 09:58:46 30.452831 ... 2.177452 7.392403
7 2023-06-01 09:58:47 30.452827 ... 1.929438 7.792940
8 2023-06-01 09:58:48 30.452818 ... 2.399973 9.492160
9 2023-06-01 09:58:49 30.452806 ... 2.873450 14.872643
10 2023-06-01 09:58:50 30.452782 ... 5.389130 17.373583
11 2023-06-01 09:58:51 30.452761 ... 4.262861 15.114427
12 2023-06-01 09:58:52 30.452741 ... 4.134043 14.777814
13 2023-06-01 09:58:53 30.452725 ... 4.075853 15.040074
14 2023-06-01 09:58:54 30.452717 ... 4.279743 15.715562
15 2023-06-01 09:58:55 30.452710 ... 4.451124 16.370151
16 2023-06-01 09:58:56 30.452704 ... 4.643404 13.346376
17 2023-06-01 09:58:57 30.452700 ... 2.771250 9.955965
18 2023-06-01 09:58:58 30.452696 ... 2.759842 13.890313
19 2023-06-01 09:58:59 30.452688 ... 4.956999 17.185842
20 2023-06-01 09:59:00 30.452680 ... 4.590692 17.396119
21 2023-06-01 09:59:01 30.452672 ... 5.073819 18.063651
22 2023-06-01 09:59:02 30.452665 ... 4.961543 17.782722
23 2023-06-01 09:59:03 30.452658 ... 4.917747 17.655921
24 2023-06-01 09:59:04 30.452651 ... 4.891098 17.607951
25 2023-06-01 09:59:05 30.452643 ... 4.891098 17.420183
26 2023-06-01 09:59:06 30.452638 ... 4.786782 17.164355
27 2023-06-01 09:59:07 30.452636 ... 4.748971 17.231882
28 2023-06-01 09:59:08 30.452635 ... 4.824296 17.407732
29 2023-06-01 09:59:09 30.452631 ... 4.846666 17.447997
.. ... ... ... ... ...
155 2023-06-01 10:01:15 30.451680 ... 1.308677 7.122322
156 2023-06-01 10:01:16 30.451684 ... 2.648168 14.741737
157 2023-06-01 10:01:17 30.451687 ... 5.541685 17.552431
158 2023-06-01 10:01:18 30.451686 ... 4.209665 14.294663
159 2023-06-01 10:01:19 30.451682 ... 3.731814 12.683910
160 2023-06-01 10:01:20 30.451673 ... 3.314802 11.483126
161 2023-06-01 10:01:21 30.451659 ... 3.064712 10.890838
162 2023-06-01 10:01:22 30.451639 ... 2.985753 8.692529
163 2023-06-01 10:01:23 30.451624 ... 1.843429 11.085891
164 2023-06-01 10:01:24 30.451587 ... 4.315399 13.704922
165 2023-06-01 10:01:25 30.451558 ... 3.298446 11.427151
166 2023-06-01 10:01:26 30.451530 ... 3.049971 8.631806
167 2023-06-01 10:01:27 30.451514 ... 1.745477 10.830216
168 2023-06-01 10:01:28 30.451476 ... 4.271310 13.934782
169 2023-06-01 10:01:29 30.451445 ... 3.470236 12.391505
170 2023-06-01 10:01:30 30.451414 ... 3.413934 12.368084
171 2023-06-01 10:01:31 30.451383 ... 3.457224 12.377582
172 2023-06-01 10:01:32 30.451353 ... 3.419210 11.702734
173 2023-06-01 10:01:33 30.451326 ... 3.082309 10.101783
174 2023-06-01 10:01:34 30.451305 ... 2.529793 2.130881
175 2023-06-01 10:01:54 30.451227 ... 9.900348 2.152631
176 2023-06-01 10:01:55 30.451204 ... 2.656664 9.511795
177 2023-06-01 10:01:56 30.451181 ... 2.627666 9.192733
178 2023-06-01 10:01:57 30.451159 ... 2.479408 3.373405
179 2023-06-01 10:02:13 30.451038 ... 13.450560 2.933653
180 2023-06-01 10:02:14 30.451035 ... 0.402802 1.450089
181 2023-06-01 10:02:15 30.451031 ... 0.402802 2.195135
182 2023-06-01 10:02:16 30.451024 ... 0.816717 3.477648
183 2023-06-01 10:02:17 30.451015 ... 1.115310 11.646074
184 2023-06-01 10:02:18 30.450968 ... 5.354732 19.277034
[185 rows x 6 columns]
整体代码
# -*- coding: utf-8 -*-
"""
Created on Tue Jun 6 13:58:42 2023
@author: ZHOU
"""
import numpy as np
import pandas as pd
import time
keywords_list=["heartrate","cadence","power","distance"]
def read_gpx(gpx):
first_time=0
first_str_time=""
trkpt_flag=0
j=0
num_list=[0]
time_list=[None]
ele_list=[None]
lat_list=[None]
lon_list=[None]
key_list=[]
gpx_dict={}
key_dict={}
for i in keywords_list:
key_list.append([None])
for i in range(len(gpx)):
try:
ti=str((gpx[i].split("<time>")[1]).split("</time>")[0])
now_time = time.mktime(time.strptime(ti, "%Y-%m-%dT%H:%M:%SZ"))
first_time=now_time
first_str_time=time.strftime("%Y-%m-%d %H:%M:%S",time.localtime(first_time))
break
except:
pass
time_list[0]=first_str_time
for i in range(len(gpx)):
if gpx[i].count('<trkpt'):
trkpt_flag=1
j=j+1
num_list.append(j)
time_list.append(j)
ele_list.append(j)
lat_list.append(j)
lon_list.append(j)
for k in range(len(keywords_list)):
key_list[k].append(j)
if trkpt_flag==1:
try:
ti=str((gpx[i].split("<time>")[1]).split("</time>")[0])
now_time = time.mktime(time.strptime(ti, "%Y-%m-%dT%H:%M:%SZ"))
now_str_time=time.strftime("%Y-%m-%d %H:%M:%S",time.localtime(now_time))
time_list[j]=now_str_time
except:
pass
if gpx[i].count('<trkpt'):
lat_list[j]=float(gpx[i].split('"')[1])
lon_list[j]=float(gpx[i].split('"')[3])
try:
ele_list[j]=float(str((gpx[i].split("<ele>")[1]).split("</ele>")[0]))
except:
pass
for k in range(len(keywords_list)):
try:
dat=str((gpx[i].split("<"+keywords_list[k]+">")[1]).split("</"+keywords_list[k]+">")[0])
key_list[k][j]=float(dat)
except:
pass
if gpx[i].count('</trkpt>'):
trkpt_flag=0
if gpx[i].count('</trkseg>'):
break
gpx_dict["num"]=num_list
gpx_dict["time"]=time_list
gpx_dict["lat"]=lat_list
gpx_dict["lon"]=lon_list
gpx_dict["ele"]=ele_list
for k in range(len(keywords_list)):
key_dict[keywords_list[k]]=key_list[k]
gpx_dict["key"]=key_dict
return gpx_dict
def calculate_speed(time_list,lat_list,lon_list,ele_list):
if len(time_list)==len(lat_list) and len(time_list)==len(lon_list) and len(time_list)==len(ele_list):
pass
else:
return
df = pd.DataFrame({'time': time_list, 'lat': lat_list, 'lon': lon_list, 'ele': ele_list})
columns = df.columns.tolist()
df['r'] = 6371393+df['ele'] # radius of the Earth in meters
df['theta'] = np.deg2rad(df['lon'])
df['phi'] = np.deg2rad(df['lat'])
df['theta2']=df['theta'].shift()
df['phi2']=df['phi'].shift()
df['arclength'] = df['r'] * np.arccos(np.cos(df['phi']) * np.cos(df['phi2']) * np.cos(df['theta2']-df['theta']) + np.sin(df['phi'])*np.sin(df['phi2']))
elapsed_time_list=[]
stamp_list=[]
speed_list=[]
stamp_same_list=[]
same_flag=0
enable_flag=0
exit_same_list=[]
for i in range(len(time_list)):
try:
stamp_list.append(time.mktime(time.strptime(time_list[i], "%Y-%m-%d %H:%M:%S")))
enable_flag=1
if i>0 and enable_flag==1:
if stamp_list[i]>stamp_list[i-1]:
elapsed_time_list.append(stamp_list[i]-stamp_list[i-1])
if same_flag==1:
same_flag=0
exit_same_list.append(i)
else:
if same_flag==0:
stamp_same_list.append(i)
same_flag=1
elapsed_time_list.append(0.0)
else:
elapsed_time_list.append(None)
except:
if enable_flag==0:
elapsed_time_list.append(None)
else:
if same_flag==0:
stamp_same_list.append(i)
same_flag=1
elapsed_time_list.append(0.0)
if len(stamp_same_list)>len(exit_same_list):
exit_same_list.append(0)
j=0
displacement=0.0
displacement_time=0.0
end_displacement=0.0
same_flag=0
end_elapsed_time=0.0
stamp_same_in_1st_flag=0
if len(stamp_same_list)==0:
for i in range(len(elapsed_time_list)):
try:
try:
speed_list.append((df['arclength'][i]+df['arclength'][i+1])/ (elapsed_time_list[i]+elapsed_time_list[i+1])) # km/h
except:
speed_list.append(df['arclength'][i]/ elapsed_time_list[i]) # m/s
except:
speed_list.append(None)
else:
for i in range(len(elapsed_time_list)):
try:
if i>0:
try:
if i==stamp_same_list[j]-1:
same_flag=1
if stamp_same_list[0]==1 and stamp_same_in_1st_flag==0:
stamp_same_in_1st_flag=1
same_flag=1
except:
pass
if same_flag==0:
try:
speed_list.append((df['arclength'][i]+df['arclength'][i+1])/ (elapsed_time_list[i]+elapsed_time_list[i+1])) # m/s
except:
speed_list.append(df['arclength'][i]/ elapsed_time_list[i]) # m/s
else:
try:
displacement=displacement+df['arclength'][i]
except:
displacement=displacement+0.0
try:
displacement_time=displacement_time+elapsed_time_list[i]
except:
displacement_time=displacement_time+0.0
if j==len(stamp_same_list)-1 and exit_same_list[j]==0:
if end_elapsed_time==0.0:
end_elapsed_time=elapsed_time_list[i]
end_displacement=end_displacement+df['arclength'][i]
if end_elapsed_time>0.0:
speed_list.append(end_displacement/end_elapsed_time)
else:
speed_list.append(end_displacement/1.0)
else:
speed_list.append(None)
if i==exit_same_list[j]:
avg_speed=displacement/displacement_time
for k in range(stamp_same_list[j]-1,i+1):
speed_list[k]=avg_speed
j=j+1
try:
if elapsed_time_list[j]-end_elapsed_time[j-1]<=1:
pass
else:
same_flag=0
displacement=0.0
displacement_time=0.0
except:
same_flag=0
displacement=0.0
displacement_time=0.0
else:
speed_list.append(None)
except:
speed_list.append(None)
df['elapsed_time'] = elapsed_time_list
df['speed'] = speed_list # m/s
df['speed'] = 3.6*df['speed'] # km/h
df = df[columns + ['arclength']+['speed']]
return df
if __name__ == '__main__':
calculate_speed(['2017-07-08 22:05:45', '2017-07-08 22:05:46', '2017-07-08 22:05:47', '2017-07-08 22:05:48', '2017-07-08 22:05:49','2017-07-08 22:05:50'],[-33.81612, -33.81615, -33.816117, -33.816082, -33.816043,-33.816001],[150.871031, 150.871035, 150.87104399999998, 150.87105400000002, 150.871069,150.871080],[74.0, 73.0, 74.0, 75.0, 73.0,75.0])
path="./2.gpx"
f=open(path, 'r', encoding="utf-8")
gpx=f.readlines()
f.close()
gpx=read_gpx(gpx)
print(gpx)
df=calculate_speed(gpx["time"],gpx["lat"],gpx["lon"],gpx["ele"])
print(df)
