I have a water level time series data (filename:high.csv)where the independent variable is the time in minutes and the dependent variable is the water level of the river. The water level of a river changes continuously over time, so the average water-time curve should look very smooth. However, in the measurement of water level, sometimes the measured data are abnormal due to some factors, which can be easily found in the water-time scatter plot.
> df<-read.csv("high.csv")
> df
time high
1 2022-9-8 00:00 170.676
2 2022-9-8 00:05 170.668
3 2022-9-8 00:10 170.666
4 2022-9-8 00:15 170.666
5 2022-9-8 00:20 170.663
6 2022-9-8 00:25 170.657
7 2022-9-8 00:30 170.653
8 2022-9-8 00:35 170.649
9 2022-9-8 00:40 170.646
10 2022-9-8 00:45 170.644
11 2022-9-8 00:50 170.642
12 2022-9-8 00:55 170.636
13 2022-9-8 01:00 170.634
14 2022-9-8 01:05 170.636
15 2022-9-8 01:10 170.628
16 2022-9-8 01:35 170.615
17 2022-9-8 01:40 170.615
18 2022-9-8 01:45 170.614
19 2022-9-8 01:50 170.608
20 2022-9-8 01:55 170.605
21 2022-9-8 02:00 170.603
22 2022-9-8 02:05 170.602
23 2022-9-8 02:10 170.598
24 2022-9-8 02:15 170.588
25 2022-9-8 02:20 170.593
26 2022-9-8 02:25 170.585
27 2022-9-8 02:30 170.579
28 2022-9-8 02:35 170.581
29 2022-9-8 02:40 170.579
30 2022-9-8 02:45 170.579
31 2022-9-8 02:50 170.579
32 2022-9-8 02:55 170.579
33 2022-9-8 03:00 170.573
34 2022-9-8 03:05 170.563
35 2022-9-8 03:10 170.569
36 2022-9-8 03:15 170.562
37 2022-9-8 03:20 170.559
38 2022-9-8 03:25 170.557
39 2022-9-8 03:30 170.557
40 2022-9-8 03:35 170.549
41 2022-9-8 03:40 170.549
42 2022-9-8 03:45 170.549
43 2022-9-8 03:50 170.549
44 2022-9-8 03:55 170.545
45 2022-9-8 04:00 170.542
46 2022-9-8 04:05 170.542
47 2022-9-8 04:10 170.539
48 2022-9-8 04:15 170.539
49 2022-9-8 04:20 170.539
50 2022-9-8 04:25 170.537
51 2022-9-8 04:30 170.537
52 2022-9-8 04:35 170.532
53 2022-9-8 04:40 170.528
54 2022-9-8 04:45 170.528
55 2022-9-8 04:50 170.526
56 2022-9-8 04:55 170.527
57 2022-9-8 05:00 170.523
58 2022-9-8 05:05 170.518
59 2022-9-8 05:10 170.518
60 2022-9-8 05:15 170.518
61 2022-9-8 05:20 170.517
62 2022-9-8 05:25 170.511
63 2022-9-8 05:30 170.508
64 2022-9-8 05:35 170.502
65 2022-9-8 05:40 170.502
66 2022-9-8 05:45 170.498
67 2022-9-8 05:50 170.484
68 2022-9-8 05:55 170.496
69 2022-9-8 06:00 170.498
70 2022-9-8 06:05 170.493
71 2022-9-8 06:10 170.488
72 2022-9-8 06:15 170.483
73 2022-9-8 06:20 170.483
74 2022-9-8 06:25 170.483
75 2022-9-8 06:30 170.476
76 2022-9-8 06:35 170.472
77 2022-9-8 06:40 170.472
78 2022-9-8 06:45 170.472
79 2022-9-8 06:50 170.472
80 2022-9-8 06:55 170.472
81 2022-9-8 07:00 170.462
82 2022-9-8 07:05 170.468
83 2022-9-8 07:10 170.462
84 2022-9-8 07:15 170.462
85 2022-9-8 07:20 170.462
86 2022-9-8 07:25 170.462
87 2022-9-8 07:30 170.462
88 2022-9-8 07:35 170.462
89 2022-9-8 07:40 170.462
90 2022-9-8 07:45 170.457
91 2022-9-8 07:50 170.459
92 2022-9-8 07:55 170.455
93 2022-9-8 08:00 170.455
94 2022-9-8 08:05 170.455
95 2022-9-8 08:10 170.452
96 2022-9-8 08:15 170.452
97 2022-9-8 08:20 170.452
98 2022-9-8 08:25 170.452
99 2022-9-8 08:30 170.456
100 2022-9-8 08:35 170.452
101 2022-9-8 08:40 170.452
102 2022-9-8 08:45 170.461
103 2022-9-8 08:50 170.484
104 2022-9-8 08:55 170.501
105 2022-9-8 09:00 170.518
106 2022-9-8 09:05 170.476
107 2022-9-8 09:10 170.518
108 2022-9-8 09:15 170.527
109 2022-9-8 09:20 170.498
110 2022-9-8 09:25 170.501
111 2022-9-8 09:30 170.501
112 2022-9-8 14:10 170.588
113 2022-9-8 14:15 170.573
114 2022-9-8 14:20 170.565
115 2022-9-8 14:25 170.605
116 2022-9-8 14:30 170.690
117 2022-9-8 14:35 170.805
118 2022-9-8 14:40 170.847
119 2022-9-8 14:45 170.929
120 2022-9-8 15:00 171.136
121 2022-9-8 15:05 171.140
122 2022-9-8 15:10 171.179
123 2022-9-8 15:15 171.202
124 2022-9-8 15:20 171.220
125 2022-9-8 15:25 171.228
126 2022-9-8 16:25 171.279
127 2022-9-8 16:30 171.261
128 2022-9-8 16:45 171.285
129 2022-9-8 17:10 171.326
130 2022-9-8 17:15 171.281
131 2022-9-8 17:20 171.424
132 2022-9-8 17:25 171.275
133 2022-9-8 17:30 171.279
134 2022-9-8 17:35 171.316
135 2022-9-8 17:40 171.265
136 2022-9-8 17:45 171.240
137 2022-9-8 17:50 171.227
138 2022-9-8 17:55 171.208
139 2022-9-8 18:00 171.195
140 2022-9-8 18:05 171.195
141 2022-9-8 18:10 171.195
142 2022-9-8 18:15 171.174
143 2022-9-8 18:20 171.169
144 2022-9-8 18:25 171.164
145 2022-9-8 18:30 171.154
146 2022-9-8 18:35 171.151
147 2022-9-8 18:40 171.144
148 2022-9-8 18:45 171.154
149 2022-9-8 18:50 171.154
150 2022-9-8 18:55 171.126
151 2022-9-8 19:00 171.113
152 2022-9-8 19:05 171.113
153 2022-9-8 19:10 171.106
154 2022-9-8 19:15 171.094
155 2022-9-8 19:20 171.088
156 2022-9-8 19:25 171.083
157 2022-9-8 19:30 171.288
158 2022-9-8 19:35 171.093
159 2022-9-8 19:40 171.080
160 2022-9-8 19:45 171.072
161 2022-9-8 19:50 171.071
162 2022-9-8 19:55 171.071
163 2022-9-8 20:00 171.064
164 2022-9-8 20:05 171.057
165 2022-9-8 20:10 171.054
166 2022-9-8 20:15 171.047
167 2022-9-8 20:20 171.047
168 2022-9-8 20:25 171.037
169 2022-9-8 20:30 171.042
170 2022-9-8 20:35 171.035
171 2022-9-8 20:40 171.032
172 2022-9-8 20:45 171.023
173 2022-9-8 20:50 171.014
174 2022-9-8 20:55 171.021
175 2022-9-8 21:00 171.016
176 2022-9-8 21:05 171.010
177 2022-9-8 21:10 171.000
178 2022-9-8 21:15 170.999
179 2022-9-8 21:20 170.997
180 2022-9-8 21:25 170.996
181 2022-9-8 21:30 170.993
182 2022-9-8 21:35 170.992
183 2022-9-8 21:40 170.991
184 2022-9-8 21:45 170.991
185 2022-9-8 21:50 170.989
186 2022-9-8 21:55 170.982
187 2022-9-8 22:00 170.983
188 2022-9-8 22:05 170.981
189 2022-9-8 22:10 170.981
190 2022-9-8 22:15 170.971
191 2022-9-8 22:20 170.970
192 2022-9-8 22:25 170.970
193 2022-9-8 22:30 170.966
194 2022-9-8 22:35 170.965
195 2022-9-8 22:40 170.960
196 2022-9-8 22:45 170.959
197 2022-9-8 22:50 170.950
198 2022-9-8 22:55 170.950
199 2022-9-8 23:00 170.950
200 2022-9-8 23:05 170.944
201 2022-9-8 23:10 170.940
202 2022-9-8 23:15 170.940
203 2022-9-8 23:20 170.940
204 2022-9-8 23:25 170.940
205 2022-9-8 23:30 170.940
206 2022-9-8 23:35 170.936
207 2022-9-8 23:40 170.934
208 2022-9-8 23:45 170.929
209 2022-9-8 23:50 170.929
210 2022-9-8 23:55 170.929