Finding beginning & end index of two hills in numpy array
Question:
Information
I have this numpy array
[ 23 22 21 22 21 22 23 23 23 21 21 22 22 22 22 22 22 22
22 22 21 21 22 22 22 22 23 22 22 21 21 20 20 19 19 19
19 19 19 19 19 20 21 22 23 23 23 22 22 22 22 21 20 20
19 19 19 19 19 19 19 19 19 19 20 20 21 21 23 24 24 25
25 26 26 25 24 24 24 24 23 23 23 23 23 22 21 20 19 19
19 18 18 18 18 18 19 18 18 18 18 18 18 18 18 18 18 17
17 17 17 17 17 18 19 19 19 19 19 19 19 19 19 19 19 19
19 19 19 19 19 19 19 18 18 18 17 16 16 16 15 14 15 14
14 15 15 16 16 16 16 16 15 15 15 14 14 14 14 14 13 13
13 13 13 13 11 11 10 10 11 9 9 8 9 11 11 12 12 10
10 10 11 12 12 12 13 15 14 14 12 14 13 18 24 32 40 51
63 62 68 78 82 90 92 93 95 96 106 112 118 123 123 125 130 134
136 137 138 140 144 148 153 158 163 163 163 159 161 164 165 163 166 176
179 184 190 200 207 210 213 214 216 218 221 228 233 236 237 238 238 241
243 243 243 243 242 236 208 192 177 165 163 160 152 148 143 130 121 113
94 81 61 53 48 41 31 30 29 28 21 19 13 5 3 7 9 9
10 9 10 10 10 10 10 10 9 10 10 10 10 10 10 11 11 13
16 21 22 21 22 22 26 24 22 22 19 19 19 19 19 19 24 32
40 47 49 58 62 65 63 70 79 82 84 89 93 95 96 101 105 105
111 111 117 117 117 118 122 123 126 128 133 134 138 141 150 154 157 159
160 160 160 173 183 201 220 227 241 253 254 266 272 272 271 276 278 280
284 285 284 271 262 248 247 248 252 253 256 259 266 266 266 258 256 268
265 271 278 281 288 285 286 277 266 250 240 207 180 137 99 92 82 81
82 80 81 80 80 80 77 77 78 79 75 73 72 72 71 72 70 71
73 73 72 70 71 70 69 68 68 70 67 65 64 65 64 63 63 63
63 63 61 62 62 62 62 63 63 63 63 63 63 63 63 64 61 60
62 61 60 60 60 60 60 60 59 57 57 55 55 53 52 50 49 47
46 44 44 42 40 39 37 36 32 30 27 24 25 26 22 18 6 7
7 8 11 12 17 18 20 20 20 19 20 20 20 19 20 21 22 21
24 22 22 20 20 19 19 17 17 16 17 15 15 15 14 14 15 13]
Question
I would like to know the index of the beginning & end of the left & right hill. This should be automated so a python function or a math approach to this problem would be very welcome.
Required Result
left = [ 181, 284 ]
right = [ 320, 502 ]
Answers:
It sounds like you’re going to want some combination of peak_width https://docs.scipy.org/doc/scipy/reference/generated/scipy.signal.peak_widths.html and find_peaks https://docs.scipy.org/doc/scipy/reference/generated/scipy.signal.find_peaks.html.
Use find_peaks to get the x position of the peaks, and then use those x position values as input to peak_widths. In peak_widths set the rel_height flag to something in the range of 0.1-0.2 0.95.
EDIT: Changed relative height flag recommendation as per Tdemunck’s comment
Information
I have this numpy array
[ 23 22 21 22 21 22 23 23 23 21 21 22 22 22 22 22 22 22
22 22 21 21 22 22 22 22 23 22 22 21 21 20 20 19 19 19
19 19 19 19 19 20 21 22 23 23 23 22 22 22 22 21 20 20
19 19 19 19 19 19 19 19 19 19 20 20 21 21 23 24 24 25
25 26 26 25 24 24 24 24 23 23 23 23 23 22 21 20 19 19
19 18 18 18 18 18 19 18 18 18 18 18 18 18 18 18 18 17
17 17 17 17 17 18 19 19 19 19 19 19 19 19 19 19 19 19
19 19 19 19 19 19 19 18 18 18 17 16 16 16 15 14 15 14
14 15 15 16 16 16 16 16 15 15 15 14 14 14 14 14 13 13
13 13 13 13 11 11 10 10 11 9 9 8 9 11 11 12 12 10
10 10 11 12 12 12 13 15 14 14 12 14 13 18 24 32 40 51
63 62 68 78 82 90 92 93 95 96 106 112 118 123 123 125 130 134
136 137 138 140 144 148 153 158 163 163 163 159 161 164 165 163 166 176
179 184 190 200 207 210 213 214 216 218 221 228 233 236 237 238 238 241
243 243 243 243 242 236 208 192 177 165 163 160 152 148 143 130 121 113
94 81 61 53 48 41 31 30 29 28 21 19 13 5 3 7 9 9
10 9 10 10 10 10 10 10 9 10 10 10 10 10 10 11 11 13
16 21 22 21 22 22 26 24 22 22 19 19 19 19 19 19 24 32
40 47 49 58 62 65 63 70 79 82 84 89 93 95 96 101 105 105
111 111 117 117 117 118 122 123 126 128 133 134 138 141 150 154 157 159
160 160 160 173 183 201 220 227 241 253 254 266 272 272 271 276 278 280
284 285 284 271 262 248 247 248 252 253 256 259 266 266 266 258 256 268
265 271 278 281 288 285 286 277 266 250 240 207 180 137 99 92 82 81
82 80 81 80 80 80 77 77 78 79 75 73 72 72 71 72 70 71
73 73 72 70 71 70 69 68 68 70 67 65 64 65 64 63 63 63
63 63 61 62 62 62 62 63 63 63 63 63 63 63 63 64 61 60
62 61 60 60 60 60 60 60 59 57 57 55 55 53 52 50 49 47
46 44 44 42 40 39 37 36 32 30 27 24 25 26 22 18 6 7
7 8 11 12 17 18 20 20 20 19 20 20 20 19 20 21 22 21
24 22 22 20 20 19 19 17 17 16 17 15 15 15 14 14 15 13]
Question
I would like to know the index of the beginning & end of the left & right hill. This should be automated so a python function or a math approach to this problem would be very welcome.
Required Result
left = [ 181, 284 ]
right = [ 320, 502 ]
It sounds like you’re going to want some combination of peak_width https://docs.scipy.org/doc/scipy/reference/generated/scipy.signal.peak_widths.html and find_peaks https://docs.scipy.org/doc/scipy/reference/generated/scipy.signal.find_peaks.html.
Use find_peaks to get the x position of the peaks, and then use those x position values as input to peak_widths. In peak_widths set the rel_height flag to something in the range of 0.1-0.2 0.95.
EDIT: Changed relative height flag recommendation as per Tdemunck’s comment