Add: slope_sign_change, log_detector and willison_amplitude #826
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Features : slope_sign_change, log_detector and willison_amplitude. This features are popular and useful in time domain analisys for EMG signals. The main reference for this features are: [1] Phinyomark, A., Phukpattaranont, P., & Limsakul, C. (2012). Feature reduction and selection for EMG signal classification. Expert systems with applications, 39(8), 7420-7431.
| # Calculation of feature as float | ||
| x = np.asarray(x) | ||
| n = len(x) | ||
| x = x + (x == 0)*0.000000000001 |
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what is the motivation behind this line?
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I investigated it better and I think what I did is not a good strategy. The idea was to avoid errors generated by values equal to zero for the next line but we use a low value, and this tends to infinity.
| | [1] Phinyomark, A., Phukpattaranont, P., & Limsakul, C. (2012). Feature reduction and selection for EMG signal classification. Expert systems with applications, 39(8), 7420-7431. | ||
| """ | ||
| # Calculation of feature as int | ||
| return np.sum(np.abs(x[1:] - x[:-1]) > t) |
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instead of x[1:] - x[:-1] I think you could use np.diff
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Great, @theinem ! Three really interesting features. As @MaxBenChrist mentioned, could you add some unittests for your new feature calculators? We try to test every calculator :-) |
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As I said in my other PR, I would like to make the improvements you asked for, but for several weeks I have had problems with available time and it will continue like this for several weeks/months. |
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Thanks for the info, @theinem. As mentioned in #825, this is not a problem for us! |
Features : slope_sign_change, log_detector and willison_amplitude.
This features are popular and useful in time domain analisys for EMG signals. The main reference for this features are: [1] Phinyomark, A., Phukpattaranont, P., & Limsakul, C. (2012). Feature reduction and selection for EMG signal classification. Expert systems with applications, 39(8), 7420-7431.
I'm a newbie to contributing to projects on Github, but I tried to follow the steps in your documentation.