26 lines
932 B
Python
26 lines
932 B
Python
import numpy as np
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from scipy.optimize import leastsq
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def hfitoff(data, xdeg):
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"""
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Harmonic fit with offset
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"""
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start, end = min(xdeg), max(xdeg)
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guess_amplitude = 2 ** 0.5 * np.std(data)
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guess_phase = 0
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guess_offset = np.mean(data)
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xrad = xdeg / 180 * np.pi
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optimize_func = lambda x: x[0] * np.sin(xrad + x[1]) + x[2] - data
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fit_amplitude, fit_phase, fit_offset = leastsq(optimize_func, [guess_amplitude, guess_phase, guess_offset])[0]
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if fit_amplitude < 0:
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fit_amplitude = -fit_amplitude
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fit_phase = fit_phase - np.pi
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fit_xdeg = np.linspace(start, end, 100)
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fit_data = fit_amplitude * np.sin(fit_xdeg / 180 * np.pi + fit_phase) + fit_offset
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fit_phase_deg = fit_phase / np.pi * 180
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ph_crest = 90 - fit_phase_deg
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if ph_crest > 180:
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ph_crest = ph_crest - 360
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return (fit_amplitude, fit_phase_deg, fit_offset, ph_crest, fit_xdeg, fit_data)
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