49 lines
1.7 KiB
Python
49 lines
1.7 KiB
Python
# waves.py
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# Eryn Wells <eryn@erynwells.me>
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'''
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Several functions for creating audio waves.
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'''
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import numpy as np
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__default_num_harmonics = 10
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def sine(domain, freq=1.0, phase=0):
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'''Render a sine wave in the given time domain with the specified frequency and phase.'''
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return np.sin(2.0 * np.pi * freq * domain + phase)
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def saw(domain, freq=1.0, num_harmonics=__default_num_harmonics):
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'''
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Render a saw wave in the given domain at the specified frequency.
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This function produces a saw wave by computing the first `harmonics` terms of the
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infinite series defining its shape.
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'''
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harmonics = np.asarray([1.0 / h * sine(domain, freq=freq * h) for h in range(1, num_harmonics)])
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wave = np.sum(harmonics, axis=0)
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return wave
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def square(domain, freq=1, num_harmonics=__default_num_harmonics):
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'''
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Render a square wave in the given domain at the specified frequency.
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This function produces a saw wave by computing the first `harmonics` terms of the
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infinite series defining its shape.
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'''
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harmonics = np.asarray([1.0 / h * sine(domain, freq=freq * h) for h in range(1, num_harmonics, 2)])
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wave = np.sum(harmonics, axis=0)
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return wave
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def triangle(domain, freq=1, num_harmonics=__default_num_harmonics):
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'''
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Render a triangle wave in the given domain at the specified frequency.
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This function produces a saw wave by computing the first `num_harmonics` terms of the
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infinite series defining its shape.
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'''
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def label(i):
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return 2.0 * i + 1.0
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harmonics = np.asarray([((-1) ** h) * (label(h) ** -2) * sine(domain, freq=freq * label(h)) for h in
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range(num_harmonics)])
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wave = np.sum(harmonics, axis=0)
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return wave
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