31 lines
1.0 KiB
Python
31 lines
1.0 KiB
Python
from stimuli.AbstractStimulus import AbstractStimulus
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import numpy as np
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class SinusAmplitudeModulationStimulus(AbstractStimulus):
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def __init__(self, carrier_frequency, amplitude, contrast, modulation_frequency, start_time=0, duration=np.inf):
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self.contrast = contrast
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self.modulation_frequency = modulation_frequency
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self.amplitude = amplitude
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self.carrier_frequency = carrier_frequency
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self.start_time = start_time
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self.duration = duration
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def value_at_time_in_s(self, time_point):
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if time_point < self.start_time or time_point > self.start_time + self.duration:
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return 0
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am = (1 + self.contrast * np.sin(2*np.pi*self.modulation_frequency * time_point))
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carrier = np.sin(2*np.pi*self.carrier_frequency*time_point)
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return self.amplitude * am * carrier
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def get_stimulus_start_ms(self):
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return self.start_time
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def get_stimulus_duration_ms(self):
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return self.duration
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def get_amplitude(self):
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return self.contrast
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