Created
December 19, 2012 16:54
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Sine table generation using Python
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#!/usr/bin/env python | |
## Generate sine table | |
import math | |
def rescale(X,A,B,C,D,force_float=False): | |
retval = ((float(X - A) / (B - A)) * (D - C)) + C | |
if not force_float and all(map(lambda x: type(x) == int, [X,A,B,C,D])): | |
return int(round(retval)) | |
return retval | |
SAMPLES = 256 | |
SCALE = 0,255 ## Output scale range | |
if __name__ == '__main__': | |
## Angles in degrees for which to calculate sine | |
angles = [rescale(i,0,SAMPLES,90,360) for i in range(SAMPLES)] | |
sin_table = [int(round(rescale(s,-1,1,SCALE[0],SCALE[1]))) for s in [ | |
math.sin(math.radians(a)) for a in angles | |
]] | |
print sin_table |
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import math | |
SAMPLES = 256 | |
OUTMAX = 255 | |
import sys | |
if len(sys.argv) > 1: | |
SAMPLES = int(sys.argv[1]) | |
if len(sys.argv) > 2: | |
OUTMAX = int(sys.argv[2]) | |
angle_range = [9999, -9999] | |
sine_range = [99, -99] | |
rescaled_range = [9999, -9999] | |
for sample in range(SAMPLES): | |
angle = (sample * 360.0) / SAMPLES | |
sine = math.sin(math.radians(angle)) | |
rescaled = int(round(((sine + 1) * OUTMAX ) / 2.0)) | |
angle_range[0] = min(angle_range[0], angle) | |
angle_range[1] = max(angle_range[1], angle) | |
sine_range[0] = min(sine_range[0], sine) | |
sine_range[1] = max(sine_range[1], sine) | |
rescaled_range[0] = min(rescaled_range[0], rescaled) | |
rescaled_range[1] = max(rescaled_range[1], rescaled) | |
print "%4d" % sample, | |
print "%4d" % angle, | |
print "%7.3f" % sine, | |
print "%4d" % rescaled, | |
print "#" * rescaled, | |
print "-"*60 | |
print "Angle range:", angle_range | |
print "Sine range:", sine_range | |
print "Rescaled range:",rescaled_range |
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