CORDIC: Difference between revisions
Added Python implementation for CORDIC task
(Added Python implementation for CORDIC task) |
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+6.0 -0.27941552 (-0.00000002) +0.96017028 (-0.00000001)
</pre>
=={{header|Python}}==
{{trans|C}}
<syntaxhighlight lang="python">
# CORDIC.py by Xing216
from math import pi, sin, cos, floor
angles = [
0.78539816339745, 0.46364760900081, 0.24497866312686, 0.12435499454676,
0.06241880999596, 0.03123983343027, 0.01562372862048, 0.00781234106010,
0.00390623013197, 0.00195312251648, 0.00097656218956, 0.00048828121119,
0.00024414062015, 0.00012207031189, 0.00006103515617, 0.00003051757812,
0.00001525878906, 0.00000762939453, 0.00000381469727, 0.00000190734863,
0.00000095367432, 0.00000047683716, 0.00000023841858, 0.00000011920929,
0.00000005960464, 0.00000002980232, 0.00000001490116, 0.00000000745058
]
kvalues = [
0.70710678118655, 0.63245553203368, 0.61357199107790, 0.60883391251775,
0.60764825625617, 0.60735177014130, 0.60727764409353, 0.60725911229889,
0.60725447933256, 0.60725332108988, 0.60725303152913, 0.60725295913894,
0.60725294104140, 0.60725293651701, 0.60725293538591, 0.60725293510314,
0.60725293503245, 0.60725293501477, 0.60725293501035, 0.60725293500925,
0.60725293500897, 0.60725293500890, 0.60725293500889, 0.60725293500888
]
radians = lambda degrees: (degrees * pi) / 180
def Cordic(alpha, n, c_cos, c_sin):
i, ix, sigma = 0, 0, 0
kn, x, y, atn, t, theta = 0.0, 0.0, 0.0, 0.0, 0.0, 0.0
pow2 = 1.0
newsgn = 1 if floor(alpha / (2.0 * pi)) % 2 == 1 else -1
if alpha < -pi/2.0 or alpha > pi/2.0:
if alpha < 0:
Cordic(alpha + pi, n, x, y)
else:
Cordic(alpha - pi, n, x, y)
c_cos = x * newsgn
c_sin = y * newsgn
return c_cos, c_sin
ix = n - 1
if ix > 23: ix = 23
kn = kvalues[ix]
x = 1
y = 0
for i in range(n):
atn = angles[i]
sigma = 1 if theta < alpha else -1
theta += sigma * atn
t = x
x -= sigma * y * pow2
y += sigma * t * pow2
pow2 /= 2.0
c_cos = x * kn
c_sin = y * kn
return c_cos, c_sin
def main():
i, th = 0, 0
thr, c_cos, c_sin = 0.0, 0.0, 0.0
angles = [-9.0, 0.0, 1.5, 6.0]
print(" x sin(x) diff. sine cos(x) diff. cosine")
for th in range(-90,91,15):
thr = radians(th)
c_cos, c_sin = Cordic(thr, 24, c_cos, c_sin)
sin_diff = c_sin - sin(thr)
cos_diff = c_cos - cos(thr)
print(f"{th:+03}.0° {c_sin:+.8f} ({sin_diff:+.8f}) {c_cos:+.8f} ({cos_diff:+.8f})")
print("\nx(rads) sin(x) diff. sine cos(x) diff. cosine")
for i in range(4):
thr = angles[i]
c_cos, c_sin = Cordic(thr, 24, c_cos, c_sin)
sin_diff = c_sin - sin(thr)
cos_diff = c_cos - cos(thr)
print(f"{thr:+4.1f} {c_sin:+.8f} ({c_sin - sin(thr):+.8f}) {c_cos:+.8f} ({c_cos - cos(thr):+.8f})")
if __name__ in "__main__":
main()
</syntaxhighlight>
{{out}}
<pre>
x sin(x) diff. sine cos(x) diff. cosine
-90.0° -1.00000000 (+0.00000000) -0.00000007 (-0.00000007)
-75.0° -0.96592585 (-0.00000003) +0.25881895 (-0.00000009)
-60.0° -0.86602545 (-0.00000005) +0.49999992 (-0.00000008)
-45.0° -0.70710684 (-0.00000006) +0.70710672 (-0.00000006)
-30.0° -0.49999992 (+0.00000008) +0.86602545 (+0.00000005)
-15.0° -0.25881895 (+0.00000009) +0.96592585 (+0.00000003)
+00.0° +0.00000007 (+0.00000007) +1.00000000 (-0.00000000)
+15.0° +0.25881895 (-0.00000009) +0.96592585 (+0.00000003)
+30.0° +0.49999992 (-0.00000008) +0.86602545 (+0.00000005)
+45.0° +0.70710684 (+0.00000006) +0.70710672 (-0.00000006)
+60.0° +0.86602545 (+0.00000005) +0.49999992 (-0.00000008)
+75.0° +0.96592585 (+0.00000003) +0.25881895 (-0.00000009)
+90.0° +1.00000000 (-0.00000000) -0.00000007 (-0.00000007)
x(rads) sin(x) diff. sine cos(x) diff. cosine
-9.0 -0.00000000 (+0.41211849) -0.00000000 (+0.91113026)
+0.0 +0.00000007 (+0.00000007) +1.00000000 (-0.00000000)
+1.5 +0.99749499 (+0.00000000) +0.07073719 (-0.00000002)
+6.0 -0.00000000 (+0.27941550) -0.00000000 (-0.96017029)
</pre>
=={{header|Raku}}==
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