blob: 6511429889744ab0ad823ef480c27a723b4ff25b (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
|
#!/usr/bin/env python3
# compute arctangent table for CORDIC computations in fttrigon.c
import math
# units = 64*65536.0 # don't change !!
units = 180 * 2 ** 16
scale = units / math.pi
shrink = 1.0
angles2 = []
print("")
print("table of arctan( 1/2^n ) for PI = " + repr(units / 65536.0) + " units")
for n in range(1, 32):
x = 0.5 ** n # tangent value
angle = math.atan(x) # arctangent
angle2 = round(angle * scale) # arctangent in FT_Angle units
if angle2 <= 0:
break
angles2.append(repr(int(angle2)))
shrink /= math.sqrt(1 + x * x)
print(", ".join(angles2))
print("shrink factor = " + repr(shrink))
print("shrink factor 2 = " + repr(int(shrink * (2 ** 32))))
print("expansion factor = " + repr(1 / shrink))
print("")
|
