HP-35 style trig functions

[Thomas Klemm]

(01-14-2019 02:34 AM)Druzyek Wrote:  I'm starting to think it is not possible

Since you have plenty of space for lookup-tables you could pre-compute COS and SIN:

Code:

from math import radians, sin, cos

COS = [ [ cos(radians(10**i * j)) for j in range(10)] for i in range(1, -18, -1)]
SIN = [ [ sin(radians(10**i * j)) for j in range(10)] for i in range(1, -18, -1)]

arg = radians(17.188733853924695)
digits = [1, 7, 1, 8, 8, 7, 3, 3, 8, 5, 3, 9, 2, 4, 6, 9, 5]

x, y = 1.0, 0.0
for i, j in enumerate(digits):
    u, v = COS[i][j], SIN[i][j]
    x, y = x * u - y * v, x * v + y * u

print(x, y)
print(cos(arg), sin(arg))

This results in:

Code:

# 0.9553364891256062 0.2955202066613395
# 0.955336489125606 0.29552020666133955

However now 4 multiplications are needed for each digit.
Here you can use degrees for the angle.
But of course you could use radians instead.

Cheers
Thomas