Last active
April 30, 2016 06:32
-
-
Save louisswarren/238361daebf464117d6d7f1cbdbb933a to your computer and use it in GitHub Desktop.
Test Taylor series approximations to sin
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
from math import factorial, pi, sin | |
def max_diff(f, g, v): | |
return max(abs(f(x) - g(x)) for x in v) | |
def zigrange(x, s=1.0): | |
yield 0 | |
for y in range(1, int(x / s + 0.5) + 1): | |
yield y * s; | |
yield -y * s; | |
# Test up to x**9 / (9!) | |
max_terms = 5 | |
odd = lambda n: 2 * n + 1 | |
terms = [lambda x, i=i: | |
(-1)**i * x**(odd(i)) / factorial(odd(i)) for i in range(max_terms)] | |
apprs = [lambda x, n=n: | |
sum(f(x) for f in terms[:n + 1]) for n in range(max_terms)] | |
for n, appr in enumerate(apprs): | |
error = max_diff(sin, appr, zigrange(pi / 2, 1e-3)) | |
print("With {} terms, the maximum error is {}".format(n + 1, error)) | |
# Results: | |
# With 1 terms, the maximum error is 0.5710000207413871 | |
# With 2 terms, the maximum error is 0.07521538109194614 | |
# With 3 terms, the maximum error is 0.004528924235860932 | |
# With 4 terms, the maximum error is 0.00015708088474730708 | |
# With 5 terms, the maximum error is 3.5476258620770196e-06 | |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment