I've been trying around with this piece of code to get it to draw a C-Curve(https://en.wikipedia.org/wiki/Lévy_C_curve), but somehow it keeps giving me this error:
IndexError: list index out of range
But the length of the list seems to be fine to me as it's set to n-1,so why does this error keep showing up?
I've had this exact same problem a little while ago when I tried something similar (the Sierprinski triangle), so I'd really appreciate some help.
import matplotlib.pyplot as plt
from math import *
def DrawC(direction, length, n):
"""Drawing the curve."""
if n > 0:
direction = direction + (pi / 4.0)
DrawC(direction, length / sqrt(2.0), n-1)
direction = direction - (pi / 2.0)
DrawC(direction, length / sqrt(2.0), n-1)
else:
x = x_lst[-1] + length * cos(direction)
y = y_lst[-1] + length * sin(direction)
x_lst.append(x)
y_lst.append(y)
n = int(raw_input('Generation of the curve: '))
x_lst = []
y_lst = [-150]
direction = pi / 2
length = 300
DrawC(direction, length, n)
plt.plot(x_lst, y_lst)
plt.title("C-curve")
plt.axis([-350, 350, -350, 350])
plt.show()
raw_input('Push the ENTER key: ')
The lists x_lst should not start empty.
Whatever path is taken in your code, when x = x_lst[-1] + length * cos(direction) the list cannot be empty. This makes sense as you are building a list of points, so start with, for instance, [0] for x_lst. That gives me nice pictures anyway :-)