I am attempting to translate a Julia set generator that I made previously to Python code. However, when the code is run, the turtle graphics window stops responding immediately and draws nothing. Have I done something horribly wrong or is there something I'm missing? Perhaps I'm asking too much of python to do in 1 frame. Please explain what is causing this to happen and how I can fix it. Thanks!
import turtle
import time
y_set = []
map_output = 0
iterations = 0
#turtle.hideturtle()
#turtle.speed(1)
generate a list of y-values
def y_set (r):
global y_set
y_set = []
for n in range ((360*2)+1):
y_set.append(n)
create a color value
def color (i, n):
output = map(i, 2, 10000, 0, 2500)
if output < 0:
output = 0
if output > 0:
output = 255
iterate on the x's
def repeat (n, r, i):
global iterations
global x
global y
aa = 0
ba = 0
ab = 0
a = 0
b = 0
for j in range (n):
iterations += 1
aa = a * a
bb = b * b
ab = 2 * a * b
a = ((aa - bb) + float(r))
b = (ab + float(i))
if (ab + bb) > 4:
break
turtle.setx(100 * x)
turtle.sety(100 * y)
color(iterations, n)
turtle.pendown()
turtle.penup()
Iterate on the y's
def Julia (s, r, i, d):
global iterations
global y_set
global x
global y
global a
global b
y_set(s)
while len(y_set) > 0:
y = y_set[0]/360
del y_set[0]
x = -1.5
for n in range (round((700/(float(r)+1))+1)):
a = x
b = y
iterations = 0
repeat(10**d, r, i)
x += ((1/240)*s)
user input
real = input('Real: ')
imag = input('Imaginary: ')
Julia (1, real, imag, 100)
turtle.done()
There are too many problems with this code to focus on an algorithm error. When I try to run it, I get, TypeError: 'int' object is not iterable. Specific issues:
The i argument here is being passed a number:
iterations += 1
...
color(iterations, n)
...
def color(i, n):
output = map(i, 2, 10000, 0, 2500)
but Python's map function (and Julia's) expects a function as its first argument:
map(func, *iterables)
and it returns a list of the results of applying func to iterables but you treat the result as a scalar value:
output = map(i, 2, 10000, 0, 2500)
if output < 0:
output = 0
if output > 0:
output = 255
The color() function never uses its second argument, and never returns anything!
The variables a & b here are being treated as globals, set but not used, as if prepared for use by repeat():
global a
global b
...
a = x
b = y
iterations = 0
repeat(10 ** d, r, i)
but the a & b used by repeat() are locals initialized to zero:
a = 0
b = 0
You have a function and global variable with the same name y_set!
And your globals are out of control.
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