Resolved: Program not working. Please check!

Hey Arkajit,

Thank you for reaching out!

Note the definition of your sierpinski_triangle() function

def sierpinski_triangle(x=0,y=0,n=1000)

as well as the following line of code

a,b=trans(x,y)

Calling trans() with parameters x and y results in evaluating the function at x=0 and y=0 each time. You will get three different outcomes depending on the choice of transformation function:

- The function trans1(x=0, y=0) would always return (0, 0).

- The function trans2(x=0, y=0) would always return (0.5, 0.5).

- The function trans3(x=0, y=0) would always return (1, 0).

This is the reason why you plot only these three points in your graph.

To remedy this, change the following line of code 

a,b=trans(x,y)

to instead read the following

a,b=trans(a,b)

In this way, you will always update the latest values of the variables a and b. Of course, you should also specify their initial values. You would therefore need to add the following line of code before the for-loop:

a, b = 0.0, 0.0

Having done that, the parameters x and y become redundant and can be removed from the definition of the sierpinski_triangle() function.

The final look of the function is the following:

def sierpinski_triangle(n=1000):
    '''Sierpinski Triangle'''

    transformation=[trans1,trans2,trans3]
    a1,b1=[0.0],[0.0]    
    a, b = 0.0, 0.0
    for i in range(n):
        trans=choice(transformation)
        a,b=trans(a,b)
        a1.append(a)
        b1.append(b)
    plt.rc('figure',figsize=(16,16))
    plt.plot(a1,b1,'o')

Hope this helped! Good luck on your Python journey!

Kind regards,

365 Hristina