'''

Here is a brain-bending task for the daring.
It's based on an idea I'd like to solve:

how to write a script to recognise constellations of stars from photographs.

I've simplified that concept down to constellations having 3 stars of different colours.

# a, b, c and d represent 4 triangles plotted on graph paper
# One triangle has been plotted three times, from different points of view and at different magnifications
# A fourth, different, triangle has been plotted once.
# The tuples contain the x, y co-ordinates of the 3 points of a triangle.
# In each triangle, the 3 points have different colours and
# for all triangles, the points are listed in the same colour order.


'''

# Can you write a script to determine which is the odd one out?

a = [(3.0, 6.0), (3.0, 3.0), (7.0, 3.0)]
b = [(4.4, 3.2), (4.4, 5.0), (2.0, 5.0)]
c = [(3.0, 5.2), (5.4, 5.2), (5.4, 2.0)]
d = [(4.0, 1.0), (5.5, 1.0), (5.5, 3.0)]

triangles = [a, b, c, d]

new_triangles = []
for triangle in triangles:
    new_triangles.append(triangle + [triangle[0]])
new_triangles.append(new_triangles[0] + [new_triangles[0][0]])

P1 = []
P2 = []
P3 = []

for triangle in new_triangles:
    P1.append(triangle[0])
    P2.append(triangle[1])
    P3.append(triangle[2])

import matplotlib.pyplot as plt

points = [P1, P2, P3]
colors = ['red', 'green', 'blue']
# plot each group of points with the same colour
for point,color in zip(points, colors):
    Xs = [x[0] for x in point]
    Ys = [x[1] for x in point]
    # plot the points only not the line
    plt.scatter(Xs, Ys, c=color, marker='o')

# plot the line between the points for the triangles
for triangle in new_triangles:
    Xs = [x[0] for x in triangle]
    Ys = [x[1] for x in triangle]
    plt.plot(Xs, Ys, c='grey')


plt.show()