Calling a function inside a class to set the element of list

I'm trying to implement my first class, partly as a way to break up the modeling and solving of a math problem I'm having trouble with. I don't think my problem relates to the class, but...?

The error keeps telling me that: "NameError: global name 'corner2' is not defined"

I tried moving the function call, but it still doesn't recognize it, so I put it back into the list declaration in my init function.

Here is my code:

class RotatedRectangle(object):

def corner1(a,b):
    a/=2
    b/=2
    x=(a-b)*math.sin(math.pi/4)
    y=(a+b)*math.sin(math.pi/4)
    return (x,y)

def corner2(a,b):
    a/=-2
    b/=2
    x=(a-b)*math.sin(math.pi/4)
    y=(a+b)*math.sin(math.pi/4)
    return (x,y)

def corner3(a,b):
    a/=-2
    b/=-2
    x=(a-b)*math.sin(math.pi/4)
    y=(a+b)*math.sin(math.pi/4)
    return (x,y)

def corner4(a,b):
    a/=2
    b/=2
    x=(a-b)*math.sin(math.pi/4)
    y=(a+b)*math.sin(math.pi/4)
    return (x,y)

def __init__(self, a, b,):
        """Return a Rotated rectangle object whose name is a function of a and b."""
        self.name = str(a) + "," + str(b) + "-rectangle"
        self.corners = [corner1(a,b), corner2(a,b), corner3(a,b), corner4(a,b)]



"""A rectangle with sides equal to even integers a and b is drawn on the          Cartesian plane.Its center (the intersection point of its diagonals) coincides with the point (0, 0),but the sides of the rectangle are not parallel to the axes; instead, they are forming 45 degree angles with the axes.

How many points with integer coordinates are located inside the given   rectangle (including on its sides)? """

Solution

You have to use self as the first parameter of your class methods
When calling class methods inside your class you have to pass self as their first parameter(so that the class knows that you are talking about the current object)

You have to indent when defining a method inside your class

import math
class RotatedRectangle(object):
    def corner1(self,a,b):
        a/=2
        b/=2
        x=(a-b)*math.sin(math.pi/4)
        y=(a+b)*math.sin(math.pi/4)
        return (x,y)

    def corner2(self,a,b):
        a/=-2
        b/=2
        x=(a-b)*math.sin(math.pi/4)
        y=(a+b)*math.sin(math.pi/4)
        return (x,y)

    def corner3(self,a,b):
        a/=-2
        b/=-2
        x=(a-b)*math.sin(math.pi/4)
        y=(a+b)*math.sin(math.pi/4)
        return (x,y)

    def corner4(self,a,b):
        a/=2
        b/=2
        x=(a-b)*math.sin(math.pi/4)
        y=(a+b)*math.sin(math.pi/4)
        return (x,y)

    def __init__(self, a, b,):
        """Return a Rotated rectangle object whose name is a function of a and b."""
        self.name = str(a) + "," + str(b) + "-rectangle"
        self.corners = [self.corner1(a,b), self.corner2(a,b), self.corner3(a,b), self.corner4(a,b)]