#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Sat Sep 21 08:26:54 2019

@author: FranChan
"""
import matplotlib.pyplot, pylab
from copy import deepcopy
prices = []
prices.append([40,50000])
prices.append([52,72000])
prices.append([85,120000])
prices.append([120,180000])
pprices = []
for p in prices:
    pp = deepcopy(p)
    pp.append(p[0]*p[1])
    pp.append(p[0]**2)
    pp.append(p[1]**2)
    pprices.append(pp)
sy = 0
sx = 0
sy2 = 0
sx2 = 0
sxy = 0
for p in pprices:
    sy+=p[1]
    sx+=p[0]
    sxy+=p[2]
    sx2+=p[3]
    sy2+=p[4]
n = len(prices)
print(sx,sy,sxy,sx2,sy2)
a = (sy*sx2-sx*sxy)/(n*sx2-(sx**2))
b = (n*(sxy)-sx*sy)/(n*sx2-(sx**2))
print(a,b)
prediction = []
for p in pprices:
    prediction.append([p[0],b*p[0]+a])
c = int(input("How many x would you like to enter"))
xinp = []
for i in range(c):
    nx = int(input("Enter x: "))
    xinp.append([nx,b*nx+a])
matplotlib.pyplot.scatter(*zip(*prices))
matplotlib.pyplot.plot(*zip(*prediction))
matplotlib.pyplot.scatter(*zip(*xinp))
matplotlib.pyplot.show()