#!/usr/bin/env python
# -*- coding: utf-8 -*-
import numpy

# Polynomial Regression
def reg_lin1(x, y, degree):
    results = {}

    m, c = numpy.polyfit(x, y, degree)

    # r-squared
    p = numpy.poly1d(m,c)
    # fit values, and mean
    yhat = [p(z) for z in x]
    ybar = sum(y)/len(y)
    ssreg = sum([ (yihat - ybar)**2 for yihat in yhat])
    sstot = sum([ (yi - ybar)**2 for yi in y])
    r = ssreg / sstot

    return m,c, r