From d0faaddc911376edd266fbaaa8e2a4b73ed5a56f Mon Sep 17 00:00:00 2001
From: neingeist <neingeist@bl0rg.net>
Date: Mon, 21 Apr 2014 11:28:51 +0200
Subject: [PATCH] simplify S before printing it

---
 least-squares.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/least-squares.py b/least-squares.py
index ea21491..9603523 100755
--- a/least-squares.py
+++ b/least-squares.py
@@ -1,6 +1,6 @@
 #!/usr/bin/python2.7
 from __future__ import division, print_function
-from sympy import Symbol, diff, solve, lambdify
+from sympy import Symbol, diff, solve, lambdify, simplify
 import matplotlib.pyplot as plt
 import numpy as np
 
@@ -16,6 +16,7 @@ data = [(1,14), (2, 13), (3, 12), (4, 10), (5,9), (7,8), (9,5)]
 # For each data point the vertical error/residual is x*b1 + b2 - y. We want to
 # minimize the sum of the squared residuals (least squares).
 S = sum((p[0] * b1 + b2 - p[1]) ** 2 for p in data)
+S = simplify(S)
 print("Function to minimize: S = {}".format(S))
 
 # Minimize S by setting its partial derivatives to zero.