#This source code is public domain
import numpy, pylab
from matplotlib.font_manager import FontProperties
import matplotlib.pyplot as plt
import matplotlib.patches as mpatches
from numpy.random import randn

x=[1,2,3,4,5,6,7]
y=[2.0,2.5,2.5,3.4,3.7,6.6,3]

for N in range(1,8):
   A=numpy.zeros((N,N))
   for i in range(N):
       for j in range(N):
           A[i,j]=sum(xi**(i+j) for xi in x)
   b=numpy.zeros((N))
   for i in range(N):
       b[i]=sum(xi**(i)*yi for xi,yi in zip(x,y))
   c=numpy.linalg.solve(A, b)
   xr=numpy.asarray(x)
   yr=numpy.sum([c[i]*xr**i for i in range(len(c))],axis=0)
   residuen=[]
   for i in range(len(x)): residuen+=[[xr[i],xr[i]],[y[i],yr[i]],'g-']
   xneu=numpy.linspace(0, 8, num=100)
   yneu=numpy.sum([c[i]*xneu**i for i in range(len(c))],axis=0)
   plt.clf()
   fig = plt.figure(figsize=(4.5, 3.5))
   fig.subplotpars.bottom=0.13
   y0=plt.plot(*residuen[:-3])
   plt.setp(y0, color='#80d080', linewidth=1.5)
   #y0=plt.plot(*residuen[-3:], label="Residuen")
   y0,=plt.plot(*residuen[-3:])
   plt.setp(y0, color='#80d080', linewidth=1.5)
   #y2=plt.plot(xneu,yneu,'r-', label="Modellfunktion")
   y2,=plt.plot(xneu,yneu,'r-')
   #y1=plt.plot(x,y,'o', label="Messpunkte")
   y1,=plt.plot(x,y,'o')
   plt.xlabel('x')
   plt.ylabel('y')
   font = FontProperties()
   font.set_size('medium')
   leg = plt.legend([y1,y2,y0],['Messpunkte','Modellfunktion','Residuen'],frameon=True,loc='lower right',labelspacing=0.3,prop=font)
   #leg = plt.legend(frameon=True,loc='lower right',labelspacing=0.3,prop=font)
   plt.grid(True)
   plt.axis([0, 8, 0, 8])
   plt.text(1,7, "Polynomgrad "+str(N-1),bbox=dict(boxstyle="square,pad=0.5",color='white',ec='black',fill=True))
   #plt.show()
   plt.savefig('MDKQ_anim%i.png'%N)
   plt.savefig('test.eps', format='eps', dpi=900)
   plt.savefig("MDKQ_anim%i.svg"%N)