Curve fit demonstration

curve_fit_ex.py

def fit_curve(x, y, plot_res=True):
  A = vstack((ones(100), ones(100)/x)).T
  k = linalg.lstsq(A, y)[0]
  print "Correct:", [a0, a1]
  print "Estimated:", k
  print "Error:", k-[a0, a1]
  
  if plot_res:
    figure()
    figsize(13,6)
    subplot(211)
    plot(x,y)
    plot(x, k[0] + k[1]/x)
    subplot(212)
    plot(x, y-k[0]-k[1]/x)
  

#Set up the test
x = linspace(0.1, 10, 100)
noise = random.randn(100)/8
#Our parameters
a0 = 1.234
a1 = 3
y0 = a0 + a1/x + noise
y1 = a0 + a1/x

print("Fit Curve to ideal data")
fit_curve(x, y0)
print("Fit Curve to noisy data")
fit_curve(x, y1)