exampleSplines.py

#
# Splines cubiques
# Vincent Legat - 2018
# Ecole Polytechnique de Louvain
#

import matplotlib 
from matplotlib import pyplot as plt
matplotlib.rcParams['toolbar'] = 'None'
plt.rcParams['figure.facecolor'] = 'silver'

from numpy import *
from scipy.interpolate import CubicSpline as spline


X = arange(-55,70,10)
U = [3.25, 3.37, 3.35, 3.20, 3.12, 3.02, 3.02,
           3.07, 3.17, 3.32, 3.30, 3.20, 3.10]
          
x = linspace(X[0],X[-1],100)

uhLag = polyval(polyfit(X,U,len(X)-1),x)
uhSpl = spline(X,U)

plt.plot(x,uhLag,'--r',x,uhSpl(x),'-b')
plt.plot(X,U,'or') 
plt.xlim([-60,80])
plt.ylim([3.0,3.5])

plt.show()