# -*- coding: utf-8 -*-
"""
Created on Mon Dec 08 14:11:09 2014

@author: grivet

Exercice 2.5 : Calcul et tracé des fonctions d'Airy A(x) et B(x)

"""
from pylab import *

def f(x):
    terme = 1.0; somme = terme; k = 0
    while abs(terme) > 10**(-7):
        terme = x*x*x*terme/(3*k+2)/(3*k+3)
        somme = somme + terme
        k = k+1
    return somme
def g(x):
    terme = x; somme = terme; k = 0
    while abs(terme) > 10**(-7):
        terme = x*x*x*terme/(3*k+3)/(3*k+4)
        somme = somme + terme
        k = k+1
    return somme
c1 = 0.3550281; c2 = 0.2588194
def Ai(x):
    return c1*f(x) - c2*g(x)
def Bi(x):
    return sqrt(3)*(c1*f(x) + c2*g(x))
pas = 0.01; x = -14.0; i = 0
X = zeros(1500); AA = zeros(1500); BB = zeros(1500)
while x < 0.99:
    X[i] = x; AA[i] = Ai(x); BB[i] = Bi(x);
    i = i+1; x = x+pas
plot(X,AA,'-k',X,BB,'-b')
show()