CODE EXAMPLE FOR PYTHON

Problème determinant algebre lineaire pdf mpsi

import math 
import numpy
from scipy.integrate import odeint
from scipy.special import ellipk, ellipe
from matplotlib.pyplot import *

            
class Spire:
    def __init__(self,a,zs,i):
        self.a = a
        self.a2 = a*a
        self.a4 = self.a2*self.a2
        self.zs = zs
        self.i = i
    def champB(self,x,z):
        if abs(x) < 1e-8:
            x=0
        if x>0:
            sx = 1
            x = -x
        else:
            sx = -1
        z = z-self.zs
        x2 = x*x
        z2 = z*z
        r2 = x2+z2
        b1 = self.a2+ r2
        b2 = 2*x*self.a
        b3 = b1+b2
        b4 = b1-b2
        b5 = -2*b2/b4
        b6 = math.sqrt(b3/b4)*self.i 
        rb3 = math.sqrt(b3)
        b7 = self.a*b3*rb3
        b8 = self.a4-self.a2*(x2-2*z2)+z2*(x2+z2)
        b9 = (self.a2+z2)*b3
        e = ellipe(b5)
        k = ellipk(b5)
        bz = b6*((self.a2-r2)*e+b3*k)/b7
        if x==0:
            bx = 0.0
            Atheta = 0.0
            Adx = bz/2
        else:
            bx = -sx*z/x*b6*(b1*e-b3*k)/b7
            Atheta = -sx*b6/x*(-b4*e+(self.a2+r2)*k)/(self.a*rb3)
            Adx = b6/x2*(b8*e-b9*k)/b7
        return [bx,bz,Atheta,Adx]