File:Shooting method error.svg

Summary

Description
English: Graph showing error of the shooting method as a function of the initial value of w'(0).
Español: Gráfico mostrando el error del método de disparo como una función del valor inicial para w'(0).
Date
Source Own work
Author Nicoguaro
SVG development
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Source code
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Python code

# -*- coding: utf-8 -*-
"""
Illustrate the shooting method for the equation

    w'' = 3/2*w**2

It plots the error for picking different initial values in the range
[-100, 0]. There are two (approximated) roots -36 and 8.
"""
from __future__ import division
import numpy as np
import matplotlib.pyplot as plt
from scipy.integrate import odeint
import seaborn as sns

sns.set_style("white")


def func(y, t):
    return [y[1], 1.5*y[0]**2]


t = np.linspace(0, 1, 50)
diff_ini = np.linspace(-100, 0, 200)
err = np.zeros_like(diff_ini)
plt.figure(figsize=(6, 4))
for cont, dy in enumerate(diff_ini):
    y0 = [4, dy]    
    y = odeint(func, y0, t)
    err[cont] = y[-1, 0]

plt.hlines(0, -100, 0, linestyles="dashed", color="#3c3c3c",
           linewidth=1)
plt.plot(diff_ini, err)
plt.xlabel(r"$w'(0)=s$")
plt.ylabel(r"$w(t; s) - 1$")
plt.savefig("Shooting_method_error.svg", bbox_inches="tight")
plt.show()

Licensing

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w:en:Creative Commons
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Category:CC-BY-4.0#Shooting%20method%20error.svg
Category:Self-published work Category:Numerical analysis Category:Differential equations
Category:CC-BY-4.0 Category:Differential equations Category:Numerical analysis Category:Self-published work Category:Valid SVG created with Matplotlib code