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Draw the Lorenz system in Python/GTK
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# lorenz.py | |
# 5 March 2016 | |
# | |
# Copyright 2016 Jason Milldrum | |
# | |
# Draw the Lorenz system in a GTK window | |
# See https://en.wikipedia.org/wiki/Lorenz_system | |
import math | |
import gi | |
gi.require_version('Gtk', '3.0') | |
from gi.repository import Gtk | |
class MyWindow(Gtk.Window): | |
def __init__(self): | |
Gtk.Window.__init__(self, title="Lorenz Attractor") | |
self.move(100, 100) | |
self.drawing = Gtk.DrawingArea() | |
self.drawing.set_size_request(400, 400) | |
self.drawing.connect("draw", self.draw) | |
self.add(self.drawing) | |
self.coords = [] | |
def draw(self, widget, cr): | |
center_x = self.get_size()[0] / 2 | |
center_y = self.get_size()[1] / 2 | |
scale_x = self.get_size()[0] / 60 | |
scale_y = self.get_size()[1] / 60 | |
offset_y = center_y * 0.9 | |
cr.set_line_width(1) | |
cr.set_source_rgb(0.0, 0.0, 0.0) | |
cr.move_to(center_x, center_y - offset_y) | |
for i in self.coords: | |
# Draw the X-Z view | |
cr.line_to((i[0] * scale_x) + center_x, (i[2] * scale_y) + center_y - offset_y) | |
cr.stroke() | |
def lorenz(self): | |
h = 0.01 | |
sigma = 10.0 | |
rho = 28.0 | |
beta = 8.0 / 3.0 | |
x0 = 0.1 | |
y0 = 0.0 | |
z0 = 0.0 | |
for i in range(10000): | |
x1 = x0 + h * sigma * (y0 - x0) | |
y1 = y0 + h * (x0 * (rho - z0) - y0) | |
z1 = z0 + h * (x0 * y0 - beta * z0) | |
x0 = x1 | |
y0 = y1 | |
z0 = z1 | |
self.coords.append([x0, y0, z0]) | |
win = MyWindow() | |
win.connect("delete-event", Gtk.main_quit) | |
win.show_all() | |
win.lorenz() | |
Gtk.main() |
Author
NT7S
commented
Mar 5, 2016
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