animate.py

import logging

import flet_charts
import matplotlib.pyplot as plt
import numpy as np

import flet as ft

logging.basicConfig(level=logging.INFO)

state = {}


def main(page: ft.Page):
    import matplotlib.animation as animation

    # Fixing random state for reproducibility
    np.random.seed(19680801)

    def random_walk(num_steps, max_step=0.05):
        """Return a 3D random walk as (num_steps, 3) array."""
        start_pos = np.random.random(3)
        steps = np.random.uniform(-max_step, max_step, size=(num_steps, 3))
        walk = start_pos + np.cumsum(steps, axis=0)
        return walk

    def update_lines(num, walks, lines):
        for line, walk in zip(lines, walks):
            line.set_data_3d(walk[:num, :].T)
        return lines

    # Data: 40 random walks as (num_steps, 3) arrays
    num_steps = 30
    walks = [random_walk(num_steps) for index in range(40)]

    # Attaching 3D axis to the figure
    fig = plt.figure()
    ax = fig.add_subplot(projection="3d")

    # Create lines initially without data
    lines = [ax.plot([], [], [])[0] for _ in walks]

    # Setting the Axes properties
    ax.set(xlim3d=(0, 1), xlabel="X")
    ax.set(ylim3d=(0, 1), ylabel="Y")
    ax.set(zlim3d=(0, 1), zlabel="Z")

    # Creating the Animation object
    state["anim"] = animation.FuncAnimation(
        fig, update_lines, num_steps, fargs=(walks, lines), interval=100
    )

    page.add(flet_charts.MatplotlibChartWithToolbar(figure=fig, expand=True))


ft.run(main)