Ratefunction

import matplotlib.pyplot as plt
import numpy as np
from manim import *
config.media_embed = True

def figtoimg(fig):
    fig.canvas.draw()
    img = fig.canvas.buffer_rgba()
    plt.close(fig)
    return img

Manim Community v0.17.2

def my_function(amplitude, x):
    return amplitude * np.sin(x)

def make_plot(amplitude, x):
    fig, ax = plt.subplots(dpi=200)
    ax.plot(x, my_function(amplitude, x), lw=3)
    ax.set_ylim(-1, 1)
    return figtoimg(fig)

class Example(Scene):
    def construct(self):
        self.camera.background_color = BLUE_A
        x_values = np.linspace(0, 30, 400)
        amp1 = 0.5
        amp2 = 1
        tr_amplitude = ValueTracker(amp1)
        image = ImageMobject(make_plot(amp1, x_values))
        self.add(image)

        def update_image(mob):
            new_mob = ImageMobject(make_plot(tr_amplitude.get_value(), x_values))
            mob.become(new_mob)

        image.add_updater(update_image)
        self.play(tr_amplitude.animate.set_value(amp2), rate_func=smooth, run_time=1.0)
        self.play(tr_amplitude.animate.set_value(amp1), rate_func=smooth, run_time=1.0)


%manim -v WARNING -qh --disable_caching --progress_bar None Example