feat: menambahkan pendulum

Author: Ateng-labrador

implementation/physics/pendulum.py

@@ -0,0 +1,73 @@
+# https://en.wikipedia.org/wiki/Pendulum
+import numpy as np
+import matplotlib.pyplot as plt
+from matplotlib.animation import FuncAnimation
+
+
+def full_pendulum(g, l, theta, theta_velocity, time_step):
+    """
+    fungsi untuk menghitung persamaan pendulum.
+    """
+    theta_acceleration = -(g / l) * np.sin(theta)
+    theta_velocity += time_step * theta_acceleration
+    theta += time_step * theta_velocity
+    return theta, theta_velocity
+
+
+g = 9.8  # konstanta gravitasi
+l = 1.0  # panjang tali
+
+
+theta = [np.radians(90)]
+theta_velocity = 0
+time_step = 20 / 300
+
+
+time_stap = np.linspace(0, 20, 300)
+"""
+Looping untuk memasukkan setiap angka.
+"""
+for t in time_stap:
+    theta_new, theta_velocity = full_pendulum(g, l, theta[-1],
+                                              theta_velocity, time_step)
+    theta.append(theta_new)
+
+# persamaan proyeksi panjang tali
+x = l * np.sin(theta)
+y = -l * np.cos(theta)
+
+fig, axis = plt.subplots()
+
+# batas sumbu x dan y
+axis.set_xlim(-l - 0.2 , l + 0.2)
+axis.set_ylim(-l - 0.2 , l)
+
+plt.grid()
+
+# benda yang akan bergerak
+rod_line, = axis.plot([], [], lw=2)
+mass_point, = axis.plot([], [], marker='o', markersize=10)
+trace, = axis.plot([], [], '-', lw=1, alpha=0.6)
+
+
+def animate(frame):
+    """
+    Fungsi ini berguna untuk mengambil setiap hasil hitungan
+    dan menjadikan setiap hitungan frame.
+    """
+    rod_line.set_data([0, x[frame]], [0, y[frame]])
+    mass_point.set_data([x[frame]], [y[frame]])
+    trace.set_data(x[:frame], y[:frame])
+
+    return rod_line, mass_point, trace
+
+
+animation = FuncAnimation(
+    fig=fig,
+    func=animate,
+    frames=len(time_stap),
+    interval=25,
+    blit=True
+)
+
+plt.show()