Saddle Point / Stagnation Flow

import matplotlib.pyplot as plt
import numpy as np

# Saddle point / stagnation flow
n = 6
x = np.linspace(-2, 2, n)
y = np.linspace(-2, 2, n)
z = np.linspace(-2, 2, n)
X, Y, Z = np.meshgrid(x, y, z)

# Saddle point flow
U = X
V = -Y
W = np.zeros_like(Z)

fig = plt.figure(figsize=(10, 8), facecolor='#ffffff')
ax = fig.add_subplot(111, projection='3d', facecolor='#ffffff')

ax.quiver(X, Y, Z, U, V, W, length=0.3, normalize=True,
          color='#ea580c', alpha=0.8, arrow_length_ratio=0.3)

# Mark saddle point
ax.scatter([0], [0], [0], color='#1f2937', s=100, marker='x', linewidths=3)

ax.set_xlim(-2.5, 2.5)
ax.set_ylim(-2.5, 2.5)
ax.set_zlim(-2.5, 2.5)

ax.set_xlabel('X', color='#1f2937', fontsize=10)
ax.set_ylabel('Y', color='#1f2937', fontsize=10)
ax.set_zlabel('Z', color='#1f2937', fontsize=10)
ax.set_title('Saddle Point / Stagnation Flow', color='#1f2937', fontsize=14, fontweight='bold', pad=20)

ax.tick_params(colors='#6b7280', labelsize=8)
ax.xaxis.pane.fill = False
ax.yaxis.pane.fill = False
ax.zaxis.pane.fill = False
ax.xaxis.pane.set_edgecolor('#e5e7eb')
ax.yaxis.pane.set_edgecolor('#e5e7eb')
ax.zaxis.pane.set_edgecolor('#e5e7eb')

ax.view_init(elev=35, azim=45)
plt.tight_layout()
plt.show()