Python Matplotlib库实现画局部图(坐标轴坐标)

在画图中，我们需要放大图像的某一部分，看清其变化。最近在写论文时，就遇到了这个问题，还有坐标轴加粗、控制线型和大小等要求。这些，都可以通过Python Matplotlib库实现。具体看下面的代码：

import matplotlib.pyplot as plt
init_np = np.array(x0_list)
xopt_net_np = np.array(xopt_net)
plt.figure(figsize=(8,5))
plt.subplot(311)
ax = plt.gca() # 获取坐标轴
bwith = 1.2
ax.spines['bottom'].set_linewidth(bwith)
ax.spines['left'].set_linewidth(bwith)
ax.spines['top'].set_linewidth(bwith)
ax.spines['right'].set_linewidth(bwith)
plt.yticks([])
plt.xlim([-21,21])
plt.plot(init_np, np.zeros_like(init_np), '.b', markersize=2, label='initial value Distri.')
plt.legend()
plt.subplot(312)
ax = plt.gca()
bwith = 1.2
ax.spines['bottom'].set_linewidth(bwith)
ax.spines['left'].set_linewidth(bwith)
ax.spines['top'].set_linewidth(bwith)
ax.spines['right'].set_linewidth(bwith)
plt.yticks([])
plt.xlabel('x')
plt.plot(xopt_gd, np.zeros_like(xopt_gd), '.r', markersize=2, label='optimal value Distri. by GD')
plt.xlim([-21,21])
plt.legend()
plt.subplot(313)
ax = plt.gca()
bwith = 1.2
ax.spines['bottom'].set_linewidth(bwith)
ax.spines['left'].set_linewidth(bwith)
ax.spines['top'].set_linewidth(bwith)
ax.spines['right'].set_linewidth(bwith)
plt.yticks([])
plt.plot(xopt_net_np, np.zeros_like(xopt_net_np), '.r', markersize=2, label='optimal value Distri. by Network')
plt.xlim([-21,21])
plt.legend()
plt.axes([0.125,0.275,0.25,0.07])# list:[左下角水平坐标, 左下角垂直坐标, 宽度, 高度]
# plt.xticks(())
plt.yticks(())
plt.plot(xopt_net_np, np.zeros_like(xopt_net_np), '.r', markersize=1, label='optimal value Distr.')
plt.savefig('sol_scipy_ai.png', dpi=400, bbox_inches='tight')
plt.show()

得到了下面的效果：