如何在matplotlib中调整tight_layout下独立颜色栏的大小(高和宽)

import matplotlib.pyplot as plt
from matplotlib.gridspec import GridSpec

fig = plt.figure()
gs = GridSpec(2, 2)

ax1 = fig.add_subplot(gs[0, 0])
ax2 = fig.add_subplot(gs[0, 1])
ax3 = fig.add_subplot(gs[1, :])

# 在ax1上绘制图形
im1 = ax1.imshow(data1, cmap='viridis')
# 在ax2上绘制图形
im2 = ax2.imshow(data2, cmap='viridis')
# 在ax3上绘制图形
im3 = ax3.imshow(data3, cmap='viridis')

# 添加独立颜色栏
cax = fig.add_axes([0.95, 0.15, 0.02, 0.7])  # 调整颜色栏的位置和大小
fig.colorbar(im3, cax=cax)

import matplotlib.pyplot as plt
from matplotlib.gridspec import GridSpec

# 创建数据
data1 = [[1, 2], [3, 4]]
data2 = [[5, 6], [7, 8]]
data3 = [[9, 10], [11, 12]]

# 创建图形和子图
fig = plt.figure()
gs = GridSpec(2, 2)
ax1 = fig.add_subplot(gs[0, 0])
ax2 = fig.add_subplot(gs[0, 1])
ax3 = fig.add_subplot(gs[1, :])

# 在子图上绘制图形
im1 = ax1.imshow(data1, cmap='viridis')
im2 = ax2.imshow(data2, cmap='viridis')
im3 = ax3.imshow(data3, cmap='viridis')

# 添加独立颜色栏
cax = fig.add_axes([0.95, 0.15, 0.02, 0.7])
fig.colorbar(im3, cax=cax)

# 调整布局
plt.tight_layout()

# 显示图形
plt.show()