我使用pcolormesh绘制了一个图表：

fig, ax = plt.subplots()
ax.pcolormesh(Omega_re, Omega_im, brightness, cmap="gray", shading="gouraud")
ax.set_xlabel(r"$Re(\omega)$")
ax.set_ylabel(r"$Im(\omega)$")
ax.set_aspect(1)
fig.show()

哪里

Omega_re = array([[2.  , 2.75, 3.5 , 4.25, 5.  ], [2.  , 2.75, 3.5 , 4.25, 5.  ],
       [2.  , 2.75, 3.5 , 4.25, 5.  ], [2.  , 2.75, 3.5 , 4.25, 5.  ],
       [2.  , 2.75, 3.5 , 4.25, 5.  ]])

Omega_im = array([[0. , 0. , 0. , 0. , 0. ], [0.0005, 0.0005, 0.0005, 0.0005, 0.0005],
       [0.001 , 0.001 , 0.001 , 0.001 , 0.001 ], [0.0015, 0.0015, 0.0015, 0.0015, 0.0015],
       [0.002 , 0.002 , 0.002 , 0.002 , 0.002 ]])

brightness = array([[4.05649772, 3.7299948 , 2.61262439, 4.2841897 , 3.40368949],
                    [4.05649076, 3.72997624, 2.61258381, 4.2841071 , 3.40353591],
                    [4.05648399, 3.72995772, 2.61254052, 4.28402084, 3.40338229],
                    [4.05647716, 3.72993901, 2.6124984 , 4.28393373, 3.40322865],
                    [4.05647025, 3.72992049, 2.61245428, 4.2838476 , 3.40307499]])

但由于x轴的范围为0到5，y轴的范围为0到0.002，因此结果显示为“扁平"。

有没有一种方法可以重新调整y轴，使图形看起来更好？下面是它当前显示方式的图片。