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如何使用Python修改matplotlib.pyplot.colorbar的位置以对齐主图_python_

2023-05-26 461人已围观

简介如何使用Python修改matplotlib.pyplot.colorbar的位置以对齐主图_python_

问题描述

像这样的图，我想把右边的colorbar设置成和主图一样高度

方法

0. plt.colorbar参数介绍

https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.colorbar.html?highlight=colorbar#matplotlib.pyplot.colorbar

1. plt.colorbar(im, fraction=0.046, pad=0.04, shrink=1.0)

fraction可以从0.035-0.046调节以找到合适大小

但当图像的长、高对比过大时，可能不起作用

2. make_axes_locatable

这是matplotlib包里的一个函数

from mpl_toolkits.axes_grid1 import make_axes_locatable im = plt.imshow(data) divider = make_axes_locatable(plt.gca()) cax = divider.append_axes("right", size="5%", pad="3%") plt.colorbar(im, cax=cax)

不适用于有投影参数的axe（会报错），如cartopy的GeoAxes

3. make_axes_locatables 升级版

https://stackoverflow.com/questions/18195758/set-matplotlib-colorbar-size-to-match-graph @Matthias

import matplotlib.pyplot as plt from mpl_toolkits import axes_grid1 def add_colorbar(im, aspect=20, pad_fraction=0.5, **kwargs): """Add a vertical color bar to an image plot.""" divider = axes_grid1.make_axes_locatable(im.axes) width = axes_grid1.axes_size.AxesY(im.axes, aspect=1./aspect) pad = axes_grid1.axes_size.Fraction(pad_fraction, width) current_ax = plt.gca() cax = divider.append_axes("right", size=width, pad=pad) plt.sca(current_ax) return im.axes.figure.colorbar(im, cax=cax, **kwargs)

用法示例

im = plt.imshow(np.arange(200).reshape((20, 10))) add_colorbar(im)

4. 手动给colorbar添加一个axe

https://stackoverflow.com/questions/18195758/set-matplotlib-colorbar-size-to-match-graph @Fei Yao

import matplotlib.pyplot as plt import numpy as np fig=plt.figure() ax = plt.axes() im = ax.imshow(np.arange(100).reshape((10,10))) # Create an axes for colorbar. The position of the axes is calculated based on the position of ax. # You can change 0.01 to adjust the distance between the main image and the colorbar. # You can change 0.02 to adjust the width of the colorbar. # This practice is universal for both subplots and GeoAxes. cax = fig.add_axes([ax.get_position().x1+0.01,ax.get_position().y0,0.02,ax.get_position().height]) plt.colorbar(im, cax=cax) # Similar to fig.colorbar(im, cax = cax)

效果展示