在同一个图形中有两个图形并打印i

Question

我用python中的plotnine绘制了两个绘图。我知道不支持绘制子图（here）。我想知道是否有一种方法可以在一个图中创建子图。在

我想用plotineplot.draw()把它们做成一个图形，然后用matplotlib读取，或者先将它们保存为png，然后用matplotlib读取它们并将它们组合在一起。但是，我对matplotlib不是很在行，直到现在，每次尝试都是徒劳的。在

示例图9：

from plotnine import data
from plotnine import *

plot1 = (ggplot(data.mtcars, aes('wt', 'mpg', color='factor(gear)'))
 + geom_point()
 + stat_smooth(method='lm')
 + facet_wrap('~gear'))

任何帮助都会很有帮助的。在

Answer 1

最后，我创建了一个解决方案，将图保存为图像，然后再次加载并组合它们。这不是最快或最有效的方法，但它工作得很好。在

    import plotnine as gg
    import matplotlib.pyplot as plt
    import matplotlib.image as img
    import os
    import numpy as np

    def _check_plotnine_grid(plots_list, figsize):
        if not type(plots_list) == list:
            raise ValueError('Input plots_list is not a list')
        if (not type(figsize) == tuple) or (not len(figsize) == 2):
            raise ValueError('Input figsize should be a tuple of length 2')


    def plotnine_grid(plots_list, row=None, col=1, height=None, width=None, dpi=500, ratio=None, pixels=10000,
                      figsize=(12, 8)):

    """
    Create a grid of plotnine plots.


Function input
     
plots_list      : a list of plotnine.ggplots
row, col        : numerics to indicate in how many rows and columns the plots should be ordered in the grid
                  defaults: row -> length of plots_list; col -> 1
height, width   : the height and width of the individual subplots created by plotnine
                    can be automatically determined by a combination of dpi, ratio and pixels
dpi             : the density of pixels in the image. Default: 500. Higher numbers could lead to crisper output,
                    depending on exact situation
ratio           : the ratio of heigth to width in the output. Standard value is 1.5 x col/row.
                    Not used if height & width are given.
pixels          : the total number of pixels used, default 10000. Not used if height & width are given.
figsize         : tuple containing the size of the final output after making a grid, in pixels (default: (1200,800))



Function output
     
A matplotlib figure that can be directly saved with output.savefig().


_check_plotnine_grid(plots_list, figsize)  # Check the input

# Assign values that have not been provided based on others. In the end, height and width should be provided.
if row is None:
    row = len(plots_list)

if ratio is None:
    ratio = 1.5 * col / row

if height is None and width is not None:
    height = ratio * width

if height is not None and width is None:
    width = height / ratio

if height is None and width is None:
    area = pixels / dpi
    width = np.sqrt(area/ratio)
    height = ratio * width

# Do actual subplot creation and plot output.
i = 1
fig = plt.figure(figsize=figsize)
plt.autoscale(tight=True)
for image_sel in plots_list:  # image_sel = plots_list[i]
    image_sel.save('image' + str(i) + '.png', height=height, width=width, dpi=500, verbose=False)
    fig.add_subplot(row, col, i)
    plt.imshow(img.imread('image' + str(i) + '.png'), aspect='auto')
    fig.tight_layout()
    fig.get_axes()[i-1].axis('off')
    i = i + 1
    os.unlink('image' + str(i - 1) + '.png')  # os.unlink is basically os.remove but in some cases quicker
fig.patch.set_visible(False)
return fig