Python、Matplotlib : Suptitle with arbitrary number of vertical figures

Question

我有一个网站可以生成(取决于运行的可用数据站)任意数量的图(作为图像)，这些图相互垂直堆叠。示例如下:

问题在于，根据垂直图的数量，suptitle(顶部标题)会转到不同的位置。检查以下 5 和 10 图的示例:

5 个地 block :

这里有 10 个图:

因此，对于每一个地 block ，我都会得到不同的结果。使用 fig.tight_layout() 没有帮助。

我需要的是让我的文本底部与图表顶部保持一定距离。这个问题有一个通用的答案吗？

我创建了一些最小的工作代码，其中包含参数化的地 block 数量。如果您想重现此问题，请检查一下。

import datetime
import random
import matplotlib
matplotlib.use('Agg') # Force matplotlib not to use any Xwindows backend.

import matplotlib.pyplot as plt
import matplotlib.dates as mdates
import matplotlib.image as mpimg
import matplotlib.gridspec as gridspec
import numpy as np


random.seed(datetime.datetime.now())

#initial parameters
numOfPlots  = 2
dataLen     = 100
randomRange = 10*dataLen
dpiVal      = 180

#create data
xData = list(range(dataLen) for x in range(numOfPlots))
yData = list(random.sample(range(randomRange), dataLen) for x in range(numOfPlots))

#matplotlib initialize plot
gs = gridspec.GridSpec(numOfPlots,1)
plt.cla()
plt.clf()
fig = plt.figure()
ax = None

for i in list(range(numOfPlots)):
    if i == 0:
        ax = fig.add_subplot(gs[i])
    else:
        ax = fig.add_subplot(gs[i],sharex=ax)

    ax.plot(xData[i], yData[i])

    labelSize = 10
    ax.set_ylabel("Hi there",size=8)
    ax.get_yaxis().set_label_coords(-0.07,0.5)
    plt.yticks(size=8)
    plt.ticklabel_format(style='sci', axis='y', scilimits=(0,0),useOffset=True)
    plt.subplots_adjust(hspace = 0.3)
    if i == numOfPlots-1:
        plt.xticks(rotation=0,size=7)
        max_xticks = 10
        xloc = plt.MaxNLocator(max_xticks)
        ax.xaxis.set_major_locator(xloc)
        ax=plt.gca()
    else:
        plt.tick_params(
        axis='x',          # changes apply to the x-axis
        labelbottom='off') # labels along the bottom edge are off
    ax_right = ax.twinx()
    ax_right.yaxis.set_ticks_position('right')
    ax_right.set_ylabel("Nice to see you!",size=labelSize)
    ax_right.get_yaxis().set_ticks([])


#the following sets the size and the aspect ratio of the plot
fig.set_size_inches(10, 1.8*numOfPlots)

fig.suptitle("Hi there, this is the first line\nAnd this is the second!!!")
fig.savefig("img_"+str(numOfPlots)+".png",bbox_inches='tight',dpi=dpiVal)

Answer 1

我建议尝试手动操作:以图形相对坐标为单位添加带有位置的文本注释。

考虑这两个虚拟示例:

hf,ax = plt.subplots(nrows=3)
hf.text(0.5,0.92,
        "Hi there, this is the first line\nAnd this is the second!!!",
        horizontalalignment='center')
hf,ax = plt.subplots(nrows=7)
hf.text(0.5,0.92,
        "Hi there, this is the first line\nAnd this is the second!!!",
        horizontalalignment='center')

结果的“副标题”位于完全相同的位置: