在 PyQt5 中调整父窗口大小时，如何更改 matplotlib 图形/轴的拉伸方式？

Question

我有一个带有嵌入式图形的程序，该程序还显示带有自定义刻度标签的颜色条。但是，图形的自动调整大小会切断部分刻度标签。如果我可以简单地手动调整窗口大小以便再次显示所有内容，这不会太糟糕。但是，当您调整窗口大小时，图形会以这样一种方式拉伸，即在左侧创建了一个大的空白区域，而右侧的刻度标签仍然无法完全看到，除非您将窗口拉伸得不必要的宽。我怎样才能改变这种行为？下面是一个例子。正如你所看到的，我已经尝试了一些东西，但都没有奏效。import numpy as npimport sysimport matplotlib.pyplot as pltfrom matplotlib.backends.backend_qt5agg import \    FigureCanvasQTAgg as FigureCanvasimport matplotlib.ticker as mtickerfrom PyQt5.QtWidgets import QApplication, QDialog, QGridLayoutfrom PyQt5.QtCore import QSizeclass MathTextSciFormatter(mticker.Formatter):    def __init__(self, fmt="%1.1e"):        self.fmt = fmt    def __call__(self, x, pos=None):        s = self.fmt % x        decimal_point = '.'        positive_sign = '+'        tup = s.split('e')        significand = tup[0].rstrip(decimal_point)        sign = tup[1][0].replace(positive_sign, '')        exponent = tup[1][1:].lstrip('0')        if exponent:            exponent = '10^{%s%s}' % (sign, exponent)        if significand and exponent:            s = r'%s{\times}%s' % (significand, exponent)        else:            s = r'%s%s' % (significand, exponent)        return "${}$ W/m${{}}^2$".format(s)class Test(QDialog):    def __init__(self):        super().__init__()        self.lay = QGridLayout(self)        self.fig, self.ax = plt.subplots()        # self.ax.set_anchor('SW')        # self.ax.set_position([0, 0, 0, 0])        # self.fig.tight_layout()        # self.ax.margins(0, 0)        self.canvas = FigureCanvas(self.fig)        self.lay.addWidget(self.canvas)        self.resize(QSize(380, 290))        self.setMaximumHeight(290)        self.image = np.reshape(np.random.randint(0, 1000, 10000), (100, 100))        self.image_artist = self.ax.imshow(self.image)        self.colorbar = self.fig.colorbar(self.image_artist)        self.colorbar.ax.yaxis.set_major_formatter(            MathTextSciFormatter()        )

Answer 1

正如 ImportanceOfBeingErnest 在评论中指出的那样，利用就constrained_layout可以了。

import numpy as np

import sys

import matplotlib.pyplot as plt

from matplotlib.backends.backend_qt5agg import \

    FigureCanvasQTAgg as FigureCanvas

import matplotlib.ticker as mticker

from PyQt5.QtWidgets import QApplication, QDialog, QGridLayout

from PyQt5.QtCore import QSize

class MathTextSciFormatter(mticker.Formatter):

    def __init__(self, fmt="%1.1e"):

        self.fmt = fmt

    def __call__(self, x, pos=None):

        s = self.fmt % x

        decimal_point = '.'

        positive_sign = '+'

        tup = s.split('e')

        significand = tup[0].rstrip(decimal_point)

        sign = tup[1][0].replace(positive_sign, '')

        exponent = tup[1][1:].lstrip('0')

        if exponent:

            exponent = '10^{%s%s}' % (sign, exponent)

        if significand and exponent:

            s = r'%s{\times}%s' % (significand, exponent)

        else:

            s = r'%s%s' % (significand, exponent)

        return "${}$ W/m${{}}^2$".format(s)

class Test(QDialog):

    def __init__(self):

        super().__init__()

        self.lay = QGridLayout(self)

        self.fig, self.ax = plt.subplots(constrained_layout=True)

        # self.ax.set_anchor('SW')

        # self.ax.set_position([0, 0, 0, 0])

        # self.fig.tight_layout()

        # self.ax.margins(0, 0)

        self.canvas = FigureCanvas(self.fig)

        self.lay.addWidget(self.canvas)

        self.resize(QSize(380, 290))

        self.setMaximumHeight(290)

        self.image = np.reshape(np.random.randint(0, 1000, 10000), (100, 100))

        self.image_artist = self.ax.imshow(self.image)

        self.colorbar = self.fig.colorbar(self.image_artist)

        self.colorbar.ax.yaxis.set_major_formatter(

            MathTextSciFormatter()

        )

if __name__ == '__main__':

    app = QApplication(sys.argv)

    test = Test()

    test.show()

    sys.exit(app.exec_())