python - PYQT 和嵌入 matplotlib : Graph not showing

Question

您好，我正在尝试将自定义图形添加到我拥有的 pyqt 界面中。它没有显示任何数据，但显示了占位符 matplotlib 图表。有什么帮助吗？另外，如果我只绘制图形数据而不将其放入 PYQT，它也会显示出来。谢谢!

class MyMplCanvas(FigureCanvas):
"""Ultimately, this is a QWidget (as well as a FigureCanvasAgg, etc.)."""
def __init__(self, parent=None, width=5, height=4, dpi=100):
    fig = Figure(figsize=(width, height), dpi=dpi)
    #self.axes = fig.add_subplot(111)
    # We want the axes cleared every time plot() is called
    self.axes.hold(False)

    self.compute_initial_figure()
    FigureCanvas.__init__(self, fig)
    self.setParent(parent)

    FigureCanvas.setSizePolicy(self,
                               QtGui.QSizePolicy.Expanding,
                               QtGui.QSizePolicy.Expanding)
    FigureCanvas.updateGeometry(self)

def compute_initial_figure(self):
    pass


class MyStaticMplCanvas(MyMplCanvas):

def mystatic(self, parent=None):
    super(MyStaticMplCanvas, self).__init__(parent)

    rate,data = read('test.wav') # reading
    subplot(411)
    self.plot(range(len(data)),data)
    subplot(412)
    self.specgram(data, NFFT=128, noverlap=0) # small window
    subplot(413)
    self.specgram(data, NFFT=512, noverlap=0) 
    subplot(414)
    self.specgram(data, NFFT=1024, noverlap=0) # big window

    self.show()


class ApplicationWindow(QtGui.QMainWindow):
    def __init__(self):
        QtGui.QMainWindow.__init__(self)

        l = QtGui.QVBoxLayout(self.main_widget)
        sc = MyStaticMplCanvas(self.main_widget, width=5, height=4, dpi=100)

        l.addWidget(sc)

Answer 1

在您提供的代码示例中，没有调用用于绘制数据的 mystatic 方法。因此，您的图形上没有绘制任何内容。

此外，您似乎正在使用pyplot接口(interface)通过直接调用subplot和plot来绘制数据，例如神秘的。在应用程序中嵌入 mpl 图形时，建议使用 mpl documentation坚持面向对象的 API。

我根据您提供的代码生成了一个最小的工作示例，该示例遵循上述文档中提供的指南。希望对您有所帮助。

from PyQt4 import QtGui
import sys
import numpy as np
import matplotlib as mpl    
mpl.use('Qt4Agg')
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas

class MyMplCanvas(FigureCanvas):
    def __init__(self, parent=None, width=5, height=4, dpi=100):        
        fig = mpl.figure.Figure(figsize=(width, height), dpi=dpi)   
        fig.set_tight_layout('tight')
        super(MyMplCanvas, self).__init__(fig)

class MyStaticMplCanvas(MyMplCanvas):

    def mystatic(self, parent=None):

        x, y = np.random.rand(50), np.random.rand(50)
        ax1 = self.figure.add_subplot(411)
        ax1.plot(x,y, '.')
        ax2 = self.figure.add_subplot(412)
        ax2.plot(x,y, '.')
        ax3 = self.figure.add_subplot(413)
        ax3.plot(x,y, '.')
        ax4 = self.figure.add_subplot(414)
        ax4.plot(x,y, '.')

if __name__ == '__main__' :

    app = QtGui.QApplication(sys.argv)

    w = MyStaticMplCanvas(width=5, height=6, dpi=100)
    w.mystatic()
    w.show()

    sys.exit(app.exec_()) 

结果是: