python - 如何在 pyqt 中嵌入 matplotlib - For Dummies

Question

我目前正在尝试在我设计的 pyqt4 用户界面中嵌入我想要绘制的图表。因为我对编程几乎是全新的 - 我不明白人们是如何在我发现的示例中进行嵌入的 -这个（在底部） 和那个。

如果有人可以发布一步一步的解释，或者至少是一个非常小的、非常简单的代码，只在一个 pyqt4 GUI 中创建一个图形和一个按钮，那就太棒了。

Answer 1

实际上并没有那么复杂。相关的 Qt 小部件位于matplotlib.backends.backend_qt4agg. FigureCanvasQTAgg并且NavigationToolbar2QT通常是您需要的。这些是常规的 Qt 小部件。您将它们视为任何其他小部件。下面是一个非常简单的示例，其中包含一个Figure,Navigation和一个绘制一些随机数据的按钮。我添加了评论来解释事情。

import sys
from PyQt4 import QtGui

from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.backends.backend_qt4agg import NavigationToolbar2QT as NavigationToolbar
from matplotlib.figure import Figure

import random

class Window(QtGui.QDialog):
    def __init__(self, parent=None):
        super(Window, self).__init__(parent)

        # a figure instance to plot on
        self.figure = Figure()

        # this is the Canvas Widget that displays the `figure`
        # it takes the `figure` instance as a parameter to __init__
        self.canvas = FigureCanvas(self.figure)

        # this is the Navigation widget
        # it takes the Canvas widget and a parent
        self.toolbar = NavigationToolbar(self.canvas, self)

        # Just some button connected to `plot` method
        self.button = QtGui.QPushButton('Plot')
        self.button.clicked.connect(self.plot)

        # set the layout
        layout = QtGui.QVBoxLayout()
        layout.addWidget(self.toolbar)
        layout.addWidget(self.canvas)
        layout.addWidget(self.button)
        self.setLayout(layout)

    def plot(self):
        ''' plot some random stuff '''
        # random data
        data = [random.random() for i in range(10)]

        # create an axis
        ax = self.figure.add_subplot(111)

        # discards the old graph
        ax.clear()

        # plot data
        ax.plot(data, '*-')

        # refresh canvas
        self.canvas.draw()

if __name__ == '__main__':
    app = QtGui.QApplication(sys.argv)

    main = Window()
    main.show()

    sys.exit(app.exec_())

编辑：

更新以反映评论和 API 更改。

• NavigationToolbar2QTAgg更改为NavigationToolbar2QT
• 直接导入Figure而不是pyplot
• 将弃用的替换ax.hold(False)为ax.clear()

Answer 2

下面是在PyQt5和Matplotlib 2.0下使用的先前代码的改编。有一些小的变化：PyQt 子模块的结构，matplotlib 中的其他子模块，已弃用的方法已被替换......

import sys
from PyQt5.QtWidgets import QDialog, QApplication, QPushButton, QVBoxLayout

from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.backends.backend_qt5agg import NavigationToolbar2QT as NavigationToolbar
import matplotlib.pyplot as plt

import random

class Window(QDialog):
    def __init__(self, parent=None):
        super(Window, self).__init__(parent)

        # a figure instance to plot on
        self.figure = plt.figure()

        # this is the Canvas Widget that displays the `figure`
        # it takes the `figure` instance as a parameter to __init__
        self.canvas = FigureCanvas(self.figure)

        # this is the Navigation widget
        # it takes the Canvas widget and a parent
        self.toolbar = NavigationToolbar(self.canvas, self)

        # Just some button connected to `plot` method
        self.button = QPushButton('Plot')
        self.button.clicked.connect(self.plot)

        # set the layout
        layout = QVBoxLayout()
        layout.addWidget(self.toolbar)
        layout.addWidget(self.canvas)
        layout.addWidget(self.button)
        self.setLayout(layout)

    def plot(self):
        ''' plot some random stuff '''
        # random data
        data = [random.random() for i in range(10)]

        # instead of ax.hold(False)
        self.figure.clear()

        # create an axis
        ax = self.figure.add_subplot(111)

        # discards the old graph
        # ax.hold(False) # deprecated, see above

        # plot data
        ax.plot(data, '*-')

        # refresh canvas
        self.canvas.draw()

if __name__ == '__main__':
    app = QApplication(sys.argv)

    main = Window()
    main.show()

    sys.exit(app.exec_())

Answer 3

对于那些寻找在 PyQt5 中嵌入 Matplotlib 的动态解决方案的人（甚至使用拖放绘制数据）。在 PyQt5 中，您需要在主窗口类上使用 super 来接受 drop。dropevent 函数可用于获取文件名，其余的很简单：

def dropEvent(self,e):
        """
        This function will enable the drop file directly on to the 
        main window. The file location will be stored in the self.filename
        """
        if e.mimeData().hasUrls:
            e.setDropAction(QtCore.Qt.CopyAction)
            e.accept()
            for url in e.mimeData().urls():
                if op_sys == 'Darwin':
                    fname = str(NSURL.URLWithString_(str(url.toString())).filePathURL().path())
                else:
                    fname = str(url.toLocalFile())
            self.filename = fname
            print("GOT ADDRESS:",self.filename)
            self.readData()
        else:
            e.ignore() # just like above functions  

对于初学者，参考完整代码给出了以下输出：