Question

我正在使用PyQt 4作为基本GUI和matplotlib用于绘图，我想从中读取绘制数据点的坐标。基于these examples（简单的选取示例），我有一个简单的问题，即我无法在文本字段中显示数据点的坐标，例如QtGui.QLabel（）。我不明白为什么我不能在方法Window.msg中调用实例onpick()。可能是因为没有给出该方法的实例。我对面向对象编程只有基本的了解（但我正在研究它），所以问题在于我缺乏知识。

我的问题：如何在基于PyQT的GUI中的matplotlib图中显示所选数据的坐标（通过点击它）（在我的标签lbl中）？

此外，在图中突出显示所选数据点会很好。

这是我的代码（工作）：

import numpy as np
import matplotlib.pyplot as plt
from PyQt4 import QtGui
import sys
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.backends.backend_qt4agg import NavigationToolbar2QTAgg as NavigationToolbar
import matplotlib.pyplot as plt


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

    def initUI(self):  
       self.msg = '0'

       # a figure instance to plot on
       self.figure = plt.figure()
       self.canvas = FigureCanvas(self.figure)
       self.toolbar = NavigationToolbar(self.canvas, self)

       # a label
       self.lbl = QtGui.QLabel(self.msg)

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

       self.plot()

    def plot(self):
        # random data
        data = [np.random.random() for i in range(10)]
        # create an axis
        ax = self.figure.add_subplot(111)
        # discards the old graph
        ax.hold(False)
        # plot data
        line, = ax.plot(data, 'o', picker=5)  # 5 points tolerance
        self.canvas.draw()
        self.canvas.mpl_connect('pick_event',  Window.onpick)

    def onpick(self):
        thisline = self.artist
        xdata = thisline.get_xdata()
        ydata = thisline.get_ydata()
        ind = self.ind

        # show data
        self.msg = (xdata[ind], ydata[ind])
        print(self.msg)

        # This does not work:
        #Window.lbl.setText(self.msg)


if __name__ == '__main__':
    app = QtGui.QApplication(sys.argv)
    main = Window()
    main.show()
    sys.exit(app.exec_())

Answer 1

自我被选择器重叠（不知道为什么）。无论如何，这应该有效：

import numpy as np
import matplotlib.pyplot as plt
from PyQt4 import QtGui
import sys
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.backends.backend_qt4agg import NavigationToolbar2QTAgg as NavigationToolbar
import matplotlib.pyplot as plt

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

    def initUI(self):  
       self.msg = '0'

       # a figure instance to plot on
       self.figure = plt.figure()
       self.canvas = FigureCanvas(self.figure)
       self.toolbar = NavigationToolbar(self.canvas, self)

       # a label
       self.lbl = QtGui.QLabel(self.msg)

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

       self.plot()

    def changelabel(arg):
        main.lbl.setText(str(arg[0])+' '+str(arg[1]))

    def plot(self):
        # random data
        data = [np.random.random() for i in range(10)]
        # create an axis
        ax = self.figure.add_subplot(111)
        # discards the old graph
        ax.hold(False)
        # plot data
        line, = ax.plot(data, 'o', picker=5)  # 5 points tolerance
        self.canvas.draw()
        self.canvas.mpl_connect('pick_event',  Window.onpick)

    def onpick(self):
        thisline = self.artist
        xdata = thisline.get_xdata()
        ydata = thisline.get_ydata()
        ind = self.ind

        # show data
        self.msg = (xdata[ind], ydata[ind])
        print(self.msg)
#        Window.changelabel(self.msg)
        main.lbl.setText(str(self.msg[0])+' '+str(self.msg[1]))


if __name__ == '__main__':
    app = QtGui.QApplication(sys.argv)
    main = Window()
    main.show()
    sys.exit(app.exec_())

，更改位于setText函数中，因为我直接从变量（无self或Window）调用它。

main.lbl.setText(str(self.msg[0])+' '+str(self.msg[1]))

如何使用matplotlib的对象拾取功能在PyQt文本字段中显示值？

1 个答案: