在pyqtgraph中用鼠标单击时从图获取图坐标

如何解决在pyqtgraph中用鼠标单击时从图获取图坐标

我正在使用pyqtgraph示例中的十字线示例。单击某个点上的绘图图时，我试图获取一个点的坐标。

在代码中标记为

import numpy as np
import pyqtgraph as pg
from pyqtgraph.Qt import QtGui,QtCore

#generate layout
app = QtGui.QApplication([])
win = pg.GraphicslayoutWidget(show=True)
win.setwindowTitle('pyqtgraph example: crosshair')
label = pg.LabelItem(justify='right')
win.addItem(label)
p1 = win.addplot(row=1,col=0)

#pg.dbg()
p1.setAutoVisible(y=True)


#create numpy arrays
#make the numbers large to show that the xrange shows data from 10000 to all the way 0
data1 = 10000 + 15000 * pg.gaussianFilter(np.random.random(size=10000),10) + 3000 * np.random.random(size=10000)
data2 = 15000 + 15000 * pg.gaussianFilter(np.random.random(size=10000),10) + 3000 * np.random.random(size=10000)

p1.plot(data1,pen="r")
p1.plot(data2,pen="g")


vb = p1.vb

def mouseMoved(evt):
    pos = evt[0]  ## using signal proxy turns original arguments into a tuple
    mousePoint = vb.mapScenetoView(pos)    <<<<<<<<<<<<<<
    print(mousePoint.x(),mousePoint.y())

proxy = pg.SignalProxy(p1.scene().sigMouseClicked,slot=mouseMoved)



# Start Qt event loop unless running in interactive mode or using pyside.
if __name__ == '__main__':
    import sys
    if (sys.flags.interactive != 1) or not hasattr(QtCore,'PYQT_VERSION'):
        QtGui.QApplication.instance().exec_()

解决方法

我用另一种方法修改了代码。现在可以正常工作了。

import pyqtgraph as pg
from pyqtgraph.Qt import QtGui,QtCore

#generate layout
app = QtGui.QApplication([])
win = pg.GraphicsLayoutWidget(show=True)
win.setWindowTitle('pyqtgraph example: crosshair')
label = pg.LabelItem(justify='right')
win.addItem(label)
p1 = win.addPlot(row=1,col=0)

#pg.dbg()
p1.setAutoVisible(y=True)


#create numpy arrays
#make the numbers large to show that the xrange shows data from 10000 to all the way 0
data1 = 10000 + 15000 * pg.gaussianFilter(np.random.random(size=10000),10) + 3000 * np.random.random(size=10000)
data2 = 15000 + 15000 * pg.gaussianFilter(np.random.random(size=10000),10) + 3000 * np.random.random(size=10000)

p1.plot(data1,pen="r")
p1.plot(data2,pen="g")


vb = p1.vb


def onClick(event):
    items = p1.scene().items(event.scenePos())
    mousePoint = vb.mapSceneToView(event._scenePos)
    print(mousePoint.x(),mousePoint.y())
    if p1.sceneBoundingRect().contains(event._scenePos):
        mousePoint = vb.mapSceneToView(event._scenePos)
        index = int(mousePoint.x())
        if index > 0 and index < len(data1):
            label.setText(
                "<span style='font-size: 12pt'>x=%0.1f,<span style='color: red'>y1=%0.1f</span>,<span style='color: green'>y2=%0.1f</span>" % (
                mousePoint.x(),data1[index],data2[index]))


p1.scene().sigMouseClicked.connect(onClick)



## Start Qt event loop unless running in interactive mode or using pyside.
if __name__ == '__main__':
    import sys
    if (sys.flags.interactive != 1) or not hasattr(QtCore,'PYQT_VERSION'):
        QtGui.QApplication.instance().exec_()```