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Mouse coordinates of pytqt graph line

由 流过昼夜 提交于 2021-02-07 20:28:15

问题


I am trying to get the (x,y) values of my random function plot whenever I move the moused on top of the graph. I am using pyqtgraph.SignalProxy and connect it to a callback mousedMoved.

I am getting this as error: NameError: global name 'mouseMoved' is not defined

Here is the code:

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

class TestClass(QtGui.QMainWindow):
  #####################################################
  def __init__(self):
    super(TestClass, self).__init__()
    self.initUI()

  #####################################################
  # GUI construction
  def initUI(self):
    win = pg.GraphicsWindow(title="Mouse Point, x & y")

    # creates plot
    self.plot = pg.PlotWidget()
    self.plot.setLabel('left', "B", units='T')
    self.plot.setLabel('bottom', "t", units='s')
    self.plot.showGrid(x=1, y=1, alpha=None)
    self.setCentralWidget(win)
    self.setGeometry(600, 600, 600, 600)
    self.setWindowTitle('Mouse Point, x& y GUI')

    # Create some widgets to be placed inside
    btnRandon = QtGui.QPushButton('Random Function')


    # Create a grid layout to manage the widgets size and position
    layout = QtGui.QGridLayout()
    win.setLayout(layout)

    # Add widgets to the layout in their proper positions
    layout.addWidget(btnRandon, 0, 0) # button to show or hide the OldB
    layout.addWidget(self.plot, 1, 0)

    mypen = pg.mkPen('y', width=1)
    self.curve = self.plot.plot(pen=mypen)

    # Plot
    self.t_plot_max = 30
    self.fe = 10e3
    self.t = np.arange(-1 * self.t_plot_max, 0, 1.0 / self.fe)
    self.len_signal = len(self.t)
    self.signal = np.zeros(self.len_signal, dtype=np.double)

    # status bar
    self.statusBar()

    # clicked button evt
    btnRandon.clicked.connect(self.buttonRandomClicked)

    # show graph
    self.show()

  #####################################################
  def mouseMoved(evt):
    mousePoint = self.curve.vb.mapSceneToView(evt[0])
    label.setText("<span style='font-size: 14pt; color: white'> x = %0.2f, <span style='color: white'> y = %0.2f</span>" % (mousePoint.x(), mousePoint.y()))


  #####################################################
  def buttonRandomClicked(self):
    print ("Show/Hide OldB")
    self.signal = np.random.rand(20)
    self.curve.setData(self.signal)

#####################################################
  def update(self):
    proxy = pg.SignalProxy(self.curve.scene().sigMouseMoved, rateLimit=60, slot=mouseMoved)
    self.statusBar().showMessage('Update timer event')

# MAIN ##################################################
def main():
  app = QtGui.QApplication(sys.argv)
  ex = TestClass()
  timer = QtCore.QTimer()
  timer.timeout.connect(ex.update)
  timer.start(200)
  sys.exit(app.exec_())


if __name__ == '__main__':
  main()

Amy idea what I'm doing wrong?

Thanks.


回答1:


It is not necessary to use a QTimer to perform this task and to create a method called update() since QMainWindow has a similar method and could be interfering with the correct operation.

The sigMouseMoved signal is emitted every time you move the mouse, so in general it is not necessary to use the SignalProxy.

The signal sigMouseMoved returns the coordinates in pixels with respect to the PlotWidget, not in the coordinates of the plot, so a conversion must be done using the mapSceneToView method of the ViewBox--> PlotItem --> PlotWidget.

Finally, it is not necessary to use GraphicsWindow(), this creates another window, just a QWidget is enough.

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

class TestClass(QtGui.QMainWindow):
    #####################################################
    def __init__(self):
        super(TestClass, self).__init__()
        self.initUI()
    ####################################################
    # GUI construction
    def initUI(self):
        self.setWindowTitle("Mouse Point, x & y")
        win = QtGui.QWidget()
        # creates plot
        self.plot = pg.PlotWidget()
        self.plot.setLabel('left', "B", units='T')
        self.plot.setLabel('bottom', "t", units='s')
        self.plot.showGrid(x=1, y=1, alpha=None)
        self.setCentralWidget(win)
        self.setGeometry(600, 600, 600, 600)
        self.setWindowTitle('Mouse Point, x& y GUI')

        # Create some widgets to be placed inside
        btnRandon = QtGui.QPushButton('Random Function')
        # Create a grid layout to manage the widgets size and position
        layout = QtGui.QGridLayout(win)

        # Add widgets to the layout in their proper positions
        layout.addWidget(btnRandon, 0, 0) # button to show or hide the OldB
        layout.addWidget(self.plot, 1, 0)

        mypen = pg.mkPen('y', width=1)
        self.curve = self.plot.plot(x=[], y=[], pen=mypen)

        # Plot
        self.t_plot_max = 30
        self.fe = 10e3
        self.t = np.arange(-1 * self.t_plot_max, 0, 1.0 / self.fe)
        self.len_signal = len(self.t)
        self.signal = np.zeros(self.len_signal, dtype=np.double)

        btnRandon.clicked.connect(self.buttonRandomClicked)
        self.curve.scene().sigMouseMoved.connect(self.onMouseMoved)

    def onMouseMoved(self, point):
        p = self.plot.plotItem.vb.mapSceneToView(point)
        self.statusBar().showMessage("{}-{}".format(p.x(), p.y()))

    def buttonRandomClicked(self):
        print ("Show/Hide OldB")
        self.signal = np.random.rand(20)
        self.curve.setData(self.signal)


# MAIN ##################################################
def main():
    app = QtGui.QApplication(sys.argv)
    ex = TestClass()
    ex.show()
    sys.exit(app.exec_())


if __name__ == '__main__':
    main()



回答2:


Sorry, I'm using PyQt5. Try it:

import sys

#from pyqtgraph.Qt import QtGui, QtCore     # ---
from PyQt5 import QtWidgets, QtGui, QtCore  # +++

import numpy as np
import pyqtgraph as pg
import time
import random

class TestClass(QtGui.QMainWindow):
  #####################################################
  def __init__(self):
    super(TestClass, self).__init__()
    self.num = 0                        ### +++
    self.initUI()

  #####################################################
  # GUI construction
  def initUI(self):
    win = pg.GraphicsWindow(title="Mouse Point, x & y")

    # creates plot
    self.plot = pg.PlotWidget()
    self.plot.setLabel('left', "B", units='T')
    self.plot.setLabel('bottom', "t", units='s')
    self.plot.showGrid(x=1, y=1, alpha=None)
    self.setCentralWidget(win)
    self.setGeometry(600, 600, 600, 600)
    self.setWindowTitle('Mouse Point, x& y GUI')

    # Create some widgets to be placed inside
    btnRandon = QtGui.QPushButton('Random Function')


    # Create a grid layout to manage the widgets size and position
    layout = QtGui.QGridLayout()
    win.setLayout(layout)

    # Add widgets to the layout in their proper positions
    layout.addWidget(btnRandon, 0, 0) # button to show or hide the OldB
    layout.addWidget(self.plot, 1, 0)

    mypen = pg.mkPen('y', width=1)
    self.curve = self.plot.plot(pen=mypen)

    # Plot
    self.t_plot_max = 30
    self.fe = 10e3
    self.t = np.arange(-1 * self.t_plot_max, 0, 1.0 / self.fe)
    self.len_signal = len(self.t)
    self.signal = np.zeros(self.len_signal, dtype=np.double)

    # status bar
    self.statusBar()

    # clicked button evt
    btnRandon.clicked.connect(self.buttonRandomClicked)

    # show graph
    self.show()

#  ### ------------------------------------------------
#  def mouseMoved(evt):
#    mousePoint = self.curve.vb.mapSceneToView(evt[0])
#    label.setText("<span style='font-size: 14pt; color: white'> x = %0.2f, <span style='color: white'> y = %0.2f</span>" % (mousePoint.x(), mousePoint.y()))


  #####################################################
  def buttonRandomClicked(self):
    print ("Show/Hide OldB")
    self.signal = np.random.rand(20)
    self.curve.setData(self.signal)

#####################################################
#  def update(self):
#    proxy = pg.SignalProxy(self.curve.scene().sigMouseMoved, rateLimit=60, slot=mouseMoved)
#    self.statusBar().showMessage('Update timer event')
### vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
  def update(self):
    ### +++++++++++++++++++++++++++++++++++++++++++++
    def mouseMoved(evt): 
      print("-->> def mouseMoved(evt):", evt)
      print("\tevt.x()=`{}`, evt.y()=`{}`".format(evt.x(), evt.y()))

      # AttributeError: 'PlotDataItem' object has no attribute 'vb'        ### ???????
      #mousePoint = self.curve.vb.mapSceneToView(evt[0])

      # vvvv - > label what is it? <-- NameError: name `label` is not defined ### ???????
      #label.setText("<span style='font-size: 14pt; color: white'> x = %0.2f, <span style='color: white'> y = %0.2f</span>" % (mousePoint.x(), mousePoint.y()))


    self.source = self.curve.scene().sigMouseMoved
    #print(" source ", self.source)
    proxy = pg.SignalProxy(self.source, rateLimit=60, slot=mouseMoved) #+self
    #print("def update(self):222", proxy)
    if self.source is None:
        pass
        #sp.connect(sp, QtCore.SIGNAL('signal'), slot)
    else:
        #sp.connect(sp, signal, slot)
        proxy.signal.connect(mouseMoved)

    self.statusBar().showMessage('Update timer event `{}`'.format(self.num))
    self.num += 1    
    return proxy    



# MAIN ##################################################
def main():
  app = QtGui.QApplication(sys.argv)
  ex = TestClass()
  timer = QtCore.QTimer()
  timer.timeout.connect(ex.update)
  timer.start(200)
  sys.exit(app.exec_())


if __name__ == '__main__':
  main()



来源：https://stackoverflow.com/questions/50833107/mouse-coordinates-of-pytqt-graph-line

标签
python
pyqt
pyqt4
mouseevent
pyqtgraph
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