使用鼠标横发从SCATTR图中选择点-Pyqt

Question

我是PYQT的新手，并且IM正在开发一个实用程序，用户可以使用以下代码从Excel文件中导入数据并在2D散点图中绘制其X和Y：

def plot_2d_scatter(graphWidget,x,z,color=(66, 245, 72)):
    graphWidget.clear()
    brush = pg.mkBrush(color)
    scatter = pg.ScatterPlotItem(size=5, brush=brush)
    scatter.addPoints(x,z)
    graphWidget.addItem(scatter)

现在我想要一个功能，该功能将使用户可以将其鼠标移至散点图使用横发 /指针 /等，并在散点图上选择点。

每当用户左键单击散点图上的十字 /标记时，我都希望将其x，y坐标保存以进一步使用。

我已经尝试了以下片段从互联网上的某个地方使用鼠标事件并获取我的散布点，但这并没有给我散落的散布点，

def mouseMoved(self, evt):
    pos = evt
    if self.plotWidget.sceneBoundingRect().contains(pos):
        mousePoint = self.plotWidget.plotItem.vb.mapSceneToView(pos)
        mx = np.array([abs(float(i) - float(mousePoint.x())) for i in self.plotx])
        index = mx.argmin()
        if index >= 0 and index < len(self.plotx):
            self.cursorlabel.setHtml(
                "<span style='font-size: 12pt'>x={:0.1f}, \
                 <span style='color: red'>y={:0.1f}</span>".format(
                    self.plotx[index], self.ploty[index])
            )
        self.vLine.setPos(self.plotx[index])
        self.hLine.setPos(self.ploty[index])

值得赞赏的是，任何指南都非常感谢

Answer 1

我最好的快速努力，今天从未使用过PG：

import sys
from PyQt5.QtWidgets import QApplication, QMainWindow, QDesktopWidget, QWidget

from PyQt5.QtCore import Qt

from PyQt5 import QtGui, QtCore, QtWidgets

import pyqtgraph as pg

import numpy as np

class MyApp(QMainWindow):
    
    def __init__(self, parent=None):
        super(MyApp, self).__init__(parent)
        
        
        self.resize(781, 523)
        
        self.graphWidget = pg.PlotWidget()
        self.setCentralWidget(self.graphWidget)
        
        self.show()
        
        self.x = [1,2,3,4,5,6,7,8,9,5,6,7,8]
        
        self.y = [1,2,3,4,5,6,7,8,9,5,6,7,8]
        
        
        # self.y.reverse()
        
            
        self.plot_2d_scatter(self.graphWidget, self.x, self.y)
        
        self.cursor = Qt.CrossCursor
        
        # self.cursor = Qt.BlankCursor
        
        self.graphWidget.setCursor(self.cursor)
       
        # Add crosshair lines.
        self.crosshair_v = pg.InfiniteLine(angle=90, movable=False)
        self.crosshair_h = pg.InfiniteLine(angle=0, movable=False)
        self.graphWidget.addItem(self.crosshair_v, ignoreBounds=True)
        self.graphWidget.addItem(self.crosshair_h, ignoreBounds=True)
        self.cursorlabel = pg.TextItem()

        
        self.graphWidget.addItem(self.cursorlabel)
        
        
        self.proxy = pg.SignalProxy(self.graphWidget.scene().sigMouseMoved, rateLimit=60, slot=self.update_crosshair)
        
        self.mouse_x = None
        
        self.mouse_y = None
        
    def plot_2d_scatter(self,graphWidget,x,z,color=(66, 245, 72)):
        # graphWidget.clear()
        brush = pg.mkBrush(color)
        scatter = pg.ScatterPlotItem(size=5, brush=brush)
        scatter.addPoints(x,z)
        graphWidget.addItem(scatter)
    
    

    def update_crosshair(self, e):
            
        pos = e[0]
        if self.graphWidget.sceneBoundingRect().contains(pos):
            mousePoint = self.graphWidget.plotItem.vb.mapSceneToView(pos)
            mx = np.array([abs(float(i) - float(mousePoint.x())) for i in self.x])
            index = mx.argmin()
            if index >= 0 and index < len(self.x):
                self.cursorlabel.setText(
                        str((self.x[index], self.y[index])))
                
                self.crosshair_v.setPos(self.x[index])
                self.crosshair_h.setPos(self.y[index]) 
                
                self.mouse_x = self.crosshair_v.setPos(self.x[index])
                self.mouse_y = self.crosshair_h.setPos(self.y[index])
                
                self.mouse_x = (self.x[index])
                self.mouse_y = (self.y[index])
            
            
    def mousePressEvent(self, e):
        if e.buttons() & QtCore.Qt.LeftButton:
            print('pressed')
            
            # if self.mouse_x in self.x and self.mouse_y in self.y:
           
            print(self.mouse_x, self.mouse_y)
            
    
if __name__ == '__main__':

    app = QApplication(sys.argv)
    myapp = MyApp()
    # myapp.show()

    try:
        sys.exit(app.exec_())
    except SystemExit:
        print('Closing Window...')

图中”打印出pg的坐标

它只是在 https://www.pythonguis.com/faq/pyqt-show-custom-custom-cursor-pyqtgraph/ ，您的代码结果看起来像：

还有其他示例，例如试图在pyqt5中的pyqtgraph plotwidget中获得光标等等