使用 pyqtgraph 和 LiDAR 快速实时绘制点 [英] Fast, Real-time plotting of points using pyqtgraph and a LiDAR

问题描述

我想创建一个实时的点绘图 GUI.我正在使用 Scanse Sweep LiDAR，并且在每次扫描该 LiDAR(在 1 - 10Hz 之间工作)时，我都会收到大约 1000 个描述周围 LiDAR 的点 (x, y).这是一个二维激光雷达.

I want to create a real-time, point plotting GUI. I am using the Scanse Sweep LiDAR, and at each sweep of this LiDAR (working between 1 - 10Hz) I receive approximately 1000 points (x, y) describing the LiDARs surrounding. This is a 2D LiDAR.

我到处寻找并尝试了无数的 pyqtgraph 代码片段，但要么崩溃，要么速度超慢，要么根本无法工作.

I have looked everywhere and tried countless of code snippets for pyqtgraph, but either it crashes, is super slow or doesn't work at all.

是否有一种直接的方法来创建绘图仪窗口，并在每次新的扫描/数据传送时将这些点推到绘图仪窗口?

Is there a straight-forward way of creating a plotter window and upon each new scan/data delivery, push those points to the plotter window?

感谢您的任何帮助

推荐答案

我不清楚你到底想做什么，所以我假设你想制作一个 1000 个点的散点图，每个点刷新 10 次第二.下次请包含您的代码，以便我们可以重现您的问题并查看您想要实现的目标.

It is unclear to me what exactly you want to do, so I assume that you want to make a scatter plot with a 1000 points that are refreshed 10 times a second. Next time please include your code so that we can reproduce your issues and see what you want to achieve.

根据我的经验，PyQtGraph 是 Python 中最快的选项.它可以轻松地以 10 Hz 的频率绘制 1000 个点.请参阅下面的示例.

In my experience PyQtGraph is the fastest option in Python. It can easily plot a 1000 points at 10 Hz. See the example below.

#!/usr/bin/env python

from PyQt5 import QtCore, QtWidgets
import pyqtgraph as pg
import numpy as np


class MyWidget(pg.GraphicsWindow):

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

        self.mainLayout = QtWidgets.QVBoxLayout()
        self.setLayout(self.mainLayout)

        self.timer = QtCore.QTimer(self)
        self.timer.setInterval(100) # in milliseconds
        self.timer.start()
        self.timer.timeout.connect(self.onNewData)

        self.plotItem = self.addPlot(title="Lidar points")

        self.plotDataItem = self.plotItem.plot([], pen=None, 
            symbolBrush=(255,0,0), symbolSize=5, symbolPen=None)


    def setData(self, x, y):
        self.plotDataItem.setData(x, y)


    def onNewData(self):
        numPoints = 1000  
        x = np.random.normal(size=numPoints)
        y = np.random.normal(size=numPoints)
        self.setData(x, y)


def main():
    app = QtWidgets.QApplication([])

    pg.setConfigOptions(antialias=False) # True seems to work as well

    win = MyWidget()
    win.show()
    win.resize(800,600) 
    win.raise_()
    app.exec_()

if __name__ == "__main__":
    main()

它的工作方式如下.通过绘制一个空列表，一个 PlotDataItem 被创建.这表示点的集合.当新数据点到达时，使用setData 方法将它们设置为PlotDataItem 的数据，从而去除旧点.

The way it works is as follows. By plotting an empty list a PlotDataItem is created. This represents a collection of points. When new data points arrive, the setData method is used to set them as the data of the PlotDataItem, which removes the old points.

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