使用PyQt5和Matplotlib制作动态图形

Question

我想读取数据并绘制动态图，所以我学习了使用PyQt5的matplotlib。我找到了一个例子，但它是针对PyQt4的。我将其修改为PyQt5，但它有一些问题，当我单击开始按钮时，它显示错误

回溯（最后一次调用）：文件“/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site packages/matplotlib/backend_base.py”，第1305行，在_on_timer ret=func（*args，**kwargs）文件“/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site packages/matplotlib/animation/animation.py”，第1049行，步进静止=动画_步骤（self，*args）文件“/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site packages/matplotlib/animation.py”，第855行，在步骤self中_绘制下一帧（framedata，self.\blit）文件“/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site packages/matplotlib/animation.py”，第873行，绘制下一帧self_pre_draw（framedata，blit）文件“/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site packages/matplotlib/animation.py”，第886行，在pre_draw self中_blit_clear（自绘制艺术家、自绘制缓存）文件“/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site packages/matplotlib/animation.py”，第926行，在blit_clear a.图中。帆布restore_region（bg_缓存[a]）键错误：matplotlib。斧头_子地块。0x1067718d0处的AxesSubplot对象

这是我的密码，有人能帮我吗？？

import sys, os, random
from PyQt5 import QtCore
from PyQt5.QtWidgets import *

import numpy as np
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figure
import matplotlib.animation as animation

class MyMplCanvas(FigureCanvas):
    """Ultimately, this is a QWidget (as well as a FigureCanvasAgg, etc.)."""
    def __init__(self, parent=None, width=5, height=4, dpi=100):
        fig = Figure(figsize=(width, height), dpi=dpi)
        self.axes = fig.add_subplot(111)
        # We want the axes cleared every time plot() is called
        self.axes.hold(False)

        self.compute_initial_figure()

        #
        FigureCanvas.__init__(self, fig)
        self.setParent(parent)

    def compute_initial_figure(self):
        pass

class AnimationWidget(QWidget):
    def __init__(self):
        QMainWindow.__init__(self)

        vbox = QVBoxLayout()
        self.canvas = MyMplCanvas(self, width=5, height=4, dpi=100)
        vbox.addWidget(self.canvas)

        hbox = QHBoxLayout()
        self.start_button = QPushButton("start", self)
        self.stop_button = QPushButton("stop", self)
        self.start_button.clicked.connect(self.on_start)
        self.stop_button.clicked.connect(self.on_stop)
        hbox.addWidget(self.start_button)
        hbox.addWidget(self.stop_button)
        vbox.addLayout(hbox)
        self.setLayout(vbox)

        self.x = np.linspace(0, 5*np.pi, 400)
        self.p = 0.0
        self.y = np.sin(self.x + self.p)
        self.line, = self.canvas.axes.plot(self.x, self.y, animated=True, lw=2)




    def update_line(self, i):
        self.p += 0.1
        y = np.sin(self.x + self.p)
        self.line.set_ydata(y)
        return [self.line]

    def on_start(self):
        self.ani = animation.FuncAnimation(self.canvas.figure, self.update_line,
                                 blit=True, interval=25)

    def on_stop(self):
        self.ani._stop()



if __name__ == "__main__":
    qApp = QApplication(sys.argv)
    aw = AnimationWidget()
    aw.show()
    sys.exit(qApp.exec_())

Answer 1

我尝试了你的代码，似乎唯一真正的问题发生在你点击开始两次而没有停止动画的时候。

解决这个问题的一个方法（不涉及动画情节的细节）是防止开始和停止按钮做任何不应该做的事情。

方法是向AnimationWidget类添加一个属性，该属性记录动画是否正在播放。所以把它放在AnimationWidget的\uuuu init\uuuu方法中的某个地方：

self.playing = False

然后，将启动时的和停止时的方法更改为

def on_start(self):
    if self.playing:
        pass
    else:
        self.playing = True
        self.ani = animation.FuncAnimation(
            self.canvas.figure,
            self.update_line,
            blit=True, interval=25
        )

和

def on_stop(self):
    if self.playing:
        self.playing = False
        self.ani._stop()
    else:
        pass

这使得动画不会启动两次，并且不会出现错误和图形故障。