在 Python 中使用 matplotlib 和 kivy 进行实时绘图

2022-01-15 00:00:00 python kivy matplotlib

问题描述

所以...我一直在尝试让 kivy 使用 matplotlib 绘制实时生成的数据.我之前在 TkInter 中使用过与此类似的代码，它就像一个魅力，所以我真的很困惑为什么它在这里不起作用.

so... I've been trying to get kivy to plot data generated in real time, using matplotlib. I've used similar code to this one before in TkInter and it worked like a charm so I'm really confused why it does not work here.

代码如下:

import numpy as np
import matplotlib
matplotlib.use('module://kivy.garden.matplotlib.backend_kivy')
from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.clock import Clock
import matplotlib.pyplot as plt

class MyApp(App):
    def build(self):
        box = BoxLayout()

        self.fig,self.ax = plt.subplots(1)
        self.plt_canvas = self.fig.canvas
        box.add_widget(self.plt_canvas)

        self.line = self.ax.plot([])[0]
        self.i = 0
        plt.show()
        Clock.schedule_interval(self.update, 1)

        return box

    def update(self, *args):
        self.line.set_xdata(np.arange(self.i))
        self.line.set_ydata(np.arange(self.i))
        self.i +=1

        plt.draw()

MyApp().run()

我想让它绘制线，每秒 1 个点.但相反，我得到了这个:

I wanted to get it to plot the line, 1 point each second. But instead I get this:

似乎画布没有重绘.我究竟做错了什么?

Seems like the canvas is not redrawing. What am I doing wrong?

解决方案

根据@ImportanceOfBeingErnest 的建议，需要更新坐标区限制.

As suggested by @ImportanceOfBeingErnest, the axes limits need to be updated.

以下代码应该可以解决您的问题:

The following code should solve your problem:

import matplotlib
matplotlib.use('module://kivy.garden.matplotlib.backend_kivy')
from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.clock import Clock
import matplotlib.pyplot as plt

fig, ax = plt.subplots()
canvas = fig.canvas


class MyApp(App):
    def build(self):
        box = BoxLayout()
        self.i = 0
        self.line = [self.i]
        box.add_widget(canvas)
        plt.show()
        Clock.schedule_interval(self.update, 1)
        return box

    def update(self, *args):
        plt.plot(self.line, self.line)
        self.i += 1
        self.line.append(self.i)
        canvas.draw_idle()


MyApp().run()

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