python - 为什么我的情节没有出现在使用 Tkinter 的 set_data 中?
问题描述
我正在尝试改进我的绘图功能。我想使用plotGraph
来自 EEG 板的函数实时绘制数据,从 LSL @ 250Hz 中提取样本。以前,我有一个使用常规的功能版本,每次需要刷新绘图时都会self.ax.plot(x,y)
清除数据。self.ax.clear()
尽管如此,一些分析表明,与其他部分相比,我的代码花费了太多时间来绘制。
我得到的建议之一是使用set_data
而不是情节和清晰。我有多行数据要同时绘制,所以我尝试按照Matplotlib multiple animate multiple lines进行操作,您可以在下面看到(改编代码)。另外,有人告诉我使用self.figure.canvas.draw_idle()
,我试过了,但我不确定我是否做得正确。
不幸的是,它没有用,图表没有更新,我似乎找不到原因。我知道我刚才提到的来源使用animation.FuncAnimation
但我不确定这会是问题。是吗?
关于为什么我的画布图表中没有显示我的线条的任何想法?
import tkinter as tk
import matplotlib
import matplotlib.pyplot as plt
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
import numpy as np
class AppWindow:
def plotGraph(self, x, y):
for lnum,line in enumerate(self.lines):
line.set_data(x[:], y[:, lnum])
self.figure.canvas.draw_idle()
plt.ylabel('Magnitude', fontsize = 9, color = tx_color)
plt.xlabel('Freq', fontsize = 9, color = tx_color)
self.figure.canvas.draw()
def __init__(self):
self.root = tk.Tk() #start of application
self.canvas = tk.Canvas(self.root, height = 420, width = 780, bg =
bg_color, highlightthickness=0)
self.canvas.pack(fill = 'both', expand = True)
self.figure = plt.figure(figsize = (5,6), dpi = 100)
self.figure.patch.set_facecolor(sc_color)
self.ax = self.figure.add_subplot(111)
self.ax.clear()
self.line, = self.ax.plot([], [], lw=1, color = tx_color)
self.line.set_data([],[])
#place graph
self.chart_type = FigureCanvasTkAgg(self.figure, self.canvas)
self.chart_type.get_tk_widget().pack()
self.lines = []
numchan = 8 #let's say I have 8 channels
for index in range(numchan):
lobj = self.ax.plot([],[], lw=2, color=tx_color)[0]
self.lines.append(lobj)
for line in self.lines:
line.set_data([],[])
def start(self):
self.root.mainloop()
解决方案
您的图表是空的,因为您正在绘制空数组:
line.set_data([],[])
如果您填写线阵列,图表将正确绘制。
试试这个代码。它每秒用新的随机数据更新图表。
import tkinter as tk
import matplotlib
import matplotlib.pyplot as plt
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
import numpy as np
import random
bg_color='grey'
tx_color='green'
sc_color='linen'
numchan = 8
chlen = 100
xvals=[(x-40)/20 for x in range(chlen)] # X coordinates
chcolors= ['gold','blue','green','maroon','red','brown','purple','cyan']
class AppWindow:
def plotGraph(self):
self.figure.canvas.draw_idle()
plt.ylabel('Magnitude', fontsize = 9, color = tx_color)
plt.xlabel('Freq', fontsize = 9, color = tx_color)
self.figure.canvas.draw()
def UpdateChannelData(self): # callback with new data
# fake random data
for i,ch in enumerate(self.chdata):
for p in range(len(ch)):
ch[p] += (random.random()-.5)/100
self.lines[i].set_data(xvals, ch)
self.plotGraph()
self.root.after(100, self.UpdateChannelData) # simulate next call
def __init__(self):
global chzero
self.root = tk.Tk() #start of application
self.canvas = tk.Canvas(self.root, height = 420, width = 780, bg = bg_color, highlightthickness=0)
self.canvas.pack(fill = 'both', expand = True)
self.figure = plt.figure(figsize = (5,6), dpi = 100)
self.figure.patch.set_facecolor(sc_color)
self.ax = self.figure.add_subplot(111)
self.ax.clear()
self.line, = self.ax.plot([], [], lw=1, color = tx_color)
self.line.set_data([],[])
#place graph
self.chart_type = FigureCanvasTkAgg(self.figure, self.canvas)
self.chart_type.get_tk_widget().pack()
self.lines = []
#numchan = 8 #let's say I have 8 channels
for index in range(numchan):
lobj = self.ax.plot([],[], lw=1, color=chcolors[index])[0]
self.lines.append(lobj)
# set flat data
self.chdata = [[0 for x in range(chlen)] for ch in range(numchan)]
self.root.after(1000, self.UpdateChannelData) # start data read
def start(self):
self.root.mainloop()
AppWindow().start()
输出: