matplotlib中的动画与散射和使用set_offsets:图的自动缩放不起作用

Question

我在使用动画的python GUI中使用matplotlib绘图.以下是代码

import sys
from PyQt4 import QtGui

from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.backends.backend_qt4agg import NavigationToolbar2QT as NavigationToolbar
import matplotlib.pyplot as plt
import matplotlib.animation
import numpy as np
class Window(QtGui.QDialog):
    def __init__(self, parent=None):
    super(Window, self).__init__(parent)
    self.figure = plt.figure()
    self.canvas = FigureCanvas(self.figure)
    self.toolbar = NavigationToolbar(self.canvas, self)
    layout = QtGui.QVBoxLayout()
    layout.addWidget(self.toolbar)
    layout.addWidget(self.canvas)
    self.setLayout(layout)
    self.ax=self.figure.add_subplot(111)

    plt.autoscale(enable=True, axis='both', tight=None #for auto scaling

    self.data = [500, -500, 501, -502,.... 623] #some list of data
    self.ax = plt.gca()
    self.ax.grid()
    self.sc = self.ax.scatter(self.data[::2], self.data[1::2]

def plot(self, a):
    for i in range(len(self.data)):
        self.data[i] = int(self.data[i])+5
    self.sc.set_offsets(np.c_[self.data[::2], self.data[1::2]])
    self.canvas.draw()

if __name__ == '__main__':
    app = QtGui.QApplication(sys.argv)

    main = Window()
    ani = matplotlib.animation.FuncAnimation(main.figure, main.plot, 
            frames=4, interval=100, repeat=True) 
    main.show()

    sys.exit(app.exec_())

我正在使用动画调用的绘图函数中的set_offsets更新绘图.当绘图值保持增加并且绘图完成时,绘图将超出图.所以我使用了autoscale().但它不起作用.静止轴保持固定,图表不在视野范围内.请帮我做图中的自动缩放.提前致谢.

Answer 1

问题是当轴自动调整时不考虑散点偏移.这可能是一个错误或所需的功能; 无论如何,有两种解决方法:

运用 plot

在许多情况下可接受的一种解决方法是使用线图plt.plot而不是plt.scatter.在这种情况下,轴可以使用ax.relim随后的自动标定ax.autoscale_view().

import matplotlib.pyplot as plt
import matplotlib.animation
import numpy as np

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

data = np.cumsum(np.random.normal(size=100)) #some list of data
sc, = ax.plot(data[::2], data[1::2], marker="o", ls="") # set linestyle to none

def plot(a, data):
    data += np.cumsum(np.random.normal(size=100)+3e-2)
    sc.set_data(data[::2], data[1::2])
    ax.relim()
    ax.autoscale_view(True,True,True)

ani = matplotlib.animation.FuncAnimation(fig, plot, fargs=(data,),
            frames=4, interval=100, repeat=True) 
plt.show()

以scatter编程方式使用和设置限制

如果不能使用上述内容(例如,因为散点应具有不同的大小或颜色),则需要根据数据更新限制.

import matplotlib.pyplot as plt
import matplotlib.animation
import numpy as np

fig, ax = plt.subplots()    

data = np.cumsum(np.random.normal(size=100)) #some list of data

ax.grid()
sc = ax.scatter(data[::2], data[1::2], c=data[1::2])

def plot(a, data):
    data += np.cumsum(np.random.normal(size=100)+3e-2)
    X = np.c_[data[::2], data[1::2]]
    sc.set_offsets(X)
    # manually relim:
    xmin=X[:,0].min(); xmax=X[:,0].max()
    ymin=X[:,1].min(); ymax=X[:,1].max()
    ax.set_xlim(xmin-0.1*(xmax-xmin),xmax+0.1*(xmax-xmin))
    ax.set_ylim(ymin-0.1*(ymax-ymin),ymax+0.1*(ymax-ymin))

ani = matplotlib.animation.FuncAnimation(fig, plot, fargs=(data,),
            frames=4, interval=100, repeat=True) 
plt.show()