如何阻止 Matplotlib 导航工具栏缩放在绘图更新时重置？
How to stop Matplotlib's navigation toolbar zoom from reseting on plot update?
我希望使用 Matplotlib 的导航工具栏的情况相对简单。我希望能够在图形更新之间保留之前的缩放值、相机平移等。我一直在此处嵌入 PyQt5（我在我的项目中使用它），以防两者之间需要一些额外的互连。非常感谢您的观看！
import sys
import os
import random
import matplotlib
matplotlib.use('Qt5Agg')
from PyQt5 import QtCore, QtWidgets
from PyQt5.QtWidgets import QGridLayout, QFileDialog, QPushButton
from numpy import arange
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.backends.backend_qt5agg import NavigationToolbar2QT as NavigationToolbar
from matplotlib.figure import Figure
class MyMplCanvas(FigureCanvas):
def __init__(self, parent=None, width=5, height=4, dpi=100):
fig = Figure(figsize=(width, height), dpi=dpi)
self.fig = fig ###
self.axes = fig.add_subplot(111)
self.axes.hold(False)
self.compute_initial_figure()
FigureCanvas.__init__(self, fig)
self.setParent(parent)
FigureCanvas.setSizePolicy(self,
QtWidgets.QSizePolicy.Expanding,
QtWidgets.QSizePolicy.Expanding)
FigureCanvas.updateGeometry(self)
def compute_initial_figure(self):
pass
class MyDynamicMplCanvas(MyMplCanvas):
def __init__(self, *args, **kwargs):
MyMplCanvas.__init__(self, *args, **kwargs)
timer = QtCore.QTimer(self)
timer.timeout.connect(self.update_figure)
timer.start(1000)
def compute_initial_figure(self):
self.axes.plot([0, 1, 2, 3], [1, 2, 0, 4], 'b')
def update_figure(self):
l = [random.randint(0, 10) for i in range(4)]
self.axes.cla()
self.axes.plot([0, 1, 2, 3], l, 'b')
self.draw()
class P1(QtWidgets.QWidget):
def __init__(self, parent=None):
super(P1, self).__init__(parent)
layout = QGridLayout(self)
self.plot_canvas = MyDynamicMplCanvas(self, width=5, height=4, dpi=100)
self.navi_toolbar = NavigationToolbar(self.plot_canvas, self)
layout.addWidget(self.plot_canvas, 1, 1, 1, 1)
layout.addWidget(self.navi_toolbar, 2, 1, 1, 1)
class MainWindow(QtWidgets.QMainWindow):
def __init__(self, parent=None):
super(MainWindow, self).__init__(parent)
self.setAttribute(QtCore.Qt.WA_DeleteOnClose)
self.stack = QtWidgets.QStackedWidget(self)
P1f = P1(self)
self.stack.addWidget(P1f)
self.setCentralWidget(self.stack)
if __name__ == '__main__':
qApp = QtWidgets.QApplication(sys.argv)
aw = MainWindow()
aw.show()
sys.exit(qApp.exec_())
这里的大反派是axes.hold(False)和axes.cla()。他们负责清除坐标轴和图形，这（通常）会重置绘图视图。
有了这些，您可以正确使用 self.axes.autoscale(enable=False)，我建议您将它放在 compute_initial_figure() 中的第一个情节之后，这样情节至少在开始时会有所缩放。
然后，为了能够清除您之前的情节，您可以为 MyMplCanvas class 创建另一个属性，也许 self.plotted_line 或类似的东西，用 [=18 初始化=].每次调用 self.axes.plot(...) 时，将 return 值分配给 self.plotted_line，就像这样：self.plotted_line, = self.axes.plot(...)。请注意 self.plotted_line 后的逗号，这是仅分配第一个 return 值的方法之一，这是您感兴趣的值。
最后，在每个新情节之前，检查并调用
if self.plotted_line is not None:
self.plot.remove()
这将有效删除之前的情节。
canvas classes 看起来像这样（变化很小）。
class MyMplCanvas(FigureCanvas):
def __init__(self, parent=None, width=5, height=4, dpi=100):
fig = Figure(figsize=(width, height), dpi=dpi)
self.fig = fig ###
self.axes = fig.add_subplot(111)
self.plotted_line = None
self.compute_initial_figure()
FigureCanvas.__init__(self, fig)
self.setParent(parent)
FigureCanvas.setSizePolicy(self,
QtWidgets.QSizePolicy.Expanding,
QtWidgets.QSizePolicy.Expanding)
FigureCanvas.updateGeometry(self)
def compute_initial_figure(self):
pass
class MyDynamicMplCanvas(MyMplCanvas):
def __init__(self, *args, **kwargs):
MyMplCanvas.__init__(self, *args, **kwargs)
timer = QtCore.QTimer(self)
timer.timeout.connect(self.update_figure)
timer.start(1000)
def compute_initial_figure(self):
self.plotted_line, = self.axes.plot([0, 1, 2, 3], [1, 2, 0, 4], 'b')
self.axes.autoscale(enable=False)
def update_figure(self):
l = [random.randint(0, 10) for i in range(4)]
if self.plotted_line is not None:
self.plotted_line.remove()
self.plotted_line, = self.axes.plot([0, 1, 2, 3], l, 'b')
self.draw()
缩放值可以通过连接 mpl 'draw_event' 直接存储：
def __init__(self, parent=None, width=5, height=4, dpi=100):
...
self.mpl_connect('draw_event', self.on_draw)
def on_draw(self, event):
self.xlim = self.axes.get_xlim()
self.ylim = self.axes.get_ylim()
然后在 plot() 调用后恢复：
def update_figure(self):
...
self.axes.plot([0, 1, 2, 3], l, 'b')
self.axes.set_xlim(self.xlim)
self.axes.set_ylim(self.ylim)
...
https://matplotlib.org/users/event_handling.html
完整代码：
import random
import sys
import matplotlib
matplotlib.use('Qt5Agg')
from PyQt5 import QtCore, QtWidgets
from PyQt5.QtWidgets import QGridLayout
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.backends.backend_qt5agg import NavigationToolbar2QT as NavigationToolbar
from matplotlib.figure import Figure
class MyMplCanvas(FigureCanvas):
def __init__(self, parent=None, width=5, height=4, dpi=100):
fig = Figure(figsize=(width, height), dpi=dpi)
self.fig = fig ###
self.axes = fig.add_subplot(111)
self.axes.hold(False)
self.compute_initial_figure()
FigureCanvas.__init__(self, fig)
self.setParent(parent)
FigureCanvas.setSizePolicy(self,
QtWidgets.QSizePolicy.Expanding,
QtWidgets.QSizePolicy.Expanding)
FigureCanvas.updateGeometry(self)
self.xlim = self.axes.get_xlim()
self.ylim = self.axes.get_ylim()
self.mpl_connect('draw_event', self.on_draw)
def on_draw(self, event):
self.xlim = self.axes.get_xlim()
self.ylim = self.axes.get_ylim()
def compute_initial_figure(self):
pass
class MyDynamicMplCanvas(MyMplCanvas):
def __init__(self, *args, **kwargs):
MyMplCanvas.__init__(self, *args, **kwargs)
timer = QtCore.QTimer(self)
timer.timeout.connect(self.update_figure)
timer.start(1000)
def compute_initial_figure(self):
self.axes.plot([0, 1, 2, 3], [1, 2, 0, 4], 'b')
def update_figure(self):
l = [random.randint(0, 10) for i in range(4)]
self.axes.cla()
self.axes.plot([0, 1, 2, 3], l, 'b')
self.axes.set_xlim(self.xlim)
self.axes.set_ylim(self.ylim)
self.draw()
class P1(QtWidgets.QWidget):
def __init__(self, parent=None):
super(P1, self).__init__(parent)
layout = QGridLayout(self)
self.plot_canvas = MyDynamicMplCanvas(self, width=5, height=4, dpi=100)
self.navi_toolbar = NavigationToolbar(self.plot_canvas, self)
layout.addWidget(self.plot_canvas, 1, 1, 1, 1)
layout.addWidget(self.navi_toolbar, 2, 1, 1, 1)
class MainWindow(QtWidgets.QMainWindow):
def __init__(self, parent=None):
super(MainWindow, self).__init__(parent)
self.setAttribute(QtCore.Qt.WA_DeleteOnClose)
self.stack = QtWidgets.QStackedWidget(self)
P1f = P1(self)
self.stack.addWidget(P1f)
self.setCentralWidget(self.stack)
if __name__ == '__main__':
qApp = QtWidgets.QApplication(sys.argv)
aw = MainWindow()
aw.show()
sys.exit(qApp.exec_())
我希望使用 Matplotlib 的导航工具栏的情况相对简单。我希望能够在图形更新之间保留之前的缩放值、相机平移等。我一直在此处嵌入 PyQt5（我在我的项目中使用它），以防两者之间需要一些额外的互连。非常感谢您的观看！
import sys
import os
import random
import matplotlib
matplotlib.use('Qt5Agg')
from PyQt5 import QtCore, QtWidgets
from PyQt5.QtWidgets import QGridLayout, QFileDialog, QPushButton
from numpy import arange
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.backends.backend_qt5agg import NavigationToolbar2QT as NavigationToolbar
from matplotlib.figure import Figure
class MyMplCanvas(FigureCanvas):
def __init__(self, parent=None, width=5, height=4, dpi=100):
fig = Figure(figsize=(width, height), dpi=dpi)
self.fig = fig ###
self.axes = fig.add_subplot(111)
self.axes.hold(False)
self.compute_initial_figure()
FigureCanvas.__init__(self, fig)
self.setParent(parent)
FigureCanvas.setSizePolicy(self,
QtWidgets.QSizePolicy.Expanding,
QtWidgets.QSizePolicy.Expanding)
FigureCanvas.updateGeometry(self)
def compute_initial_figure(self):
pass
class MyDynamicMplCanvas(MyMplCanvas):
def __init__(self, *args, **kwargs):
MyMplCanvas.__init__(self, *args, **kwargs)
timer = QtCore.QTimer(self)
timer.timeout.connect(self.update_figure)
timer.start(1000)
def compute_initial_figure(self):
self.axes.plot([0, 1, 2, 3], [1, 2, 0, 4], 'b')
def update_figure(self):
l = [random.randint(0, 10) for i in range(4)]
self.axes.cla()
self.axes.plot([0, 1, 2, 3], l, 'b')
self.draw()
class P1(QtWidgets.QWidget):
def __init__(self, parent=None):
super(P1, self).__init__(parent)
layout = QGridLayout(self)
self.plot_canvas = MyDynamicMplCanvas(self, width=5, height=4, dpi=100)
self.navi_toolbar = NavigationToolbar(self.plot_canvas, self)
layout.addWidget(self.plot_canvas, 1, 1, 1, 1)
layout.addWidget(self.navi_toolbar, 2, 1, 1, 1)
class MainWindow(QtWidgets.QMainWindow):
def __init__(self, parent=None):
super(MainWindow, self).__init__(parent)
self.setAttribute(QtCore.Qt.WA_DeleteOnClose)
self.stack = QtWidgets.QStackedWidget(self)
P1f = P1(self)
self.stack.addWidget(P1f)
self.setCentralWidget(self.stack)
if __name__ == '__main__':
qApp = QtWidgets.QApplication(sys.argv)
aw = MainWindow()
aw.show()
sys.exit(qApp.exec_())
这里的大反派是axes.hold(False)和axes.cla()。他们负责清除坐标轴和图形，这（通常）会重置绘图视图。
有了这些，您可以正确使用 self.axes.autoscale(enable=False)，我建议您将它放在 compute_initial_figure() 中的第一个情节之后，这样情节至少在开始时会有所缩放。
然后，为了能够清除您之前的情节，您可以为 MyMplCanvas class 创建另一个属性，也许 self.plotted_line 或类似的东西，用 [=18 初始化=].每次调用 self.axes.plot(...) 时，将 return 值分配给 self.plotted_line，就像这样：self.plotted_line, = self.axes.plot(...)。请注意 self.plotted_line 后的逗号，这是仅分配第一个 return 值的方法之一，这是您感兴趣的值。
最后，在每个新情节之前，检查并调用
if self.plotted_line is not None:
self.plot.remove()
这将有效删除之前的情节。
canvas classes 看起来像这样（变化很小）。
class MyMplCanvas(FigureCanvas):
def __init__(self, parent=None, width=5, height=4, dpi=100):
fig = Figure(figsize=(width, height), dpi=dpi)
self.fig = fig ###
self.axes = fig.add_subplot(111)
self.plotted_line = None
self.compute_initial_figure()
FigureCanvas.__init__(self, fig)
self.setParent(parent)
FigureCanvas.setSizePolicy(self,
QtWidgets.QSizePolicy.Expanding,
QtWidgets.QSizePolicy.Expanding)
FigureCanvas.updateGeometry(self)
def compute_initial_figure(self):
pass
class MyDynamicMplCanvas(MyMplCanvas):
def __init__(self, *args, **kwargs):
MyMplCanvas.__init__(self, *args, **kwargs)
timer = QtCore.QTimer(self)
timer.timeout.connect(self.update_figure)
timer.start(1000)
def compute_initial_figure(self):
self.plotted_line, = self.axes.plot([0, 1, 2, 3], [1, 2, 0, 4], 'b')
self.axes.autoscale(enable=False)
def update_figure(self):
l = [random.randint(0, 10) for i in range(4)]
if self.plotted_line is not None:
self.plotted_line.remove()
self.plotted_line, = self.axes.plot([0, 1, 2, 3], l, 'b')
self.draw()
缩放值可以通过连接 mpl 'draw_event' 直接存储：
def __init__(self, parent=None, width=5, height=4, dpi=100):
...
self.mpl_connect('draw_event', self.on_draw)
def on_draw(self, event):
self.xlim = self.axes.get_xlim()
self.ylim = self.axes.get_ylim()
然后在 plot() 调用后恢复：
def update_figure(self):
...
self.axes.plot([0, 1, 2, 3], l, 'b')
self.axes.set_xlim(self.xlim)
self.axes.set_ylim(self.ylim)
...
https://matplotlib.org/users/event_handling.html
完整代码：
import random
import sys
import matplotlib
matplotlib.use('Qt5Agg')
from PyQt5 import QtCore, QtWidgets
from PyQt5.QtWidgets import QGridLayout
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.backends.backend_qt5agg import NavigationToolbar2QT as NavigationToolbar
from matplotlib.figure import Figure
class MyMplCanvas(FigureCanvas):
def __init__(self, parent=None, width=5, height=4, dpi=100):
fig = Figure(figsize=(width, height), dpi=dpi)
self.fig = fig ###
self.axes = fig.add_subplot(111)
self.axes.hold(False)
self.compute_initial_figure()
FigureCanvas.__init__(self, fig)
self.setParent(parent)
FigureCanvas.setSizePolicy(self,
QtWidgets.QSizePolicy.Expanding,
QtWidgets.QSizePolicy.Expanding)
FigureCanvas.updateGeometry(self)
self.xlim = self.axes.get_xlim()
self.ylim = self.axes.get_ylim()
self.mpl_connect('draw_event', self.on_draw)
def on_draw(self, event):
self.xlim = self.axes.get_xlim()
self.ylim = self.axes.get_ylim()
def compute_initial_figure(self):
pass
class MyDynamicMplCanvas(MyMplCanvas):
def __init__(self, *args, **kwargs):
MyMplCanvas.__init__(self, *args, **kwargs)
timer = QtCore.QTimer(self)
timer.timeout.connect(self.update_figure)
timer.start(1000)
def compute_initial_figure(self):
self.axes.plot([0, 1, 2, 3], [1, 2, 0, 4], 'b')
def update_figure(self):
l = [random.randint(0, 10) for i in range(4)]
self.axes.cla()
self.axes.plot([0, 1, 2, 3], l, 'b')
self.axes.set_xlim(self.xlim)
self.axes.set_ylim(self.ylim)
self.draw()
class P1(QtWidgets.QWidget):
def __init__(self, parent=None):
super(P1, self).__init__(parent)
layout = QGridLayout(self)
self.plot_canvas = MyDynamicMplCanvas(self, width=5, height=4, dpi=100)
self.navi_toolbar = NavigationToolbar(self.plot_canvas, self)
layout.addWidget(self.plot_canvas, 1, 1, 1, 1)
layout.addWidget(self.navi_toolbar, 2, 1, 1, 1)
class MainWindow(QtWidgets.QMainWindow):
def __init__(self, parent=None):
super(MainWindow, self).__init__(parent)
self.setAttribute(QtCore.Qt.WA_DeleteOnClose)
self.stack = QtWidgets.QStackedWidget(self)
P1f = P1(self)
self.stack.addWidget(P1f)
self.setCentralWidget(self.stack)
if __name__ == '__main__':
qApp = QtWidgets.QApplication(sys.argv)
aw = MainWindow()
aw.show()
sys.exit(qApp.exec_())