pyqtgraph：同步不同图中轴的缩放

Question

我想同步几个 pyqtgraph 图的 X 轴。当用户通过鼠标交互（例如，鼠标在 x 轴上时滚动滚轮）重新缩放 X 轴时，我想将相同的更改分配给所有其他图。那么我该怎么做呢？

我从下面的一个基本示例中导出了一个最小化代码。

我是否必须覆盖 w1 和 w2 的 viewRangeChanged() 函数？

import pyqtgraph as pg
from pyqtgraph.Qt import QtCore, QtGui
import pyqtgraph.console
import numpy as np

from pyqtgraph.dockarea import *


win = QtGui.QMainWindow()
area = DockArea()
win.setCentralWidget(area)
win.resize(1000,500)
win.setWindowTitle('pyqtgraph example: dockarea')


d1 = Dock("Dock1")
d2 = Dock("Dock2")
area.addDock(d1, 'bottom')
area.addDock(d2, 'bottom', d1)

w1 = pg.PlotWidget(title="Dock 1 plot")
w1.plot(np.random.normal(size=100))
d1.addWidget(w1)

w2 = pg.PlotWidget(title="Dock 2 plot")
w2.plot(np.random.normal(size=100))
d2.addWidget(w2)

win.show()

## Start Qt event loop unless running in interactive mode or using pyside.
if __name__ == '__main__':
    import sys
    if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
        QtGui.QApplication.instance().exec_()

这个问题有跟进这个问题的另一个答案。

Answer 1

我们需要使用 sigRangeChanged 信号并将其连接到插槽，问题是另一个项目的范围变化会产生信号 sigRangeChanged 等等产生无限循环，要解决这个问题你必须断开那些在进行修改之前发出信号并将它们重新连接到最终。

w1.sigRangeChanged.connect(onSigRangeChanged)
w2.sigRangeChanged.connect(onSigRangeChanged)

def onSigRangeChanged(r):
    w1.sigRangeChanged.disconnect(onSigRangeChanged)
    w2.sigRangeChanged.disconnect(onSigRangeChanged)
    if w1 == r:
        w2.setRange(xRange=r.getAxis('bottom').range)
    elif w2 == r:
        w1.setRange(xRange=r.getAxis('bottom').range)

    w1.sigRangeChanged.connect(onSigRangeChanged)
    w2.sigRangeChanged.connect(onSigRangeChanged)

示例：

import pyqtgraph as pg
from pyqtgraph.Qt import QtCore, QtGui
import numpy as np
from pyqtgraph.dockarea import *
import sys


def onSigRangeChanged(r):
    w1.sigRangeChanged.disconnect(onSigRangeChanged)
    w2.sigRangeChanged.disconnect(onSigRangeChanged)
    if w1==r:
        w2.setRange(xRange=r.getAxis('bottom').range)
    elif w2 == r:
        w1.setRange(xRange=r.getAxis('bottom').range)

    w1.sigRangeChanged.connect(onSigRangeChanged)
    w2.sigRangeChanged.connect(onSigRangeChanged)

app = QtGui.QApplication(sys.argv)

win = QtGui.QMainWindow()
area = DockArea()
win.setCentralWidget(area)
win.resize(1000,500)
win.setWindowTitle('pyqtgraph example: dockarea')


d1 = Dock("Dock1")
d2 = Dock("Dock2")
area.addDock(d1, 'bottom')
area.addDock(d2, 'bottom', d1)

w1 = pg.PlotWidget(title="Dock 1 plot")
it=w1.plot(np.random.normal(size=100))

d1.addWidget(w1)

w2 = pg.PlotWidget(title="Dock 2 plot")
w2.plot(np.random.normal(size=100))
d2.addWidget(w2)

w1.sigRangeChanged.connect(onSigRangeChanged)
w2.sigRangeChanged.connect(onSigRangeChanged)

win.show()

sys.exit(app.exec_())

Answer 2

更好的是，

可以使用 blockSignals 而不是断开然后重新连接信号。

这是同步任意数量绘图的通用方法：

syncedPlots = [w1, w2, w3] # put as many plots as you wish

def onSigRangeChanged(r):
    for g in syncedPlots:
        if g !=r :
            g.blockSignals(True)
            g.setRange(xRange=r.getAxis('bottom').range)
            g.blockSignals(False)

for g in syncedPlots:
     g.sigRangeChanged.connect(onSigRangeChanged)

Answer 3

中有更好的答案：

Instead of connecting to the sigRangeChanged event we can directly link the axes scales by w2.setXLink(w1).

pyqtgraph：同步不同图中轴的缩放

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