pyqtgraph/examples/MultiplePlotAxes.py

# -*- coding: utf-8 -*-
"""
Demonstrates a way to put multiple axes around a single plot. 

(This will eventually become a built-in feature of PlotItem)

"""
import initExample ## Add path to library (just for examples; you do not need this)

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

pg.mkQApp()

pw = pg.PlotWidget()
pw.show()
pw.setWindowTitle('pyqtgraph example: MultiplePlotAxes')
p1 = pw.plotItem
p1.setLabels(left='axis 1')

## create a new ViewBox, link the right axis to its coordinate system
p2 = pg.ViewBox()
p1.showAxis('right')
p1.scene().addItem(p2)
p1.getAxis('right').linkToView(p2)
p2.setXLink(p1)
p1.getAxis('right').setLabel('axis2', color='#0000ff')

## create third ViewBox. 
## this time we need to create a new axis as well.
p3 = pg.ViewBox()
ax3 = pg.AxisItem('right')
p1.layout.addItem(ax3, 2, 3)
p1.scene().addItem(p3)
ax3.linkToView(p3)
p3.setXLink(p1)
ax3.setZValue(-10000)
ax3.setLabel('axis 3', color='#ff0000')


## Handle view resizing 
def updateViews():
    ## view has resized; update auxiliary views to match
    global p1, p2, p3
    p2.setGeometry(p1.vb.sceneBoundingRect())
    p3.setGeometry(p1.vb.sceneBoundingRect())
    
    ## need to re-update linked axes since this was called
    ## incorrectly while views had different shapes.
    ## (probably this should be handled in ViewBox.resizeEvent)
    p2.linkedViewChanged(p1.vb, p2.XAxis)
    p3.linkedViewChanged(p1.vb, p3.XAxis)

updateViews()
p1.vb.sigResized.connect(updateViews)


p1.plot([1,2,4,8,16,32])
p2.addItem(pg.PlotCurveItem([10,20,40,80,40,20], pen='b'))
p3.addItem(pg.PlotCurveItem([3200,1600,800,400,200,100], pen='r'))

if __name__ == '__main__':
    pg.exec()