Python: In pyqtgraph, how to obtain the axes range of a PlotWidget

Question

I'm working with the plot of pyqtgraph. There is a built-in function viewRange() returns the axes range of the view box, rather than the plot itself. Is there any function or variables store the axes range of the plot?

Answer 1

Note that the range will give you the current view limits (e.g. if you are zoomed), you can get both the current view range and full x/y axis limits with:

plot.getViewBox().state

which is a dict with quite a few useful parameters.

Answer 2

You can access to axes range from AxisItem. Here is sample code.

import sys
from pyqtgraph.Qt import QtGui #from PyQt4 import QtGui
import pyqtgraph

# make window
app = QtGui.QApplication(sys.argv) # construct a QApplication (must).

mw = QtGui.QMainWindow()
mw.resize(800,800)
mw.setWindowTitle('my qt window')

# make view
view = pyqtgraph.GraphicsLayoutWidget()
# view.show()
mw.setCentralWidget(view)
mw.show()

# make plot area
w1 = view.addPlot(title = "my plot area")

# plot data
# mkPen(color,width,name)
w1.addLegend(offset=(0, 0))
w1.plot([0,1,2,3,4],[3,6,5,8,7],pen=pyqtgraph.mkPen(1, width=1),name="foo")
w1.plot([0,1,2,3,4],[5,7,6,2,9],pen=pyqtgraph.mkPen(2, width=1),name="bar")

axX = w1.getAxis('bottom')
print('x axis range: {}'.format(axX.range)) # <------- get range of x axis
axY = w1.getAxis('left')
print('x axis range: {}'.format(axY.range)) # <------- get range of y axis

sys.exit(app.exec_())