4

Having a simple graphics layout with PyQtGraph in which the x-axis of the plots are linked together and the grid is displayed in both plots as well:

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

app = QtGui.QApplication([])                                                        
view = pg.GraphicsView()                                                            
l = pg.GraphicsLayout()                                                             
view.setCentralItem(l)                                                              
view.show()                                                                         
view.resize(800,600)                                                                

p0 = l.addPlot(0, 0)                                                                
p0.showGrid(x = True, y = True, alpha = 0.3)                                        
#p0.hideAxis('bottom')                                                              
p1 = l.addPlot(1, 0)                                                                
p1.showGrid(x = True, y = True, alpha = 0.3)                                        

p1.setXLink(p0)                                                                     

l.layout.setSpacing(0.)                                                             
l.setContentsMargins(0., 0., 0., 0.)                                                

if __name__ == '__main__':                                                          
    import sys                                                                      
    if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):         
        QtGui.QApplication.instance().exec_()

enter image description here

If I hide the x-axis in the first plot (uncommenting the p0.hideAxis('bottom') line in the code) then the axis will be gone, but the grid will disappear too:

enter image description here

How could I force it to stay there? As both x-axis are linked together, I would expect that to be possible (the grid in the upper plot could be taken from the lower plot's x-axis).

Peque
  • 13,638
  • 11
  • 69
  • 105

2 Answers2

7

Instead of hiding the axis, try axis.setStyle(showValues=False).

(This might only be available in the development branch)

Luke
  • 11,374
  • 2
  • 48
  • 61
  • It works great, but when using `showValues = False` the line which separates the AxisItem and the ViewBox is still there. Would there be a way of getting rid of it as when `hideAxis` is used? – Peque Nov 24 '14 at 12:34
  • Thanks... to other people trying to get this working you will need to hide the label as well with `axis.showLabel(False)` – pev.hall Nov 15 '16 at 07:43
  • @pev.hall In the most recent versions, you don't need to set anything with showLabel. If you showLabel(True) then the label space will be created but it will be empty, therefore showLabel is False by default when using showValues=False. – misantroop Feb 11 '20 at 20:26
1

So, this is complete code with the amendments:

#https://stackoverflow.com/questions/27100277/pyqtgraph-grid-with-linked-axes
from pyqtgraph.Qt import QtGui, QtCore
import pyqtgraph as pg

app = QtGui.QApplication([])
view = pg.GraphicsView()
l = pg.GraphicsLayout()
view.setCentralItem(l)
view.show()
view.resize(800,600)

p0 = l.addPlot(0, 0)
p0.showGrid(x = True, y = True, alpha = 1.0)

#have no x-axis tickmark below the upper plot (coordinate 0,0)
#without these lines, there will be separate coordinate systems with a gap inbetween
ax0 = p0.getAxis('bottom')      #get handle to x-axis 0
ax0.setStyle(showValues=False)  #this will remove the tick labels and reduces gap b/w plots almost to zero
                                #there will be a double line separating the plot rows


p1 = l.addPlot(1, 0)
p1.showGrid(x = True, y = True, alpha = 1.0)

p1.setXLink(p0)

l.layout.setSpacing(0.)
l.setContentsMargins(0., 0., 0., 0.)

if __name__ == '__main__':
    import sys
    if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
        QtGui.QApplication.instance().exec_()
papa
  • 11
  • 3