Getting PySide to work with matplotlib

Question

I have tried running the example code on the SciPy website, but I get this error:

Traceback (most recent call last):   File ".\matplotlibPySide.py", line 24, in <module>     win.setCentralWidget(canvas) TypeError: 'PySide.QtGui.QMainWindow.setCentralWidget' called with wrong argument types:   PySide.QtGui.QMainWindow.setCentralWidget(FigureCanvasQTAgg) Supported signatures:   PySide.QtGui.QMainWindow.setCentralWidget(PySide.QtGui.QWidget) 

I am building a simple scientific data logger that will eventually be used in commercial applications, so I really need both the LGPL from PySide and plotting functionality. Does anyone have experience on how to get this to work or alternative plotting packages or ideas?

Thanks in advance.

Answer 1

The example that you mention:

http://www.scipy.org/Cookbook/Matplotlib/PySide

works, but you might need to suggest the use of PySide:

... matplotlib.use('Qt4Agg') matplotlib.rcParams['backend.qt4']='PySide' import pylab ... 

Answer 2

I had similar goals (LGPL, potential commercial use) and here's how I ended up getting it to work.

Create a matplotlib widget (see here for a more detailed one for PyQt):

import matplotlib  matplotlib.use('Qt4Agg') matplotlib.rcParams['backend.qt4']='PySide'  from matplotlib.figure import Figure from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas  class MatplotlibWidget(FigureCanvas):      def __init__(self, parent=None,xlabel='x',ylabel='y',title='Title'):         super(MatplotlibWidget, self).__init__(Figure())          self.setParent(parent)         self.figure = Figure()         self.canvas = FigureCanvas(self.figure)         self.axes = self.figure.add_subplot(111)          self.axes.set_xlabel(xlabel)         self.axes.set_ylabel(ylabel)         self.axes.set_title(title) 

In Qt Designer I created a blank widget to hold my plot and then when I __init__ the main window I call setupPlot:

def  setupPlot(self):     # create a matplotlib widget     self.DataPlot = MatplotlibWidget()     # create a layout inside the blank widget and add the matplotlib widget             layout = QtGui.QVBoxLayout(self.ui.widget_PlotArea)             layout.addWidget(self.DataPlot,1) 

Then I call plotDataPoints as needed:

def plotDataPoints(self,x,y):             self.DataPlot.axes.clear()     self.DataPlot.axes.plot(x,y,'bo-')     self.DataPlot.draw() 

Note: this clears and redraws the entire plot every time (since the shape of my data keeps changing) and so isn't fast.