merge from dev

GraphicsScene/GraphicsScene.py

 from pyqtgraph.Qt import QtCore, QtGui
+from pyqtgraph.python2_3 import sortList
 #try:
     #from PyQt4 import QtOpenGL
     #HAVE_OPENGL = True
@@ -505,18 +506,19 @@ class GraphicsScene(QtGui.QGraphicsScene):
         menusToAdd = []
         while item is not self:
             item = item.parentItem()
- 
+            
             if item is None:
                 item = self
                 
             if not hasattr(item, "getContextMenus"):
                 continue
-
             
             subMenus = item.getContextMenus(event)
+            if subMenus is None:
+                continue
             if type(subMenus) is not list: ## so that some items (like FlowchartViewBox) can return multiple menus
                 subMenus = [subMenus]
-
+            
             for sm in subMenus:
                 menusToAdd.append(sm)
         

Qt.py

 ## Do all Qt imports from here to allow easier PyQt / PySide compatibility
 
-#from PySide import QtGui, QtCore, QtOpenGL, QtSvg
-from PyQt4 import QtGui, QtCore
-try:
-    from PyQt4 import QtSvg
-except ImportError:
-    pass
-try:
-    from PyQt4 import QtOpenGL
-except ImportError:
-    pass
+USE_PYSIDE = False   ## If False, import PyQt4. If True, import PySide
+                     ## Note that when switching between PyQt and PySide, all template
+                     ## files (*.ui) must be rebuilt for the target library.
+
+if USE_PYSIDE:
+    from PySide import QtGui, QtCore, QtOpenGL, QtSvg
+    import PySide
+    VERSION_INFO = 'PySide ' + PySide.__version__
+else:
+    from PyQt4 import QtGui, QtCore
+    try:
+        from PyQt4 import QtSvg
+    except ImportError:
+        pass
+    try:
+        from PyQt4 import QtOpenGL
+    except ImportError:
+        pass
 
-if not hasattr(QtCore, 'Signal'):
     QtCore.Signal = QtCore.pyqtSignal
+    VERSION_INFO = 'PyQt4 ' + QtCore.PYQT_VERSION_STR + ' Qt ' + QtCore.QT_VERSION_STR

SRTTransform.py

@@ -76,7 +76,7 @@ class SRTTransform(QtGui.QTransform):
         m = pg.SRTTransform3D(m)
         angle, axis = m.getRotation()
         if angle != 0 and (axis[0] != 0 or axis[1] != 0 or axis[2] != 1):
-            print angle, axis
+            print("angle: %s  axis: %s" % (str(angle), str(axis)))
             raise Exception("Can only convert 4x4 matrix to 3x3 if rotation is around Z-axis.")
         self._state = {
             'pos': Point(m.getTranslation()),

SRTTransform3D.py

 # -*- coding: utf-8 -*-
-from Qt import QtCore, QtGui
-from Vector import Vector
-from SRTTransform import SRTTransform
+from .Qt import QtCore, QtGui
+from .Vector import Vector
+from .SRTTransform import SRTTransform
 import pyqtgraph as pg
 import numpy as np
 import scipy.linalg
@@ -136,15 +136,15 @@ class SRTTransform3D(QtGui.QMatrix4x4):
         try:
             evals, evecs = scipy.linalg.eig(r)
         except:
-            print "Rotation matrix:", r
-            print "Scale:", scale
-            print "Original matrix:", m
+            print("Rotation matrix: %s" % str(r))
+            print("Scale: %s" % str(scale))
+            print("Original matrix: %s" % str(m))
             raise
         eigIndex = np.argwhere(np.abs(evals-1) < 1e-7)
         if len(eigIndex) < 1:
-            print "eigenvalues:", evals
-            print "eigenvectors:", evecs
-            print "index:", eigIndex, evals-1
+            print("eigenvalues: %s" % str(evals))
+            print("eigenvectors: %s" % str(evecs))
+            print("index: %s, %s" % (str(eigIndex), str(evals-1)))
             raise Exception("Could not determine rotation axis.")
         axis = evecs[eigIndex[0,0]].real
         axis /= ((axis**2).sum())**0.5
@@ -259,23 +259,23 @@ if __name__ == '__main__':
     tr3 = QtGui.QTransform()
     tr3.translate(20, 0)
     tr3.rotate(45)
-    print "QTransform -> Transform:", SRTTransform(tr3)
+    print("QTransform -> Transform: %s" % str(SRTTransform(tr3)))
     
-    print "tr1:", tr1
+    print("tr1: %s" % str(tr1))
     
     tr2.translate(20, 0)
     tr2.rotate(45)
-    print "tr2:", tr2
+    print("tr2: %s" % str(tr2))
     
     dt = tr2/tr1
-    print "tr2 / tr1 = ", dt
+    print("tr2 / tr1 = %s" % str(dt))
     
-    print "tr2 * tr1 = ", tr2*tr1
+    print("tr2 * tr1 = %s" % str(tr2*tr1))
     
     tr4 = SRTTransform()
     tr4.scale(-1, 1)
     tr4.rotate(30)
-    print "tr1 * tr4 = ", tr1*tr4
+    print("tr1 * tr4 = %s" % str(tr1*tr4))
     
     w1 = widgets.TestROI((19,19), (22, 22), invertible=True)
     #w2 = widgets.TestROI((0,0), (150, 150))

Vector.py

@@ -5,7 +5,7 @@ Copyright 2010  Luke Campagnola
 Distributed under MIT/X11 license. See license.txt for more infomation.
 """
 
-from Qt import QtGui, QtCore
+from .Qt import QtGui, QtCore
 import numpy as np
 
 class Vector(QtGui.QVector3D):

WidgetGroup.py

@@ -10,6 +10,7 @@ of a large group of widgets.
 
 from .Qt import QtCore, QtGui
 import weakref, inspect
+from .python2_3 import asUnicode
 
 
 __all__ = ['WidgetGroup']

__init__.py

 # -*- coding: utf-8 -*-
+REVISION = None
+
 ### import all the goodies and add some helper functions for easy CLI use
 
 ## 'Qt' is a local module; it is intended mainly to cover up the differences
 ## between PyQt4 and PySide.
-from .Qt import QtGui 
+from .Qt import QtGui
 
 ## not really safe--If we accidentally create another QApplication, the process hangs (and it is very difficult to trace the cause)
 #if QtGui.QApplication.instance() is None:
     #app = QtGui.QApplication([])
 
-import sys
+import os, sys
 
 ## check python version
-if sys.version_info[0] < 2 or (sys.version_info[0] == 2 and sys.version_info[1] != 7):
+## Allow anything >= 2.7
+if sys.version_info[0] < 2 or (sys.version_info[0] == 2 and sys.version_info[1] < 7):
     raise Exception("Pyqtgraph requires Python version 2.7 (this is %d.%d)" % (sys.version_info[0], sys.version_info[1]))
 
 ## helpers for 2/3 compatibility
@@ -30,13 +33,15 @@ else:
     useOpenGL = False  ## on windows there's a more even performance / bugginess tradeoff. 
                 
 CONFIG_OPTIONS = {
-    'useOpenGL': useOpenGL,   ## by default, this is platform-dependent (see widgets/GraphicsView). Set to True or False to explicitly enable/disable opengl.
+    'useOpenGL': useOpenGL, ## by default, this is platform-dependent (see widgets/GraphicsView). Set to True or False to explicitly enable/disable opengl.
     'leftButtonPan': True,  ## if false, left button drags a rubber band for zooming in viewbox
-    'foregroundColor': (200,200,200),
-    'backgroundColor': (0,0,0),
+    'foreground': (150, 150, 150),  ## default foreground color for axes, labels, etc.
+    'background': (0, 0, 0),        ## default background for GraphicsWidget
     'antialias': False,
+    'editorCommand': None,  ## command used to invoke code editor from ConsoleWidgets
 } 
 
+
 def setConfigOption(opt, value):
     CONFIG_OPTIONS[opt] = value
 
@@ -44,6 +49,23 @@ def getConfigOption(opt):
     return CONFIG_OPTIONS[opt]
 
 
+def systemInfo():
+    print("sys.platform: %s" % sys.platform)
+    print("sys.version: %s" % sys.version)
+    from .Qt import VERSION_INFO
+    print("qt bindings: %s" % VERSION_INFO)
+    
+    global REVISION
+    if REVISION is None:  ## this code was probably checked out from bzr; look up the last-revision file
+        lastRevFile = os.path.join(os.path.dirname(__file__), '.bzr', 'branch', 'last-revision')
+        if os.path.exists(lastRevFile):
+            REVISION = open(lastRevFile, 'r').read().strip()
+    
+    print("pyqtgraph: %s" % REVISION)
+    print("config:")
+    import pprint
+    pprint.pprint(CONFIG_OPTIONS)
+
 ## Rename orphaned .pyc files. This is *probably* safe :)
 
 def renamePyc(startDir):
@@ -105,7 +127,7 @@ def importAll(path, excludes=()):
                 globals()[k] = getattr(mod, k)
 
 importAll('graphicsItems')
-importAll('widgets', excludes=['MatplotlibWidget'])
+importAll('widgets', excludes=['MatplotlibWidget', 'RemoteGraphicsView'])
 
 from .imageview import *
 from .WidgetGroup import *

configfile.py

@@ -13,6 +13,7 @@ import re, os, sys
 from collections import OrderedDict
 GLOBAL_PATH = None # so not thread safe.
 from . import units
+from .python2_3 import asUnicode
 
 class ParseError(Exception):
     def __init__(self, message, lineNum, line, fileName=None):

console/CmdInput.py

-from PyQt4 import QtCore, QtGui
+from pyqtgraph.Qt import QtCore, QtGui
+from pyqtgraph.python2_3 import asUnicode
 
 class CmdInput(QtGui.QLineEdit):
     
@@ -25,10 +26,10 @@ class CmdInput(QtGui.QLineEdit):
             self.execCmd()
         else:
             QtGui.QLineEdit.keyPressEvent(self, ev)
-            self.history[0] = unicode(self.text())
+            self.history[0] = asUnicode(self.text())
         
     def execCmd(self):
-        cmd = unicode(self.text())
+        cmd = asUnicode(self.text())
         if len(self.history) == 1 or cmd != self.history[1]:
             self.history.insert(1, cmd)
         #self.lastCmd = cmd

console/Console.py

 
 from pyqtgraph.Qt import QtCore, QtGui
-import sys, re, os, time, traceback
+import sys, re, os, time, traceback, subprocess
 import pyqtgraph as pg
-import template
+from . import template
 import pyqtgraph.exceptionHandling as exceptionHandling
 import pickle
 
-EDITOR = "pykate {fileName}:{lineNum}"
-
 class ConsoleWidget(QtGui.QWidget):
     """
     Widget displaying console output and accepting command input.
@@ -24,7 +22,7 @@ class ConsoleWidget(QtGui.QWidget):
       be baffling and frustrating to users since it would appear the program has frozen.
     - some terminals (eg windows cmd.exe) have notoriously unfriendly interfaces
     - ability to add extra features like exception stack introspection
-    - ability to have multiple interactive prompts for remotely generated processes
+    - ability to have multiple interactive prompts, including for spawned sub-processes
     """
     
     def __init__(self, parent=None, namespace=None, historyFile=None, text=None, editor=None):
@@ -72,8 +70,8 @@ class ConsoleWidget(QtGui.QWidget):
         self.ui.historyList.itemDoubleClicked.connect(self.cmdDblClicked)
         self.ui.exceptionBtn.toggled.connect(self.ui.exceptionGroup.setVisible)
         
-        self.ui.catchAllExceptionsBtn.toggled.connect(self.catchAllToggled)
-        self.ui.catchNextExceptionBtn.toggled.connect(self.catchNextToggled)
+        self.ui.catchAllExceptionsBtn.toggled.connect(self.catchAllExceptions)
+        self.ui.catchNextExceptionBtn.toggled.connect(self.catchNextException)
         self.ui.clearExceptionBtn.clicked.connect(self.clearExceptionClicked)
         self.ui.exceptionStackList.itemClicked.connect(self.stackItemClicked)
         self.ui.exceptionStackList.itemDoubleClicked.connect(self.stackItemDblClicked)
@@ -229,15 +227,25 @@ class ConsoleWidget(QtGui.QWidget):
     def flush(self):
         pass
 
-    def catchAllToggled(self, b):
-        if b:
+    def catchAllExceptions(self, catch=True):
+        """
+        If True, the console will catch all unhandled exceptions and display the stack
+        trace. Each exception caught clears the last.
+        """
+        self.ui.catchAllExceptionsBtn.setChecked(catch)
+        if catch:
             self.ui.catchNextExceptionBtn.setChecked(False)
             exceptionHandling.register(self.allExceptionsHandler)
         else:
             exceptionHandling.unregister(self.allExceptionsHandler)
         
-    def catchNextToggled(self, b):
-        if b:
+    def catchNextException(self, catch=True):
+        """
+        If True, the console will catch the next unhandled exception and display the stack
+        trace.
+        """
+        self.ui.catchNextExceptionBtn.setChecked(catch)
+        if catch:
             self.ui.catchAllExceptionsBtn.setChecked(False)
             exceptionHandling.register(self.nextExceptionHandler)
         else:
@@ -254,11 +262,15 @@ class ConsoleWidget(QtGui.QWidget):
         pass
     
     def stackItemDblClicked(self, item):
-        global EDITOR
+        editor = self.editor
+        if editor is None:
+            editor = pg.getConfigOption('editorCommand')
+        if editor is None:
+            return
         tb = self.currentFrame()
         lineNum = tb.tb_lineno
         fileName = tb.tb_frame.f_code.co_filename
-        os.system(EDITOR.format(fileName=fileName, lineNum=lineNum))
+        subprocess.Popen(self.editor.format(fileName=fileName, lineNum=lineNum), shell=True)
         
     
     def allExceptionsHandler(self, *args):

console/__init__.py

-from Console import ConsoleWidget
\ No newline at end of file
+from .Console import ConsoleWidget
\ No newline at end of file

console/template.py

@@ -91,7 +91,7 @@ class Ui_Form(object):
         QtCore.QMetaObject.connectSlotsByName(Form)
 
     def retranslateUi(self, Form):
-        Form.setWindowTitle(QtGui.QApplication.translate("Form", "Form", None, QtGui.QApplication.UnicodeUTF8))
+        Form.setWindowTitle(QtGui.QApplication.translate("Console", "Console", None, QtGui.QApplication.UnicodeUTF8))
         self.historyBtn.setText(QtGui.QApplication.translate("Form", "History..", None, QtGui.QApplication.UnicodeUTF8))
         self.exceptionBtn.setText(QtGui.QApplication.translate("Form", "Exceptions..", None, QtGui.QApplication.UnicodeUTF8))
         self.exceptionGroup.setTitle(QtGui.QApplication.translate("Form", "Exception Handling", None, QtGui.QApplication.UnicodeUTF8))
@@ -101,4 +101,4 @@ class Ui_Form(object):
         self.runSelectedFrameCheck.setText(QtGui.QApplication.translate("Form", "Run commands in selected stack frame", None, QtGui.QApplication.UnicodeUTF8))
         self.exceptionInfoLabel.setText(QtGui.QApplication.translate("Form", "Exception Info", None, QtGui.QApplication.UnicodeUTF8))
 
-from CmdInput import CmdInput
+from .CmdInput import CmdInput

console/template.ui

@@ -11,7 +11,7 @@
    </rect>
   </property>
   <property name="windowTitle">
-   <string>Form</string>
+   <string>Console</string>
   </property>
   <layout class="QGridLayout" name="gridLayout">
    <property name="margin">
@@ -153,7 +153,7 @@
   <customwidget>
    <class>CmdInput</class>
    <extends>QLineEdit</extends>
-   <header>CmdInput</header>
+   <header>.CmdInput</header>
   </customwidget>
  </customwidgets>
  <resources/>

dockarea/DockArea.py

@@ -2,6 +2,7 @@
 from pyqtgraph.Qt import QtCore, QtGui
 from .Container import *
 from .DockDrop import *
+from .Dock import Dock
 import pyqtgraph.debug as debug
 import weakref
 

dockarea/__main__.py

-import sys
-
-## Make sure pyqtgraph is importable
-p = os.path.dirname(os.path.abspath(__file__))
-p = os.path.join(p, '..', '..')
-sys.path.insert(0, p)
-
-from pyqtgraph.Qt import QtCore, QtGui
-
-from .DockArea import *
-from .Dock import *
-
-app = QtGui.QApplication([])
-win = QtGui.QMainWindow()
-area = DockArea()
-win.setCentralWidget(area)
-win.resize(800,800)
-from .Dock import Dock
-d1 = Dock("Dock1", size=(200,200))
-d2 = Dock("Dock2", size=(100,100))
-d3 = Dock("Dock3", size=(1,1))
-d4 = Dock("Dock4", size=(50,50))
-d5 = Dock("Dock5", size=(100,100))
-d6 = Dock("Dock6", size=(300,300))
-area.addDock(d1, 'left')
-area.addDock(d2, 'right')
-area.addDock(d3, 'bottom')
-area.addDock(d4, 'right')
-area.addDock(d5, 'left', d1)
-area.addDock(d6, 'top', d4)
-
-area.moveDock(d6, 'above', d4)
-d3.hideTitleBar()
-
-print("===build complete====")
-
-for d in [d1, d2, d3, d4, d5]:
-    w = QtGui.QWidget()
-    l = QtGui.QVBoxLayout()
-    w.setLayout(l)
-    btns = []
-    for i in range(4):
-        btns.append(QtGui.QPushButton("%s Button %d"%(d.name(), i)))
-        l.addWidget(btns[-1])
-    d.w = (w, l, btns)
-    d.addWidget(w)
-
-
-
-import pyqtgraph as pg
-p = pg.PlotWidget()
-d6.addWidget(p)
-
-print("===widgets added===")
-
-
-#s = area.saveState()
-
-
-#print "\n\n-------restore----------\n\n"
-#area.restoreState(s)
-s = None
-def save():
-    global s
-    s = area.saveState()
-    
-def load():
-    global s
-    area.restoreState(s)
-
-
-#d6.container().setCurrentIndex(0)
-#d2.label.setTabPos(40)
-
-#win2 = QtGui.QMainWindow()
-#area2 = DockArea()
-#win2.setCentralWidget(area2)
-#win2.resize(800,800)
-
-
-win.show()
-#win2.show()
-

documentation/source/conf.py

@@ -18,6 +18,7 @@ import sys, os
 # documentation root, use os.path.abspath to make it absolute, like shown here.
 path = os.path.dirname(os.path.abspath(__file__))
 sys.path.insert(0, os.path.join(path, '..', '..', '..'))
+print sys.path
 
 # -- General configuration -----------------------------------------------------
 

documentation/source/how_to_use.rst

@@ -43,5 +43,12 @@ While I consider this approach somewhat lazy, it is often the case that 'lazy' i
 Embedding widgets inside PyQt applications
 ------------------------------------------
 
-For the serious application developer, all of the functionality in pyqtgraph is available via widgets that can be embedded just like any other Qt widgets. Most importantly, see: :class:`PlotWidget <pyqtgraph.PlotWidget>`, :class:`ImageView <pyqtgraph.ImageView>`, :class:`GraphicsLayoutWidget <pyqtgraph.GraphicsLayoutWidget>`, and :class:`GraphicsView <pyqtgraph.GraphicsView>`. Pyqtgraph's widgets can be included in Designer's ui files via the "Promote To..." functionality.
+For the serious application developer, all of the functionality in pyqtgraph is available via :ref:`widgets <api_widgets>` that can be embedded just like any other Qt widgets. Most importantly, see: :class:`PlotWidget <pyqtgraph.PlotWidget>`, :class:`ImageView <pyqtgraph.ImageView>`, :class:`GraphicsLayoutWidget <pyqtgraph.GraphicsLayoutWidget>`, and :class:`GraphicsView <pyqtgraph.GraphicsView>`. Pyqtgraph's widgets can be included in Designer's ui files via the "Promote To..." functionality:
+    
+#. In Designer, create a QGraphicsView widget ("Graphics View" under the "Display Widgets" category).
+#. Right-click on the QGraphicsView and select "Promote To...".
+#. Under "Promoted class name", enter the class name you wish to use ("PlotWidget", "GraphicsLayoutWidget", etc).
+#. Under "Header file", enter "pyqtgraph".
+#. Click "Add", then click "Promote".
 
+See the designer documentation for more information on promoting widgets.

documentation/source/style.rst

 Line, Fill, and Color
 =====================
 
-Many functions and methods in pyqtgraph accept arguments specifying the line style (pen), fill style (brush), or color. 
+Qt relies on its QColor, QPen and QBrush classes for specifying line and fill styles for all of its drawing.
+Internally, pyqtgraph uses the same system but also allows many shorthand methods of specifying
+the same style options.
 
-For these function arguments, the following values may be used:
+Many functions and methods in pyqtgraph accept arguments specifying the line style (pen), fill style (brush), or color. 
+For most of these function arguments, the following values may be used:
     
 * single-character string representing color (b, g, r, c, m, y, k, w)
 * (r, g, b) or (r, g, b, a) tuple
 * single greyscale value (0.0 - 1.0)
-* (index, maximum) tuple for automatically iterating through colors (see functions.intColor)
+* (index, maximum) tuple for automatically iterating through colors (see :func:`intColor <pyqtgraph.intColor>`)
 * QColor
 * QPen / QBrush where appropriate
 
-Notably, more complex pens and brushes can be easily built using the mkPen() / mkBrush() functions or with Qt's QPen and QBrush classes::
+Notably, more complex pens and brushes can be easily built using the 
+:func:`mkPen() <pyqtgraph.mkPen>` / :func:`mkBrush() <pyqtgraph.mkBrush>` functions or with Qt's QPen and QBrush classes::
 
     mkPen('y', width=3, style=QtCore.Qt.DashLine)          ## Make a dashed yellow line 2px wide
     mkPen(0.5)                                             ## solid grey line 1px wide
     mkPen(color=(200, 200, 255), style=QtCore.Qt.DotLine)  ## Dotted pale-blue line
     
-See the Qt documentation for 'QPen' and 'PenStyle' for more options.
-Colors can also be built using mkColor(), intColor(), hsvColor(), or Qt's QColor class
+See the Qt documentation for 'QPen' and 'PenStyle' for more line-style options and 'QBrush' for more fill options.
+Colors can also be built using :func:`mkColor() <pyqtgraph.mkColor>`, 
+:func:`intColor() <pyqtgraph.intColor>`, :func:`hsvColor() <pyqtgraph.hsvColor>`, or Qt's QColor class.
+
+
+Default Background and Foreground Colors
+----------------------------------------
+
+By default, pyqtgraph uses a black background for its plots and grey for axes, text, and plot lines.
+These defaults can be changed using pyqtgraph.setConfigOption()::
+    
+    import pyqtgraph as pg
+
+    ## Switch to using white background and black foreground
+    pg.setConfigOption('background', 'w')
+    pg.setConfigOption('foreground', 'k')
+
+    ## The following plot has inverted colors
+    pg.plot([1,4,2,3,5])
+    
+(Note that this must be set *before* creating any widgets)
+
+

documentation/source/widgets/index.rst

+.. _api_widgets:
+
 Pyqtgraph's Widgets
 ===================
 

examples/GraphicsLayout.py

@@ -4,41 +4,73 @@ sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..', '..'))
 
 from pyqtgraph.Qt import QtGui, QtCore
 import pyqtgraph as pg
-import user
+import numpy as np
 
 app = QtGui.QApplication([])
 view = pg.GraphicsView()
-l = pg.GraphicsLayout(border=pg.mkPen(0, 0, 255))
+l = pg.GraphicsLayout(border=(100,100,100))
 view.setCentralItem(l)
 view.show()
+view.resize(800,600)
+
+## Title at top
+text = """
+This example demonstrates the use of GraphicsLayout to arrange items in a grid.<br>
+The items added to the layout must be subclasses of QGraphicsWidget (this includes <br>
+PlotItem, ViewBox, LabelItem, and GrphicsLayout itself).
+"""
+l.addLabel(text, col=1, colspan=4)
+l.nextRow()
+
+## Put vertical label on left side
+l.addLabel('Long Vertical Label', angle=-90, rowspan=3)
 
 ## Add 3 plots into the first row (automatic position)
-p1 = l.addPlot()
-p2 = l.addPlot()
-p3 = l.addPlot()
+p1 = l.addPlot(title="Plot 1")
+p2 = l.addPlot(title="Plot 2")
+vb = l.addViewBox(lockAspect=True)
+img = pg.ImageItem(np.random.normal(size=(100,100)))
+vb.addItem(img)
+vb.autoRange()
+
 
-## Add a viewbox into the second row (automatic position)
+## Add a sub-layout into the second row (automatic position)
+## The added item should avoid the first column, which is already filled
 l.nextRow()
-vb = l.addViewBox(colspan=3)
+l2 = l.addLayout(colspan=3, border=(50,0,0))
+l2.setContentsMargins(10, 10, 10, 10)
+l2.addLabel("Sub-layout: this layout demonstrates the use of shared axes and axis labels", colspan=3)
+l2.nextRow()
+l2.addLabel('Vertical Axis Label', angle=-90, rowspan=2)
+p21 = l2.addPlot()
+p22 = l2.addPlot()
+l2.nextRow()
+p23 = l2.addPlot()
+p24 = l2.addPlot()
+l2.nextRow()