Bugfixes:

  - Fixed some floating-point precision issues. (Added a workaround for QTransform.inverted() bug)
  - No longer putting asUnicode inside __builtin__ since this causes problems in some rare circumstances
    (pyshell, lazy import recipe)
  - Minor docstring updates

GraphicsScene/GraphicsScene.py

 from pyqtgraph.Qt import QtCore, QtGui
+from pyqtgraph.python2_3 import sortList
 #try:
     #from PyQt4 import QtOpenGL
     #HAVE_OPENGL = True

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

@@ -14,7 +14,8 @@ from .Qt import QtGui
 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

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 pyqtgraph.Qt import QtCore, QtGui
+from pyqtgraph.python2_3 import asUnicode
 
 class CmdInput(QtGui.QLineEdit):
     

functions.py

@@ -5,6 +5,7 @@ Copyright 2010  Luke Campagnola
 Distributed under MIT/X11 license. See license.txt for more infomation.
 """
 
+from .python2_3 import asUnicode
 Colors = {
     'b': (0,0,255,255),
     'g': (0,255,0,255),
@@ -1275,3 +1276,19 @@ def isosurface(data, level):
 
     return facets
 
+
+    
+def invertQTransform(tr):
+    """Return a QTransform that is the inverse of *tr*.
+    Rasises an exception if tr is not invertible.
+    
+    Note that this function is preferred over QTransform.inverted() due to
+    bugs in that method. (specifically, Qt has floating-point precision issues
+    when determining whether a matrix is invertible)
+    """
+    #return tr.inverted()[0]
+    arr = np.array([[tr.m11(), tr.m12(), tr.m13()], [tr.m21(), tr.m22(), tr.m23()], [tr.m31(), tr.m32(), tr.m33()]])
+    inv = scipy.linalg.inv(arr)
+    return QtGui.QTransform(inv[0,0], inv[0,1], inv[0,2], inv[1,0], inv[1,1], inv[1,2], inv[2,0], inv[2,1])
+    
+    
\ No newline at end of file

graphicsItems/AxisItem.py

 from pyqtgraph.Qt import QtGui, QtCore
+from pyqtgraph.python2_3 import asUnicode
 import numpy as np
 from pyqtgraph.Point import Point
 import pyqtgraph.debug as debug

graphicsItems/GradientEditorItem.py

 from pyqtgraph.Qt import QtGui, QtCore
+from pyqtgraph.python2_3 import sortList
 import pyqtgraph.functions as fn
 from .GraphicsObject import GraphicsObject
 from .GraphicsWidget import GraphicsWidget

graphicsItems/GraphicsItem.py

 from pyqtgraph.Qt import QtGui, QtCore  
 from pyqtgraph.GraphicsScene import GraphicsScene
 from pyqtgraph.Point import Point
+import pyqtgraph.functions as fn
 import weakref
 
 class GraphicsItem(object):
@@ -149,16 +150,32 @@ class GraphicsItem(object):
         """Return vectors in local coordinates representing the width and height of a view pixel.
         If direction is specified, then return vectors parallel and orthogonal to it.
         
-        Return (None, None) if pixel size is not yet defined (usually because the item has not yet been displayed)."""
+        Return (None, None) if pixel size is not yet defined (usually because the item has not yet been displayed)
+        or if pixel size is below floating-point precision limit.
+        """
 
         dt = self.deviceTransform()
         if dt is None:
             return None, None
         
         if direction is None:
-            direction = Point(1, 0)
+            direction = Point(1, 0)  
+        if direction.manhattanLength() == 0:
+            raise Exception("Cannot compute pixel length for 0-length vector.")
             
+        ## attempt to re-scale direction vector to fit within the precision of the coordinate system
+        if direction.x() == 0:
+            r = abs(dt.m32())/(abs(dt.m12()) + abs(dt.m22()))
+        elif direction.y() == 0:
+            r = abs(dt.m31())/(abs(dt.m11()) + abs(dt.m21()))
+        else:
+            r = ((abs(dt.m32())/(abs(dt.m12()) + abs(dt.m22()))) * (abs(dt.m31())/(abs(dt.m11()) + abs(dt.m21()))))**0.5
+        direction = direction * r
+        
         viewDir = Point(dt.map(direction) - dt.map(Point(0,0)))
+        if viewDir.manhattanLength() == 0:
+            return None, None   ##  pixel size cannot be represented on this scale
+            
         orthoDir = Point(viewDir[1], -viewDir[0])  ## orthogonal to line in pixel-space
         
         try:  
@@ -168,7 +185,7 @@ class GraphicsItem(object):
             raise Exception("Invalid direction %s" %direction)
             
         
-        dti = dt.inverted()[0]
+        dti = fn.invertQTransform(dt)
         return Point(dti.map(normView)-dti.map(Point(0,0))), Point(dti.map(normOrtho)-dti.map(Point(0,0)))  
     
         #vt = self.deviceTransform()
@@ -194,23 +211,26 @@ class GraphicsItem(object):
         
 
     def pixelSize(self):
+        ## deprecated
         v = self.pixelVectors()
         if v == (None, None):
             return None, None
         return (v[0].x()**2+v[0].y()**2)**0.5, (v[1].x()**2+v[1].y()**2)**0.5
 
     def pixelWidth(self):
+        ## deprecated
         vt = self.deviceTransform()
         if vt is None:
             return 0
-        vt = vt.inverted()[0]
+        vt = fn.invertQTransform(vt)
         return Point(vt.map(QtCore.QPointF(1, 0))-vt.map(QtCore.QPointF(0, 0))).length()
         
     def pixelHeight(self):
+        ## deprecated
         vt = self.deviceTransform()
         if vt is None:
             return 0
-        vt = vt.inverted()[0]
+        vt = fn.invertQTransform(vt)
         return Point(vt.map(QtCore.QPointF(0, 1))-vt.map(QtCore.QPointF(0, 0))).length()
         
         
@@ -232,7 +252,7 @@ class GraphicsItem(object):
         vt = self.deviceTransform()
         if vt is None:
             return None
-        vt = vt.inverted()[0]
+        vt = fn.invertQTransform(vt)
         return vt.map(obj)
 
     def mapRectToDevice(self, rect):
@@ -253,7 +273,7 @@ class GraphicsItem(object):
         vt = self.deviceTransform()
         if vt is None:
             return None
-        vt = vt.inverted()[0]
+        vt = fn.invertQTransform(vt)
         return vt.mapRect(rect)
     
     def mapToView(self, obj):
@@ -272,14 +292,14 @@ class GraphicsItem(object):
         vt = self.viewTransform()
         if vt is None:
             return None
-        vt = vt.inverted()[0]
+        vt = fn.invertQTransform(vt)
         return vt.map(obj)
 
     def mapRectFromView(self, obj):
         vt = self.viewTransform()
         if vt is None:
             return None
-        vt = vt.inverted()[0]
+        vt = fn.invertQTransform(vt)
         return vt.mapRect(obj)
 
     def pos(self):

graphicsItems/GridItem.py

@@ -2,6 +2,7 @@ from pyqtgraph.Qt import QtGui, QtCore
 from .UIGraphicsItem import *
 import numpy as np
 from pyqtgraph.Point import Point
+import pyqtgraph.functions as fn
 
 __all__ = ['GridItem']
 class GridItem(UIGraphicsItem):
@@ -47,7 +48,7 @@ class GridItem(UIGraphicsItem):
         p = QtGui.QPainter()
         p.begin(self.picture)
         
-        dt = self.viewTransform().inverted()[0]
+        dt = fn.invertQTransform(self.viewTransform())
         vr = self.getViewWidget().rect()
         unit = self.pixelWidth(), self.pixelHeight()
         dim = [vr.width(), vr.height()]
@@ -112,7 +113,7 @@ class GridItem(UIGraphicsItem):
                         texts.append((QtCore.QPointF(x, y), "%g"%p1[ax]))
         tr = self.deviceTransform()
         #tr.scale(1.5, 1.5)
-        p.setWorldTransform(tr.inverted()[0])
+        p.setWorldTransform(fn.invertQTransform(tr))
         for t in texts:
             x = tr.map(t[0]) + Point(0.5, 0.5)
             p.drawText(x, t[1])

graphicsItems/PlotItem/PlotItem.py

@@ -1053,6 +1053,7 @@ class PlotItem(GraphicsWidget):
             s.hide()
             
     def hideAxis(self, axis):
+        """Hide one of the PlotItem's axes. ('left', 'bottom', 'right', or 'top')"""
         self.showAxis(axis, False)
             
     def showScale(self, *args, **kargs):
@@ -1060,6 +1061,7 @@ class PlotItem(GraphicsWidget):
         return self.showAxis(*args, **kargs)
             
     def hideButtons(self):
+        """Causes auto-scale button ('A' in lower-left corner) to be hidden for this PlotItem"""
         #self.ctrlBtn.hide()
         self.autoBtn.hide()
         

graphicsItems/ROI.py

@@ -800,7 +800,7 @@ class ROI(GraphicsObject):
         #print "  dshape", dShape
         
         ## Determine transform that maps ROI bounding box to image coordinates
-        tr = self.sceneTransform() * img.sceneTransform().inverted()[0] 
+        tr = self.sceneTransform() * fn.invertQTransform(img.sceneTransform())
         
         ## Modify transform to scale from image coords to data coords
         #m = QtGui.QTransform()
@@ -1251,7 +1251,7 @@ class Handle(UIGraphicsItem):
         v = dt.map(QtCore.QPointF(1, 0)) - dt.map(QtCore.QPointF(0, 0))
         va = np.arctan2(v.y(), v.x())
         
-        dti = dt.inverted()[0]
+        dti = fn.invertQTransform(dt)
         devPos = dt.map(QtCore.QPointF(0,0))
         tr = QtGui.QTransform()
         tr.translate(devPos.x(), devPos.y())

graphicsItems/TextItem.py

 from pyqtgraph.Qt import QtCore, QtGui
 import pyqtgraph as pg
 from .UIGraphicsItem import *
+import pyqtgraph.functions as fn
 
 class TextItem(UIGraphicsItem):
     """
@@ -87,7 +88,7 @@ class TextItem(UIGraphicsItem):
         if br is None:
             return
         self.prepareGeometryChange()
-        self._bounds = self.deviceTransform().inverted()[0].mapRect(br)
+        self._bounds = fn.invertQTransform(self.deviceTransform()).mapRect(br)
         #print self._bounds
 
     def boundingRect(self):

graphicsItems/ViewBox/ViewBox.py

 from pyqtgraph.Qt import QtGui, QtCore
+from pyqtgraph.python2_3 import sortList
 import numpy as np
 from pyqtgraph.Point import Point
 import pyqtgraph.functions as fn
@@ -451,10 +452,8 @@ class ViewBox(GraphicsWidget):
             center = Point(vr.center())
         else:
             center = Point(center)
-        
         tl = center + (vr.topLeft()-center) * scale
         br = center + (vr.bottomRight()-center) * scale
-       
         self.setRange(QtCore.QRectF(tl, br), padding=0)
         
     def translateBy(self, t):
@@ -764,7 +763,7 @@ class ViewBox(GraphicsWidget):
 
     def mapToView(self, obj):
         """Maps from the local coordinates of the ViewBox to the coordinate system displayed inside the ViewBox"""
-        m = self.childTransform().inverted()[0]
+        m = fn.invertQTransform(self.childTransform())
         return m.map(obj)
 
     def mapFromView(self, obj):
@@ -830,7 +829,7 @@ class ViewBox(GraphicsWidget):
             mask[axis] = mv
         s = ((mask * 0.02) + 1) ** (ev.delta() * self.state['wheelScaleFactor']) # actual scaling factor
         
-        center = Point(self.childGroup.transform().inverted()[0].map(ev.pos()))
+        center = Point(fn.invertQTransform(self.childGroup.transform()).map(ev.pos()))
         #center = ev.pos()
         
         self.scaleBy(s, center)
@@ -913,8 +912,11 @@ class ViewBox(GraphicsWidget):
             dif = np.array([dif.x(), dif.y()])
             dif[0] *= -1
             s = ((mask * 0.02) + 1) ** dif
-            center = Point(self.childGroup.transform().inverted()[0].map(ev.buttonDownPos(QtCore.Qt.RightButton)))
-            #center = Point(ev.buttonDownPos(QtCore.Qt.RightButton))
+            
+            tr = self.childGroup.transform()
+            tr = fn.invertQTransform(tr)
+            
+            center = Point(tr.map(ev.buttonDownPos(QtCore.Qt.RightButton)))
             self.scaleBy(s, center)
             self.sigRangeChangedManually.emit(self.state['mouseEnabled'])
 

graphicsItems/ViewBox/ViewBoxMenu.py

 from pyqtgraph.Qt import QtCore, QtGui
+from pyqtgraph.python2_3 import asUnicode
 from pyqtgraph.WidgetGroup import WidgetGroup
 from .axisCtrlTemplate import Ui_Form as AxisCtrlTemplate
 import weakref 

parametertree/parameterTypes.py

 from pyqtgraph.Qt import QtCore, QtGui
+from pyqtgraph.python2_3 import asUnicode
 from .Parameter import Parameter, registerParameterType
 from .ParameterItem import ParameterItem
 from pyqtgraph.widgets.SpinBox import SpinBox

python2_3.py

@@ -42,8 +42,9 @@ def sortList(l, cmpFunc):
 if sys.version_info[0] == 3:
     import builtins
     builtins.basestring = str
-    builtins.asUnicode = asUnicode
-    builtins.sortList = sortList
+    #builtins.asUnicode = asUnicode
+    #builtins.sortList = sortList
+    basestring = str
     def cmp(a,b):
         if a>b:
             return 1
@@ -52,7 +53,7 @@ if sys.version_info[0] == 3:
         else:
             return 0
     builtins.cmp = cmp
-else:
-    import __builtin__
-    __builtin__.asUnicode = asUnicode
-    __builtin__.sortList = sortList
+#else:    ## don't use __builtin__  -- this confuses things like pyshell and ActiveState's lazy import recipe
+    #import __builtin__
+    #__builtin__.asUnicode = asUnicode
+    #__builtin__.sortList = sortList

widgets/SpinBox.py

 # -*- coding: utf-8 -*-
 from pyqtgraph.Qt import QtGui, QtCore
+from pyqtgraph.python2_3 import asUnicode
 from pyqtgraph.SignalProxy import SignalProxy
 
 import pyqtgraph.functions as fn

widgets/TableWidget.py

 # -*- coding: utf-8 -*-
 from pyqtgraph.Qt import QtGui, QtCore
+from pyqtgraph.python2_3 import asUnicode
 
 import numpy as np
 try: