Updates to IsocurveItem, added isocurve example

minor updates for other examples

examples/Arrow.py

@@ -7,8 +7,6 @@
 ## To place a static arrow anywhere in a scene, use ArrowItem.
 ## To attach other types of item to a curve, use CurvePoint.
 
-
-## Add path to library (just for examples; you do not need this)                                                                           
 import initExample ## Add path to library (just for examples; you do not need this)
 
 import numpy as np

examples/VideoSpeedTest.py

@@ -1,8 +1,13 @@
-#!/usr/bin/python
 # -*- coding: utf-8 -*-
-## Add path to library (just for examples; you do not need this)
+"""
-import sys, os, time
+Tests the speed of image updates for an ImageItem and RawImageWidget.
-sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..', '..'))
+The speed will generally depend on the type of data being shown, whether
+it is being scaled and/or converted by lookup table, and whether OpenGL
+is used by the view widget
+"""
+
+
+import initExample ## Add path to library (just for examples; you do not need this)
 
 
 from pyqtgraph.Qt import QtGui, QtCore
@@ -136,6 +141,7 @@ timer.start(0)
     
 
 
-## Start Qt event loop unless running in interactive mode.
+## Start Qt event loop unless running in interactive mode or using pyside.
-if sys.flags.interactive != 1:
+import sys
+if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
     app.exec_()

examples/__main__.py

@@ -12,9 +12,13 @@ examples = OrderedDict([
     ('Basic Plotting', 'Plotting.py'),
     ('ImageView', 'ImageView.py'),
     ('ParameterTree', '../parametertree'),
+    ('Crosshair / Mouse interaction', 'crosshair.py'),
+    ('Video speed test', 'VideoSpeedTest.py'),
+    ('Plot speed test', 'PlotSpeedTest.py'),
     ('GraphicsItems', OrderedDict([
         ('Scatter Plot', 'ScatterPlot.py'),
         #('PlotItem', 'PlotItem.py'),
+        ('IsocurveItem', 'isocurve.py'),
         ('ImageItem - video', 'ImageItem.py'),
         ('ImageItem - draw', 'Draw.py'),
         ('Region-of-Interest', 'ROItypes.py'),
@@ -90,7 +94,10 @@ class ExampleLoader(QtGui.QMainWindow):
         fn = self.currentFile()
         if fn is None:
             return
-        os.spawnl(os.P_NOWAIT, sys.executable, sys.executable, '"' + fn + '"')
+        if sys.platform.startswith('win'):
+            os.spawnl(os.P_NOWAIT, sys.executable, sys.executable, '"' + fn + '"')
+        else:
+            os.spawnl(os.P_NOWAIT, sys.executable, sys.executable, fn)
         
             
     def showFile(self):

examples/isocurve.py

@@ -0,0 +1,58 @@
+# -*- coding: utf-8 -*-
+"""
+Tests use of IsoCurve item displayed with image
+"""
+
+
+import initExample ## Add path to library (just for examples; you do not need this)
+
+
+from pyqtgraph.Qt import QtGui, QtCore
+import numpy as np
+import pyqtgraph as pg
+import scipy.ndimage as ndi
+
+app = QtGui.QApplication([])
+
+## make pretty looping data
+frames = 200
+data = np.random.normal(size=(frames,30,30), loc=0, scale=100)
+data = np.concatenate([data, data], axis=0)
+data = ndi.gaussian_filter(data, (10, 10, 10))[frames/2:frames + frames/2]
+
+win = pg.GraphicsWindow()
+vb = win.addViewBox()
+img = pg.ImageItem(data[0])
+vb.addItem(img)
+vb.setAspectLocked()
+
+## generate empty curves
+curves = []
+levels = np.linspace(data.min(), data.max(), 10)
+for i in range(len(levels)):
+    v = levels[i]
+    ## generate isocurve with automatic color selection
+    c = pg.IsocurveItem(level=v, pen=(i, len(levels)*1.5))
+    c.setParentItem(img)  ## make sure isocurve is always correctly displayed over image
+    c.setZValue(10)
+    curves.append(c)
+
+## animate!
+ptr = 0
+imgLevels = (data.min(), data.max() * 2)
+def update():
+    global data, curves, img, ptr, imgLevels
+    ptr = (ptr + 1) % data.shape[0]
+    data[ptr]
+    img.setImage(data[ptr], levels=imgLevels)
+    for c in curves:
+        c.setData(data[ptr])
+
+timer = QtCore.QTimer()
+timer.timeout.connect(update)
+timer.start(50)
+    
+## Start Qt event loop unless running in interactive mode or using pyside.
+import sys
+if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
+    app.exec_()

graphicsItems/IsocurveItem.py

@@ -2,7 +2,7 @@
 
 from GraphicsObject import *
 import pyqtgraph.functions as fn
-from pyqtgraph.Qt import QtGui
+from pyqtgraph.Qt import QtGui, QtCore
 
 
 class IsocurveItem(GraphicsObject):
@@ -13,26 +13,50 @@ class IsocurveItem(GraphicsObject):
     call isocurve.setParentItem(image)
     """
     
-    def __init__(self, data, level, pen='w'):
+    def __init__(self, data=None, level=0, pen='w'):
         GraphicsObject.__init__(self)
-        
+        self.level = 0
-        lines = fn.isocurve(data, level)
+        self.data = None
-        
+        self.path = None
-        self.path = QtGui.QPainterPath()
+        self.setData(data, level)
         self.setPen(pen)
         
-        for line in lines:
+    
-            self.path.moveTo(*line[0])
+    def setData(self, data, level=None):
-            self.path.lineTo(*line[1])
+        if level is None:
+            level = self.level
+        self.level = level
+        self.data = data
+        self.path = None
+        self.prepareGeometryChange()
+        self.update()
+        
+    def setLevel(self, level):
+        self.level = level
+        self.path = None
+        self.update()
     
     def setPen(self, *args, **kwargs):
         self.pen = fn.mkPen(*args, **kwargs)
         self.update()
 
     def boundingRect(self):
+        if self.path is None:
+            return QtCore.QRectF()
         return self.path.boundingRect()
     
+    def generatePath(self):
+        self.path = QtGui.QPainterPath()
+        if self.data is None:
+            return
+        lines = fn.isocurve(self.data, self.level)
+        for line in lines:
+            self.path.moveTo(*line[0])
+            self.path.lineTo(*line[1])
+    
     def paint(self, p, *args):
+        if self.path is None:
+            self.generatePath()
         p.setPen(self.pen)
         p.drawPath(self.path)