added a few examples

examples/LogPlotTest.py

@@ -0,0 +1,42 @@
+# -*- coding: utf-8 -*-
+
+## This example demonstrates many of the 2D plotting capabilities
+## in pyqtgraph. All of the plots may be panned/scaled by dragging with 
+## the left/right mouse buttons. Right click on any plot to show a context menu.
+
+
+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
+
+#QtGui.QApplication.setGraphicsSystem('raster')
+app = QtGui.QApplication([])
+#mw = QtGui.QMainWindow()
+#mw.resize(800,800)
+
+win = pg.GraphicsWindow(title="Basic plotting examples")
+win.resize(1000,600)
+
+
+
+p5 = win.addPlot(title="Scatter plot, axis labels, log scale")
+x = np.random.normal(size=1000) * 1e-5
+y = x*1000 + 0.005 * np.random.normal(size=1000)
+y -= y.min()-1.0
+mask = x > 1e-15
+x = x[mask]
+y = y[mask]
+p5.plot(x, y, pen=None, symbol='t', symbolPen=None, symbolSize=10, symbolBrush=(100, 100, 255, 50))
+p5.setLabel('left', "Y Axis", units='A')
+p5.setLabel('bottom', "Y Axis", units='s')
+p5.setLogMode(x=True, y=False)
+
+
+## Start Qt event loop unless running in interactive mode or using pyside.
+if __name__ == '__main__':
+    import sys
+    if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
+        QtGui.QApplication.instance().exec_()

examples/SimplePlot.py

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+import initExample ## Add path to library (just for examples; you do not need this)
+
+from pyqtgraph.Qt import QtGui, QtCore
+import pyqtgraph as pg
+import numpy as np
+pg.plot(np.random.normal(size=100000), title="Simplest possible plotting example")
+
+## Start Qt event loop unless running in interactive mode or using pyside.
+if __name__ == '__main__':
+    import sys
+    if sys.flags.interactive != 1 or not hasattr(QtCore, 'PYQT_VERSION'):
+        pg.QtGui.QApplication.exec_()

examples/multiplePlotSpeedTest.py

@@ -0,0 +1,93 @@
+# -*- coding: utf-8 -*-
+import initExample ## Add path to library (just for examples; you do not need this)
+
+import pyqtgraph as pg
+from pyqtgraph.Qt import QtCore, QtGui
+import numpy as np
+
+app = pg.mkQApp()
+plt = pg.PlotWidget()
+
+app.processEvents()
+
+## Putting this at the beginning or end does not have much effect
+plt.show()   
+
+## The auto-range is recomputed after each item is added,
+## so disabling it before plotting helps
+plt.enableAutoRange(False, False)
+
+def plot():
+    start = pg.ptime.time()
+    n = 15
+    pts = 100
+    x = np.linspace(0, 0.8, pts)
+    y = np.random.random(size=pts)*0.8
+    for i in xrange(n):
+        for j in xrange(n):
+            ## calling PlotWidget.plot() generates a PlotDataItem, which 
+            ## has a bit more overhead than PlotCurveItem, which is all 
+            ## we need here. This overhead adds up quickly and makes a big
+            ## difference in speed.
+            
+            #plt.plot(x=x+i, y=y+j)
+            plt.addItem(pg.PlotCurveItem(x=x+i, y=y+j))
+            
+            #path = pg.arrayToQPath(x+i, y+j)
+            #item = QtGui.QGraphicsPathItem(path)
+            #item.setPen(pg.mkPen('w'))
+            #plt.addItem(item)
+            
+    dt = pg.ptime.time() - start
+    print "Create plots took: %0.3fms" % (dt*1000)
+
+## Plot and clear 5 times, printing the time it took
+for i in range(5):
+    plt.clear()
+    plot()
+    app.processEvents()
+    plt.autoRange()
+
+
+
+
+
+def fastPlot():
+    ## Different approach:  generate a single item with all data points.
+    ## This runs about 20x faster.
+    start = pg.ptime.time()
+    n = 15
+    pts = 100
+    x = np.linspace(0, 0.8, pts)
+    y = np.random.random(size=pts)*0.8
+    xdata = np.empty((n, n, pts))
+    xdata[:] = x.reshape(1,1,pts) + np.arange(n).reshape(n,1,1)
+    ydata = np.empty((n, n, pts))
+    ydata[:] = y.reshape(1,1,pts) + np.arange(n).reshape(1,n,1)
+    conn = np.ones((n*n,pts))
+    conn[:,-1] = False # make sure plots are disconnected
+    path = pg.arrayToQPath(xdata.flatten(), ydata.flatten(), conn.flatten())
+    item = QtGui.QGraphicsPathItem(path)
+    item.setPen(pg.mkPen('w'))
+    plt.addItem(item)
+    
+    dt = pg.ptime.time() - start
+    print "Create plots took: %0.3fms" % (dt*1000)
+
+
+## Plot and clear 5 times, printing the time it took
+if hasattr(pg, 'arrayToQPath'):
+    for i in range(5):
+        plt.clear()
+        fastPlot()
+        app.processEvents()
+else:
+    print "Skipping fast tests--arrayToQPath function is missing."
+
+plt.autoRange()
+
+## Start Qt event loop unless running in interactive mode or using pyside.
+if __name__ == '__main__':
+    import sys
+    if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
+        QtGui.QApplication.instance().exec_()