513e904a59
- reduced cost of transferring arrays between processes (pickle is too slow) - avoid unnecessary synchronous calls Added RemoteSpeedTest example
79 lines
2.9 KiB
Python
79 lines
2.9 KiB
Python
# -*- coding: utf-8 -*-
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"""
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This example demonstrates the use of RemoteGraphicsView to improve performance in
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applications with heavy load. It works by starting a second process to handle
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all graphics rendering, thus freeing up the main process to do its work.
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In this example, the update() function is very expensive and is called frequently.
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After update() generates a new set of data, it can either plot directly to a local
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plot (bottom) or remotely via a RemoteGraphicsView (top), allowing speed comparison
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between the two cases. IF you have a multi-core CPU, it should be obvious that the
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remote case is much faster.
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"""
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import initExample ## Add path to library (just for examples; you do not need this)
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from pyqtgraph.Qt import QtGui, QtCore
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import pyqtgraph as pg
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import pyqtgraph.widgets.RemoteGraphicsView
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import numpy as np
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app = pg.mkQApp()
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view = pg.widgets.RemoteGraphicsView.RemoteGraphicsView()
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pg.setConfigOptions(antialias=True) ## this will be expensive for the local plot
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view.pg.setConfigOptions(antialias=True) ## prettier plots at no cost to the main process!
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label = QtGui.QLabel()
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rcheck = QtGui.QCheckBox('plot remote')
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rcheck.setChecked(True)
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lcheck = QtGui.QCheckBox('plot local')
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lplt = pg.PlotWidget()
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layout = pg.LayoutWidget()
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layout.addWidget(rcheck)
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layout.addWidget(lcheck)
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layout.addWidget(label)
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layout.addWidget(view, row=1, col=0, colspan=3)
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layout.addWidget(lplt, row=2, col=0, colspan=3)
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layout.resize(800,800)
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layout.show()
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## Create a PlotItem in the remote process that will be displayed locally
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rplt = view.pg.PlotItem()
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rplt._setProxyOptions(deferGetattr=True) ## speeds up access to rplt.plot
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view.setCentralItem(rplt)
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lastUpdate = pg.ptime.time()
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avgFps = 0.0
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def update():
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global check, label, plt, lastUpdate, avgFps, rpltfunc
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data = np.random.normal(size=(10000,50)).sum(axis=1)
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data += 5 * np.sin(np.linspace(0, 10, data.shape[0]))
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if rcheck.isChecked():
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rplt.plot(data, clear=True, _callSync='off') ## We do not expect a return value.
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## By turning off callSync, we tell
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## the proxy that it does not need to
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## wait for a reply from the remote
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## process.
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if lcheck.isChecked():
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lplt.plot(data, clear=True)
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now = pg.ptime.time()
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fps = 1.0 / (now - lastUpdate)
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lastUpdate = now
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avgFps = avgFps * 0.8 + fps * 0.2
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label.setText("Generating %0.2f fps" % avgFps)
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timer = QtCore.QTimer()
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timer.timeout.connect(update)
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timer.start(0)
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## Start Qt event loop unless running in interactive mode or using pyside.
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if __name__ == '__main__':
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import sys
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if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
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QtGui.QApplication.instance().exec_()
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