# -*- coding: utf-8 -*- """ Example demonstrating a variety of scatter plot features. """ ## Add path to library (just for examples; you do not need this) import initExample from pyqtgraph.Qt import QtGui, QtCore import pyqtgraph as pg import numpy as np app = QtGui.QApplication([]) mw = QtGui.QMainWindow() mw.resize(800,800) view = pg.GraphicsLayoutWidget() ## GraphicsView with GraphicsLayout inserted by default mw.setCentralWidget(view) mw.show() mw.setWindowTitle('pyqtgraph example: ScatterPlot') ## create four areas to add plots w1 = view.addPlot() w2 = view.addViewBox() w2.setAspectLocked(True) view.nextRow() w3 = view.addPlot() w4 = view.addPlot() print("Generating data, this takes a few seconds...") ## There are a few different ways we can draw scatter plots; each is optimized for different types of data: ## 1) All spots identical and transform-invariant (top-left plot). ## In this case we can get a huge performance boost by pre-rendering the spot ## image and just drawing that image repeatedly. n = 300 s1 = pg.ScatterPlotItem(size=10, pen=pg.mkPen(None), brush=pg.mkBrush(255, 255, 255, 120)) pos = np.random.normal(size=(2,n), scale=1e-5) spots = [{'pos': pos[:,i], 'data': 1} for i in range(n)] + [{'pos': [0,0], 'data': 1}] s1.addPoints(spots) w1.addItem(s1) ## Make all plots clickable lastClicked = [] def clicked(plot, points): global lastClicked for p in lastClicked: p.resetPen() print("clicked points", points) for p in points: p.setPen('b', width=2) lastClicked = points s1.sigClicked.connect(clicked) ## 2) Spots are transform-invariant, but not identical (top-right plot). ## In this case, drawing is almsot as fast as 1), but there is more startup ## overhead and memory usage since each spot generates its own pre-rendered ## image. s2 = pg.ScatterPlotItem(size=10, pen=pg.mkPen('w'), pxMode=True) pos = np.random.normal(size=(2,n), scale=1e-5) spots = [{'pos': pos[:,i], 'data': 1, 'brush':pg.intColor(i, n), 'symbol': i%5, 'size': 5+i/10.} for i in range(n)] s2.addPoints(spots) w2.addItem(s2) s2.sigClicked.connect(clicked) ## 3) Spots are not transform-invariant, not identical (bottom-left). ## This is the slowest case, since all spots must be completely re-drawn ## every time because their apparent transformation may have changed. s3 = pg.ScatterPlotItem(pxMode=False) ## Set pxMode=False to allow spots to transform with the view spots3 = [] for i in range(10): for j in range(10): spots3.append({'pos': (1e-6*i, 1e-6*j), 'size': 1e-6, 'pen': {'color': 'w', 'width': 2}, 'brush':pg.intColor(i*10+j, 100)}) s3.addPoints(spots3) w3.addItem(s3) s3.sigClicked.connect(clicked) ## Test performance of large scatterplots s4 = pg.ScatterPlotItem(size=10, pen=pg.mkPen(None), brush=pg.mkBrush(255, 255, 255, 20)) pos = np.random.normal(size=(2,10000), scale=1e-9) s4.addPoints(x=pos[0], y=pos[1]) w4.addItem(s4) s4.sigClicked.connect(clicked) ## Start Qt event loop unless running in interactive mode. if __name__ == '__main__': import sys if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'): QtGui.QApplication.instance().exec_()