pyqtgraph/examples/histogram.py

# -*- coding: utf-8 -*-
"""
In this example we draw two different kinds of histogram.
"""
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

win = pg.GraphicsLayoutWidget(show=True)
win.resize(800,350)
win.setWindowTitle('pyqtgraph example: Histogram')
plt1 = win.addPlot()
plt2 = win.addPlot()

## make interesting distribution of values
vals = np.hstack([np.random.normal(size=500), np.random.normal(size=260, loc=4)])

## compute standard histogram
y,x = np.histogram(vals, bins=np.linspace(-3, 8, 40))

## Using stepMode=True causes the plot to draw two lines for each sample.
## notice that len(x) == len(y)+1
plt1.plot(x, y, stepMode=True, fillLevel=0, brush=(0,0,255,150))

## Now draw all points as a nicely-spaced scatter plot
y = pg.pseudoScatter(vals, spacing=0.15)
#plt2.plot(vals, y, pen=None, symbol='o', symbolSize=5)
plt2.plot(vals, y, pen=None, symbol='o', symbolSize=5, symbolPen=(255,255,255,200), symbolBrush=(0,0,255,150))

## 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_()