pyqtgraph/examples/Flowchart.py

# -*- coding: utf-8 -*-
"""
This example demonstrates a very basic use of flowcharts: filter data,
displaying both the input and output of the filter. The behavior of
he filter can be reprogrammed by the user.

Basic steps are:
  - create a flowchart and two plots
  - input noisy data to the flowchart
  - flowchart connects data to the first plot, where it is displayed
  - add a gaussian filter to lowpass the data, then display it in the second plot.
"""
import initExample ## Add path to library (just for examples; you do not need this)


from pyqtgraph.flowchart import Flowchart
from pyqtgraph.Qt import QtGui, QtCore
import pyqtgraph as pg
import numpy as np
import pyqtgraph.metaarray as metaarray

app = QtGui.QApplication([])

## Create main window with grid layout
win = QtGui.QMainWindow()
win.setWindowTitle('pyqtgraph example: Flowchart')
cw = QtGui.QWidget()
win.setCentralWidget(cw)
layout = QtGui.QGridLayout()
cw.setLayout(layout)

## Create flowchart, define input/output terminals
fc = Flowchart(terminals={
    'dataIn': {'io': 'in'},
    'dataOut': {'io': 'out'}    
})
w = fc.widget()

## Add flowchart control panel to the main window
layout.addWidget(fc.widget(), 0, 0, 2, 1)

## Add two plot widgets
pw1 = pg.PlotWidget()
pw2 = pg.PlotWidget()
layout.addWidget(pw1, 0, 1)
layout.addWidget(pw2, 1, 1)

win.show()

## generate signal data to pass through the flowchart
data = np.random.normal(size=1000)
data[200:300] += 1
data += np.sin(np.linspace(0, 100, 1000))
data = metaarray.MetaArray(data, info=[{'name': 'Time', 'values': np.linspace(0, 1.0, len(data))}, {}])

## Feed data into the input terminal of the flowchart
fc.setInput(dataIn=data)

## populate the flowchart with a basic set of processing nodes. 
## (usually we let the user do this)
plotList = {'Top Plot': pw1, 'Bottom Plot': pw2}

pw1Node = fc.createNode('PlotWidget', pos=(0, -150))
pw1Node.setPlotList(plotList)
pw1Node.setPlot(pw1)

pw2Node = fc.createNode('PlotWidget', pos=(150, -150))
pw2Node.setPlot(pw2)
pw2Node.setPlotList(plotList)

fNode = fc.createNode('GaussianFilter', pos=(0, 0))
fNode.ctrls['sigma'].setValue(5)
fc.connectTerminals(fc['dataIn'], fNode['In'])
fc.connectTerminals(fc['dataIn'], pw1Node['In'])
fc.connectTerminals(fNode['Out'], pw2Node['In'])
fc.connectTerminals(fNode['Out'], fc['dataOut'])



## 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_()