Added in flowchart's filter functions

examples/Flowchart.py

@@ -1,61 +1,88 @@
 # -*- coding: utf-8 -*-
-import sys, os
+import initExample ## Add path to library (just for examples; you do not need this)
-
-## Make sure pyqtgraph is importable
-p = os.path.dirname(os.path.abspath(__file__))
-p = os.path.join(p, '..', '..')
-sys.path.insert(0, p)
 
 
 from pyqtgraph.flowchart import Flowchart
 from pyqtgraph.Qt import QtGui
-
+import pyqtgraph as pg
-#import pyqtgraph.flowchart as f
+import numpy as np
 
 app = QtGui.QApplication([])
 
-#TETRACYCLINE = True
+
+win = QtGui.QMainWindow()
+cw = QtGui.QWidget()
+win.setCentralWidget(cw)
+layout = QtGui.QGridLayout()
+cw.setLayout(layout)
 
 fc = Flowchart(terminals={
     'dataIn': {'io': 'in'},
     'dataOut': {'io': 'out'}    
 })
 w = fc.widget()
-w.resize(400,200)
-w.show()
 
-n1 = fc.createNode('Add', pos=(0,-80))
+layout.addWidget(fc.widget(), 0, 0, 2, 1)
-n2 = fc.createNode('Subtract', pos=(140,-10))
-n3 = fc.createNode('Abs', pos=(0, 80))
-n4 = fc.createNode('Add', pos=(140,100))
 
-fc.connectTerminals(fc.dataIn, n1.A)
+pw1 = pg.PlotWidget()
-fc.connectTerminals(fc.dataIn, n1.B)
+pw2 = pg.PlotWidget()
-fc.connectTerminals(fc.dataIn, n2.A)
+layout.addWidget(pw1, 0, 1)
-fc.connectTerminals(n1.Out, n4.A)
+layout.addWidget(pw2, 1, 1)
-fc.connectTerminals(n1.Out, n2.B)
+
-fc.connectTerminals(n2.Out, n3.In)
+win.show()
-fc.connectTerminals(n3.Out, n4.B)
-fc.connectTerminals(n4.Out, fc.dataOut)
 
 
-def process(**kargs):
+data = np.random.normal(size=1000)
-    return fc.process(**kargs)
+data[200:300] += 1
+data += np.sin(np.linspace(0, 100, 1000))
+
+fc.setInput(dataIn=data)
+
+pw1Node = fc.createNode('PlotWidget', pos=(0, -150))
+pw1Node.setPlot(pw1)
+
+pw2Node = fc.createNode('PlotWidget', pos=(150, -150))
+pw2Node.setPlot(pw2)
+
+fNode = fc.createNode('GaussianFilter', pos=(0, 0))
+fc.connectTerminals(fc.dataIn, fNode.In)
+fc.connectTerminals(fc.dataIn, pw1Node.In)
+fc.connectTerminals(fNode.Out, pw2Node.In)
+fc.connectTerminals(fNode.Out, fc.dataOut)
+
+
+#n1 = fc.createNode('Add', pos=(0,-80))
+#n2 = fc.createNode('Subtract', pos=(140,-10))
+#n3 = fc.createNode('Abs', pos=(0, 80))
+#n4 = fc.createNode('Add', pos=(140,100))
+
+#fc.connectTerminals(fc.dataIn, n1.A)
+#fc.connectTerminals(fc.dataIn, n1.B)
+#fc.connectTerminals(fc.dataIn, n2.A)
+#fc.connectTerminals(n1.Out, n4.A)
+#fc.connectTerminals(n1.Out, n2.B)
+#fc.connectTerminals(n2.Out, n3.In)
+#fc.connectTerminals(n3.Out, n4.B)
+#fc.connectTerminals(n4.Out, fc.dataOut)
+
+
+#def process(**kargs):
+    #return fc.process(**kargs)
 
     
-print process(dataIn=7)
+#print process(dataIn=7)
 
-fc.setInput(dataIn=3)
+#fc.setInput(dataIn=3)
 
-s = fc.saveState()
+#s = fc.saveState()
-fc.clear()
+#fc.clear()
 
-fc.restoreState(s)
+#fc.restoreState(s)
 
-fc.setInput(dataIn=3)
+#fc.setInput(dataIn=3)
 
-#f.NodeMod.TETRACYCLINE = False
 
-if sys.flags.interactive == 0:
+## Start Qt event loop unless running in interactive mode or using pyside.
+import sys
+if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
     app.exec_()
-

flowchart/library/functions.py

@@ -0,0 +1,216 @@
+def downsample(data, n, axis=0, xvals='subsample'):
+    """Downsample by averaging points together across axis.
+    If multiple axes are specified, runs once per axis.
+    If a metaArray is given, then the axis values can be either subsampled
+    or downsampled to match.
+    """
+    ma = None
+    if isinstance(data, MetaArray):
+        ma = data
+        data = data.view(ndarray)
+        
+    
+    if hasattr(axis, '__len__'):
+        if not hasattr(n, '__len__'):
+            n = [n]*len(axis)
+        for i in range(len(axis)):
+            data = downsample(data, n[i], axis[i])
+        return data
+    
+    nPts = int(data.shape[axis] / n)
+    s = list(data.shape)
+    s[axis] = nPts
+    s.insert(axis+1, n)
+    sl = [slice(None)] * data.ndim
+    sl[axis] = slice(0, nPts*n)
+    d1 = data[tuple(sl)]
+    #print d1.shape, s
+    d1.shape = tuple(s)
+    d2 = d1.mean(axis+1)
+    
+    if ma is None:
+        return d2
+    else:
+        info = ma.infoCopy()
+        if 'values' in info[axis]:
+            if xvals == 'subsample':
+                info[axis]['values'] = info[axis]['values'][::n][:nPts]
+            elif xvals == 'downsample':
+                info[axis]['values'] = downsample(info[axis]['values'], n)
+        return MetaArray(d2, info=info)
+
+
+def applyFilter(data, b, a, padding=100, bidir=True):
+    """Apply a linear filter with coefficients a, b. Optionally pad the data before filtering
+    and/or run the filter in both directions."""
+    d1 = data.view(ndarray)
+    
+    if padding > 0:
+        d1 = numpy.hstack([d1[:padding], d1, d1[-padding:]])
+    
+    if bidir:
+        d1 = scipy.signal.lfilter(b, a, scipy.signal.lfilter(b, a, d1)[::-1])[::-1]
+    else:
+        d1 = scipy.signal.lfilter(b, a, d1)
+    
+    if padding > 0:
+        d1 = d1[padding:-padding]
+        
+    if isinstance(data, MetaArray):
+        return MetaArray(d1, info=data.infoCopy())
+    else:
+        return d1
+    
+def besselFilter(data, cutoff, order=1, dt=None, btype='low', bidir=True):
+    """return data passed through bessel filter"""
+    if dt is None:
+        try:
+            tvals = data.xvals('Time')
+            dt = (tvals[-1]-tvals[0]) / (len(tvals)-1)
+        except:
+            raise Exception('Must specify dt for this data.')
+    
+    b,a = scipy.signal.bessel(order, cutoff * dt, btype=btype) 
+    
+    return applyFilter(data, b, a, bidir=bidir)
+    #base = data.mean()
+    #d1 = scipy.signal.lfilter(b, a, data.view(ndarray)-base) + base
+    #if isinstance(data, MetaArray):
+        #return MetaArray(d1, info=data.infoCopy())
+    #return d1
+
+def butterworthFilter(data, wPass, wStop=None, gPass=2.0, gStop=20.0, order=1, dt=None, btype='low', bidir=True):
+    """return data passed through bessel filter"""
+    if dt is None:
+        try:
+            tvals = data.xvals('Time')
+            dt = (tvals[-1]-tvals[0]) / (len(tvals)-1)
+        except:
+            raise Exception('Must specify dt for this data.')
+    
+    if wStop is None:
+        wStop = wPass * 2.0
+    ord, Wn = scipy.signal.buttord(wPass*dt*2., wStop*dt*2., gPass, gStop)
+    #print "butterworth ord %f   Wn %f   c %f   sc %f" % (ord, Wn, cutoff, stopCutoff)
+    b,a = scipy.signal.butter(ord, Wn, btype=btype) 
+    
+    return applyFilter(data, b, a, bidir=bidir)
+
+
+def rollingSum(data, n):
+    d1 = data.copy()
+    d1[1:] += d1[:-1]  # integrate
+    d2 = np.empty(len(d1) - n + 1, dtype=data.dtype)
+    d2[0] = d1[n-1]  # copy first point
+    d2[1:] = d1[n:] - d1[:-n]  # subtract
+    return d2
+
+
+def mode(data, bins=None):
+    """Returns location max value from histogram."""
+    if bins is None:
+        bins = int(len(data)/10.)
+        if bins < 2:
+            bins = 2
+    y, x = np.histogram(data, bins=bins)
+    ind = np.argmax(y)
+    mode = 0.5 * (x[ind] + x[ind+1])
+    return mode
+    
+def modeFilter(data, window=500, step=None, bins=None):
+    """Filter based on histogram-based mode function"""
+    d1 = data.view(np.ndarray)
+    vals = []
+    l2 = int(window/2.)
+    if step is None:
+        step = l2
+    i = 0
+    while True:
+        if i > len(data)-step:
+            break
+        vals.append(mode(d1[i:i+window], bins))
+        i += step
+            
+    chunks = [np.linspace(vals[0], vals[0], l2)]
+    for i in range(len(vals)-1):
+        chunks.append(np.linspace(vals[i], vals[i+1], step))
+    remain = len(data) - step*(len(vals)-1) - l2
+    chunks.append(np.linspace(vals[-1], vals[-1], remain))
+    d2 = np.hstack(chunks)
+    
+    if isinstance(data, MetaArray):
+        return MetaArray(d2, info=data.infoCopy())
+    return d2
+
+def denoise(data, radius=2, threshold=4):
+    """Very simple noise removal function. Compares a point to surrounding points,
+    replaces with nearby values if the difference is too large."""
+    
+    
+    r2 = radius * 2
+    d1 = data.view(ndarray)
+    d2 = data[radius:] - data[:-radius] #a derivative
+    #d3 = data[r2:] - data[:-r2]
+    #d4 = d2 - d3
+    stdev = d2.std()
+    #print "denoise: stdev of derivative:", stdev
+    mask1 = d2 > stdev*threshold #where derivative is large and positive
+    mask2 = d2 < -stdev*threshold #where derivative is large and negative
+    maskpos = mask1[:-radius] * mask2[radius:] #both need to be true
+    maskneg = mask1[radius:] * mask2[:-radius]
+    mask = maskpos + maskneg
+    d5 = np.where(mask, d1[:-r2], d1[radius:-radius]) #where both are true replace the value with the value from 2 points before
+    d6 = np.empty(d1.shape, dtype=d1.dtype) #add points back to the ends
+    d6[radius:-radius] = d5
+    d6[:radius] = d1[:radius]
+    d6[-radius:] = d1[-radius:]
+    
+    if isinstance(data, MetaArray):
+        return MetaArray(d6, info=data.infoCopy())
+    return d6
+
+def adaptiveDetrend(data, x=None, threshold=3.0):
+    """Return the signal with baseline removed. Discards outliers from baseline measurement."""
+    if x is None:
+        x = data.xvals(0)
+    
+    d = data.view(ndarray)
+    
+    d2 = scipy.signal.detrend(d)
+    
+    stdev = d2.std()
+    mask = abs(d2) < stdev*threshold
+    #d3 = where(mask, 0, d2)
+    #d4 = d2 - lowPass(d3, cutoffs[1], dt=dt)
+    
+    lr = stats.linregress(x[mask], d[mask])
+    base = lr[1] + lr[0]*x
+    d4 = d - base
+    
+    if isinstance(data, MetaArray):
+        return MetaArray(d4, info=data.infoCopy())
+    return d4
+    
+
+def histogramDetrend(data, window=500, bins=50, threshold=3.0):
+    """Linear detrend. Works by finding the most common value at the beginning and end of a trace, excluding outliers."""
+    
+    d1 = data.view(np.ndarray)
+    d2 = [d1[:window], d1[-window:]]
+    v = [0, 0]
+    for i in [0, 1]:
+        d3 = d2[i]
+        stdev = d3.std()
+        mask = abs(d3-np.median(d3)) < stdev*threshold
+        d4 = d3[mask]
+        y, x = np.histogram(d4, bins=bins)
+        ind = np.argmax(y)
+        v[i] = 0.5 * (x[ind] + x[ind+1])
+        
+    base = np.linspace(v[0], v[1], len(data))
+    d3 = data.view(np.ndarray) - base
+    
+    if isinstance(data, MetaArray):
+        return MetaArray(d3, info=data.infoCopy())
+    return d3
+