annotate novelty.py @ 7:294f66d285af

some previous changes
author mitian
date Tue, 05 May 2015 08:54:09 +0100
parents c11ea9e0357f
children a34f9c5d0cd9
rev   line source
mi@0 1 #!/usr/bin/env python
mi@0 2 # encoding: utf-8
mi@0 3 """
mi@0 4 novelty.py
mi@0 5
mi@0 6 Created by mi tian on 2015-04-02.
mi@0 7 Copyright (c) 2015 __MyCompanyName__. All rights reserved.
mi@0 8 """
mi@0 9
mi@0 10 import sys, os
mi@0 11 import numpy as np
mi@0 12 from scipy.signal import correlate2d, convolve2d
mitian@1 13 import matplotlib.pyplot as plt
mitian@7 14 from utils.PeakPickerUtil import PeakPicker
mi@0 15
mitian@7 16
mitian@7 17 peak_picker = PeakPicker()
mitian@7 18 peak_picker.params.alpha = 9.0 # Alpha norm
mitian@7 19 peak_picker.params.delta = 0.0 # Adaptive thresholding delta
mitian@7 20 peak_picker.params.QuadThresh_a = (100 - 20.0) / 1000.0
mitian@7 21 peak_picker.params.QuadThresh_b = 0.0
mitian@7 22 peak_picker.params.QuadThresh_c = (100 - 20.0) / 1500.0
mitian@7 23 peak_picker.params.rawSensitivity = 20
mitian@7 24 peak_picker.params.aCoeffs = [1.0000, -0.5949, 0.2348]
mitian@7 25 peak_picker.params.bCoeffs = [0.1600, 0.3200, 0.1600]
mitian@7 26 peak_picker.params.preWin = 5
mitian@7 27 peak_picker.params.postWin = 5 + 1
mitian@7 28 peak_picker.params.LP_on = True
mitian@7 29 peak_picker.params.Medfilt_on = True
mitian@7 30 peak_picker.params.Polyfit_on = True
mitian@7 31 peak_picker.params.isMedianPositive = False
mitian@7 32
mi@0 33 def getNoveltyCurve(ssm, kernel_size, normalise=False):
mi@0 34 '''Return novelty score from ssm.'''
mi@0 35
mi@0 36 kernel_size = int(np.floor(kernel_size/2.0) + 1)
mi@0 37 stripe = getDiagonalSlice(ssm, kernel_size)
mi@0 38 kernel = gaussian_kernel(kernel_size)
mi@0 39 xc = convolve2d(stripe,kernel,mode='same')
mi@0 40 xc[abs(xc)>1e+10]=0.00001
mi@0 41
mi@0 42 novelty = xc[int(np.floor(xc.shape[0]/2.0)),:]
mi@0 43 novelty = [0.0 if (np.isnan(x) or np.isinf(x) or x > 1e+100) else x for x in novelty]
mi@0 44
mi@0 45 if normalise:
mi@0 46 novelty = (novelty - np.min(novelty)) / (np.max(novelty) - np.min(novelty))
mi@0 47 return novelty
mi@0 48
mi@0 49 def getDiagonalSlice(ssm, width):
mi@0 50 ''' Return a diagonal stripe of the ssm given its width, with 45 degrees rotation.
mi@0 51 Note: requres 45 degrees rotated kernel also.'''
mi@0 52 w = int(np.floor(width/2.0))
mi@0 53 length = len(np.diagonal(ssm))
mi@0 54 stripe = np.zeros((2*w+1,length))
mi@0 55 # print 'diagonal', length, w, stripe.shape
mi@0 56 for i in xrange(-w, w+1) :
mi@0 57 stripe[w+i,:] = np.hstack(( np.zeros(int(np.floor(abs(i)/2.0))), np.diagonal(ssm,i), np.zeros(int(np.ceil(abs(i)/2.0))) ))
mi@0 58 return stripe
mi@0 59
mi@0 60 def gaussian_kernel(size):
mi@0 61 '''Create a gaussian tapered 45 degrees rotated checkerboard kernel.
mi@0 62 TODO: Unit testing: Should produce this with kernel size 3:
mi@0 63 0.1353 -0.3679 0.1353
mi@0 64 0.3679 1.0000 0.3679
mi@0 65 0.1353 -0.3679 0.1353
mi@0 66 '''
mi@0 67 n = float(np.ceil(size / 2.0))
mi@0 68 kernel = np.zeros((size,size))
mi@0 69 for i in xrange(1,size+1) :
mi@0 70 for j in xrange(1,size+1) :
mi@0 71 gauss = np.exp( -4.0 * (np.square( (i-n)/n ) + np.square( (j-n)/n )) )
mi@0 72 # gauss = 1
mi@0 73 if np.logical_xor( j - n > np.floor((i-n) / 2.0), j - n > np.floor((n-i) / 2.0) ) :
mi@0 74 kernel[i-1,j-1] = -gauss
mi@0 75 else:
mi@0 76 kernel[i-1,j-1] = gauss
mi@0 77
mi@0 78 return kernel
mi@0 79
mitian@7 80 def segmentation(ssm, peak_picker=peak_picker, kernel_size=48, normalise=False, plot=False):
mi@0 81 '''Detect segment boundaries in the ssm.'''
mitian@7 82 # peak_picker for the 1st round boudary detection
mitian@7 83
mitian@7 84
mi@0 85 novelty = getNoveltyCurve(ssm, kernel_size, normalise=False)
mi@0 86 smoothed_novelty, novelty_peaks = peak_picker.process(novelty)
mi@0 87
mitian@1 88 if plot:
mitian@1 89 plot_detection(smoothed_novelty, novelty_peaks)
mitian@1 90 return novelty, smoothed_novelty, novelty_peaks
mitian@1 91
mitian@1 92 def plot_detection(smoothed_novelty, novelty_peaks):
mitian@1 93 pass