Mercurial > hg > nsaunier > traffic-intelligence

comparison python/utils.py @ 29:ca8e716cc231

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added moving average filter
author Nicolas Saunier <nico@confins.net>
date Sat, 30 Jan 2010 21:43:07 -0500
parents 44689029a86f
children c000f37c316d
comparison
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28:9ae709a2e8d0 29:ca8e716cc231
46 else: 46 else:
47 return None 47 return None
48 48
49 def crossProduct(l1, l2): 49 def crossProduct(l1, l2):
50 return l1[0]*l2[1]-l1[1]*l2[0] 50 return l1[0]*l2[1]-l1[1]*l2[0]
51
52 def filterMovingWindow(input, halfWidth):
53 '''Returns an array obtained after the smoothing of the input by a moving average
54 The first and last points are copied from the original.'''
55 width = float(halfWidth*2+1)
56 win = ones(width,'d')
57 result = convolve(win/width,array(inputSignal),'same')
58 result[:halfWidth] = inputSignal[:halfWidth]
59 result[-halfWidth:] = inputSignal[-halfWidth:]
60 return result
51 61
52 ######################### 62 #########################
53 # file I/O section 63 # file I/O section
54 ######################### 64 #########################
55 65
111 from numpy.linalg.linalg import inv 121 from numpy.linalg.linalg import inv
112 invH = inv(homography) 122 invH = inv(homography)
113 invH /= invH[2,2] 123 invH /= invH[2,2]
114 return invH 124 return invH
115 125
116 def project(homography, p):
117 '''Returns the coordinates of the projection of the point p
118 through homography'''
119 from numpy.core._dotblas import dot
120 from numpy.core.multiarray import array
121 from numpy.lib.function_base import insert
122 if (homography!=None) and (len(homography)>0):
123 pAugmented = insert(array(p), [2],[1], axis=0)
124 projected = dot(homography, pAugmented)
125 projected[0] /= projected[2]
126 projected[1] /= projected[2]
127 else:
128 projected = p
129 return projected[:2]
130
131 def projectTrajectory(homography, trajectory):
132 '''Projects a series of points in the format
133 [[x1, x2, ...],
134 [y1, y2, ...]]
135
136 Warning: not optimized, calls project()'''
137 projected = [[],[]]
138 for x, y in zip(trajectory[0], trajectory[1]):
139 p = [x,y]
140 pp = project(homography, p)
141 projected[0].append(pp[0])
142 projected[1].append(pp[1])
143 return projected
144
145 def plotPolygon(poly, options = ''): 126 def plotPolygon(poly, options = ''):
146 from numpy.core.multiarray import array 127 from numpy.core.multiarray import array
147 from matplotlib.pyplot import plot 128 from matplotlib.pyplot import plot
148 from shapely.geometry import Polygon 129 from shapely.geometry import Polygon
149 130