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comparison python/utils.py @ 31:c000f37c316d

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moved tests to independent file, added chi2 computation
author Nicolas Saunier <nico@confins.net>
date Sat, 13 Feb 2010 19:46:33 -0500
parents ca8e716cc231
children 48e56179c39e
comparison
equal deleted inserted replaced
30:418b41056e6c 31:c000f37c316d
2 ''' Generic utilities.''' 2 ''' Generic utilities.'''
3 3
4 #from numpy import * 4 #from numpy import *
5 #from pylab import * 5 #from pylab import *
6 6
7 from moving import Point,Interval 7 import moving
8 8
9 __metaclass__ = type 9 __metaclass__ = type
10 10
11 commentChar = '#'; 11 commentChar = '#';
12 12
13 ######################### 13 #########################
14 # simple statistics
15 #########################
16
17 def computeChi2(expected, observed):
18 '''Returns the Chi2 statistics'''
19 result = 0.
20 for e, o in zip(expected, observed):
21 result += ((e-o)*(e-o))/e
22 return result
23
24 class histogram:
25 '''Class to represent a sample of a distribution for a continuous random variable
26 with the number of observations for each interval'''
27
28
29
30 #########################
14 # maths section 31 # maths section
15 ######################### 32 #########################
16 33
17 def segmentIntersection(p1, p2, p3, p4): 34 def segmentIntersection(p1, p2, p3, p4):
18 '''Returns the intersecting point of the segments [p1, p2] and [p3, p4], None otherwise 35 '''Returns the intersecting point of the segments [p1, p2] and [p3, p4], None otherwise'''
19
20 >>> segmentIntersection(Point(0,0),Point(1,1), Point(0,1), Point(1,2))
21 >>> segmentIntersection(Point(0,1),Point(1,0), Point(0,2), Point(2,1))
22 >>> segmentIntersection(Point(0,0),Point(2,0), Point(1,-1),Point(1,1))
23 (1.000000,0.000000)
24 >>> segmentIntersection(Point(0,1),Point(2,0),Point(1,1),Point(1,2))
25 '''
26 from numpy import matrix 36 from numpy import matrix
27 from numpy.linalg import linalg, det 37 from numpy.linalg import linalg, det
28 38
29 dp1 = p2-p1#[s1[0][1]-s1[0][0], s1[1][1]-s1[1][0]] 39 dp1 = p2-p1#[s1[0][1]-s1[0][0], s1[1][1]-s1[1][0]]
30 dp2 = p4-p3#[s2[0][1]-s2[0][0], s2[1][1]-s2[1][0]] 40 dp2 = p4-p3#[s2[0][1]-s2[0][0], s2[1][1]-s2[1][0]]
36 46
37 if linalg.det(A) == 0:#crossProduct(ds1, ds2) == 0: 47 if linalg.det(A) == 0:#crossProduct(ds1, ds2) == 0:
38 return None 48 return None
39 else: 49 else:
40 intersection = linalg.solve(A,B) 50 intersection = linalg.solve(A,B)
41 if (Interval(p1.x, p2.x, True).contains(intersection[0,0]) 51 if (moving.Interval(p1.x, p2.x, True).contains(intersection[0,0])
42 and Interval(p3.x, p4.x, True).contains(intersection[0,0]) 52 and moving.Interval(p3.x, p4.x, True).contains(intersection[0,0])
43 and Interval(p1.y, p2.y, True).contains(intersection[1,0]) 53 and moving.Interval(p1.y, p2.y, True).contains(intersection[1,0])
44 and Interval(p3.y, p4.y, True).contains(intersection[1,0])): 54 and moving.Interval(p3.y, p4.y, True).contains(intersection[1,0])):
45 return Point(intersection[0,0], intersection[1,0]) 55 return moving.Point(intersection[0,0], intersection[1,0])
46 else: 56 else:
47 return None 57 return None
48 58
49 def crossProduct(l1, l2): 59 def crossProduct(l1, l2):
50 return l1[0]*l2[1]-l1[1]*l2[0] 60 return l1[0]*l2[1]-l1[1]*l2[0]
63 # file I/O section 73 # file I/O section
64 ######################### 74 #########################
65 75
66 def openCheck(filename, option = 'r', quit = False): 76 def openCheck(filename, option = 'r', quit = False):
67 '''Open file filename in read mode by default 77 '''Open file filename in read mode by default
68 and checks it is open 78 and checks it is open'''
69
70 >>> f = openCheck('non_existant_file.txt')
71 File non_existant_file.txt could not be opened.
72 '''
73 try: 79 try:
74 return open(filename, option) 80 return open(filename, option)
75 except IOError: 81 except IOError:
76 print 'File %s could not be opened.' % filename 82 print 'File %s could not be opened.' % filename
77 if quit: 83 if quit:
85 while (len(s) > 0) and s.startswith(commentChar): 91 while (len(s) > 0) and s.startswith(commentChar):
86 s = f.readline() 92 s = f.readline()
87 return s.strip() 93 return s.strip()
88 94
89 def removeExtension(filename, delimiter = '.'): 95 def removeExtension(filename, delimiter = '.'):
90 '''Returns the filename minus the extension (all characters after last .) 96 '''Returns the filename minus the extension (all characters after last .)'''
91 >>> removeExtension('test-adfasdf.asdfa.txt')
92 'test-adfasdf.asdfa'
93 >>> removeExtension('test-adfasdf')
94 'test-adfasdf'
95 '''
96 i = filename.rfind(delimiter) 97 i = filename.rfind(delimiter)
97 if i>0: 98 if i>0:
98 return filename[:i] 99 return filename[:i]
99 else: 100 else:
100 return filename 101 return filename
129 from shapely.geometry import Polygon 130 from shapely.geometry import Polygon
130 131
131 tmp = array(poly.exterior) 132 tmp = array(poly.exterior)
132 plot(tmp[:,0], tmp[:,1], options) 133 plot(tmp[:,0], tmp[:,1], options)
133 134
135
136 #########################
137 # running tests
138 #########################
139
134 if __name__ == "__main__": 140 if __name__ == "__main__":
135 import doctest 141 import doctest
136 import unittest 142 import unittest
137 #suite = doctest.DocFileSuite('tests/ubc_utils.txt') 143 suite = doctest.DocFileSuite('tests/utils.txt')
138 suite = doctest.DocTestSuite() 144 #suite = doctest.DocTestSuite()
139 unittest.TextTestRunner().run(suite) 145 unittest.TextTestRunner().run(suite)
140 #doctest.testmod() 146 #doctest.testmod()
141 #doctest.testfile("example.txt") 147 #doctest.testfile("example.txt")