Source Code for Module pycv.cs.dm.dm

 1  # PyCV - A Computer Vision Package for Python Incorporating Fast Training of Face Detection 
 2   
 3  # Copyright 2007 Nanyang Technological University, Singapore. 
 4  # Authors: Minh-Tri Pham, Viet-Dung D. Hoang, and Tat-Jen Cham. 
 5   
 6  # This file is part of PyCV. 
 7   
 8  # PyCV is free software: you can redistribute it and/or modify 
 9  # it under the terms of the GNU General Public  
10  # License as published by the Free Software Foundation, either version  
11  # 3 of the License, or (at your option) any later version. 
12   
13  # PyCV is distributed in the hope that it will be useful, 
14  # but WITHOUT ANY WARRANTY; without even the implied warranty of 
15  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
16  # GNU General Public License for more details. 
17   
18  # You should have received a copy of the GNU General Public License 
19  # along with this program.  If not, see <http://www.gnu.org/licenses/>. 
20   
21  # --------------------------------------------------------------------- 
22  #!/usr/bin/env python 
23   
24   
25  __all__ = ['argsort','argsort_and_cut'] 
26   
27  from numpy import zeros, arange, array 
28   
29  from pycv import ext 
30   
31 -def argsort(a): 
32      """Take a 1D array of type '[u]int<8|16|32|64>' or 'float<32|64>', and return a 1D array of indices that sorts the former in ascending order. 
33      """ 
34      if a.ndim != 1: 
35          raise TypeError("Input a is not 1D") 
36       
37      id = zeros(len(a),'int') 
38       
39      try: 
40          eval('ext.dm_argsort_'+a.dtype.name+'(a, id)') 
41      except KeyError: 
42          raise TypeError("Input has an unknown dtype") 
43       
44      return id 
45       
46 -def argsort_and_cut(a): 
47      """Find argsort and 'list of cuts' of a 1D 'double' array 
48   
49      Input: 
50          a: a 1D 'double' array 
51      Output: 
52          id: an index array that sorts a in ascending orders 
53          B: an array of thresholds that cuts a properly 
54      """ 
55      if a.ndim != 1: 
56          raise TypeError("Input a is not 1D") 
57      if a.dtype.name != 'float64': 
58          raise TypeError("dtype of a is not 'float64'") 
59           
60      bid = argsort(a) 
61      B = zeros(len(a)+1) 
62       
63      n = ext.dm_argsort_and_cut(a, bid, B) 
64   
65      return (bid,B[:n]) 
66