1 /***********************************************************************
2 * Software License Agreement (BSD License)
3 *
4 * Copyright 2008-2009 Marius Muja (mariusm@cs.ubc.ca). All rights reserved.
5 * Copyright 2008-2009 David G. Lowe (lowe@cs.ubc.ca). All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *************************************************************************/
28
29
30 #ifndef OPENCV_FLANN_SAMPLING_H_
31 #define OPENCV_FLANN_SAMPLING_H_
32
33 #include "matrix.h"
34 #include "random.h"
35
36 namespace cvflann
37 {
38
39 template<typename T>
40 Matrix<T> random_sample(Matrix<T>& srcMatrix, long size, bool remove = false)
41 {
42 Matrix<T> newSet(new T[size * srcMatrix.cols], size,srcMatrix.cols);
43
44 T* src,* dest;
45 for (long i=0; i<size; ++i) {
46 long r = rand_int((int)(srcMatrix.rows-i));
47 dest = newSet[i];
48 src = srcMatrix[r];
49 std::copy(src, src+srcMatrix.cols, dest);
50 if (remove) {
51 src = srcMatrix[srcMatrix.rows-i-1];
52 dest = srcMatrix[r];
53 std::copy(src, src+srcMatrix.cols, dest);
54 }
55 }
56 if (remove) {
57 srcMatrix.rows -= size;
58 }
59 return newSet;
60 }
61
62 template<typename T>
random_sample(const Matrix<T> & srcMatrix,size_t size)63 Matrix<T> random_sample(const Matrix<T>& srcMatrix, size_t size)
64 {
65 UniqueRandom rand((int)srcMatrix.rows);
66 Matrix<T> newSet(new T[size * srcMatrix.cols], size,srcMatrix.cols);
67
68 T* src,* dest;
69 for (size_t i=0; i<size; ++i) {
70 long r = rand.next();
71 dest = newSet[i];
72 src = srcMatrix[r];
73 std::copy(src, src+srcMatrix.cols, dest);
74 }
75 return newSet;
76 }
77
78 } // namespace
79
80
81 #endif /* OPENCV_FLANN_SAMPLING_H_ */
82