sampling.h

/***********************************************************************





* Software License Agreement (BSD License)





*





* Copyright 2008-2009  Marius Muja (mariusm@cs.ubc.ca). All rights reserved.





* Copyright 2008-2009  David G. Lowe (lowe@cs.ubc.ca). All rights reserved.





*





* Redistribution and use in source and binary forms, with or without





* modification, are permitted provided that the following conditions





* are met:





*





* 1. Redistributions of source code must retain the above copyright





*    notice, this list of conditions and the following disclaimer.





* 2. Redistributions in binary form must reproduce the above copyright





*    notice, this list of conditions and the following disclaimer in the





*    documentation and/or other materials provided with the distribution.





*





* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR





* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES





* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.





* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,





* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT





* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,





* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY





* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT





* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF





* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.





*************************************************************************/












#ifndef OPENCV_FLANN_SAMPLING_H_




#define OPENCV_FLANN_SAMPLING_H_












#include "matrix.h"




#include "random.h"








namespace
cvflann


{







template<typename
T>


Matrix<T> random_sample(Matrix<T>& srcMatrix,
long
size,
bool
remove =
false)


{



Matrix<T> newSet(new
T[size * srcMatrix.cols], size,srcMatrix.cols);







T* src,* dest;



for
(long
i=0; i<size; ++i) {



long
r = rand_int((int)(srcMatrix.rows-i));



dest = newSet[i];



src = srcMatrix[r];



std::copy(src, src+srcMatrix.cols, dest);



if
(remove) {



src = srcMatrix[srcMatrix.rows-i-1];



dest = srcMatrix[r];



std::copy(src, src+srcMatrix.cols, dest);



}



}



if
(remove) {



srcMatrix.rows -= size;



}



return
newSet;


}







template<typename
T>


Matrix<T> random_sample(const
Matrix<T>& srcMatrix,
size_t
size)


{



UniqueRandom rand((int)srcMatrix.rows);



Matrix<T> newSet(new
T[size * srcMatrix.cols], size,srcMatrix.cols);







T* src,* dest;



for
(size_t
i=0; i<size; ++i) {



long
r = rand.next();



dest = newSet[i];



src = srcMatrix[r];



std::copy(src, src+srcMatrix.cols, dest);



}



return
newSet;


}






}
// namespace












#endif

/* OPENCV_FLANN_SAMPLING_H_ */