251 lines
7.4 KiB
C++
251 lines
7.4 KiB
C++
// ____ ______ __
|
|
// / __ \ / ____// /
|
|
// / /_/ // / / /
|
|
// / ____// /___ / /___ PixInsight Class Library
|
|
// /_/ \____//_____/ PCL 2.4.23
|
|
// ----------------------------------------------------------------------------
|
|
// pcl/Selection.h - Released 2022-03-12T18:59:29Z
|
|
// ----------------------------------------------------------------------------
|
|
// This file is part of the PixInsight Class Library (PCL).
|
|
// PCL is a multiplatform C++ framework for development of PixInsight modules.
|
|
//
|
|
// Copyright (c) 2003-2022 Pleiades Astrophoto S.L. All Rights Reserved.
|
|
//
|
|
// Redistribution and use in both source and binary forms, with or without
|
|
// modification, is permitted provided that the following conditions are met:
|
|
//
|
|
// 1. All redistributions of source code must retain the above copyright
|
|
// notice, this list of conditions and the following disclaimer.
|
|
//
|
|
// 2. All 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.
|
|
//
|
|
// 3. Neither the names "PixInsight" and "Pleiades Astrophoto", nor the names
|
|
// of their contributors, may be used to endorse or promote products derived
|
|
// from this software without specific prior written permission. For written
|
|
// permission, please contact info@pixinsight.com.
|
|
//
|
|
// 4. All products derived from this software, in any form whatsoever, must
|
|
// reproduce the following acknowledgment in the end-user documentation
|
|
// and/or other materials provided with the product:
|
|
//
|
|
// "This product is based on software from the PixInsight project, developed
|
|
// by Pleiades Astrophoto and its contributors (https://pixinsight.com/)."
|
|
//
|
|
// Alternatively, if that is where third-party acknowledgments normally
|
|
// appear, this acknowledgment must be reproduced in the product itself.
|
|
//
|
|
// THIS SOFTWARE IS PROVIDED BY PLEIADES ASTROPHOTO AND ITS CONTRIBUTORS
|
|
// "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 PLEIADES ASTROPHOTO OR ITS
|
|
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
|
// EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, BUSINESS
|
|
// INTERRUPTION; PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; AND LOSS OF USE,
|
|
// DATA OR PROFITS) 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 __PCL_Selection_h
|
|
#define __PCL_Selection_h
|
|
|
|
/// \file pcl/Selection.h
|
|
|
|
#include <pcl/Defs.h>
|
|
|
|
#include <pcl/Iterator.h>
|
|
#include <pcl/Utility.h>
|
|
|
|
// Template formal parameters:
|
|
//
|
|
// FI Forward iterator
|
|
// BI Bidirectional iterator
|
|
// RI Random access iterator
|
|
// UP Unary predicate
|
|
// BP Binary predicate
|
|
// T Item type
|
|
// F Function
|
|
|
|
namespace pcl
|
|
{
|
|
|
|
// ----------------------------------------------------------------------------
|
|
|
|
/*!
|
|
* \defgroup selection_algorithms Selection Algorithms
|
|
*/
|
|
|
|
// ----------------------------------------------------------------------------
|
|
|
|
template <class RI, typename T> inline
|
|
RI __pcl_quick_select__( RI i, RI j, distance_type k, T* )
|
|
{
|
|
distance_type n = j - i;
|
|
if ( k < 0 || n < 1 || n <= k )
|
|
return j;
|
|
|
|
for ( distance_type l = 0, r = n-1; ; )
|
|
{
|
|
RI x0 = i + l;
|
|
RI y = i + r;
|
|
|
|
if ( r <= l+1 )
|
|
{
|
|
if ( r == l+1 && *y < *x0 )
|
|
Swap( *x0, *y );
|
|
return i + k;
|
|
}
|
|
|
|
RI x = x0;
|
|
|
|
Swap( *++x, *(i + ((l+r) >> 1)) );
|
|
|
|
if ( *y < *x0 )
|
|
Swap( *x0, *y );
|
|
if ( *y < *x )
|
|
Swap( *x, *y );
|
|
if ( *x < *x0 )
|
|
Swap( *x, *x0 );
|
|
|
|
T v = *x;
|
|
|
|
for ( ;; )
|
|
{
|
|
while ( *++x < v );
|
|
while ( v < *--y );
|
|
if ( y < x )
|
|
break;
|
|
Swap( *x, *y );
|
|
}
|
|
|
|
*(x0+1) = *y;
|
|
*y = v;
|
|
|
|
distance_type dy = y - i;
|
|
if ( dy >= k )
|
|
r = dy - 1;
|
|
if ( dy <= k )
|
|
l = x - i;
|
|
}
|
|
}
|
|
|
|
/*!
|
|
* Generic quick selection algorithm.
|
|
*
|
|
* Given a range defined by two random access iterators [i,j) and a distance k,
|
|
* such that j-i > k, returns an iterator t whose associated value is the k-th
|
|
* element in the sorted sequence [i,j) in ascending order.
|
|
*
|
|
* For example, the following call:
|
|
*
|
|
* \code t = Select( i, j, (j - i) >> 1 ); \endcode
|
|
*
|
|
* will return the \e median of the distribution of elements in the [i,j)
|
|
* sequence: the central value for which the probabilities that a greater and a
|
|
* lesser element exist are equal.
|
|
*
|
|
* \b References
|
|
*
|
|
* \li William H. Press et al., <em>Numerical Recipes 3rd Edition: The Art of
|
|
* Scientific Computing,</em> Cambridge University Press, 2007, Section 8.5.
|
|
*
|
|
* \li Robert Sedgewick, Kevin Wayne, <em>Algorithms, 4th Edition,</em>
|
|
* Addison-Wesley Professional, 2011, pp. 345-347.
|
|
*
|
|
* \warning This function performs a <em>destructive selection search</em>:
|
|
* There is no guarantee that the existing order of elements in the [i,j)
|
|
* sequence is preserved after calling this function.
|
|
*
|
|
* \ingroup selection_algorithms
|
|
*/
|
|
template <class RI> inline
|
|
RI Select( RI i, RI j, distance_type k )
|
|
{
|
|
return __pcl_quick_select__( i, j, k, ItemType( i ) );
|
|
}
|
|
|
|
// ----------------------------------------------------------------------------
|
|
|
|
template <class RI, class BP, class T> inline
|
|
RI __pcl_quick_select__( RI i, RI j, distance_type k, BP p, T* )
|
|
{
|
|
distance_type n = j - i;
|
|
if ( k < 0 || n < 1 || n <= k )
|
|
return j;
|
|
|
|
for ( distance_type l = 0, r = n-1; ; )
|
|
{
|
|
RI x0 = i + l;
|
|
RI y = i + r;
|
|
|
|
if ( r <= l+1 )
|
|
{
|
|
if ( r == l+1 && p( *y, *x0 ) )
|
|
Swap( *x0, *y );
|
|
return i + k;
|
|
}
|
|
|
|
RI x = x0;
|
|
|
|
Swap( *++x, *(i + ((l+r) >> 1)) );
|
|
|
|
if ( p( *y, *x0 ) )
|
|
Swap( *x0, *y );
|
|
if ( p( *y, *x ) )
|
|
Swap( *x, *y );
|
|
if ( p( *x, *x0 ) )
|
|
Swap( *x, *x0 );
|
|
|
|
T v = *x;
|
|
|
|
for ( ;; )
|
|
{
|
|
while ( p( *++x, v ) );
|
|
while ( p( v, *--y ) );
|
|
if ( y < x )
|
|
break;
|
|
Swap( *x, *y );
|
|
}
|
|
|
|
*(x0+1) = *y;
|
|
*y = v;
|
|
|
|
distance_type dy = y - i;
|
|
if ( dy >= k )
|
|
r = dy - 1;
|
|
if ( dy <= k )
|
|
l = x - i;
|
|
}
|
|
}
|
|
|
|
/*!
|
|
* Generic quick selection algorithm.
|
|
*
|
|
* Given a range defined by two random access iterators [i,j) and a distance k,
|
|
* such that j-i > k, returns an iterator t whose associated value is the k-th
|
|
* element in the sorted sequence [i,j) in ascending order. Element comparison
|
|
* is given by a binary predicate \a p such that p( a, b ) is true for any pair
|
|
* a, b of elements such that a precedes b.
|
|
*
|
|
* See Select( RI, RI, distance_type ) for more information.
|
|
*
|
|
* \ingroup selection_algorithms
|
|
*/
|
|
template <class RI, class BP> inline
|
|
RI Select( RI i, RI j, distance_type k, BP p )
|
|
{
|
|
return __pcl_quick_select__( i, j, k, p, ItemType( i ) );
|
|
}
|
|
|
|
// ----------------------------------------------------------------------------
|
|
|
|
} // pcl
|
|
|
|
#endif // __PCL_Selection_h
|
|
|
|
// ----------------------------------------------------------------------------
|
|
// EOF pcl/Selection.h - Released 2022-03-12T18:59:29Z
|