casacore
scimath
Mathematics
Combinatorics.h
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//# Smooth.h: smooth vectors and arrays
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//# Copyright (C) 2010 by ESO (in the framework of the ALMA collaboration)
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//# Copyright (C) 1996,1997,1998,1999,2000,2001
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//# Associated Universities, Inc. Washington DC, USA.
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//#
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//# This library is free software; you can redistribute it and/or modify it
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//# under the terms of the GNU Library General Public License as published by
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//# the Free Software Foundation; either version 2 of the License, or (at your
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//# option) any later version.
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//#
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//# This library is distributed in the hope that it will be useful, but WITHOUT
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//# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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//# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
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//# License for more details.
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//#
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//# You should have received a copy of the GNU Library General Public License
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//# along with this library; if not, write to the Free Software Foundation,
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//# Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
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//#
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//# Correspondence concerning AIPS++ should be addressed as follows:
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//# Internet email: aips2-request@nrao.edu.
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//# Postal address: AIPS++ Project Office
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//# National Radio Astronomy Observatory
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//# 520 Edgemont Road
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//# Charlottesville, VA 22903-2475 USA
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//#
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//# $Id$
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#ifndef SCIMATH_COMBINATORICS_H
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#define SCIMATH_COMBINATORICS_H
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//# Includes
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#include <casacore/casa/aips.h>
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#include <casacore/casa/Arrays/Vector.h>
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#include <casacore/casa/OS/Mutex.h>
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namespace
casacore
{
//# NAMESPACE CASACORE - BEGIN
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// <summary>
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// Combinatorics related functions.
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// </summary>
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// <use visibility=export>
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//# <author>Dave Mehringer</author>
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// <reviewed reviewer="" date="yyyy/mm/dd" tests="" demos="">
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// </reviewed>
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// <prerequisite>
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// <li> <linkto class="Vector">Vector</linkto>
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// <li> <linkto class="Array">Array</linkto>
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// </prerequisite>
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// <etymology>
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// self-explanatory
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// </etymology>
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// <synopsis>
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// Various factorial and combinatorical functions.
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// </synopsis>
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// <motivation>
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// Binomial coefficients needed for Images/ImageProfileFitter
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// </motivation>
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class
Combinatorics
{
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public
:
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// Get n!
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static
uInt
factorial
(
const
uInt
n)
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{
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fillCache
(n);
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return
_factorialCache
[n];
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}
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// "n choose k" = n!/(k!(n-k)!)
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// Exception is thrown if k > n.
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static
uInt
choose
(
const
uInt
n,
const
uInt
k);
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private
:
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static
void
fillCache
(
const
uInt
n);
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static
Vector<uInt>
_factorialCache
;
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static
volatile
uInt
_factorialCacheSize
;
//# volatile for double checked lock
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static
Mutex
theirMutex
;
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};
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}
//# NAMESPACE CASACORE - END
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#endif
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casacore::Combinatorics::theirMutex
static Mutex theirMutex
Definition:
Combinatorics.h:87
casacore::Combinatorics::factorial
static uInt factorial(const uInt n)
Get n!
Definition:
Combinatorics.h:72
casacore::uInt
unsigned int uInt
Definition:
aipstype.h:51
casacore::Combinatorics::_factorialCacheSize
static volatile uInt _factorialCacheSize
Definition:
Combinatorics.h:86
casacore::Combinatorics::_factorialCache
static Vector< uInt > _factorialCache
Definition:
Combinatorics.h:85
casacore::Combinatorics::fillCache
static void fillCache(const uInt n)
casacore
this file contains all the compiler specific defines
Definition:
mainpage.dox:28
casacore::Combinatorics::choose
static uInt choose(const uInt n, const uInt k)
"n choose k" = n!/(k!(n-k)!) Exception is thrown if k > n.
casacore::Mutex
Wrapper around a pthreads mutex.
Definition:
Mutex.h:58
casacore::Combinatorics
Combinatorics related functions.
Definition:
Combinatorics.h:67
casacore::Vector< uInt >
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