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//# Copyright (C) 2000,2001
//# Associated Universities, Inc. Washington DC, USA.
//#
//# This library is free software; you can redistribute it and/or modify it
//# under the terms of the GNU Library General Public License as published by
//# the Free Software Foundation; either version 2 of the License, or (at your
//# option) any later version.
//#
//# This library is distributed in the hope that it will be useful, but WITHOUT
//# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
//# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
//# License for more details.
//#
//# You should have received a copy of the GNU Library General Public License
//# along with this library; if not, write to the Free Software Foundation,
//# Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
//#
//# Correspondence concerning AIPS++ should be addressed as follows:
//# Internet email: casa-feedback@nrao.edu.
//# Postal address: AIPS++ Project Office
//# National Radio Astronomy Observatory
//# 520 Edgemont Road
//# Charlottesville, VA 22903-2475 USA
//#
#ifndef SCIMATH_STATSHISTOGRAM_TCC
#define SCIMATH_STATSHISTOGRAM_TCC
#include <casacore/scimath/StatsFramework/StatsHistogram.h>
#include <algorithm>
#include <iterator>
#include <iomanip>
namespace casacore {
template <class AccumType>
StatsHistogram<AccumType>::StatsHistogram(
AccumType minLimit, AccumType maxLimit, uInt nBins
) : _binWidth(0), _minHistLimit(minLimit), _maxHistLimit(maxLimit),
_nBins(nBins), _maxBinLimits(nBins) {
ThrowIf (minLimit > maxLimit, "minLimit must be less than maxLimit");
_binWidth = (_maxHistLimit - _minHistLimit)/(AccumType)nBins;
// in case of AccumType = Int, this can happen even if max and min are
// different. One would hope that AccumType=Int would never be used, but
// just in case. The check incurs a negligible performance hit.
ThrowIf(_binWidth == AccumType(0), "Histogram bin width is 0");
uInt j = 1;
for_each(
_maxBinLimits.begin(), _maxBinLimits.end(), [&j, this]
(AccumType& val) {
val = _minHistLimit + _binWidth * (AccumType)(j);
++j;
}
);
}
template <class AccumType> StatsHistogram<AccumType>::~StatsHistogram() {}
template <class AccumType>
AccumType StatsHistogram<AccumType>::getBinWidth() const {
return _binWidth;
}
template <class AccumType>
uInt StatsHistogram<AccumType>::getIndex(AccumType value) const {
// we do not explicitly check if the value is within the histogram,
// because the caller has already done that
// estimate the index
auto idx = _getUInt((value - _minHistLimit)/_binWidth);
auto mymin = idx == 0 ? _minHistLimit : _maxBinLimits[idx - 1];
if (value >= mymin && value < _maxBinLimits[idx]) {
return idx;
}
auto higher = value >= _maxBinLimits[idx];
Int testIdx = higher ? idx + 1 : idx - 1;
// should never happen, but check just in case...
if (higher) {
ThrowIf(testIdx >= (Int)_nBins, "testIdx >= nBins");
}
else {
ThrowIf(testIdx < 0, "testIdx < 0");
}
Int minIdx = higher ? idx : testIdx;
Int maxIdx = higher ? testIdx : idx;
// we must first establish a bin index
// range which includes the target value
_minMaxIdxRange(minIdx, maxIdx, value, higher);
// bin index limits established, so now do binary search to find the
// correct bin
while (True) {
ThrowIf(
maxIdx < minIdx,
"Logic Error: maxIdx (" + String::toString(maxIdx) + ") < minIdx ("
+ String::toString(minIdx) + ")"
);
// integer division
testIdx = (minIdx + maxIdx)/2;
if (
value >= _maxBinLimits[testIdx - 1]
&& value < _maxBinLimits[testIdx]
) {
// bin found
return testIdx;
}
// the = part is important, for machine precision issues if the mean
// binwidth is very small, since some (but not all) bins for all
// intents and purposes may have zero width. See eg CAS-11828
if (value >= _maxBinLimits[testIdx - 1]) {
minIdx = testIdx + 1;
}
else {
maxIdx = testIdx - 1;
}
}
ostringstream os;
os << std::setprecision(20) << "Logic Error: Unable to locate bin "
<< "containing value " << value << endl;
os << "Histogram spec " << *this << endl;
os << "Guessed index " << idx << " with limits " << mymin << ", "
<< _maxBinLimits[idx] << endl;
ThrowCc(os.str());
}
template <class AccumType>
const std::vector<AccumType>&
StatsHistogram<AccumType>::getMaxBinLimits() const {
return _maxBinLimits;
}
template <class AccumType>
AccumType StatsHistogram<AccumType>::getMaxHistLimit() const {
return _maxHistLimit;
}
template <class AccumType>
AccumType StatsHistogram<AccumType>::getMinHistLimit() const {
return _minHistLimit;
}
template <class AccumType> uInt StatsHistogram<AccumType>::getNBins() const {
return _nBins;
}
template <class AccumType> void StatsHistogram<AccumType>::_minMaxIdxRange(
Int& minIdx, Int& maxIdx, AccumType value, Bool higher
) const {
Int mult = 2;
while(True) {
auto mymin = minIdx == 0 ? _minHistLimit : _maxBinLimits[minIdx - 1];
if (value >= mymin && value < _maxBinLimits[maxIdx]) {
// limits established
return;
}
mult *= 2;
if (higher) {
minIdx = maxIdx + 1;
if (minIdx >= (Int)_nBins) {
minIdx = _nBins - 1;
maxIdx = minIdx;
// minIdx can't get any larger, so return
return;
}
maxIdx = minIdx + mult;
if (maxIdx >= (Int)_nBins) {
maxIdx = _nBins - 1;
// maxIdx can't get any larger, so return
return;
}
}
else {
maxIdx = minIdx - 1;
if (maxIdx <= 0) {
maxIdx = 0;
minIdx = 0;
// maxIdx can't get any smaller, so return
return;
}
minIdx = maxIdx - mult;
if (minIdx < 0) {
minIdx = 0;
// minIdx can't get any smaller, so return
return;
}
}
}
}
}
#endif
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