62 lines
1.7 KiB
C++
62 lines
1.7 KiB
C++
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/*
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This file is part of SECONDO.
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Copyright (C) 2011, University in Hagen, Department of Computer Science,
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Database Systems for New Applications.
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SECONDO is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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SECONDO is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with SECONDO; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <cmath>
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#include <limits>
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#include "util.h"
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namespace raster2
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{
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namespace util
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{
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bool equals(double d1, double d2, int ulp /* = 4 */) {
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if (d1 == d2) return true;
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if (std::numeric_limits<double>::has_quiet_NaN)
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{
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if (d1 != d1 || d2 != d2) return false;
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}
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if (std::numeric_limits<double>::has_infinity) {
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if (d1 == std::numeric_limits<double>::infinity() ||
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d2 == std::numeric_limits<double>::infinity() ||
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d1 == -std::numeric_limits<double>::infinity() ||
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d2 == -std::numeric_limits<double>::infinity())
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{
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return d1 == d2;
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}
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}
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double abs1 = std::abs(d1);
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double abs2 = std::abs(d2);
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double scale = abs1 > abs2 ? abs1 : abs2;
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abs1 /= scale;
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abs2 /= scale;
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double diff = abs1 < abs2 ? abs2 - abs1 : abs1 - abs2;
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return diff <= ulp * std::numeric_limits<double>::epsilon();
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}
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}
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}
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