sci.h

// Copyright 2009-2018 Toby Schneider (http://gobysoft.org/index.wt/people/toby)
//                     GobySoft, LLC (2013-)
//                     Massachusetts Institute of Technology (2007-2014)
//                     Community contributors (see AUTHORS file)
//
//
// This file is part of the Goby Underwater Autonomy Project Libraries
// ("The Goby Libraries").
//
// The Goby Libraries are free software: you can redistribute them and/or modify
// them under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 2.1 of the License, or
// (at your option) any later version.
//
// The Goby Libraries are distributed in the hope that they will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with Goby.  If not, see <http://www.gnu.org/licenses/>.

#ifndef SCI20100713H
#define SCI20100713H

#include <cmath>

namespace goby
{
namespace util
{


inline double unbiased_round(double r, double dec)
{
    double ex = std::pow(10.0, dec);
    double final = std::floor(r * ex);
    double s = (r * ex) - final;

    // remainder less than 0.5 or even number next to it
    if (s < 0.5 || (s == 0.5 && !(static_cast<unsigned long>(final) & 1)))
        return final / ex;
    else
        return (final + 1) / ex;
}

inline double mackenzie_soundspeed(double T, double S, double D)
{
    return 1448.96 + 4.591 * T - 5.304e-2 * T * T + 2.374e-4 * T * T * T + 1.340 * (S - 35) +
           1.630e-2 * D + 1.675e-7 * D * D - 1.025e-2 * T * (S - 35) - 7.139e-13 * T * D * D * D;
}

inline unsigned ceil_log2(unsigned v)
{
    // r will be one greater (ceil) if v is not a power of 2
    unsigned r = ((v & (v - 1)) == 0) ? 0 : 1;
    while (v >>= 1) r++;
    return r;
}

inline unsigned ceil_log2(double d) { return ceil_log2(static_cast<unsigned>(std::ceil(d))); }

inline unsigned ceil_log2(int i) { return ceil_log2(static_cast<unsigned>(i)); }

inline double log2(double d)
{
    static double log_2 = log(2);
    return log(d) / log_2;
}

} // namespace util


} // namespace goby

#endif