units.h

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/*
 * units.h - some conversion definitions
 *
 * Copyright (C) 1992-2011 jean-pierre.charras
 * Copyright (C) 1992-2011 Kicad Developers, see change_log.txt for contributors.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this package; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */
 
#ifndef __UNITS_H
#define __UNITS_H
 
#include <config.h>
#include <cmath>
 
#include "units_scales.h"
 
#ifndef HAVE_CMATH_ASINH
inline double asinh( double x )
{
    return log( x+sqrt(x*x+1) );
}
#endif
 
#ifndef HAVE_CMATH_ACOSH
inline double acosh( double x )
{
    // must be x>=1, if not return Nan (Not a Number)
    if( x < 1.0 ) return sqrt( -1.0 );
 
    // return only the positive result (as sqrt does).
    return log( x+sqrt( x*x-1.0 ) );
}
#endif
 
#ifndef HAVE_CMATH_ATANH
inline double atanh( double x )
{
    // must be x>-1, x<1, if not return Nan (Not a Number)
    if( !(x>-1.0 && x<1.0) ) return sqrt( -1.0 );
 
    return log( (1.0+x)/(1.0-x) ) / 2.0;
}
#endif
 
#define MU0  12.566370614e-7          // magnetic constant
#define C0   299792458.0              // speed of light in vacuum
#define ZF0  376.730313668           // wave resistance in vacuum
 
// ZF0 value update:
// https://physics.nist.gov/cgi-bin/cuu/Value?z0
 
#endif /* __UNITS_H */