util.h

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/*
        dsp/util.h
        
        Copyright 2002-4 Tim Goetze <tim@quitte.de>
        
        http://quitte.de/dsp/
 
        Common math utility functions.
 
*/
/*
        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 program; if not, write to the Free Software
        Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
        02111-1307, USA or point your web browser to http://www.gnu.org.
*/
 
#ifndef _DSP_UTIL_H_
#define _DSP_UTIL_H_
 
namespace DSP {
 
inline int next_power_of_2 (int n)
{
        assert (n <= 0x40000000);
 
        int m = 1;
        
        while (m < n)
                m <<= 1;
 
        return m;
}
 
inline bool
isprime (int v)
{
        if (v <= 3)
                return true;
        
        if (!(v & 1))
                return false;
 
        for (int i = 3; i < (int) sqrt (v) + 1; i += 2)
                if ((v % i) == 0)
                        return false;
 
        return true;
}
 
inline double 
db2lin (double db)
{
        return pow (10., db * .05);
}
 
inline double
lin2db (double lin)
{
        return 20. * log10 (lin);
}
 
} /* namespace DSP */
 
#endif /* _DSP_UTIL_H_ */