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/*
* Copyright (c) Medical Research Council 2002. All rights reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation for any purpose is hereby granted without fee, provided that
* this copyright and notice appears in all copies.
*
* This file was written as part of the Staden Package at the MRC Laboratory
* of Molecular Biology, Hills Road, Cambridge, CB2 2QH, United Kingdom.
*
* MRC disclaims all warranties with regard to this software.
*
*/
#include <cmath> // For std::log10()
#include <caller_snr.hpp>
void SNRCaller::MakeCall( Trace& Tr, int nPos )
{
call_t Signal[4];
// Load in data
m_nPosition = nPos;
Signal[0].Index = 0;
Signal[0].Amplitude = Tr[0][nPos];
Signal[1].Index = 1;
Signal[1].Amplitude = Tr[1][nPos];
Signal[2].Index = 2;
Signal[2].Amplitude = Tr[2][nPos];
Signal[3].Index = 3;
Signal[3].Amplitude = Tr[3][nPos];
// Sort into ascending order of amplitude
SortAscending( Signal );
// Compute SNR=confidence, based on 1st and 2nd highest trace levels
// S/N (db) = 20*log(s/n).
//
double S = static_cast<double>( Signal[3].Amplitude );
double N = static_cast<double>( Signal[2].Amplitude );
if( N <= 0.0 )
N = 1.0;
m_nRatio = S / N;
m_nSNR = 20.0 * std::log10( m_nRatio );
}
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