/**
    @file ApplyDrift.cpp
    @author Brian Magill
    @creation date 1/1/2007

	$Date:$
    $Revision:$

    @copyright
     (©) Copyright 2006 by GATS Inc.
     11864 Canon Blvd., Suite 101, Newport News, VA 23606

     All Rights Reserved. No part of this software or publication may be
     reproduced, stored in a retrieval system, or transmitted, in any form
     or by any means, electronic, mechanical, photocopying, recording, or
     otherwise without the prior written permission of GATS Inc.
        
    @brief Applies the drift signal correction for a given channel
    Corrects multiplicative drift to first order
*/

#include <valarray>
#include "ApplyDrift.h"
#include "SOFIE_namespace.h"

using namespace std;

ChannelSignals ApplyDrift::operator()(std::valarray<double> const &time, 
                                ChannelSignals const &in, DriftParam const &param) const
{
    int gasId = in.getID();
    std::valarray<double> strong = in.getSignal(SOFIE::Strong);
    std::valarray<double> weak = in.getSignal(SOFIE::Weak);
    std::valarray<double> diff = in.getSignal(SOFIE::Diff);
    double strong_atten = in.getAttenuation(SOFIE::Strong); 
    double weak_atten   = in.getAttenuation(SOFIE::Weak);    
    
    
    double Ka = param.getSlope(SOFIE::Strong);
    double t_0 = param.getTimeRef();
    double v_0 = param.getSigRef(SOFIE::Strong);    
    strong = strong*(1. + Ka*(time - t_0));
    
    Ka  = param.getSlope(SOFIE::Weak);
    v_0 = param.getSigRef(SOFIE::Weak);    
    weak = weak*(1. + Ka*(time - t_0));

    Ka  = param.getSlope(SOFIE::Diff);
    v_0 = param.getSigRef(SOFIE::Diff);    
    diff = diff - Ka*(time - t_0);
    
    return ChannelSignals(gasId, strong_atten, weak_atten, strong, weak, diff); 
}