FiniteSpikeResponse.h

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#ifndef FINITESPIKERESPONSE_H_
#define FINITESPIKERESPONSE_H_

#include "SimObject.h"
#include <cmath>

class FiniteSpikeResponse : public SimObject
{
public:
    FiniteSpikeResponse()
    {
        psr = 0;
        steps2cutoff = 0;
    }

    virtual ~FiniteSpikeResponse()
    { /* NOOP */ }

    // Reset to initial condition.
    virtual int reset( double dt )
    {
        steps2cutoff = 0;
        psr = 0;
        return 0;
    }

    /* Return the number of time steps it will take from the
     * time a spike arrives until the postynaptic response has vanished.
     */
    virtual int psrLength(double dt) const = 0;

    double psr;

    virtual double getAnalogOutput(analog_port_id_t p) const
    {
        if (p == 0)
                return psr;        
        return steps2cutoff;
    };

    virtual int nSpikeInputPorts() const { return 1; };
    virtual int nSpikeOutputPorts() const { return 0; };
    virtual int nAnalogInputPorts() const { return 0; };
    virtual int nAnalogOutputPorts() const { return 1; };
    virtual PortType outputPortType(port_t o) const
    {
        if ( o== 0 || o == 1) return analog; else return undefined;
    };
    virtual PortType inputPortType(port_t i) const
    {
        if( i==0) return spiking; else return undefined;
    };
    
    virtual bool isActive()
    {
        return steps2cutoff;    
    }
    

protected:

    inline int spikeHitReturn(AdvanceInfo const &ai)
    {
        /* do we need to activate this synapse? */
        int register activate = (steps2cutoff == 0) * SPIKEHITFLAG_ACTIVATE;
        /* now calc the new cutoff point */
        steps2cutoff = psrLength(ai.dt.in_sec()); // (int)(PSR_MULTIPLE_TAU*tau/DT+0.5);
        return activate;
    }

    inline int advanceReturn(void)
    {
        if (--steps2cutoff > 0) {
            // signal nothing special to the sim engine by returning 0
            return 0;
        } else {
            // the psr has vanished, so we set it to zero and signal the sim engine that we are idle now
            psr = 0;
            return ADVANCEFLAG_DEACTIVATE;
        }
    }


    int steps2cutoff;

};

#endif /*FINITESPIKERESPONSE_H_*/

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