fstim.cpp

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#include <../../nrnconf.h>
/* /local/src/master/nrn/src/nrnoc/fstim.cpp,v 1.2 1997/08/15 13:04:11 hines Exp */
/* copy of synapse.cpp modified to simulate current stimulus pulses */
/* 4/9/2002 modified to conform to new treeset.cpp */

/*
fstim(maxnum)
 allocates space for maxnum synapses. Space for
 previously existing synapses is released. All synapses initialized to
 0 maximum conductance.

fstim(i, loc, delay, duration, stim)
 The ith current stimulus is injected at parameter `loc'
 different current stimuli do not concatenate but can ride on top of
 each other. delay refers to onset of stimulus relative to t=0
 delay and duration are in msec.
 stim in namps.
  
fstimi(i)
 returns stimulus current for ith stimulus at the value of the
 global time t.

*/

#include <stdlib.h>
#include "neuron.h"
#include "section.h"
#include "nrniv_mf.h"


typedef struct Stimulus {
    double loc;    /* parameter location (0--1) */
    double delay;    /* value of t in msec for onset */
    double duration;/* turns off at t = delay + duration */
    double mag;    /* magnitude in namps */
    double mag_seg;    /* value added to rhs, depends on area of seg*/
    Node *pnd;    /* segment location */
    Section *sec;
} Stimulus;

static int maxstim = 0;        /* size of stimulus array */
static Stimulus *pstim;        /* pointer to stimulus array */
static void free_stim(void);

static void stim_record(int);

#define nt_t nrn_threads->_t

void print_stim() {
    int i;

    if (maxstim == 0) return;
    /*SUPPRESS 440*/
    Printf("fstim(%d)\n/* section   fstim( #, loc, delay(ms), duration(ms), magnitude(namp)) */\n", maxstim);
    for (i = 0; i < maxstim; i++) {
        Printf("%-15s fstim(%2d,%4g,%10g,%13g,%16g)\n",
               secname(pstim[i].sec), i,
               pstim[i].loc, pstim[i].delay, pstim[i].duration, pstim[i].mag);
    }
}

static double stimulus(int i) {
#if CVODE
    at_time(nrn_threads, pstim[i].delay);
    at_time(nrn_threads, pstim[i].delay + pstim[i].duration);
#endif
    if (nt_t < pstim[i].delay - 1e-9
        || nt_t > pstim[i].delay + pstim[i].duration - 1e-9) {
        return 0.0;
    }
    return pstim[i].mag_seg;
}

void fstimi(void) {
    int i;
    double cur;

    i = chkarg(1, 0., (double) (maxstim - 1));
    if ((cur = stimulus(i)) != 0.) {
        cur = pstim[i].mag;
    }
    hoc_retpushx(cur);
}

void fstim(void) {
    int i;

    if (nrn_nthread > 1) {
        hoc_execerror("fstim does not allow threads", "");
    }
    i = chkarg(1, 0., 10000.);
    if (ifarg(2)) {
        if (i >= maxstim) {
            hoc_execerror("index out of range", (char *) 0);
        }
        pstim[i].loc = chkarg(2, 0., 1.);
        pstim[i].delay = chkarg(3, 0., 1e21);
        pstim[i].duration = chkarg(4, 0., 1e21);
        pstim[i].mag = *getarg(5);
        pstim[i].sec = chk_access();
        section_ref(pstim[i].sec);
        stim_record(i);
    } else {
        free_stim();
        maxstim = i;
        if (maxstim) {
            pstim = (Stimulus *) emalloc((unsigned) (maxstim * sizeof(Stimulus)));
        }
        for (i = 0; i < maxstim; i++) {
            pstim[i].loc = 0;
            pstim[i].mag = 0.;
            pstim[i].delay = 1e20;
            pstim[i].duration = 0.;
            pstim[i].sec = 0;
            stim_record(i);
        }
    }
    hoc_retpushx(0.);
}

static void free_stim(void) {
    int i;
    if (maxstim) {
        for (i = 0; i < maxstim; ++i) {
            if (pstim[i].sec) {
                section_unref(pstim[i].sec);
            }
        }
        free((char *) pstim);
        maxstim = 0;
    }
}

static void stim_record(int i)    /*fill in the section info*/
{
    double area;
    Section *sec;

    sec = pstim[i].sec;
    if (sec) {
        if (sec->prop) {
            pstim[i].pnd = node_ptr(sec, pstim[i].loc, &area);
            pstim[i].mag_seg = 1.e2 * pstim[i].mag / area;
        } else {
            section_unref(sec);
            pstim[i].sec = 0;
        }
    }
}

void stim_prepare(void) {
    int i;

    for (i = 0; i < maxstim; i++) {
        stim_record(i);
    }
}

void activstim_rhs(void) {
    int i;

    for (i = 0; i < maxstim; i++) {
        if (pstim[i].sec) {
            NODERHS(pstim[i].pnd) += stimulus(i);
        }
    }
}