COMMENT

Four helpful hints:

1) before calling scale_connection_coef, one must call some NEURON

function (such as ri(x)) that forces calculation of all the connection

coefficients for all the sections.

2) if any diam or L is changed, then one must re-call the

scale_connection_coef procedure again for all compartments AFTER

re-forcing the normal calculation of them via a call to, e.g. ri(x).

3) note that ri(0.5) gives the resistance in mega ohms between 0.5

location and the 0 end and ri(1) gives the resistance in mega ohms

between the 0.5 location and the 1 end.

4) Call with a section access'ed. Call below with (1,factor) to

change the axial resistance of (a parent's) x=0.5 to x=1 part and call

with (0.5, factor) to change the axial resistance for (a child's) x=0

to x=0.5 part. Note: factor = current_ri_value/desired__ri_value.

ENDCOMMENT

NEURON { SUFFIX nothing }

VERBATIM

const char* secname();

ENDVERBATIM

VERBATIM

#ifndef _NrnThread

#define _NrnThread NrnThread

#endif

#ifdef NRN_MECHANISM_DATA_IS_SOA

#define get_nnode(sec) _nrn_mechanism_get_nnode(sec)

#define get_node(sec, node_index) _nrn_mechanism_get_node(sec, node_index)

#define get_thread(node) _nrn_mechanism_get_thread(node)

#else

#define get_nnode(sec) sec->nnode

#define get_node(sec, node_index) sec->pnode[node_index]

#define get_thread(node) node->_nt

#endif

ENDVERBATIM

PROCEDURE scale_connection_coef(x, factor) {

VERBATIM {

Section* sec;

Node* nd;

#if defined(t)

_NrnThread* _nt = nrn_threads;

#endif /* t */

sec = chk_access();

if (_lx <= 0. || _lx > 1.) {

hoc_execerror("out of range, must be 0 < x <= 1", (char*)0);

}

/*printf("scale_connection_coefs %s(%g) %d\n", secname(sec), _lx, get_nnode(sec));*/

/* assumes 0 end of child connected to parent */

if (_lx == 1.) {

nd = get_node(sec, get_nnode(sec) - 1);

}else{

nd = get_node(sec, (int)(_lx*(double)(get_nnode(sec) - 1)));

}

#if defined(t)

_nt = get_thread(nd);

#endif /* t */

/*printf("%g %g\n", NODEA(nd), NODEB(nd));*/

NODEA(nd) *= _lfactor;

NODEB(nd) *= _lfactor;

}

ENDVERBATIM

}