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
PROCEDURE scale_connection_coef(x, factor) {
VERBATIM {
Section* sec;
Node* nd;
#if defined(t)
NrnThread* _nt = nrn_threads;
#endif
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, sec->nnode);*/
/* assumes 0 end of child connected to parent */
if (_lx == 1.) {
nd = sec->pnode[sec->nnode-1];
}else{
nd = sec->pnode[(int) (_lx*(double)(sec->nnode-1))];
}
/*printf("%g %g\n", NODEA(nd), NODEB(nd));*/
NODEA(nd) *= _lfactor;
NODEB(nd) *= _lfactor;
}
ENDVERBATIM
}