void
surrogate(pNode me, int n1, int n2)
{
int i, j, k;
int var; /* the primary split variable */
double split;
double improve;
double lcount, rcount; /* weight sent left and right by
* primary */
int extra;
pSplit ss;
int *index;
int *tempy;
int **sorts;
double **xdata;
int ncat;
double adj_agree;
tempy = ct.tempvec;
sorts = ct.sorts;
xdata = ct.xdata;
/*
* First construct, in tempy, the "y" variable for this calculation.
* It will be LEFT:goes left, 0:missing, RIGHT:goes right.
* Count up the number of obs the primary sends to the left, as my
* last surrogate (or to the right, if larger).
*/
var = (me->primary)->var_num;
if (ct.numcat[var] == 0) { /* continuous variable */
split = (me->primary)->spoint;
extra = (me->primary)->csplit[0];
for (i = n1; i < n2; i++) {
j = sorts[var][i];
if (j < 0)
tempy[-(j + 1)] = 0;
else
tempy[j] = (xdata[var][j] < split) ? extra : -extra;
}
} else { /* categorical variable */
index = (me->primary)->csplit;
for (i = n1; i < n2; i++) {
j = sorts[var][i];
if (j < 0)
tempy[-(j + 1)] = 0;
else
tempy[j] = index[(int) xdata[var][j] - 1];
}
}
/* count the total number sent left and right */
lcount = 0;
rcount = 0;
for (i = n1; i < n2; i++) {
j = sorts[var][i];
if (j < 0)
j = -(1 + j);
switch (tempy[j]) {
case LEFT:
lcount += ct.wt[j];
break;
case RIGHT:
rcount += ct.wt[j];
break;
default:
break;
}
}
if (lcount < rcount)
me->lastsurrogate = RIGHT;
else {
if (lcount > rcount)
me->lastsurrogate = LEFT;
else
me->lastsurrogate = 0; /* no default */
}
/*
* Now walk through the variables
*/
me->surrogate = (pSplit) NULL;
for (i = 0; i < ct.nvar; i++) {
if (var == i)
continue;
ncat = ct.numcat[i];
choose_surg(n1, n2, tempy, xdata[i], sorts[i], ncat,
&improve, &split, ct.csplit, lcount, rcount, &adj_agree);
if (adj_agree <= 1e-10) /* was 0 */
continue; /* no better than default */
/* sort it onto the list of surrogates */
ss = insert_split(&(me->surrogate), ncat, improve, ct.maxsur);
if (ss) {
ss->improve = improve;
ss->var_num = i;
ss->count = 0; /* corrected by nodesplit() */
ss->adj = adj_agree;
if (ct.numcat[i] == 0) {
ss->spoint = split;
ss->csplit[0] = ct.csplit[0];
} else
for (k = 0; k < ct.numcat[i]; k++)
ss->csplit[k] = ct.csplit[k];
}
}
}
void surrogate(struct node *me, int nodenum)
{
int i, j, k;
int var; /* the primary split variable */
FLOAT split;
double improve;
double lcount, rcount; /* weight sent left and right by primary */
int extra;
struct split *ss;
int *index;
int *which,
*tempy;
Sint **sorts;
FLOAT **xdata;
int ncat;
double adj_agree;
which = rp.which;
tempy = rp.tempvec;
sorts = rp.sorts;
xdata = rp.xdata;
/*
** First construct, in tempy, the "y" variable for this calculation.
** It will be LEFT:goes left, 0:missing, RIGHT:goes right.
** Count up the number of obs the primary sends to the left, as my
** last surrogate (or to the right, if larger).
*/
var = (me->primary)->var_num;
if (rp.numcat[var]==0) { /* continuous variable */
split = (me->primary)->spoint;
extra = (me->primary)->csplit[0];
for (i=0; i<rp.n; i++) {
j = sorts[var][i];
if (j<0) tempy[-(j+1)]=0;
else if (which[j] == nodenum) {
if (xdata[var][i] < split)
tempy[j] = extra;
else
tempy[j] = -extra;
}
}
}
else { /* categorical variable */
index = (me->primary)->csplit;
for (i=0; i<rp.n; i++) {
if (which[i] != nodenum) continue;
if (sorts[var][i]<0) tempy[i] =0;
else tempy[i] = index[(int)xdata[var][i] -1];
}
}
lcount=0; rcount=0;
for (i=0; i<rp.n; i++) {
if (which[i] != nodenum) continue;
switch(tempy[i]) {
case LEFT : lcount += rp.wt[i]; break;
case RIGHT: rcount += rp.wt[i]; break;
default: break;
}
}
if (lcount < rcount) me->lastsurrogate = RIGHT;
else me->lastsurrogate = LEFT;
/*
** Now walk through the variables
*/
me->surrogate =0;
for (i=0; i<rp.nvar; i++) {
if (var == i) continue;
ncat = rp.numcat[i];
choose_surg(nodenum, tempy, xdata[i], sorts[i], ncat,
&improve, &split, rp.csplit, lcount, rcount,
&adj_agree);
if (adj_agree <=0) continue; /*no better than default */
/* sort it onto the list of surrogates */
ss = insert_split( &(me->surrogate), ncat, improve, rp.maxsur);
if (ss !=0) {
ss->improve = improve;
ss->var_num = i;
ss->count = 0; /*corrected by nodesplit() */
ss->adj = adj_agree;
if (rp.numcat[i]==0) {
ss->spoint = split;
ss->csplit[0] = rp.csplit[0];
}
else for (k=0; k<rp.numcat[i]; k++) ss->csplit[k] = rp.csplit[k];
}
}
}
