void Node::CopyTree(Node *copy)
{
int i;
copy->Top = Top;
copy->Bot = Bot;
copy->Nog = Nog;
for(i=1;i<=NumX;i++) copy->VarAvail[i] = VarAvail[i];
if(!Bot) {
CopyRule(&rule,&(copy->rule));
Node *Left,*Right;
Left = new Node;
Right = new Node;
copy->LeftC = Left;
copy->RightC = Right;
LeftC->CopyTree(Left);
RightC->CopyTree(Right);
Left->Parent = copy;
Right->Parent = copy;
}
if (Top) {
copy->SetData();
}
}
double BirthDeath(Node *top,int *BD,int *Done)
//does either a birth or death step
//top: top of tree
//BD: on exit, 1 if birth , 0 if death
//Done: on exit, 1 if step taken , 0 otherwise
{
double PGn,Pbot,PBx,PGl,PGr,PDy,Pnog;
double PDx,PBy;
double temprob;
int VarI;
int LeftEx,RightEx;
double alpha1,alpha2,alpha;
double Ly,Lx;
Rule *rule=new Rule;
Node *n,*tempnode;
PBx=PBirth(top,&n,&Pbot);
if(Bern(PBx)) {
*BD=1;
PGn = PGrow(n);
Lx = LogLT(n,top);
VarI = DrPriVar(n);//draw variable
DrPriRule(VarI,n,&LeftEx,&RightEx);//draw rule
SpawnChildren(n,LeftEx,RightEx); //create children
// this omitted because we will implement it at the metrop level
/*if ((((n->LeftC)->DataList).length < 5) || (((n->RightC)->DataList).length < 5)){
// back out if we have less than 5 obs in either new kid; clean up first
KillChildren(n);
return -1;
}*/
PGl = PGrow(n->LeftC);
PGr = PGrow(n->RightC);
Ly = LogLT(n,top);
Pnog = 1.0/((double)(top->NumNogNodes()));
PDy = 1.0-PBirth(top,&tempnode,&temprob);
alpha1 = (PGn*(1.0-PGl)*(1.0-PGr)*PDy*Pnog)/((1.0-PGn)*PBx*Pbot);
alpha2 = alpha1*exp(Ly-Lx);
alpha = min(1.0,alpha2);
if(Bern(alpha)) {
*Done=1;
} else {
KillChildren(n);
*Done=0;
}
} else {
*BD=0;
PDx=1-PBx;
Pnog = DrNogNode(top,&n);
PGl = PGrow(n->LeftC);
PGr = PGrow(n->RightC);
Lx = LogLT(n,top);
CopyRule(&(n->rule),rule);
LeftEx=1-((n->LeftC)->VarAvail[(n->rule).Var]);
RightEx=1-((n->RightC)->VarAvail[(n->rule).Var]);
KillChildren(n);
Ly = LogLT(n,top);
PBy = PBirth(top,&tempnode,&temprob);
PGn = PGrow(n);
Pbot=PrBotNode(top,n);
alpha1 =((1.0-PGn)*PBy*Pbot)/(PGn*(1.0-PGl)*(1.0-PGr)*PDx*Pnog);
alpha2 = alpha1*exp(Ly-Lx);
alpha = min(1,alpha2);
if(Bern(alpha)) {
*Done=1;
} else {
//put back rule and children
CopyRule(rule,&(n->rule));
SpawnChildren(n,LeftEx,RightEx);
*Done=0;
}
}
delete rule;
return alpha;
}
double ChangeRule(Node *top,int *Done)
// step which tries changing the rule
{
int i,j;
double XLogPi,XLogL,YLogPi,YLogL;
int ruleI;
double alpha;
double u;
int Nnotbot;
NodeP *notbotvec;
// get list of nodes with rule = nodes which are not bottom
MakeNotBotVec(top,¬botvec,&Nnotbot);
if(Nnotbot==0) {
delete [] notbotvec;
return -1;
}
// randomly choose a notbot node = cnode
//u=ran1(&idum);
u= unif_rand();
int NodeI = (int)floor(u*Nnotbot)+1;
Node *cnode = notbotvec[NodeI];
//given the node, choose a new variable for the new rule
int YVarI = DrPriVar(cnode);
// if new var is CAT do one thing, if ORD another
if(VarType[YVarI]==CAT) {
// get the list of good cat rules given var choice
int firstone;
int NR = RuleNum[YVarI];
int numr = (int)pow(2.0,NR-1)-1;
int *RuleInd = new int [numr+1];
FindGoodCatRules(cnode,YVarI,RuleInd,firstone);
int sum = 0;
for(i=1;i<=numr;i++) sum += RuleInd[i];
//if there are any good cat rules
if(sum) {
// draw the rule from list of good ones
//u=ran1(&idum);
u = unif_rand();
ruleI = (int)floor(u*sum)+1;
ruleI = GetSkipBadInd(numr,RuleInd,ruleI);
//get logpri and logL from current tree (X)
XLogPi = LogPriT(top);
XLogL = LogLT(cnode,top);
// copy old rule
Rule rule;
CopyRule(&(cnode->rule),&rule);
// change rule at cnode to the new one
int *sel = new int [NR-1+1];
indtd(NR-1,ruleI-1,sel);
(cnode->rule).Var = YVarI;
delete [] (cnode->rule).CatRule;
(cnode->rule).CatRule = new int [NR+1];
for(j=1;j<firstone;j++) (cnode->rule).CatRule[j]=sel[j];
(cnode->rule).CatRule[firstone]=1;
for(j=(firstone+1);j<=NR;j++) (cnode->rule).CatRule[j] = sel[j-1];
//fix data at nodes below cnode given new rule
FixDataBelow(cnode);
// fix VarAvail
UpDateVarAvail(cnode,YVarI);
if(!(YVarI==rule.Var)) UpDateVarAvail(cnode,rule.Var);
//get logpri and logL from candidate tree (Y)
YLogPi = LogPriT(top);
YLogL = LogLT(cnode,top);
//draw go nogo
alpha = min(1.0,exp(YLogPi+YLogL-XLogPi-XLogL));
if(Bern(alpha)) {
*Done=1;
} else {
// if nogo put rule, data, and VarAvail back
CopyRule(&rule,&(cnode->rule));
FixDataBelow(cnode);
// fix VarAvail
UpDateVarAvail(cnode,YVarI);
if(!(YVarI==rule.Var)) UpDateVarAvail(cnode,rule.Var);
*Done=0;
}
delete [] sel;
} else {
// if no rules for that var abort step
alpha = -1;
}
delete [] RuleInd;
} else {
//ORD variable
// get the set of good rules = [l,r]
int l,r;
FindGoodOrdRules(cnode,YVarI,l,r);
int numsplit = r-l+1;
// if there are any rules
if(numsplit>0) {
//draw the rule
//u=ran1(&idum);
u = unif_rand();
ruleI = l+(int)floor(u*numsplit);
//get logpri and logL from current tree (X)
XLogPi = LogPriT(top);
XLogL = LogLT(cnode,top);
// copy old rule
int XVarI = (cnode->rule).Var;
int XOrdRule = (cnode->rule).OrdRule;
// change rule at cnode to the new one
(cnode->rule).Var = YVarI;
(cnode->rule).OrdRule = ruleI;
//fix data at nodes below cnode given new rule
FixDataBelow(cnode);
UpDateVarAvail(cnode,YVarI);
if(!(YVarI==XVarI)) UpDateVarAvail(cnode,XVarI);
//get logpri and logL from candidate tree (Y)
YLogPi = LogPriT(top);
YLogL = LogLT(cnode,top);
//draw go nogo
alpha = min(1.0,exp(YLogPi+YLogL-XLogPi-XLogL));
if(Bern(alpha)) {
// if go fix VarAvail
*Done=1;
} else {
// if nogo put rule and data back
(cnode->rule).Var = XVarI;
(cnode->rule).OrdRule = XOrdRule;
FixDataBelow(cnode);
UpDateVarAvail(cnode,YVarI);
if(!(YVarI==XVarI)) UpDateVarAvail(cnode,XVarI);
*Done=0;
}
} else {
// if no rules for that var abort step
alpha=-1;
}
}
delete [] notbotvec;
return alpha; // note -1 means backed out
}