void fingerprint2::DoRings()
{
//For each complete ring fragment, find its largest chemically identical representation
//by rotating and reversing, and insert into the main set of fragments
SetItr itr;
for(itr=ringset.begin();itr!=ringset.end();++itr)
{
vector<int> t1(*itr); //temporary copy
vector<int> maxring(*itr); //the current largest vector
unsigned int i;
for(i=0;i<t1.size()/2;++i)
{
//rotate atoms in ring
rotate(t1.begin(),t1.begin()+2,t1.end());
if(t1>maxring)
maxring=t1;
//reverse the direction around ring
vector<int> t2(t1);
reverse(t2.begin()+1, t2.end());
if(t2>maxring)
maxring=t2;
}
fragset.insert(maxring);
//PrintFpt(maxring,0);
}
}
void fingerprint2::getFragments(vector<int> levels, vector<int> curfrag,
int level, OBAtom* patom, OBBond* pbond)
{
//Recursive routine to analyse schemical structure and populate fragset and ringset
//Hydrogens,charges(except dative bonds), spinMultiplicity ignored
const int Max_Fragment_Size = 7;
int bo=0;
if(pbond)
{
bo = pbond->IsAromatic() ? 5 : pbond->GetBO();
// OBAtom* pprevat = pbond->GetNbrAtom(patom);
// if(patom->GetFormalCharge() && (patom->GetFormalCharge() == -pprevat->GetFormalCharge()))
// ++bo; //coordinate (dative) bond eg C[N+]([O-])=O is seen as CN(=O)=O
}
curfrag.push_back(bo);
curfrag.push_back(patom->GetAtomicNum());
levels[patom->GetIdx()-1] = level;
vector<OBEdgeBase*>::iterator itr;
OBBond *pnewbond;
// PrintFpt(curfrag,(int)patom);
for (pnewbond = patom->BeginBond(itr);pnewbond;pnewbond = patom->NextBond(itr))
{
if(pnewbond==pbond) continue; //don't retrace steps
OBAtom* pnxtat = pnewbond->GetNbrAtom(patom);
if(pnxtat->GetAtomicNum() == OBElements::Hydrogen) continue;
int atlevel = levels[pnxtat->GetIdx()-1];
if(atlevel) //ring
{
if(atlevel==1)
{
//If complete ring (last bond is back to starting atom) add bond at front
//and save in ringset
curfrag[0] = pnewbond->IsAromatic() ? 5 : pnewbond->GetBO();
ringset.insert(curfrag);
curfrag[0] = 0;
}
}
else //no ring
{
if(level<Max_Fragment_Size)
{
// TRACE("level=%d size=%d %p frag[0]=%p\n",level, curfrag.size(),&curfrag, &(curfrag[0]));
//Do the next atom; levels, curfrag are passed by value and hence copied
getFragments(levels, curfrag, level+1, pnxtat, pnewbond);
}
}
}
//do not save C,N,O single atom fragments
if(curfrag[0]==0 &&
(level>1 || patom->GetAtomicNum()>8 || patom->GetAtomicNum()<6))
{
fragset.insert(curfrag); //curfrag ignored if an identical fragment already present
// PrintFpt(curfrag,level);
}
}
bool fingerprint2::GetFingerprint(OBBase* pOb, vector<unsigned int>&fp, int nbits)
{
OBMol* pmol = dynamic_cast<OBMol*>(pOb);
if(!pmol) return false;
fp.resize(1024/Getbitsperint());
fragset.clear();//needed because now only one instance of fp class
ringset.clear();
//identify fragments starting at every atom
OBAtom *patom;
vector<OBNodeBase*>::iterator i;
for (patom = pmol->BeginAtom(i);patom;patom = pmol->NextAtom(i))
{
if(patom->GetAtomicNum() == OBElements::Hydrogen) continue;
vector<int> curfrag;
vector<int> levels(pmol->NumAtoms());
getFragments(levels, curfrag, 1, patom, NULL);
}
// TRACE("%s %d frags before; ",pmol->GetTitle(),fragset.size());
//Ensure that each chemically identical fragment is present only in a single
DoRings();
DoReverses();
SetItr itr;
_ss.str("");
for(itr=fragset.begin();itr!=fragset.end();++itr)
{
//Use hash of fragment to set a bit in the fingerprint
int hash = CalcHash(*itr);
SetBit(fp,hash);
if(!(Flags() & FPT_NOINFO))
PrintFpt(*itr,hash);
}
if(nbits)
Fold(fp, nbits);
// TRACE("%d after\n",fragset.size());
return true;
}
void fingerprint2::DoReverses()
{
SetItr itr;
for(itr=fragset.begin();itr!=fragset.end();)
{
//Reverse the order of the atoms, add the smallest fragment and remove the larger
SetItr titr = itr++; //Ensure have valid next iterator in case current one is erased
vector<int> t1(*titr); //temporary copy
reverse(t1.begin()+1, t1.end()); //(leave 0 at front alone)
if(t1!=*titr)
{
//Add the larger fragment and delete the smaller
if(t1>*titr)
{
fragset.erase(titr);
fragset.insert(t1);
}
else
fragset.erase(t1);
}
}
}