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rdkit/Code/GraphMol/RascalMCES/RascalMCES.cpp

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//
// Copyright (C) David Cosgrove 2023
//
// @@ All Rights Reserved @@
// This file is part of the RDKit.
// The contents are covered by the terms of the BSD license
// which is included in the file license.txt, found at the root
// of the RDKit source tree.
//
// This file contains the driving functions for the determination of
// the Maximum Common Edge Substructure (MCES) between 2 molecules.
// It uses the RASCAL algorithm of John Raymond:
// RASCAL: Calculation of Graph Similarity using Maximum Common
// Edge Subgraphs, John W. Raymond, Eleanor J. Gardiner, Peter Willett
// 'The Computer Journal', 45, 631-644 (2002).
// https://eprints.whiterose.ac.uk/3568/1/willets3.pdf
#include <chrono>
#include <iostream>
#include <map>
#include <regex>
#include <stdexcept>
#include <unordered_set>
#include <vector>
#include <RDGeneral/BoostStartInclude.h>
#include <boost/dynamic_bitset.hpp>
#include <boost/algorithm/string.hpp>
#include <RDGeneral/BoostEndInclude.h>
#include <GraphMol/ROMol.h>
#include <GraphMol/MolOps.h>
#include <GraphMol/new_canon.h>
#include <GraphMol/SmilesParse/SmilesParse.h>
#include <GraphMol/SmilesParse/SmilesWrite.h>
#include <GraphMol/Substruct/SubstructMatch.h>
#include <GraphMol/RascalMCES/RascalMCES.h>
#include <GraphMol/RascalMCES/PartitionSet.h>
#include <GraphMol/RascalMCES/RascalOptions.h>
#include <GraphMol/RascalMCES/RascalResult.h>
#include <GraphMol/RascalMCES/RascalDetails.h>
namespace RDKit {
namespace RascalMCES {
class TimedOutException : public std::exception {
public:
TimedOutException(long long int run_time,
std::vector<std::vector<unsigned int>> &bestCliques)
: d_cliques(bestCliques) {
d_message = "Timed out after " + std::to_string(run_time) + " second";
if (run_time == 1) {
d_message += ".";
} else {
d_message += "s.";
}
}
const char *what() const throw() override { return d_message.c_str(); }
std::vector<std::vector<unsigned int>> d_cliques;
private:
std::string d_message;
};
// This is in lap_a_la_scipy.cpp and solves the linear assignment problem.
int lapMaximize(const std::vector<std::vector<int>> &costsMat,
std::vector<size_t> &a, std::vector<size_t> &b);
// Contains the information used to start off a Rascal job.
struct RascalStartPoint {
// The tier one and tier two similarities. The initial PartitionSet
// will only be constructed if they are both above the RascalOptions
// threshold.
double d_tier1Sim{-1.0};
double d_tier2Sim{-1.0};
// The lower bound on the maximum clique size. Depends, amongst other things,
// on opts.similarityThreshold.
unsigned int d_lowerBound{0};
// a Delta-Y exchange requires extra treatment. They're rare, though.
bool d_deltaYPoss{false};
// Some parts require mol2 to be the larger molecule. This records if they
// have been swapped with respect to the input molecules.
bool d_swapped{false};
// Pointers to copies of the input molecules, swapped if necessary,
// so that d_mol1 is always the smaller molecule.
std::unique_ptr<ROMol> d_mol1;
std::unique_ptr<ROMol> d_mol2;
std::vector<std::vector<int>> d_adjMatrix1, d_adjMatrix2;
std::vector<std::pair<int, int>> d_vtxPairs;
std::vector<boost::dynamic_bitset<>> d_modProd;
// We might need to know which bonds are symmetrical equivalent.
std::vector<int> d_equivBonds1, d_equivBonds2;
// The initial partition set. May be empty if the thresholds weren't met.
std::shared_ptr<PartitionSet> d_partSet;
};
// Get the sorted degree sequences for the molecule, one sequence for each
// atomic number in the molecule. Each element in the degree sequence is
// the degree of the atom and its index.
void sortedDegreeSeqs(
const ROMol &mol,
std::map<int, std::vector<std::pair<int, int>>> &degSeqs) {
for (const auto &a : mol.atoms()) {
degSeqs[a->getAtomicNum()].push_back(
std::make_pair(a->getDegree(), a->getIdx()));
}
for (auto &it : degSeqs) {
std::sort(it.second.begin(), it.second.end(),
[](const std::pair<int, int> &p1, const std::pair<int, int> &p2)
-> bool { return p1.first > p2.first; });
}
}
// Make labels for the atoms - by default the atomic symbol.
void getAtomLabels(const ROMol &mol, const RascalOptions &opts,
std::vector<std::string> &atomLabels) {
atomLabels.resize(mol.getNumAtoms());
for (const auto &a : mol.atoms()) {
std::string label = a->getSymbol();
if (opts.exactConnectionsMatch) {
label += "X" + std::to_string(a->getDegree());
}
if (!opts.ignoreAtomAromaticity && a->getIsAromatic()) {
label = "a" + label;
}
atomLabels[a->getIdx()] = label;
}
}
int calcCost(const std::vector<unsigned int> &atomiBLs,
const std::vector<unsigned int> &atomjBLs) {
std::unordered_set<unsigned int> uniqAtomiBLs;
for (const auto bl : atomiBLs) {
uniqAtomiBLs.insert(bl);
}
int cost = 0;
for (const auto &uai : uniqAtomiBLs) {
int numAtomi = std::count(atomiBLs.begin(), atomiBLs.end(), uai);
int numAtomj = std::count(atomjBLs.begin(), atomjBLs.end(), uai);
cost += std::min(numAtomi, numAtomj);
}
return cost;
}
// assign the costs of matching each atom in atomDegrees1 to each atom in
// atomDegrees2.
void assignCosts(const std::vector<std::pair<int, int>> &atomDegrees1,
const std::vector<std::pair<int, int>> &atomDegrees2,
const std::vector<unsigned int> &bondLabels1,
const std::vector<unsigned int> &bondLabels2,
const ROMol &mol1, const ROMol &mol2,
std::vector<std::vector<int>> &costsMat) {
std::vector<unsigned int> atomiBLs, atomjBLs;
for (auto i = 0u; i < atomDegrees1.size(); ++i) {
atomiBLs.clear();
const auto atomi = mol1.getAtomWithIdx(atomDegrees1[i].second);
for (const auto b : mol1.atomBonds(atomi)) {
atomiBLs.push_back(bondLabels1[b->getIdx()]);
}
for (auto j = 0u; j < atomDegrees2.size(); ++j) {
const auto atomj = mol2.getAtomWithIdx(atomDegrees2[j].second);
atomjBLs.clear();
for (const auto b : mol2.atomBonds(atomj)) {
atomjBLs.push_back(bondLabels2[b->getIdx()]);
}
costsMat[i][j] = calcCost(atomiBLs, atomjBLs);
}
}
}
// Return the assignment score for the best match of the atoms and bonds in mol1
// to the atoms and bonds in mol2.
int getAssignmentScore(const std::vector<std::pair<int, int>> &atomDegrees1,
const std::vector<std::pair<int, int>> &atomDegrees2,
const std::vector<unsigned int> &bondLabels1,
const std::vector<unsigned int> &bondLabels2,
const ROMol &mol1, const ROMol &mol2) {
constexpr int bigScore(9999);
constexpr size_t unassignedValue(99999999);
std::vector<std::vector<int>> costsMat(
atomDegrees1.size(), std::vector<int>(atomDegrees2.size(), bigScore));
assignCosts(atomDegrees1, atomDegrees2, bondLabels1, bondLabels2, mol1, mol2,
costsMat);
std::vector<size_t> a(std::min(atomDegrees1.size(), atomDegrees2.size()),
unassignedValue);
std::vector<size_t> b(std::min(atomDegrees1.size(), atomDegrees2.size()),
unassignedValue);
int retVal = lapMaximize(costsMat, a, b);
if (retVal < 0) {
// no solution for the LAP was possible.
return 0;
}
int totalCost = 0;
for (auto i = 0u; i < a.size(); ++i) {
totalCost += costsMat[a[i]][b[i]];
}
return totalCost;
}
namespace details {
// calculate the tier 1 similarity between the 2 mols.
double tier1Sim(const ROMol &mol1, const ROMol &mol2,
std::map<int, std::vector<std::pair<int, int>>> &degSeqs1,
std::map<int, std::vector<std::pair<int, int>>> &degSeqs2) {
sortedDegreeSeqs(mol1, degSeqs1);
sortedDegreeSeqs(mol2, degSeqs2);
int vg1g2 = 0;
int eg1g2 = 0;
for (const auto &it1 : degSeqs1) {
const auto &seq2 = degSeqs2.find(it1.first);
if (seq2 != degSeqs2.end()) {
vg1g2 += std::min(it1.second.size(), seq2->second.size());
auto numToDo = std::min(it1.second.size(), seq2->second.size());
for (auto i = 0U; i < numToDo; ++i) {
eg1g2 += std::min(it1.second[i].first, seq2->second[i].first);
}
}
}
eg1g2 /= 2;
double sim = double((vg1g2 + eg1g2) * (vg1g2 + eg1g2)) /
double((mol1.getNumAtoms() + mol1.getNumBonds()) *
(mol2.getNumAtoms() + mol2.getNumBonds()));
return sim;
}
// Calculate the tier 2 similarity between the 2 mols.
double tier2Sim(const ROMol &mol1, const ROMol &mol2,
const std::map<int, std::vector<std::pair<int, int>>> &degSeqs1,
const std::map<int, std::vector<std::pair<int, int>>> &degSeqs2,
const std::vector<unsigned int> &bondLabels1,
const std::vector<unsigned int> &bondLabels2) {
int vg1g2 = 0;
int eg1g2 = 0;
for (const auto &it1 : degSeqs1) {
const auto &seq2 = degSeqs2.find(it1.first);
if (seq2 != degSeqs2.end()) {
vg1g2 += std::min(it1.second.size(), seq2->second.size());
eg1g2 += getAssignmentScore(it1.second, seq2->second, bondLabels1,
bondLabels2, mol1, mol2);
}
}
eg1g2 /= 2;
double sim = double((vg1g2 + eg1g2) * (vg1g2 + eg1g2)) /
double((mol1.getNumAtoms() + mol1.getNumBonds()) *
(mol2.getNumAtoms() + mol2.getNumBonds()));
return sim;
}
// For each bond in the molecule, encode it with its type and the labels of the
// two end atoms, returning the results as strings.
// Note that the molecule should not be in kekulized form.
void getBondLabels(const ROMol &mol, const RascalOptions &opts,
std::vector<std::string> &bondLabels) {
std::vector<std::string> atomLabels;
getAtomLabels(mol, opts, atomLabels);
bondLabels = std::vector<std::string>(mol.getNumBonds());
for (const auto &b : mol.bonds()) {
std::string bondType;
if (opts.ignoreBondOrders) {
bondType = "0";
} else {
bondType = std::to_string(b->getBondType());
}
// The atom labels need to be in consistent order irrespective
// of input order.
auto lbl1 = atomLabels[b->getBeginAtomIdx()];
auto lbl2 = atomLabels[b->getEndAtomIdx()];
if (lbl1 < lbl2) {
std::swap(lbl1, lbl2);
}
bondLabels[b->getIdx()] = lbl1 + bondType + lbl2;
}
}
// Fills bondLabels[12] with a small integer denoting the type of the bond and
// the types of the atoms at each end. Both molecules need to be done at the
// same time so that the labels are consistent across both.
void getBondLabels(const ROMol &mol1, const ROMol &mol2,
const RascalOptions &opts,
std::vector<unsigned int> &bondLabels1,
std::vector<unsigned int> &bondLabels2) {
std::vector<std::string> tmpBondLabels1, tmpBondLabels2;
getBondLabels(mol1, opts, tmpBondLabels1);
getBondLabels(mol2, opts, tmpBondLabels2);
// convert the bond labels, which are currently encoding the atoms and
// bond type to a small set of sequential integers for ease of use later.
// This results in loss of information, but that information is not currently
// used anywhere.
std::set<std::string> allLabels;
for (auto bl : tmpBondLabels1) {
allLabels.insert(bl);
}
for (auto bl : tmpBondLabels2) {
allLabels.insert(bl);
}
auto recodeBondLabels = [&](std::vector<std::string> &strBondLabels,
std::vector<unsigned int> &bondLabels) {
for (auto &bl : strBondLabels) {
auto it = allLabels.find(bl);
bondLabels.push_back(std::distance(allLabels.begin(), it));
}
};
recodeBondLabels(tmpBondLabels1, bondLabels1);
recodeBondLabels(tmpBondLabels2, bondLabels2);
}
} // namespace details
// make the line graph for the molecule, as an adjacency matrix. Each
// row/column is a bond, with a connection between 2 bonds if they share an
// atom. The adjacency matrix is 0 for no bond, the atomic number of the
// connecting atom otherwise.
void makeLineGraph(const ROMol &mol, std::vector<std::vector<int>> &adjMatrix) {
adjMatrix = std::vector<std::vector<int>>(
mol.getNumBonds(), std::vector<int>(mol.getNumBonds(), 0));
for (const auto &a : mol.atoms()) {
for (const auto &b1 : mol.atomBonds(a)) {
for (const auto &b2 : mol.atomBonds(a)) {
if (b1 != b2) {
adjMatrix[b1->getIdx()][b2->getIdx()] = a->getAtomicNum();
}
}
}
}
}
// make sure that mol1_bond in mol1 and mol2_bond in mol2 are, in at least one
// ring that is the same. If aromaticRingsMatchOnly is true, then only aromatic
// bonds are considered.
bool checkRings(const ROMol &mol1,
std::vector<std::string> &mol1RingSmiles,
int mol1BondIdx, const ROMol &mol2,
std::vector<std::string> &mol2RingSmiles,
int mol2BondIdx,
bool aromaticRingsMatchOnly) {
auto mol1Bond = mol1.getBondWithIdx(mol1BondIdx);
auto mol2Bond = mol2.getBondWithIdx(mol2BondIdx);
if (aromaticRingsMatchOnly && (!mol1Bond->getIsAromatic() || !mol2Bond->getIsAromatic())) {
return true;
}
if (mol1Bond->getBondType() != mol2Bond->getBondType()) {
return false;
}
// If neither bond was in a ring, but they were marked aromatic, then
// the two mols are fragments so it's ok to match these bonds.
const auto &mol1BondRings = mol1.getRingInfo()->bondRings();
const auto &mol2BondRings = mol2.getRingInfo()->bondRings();
bool mol1BondInRing = mol1.getRingInfo()->numBondRings(mol1BondIdx);
bool mol2BondInRing = mol2.getRingInfo()->numBondRings(mol2BondIdx);
if (!mol1BondInRing && !mol2BondInRing) {
return true;
}
for (size_t i = 0u; i < mol1BondRings.size(); ++i) {
if (std::find(mol1BondRings[i].begin(), mol1BondRings[i].end(),
mol1BondIdx) == mol1BondRings[i].end()) {
continue;
}
for (size_t j = 0u; j < mol2BondRings.size(); ++j) {
if (std::find(mol2BondRings[j].begin(), mol2BondRings[j].end(),
mol2BondIdx) == mol2BondRings[j].end()) {
continue;
}
if (mol1RingSmiles[i] == mol2RingSmiles[j]) {
return true;
}
}
}
return false;
}
// Extract the rings from the given molecule, both as mol objects and SMILES
// strings. The mol objects will have the original bond indices stored in the
// property ORIG_INDEX.
void extractRings(const ROMol &mol,
std::vector<std::unique_ptr<ROMol>> &molRings,
std::vector<std::string> &molRingSmiles) {
const auto &molBondRings = mol.getRingInfo()->bondRings();
for (size_t i = 0u; i < molBondRings.size(); ++i) {
std::unique_ptr<RWMol> ringMol(new RWMol(mol));
const auto &molAtomRings = mol.getRingInfo()->atomRings();
boost::dynamic_bitset<> atomsInRing(mol.getNumAtoms());
for (auto a : molAtomRings[i]) {
atomsInRing.set(a);
}
for (auto ringBondIdx : molBondRings[i]) {
auto ringBond = ringMol->getBondWithIdx(ringBondIdx);
ringBond->setProp<int>("ORIG_INDEX", ringBond->getIdx());
}
ringMol->beginBatchEdit();
for (auto b : ringMol->bonds()) {
if (!b->hasProp("ORIG_INDEX)")) {
if (!atomsInRing[b->getBeginAtomIdx()]) {
ringMol->removeAtom(b->getBeginAtom());
}
if (!atomsInRing[b->getEndAtomIdx()]) {
ringMol->removeAtom(b->getEndAtom());
}
}
}
ringMol->commitBatchEdit();
molRingSmiles.push_back(MolToSmiles(*ringMol));
molRings.push_back(std::move(ringMol));
}
}
bool checkRingMatchesRing(const ROMol &mol1, int mol1BondIdx, const ROMol &mol2,
int mol2BondIdx) {
if (mol1.getRingInfo()->numBondRings(mol1BondIdx) &&
!mol2.getRingInfo()->numBondRings(mol2BondIdx)) {
return false;
}
if (!mol1.getRingInfo()->numBondRings(mol1BondIdx) &&
mol2.getRingInfo()->numBondRings(mol2BondIdx)) {
return false;
}
return true;
}
// Make the set of pairs of vertices, where they're a pair if the labels
// match.
void buildPairs(const ROMol &mol1, const std::vector<unsigned int> &vtxLabels1,
const ROMol &mol2, const std::vector<unsigned int> &vtxLabels2,
const RascalOptions &opts,
std::vector<std::pair<int, int>> &vtxPairs) {
std::vector<std::string> mol1RingSmiles, mol2RingSmiles;
std::vector<std::unique_ptr<ROMol>> mol1Rings, mol2Rings;
// For these purposes, it is correct that n1cccc1 and [nH]1cccc1 match - the
// former would be from an N-substituted pyrrole, the latter from a plain
// one.
static const std::regex reg(R"(\[([np])H\])");
if (opts.completeAromaticRings) {
extractRings(mol1, mol1Rings, mol1RingSmiles);
for (auto &mrs : mol1RingSmiles) {
mrs = std::regex_replace(mrs, reg, "$1");
}
extractRings(mol2, mol2Rings, mol2RingSmiles);
for (auto &mrs : mol2RingSmiles) {
mrs = std::regex_replace(mrs, reg, "$1");
}
}
for (auto i = 0u; i < vtxLabels1.size(); ++i) {
for (auto j = 0u; j < vtxLabels2.size(); ++j) {
if (vtxLabels1[i] == vtxLabels2[j]) {
// completeSmallestRings automatically implies completeAromaticRings and
// ringMatchesRingsOnly
if (opts.completeSmallestRings &&
!checkRings(mol1, mol1RingSmiles, i, mol2, mol2RingSmiles, j, false)) {
continue;
} else if (opts.completeAromaticRings &&
!checkRings(mol1, mol1RingSmiles, i, mol2, mol2RingSmiles, j, true)) {
continue;
}
if (!opts.completeSmallestRings && opts.ringMatchesRingOnly &&
!checkRingMatchesRing(mol1, i, mol2, j)) {
continue;
}
vtxPairs.push_back(std::make_pair(i, j));
}
}
}
}
// Make the modular product between the 2 graphs passed in. Each node in the
// graph is a pair of vertices, one from the first graph, the other from the
// second, whose labels match. Two vertices are connected in the modular
// product if either the 2 matching vertices in the 2 input vertices are
// connected by edges with the same label, or neither is connected.
void makeModularProduct(const ROMol &mol1,
const std::vector<std::vector<int>> &adjMatrix1,
const std::vector<unsigned int> &vtxLabels1,
const std::vector<std::vector<int>> &distMatrix1,
const ROMol &mol2,
const std::vector<std::vector<int>> &adjMatrix2,
const std::vector<unsigned int> &vtxLabels2,
const std::vector<std::vector<int>> &distMatrix2,
const RascalOptions &opts,
std::vector<std::pair<int, int>> &vtxPairs,
std::vector<boost::dynamic_bitset<>> &modProd) {
buildPairs(mol1, vtxLabels1, mol2, vtxLabels2, opts, vtxPairs);
if (vtxPairs.empty()) {
// There was nothing in common at all. But, what was the screening doing?
modProd.clear();
return;
}
if (vtxPairs.size() > opts.maxBondMatchPairs) {
BOOST_LOG(rdErrorLog) << "Too many matching bond pairs (" << vtxPairs.size()
<< ") so can't continue." << std::endl;
modProd.clear();
return;
}
modProd = std::vector<boost::dynamic_bitset<>>(
vtxPairs.size(), boost::dynamic_bitset<>(vtxPairs.size()));
for (auto i = 0u; i < vtxPairs.size() - 1; ++i) {
for (auto j = i + 1; j < vtxPairs.size(); ++j) {
if (vtxPairs[i].first == vtxPairs[j].first ||
vtxPairs[i].second == vtxPairs[j].second) {
continue;
}
bool distsOk = true;
if (opts.maxFragSeparation != -1) {
if (std::abs(distMatrix1[vtxPairs[i].first][vtxPairs[j].first] -
distMatrix2[vtxPairs[i].second][vtxPairs[j].second]) >
opts.maxFragSeparation) {
distsOk = false;
}
}
if (opts.singleLargestFrag &&
distMatrix1[vtxPairs[i].first][vtxPairs[j].first] !=
distMatrix2[vtxPairs[i].second][vtxPairs[j].second]) {
distsOk = false;
}
if (distsOk && adjMatrix1[vtxPairs[i].first][vtxPairs[j].first] ==
adjMatrix2[vtxPairs[i].second][vtxPairs[j].second]) {
modProd[i][j] = modProd[j][i] = 1;
}
}
}
}
// Calculate the lower bound on the size of the MCES. This requires that mol1
// has more atoms than mol2 which is not checked. Returns a minimum of 1.
unsigned int calcLowerBound(const ROMol &mol1, const ROMol &mol2,
double simThresh) {
std::unordered_set<int> mol1AtNos;
int maxAtNo = 0;
for (const auto &a : mol1.atoms()) {
mol1AtNos.insert(a->getAtomicNum());
maxAtNo = std::max(a->getAtomicNum(), maxAtNo);
}
boost::dynamic_bitset<> mol2AtNos(maxAtNo + 1);
for (const auto &a : mol2.atoms()) {
// since we're interested in the atoms that match in the 2 molecules,
// it doesn't matter if mol2 has an atomic number higher than anything
// in mol1 - that can't be a match.
if (a->getAtomicNum() < maxAtNo) {
mol2AtNos.set(a->getAtomicNum());
}
}
int deltaVg1 = 0;
for (auto mol1AtNo : mol1AtNos) {
if (!mol2AtNos[mol1AtNo]) {
++deltaVg1;
}
}
double lb = sqrt((mol1.getNumAtoms() + mol1.getNumBonds()) *
(mol2.getNumAtoms() + mol2.getNumBonds()));
lb = lb * simThresh - mol1.getNumAtoms() + deltaVg1;
lb = lb < 0 ? 0 : lb;
unsigned int ilb(lb);
if (ilb < 1) {
ilb = 1;
}
return ilb;
}
void printClique(const std::vector<unsigned int> &clique,
const std::vector<std::pair<int, int>> &vtxPairs, bool swapped,
std::ostream &os) {
os << "Clique : " << clique.size() << " :";
for (auto mem : clique) {
os << " " << mem;
}
os << std::endl;
for (auto mem : clique) {
if (swapped) {
os << "{" << vtxPairs[mem].second << ", " << vtxPairs[mem].first << "},";
} else {
os << "{" << vtxPairs[mem].first << ", " << vtxPairs[mem].second << "},";
}
}
std::cout << std::endl;
std::cout << "mol 1 bonds : [";
for (auto mem : clique) {
if (swapped) {
os << vtxPairs[mem].second << ", ";
} else {
os << vtxPairs[mem].first << ", ";
}
}
std::cout << "]" << std::endl;
std::cout << "mol 2 bonds : [";
for (auto mem : clique) {
if (swapped) {
os << vtxPairs[mem].first << ", ";
} else {
os << vtxPairs[mem].second << ", ";
}
}
std::cout << "]" << std::endl;
}
// if the clique involves a delta-y exchange, returns true. Should only be
// called if it's a possibility.
bool deltaYInClique(const std::vector<unsigned int> &clique, const ROMol &mol1,
const ROMol &mol2,
const std::vector<std::pair<int, int>> &vtxPairs) {
if (clique.size() < 3) {
// there must be 3 bonds for a delta-y exchange, obs.
return false;
}
// Map the clique onto the 2 molecules, counting the degrees of the atoms
// if they are involved in the clique. When sorted, they will be the same
// if no delta-y exchange has occurred.
std::vector<std::pair<int, int>> bondMatches;
for (auto mem : clique) {
bondMatches.push_back(
std::make_pair(vtxPairs[mem].first, vtxPairs[mem].second));
}
std::vector<int> cliqueDegs1(mol1.getNumAtoms(), 0);
std::vector<int> cliqueDegs2(mol2.getNumAtoms(), 0);
for (const auto &bm : bondMatches) {
const auto b1 = mol1.getBondWithIdx(bm.first);
cliqueDegs1[b1->getBeginAtomIdx()]++;
cliqueDegs1[b1->getEndAtomIdx()]++;
const auto b2 = mol2.getBondWithIdx(bm.second);
cliqueDegs2[b2->getBeginAtomIdx()]++;
cliqueDegs2[b2->getEndAtomIdx()]++;
}
cliqueDegs1.erase(std::remove(cliqueDegs1.begin(), cliqueDegs1.end(), 0),
cliqueDegs1.end());
std::sort(cliqueDegs1.begin(), cliqueDegs1.end());
cliqueDegs2.erase(std::remove(cliqueDegs2.begin(), cliqueDegs2.end(), 0),
cliqueDegs2.end());
std::sort(cliqueDegs2.begin(), cliqueDegs2.end());
return cliqueDegs1 != cliqueDegs2;
}
// Return a molecule with the clique in it. Each atom will have the property
// ORIG_INDEX giving its index in the original molecule.
RWMol *makeCliqueFrags(const ROMol &mol,
const std::vector<unsigned int> &clique,
const std::vector<std::pair<int, int>> &vtxPairs,
int pairNum) {
auto *molFrags = new RWMol(mol);
boost::dynamic_bitset<> aInClique(mol.getNumAtoms());
boost::dynamic_bitset<> bInClique(mol.getNumBonds());
for (auto mem : clique) {
const Bond *bond = nullptr;
if (pairNum == 1) {
bond = molFrags->getBondWithIdx(vtxPairs[mem].first);
} else {
bond = molFrags->getBondWithIdx(vtxPairs[mem].second);
}
bInClique[bond->getIdx()] = 1;
aInClique.set(bond->getBeginAtomIdx());
bond->getBeginAtom()->setProp<int>("ORIG_INDEX", bond->getBeginAtomIdx());
aInClique.set(bond->getEndAtomIdx());
bond->getEndAtom()->setProp<int>("ORIG_INDEX", bond->getEndAtomIdx());
}
molFrags->beginBatchEdit();
for (auto &a : molFrags->atoms()) {
if (!aInClique[a->getIdx()]) {
molFrags->removeAtom(a);
}
}
for (auto &b : molFrags->bonds()) {
if (!bInClique[b->getIdx()]) {
molFrags->removeBond(b->getBeginAtomIdx(), b->getEndAtomIdx());
}
}
molFrags->commitBatchEdit();
return molFrags;
}
// Calculate the shortest bond distance between the 2 fragments in the
// molecule.
int minFragSeparation(const ROMol &mol, const ROMol &molFrags,
std::vector<int> &fragMapping, int frag1, int frag2) {
auto extractFragAtoms = [&](int fragNum, std::vector<int> &fragAtoms) {
for (size_t i = 0u; i < fragMapping.size(); ++i) {
if (fragMapping[i] == fragNum) {
int origIdx = molFrags.getAtomWithIdx(i)->getProp<int>("ORIG_INDEX");
fragAtoms.push_back(origIdx);
}
}
};
std::vector<int> frag1Atoms, frag2Atoms;
extractFragAtoms(frag1, frag1Atoms);
extractFragAtoms(frag2, frag2Atoms);
auto pathMatrix = MolOps::getDistanceMat(mol);
double minDist = std::numeric_limits<double>::max();
for (const auto &at1 : frag1Atoms) {
for (const auto &at2 : frag2Atoms) {
auto dist = pathMatrix[mol.getNumAtoms() * at1 + at2];
minDist = std::min(dist, minDist);
}
}
return std::nearbyint(minDist);
}
// Assess the clique in terms of opts, returning true if it satisfies them all
bool cliqueOk(const std::vector<unsigned int> clique, const RascalOptions &opts,
const ROMol &mol1, const ROMol &mol2,
const std::vector<std::pair<int, int>> &vtxPairs) {
std::unique_ptr<RWMol> mol1Frags, mol2Frags;
std::vector<int> mol1FragMapping, mol2FragMapping;
int numMol1Frags = 0, numMol2Frags = 0;
auto buildFrags = [&]() -> void {
if (mol1Frags) {
return;
}
mol1Frags.reset(makeCliqueFrags(mol1, clique, vtxPairs, 1));
mol2Frags.reset(makeCliqueFrags(mol2, clique, vtxPairs, 2));
numMol1Frags = MolOps::getMolFrags(*mol1Frags, mol1FragMapping);
numMol2Frags = MolOps::getMolFrags(*mol2Frags, mol2FragMapping);
};
if (opts.minFragSize > 0) {
buildFrags();
// only need to do it for mol1, as the fragments should match.
for (int i = 0; i < numMol1Frags; ++i) {
auto fragSize =
std::count(mol1FragMapping.begin(), mol1FragMapping.end(), i);
if (fragSize < opts.minFragSize) {
return false;
}
}
}
return true;
}
// If this clique warrants it, update maxCliques.
void updateMaxClique(const std::vector<unsigned int> &clique, bool deltaYPoss,
const RascalOptions &opts, const ROMol &mol1,
const ROMol &mol2,
const std::vector<std::pair<int, int>> &vtxPairs,
std::vector<std::vector<unsigned int>> &maxCliques,
unsigned int &lowerBound) {
if (!maxCliques.empty() && clique.size() < maxCliques.front().size()) {
return;
}
bool didDeltaY =
!deltaYPoss ? false : deltaYInClique(clique, mol1, mol2, vtxPairs);
if (!didDeltaY) {
if (maxCliques.empty()) {
if (cliqueOk(clique, opts, mol1, mol2, vtxPairs)) {
maxCliques.push_back((clique));
}
} else {
bool goodClique = false, didCliqueOk = false;
if (clique.size() > maxCliques.front().size()) {
goodClique = cliqueOk(clique, opts, mol1, mol2, vtxPairs);
didCliqueOk = true;
if (goodClique) {
maxCliques.clear();
}
}
if (!didCliqueOk) {
goodClique = cliqueOk(clique, opts, mol1, mol2, vtxPairs);
}
if (goodClique &&
(maxCliques.empty() || clique.size() == maxCliques.front().size())) {
maxCliques.push_back(clique);
}
}
if (!maxCliques.empty() && maxCliques.front().size() > lowerBound) {
lowerBound = maxCliques.front().size();
}
}
}
// If the current time is beyond the timeout limit, throws a
// TimedOutException.
void checkTimeout(
const std::chrono::time_point<std::chrono::high_resolution_clock>
&startTime,
const RascalOptions &opts, const std::vector<unsigned int> &clique,
std::vector<std::vector<unsigned int>> &maxCliques,
unsigned long long &numSteps) {
++numSteps;
if (numSteps == 100) {
// This clock is very convenient, but seems quite expensive. Calling it
// every step added 10% to the runtime.
auto currTime = std::chrono::high_resolution_clock::now();
auto runTime =
std::chrono::duration_cast<std::chrono::seconds>(currTime - startTime)
.count();
if (runTime > opts.timeout) {
if (maxCliques.empty()) {
maxCliques.push_back(clique);
} else {
if (clique.size() > maxCliques.front().size()) {
maxCliques.clear();
}
if (clique.size() >= maxCliques.front().size()) {
maxCliques.push_back(clique);
}
}
throw TimedOutException(runTime, maxCliques);
}
numSteps = 0ULL;
}
}
bool equivalentRootAlreadyDone(unsigned int rootVtx,
const std::vector<std::pair<int, int>> &vtxPairs,
const std::vector<int> &equivBonds1,
const std::vector<int> &equivBonds2,
std::set<std::pair<int, int>> &rootClasses) {
std::pair<int, int> newClasses{equivBonds1[vtxPairs[rootVtx].first],
equivBonds2[vtxPairs[rootVtx].second]};
if (newClasses.first == -1) {
return false;
}
if (!rootClasses.empty() &&
rootClasses.find(newClasses) != rootClasses.end()) {
return true;
}
rootClasses.insert(newClasses);
return false;
}
namespace {
bool hasSubstructMatch(const ROMol &mol, const ROMol &query) {
SubstructMatchParameters ps;
ps.maxMatches = 1;
return !SubstructMatch(mol, query, ps).empty();
}
} // namespace
// There are some simple substructures for which equivalent bond pruning isn't
// allowed.
bool checkEquivalentsAllowed(const ROMol &mol) {
const static std::vector<std::string> notSmarts{
"*~*", "*~*1~*~*~1", "*12~*~*~2~*~1", "*14~*(~*~2~3~4)~*~2~*~3~1"};
static std::vector<std::unique_ptr<ROMol>> notStructs;
if (notStructs.empty()) {
for (const auto &smt : notSmarts) {
notStructs.emplace_back(SmartsToMol(smt));
}
}
const static std::vector<std::pair<unsigned int, unsigned int>> notStats{
{2, 1}, {4, 4}, {4, 5}, {5, 8}};
for (size_t i = 0; i < notStructs.size(); ++i) {
if (mol.getNumAtoms() == notStats[i].first &&
mol.getNumBonds() == notStats[i].second &&
hasSubstructMatch(mol, *notStructs[i])) {
return false;
}
}
return true;
}
void explorePartitions(
RascalStartPoint &starter,
const std::chrono::time_point<std::chrono::high_resolution_clock>
&startTime,
const RascalOptions &opts,
std::vector<std::vector<unsigned int>> &maxCliques) {
unsigned long long numSteps = 0ULL;
std::vector<std::shared_ptr<PartitionSet>> parts(1, starter.d_partSet);
std::vector<unsigned int> clique;
std::set<std::pair<int, int>> rootClasses;
bool canDoEquivs = false;
if (opts.doEquivBondPruning) {
canDoEquivs = checkEquivalentsAllowed(*starter.d_mol1) &&
checkEquivalentsAllowed(*starter.d_mol2);
}
while (!parts.empty()) {
if (opts.timeout != -1) {
checkTimeout(startTime, opts, clique, maxCliques, numSteps);
}
auto part = parts.back();
bool goDeeper = false;
bool backtrack = false;
if (opts.allBestMCESs) {
if (clique.size() + part->numParts() < starter.d_lowerBound) {
backtrack = true;
}
} else {
if (clique.size() + part->numParts() <= starter.d_lowerBound) {
backtrack = true;
}
}
if (!backtrack) {
if (opts.allBestMCESs) {
goDeeper = clique.size() + part->upperBound() >= starter.d_lowerBound;
} else {
goDeeper = clique.size() + part->upperBound() > starter.d_lowerBound;
}
if (goDeeper) {
if (!part->isEmpty()) {
std::shared_ptr<PartitionSet> nextPart(new PartitionSet(*part));
clique.push_back(nextPart->popLastVertex());
if (clique.size() == 1 && canDoEquivs &&
equivalentRootAlreadyDone(clique.front(), starter.d_vtxPairs,
starter.d_equivBonds1,
starter.d_equivBonds2, rootClasses)) {
clique.pop_back();
backtrack = true;
} else {
nextPart->pruneVertices(clique.back());
updateMaxClique(clique, starter.d_deltaYPoss, opts, *starter.d_mol1,
*starter.d_mol2, starter.d_vtxPairs, maxCliques,
starter.d_lowerBound);
parts.push_back(nextPart);
}
} else {
backtrack = true;
}
} else {
backtrack = true;
}
}
if (backtrack || (!parts.empty() && parts.back()->isEmpty())) {
while (!parts.empty()) {
if (parts.back()->isEmpty()) {
parts.pop_back();
if (!clique.empty()) {
clique.pop_back();
}
} else {
parts.back()->popLastVertex();
if (!parts.back()->isEmpty()) {
break;
}
}
}
}
if (parts.empty()) {
break;
}
}
}
bool deltaYExchangePossible(const ROMol &mol1, const ROMol &mol2) {
// A Delta-y exchange is an incorrect match when a cyclopropyl ring (the
// delta) is matched to a C(C)(C) group (the y) because they both have
// isomorphic line graphs. This checks to see if that's something we need
// to worry about for these molecules.
const static std::unique_ptr<ROMol> delta(SmartsToMol("C1CC1"));
const static std::unique_ptr<ROMol> y(SmartsToMol("C(C)C"));
return (hasSubstructMatch(mol1, *delta) && hasSubstructMatch(mol2, *y)) ||
(hasSubstructMatch(mol2, *delta) && hasSubstructMatch(mol1, *y));
}
void findEquivalentBonds(const ROMol &mol, std::vector<int> &equivBonds) {
equivBonds = std::vector<int>(mol.getNumBonds(), -1);
std::vector<unsigned int> ranks(mol.getNumAtoms());
bool breakTies = false;
Canon::rankMolAtoms(mol, ranks, breakTies);
int nextClass = 0;
for (const auto &b1 : mol.bonds()) {
for (const auto &b2 : mol.bonds()) {
if (b1->getIdx() != b2->getIdx()) {
if ((ranks[b1->getBeginAtomIdx()] == ranks[b2->getBeginAtomIdx()] &&
ranks[b1->getEndAtomIdx()] == ranks[b2->getEndAtomIdx()]) ||
(ranks[b1->getBeginAtomIdx()] == ranks[b2->getEndAtomIdx()] &&
ranks[b1->getEndAtomIdx()] == ranks[b2->getBeginAtomIdx()])) {
if (equivBonds[b1->getIdx()] == -1 &&
equivBonds[b2->getIdx()] == -1) {
equivBonds[b1->getIdx()] = nextClass;
equivBonds[b2->getIdx()] = nextClass;
++nextClass;
} else if (equivBonds[b1->getIdx()] == -1) {
equivBonds[b1->getIdx()] = equivBonds[b2->getIdx()];
} else if (equivBonds[b2->getIdx()] == -1) {
equivBonds[b2->getIdx()] = equivBonds[b1->getIdx()];
}
}
}
}
}
}
// Use the Floyd-Warshall algorithm to compute the distance matrix from the
// adjacency matrix.
// Adapted from https://en.wikipedia.org/wiki/FloydWarshall_algorithm
void calcDistMatrix(const std::vector<std::vector<int>> &adjMatrix,
std::vector<std::vector<int>> &distMatrix) {
distMatrix = std::vector<std::vector<int>>(
adjMatrix.size(),
std::vector<int>(adjMatrix.size(), adjMatrix.size() + 1));
for (size_t i = 0u; i < adjMatrix.size(); ++i) {
distMatrix[i][i] = 0;
for (size_t j = 0u; j < adjMatrix.size(); ++j) {
if (i != j && adjMatrix[i][j]) {
distMatrix[i][j] = 1;
}
}
}
for (size_t k = 0u; k < adjMatrix.size(); ++k) {
for (size_t i = 0u; i < adjMatrix.size(); ++i) {
for (size_t j = 0u; j < adjMatrix.size(); ++j) {
if (distMatrix[i][j] > distMatrix[i][k] + distMatrix[k][j]) {
distMatrix[i][j] = distMatrix[i][k] + distMatrix[k][j];
}
}
}
}
}
// Set the atomic number of the atoms that match the SMARTS in
// RascalOptions.EquivalentAtoms to 110, 111 etc. These will
// be mapped back at the end.
void assignEquivalentAtoms(ROMol &mol, const std::string &equivalentAtoms) {
if (equivalentAtoms.empty()) {
return;
}
std::vector<std::string> classSmarts;
boost::split(classSmarts, equivalentAtoms, boost::is_any_of(" "),
boost::token_compress_on);
if (classSmarts.size() > 9) {
throw ValueErrorException(
"Too many classes of equivalent atoms. Maximum is 9.");
}
int atNum = 110;
for (auto &smt : classSmarts) {
if (smt.empty()) {
continue;
}
auto qmol = v2::SmilesParse::MolFromSmarts(smt);
std::vector<RDKit::MatchVectType> hits_vect;
if (RDKit::SubstructMatch(mol, *qmol, hits_vect)) {
for (const auto &hv : hits_vect) {
for (const auto &h : hv) {
auto a = mol.getAtomWithIdx(h.second);
a->setAtomicNum(atNum);
}
}
}
++atNum;
}
}
RascalStartPoint makeInitialPartitionSet(const ROMol *mol1, const ROMol *mol2,
const RascalOptions &opts) {
RascalStartPoint starter;
if (mol1->getNumAtoms() <= mol2->getNumAtoms()) {
starter.d_swapped = false;
starter.d_mol1.reset(new ROMol(*mol1));
starter.d_mol2.reset(new ROMol(*mol2));
} else {
starter.d_swapped = true;
starter.d_mol1.reset(new ROMol(*mol2));
starter.d_mol2.reset(new ROMol(*mol1));
}
assignEquivalentAtoms(*starter.d_mol1, opts.equivalentAtoms);
assignEquivalentAtoms(*starter.d_mol2, opts.equivalentAtoms);
std::map<int, std::vector<std::pair<int, int>>> degSeqs1, degSeqs2;
starter.d_tier1Sim =
details::tier1Sim(*starter.d_mol1, *starter.d_mol2, degSeqs1, degSeqs2);
if (starter.d_tier1Sim < opts.similarityThreshold) {
return starter;
}
std::vector<unsigned int> bondLabels1, bondLabels2;
details::getBondLabels(*starter.d_mol1, *starter.d_mol2, opts, bondLabels1,
bondLabels2);
starter.d_tier2Sim =
details::tier2Sim(*starter.d_mol1, *starter.d_mol2, degSeqs1, degSeqs2,
bondLabels1, bondLabels2);
if (starter.d_tier2Sim < opts.similarityThreshold) {
return starter;
}
// Get the line graphs for the two molecules as adjacency matrices.
makeLineGraph(*starter.d_mol1, starter.d_adjMatrix1);
makeLineGraph(*starter.d_mol2, starter.d_adjMatrix2);
std::vector<std::vector<int>> distMat1, distMat2;
if (opts.maxFragSeparation > -1 || opts.singleLargestFrag) {
calcDistMatrix(starter.d_adjMatrix1, distMat1);
calcDistMatrix(starter.d_adjMatrix2, distMat2);
}
// pairs are vertices in the 2 line graphs that are the same type.
// d_modProd is the modular product/correspondence graph of the two
// line graphs.
makeModularProduct(*starter.d_mol1, starter.d_adjMatrix1, bondLabels1,
distMat1, *starter.d_mol2, starter.d_adjMatrix2,
bondLabels2, distMat2, opts, starter.d_vtxPairs,
starter.d_modProd);
if (starter.d_modProd.empty()) {
return starter;
}
if (opts.minCliqueSize > 0) {
starter.d_lowerBound = opts.minCliqueSize;
} else {
starter.d_lowerBound = calcLowerBound(*starter.d_mol1, *starter.d_mol2,
opts.similarityThreshold);
}
starter.d_partSet.reset(new PartitionSet(starter.d_modProd,
starter.d_vtxPairs, bondLabels1,
bondLabels2, starter.d_lowerBound));
starter.d_deltaYPoss =
deltaYExchangePossible(*starter.d_mol1, *starter.d_mol2);
if (opts.doEquivBondPruning) {
// if equiv_bonds1[i] and equiv_bonds1[j] are equal, the bonds are
// equivalent.
findEquivalentBonds(*starter.d_mol1, starter.d_equivBonds1);
findEquivalentBonds(*starter.d_mol2, starter.d_equivBonds2);
} else {
starter.d_equivBonds1 = std::vector<int>(starter.d_mol1->getNumBonds(), -1);
starter.d_equivBonds2 = std::vector<int>(starter.d_mol2->getNumBonds(), -1);
}
return starter;
}
std::vector<RascalResult> findMCES(RascalStartPoint &starter,
const RascalOptions &opts) {
std::vector<unsigned int> clique;
std::vector<std::vector<unsigned int>> maxCliques;
auto startTime = std::chrono::high_resolution_clock::now();
bool timedOut = false;
RascalOptions tmpOpts{opts};
if (opts.singleLargestFrag) {
tmpOpts.allBestMCESs = true;
}
try {
explorePartitions(starter, startTime, tmpOpts, maxCliques);
} catch (TimedOutException &e) {
BOOST_LOG(rdWarningLog) << e.what() << std::endl;
maxCliques = e.d_cliques;
timedOut = true;
}
std::vector<RascalResult> results;
for (const auto &c : maxCliques) {
results.push_back(
RascalResult(*starter.d_mol1, *starter.d_mol2, starter.d_adjMatrix1,
starter.d_adjMatrix2, c, starter.d_vtxPairs, timedOut,
starter.d_swapped, starter.d_tier1Sim, starter.d_tier2Sim,
opts.ringMatchesRingOnly, opts.singleLargestFrag,
opts.maxFragSeparation, opts.exactConnectionsMatch,
opts.equivalentAtoms, opts.ignoreBondOrders));
}
if (opts.singleLargestFrag) {
std::sort(
results.begin(), results.end(),
[](const RascalResult &r1, const RascalResult &r2) -> bool {
if (r1.getAtomMatches().size() == r2.getAtomMatches().size()) {
if (r1.getBondMatches().size() == r2.getBondMatches().size()) {
if (r1.getAtomMatches() == r2.getAtomMatches()) {
return (r1.getBondMatches() < r2.getBondMatches());
}
return r1.getAtomMatches() < r2.getAtomMatches();
}
return r1.getBondMatches().size() > r2.getBondMatches().size();
}
return (r1.getAtomMatches().size() > r2.getAtomMatches().size());
});
// the singleLargestFrag method throws bits of solutions out, so there may
// now be duplicates and results that are different sizes.
results.erase(
std::unique(results.begin(), results.end(),
[](const RascalResult &r1, const RascalResult &r2) -> bool {
return (r1.getAtomMatches() == r2.getAtomMatches() &&
r1.getBondMatches() == r2.getBondMatches());
}),
results.end());
boost::dynamic_bitset<> want(results.size());
want.set();
for (size_t i = 1; i < results.size(); ++i) {
if (results[i].getAtomMatches().size() <
results[0].getAtomMatches().size() ||
results[i].getBondMatches().size() <
results[0].getBondMatches().size()) {
want[i] = false;
}
}
if (want.count() < results.size()) {
size_t j = 0;
for (size_t i = 0; i < results.size(); ++i) {
if (want[i]) {
results[j++] = results[i];
}
}
results.erase(results.begin() + j, results.end());
}
} else {
// If 2 cliques are the same size, this sort puts the one with the smaller
// number of fragments first, which may have fewer atoms.
std::sort(results.begin(), results.end(), details::resultCompare);
}
return results;
}
// calculate the RASCAL MCES between the 2 molecules, provided it is within
// the similarity threshold given.
std::vector<RascalResult> rascalMCES(const ROMol &mol1, const ROMol &mol2,
const RascalOptions &opts) {
auto starter = makeInitialPartitionSet(&mol1, &mol2, opts);
if (!starter.d_partSet) {
if (opts.returnEmptyMCES) {
return std::vector<RascalResult>(
1, RascalResult(starter.d_tier1Sim, starter.d_tier2Sim));
}
return std::vector<RascalResult>();
}
auto results = findMCES(starter, opts);
if (results.empty() && opts.returnEmptyMCES) {
return std::vector<RascalResult>(
1, RascalResult(starter.d_tier1Sim, starter.d_tier2Sim));
}
if (!opts.allBestMCESs && results.size() > 1) {
results.erase(results.begin() + 1, results.end());
}
return results;
}
} // namespace RascalMCES
} // namespace RDKit