/**
* Choose any possible quadruple of the set of atoms in ac and establish all of the possible
* bonding schemes according to Faulon's equations.
*/
public static List sample(IMolecule ac) {
logger.debug("RandomGenerator->mutate() Start");
List structures = new ArrayList();
int nrOfAtoms = ac.getAtomCount();
double a11 = 0, a12 = 0, a22 = 0, a21 = 0;
double b11 = 0, lowerborder = 0, upperborder = 0;
double b12 = 0;
double b21 = 0;
double b22 = 0;
double[] cmax = new double[4];
double[] cmin = new double[4];
IAtomContainer newAc = null;
IAtom ax1 = null, ax2 = null, ay1 = null, ay2 = null;
IBond b1 = null, b2 = null, b3 = null, b4 = null;
// int[] choices = new int[3];
/* We need at least two non-zero bonds in order to be successful */
int nonZeroBondsCounter = 0;
for (int x1 = 0; x1 < nrOfAtoms; x1++) {
for (int x2 = x1 + 1; x2 < nrOfAtoms; x2++) {
for (int y1 = x2 + 1; y1 < nrOfAtoms; y1++) {
for (int y2 = y1 + 1; y2 < nrOfAtoms; y2++) {
nonZeroBondsCounter = 0;
ax1 = ac.getAtom(x1);
ay1 = ac.getAtom(y1);
ax2 = ac.getAtom(x2);
ay2 = ac.getAtom(y2);
/* Get four bonds for these four atoms */
b1 = ac.getBond(ax1, ay1);
if (b1 != null) {
a11 = BondManipulator.destroyBondOrder(b1.getOrder());
nonZeroBondsCounter++;
} else {
a11 = 0;
}
b2 = ac.getBond(ax1, ay2);
if (b2 != null) {
a12 = BondManipulator.destroyBondOrder(b2.getOrder());
nonZeroBondsCounter++;
} else {
a12 = 0;
}
b3 = ac.getBond(ax2, ay1);
if (b3 != null) {
a21 = BondManipulator.destroyBondOrder(b3.getOrder());
nonZeroBondsCounter++;
} else {
a21 = 0;
}
b4 = ac.getBond(ax2, ay2);
if (b4 != null) {
a22 = BondManipulator.destroyBondOrder(b4.getOrder());
nonZeroBondsCounter++;
} else {
a22 = 0;
}
if (nonZeroBondsCounter > 1) {
/* Compute the range for b11 (see Faulons formulae for details) */
cmax[0] = 0;
cmax[1] = a11 - a22;
cmax[2] = a11 + a12 - 3;
cmax[3] = a11 + a21 - 3;
cmin[0] = 3;
cmin[1] = a11 + a12;
cmin[2] = a11 + a21;
cmin[3] = a11 - a22 + 3;
lowerborder = MathTools.max(cmax);
upperborder = MathTools.min(cmin);
for (b11 = lowerborder; b11 <= upperborder; b11++) {
if (b11 != a11) {
b12 = a11 + a12 - b11;
b21 = a11 + a21 - b11;
b22 = a22 - a11 + b11;
logger.debug("Trying atom combination : " + x1 + ":" + x2 + ":" + y1 + ":" + y2);
try {
newAc = (IAtomContainer) ac.clone();
change(newAc, x1, y1, x2, y2, b11, b12, b21, b22);
if (ConnectivityChecker.isConnected(newAc)) {
structures.add(newAc);
} else {
logger.debug("not connected");
}
} catch (CloneNotSupportedException e) {
logger.error("Cloning exception: " + e.getMessage());
logger.debug(e);
}
}
}
}
}
}
}
}
return structures;
}
