// /////////////////////////////////////////////////////////////////
// // private methods ////
private void _flatten() {
if (_isFlat) {
return;
}
Vector newUTerms = new Vector();
for (int i = 0; i < _uTerms.size(); i++) {
UnitTerm unitTerm = (UnitTerm) (_uTerms.elementAt(i));
if (unitTerm.isUnitExpr()) {
UnitExpr uExpr = unitTerm.getUnitExpr();
if (uExpr != null) {
uExpr._flatten();
newUTerms.addAll(uExpr.getUTerms());
}
} else {
newUTerms.add(unitTerm);
}
}
_isFlat = true;
_setUTerms(newUTerms);
}
/**
* Create a new UnitExpr that is the inverse of this UnitExpr.
*
* @return The inverse of this UnitExpr.
*/
public UnitExpr invert() {
UnitExpr retv = new UnitExpr();
Vector myUTerms = new Vector();
for (int i = 0; i < _uTerms.size(); i++) {
myUTerms.add(((UnitTerm) (_uTerms.elementAt(i))).invert());
}
retv._setUTerms(myUTerms);
return retv;
}
/**
* Create a copy of this UnitExpr.
*
* @return The new UnitExpr.
*/
public UnitExpr copy() {
UnitExpr retv = new UnitExpr();
Vector newUTerms = new Vector();
for (int i = 0; i < _uTerms.size(); i++) {
UnitTerm term = (UnitTerm) (_uTerms.elementAt(i));
newUTerms.add(term.copy());
}
retv._setUTerms(newUTerms);
return retv;
}
/**
* Reduce a UnitExpr to produce a UnitExpr that has at most one Unit. Any embedded UnitExpr is
* first transformed so that all embedded UnitExprs are replaced with Units. This intermediate
* result is a mixture of Units and variables. The Units are then replaced with their product. The
* result is a single Unit and all of the original variables.
*
* @return The reduced UnitExpr.
*/
public UnitExpr reduce() {
_flatten();
Unit reductionUnit = UnitLibrary.Identity.copy();
Vector newUTerms = new Vector();
for (int i = 0; i < _uTerms.size(); i++) {
UnitTerm unitTerm = (UnitTerm) (_uTerms.elementAt(i));
if (unitTerm.isUnit()) {
reductionUnit = reductionUnit.multiplyBy(unitTerm.getUnit().pow(unitTerm.getExponent()));
} else {
newUTerms.add(unitTerm);
}
}
newUTerms.add(new UnitTerm(reductionUnit));
UnitExpr retv = new UnitExpr();
retv._setUTerms(newUTerms);
return retv;
}