/**
* Invert this UnitTerm.
*
* @return The inverse of this UnitTerm.
*/
public UnitTerm invert() {
UnitTerm retv = copy();
switch (_type) {
case _VARIABLE:
case _UNIT:
{
retv.setExponent(-getExponent());
break;
}
case _UNITEXPR:
{
retv.setUnitExpr(_unitExpr.invert());
break;
}
}
return retv;
}
/**
* Transform to the canonical form of the equation. The canonical form of an equation is <b> Ex1,
* Ex2, ..., Exn = A <b> where each Exi is a Unit term containing only one variable, and A is a
* Unit term containing one Unit and no variables.
*
* @return unitEquation The UnitEquation in canonical form.
*/
public UnitEquation canonicalize() {
UnitExpr lhsUExpr = getLhs();
UnitExpr rhsUExpr = getRhs();
UnitExpr newLeftUExpr = new UnitExpr();
UnitExpr newRightUExpr = new UnitExpr();
Vector leftUTerms = lhsUExpr.getUTerms();
for (int i = 0; i < leftUTerms.size(); i++) {
UnitTerm uTerm = ((UnitTerm) (leftUTerms.elementAt(i)));
if (uTerm.isUnit()) {
newRightUExpr.addUnitTerm(uTerm.invert());
} else if (uTerm.isVariable()) {
newLeftUExpr.addUnitTerm(uTerm);
}
}
Vector rightUTerms = rhsUExpr.getUTerms();
for (int i = 0; i < rightUTerms.size(); i++) {
UnitTerm uTerm = ((UnitTerm) (rightUTerms.elementAt(i)));
if (uTerm.isUnit()) {
newRightUExpr.addUnitTerm(uTerm);
} else if (uTerm.isVariable()) {
newLeftUExpr.addUnitTerm(uTerm.invert());
}
}
if (newRightUExpr.getUTerms().isEmpty()) {
UnitTerm x = new UnitTerm();
x.setUnit(UnitLibrary.Identity);
newRightUExpr.addUnitTerm(x);
}
newRightUExpr = newRightUExpr.reduce();
return new UnitEquation(newLeftUExpr, newRightUExpr);
}
/**
* Make a shallow copy of this UnitTerm. That is, the underlying Unit or UnitExpr is not copied.
*
* @return The copy of this UnitTerm
*/
public UnitTerm copy() {
UnitTerm retv = new UnitTerm();
retv.setVariable(_variable);
retv.setExponent(getExponent());
retv.setUnit(_unit);
retv.setUnitExpr(_unitExpr);
retv._setType(_type);
return retv;
}