// add a UOM and exponent pair to the map of reduced Terms
private void AddTerm(UnitOfMeasure uom, bool invert)
{
int unitPower = 1;
int power = 0;
if (!invert)
{
// get existing power
if (!Terms.ContainsKey(uom))
{
// add first time
power = unitPower;
}
else
{
// increment existing power
if (!uom.Equals(MeasurementSystem.GetSystem().GetOne()))
{
power = Terms[uom] + unitPower;
}
}
}
else
{
// denominator with negative powers
if (!Terms.ContainsKey(uom))
{
// add first time
power = -unitPower;
}
else
{
// decrement existing power
if (!uom.Equals(MeasurementSystem.GetSystem().GetOne()))
{
power = Terms[uom] - unitPower;
}
}
}
if (power == 0)
{
Terms.Remove(uom);
}
else
{
if (!uom.Equals(MeasurementSystem.GetSystem().GetOne()))
{
Terms[uom] = power;
}
}
}
// compose the base symbol
internal String BuildBaseString()
{
StringBuilder numerator = new StringBuilder();
StringBuilder denominator = new StringBuilder();
int numeratorCount = 0;
int denominatorCount = 0;
// sort units by symbol (ascending)
SortedDictionary <UnitOfMeasure, int> keys = new SortedDictionary <UnitOfMeasure, int>(Terms);
foreach (KeyValuePair <UnitOfMeasure, int> pair in keys)
{
UnitOfMeasure unit = pair.Key;
int power = pair.Value;
if (power < 0)
{
// negative, put in denominator
if (denominator.Length > 0)
{
denominator.Append(MULT);
}
if (!unit.Equals(MeasurementSystem.GetSystem().GetOne()))
{
denominator.Append(unit.Symbol);
denominatorCount++;
}
if (power < -1)
{
if (power == -2)
{
denominator.Append(SQ);
}
else if (power == -3)
{
denominator.Append(CUBED);
}
else
{
denominator.Append(POW).Append(Math.Abs(power));
}
}
}
else if (power >= 1 && !unit.Equals(MeasurementSystem.GetSystem().GetOne()))
{
// positive, put in numerator
if (numerator.Length > 0)
{
numerator.Append(MULT);
}
numerator.Append(unit.Symbol);
numeratorCount++;
if (power > 1)
{
if (power == 2)
{
numerator.Append(SQ);
}
else if (power == 3)
{
numerator.Append(CUBED);
}
else
{
numerator.Append(POW).Append(power);
}
}
}
else
{
// unary, don't add a '1'
}
}
if (numeratorCount == 0)
{
numerator.Append(ONE_CHAR);
}
String result = null;
if (denominatorCount == 0)
{
result = numerator.ToString();
}
else
{
if (denominatorCount == 1)
{
result = numerator.Append(DIV).Append(denominator).ToString();
}
else
{
result = numerator.Append(DIV).Append(LP).Append(denominator).Append(RP).ToString();
}
}
return(result);
} // end unit of measure iteration