/// <summary>
/// Simplifies an array of UnitPowerPairs so it contains only one instance of each unit
/// </summary>
/// <param name="units">The array of pairs to simplify</param>
/// <returns>A simplified array of UnitPowerPairs</returns>
public static UnitPowerPair[] SimplifyUnits(UnitPowerPair[] units)
{
List <UnitPowerPair> newUnits = new List <UnitPowerPair>();
foreach (UnitPowerPair pair in units)
{
if (newUnits.Count == 0)
{
newUnits.Add(pair);
}
else
{
bool added = false;
for (int i = 0; i < newUnits.Count; i++)
{
if (newUnits[i].Unit == pair.Unit)
{
newUnits[i] = new UnitPowerPair {
Unit = newUnits[i].Unit, Power = newUnits[i].Power + pair.Power
};
added = true;
break;
}
}
if (!added)
{
newUnits.Add(pair);
}
}
}
// Remove all units with a power of 0
bool isTarget(UnitPowerPair pair)
{
return(pair.Power == 0);
}
newUnits.RemoveAll(new Predicate <UnitPowerPair>(isTarget));
if (newUnits.Count == 0)
{
newUnits.Add(new UnitPowerPair {
Unit = Units.NoUnit, Power = 0
});
}
else if (newUnits.Count > 1)
{
bool isTarget2(UnitPowerPair pair)
{
return(pair.Unit == Units.NoUnit);
}
newUnits.RemoveAll(new Predicate <UnitPowerPair>(isTarget2));
}
return(newUnits.ToArray());
}
/// <summary>
/// Gets the conversion multiplier applied to the current value needed to associate the value with a different unit
/// </summary>
/// <param name="currentUnit">The current units</param>
/// <param name="newUnit">The units to convert to</param>
/// <returns>A multiplier as a double. current * multiplier = new</returns>
public static double GetUnitConversion(IGeneralUnit currentUnit, IGeneralUnit newUnit)
{
double conversion = 1;
CompoundUnit currentCompound = new CompoundUnit(currentUnit);
CompoundUnit newCompound = new CompoundUnit(newUnit);
List <UnitPowerPair> currentValues = currentCompound.Values.OrderBy(new Func <UnitPowerPair, Quantities>((UnitPowerPair pair) => pair.Unit.GetQuantity())).ToList();
List <UnitPowerPair> newValues = newCompound.Values.OrderBy(new Func <UnitPowerPair, Quantities>((UnitPowerPair pair) => pair.Unit.GetQuantity())).ToList();
if (currentValues.Count == newValues.Count)
{
for (int i = 0; i < currentValues.Count; i++)
{
if (currentValues[i].Power == newValues[i].Power)
{
conversion *= Math.Pow(GetUnitConversion(currentValues[i].Unit, newValues[i].Unit), currentValues[i].Power);
}
else
{
// The units have different powers and therfore aren't convertable
throw new ArgumentException("Unit conversion failed - the units provided had different powers so they don't represent the same physical quantity and therfore can't be converted.");
}
}
}
else
{
// Pre convert all units to their system's base unit
for (int i = 0; i < currentValues.Count; i++)
{
Units preConvertedUnit = currentValues[i].Unit.GetQuantity().GetSystemBaseUnit(currentValues[i].Unit.GetSystem());
conversion *= Math.Pow(GetUnitConversion(currentValues[i].Unit, preConvertedUnit), currentValues[i].Power);
currentValues[i] = new UnitPowerPair {
Unit = preConvertedUnit, Power = currentValues[i].Power
};
}
for (int i = 0; i < newValues.Count; i++)
{
Units preConvertedUnit = newValues[i].Unit.GetQuantity().GetSystemBaseUnit(newValues[i].Unit.GetSystem());
conversion *= Math.Pow(GetUnitConversion(newValues[i].Unit, preConvertedUnit), newValues[i].Power);
newValues[i] = new UnitPowerPair {
Unit = preConvertedUnit, Power = newValues[i].Power
};
}
conversion *= GetUnitConversion(new CompoundUnit(currentValues.ToArray()), new CompoundUnit(newValues.ToArray()));
}
return(conversion);
}
/// <summary>
/// Raises a unit to a power
/// </summary>
/// <param name="p">The power</param>
/// <returns>A new IGeneralUnit instance</returns>
public IGeneralUnit Pow(int p)
{
UnitPowerPair[] newValues = new UnitPowerPair[Values.Length];
for (int i = 0; i < Values.Length; i++)
{
newValues[i] = new UnitPowerPair {
Unit = Values[i].Unit, Power = Values[i].Power * p
};
}
return(new CompoundUnit(newValues));
}
/// <summary>
/// Creates a new compound unit from an array of tuples containing units and their corisponding powers
/// </summary>
/// <param name="units">Array of units and their powers as Tuples</param>
public CompoundUnit(params Tuple <Units, int>[] units)
{
Values = new UnitPowerPair[units.Length];
for (int i = 0; i < units.Length; i++)
{
Values[i] = new UnitPowerPair {
Unit = units[i].Item1, Power = units[i].Item2
};
}
Values = SimplifyUnits(Values);
}
