/// <summary>
/// Converts this quantity from this <see cref="Unit"/> to another <see cref="MeasureUnit"/>.
/// Must be called only if <see cref="CanConvertTo(MeasureUnit)"/> returned true otherwise an <see cref="ArgumentException"/>
/// is thrown.
/// </summary>
/// <param name="u">The target unit of measure.</param>
/// <returns>The quantity exporessed with the target unit.</returns>
public Quantity ConvertTo(MeasureUnit u)
{
if (Unit == u)
{
return(this);
}
if (!CanConvertTo(u))
{
if (u.Context != Unit.Context)
{
throw new ArgumentException($"Can not convert between units in different contexts ('{Unit}' to '{u}').");
}
throw new ArgumentException($"Can not convert from '{Unit}' to '{u}'.");
}
if (Unit.Normalization == u.Normalization)
{
FullFactor ratio = Unit.NormalizationFactor.DivideBy(u.NormalizationFactor);
return(new Quantity(Value * ratio.ToDouble(), u));
}
else
{
FullFactor ratio = Unit.NormalizationFactor.Multiply(u.NormalizationFactor);
return(new Quantity(1 / (Value * ratio.ToDouble()), u));
}
}
/// <summary>
/// Compares this quantity to another one.
/// </summary>
/// <param name="other">The other quantity to compare.</param>
/// <returns></returns>
public int CompareTo(Quantity other)
{
var tU = Unit;
var oU = other.Unit;
// Do the 2 units belong to the same (possibly null) context?
if (tU.Context == oU.Context)
{
// First chexk our equality: we must do this first to ensure coherency.
if (ToNormalizedString() == other.ToNormalizedString())
{
return(0);
}
// Same unit, we compare the Values.
if (tU == oU)
{
return(Value.CompareTo(other.Value));
}
// Same normalized units, we convert this Value to the other unit before comparison.
if (tU.Normalization == oU.Normalization)
{
FullFactor ratio = tU.NormalizationFactor.DivideBy(oU.NormalizationFactor);
return((Value * ratio.ToDouble()).CompareTo(other.Value));
}
// Inverted normalized units, we convert this Value to the other unit before comparison.
if (tU.Normalization == oU.Normalization.Invert())
{
FullFactor ratio = tU.NormalizationFactor.Multiply(oU.NormalizationFactor);
return((1 / (Value * ratio.ToDouble())).CompareTo(other.Value));
}
// No possible conversion. How to compare kilograms and milliSievert?
// Using their abbreviation (here kilogram will be "smaller" than milliSievert)
return(tU.Abbreviation.CompareTo(oU.Abbreviation));
}
// Not in the same context.
if (tU == MeasureUnit.None)
{
return(-1);
}
if (oU == MeasureUnit.None)
{
return(1);
}
return(tU.Context.Name.CompareTo(oU.Context.Name));
}