I must admit that I don't think this problem is really new. However, I haven't found a post dealing exactly with this aspect of the issue.
I am doing calculation using Quantities, but I have problems dealing with dimensionless quantities. Suppose you define:
h = Quantity[b, "m"]
Now I would like to multiply
h by a dimensionless parameter
a, so to obtain the equivalent of the expression:
Quantity[a b, "m"]
Simply multiplying by
a doesn't work (as you can check by trying to evaluate
QuantitymMagnitude[a h]); this is understandable, since
a is just an undefined symbol and as such has "unknown" units. I though, however, that multiplying by
Quantity[a,"DimensionlessUnit"] would do the trick. Nope (same check).
The only solution I have found is to use
Quantity[a QuantityMagnitude[h], QuantityUnit[h]]
Rather involved... any idea or consideration in regard to this? Is there a profound reason I am not seeing for not supporting dimensionless symbols?