[QUANTITY] The quandary

[Ivo Busko]

David Berry wrote:
<snip>
> the operation. This potentially has many aspects. The simplest aspect is
> the issue of Units: obviously if you are comparing a frequency in Hz with
> another frequency in GHz, the Quantity class needs to transform them into
> the same units before comparing them - simple enough. But as I mentioned last
> week, there are many Quantities which are not completely defined simply
> by a Units string. Continuing with the above example, a frequency is not
<snip>

Another example where this happens is with flux units. To convert a measurement
expressed in, say, Flambda units, to Fnu units, one needs to know the
wavelength or frequency at which the measurement took place. 

-Ivo