"Strong typing vs. strong testing"

[Thomas A. Russ]

torbenm at diku.dk (Torben ŽÆgidius Mogensen) writes:

> Trigonometric functions do take arguments of particular units: radians
> or (less often) degrees, with conversion needed if you use the "wrong"
> unit.

But radians are dimensionless.

The definition of a radian is length/length (or m/m) which simplifies to
dimensionless.

In fact, the units package in Lisp that I worked on actually handles
this by making "radian" one of the dimensionless "units" precisely so
that one can use degrees and radians with appropriate conversion.  But
they remain dimensionless.  Interestingly, that also allows one to treat
percent (%) as a dimensionless unit with a conversion factor of 1/100.



-- 
Thomas A. Russ,  USC/Information Sciences Institute