Signed Distance -- What?

[Halsafar]

I know this is silly...but I can compute and use the signed distance.

But is it exactly what it sounds like...I can't find any nice definitions of the term.

Distance is always in the form of positive...you can't travel a negetive distance. But I assume this rule in broken with the signed distance function which obviously finds the sign of a distance (+ or -)

right?

em I way off?

[kebo]

Hi,
It depends on whether you are dealing with scalers or vectors. When you drive your car, the speed given on your speedometer is a scaler: it is always positive and gives no indication of direction, futhermore, it is never negative. On the other hand if you are standing, then take 2 steps forward, then 3 steps backward, you have travelled a net distance of -1 steps. The "-" indicates the direction you have travelled.
HTH
kevin

[twanvl]

Distance is always positive, to quote mathworld:

A nonnegative function g(x,y) describing the "distance" between neighboring points for a given set.
http://mathworld.wolfram.com/Distance.html and
http://mathworld.wolfram.com/Metric.html

While officially there is no such thing as a negative distance you can of course use something like distance that also stores a component of the direction, givining you a 'signed distance'.