SPIRAL TERMS IN LDD

[JWS6776]

i am trying to define a spiral-curve-spiral and i can get it to work with length in - length out and a degree of curve definition on the circular segment, but during definition it asked if i want to use spiral length in (or A) .....
does anyone know what they are referring to as "A" in old school math terms,
i got some graybeard surveyors here and we cant find this terminology in any of the highway curve manuals anywhere
someone must know..please help

and does anyone know if you can change the increment for the spiral p-line, i can get it to divide the spiral length in-out by ten but i want them closer together so i can intersect section lines with a centerline offset and not wonder if it is interpolating to much

[Anonymous]

Hit F1 and ye shall know all!

The spiral commands prompt for either a length or spiral A parameter. The A
parameter describes the flatness of the spiral, and is a commonly used
metric parameter that equals the square root of the product of the length
and the radius. To use the A value, type A at the First spiral length (or A)
and/or Second length (or A) prompt, and then enter the "A" value.

Allen

wrote in message news:5156537@discussion.autodesk.com...
i am trying to define a spiral-curve-spiral and i can get it to work with
length in - length out and a degree of curve definition on the circular
segment, but during definition it asked if i want to use spiral length in
(or A) .....
does anyone know what they are referring to as "A" in old school math terms,
i got some graybeard surveyors here and we cant find this terminology in any
of the highway curve manuals anywhere
someone must know..please help

and does anyone know if you can change the increment for the spiral p-line,
i can get it to divide the spiral length in-out by ten but i want them
closer together so i can intersect section lines with a centerline offset
and not wonder if it is interpolating to much