[GRASS5] v.to.db 2 new features compactness and perimeter

[Wolf Bergenheim]

Wolf Bergenheim wrote:
> Radim Blazek wrote:
> 
>> On 11/10/05, Wolf Bergenheim <wolf at bergenheim.net> wrote:
>>
>>> Heh. defenately not... I use Vect_line_length() to calculate the length.
>>> perhaps the the fix should go in here? perhaps an additional parameter
>>> or a new fun Vect_line_length_meters(). I guess that the area is ok? or
>>> does it have a unit of square degrees? (;
>>
>>
>>
>> There is Vect_line_geodesic_length but it should only be used with -g 
>> flag.
>>
> 
> How about calculating the distance normally (the circumference, and then 
> converting the angular distance to metric, by using:
> distance in meters = angle * pi * radius (which is what? 6365 km? Is 
> there any way of getting the radius of the projection?)

Umm I meant to write:
length = (angle_length/360)*2*M_PI*radius;

> 
> How can I deterimin if the projection is LL?
> 
> --W
> 

-- 

<:3 )---- Wolf Bergenheim ----( 8:>