[GRASS-dev] v.distance to_along,
to angle [was: commercial use of GRASS in Australia]
landa.martin at gmail.com
Fri Oct 26 04:39:00 EDT 2007
'to_along' gives distance measured along linear feature (from it's
begining) to the point on that feature (blue point) given by
point/centroid from 'to' map (highlighted part of line in the attached
picture). 'to_angle' is angle of line in that point (blue point on
line) (radians, counter clockwise from x axis)
2007/10/26, Maciej Sieczka <tutey at o2.pl>:
> > Regardless, it would be nice to fix 'v.distance upload=dist,to_along'
> Some time ago I asked on GRASS user ml about to_along and
> to_angle in v.distance (see below), because I don't
> understand how they work, and documenation is lacking here.
> You seem to know more. If you can shed some light on this
> please do, and I'll update docs.
> Maciek wrote:
> >> "to_angle: angle of linear feature in nearest point,
> >> counterclockwise from positive x axis, in radians, which is
> >> between -PI and PI inclusive"
> >> Anybody knows what is "angle of linear feature in nearest
> >> point" supposed to mean?
> >> BTW - another thing I don't understand in v.distance is the
> >> to_along option: "to_along: distance to the nearest point on
> >> 'from' feature along linear feature". Anybody knows if the
> >> "linear feature" is supposed to be present in vector "from"
> >> or vector "to"?
> grass-dev mailing list
> grass-dev at grass.itc.it
Martin Landa <landa.martin at gmail.com> * http://gama.fsv.cvut.cz/~landa *
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