[postgis-users] Rhumb lines

[David Bitner]

Just looked a little more and I think I was actually correct as such,
assuming segmentize will work on lines (if not, anyone know how to
accomplish similar?) the following should work where a and b are the
two points in your original projection (substitute your epsg for 4326)
to make a rhumb between:

select transform(segmentize(transform(makeline(a,b),9804)),4326)



On 5/5/06, David Bitner <osgis.lists at gmail.com> wrote:
> Am I completely off base, or would reprojecting the start and end
> point to a mercator (not a transverse mercator) projection, connect
> the points, fill in the gap with additional points (would the
> segmentize() function do this?  it seems to be just for polygons) and
> reproject back to original projection.
>
> On 5/5/06, Stephen Woodbridge <woodbri at swoodbridge.com> wrote:
> > Paul Scott wrote:
> > > Is there a quick and easy way that anyone has implemented calculating
> > > Rhumb lines from geometries in PostGIS? If not, I would like to try and
> > > get something working in PHP and then as a PostGIS function.
> > >
> > > Any hints/clues?
> >
> > http://en.wikipedia.org/wiki/Rhumb_lines
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