[GRASS5] v.in,dxf

[Radim Blazek]

David D Gray wrote:
> 
> It's only a direct import if the original format supports component
> arcs. Many formats record the data as whole polygons, so must be 'split'
> to arcs before writing to dig files, so some kind of intermediate is
> necessary.
> 
> The first stage is substantially diffferent for different formats. Also
> there is often pre-processing or different fields to be read. A Mapinfo
> import has to record the Pen and Brush attributes (or will if we are
> going down the road of incorporating these). More significantly, you
> have to `deconstruct' the topology of a set of components in a shapefile
> as a shape can be compound. So stage 1 reads the original format,
> pre-processes the data and deals with spatial and data attributes. Stage
> two imports the linework as arcs regardless of the original format, from
> a common intermediate.
> 
> Of course this isn't necessarily a time separation. It's just a logical
> or programmatic separation. Some stages may be carried out in parallel
> as lines are imported or they may be sequential.
> 
> David

Is it second stage more than v.spag + v.rmdup (if working correctly)?

I would prefer two import stages separated into modules because second
stage proces may be used for other (non import) tasks also
(clening patched maps for example).

Cleaning proces will be always problem for dirty maps and so may be
useful to have possibility to compare map before and after cleaning proces
to find problems and occasionally edit by hand.


Radim