[Qgis-user] network building tool

[Brent Fraser]

Tim,

   I've used a relational database with a table of nodes (with lat, lon) 
and a table of connections (from_node, to_node), then created a view to 
represent lines in well-known-text.  Move a node and all the lines would 
move along with it since they're defined as a view.   The line movement 
was not dynamic; it would require a pan/zoom/refresh in the web app as 
the graphics were rendered on the server (via Mapserver).

Best Regards,
Brent Fraser

On 11/20/2013 2:38 PM, Tim Michelsen wrote:
>>    Graphviz (http://www.graphviz.org/) will do most of what you
>> described, but I don't think you can specify the coordinates of the
>> nodes (that would be nice) so the result is just a diagram, not a map .
> Not exactly.
>
> Via
> Representation of network flows /
> http://gis.stackexchange.com/questions/778/representation-of-network-flows
>
> I found JFlowMap.
>
> It uses the approach I described:
> https://code.google.com/p/jflowmap/wiki/HowToPrepareData
>
> I just don't know if it can also export to shape...
>
>
> [question off-list:]
>> do you mean something that just draw the lines or that will
> create/manage actual line features?
> A line drawing tool which would allow to maintain connections of lines
> if nodes are shifted.
>
> The background for all is that the simlation and design tools for
> networks can export lines (e.g. power lines, telecom lines) or nodes as
> lists but no logical structure.
> A typical schema:
> http://en.wikipedia.org/wiki/File:Electricity_Grid_Schematic_English.svg
> http://en.wikipedia.org/wiki/File:One-line_diagram.svg
>
> So I wonder how others are transferring such information into the
> GIS/geo domain.
>
> Regards,
> Timmie
>
>
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