[mapguide-users] vector editing

[Paul Spencer]

Thanks Jason :)  I've never heard that term before!

I'm 100% certain that our digitizing tools will not include this  
capability (at least not the first version).   Sounds like more than  
a light-weight editing capability and we are trying to stay focussed.

Cheers

Paul

On 28-Oct-06, at 6:35 PM, Jason Birch wrote:

> Heh.  I wasn't entirely serious; COGO is extremely tricky to do right.
>
> Apart from being a field of mathematics, COordinate GeOmetry is  
> also jargon for a way of creating features by entering their  
> surveyed geometry on a command line.  It has traditionally been the  
> realm of CAD tools, though ArcInfo Workstation had a COGO module,  
> and I believe that the latest ArcGIS versions have had some COGO  
> support.  With AJAX, this is something that could actually be  
> considered for web-based feature creation.
>
> It isn't as simple as X/Y entry.  This isn't my area of expertise,  
> but I think that typically you start out with a well known point  
> (GCP, monument, etc) and start from there.  Sometimes the first  
> point in the feature is the well known point, but more frequently  
> your feature's first point an offset from this reference.  From  
> there, each additional coordinate in the feature is typically  
> entered by azimuth and distance (curves are more complicated) until  
> you get to the final point.  At the final point, closure error is  
> determined.  You need to be able to adjust for different azimuth  
> entry systems and units, and probably also deal with the local  
> datum's scale factor.  We'd need survey and math expertise to help  
> out.
>
> Sound like fun?  Maybe in a year or so once we get a bit more  
> feature-complete...  definitely not our first RFC ;)
>
> Jason
>
> ________________________________
>
> From: Paul Spencer [mailto:pspencer at dmsolutions.ca]
> Sent: Sat 2006-10-28 11:10 AM
> To: users at mapguide.osgeo.org
> Subject: Re: [mapguide-users] vector editing
>
>
>
> you lost me ... what is "command-line" COGO?
>
> Cheers
>
> Paul
>
>
> <winmail.dat>
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|Paul Spencer                          pspencer at dmsolutions.ca    |
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|Chief Technology Officer                                         |
|DM Solutions Group Inc                http://www.dmsolutions.ca/ |
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