Importing point toplogy from Shape files

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Importing point toplogy from Shape files

Postby Evan Williams » Wed Feb 04, 2009 4:19 am

Hi everyone,

I have a question about the way that Carlson GIS creates point topology using the Shape file import routine. It seems to treat point data differently from line and polygon topology.

As I understand it, if the Carlson routine detects point data in the Shape file, it stuffs that point data into a *.CRD file and imports that point data into the drawing as Carlson point blocks. Does this mean that the attributes associated with the points are subject to the limitations of the point blocks (defined by the small number of "SRVPNO#.DWG" drawings)? Is there a way to have Carlson GIS treat points the same way that it treats polygons: i.e., have AutoCAD entities — in this case, points or point symbols — with links to associated database records? What if each point is associated with 25 distinct attributes; how can Carlson point blocks work with this?

It appears to turn quite richly endowed point infomation into survey points, limited to something like a common PNEZD format. In many cases, elevation is totally irrelevant to the data the points carry.

I am probably missing something fundamental in the settings that control this import process, but I have not found any detailed documentation on this. Could someone fill me in on the details of importing point topology by the Shape file import routine in a way that retains the full attribute data, and makes it available for querying and thematic mapping?

Thanks very much, in advance.

--- Evan
Evan Williams
 
Posts: 5
Joined: Sat Sep 27, 2008 11:51 pm
Location: B.C., Canada

Postby Evan Williams » Wed Feb 11, 2009 7:25 pm

For anyone who's interested in my original question, I put the same question to Carlson tech support and got the following prompt reply:

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Import SHP files works in this manner:

The Geometry from the SHP file is saved in the current DWG in the form of polylines, which could be: closed (SHP polygon type) or open (SHP arc type). If the SHP file is of the point type, than Carlson products also put the point geometry and minimal required data (PT ID, etc) into a CRD file. At the moment when the points from the CRD files are plotted in the current DWG, it could be at the end of the Import SHP routine, or as an after the fact process (using Create Links routine), the GIS specific data could be linked to the actual blocks (points) from the current Drawing. This allows the actual data (25 or more attributes values to be associated with the actual point (block) from the DWG.

Plotted points having GIS links can be queried using "Query Report".

Remarks:
- Carlson GIS products, do not maintain/create/process topologies, as per the definition of "topology" object.
- Carlson GIS products at this time, do not create thematic maps. We currently are in the process of adding more routines in this direction for the newer version of Carlson Desktop products.

The GIS module in Carlson Desktop product contains tools to prepare and do minimal manipulation of GIS sets with the intention of being later delivered to adequate GIS processing software. Our GIS routine cannot work with large GIS data sets, cannot do GIS network or statistical analysis, cannot work with topologies.
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Thanks go to Derek of Carlson tech support for clearing up my confusion on this aspect of SHP import.

--- Evan
Evan Williams
 
Posts: 5
Joined: Sat Sep 27, 2008 11:51 pm
Location: B.C., Canada


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