Question

MITAB and MFAL Writer outputs are offset from source Oracle Spatial data?

  • 12 December 2014
  • 2 replies
  • 2 views

I am running FME 2014 SP4 and am having trouble when transforming data between Oracle Spatial Object to MapInfo TAB file. The transformation is very easy: I am simply stripping out a few attributes from a parcel dataset and then writing to TAB file. When I compare the output TAB file to the original data there is quite a bit of offset. It seems that almost every parcel has at least one vertex added or removed that changes the shape. It seems that coincident boundaries are preserved.

 

 

My original thought was that there was a problem with the Arcs in the data so I introduced the "ArcStroker" transformer and no matter what the settings, the data comes out looking similar. There are large gaps and slivers(>4 feet(1+ meter)) being taken away or added to many parcels.

 

 

I need the data to be accurate as it will be used to digitize other features based on property lines. I work for a large metropolitan city of more than a million people so if the data is not accurate then this could cause big issues. Anyone have an idea of what could be going on?

2 replies

Userlevel 2
Badge +17
Hi,

 

 

I cannot find any issue that caused the geometry change, as long as seeing the screenshot.

 

A possible reason I can imagine is that the geometries have been reprojected unexpectedly. If you've set the Coordinate System parameter of the writer to a different one from the input features' (CA83IIIF?), the writer will reproject geometries automatically when writing.

 

Check if there is such a situation.

 

 

Takashi
Hi Takashi,

 

The coordinate system is being set correctly and the tranformation is very simple. That is why I am baffled with this one. Entire features are not offset as with a CS change, it is individual vertexes, but on a large scale. Thanks for the thought.

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