SplitGrid water polygon

Hmm, I am running the following script:

ImportOGR|E:\Scenery Design Workshop\UK_coast_hydro_polygon 2.shp|*|*|NOREPROJ
SplitGrid|LOD09|*
MergeGrid
ExportOGR|FTYPE="POLYGON"|ESRI Shapefile|LOD9hydropoly_grid.shp|LOD9hydropoly_grid
ExportOGR|FTYPE="POLYGON"|KML|LOD9hydropoly_grid.kml|LOD9hydropoly_grid

I've been running it for an hour and not noticed any progress in a bar at all!? Th:)
 
I did notice that for big areas the SplitGrid is sometimes slow and seems to stall. That's something I need to check, might be a bug.

Yes, you can tell SplitGrid to use other sizes than the AGN grid as well.
Am trying this...
ImportOGR|E:\Scenery Design Workshop\UK_coast_hydro_polygon 2.shp|*|*|NOREPROJ
SplitGrid|LOD09|*
MergeGrid
ExportOGR|FTYPE="POLYGON"|ESRI Shapefile|LOD9hydropoly_grid.shp|LOD9hydropoly_grid
ExportOGR|FTYPE="POLYGON"|KML|LOD9hydropoly_grid.kml|LOD9hydropoly_grid

It thinks it's running consuming 25% approx. CPU cycles, but no progress has been indicated and it's been 'running' for over an hour and 45mins now :s

Will attach source file in case you want to review.. (its 10Mb, so too large to upload here sorry)

EDIT: Must be something strange with the UK_coast_hydro_polygon 2.shp file, as the same workflow but with a much simpler test polygon works just fine (as can be seen by the kml output image), and very quickly? :s

EDIT2: Link (https://www.dropbox.com/s/d5ry6trfkndub9w/UK_coast.rar?dl=0) to UK_coast_hydro_polygon 2.shp
 

Attachments

Last edited:
Hi Kevin
What step are you at? Did you at least get to load the file? I'm looking specifically at the SplitGrid progress bar but I think the file loading progress is probably a function of filesize in some way. Better wait for Arno's input on that, I guess.
 
How big is your file? You should be getting something on the progress bar by now I would think unless it's massive. I have seen instances when that's happened to me.
 
Something else wrong then - I think normally that should load easily and start the progress bar quickly. Anything odd about specific records in the file? Might be worth validating again in QGis - perhaps even writing out again as a new copy to make sure it's not corrupt.
 
Nothing odd that I know of, the file opens and is viewable in QGIS as expected. I'll try writing it out again and see...
 
Probably worth letting Arno have a look then. I'm not much help. Sorry!
Still interested in finding out about my SplitGrid question though!
ian
 
Probably worth letting Arno have a look then. I'm not much help. Sorry!
Still interested in finding out about my SplitGrid question though!
ian
Me too Ian, there's always lots to learn :) Thanks for your help anyway and sorry to kind of half hijack your thread :p
 

arno

Administrator
Staff member
FSDevConf team
Resource contributor
Hi Kevin,

If it's stuck on the ImportOGR step that's probably because you have complex polygons with many holes. These take very long to process sometimes. I guess I should have a look at optimizing the code more.

Are there many complex polygons in your data?
 

arno

Administrator
Staff member
FSDevConf team
Resource contributor
Hi,

That is one very complex polygon to take as input. I think you can best try to use QGIS or so to slide it into some smaller parts to start with. I recently did that for another project and QGIS can do it very fast. I should probably check if I can use the internal OGR logic in scenProc as well, since it seems faster.
 

arno

Administrator
Staff member
FSDevConf team
Resource contributor
Hi Kevin,

I have combined all posts about this issue from the two threads (where they were a bit off topic), into this new thread. Let's try to work out the issue here.
 
Sorted, I should have tried to do this in GQIS to start with I think :p
I created a LOD7 grid then clipped the landmass shp file to fit, then used that clipped area with the difference tool on the LOD9 hydropoly grid :)
Thanks for the prompts for some wider thought, and for the scenproc tool which is SOOOO useful!
Cheers K
 

Attachments

Top