4,157 reputation
11227
bio website whatutmzoneamiin.blogspot.com
location Ontario, Canada
age 34
visits member for 4 years, 7 months
seen May 20 at 19:52

Open source GIS user & advocate.


Mar
17
comment PostGIS ST_Union Performance
@zimmi; unfortunately not :( I'm still where I was before! Are you doing the exact same thing? Perhaps share an example and see if there are any similarities
Mar
5
comment Opening MPK file with other than ArcGIS?
...and QGIS will read the fGDB you find inside--no need to purchase any other software.
Mar
2
comment Split Lines at Intersection of Other Lines
Thank you! This is the only solution that actually works so far! I would still love feedback on how to get it working in PostGIS, but this does the trick for now!
Feb
13
comment Is it possible to generate a boustrophedon pattern which fill a vector Region with GRASS?
Interesting question. How would you determine the starting point? "Top Left" may not always relate to a nice corner point as in your example.
Feb
5
comment PostGIS ST_Union Performance
Thanks. Due to a prior processing step, most of the smaller polygons are in fact already unioned!
Feb
3
comment PostGIS ST_Union Performance
Thanks. I just tried ANALYZE, VACUUM and increasing shared_buffers and effective_cache_size, and had the same issue. I'll keep tweaking as time allows.
Feb
3
comment PostGIS ST_Union Performance
I'm now having an issue similar to this: stackoverflow.com/questions/17439703/… where the query will start, but after some time will lose the connection. The comment there suggests it's also a memory issue. I'm stuck!
Feb
3
comment Split Lines at Intersection of Other Lines
No: I'm trying to do this using open source software.
Feb
2
comment Split Lines at Intersection of Other Lines
@simplexio as mentioned above, there are no multilines. All features in both tables are simple LINESTRINGS.
Jan
26
comment PostGIS ST_Union Performance
Updated version info above.
Jan
24
comment PostGIS ST_Union Performance
I believe I'm on GEOS 3.3.3. but will have to confirm on Monday.
Jan
23
comment PostGIS ST_Union Performance
John; yes, I want the union for every combination of column1,2 and 3. I'm not sure how to quantify 'large' - but it is a number of very complex (many vertices) polygons with messy overlaps and islands, etc. I'll have to do some research into 'explain' before I can answer your last question!
Sep
25
comment QGIS, drawing entity with a magnetized knot
I'm guessing you may mean 'snapping'? If so, check the Snapping Options in QGIS, or do a search using that as a keyword.
Sep
18
comment Unknown red rectangle appears in map window
Glad to hear it Silvia. If this answered your question, please mark my answer as the accepted answer.
Sep
16
comment Unknown red rectangle appears in map window
QGIS editing doesn't have the concept of a 'region' and thus would have no reason to have an extent rectangle shown. As per my answer, the rectangle is the Grass region being shown.
Sep
5
comment Wrong $area from field calculator (QGIS)
Is it possible you have multipolygons, and the $area is returning the total area of all constituent pieces?
Jul
25
comment Extract one GPS fix per day from data?
In this case, however, it would not, especially given the colon at the end of the 12--even December would not match that pattern. Obviously it's a very data-specific answer, and your answer would work for other data.
Jul
23
comment Displaying large number of polygons on web map?
If you are open to different platforms, you may want to take a look at GIS Cloud. Their HTML5 Canvas implementation is able to handle huge datasets: directionsmag.com/articles/…
Jun
25
comment How to create atlas along line/route in QGIS
Are you sure you have "Controlled by Atlas" enabled under the map frame "Item Properties", with a "Margin Around Feature" set (to say 10%)? You should have a page centered on each feature, with the appropriate margin. If you're only getting a small segment (smaller than your 'split' length?) then you've got something set wrong.
Jun
25
comment Qgis making a backgound map for topolines on Garmin
It creates a raster map in .kmz format.