Re: [geos-devel] [GEOS] #343: After applying a buffer over a multiline the library starts growing in memory usage and hungs

2010-05-14 Thread strk
On Fri, May 14, 2010 at 03:05:29PM -0700, Martin Davis wrote: > Yes, that would be very interesting. Does GGL provide polygon union now? Seems so: http://geometrylibrary.geodan.nl/group__union.html --strk; () Free GIS & Flash consultant/developer /\ http://strk.keybit.net/services.html

Re: [geos-devel] [GEOS] #343: After applying a buffer over a multiline the library starts growing in memory usage and hungs

2010-05-14 Thread Martin Davis
Yes, that would be very interesting. Does GGL provide polygon union now? strk wrote: On Fri, May 14, 2010 at 02:28:39PM -0700, Martin Davis wrote: Interesting that GEOS seems to have caught up to JTS in terms of performance. I seem to remember it used to be slower. (But it's not really

Re: [geos-devel] [GEOS] #343: After applying a buffer over a multiline the library starts growing in memory usage and hungs

2010-05-14 Thread strk
On Fri, May 14, 2010 at 02:28:39PM -0700, Martin Davis wrote: > Interesting that GEOS seems to have caught up to JTS in terms of > performance. I seem to remember it used to be slower. (But it's not > really any faster, either, in spite of all that C goodness! 8^) That's the price to pay for

Re: [geos-devel] [GEOS] #343: After applying a buffer over a multiline the library starts growing in memory usage and hungs

2010-05-14 Thread Martin Davis
Ok, then that's in the same ballpark as JTS. And yes, the union is much slower than the buffer creation. Interesting that GEOS seems to have caught up to JTS in terms of performance. I seem to remember it used to be slower. (But it's not really any faster, either, in spite of all that C goo

Re: [geos-devel] [GEOS] #343: After applying a buffer over a multiline the library starts growing in memory usage and hungs

2010-05-14 Thread strk
On Fri, May 14, 2010 at 11:35:45AM -0700, Martin Davis wrote: > Ok, I tried the roads_broken geometry in JTS using the buffer-and-union > approach. The result matches the one you posted, strk. > > Time was 2.7 s. So the two systems are pretty close. > > It would be interesting if you tried the

Re: [geos-devel] [GEOS] #343: After applying a buffer over a multiline the library starts growing in memory usage and hungs

2010-05-14 Thread Martin Davis
Ok, I tried the roads_broken geometry in JTS using the buffer-and-union approach. The result matches the one you posted, strk. Time was 2.7 s. So the two systems are pretty close. It would be interesting if you tried the other geometry as well. Martin Davis wrote: Ah, ok. I was using this

Re: [geos-devel] [GEOS] #343: After applying a buffer over a multiline the library starts growing in memory usage and hungs

2010-05-14 Thread Martin Davis
Ah, ok. I was using this one. http://trac.osgeo.org/geos/attachment/ticket/344/fail_geom.txt.gz I'll try the other one and see what kind of performance I get. strk wrote: On Fri, May 14, 2010 at 09:11:30AM -0700, Martin Davis wrote: I'm surprise that PostGIS is so much faster too! Can y

Re: [geos-devel] [GEOS] #343: After applying a buffer over a multiline the library starts growing in memory usage and hungs

2010-05-14 Thread strk
On Fri, May 14, 2010 at 09:11:30AM -0700, Martin Davis wrote: > I'm surprise that PostGIS is so much faster too! Can you supply the > output, so I can check it against JTS? > > One thing I notice is that the input I'm using has 5615 elements and > 11502 points. The input I'm using is this: htt

Re: [geos-devel] [GEOS] #343: After applying a buffer over a multiline the library starts growing in memory usage and hungs

2010-05-14 Thread Martin Davis
I'm surprise that PostGIS is so much faster too! Can you supply the output, so I can check it against JTS? One thing I notice is that the input I'm using has 5615 elements and 11502 points. This *might* make a big difference, if you are missing some of the bigger linestrings which (a) have

Re: [geos-devel] [GEOS] #343: After applying a buffer over a multiline the library starts growing in memory usage and hungs

2010-05-14 Thread strk
On Fri, May 14, 2010 at 03:09:40PM +0200, strk wrote: > On Thu, May 13, 2010 at 09:22:49AM -0700, Martin Davis wrote: > > Just tried the buffer-and-union approach in JTS. It works fine - about > > 70 s for the union, less for the initial buffering. Memory usage was low. > > I tried buffer-and-u

Re: [geos-devel] [GEOS] #343: After applying a buffer over a multiline the library starts growing in memory usage and hungs

2010-05-14 Thread strk
On Thu, May 13, 2010 at 09:22:49AM -0700, Martin Davis wrote: > Just tried the buffer-and-union approach in JTS. It works fine - about > 70 s for the union, less for the initial buffering. Memory usage was low. I tried buffer-and-union approach in PostGIS. It was very fast ! Some stats: - Or

Re: [geos-devel] [GEOS] #343: After applying a buffer over a multiline the library starts growing in memory usage and hungs

2010-05-13 Thread Mateusz Loskot
On 13/05/10 17:22, Martin Davis wrote: At the moment I haven't spent much time thinking about how to detect these cases automatically. Of course it would be possible to switch to using an automated buffer-and-union approach if this could be detected. But this seems like such a pathological case I

Re: [geos-devel] [GEOS] #343: After applying a buffer over a multiline the library starts growing in memory usage and hungs

2010-05-13 Thread Martin Davis
Just tried the buffer-and-union approach in JTS. It works fine - about 70 s for the union, less for the initial buffering. Memory usage was low. This geometry is pretty much a poster child for things that defeat the optimizations used in buffering. It has lots of small geometries, thus prev

Re: [geos-devel] [GEOS] #343: After applying a buffer over a multiline the library starts growing in memory usage and hungs

2010-05-13 Thread Martin Davis
Yikes! That's one nasty dataset. JTS has issues with it as well - I wasn't able to get the buffer to complete. As a workaround, you could buffer each line separately and then UnaryUnion the results. GEOS wrote: #343: After applying a buffer over a multiline the library starts growing in m

[geos-devel] [GEOS] #343: After applying a buffer over a multiline the library starts growing in memory usage and hungs

2010-05-13 Thread GEOS
#343: After applying a buffer over a multiline the library starts growing in memory usage and hungs +--- Reporter: sberna | Owner: geos-devel@lists.osgeo.org Type: defect | Status: new