Re: [Qgis-user] Projections
I agree with Hernán, that you are probably better off using ellipsoidal (geodetic) distances rather than projected distances for such large tracks. Of course, you can use whatever projection you want to RENDER the routes. For example you can use a conic projection to render the bird tracks or a orthographic map projection. It all depends on what message you are trying to convey to your audience. On Thursday, October 22, 2020, 3:14:34 PM EDT, Charles Dixon-Paver wrote: Pardon my ignorance, but my brain is burning a bit with this topic... Is there a particular reason nobody is suggesting the utilisation of an equidistant projection? I thought this was what they are optimised for. Albers conic equal area is for the preservation of area, not distance as far as I'm aware. I know pretty much nothing of Two Point Equidistant projections, but considering the field of interest is migration I feel like this is probably the most accurate method (depending on implementation)? I would think an Azimuthal Equidistant projection centered on the area of interest would be more accurate than albers at least... And if the maps look way too funny then use something like the equidistant conic? This is pure conjecture on my part, so I'd appreciate the correction if I'm missing the plot... On Thu, 22 Oct 2020 at 19:35, Falk Huettmann wrote: Hi there, Mike et al, thanks,but if you check up with Thomas Alerstam from Sweden - as a bird tracking migration person you really ought to know those things and his entire books/papers -there is sufficient literature on the topic for years re. projections, e.g. this one for starters. https://www.researchgate.net/publication/12122402_Migration_Along_Orthodromic_Sun_Compass_Routes_by_Arctic_Birds Some others are found with the navigation sciences, with sea turtle math work (former Ram Myers) and then rocket and missile targeting of course.It's usually not written though by geography or GIS experts. The Google Earth maps boldly ignore the projection issue (as they are just a shiny commercial PR tool). Overall, for birds these days, the public resource question should sit on CONSERVATION and sustainable management,not ivory-tower questions. The latter have been done for centuries without relevant outcome and progress.Yes, the earth is round and an optimal route exist, but now what ? Birds know and used that for millennia and their presences show it no other.. Data exist to that degree.Other problems are more relevant these days. A nice question why after 100 years of research on bird migration, state-funded with $Mio's, and with MPI and Movebank, ICARUS etcno readily available solution or answer exist in R or GIS etc. That's my opinion and answer on your question. Feel free to follow up as needed. Best regards Falk Huettmann PhD, Professor Uni of Alaska Fairbanks On Wed, Oct 21, 2020 at 11:53 PM MIKE MCGRADY wrote: As far as I can recall, few studies of long-distance migratory species state what projections are used. Is there any published study of the effect of projections on analyses of animal movement? M M. J. McGrady Am Rosenhugel 59A-3500 KremsAustria From: Qgis-user on behalf of Hernán De Angelis Sent: Thursday, October 22, 2020 6:57 AM To: qgis-user@lists.osgeo.org Subject: Re: [Qgis-user] Projections Mike For measuring the kind of distances you are mentioning I would suggest using ellipsoidal (geodetic) distances rather than projected distances. This is because projected distances can become very inaccurate over large regions (depending on the particular projection of course). If measuring areas is important consider an equal area projection, like Albers for example, not a conformal one like Lambert. Hope this helps. /H. On 2020-10-22 07:43, MIKE MCGRADY wrote: I have data on tracked migratory birds, and want accurate measures of distance travelled during migration and areas of summering and wintering ranges. These birds are summering in central Asia (mostly Kazakhstan and southern Russia), and wintering in Arabia. Any advice on which projection to use? My guess is Lambert conformal conic. I'd really like to avoid using different projections for different phases of the birds' annual cycle, unless absolutely necessary. M. J. McGrady Am Rosenhugel 59A-3500 KremsAustria ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https:/
Re: [Qgis-user] Adding PostGIS Layer (Query Before Load)
Also, after successfully adding the layer, if I go to Layers and right click
on the layer and select "Update SQL Layer..." the DB Manager dialog pops up but
hangs. The offending query seems to be:
SELECT * FROM "device_location"
Again, I wound expect the above query to include the filter (where clause) I
defined in the Data Source Manager.
Thanks,Peter
On Tuesday, August 6, 2019, 7:43:44 AM EDT, Peter Borissow
wrote:
OK, after enabling "Use estimated metadata" on the connection, the Data
Source Manager comes up (doesn't hang). I am able to select a table and apply a
filter. After a brief delay, QGIS starts to load data. However, is see an odd
query consuming resources in the database:
SELECT st_extent("coordinate") FROM "public"."device_location"
The device_location table is the partitioned table with billions of rows. I
wound expect the above query to include the filter (where clause) I defined in
the Data Source Manager.
To summarize, I am able to create a filter before loading data thanks to the
"Use estimated metadata" but I seem to have found a new issue.
Thanks,Peter
On Tuesday, August 6, 2019, 3:34:06 AM EDT, Jürgen E. Fischer
wrote:
Hi Peter,
On Mon, 05. Aug 2019 at 22:29:19 +, Peter Borissow wrote:
> I looked at the Data Source Manager (Layer -> Add Layer -> Add PostGIS
> Layers...) but I don't see any filtering options there and the app hangs when
> I hit the "Connect" button.
Did you enable "Use estimated metadata" on that connection?
Jürgen
--
Jürgen E. Fischer norBIT GmbH Tel. +49-4931-918175-31
Dipl.-Inf. (FH) Rheinstraße 13 Fax. +49-4931-918175-50
Software Engineer D-26506 Norden https://www.norbit.de
QGIS release manager (PSC) Germany IRC: jef on
FreeNodenorBIT Gesellschaft fuer Unternehmensberatung und Informationssysteme
mbH
Rheinstrasse 13, 26506 Norden
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Re: [Qgis-user] Adding PostGIS Layer (Query Before Load)
OK, after enabling "Use estimated metadata" on the connection, the Data
Source Manager comes up (doesn't hang). I am able to select a table and apply a
filter. After a brief delay, QGIS starts to load data. However, is see an odd
query consuming resources in the database:
SELECT st_extent("coordinate") FROM "public"."device_location"
The device_location table is the partitioned table with billions of rows. I
wound expect the above query to include the filter (where clause) I defined in
the Data Source Manager.
To summarize, I am able to create a filter before loading data thanks to the
"Use estimated metadata" but I seem to have found a new issue.
Thanks,Peter
On Tuesday, August 6, 2019, 3:34:06 AM EDT, Jürgen E. Fischer
wrote:
Hi Peter,
On Mon, 05. Aug 2019 at 22:29:19 +, Peter Borissow wrote:
> I looked at the Data Source Manager (Layer -> Add Layer -> Add PostGIS
> Layers...) but I don't see any filtering options there and the app hangs when
> I hit the "Connect" button.
Did you enable "Use estimated metadata" on that connection?
Jürgen
--
Jürgen E. Fischer norBIT GmbH Tel. +49-4931-918175-31
Dipl.-Inf. (FH) Rheinstraße 13 Fax. +49-4931-918175-50
Software Engineer D-26506 Norden https://www.norbit.de
QGIS release manager (PSC) Germany IRC: jef on
FreeNodenorBIT Gesellschaft fuer Unternehmensberatung und Informationssysteme
mbH
Rheinstrasse 13, 26506 Norden
GF: Juergen Fischer, Nils Kutscher HR: Amtsgericht Aurich HRB 100827
Datenschutzerklaerung: https://www.norbit.de/83/
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[Qgis-user] Adding PostGIS Layer (Query Before Load)
Hello, I have a partitioned table in a PostgreSQL/PostGIS database with ~30 billion points. I would like to render a subset of this data in QGIS and run some analytics. Normally, with a smaller dataset, I would simply navigate to the table I want via the "Browser" and add it to the map via a double click. Once the data is loaded, I can filter the data, run analysis, etc. However, in my case, this is impossible. What I need is an option to filter the data before loading it into the map. I looked at the Data Source Manager (Layer -> Add Layer -> Add PostGIS Layers...) but I don't see any filtering options there and the app hangs when I hit the "Connect" button. Obviously, I can create views in the database to circumvent this issue but I don't want to create dozens of custom views. Is there another way to create a layer from PostgreSQL/PostGIS using a filter-first strategy in QGIS? Thanks in advance,Peter ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] Release Schedule
Thanks Andreas- I appreciate the clarification and I'm looking forward to the stable release. Keep up the great work! Peter From: Andreas Neumann To: qgis-user@lists.osgeo.org Sent: Tuesday, June 30, 2015 9:59 AM Subject: Re: [Qgis-user] Release Schedule Hi Peter, There is no stable 2.9 release, but the last 2.9 release is basically identical to 2.10. Even numbers are the releases, odd numbers are dev build in between. To really identify a release properly you need to identify the last github number, which you can see at https://github.com/qgis/QGIS (see latest commit) for each branch. 2.10 was already released in Source code but the package building for the various operating system takes a while. You can expect the download probably tomorrow or later this week, depending on the operating system you use. BTW: we would like users to test the nightly releases which are available each day through OSGeo4W or each week as an installer at http://qgis.org/downloads/weekly/ - this would help us deliver a more stable official release (the ones with the even numbers). So please be patient a day or two until the package for your OS is available. Andreas On 30.06.2015 15:52, Peter Borissow wrote: Hello, I saw an email yesterday regarding QGIS 2.10 and I got excited but I see that the current release is 2.8. According to this page, 2.10 should have been released last week :-) https://www.qgis.org/en/site/getinvolved/development/index.html#release-schedule And according to this page, 2.10 is only coming out next year: http://changelog.qgis.org/qgis/version/2.10/ Of course, I would be happy to see a stable 2.9 release first. When is 2.9 scheduled for release? Best regards, Peter ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
[Qgis-user] Release Schedule
Hello, I saw an email yesterday regarding QGIS 2.10 and I got excited but I see that the current release is 2.8. According to this page, 2.10 should have been released last week :-) https://www.qgis.org/en/site/getinvolved/development/index.html#release-schedule And according to this page, 2.10 is only coming out next year: http://changelog.qgis.org/qgis/version/2.10/ Of course, I would be happy to see a stable 2.9 release first. When is 2.9 scheduled for release? Best regards,Peter ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] QGIS on rollApp
Very cool. Thanks for sharing. It would be interesting to learn more from whoever put this together. What's the process, level of effort, long term plans, support, etc. From: Larry Shaffer To: QGIS Developer List ; QGIS User List Sent: Tuesday, April 21, 2015 12:16 PM Subject: [Qgis-user] QGIS on rollApp Hi, I don't normally cross-post to dev/user lists (sorry for the extra noise), but I found this to be quite an interesting advancement for QGIS. https://www.rollapp.com/app/qgis QGIS in the cloud, and almost fully functional, e.g. Python, etc. Seems browser's filesystem integration is broken (maybe it needs a cloud drive attached). Who did this awesome port? Was it rollApp folks themselves? Regards, Larry Shaffer Dakota Cartography Black Hills, South Dakota ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] getting square raster images from MODIS tiff files into QGIS
I don't know if QGIS supports this feature out of the box. In the past, I used MRTSwath to orthorectify MODIS: https://lpdaac.usgs.gov/tools/modis_reprojection_tool_swath OTB and OSSIM are 2 open source libraries that can be used to rectify satellite images as well. Peter From: Don McNeil To: qgis-user@lists.osgeo.org Sent: Tuesday, April 14, 2015 1:09 AM Subject: [Qgis-user] getting square raster images from MODIS tiff files into QGIS Dear QGIS Gurus: My problem is that, having already created vector layers for a region in separate sub-windows of QGIS, when I create an additional layer for a raster image by opening a MODIS TIFF file for the same region, it appears as a trapezium rather than a rectangle, and when I try to convert it to a rectangle by specifying the UTM location, the vector images disappear. So I can't show both the squared raster image and the vector images together. I emailed a friend who uses other GIS software (including ArcGIS, ERDAS and IDRISI) and he suggested that I might need a process of rectification for adjusting the shape and position of the image to the real position instead of just changing the coordination. If so, does Quantum GIS have a function to do that? kind regardsDon ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] BBox Filter for WFS
Wow, this is great news! I can't wait to test it.
Thanks for your help!
Peter
From: Marco Hugentobler
To: qgis-user@lists.osgeo.org; peter.boris...@yahoo.com
Sent: Thursday, April 2, 2015 11:34 AM
Subject: Re: [Qgis-user] BBox Filter for WFS
Hi all
I've added the checkbox to only load the features intersecting the current
extent(https://github.com/qgis/QGIS/commit/e4e4839823fad1b980cb815889c18edb9c4352b7).
Regards,
Marco
--
Dr. Marco Hugentobler
Sourcepole - Linux & Open Source Solutions
Weberstrasse 5, CH-8004 Zürich, Switzerland
marco.hugentob...@sourcepole.ch http://www.sourcepole.ch
Technical Advisor QGIS Project Steering Committee
On 31.03.2015 12:01, Peter Borissow wrote:
Thanks Giovanni- Do you know when the dev team is planning the next
release? I wonder if there's time to get this fixed before the next release.
Peter
From: G. Allegri
To: Peter Borissow
Cc: "t...@wildintellect.com" ;
"qgis-user@lists.osgeo.org"
Sent: Tuesday, March 31, 2015 5:15 AM
Subject: Re: [Qgis-user] BBox Filter for WFS
I totally agree with you... but I'm not the mantainer of this code :) I
think that a nre ticket is not necessary. Yuo could add new suggestions/ideas
to the existing one.
giovanni
2015-03-27 10:04 GMT+01:00 Peter Borissow :
Thanks Alex- Do you think we should open a new ticket?
Peter
From: Alex Mandel
To: Peter Borissow ; G. Allegri
Cc: "qgis-user@lists.osgeo.org"
Sent: Thursday, March 26, 2015 5:10 PM
Subject: Re: [Qgis-user] BBox Filter for WFS
That's exactly how I would expect it to work.
To cache a whole WFS and start seems overboard, in that case why
wouldn't you just download the data set. BBOX is a must for web services
as a main part of the purpose is to allow users to only grab the part
they need when they need it.
Thanks,
Alex
On 03/26/2015 01:28 PM, Peter Borissow wrote:
> Thanks Giovanni- It seems to me that the "cache features" option and the
> option to fetch only the features intersecting the current map extent should
> be 2 separate options.
>
> For example, when I open a WFS layer, I might want to retrieve only the
> features intersecting the current map extent. Once it is loaded, I would
> want QGIS to cache the features.
>
> This is a common rendering technique used for WMS. A client requests an
> initial BBOX and renders the image. The when the client pans, a new request
> is made but only for the "missing" area. The original response is cached
> and merged with the second response. Just a thought...
>
>
> Peter
>
>
> From: G. Allegri
> To: Peter Borissow
> Cc: "qgis-user@lists.osgeo.org"
> Sent: Thursday, March 26, 2015 1:27 PM
> Subject: Re: [Qgis-user] BBox Filter for WFS
>
> As Marco explained in the realted post on qgis-dev the bbox filter should be
> used if "cahce features" option is turned off, but at the moment it seems
> broken, maybe because of new improvements in the rendering process. The
> issue has been already reported in http://hub.qgis.org/issues/11968
> In the meanwhile a manual filter could be set within the WFS add layer
> dialog.
> giovanni
> 2015-03-26 16:07 GMT+01:00 G. Allegri :
>
>
>
> It's an intereseting question Peter. I've verified that the wfs provider
> still requests the whole data the first time, then it stores eveything (and
> create a spatial index for subsequent calls).I suppose that sponsoring this
> feature could be the right way to have it, but I'm curious to know what the
> latest answer from Marco was referring to (I mean within the svn code he
> indicates) [1]
> Giovanni
> [1] http://hub.qgis.org/issues/1421#note-4
> 2015-03-25 12:25 GMT+01:00 Peter Borissow :
>
> Sorry for being impatient but I was wondering if anyone can shed some light
> on this issue.
> I have a WFS that's serving out over a billion features (several million
> records per layer). When I add a layer from the WFS into QGIS, it calls
> DescribeFeature and then GetFeature without a BBOX filter. QGIS then waits
> for ALL of the data to come back (which can take a while).
> In the past, there was an option only fetch features that intersect the
> current map extent. Without this option, it is extremely difficult to do
> anything with the WFS using QGIS.
>
> IMHO, this is a pretty significant bug but hopefully one that should be
> really easy to fix. Afterall, the code was there at some point...
>
>
> Related (unanswered) questions on stack exchange:
>
> http://gis.stackexchange.com/ques
Re: [Qgis-user] BBox Filter for WFS
I'm not familiar with sponsoring QGIS development. The sponsorship page makes
it sound like there's an annual commitment and there's no indication of how to
direct funds for a specific task:
http://qgis.org/en/site/getinvolved/governance/sponsorship/sponsorship.html
Perhaps a kickstarter campaign would be better? I personally would donate my
own time/money to get this fixed. Maybe others would too.
In any event (sponsorship vs kickstarter), we would need to know much money I
would need to raise to support this initiative.
Thoughts/suggestions?
Thanks,
Peter
From: G. Allegri
To: Peter Borissow
Cc: "t...@wildintellect.com" ;
"qgis-user@lists.osgeo.org"
Sent: Tuesday, March 31, 2015 6:26 AM
Subject: Re: [Qgis-user] BBox Filter for WFS
The next release (2.10) will be the 26th of June. The time is enough for fixing
but I suspect that, if no dev is working on it at the moment, a sponsorhip
would be the right solution.
2015-03-31 12:01 GMT+02:00 Peter Borissow :
Thanks Giovanni- Do you know when the dev team is planning the next release?
I wonder if there's time to get this fixed before the next release.
Peter
From: G. Allegri
To: Peter Borissow
Cc: "t...@wildintellect.com" ;
"qgis-user@lists.osgeo.org"
Sent: Tuesday, March 31, 2015 5:15 AM
Subject: Re: [Qgis-user] BBox Filter for WFS
I totally agree with you... but I'm not the mantainer of this code :)I think
that a nre ticket is not necessary. Yuo could add new suggestions/ideas to the
existing one.
giovanni
2015-03-27 10:04 GMT+01:00 Peter Borissow :
Thanks Alex- Do you think we should open a new ticket?
Peter
From: Alex Mandel
To: Peter Borissow ; G. Allegri
Cc: "qgis-user@lists.osgeo.org"
Sent: Thursday, March 26, 2015 5:10 PM
Subject: Re: [Qgis-user] BBox Filter for WFS
That's exactly how I would expect it to work.
To cache a whole WFS and start seems overboard, in that case why
wouldn't you just download the data set. BBOX is a must for web services
as a main part of the purpose is to allow users to only grab the part
they need when they need it.
Thanks,
Alex
On 03/26/2015 01:28 PM, Peter Borissow wrote:
> Thanks Giovanni- It seems to me that the "cache features" option and the
> option to fetch only the features intersecting the current map extent should
> be 2 separate options.
>
> For example, when I open a WFS layer, I might want to retrieve only the
> features intersecting the current map extent. Once it is loaded, I would want
> QGIS to cache the features.
>
> This is a common rendering technique used for WMS. A client requests an
> initial BBOX and renders the image. The when the client pans, a new request
> is made but only for the "missing" area. The original response is cached and
> merged with the second response. Just a thought...
>
>
> Peter
>
>
> From: G. Allegri
> To: Peter Borissow
> Cc: "qgis-user@lists.osgeo.org"
> Sent: Thursday, March 26, 2015 1:27 PM
> Subject: Re: [Qgis-user] BBox Filter for WFS
>
> As Marco explained in the realted post on qgis-dev the bbox filter should be
> used if "cahce features" option is turned off, but at the moment it seems
> broken, maybe because of new improvements in the rendering process. The issue
> has been already reported in http://hub.qgis.org/issues/11968
> In the meanwhile a manual filter could be set within the WFS add layer dialog.
> giovanni
> 2015-03-26 16:07 GMT+01:00 G. Allegri :
>
>
>
> It's an intereseting question Peter. I've verified that the wfs provider
> still requests the whole data the first time, then it stores eveything (and
> create a spatial index for subsequent calls).I suppose that sponsoring this
> feature could be the right way to have it, but I'm curious to know what the
> latest answer from Marco was referring to (I mean within the svn code he
> indicates) [1]
> Giovanni
> [1] http://hub.qgis.org/issues/1421#note-4
> 2015-03-25 12:25 GMT+01:00 Peter Borissow :
>
> Sorry for being impatient but I was wondering if anyone can shed some light
> on this issue.
> I have a WFS that's serving out over a billion features (several million
> records per layer). When I add a layer from the WFS into QGIS, it calls
> DescribeFeature and then GetFeature without a BBOX filter. QGIS then waits
> for ALL of the data to come back (which can take a while).
> In the past, there was an option only fetch features that intersect the
> current map extent. Without this option, it is extremely difficult to do
> anything with the WFS using QGIS.
>
> IMHO, this is a pretty significant bug but hopefully one that should be
> really easy to fix. Afterall, t
Re: [Qgis-user] BBox Filter for WFS
Thanks Giovanni- Do you know when the dev team is planning the next release? I wonder if there's time to get this fixed before the next release. Peter From: G. Allegri To: Peter Borissow Cc: "t...@wildintellect.com" ; "qgis-user@lists.osgeo.org" Sent: Tuesday, March 31, 2015 5:15 AM Subject: Re: [Qgis-user] BBox Filter for WFS I totally agree with you... but I'm not the mantainer of this code :)I think that a nre ticket is not necessary. Yuo could add new suggestions/ideas to the existing one. giovanni 2015-03-27 10:04 GMT+01:00 Peter Borissow : Thanks Alex- Do you think we should open a new ticket? Peter From: Alex Mandel To: Peter Borissow ; G. Allegri Cc: "qgis-user@lists.osgeo.org" Sent: Thursday, March 26, 2015 5:10 PM Subject: Re: [Qgis-user] BBox Filter for WFS That's exactly how I would expect it to work. To cache a whole WFS and start seems overboard, in that case why wouldn't you just download the data set. BBOX is a must for web services as a main part of the purpose is to allow users to only grab the part they need when they need it. Thanks, Alex On 03/26/2015 01:28 PM, Peter Borissow wrote: > Thanks Giovanni- It seems to me that the "cache features" option and the > option to fetch only the features intersecting the current map extent should > be 2 separate options. > > For example, when I open a WFS layer, I might want to retrieve only the > features intersecting the current map extent. Once it is loaded, I would want > QGIS to cache the features. > > This is a common rendering technique used for WMS. A client requests an > initial BBOX and renders the image. The when the client pans, a new request > is made but only for the "missing" area. The original response is cached and > merged with the second response. Just a thought... > > > Peter > > > From: G. Allegri > To: Peter Borissow > Cc: "qgis-user@lists.osgeo.org" > Sent: Thursday, March 26, 2015 1:27 PM > Subject: Re: [Qgis-user] BBox Filter for WFS > > As Marco explained in the realted post on qgis-dev the bbox filter should be > used if "cahce features" option is turned off, but at the moment it seems > broken, maybe because of new improvements in the rendering process. The issue > has been already reported in http://hub.qgis.org/issues/11968 > In the meanwhile a manual filter could be set within the WFS add layer dialog. > giovanni > 2015-03-26 16:07 GMT+01:00 G. Allegri : > > > > It's an intereseting question Peter. I've verified that the wfs provider > still requests the whole data the first time, then it stores eveything (and > create a spatial index for subsequent calls).I suppose that sponsoring this > feature could be the right way to have it, but I'm curious to know what the > latest answer from Marco was referring to (I mean within the svn code he > indicates) [1] > Giovanni > [1] http://hub.qgis.org/issues/1421#note-4 > 2015-03-25 12:25 GMT+01:00 Peter Borissow : > > Sorry for being impatient but I was wondering if anyone can shed some light > on this issue. > I have a WFS that's serving out over a billion features (several million > records per layer). When I add a layer from the WFS into QGIS, it calls > DescribeFeature and then GetFeature without a BBOX filter. QGIS then waits > for ALL of the data to come back (which can take a while). > In the past, there was an option only fetch features that intersect the > current map extent. Without this option, it is extremely difficult to do > anything with the WFS using QGIS. > > IMHO, this is a pretty significant bug but hopefully one that should be > really easy to fix. Afterall, the code was there at some point... > > > Related (unanswered) questions on stack exchange: > > http://gis.stackexchange.com/questions/53387/quantumgis-1-8-how-to-define-bounding-box-within-add-wfs-layer-dialog > http://gis.stackexchange.com/questions/59656/is-there-free-desktop-wfs-client-with-bbox-support > > Thanks,Peter > > > > From: Peter Borissow > To: "qgis-user@lists.osgeo.org" > Sent: Monday, March 23, 2015 2:03 PM > Subject: BBox Filter for WFS > > Hello- I noticed that the WFS client in QGIS 2.8 and 2.6 do not seem to > pass a bbox filter when requesting features. > > It seems that in the past, QGIS had an option to only fetch features that > intersect the current map extent: > > http://hub.qgis.org/issues/1421 > > Based on this thread, it looks like this feature was disabled in 1.8: > http://osdir.com/ml/qgis-user-gis/2011-10/msg00308.html > > Is this feature still missing or is there a w
Re: [Qgis-user] BBox Filter for WFS
Thanks Alex- Do you think we should open a new ticket? Peter From: Alex Mandel To: Peter Borissow ; G. Allegri Cc: "qgis-user@lists.osgeo.org" Sent: Thursday, March 26, 2015 5:10 PM Subject: Re: [Qgis-user] BBox Filter for WFS That's exactly how I would expect it to work. To cache a whole WFS and start seems overboard, in that case why wouldn't you just download the data set. BBOX is a must for web services as a main part of the purpose is to allow users to only grab the part they need when they need it. Thanks, Alex On 03/26/2015 01:28 PM, Peter Borissow wrote: > Thanks Giovanni- It seems to me that the "cache features" option and the > option to fetch only the features intersecting the current map extent should > be 2 separate options. > > For example, when I open a WFS layer, I might want to retrieve only the > features intersecting the current map extent. Once it is loaded, I would want > QGIS to cache the features. > > This is a common rendering technique used for WMS. A client requests an > initial BBOX and renders the image. The when the client pans, a new request > is made but only for the "missing" area. The original response is cached and > merged with the second response. Just a thought... > > > Peter > > > From: G. Allegri > To: Peter Borissow > Cc: "qgis-user@lists.osgeo.org" > Sent: Thursday, March 26, 2015 1:27 PM > Subject: Re: [Qgis-user] BBox Filter for WFS > > As Marco explained in the realted post on qgis-dev the bbox filter should be > used if "cahce features" option is turned off, but at the moment it seems > broken, maybe because of new improvements in the rendering process. The issue > has been already reported in http://hub.qgis.org/issues/11968 > In the meanwhile a manual filter could be set within the WFS add layer dialog. > giovanni > 2015-03-26 16:07 GMT+01:00 G. Allegri : > > > > It's an intereseting question Peter. I've verified that the wfs provider > still requests the whole data the first time, then it stores eveything (and > create a spatial index for subsequent calls).I suppose that sponsoring this > feature could be the right way to have it, but I'm curious to know what the > latest answer from Marco was referring to (I mean within the svn code he > indicates) [1] > Giovanni > [1] http://hub.qgis.org/issues/1421#note-4 > 2015-03-25 12:25 GMT+01:00 Peter Borissow : > > Sorry for being impatient but I was wondering if anyone can shed some light > on this issue. > I have a WFS that's serving out over a billion features (several million > records per layer). When I add a layer from the WFS into QGIS, it calls > DescribeFeature and then GetFeature without a BBOX filter. QGIS then waits > for ALL of the data to come back (which can take a while). > In the past, there was an option only fetch features that intersect the > current map extent. Without this option, it is extremely difficult to do > anything with the WFS using QGIS. > > IMHO, this is a pretty significant bug but hopefully one that should be > really easy to fix. Afterall, the code was there at some point... > > > Related (unanswered) questions on stack exchange: > > http://gis.stackexchange.com/questions/53387/quantumgis-1-8-how-to-define-bounding-box-within-add-wfs-layer-dialog > http://gis.stackexchange.com/questions/59656/is-there-free-desktop-wfs-client-with-bbox-support > > Thanks,Peter > > > > From: Peter Borissow > To: "qgis-user@lists.osgeo.org" > Sent: Monday, March 23, 2015 2:03 PM > Subject: BBox Filter for WFS > > Hello- I noticed that the WFS client in QGIS 2.8 and 2.6 do not seem to > pass a bbox filter when requesting features. > > It seems that in the past, QGIS had an option to only fetch features that > intersect the current map extent: > > http://hub.qgis.org/issues/1421 > > Based on this thread, it looks like this feature was disabled in 1.8: > http://osdir.com/ml/qgis-user-gis/2011-10/msg00308.html > > Is this feature still missing or is there a way to enable this feature in the > latest release? > > Thanks,Peter > > > > ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] BBox Filter for WFS
Thanks Giovanni- It seems to me that the "cache features" option and the option to fetch only the features intersecting the current map extent should be 2 separate options. For example, when I open a WFS layer, I might want to retrieve only the features intersecting the current map extent. Once it is loaded, I would want QGIS to cache the features. This is a common rendering technique used for WMS. A client requests an initial BBOX and renders the image. The when the client pans, a new request is made but only for the "missing" area. The original response is cached and merged with the second response. Just a thought... Peter From: G. Allegri To: Peter Borissow Cc: "qgis-user@lists.osgeo.org" Sent: Thursday, March 26, 2015 1:27 PM Subject: Re: [Qgis-user] BBox Filter for WFS As Marco explained in the realted post on qgis-dev the bbox filter should be used if "cahce features" option is turned off, but at the moment it seems broken, maybe because of new improvements in the rendering process. The issue has been already reported in http://hub.qgis.org/issues/11968 In the meanwhile a manual filter could be set within the WFS add layer dialog. giovanni 2015-03-26 16:07 GMT+01:00 G. Allegri : It's an intereseting question Peter. I've verified that the wfs provider still requests the whole data the first time, then it stores eveything (and create a spatial index for subsequent calls).I suppose that sponsoring this feature could be the right way to have it, but I'm curious to know what the latest answer from Marco was referring to (I mean within the svn code he indicates) [1] Giovanni [1] http://hub.qgis.org/issues/1421#note-4 2015-03-25 12:25 GMT+01:00 Peter Borissow : Sorry for being impatient but I was wondering if anyone can shed some light on this issue. I have a WFS that's serving out over a billion features (several million records per layer). When I add a layer from the WFS into QGIS, it calls DescribeFeature and then GetFeature without a BBOX filter. QGIS then waits for ALL of the data to come back (which can take a while). In the past, there was an option only fetch features that intersect the current map extent. Without this option, it is extremely difficult to do anything with the WFS using QGIS. IMHO, this is a pretty significant bug but hopefully one that should be really easy to fix. Afterall, the code was there at some point... Related (unanswered) questions on stack exchange: http://gis.stackexchange.com/questions/53387/quantumgis-1-8-how-to-define-bounding-box-within-add-wfs-layer-dialog http://gis.stackexchange.com/questions/59656/is-there-free-desktop-wfs-client-with-bbox-support Thanks,Peter From: Peter Borissow To: "qgis-user@lists.osgeo.org" Sent: Monday, March 23, 2015 2:03 PM Subject: BBox Filter for WFS Hello- I noticed that the WFS client in QGIS 2.8 and 2.6 do not seem to pass a bbox filter when requesting features. It seems that in the past, QGIS had an option to only fetch features that intersect the current map extent: http://hub.qgis.org/issues/1421 Based on this thread, it looks like this feature was disabled in 1.8: http://osdir.com/ml/qgis-user-gis/2011-10/msg00308.html Is this feature still missing or is there a way to enable this feature in the latest release? Thanks,Peter ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user -- Giovanni Allegri http://about.me/giovanniallegriGis3W - http://gis3w.itIkare - http://ikare.it Twitter: https://twitter.com/_giohappy_blog: http://blog.spaziogis.it GEO+ geomatica in Italia http://bit.ly/GEOplus -- Giovanni Allegri http://about.me/giovanniallegriGis3W - http://gis3w.itIkare - http://ikare.it Twitter: https://twitter.com/_giohappy_blog: http://blog.spaziogis.it GEO+ geomatica in Italia http://bit.ly/GEOplus ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] BBox Filter for WFS
Sorry for being impatient but I was wondering if anyone can shed some light on this issue. I have a WFS that's serving out over a billion features (several million records per layer). When I add a layer from the WFS into QGIS, it calls DescribeFeature and then GetFeature without a BBOX filter. QGIS then waits for ALL of the data to come back (which can take a while). In the past, there was an option only fetch features that intersect the current map extent. Without this option, it is extremely difficult to do anything with the WFS using QGIS. IMHO, this is a pretty significant bug but hopefully one that should be really easy to fix. Afterall, the code was there at some point... Related (unanswered) questions on stack exchange: http://gis.stackexchange.com/questions/53387/quantumgis-1-8-how-to-define-bounding-box-within-add-wfs-layer-dialog http://gis.stackexchange.com/questions/59656/is-there-free-desktop-wfs-client-with-bbox-support Thanks,Peter From: Peter Borissow To: "qgis-user@lists.osgeo.org" Sent: Monday, March 23, 2015 2:03 PM Subject: BBox Filter for WFS Hello- I noticed that the WFS client in QGIS 2.8 and 2.6 do not seem to pass a bbox filter when requesting features. It seems that in the past, QGIS had an option to only fetch features that intersect the current map extent: http://hub.qgis.org/issues/1421 Based on this thread, it looks like this feature was disabled in 1.8: http://osdir.com/ml/qgis-user-gis/2011-10/msg00308.html Is this feature still missing or is there a way to enable this feature in the latest release? Thanks,Peter ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
[Qgis-user] BBox Filter for WFS
Hello- I noticed that the WFS client in QGIS 2.8 and 2.6 do not seem to pass a bbox filter when requesting features. It seems that in the past, QGIS had an option to only fetch features that intersect the current map extent: http://hub.qgis.org/issues/1421 Based on this thread, it looks like this feature was disabled in 1.8: http://osdir.com/ml/qgis-user-gis/2011-10/msg00308.html Is this feature still missing or is there a way to enable this feature in the latest release? Thanks,Peter ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
