Re: [Qgis-developer] Using the QgsBrowserModel in Python
Le 30/07/2015 13:47, Hugo Mercier a écrit : Hi, On 29/07/2015 17:50, Ludovic Delauné wrote: Hi devs, i'm trying to use the QgsBrowserModel in a Python plugin. I need to get the URI from a selected Item in the QTreeView, i expected to have a QgsLayerItem returned by the dataItem() in order to get the uri() member but a QgsDataItem is returned instead. Given a QgsDataItem, is it possible to get the uri of my data source ? Is this a bug due to the binding (https://github.com/qgis/QGIS/blob/feb3bee85837d707b1b10c14064fcb55364e282d/python/core/qgsbrowsermodel.sip) or i'm not in the right way ? Here are the few steps to reproduce the problem in a console: --- from PyQt4.QtGui import QTreeView tv = QTreeView(None) m = QgsBrowserModel() tv.setModel(m) tv.show() m.dataItem(tv.currentIndex()) output is : qgis._core.QgsDataItem object at 0x7f6cb8bcca68 Apparently, this is because QgsDataItem has nothing to convert to its derived types in the Python bindings. I'll add a %ConvertToSubClassCode. Thanks for the report Thanks for that clarification. My current workaround is to use the mimeData method and deserialize the item to obtain the URI : Add to the steps above : from qgis.core import QgsMimeDataUtils uri_list = QgsMimeDataUtils.decodeUriList(m.mimeData([tv.currentIndex()])) uri_list[0].uri -- Ludovic ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] Using the QgsBrowserModel in Python
Hi, On 29/07/2015 17:50, Ludovic Delauné wrote: Hi devs, i'm trying to use the QgsBrowserModel in a Python plugin. I need to get the URI from a selected Item in the QTreeView, i expected to have a QgsLayerItem returned by the dataItem() in order to get the uri() member but a QgsDataItem is returned instead. Given a QgsDataItem, is it possible to get the uri of my data source ? Is this a bug due to the binding (https://github.com/qgis/QGIS/blob/feb3bee85837d707b1b10c14064fcb55364e282d/python/core/qgsbrowsermodel.sip) or i'm not in the right way ? Here are the few steps to reproduce the problem in a console: --- from PyQt4.QtGui import QTreeView tv = QTreeView(None) m = QgsBrowserModel() tv.setModel(m) tv.show() m.dataItem(tv.currentIndex()) output is : qgis._core.QgsDataItem object at 0x7f6cb8bcca68 Apparently, this is because QgsDataItem has nothing to convert to its derived types in the Python bindings. I'll add a %ConvertToSubClassCode. Thanks for the report ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] function similar to Excel VLOOKUP - SOLVED
Awesome. Thank you.
I added the extra column to the shapefile attributes, joined the
shapefile to the CSV file, and then updated the new column in my
shapefile using:
attribute($currentfeature,'joinedcolumn') (NOTE: single quotes for
field name)
I'm sure I could have skipped the Join step and just used getfeature as
suggested below, but I went the Join route anyway.
Big thanks,
Zoltan
On 2015/07/30 14:34, DelazJ wrote:
Hi,
I think combining getFeature and attribute functions should help u do
that in the field calculator, though I haven't used them on csv files.
Assuming col1 in your csv contains also the code you are looking for,
applying this expression on shapefile col 6 in QGIS field calculator
may do the job:
attribute (getFeature ('mycsvfile', 'mycsv_col1', myshape_col1), 'col2')
Regards,
DelazJ
2015-07-30 13:06 GMT+02:00 Zoltan Szecsei zolt...@geograph.co.za
mailto:zolt...@geograph.co.za:
Hi,
How could I implement something like vlookup in QGIS?
I have a shapefile with 2000 polygons and column 1 of its
attribute table has a code value.
Using the code in this column 1, I need to look up which row of a
CSV file has that code, and return column 2 of the CSV file.
This returned value must then be placed into a new column (say
column 6) on the shapefile attribute table.
I could pre-add the new column to this shapefile, and then run the
vlookup equivalent too, of course.
I tried this by opening the DBF file in Libreoffice calc, sorting
the columns, adding the extra two columns of my lookup data, then
ran vlookup and saved/closed the DBF file.
Once back in QGIS the attributes ended up being linked to the
wrong polygons (probably because I sorted the DBF file outside of
QGIS).
Thanks in advance,
Zoltan
--
===
Zoltan Szecsei PrGISc [PGP0031]
Geograph (Pty) Ltd.
GIS and Photogrammetric Services
P.O. Box 7, Muizenberg 7950, South Africa.
Mobile: +27-83-6004028 tel:%2B27-83-6004028
Fax: +27-86-6115323 tel:%2B27-86-6115323 www.geograph.co.za
http://www.geograph.co.za
===
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Geograph (Pty) Ltd.
GIS and Photogrammetric Services
P.O. Box 7, Muizenberg 7950, South Africa.
Mobile: +27-83-6004028
Fax:+27-86-6115323 www.geograph.co.za
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Re: [Qgis-developer] function similar to Excel VLOOKUP
How about a Join QGIS join Il 30/07/2015 13.06, Zoltan Szecsei ha scritto: Hi, How could I implement something like vlookup in QGIS? I have a shapefile with 2000 polygons and column 1 of its attribute table has a code value. Using the code in this column 1, I need to look up which row of a CSV file has that code, and return column 2 of the CSV file. This returned value must then be placed into a new column (say column 6) on the shapefile attribute table. I could pre-add the new column to this shapefile, and then run the vlookup equivalent too, of course. I tried this by opening the DBF file in Libreoffice calc, sorting the columns, adding the extra two columns of my lookup data, then ran vlookup and saved/closed the DBF file. Once back in QGIS the attributes ended up being linked to the wrong polygons (probably because I sorted the DBF file outside of QGIS). Thanks in advance, Zoltan ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] function similar to Excel VLOOKUP
Hi,
I think combining getFeature and attribute functions should help u do that
in the field calculator, though I haven't used them on csv files.
Assuming col1 in your csv contains also the code you are looking for,
applying this expression on shapefile col 6 in QGIS field calculator may
do the job:
attribute (getFeature ('mycsvfile', 'mycsv_col1', myshape_col1), 'col2')
Regards,
DelazJ
2015-07-30 13:06 GMT+02:00 Zoltan Szecsei zolt...@geograph.co.za:
Hi,
How could I implement something like vlookup in QGIS?
I have a shapefile with 2000 polygons and column 1 of its attribute table
has a code value.
Using the code in this column 1, I need to look up which row of a CSV file
has that code, and return column 2 of the CSV file.
This returned value must then be placed into a new column (say column 6)
on the shapefile attribute table.
I could pre-add the new column to this shapefile, and then run the vlookup
equivalent too, of course.
I tried this by opening the DBF file in Libreoffice calc, sorting the
columns, adding the extra two columns of my lookup data, then ran vlookup
and saved/closed the DBF file.
Once back in QGIS the attributes ended up being linked to the wrong
polygons (probably because I sorted the DBF file outside of QGIS).
Thanks in advance,
Zoltan
--
===
Zoltan Szecsei PrGISc [PGP0031]
Geograph (Pty) Ltd.
GIS and Photogrammetric Services
P.O. Box 7, Muizenberg 7950, South Africa.
Mobile: +27-83-6004028
Fax:+27-86-6115323 www.geograph.co.za
===
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Re: [Qgis-developer] memory layer performance while adding many features?
Merci Denis, I will try both options later today. Raymond On 30-07-15 09:34, Denis Rouzaud wrote: From your code [0] , I would see 2 options: * add features all at once on the provider using QgsVectorDataProvider::addFeatures (the method you currently use) * work on the layer level rather than the provider, which I believe is the recommended way for plugins. Make the layer editable, and add features to the edit buffer and commit at once. Or maybe commit 1000 by 1000. I hope this helps. [0] https://github.com/opengeogroep/AERIUS-QGIS-plugins/blob/master/ImaerReader/imaer_reader.py#L228 On 07/30/2015 09:20 AM, Raymond Nijssen wrote: Hi Denis, The code is in the ImaerReader plugin in the qgis repo and in github: https://github.com/opengeogroep/AERIUS-QGIS-plugins I'm adding the features one by one. Regards, Raymond On 30-07-15 08:46, Denis Rouzaud wrote: Hi Raymond, Can you show us the code doing this? Do you commit features one by one ar all at once? Best wishes, Denis On 07/29/2015 09:04 AM, Raymond Nijssen wrote: Dear developers, ;) A plugin of mine imports data from a gml file into a memory layer. Works fine for tiny gml files, but takes forever on huge ones. Sounds plausible maybe, but the relation is not linear. So I did did some tests and found out that reading and parsing the gml and creating the features always goes at the same speed of about 400 features a second (fps). But when adding these to my memory layer, the process slows down tremendously. I output the fps for every 1000 features and it gave me this graph: http://terglobo.nl/downloads/memory-layer-performance.png At the end of the importing process I'm processing just 3 features per second. Is this expected behaviour? Is a memory layer not meant for something like this? Or is this a bug? In the source code I found that for every feature I add to a memory layer the index is updated. Could that be inefficient? Hoping anyone can explain! Regards, Raymond -- Terglobo Ampèrestraat 110 5223 CT 's-Hertogenbosch 06-25314983 ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
[Qgis-developer] Dissolve/Intersection/Clip in 2.10 doesn´t work (Regression)
Hi, I have installed QGIS 2.10.1 on Windows 7 (64 bit). When I use the Geoprocessing tool - Dissolve, Clip and Intersection Dissolve and add Unique ID field – All polygons that are unique are stored and all the rest are not are not created. The problem is both in the vector menu and in the Processing toolbox. Can anyone confirm ? Regards Lene Fischer ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] Freeze on release-2_8 branch
Hi, On Thu, 30. Jul 2015 at 09:05:11 +1000, Nyall Dawson wrote: They were both backported to 2.8.3 (thanks Jürgen!). I assume the release announcement is waiting on the packages being built and available for the major platforms. We need to be noisy about point releases, too? It's all on github anyway. Can't sales or marketing take care of that? ;) 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 http://www.norbit.de QGIS release manager (PSC) GermanyIRC: jef on FreeNode signature.asc Description: Digital signature ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] Definition of Perimeter for polygons with holes
Hi Marco, On 28/07/2015 10:38, Marco Hugentobler wrote: Hi While working on QgsDistanceArea, I noticed the definition of perimeter in QGIS is not the same as in PostGIS. PostGIS returns the length of outer and inner rings, while QGIS expects the length of the outer ring only: test_distancearea.py: polygon = QgsGeometry.fromPolygon( [ [ QgsPoint(0,0), QgsPoint(3,0), QgsPoint(3,3), QgsPoint(0,3), QgsPoint(0,0) ], [ QgsPoint(1,1), QgsPoint(2,1), QgsPoint(2,2), QgsPoint(1,2), QgsPoint(1,1) ], ] ) perimeter = da.measurePerimeter(polygon) assert perimeter == 12, Expected:\n%f\nGot:\n%f\n % (12, perimeter) Using the following in PostGis returns 16 (length of inner and outer rings): SELECT ST_Perimeter( ST_GeomFromText( 'POLYGON(( 0 0, 3 0, 3 3, 0 3, 0 0),(1 1, 2 1, 2 2, 1 2, 1 1))', -1 ) ); What is your opinion? Is it okay to change it in QGIS to also consider the length of inner rings or are there any strong arguments against that? Good question ! :) I don't know if there is one ideal definition of the perimeter of inner rings. After all, we may decide to see the inner perimeter as a negative one ... as it is for the area. So, just a proposition: let the user decide what to do with the two perimeters (outer and inner), adding an option to retrieve separately the inner perimeter ? ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] memory layer performance while adding many features?
Hi Raymond, Can you show us the code doing this? Do you commit features one by one ar all at once? Best wishes, Denis On 07/29/2015 09:04 AM, Raymond Nijssen wrote: Dear developers, ;) A plugin of mine imports data from a gml file into a memory layer. Works fine for tiny gml files, but takes forever on huge ones. Sounds plausible maybe, but the relation is not linear. So I did did some tests and found out that reading and parsing the gml and creating the features always goes at the same speed of about 400 features a second (fps). But when adding these to my memory layer, the process slows down tremendously. I output the fps for every 1000 features and it gave me this graph: http://terglobo.nl/downloads/memory-layer-performance.png At the end of the importing process I'm processing just 3 features per second. Is this expected behaviour? Is a memory layer not meant for something like this? Or is this a bug? In the source code I found that for every feature I add to a memory layer the index is updated. Could that be inefficient? Hoping anyone can explain! Regards, Raymond ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] memory layer performance while adding many features?
Hi Raymond, On 29/07/2015 09:04, Raymond Nijssen wrote: Dear developers, ;) A plugin of mine imports data from a gml file into a memory layer. Works fine for tiny gml files, but takes forever on huge ones. Sounds plausible maybe, but the relation is not linear. So I did did some tests and found out that reading and parsing the gml and creating the features always goes at the same speed of about 400 features a second (fps). But when adding these to my memory layer, the process slows down tremendously. I output the fps for every 1000 features and it gave me this graph: http://terglobo.nl/downloads/memory-layer-performance.png At the end of the importing process I'm processing just 3 features per second. Is this expected behaviour? Is a memory layer not meant for something like this? Or is this a bug? In the source code I found that for every feature I add to a memory layer the index is updated. Could that be inefficient? If I am correct the spatial index is created only if you ask so (by passing index=yes). Do you have the same results without spatial index ? ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] memory layer performance while adding many features?
Hi Hugo, I'm not specifically adding an index. So if you are right, I'm not using that. Regards, Raymond On 30-07-15 09:10, Hugo Mercier wrote: Hi Raymond, On 29/07/2015 09:04, Raymond Nijssen wrote: Dear developers, ;) A plugin of mine imports data from a gml file into a memory layer. Works fine for tiny gml files, but takes forever on huge ones. Sounds plausible maybe, but the relation is not linear. So I did did some tests and found out that reading and parsing the gml and creating the features always goes at the same speed of about 400 features a second (fps). But when adding these to my memory layer, the process slows down tremendously. I output the fps for every 1000 features and it gave me this graph: http://terglobo.nl/downloads/memory-layer-performance.png At the end of the importing process I'm processing just 3 features per second. Is this expected behaviour? Is a memory layer not meant for something like this? Or is this a bug? In the source code I found that for every feature I add to a memory layer the index is updated. Could that be inefficient? If I am correct the spatial index is created only if you ask so (by passing index=yes). Do you have the same results without spatial index ? ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer -- Terglobo Ampèrestraat 110 5223 CT 's-Hertogenbosch 06-25314983 ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] memory layer performance while adding many features?
From your code [0] , I would see 2 options: * add features all at once on the provider using QgsVectorDataProvider::addFeatures (the method you currently use) * work on the layer level rather than the provider, which I believe is the recommended way for plugins. Make the layer editable, and add features to the edit buffer and commit at once. Or maybe commit 1000 by 1000. I hope this helps. [0] https://github.com/opengeogroep/AERIUS-QGIS-plugins/blob/master/ImaerReader/imaer_reader.py#L228 On 07/30/2015 09:20 AM, Raymond Nijssen wrote: Hi Denis, The code is in the ImaerReader plugin in the qgis repo and in github: https://github.com/opengeogroep/AERIUS-QGIS-plugins I'm adding the features one by one. Regards, Raymond On 30-07-15 08:46, Denis Rouzaud wrote: Hi Raymond, Can you show us the code doing this? Do you commit features one by one ar all at once? Best wishes, Denis On 07/29/2015 09:04 AM, Raymond Nijssen wrote: Dear developers, ;) A plugin of mine imports data from a gml file into a memory layer. Works fine for tiny gml files, but takes forever on huge ones. Sounds plausible maybe, but the relation is not linear. So I did did some tests and found out that reading and parsing the gml and creating the features always goes at the same speed of about 400 features a second (fps). But when adding these to my memory layer, the process slows down tremendously. I output the fps for every 1000 features and it gave me this graph: http://terglobo.nl/downloads/memory-layer-performance.png At the end of the importing process I'm processing just 3 features per second. Is this expected behaviour? Is a memory layer not meant for something like this? Or is this a bug? In the source code I found that for every feature I add to a memory layer the index is updated. Could that be inefficient? Hoping anyone can explain! Regards, Raymond ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
