Re: [Qgis-user] python(3) script to calculate latitude longitude values from (ESRI) shape file
Good pointers Nyall, I need to start working with this stuff. Nicolas Cadieux https://gitlab.com/njacadieux > Le 21 avr. 2021 à 21:24, Nyall Dawson a écrit : > > On Thu, 22 Apr 2021 at 06:43, wxgis wrote: >> >> Hi - >> Wondering if there is existing Python(3) script code that can take an (ESRI) >> shape file as input and then calculate latitude/longitude/elevation values >> for country boundaries. For example, if the input file is a SHP file for >> France, the output would be the lat/lon/elevation values for the country >> boundaries. I am quite new to QGIS, looking at version 3.18 (so only know >> about ESRI shape files, maybe there are other types of SHP files?), and read >> that in QGIS I can edit the attribute table for a given layer and add >> latitude/longitude attributes, but I am hoping to this more >> programmatically, using the QGIS Python console. I gladly welcome any ideas >> on this. > > If you're new to this then I'd suggest skipping the Python part and > instead making a graphical model using Processing tools to do what you > want. The visual aspect of making models will help guide you through > the process, and there's plently of video tutorials on Youtube showing > how to do this. > > You can even then take the model and automatically convert it directly > to a Python script with a single button click! > > Hope that helps, > Nyall > ___ > 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
Re: [Qgis-user] python(3) script to calculate latitude longitude values from (ESRI) shape file
Nyall and Nicholas (earlier) and qgis list -- This is fantastic information. I'm going to dive in and see what I can discover. Automatic conversion of the model to Python script is definitely neat! Really appreciate this awesome forum and the availability of QGIS! Best to all, Steve On Wed, Apr 21, 2021 at 7:24 PM Nyall Dawson wrote: > On Thu, 22 Apr 2021 at 06:43, wxgis wrote: > > > > Hi - > > Wondering if there is existing Python(3) script code that can take an > (ESRI) > > shape file as input and then calculate latitude/longitude/elevation > values > > for country boundaries. For example, if the input file is a SHP file for > > France, the output would be the lat/lon/elevation values for the country > > boundaries. I am quite new to QGIS, looking at version 3.18 (so only > know > > about ESRI shape files, maybe there are other types of SHP files?), and > read > > that in QGIS I can edit the attribute table for a given layer and add > > latitude/longitude attributes, but I am hoping to this more > > programmatically, using the QGIS Python console. I gladly welcome any > ideas > > on this. > > If you're new to this then I'd suggest skipping the Python part and > instead making a graphical model using Processing tools to do what you > want. The visual aspect of making models will help guide you through > the process, and there's plently of video tutorials on Youtube showing > how to do this. > > You can even then take the model and automatically convert it directly > to a Python script with a single button click! > > Hope that helps, > Nyall > ___ 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] python(3) script to calculate latitude longitude values from (ESRI) shape file
On Thu, 22 Apr 2021 at 06:43, wxgis wrote: > > Hi - > Wondering if there is existing Python(3) script code that can take an (ESRI) > shape file as input and then calculate latitude/longitude/elevation values > for country boundaries. For example, if the input file is a SHP file for > France, the output would be the lat/lon/elevation values for the country > boundaries. I am quite new to QGIS, looking at version 3.18 (so only know > about ESRI shape files, maybe there are other types of SHP files?), and read > that in QGIS I can edit the attribute table for a given layer and add > latitude/longitude attributes, but I am hoping to this more > programmatically, using the QGIS Python console. I gladly welcome any ideas > on this. If you're new to this then I'd suggest skipping the Python part and instead making a graphical model using Processing tools to do what you want. The visual aspect of making models will help guide you through the process, and there's plently of video tutorials on Youtube showing how to do this. You can even then take the model and automatically convert it directly to a Python script with a single button click! Hope that helps, Nyall ___ 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] python(3) script to calculate latitude longitude values from (ESRI) shape file
Hi, Users of this group will give you good information on the QGIS Python api. You can use that. Another way is to use the python Shapely library. Using the object.bounds method, you will have you xy min and max coordinate. If you use the geopandas library, you can use he same shapely method but use the power on the pandas dataframe. Of course, you can also make a vector query in QGIS and add the boundaries limite in a new field. https://shapely.readthedocs.io/en/stable/manual.html?highlight=bound#object.bounds You also achieve the same goal using Gdal. This page is full of code and will give you 99% of what you need. https://pcjericks.github.io/py-gdalogr-cookbook/geometry.html#calculate-envelope-of-a-geometry Nicolas Cadieux https://gitlab.com/njacadieux > Le 21 avr. 2021 à 16:42, wxgis a écrit : > > Hi - > Wondering if there is existing Python(3) script code that can take an (ESRI) > shape file as input and then calculate latitude/longitude/elevation values > for country boundaries. For example, if the input file is a SHP file for > France, the output would be the lat/lon/elevation values for the country > boundaries. I am quite new to QGIS, looking at version 3.18 (so only know > about ESRI shape files, maybe there are other types of SHP files?), and read > that in QGIS I can edit the attribute table for a given layer and add > latitude/longitude attributes, but I am hoping to this more > programmatically, using the QGIS Python console. I gladly welcome any ideas > on this. > > TIA, > Steve > > > > -- > Sent from: http://osgeo-org.1560.x6.nabble.com/QGIS-User-f4125267.html > ___ > 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
Re: [Qgis-user] python(3) script to calculate latitude longitude values from (ESRI) shape file
Chris and list -- "...you can convert your polygons or lines to points and then again assuming you have a DEM you can interpolate the elevations at the points." Thanks for your answer - from your last sentence Chris, does anyone know of some python code (or snippets will help too) that can take a country boundary (i.e., the polygon/lines you mention above) and convert to lat/lon? Again, do you recommend I start with an ESRI .shp file? Can I get country boundaries from an ESRI .shp file (this is critical for me, i.e., to get country boundaries) or is there some other type of file I should use? I do like the idea of getting elevation from a DEM file. TIA, Steve -- Sent from: http://osgeo-org.1560.x6.nabble.com/QGIS-User-f4125267.html ___ 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] python(3) script to calculate latitude longitude values from (ESRI) shape file
Steve and list, On Wed, Apr 21, 2021 at 1:41 PM wxgis wrote: > Hi - > Wondering if there is existing Python(3) script code that can take an > (ESRI) > shape file as input and then calculate latitude/longitude/elevation values > for country boundaries. For example, if the input file is a SHP file for > France, the output would be the lat/lon/elevation values for the country > boundaries. I am quite new to QGIS, looking at version 3.18 (so only know > about ESRI shape files, maybe there are other types of SHP files?), and > read > that in QGIS I can edit the attribute table for a given layer and add > latitude/longitude attributes, but I am hoping to this more > programmatically, using the QGIS Python console. I gladly welcome any > ideas > on this. > Most polygon data that I've run into tends to be 2D ie there's no elevation value. Things like contours are 2½D ie each line is at the same elevation and so the elevation is stored as an attribute of the line. Boundaries would typically be either polygons or lines. As the elevation varies along the polygon or line, you would need 3D data. If you have 2D data and a DEM you can convert the 2D data to 3D and then interpolate the elevation values along the polygon or line from the DEM. Some file formats will not support 3D polygons or lines. But something in the way you're stating what you want makes me think you actually want points along the boundary, each point with latitude, longitude and elevation. If that's the case, you can convert your polygons or lines to points and then again assuming you have a DEM you can interpolate the elevations at the points. If your data is not in lat/lon you can project it to lat/lon either before you start or after you finish. Does this help? -- Chris Hermansen · clhermansen "at" gmail "dot" com C'est ma façon de parler. ___ 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] python(3) script to calculate latitude longitude values from (ESRI) shape file
Hi - Wondering if there is existing Python(3) script code that can take an (ESRI) shape file as input and then calculate latitude/longitude/elevation values for country boundaries. For example, if the input file is a SHP file for France, the output would be the lat/lon/elevation values for the country boundaries. I am quite new to QGIS, looking at version 3.18 (so only know about ESRI shape files, maybe there are other types of SHP files?), and read that in QGIS I can edit the attribute table for a given layer and add latitude/longitude attributes, but I am hoping to this more programmatically, using the QGIS Python console. I gladly welcome any ideas on this. TIA, Steve -- Sent from: http://osgeo-org.1560.x6.nabble.com/QGIS-User-f4125267.html ___ 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
