Geographic Information Systems Questions, Problems & Solutions : TransWikia.com ~ Page 34

Grade separation routing using pgRouting

I am using pgRouting version 2.6. I am creating a routing topology from a subset of lion data https://www1.nyc.gov/site/planning/data-maps/open-data/dwn-lion.page I have gone through the process of setting...

Asked on 11/01/2021

1 answer

Select by Expression and Extract by Expression generate different results

I have a polygon layer and want to extract all Polygons with the field "street" = 1. When I use "Select by Expression" I get the following correct result: ...

Asked on 11/01/2021

1 answer

Get best fitting rectangle polygon in PostGIS

There is a polygon and i want to get the best fitting rectangle.POLYGON((530298.250279478 162222.258455872,530298.231436834 162222.252144356,530291.717023011 162220.760892999,530291.4 162222.2,530307.3 162226.15,530307.78 162226.28,530310.87 162227.09,530311.081382153 162226.14214151,530298.915241086 162222.434365185,530298.586991142 162222.368630039,530298.26998128 162222.261048055,530298.250279478 162222.258455872))I tried using ST_SetSRID(ST_Extent(geom),27700) but...

Asked on 11/01/2021

1 answer

Creating new polygon in between other polygons?

I want to fill the missing space and create a polygon out of it. How do you do that with QGIS? The missing space is the white part between the...

Asked on 11/01/2021

1 answer

Including float value in loop processing of Surface Volume tool using ArcMap ModelBuilder

How do I use the Surface Volume tool in ArcMap via Model Builder, without using Python, to process a set of multiple float values in a loop, since an...

Asked on 11/01/2021

3 answer

Extract field's names in R without reading the file

I was wondering if it's possible to use the R package sf for extracting the names of the fields in a file without reading it. For example, I would like...

Asked on 11/01/2021

1 answer

Access SpatiaLite connections with PyQGIS QgsProviderMetadata (QGIS 3.10.7 LTR)

I would like to list spatialite connections and access a specific connectionwith PyQGIS. For postgres provider it's pretty straightforward:>>> QgsProviderRegistry.instance().providerMetadata('postgres').connections(){'alkis (authcfg)': <qgis._core.QgsAbstractDatabaseProviderConnection object at 0x000001D663232CA8>, 'baumradar (authcfg)': <qgis._core.QgsAbstractDatabaseProviderConnection object...

Asked on 11/01/2021

1 answer

How to read geometry from gpkg?

I have a gpkg file. I trying to open it with spatial_lite gui and cast geometry to GML.select AsGML(geom) from MyTablebut i got null. I tried another functions AsText(),...

Asked on 11/01/2021

1 answer

Trying to set custom projection for shapefile in QGIS

I'm trying to open and use a dataset (in the form of a shapefile) (https://webarchive.iiasa.ac.at/Research/FOR/forest_cdrom/data/landscapes/landscapes.zip) with QGis. The readme of the dataset says following about projection:Projection:...

Asked on 11/01/2021

2 answer

Arcgis JS API 4.x how to localize?

I'm looking for ways to customize built in widgets, but couldn't find anything in version 4.x. In version 3.x you can do it in following way as mentioned in doc...

Asked on 11/01/2021 by digz6666

1 answer

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