All Questions
160,535
questions
0
votes
0
answers
5
views
merged tiff turned has black background (white in individual tiffs)
I downloaded Geotiff tiles (multi-channel band). In QGIS I used GDAL --> Raster Miscellaneous --> Merge.
In the merging tool I used my downloaded tiffs as input. I changed nothing else. The ...
- 31
0
votes
0
answers
6
views
Access to the coordinates of a NetCDF file?
I started working with NetCDF files recently, sorry this may be a silly question.
I'm working with projected Surge Levels; Data is stored as filename.nc files at Copernicus. This is the file.
After ...
- 33
0
votes
0
answers
8
views
Visualize a linestring and point from a PostGIS database in QGIS?
I ran a query in PostGIS table using a table of roads/linestrings in Hawaii and another table with 400,000 (latitude,longitude) points in Hawaii. The output table is meant to provide nearest road in ...
- 11
0
votes
0
answers
12
views
QGIS: Shapefiles showing in wrong place even when reproject
In QGIS, I imported a shapefile but the polygons are showing a few 100 km south of where they should be. In the picture, the yellow polygons should be overlapping the red pixels. I've tried to ...
- 59
0
votes
0
answers
4
views
How to use gdal exceptions in .NET?
I'm converting a .vrt to a .tif with Gdal.wrapper_GDALWarpDestName(). I know the .vrt has been calculated to a size that causes an integer overflow error during warping because the command line ...
- 555
0
votes
1
answer
8
views
Obtaining label-node instead of city boundry polygon when using OSM Place Search in QGIS
I am using OSM Place Search Plugin in QGIS for searching and importing places, cities, towns etc. from Openstreetmap database into my projects. Great Plugin by the way. But I have a big problem.
When ...
- 1
0
votes
0
answers
11
views
Calculating MESO-scale slopes from a DEM
I have a coastal DEM which I want to use to calculate the cross-shore slope with ArcGIS Pro. In the image below I've plotted the zer and five meter contours, and what I want is to calculate the ...
- 53
0
votes
0
answers
7
views
Make audio control in popup in ArcGIS Online when the audio file is attached to each feature
In ArcGIS Online, is it possible to show audio controls to play an audio file in the popup when I click on a point when the audio file was already attached to that file in ArcGIS Pro? I am trying to ...
- 716
0
votes
0
answers
12
views
GeoPandas multipoint has inverted coordinates when exporting to KML (via Fiona)
I'm doing some searches in a geodataframe of multipoints and outputting the results as a KML file but the exported KML file has the coordinates inverted, ie:
<?xml version="1.0" encoding=&...
- 101
0
votes
0
answers
14
views
How to perform pixel level moving window analysis [closed]
I want to calculate the urban sprawl metric (USM) after Angel et al. (2007). The calculation is done in the following manner: a 1000m circular buffer is first created around each built-up pixel, and ...
0
votes
0
answers
5
views
PyQGIS: .disjoint() and .equals() do not work
I have to clean a data set for research. It is just one layer, but I need to remove features that are registered several times or have a geometry that is somehow faulty. The dataset is too large to do ...
- 115
0
votes
0
answers
19
views
Bamboo indices in ArcMap
I have been working from a long time for bamboo area assessment using ArcMap. I used Bamboo (BI) to assess potential bamboo area of my study site. I used last 5 year’s Landsat-8 and Sentinel-2 data ...
- 173
0
votes
0
answers
7
views
Limitations in running PostGIS container by Kartoza on Azure Container Apps
I'm working with a project where I need to implement openpoiservice, an open-source project that uses by default a PostgreSQL database made by Kartoza: https://github.com/kartoza/docker-postgis
I'm ...
- 1
1
vote
0
answers
28
views
QGIS measurement tool seems unrealistic
I have created a buffer of 150m around a point. This should give (a polygonal approximation of) a circle with radius 150m.
I tried to verify this with the measurement tool, and I am baffled to see a ...
- 123
0
votes
0
answers
22
views
Select by style mapinfo to QGIS
Mapinfo/Discover has a wonderful digitizing tool "select by graphical style". Is there something equivalent in QGIS?
- 11
0
votes
0
answers
9
views
how to install fiona on a newly generated github codespace?
This question as been asked multiple times here and on SO but it seems anything related to GDAL in the python realm requires special care on any new environment. So here is the Github codespace one.
I ...
- 2,540
4
votes
1
answer
35
views
How to decide when to use the SQLite dialect when running ogr2ogr on large files
When using ogr2ogr, I got used to using the -dialect sqlite option. I often see this option in GIS.SE answers (examples), and I notice others also found it helpful:
+1 for the inclusion of -dialect ...
- 1,350
0
votes
1
answer
28
views
Hide elements from QGIS-Browser [closed]
I have a lot of services saved in my QGIS-Browser (a few WFS, WMS ...).
But there are also a few service-types I do not use.
For a clean QGIS-GUI I search for a way to hide some Elements in the QGIS-...
- 617
3
votes
0
answers
27
views
How to find the minimal_circle of a given group of points based on the distances and proximity between a selected points
With the following expression presented in the question (Creating the minimum convex hull that contains certain percentage of points in QGIS) it is possible to calculate the closest distances between ...
- 813
0
votes
1
answer
27
views
How to use ST_Union if polygons share the same name using PostGIS SQL
Say I have a polygons that overlaps with each other, How do I achieve the same output as dissolve -> dissolve field(check "name") using SQL code?
layer fields information:
- name # <-- ...
- 311
1
vote
1
answer
43
views
How to prevent duplicates from being generated in Spatial Join in PostGIS
I'm trying to create a spatial view which meets the following criteria:
Sentinel hotspots registered within 2km of powerline (feeder)
AND
QRFS point located within 4km radius of sentinel hotspots
AND
...
- 21.8k
0
votes
0
answers
15
views
PostgreSQL trigger function not recognizing NEW.(timestamp field)<> old.(timestamp field)
It seems like my function for my trigger does not recognize if a field that happens to be of type timestamp changes.
example:
CREATE OR REPLACE FUNCTION "public"."...
- 21
-2
votes
1
answer
33
views
Using QuickOSM plugin on QGIS. I want to select all the points that would show food options(convenience stores, fast food, supermarkets, etc) [duplicate]
I'm generating a map of Tennessee based on OSM data. How can I choose the features/layers a need for my task?
- 3
0
votes
0
answers
14
views
Colouring of a pie chart
How can I automatically insert different colors for different attributes in creating pie chart in QGIS. I have multiple attributes and coloring them differently takes alot of time. Is there way that I ...
- 1
-1
votes
1
answer
44
views
Using quick OSM plugin in QGIS to create a map of Tennessee
I want to just make a map of Tennessee from the Quick OSM plugin in QGIS. How to achieve that?
- 3
0
votes
1
answer
27
views
Hyperlinks in ArcGIS Pro not working
I am in the process of moving years of ArcMap projects to ArcGIS Pro 3.1.2 and have run into a serious issue. I have thousands of hyperlinks in the data tables which are in dbf format (derived from a ...
- 1
0
votes
1
answer
16
views
Extracting mean value per layer for raster with terra package in R
I have a stack of monthly temperature raster data and would like to calculate the global spatial mean per area using the terra package in R to obtain a monthly time series.
I tried terra::app and ...
- 25
1
vote
1
answer
106
views
How to to create lines from points where the point attributes are transferred to the line segments?
Background:
I need to create lines from points where the point attributes are transferred to the line segments.
The screenshot below shows two point tracks. Each track's point has a unique id and an ...
- 7,970
0
votes
0
answers
23
views
Issues with QGIS map projection and symbolizing point data
First off, I am using version 3.28 QGIS-LR on a Macbook 2015. I am currently taking an introduction course to GIS. One of the assignments was learning to project maps and visualize point data using ...
-1
votes
0
answers
23
views
Create fake isolines based on a text [closed]
I am trying to generate fake isolines/contour lines that are representing a text, let's say "TEST".
I can't find a proper way to do this if I don't want to do it all manually.
Anyone has an ...
- 91
0
votes
0
answers
23
views
Get errors featureclasses of Trace Network ArcGIS Pro
I try to analyse road featureclass for errors of topology and I use Trace network tool in arcpy.
I cannot just create topology and add some rules, because it doesn't work like I want.
When I use the ...
0
votes
0
answers
9
views
Specify pixel data type importing raster into GRASS with r.in.gdal
When I import 8-bit grayscale images into GRASS with r.in.gdal the datatype used is float32 and is unnecessarily 4 times larger. I can specify the datatype when I export with r.out.gdal but I can't ...
- 151
0
votes
0
answers
17
views
Create shaded relief raster from a Virtual Raster Dataset (.vrt) in R
I have a series of adjacent DEMs that are stored as 1 km^2 tiles. To avoid artifacts on the seams I want to first create a Virtual Raster Dataset, apply terra::shade(), and then retile to match the ...
- 549
0
votes
0
answers
10
views
Store remote sensing metadata created from STAC into PostgreSQL/PostGIS
I have created some STAC catalogs for remote sensing data (Landsat, etc.) that I would like to store in PostgreSQL/PostGIS for easier access and management. How would I import the STAC created ...
- 3
0
votes
0
answers
25
views
How to get back spaces in administrative names in GADM 4.1
I recently downloaded the GeoJSON of Republic of the Congo and I realized that the data have no spaces for the name fields anymore since version 4.1.
Is there a simple way to compute them back or is ...
- 2,540
1
vote
1
answer
26
views
Creating QgsRasterLayer from WMS layer using PyQGIS in QGIS 3.28
I'm developing a QGIS plugin in Python that lets you add layers from Web Map Services (WMS) to the canvas.
This feature does not work with certain layers of certain WMS services from QGIS Server.
When ...
0
votes
0
answers
28
views
Does ST_ClusterKMeans benefit from a spatial index?
Does ST_ClusterKMeans benefit from a spatial index? here is how I am using it (24313 is projection in meters):
ST_ClusterKMeans(
ST_Transform(d.bf_polygon, 24313),
...
- 809
0
votes
0
answers
9
views
Why I can't use eas snap on MacBook M1
I downloaded eas snap on my MacBook Air M1, version 13.9,
but after opening the application and uploading the plugins, I can't open any file on it and it gets frozen, and I have to make force quit ...
0
votes
0
answers
10
views
Field Calculator to generate a hyperlink
I am trying to create a hyperlink using the field calculator the problem is the field I am pulling from has numbers and letters and I only need to pull the numbers. I am currently using this field ...
0
votes
0
answers
16
views
How to preserve feature class representations when exporting the map to DGN format
I got a map in geodatabase format. I used the conversion tool of ArcCatalog in ArcGIS to export the map in DGN format. Then I open the files in Microstation Connect Edition but found that the feature ...
- 1
1
vote
1
answer
60
views
URL with plus sign in it cannot be load
There is a formula parameter in URL continues with mathematical expression. I noticed if there is + char the layer cannot be loaded. I had similer error with {, } chars. Replacing them with %7B, %7D ...
- 41
0
votes
0
answers
36
views
Seeking geological standard symbol for folding
I'm looking for a symbol for a geological map.
And I can't find it. It's a symbol to represent the folding of the geological layers.
- 1
0
votes
0
answers
17
views
persiann monthly yearly [closed]
the results of monthly and annual rainfall not correct?
Monthly precipitation should be the sum of daily precipitation.
Annual precipitation should be the sum of monthly precipitation.
What is the ...
0
votes
0
answers
26
views
Plotting geodataframe with holoviews
I have a geopandas data frame combined_gdf that consists of circular polygons like below.
fid Plot_name Registered Longitude Latitude geometry
0 130.0 2014-10-29 1 -51.460000 -1.740000 ...
- 892
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votes
0
answers
40
views
How to reposition and rescale Alaska and Hawaii in a shapefile using QGIS 3
I have barely used QGIS at all but I am trying to produce a colored map (based on opioid overdose rates) in Python using a county level shapefile from the Census Bureau. What I would like to do is ...
0
votes
0
answers
22
views
WMS layer issue at higher zoom level
When zooming out to higher level for a WMS layer, getting this error:
msDrawMap(): Image handling error. Failed to draw layer named 'PICT-INHEND19-psQwiZ1L4t'. drawGDAL(): Unable to access file. ...
- 1
0
votes
1
answer
33
views
Differentiate vertical and horizontal shapes
I have the following shape file:
Each polygonal area (the lines are areas) is one feature in a single Shapefile.
Can anyone think of a simple method that can be implemented with qgis to separate the ...
- 78
0
votes
1
answer
25
views
GeoServer manual version ahead
This is not a big deal but makes me wonder if I'm missing something as we use GeoServer. Why is it that the official documentation is ahead of the release? I've not seen any issues with that, but am ...
- 225
0
votes
0
answers
16
views
Find walkable routes from polygons to points
I have a dataset that contains specific census tract polygons and schools, hospitals and police stations point data.
The goal is to generate walkable distance routes from the polygons to the point ...
- 1,048
0
votes
1
answer
20
views
Get index based on a condition in Google Earth Engine
I have a list of cumulative proportions based off of a histogram that I calculated in Google Earth Engine. Now I want to find the index of this list where the value is >= 0.995 and then use that ...
- 37