Unanswered Questions
21,193 questions with no upvoted or accepted answers
15
votes
0answers
469 views
Can qgis_core work with external python distribution (such as Anaconda)?
I've built a python application that has its own GUI. I am trying to use qgis.core/PyQGIS as map display only. Specifically, I have anaconda 2.3 and its python distribution (2.7.11).
After research ...
14
votes
0answers
332 views
SNAP vs. GDAL vs. Orfeo - image rescale, histogram cut
I work with a Sentinel-2 .jp2 image (red band, 10950 x 10950 pixels). My aim is to reach the same result what SNAP does with a Python script. See the SNAP method and parameters:
So this is my ...
14
votes
0answers
317 views
Determining flow path length in QGIS?
I need help with qgis flow path length.
I try to run the program and when I run the program I get a raster with 0 values, as input I'm using filled raster, I don't now if I'm doing something wrong or ...
14
votes
1answer
573 views
How to control the arrow length of vector field markers in the layer list legend?
In QGIS 2.14.5 LTR (and recently in QGIS 3.0) I've set up a beautiful map design with a graduated renderer and vector field markers for each value range (arrow length is directly proportional to ...
13
votes
1answer
576 views
Configure which bands to display from a 4-band ArcGIS image service?
The USDA (via the National Map) provides 4-band NAIP ArcGIS "ImageServer" (services) for most states in the US. I am able to successfully connect to the WMS service in QGIS as described here, which ...
12
votes
0answers
885 views
Leaflet v1 plugin: layer control for ungrouped, grouped, and nested-grouped layers
I need a Leaflet plugin which extends L.Control.Layers. I have the following requirements:
works with Leaflet 1.x
handles ungrouped layers alongside grouped ones
handles nested layer groups
does not ...
12
votes
0answers
357 views
rMaps choropleth with custom json
With R I want to make an animated choropleth map with the rMaps package and a custom map. I tried to follow the example of Diego Valle described here and to use the custom map info for Datamaps.
...
12
votes
1answer
200 views
Integrating NTv2-transformation in QGIS?
I am wondering what's the correct way to integrate a NTv2-transformation in QGIS.
I have successfully integrated a NTv2-transformation in QGIS but I am not sure if it's done the way it's meant to be.
...
11
votes
0answers
179 views
Showing startup-messages on QGIS splashscreen
During the startup of QGIS there are status messages shown in the lower part of the splashscreen like "restoring loaded plugins".
I am using a startup.py from which I would like to inform the user ...
10
votes
0answers
104 views
Is the ST_ prefix appropriate for functions not included in SQL/MM Part 3?
I was reading a thread on the geospatial extension for Presto in this Github issue, where a function, line_locate_point, was introduced. It was based off PostGIS's ST_LineLocatePoint function, which ...
9
votes
1answer
1k views
Plotting bar charts on maps in R?
I'm using plotrix in R to plot a state level map of the US. It has an excellent function floating.pie to put pie charts on each state.
I'm wondering if there are similar functions within the plotrix ...
9
votes
1answer
339 views
Attaching ArcGIS image server dataset in QGIS?
I have tried adding the dataset in QGIS using
'qgis.utils.iface.addRasterLayer()'. But it throws this error.
Invalid Layer: GDAL provider Cannot open GDAL dataset
http://precisionedgeag.com:8080/...
9
votes
0answers
221 views
Cannot Open VRT of Sentinel2 image created by AutoCreateWarpedVRT
I am trying to create a warped VirtualRaster of a Sentinel2 image. Here the Python code I tried:
from osgeo import gdal, osr
srs = osr.SpatialReference()
srs.SetFromUserInput('EPSG:32632')
gdal....
9
votes
0answers
680 views
Why does @data@values slot for RasterLayer only contain logical(0) and not the actual values?
Trying to get to the bottom of why, when I read in a raster of NDVI, the @data@values slot does not contain the actual values until I set them manually. For example:
NDVI <- raster("./filename....
9
votes
0answers
506 views
Parsing file format for attributes in Raster Product Format (RPF) maps and imagery?
I'm trying to implement an open-source NITF reader (using only java, no external libraries such as GDAL or NITRO), and its mostly going OK. However I'm having trouble understanding the RPF extensions, ...
