A coordinate-based data model that represents geographic features as points, lines, and polygons.
0
votes
0answers
9 views
Vectorising lines appear as a mixture of bubbles and lines from raster map
I have these road raster maps which I have reclassified into binary images to try and vectorise. However, when I click on vectorise and generate feature, it comes out as a mixture of bubbles and lines ...
1
vote
1answer
14 views
'Regular Points' vector layer in Bonn
I've downloaded the bonn version of QGIS. Using the 'regular points' vector analysis tool, I've set some 5m regular points over a field so that I can use the x,y coordinates to plot them and measure ...
1
vote
1answer
26 views
Discerning dwelling types in QGIS? [on hold]
In QGIS, I want to discern between a number of building types, based on topology. I have data on buildings, parcels and addresses.
I'm having a hard time to discern between row/terrace, end-of-...
0
votes
0answers
18 views
Splitting one vector file with multiple polygons into individual files using QGIS? [duplicate]
I download the administrative divisions of a country from gadm.org as a kmz vector file.
I imported it into QGIS Desktop.
How do I split the polygons from this file and then export them as ...
1
vote
1answer
64 views
Digitize objects in a LiDAR point cloud?
I am working with LiDAR point cloud data of road networks. The goal is to digitize all visible objects like hydrants, streets, sidewalks.
My input data is available in LAS or ASCII format.
My first ...
1
vote
0answers
23 views
Cluster spatial - cannot allocate vector
I'm trying use this code for create cluster spatial in R, I get from @ssanch:
# example data from the thread
x <- c(-22.83982, -23.49961, -27.08745, -22.98890, -19.92278)
y <- c(-47.20671, -46....
1
vote
1answer
21 views
pyqgis 3 setup vector labeling not working
I have a standalone pyqgis3.2.1 (Bonn) application that can display maps (vectors, rasters). I tried to setup labeling of vector layers using the following codes, but it only works for point layers, ...
0
votes
0answers
9 views
Vector and raster distortion [closed]
The image I am digitizing suddenly rotated and it is saying .db error too. I have a complete distortion on my work. vector and raster image distortion
1
vote
0answers
18 views
Create a path in mapping software and export as vector?
Is it possible to map a route in any mapping software (OpenStreetMaps, Google Maps/Earth, QGIS, etc. preferably Open Source or free) and export this route as a vector (PDF, AI, SVG etc.)?
I'm only ...
0
votes
0answers
35 views
QGIS raster data to shapefile data as decimal number
in QGIS I have a problem with converting raster data to shapefile data.
My data from the raster (values such as 0.13, 0.65, 0.67 etc) converts into a rounded value in the shapefile. At first, I tried ...
1
vote
2answers
52 views
Convert Raster to vector - create polygons based on each pixel
I want to convert a raster file (100x100m pixel size) which contains population counts as pixel values. I need a vector based file of the 100x100m grids and the population as attributes.
I tried ...
0
votes
0answers
5 views
QGIS Error while Reprojecting a ATLAS BNA file (.bna vector format) from WGS84 to UTM Zone
In QGIS, I want to reproject a ATLAS BNA (.bna vector format) from WGS84(EPSG:4326) to UTM zone 37S(EPSG:32737).
I have tried all the options in GDAL/OGR Toolbox, GRASS GIS, SAGA GIS and QGIS ...
1
vote
1answer
52 views
How do I create a line with fixed size from a single point in QGIS?
My question pretty much sums up my problem. Basically, I have a layer containing points:
And I need to convert them into lines with fixed size (25 meters). I don't care if the point will be taken as ...
0
votes
1answer
44 views
Count how many times an attribute in a polyline intersects a polygon in QGIS
I am trying to count how many times a polyline with a specific attribute intersects a polygon in QGIS. For example, I have a polyline with a feature class called "size", this contains a text value i.e....
4
votes
1answer
67 views
LiDAR returns over water bodies?
I have obtained LiDAR data from my environmental agency in order to obtain the relative heights of each watercourse station. A far as I know, LiDAR signals do not get returned over water bodies. ...
2
votes
1answer
41 views
Read a Raster Band Value inside of a VectorLayer in QGIS [closed]
How to read pixel values in RasterLayer that intersects line features of VectorLayer, applying Python in QGIS?
8
votes
1answer
121 views
Split up shapefile into little shapefiles
I have a very large shapefile (all the roads in RI). I need to split it up into chunks so that I can process the file with multiple worker threads in Python. So far I have created a grid in QGIS that ...
2
votes
1answer
50 views
Distance to Nearest Hub QGIS not working when 'hub' is a line?
QGIS 2.18.20 working in CRS: WGS 84/UTM Zone 35S (EPSG:32735 OTF), with shapefiles of map features (roads, river, point water sources) reprojected from WGS84 EPSG:4326.
All shapefiles have been ...
1
vote
1answer
25 views
QGIS Union erroneously creating gaps
I'm trying to do a union between two Polygon Shapefiles, but when I do Vector > Geoprocessing Tools > Union I have the odd issue where most of it works fine, but some areas are returned in the union ...
0
votes
1answer
31 views
Openlayers 3.10 can't display features added manually
I'm trying to add features manually to vector layer but with no luck.
This is my code:
cords[0] = {
[19.1820888104, 49.6835693017],
[19.1819108957, 49.6850423191],
[19.1846518426, 49.6853635871],
[19....
2
votes
2answers
70 views
Clip Raster by Attribute values
I have a raster which I want to do a clip with a vector layer (polygon) using its atttribute values.
What I have done so far is the folliwing:
from qgis.core import *
from qgis.gui import *
import ...
1
vote
1answer
44 views
Attribute Error: 'unicode' object has no attribute 'extent'
I keep getting this error from this line.
arcpy.CreateFishnet_management(os.path.join(Output_Folder, "Full_Grid.shp"), str(NAR_U9.extent.XMin) + " " + str(NAR_U9.extent.YMin), str(NAR_U9.extent.XMin)...
0
votes
0answers
29 views
QGIS topology check shows different topology check results for same area
I used QGIS topology checker for parcel data of an area in QGIS 2.18. The rule used was- 'Parcel must not have gaps'. The result showed many error (gaps) and while zooming in and zooming out, the ...
0
votes
0answers
15 views
Polygon interpolation neighbour average?
I am trying to estimate empty values based on a polygon layer we received from another study. Is there a way to calculate an average value for polygon A based on neighbours B,C, etc that border it?
I ...
1
vote
0answers
35 views
QGIS: Fill shapefile vectors with grayscale based on elevation
I am very new to this and feel like this is probably an easy answer, but after days of searching this forum I still am unsuccessful.
I have shapefile data with elevation and I want to create a raster ...
0
votes
2answers
45 views
How to assign raster layer's colors to polygons in QGIS?
I have a georeferenced raster file showing parcels of a town with different colors (yellow for the category single-household residential, green for agricultural areas, etc.). I also have the shapes of ...
0
votes
0answers
30 views
Opening National Land Cover data?
How do I open the National Land Cover data in QGIS 3.0? Attached is an image of the files. It looks like it's an .rrd file.
2
votes
2answers
46 views
How are the coordinates for multipolygons arranged?
How are the coordinates for a multipolygon (i.e. polygon with a hole in it) arranged?
Do shapefiles and geoJSON files always save the coordinates for the outer ring first?
I'm asking because I ...
0
votes
1answer
48 views
How to get parcel boundaries with tax roll, land use, and zoning info?
How do I get parcel boundary shapefiles with tax roll, land use and zoning info included?
Is it possible to just create the parcel boundaries data from scratch, i.e. could I create parcel polygons in ...
0
votes
0answers
32 views
Spatial Bookmarks to vector conversion
I have created spatial bookmarks in QGIS. Is there a way to convert them into a shapefile, or any other vector data format?
-1
votes
1answer
65 views
Get PostGIS geometry data and display it on map using GetMapRequest
How can I get the data from PostgreSQL db and display on map using GetMapRequest?
I have done connecting the PostgreSQL db which contains the geometry data.
Now I want to redirect that data to map ...
0
votes
1answer
39 views
Exporting point pattern fill as vector data in PDF
In QGIS 3.2, I have a map with parks/other green areas to be displayed as a simple vector point pattern fill. No matter what I do, the pattern fill is always exported to PDF as raster data, which is ...
0
votes
0answers
19 views
TileStache serving vector MBTiles
Is this possible? I have D/L vector .MBtiles files from openmaptiles and want to serve them to leaflet via tilestache.
This is all in hopes of saving disk space and bandwidth over server straight up ...
0
votes
0answers
16 views
Getting static .pngs from mbtiles file or other sources
My nomenclature may be astray because mapping and GIS is not my domain.
We need to be able to serve tiles locally in a structure lik the folder example provided here:
https://www.maptiler.com/how-to/...
2
votes
1answer
45 views
How to merge all layers in QGIS project using 'merge vector layers' within PyQGIS
I am trying to use the 'merge vector layers' tool in PyQGIS to merge all of the layers in my QGIS project into one shapefile, as part of a larger script I am developing. I tried this script, but I get ...
1
vote
3answers
86 views
Creating a source and a layer from vector tile features in Openlayers
So I retrieve all my features from a vectorTile layer (PBF from Geoserver), and now I want to recreate a layer by filtering on those features and getting only those that satisfy a request.
I ...
1
vote
1answer
38 views
Getting data on area where shapefile overlaps raster file using QGIS?
I have attached an image to help explain what I am asking. I want to get the average value of where the heat map crosses over each municipality in the shapefile and export those values into a ...
0
votes
0answers
25 views
How to extract polygons/vectors of a scanned map in raster format?
I have 8 scanned maps in .tif format. They are already georeferenced, but as they are historical maps almost each of them is colored differently. Now the areas of the single components like streets, ...
8
votes
4answers
618 views
Understanding resolution in vector maps?
I'm developing a vector maps with detailed features such as road edges, cross walks, traffic lights , street lights etc., by using 3D points (x,y,z) without geo-referencing, generated from stereo ...
1
vote
1answer
34 views
Statistics for point data within each polygon using ArcMap?
I think this is a pretty basic GIS operation but I'm not sure how to do it.
I have hundreds of polygons, and within each polygon there is point data (see picture). The point data has a field "Type" ...
1
vote
1answer
55 views
How to calculate the overlap of two polygons in PostGIS
I am trying to calculate the percentage overlap of two vector polygon layers and saving the result as a separate column. The code below is working:
CREATE TABLE parcels_all_shapefile_new AS
SELECT ...
3
votes
4answers
154 views
Calculate length of huge vector lines dataset
I have a MultiLineString vector layer from which I would like to calculate the length.
I have tried to calculate the length with the Field Calculator by putting in the expression $length. The ...
0
votes
1answer
93 views
Request a WFS layer using OpenLayers
I am new to OpenLayers and GeoServer... can someone please help me to show a WFS layer... here is my code:
const vectorSource = new ol.source.Vector({
format: new ol.format.GeoJSON(),
url: ...
0
votes
0answers
11 views
vector from raster, with the information of the raster, for area estimation
As you will probably understand, i am new to using GIS applications and software. So far, i tried SNAP and now i am trying to learn just a few modules for certain research applications, in QGIS. I ...
1
vote
1answer
37 views
Mask a Raster layer in QGIS using a vector layer with multiple polygons
I would like to extract statistics from a raster file based on a land cover classification vector file, however the land covers (features) are not contiguous (see pic).
In the example below, I would ...
0
votes
0answers
23 views
OpenLayers receive all feature data from Vector (WFS)
I would like to display a Diagram for the data that is received via a WFS.
As this data is already displayed on the map, a second request is not necessary. Normally I receive the underlying data on a ...
1
vote
1answer
105 views
Only show buffers that overlap geometry
I have multiple sites that are surrounded by a buffer. I also have a layer which corresponds to areas affected by changes. I am trying to filter out buffers that are not overlapped by the change ...
0
votes
0answers
13 views
QGIS line editing? [duplicate]
I am fairly new to QGIS, but how do you edit this line? I added line 1-3 and 2-3 and I need to get rid of line 1-2. 1-2 is one part of the large boundary lines connected to each other. Before I delete ...
1
vote
2answers
202 views
Create Strava Heatmap with QGIS
I have loaded my bike tours as .gpx files into QGIS.
It already looks quite nice but I was wondering if it might be possible to create something similar to the strava heatmap with tools of QGIS.
I ...
0
votes
0answers
16 views
Register Vector utility Mapinfo
I want to register a table that contains vectors obtained from using Inkscape (contour detection ) to a map georeferenced .
and this is the vector file :
when i finish , i should have the vector map ...
