Questions tagged [vector]

A coordinate-based data model that represents geographic features as points, lines, and polygons.

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1answer
582 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: ...
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1answer
76 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 ...
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1answer
130 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 ...
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1answer
117 views

Using Presence/Absence method in QGIS?

I seek advice for calculating presence/absence of features in QGIS. I have a polygon dataset of boundary outlines and a number of other datasets which I want to compare it against for presence/...
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1answer
53 views

Is there a vector format for depicting continuous 2D polygons with attributes?

I'm working within the QGIS environment and looking for a 2D continuous vector attributed editable file format to work with. My goal is to find a vector layer that has different features with no ...
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1answer
1k views

How to change layer symbology in QGIS 3 with QgsFeatureRendererV2?

I am updating a QGIS plugin from QGIS 2 to 3 and I am struggling with changing the layer symbology (a single symbol type for a line layer). I would like to have all lines in my layer to have the same ...
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2answers
445 views

Changing vector extent in QGIS

I've been looking for a manner to change a vector extent in QGIS, but it's unsuccessfull! I want change extent because in the past, I had problems to convert vector to raster. I try present the ...
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0answers
161 views

Saga difference vector tool

My QGis Difference tool doesn't work really well, it gives me lots of little squigly lines. i read in the link below there is such a thing as a vector diffence tool from SAGA, but i can't find it. ...
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1answer
268 views

Load and apply Style from Postgres in QGIS 3

I want to write a plugin in QGIS3 that changes the style of a vector layer. The styles to be loaded are saved in a postgres database in the table 'layer_styles'. I read here or here , to use ...
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1answer
151 views

QGIS 2.18 buffer [duplicate]

I'm trying to use fixed distance buffer, and had a few questions. One, what units is the distance being measured in? I assumed meters, but after doing a test run it clearly isn't. And two, what is "...
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1answer
37 views

Non-destructive improvement of vector layer (shapefile) representing a road network?

I have a QGIS project with some vector layers backed by shapefiles. One of these layers contains all the roads, and I would like to "improve" it: It is organized in a way that each vector feature ...
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0answers
212 views

How to open memory data with ogr in rasterstats function?

I would like to reuse vector data created in memory in another function called rasterstats (source code, documentation): I have a function that creates vector data: def createPolygons: ...
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1answer
309 views

QGIS 2.18 Polygonize (raster to vector)

I'm a bit confused about how to use polygonize (raster to vector). Particularly what to put in the field name box. The documentation states that it "Defines the field name in which the attributes of ...
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2answers
2k views

Identify polygon containing point with R sf package

I would like to be able to map geocoded coordinates to a region on a .shp file in R using the sf package. I can load up the map and plot it but I am struggling with the code to return the region for ...
3
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1answer
222 views

Density map of pedestrian paths and footways in QGIS

I need to identify public places within pedestrian areas in London, so I need to calculate the density of both pedestrian links and footways. I have classified my data according to the categorization ...
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3answers
2k views

Is raster lossy and vector not lossy?

I am new to GIS, in school for it actually, but I come from a photography / graphic design background. So that said, I always thought that vector graphics were not lossy (scale up or down, doesn't ...
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1answer
125 views

QGIS - Split Vector Layer returns empty layer

I'm to split a vector layer by feature with "split vector layer" tool in qgis I want to split the "switchboar" column after I fill the tool I receive the new empty layer Does anybody know why I don'...
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1answer
79 views

Styling/labeling specific features in QGIS?

I need to styling/labeling some specific features in a vector layer. I thought I could use the rule-based option in the style/label window with a "field=value" expression if i have only one specific ...
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0answers
46 views

Area calc gives odd answers [duplicate]

I made a shapefile from a DEM raster of Ethiopia, and I want to find the total area of the shapefile. I have changed the CRS of all files to Africa_Albers_Equal_Area_Conic (ESPG: 102022), and the ...
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1answer
699 views

Creating Vector Buffers in QGIS 3

I am mapping the accessibility of job opportunities in Detroit for those who rely on public transportation. To do this, I need to create a circular buffer surrounding each bus stop with a radius ...
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1answer
154 views

Create a pivot table for m-n relationship in QGIS?

My dataset comprises many polygons representing workspaces over a large area: -1 vector layer comprising my polygons (each polygon ID appears 1 time) For my online atlas however I need to obtain a ...
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1answer
351 views

Overlap of raster over a vector in QGIS

I have a single band raster image with values of pixel 0 and 1. There's another line vector layer over the same area. I need to find the percentage of line which is overlapped by the pixels of value 1....
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1answer
66 views

openlayers vector layer annihilating browser

I am trying to render a layer with polygons so that I can utilise the snap-to feature in openlayers. This layer has got a lot of data, I had assumed utilising the strategy: ol.loadingstrategy.bbox ...
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0answers
24 views

Vector CRS change 'extents too large'

Just trying to update an old project but for some reason it was set up in EPSG:4326, WGS 84. I have no idea what base maps were originally used to create it as they are no longer on the system, and ...
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1answer
1k views

Why is the Vector menu missing upon installation of QGIS 3.0?

Why is the Vector menu missing upon installation of QGIS 3.0? Others mentioned that some of the tools were missing from the menu when they installed a previous version, but in my case the entire ...
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4answers
580 views

Creating custom symbology in ArcMap?

Can I change the shape of the shield on a point symbol from square to circle as shown in the image? Alternatively, can I import symbols (specifically in a vector format) from Corel Draw? It can'...
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1answer
374 views

how to map/drape polygon layers over raster in QGIS?

I want to "map" or "drape" a 2D vector (polygon) over a raster. Obtaining a 3D vector with z-values according to the raster it's draped over. Most of my internet findings point towards v.drape. ...
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0answers
484 views

QGIS 3 missing vector tab mac [duplicate]

I installed QGIS 3 as instructed and the Vector processing tab is missing. I did uninstall all previous versions and Python.
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2answers
90 views

Calculate perimeter of a large polygon using geodesic calculations

How do I calculate perimeter of a large vector polygon (polygon set) which spans almost half the globe? I guess regular calculations do not produce accurate results in this case.
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0answers
44 views

Vector-Viewing Properties on Multipoint Geometric Correction in Erdas Imagine 2014?

I am following some old instructions that are not up to date with my latest version of Erdas Imagine. Where can I find the Vector viewing properties within the Multipoint Geometric Viewer? The ...
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0answers
33 views

Color Fluctuation when moving vector data over raster background in ArcMap

My ArcMap view has a raster background. When moving vector polygons, there is a colour fluctuation inside the polygon. If I change the polygon's symbology to hollow, the effect disappears and there is ...
2
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1answer
163 views

How to add time in geoserver layer with gsconfig

Find below the code I use to add a raster to geoserver through python3 with gsconfig-py3 (1.0.7) What I do from geoserver import catalog from geoserver.util import shapefile_and_friends from ...
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2answers
373 views

Joining raster and vector layer using QGIS?

I have a raster layer (DTM of central Scotland) and a vector layer that shows the location of archaeological sites. I want to know how to join the layers so that I can figure out what height each ...
3
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1answer
350 views

r - sf::st_within output is sparse geometry binary predicament format. How to convert to character or logical vector

The same question is asked here: https://stackoverflow.com/questions/49294933/r-convert-output-from-sfst-within-to-vector but I thought this might be a more suitable place for GIS related questions. ...
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2answers
168 views

Disable saving vector layer in QGIS, especially in DXF and KML file?

Can you help me on how to disable the exportation of vector layers especially in AutoCAD DXF, DBF File and ESRI Shapefile?
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1answer
241 views

Accessing “Save Vector Layer As” algorithm in QGIS Processing Model?

I'm building a Processing Model in QGIS that ultimately exports a points shapefile (vector layer) as a CSV in a different coordinate system than the shapefile. I ordinarily accomplish this in the "...
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1answer
42 views

Where can I find the viewing properties on ERDAS?

The instructions state to click on vector and then viewing properties yet I cannot find the viewing properties. When I click on vector in the main menu there is no option for viewing properties.
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1answer
108 views

Hydrological conditioning using stream vector in GRASS?

I would like to make an hydrological conditioning of a DEM using an available stream network in vector form. I know r.hydrodem but it doesn't allow to use the stream vector. I need something to burn ...
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0answers
483 views

clip vector by polygons in python script

I have a big shapefile, and I want to divide in x by y tiles. For testing purposes let's say just 2 by 1. I take the bounds of the big shapefile, create a polygon with smaller dimensions, and try to ...
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1answer
133 views

Keeping polygon's field when generating random points within overlapping polygons

I have a shapefile with a lot of polygons, representing events occuring for a given year. Every area can be covered several times, for every year it occured on the same coverage. Each polygon is ...
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2answers
2k views

Empty vector menu in QGIS 3.0.0

I installed QGIS 3.0.0 on a PC with French as default language. After changing the language of QGIS to English, the 'Vector' menu is empty and there is a French 'Vecteur' menu. Any ideas how to fix ...
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2answers
500 views

Clipping raster using a vector 's extent in GDAL

I am trying to take a raster (landsat_tm.img) and clip it to the spatial extent of the vector (clip.shp). My problem is that the band 1 values are being copied for all 7 bands. #import modules ...
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2answers
3k views

Clipping Error 1: Cutline polygon is invalid

I used the sample files located at this URL to learn QGIS: https://qgis.org/downloads/data/. I tried to clip SR_50M_alaska_nad.tif using a shapefile as a mask (alaska.shp). The problem is I ...
2
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1answer
38 views

Join from list with duplicates in list

I have a vector layer that i would like to join with a list. The problem is that my vactor layer does not hold any overlapping or dublicate objects, but my list does. The list does not have any ...
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1answer
1k views

Geoserver WMTS Service REST url

recently I have installed the Geoserver with vector tile layer extension, getting the data in pbf (Mapbox vector tile format) with this URL AND I think there is gzip problem too with this. http://...
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1answer
90 views

Visualising most likely direction of migration given points with ages using R?

I have a question about how best to visualise the predicted direction of migration given a set of points with estimated ages. Imagine I have a set of geo coordinates, representing communities. For ...
2
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1answer
261 views

Where can I get British Agricultural Field Boundaries as Vector Data?

I am looking for vector data outlining the agricultural field boundaries in the UK (Specifically Scotland, England and Wales). I have tried all sources of open source data I can find and looked at ...
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1answer
90 views

Create a vector layer from a raster layer contour

I am using QGIS 2.18. I have several sheets (about 430 MrSid raster files) that represents a full map. Each sheet is already geo-referenced. I need to create a vector layer that represents the ...
3
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1answer
84 views

v.reclass no output

I want to reclassify a polygon vector and use v.reclass. Feature type: boundary Name of column: LBA Reclass Rule: I use a .txt with the following content: CASE WHEN LBA = 68 THEN 2 WHEN LBA = ...
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0answers
29 views

Reducing/merging vector features after QGIS Vectorize?

i have a high res raster layer. Each pixel has an attribute value between 0 - 10000. I would like to vectorize the layer and finally get a geojson object. But atm i get for each pixel an own vector ...