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Questions tagged [vector]

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

0
votes
2answers
486 views

Getting feature coordinates from dynamically loaded layer using OpenLayers?

i want to load the coordinates of a point that is stored inside a vector layer and the vector layer is stored inside a layergroup. I do load the vector layers dynamically to the layergroup "Runs". So ...
2
votes
1answer
35 views

3-D Terrain effects for vectors in QGIS?

I'm a bit new to QGIS, and making a few maps of roads through mountains. I'm looking to have a 3-D effect within my 2-D map. I got a DEM, made a hillshade, and blended a basemap over it. Nice ...
0
votes
2answers
13 views

Reclassifying vector polygons based on text string to integer

So I am trying to reclassify a text string by searching for bits of strings and converting those strings to an integer value in a new field within the field calculator. e.g. I want to find all values ...
0
votes
3answers
50 views

Converting raster pixels to vector cells?

Is there any way to convert raster pixels to vector cells? I mean each pixel to a polygon. I tried the SAGA tool 'Raster values to points' by choosing cells option instead of nodes option. As a ...
1
vote
2answers
573 views

Seeking data source for worldwide urban/statistical areas as polygons?

I am looking for a shapefile (or any format really) that has worldwide coverage of major urban areas / statistical areas as polygons with names. Similar to what the US census Bureau' Core Based ...
7
votes
5answers
9k views

Merge overlapping lines in ArcGIS

I have a polyline shapefile containing a number of lines, some of which overlap. By overlap, I mean that they follow exactly the same path for some of their route, but also have bits that are not ...
1
vote
1answer
25 views

Calculating areas of polygons that match with overlapping raster threshold value?

I have a polygon of districts (districts.shp) and a raster of rainfall (rainfall.tiff). I want to calculate the area of each district that saw rainfall greater than various numbers. I'd like to ...
9
votes
3answers
20k views

Getting extent of layer in QGIS?

Is there a way to get the extent (bbox) of a vector layer in QGIS? I see that I can update the extent, but I am looking for the actually coordinates of the extent.
0
votes
2answers
53 views

Seeking tool to work out overlap between two polygon layers and their statistics using QGIS

I have two polygons in QGIS. One is a land-use map, which polygons that include different types (forest, agriculture, urban etc). I also have a vector polygon that represents a flood extent. I want to ...
5
votes
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 ...
2
votes
2answers
400 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 ...
0
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0answers
17 views

Can only select certain polygons

I have only one vector layer on my map, and it's not letting me select some polygons. For instance, this is what happens when I try to select a certain polygon (the yellow outline with the blue star ...
-2
votes
1answer
228 views

Why don't shapefiles online contain the coastline (country borders)?

I have searched everywhere and Geofabric has the best packages of shps yet doesn't have the coastline of countries. I'm talking about the line that demarcates a country i suppose they are called ...
0
votes
1answer
53 views

Changing unknown coordinate system of raster data to known coordinate system?

I have a set of raster datasets and have created a raster catalog out of them. These datasets should cover specific vector data. I have just realised that the raster as tif data have a coordinate ...
1
vote
1answer
34 views

Map based on highest percentage from different variables

I've the 8 social classes (see under) for +- 900 polygons. I would like to create a new column that keep only name of the main social class for each row (based on the percentage). After that I would ...
14
votes
5answers
9k views

Defining layer CRS and avoiding CRS dialog in PyQGIS?

There is an existing Shapefile, which I want to add. At the moment my code looks like: self.iface.addVectorLayer(self.shpFilePath, "Track", "ogr") It works fine, but i want to define the crs within ...
3
votes
3answers
339 views

Plotting Geo Points with “by arc centered at” Instructions

A recent Supreme Court decision redefined the legal boundaries of California along the Pacific Ocean: http://www.theverge.com/tldr/2014/12/15/7397085/supreme-court-california-boundaries-map I am ...
1
vote
0answers
45 views

Fixed distance buffer is oval in QGIS?

I want to create circles of diameter 20m in QGIS. I create a point and then use vector - geoprocessing tools - fixed distance buffer. My problem is that the size is crazy and worse, the shape is not a ...
0
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0answers
18 views

Computing Moran's I for vector data in GRASS

Does GRASS allow for computing Auto-Correlation using Moran's I statistic from vector files. GeoDa and ArcGis can do this. But seems grass lacks this functionality https://grass.osgeo.org/grass76/...
3
votes
3answers
3k views

“Node tool: could not snap to a segment on the current layer” message

I have a strange issue. Editing a layer with node tool I get always the following message: "Node tool: could not snap to a segment on the current layer." This error happens to me even with a fresh ...
1
vote
0answers
115 views

PyQGIS raster image shifted from vector shapefile

I previously asked a question about my raster image being larger and shifted over from my vector image here, but now I realize that the raster image is only shifted to the left and up from the vector ...
-1
votes
1answer
44 views

Summing amount of vector points in area of another vector using Google Earth Engine?

So I have 2 layers each are both vectors and not images. here the link: https://code.earthengine.google.com/e7aec6c9683ed40a959a01a7ed5dd31f I have written some basic code to display the data which ...
0
votes
2answers
62 views

How to convert multiple shapefiles of different geometries into a georeferenced raster

I have multiple shapefiles extracted from OSM vector data, as shown in the image bellow: How can I render this into a raster of a specified resolution? Is there a way to do that using QGIS or ...
3
votes
1answer
33 views

Fixing self-connect polygon in QGIS 3.2

I'm trying to clip a soil map layer and am getting invalid geometry that affects my clip result. The problem appears to be a self-intersecting polygon. I've tried using the 'check geometries', and ...
4
votes
5answers
4k views

How to sum raster image values with vector overlay

I'm new to this and haven't been able to figure out how to do this on my own. I have two files: a raster image of land use data and a vector-based shapefile of my territories. The raster image has ...
2
votes
3answers
120 views

How can I save a vector layer to memory (or is there a reason QGIS doesn't allow this)?

It's impressive how many different vector file formats QGIS (using ver 3.6.0) allows me to save a layer as: But as far as I can tell, QGIS doesn't allow me to save a vector layer to memory. In my ...
0
votes
0answers
14 views

Clipping features with the attributes of another feature

I have a vector polygon for a catchment which contains numerous subbasins. In addition, I also, possess another vector polygon showing the impervious areas of the catchment. What I want to do is ...
0
votes
0answers
48 views

Creating memory layer with .png image using PyQGIS?

In Aligning Raster and vector layer using PyQGIS when they do not match?, someone gave a solution for creating a point memory layer to correctly align a raster image with a vector. I am wondering ...
3
votes
1answer
58 views

Buffer with unknown distance by adding numerical values of a column until a maximum

In my QGIS project, I have a vector of polygons representing slope zones around an archaeological site and I want to calculate the area which is necessary to supply the ancient population with a ...
1
vote
1answer
283 views

Aligning Raster and vector layer using PyQGIS when they do not match?

Relatively new to GIS. I've created a vector layer of points based on row/col position of high population density pixels in a raster layer. The layers do not align even though they have the same CRS, ...
3
votes
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 ...
1
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0answers
40 views

Storing a large amount of vector layers on PostGIS

I'm developing a web application where PostGIS will be used as a vector tile server backend to serve mvt tiles. For each user of the application at least one vector layer will be created. So, ...
0
votes
1answer
61 views

How do I get Table from Vector layers for use with joinattributestable

I am attempting to run: processing.runandload('qgis:joinattributestable', layer1, layer2, 'id', 'id', None) To join my tables and output to a temporary viewing layer. layer1 and layer2 are both ...
3
votes
3answers
295 views

QGIS split vector layer gives me GPKG files but I need shp files

QGIS 3.6.0 I am new to QGIS software and not very technical on its deep workings. I am trying to split a .shp file using split vector layer. I need .shp file outputs but it auto creates .gpkg files. ...
0
votes
1answer
20 views

How can I keep the minimum when converting from shapefile to raster

I have a shapefile that I am trying to convert to raster. The shapefile has overlapping polygons. I would like to keep the minumum value of these overlapping polygons when converting to raster. ...
2
votes
1answer
54 views

PyQGIS code for Merge Vector Layers

I've been trying to automate the merge vector layers via PyQGIS but I can't seem to get it right. This is my code: import os import processing loc = r"C:\Users\loc" os.chdir(loc) shapelist = os....
1
vote
0answers
44 views

Can relation reference in QGIS and QField be used to fill stochastic matrices?

I am a novice GIS user and am just seeing the potential for relations in my work. A problem I've come across and would like a solution to it. I have two stochastic matrices (risk matrices) that ...
4
votes
0answers
41 views

Referencing an output in an expression in process modeler

In the process modeler, I'd like to reference an output of a previous step as one of the parameters of an algorithm. In this case, the previous step was clipping a large raster and I want to use the ...
1
vote
2answers
59 views

Selecting latest date with QGIS field calculator?

My shapefile contains columns like "Street", "number" and "date". What I want to do is, to find the latest date (where we have done house services). If we have 2 dates for one house number ("number")...
1
vote
0answers
684 views

Editing QGIS point layer to retrieve attributes of intersecting line layer? [closed]

I'm creating a custom editing form using QGIS 2.0 and would like to modify the mouse event when creating a point. I've gotten a start by reading Programatically check for mouse click in PyQGIS? In ...
3
votes
2answers
68 views

QGIS how to sum a certain vector field inside a polygon and populate a field in the polygon?

I have a polygon with vector point civic addresses inside it. Each civic address has a different number residence. I want to sum the total number of residence inside that polygon and it populate a ...
0
votes
0answers
24 views

QGIS 3.4 (mac) std::bad_alloc error

I get the above error when trying to add a new raster or vector layer. Does anyone know how to correct it as the resulting projection is nowhere near where I need it.
5
votes
2answers
2k views

Splitting lines at a specified distance

Does exist some plugin with it is possible to Splitting lines at a specified distance in Qgis?
0
votes
2answers
67 views

QGIS Hex grid with the shape of vector

I'm trying to make a hex grid net with the shape of polygon. Unfortunately, the grid net is in the rectangle shape (see the screenshot). Any advice how to do it?
2
votes
2answers
44 views

Unite several polygons that share boundaries in QGIS

My study zone is in the middle of two geologic maps with two different shp files. Is it possible to remove the boundaries of the polygons between these two maps that are created at the union of ...
2
votes
1answer
46 views

average weighted value by region with use of Voronoi in Qgis

I have a vector layer of Voronoi polygons. This layer has three columns -longitude, latitude, Z-value. I need to cut polygons by mask of administrative area and then I need to calculate average-...
1
vote
1answer
32 views

QFIELD digitalizing window never close

I use QFIELD on Android 5.1.1 (Samsung Galaxy), I tried several versions of QFIELD without solving my problem: when I click on a vector I just created, the attribute window opens on the right side of ...
0
votes
0answers
22 views

Export vector graphic from ArcGIS?DPI setting?

When I plot the map in ArcGIS, I wish to export it to the vector figure. And the file is shapefile, no raster files loaded. However, when I try to export the Map. The setting from the window ask me to ...
1
vote
1answer
116 views

QGIS 3.6: Vector “Polygons to Lines” missing

I use the tool Vector-->Geometry Tools-->Polygons to Lines all the time. It is in the menu up until 3.4. In 3.6, that menu item is no longer available. Where did it go? Is there another way to do ...
0
votes
0answers
11 views

Get visible polygon form one point (visibility graph with one point)

Problem I would like to get the visibility of one point in regard to a polygon layer. E.g. which island can I see from the beach. What I found It's possible to get a visibility graph via Grass v....