Questions tagged [vector]

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

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73 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
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1answer
78 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 ...
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1answer
290 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, ...
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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 ...
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43 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, ...
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1answer
64 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 ...
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3answers
473 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. ...
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1answer
67 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....
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0answers
64 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
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0answers
49 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 ...
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2answers
65 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")...
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687 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 ...
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2answers
77 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 ...
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0answers
30 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.
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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?
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2answers
70 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?
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2answers
46 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
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1answer
48 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-...
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1answer
33 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 ...
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1answer
160 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 ...
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0answers
12 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....
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0answers
193 views

Error in reproject vector file using GeoPandas

I have a vector file (in this case shp file) and I read it with GeoPandas (gpd). vector_folder = r'C:\poly' vector_file = 'poly.shp' df = gpd.read_file(os.path.join(vector_folder,vector_file)) df ...
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1answer
920 views

TypeError: “unsupported operand type(s) for /: 'int' and 'list'” in QGIS?

In a academic project I've produced a small python script for watershed analysis. This script relates shapefiles attributes and generates a .txt file. I am trying to adjust the script to use within ...
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2answers
70 views

Calculate the percentage of a Line passing through Polygons

I have a polygon layer of a region (100% coverage, no overlaps) and a line layer in the same region. I want to calculate for each line to which percentage it crosses certain polygons. I have seen ...
2
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1answer
80 views

Creating new lines based on another line feature and point feature using QGIS?

I have line layer (roads) and point layer (milestones) and I need to create a new line layer based on roads layer, where the start and the end points will be milestone points. Can you advise me some ...
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3answers
66 views

Calculating the shortest distance coordinate to vector layer

I want to calculate the nearest distance from each coordinate in a vector layer containing more than 17 000 coordinates to another vector layer. I tried the GRASS v.distance tool but it gives the ...
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0answers
579 views

Polygonizing only pixel values of 1 from raster using QGIS?

I have a raster mask that I have created in QGIS (2.2.0) that consist of 0, 1 and nodata values. I would like to end up with a polygon dataset that consist of only the value of one pixels from this ...
5
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1answer
3k views

Getting result in metric from QGIS Distance Matrix tool in QGIS? [closed]

I'm trying to calculate the distance between points in layer with distance matrix tool. And keep getting strange results no matter what. Like this MASTER ------------SLAVE ---------------- DISTANCE ...
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2answers
279 views

Estimating resolution of vector data?

I got an old vector dataset with polygons covering a continent. The data was first published on paper at scale 1:5 000 000 and was later digitalized. I don't have the original data and no information ...
3
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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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1answer
114 views

How can I export selected features in Processing Modeler?

This question is a follow up from a suggestion from this thread: How to export a single feature (line) from multiple layers and export to individual layers? I'm creating a batch process that selects ...
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0answers
138 views

Does any version of QGIS support GDB 10.5?

Does any version of QGIS support GDB 10.5? I have a GDB 10.5 file that I need to open in QGIS and I can't. I'm using QGIS 3.6. The file is named Virginia_Parcel_Dataset_2018Q4.gdb -- it can be ...
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59 views

ArcGIS: Train Support Vector Machine Classifier on a Segmented Raster

I have a raster (.jpg) which I have segmented utilising Segment Mean Shift to smooth out JPEG artefact (aim is to classify it as accurately as possible for conversion into vectors). START .JPG Input ...
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1answer
96 views

How to make a rectangle of an exact size/aspect ratio in QGIS?

Is there any way in QGIS to make a vector layer with a rectangle of an exact size or aspect ratio? Ideally, it would be nice if the rectangle from extent tool could be limited to a set aspect ratio, ...
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0answers
116 views

Vector Rasterize Error

I am running QGIS 3.4.4 With GRASS 7.4.4 and I get an error while rasterizing a vector layer and I don't know why. The same error pops up while using GDAL->Rasterize(vector to raster) and while using ...
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2answers
110 views

What is the proper name for the “Venn diagram” of a set of geometries?

Sometimes, you have a set of overlapping geometries, and you want to generate an output like this: Image taken from this answer. The resulting polygons have no overlaps; each region of space is ...
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1answer
51 views

Replacing Multiple Polygon Geometry

I am carrying out a piece of work in ArcGIS 10.4.1 that involves realigning polygons to an updated vector map. The polygons in question are planning permission boundaries that are created showing the ...
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4answers
4k views

Checking if polygon fits inside another polygon using ArcGIS Desktop?

How do I check if one polygon fits inside another polygon? Furthermore how do I automatically check if one polygon fits in other polygons of my shapefile? I have a shapefile with thousands of ...
2
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1answer
59 views

Translating vector by raster DEM data in QGIS?

I'm trying to follow the set of instructions here: https://twitter.com/imhere_asia/status/1023055838787690496 [EDIT] Pasting the instructions here for reference so people can avoid twitter. ...
3
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1answer
138 views

Exporting crown boundaries from tree segmentation in R?

I am using lidR package to segment my trees using lastrees directly from the points clouds. The function works fine, however I would like to export to vector file the canopy boundaries from ...
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0answers
22 views

Prevent Export/Save As of Vector Layers/Shapefiles

I have created a database using postgreSQL and created multiple users assigned with different roles Some of the users can only select and view the data and not update or delete any record. It works ...
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1answer
75 views

How to batch geocode country names to polygons? [closed]

I have .xlsx dataset file with column "Country Name" and "Country Code" which have text records. I would like to geocode (assign) it to adequate country polygon in batch mode. The expected result ...
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1answer
39 views

QGIS3 How to export shapefile symbology to scale?

I'm looking how to export in QGIS3 a vector layer with a determined scale. It was straightforward in QGIS2 when I was exporting to a shapefile I had the option symbology scale but it disapear in QGIS3 ...
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2answers
266 views

Create line segments at point coordinates in QGIS

I have a point vector layer with angle field. How can I create line segments at these points with certain length and angle? I did this with style options but I need this physically as lines vector ...
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2answers
131 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 ...
5
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1answer
454 views

Why is QGIS points in polygon so slow when select is fast?

I'm looking at QGIS 2.18.9 and using a polygon to select points from a large point layer (file based tab file). I wondered why the process is so slow if you use plugins or analysis options? I ask ...
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2answers
7k views

How do I find vector line bearing in QGIS or GRASS?

How can one extract the bearings from a set of lines in a vector file? I'm trying to find the bearings of several straight vector line segments (simplified contour lines, actually) and can't figure ...
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1answer
393 views

QGIS's “Points in Polygon” counts zero in every census tract

I am mapping the location of incidents of asthma using QGIS. I would like to count how many points are in census tracts to better understand the areas where asthma occurs most frequently. My map ...
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0answers
27 views

Vector to grid - Computing statistics by grid cells

I have a vector point data from drifting buoys (speed, direction, sst, slp) that I want to analyse in a grid. What are the right tools for this? Example of my points data below. Each point has the ...
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1answer
81 views

Saving output from vector-tools as temporary file or straight into input layer?

In mapinfo it is possible to save an output without creating new shp. Either by saving into the input- layer or to a temporary file. For example if you want to ”union” two layers you may want to get ...