Questions tagged [vector]

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

Filter by
Sorted by
Tagged with
3
votes
1answer
2k views

Why can't I clip my Shapefile?

I've tried all of these solutions (How to clip a line layer based on polygons with QGIS?) and still can't clip a shapefile. I'm trying to create a coastal shapefile for one region (NW France) from a ...
1
vote
0answers
17 views

Interactive tool for editing TIN data

I created TIN to generate DTM using Mass points from Lidar data and river data that I made from stereoplotting. TIN results show there are several locations where the river elevation floats. So I have ...
1
vote
1answer
85 views

Turning “normal” Vector Data into a GIS

I have a map in Adobe Illustrator with several vector layers. ( Therefore the vector data have no spatial reference and no attributes. What is the best way to turn these vector data into a GIS and ...
3
votes
1answer
42 views

Creating DEM Contour files from shapefile line data in QGIS

There are many question occurring on this forum regarding this issue, however the issue I am facing has not been answered in Generating DEM from contour Shapefile using QGIS?, which is that I have ...
1
vote
1answer
107 views

Replacing multiple polygon features by their shared center point in GRASS GIS

I have three polygon features of the same category in a larger vector layer from which I would like to create a center point (mean coordinate) that holds the same attributes as the three polygons. I ...
0
votes
0answers
19 views

Identifying Optimal Site Locations with Variables Weighted By Level of Importance

I'm using QGIS 3.4. I have a point shapefile representing population density, and I have used the "K means" vector tool to identify the 12 most optimal locations for service centers that would serve ...
0
votes
1answer
84 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 ...
2
votes
2answers
1k views

Convert point to line

I recently completed a long bike trip and used a GPS to gather data during the ride, including average speed and elevation loss/gain. I imported the data into QGIS. These data were gathered per mile, ...
1
vote
1answer
22 views

Intersection of raster and vector - road file and maps (tif)

ArcGIS Desktop 10.6.1 I have a railroad vector layer (with 10 rows, that is 10 segments) and 30 USGS historic maps (tif files) that cover that route. I'd like to find the intersection, such that one ...
1
vote
1answer
772 views

Problem or ERROR in converting from raster to vector!

I wonder if anyone could help me out, i am kind of a beginner at QGIS. I´ve built a DEM for a project that i am developing than i´ve made the slope raster with the terrain analysis,it seemed that ...
13
votes
3answers
11k views

Calculating roundness/compactness of polygon?

I am trying to find ways to quantitatively describe the shapes of various polygons. For my project, these polygons represent lakes, rivers, lagoons, and parks. So they can be almost any shape. One ...
1
vote
2answers
468 views

How to convert vector format (geopackage, shapefile) to raster format (geotiff) using rasterio without template raster

I'm looking to create a raster given just a geopackage (or shapefile, or other vector format). I don't have a template raster, and all I wish to do is burn the shapes into a raster using rasterio. ...
1
vote
0answers
34 views

QGIS: Polygonize error

Running the Polygonize tool in QGIS keeps generating the following error: Processing algorithm… Algorithm 'Polygonize (raster to vector)' starting… Input parameters: { 'BAND' : 1, '...
2
votes
3answers
4k views

Splitting raster in QGIS? without cliper

I have polygon grid layer and raster image whitch want to split with my grid layer to have 9 new raster layers. I was doing it like this guy but my QGIS stop working and shut down every time when I ...
2
votes
0answers
23 views

Query of line direction histogram plugin

I was wondering if anyone could explain how this plugin works I have had a play around with it and I do like how it visualizes how vectors are orientated. However I ran one and opened the CSV file ...
1
vote
0answers
147 views

Determining Affine Transformation Parameters? [duplicate]

I am trying to use the qgsAffine plugin to do the transformation but I have no idea in its usage. How to find the transformation parameters? I found some posts suggest using the OpenJump How to use ...
5
votes
2answers
2k views

Seeking QGIS affine equation?

I am at the mercy of a govt authority who have provided utility information in a cad format with a 0,0 origin and a nonsense grid. About a dozen files, the grid and origin are entirely arbitrary. To ...
1
vote
0answers
16 views

Calculating the distance of raster cells from a vector within a polygon using QGIS

I am quite new to QGIS and am trying to use QGIS 3.6 to create a raster layer of calculated values of the minimum distance of each cells within a polygon (orange) from a vector (the river channel in ...
2
votes
1answer
30 views

Store results including style in vector format for QGIS, ArcGIS [closed]

As I am wrapping up my project, I would like to make my results available for download. There are however many flavors to choose from and I was wondering what format is best. My criteria include: ...
1
vote
1answer
82 views

Automatic correction of many topological errors in shapefile?

I have a database with topological error. In particular I have an overlay of polygons. I would like to correct these errors. I thought to use an automatic procedure since I have a lot of errors. I ...
2
votes
0answers
23 views

How to delete a file after processing an algorithm in QGIS 2.18?

I am trying to delete an intermediate file ("Temp_merged.shp") after running the singleparts to multiparts algorithm in QGIS 2.18. import glob, os, processing path_to_shp = "C:/Temp/Tracks/" ...
3
votes
1answer
73 views

Merging all vector files within directory with QGIS?

I am unsuccessfully trying to merge all shapefiles in a given directory using QGIS 2.18. I do not want to navigate to the folder using QGIS GUI tools. Instead, I want my script to include all ...
2
votes
3answers
352 views

Extracting a small subset of an .sdc file

There are some line features in the form of an .sdc file. I do not need all the data in the file, just a very small subset of it. I understand that .sdc files are highly compressed, and my file is ...
1
vote
2answers
515 views

Converting Direction Of Travel OSM vectors from “system” to another?

I have a painful doubt according Direction of Travel (DOT) vectors in OSM data. I'm using ArcGIS10, and a OSM data shapefile. I have a OSM road layer, that has many "Both ways" vectors and many "One ...
3
votes
1answer
394 views

Aligning raster data to vector data in QGIS?

I'm in the midst of aligning century-old maps (of Paris) to vector data of the modern same: Qgis' Georeferencer tool works fine, but doing the entire city that way is a gargantuan task. Paris hasn't ...
2
votes
0answers
47 views

Vector map (rivers) to Raster. [ **ERROR 1: Wrong value for -outsize parameter.**]

I want to transform this vector map: To something like this I only tried to convert the vector map through Raster> Conversion> Rasterize But I get this Error: QGIS version: 3.6.3-Noosa QGIS code ...
1
vote
0answers
19 views

Can QGIS be used to calculate the up-slopes (total area draining to a specified point) of multiple separate points simultaneously?

I am trying to calculate the area draining to a point of 240 separate points using QGIS. At the moment I'm using the Saga - Upslope Area algorithm to individually work this out for each of the 240 ...
2
votes
0answers
45 views

Isolating main polyline using QGIS?

I am trying to convert a line shapefile with branches into just one polyline, actually deleting every other diramation. Imagine something like this: :________|__________|____|||______ into :...
21
votes
3answers
10k views

How to access feature classes in file geodatabases with Python and GDAL?

I am trying to access a vector dataset in a ESRI File Geodatabase using Python + GDAL. I have successfully compiled GDAL with the file geodatabase API. The FileGDB driver is working correctly since ...
1
vote
1answer
53 views

Python: Convert shapefile to GeoJSON whilst stripping and renaming fields

I'm writing a Python script to convert shapefiles into GeoJSONs but I would like to remove many of the fields as they are redundant and rename the ones I am retaining. Here's an extract of where I ...
0
votes
1answer
24 views

Keeping 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. ...
0
votes
1answer
212 views

How to make layer stacking in envi for landsat 8

I downloaded landsat image 8 and i made layer stacking for RGB layers in ENVI (Bands 4,3,2) to classify the land cover types. but the problem appeared when i conducted supervised classification. I ...
-3
votes
1answer
9k views

A easy way to create buffer in QGIS?

In the old version of QGIS creating buffer was relatively complicated task. Basically you had to save your layer as a new one with metric cylinder CRS in order to calculate distance correctly. If ...
1
vote
0answers
29 views

QGIS 1.8 and Shapefile units in seconds [closed]

I have QGIS 1.8 on Centos 6.5 (I cannot update this system). I have a problem with opening a shapefile layer with units in seconds (created in ERDAS). QGIS doesn't display and doesn't save ...
2
votes
1answer
91 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 ...
1
vote
3answers
129 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 ...
2
votes
1answer
94 views

Retrieving lines radiating from point with v.select in GRASS GIS 7.6

I am attempting to select lines that radiate from a point using v.select in GRASS GIS 7.6 (also tested with 7.4.4) in Windows 10. I start out with 48 lines radiating from a point every 7.5 degrees. ...
15
votes
6answers
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 ...
1
vote
1answer
49 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 ...
0
votes
0answers
26 views

Loading layer with QgsVectorLayer in standalone PyQgis 3

I can't seem to figure out why my layer won't charge in QGIS. After reading many topics, it seems to be linked to the prefix path. However changing this, does not seem to work (I tried around 10 ...
0
votes
1answer
39 views

Correcting topological errors in QGIS?

Using the topological corrector inside Qgis I have identified overlapping polygons. My situation is represented into this image My polygon of interest is located below another polygon (the red ...
1
vote
1answer
31 views

Is there an alternative function which does the same thing as clip raster by masked layer on QGIS?

I am having some technical problems with the clip raster by masked layer and I faintly remember using a different method a long time ago for a similar problem. Anybody familiar with another function?
1
vote
0answers
40 views

Vector tile generation

I have a full planet imported in PostgreSQL with imposm3. What is the best way to generate vector tiles (MVT in .mbtiles) from PBF/PostgreSQL with maximum hardware utilization (distributed generation ...
4
votes
2answers
176 views

Creating building shadows in QGIS?

Can anyone think of a simple way to create a polygon to represent building shadows? I have a shapefile with height information for the buildings and I want to create a simple plan looking like the ...
5
votes
2answers
131 views

Splitting polygon using another polygon in QGIS?

I have two polygon layers (yellow and orange in the attached image). I am wondering if there is a way to get a count of the number of isolated areas that the orange polygon has divided the yellow ...
1
vote
2answers
121 views

Problem with intersecting lines over a polygon layer in QGIS

I have a shapefile with lines (a road network) and I want to intersect it over a polygon layer in order to finally have a polygon layer (each cell has an ID number) with the intersected lines for each ...
1
vote
0answers
511 views

Converting vector in NED to ECEF? [closed]

I have a geodetic WGS84 position, lat, lon, alt, and direction cosines from the same point, uN, uE, uD. I'm brand new to geodetic/ecef conventions. How do I take a vector (say, a unit vector with ...
3
votes
1answer
91 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 = ...
0
votes
2answers
41 views

Reclassifying vector polygons based on text string to integer using Python Parser of ArcGIS Field Calculator?

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
2answers
755 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 ...