Questions tagged [vector]
A coordinate-based data model that represents geographic features as points, lines, and polygons.
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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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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 ...
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Road Network Accessibility
I am working in QGIS with 3 layers: one is road network and other is hospitals and locations of accidents , later two layers are as points, I want to figure out what accident location (points ) are ...
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Raster to vector, matching another vector in QGIS?
I have taken a pdf of a map and managed to import it into my map using the QGIS geolocator. Now I want to convert the resulting raster layer to a set of polygons that match up with the existing vector ...
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Clip a raster by vector in QGIS while keep raster cells that do not touch the vector boundary
I am using QGIS 2.18.11 with the Semi - Automatic Classification Plugin (SCP). I use Sentinel 2a as well as Landsat 8 Scenes and run some Classifications with SCP.
Inside my Sentinel 2a scene I have ...
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import OSM to GRASS not a valid flag error
I've downloaded an OpenStreetMap data extract from geofabrik.de. I installed the v.in.osm extension. When I run
v.in.osm -l input=country-latest.osm.pbf
it works well enough to identify the ...
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Include polygons that don't contain line segments in Summarize
I would like to get a summary of road lengths per township, but also include townships that have no roads.
Using the first answer from this question Calculate line distances inside of polygons using ...
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Extracting Roads and Trails from SPOT Imagery
Is it possible to extract Roads and Trails vectors from SPOT Raster Tiff Image? Actually I have tried SPRING software to extract road vectors from this raster. Yes, It gives good result, But ...
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Difference tool QGIS
I am trying to use difference tool in QGIS to get a mask out the ice coverage from a base vector map. The number of features in ice coverage is around 2000 while my base map has 237 features. I am ...
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334
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Least Cost Path point & polygon QGIS
I am trying to calculate the least cost path between a point and a polygon using the tool "least cost path" from SAGA. This tool works fine with the exception that it calculates the least cost path ...
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Merge Symmetrical Difference and Intersection Line
I tried to merge these two types of lines I have from using the geometric tools "Intersection & Symmetrical difference". They end up being part of the same line and I want to join them together ...
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Getting vector layers to appear in map rendering?
I am using QGIS 2.18.7 on Windows 7. I am attempting to write a pyqgis script that will create a map rendering and save it, using a raster layer, a polygon layer, a line layer and a point layer. The ...
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Intersection of two vector shapefiles?
I have a shapefile of the 8830 election precincts in Texas as of the 2016 election. I also have shapefiles of the Texas US House districts and the Texas Senate and House districts. I want to ...
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Creating minumum polygon coverage from set of lines in ArcGIS Desktop?
Does anyone know of a tool or methodology I could use to create a polygon layer enveloping the end nodes of the line layer using ArcMap?
I need a coverage layer for the lines below, I was hoping to ...
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Problem with style with svg file for linear layer
I have a problem with styling line with svg file. Line should be style with image like below:
but on layer it looks like this:
My style is:
<?xml version="1.0" encoding="UTF-8"?>
<...
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Simplify multidimensional list of points into track/linestring
I have a bunch of points representing the movement of a target:
Track_123 = [Point_1, Point_2, Point_3 ... Point_N]
Where each point is a multidimensional vector:
Point_N = [Lat, Lon, Time, Speed, ...
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420
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Calculating normal vector distance between two surfaces using ArcGIS Desktop?
I have two surfaces mapped out from seismic data, imported as x,y,z datasets in ArcMap and then converted to rasters using the point to raster tool. These surfaces are rugose (seafloor and an ...
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Clipping raster layer using vector polygon as mask in qgis
I wish to clip an area out of a raster layer for further processing based on a previously created vector polygon layer. Thus vector being the mask for the raster layer.
I am on QGIS.
I tried Raster>...
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947
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QGIS: Raster to vector too large
I am working with a DTM of 5x5m for a large area (already clipped it). I calculated the slopes and want to maintain only the slopes above 2 degrees. I already used the raster calculator to set all ...
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Trouble when append values from attribute table of shapefile
I need to record the values for all fields of a shapefile in a dictionary. When I run a loop that for the first index of list picked up values from attribute table correctly. The problem for the ...
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906
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QGIS: Python script to batch clip vector layers and set their CRS
Here below the sript I'm trying to run.
clip_zone is a polygon and in my input_folder, I have a point layer and polyline layer.
#Tell Python where you will get processing from
sys.path.append('C:\...
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67
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Codecing vectorial field qgis
I have vectorial data that I have loaded in qgis setting as UTF-8. I was checking if the values of field in atribute table is standartized. So I am creating a script to do it. However, when I print ...
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Matching vectors in separate layers in QGIS. Overlay Question?
I am not exactly sure how to phrase this question since I do not know the term I need to use for this. I am planning driving routes to cover an entire state's road system. I already have a driving ...
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Fixed buffers Nodebo as shape
I want to make different buffers with Nodebo, tool fixed buffers. e.g. 300m 500m from layer a 200 m and 300 m from layer b. etc. When I try to set the file direction, there is only the possibility to ...
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370
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Shapefiles not editable anymore?
From this morning if I open a qgis project all the shapefiles are not editable anymore. I've tried different projects in both 2.14 and 2.16 qgis versions. Has anyone encountered the same problem?
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Add feature no longer working
I'm using QGIS 2.16 but this was happening on 2.14 as well and I hoped updating would fix it but no.
I create a new shapefile, doesn't matter whether it's a point, line or polygon, toggle edit ...
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378
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Cropping vector map into tiles with QGIS - how to get around shapefiles which have stray points on boundary of tiles?
I am trying to use QGIS to generate a set of tiles in Shapefile format from a vector coastline map.
My script is correctly generating the 5x5 degree tiles I want, however a few tiles clearly have ...
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470
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Problem with viewing DXF files in QGIS
The problem of getting from DXF format, to display in QGIS correctly. We have loaded it in and fixed the rotation and TTF font mapping problems. That is all great, however the objects are coming in ...
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56
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Missing vector features when import from .sqlite to postgis?
I imported vector data from a .sqlite file to PostGIS but not all of my vector features imported.
I haven't been able to determine a reason for most of the loss of features between the databases (...
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65
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Clipping vector polygons by previous vector polygons in same layer in QGIS
I have extremely large datasets as vector polygons in single layers. The polygons are in an order. I want the previous ordered polygons to clip the later polygons. Therefore, once an area has been ...
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256
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Importing geospatial PDFs with QGIS
I've been using GDAL to work with geospatial PDFs to make geotifs and have been running into some issues, so I started working with QGIS. A fine product I might add.
When I select a directory ...
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369
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Save shapefile as grouped/layered vector file
I want to get the 10m natural earth countries file into a Mercator projection and then into a vector file (SVG, ai, etc) where for each country, its main land and any of its islands are in a single ...
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How do I generate a sampling path by numbering points?
I need to number points from left to right and then the next row of points the numbering must continue from right to left, then again from left to right the row thereafter - and so on, and so on.
...
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58
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Using arcpy to add several rasters
I need to do some raster/vector processing on some non-overlapping tiles. My python script needs to find the correct tiles and then extract the raster values and count them up. My script needs to be ...
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GRASS: strange classification output and reject map from "i.maxlik"
I am trying to perform a supervised classification with "i.maxlik".
I have three bands: 1) elevation (a dem); 2) reflectance (derived from Landsat ETM+ band4); 3) cumulative solar radiation (derived ...
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I clip a raster with a vector mask in qgis, the result is correct but its a little bit of, why is this?
On one side the result is "bleeding" over the vector on the other side its more than one raster pixel from the vector on the inside.
How to correct this?
https://i.stack.imgur.com/xPMiW.png
https:/...
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602
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Using MySQL vector with QGIS?
I have a problem with mysql vector; when I connect to the MySQL table (containing a geometry column), the attribute table is loaded correctly, the map is centered properly but the geometries are not ...
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126
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Data dependent override on colour and linewidth of line pattern fill not working after upgrade to QGIS 2.12
I have recently upgraded to QGIS 2.12 which has resulted in a problem with one of my projects, whereby the data dependent override of the line width and colour of a line pattern fill and SVG marker ...
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50
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Accessing feature legend style name using QGIS?
I have a vector layer classified by some combination of field values.
I want to add a field for each feature, filled with the legend style name of the element.
How can I do this? via Function Editor?...
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How does qgis render vector layer on screen ? How can I do the same in a mobile device
Can you please tell me how does qgis software render the vector layers on the screen. I have a geojson file and I need to map its contents on the screen just like qgis does but without using base map ...
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935
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Distance Analysis from single point to multiple points on vector layers
Is it possible to do the following in QGIS:
Create a text file that plots the distance from a single point (stored in one layer) and multiple points (stored in another layer).
I have tried to use ...
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775
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Alternatives to QGIS difference tool
I have a very large shapefile of building polygons and a shapefile of the country they reside in (England). The building shapefile was built by merging 94 smaller shapefiles. Both files have the same ...
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Clipping polygon using QGIS?
I want to clip a polygon using Qgis "clip" tool. The problem is that the resulting polygon presents areas that where not clipped off.
The first screenshot shows the layer I want to clip using the ...
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How do I create a map of addresses?
This is a tricky one.
A little context first: Bentiu wiki page: https://en.wikipedia.org/wiki/Bentiu + OSM map of Bentiu refugee camp, South Sudan: http://www.openstreetmap.org/#map=16/9.3314/29.7920
...
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646
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How to create contours from an IDW raster
I'm new to QGIS and am trying to create vector contours from this IDW raster. I followed Ujaval Gandhi's "Interpolating Point Data" tutorial step by step but am not getting the same results for step ...
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Passing ranks to different buffers?
I have a SpatialPointsDataFrame which refers to a city.I needed to perform a join with a dbf in order to attach the population column which i did with help from a couple of people from here. Next step ...
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Why does the transformation bring bad results?
I have this map which has a polygon drawn on it. For the background map I use a WMS via ol.source.TileWMS and the polygon uses a ol.source.Vector object. Normally my view projection is EPSG:31467 but ...
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Select features intersecting a linestring in QGIS
I wrote a python plugin that grabs all (vector, linestring) features between two points on the map. At the moment, I select all features intersecting the rectangle around these two points, and then ...
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Tool, API of or code samples for calculating spatial similarity between Lines
I am migrating a database with a road network to an other external data provider.
We have joined our own data about roadworks, temporary speed-limits, etc., using ID and linear referencing on this ...
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Does interpolation create a vector or raster?
I have been reading about interpolation and am trying to understand whether interpolation results in a vector or raster. Say I have a layer of points and I am interested in creating a raster that fits ...