Questions tagged [vector]
A coordinate-based data model that represents geographic features as points, lines, and polygons.
1,399
questions
1
vote
1answer
37 views
Calculate area with a buffer
I am looking for help for my master thesis.
I have two layers, a set of households and burned area (vector data). I created buffer zones around each household and now want to estimate the burned area ...
0
votes
0answers
17 views
Calculating Cut & Fill amounts for a road, using a feature class representing road and DEM?
I have designed a road centerline in the context of my study area using CAD scripts in python. Then I have converted it to a feature class containing Z-values using ArcPy.
Now I need to calculate ...
0
votes
0answers
25 views
Deleting features with Null value in attribute field
I have polygonized a single band raster and created an area field. I want to keep the 10 largest polygons by area and delete the rest. The following script computes the area for all polygons and sorts ...
1
vote
2answers
29 views
RAT and cell values in R's raster-objects
I really struggle to understand some basic concepts in the structure of how R's raster-objects save values. Namely the RasterLayer, the RasterBrick and the RasterStack.
I understand that the values (...
1
vote
0answers
23 views
Adding multiple vertices in QGIS
I created a new polygon feature in QGIS 3.4 using the add polygon feature tool. I accidentally clicked the right mouse button to finish creating the feature. I want to continue being able to add ...
2
votes
1answer
24 views
Erode islands of pixels while polygozing a raster
I am polygonizing a single band raster.
I am using gdal.Polygonize() function to vectorize the raster.
img= r"C:\Users\aoi2.tif"
src_ds = gdal.Open(img)
srcband = src_ds.GetRasterBand(1)
# create ...
1
vote
1answer
35 views
QGIS Natural Earth Geometries
When I insert country borders from Natural Earth, they look broken when zoomed out. When I zoom in they look correct. Is there any way to correct this, particularly when creating a map in layout?
0
votes
0answers
32 views
Creating a new layer for free space between existing layers
How can I create a new layer that will only show the 'free space' between the raster and vector layers that are currently on my map?
Will I have to merge my existing raster and vector layers and use ...
1
vote
1answer
37 views
How to get a Confusion matrix in QGIS from two vectors
How and with what QGIS tools can I get a confusion matrix from a vector polygon layer as a verifiable classification and a vector point sample layer as a reference classification?
That is, if the ...
0
votes
0answers
18 views
How to calculate the number of pixels in each class using QGIS?
I have a raster file with slope values. These slope values are divided among several classes like A,B,C. Then there's a vector map with points. For an example a point can belong to class A of slope ...
0
votes
0answers
20 views
Simultaneously editing 2 features from 2 different layers in QGIS [duplicate]
Is there a way in QGIS to edit 2 different features from 2 different layers at once.
For example I selected a point in a point layer and a polygon in a polygon layer and I want to move them to ...
1
vote
2answers
89 views
CRS error working with Solaris [closed]
result_polys = sol.vector.polygon.georegister_px_df(mask2poly,
affine_obj=tile_tfm,
crs= 'epsg:4326')
...
0
votes
0answers
30 views
Splitting Large MapInfo Table into Individual Parts
Can a MapInfo .tab file made up of 400 territories (polygons) be split up or "exploded" into its individual polygon parts using MapInfo?
7
votes
1answer
120 views
QGIS Point on Surface
As far as I can tell, the option to "Create point on surface for each part" in the QGIS Centroid tool is not returning the correct geometry when activated in QGIS (version 3.8.1-Zanzibar/GDAL v 2.2.3 ...
1
vote
2answers
50 views
Snapping objects to grid without grid?
Is there a function to snap new or moved vectors to a (user-defined) grid on the map similar to the AutoCAD snapping-function without generation a point/line/polygon-grid over the whole region first?
...
2
votes
2answers
76 views
Populate field in one layer with corresponding value from another layer
I have 2 existing vector layers: 1 point, 1 polygon. In almost all cases the points overlap a polygon.
The point layer has multiple features (1,000+) with an existing field which I need to ...
4
votes
1answer
110 views
PostGIS erase/difference vector polygons from raster
I have a raster and a vector table in Postgres 12 PostGIS 3.0
The vector polygon(orange) overlaps the slope raster(grid in black, whiteish)
All I want to do is cut out/erase the orange polygon from ...
1
vote
1answer
51 views
SAGA difference tool in QGIS
I am using QGIS 3.4 Madeira. I want to use difference tool from SAGA from the processing tool box since my data has some invalid geometries and want to fix the issue later after using difference tool ...
2
votes
0answers
26 views
Reprojecting a shapefile Error
I am trying to write a function to reproject a vector file , by taking the original shapefile as input and giving out the name of the reprojected layer . Though when I call this function I get an ...
0
votes
0answers
22 views
Reprojection of Landsat 8 using the existing shapefile in ArcGis
I have downloaded a landsat8 and when I overlay it with a shapefile of the location where I want to extract by mask , the combination of landsat 8 and the shapefile are not matching. The shapefile is ...
0
votes
0answers
13 views
Analyzing Sonoma County's topography/slope in 2017 fires
I am looking to create a map of sonoma county's topography. I am looking at one of the components of a fire: slope.
I want to first isolate sonoma county, which is easy enough to do, after that ...
2
votes
1answer
28 views
Convert sfc-column into two columns with their corresponding x and y coordinates
I have a sfc-column with just 6 points. I'd like to make these point to markers in a leaflet-map in R. So I thought that it would be a nice idea to convert them into two columns: x and y. The sfc-...
1
vote
1answer
28 views
ggplot2lend for sf-objects
I wanted to make a simple plot of four sf-objects which don't contain much more than the sfc-column and some postal-code information.
The sf-objects have the names level 1-4 and plz. What I would ...
0
votes
1answer
36 views
Reading vector-dataset with rgrass7
I have read in some vector data with rgrass7 and produced some output Layers using Grass in R. Now I wanted to import one of the created layers back into R and convert it into an sf- object. When I ...
2
votes
1answer
30 views
Road Names - Multiple Lines and Single Lines [closed]
Fairly new to the GIS world. I have been creating maps for my employer using OS Vector map data. Up until recently everything has been going smoothly - I only use vector based data so that I can ...
1
vote
1answer
22 views
Clip polygon to multiple polygons
I have nine vector land use .shp and I had to make a cropland shapefile, but I thought of giving my study region polygon an attribute to be cropland, instead of digitizing it.
I forgot what function ...
0
votes
0answers
30 views
Can't import WKT polygon to SNAP
I have big size Sentinel-1 image and I would like to clip it to smaller size. For that i'm trying to import shapefile but I get errors all the time:
This is my polygon WKT:
PolygonZ ((102....
1
vote
1answer
32 views
OpenLayers get closest feature over multiple vector layers
My OpenLayers map has multiple, vector layers, each with unique features. I need a way to find the closest feature to a location across all the layers, in the same way that ...
2
votes
1answer
72 views
PostGIS raster calculate average slope of 3x3 neighborhood around a geometry point
I have two tables
corners_final (vector point data)
dem_slope (1ft slope DEM, calculated in degrees)
With this simple query I am able to extract the slope value that intersects a given point
SELECT ...
3
votes
1answer
57 views
Subset point vector based on attribute classification in underlying raster
I have two datasets:
A raster file containing per-pixel vegetation classifications across Australia.
The file is described to have projection of EPSG:3577 https://epsg.io/3577. All additional meta ...
2
votes
1answer
57 views
Lat/Long co-ordinates are not plotting onto EPSG:3857 OSM basemap correctly
Excuse me if this is a stupid question, but I've honestly tried to find the answer in a few threads here on SE, and I cannot seem to follow the suggested steps correctly.
Project is in EPSG:3857 (...
3
votes
1answer
111 views
Splitting feature in OpenLayers 5?
How do you split an OpenLayers Vector Feature (Polygon or a LineString)?
i.e
ux: select feature, select a 'split' UI button, draw a split on-top of the polygon or through the line. The feature ...
1
vote
1answer
78 views
Adding Street Names and Labels to QGIS Map as separate layer
I'm trying to add all the street, river, town (all words in fact) as a separate vector layer in QGIS.
I am looking to extract just the words from a London map as a PDF which I can then change to ...
0
votes
1answer
25 views
Rasterization - choosing attribute from attribute table for cell value of raster - why?
When a polygon shapefile is converted into a raster, an attribute from
the shapefile's attribute table must be chosen for the cell value of
the raster.
I am pretty sure the above statement is ...
1
vote
0answers
14 views
Vector to Raster
I traced land use as forest (purple) and non-forest (Teal) in my study area of 117sq.km. from google earth. I have attached a copy of the landcover file which I have created. I need to convert this ...
2
votes
2answers
65 views
DEM and vector data won't match using QGIS
I have just started using QGIS for my research at university. I have a DEM comprising Italian regions of Lazio, Tuscany and Umbria. I then have a set of vector data from surveys carried out in these ...
1
vote
1answer
35 views
Delete unattached internal polygons in single polygon
My shapefile is a single MultiPolygon (1 feature) which has some holes, within which there exist multiple parts of this polygon, remnants of vectorization.
I need to eliminate those small as shown on ...
1
vote
1answer
57 views
How do I find the area of a polygon covered by points of a defined size? (QGIS 2.18)
I'm using point vectors to portray 264 marked trees in a stand using the 'Random points inside polygons' tool (it doesn't matter where they are). Each point is 4.5m across (the average single tree ...
4
votes
1answer
63 views
Split vector layer in R
Is there a way to replicate the Split Vector Layer function from QGIS in R?
I have a Shapefile containing around 20 polygons that I'd like to split into 20 separate files.
I guess since it's in ...
2
votes
1answer
39 views
Select raster tiles within vector polygons
I have a shapefile with polygons of all the countries of the world. I also have a raster .tiff (250m square pixels) of average wind speed per pixel.
I want to select all the tiles which lie within ...
1
vote
1answer
40 views
Selecting Matching Features in shapefile [closed]
I have a shapefile that draws up all 200 districts in a country. I want to select and colour 100 of these that I have on my list.
What would be the simplest way of going about this rather than me ...
0
votes
0answers
34 views
How to add a vector layers to my map using OpenLayers 3?
I'm trying to add a vector layer manually to my map but i receive this error: Uncaught TypeError: b.attachEvent is not a function
the code is :
// adding data
// Define Geometries
var point = new ...
0
votes
1answer
36 views
Treetop location in 3D: How can I find the coordinates (x,y,z) of point cloud's local maxima within polygon vectors?
I'm doing forestry analysis of some point cloud data and I have used segmentation procedures (i.e. watershed algorithm, etc..) to delineate the crown boundaries of individual trees in 2D.
The vector ...
0
votes
0answers
32 views
Adding vector layers to map using OpenLayers?
I'm trying to add a vector layer manually to my map using OpenLayers 3 but I receive this error:
Uncaught TypeError: b.attachEvent is not a function
The code is :
// adding data
// Define ...
0
votes
1answer
71 views
How to make sure that vector and raster data align correctly in ArcGIS?
I have a shapefile of European states (open-access from here: http://tapiquen-sig.jimdo.com) and DEM data downloaded from Copernicus.
Europe states vector is in GCS_WGS_1984
(Datum: D_WGS_1984,
...
1
vote
1answer
39 views
How to get pure base topo map without any human made things?
I need detailed world map (preferably vector), just like Google Maps Terrain, but without roads, streets, airports etc. Just pure base map like an atlas with mountains, deserts, rivers, lakes etc. ...
2
votes
1answer
56 views
QGIS Measure Distance Using Field Calculator
I have a point shapefile with 80K+ records. Shapefile is projected in wgs84. The shapefile contains fields with the latitude and longitude of the point. I need a new field that contains a distance ...
1
vote
1answer
45 views
Creating gradient-filled rectangle in PyQGIS layout?
I have created a print layout with some of the layers of my QGIS Project using PyQGIS. I am trying to add a gradient filled rectangle to the layout. In the GUI, I would use the "Add Shape" --> "Add ...
0
votes
0answers
71 views
rasterio rasterize does not take geometry
rasterize(allshapes) return;
"ValueError: No valid geometry objects found for rasterize"
Testung a single shape:
print(shape.GetGeomFieldRef(0))
POINT (56.91288 27.33519)
print(is_valid_geom(...
1
vote
1answer
56 views
QGIS Raster to Vector Conversion - 3.4.6-Madeira
I have some contour lines in raster format, I want to convert them vector. I tried with QGIS (version 3.4.6) I got the vector form.
But when I tried to select the contour lines to put the actual ...
