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6

You can use a data-defined override for the 'Fill color' property of the point layer to achieve this. First you need to export your singleband raster as 3-band RGB image. Once you apply the colormap, right-click -> Export -> Save As.. In the export raster layer dialog, choose Output mode as 'Rendered Image'. Once exported and loaded, you can use the ...


4

Use the minimum bounding geometry tool in the Procesing Toolbox. Choose the geometry type: "Minimum enclosing circle" Note that some vector layer formats don't support circles. The circle layer will be converted to a nearly-circular polygon if you save it one of those formats.


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geomnearest is a function of the refFunctions plugin, search it in the QGIS extension menu and install it, it's available in QGIS 3.x. see Plugin page : geomnearest(targetLayer,targetField) Retrieve target field value from the nearest target feature in target layer


3

You can use Point Cluster symbology. On the Layer Properties > Symbology tab; Select Point cluster Change the Cluster symbol to make it the same as your original layer. Set Distance to 50.0 Set the Distance Unit to Map Unit


2

You can have many joins, so this should just work: SELECT utmid, count(points1.geom1) AS points1, count(points2.geom1) AS points2 FROM utm LEFT JOIN points1 ON ST_Contains(utm.geom, points1.geom1) LEFT JOIN points2 ON ST_Contains(utm.geom, points2.geom1) GROUP BY utmid; I highly recommend not naming fields in your tables after the table name....


2

Lets do an example with some supplied sample data from the spData package. I know columbus isn't a grid but I guess your shape is a set of square polygons that make a grid. library(rgdal) shape <- readOGR(system.file("shapes/columbus.shp", package="spData")[1]) Now if your shape object doesn't have a row index, add one: shape$row = 1:nrow(shape) Let's ...


2

Welcome to Stack Exchange GIS, Tina! Without seeing a screenshot of your situation, I think you need to use the NNJoin tool. It can be activated by going to Pugins > Manage and Install Plugins > and installing NNJoin. Once installed, it can be accessed by selecting Vector > NNJoin. NNJoin calculates the distance from each feature in your first point ...


1

One approach is to use the SQLite SQL dialect. It seems to work at least with a point shapefile where I digitized a few points, some of them in the same location. ogrinfo -dialect sqlite -sql "select geometry, count(*) from duplicate_points group by geometry" duplicate_points.shp Layer name: SELECT Geometry: Unknown (any) Feature Count: 4 Extent: (271....


1

If you only want to use tools which are present in QGIS (so no scripting) you can have a look at the Random points inside a polygonplug-in. Which can be found in Vector --> Research Tools. You need the boundaries for each city as a polygon layer.


1

Using your QGIS 3.4 install you could use the field calculator to add a column to the bathymetry layer to show the number of points with each polygon. The expression to use would be like: aggregate(layer:=NameOfPointLayer',aggregate:='count',expression:='id', filter:=intersects($geometry, geometry(@parent))) You would need to replace ...


1

After @Spacedman’s guidance I could finish my own function for what I wanted. I added the continuation to get the number of matches and mismatches and percentage of matching and made it to a function with the 1000 replicate. Here is how I did it. Probably there is a shorter and cleaner way to do it but I am a beginner so: overlap<-function(x,y, shapefile)...


1

Ok, I think I found a solution. I used the following tool: Processing Toolbox --> QGIS geoalgorithms --> Vector selection tools --> Extract by location ( to create new layer with all overlapping points using intersects, overlaps and within as Geometric predicate and a precision of 0.2 for my all US data sets) That new layer can then be used to count the ...


1

Yes, it is. EPSG 4326 is the identifier for the World Geodetic System 84 (WGS84). If you check the Well Known Text (WKT) for WGS84 you will see it uses degrees as units: GEOGCS["WGS 84", DATUM["WGS_1984", SPHEROID["WGS 84",6378137,298.257223563, AUTHORITY["EPSG","7030"]], AUTHORITY["EPSG","6326"]], PRIMEM["Greenwich",0, ...


1

The ramp_color(ramp_name,value) allows you to set symbol color based on a color ramp. The value parameter controls the position on the ramp to select the color from (as a real number between 0 and 1). Your point attribute has numbers between -0.5 and -2.3, but you want to use them as though the range was between -5 and 5. To convert the point attribute into ...


1

You can turn point data into raster data via Point to Raster (or Feature to Raster in the same toolbox), and then apply the raster-based methods you mention.


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