New answers tagged

0

If you have 3D Analyst, this works - for individual polygons: Create a TIN using your polygon Use Add Surface Information with your polygon as input feature class and the corresponding TIN as input surface. Check "SURFACE_AREA" as output property. The 3D area is then added in a new field to your polygon feature class' attribute table. You can automate ...


-2

It's not possible to edit more than one layer now.


6

Go to Layer -> Add Layer -> Add Delimited Text Layer. You should be able to find the csv file you have, give it a layer name, and choose file format as CSV. In the Geometry Definition, you will have to use Well known Text (WKT) by ticking that box. Set the Geometry field to the column you want, and you might want to set the Geometry type as Polygon. See ...


0

Here is one option: Use the Spatial Join method to join the polygon info to the points Create a new text field in the joined point layer Field calculate/concatenate the dcpWaterBodyType field values with the polygon name or id field Finally, right click on field created in step three and choose the Summarize option This should produce a count of the ...


1

As commented by @Vince: There's a number of ways to address this, some manual and some scripted. Unioning the two FCs, then doing summary statistics on block count by precinct is probably easiest.


1

The general approach would be: Rasterize the point "west Myara site" Generate the buffer (there are plenty of tools for buffering raster, look for "raster distance" or "proximity". QGIS has this algorithm) Use raster calculator using the formula, f stands for frequency of the wave (a constant value) and d will be buffer layer you calculated previously.


0

create a cost allocation for each line segment based on segment_ID, convert the cost allocation to polygons and intersect each cost allocation polygon with you road polygons.


2

Esri Help File link Look at the "Angle of Rotation" section on the link, I followed the steps and it was really easy to rotate


0

I don't know about the way to do it in one step but here is a 3 step way: Use Raster / Raster calculator... to get raster 1 / Null with 1 for your altitude interval and null for the rest like: General: "dem@1" > min_altitude AND "dem@1" < max_altitude Example: "dem@1" > 250 AND "dem@1" < 300 Use Raster / Conversion / Polygonize (Raster to Polygon) ...


0

One of the problems might be this: // creat a select to choose geometry type var typeSelect = document.getElementById('type'); There is no DOM element with id "type", I think that should be: var typeSelect = document.getElementById('geom_type'); More general: the line gives a clear error. Most browsers will show this somewhere. You'll need to learn how ...


2

Try to disable the "Support on the fly geometry simplification" parameter in the postgis store configuration in GeoServer. And make sure your polygon stays within the "world" boundaries, best if it's not touching the datelines. Also disable "advanced projection handling" in the WMS settings


0

You can compare the coordinates of the 2 geometries in a loop or you can retirieve the geometries as WKT and compare them as strings like this : var formatWKT = new ol.format.WKT(); var feature1 = formatwkt.writeGeometry(feature1.getGeometry()); var feature2 = formatwkt.writeGeometry(feature2.getGeometry()); if(feature1 == feature2){ console.log("equal ...


0

Wow, that long query is really necessary? What's wrong with: SELECT 1 gid, ST_Difference(ST_Union(lparcels.geom), ST_Union(luse.geom)) geom FROM boundary_test.land_use luse, boundary_test.land_parcels lparcels Or if you really need single part geometry: SELECT (dump_geom).path[1],(dump_geom).geom geom FROM (SELECT (ST_Dump(ST_Difference(ST_Union(...


0

This doesn't directly answer your questions, but some time ago I wrote a basic code to do what you're looking for. It extracts the orientation and inclination of RoofSurface polygons in CityGML, to estimate the solar irradiation of rooftops. The code is released on Github, so you might want to have a look. The part of the code that would probably interest ...


1

I have found that the Random Points tool will deal with each polygon one at a time. So every group of 1000 points will only be associated with 1 polygon. Use "floor(id/1000)" to calculate the id of the polygon that each point is associated with.


0

I created distances rasters to all 3 types of water bodies (cell size = 1000m*1000m) and used cell statistics (min) to find nearest distance. After that I ran zonal statistics as table and joined results back to polygons. This is how max distance looks like: What you call nuts is a set overlapping polygons, make sure to remove all with status < 3.


1

Start with: symbol = QgsSymbolV2.defaultSymbol(layer.geometryType()) renderer = QgsSingleSymbolRendererV2(symbol) Now you have 10 types of fill: Simple fill, QgsSimpleFillSymbolLayerV2 Gradient fill, QgsGradientFillSymbolLayerV2 Centroid fill, QgsCentroidFillSymbolLayerV2 Line pattern fill, QgsLinePatternFillSymbolLayer Point pattern fill, ...


0

Couldn't you just run an erase and end up with any stray line segments or add an erase to your script. Could you just covert your land use polygon to a polyline and run an intersect to see which areas actually overlap?


2

Union the Polygon feature class Add Centroid xy to the attribute table (steps below) Summary Statistics - get the Max value at each Centroid for the Statistics field select Value and max for the Case field select xy Join the Summary Table to the Unioned FC on xy Dissolve the Union FC on Max value Addxy steps: add field x_coord Double add field y_coord ...


3

First of all, this is not a new feature in 2.16, it's also possible at least with 2.14 You can combine several styles for one layer, so you can create such a visualization. In this particular case, I would recommend to combine a shapeburst fill, a line pattern fill and a simple fill. See also the following image for the different fill types: The inner ...


1

In Layer Property --> Style --> for a symbol: in "Symbol layer type" = Shapeburst fill, and then, you can to choose your favorite configuration.


0

Well, I've been using a PostGIS function (I use on my QGIS directly) that executes a recursive snap to solve this problem. The results are quite good, it just demand a good joice of tolerance values to get best results. If you are willing to try, check it (in my case the geometries are all multi, hence the st_multi in my execute): CREATE OR REPLACE FUNCTION ...


4

As commented by @Kirk Kuykendall, it appears your buffer is being saved into a Shapefile. Shapefiles do not support true arcs/curves, so saves the features with multiple segments. Shapefiles do not support true parametric curves, including circular arcs, ellipses, and Bézier curves, so these shapes are stored as straight segments. True curves are ...


2

I haven't looked at this in a long while, but as far as I know it hasn't changed. ArcGIS draws the buffers at a fixed graphical resolution, so they appear smooth when viewed at that zoom level but if you zoom in you see the straight lines as you observe. If you zoom in the layer to buffer and then run the buffer tool you should see that these straight ...


0

There is certainly a neater approch, but this worked # convert SPDF to SLDF bound <- as(poly, 'SpatialLinesDataFrame') # overlay SLDF and SPDF bound <- raster::intersect(bound, poly) str(bound@data) 'data.frame': 43 obs. of 4 variables: $ ID_poly.1: num 6249 6249 6249 6249 6249 ... $ Code.1 : chr "33200" "33200" "33200" "33200"...


2

The name of the Plugin is Polygon Splitter which splits polygons into equal area parts. The Plugin is marked as experimental, therefore, you need to enable "Show also experimental plugins" from the settings as shown below Here is the plugin after enabling "Show also experimental plugins"


1

In your csv, create a new 'size' field that counts the number of decimals in the lat/long fields. Use that as a sort of key to buffer the points at variable distances (and hence, create your polygons of different sizes). EDIT for less vagueness: In Excel or similar, extract the number of decimal places into a new column (let's call it 'size' since you are ...


3

Do an intersect of the line with the polygon layer. Then calculate the length of all the segments and sum them.


2

First of all, if you want to work with heights, normalize the LiDAR point cloud. You have a dense point cloud (4 pts/m²) and also high resolution aerial photos, hence, as you said getting the outside roof perimeter is not an issue. Therefore, assuming you'll manage to have a shapefile with the outer roof boundaries, use it to horizontally clip the point ...


0

It seems that a "geometry repair" feature is completely missed from Open Source while is a full prerogative of enterprise solution. I use the FME GeometryValidator, even if this require to the geometry to be passed some times to the validator. Grass have a v_clean function that works aligned to the topology, if I'm not wrong. PostGIS have the ...


1

I also had this same error using gContains(). I didn't realise I had anything internal in my polygon. I dissolved the internal structure like this: spgeom1$rowNo = 1 spgeom1= unionSpatialPolygons(spgeom1, spgeom1$rowNo) and went on to use gContains() with no problem.


2

In the future please provide information on what you have already tried and a reproducible example. Whereas this Q&A site is a great resource we are not a coding service. The rgeos library provides functions for overlay/intersection analysis. There are important nuances in the type of function (covers, within, contains) that is appropriate here. There ...


0

There's also this jsfiddle I stumbled upon. I can't claim it as my own but you can sort through the options objects via event.target.options or even set the color attribute for a target event via event.target.setAttribute()


2

If I understand what you are trying to do, you don't need to dissolve, you just need to summarize by landscape zone after intersecting the two datasets. If you do this in a geodatabase the area of each polygon is calculated when the intersection is completed.


0

My qgis plugin/python module allows you to simplify geometries by "contract" (shrink only) or expansion only: https://github.com/albertferras/simplipy https://plugins.qgis.org/plugins/simplipy/



Top 50 recent answers are included