On a map, a closed shape defined by a connected sequence of x,y coordinate pairs, where the first and last coordinate pair are the same and all other pairs are unique.

learn more… | top users | synonyms

1
vote
2answers
987 views

Looking for dissolve algorithm for Javascript

I have three adjacent polygons that together make up a larger shape. I need an algorithm that will dissolve the internal borders leaving only the outside border. An example would be a group of ...
0
votes
0answers
29 views

Feature Layer parameter showing only Polygon Shapefiles

I have created a Python Tool in ArcGIS where most of the paramaters musts be ONLY Polygon Shapefiles. You can also look on my previous question: Filter the Feature Layer parameter in Python Script ...
4
votes
1answer
46 views

Find polygons that does not contain (any) polygons with PostGIS

New to PostGIS, I have a polygon layer of water catchment areas which are formed by the specific monitoring points along the river upstream. For example, on one river, there could be multiple areas, ...
3
votes
1answer
1k views

How to fill in a ring polygon in QGIS 2.2?

I created a polygon which covers a park. But I want to distinguish some small buildings located inside the park. Consequently, I want to distinguish them and use them as independent patches inside the ...
0
votes
0answers
18 views

How to make match two same rasters after conversion "Polygon to Raster?

I am trying to convert two .shp files of polygons of same buildings but with different layers of values into raster. When I do conversion from polygons to raster it always generates bit different ...
0
votes
1answer
219 views

How to copy closed loop lines into polygon feature class

I'm trying to utilize line contour data to find the volumes of local depressions. To do this, I want to copy the closed loops formed by depression contours into a polygon feature class to find the ...
2
votes
1answer
97 views

2D polygons with height attribute to 3D features for ArcGIS Online

I have a 2D shapefile made of many polygons representing buildings. Each polygon has a height attribute. The goal is to get these into ArcGIS Online's "Scene" feature, showing extruded buildings, ...
12
votes
1answer
411 views

Is there ArcPy tool for polygon resizing like Scale tool of Advanced Editing toolbar in ArcMap?

I am writing a python script for ArcGIS 10.3. I know about Scale tool in ArcGIS interface but I can't find such arcpy command. It exists? As you can see on the picture the Scale tool works different ...
13
votes
6answers
5k views

Get Raster Values from a Polygon Overlay in Opensource GIS Solutions

I have two layers. A polygon-shape-layer with many tiles and a raster-layer containing CORINE 2006 land cover with many categories in a colourmap. I want to obtain for each polygon in the shapelayer a ...
2
votes
0answers
18 views

layer styling switches after zooming in with no reason

Does anybody have an explanation how it is possible? I have a strange trouble on the following map. The surrounding land layer, which is only a one polygon layer and is styled normally like: var ...
1
vote
0answers
46 views

Toggling selected feature when using Node Tool of QGIS?

Does anyone know of a way, when using the Node tool in QGIS to edit a polygon, to choose or toggle which feature (within the same layer) is being selected if they share a boundary? It seems to just ...
0
votes
0answers
50 views

Dividing a shape in equal pieces?

I have data in Autocad. As you can see there's a buffer (purple) inside of the blue shape, I want to divide the blue shape to small equal pieces that have the same surface area. What I'm looking for ...
0
votes
1answer
858 views

R solution for 'TopologyException: Input geom 1 is invalid' self-intersection error?

The 'TopologyException: Input geom 1 is invalid' self-intersection error which arises from invalid polygon geometries has been widely discussed. However, I haven't found a convenient solution on the ...
4
votes
1answer
59 views

Reshape polygon to boundary of other polygon

I have two polygons. The first one has a white background and brown boundary. To othr has the pink background. how is it possible to reshape to first polygon to the boundary of the other polygon?
1
vote
3answers
121 views

Creating line from point based on intersecting line at 90 degrees to line in ArcMap?

I am using ArcMap 10.2/10.3 and I need to create lines from points, so I can split polygons at the created line, as per the image below. So I have to cut the polygon at a 90 degree angle to the line ...
1
vote
1answer
50 views

Joining multiple polygons inside a single polygon in QGIS

I need to somehow "join" information from two shape files: zoning - these are large polygons indicating the zoning code for a moderately large area, typically hundreds of separately owned parcels ...
1
vote
2answers
2k views

accurately find the bounding box of geography polygons

Im displaying polygons on a map and have had issues with the spatial index where the index performs well only for certain data sets (large areas with low density / high density small map areas). I've ...
2
votes
1answer
93 views

Grouping polygons by spatial attributes

I'm working with a dataset that contains millions of polygons representing leased properties. In many cases, there are multiple polygons that are drawn on top of one another (representing multiple ...
1
vote
1answer
50 views

Applying Snap_edit to polygon Geometry Object

I have a project where I am modifying over 1 million polygons (representing tracts of land) to make them line up with the PLSS land grid. My process works (mostly) by cutting up polygons based on a ...
6
votes
3answers
4k views

How to subtract (erase) polygons from polygon?

I have two polygon layers, one is green that represents all non-public right-of-way land. I have another polygon that is just a circle with a specified radius. I would like my output to be a polygon ...
2
votes
1answer
44 views

Grid with data table attached to each polygon

I'm trying to wrap my head around a request a colleague gave for some data visualization. She is performing field observations and for every observation, she is assigning a grid # that corresponds ...
1
vote
2answers
463 views

Correlation analysis of two polygon shapefiles with nominal data

I am working on a research- trying to model vegetation types based on factors affecting their distribution. In that case I have observed a strong relation between vegetation and soil types, from just ...
0
votes
0answers
48 views

Showing city border in Google Maps using OSM data

What I want is a border like in Google Maps: In my solution, i use the overpass-turbo service to get all long/lat for a city. All works fine! But sometimes, borders will be rendered not correct. I ...
2
votes
0answers
41 views

How can I create a grid of polygons from a .csv file or line vector in qgis?

I have a map defined by two seperate reference systems: one is a standard grid coordinate system, the other a series of irregualar polygons. I want to find which polygon each grid square overlays, and ...
1
vote
0answers
44 views

What to do with polygons that were created from a raster file? [closed]

I need some suggestions. I'm working in Arcmap 10.3. I used a NDVI landsat product to find patches of row crops. I then extracted these cells and turned them into shapefiles. I want to measure the ...
8
votes
1answer
399 views

How to smooth adjacent polygons?

I want to smooth polygons which share a common boundary. How can I smooth them so that the shared boundaries stay shared? I'm using Arcgis 10.3
1
vote
0answers
50 views

how to separate land-use type from rows to columns from one shapefile

i am new to using ArcGIS. i have one shapefile of land-use data (100 rows) that has different land-use areas for each neighborhood (which are 10 neighborhoods), what i want is to have one row for ...
0
votes
1answer
40 views

Unexpected results when using ST_Intersection for polygon features

I've to create a spatial intersection of two tables (poly_a and poly_b) containing polygon features. Is there any way to remove unexpected linestring results? CREATE VIEW poly_intersection AS SELECT ...
13
votes
4answers
263 views

How to create lines to visualize differences between polygon features in PostGIS?

I've a PostGIS table polygon_b with some polygon features. There is also a table polygon_a which contains the same polygons as polygon_b but with minor changes. Now I want to create lines to visualize ...
6
votes
4answers
356 views

Filtering features using geometric attributes of polygons in ArcGIS Desktop?

Given a polygon featureclass containing many polygons of different sizes and shapes, which geometric attributes (area, perimeter, etc) could be used to filter the polygons? It's probably best to ask ...
5
votes
4answers
76 views

How to change feature draw order in QGIS?

Probably a very basic question here, I want to change the draw order of a shapefile in qgis, how can this be done? As you can see in the picture below, only the "10" layer is shown, but since this ...
0
votes
1answer
100 views

Cannot edit polygons in Qgis

I have a google Layer map on top of which I have added a raster layer of Image and then mapped image coordinates from Google layer. I made transparent (75%) image map layer and now mapping and ...
3
votes
3answers
132 views

Where to find a polygon shapefile of countries, states and islands?

As often happens, the hardest part of GIS is to come up with clean shapefile with an attribute table. I need to create a choropleth map, but all I have is this: Domicile,Captives New Zealand,24 ...
2
votes
3answers
62 views

How do I create random points only within a multi-part polygon and none outside?

I am currently using a shapefile consisting of an area smaller than the entire study boundary ie. I want this to to be my overall study area. I used a raster to polygon tool and converted it to a ...
12
votes
2answers
175 views

Project an attribute from one polygon layer to another

I have 2 polygon layers which can be found here. The two layers are overlapping. The first contains a map of the German counties in 1928 and the second the counties how they are in 2014. The 2014 ...
1
vote
1answer
247 views

Is it possible to use Leaflet.draw on a map in R?

I want to develop an application where a user can draw a line, polygon etc... I currently develop with R and leaflet package and I found that it is possible to work with Leaflet.draw under ...
1
vote
0answers
28 views

How to assign a grid of point data to corresponding grid of polygons

I'm using QGIS 2/12.3 I have a point layer with modelled data on a 1km grid, each point has a value (0-5, modelling temperatures) and lies at the centre point of a 1km grid square. I also have a ...
1
vote
1answer
23 views

Vector to raster conversion: Gaps within the vector boundary

Is there a tool in ArcGIS that will make the output raster completely encompass the vector boundary? Somewhat similar to select by attributes where all overlapping features however minuscule is added ...
1
vote
3answers
2k views

How to get a list of OSM relations (id numbers) of cities and countries only?

I want to get OSM polygon shapes (GEOJson or WKT) of countries and cities only. I know that it is called a "relation" in OSM and each relation has its own id (New York is 175905, for example). How may ...
0
votes
1answer
200 views

Open Layers: Get Coordinates of drawn features

Can someone help in finding coordinates of drawn features? I am using this example OpenLayers website. I need to be able to export drawn objects as set of coordinates. Posting the code from the ...
4
votes
1answer
506 views

Edit existing polygons to include several new nodes

I want to define catchments which are quite large from vector contour data. I normally start zoomed out to define the catchment generally as it is easier to see. I then zoom in and refine the ...
11
votes
3answers
2k views

Combining corner-touching polygons into a single feature

I have created a polygon layer from rasters, and only have a single classification ID (and calculated acres) for each polygon. I would like to "dissolve" all touching features into larger, individual ...
2
votes
1answer
52 views

Polygons drawn in editable feature service through Collector cause reverse or negative geometry

I have been experiencing a very odd situation where polygons – when drawn in an editable feature service through Collector on iPad – will draw and save, then seconds later the geometry will be ...
4
votes
1answer
97 views

Find out if overlaying polyline matches polygon centerline in qgis

I have a polygon and a polyline and I need to find a scientific way of how close that polyline is to the actual polygon centerline. Is there any way of doing this in qgis? Any extensions, models, ...
1
vote
2answers
95 views

How to combine two polyline shapefile together

Here is my question Two shapefile: * A: represent the outer boundary of the city area * B: represent the inner boundaries of the city divisions. I want to * Combine these two shapefile * ...
0
votes
1answer
194 views

calculate distance between points crossing the antimeridian

How can I calculate the distance between two points (lon/lat) if any of the points exceeds the antimeridian (+-180 longitude)? Im using the distVincentyEllipsoid {geosphere} to calculate the shortest ...
0
votes
2answers
27 views

Keeping attribute table when converting from polygon-based feature layer to grid layer

I am trying to transfer (or extract) attribute data from a polygon-feature class to point data. I can do this for a grid file using the Spatial Analyst-Extraction-Extract multi-values to points ...
2
votes
1answer
38 views

How can I split a polygon by network line in QGIS?

I have a road network as line layer and a land cover as polygon layer, I want to find number of subpolygon for each polygon that divided by line layer in QGIS? I used union function in Geoprocessing ...
1
vote
1answer
28 views

transformations from a sphere using R for raster and polygon data [duplicate]

I am planning on using the MODIS burned area products which were produced by Maryland University. These come as either polygons or rasters. In the user guide it says A shapefile version of the MCD45 ...
2
votes
1answer
34 views

Catchment boundary polygon from catchment area raster

I am trying to generate a catchment area polygon from a digital elevation model. I am using SAGA tools in QGIS and used the Flow Accumulation (Flow Tracing) tool to generate a catchment area raster ...