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.

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51 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
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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 ...
1
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3answers
140 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 ...
2
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1answer
131 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, ...
5
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4answers
83 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 ...
2
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3answers
78 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 ...
3
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3answers
137 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 ...
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1answer
65 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 ...
1
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0answers
29 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
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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
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1answer
469 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 JavaScript....
0
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1answer
401 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 ...
0
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2answers
28 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 ...
4
votes
1answer
84 views

Altering elevation of specific cells in raster layer of QGIS?

I'm looking to alter the height of some cells within a raster and it's been suggested that I do this by creating a polygon layer and use that as a mask to alter only the heights of cells within the ...
1
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1answer
32 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
44 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 ...
0
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0answers
52 views

Adding custom vertices to a Leftlet LineString / Polyline

I have a normal Leaflet Draw page here, when I'm not in editing mode I would like to have custom vertex icon in some of the vertices that will also respond to click events, showing a popup. I looked ...
1
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1answer
49 views

Highlighting selected polygon features without filling colors in QGIS while editing?

When editing in QGIS, how can I highlight the selected polygon features without filling them with colors i.e. just outline the polygon boundary?
2
votes
1answer
69 views

Create frequency polygon from overlapping features in another polygon

Mac 10.9.5; QGIS 2.8.4-Wien; history and unioned data, in GDA94, zone 55 here. I have a polygon of fire history with a number of overlapping features. I want to create a new polygon for fire ...
2
votes
1answer
17 views

WFS Filter performed before or after reprojection?

I'm trying to perform a WFS filter with a polygon in EPSG:3031, (the native projection is EPSG:4326 I think). And I'm aware that WFS/GeoServer supports reprojection on the fly. But will the features ...
4
votes
1answer
34 views

How to extract a buffer layer from a vast amount of individual buffers around polygons using ArcMap?

I have a vector layer containing nearly 8000 singlepart polygons. It looks like this: I want statistics on the area that is further than 2,5m away from any border. I thought I could do this by ...
0
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0answers
21 views

Extracting coordinates and climatic conditions of grids where species polygon overlaps with the climatic layer in R?

I have species’ shapefiles and climatic raster files. The climatic file is in 50 * 50 km equal area grid. Now, I want to calculate the climatic conditions in each grid cell where species polygon ...
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0answers
43 views

How to correctly rasterize a polygon which crosses 180E longitude?

I want to rasterize a polygon wich crosses 180E lon with gdal_rasterize. The polygon is in the WGS84 projection. I used the following command: gdal_rasterize -burn 1 -of GTiff -ot Byte -ts 1500 ...
2
votes
1answer
38 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 ...
3
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1answer
43 views

Is it possible to remove small polygons from Census Block shapefile?

I just pulled up a shapefile that plots census blocks (TIGER product) using Quantum and I noticed that there are well over 1000 small polygons that aren't census blocks that are (I assume) used to ...
2
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1answer
60 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 ...
1
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1answer
50 views

What is the easiest way to create rings from existing polygons?

I have been given a shapefile from a client that features pivots, yet they were recorded as 10 circles overlapping. The software my company uses requires that these polygons be rings that don't ...
1
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1answer
90 views

How to map geoJSON polygon from a url request in python

Using Python I have loaded json data from the url http://environment.data.gov.uk/flood-monitoring/id/floods and have found that the flood areas encoded as geoJSON polygons are displayed as url links. ...
1
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1answer
42 views

How to assign the attributes of the largest overlapping polygon area to each overlapping gridcell?

I am new to R, and I am trying to use it to calculate the areas of polygons that overlap with each gridcell, in order to assign the attributes of the largest overlapping polygon area to the ...
2
votes
1answer
59 views

Selecting many maximum points within polygons

I've got a point layer with three values such as high, age etc. and polygon layer with many forest area. What I want to do is to select the 100 maximum (highest) points in every polygon. I can't do ...
4
votes
1answer
60 views

Add column to point data of whether point falls inside polygon

This seems like it should be fairly simple, but have been having quite a bit of trouble. I am no expert in ArcGIS for Desktop I have: one layer of points, and 4 polygons, which partly overlap I can ...
2
votes
2answers
85 views

Drawing a polygon of a given area

First, I am using QGIS 2.8.2. I have GPS waypoints and satellite imagery and am trying to draw polygons. This is easy enough, but I need to make sure each polygon is 1ha exactly. Is there a way to ...
1
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0answers
22 views

Convert a polygon grid into an edge table

I'm working on a robotics project. I've got a rectangular grid (polygon shape file) that is a navigateable/routable region (i.e. I can travel anywhere in this grid). That is I took my bounding area ...
13
votes
4answers
285 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 ...
2
votes
1answer
58 views

Can't Find the Split selected features with selected line from another layer tool

I'm trying to split a selected polygon features with a selected line from another feature layer. I, however, can't seem to get the tool for this to show up in my advanced digitize toolbar. In ...
5
votes
3answers
142 views

Merge a list of spatial polygon objects in R

I have a list of spatial buffers (30000 buffers) that I built with the function lapply: buff.pts <- lapply(1:nrow(pts.prj), FUN=function(l){ buff <- gBuffer(pts.prj[l,], width=1000) ## 1km ...
6
votes
3answers
281 views

How to select specific rows of polygons from a grid in QGIS?

I have a polygon layer. I would like to select every second row of the polygons but not manually. Is there an expression to select every second row as seen on the picture with Select by expression in ...
1
vote
0answers
76 views

Problem in polygon division using the union tool from QGIS

I am trying to overlay two polygon layers using the union tool from QGIS, to then compute the areas from the resulting polygons. However, in the resulting layer some polygons are not divided as ...
4
votes
4answers
146 views

Google Earth Polygon surface area to follow the curvature of the earth model

Question: When drawing a polygon in Google Earth with latitude, longitude and elevation values at each node, how do you ensure that the surface area of the polygon also represents the desired ...
3
votes
2answers
69 views

How to calculate area in sq m - troubleshooting projection issues in a global dataset in QGIS

I am using QGIS version 2.12.3. I have 3 polygon shapefiles: A, B and the intersect of A and B, which we can call C. All I want is to add a field to the attributes table of each shapefile giving ...
3
votes
1answer
95 views

How to create a fishnet/grid along a polyline or polygon

I am trying to generate a fishnet/grid along a line/polyline or polygon boundary in ArcGis 10.3 or QGIS. While it is totally intuitive and easy to generate a box-standard grid, what I am trying to do ...
2
votes
1answer
102 views

Converting Shapely MultiPolygon to Polygon: Technique doesn't always work

In order to get the exterior coordinates I need to convert a shapely MultiPolygon to a Polygon. I do it like this: if poly.geometry.type == 'Polygon': x, y = poly.geometry.exterior.xy elif poly....
2
votes
1answer
99 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 ...
0
votes
2answers
92 views

Dividing an irregular polygon into sub-regions

I am trying to divide an irregular polygon into equal widths and am having trouble understanding the proper tool to use. I am in possession of ArcGIS and am aware that the Parcel Editor is the closest ...
0
votes
1answer
40 views

How to select congruent polygons in PostGIS?

Title says it all. What is the best way to select congruent polygons in PostGIS? CREATE TABLE polygon_a ( gid serial NOT NULL, geom geometry(Polygon, your_SRID), CONSTRAINT polygon_a_pkey PRIMARY KEY ...
2
votes
0answers
110 views

Merge n number of adjacent polygons [closed]

I have over 17,000 individual polygons. I want to merge two adjacent polygons so that I finish with approximately 8,500 polygons. The polygons need to be merged based on location, merge two adjacent ...
2
votes
0answers
55 views

Geocode area/neigborhood into polygon vertices

I have been successfully using the Google Maps API using the R package ggmap to find location coordinates for e.g. addresses or city names. However, Google Maps now shows areas as well, indicating ...
2
votes
1answer
53 views

Polygon data to Point Feature Data

Using ArcGis 10.0. What I am looking for is a way to get point features that are placed in a polygon to have the same "Address" value. This is the same as the "Spatial Join" feature, however, I am ...
12
votes
2answers
184 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 ...
4
votes
1answer
61 views

Edit polygon borders in QGIS preserving topological correctness (planar partition)

Given a layer of polygons that is topologically perfect, i.e., has no overlaps or gaps between the polygons, is it possible to manually edit the edges of the polygons in QGIS in a way that preserves ...