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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1answer
3k views

Create polygon based on the spatial extent in arcgis

Is there anyway that I can input 1) The Coordinates System (projected is OK) 2) The boundingbox and create a rectangle polygon based on these?
3
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1answer
279 views

PostGIS - when I add a polygon, delete overlapping areas in other layers

I'm starting to work with PostGIS and I'd like to solve the following problem: In my database, I have multiple land use class layers, for example: "residential", "industrial", "commercial". The ...
3
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2answers
665 views

How to filter out multipart polygons and then buffer?

I've written a small script trying to accomplish the task described in the question title. It basically looks like: in_fc = '...' # Some shapefile goes here # Get the fields (column names) of the ...
3
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1answer
3k views

How can GeoJson polygons be colored programmatically using OpenLayers?

I'm experimenting with dynamically setting the color values of a geojson polygon. In my geojson file, there is an attribute for each polygon called pop_den. I am trying to update the fillcolor of the ...
3
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2answers
2k views

How to perform spatial queries on polygons in mongodb?

I will build a GIS system based on polygons, not just points. I wanted to use mongodb or postgis. how do this in mongodb? Query A - get the center of a polygon Query B - distance between two ...
3
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3answers
498 views

Selecting polygons with a minimum internal straight line value - ArcGIS 10

I have a map of polygons representing forest stands. I am trying to sort through them to find those polygons that have a minimum internal distance of 200 m in a straight line (my field sampling will ...
3
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2answers
3k views

Measure the area of a polygon resulting from the intersection of two other polygons?

How can I measure the area of a polygon resulting from the intersection of two other polygons? If I use the measure tool or open the attribute table for the resulting polygon, it shows me the areas of ...
3
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2answers
3k views

Label *beside* polygons in ArcMap 10?

I try to add labels to polygons in ArcMap 10 based on a field in the corresponding attribute table. However, the labels always appear inside the polygon, and I can't find an option that lets me put ...
3
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1answer
170 views

Displaying adjacent polygon lines beside each other instead of overlapping

I would like to display adjacent polygons with the line work beside each other, not one on top of the other for that shared boundary. I do not want to edit the polygon boundaries - only want to ...
3
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2answers
173 views

Remove Holes Existing Within a Single Polygon for a specific area in Qgis

I have a shapefile that consists of a single polygon. I have gaps within the polygon that needs to be eliminated, but only the ones that are less than 200m2. I tried different ways but none of them ...
3
votes
1answer
161 views

Highest DEM pixel in polygon

I'm working with QGIS and have a big DEM raster layer with height information and a vector layer with many polygons, representing 1 x 1 degree tiles. Now I want to find for every polygon the highest ...
3
votes
1answer
71 views

Find small polygons inside big polygons

I'm trying without success to find a solution for problem in ArcGIS and this is the reason that I'm sending this message. I have one polygon shapefile with postal codes for South Africa (no Gap, no ...
3
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1answer
1k views

Cut polygon shapefile by line shapefile

I have two shapefiles, a polygon shapefile (lake) and a line shapefile (boudary) I want to create a new shapefile "polygon to the north of the boundary" What tool can I use in QGIS or other free ...
3
votes
2answers
143 views

UK area boundaries

I'm working on a web project that requires polygons and lat long coordinates for the boundares of towns, citys, countys and postcodes. Does anyone know where i can obtain this data? i know rightmove ...
3
votes
1answer
68 views

How many polygons under a point (ArcGIS solution preferred)

Opposite of Point in Poly. How many polygons underneath a point. I have a point layer with many points. I have a polygon layer with many polygons. I need to add an attribute to the points that ...
3
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3answers
4k views

QGis: Merge intersecting polygons into one which are part of the same feature

I'm not a GIS professional so I hope I use the correct wording, at least I hope you understand my question. Let's say there are 5 polygons in the feature A. In the shape file there are more ...
3
votes
2answers
212 views

Detecting ring direction of a polygon using ArcPy

I am using ArcPy in ArcGIS 10.1 to process some geometry using the arcpy.da data access module. However I have run into a problem with complex Polygons that contain inner rings/holes. From the ...
3
votes
1answer
437 views

How to make survey lines within polygon?

I am trying to figure out how to make survey lines within a polygon. So first I make a polygon. Now I need to fill this polygon with lines, where I can choose the spacing between the lines, and the ...
3
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3answers
3k views

Polygon to Raster Tool Problem

I am trying to create a raster data set from county level polygon data for the US. I have successfully created one raster from a dataset, but when attempting another, it does not work. I am ...
3
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2answers
1k views

How to clip polygons with a fishnet layer?

I have a layer with multiple polygons (input) and a fishnet layer in polygon (clip layer). I want to clip the multiple polygons with the fishnet to be able to calculate how big portion of the input ...
3
votes
1answer
346 views

SQLServer generating invalid WKT

I am a GIS novice using SQL 2008, with C# and the NetTopologySuite WKTReader type to work with some geometries. I have some data which I have been able to save into the database but when I read back ...
3
votes
2answers
2k views

How to subtract Geometry Point Polygons in OpenLayers?

I have two json arrays, one for background polygon and one for other polygon. And from them, I got two polygon layers. backgroundLayer = new OpenLayers.Layer.Vector("Background Layer", {styleMap: ...
3
votes
1answer
371 views

Splitting raster pixels by a polygon's edge?

I have a a polygon shapefile of different regions, and a raster grid of precip data. I want to take the polygon and add up all the raster precip data in each zone. I could use zonal statistics to do ...
3
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3answers
5k views

How to create a polygon buffer from a line?

I have connected a series of points into a line in ArcMap 10 with the Points to Line tool in the ArcToolbox. The line is, of course, in its own layer, and I added a 5 meter buffer around the line. It ...
3
votes
2answers
6k views

Cannot get areas for polygon layers in ArcMap 10

For an ArcGIS project opened in ArcMap 10, we have added polygon layers representing different geographical features. After all the polygons were created, we opened the attribute tables for those ...
3
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3answers
70 views

How do I draw smooth vertexes around curves in ArcMap 10+?

I have some polygon layers (parcels) that have vertexes drawn around curves, as if traced. How do I click and drag to draw vertexes in a smooth shape? Big difference between what was originally there, ...
3
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2answers
808 views

Creating donut holes without losing existing polygons using ArcGIS for Desktop?

Using ArcGIS 10.1 for Desktop is there a way to do a similar operation to creating a donut hole or island in a polygon without losing the existing features? I have mapped small lakes as several ...
3
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2answers
156 views

Double (triple, quadruple) size of polygon using ArcGIS for Desktop?

I have several polygons, measured in acres. I'm looking to double the area, either by a buffer, or some other method. I will need to triple and quadruple in the end, as well. I have tried to use ...
3
votes
1answer
89 views

Is it possible to split a polygon inside another one in QGIS simply?

I can split polygon if I put the points of start and end outside the boundaries. How can I do the same if I have a part that I want to split completely inside a polygon. In Arcgis I can do it if the ...
3
votes
2answers
2k views

Determine if point is within an irregular polygon using Python

I would like to create a mask of a grid where points are evaluated as either 1's or 0's depending on if they lay outside of an irregular (i.e. not rectangular) polygon. I have a set of high-latitude ...
3
votes
1answer
67 views

How to re-ID polygons with sapply instead of for loop

I have a line of code that renames the id's of polygons in a SpatialPolygonsDataFrame by directly manipulating the ID slot of the polygon. I'm a bit slow when it comes to sapply, having used for loops ...
3
votes
1answer
253 views

Postgis identify points on the polygon border

I have points geom in gid,pt_geom and polygon geom in gid,pl_geom. Some of the points are inside polygon and some are outside polygon, others are on the polygon boundary. Is there any way to ...
3
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3answers
407 views

ArcGis 10 - create polygons as % of original

Could someone help me with the following? I have a polygon shapefile and need to create new polygons, within the originals, as % of original area. I used buffer by field (Field= new area as %) but the ...
3
votes
2answers
1k views

How to create a multipart polygon?

I have two polygons that consist of two separate polygons/lines in QGIS). How can I make this into a multipart polygon, which consists of 1 line in QGIS?
3
votes
1answer
2k views

find polygon corner coordinates

I am trying to get the coordinates of each node of the polygon I create. I would like the attribute table to display the name of the polygon (ex. address) and then the coordinates of the nodes (ex. ...
3
votes
1answer
270 views

ESRI/ArcGIS draw protractor

I am using ArcGIS maps and trying to follow JS API. I am trying to understand how can I add a protractor on the map which will help in angles while drawing polygons. I understand I could add a Feature ...
3
votes
1answer
2k views

How do you convert raster to polygon while avoiding small polygons

I intend to convert a raster to several polygons, but I want to ignore too small polygons, and just keep larger polygon. How can I do that? Thanks in advance!
3
votes
1answer
747 views

how do I get the “outer mantle” of a polygon shape file? (without joining all the polygons)

I am interested in finding all the vertices of all polygons which are not on the inside the most outer polygoin that can be formed in a shape file: Here is how I get all the vertices: def ...
3
votes
1answer
1k views

Changing the scale (generalisation) in ArcGIS 10

I have 2 polygon layers, accordingly 1:10 000 and 1:500 000. I want to generalize the first layer from 1:10 000 to 1:500 000. I tried using Simplify polygon tool, and since these scales relate to ...
3
votes
2answers
277 views

Search for Multiple Polygons in ArcMap

Is there a way to do a search for features that occupy more than one polygon in ArcMap? I am working with a Parcel layer, and there are some cases where the parcels will take up multiple polygons ...
3
votes
1answer
82 views

Shapefiles - Polygon type - is it in fact multipolygon?

I'm wondering about the ESRI shape file with shape type 5. When reading the spec I see that "A polygon may contain multiple outer rings.". Does this mean that these outer rings must be combined to ...
3
votes
1answer
265 views

Polygon fill colour specified by column R spplot

I am trying to plot a geological map using the spplot function in R. For every unit I already assigned a specific color in the col-column of the SpatialPolygonsDataFrame. Now I would like to plot the ...
3
votes
1answer
23 views

Bringing attributes of multiple polygons into other polygons?

I need to absorb multible attributes included in block areas into a number of ploygons. In other words, I need to bring block level data into a number of overlaying polygons. The polygons will absord ...
3
votes
2answers
183 views

Creating an outline around groups of polygons

I am trying to find a tool or workflow for creating a type of minimum bounding polygon or envelope for complex land areas. (Not just a rectangle, but a simplified perimeter) Can anyone recommend a ...
3
votes
1answer
200 views

Changing raster cells values inside of a polygon to the closest cells just outside the polygon!

I have been wrestling with this for a while and couldn't find out how I can do this. I want each cell of a raster inside of a polygon boundary to have the value of the closest cell just outside of the ...
3
votes
1answer
67 views

Extra detailed bounding polygon from many geometric points

I have a database of around 100,000 postcodes each with lat/lon which I have converted to geom type in PostGIS. Each postcode also has one of 5 "regions". I wish to generate an accurate bounding ...
3
votes
1answer
188 views

How to give elevation information to a polygon feature class using existing TIN file ? (geological mapping)

I'm an ArcGIS 10.1 user. My issue: I have a printed form of a map which depicts geological bodies being surface rock occurence. Additionaly, there are elevation contour lines. I digitized the map by ...
3
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4answers
1k views

How to import polygons from OSM to QGIS?

I am trying to import Polygons from OSM to QGIS 2.0, but so far I have no idea how to do that. E. g.: Kisterseg auf Tatabanya in HU: http://www.openstreetmap.org/?relation=1027806 Is there any fast ...
3
votes
2answers
528 views

How to do a Point to Polygon analysis with multiple variables?

I have a database of almost 10k crimes, which are divided in to 10 categories and plotted on a map I also have a database of 12k addresses, which are also plotted on the map. I aim to perform a ...
3
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1answer
132 views

How can I check if a multipolygon can be represented as a simple polygon?

I have a large (30m+ records) spatial data set I have imported into a PostGIS database. I did not expect to find multipolygons in the data set, but it does have a few of them. I'd like to take a ...