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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3
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2answers
173 views

Extract polygon points

I have a map in .shp format with buildings. I'd like extract the coordinates of this polygon. E.g. if a house has a polygone of 4 points, i'd like to know the coordinates of those points and how to ...
3
votes
2answers
95 views

Create lines from polygon borders with polygons attributes

I have a shapefile of polygons that border each other perfectly, each with a numerical attriubte. I'd to create a shapefile of lines, where every line is created from the border between two polygons, ...
3
votes
3answers
121 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
votes
3answers
270 views

Removing small polygons gaps in a Shapely polygon

I know this issue has been addressed before with different software, but I am looking for an approach with Shapely. I have a polygon with a very small gap on the interior of the shape: Here is a ...
3
votes
2answers
1k 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
votes
2answers
219 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
111 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
3k 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
74 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
3answers
3k views

Intersect (analysis) of polygons generating empty output

I have previously asked a question on determining the area of polygons with another polygon boundary. Determining the area of each polygon within a polygon boundary? I came to the conculsion that ...
3
votes
2answers
2k 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
322 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
956 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
280 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
92 views

Leaflet JS add GeoJSON shape as a hole in a polygon

I have a dataset which already contains geojson. I can add it to my map with the following line of code. L.geoJson(data.geojson).addTo(map); And I get this But I want to achieve this, where the ...
3
votes
1answer
546 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
439 views

Count overlapping polygons in single shape file with R

I have a shapefile of species ranges for ~ 346 species. Some species have multiple polygon ranges so there are 1,078 polygons and many polygons are multi-part. It looks something like this: I ...
3
votes
1answer
24 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
434 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
282 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
83 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
303 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
votes
1answer
240 views

QGIS - How can I convert a raster file to a vector file without making same value cells into one polygon?

How can I convert a raster file to a vector file without making same value cells into one polygon? In the attached image, the values "2124", "2269", "2321", "2634", and "2920" are the polygons ...
3
votes
3answers
1k views

How to get count of non-NA raster cells within polygon using R

I've been running into all sorts of issues using ArcGIS ZonalStats and thought R could be a great way. Saying that I'm fairly new to R, but got a coding background. The situation is that I have ...
3
votes
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
628 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
votes
1answer
147 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 ...
3
votes
1answer
2k views

Merging multipolygon data into a polygon

I have a MultiPolygon representation of some shapes in POSTGIS, I am trying to convert them to Polygon data. I tried, st_geometryn(r.geom, 1) but that didnt work because the way polygons are ...
3
votes
1answer
913 views

adding polygon to database in openlayers

I want to add a polygon to the database. I used the following code. The problem is that I am to able to save in database. Whatever polygon I draw on map it gets save temporary and as soon as I reload ...
3
votes
2answers
200 views

Dissolve column based on attribute in another column

I have 3 columns within a polygon layer I'm working with. Column 1 = Landowner, 3 different values Column 2 = Parcel, N different values Column 3 = Management type, 5 different values I would like ...
3
votes
1answer
221 views

Enter 4 Coordinates and get a Polygon QGIS

Is it possible to enter 4 Coordinates for getting a Polygon. I have to Clip lots of exact rectangles and i was just wondering wether you know a plugin. Thanks a lot danke! Alex
3
votes
3answers
2k views

How to digitize polygons from georeferenced raster file

I used QGIS to georeference a raster file of a custom US map. The map has features which are not strictly defined by state borders. I would like to digitize the map by creating contiguous borders for ...
3
votes
1answer
559 views

QGIS Polygon layer table of adjacent polygons

In a polygon layer, how can I generate a table of adjacent polygons?
3
votes
1answer
212 views

Create new polygon layer based on areas of varying numbers of stacked polygons

I have several species range maps (as polygons) that overlap/stack. From this, I am trying to identify areas of highest biodiversity. Ideally, I'd like to create a new polygon layer, where 1 part is ...
3
votes
1answer
471 views

How to display only one pie chart for polygon features in QGIS?

I'm working with Qgis on a project and I have a small problem. I have to do some demographic research and therefore I have a .shp file from a given country with 10 districts for example. Now, I know ...
3
votes
2answers
850 views

Merging polygons that intersect by more than a specified amount

I am working with a dataset that contains a subset of property boundaries in a local government area, thus my dataset is made up of several thousand properties but not all are touching. Since it is a ...
3
votes
1answer
284 views

Polygon Shared Boundaries in GML

Last week I was told on a phone conference that GML supports shared boundaries in Polygon's. I have been unable to find any documenatation to substantiate the claim. Here is the situation: I have a ...
3
votes
2answers
168 views

How to bring polygons closer to a point?

I have some scattered polygons with a lot of space between them. I want to make a thematic map but all that white space doesn't look very good, so I want to bring the polygons closer to the center of ...
3
votes
3answers
2k views

How to select the vertices from a polygon?

I am writing some VBA code to extract vertices from a polygon. I would like to ask, how to select the vertices from a polygon ? Regards Gary
3
votes
2answers
328 views

How to attribute lines with Ids of touching polygons?

I have two shapefiles: one contains streets of a city and one contains blocks (i.e. polygons bounded by the streets). I would like to have the streets attributed with the id of the left and right ...
3
votes
1answer
27 views

Showing multiple burials in same grave for Cemetery GIS?

I am an intern creating a Geodatabase for a municipal cemetery. The one lot can hold up to 3 people (2 people, 1 cremation) two people at the most. How would I show that information on the map ...
3
votes
1answer
293 views

problem with polygon smoothing in R

With R I am looking to smooth my Polygon: inter2.csv code: inter1 <- read.table("c:/inter2.csv", header=TRUE) # add a category (required for later rasterizing/polygonizing) inter1 <- ...
3
votes
1answer
1k views

How to perform a true GIS clip of polygons layer using a polygon layer in R?

I would like to do a true GIS Clip in R of soils polygons using a series of single boundary polygons, but I cannot find an R function to properly do it. It should work just like the CLIP function in ...
3
votes
1answer
359 views

Compute the area of a given polygon (in vector format) lying between specified lines of latitude

I have species distributions (in vector format) and I would like to calculate how much of the area for a given species distribution is within certain lines of latitude, such as temperate and tropic ...
3
votes
1answer
126 views

T-shaped polygons

Is there any coefficient that can indicate T-shaped polygons ? Examples of T-shaped polygons :
3
votes
1answer
430 views

remove land area from marine region polygons

In my pursuit to merge multiple polygons for the purpose of calculating the surface area of marine species distributions, using shapefiles from Marineregions, I am now trying to remove potential land ...
3
votes
3answers
493 views

Determining the area of each polygon within a polygon boundary?

I have a series of maps representing a 1000m diameter around a point. These maps contain 40 different types of polygons that represent a land use (ex. Corn crop, Pasture). I want to select all ...