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
18 views

Determine changes in land cover of isolated features over time?

I have a a study area of 2 Landsat scenes from 2013 which were classified for a specific natural community, and these areas have been isolated and extracted and digitized into vectors so that they can ...
0
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2answers
2k 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 ...
1
vote
1answer
48 views

How to do a “fuzzy” intersection?

I have two layers that look like this: I want the intersection (or whatever the correct term may be) to look like this where the output polygons are the same as the original base layer, just with ...
2
votes
2answers
127 views

adjusting polygons to boundary and filling holes

here's the problem: Where: 1: department boundary 3: polygons inside department boundary that "touch" the department boundary(1). They are not necesary fitting well inside 2: holes between 1 and ...
1
vote
1answer
38 views

vb.net ArcObjects is there a function the same as “Select Features by Polygon” of ArcMap's tool

I want to know whether there is a function provided by ArcObjects (vb.net) to realize the "Select Features by Polygon" on ArcMap (shown below). I am using VS 2012 (vb.net) and ArcObjects 10.2.2, ...
2
votes
2answers
335 views

Iterating polygons on a SpatialPolygonsDataFrame in R with readWKT

I have fetched some data (39 objects) from my PostGIS database and converted this data into a matrix: rs <- dbSendQuery(con, "SELECT ST_AsText(polygon_accumulation) AS ShapeWKT from ...
2
votes
1answer
77 views

Check if line crosses a polygon

What I'm trying to do is with JSTS to check with lineGeom.crosses(polygonGeom) function if a line is crossing completely a polygon. The problem is that both cases from the picture returns true. I ...
0
votes
1answer
45 views

Cannot obtain correct area values *With* correct projections

I'm trying to get the percentage of each U.S. county overlaying groundwater (data from the census and USGS respectively). They're both polygons. I have 1) correctly projected the data and the layer ...
0
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0answers
18 views

Point to polygon depending on attribute value [closed]

I have point feature layer with FId as one of the attribute. I need to create polygon layer around the point with same FId. Suppose I have 5 points with FId 102 then it should form polygon around ...
0
votes
3answers
32 views

Counting building polygons in neighborhood polygons

I have two layers, one of them is neighborhood data and the other is the buildings in the city. I want to count the buildings in a neighborhood (by using borders) and add this value to the ...
0
votes
1answer
49 views

The best way to convert points to polygons using ArcObjects

I have a set of points from GPS I want to convert them to polygons..I have two approaches to do this.1- convert points to polygon..I do this with below code: private IPolygon ...
1
vote
2answers
25 views

polygon to raster - not all polygons rasterized

I have a building footprint shapefile (polygons) that I want to convert to a raster. I use the Polygon to Raster tool, and specify a cell size by importing from another raster (which is 24m x 30m). ...
3
votes
1answer
89 views

Postgis 2.0 geographic polygon has max longitudinal range

My problem is that I have a load of geographic point data (srid 4326) in a table. A user may do a bounding box search - essentially create a polygon as follows: l_poly geography(Polygon,4326):= ...
0
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2answers
454 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 ...
2
votes
0answers
23 views

Polygon parcel division in python

Is there an open source tool or module in python that does parcel division of polygons like in ArcEditor?
3
votes
2answers
107 views

Determining closest representation of polygon as collection of points+radii

Have a bit of a tough question, which I realize there may not be an easy solution to. Figured what better place to ask. I'm attempting to transform a polygon into a series of arbitrary points with ...
1
vote
0answers
27 views

How to understand google map overlay type from object (polygon or polyLine)

var Line = new google.maps.Polyline({ path:predectionArray, editable: false, strokeColor: '#FF0000', strokeOpacity: 1.0, strokeWeight: 2 }); var Rect=new google.maps.Polygon({ ...
0
votes
0answers
47 views

Creating a polygon around features

I want to create a polygon around a number of points so that all the points occur within the polygon. The purpose is to do this to a number of different features and see where they overlap.
2
votes
3answers
101 views

How to highlight polygons within another polygon?

I want to symbolize public buildings in OSM data. For Example: There is a polygon and in column "amenity" it has the value "school". But i don't want to highlight this polygon, but the buildings ...
2
votes
0answers
21 views

ArcMap - proportion of polygon in lon/lat grid cells

I have a polygon representing a river basin on a 1 X 1 degree lat/lon grid. I need to create a boundary using the grid cells as the boundary to best represent the outline of the basin. I would like to ...
2
votes
3answers
184 views

How to change 0,360 WKT string to -180,180?

I'm reading POLYGON WKT strings using OpenLayers.Format.WKT().read(). The polygons use 0,360 longitudes but my map is -180,180. When I display the polygons on the map they are displayed outside of the ...
9
votes
5answers
1k views

Where can I get neighborhood boundaries?

Besides Zillow's creative-commons licensed neighborhood boundaries shapefiles, what sources of neighborhood boundaries are there? Not just in the US, but all over the world. Free/open source is ...
0
votes
1answer
46 views

ArcGIS10 Highest point via polygon features

I am using ArcGIS 10.0 with 3D Analyst, Spatial Analyst and Military Analyst. I feel like I am halfway to solving a problem but do not seem able to completely solve it. I have a polygon shapefile ...
2
votes
2answers
167 views

How can I split a multi-part polygon into single polygons?

i want to split a multipart polygon which consists of several polygons into single polygons so I can delete each polygon without deleting them all at one time. I am using ArcGIS 10.
1
vote
1answer
54 views

How do I peform 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 ...
0
votes
1answer
50 views

Determining direction of longest segment of polygon?

I have a shapefile with 9000 agriculture fields and what I like to do is to determine for each field (=each polygon) the direction of the longest segment. For instance, the selected polygon in the ...
0
votes
1answer
286 views

How to narrow the result from Nominatim with only cities and countries, no additional areas with the same name?

I'm trying to get WKT or GeoJson polygons of cities and countries from Nominatim (for example, Paris and France). I send a GET request but it returns me several results named "Paris" or "France". How ...
1
vote
2answers
26 views

How to extract a new linestring vector from a existing multipolygon in QGIS?

What I want to do: create a new line (named linestring in Postgis?) from existing multipolygon layer in Postgis. Purpose: once these lines are created, I'll run some distance calcs from specific ...
2
votes
1answer
107 views

Determine when I have crossed state line?

We are currently using the Google Maps API to get route information and total mileage but we would like to determine when we are crossing into a new state. When we return the route information we can ...
0
votes
1answer
222 views

How to calculate the percentage of distribution in each polygon?

I have binary map for disease suitable area and I want to calculate the percentage using pixel count in each polygon how can I do that? I use zonal histogram and do have frequency for each polygon is ...
0
votes
1answer
324 views

Reverse geocoding polygon co-ordinates?

I have a large dataset of polygons for property sections that I need to reverse geocode. It was recommended that I use a GIS like Quantam to do this however from my research I am not 100% sure if a ...
0
votes
1answer
40 views

How to create polygon feature class from UTM coordinates?

I am working to create a polygon from UTM coordinates. The script I am using fails with a "must be a sequence, not float" error: Traceback (most recent call last): File "F:/sample/clipTiles.py", ...
1
vote
2answers
25 views

Split polygon based on line segment

I am trying to split a street polygon based on the segment ID of the street, giving them the same segment_ID in the attribute table of the street lines. I did not use the line feature class to derive ...
2
votes
1answer
26 views

How to subtract lines with thickness from polygon

I have a polygon and some lines crossing it. I want to subtract the lines with a certain "thickness" from the polygon, so it splits up into various polygons which do not touch each other anymore. You ...
4
votes
0answers
21 views

Is there a limit to the number of polygon points you can export to CSV in QGIS 2.4?

Using QGIS 2.4 I am currently importing a csv file with ~30,000 polygons (polygons in WKT format). I also have a United States shapefile. I have used the Clip function to get only the polygons that ...
0
votes
2answers
51 views

Tool for rendering/drawing maps from coordinates

What tools can be used to convert a set of coordinates into polygons? For example: this code represents a room by providing information about it's four corners. <node id='-202' lat='41.015146' ...
0
votes
1answer
31 views

How to split Polygons by line grid?

I want to split a polygon by a intersecting line into different parts, exactly like in this post(Qgis - Is there a way to split a polygon layer with a line layer?). I have a vector grid to cut the ...
0
votes
1answer
32 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
48 views

Retrieving points that make up drive-time polygon generated by ArcGIS for Desktop in automated way?

One of our GIS guys showed me a demo of the ArcGIS Network Analyst extension creating a drive-time polygon for points that he clicked on a map. This is exactly what we need for our web application, ...
3
votes
2answers
94 views

Splitting worldwide roads into multiple road datasets with less than threshold number of features?

I want to split a worldwide 'road dataset' into multiple grids/blocks-extents, depending on the amount of features resides in that block-extent. If the amount of features(inside that block) is still ...
0
votes
2answers
90 views

Convert polyline to polygon Using ArcObjects

I have a polyline and I want to convert it to a single polygon feature,I used this code but I get error while I can convert the same shape file using feature to polygon on ArcGIS Where is my mistake? ...
3
votes
1answer
162 views

digitizing (tolerence) error in line data

I have designed a large number of boundaries. For accuracy, I took lines in patches from different data sets and merged them into one. Now I want to turn them into polygons from lines. I every second ...
0
votes
2answers
135 views

Calculating minimum/maximum width for overlay of two polygon strips in ArcGIS or some Opensource GIS

Is there some solution for calculating minimum and maximum width for overlay of two polygon strips? When I clip these strips the result is another strip with variable width about 1 km and 20 km long. ...
8
votes
2answers
257 views

Creating an “average” polygon

I found this thread in the old ESRI forums with the same type of problem I am facing today. The solution to the problem is explained in little detail and since I am not an expert, I was wondering if ...
0
votes
1answer
41 views

How do I overcome this problem of converting a raster layer to polygon form?

I am trying to convert a raster layer of U.S. climatic regions into polygon format using ArcMap 9.3 under Windows XP. The original data are to be found at the following address: Koppen Climate ...
1
vote
1answer
38 views

Appropriate pixel size when converting vector to raster

I am converting vector polygons into raster datasets. Is there a standard calculation for converting the scale of the vector into an appropriate pixel size (e.g. 25 metres)? My vector has been ...
1
vote
0answers
28 views

Merge overlapping GeoJSON GeometryCollections

I need to merge three overlapping GeoJSON GeometryCollections of Polygon. Ultimately, the end result needs to be a geom type for PostGIS (e.g. MULTIPOLYGON) so I can easily check if particular points ...
2
votes
2answers
60 views

QGIS polygon centriods - How are they created?

I have been using QGIS to analyses spatial data and I created polygon centroids with the vector geometry tools. Now for a report I have to explain how these centroids were created. I have not been ...
0
votes
3answers
57 views

Same size polygons giving different overall areas

I am currently working with multiple shape files that I have clipped to the exact same extent, but when I calculate area (acres) within each polygon. I am getting different results between the ...
0
votes
1answer
15 views

ggmap fortify start and end jumble

I have a census tiger line file for counties available from the Census website. I am trying to display this file on a ggmap, but fortify seems to jumble the regions. I can't find anyone else who has ...