A circle is a simple shape of Euclidean geometry that is the set of all points in a plane that are a given distance from a given point, the centre.

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Air corridor in spherical surface: calculating great circle tangent points with small circles

I have the necessity to draw on a sphere (earth) an air corridor. In the cartesian plane, this corridor is made by some circles and from outer tangents that connect these circles as you can see in ...
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29 views

How can I get the circle of a sphere (on Earth ellipsoid) around a point using the Latitude and Longitude?

Specifically finding points along the circle. If possible without converting into Northing/Easting beforehand. I'm looking for the fastest possible way to calculate points in Latitude/Longitude in a ...
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18 views

Is there a way to convert L.circle to a geodesic polygon in Leaflet

Reference: How to make a predetermined Polygon (Circle) From 4 Coordinates, The Radius and Center Longitude and Latitude in Openlayers Openlayers uses this function : createGeodesicPolygon Question: ...
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27 views

Determine the list of circles (from 100K circles), that overlap with a given polygon

This question was asked on StackOverflow, came here because no response has been posted so far. Existing data structure we have polygons represented as an ordered list of lat/long coordinates and ...
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0answers
50 views

How to create a circle vector layer with 12 sectors with Python and to save average value of underlying raster in each sector?

Hi I am writing a code with Python 2.7 using Arcpy 10.1 and I guess I am doing stuck with a silly problem that lies under my eyes. I have created a grid of points (with "Create fishnet" function) over ...
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1answer
148 views

Python: Ray-trace a WGS84 point with heading and distance

One of my services defines geofences for a mobile app. The geofences consists of a lat/lon pair and radius in meters, in JSON, e.g.: { "geofenceId":"geofence_b39da38cff7be4b4693cbc31b2394bbb", ...
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28 views

Quickest method for determining which postcode is 2 miles north of original postcode? [duplicate]

What is the Quickest method for determining which postcode is 2 miles north of original postcode? For instant L17. I know how to determine the distance between 2 points as below, but the above ...
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1answer
43 views

Hard to get my head around, generating average price for houses in each quadrant

I'm able to determine the average price of houses sold in a particular area (like the squares on image below) dependent upon postcode. Although I can generate the average sale price for a particular ...
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2answers
78 views

Is there an average size for British postcodes?

Is there an average size for British postcodes? Or a method of determining the size for a particular British postcode? Thanks. Considering creating a related program and this would be valuable ...
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1answer
53 views

How do I convert OS coordinates (X and Y) to longitude and latitude coordinates?

How do I convert OS coordinates (X and Y) - Eastings and Northings to longitude and latitude coordinates? For example X and Y below X (Eastings): 347904 Y (Northings): 287484
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1answer
85 views

How do I figure out the grid references (Eastings and Northings) necessary to create a circular 1 mile radius around one location?

How do I figure out the grid references necessary to create a circular 1 mile radius around one location? For instance: Grid Reference: SO 47904 87484 X (Eastings): 347904 Y (Northings): 287484 ...
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1answer
120 views

How do I figure out the longitude and latitude coordinates necessary to create a circular 1 mile radius around one location?

How do I figure out the longitude and latitude coordinates necessary to create a circular 1 mile radius around one location? I don't mind how many coordinates that takes. For instance: Latitude = ...
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1answer
678 views

OpenLayers - Cannot draw a circle using createRegularPolygon

I have been trying this for a while but I cannot manage to draw a circle on a vector layer although my polygons are being created without any problems. this.pj_epsg_900913 = new ...
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1answer
38 views

PostGIS | Get degrees clockwise from north of a linestring's beginning and end

I have a table full of linestrings in PostGIS. I would like to know the degrees clockwise from north of the starting point of the linestring and also of the end point. I was thinking that maybe ...
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2answers
117 views

Creating a circle with points

I want to arrange 96 points as a circle/ring. Is there a way to make this automatically, for example "Buffer", "vertices"...? Kind regards, Stefan
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1answer
204 views

How to find intersection points between two circles?

We have two points (centers of two circles) and their radius in meters, those radius make the circle. We need to find intersection points. For example we have  lat1 = 55.685025, lng1 = 21.118995, r1 = ...
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3answers
726 views

Generate random location within specified distance of a given point

In a simulation (not using any GIS), I need to generate a random location that is within a specified distance of a given location. I found a very helpful post here on this exact topic: How to ...
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0answers
42 views

Condensing sparse geocodes to weighted Geo-Circles?

I have a data-set comprising of 3 million records having latitude and longitude information associated with it, I want to condense it to form few thousands Geo-Circles, with radius and weight ...
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2answers
778 views

How to select all points within a circle in PostGIS?

I have set of points in a PostGIS Table (Type Geometry). Now, I need to filter points that lie in a circle with a center (C) and radius (R)! I expect C to be of type Point or Coordinates.. R to be ...
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2answers
267 views

How to create a circle vector layer with 12 sectors with Python/pyqgis?

From a given coordinate and radius I need to create a circle with 12 sectors. The sectors should start from north (0 degrees) in 30 degree steps clockwise. I could also imagine to create the sectors ...
3
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2answers
596 views

Create a circle or ellipse from points

Sorry if this is basic. I have an excel sheet with lat/long in it and a field with a radius, in meters, included. I would like to create a circle or ellipse feature class around these points. ...
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3answers
505 views

maximum circle inside an irregular polygon from a random point

I am trying to work out an algorithm for creating the maximum radius circle within an irregular polygon (a census tract) based on a given center of the circle. The motivation for this is to obscure ...
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1answer
134 views

Error in Min. Bounding Geometry results

I'm getting consistent, weird results from using Minimum Bounding Geometry to make circle polygons. I'm not sure if a datum issue, but I'm leaning more towards something wrong with Minimum Bounding ...
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1answer
81 views

How to get routes in the database that intersects circle?

I have routes (linestrings) recorded in the database. I want to create a query which returns the routes that have some commonality with a circle whose center and radius are passed as parameter. I ...
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2answers
190 views

How can I do a batch edit of circle diameters using the attribute table in ArcGIS?

I need to edit the diameter of a bunch of circles to reflect their correct diameters, and I wondered if there was a way of drawing from the attribute table to make all the circles equal their correct ...
3
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3answers
882 views

Summing attributes intersected by under a radius

Apologies - new user. I am working with QGIS on Mac OS X and with shapefiles downloaded from the US Census Bureau that show population data by state and by county. How do I: select certain points ...
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0answers
146 views

How to identify each circles in Google Maps API?

By the Google Maps Drawing API, I can create lot of circle and other shapes. addListner method helps to get the radius, latitude and longitude of the circle. Now I want to identify each circle for ...
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2answers
1k views

Calculate dynamic radius based on population and map resolution

Background Create a radius around the centre of a city that corresponds to the city's population, taking into consideration the map's current resolution. The populations range from 39 to 1090936, ...
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2answers
4k views

How to draw a Circle with a set radius?

I have a site and want to draw an indicative line in a 5km buffer around the centre of the site. So I want to draw a circle with a radius of 5km. I have a tool for drawing circles and ellipses and ...
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2answers
1k views

How to change the vertex style for editing?

When I use drag feature, then the circles on the polygon edge has the same style. For example, this OpenLayers site. I need to change it, I mean they need to be a different color. What is their ...
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2answers
779 views

OpenLayers Circle not visible

I'm trying to draw a circle with OpenLayers with a Google Maps Layer. I'm able to transform a simple marker and have it draw at the correct location, but I can't figure out the circle. I'm trying to ...
3
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2answers
604 views

How do I find the points of intersection between a small circle and a great circle?

I only actually need to intersect a great circle arc i.e. the shortest path between two points, with a given small circle. I found this tutorial for intersecting two great circle arcs, but ...
5
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1answer
227 views

Intermediate points on a small circle

I need to interpolate lat/lon points along a small circle, with a given centre and radius. I've successfully used these formulas for great circles. What is the equivalent for small circles?
3
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2answers
2k views

find location details within circle buffer

Wondering how would i go about getting this to work. I have a table with location data (lat, long, homevalue) in sql server 2008. Given a lat long say (32.113, -81.3225), i want to draw a 50 mile ...
2
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1answer
1k views

Transform polygon to equivalent circle, QGis

I have a polygon and I'd like to find the radius of an equivalent circle from a particular point within the polygon. The polygon would have a large (infinite) number of points evenly distributed ...
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1answer
527 views

Circle features missing in PostGIS after import from ArcGIS using ogr2ogr

I have a ArcGIS feature class of geometry type polygon. It was created as a convex hull with a 200 meter buffer on a point dataset, aggregating rows on a particular field. The number of points used to ...
4
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1answer
402 views

How to deal with direction (CW, CCW) of circles, in particular with shapely?

I am translating an input that describes zones by mixing segments and arcs. Arcs are given by a center, 2 points (beginning/end of arc) and a direction (CW or CCW). In a first prototypes using GDAL, I ...
7
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3answers
2k views

How to create a circle in arcpy

Suppose I have a dataset where each record has an x,y and r (the centroid and radius of a circle). How can I create a polygon feature class containing parametric circles? Sorry to those who have a ...
3
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2answers
6k views

Drawing circles on map using openlayers

I want to draw circles of certain radius on a map using openlayers . But the latitude,longitude & radius values are given in a excel sheet. I badly need a help from you people to how to carry in ...
2
votes
4answers
422 views

How to create a circle with ArcEngine?

I want to create a circle with IPoint P and radius r in ArcEngine and then I need to cast it to an IGeometry. Does anyone know how to do this? ESRI ArcEngine 10 VS2010 C#