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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2answers
57 views

Create circle shapefile vector in QGIS

Is it possible to create a circle shapefile feature in QGIS, like it is possible to do in ArcMap? I am trying to digitise a map wich features roundabouts, which I'd like to be part of the same ...
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1answer
34 views

Counting points in concentric circle buffer zones of different sites in a map? [closed]

I produce concentric circles of 200 and 500 m buffer zones to see water points within each buffer zones. The buffer zones are created throughout my study area. How can I count the points found in ...
0
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0answers
15 views

How to store a circle in PostGis database row [duplicate]

I'm using PostGis 2.1. I need to store different type of geometry like polygon 2D,polygon 3D and also circle. I need these polygons represent areas in which an event occurs. Then I'll have to do ...
0
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2answers
45 views

Create a circle polygon in GMaps.Net?

I found this function and converted it to VB.Net. It draws an oval rather than a circle. What do I need to do to fix the calculations? Dim seg As Double = Math.PI * 2 / segments For i As Integer ...
4
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4answers
207 views

Checking if polygon fits inside another polygon using ArcGIS or QGIS?

How do I check if one polygon fits inside another polygon? Furthermore how do I automatically check if one polygon fits in other polygons of my shapefile? I have a shapefile with thousands of ...
2
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0answers
30 views

Help Summing Raster cells to equal circles with a specific sum

So I have this application user density data that I've collected. Each gps point has a user density associated with it (for example: 150 users within a 1 km radius, which calculates to users/[pi*R-sq] ...
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1answer
153 views

Using WKT.writeGeometry for 'Circle' Geometry in OpenLayers?

In my application which I'm building using OpenLayers3, I'm trying to extract the geometry of a feature to WKT using var format = new ol.format.WKT(); console.log(format.writeGeometry(geometry)); by ...
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0answers
64 views

finding circumcenter of circle assuming 3 geo points on circumference (lat/long)

Situation: I have 3 geo points (lat/long). I have to draw a circle on a map where these 3 points are "sitting" on a circle circumference (max-distance from point to point = 500 Meters). So I need to ...
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1answer
42 views

Create Multiple Circle

I am trying to make many points in a map as a grid. The code makes what I expect but the time to load is quite long so I suppose that there should be other ways to be more efficient drawing many ...
0
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1answer
101 views

Openlayers 3 Circle Vectors Not Visible

I have two coordinates which are projected in EPSG: 3857 coord1 = [-10399758.486973494, 5604341.818491254] coord2 = [-10402629.416641055, 5593700.936383396] I'm trying to get them to appear, ...
1
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1answer
48 views

How to display radius while adding element in ArcObject?

I want to display the radius of drawing circle when user adds this figure on the map. User clicks on the icon. Then user begins drawing circle (I process the MouseDown event) IGeometry geom = ...
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0answers
51 views

Solution to draw objects on layers and share maps

I'm looking for an online solution to build custom maps on top of OSM/Bing/Google layers and share them via export or link. I need to find an address, draw and drop lines, polygons, circles, add and ...
2
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1answer
382 views

Leafletjs get latlng center position of polyline

After drawing a polyline, I would like to draw a circle from the center of this line whose radius encompasses the entire line. For polyline's that have more than 2 points I can crudely get the center ...
0
votes
1answer
98 views

limiting circles to a specific radius

I am new to ArcGIS javascript api and I have created a map which allows users to draw circle geometries. I just want to limit the functionality so that the radius is specified at 10000km. This is ...
2
votes
2answers
1k views

How to create circular polygon in openlayers 3?

So i would really like to modify this example: http://openlayers.org/en/v3.0.0/examples/tissot.html?q=circle Problem there is that wheter i try to apply it to my map it doesen`t work, probably ...
1
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1answer
47 views

How to create circle that contains a certain number of points?

In ArcGIS 10.2 (with spatial analyst ext). I have two point layers. One represents schools and one represents students. For each school I have a number of students living near the school I need to ...
1
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0answers
60 views

How can I find the center of the circle or ellipse I just created

I need to draw circles and ellipses with a certain length/width/ radius. I used the rectangles ovals digitizing plugin to create them, but only measured roughly the circles' radiuses. It would be ...
0
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2answers
226 views

How to draw a perfect circle with a set radius in meters on map?

Following this istructions on how to draw a circle I can make buffer layer on each point I need. I am not able to draw perfects circle because the buffer will be elliptic? The CSR is EPSG:4326 - WGS ...
3
votes
1answer
123 views

Extract longitude latitude and radius from POSTGIS column

I have entered the circle in the Geometry type column (name=shape) in my POSTGIS as following: ST_Buffer(ST_MakePoint($longitude, $latitude)::geography, $radius)::geometry Then I extracted the ...
2
votes
2answers
452 views

drawing concentric circles in arcmap 10.1

I am using ArcMap 10.1 and I would like to know if there is a way to draw circles at a specific distance from a georeferenced coordinate. I have a property and I would like to know how far you can ...
2
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0answers
103 views

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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1answer
158 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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0answers
90 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
152 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
344 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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0answers
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 ...
0
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1answer
46 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
417 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 ...
1
vote
1answer
98 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
0
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1answer
141 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 ...
3
votes
1answer
230 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 = ...
0
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1answer
3k 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
74 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 ...
2
votes
2answers
186 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
4
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1answer
410 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
2k 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 ...
1
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0answers
46 views

Condensing sparse geocodes to weighted Geo-Circles?

I have a dataset comprising 3 million records having latitude and longitude information associated with them. I want to condense it to form few thousands Geo-Circles, with radius and weight depending ...
1
vote
2answers
2k 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 ...
2
votes
2answers
483 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
votes
2answers
1k 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. ...
7
votes
3answers
922 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 ...
4
votes
1answer
243 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 ...
1
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1answer
92 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 ...
2
votes
3answers
319 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 ...
4
votes
3answers
2k 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 ...
2
votes
0answers
169 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 ...
2
votes
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, ...
7
votes
2answers
7k 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 ...
3
votes
2answers
2k 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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vote
2answers
889 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 ...