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I am stuck, trying to figure out how to create a simple graphic for adding a circle based on one point in my web map. I need the circle to be centered on my single point, with a radius of 5 miles. I saw examples for the geodesic circle and that didn't work for me, as well a creating a buffer, which I don't think I need. I just need a simple circle graphic. Is there a simple way to do this? I have a map with one point and need this graphic for a boundary. I apologize as I am new to this and trying to learn this API quickly.

thanks

Bob C
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  • Are you talking about this sample when saying the geodesic circle didn't work? – kenbuja Jun 11 '14 at 20:18
  • Yes, that works for me. But I just need a basic example of how to add a circle based on a point. I can just add that code to what I have to make it work and I just need a simple example, the fewer lines the better. – Bob C Jun 11 '14 at 20:19
  • Do you mean you want the code to show a circle from a pre-existing point and not where the user clicks? – kenbuja Jun 11 '14 at 20:24
  • Yes, however I do not need any onClick function. Just a fixed or static circle, centered on the single point. Thanks! – Bob C Jun 11 '14 at 20:46

3 Answers3

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From the ArcGIS website: it looks like your simplest bet is the buffer tool

you should be able to draw a buffer circle with the examples containing the buffer_analysis() command located on the page link above.

There was also some discussion earlier about creating a simplified circle polygon instead of the buffer tool you might be intereseted in checking out.

Community
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Snazzer
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  • I know how to create a buffer in ArcGIS, I am referring to the ArcGIS API for JavaScript. Not python, am I in the wrong forum? Wait, yeah I am trying to do this for my GIS website. Please advise... – Bob C Jun 11 '14 at 20:15
  • my bad. I didn't catch the javascript tag. – Snazzer Jun 11 '14 at 20:51
1

Use your point as the basis for a circle geometry. The create circles sample shows how to use that class.

Derek Swingley
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1

This will give you a 5 mile geodesic circle around a predefined point.

<!DOCTYPE html>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    <meta name="viewport" content="initial-scale=1, maximum-scale=1, user-scalable=no">
    <title></title>
    <link rel="stylesheet" href="//js.arcgis.com/3.9/js/esri/css/esri.css">
    <style>
    html, body, #map {
        height: 100%;
        width: 100%;
        margin: 0;
        padding: 0;
    }

    </style>

    <script src="//js.arcgis.com/3.9/"></script>
    <script>
    var map;

    require([
      "esri/map", "esri/geometry/Circle", "esri/symbols/SimpleFillSymbol", "esri/symbols/SimpleMarkerSymbol", "esri/symbols/SimpleLineSymbol",
      "esri/graphic", "esri/geometry/Point", "esri/Color",
      "dojo/domReady!"
    ], function (
      Map, Circle, SimpleFillSymbol, SimpleMarkerSymbol, SimpleLineSymbol,
      Graphic, Point, Color
    ) {
        map = new Map("map", {
        basemap: "streets",
        center: [-77.036744, 38.897731],
        zoom: 12
        });
        var symbol = new SimpleFillSymbol().setColor(null).outline.setColor("blue");
        var symbolPoint = new SimpleMarkerSymbol(SimpleMarkerSymbol.STYLE_X, 10,
              new SimpleLineSymbol(SimpleLineSymbol.STYLE_SOLID, new Color([255, 0, 0]), 1),
              new Color([0, 255, 0, 0.25]));

        map.on("load", function () {
            var point = new Point([-77.036744, 38.897731]);
            var pointGraphic = new Graphic(point, symbolPoint);
            map.graphics.add(pointGraphic);
            var circle = new Circle(point, {
                radius: 5,
                radiusUnit: esri.Units.MILES,
                geodesic: true
            });
            var circleGraphic = new Graphic(circle, symbol);
            map.graphics.add(circleGraphic);
        });

    });
    </script>
</head>
<body>
    <div id="map"></div>
</body>
</html>
kenbuja
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