slide gists

gistfile1.js

{
   "_id": "_design/gc-utils",
   "_rev": "2-bd8fcdf5509cb9cc99560a39f0c642f0",
   "vendor": {
       "clustering": {
           "KNNCluster": "/**\n * kNN-based Clustering\n */\n(function() {\n\tvar cluster = this.cluster = {};\n\n\tif (typeof module !== 'undefined' && module.exports) {\n\t\tmodule.exports = cluster;\n\t}\n\t\n\t//TODO\n})();",
           "ProximityCluster": "/**\n * Proximity based clustering\n */\n(function() {\n\n    var proxcluster = this.proxcluster = {};\n\tif (typeof module !== 'undefined' && module.exports) {\n\t\tmodule.exports = proxcluster;\n\t}\n\n    var gju = require('vendor/geojson-js-utils/geojson-utils');\n\n    proxcluster.PointCluster = function(threshold){\n        this.clusters = [];\n        this.points = [];\n        this.distanceThreshold = threshold;\n\n    };\n  \n    proxcluster.PointCluster.prototype.addToClosestCluster = function(point) {\n        var distance = 40000; // Some large number\n        var clusterToAddTo = null;\n        var pos = point.geometry;\n        for (var i = 0, cluster; cluster = this.clusters[i]; i++) {\n            var center = cluster.center;\n          \n            if (center) {\n                var d = gju.pointDistance(center, pos)/1000; //convert to km\n                if ( d < this.distanceThreshold) {\n                    distance = d;\n                    clusterToAddTo = cluster;\n                }\n            }\n        }\n\n        if (clusterToAddTo) {\n            clusterToAddTo.addPoint(point);\n        } else {\n            var cluster = new proxcluster.Cluster(this);\n            cluster.addPoint(point);\n            this.clusters.push(cluster);\n        }\n    };\n\n    proxcluster.PointCluster.prototype.getClusters = function(){\n\n        var clusterdata = [];\n        for (var i = 0, cluster; cluster = this.clusters[i]; i++) {\n            clusterdata.push({\"center\":cluster.center, \"points\":cluster.getPoints(), \"size\": cluster.getSize()});\n        }\n        return clusterdata;\n    }\n\n    /**\n     * A cluster that contains points.\n     *\n     * @param {PointCluster} The PointCluster that this\n     *     cluster is associated with.\n     * @constructor\n     * @ignore\n     */\n    proxcluster.Cluster = function (PointCluster) {\n        this.pointCluster = PointCluster;\n        this.center = null;\n        this.points = [];\n    }\n\n    /**\n     * Add a point the cluster.\n     *\n     * @param {point} The point to add.\n     * @return {boolean} True if the point was added.\n     */\n    proxcluster.Cluster.prototype.addPoint = function(point) {\n        if (!this.center) {\n            this.center = point.geometry;\n        } else {\n            var l = this.points.length + 1;\n            var lat = (this.center.coordinates[0] * (l-1) + point.geometry.coordinates[0]) / l;\n            var lng = (this.center.coordinates[1] * (l-1) + point.geometry.coordinates[1]) / l;\n            this.center = {\"type\": \"Point\", \"coordinates\":[lat, lng]};\n        }\n\n      \n        this.points.push(point);\n\n        return true;\n    };\n\n\n    /**\n     * Returns points in the cluster\n     *\n     * @return {Array.<points>} The points\n     */\n    proxcluster.Cluster.prototype.getPoints = function() {\n        return this.points;\n    };\n\n    /**\n     * Returns number of points\n     *\n     * @return {int} number of points\n     */\n    proxcluster.Cluster.prototype.getSize = function() {\n        return this.points.length;\n    };\n\n\n})();"
       },
       "geojson-js-utils": {
       }
   },
   "views": {
       "all": {
           "map": "/**\n * A simple map function mocking _all, but allows usage with lists etc.\n * \n */\nfunction(doc) {\n  emit(doc.id, doc);\n}"
       }
   },
   "lists": {
       "knn-clustering": "/**\n * A clustering algorithm that clusters object based on their proximity, producing k distinct clusters.\n */\nfunction(head, req) {\n\tstart({\"code\": 501,\"headers\":{\"Content-Type\" : \"text/plain\"}});\n\t//TODO: implement kNN clustering list    \n}",
       "proximity-clustering": "/**\n * A clustering algorithm that clusters object based on their proximity, using a threshold value.\n */\nfunction(head, req) {\t\n\n    var g = require('vendor/clustering/ProximityCluster'),\n        row,\n        threshold =100;\n\n    start({\"headers\":{\"Content-Type\" : \"application/json\"}});\n    if ('callback' in req.query) send(req.query['callback'] + \"(\");\n   \n    if('threshold' in req.query){ threshold = req.query.threshold;}\n    var pc = new g.PointCluster(parseInt(threshold));   \n \n    while (row = getRow()) {\n        pc.addToClosestCluster(row.value);\n    }\n\n    send(JSON.stringify({\"rows\":pc.getClusters()}));\n\n    if ('callback' in req.query) send(\")\");\n};",
       "kml": "/**\n * A list function that transforms a spatial view result set into a KML feed.\n *\n * @author Benjamin Erb\n */\nfunction(head, req) {\n    var row, out, sep = '\\n';\n\n    start({\"headers\":{\"Content-Type\" : \"application/vnd.google-earth.kml+xml\"}});\n    send('<?xml version=\"1.0\" encoding=\"UTF-8\"?>\\n');\n    send('<kml xmlns=\"http://www.opengis.net/kml/2.2\">\\n');\n    send('<Document>\\n');\n    send('<name>GeoCouch Result - KML Feed</name>\\n');\n    while (row = getRow()) {\n        if(row.geometry){\n            send('\\t<Placemark>');\n            send('<name>'+row.id+'</name>');\n            send('<Point><coordinates>'+row.geometry.coordinates[0]+','+row.geometry.coordinates[1]+',0</coordinates></Point>');\n            send('</Placemark>\\n');\n    \t}\n    }\n    send('</Document>\\n');\n    send('</kml>\\n');\n};",
       "radius": "/**\n * This will take the centroid of the bbox parameter and a supplied radius\n * parameter in meters and filter the rectangularly shaped bounding box\n * result set by circular radius.\n *\n * @author Max Ogden\n */\nfunction(head, req) {\n  var gju = require('vendor/geojson-js-utils/geojson-utils'),\n      row,\n      out,\n      radius = req.query.radius,\n      bbox = JSON.parse(\"[\" + req.query.bbox + \"]\"),\n      center = gju.rectangleCentroid({\n        \"type\": \"Polygon\",\n        \"coordinates\": [[[bbox[0], bbox[1]], [bbox[2], bbox[3]]]]\n      }),\n      callback = req.query.callback,\n      circle = gju.drawCircle(radius, center),\n      startedOutput = false;\n\n  if (req.headers.Accept.indexOf('application/json') != -1)\n    start({\"headers\":{\"Content-Type\" : \"application/json\"}});\n  else\n    start({\"headers\":{\"Content-Type\" : \"text/plain\"}});\n\n  if ('callback' in req.query) send(req.query['callback'] + \"(\");\n  send('{\"type\": \"FeatureCollection\", \"features\":[');\n  while (row = getRow()) {\n    if (gju.pointInPolygon(row.geometry, circle)) {\n      if (startedOutput) send(\",\\n\");\n      out = '{\"type\": \"Feature\", \"geometry\": ' + JSON.stringify(row.geometry) +\n          ', \"properties\": ' + JSON.stringify(row.value) + '}';\n      send(out);\n      startedOutput = true;\n    }\n  }\n  send(\"\\n]};\");\n  if ('callback' in req.query) send(\")\");\n};",
       "geojson": "/**\n * This function outputs a GeoJSON FeatureCollection (compatible with\n * OpenLayers). JSONP requests are supported as well.\n *\n * @author Volker Mische\n */\nfunction(head, req) {\n    var row, out, sep = '\\n';\n\n    // Send the same Content-Type as CouchDB would\n    if (req.headers.Accept.indexOf('application/json')!=-1) {\n        start({\"headers\":{\"Content-Type\" : \"application/json\"}});\n    }\n    else {\n        start({\"headers\":{\"Content-Type\" : \"text/plain\"}});\n    }\n\n    if ('callback' in req.query) {\n        send(req.query['callback'] + \"(\");\n    }\n\n    send('{\"type\": \"FeatureCollection\", \"features\":[');\n    while (row = getRow()) {\n        out = JSON.stringify({type: \"Feature\", geometry: row.geometry,\n                properties: row.value});\n        send(sep + out);\n        sep = ',\\n';\n    }\n    send(\"]}\");\n\n    if ('callback' in req.query) {\n        send(\")\");\n    }\n};"
   },
   "spatial": {
       "geomsOnly": "/**\n * A simple spatial view that emits only the GeoJSON object without\n * further values.\n */\nfunction(doc){\n    if(doc.geometry){\n        emit(doc.geometry, null);\n    }\n}",
       "geomsFull": "/**\n * A simple spatial view that emits the GeoJSON plus the complete document.\n */\nfunction(doc){\n    if(doc.geometry){\n        emit(doc.geometry, doc);\n    }\n}",
       "recentFull": "/**\n * A simple spatial view that emits the GeoJSON plus the complete document.\n */\nfunction(doc){\n\tif(doc.geometry){\n        startdate = new Date();\n\n        //Only in the last hour.\n        startdate.setTime(startdate.getTime() - (1000*60*60));\n        messagedate = new Date(doc.date);\n        if(messagedate > startdate){\n\t\t    emit(doc.geometry, doc);\n        }\n\t}\n}",
       "geoms": "/**\n * A simple spatial view that emits GeoJSON plus the original document id.\n */\nfunction(doc){\n    if(doc.geometry){\n        emit(doc.geometry, doc._id);\n    }\n}"
   },
   "couchapp": {
       "signatures": {
       },
       "objects": {
       },
       "manifest": [
           "lists/",
           "lists/geojson.js",
           "lists/kml.js",
           "lists/knn-clustering.js",
           "lists/proximity-clustering.js",
           "lists/radius.js",
           "spatial/",
           "spatial/geoms.js",
           "spatial/geomsFull.js",
           "spatial/geomsOnly.js",
           "spatial/recentFull.js",
           "vendor/",
           "vendor/clustering/",
           "vendor/clustering/KNNCluster.js",
           "vendor/clustering/ProximityCluster.js",
           "vendor/geojson-js-utils/",
           "views/",
           "views/all/",
           "views/all/map.js"
       ]
   }
}