First check in of map of science visualization

productMods/js/visualization/mapofscience/SizeCoding.js

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+/* $This file is distributed under the terms of the license in /doc/license.txt$ */
+/**
+ * The scaler is used for scaling based on the predefined minimum value and
+ * maximum value. You also can control the returned maximum scale and minimum 
+ * scale.
+ */
+var Scaler = Class.extend({ 
+	init: function(options) {
+		this.options = $.extend({}, this.options, options);
+	},
+	options: {
+		scaleFunc: ReallySimpleAreaScale,
+		minValue: 0.0,
+		maxValue: 0.0,
+		minScale: 0.0,
+		maxScale: 1.0
+	},
+	getScale: function(value) {
+		var o = this.options;
+		var scale = o.scaleFunc(value, o.minValue, o.maxValue, o.minScale, o.maxScale);
+		if (scale > o.maxScale) {
+			scale = maxScale;
+		} else if (scale < o.minScale) {
+			scale = minScale;
+		}
+		return scale;
+	}
+});
+
+/* Scaling that ignore minScale and maxScale */
+function ReallySimpleAreaScale(value, minValue, maxValue, minScale, maxScale) {
+	return maxScale * Math.sqrt(value / maxValue);
+}
+
+/* Scaling that cares about minScale and maxScale */
+function SimpleAreaScale(value, minValue, maxValue, minScale, maxScale) {
+	if (maxValue != minValue) {
+		var scale = minScale; 
+		if (value > minValue) {
+			var valueDiff = maxValue - minValue;
+			var areaScale = value / valueDiff;
+			scale = Math.sqrt(areaScale);
+		}
+		return scale;
+	} else {
+		return maxScale;
+	}
+}
+
+/**
+ * SizeCoder use scaler to scale its interested size based on the given
+ * scaler strategy.
+ */
+var CircleSizeCoder = Class.extend({
+	init: function(options) {
+		this.options = $.extend({}, this.options, options);
+	},
+	options: {
+		minRadius: 100000.0,
+		maxRadius: 2500000.0,//2500000.0,
+		scaler: new Scaler({})
+	},
+	getSize: function(value) {
+		var o = this.options;
+		var radius = o.scaler.getScale(value) * o.maxRadius;
+		
+		if (radius < o.minRadius) {
+			radius = o.minRadius;
+		} else if (radius > o.maxRadius) {
+			radius = o.maxRadius;
+		}
+		
+		return radius;
+	}
+});
+