function Intensity(options) {

    options = options || {};
    this.gradient = options.gradient || {
        0.25: "rgba(0, 0, 255, 1)",
        0.55: "rgba(0, 255, 0, 1)",
        0.85: "rgba(255, 255, 0, 1)",
        1.0: "rgba(255, 0, 0, 1)"
    };
    this.maxSize = options.maxSize || 35;
    this.minSize = options.minSize || 0;
    this.max = options.max || 100;
    this.min = options.min || 0;
    this.initPalette();
}
@param Number value 
@param Number max of value
@param Number max of size
@param Object other options