double[] values = extractValues(attributes,elementName);
double[] values = HeatMapUtils.extractValues(attributes,elementName);
        public double computeValue(Attribute[] attributes, String elementName)            throws IllegalArgumentException        {            double[] values = extractValues(attributes,elementName);            Arrays.sort(values);                        if(values.length % 2 != 0)            {                return values[values.length/2];            }            else            {                double value1 = values[values.length/2-1];                double value2 = values[values.length/2];                return (value1+value2)/2.0;            }        }