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);            double currentVal = Double.POSITIVE_INFINITY;            for(int i=0;i<values.length;i++)            {                if(values[i] < currentVal)                {                    currentVal = values[i];                }            }            return currentVal;        }