Attribute attribute = (Attribute) enu.nextElement();
// If the attribute is numeric, determine the estimator
// numeric precision from differences between adjacent values
double numPrecision = DEFAULT_NUM_PRECISION;
if (attribute.type() == Attribute.NUMERIC) {
m_Instances.sort(attribute);
if ((m_Instances.numInstances() > 0)
&& !m_Instances.instance(0).isMissing(attribute)) {
double lastVal = m_Instances.instance(0).value(attribute);
double currentVal, deltaSum = 0;