int firstNonMissingIndex = -1;
boolean leadingMissingDates = weka.core.Utils
.isMissingValue(firstNonMissing);
for (int i = 0; i < result.numInstances(); i++) {
Instance current = result.instance(i);
if (current.isMissing(attIndex)) {
if (!weka.core.Utils.isMissingValue(previousNonMissing)) {
double newV = advanceSuppliedTimeValue(previousNonMissing, detected);
current.setValue(attIndex, newV);