/**
* Fills the supplied array with the number of examples
* from the current dataset that fall into each of the
* target categories (based on the attribute mask).
*
* @param mask The mask that determines which examples
* reach the current position in the decision
* tree.
*
* @param examples An iteration over a series of
* examples from the current dataset.
*
* @param counts The method expects the parameter to be
* an array with a size equal to the number of
* target attribute values. Each position in
* the array is filled with a corresponding count
* of the number of training examples that fall into
* that particular target class, at the current
* position in the decision tree.
*
* @param reachedHere The method expects the parameter
* to be an array with a size equal to the
* <i>total</i> number of examples being examined.
* Each cell in the array is set to true or
* false, depending on whether or not the
* corresponding example reaches the current
* position in the decision tree.
*/
private void getExampleCounts(AttributeMask mask, IEnumerator<int[]> examples, int[] counts, bool[] reachedHere)
{
// Zero any values currently in stats.
for (int i = 0; i < counts.Length; i++)
{
counts[i] = 0;
}
int j = 0;
// Loop through and get totals.
while (examples.MoveNext())
{
int[] example = (int[])examples.Current;
if (mask.matchMask(example))
{
counts[example[0]]++; // Increment appropriate
// target count.
if (reachedHere != null && reachedHere.Length > j)
reachedHere[j] = true;
}
j++;
}
}
