/**
* Convert a single instance over. The converted instance is added to the end of the output queue.
*
* @param instance the instance to convert
* @exception Exception if an error occurs
*/
private void convertInstance(Instance instance) throws Exception {
Instance inst = null;
if (instance instanceof SparseInstance) {
double[] newVals = new double[instance.numAttributes()];
int[] newIndices = new int[instance.numAttributes()];
double[] vals = instance.toDoubleArray();
int ind = 0;
for (int j = 0; j < instance.numAttributes(); j++) {
double value;
if (instance.attribute(j).isNumeric()
&& (!Instance.isMissingValue(vals[j]))
&& (getInputFormat().classIndex() != j)) {
// Just subtract the mean if the standard deviation is zero
if (m_StdDevs[j] > 0) {
value = (vals[j] - m_Means[j]) / m_StdDevs[j];
} else {
value = vals[j] - m_Means[j];
}
if (Double.isNaN(value)) {
throw new Exception(
"A NaN value was generated "
+ "while standardizing attribute "
+ instance.attribute(j).name());
}
if (value != 0.0) {
newVals[ind] = value;
newIndices[ind] = j;
ind++;
}
} else {
value = vals[j];
if (value != 0.0) {
newVals[ind] = value;
newIndices[ind] = j;
ind++;
}
}
}
double[] tempVals = new double[ind];
int[] tempInd = new int[ind];
System.arraycopy(newVals, 0, tempVals, 0, ind);
System.arraycopy(newIndices, 0, tempInd, 0, ind);
inst = new SparseInstance(instance.weight(), tempVals, tempInd, instance.numAttributes());
} else {
double[] vals = instance.toDoubleArray();
for (int j = 0; j < getInputFormat().numAttributes(); j++) {
if (instance.attribute(j).isNumeric()
&& (!Instance.isMissingValue(vals[j]))
&& (getInputFormat().classIndex() != j)) {
// Just subtract the mean if the standard deviation is zero
if (m_StdDevs[j] > 0) {
vals[j] = (vals[j] - m_Means[j]) / m_StdDevs[j];
} else {
vals[j] = (vals[j] - m_Means[j]);
}
if (Double.isNaN(vals[j])) {
throw new Exception(
"A NaN value was generated "
+ "while standardizing attribute "
+ instance.attribute(j).name());
}
}
}
inst = new Instance(instance.weight(), vals);
}
inst.setDataset(instance.dataset());
push(inst);
}
