package jscl.math.operator.stat;
import jscl.math.*;
import jscl.math.operator.Operator;
import javax.annotation.Nonnull;
/**
* User: serso
* Date: 12/26/11
* Time: 11:09 AM
*/
public class Mean extends AbstractStatFunction {
public static final String NAME = "mean";
public Mean(JsclVector vector) {
this(new Generic[]{vector});
}
private Mean(@Nonnull Generic[] parameters) {
super(NAME, parameters);
}
@Nonnull
@Override
public Operator newInstance(@Nonnull Generic[] parameters) {
return new Mean(parameters);
}
@Override
public int getMinParameters() {
return 1;
}
@Override
public Generic selfExpand() {
return expressionValue();
}
@Override
public Generic selfNumeric() {
if (parameters[0] instanceof JsclVector) {
final JsclVector vector = (JsclVector) parameters[0];
final Generic[] elements = vector.elements();
if (elements.length == 0) {
return new NumericWrapper(JsclInteger.ZERO);
} else if (elements.length == 1) {
return elements[0];
} else {
Generic result = elements[0].numeric();
for (int i = 1; i < elements.length; i++) {
result = result.add(elements[i].numeric());
}
return result.divide(JsclInteger.valueOf(elements.length).numeric());
}
} else {
return expressionValue();
}
}
@Nonnull
@Override
public Variable newInstance() {
return new Mean((JsclVector) null);
}
}