udunits/src/main/java/ucar/units/DerivedUnitImpl.java
public final float[] toDerivedUnit(final float[] input, final float[] output) {
        if (input != output) {
            System.arraycopy(input, 0, output, 0, input.length);
        }
        return output;
    }
public final float[] toDerivedUnit(final float[] input, final float[] output) {
        if (input != output) {
            System.arraycopy(input, 0, output, 0, input.length);
        }
        return output;
    }
Converts numerical values from this unit to the derived unit. Obviously,
the numerical values are unchanged.

@param input
The numerical values in this unit.
@param output
The numerical values in the derived unit. May be the same
array as <code>input</code>.
@return <code>output</code>.