udunits/src/main/java/ucar/units/LogarithmicUnit.java
public float[] fromDerivedUnit(final float[] input, final float[] output)
            throws ConversionException {
        reference.fromDerivedUnit(input, output);
        for (int i = input.length; --i >= 0;) {
            output[i] = (float) (Math.log(output[i]) / lnBase);
        }
        return output;
    }
public float[] fromDerivedUnit(final float[] input, final float[] output)
            throws ConversionException {
        reference.fromDerivedUnit(input, output);
        for (int i = input.length; --i >= 0;) {
            output[i] = (float) (Math.log(output[i]) / lnBase);
        }
        return output;
    }
Converts values in the convertible derived unit to the equivalent values
in this unit.

@param input
The values in the convertible derived unit.
@param output
The equivalent values in this unit. May be the same array as
<code>input</code>.
@return <code>output</code>.
@throws ConversionException
Can't convert between units.