code: public static MutableDoubleTuple standardDeviation(
          Collection<? extends DoubleTuple> tuples,
          MutableDoubleTuple result)
      {
          if (tuples.isEmpty())
          {
              return null;
          }
          DoubleTuple mean = arithmeticMean(tuples, null);
          return standardDeviationFromMean(tuples, mean, result);
      }
docs: Returns the component-wise standard deviation of the given collection
  of {@link DoubleTuple} objects. The method will compute
  the arithmetic mean, and then compute the actual result
  with the {@link #standardDeviationFromMean} method.
  
  @param tuples The input tuples
  @param result The result tuple
  @return The result, or <code>null</code> if the given collection is empty
  @throws IllegalArgumentException If the given result is not
  <code>null</code>, and has a {@link Tuple#getSize() size}
  that is different from that of the input tuples.