I really like the range of statistical properties that the accumulators library supports but am a little unclear about the laziness properties of the library.

Suppose I wish to offer a interface that lets the user send a bunch of data and request the k-th moments where k is specified by the user at runtime. Will the accumulator_set

accumulator_set< value_type , ba::tag::moments<k_max> > acc;

where k_max >= k (but the inequality may be strict) be efficient. I.e. I only do the calculations necessary to get the k-th moment not the k-max-th? The reason I ask is the documentation makes a distinction between variance and lazy_variance, but this distinction does not seem to be made for other statistics.

Thanks in advance for any assistance,

Pete