gives the statistic of the elements in list.


gives the statistic with scaling factor c.

Details and Options

  • SnDispersion is a robust measure of dispersion.
  • SnDispersion is a rank-based estimator with its statistic based on absolute pairwise differences. The statistic does not require location estimation.
  • For the list {x1,x2,,xn}, the value of estimator is given by the median of {zi,1in} multiplied by a scaling factor c, where zi is the median of {xi xj,1jn} over j.  »
  • When c is not specified, a positive scaling factor c* that satisfies is applied to make statistic a consistent estimator of the scale parameter for normally distributed data. Also, a finite sample correction is used by default to make the estimator unbiased for small samples.
  • SnDispersion[{{x1,y1,},{x2,y2,},}] gives {SnDispersion[{x1,x2,}],SnDispersion[{y1,y2,}],}.
  • SnDispersion supports a Method option. The following explicit settings can be specified:
  • "FiniteSample"uses finite sample correction (default)
    "None"no correction
  • The option Method is ignored if the scaling factor c is specified in the input.


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Basic Examples  (3)

SnDispersion of a list:

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SnDispersion of columns of a matrix:

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SnDispersion of a list with scaling factor 1:

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Scope  (6)

Options  (1)

Applications  (6)

Properties & Relations  (2)

Introduced in 2017