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Function List:

C++ API

: skewness (x)
: skewness (x, flag)
: skewness (x, flag, dim)

Compute the sample skewness of the elements of x.

The sample skewness is defined as 

               mean ((x - mean (x)).^3)
skewness (X) = ------------------------.
                      std (x).^3

The optional argument flag controls which normalization is used. If flag is equal to 1 (default value, used when flag is omitted or empty), return the sample skewness as defined above. If flag is equal to 0, return the adjusted skewness coefficient instead: 

                  sqrt (N*(N-1))   mean ((x - mean (x)).^3)
skewness (X, 0) = -------------- * ------------------------.
                      (N - 2)             std (x).^3

The adjusted skewness coefficient is obtained by replacing the sample second and third central moments by their bias-corrected versions.

If x is a matrix, or more generally a multi-dimensional array, return the skewness along the first non-singleton dimension. If the optional dim argument is given, operate along this dimension.

See also: var, kurtosis, moment.

Package: octave