CITAN (version 2011.04-2)

index.g: Egghe's g-index

Description

Computes the "Classical" $g$-index of a numeric vector.

Usage

index.g(x, sorted.dec=FALSE, disable.check=FALSE)

Arguments

x

a non-negative numeric vector.

sorted.dec

logical; TRUE if the vector has already been sorted non-increasingly; defaults FALSE.

disable.check

logical; TRUE to disable some validity checks on the input vector; defaults FALSE.

Value

• The function returns a single number or NA if improper input has been given.

Details

Given a sequence of $n$ non-negative numbers $x=(x_1,\dots,x_n)$, where $x_i \ge x_j$ for $i \le j$, the $g$-index (Egghe, 2006) for $x$ is defined as $$G(x)=\max{i=1,\dots,n: \sum_{j=1}^i x_i \ge i^2},$$ if $n \ge 1$ and $x_1 \ge 1$, or $G(x)=0$ otherwise.

If disable.check is set to FALSE, then eventual NA values are removed from the input vector.

If a non-increasingly sorted vector is given as input (set sorted.dec to TRUE) the value is calculated in linear time.

References

Egghe L., Theory and practise of the g-index, Scientometrics 69(1), 131-152, 2006.

See Also

index.h, index.rp, index.lp, Sstat, Sstat2