index.h: Hirsch's $h$-index

Description

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

Usage

index.h(x, sorted.dec=FALSE, disable.check=FALSE,
    algorithm=c("log-time", "linear-time"))

Arguments

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.

algorithm

type of algorithm, "linear-time" or "log-time" (default).

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 $h$-index (Hirsch, 2005) for $x$ is defined as $$H(x)=\max{i=1,\dots,n: x_i \ge i}$$ if $n \ge 1$ and $x_1 \ge 1$, or $H(x)=0$ 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 or log-time, depending on the value of the algorithm parameter.

References

Hirsch J.E., An index to quantify individual's scientific research output, Proceedings of the National Academy of Sciences 102(46), 16569-16572, 2005.

Examples

Run this code

authors <- list(  # a list of numeric sequences
# (e.g. citation counts of the articles
# written by some authors)
"A" =c(23,21,4,2,1,0,0),
"B" =c(11,5,4,4,3,2,2,2,2,2,1,1,1,0,0,0,0),
"C" =c(53,43,32,23,14,13,12,8,4,3,2,1,0)
);
index.h(authors$A);
lapply(authors, index.h);

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