hill | R Documentation |
According to Hill (1973): "a diversity number is figuratively a measure of how many species are present if we examine the sample down to a certain depth among its rarities. If we examine superficially (e.g., by using N[2]) we shall see only the more abundant species. If we look deeply (e.g., by using N[0]) we shall see all the species present."
Hill's diversity numbers are given by:
N_a=∑{i=1}^S (p_i^a)^{1/(1-a)}
Special cases are:
reciprocal of the proportional abundance of the rarest species;
total number of species present;
exp(H), where H: Shannon's index (see also
shannon
);
reciprocal of Simpson's index (see also
simpson
);
reciprocal of the proportional abundance of the commonest species.
hill(.data = NULL, taxon, count, a = 0) hill_(.data = NULL, taxon, count, a = 0) hill0(.data = NULL, taxon, count) hill0_(.data = NULL, taxon, count) hill1(.data = NULL, taxon, count) hill1_(.data = NULL, taxon, count) hill2(.data = NULL, taxon, count) hill2_(.data = NULL, taxon, count)
.data |
data in a |
taxon |
name of column in |
count |
name of column in |
a |
exponent in Hill's diversity number (R, with special cases for
|
numeric vector of Hill's numbers
hill_()
: version suitable for calling from a function
(see package lazyeval).
hill0()
: N[0]
hill0_()
: N[0], version suitable for calling
from a function (see package lazyeval).
hill1()
: N[1]
hill1_()
: N[1], version suitable for calling
from a function (see package lazyeval).
hill2()
: N[2]
hill2_()
: N[2], version suitable for calling
from a function (see package lazyeval).
Hill, M.O., 1973. Diversity and Evenness: A Unifying Notation and Its Consequences. Ecology 54:427-432
species_richness
, shannon
,
simpson
hill( taxon = c("Euspira pulchella", "Nephtys cirrosa"), count = c(6, 12), a = 0 ) hill0( taxon = c("Euspira pulchella", "Nephtys cirrosa"), count = c(6, 12) )
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