tolerance | R Documentation |
Species tolerances and sample heterogeneities.
tolerance(x, ...)
## S3 method for class 'cca'
tolerance(x, choices = 1:2, which = c("species","sites"),
scaling = "species", useN2 = TRUE, hill = FALSE, ...)
## S3 method for class 'decorana'
tolerance(x, data, choices = 1:4,
which = c("sites", "species"), useN2 = TRUE, ...)
x |
object of class |
choices |
numeric; which ordination axes to compute tolerances and heterogeneities for. Defaults to axes 1 and 2. |
which |
character; one of |
scaling |
character or numeric; the ordination scaling to
use. See |
hill |
logical; if |
useN2 |
logical; should the bias in the tolerances / heterogeneities be reduced via scaling by Hill's N2? |
data |
Original input data used in |
... |
arguments passed to other methods. |
Function to compute species tolerances and site heterogeneity measures from unimodal ordinations (CCA & CA). Implements Eq 6.47 and 6.48 from the Canoco 4.5 Reference Manual (pages 178–179).
Matrix of tolerances/heterogeneities with some additional
attributes: which
, scaling
, and N2
, the latter of
which will be NA
if useN2 = FALSE
or N2
could not
be estimated.
Gavin L. Simpson and Jari Oksanen (decorana
method).
data(dune)
data(dune.env)
mod <- cca(dune ~ ., data = dune.env)
## defaults to species tolerances
tolerance(mod)
## sample heterogeneities for CCA axes 1:6
tolerance(mod, which = "sites", choices = 1:6)
## average should be 1 with scaling = "sites", hill = TRUE
tol <- tolerance(mod, which = "sites", scaling = "sites", hill = TRUE,
choices = 1:4)
colMeans(tol)
apply(tol, 2, sd)
## Rescaling tries to set all tolerances to 1
tol <- tolerance(decorana(dune))
colMeans(tol)
apply(tol, 2, sd)
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