glog: Compute Generalized Logarithm

Description Usage Arguments Details Value Author(s) Examples

View source: R/glog.R

Description

The functions compute the generalized logarithm, which is more or less identical to the area hyperbolic sine, and their inverse; see details.

Usage

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glog(x, base = exp(1))
glog10(x)
glog2(x)
inv.glog(x, base = exp(1))
inv.glog10(x)
inv.glog2(x)

Arguments

x

a numeric or complex vector.

base

a positive or a positive or complex number: the base with respect to which logarithms are computed. Defaults to e=exp(1).

Details

The function computes

log(x + sqrt(x^2 + 1)) - log(2)

where the first part corresponds to the area hyperbolic sine. Subtracting log(2) makes the function asymptotically identical to the logarithm.

Value

A vector of the same length as x containing the transformed values.

Author(s)

Matthias Kohl [email protected]

Examples

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curve(log, from = -3, to = 5)
curve(glog, from = -3, to = 5, add = TRUE, col = "orange")
legend("topleft", fill = c("black", "orange"), legend = c("log", "glog"))

curve(log10(x), from = -3, to = 5)
curve(glog10(x), from = -3, to = 5, add = TRUE, col = "orange")
legend("topleft", fill = c("black", "orange"), legend = c("log10", "glog10"))

inv.glog(glog(10))
inv.glog(glog(10, base = 3), base = 3)
inv.glog10(glog10(10))
inv.glog2(glog2(10))

stamats/MKmisc documentation built on Nov. 10, 2018, 11:24 a.m.