rray (version 0.0.0.9000)

rray_exp: Logarithms and exponentials

Description

• rray_exp() - computes the natural exponential of x.

• rray_exp2() - computes the base 2 exponential of x.

• rray_expm1() - computes exp(x) - 1.

• rray_log() - computes the natural logarithm of x.

• rray_log2() - computes the base 2 logarithm of x.

• rray_log10() - computes the base 10 logarithm of x.

• rray_log1p() - computes log(1 + x).

Usage

rray_exp(x)
rray_exp2(x)
rray_expm1(x)
rray_log(x, base = NULL)
rray_log2(x)
rray_log10(x)
rray_log1p(x)

Arguments

x

A vector, matrix, array or rray.

base

A single positive number. The base that logarithms are computed with respect to. The default of NULL uses a natural log, i.e. exp(1).

Examples

# NOT RUN {
# Exponential
rray_exp(1L)
rray_exp(rray(1:5, c(5, 1)))

# Identical to 2 ^ x
rray_exp2(5)

# Log with different bases
rray_log(1) == rray_log(1, exp(1))
rray_log(100, 2)
rray_log(100, exp(1))

# From `?log`, the following example shows how `rray_log1p()`
# and `rray_expm1()` can be more accurate than `rray_log(1 + x)` or
# `rray_exp(x) - 1` for very small `|x|`.
x <- 10 ^ -(1 + 2 * 1:9)
x_base <- cbind(x, log(1+x), log1p(x), exp(x)-1, expm1(x))
x_rray <- cbind(x, rray_log(1+x), rray_log1p(x), rray_exp(x)-1, rray_expm1(x))

# No difference with base R!
x_base - x_rray

# }