| log {base} | R Documentation |
log computes natural logarithms,
log10 computes common (i.e., base 10) logarithms, and
log2 computes binary (i.e., base 2) logarithms.
The general form log(x, base) computes logarithms with base
base (log10 and log2 are only special cases).
log1p(x) computes log(1+x) accurately also for
|x| << 1 (and less accurately when x ~= -1).
exp computes the exponential function.
log(x) log(x, base) log10(x) log2(x) exp(x) log1p(x)
x |
a numeric or complex vector. |
base |
positive number. The base with respect to which
logarithms are computed. Defaults to e=exp(1). |
A vector of the same length as x containing the transformed
values. log(0) gives -Inf (when available).
Trig, Math, Arithmetic.
log(exp(3)) all.equal(log(1:10), log(1:10, exp(1))) log10(30) == log(30, 10) log10(1e7)# = 7 log2(2^pi) == 2^log2(pi) Mod(pi - log(exp(pi*1i)) / 1i) < .Machine$double.eps Mod(1+exp(pi*1i)) < .Machine$double.eps x <- 10^-(1+2*1:9) cbind(x, log(1+x), log1p(x))