u.log {sfsmisc} | R Documentation |
Compute log()
only for high values and keep low ones –
antisymmetrically such that u.log(x)
is (once) continuously
differentiable, it computes
f(x) = x
for |x| \le c
and
sign(x) c\cdot(1 + log(|x|/c))
for |x| \ge c
.
u.log(x, c = 1)
x |
numeric vector to be transformed. |
c |
scalar, > 0 |
numeric vector of same length as x
.
Martin Maechler, 24 Jan 1995
curve(u.log, -3, 10); abline(h=0, v=0, col = "gray20", lty = 3)
curve(1 + log(x), .01, add = TRUE, col= "brown") # simple log
curve(u.log(x, 2), add = TRUE, col=2)
curve(u.log(x, c= 0.4), add = TRUE, col=4)