Next: attachnotes()
Up: MacAnova Help File
Previous: atan()
Contents
Usage:
atanh(x), x REAL or a structure with REAL components
|
Keywords:
transformations
atanh(x) returns the inverse hyperbolic tangent of the elements of x,
when x is a REAL scalar, vector, matrix or array. The result has the
same shape as x. In terms of other functions, atanh(x) =
.5*log((1+x)/(1-x)).
This transform is sometimes called the Fisher z-transform. When r is a
sample Pearson correlation from a bivariate normal sample of size N and
population correlation rho, atanh(r) is approximately normal with mean
rho and variance 1/(N-2).
When any element of x is MISSING, so is the corresponding element of
atanh(x). When any element of x >= 1 or <= -1, the corresponding
element of atanh(x) is MISSING. In both cases a warning message is
printed.
When x is a structure, all of whose non-structure components are REAL,
atanh(x) is a structure of the same shape and with the same component
names as x, with each non-structure component transformed by atanh().
See topic 'transformations' for more information on atanh().
Gary Oehlert
2003-01-15