sign returns a vector with the signs of the corresponding elements of
x (the sign of a real number is 1, 0, or -1 if the number is positive, zero,
or negative, respectively).
# S3 method for generic_spct
sign(x)an object of class "generic_spct"
Other math operators and functions:
MathFun,
^.generic_spct(),
convolve_each(),
div-.generic_spct,
log(),
minus-.generic_spct,
mod-.generic_spct,
plus-.generic_spct,
round(),
slash-.generic_spct,
times-.generic_spct