nextn returns the smallest integer,
greater than or equal to n, which can be obtained
as a product of powers of the values contained in factors.
nextn() is intended to be used to find a suitable length
to zero-pad the argument of fft
so that the transform is computed quickly.
The default value for factors ensures this.
Usage
nextn(n, factors = c(2,3,5))
Arguments
n
a vector of integer numbers (of type "integer"or"double").
factors
a vector of positive integer factors (at least \(2\)
and preferably relative prime, see the note).
Value
a vector of the same length as n, of type
"integer" when the values are small enough (determined before
computing them) and "double" otherwise.