stats (version 3.6.0)

nextn: Find Highly Composite Numbers

Description

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.

See Also

convolve, fft.

Examples

# NOT RUN {
nextn(1001) # 1024
table(nextn(599:630))
n <- 1:100 ; plot(n, nextn(n) - n, type = "o", lwd=2, cex=1/2)
# }