nextn(n, factors=c(2,3,5))
n
| an integer. |
factors
| a vector of positive integer factors. |
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 to
so that the transform is computed quickly.
The default value for factors ensures this.
convolve, fft.