testnfreq(nfreq), nfreq a vector of positive integers |

testnfreq(nfreq) returns a LOGICAL vector the same length as nfreq, a vector of positive integers. Element j of the result is True if and only if nfreq[j] has no prime factors > 29. testnfreq() is useful in macros which use one of the fast Fourier transform functions, rft(), dft() and hft(), since these operate only on vectors or matrices x for which nrows(x) has no prime factors > 29. It allows you to test whether this condition is true. The use of testnfreq() is deprecated since goodfactors() can be used in an equivalent test. When N is a scalar, goodfactors(N) == N is True if and only if testnfreq(N) is true. Moreover, the value of goodfactors(N) is the next integer >= N with no prime factors > 29. Example: if (!testnfreq(nrows(y))){ error("nrows(y) has prime factor > 29") }else{ yft <- rft(y) } See also topics goodfactors(), primefactors(), rft(), hft(), cft(), 'fourier'

Gary Oehlert 2003-01-15