# divisorsRcpp: Vectorized Factorization (Complete) In RcppAlgos: High Performance Tools for Combinatorics and Computational Mathematics

 divisorsRcpp R Documentation

## Vectorized Factorization (Complete)

### Description

Function for generating the complete factorization for a vector of numbers.

### Usage

``````divisorsRcpp(v, namedList = FALSE, nThreads = NULL)
``````

### Arguments

 `v` Vector of integers or numeric values. Non-integral values will be coerced to whole numbers. `namedList` Logical flag. If `TRUE` and the `length(v) > 1`, a named list is returned. The default is `FALSE`. `nThreads` Specific number of threads to be used. The default is `NULL`.

### Details

Efficient algorithm that builds on `primeFactorize` to generate the complete factorization of many numbers.

### Value

• Returns an unnamed vector if `length(v) == 1` regardless of the value of `namedList`. If `v < 2^{31}`, the class of the returned vector will be integer, otherwise the class will be numeric.

• If `length(v) > 1`, a named/unnamed list of vectors will be returned. If `max(bound1, bound2)` `< 2^{31}`, the class of each vector will be integer, otherwise the class will be numeric.

### Note

The maximum value for each element in `v` is `2^{53} - 1`.

Joseph Wood

### References

`primeFactorize`

### Examples

``````## Get the complete factorization of a single number
divisorsRcpp(10^8)

## Or get the complete factorization of many numbers
set.seed(29)
myVec <- sample(-1000000:1000000, 1000)
system.time(myFacs <- divisorsRcpp(myVec))

## Return named list
myFacsWithNames <- divisorsRcpp(myVec, namedList = TRUE)