Rcpp_combn_zerostart {cladoRcpp}

Get all the combinations of descendent state pairs, in 0-based index form

Description

Given the number of states, this function returns all of the pairs of indexes corresponding to those states.

Usage

Rcpp_combn_zerostart(n_to_choose_from, k_to_choose, maxlim = 1e+07)

Arguments

n_to_choose_from

N in N choose K

k_to_choose

K in N choose K

maxlim

To avoid memory overruns, the number of combinations can be no larger than maxlim (default: 1e+07)

Details

The C++ version is MUCH faster than the plain-R version.

Value

outarray an integer matrix with outarray rows; the number of columns is the number of combinations.

Author(s)

Nicholas Matzke [e-mail]

See Also

rcpp_calc_anclikes_sp, rcpp_mult2probvect, rcpp_convolve #bibliography /Dropbox/_njm/__packages/cladoRcpp_setup/cladoRcpp_refs.bib @cite Matzke_2013 @cite Matzke_2014

Examples

Rcpp_combn_zerostart(n_to_choose_from=4, k_to_choose=2, maxlim=1e+07)
Rcpp_combn_zerostart(n_to_choose_from=4, k_to_choose=3, maxlim=1e+07)