returns a vector of indices of `x`

such that this is explored in
systematic way by `nb`

draws, spaced of `kk`

according to
its order.

Even is `ord`

is not "random", a call to
`sample`

is done so it is advised to call first `set.seed`

.

1 | ```
systematic(x, nb, kk, ord="random")
``` |

`x` |
The vector to systematically sample. |

`nb` |
desired number of draws. |

`kk` |
frequency of successive draws. Something giving
quasi-uniform draw is is |

`ord` |
indicates which type of ordering must be done on the
output: |

When `nb*kk`

is less than `length(x)`

then the sequence is
1, kk+1, 2*kk+1,..., (nb-1)*kk+1 taking into account the ordered
order of values of `x`

. If not either look at the code or
experiment the function.

A vector of length `nb`

of indices of `x`

.

1 2 3 4 5 6 7 8 9 | ```
rbsb3k("reset"); # only necessary for R checking
systematic(1:20, 5, 1);
systematic(1:20, 5, 3);
systematic(1:20, 15, 3);
systematic(1:20, 15, 3, "order");
systematic(1:20, 15, 3, "random");
sort(systematic(1:20, 55, 3));
uu <- c(2*(1:10), 1+2*(0:9));
uu[systematic(uu, 20, 3)];
``` |

Questions? Problems? Suggestions? Tweet to @rdrrHQ or email at ian@mutexlabs.com.

Please suggest features or report bugs with the GitHub issue tracker.

All documentation is copyright its authors; we didn't write any of that.