Description Usage Arguments Details Value Author(s) References See Also Examples

Select an initial spread set using the flight phase of the local cube method. Some inclusion probabilities are set to 0. The others probabilities are also modified so as not to change the sum of the inclusion probabilities.

1 | ```
Preselection(pik, coord, L = 1, EPS = 1e-09)
``` |

`pik` |
a matrix of temporal inclusion probabilities.
Columns of |

`coord` |
a matrix that contains spatial coordinates in columns. The number of columns can be more than two. Matrix rows correspond to the units. |

`L` |
a parameter to achieve good spatial balanced (see details). Default value is 1. |

`EPS` |
a tolerance parameter. Default value is 1e-9. |

`L`

is used to achieve good spatial balance. It must be equal to or larger than one.

a matrix with the same size as `pik`

that contains new temporal inclusion probabilities.
Some inclusion probabilities are updated to 0.

Esther Eustache esther.eustache@unine.ch

Grafstrom, A., Lundstrom, N. L. P., and Schelin, L. (2012). Spatially balanced sampling through the pivotal method. Biometrics, 68(2):514-520.

1 2 3 4 5 6 7 8 9 | ```
## Coordinates in two dimensions of 4 units ##
coord <- matrix(c(0.5,0.6,0.2,0.3,0.8,0.9,0.4,0.7), ncol=2)
## Temporal inclusion probabilities with 3 waves and 4 units ##
pik <- matrix(c(0.6,0.3,0.3,
0.2,0.4,0.9,
0.3,0.2,0.5,
0.9,0.1,0.3), ncol = 3, byrow = TRUE)
## Selection of an initial spread set ##
Preselection(pik, coord)
``` |

Embedding an R snippet on your website

Add the following code to your website.

For more information on customizing the embed code, read Embedding Snippets.