spatial_balance: Spatial balance of a sample

In fieldopt: Area-Frame and Dual-Frame Survey Design under Real Field Cost

Spatial balance of a sample

Description

The Voronoi measure of Stevens and Olsen (2004): every unit of the frame is assigned to its nearest sampled unit, the inclusion probabilities assigned to each sampled unit are summed, and the balance is the mean squared deviation of those sums from one. Zero is perfect balance; simple random samples give values near one. With strata the measure is computed within each stratum and pooled.

Usage

spatial_balance(sample, by_stratum = FALSE)

Arguments

sample	A select_units() sample.
by_stratum	Return one value per stratum instead of the pooled one.

Value

A number, or a named vector with by_stratum = TRUE.

References

Stevens, D. L. and Olsen, A. R. (2004). Spatially balanced sampling of natural resources. Journal of the American Statistical Association, 99, 262-278.

Examples

cells <- expand.grid(x = 1:10, y = 1:10)
spatial_balance(select_units(cells, n = 10, method = "lpm", seed = 1))
spatial_balance(select_units(cells, n = 10, method = "srs", seed = 1))

fieldopt documentation built on Oct. 22, 2026, 1:07 a.m.