smacpod: qnn.test – R documentation

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qnn.test

q Nearest Neighbors Test

Description

qnn.test calculates statistics related to the q nearest neighbors method of comparing case and control point patterns under the random labeling hypothesis.

Usage

qnn.test(x, q = 5, nsim = 499, case = 2, longlat = FALSE)

Arguments

`x`	A `ppp` object with marks for the case and control groups.
`q`	A vector of positive integers indicating the values of `q` for which to do the q nearest neighbors test.
`nsim`	The number of simulations from which to compute p-value.
`case`	The position of the name of the "case" group in levels(x$marks). The default is 2.
`longlat`	A logical value indicating whether Euclidean distance (`FALSE`) or Great Circle (WGS84 ellipsoid, `FALSE`) should be used. Default is `FALSE`, i.e., Euclidean distance.

Value

Returns a list with the following components:

`qsum`	A dataframe with the number of neighbors (q), test statistic (Tq), and p-value for each test.
`consum`	A dataframe with the contrasts (contrast), test statistic (Tcon), and p-value (pvalue) for the test of contrasts.

Author(s)

Joshua French

References

Waller, L.A., and Gotway, C.A. (2005). Applied Spatial Statistics for Public Health Data. Hoboken, NJ: Wiley.

Cuzick, J., and Edwards, R. (1990). Spatial clustering for inhomogeneous populations. Journal of the Royal Statistical Society. Series B (Methodological), 73-104.

Alt, K.W., and Vach, W. (1991). The reconstruction of "genetic kinship" in prehistoric burial complexes-problems and statistics. Classification, Data Analysis, and Knowledge Organization, 299-310.

Examples

data(grave)
qnn.test(grave, q = c(3, 5, 7, 9, 11, 13, 15))

smacpod

Statistical Methods for the Analysis of Case-Control Point Data

v2.1.1

GPL (>= 2)

Authors

Joshua French [aut, cre] (<https://orcid.org/0000-0002-9708-3353>)

Initial release