OasisR (version 1.0.0)

xPx: A function to compute Bell's isolation index (xPx)

Description

The isolation index is a exposure index that measures the probability that a member of a group shares the same spatial unit with another member of its group.

Usage

xPx(x)

Arguments

x

- an object of class matrix (or that can be coerced to that class), where each column represents the distribution of a population group, within spatial units. The number of columns should be greater than one (at least two population groups are require

Value

• A vector with isolation index

References

Bell W. (1954) A probability model for the measurement of ecological segregation. Social Forces 32(4), pp. 357-364 Massey D. S. and Denton N. A. (1988) The dimensions of residential segregation. Social Forces 67(2), pp. 281-315.

See Also

Adjusted isolation index: Eta2 Interaction index: xPy

Examples

x <- slot(GreHSize, 'data')[ ,3:5]
xPx(x)