# local_joincount_uni: Calculate the local univariate join count In spdep: Spatial Dependence: Weighting Schemes, Statistics

 local_joincount_uni R Documentation

## Calculate the local univariate join count

### Description

The univariate local join count statistic is used to identify clusters of rarely occurring binary variables. The binary variable of interest should occur less than half of the time.

### Usage

```local_joincount_uni(
fx,
chosen,
listw,
alternative = "two.sided",
nsim = 199,
iseed = NULL,
no_repeat_in_row=FALSE
)
```

### Arguments

 `fx` a binary variable either numeric or logical `chosen` a scalar character containing the level of `fx` that should be considered the observed value (1). `listw` a listw object containing binary weights created, for example, with `nbwlistw(nb, style = "B")` `alternative` default `"greater"`. One of `"less"` or `"greater"`. `nsim` the number of conditional permutation simulations `iseed` default NULL, used to set the seed for possible parallel RNGs `no_repeat_in_row` default `FALSE`, if `TRUE`, sample conditionally in each row without replacements to avoid duplicate values, https://github.com/r-spatial/spdep/issues/124

### Details

The local join count statistic requires a binary weights list which can be generated with `nb2listw(nb, style = "B")`. Additionally, ensure that the binary variable of interest is rarely occurring in no more than half of observations.

P-values are estimated using a conditional permutation approach. This creates a reference distribution from which the observed statistic is compared. For more see Geoda Glossary.

### Value

a `data.frame` with two columns `BB` and `Pr()` and number of rows equal to the length of `x`.

### Author(s)

Josiah Parry josiah.parry@gmail.com

### References

Anselin, L., & Li, X. (2019). Operational Local Join Count Statistics for Cluster Detection. Journal of geographical systems, 21(2), 189–210. doi: 10.1007/s10109-019-00299-x

### Examples

```data(oldcol)
fx <- as.factor(ifelse(COL.OLD\$CRIME < 35, "low-crime", "high-crime"))
listw <- nb2listw(COL.nb, style = "B")
set.seed(1)
(res <- local_joincount_uni(fx, chosen = "high-crime", listw))
```

spdep documentation built on March 7, 2023, 7:27 p.m.