# rule: npsp Rules In npsp: Nonparametric Spatial Statistics

 rule R Documentation

## npsp Rules

### Description

Compute the number of classes for a histogram, the number of nodes of a binning grid, etc.

### Usage

``````rule(x, d = 1, rule = c("Rice", "Sturges", "scott", "FD"), ...)

rule.binning(x, ...)

## Default S3 method:
rule.binning(x, d = ncol(x), a = 2, b = d + 1, ...)

rule.svar(x, ...)

## Default S3 method:
rule.svar(x, d = ncol(x), a = 2, b = d + 1, ...)

## S3 method for class 'bin.den'
rule.svar(x, ...)
``````

### Arguments

 `x` data vector or object used to select a method. `d` (spatial) dimension. `rule` character; rule to be used. `...` further arguments passed to or from other methods. `a` scale values. `b` exponent values.

### Details

The Rice Rule, `m = \lceil 2 n^{1/3} \rceil,` is a simple alternative to Sturges's rule (`nclass.Sturges`).

### Value

The rule values (vector or scalar).

`rule.binning` returns a vector with the suggested number of bins on each dimension.

`rule.binning.default` returns `rep(ceiling(a * nrow(x) ^ (1 / b)), d)`.

`rule.svar` returns the suggested number of bins for variogram estimation.

`rule.svar.default` returns `ceiling(a * (nrow(x)^2 / 4) ^ (1 / b))`.

`hist`, `nclass.Sturges`, `nclass.scott`, `nclass.FD`, `binning`, `np.den`, `bin.den`.