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Bin elements of x.

Source: R/binning.R
bin.Rd

bin groups elements of x into bins with either a constant number of elements per bin, a constant bin width or according to user-provided bin boundaries.

Usage

bin(
  x,
  binmode = c("equalN", "equalWidth", "breaks"),
  nElements = round(length(x)/5),
  nBins = NULL,
  minAbsX = NULL,
  breaks = NULL,
  ...
)

Arguments

x

A numerical vector with the values used for binning.

binmode

The algorithm to be used for binning. Possible values are: "equalN" (default), "equalWidth" or "breaks" (see Details).

nElements

The number of elements per bin (only for binmode="equalN"). The width of bins is adjusted accordingly.

nBins

The number of bins (only for binmode="equalWidth"). The number of elements per bin will be variable.

minAbsX

The minimal absolute value in x for elements to be binned using the binmode="equalN" or binmode="equalWidth" (ignored for other values of binmode). Elements with x values in [-minAbsX,minAbsX] will be collected in a single bin.

breaks

Numerical vector with bin boundaries (only for binmode="breaks"). breaks has to be ordered and strictly increasing, and has to be of length (number of bins) + 1.

...

further arguments to be passed to cut(x, breaks, include.lowest = TRUE, ...), such as labels=FALSE.

Value

The return value from cut(x, ...), typically a factor of the same length as x. Binning mode, bin boundaries and the "neutral" bin are available from attr(..., "binmode"), attr(..., "breaks") and attr(..., "bin0"). For binmode = "breaks", the latter will be NA.

Details

Elements are binned according to the values in x depending on binmode:

equalN

Items are grouped into a variable number of bins with nElements elements each. If minAbsX is not NULL, elements with x-values in [-minAbsX,minAbsX] will first be collected in a single bin before binning the remaining elements. The boundaries of this single bin may be slightly adjusted in order to respect the nElements elements in the other bins.

equalWidth

Items are group into nBins bins with a variable number of elements each.

breaks

Items are grouped into bins using cut(x, breaks, include.lowest = TRUE)

See also

cut which is used internally.

Examples

set.seed(1)
x <- rnorm(100)
summary(bin(x, "equalN", nElements=10))
#>    [-2.21,-1.05]   (-1.05,-0.614]  (-0.614,-0.375] (-0.375,-0.0767] 
#>               10               10               10               10 
#>  (-0.0767,0.114]    (0.114,0.377]    (0.377,0.581]    (0.581,0.771] 
#>               10               10               10               10 
#>     (0.771,1.18]       (1.18,2.4] 
#>               10               10 
summary(bin(x, "equalN", nElements=10, minAbsX=0.5))
#> Warning: Zero-bin breaks (-0.621,0.576] have been adjusted by more than 20% compared to `minAbsX` to best respect `binmode`.
#> Please use `bin(..., binmode = "breaks", breaks = X)` and optionally `setZeroBin(...)` to enforce breaks as defined by `X`.
#>  [-2.21,-1.09] (-1.09,-0.621] (-0.621,0.576]  (0.576,0.769]   (0.769,1.18] 
#>             10             10             50             10             10 
#>     (1.18,2.4] 
#>             10 
summary(bin(x, "equalWidth", nBins=5))
#>  [-2.21,-1.29] (-1.29,-0.368] (-0.368,0.555]   (0.555,1.48]     (1.48,2.4] 
#>              6             24             36             28              6 
summary(bin(x, "breaks", breaks=c(-10,-1,0,1,10)))
#> [-10,-1]   (-1,0]    (0,1]   (1,10] 
#>       11       35       39       15