Coarsen a vector into a factor with a lower number of levels

coarsen can be used to obtain a factor from a vector, similar to cut, but with less technical and more "aesthetic" labels of the factor levels.

Usage

coarsen(x,...)
# S3 method for numeric
coarsen(x,
        n=5,
        pretty=TRUE,
        quantiles=!pretty,
        breaks=NULL,
        brackets=FALSE,
        sep=if(brackets)";"else if(quantiles) "-" else " - ",
        left="[",
        right="]",
        range=FALSE,
        labels=NULL,
        ...)

Arguments

x: a vector, usually a numeric vector
n: number of categories of the resulting factor
pretty: a logical value, whether pretty should be used to compute the breaks.
quantiles: a logical value, whether quantile should be used to compute the breaks.
breaks: a vector of break points or NULL.
brackets: a logical value, whether the labels should include brackets.
sep: a character string, used as a separator between upper and lower boundaries in the labels.
left: a character string, to be used as the left bracket
right: a character string, to be used as the right bracket
range: a logical value, whether the minimum and maximum of x should be included into breaks.
labels: an optional character vector of labels.
...: further arguments, passed on to pretty or quantile if applicable.

Examples

x <- rnorm(200)

table(coarsen(x))
#> 
#> -3 - -2 -2 - -1  -1 - 0   0 - 1   1 - 2   2 - 3   3 - 4 
#>       4      22      69      76      24       3       2 

table(coarsen(x,quantiles=TRUE))
#> 
#>   0%-20%  20%-40%  40%-60%  60%-80% 80%-100% 
#>       40       40       40       40       40 

table(coarsen(x,brackets=TRUE))
#> 
#> [-3;-2] [-2;-1]  [-1;0]   [0;1]   [1;2]   [2;3]   [3;4] 
#>       4      22      69      76      24       3       2 

table(coarsen(x,breaks=c(-1,0,1)))
#> 
#> -1 - 0  0 - 1 
#>     69     76 

table(coarsen(x,breaks=c(-1,0,1),
              range=TRUE,labels=letters[1:4]))
#> 
#>  a  b  c  d 
#> 26 69 76 29