Standard deviation breaks first transforms data to standard deviation units (mean=0, stddev=1), and then divide the range of values into 6 groups.
stddev_breaks(df)
A vector of numeric values of computed breaks
library(sf)
guerry_path <- system.file("extdata", "Guerry.shp", package = "rgeoda")
guerry <- st_read(guerry_path)
#> Reading layer `Guerry' from data source
#> `/Users/runner/work/_temp/Library/rgeoda/extdata/Guerry.shp'
#> using driver `ESRI Shapefile'
#> Simple feature collection with 85 features and 29 fields
#> Geometry type: MULTIPOLYGON
#> Dimension: XY
#> Bounding box: xmin: 47680 ymin: 1703258 xmax: 1031401 ymax: 2677441
#> Projected CRS: NTF (Paris) / Lambert zone II
stddev_breaks(guerry['Crm_prs'])
#> [1] 5362.458 12661.699 19960.941 27260.183 34559.425