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Factor as Numeric

fct_to_num.Rd

Transform a factor to approximately its original numeric values.

Usage

fct_to_num(f)

Arguments

f

factor to be converted to numeric values

Value

Numeric

Details

See ‘Warning’ section of factor: “In particular, as.numeric applied to a factor is meaningless, and may happen by implicit coercion. To transform a factor f to approximately its original numeric values, as.numeric(levels(f))[f] is recommended and slightly more efficient than as.numeric(as.character(f)).”

See also

factor

Other factor-manip: add_grps()

Examples

f <- factor(2001:2020)

f
#>  [1] 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
#> [16] 2016 2017 2018 2019 2020
#> 20 Levels: 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 ... 2020

f |> as.numeric()  # Returns codes for factor levels, not what is required
#>  [1]  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20

f |> fct_to_num()  # Returns approximate numeric values, as required
#>  [1] 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
#> [16] 2016 2017 2018 2019 2020

rm(f)