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Rescale values

Source: R/stretchMinMax.r
stretchMinMax.Rd

This function rescales a vector of numeric values to an arbitrary range. Optionally, after the stretch values equal to the lowest value can be "nudged" slightly higher to half the minimum value across the rescaled vector of values > 0.

Usage

stretchMinMax(
  x,
  lower = 0,
  upper = 1,
  nudgeUp = FALSE,
  nudgeDown = FALSE,
  na.rm = FALSE
)

Arguments

x

Numeric list.

lower

Numeric, low end of range to which to stretch.

upper

Numeric, high end of range to which to stretch.

nudgeUp, nudgeDown

Logical, if FALSE (default) then do nothing. If TRUE then *after* rescaling to [0, 1], a small value will be added to all values of x equal to 0. This value is equal to 0.5 * min(x[x > 0]).

na.rm

Logical, if FALSE (default) then if any values of x are NA then the returned value will be NA. If TRUE then NA's are ignored in calculation.

Value

Numeric value.

See also

scale

Examples


x <- 1:10
stretchMinMax(x)
#>  [1] 0.0000000 0.1111111 0.2222222 0.3333333 0.4444444 0.5555556 0.6666667
#>  [8] 0.7777778 0.8888889 1.0000000
stretchMinMax(x, lower=2, upper=5)
#>  [1] 2.000000 2.333333 2.666667 3.000000 3.333333 3.666667 4.000000 4.333333
#>  [9] 4.666667 5.000000
stretchMinMax(x, nudgeUp=TRUE)
#>  [1] 0.05555556 0.11111111 0.22222222 0.33333333 0.44444444 0.55555556
#>  [7] 0.66666667 0.77777778 0.88888889 1.00000000
stretchMinMax(x, lower=2, upper=5, nudgeUp=TRUE)
#>  [1] 2.166667 2.333333 2.666667 3.000000 3.333333 3.666667 4.000000 4.333333
#>  [9] 4.666667 5.000000
stretchMinMax(x, nudgeDown=TRUE)
#>  [1] 0.0000000 0.1111111 0.2222222 0.3333333 0.4444444 0.5555556 0.6666667
#>  [8] 0.7777778 0.8888889 0.9444444
stretchMinMax(x, lower=2, upper=5, nudgeUp=TRUE, nudgeDown=TRUE)
#>  [1] 2.166667 2.333333 2.666667 3.000000 3.333333 3.666667 4.000000 4.333333
#>  [9] 4.666667 4.833333
x <- c(1:5, NA)
stretchMinMax(x)
#> [1] NA NA NA NA NA NA
stretchMinMax(x, na.rm=TRUE)
#> [1] 0.00 0.25 0.50 0.75 1.00   NA