Calculate area under the curve

This function takes a vector of x and y values and returns a scalar for the area under the curve, calculated using the trapezoid rule

Usage

auc(
  x,
  y,
  xlim = NULL,
  blank = 0,
  subset = NULL,
  na.rm = TRUE,
  neg.rm = FALSE,
  warn_xlim_out_of_range = TRUE,
  warn_negative_y = TRUE
)

Arguments

x

numeric vector of x values

y

numeric vector of y values

xlim

vector, of length 2, delimiting the x range over which the area under the curve should be calculated (where NA can be provided for the area to be calculated from the start or to the end of the data)

blank

Value to be subtracted from y values before calculating area under the curve

subset

A vector of logical values indicating which x and y values should be included (TRUE) or excluded (FALSE).

na.rm

a logical indicating whether missing values should be removed

neg.rm

a logical indicating whether y values below zero should be treated as zeros. If FALSE, area under the curve for negative y values will be calculated normally, effectively subtracting from the returned value.

warn_xlim_out_of_range

logical whether warning should be issued when xlim is lower than the lowest x value or higher than the highest x value.

warn_negative_y

logical whether warning should be issued when neg.rm == FALSE but some y values are below 0.

Value

A scalar for the total area under the curve