CentroidFunctions {gcplyr}

Calculate centroid

Description

This function takes a vector of x and y values and returns the x and/or y position of the centroid of mass of the area under the curve

Usage

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

centroid_x(x, y, return = "x", ...)

centroid_y(x, y, return = "y", ...)

centroid_both(x, y, return = "both", ...)

Arguments

x

Numeric vector of x values

y

Numeric vector of y values

return

One of c("x", "y", "both"), determining whether the function will return the x value of the centroid, the y value of the centroid, or a vector containing x then y

xlim

Vector, of length 2, delimiting the x range over which the centroid 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 the centroid

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, the centroid for negative y values will be calculated normally, effectively pulling the centroid towards the x axis.

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.

...

Other arguments to pass to centroid

Details

This function uses st_centroid to calculate the centroid of mass

Value

A scalar for the x value (if return = 'x') or y value (if return = 'y') of the centroid of the data