R/genCircle.R

In rKIN: (Kernel) Isotope Niche Estimation

#' Create a sequence of points on a circle
#'
#' This is a helper function that creates a sequence of points on a circle of
#' radius \code{r} as a resolution determined by \code{n}.
#' This function was directly borrowed from SIBER package (Intended for
#' generating various SIBER ellipses).It is not intended
#' for direct calling. NB not an exported function.
#'
#' @param n the number of points to create around the circle. Defaults to 100.
#' @param r the radius of the circle to create.
#'
#' @return A 2 x n matrix of x and y coordinates of points on a circle.
#'

# function to generate a circle of data points which
# can be transformed to form an ellipse. This function
# was directly borrowed from SIBER package (Intended for
# generating various SIBER ellipses).
# Not intended for calling on its own.

genCircle = function(n = 100, r) {
  # a uniform series of angles from 0 -> 2*pi
  theta = seq(0, 2*pi, length = n)

  # x and y coordinates on the circle
  x = r*cos(theta)
  y = r*sin(theta)

  # return the coordinates
  return(cbind(x,y))
}