R/create.test.ellipse.R

In msxakk89/dat: Data Analyst Toolkit (dat): a library of tools for data analysts and scientists

#' Provide ellipse properties to create it
#' 
#' @param Rx X-radius. Defults to 300
#' @param Ry Y-radius. Defults to 200
#' @param Cx X-center. Defults to 250
#' @param Cy Y-center. Defults to 150
#' @param Rotation Radians. Defults to 0.4
#' @param NoiseLevel Gaussian Noise level. Defults to 0.5

create.test.ellipse <- function(Rx=300,         # X-radius
                                Ry=200,         # Y-radius
                                Cx=250,         # X-center
                                Cy=150,         # Y-center
                                Rotation=0.4,   # Radians
                                NoiseLevel=0.5) # Gaussian Noise level
{
  set.seed(42)
  t <- seq(0, 100, by=1)
  x <- Rx * cos(t)
  y <- Ry * sin(t)
  nx <- x*cos(Rotation)-y*sin(Rotation) + Cx
  nx <- nx + rnorm(length(t))*NoiseLevel 
  ny <- x*sin(Rotation)+y*cos(Rotation) + Cy
  ny  <- ny + rnorm(length(t))*NoiseLevel
  cbind(x=nx, y=ny)
}