R/rotateCoords.R

In FertigLab/scatterHatch: Creates hatched patterns for scatterplots

# Rotates the coordinate system
# Tejas Guha - January 1, 2021

#' Finds the equivalent cartesian coordinates for points in a 
#' rotated coordinate system
#'
#' @param x Vector of the x coordinates
#' @param y Vector of the y coordinates
#' @param angle Angle to rotate the coordinate system by (in degrees)
#' @return Dataframe specifying the transformed coordinates for each point
#' @noRd
rotateCoords <- function(x, y, angle){
    radians <- (angle/180) * pi
    xRotate <- (x * cos(radians)) - (y * sin(radians))
    yRotate <- (x * sin(radians)) + (y * cos(radians))
    return(data.frame(x = xRotate, y = yRotate))
}