R/radialPolygon.R

In edwbaker/SonicScrewdriveR: Bioacoustic Analysis and Publication Tools

#' Plot a radial polygon
#'
#' Used to plot sectors, annuli and horizons on a dielPlot() or yearlyPlot(). The polygon
#' has an inner and outer horizon - which can be set to a fixed radius or a vector.
#' @param angle1 Angles for the inner line
#' @param angle2 Angles for the outer line
#' @param radius1 Radii for the inner line
#' @param radius2 Radii for the outer line
#' @param col Colour of the polygon
#' @param border Border colour (see polygon() for details)
#' @param rot Rotation of the plot, defaults to pi to match dielPlot() and yearlyPlot()
#' @param angleinc The angular increment in radians for calculating circular lines
#' @param reverse If FALSE plots in an anti-clockwise direction
#' @param ... Other parameters passed to polygon()
#' @importFrom graphics polygon
#' @export
radialPolygon <- function(
    angle1,angle2,
    radius1,radius2,
    col="grey",
    border=NA,
    rot=-pi,
    angleinc=0.01,
    reverse=TRUE,
    ...
) {

  if (length(angle1) == 1 & length(angle2) == 1) {
    while (angle1 > angle2) {
      angle2 <- angle2 + 2*pi
    }
  }
  if (reverse) {
    angle1 <- -angle1
    angle2 <- -angle2
  }
  min_a <- min(c(angle1, angle2), na.rm=T)
  max_a <- max(c(angle1, angle2), na.rm=T)

  angles<-seq(min_a,max_a,by=angleinc)
  angles[length(angles)]<-max_a
  if (min_a < 0) {
    angles <- rev(angles)
  }

  if (length(radius1) == 1 & length(radius2) == 1) {
    inner_x <- cos(angles)*radius1
    inner_y <- sin(angles)*radius1
    outer_x <- cos(angles)*radius2
    outer_y <- sin(angles)*radius2
  } else {
    if (length(radius1) == 1) {
      if (radius1 == 0) {
        inner_x <- 0
        inner_y <- 0
      } else {
        inner_x <- cos(angles)*radius1
        inner_y <- sin(angles)*radius1
      }
    } else {
      inner_x <- radius1*cos(angle1)
      inner_y <- radius1*sin(angle1)
    }
    if (length(radius2) == 1) {
      outer_x <- cos(angles)*radius2
      outer_y <- sin(angles)*radius2
    } else {
      outer_x <- radius2*cos(angle2)
      outer_y <- radius2*sin(angle2)
    }
  }

  outer_x <- rev(outer_x)
  outer_y <- rev(outer_y)
  xpos<-c(inner_x,outer_x)
  ypos<-c(inner_y,outer_y)

  if (rot != 0) {
    xrot <- xpos*cos(rot) + ypos*sin(rot)
    yrot <- -xpos*sin(rot) + ypos*cos(rot)
    xpos <- xrot
    ypos <- yrot
  }

  polygon(xpos,ypos,col=col,border=border,...)
}

#' Circularise a dataset
#'
#' When plotting rings or horizons that are meant to cover the entirety of the time period in a
#' dielPlot() or yearlyPlot() this function append the beginning values to the end to ensure an entire
#' loop is created.
#' @param values A vector if values
#' @export
circularise <- function(values) {
  return(c(values, values[1]))
}