Donut Charts in R

donutchart.R

#From http://stackoverflow.com/questions/13615562/ggplot-donut-chart
library(ggplot2)

# Create test data.
dat = data.frame(count=c(10, 60, 30), category=c("A", "B", "C"))

# Add addition columns, needed for drawing with geom_rect.
dat$fraction = dat$count / sum(dat$count)
dat = dat[order(dat$fraction), ]
dat$ymax = cumsum(dat$fraction)
dat$ymin = c(0, head(dat$ymax, n=-1))

p1 = ggplot(dat, aes(fill=category, ymax=ymax, ymin=ymin, xmax=4, xmin=3)) +
     geom_rect() +
     coord_polar(theta="y") +
     xlim(c(0, 4)) +
     labs(title="Basic ring plot")

p2 = ggplot(dat, aes(fill=category, ymax=ymax, ymin=ymin, xmax=4, xmin=3)) +
     geom_rect(colour="grey30") +
     coord_polar(theta="y") +
     xlim(c(0, 4)) +
     theme_bw() +
     theme(panel.grid=element_blank()) +
     theme(axis.text=element_blank()) +
     theme(axis.ticks=element_blank()) +
     labs(title="Customized ring plot")


library(gridExtra)
png("ring_plots_1.png", height=4, width=8, units="in", res=120)
grid.arrange(p1, p2, nrow=1)
dev.off()

doughnut.R

#' Doughnut plot
#'
#' Draw a doughnut plot
#' 
#' This function draws a pie chart with a hole; a doughnut plot
#' The doughnut plot is based on the pie plot, see \code{\link{pie}}.
#' 
#' @param x a vector of non-negative numerical quantities.
#'          The values in \code{x} are displayed as the areas of 
#'          doughnut slices.
#' @param labels one or more expressions or character strings giving
#'          names for the slices.  Other objects are coerced by
#'          \code{\link{as.graphicsAnnot}}.  For empty or \code{NA}
#'          (after coercion to character) labels, no label nor 
#'          pointing line is drawn.
#' @param edges the circular outline of the doughnut is approximated 
#'          by a polygon with this many edges.
#' @param outer.radius the doughnut is drawn centered in a square box 
#'          whose sides range from \eqn{-1} to \eqn{1}.  If the 
#'          character strings labeling the slices are long it may be 
#'          necessary to use a smaller radius.
#' @param inner.radius Size of the inner radius to be whited 
#' @param clockwise logical indicating if slices are drawn clockwise 
#'          or counter clockwise (i.e., mathematically positive 
#'          direction), the latter is default. 
#' @param init.angle number specifying the \emph{starting angle} (in
#'          degrees) for the slices. Defaults to 0 (i.e., 
#'          \sQuote{3 o'clock}) unless \code{clockwise} is true where 
#'          \code{init.angle} defaults to 90 (degrees), (i.e., 
#'          \sQuote{12 o'clock}).
#' @param density the density of shading lines, in lines per inch.
#'          The default value of \code{NULL} means that no shading 
#'          lines are drawn. Non-positive values of \code{density} 
#'           also inhibit the drawing of shading lines.
#' @param angle the slope of shading lines, given as an angle in  
#'          degrees (counter-clockwise).
#' @param col a vector of colors to be used in filling or shading
#'          the slices. If missing a set of 6 pastel colours is
#'          used, unless \code{density} is specified when 
#'          \code{par("fg")} is used. 
#' @param border, lty (possibly vectors) arguments passed to 
#'          \code{\link{polygon}} which draws each slice.
#' @param main an overall title for the plot.
#' @param \dots graphical parameters can be given as arguments to
#'          \code{pie}.  They will affect the main title and 
#'          labels only.
#'          
#' @author Original pie plot by R Core, amended by Markus Gesmann 
#'         for a doughnut plot
#' @keywords hplot
#' @seealso \code{\link{pie}} 
#' @export
#' @examples
#'  x <- c(2,4,3,2,4)
#'  doughnut(x)
#'  ## Add lables
#'  doughnut(x, labels=LETTERS[1:5])

doughnut <-
function (x, labels = names(x), edges = 200, outer.radius = 0.8, 
          inner.radius=0.6, clockwise = FALSE,
          init.angle = if (clockwise) 90 else 0, density = NULL, 
          angle = 45, col = NULL, border = FALSE, lty = NULL, 
          main = NULL, ...)
{
    if (!is.numeric(x) || any(is.na(x) | x < 0))
        stop("'x' values must be positive.")
    if (is.null(labels))
        labels <- as.character(seq_along(x))
    else labels <- as.graphicsAnnot(labels)
    x <- c(0, cumsum(x)/sum(x))
    dx <- diff(x)
    nx <- length(dx)
    plot.new()
    pin <- par("pin")
    xlim <- ylim <- c(-1, 1)
    if (pin[1L] > pin[2L])
        xlim <- (pin[1L]/pin[2L]) * xlim
    else ylim <- (pin[2L]/pin[1L]) * ylim
    plot.window(xlim, ylim, "", asp = 1)
    if (is.null(col))
        col <- if (is.null(density))
          palette()
        else par("fg")
    col <- rep(col, length.out = nx)
    border <- rep(border, length.out = nx)
    lty <- rep(lty, length.out = nx)
    angle <- rep(angle, length.out = nx)
    density <- rep(density, length.out = nx)
    twopi <- if (clockwise)
        -2 * pi
    else 2 * pi
    t2xy <- function(t, radius) {
        t2p <- twopi * t + init.angle * pi/180
        list(x = radius * cos(t2p), 
             y = radius * sin(t2p))
    }
    for (i in 1L:nx) {
        n <- max(2, floor(edges * dx[i]))
        P <- t2xy(seq.int(x[i], x[i + 1], length.out = n),
                  outer.radius)
        polygon(c(P$x, 0), c(P$y, 0), density = density[i], 
                angle = angle[i], border = border[i], 
                col = col[i], lty = lty[i])
        Pout <- t2xy(mean(x[i + 0:1]), outer.radius)
        lab <- as.character(labels[i])
        if (!is.na(lab) && nzchar(lab)) {
            lines(c(1, 1.05) * Pout$x, c(1, 1.05) * Pout$y)
            text(1.1 * Pout$x, 1.1 * Pout$y, labels[i], 
                 xpd = TRUE, adj = ifelse(Pout$x < 0, 1, 0), 
                 ...)
        }
        ## Add white disc          
        Pin <- t2xy(seq.int(0, 1, length.out = n*nx),
                  inner.radius)
        polygon(Pin$x, Pin$y, density = density[i], 
                angle = angle[i], border = border[i], 
                col = "white", lty = lty[i])
    }

    title(main = main, ...)
    invisible(NULL)
}