I have a plot with overlapping shaded confidence intervals that looks like this:
and I would like very much to annotate the legend with the color of the confidence interval. Something like:
except, I'd like two things:
(And I'm using base R instead of ggplot2 for a couple of reasons specific to this application that aren't really relevant to explain.)
Here is a code example that reproduces the legend:
#Build a fake plot so that legend has somewhere to sit
xx <- seq(0,10,by=.1)
yy <- 2*xx + rnorm(length(xx),0,1)
plot(xx,yy)
#Build the legend
estNames <- c('est1','est2','est3')
legend('bottomright',
c("no box, no point","no box, no point",estNames) ,
lty=c(rep('dotted',2),rep('solid',3)),
col=c('black','red',1,2,4),
pch=c(-1,-1,rep(16,3)),
lwd=1,
fill=c( 0, 0,
rep( c( rgb(0.5,0.5,0.1,0.25),
rgb(0.5,0.1,0.1,0.25),
rgb(0.1,0.1,0.5,0.25)), 2)),
inset=0,bg='white')
Any help would be appreciated. Thanks!
Ugly ad hoc solution, but seems to work.
To remove the border around the symbols, use the border
argument. Adjust colors according to your background.
legend.v2('bottomright',
c("no box, no point","no box, no point",estNames) ,
lty=c(rep('dotted',2),rep('solid',3)),
col=c('black','red',1,2,4),
pch=c(-1,-1,rep(16,3)),
lwd=1,
border = c("white", "white", "black", "black", "black"),
trace = TRUE,
fill=c( 0, 0,
rep( c( rgb(0.5,0.5,0.1,0.25),
rgb(0.5,0.1,0.1,0.25),
rgb(0.1,0.1,0.5,0.25)), 2)),
inset=0,bg='white')
The function that draws rectangles around the symbols is ?rect
.
I've multiplied the xbox
argument by 3 (scroll down to the if (mfill)
line). The correct factor of multiplication is probably a bit less, experiment.
legend.v2 <- function (x, y = NULL, legend, fill = NULL, col = par("col"),
border = "black", lty, lwd, pch, angle = 45, density = NULL,
bty = "o", bg = par("bg"), box.lwd = par("lwd"), box.lty = par("lty"),
box.col = par("fg"), pt.bg = NA, cex = 1, pt.cex = cex, pt.lwd = lwd,
xjust = 0, yjust = 1, x.intersp = 1, y.intersp = 1, adj = c(0,
0.5), text.width = NULL, text.col = par("col"), merge = do.lines &&
has.pch, trace = FALSE, plot = TRUE, ncol = 1, horiz = FALSE,
title = NULL, inset = 0, xpd, title.col = text.col, title.adj = 0.5,
seg.len = 2)
{
if (missing(legend) && !missing(y) && (is.character(y) ||
is.expression(y))) {
legend <- y
y <- NULL
}
mfill <- !missing(fill) || !missing(density)
if (!missing(xpd)) {
op <- par("xpd")
on.exit(par(xpd = op))
par(xpd = xpd)
}
title <- as.graphicsAnnot(title)
if (length(title) > 1)
stop("invalid title")
legend <- as.graphicsAnnot(legend)
n.leg <- if (is.call(legend))
1
else length(legend)
if (n.leg == 0)
stop("'legend' is of length 0")
auto <- if (is.character(x))
match.arg(x, c("bottomright", "bottom", "bottomleft",
"left", "topleft", "top", "topright", "right", "center"))
else NA
if (is.na(auto)) {
xy <- xy.coords(x, y)
x <- xy$x
y <- xy$y
nx <- length(x)
if (nx < 1 || nx > 2)
stop("invalid coordinate lengths")
}
else nx <- 0
xlog <- par("xlog")
ylog <- par("ylog")
rect2 <- function(left, top, dx, dy, density = NULL, angle,
...) {
r <- left + dx
if (xlog) {
left <- 10^left
r <- 10^r
}
b <- top - dy
if (ylog) {
top <- 10^top
b <- 10^b
}
rect(left, top, r, b, angle = angle, density = density,
...)
}
segments2 <- function(x1, y1, dx, dy, ...) {
x2 <- x1 + dx
if (xlog) {
x1 <- 10^x1
x2 <- 10^x2
}
y2 <- y1 + dy
if (ylog) {
y1 <- 10^y1
y2 <- 10^y2
}
segments(x1, y1, x2, y2, ...)
}
points2 <- function(x, y, ...) {
if (xlog)
x <- 10^x
if (ylog)
y <- 10^y
points(x, y, ...)
}
text2 <- function(x, y, ...) {
if (xlog)
x <- 10^x
if (ylog)
y <- 10^y
text(x, y, ...)
}
if (trace)
catn <- function(...) do.call("cat", c(lapply(list(...),
formatC), list("\n")))
cin <- par("cin")
Cex <- cex * par("cex")
if (is.null(text.width))
text.width <- max(abs(strwidth(legend, units = "user",
cex = cex)))
else if (!is.numeric(text.width) || text.width < 0)
stop("'text.width' must be numeric, >= 0")
xc <- Cex * xinch(cin[1L], warn.log = FALSE)
yc <- Cex * yinch(cin[2L], warn.log = FALSE)
if (xc < 0)
text.width <- -text.width
xchar <- xc
xextra <- 0
yextra <- yc * (y.intersp - 1)
ymax <- yc * max(1, strheight(legend, units = "user", cex = cex)/yc)
ychar <- yextra + ymax
if (trace)
catn(" xchar=", xchar, "; (yextra,ychar)=", c(yextra,
ychar))
if (mfill) {
xbox <- xc * 0.8
ybox <- yc * 0.5
dx.fill <- xbox
}
do.lines <- (!missing(lty) && (is.character(lty) || any(lty >
0))) || !missing(lwd)
n.legpercol <- if (horiz) {
if (ncol != 1)
warning("horizontal specification overrides: Number of columns := ",
n.leg)
ncol <- n.leg
1
}
else ceiling(n.leg/ncol)
has.pch <- !missing(pch) && length(pch) > 0
if (do.lines) {
x.off <- if (merge)
-0.7
else 0
}
else if (merge)
warning("'merge = TRUE' has no effect when no line segments are drawn")
if (has.pch) {
if (is.character(pch) && !is.na(pch[1L]) && nchar(pch[1L],
type = "c") > 1) {
if (length(pch) > 1)
warning("not using pch[2..] since pch[1L] has multiple chars")
np <- nchar(pch[1L], type = "c")
pch <- substr(rep.int(pch[1L], np), 1L:np, 1L:np)
}
}
if (is.na(auto)) {
if (xlog)
x <- log10(x)
if (ylog)
y <- log10(y)
}
if (nx == 2) {
x <- sort(x)
y <- sort(y)
left <- x[1L]
top <- y[2L]
w <- diff(x)
h <- diff(y)
w0 <- w/ncol
x <- mean(x)
y <- mean(y)
if (missing(xjust))
xjust <- 0.5
if (missing(yjust))
yjust <- 0.5
}
else {
h <- (n.legpercol + (!is.null(title))) * ychar + yc
w0 <- text.width + (x.intersp + 1) * xchar
if (mfill)
w0 <- w0 + dx.fill
if (do.lines)
w0 <- w0 + (seg.len + +x.off) * xchar
w <- ncol * w0 + 0.5 * xchar
if (!is.null(title) && (abs(tw <- strwidth(title, units = "user",
cex = cex) + 0.5 * xchar)) > abs(w)) {
xextra <- (tw - w)/2
w <- tw
}
if (is.na(auto)) {
left <- x - xjust * w
top <- y + (1 - yjust) * h
}
else {
usr <- par("usr")
inset <- rep(inset, length.out = 2)
insetx <- inset[1L] * (usr[2L] - usr[1L])
left <- switch(auto, bottomright = , topright = ,
right = usr[2L] - w - insetx, bottomleft = ,
left = , topleft = usr[1L] + insetx, bottom = ,
top = , center = (usr[1L] + usr[2L] - w)/2)
insety <- inset[2L] * (usr[4L] - usr[3L])
top <- switch(auto, bottomright = , bottom = , bottomleft = usr[3L] +
h + insety, topleft = , top = , topright = usr[4L] -
insety, left = , right = , center = (usr[3L] +
usr[4L] + h)/2)
}
}
if (plot && bty != "n") {
if (trace)
catn(" rect2(", left, ",", top, ", w=", w, ", h=",
h, ", ...)", sep = "")
rect2(left, top, dx = w, dy = h, col = bg, density = NULL,
lwd = box.lwd, lty = box.lty, border = box.col)
}
xt <- left + xchar + xextra + (w0 * rep.int(0:(ncol - 1),
rep.int(n.legpercol, ncol)))[1L:n.leg]
yt <- top - 0.5 * yextra - ymax - (rep.int(1L:n.legpercol,
ncol)[1L:n.leg] - 1 + (!is.null(title))) * ychar
if (mfill) {
if (plot) {
fill <- rep(fill, length.out = n.leg)
rect2(left = xt, top = yt + ybox/2, dx = xbox * 3, dy = ybox,
col = fill, density = density, angle = angle,
border = border)
}
xt <- xt + dx.fill
}
if (plot && (has.pch || do.lines))
col <- rep(col, length.out = n.leg)
if (missing(lwd))
lwd <- par("lwd")
if (do.lines) {
if (missing(lty))
lty <- 1
lty <- rep(lty, length.out = n.leg)
lwd <- rep(lwd, length.out = n.leg)
ok.l <- !is.na(lty) & (is.character(lty) | lty > 0)
if (trace)
catn(" segments2(", xt[ok.l] + x.off * xchar, ",",
yt[ok.l], ", dx=", seg.len * xchar, ", dy=0, ...)")
if (plot)
segments2(xt[ok.l] + x.off * xchar, yt[ok.l], dx = seg.len *
xchar, dy = 0, lty = lty[ok.l], lwd = lwd[ok.l],
col = col[ok.l])
xt <- xt + (seg.len + x.off) * xchar
}
if (has.pch) {
pch <- rep(pch, length.out = n.leg)
pt.bg <- rep(pt.bg, length.out = n.leg)
pt.cex <- rep(pt.cex, length.out = n.leg)
pt.lwd <- rep(pt.lwd, length.out = n.leg)
ok <- !is.na(pch) & (is.character(pch) | pch >= 0)
x1 <- (if (merge && do.lines)
xt - (seg.len/2) * xchar
else xt)[ok]
y1 <- yt[ok]
if (trace)
catn(" points2(", x1, ",", y1, ", pch=", pch[ok],
", ...)")
if (plot)
points2(x1, y1, pch = pch[ok], col = col[ok], cex = pt.cex[ok],
bg = pt.bg[ok], lwd = pt.lwd[ok])
}
xt <- xt + x.intersp * xchar
if (plot) {
if (!is.null(title))
text2(left + w * title.adj, top - ymax, labels = title,
adj = c(title.adj, 0), cex = cex, col = title.col)
text2(xt, yt, labels = legend, adj = adj, cex = cex,
col = text.col)
}
invisible(list(rect = list(w = w, h = h, left = left, top = top),
text = list(x = xt, y = yt)))
}