demo/pub_code/R.Figures/luke.legend.R

In USGS-R/mda.lakes: Tools for combining models, data, and processing for lakes

luke.legend = 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"), text.font = NULL, 
					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, fill.y.cex=1, fill.x.cex=1) 
{
	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, 
										...) {
		dx = dx*fill.x.cex
		dy = dy*fill.y.cex
		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, font = text.font)))
	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(gettextf("horizontal specification overrides: Number of columns := %d", 
											 n.leg), domain = NA)
		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.character(pch)) 
			pch <- as.integer(pch)
	}
	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_len(inset, 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) {
			if (!is.null(fill)) 
				fill <- rep_len(fill, n.leg)
			rect2(left = xt, top = yt + ybox/2, dx = xbox, dy = ybox, 
						col = fill, density = density, angle = angle, 
						border = border)
		}
		xt <- xt + dx.fill
	}
	if (plot && (has.pch || do.lines)) 
		col <- rep_len(col, n.leg)
	if (missing(lwd) || is.null(lwd)) 
		lwd <- par("lwd")
	if (do.lines) {
		if (missing(lty) || is.null(lty)) 
			lty <- 1
		lty <- rep_len(lty, n.leg)
		lwd <- rep_len(lwd, n.leg)
		ok.l <- !is.na(lty) & (is.character(lty) | lty > 0) & 
			!is.na(lwd)
		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_len(pch, n.leg)
		pt.bg <- rep_len(pt.bg, n.leg)
		pt.cex <- rep_len(pt.cex, n.leg)
		pt.lwd <- rep_len(pt.lwd, n.leg)
		ok <- !is.na(pch)
		if (!is.character(pch)) {
			ok <- ok & (pch >= 0 | pch <= -32)
		}
		else {
			ok <- ok & nzchar(pch)
		}
		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, font = text.font)
	}
	invisible(list(rect = list(w = w, h = h, left = left, top = top), 
								 text = list(x = xt, y = yt)))
}