本文介绍了R:点和线的颜色不同的图例(对于相同的图例项目)的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
使用legend()函数，可以使点和线具有不同的颜色吗?我感觉好像缺少了一些显而易见的东西. pt.bg选项可以更改背景颜色，但是我没有看到pt.fg选项
Using the legend() function is it possible to have the point and line be different colors? I feel like I'm missing something fairly obvious. The pt.bg option can change the background color, but I'm not seeing a pt.fg option
当您分别使用不同颜色的lines()和points()命令并希望图例代表所绘制的内容时，就会出现这种情况.
The arises in the case when you use the lines() and points() command separately with different colors and want the legend to represent what is plotted.
我认为使用merge选项可能是可行的，但是我显然不太明白这是什么目的.
I thought it might be possible with the merge options, but I clearly don't quite understand what that is for.
示例:
plot( 0, type="n", xlim=c(0,5), ylim=c(0,5) )
A <- matrix( c( c(1,2,3,4), c(2,1,2,4)), ncol=2 )
B <- matrix( c( c(1,2,3,4), c(1,3,3,2)), ncol=2 )
lines( A, col="red" )
points( A, col="blue", pch=15 )
lines( B, col="green" )
points( B, col="purple", pch=17 )
legend( x="topleft",
legend=c("Red line, blue points","Green line, purple points"),
col=c("red","green"), lwd=1, lty=c(1,2),
pch=c(15,17) )
legend( x="bottomleft",
legend=c("Red line","blue points","Green line","purple points"),
col=c("red","blue","green","purple"), lwd=1, lty=c(1,NA,2,NA),
pch=c(NA,15,NA,17) )
legend( x="left",
legend=c("Red line, blue points","Green line, purple points"),
col=c("red","green"), lwd=1, lty=c(1,2), pch=c(15,17), merge=FALSE )
legend( x="bottomright",
legend=c("Red line","blue points","Green line","purple points"),
col=c("red","blue","green","purple"), lwd=1, lty=c(1,NA,2,NA),
pch=c(NA,15,NA,17), merge=FALSE )
legend( x="topright",
legend=c("Red line, blue points","Green line, purple points"),
col=c("red","blue","green","purple"), lwd=1, lty=c(1,2),
pch=c(15,17), merge=FALSE )
解决方案
我修改了legend()函数以使用两个不同的颜色向量:
I hacked the legend() function to use two different color vectors:
LEGEND <- function (x, y = NULL, legend, fill = NULL,
col = par("col"), pt.col=col, line.col=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)
{
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, 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)) {
pt.COL <- rep_len(pt.col, n.leg)
line.COL <- rep_len(line.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 = line.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 = pt.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)))
}
并按如下方式使用:
LEGEND( x="bottomleft",
legend=c("Red line, blue points","Green line, purple points"),
col=c("red","green"),
lwd=1, lty=c(1,2), pch=c(15,17) )
LEGEND( x="bottomright",
legend=c("Red line, blue points","Green line, purple points"),
pt.col=c("blue","purple"), line.col=c("red","green"),
lwd=1, lty=c(1,2), pch=c(15,17) )
推荐答案
您可以通过两次调用legend来做到这一点，第一次是绘制线条，然后第二次是在顶部绘制带有不可见线条的线条，但是会绘制所需颜色的点:
You can do this with 2 calls to legend, the 1st time plots the lines, then the second call plots over the top with invisible lines, but plots the points in the desired colors:
plot( 0, type="n", xlim=c(0,5), ylim=c(0,5) )
A <- matrix( c( c(1,2,3,4), c(2,1,2,4)), ncol=2 )
B <- matrix( c( c(1,2,3,4), c(1,3,3,2)), ncol=2 )
lines( A, col="red" )
points( A, col="blue", pch=15 )
lines( B, col="green" )
points( B, col="purple", pch=17 )
legend( x="topleft",
legend=c("Red line, blue points","Green line, purple points"),
col=c("red","green"), lwd=1, lty=c(1,2),
pch=c(NA,NA) )
legend( x="topleft",
legend=c("Red line, blue points","Green line, purple points"),
col=c("blue","purple"), lwd=1, lty=c(0,0),
pch=c(15,17) )
或第二次调用legend时，您可以执行类似的操作(因此，彼此之间没有2个文本副本):
or for the second call to legend you can do something like this (so you don't have 2 copies of the text on top of each other):
legend( x="topleft",
legend=c("",""),
col=c("blue","purple"), lwd=1, lty=c(0,0),
pch=c(15,17), bty='n' )
当然，这只能从左开始正确排列.如果要在右角之一绘制图，则将第一次调用的返回值保存到legend，并在第二次调用中将其放置.
Of course this only lines up properly working from the left. If you want the plot in one of the right corners then save the return value from the first call to legend and use it for placement in the second call.
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