legend画图R语言学习笔记single cell 网站

单细胞研究是这几年的热点。

单基因在单细胞表达的情况，目前研究的比较深入。

https://panglaodb.se/search.html 用search功能可以直接找。

而用“legend”函数画图，图可以随意画。

Examples

## Run the example in '?matplot' or the following:

leg.txt <- c("Setosa Petals", "Setosa Sepals",

"Versicolor Petals", "Versicolor Sepals")

y.leg <- c(4.5, 3, 2.1, 1.4, .7)

cexv <- c(1.2, 1, 4/5, 2/3, 1/2)

matplot(c(1, 8), c(0, 4.5), type = "n", xlab = "Length", ylab = "Width",

main = "Petal and Sepal Dimensions in Iris Blossoms")

for (i in seq(cexv)) {

text (1, y.leg[i] - 0.1, paste("cex=", formatC(cexv[i])), cex = 0.8, adj = 0)

legend(3, y.leg[i], leg.txt, pch = "sSvV", col = c(1, 3), cex = cexv[i])

}

## cex *vector* [in R <= 3.5.1 has 'if(xc < 0)' w/ length(xc) == 2]

legend(6,1, leg.txt, pch = "sSvV", col = c(1, 3), cex = 1+(-1:2)/8)

## 'merge = TRUE' for merging lines & points:

x <- seq(-pi, pi, len = 65)

plot(x, sin(x), type = "l", ylim = c(-1.2, 1.8), col = 3, lty = 2)

points(x, cos(x), pch = 3, col = 4)

lines(x, tan(x), type = "b", lty = 1, pch = 4, col = 6)

title("legend(..., lty = c(2, -1, 1), pch = c(NA, 3, 4), merge = TRUE)",

cex.main = 1.1)

legend(-1, 1.9, c("sin", "cos", "tan"), col = c(3, 4, 6),

text.col = "green4", lty = c(2, -1, 1), pch = c(NA, 3, 4),

merge = TRUE, bg = "gray90")

## right-justifying a set of labels: thanks to Uwe Ligges

x <- 1:5; y1 <- 1/x; y2 <- 2/x

plot(rep(x, 2), c(y1, y2), type = "n", xlab = "x", ylab = "y")

lines(x, y1); lines(x, y2, lty = 2)

temp <- legend("topright", legend = c(" ", " "),

text.width = strwidth("1,000,000"),

lty = 1:2, xjust = 1, yjust = 1,

title = "Line Types")

text(temp$rect$left + temp$rect$w, temp$text$y,

c("1,000", "1,000,000"), pos = 2)

##--- log scaled Examples ------------------------------

leg.txt <- c("a one", "a two")

par(mfrow = c(2, 2))

for(ll in c("","x","y","xy")) {

plot(2:10, log = ll, main = paste0("log = '", ll, "'"))

abline(1, 1)

lines(2:3, 3:4, col = 2)

points(2, 2, col = 3)

rect(2, 3, 3, 2, col = 4)

text(c(3,3), 2:3, c("rect(2,3,3,2, col=4)",

"text(c(3,3),2:3,"c(rect(...)")"), adj = c(0, 0.3))

legend(list(x = 2,y = 8), legend = leg.txt, col = 2:3, pch = 1:2,

lty = 1, merge = TRUE) #, trace = TRUE)

}

par(mfrow = c(1,1))

##-- Math expressions: ------------------------------

x <- seq(-pi, pi, len = 65)

plot(x, sin(x), type = "l", col = 2, xlab = expression(phi),

ylab = expression(f(phi)))

abline(h = -1:1, v = pi/2*(-6:6), col = "gray90")

lines(x, cos(x), col = 3, lty = 2)

ex.cs1 <- expression(plain(sin) * phi, paste("cos", phi)) # 2 ways

utils::str(legend(-3, .9, ex.cs1, lty = 1:2, plot = FALSE,

adj = c(0, 0.6))) # adj y !

legend(-3, 0.9, ex.cs1, lty = 1:2, col = 2:3, adj = c(0, 0.6))

require(stats)

x <- rexp(100, rate = .5)

hist(x, main = "Mean and Median of a Skewed Distribution")

abline(v = mean(x), col = 2, lty = 2, lwd = 2)

abline(v = median(x), col = 3, lty = 3, lwd = 2)

ex12 <- expression(bar(x) == sum(over(x[i], n), i == 1, n),

hat(x) == median(x[i], i == 1, n))

utils::str(legend(4.1, 30, ex12, col = 2:3, lty = 2:3, lwd = 2))

## 'Filled' boxes -- for more, see example(plot.factor)

op <- par(bg = "white") # to get an opaque box for the legend

plot(cut(weight, 3) ~ group, data = PlantGrowth, col = NULL,

density = 16*(1:3))

par(op)

## Using 'ncol' :

x <- 0:64/64

matplot(x, outer(x, 1:7, function(x, k) sin(k * pi * x)),

type = "o", col = 1:7, ylim = c(-1, 1.5), pch = "*")

op <- par(bg = "antiquewhite1")

legend(0, 1.5, paste("sin(", 1:7, "pi * x)"), col = 1:7, lty = 1:7,

pch = "*", ncol = 4, cex = 0.8)

legend(.8,1.2, paste("sin(", 1:7, "pi * x)"), col = 1:7, lty = 1:7,

pch = "*", cex = 0.8)

legend(0, -.1, paste("sin(", 1:4, "pi * x)"), col = 1:4, lty = 1:4,

ncol = 2, cex = 0.8)

legend(0, -.4, paste("sin(", 5:7, "pi * x)"), col = 4:6, pch = 24,

ncol = 2, cex = 1.5, lwd = 2, pt.bg = "pink", pt.cex = 1:3)

par(op)

## point covering line :

y <- sin(3*pi*x)

plot(x, y, type = "l", col = "blue",

main = "points with bg & legend(*, pt.bg)")

points(x, y, pch = 21, bg = "white")

legend(.4,1, "sin(c x)", pch = 21, pt.bg = "white", lty = 1, col = "blue")

## legends with titles at different locations

plot(x, y, type = "n")

legend("bottomright", "(x,y)", pch=1, title= "bottomright")

legend("bottom", "(x,y)", pch=1, title= "bottom")

legend("bottomleft", "(x,y)", pch=1, title= "bottomleft")

legend("left", "(x,y)", pch=1, title= "left")

legend("topleft", "(x,y)", pch=1, title= "topleft, inset = .05", inset = .05)

legend("top", "(x,y)", pch=1, title= "top")

legend("topright", "(x,y)", pch=1, title= "topright, inset = .02",inset = .02)

legend("right", "(x,y)", pch=1, title= "right")

legend("center", "(x,y)", pch=1, title= "center")

# using text.font (and text.col):

op <- par(mfrow = c(2, 2), mar = rep(2.1, 4))

c6 <- terrain.colors(10)[1:6]

for(i in 1:4) {

plot(1, type = "n", axes = FALSE, ann = FALSE); title(paste("text.font =",i))

legend("top", legend = LETTERS[1:6], col = c6,

ncol = 2, cex = 2, lwd = 3, text.font = i, text.col = c6)

}

par(op)