在具有3个y轴的单个图中绘制4条曲线

Question

我有4组值：y1，y2，y3，y4和一组x。 y值的范围不同，我需要将它们绘制为单独的曲线，并在y轴上使用不同的值集。

简单来说，我需要3个Y轴，它们的值（比例尺）不同，以便在同一张图上进行绘制。

Answer 1

试试这个...

# The data have a common independent variable (x)
x <- 1:10

# Generate 4 different sets of outputs
y1 <- runif(10, 0, 1)
y2 <- runif(10, 100, 150)
y3 <- runif(10, 1000, 2000)
y4 <- runif(10, 40000, 50000)
y <- list(y1, y2, y3, y4)

# Colors for y[[2]], y[[3]], y[[4]] points and axes
colors = c("red", "blue", "green")

# Set the margins of the plot wider
par(oma = c(0, 2, 2, 3))

plot(x, y[[1]], yaxt = "n", xlab = "Common x-axis", main = "A bunch of plots on the same graph", 
     ylab = "")
lines(x, y[[1]])

# We use the "pretty" function go generate nice axes
axis(at = pretty(y[[1]]), side = 2)

# The side for the axes.  The next one will go on 
# the left, the following two on the right side
sides <- list(2, 4, 4) 

# The number of "lines" into the margin the axes will be
lines <- list(2, NA, 2)

for(i in 2:4) {
  par(new = TRUE)
  plot(x, y[[i]], axes = FALSE, col = colors[i - 1], xlab = "", ylab = "")
  axis(at = pretty(y[[i]]), side = sides[[i-1]], line = lines[[i-1]], 
      col = colors[i - 1])
  lines(x, y[[i]], col = colors[i - 1])
}

# Profit.

Answer 2

如果您想走学习基础图形之外的绘图软件包的道路，这是使用@Rguy答案中的变量的ggplot2解决方案：

library(ggplot2)
dat <- data.frame(x, y1, y2, y3, y4)

dat.m <- melt(dat, "x")

ggplot(dat.m, aes(x, value, colour = variable)) + geom_line() +
facet_wrap(~ variable, ncol = 1, scales = "free_y") +
scale_colour_discrete(legend = FALSE)

Answer 3

尝试以下方法。 它并不像看起来那么复杂。 观看构建的第一个图形后，您将看到其他图形非常相似。 而且，由于有四个相似的图形，因此您可以轻松地将代码重新配置为一个函数，该函数可反复使用以绘制每个图形。 但是，由于我通常使用相同的x轴绘制各种图形，因此我需要很多灵活性。 因此，我决定只复制/粘贴/修改每个图形的代码会更容易。

#Generate the data for the four graphs
x <- seq(1, 50, 1)
y1 <- 10*rnorm(50)
y2 <- 100*rnorm(50)
y3 <- 1000*rnorm(50)
y4 <- 10000*rnorm(50)

#Set up the plot area so that multiple graphs can be crammed together
par(pty="m", plt=c(0.1, 1, 0, 1), omd=c(0.1,0.9,0.1,0.9))

#Set the area up for 4 plots
par(mfrow = c(4, 1))

#Plot the top graph with nothing in it =========================
plot(x, y1, xlim=range(x), type="n", xaxt="n", yaxt="n", main="", xlab="", ylab="")
mtext("Four Y Plots With the Same X", 3, line=1, cex=1.5)

#Store the x-axis data of the top plot so it can be used on the other graphs
pardat<-par()
xaxisdat<-seq(pardat$xaxp[1],pardat$xaxp[2],(pardat$xaxp[2]-pardat$xaxp[1])/pardat$xaxp[3])

#Get the y-axis data and add the lines and label
yaxisdat<-seq(pardat$yaxp[1],pardat$yaxp[2],(pardat$yaxp[2]-pardat$yaxp[1])/pardat$yaxp[3])
axis(2, at=yaxisdat, las=2, padj=0.5, cex.axis=0.8, hadj=0.5, tcl=-0.3)
abline(v=xaxisdat, col="lightgray")
abline(h=yaxisdat, col="lightgray")
mtext("y1", 2, line=2.3)
lines(x, y1, col="red")

#Plot the 2nd graph with nothing ================================
plot(x, y2, xlim=range(x), type="n", xaxt="n", yaxt="n", main="", xlab="", ylab="")

#Get the y-axis data and add the lines and label
pardat<-par()
yaxisdat<-seq(pardat$yaxp[1],pardat$yaxp[2],(pardat$yaxp[2]-pardat$yaxp[1])/pardat$yaxp[3])
axis(2, at=yaxisdat, las=2, padj=0.5, cex.axis=0.8, hadj=0.5, tcl=-0.3)
abline(v=xaxisdat, col="lightgray")
abline(h=yaxisdat, col="lightgray")
mtext("y2", 2, line=2.3)
lines(x, y2, col="blue")

#Plot the 3rd graph with nothing =================================
plot(x, y3, xlim=range(x), type="n", xaxt="n", yaxt="n", main="", xlab="", ylab="")

#Get the y-axis data and add the lines and label
pardat<-par()
yaxisdat<-seq(pardat$yaxp[1],pardat$yaxp[2],(pardat$yaxp[2]-pardat$yaxp[1])/pardat$yaxp[3])
axis(2, at=yaxisdat, las=2, padj=0.5, cex.axis=0.8, hadj=0.5, tcl=-0.3)
abline(v=xaxisdat, col="lightgray")
abline(h=yaxisdat, col="lightgray")
mtext("y3", 2, line=2.3)
lines(x, y3, col="green")

#Plot the 4th graph with nothing =================================
plot(x, y4, xlim=range(x), type="n", xaxt="n", yaxt="n", main="", xlab="", ylab="")

#Get the y-axis data and add the lines and label
pardat<-par()
yaxisdat<-seq(pardat$yaxp[1],pardat$yaxp[2],(pardat$yaxp[2]-pardat$yaxp[1])/pardat$yaxp[3])
axis(2, at=yaxisdat, las=2, padj=0.5, cex.axis=0.8, hadj=0.5, tcl=-0.3)
abline(v=xaxisdat, col="lightgray")
abline(h=yaxisdat, col="lightgray")
mtext("y4", 2, line=2.3)
lines(x, y4, col="darkgray")

#Plot the X axis =================================================
axis(1, at=xaxisdat, padj=-1.4, cex.axis=0.9, hadj=0.5, tcl=-0.3)
mtext("X Variable", 1, line=1.5)

以下是四个图表的绘图。