Plot 4 curves in a single plot with 3 y-axes

Question

I have 4 sets of values: y1, y2, y3, y4 and one set x. The y values are of different ranges, and I need to plot them as separate curves with separate sets of values on the y

Answer 1

Try the following. It's not as complicated as it looks. Once you watch the first graph being built, you'll see that the others are very similar. And, since there are four similar graphs, you could easily reconfigure the code into a function that is used over and over to draw each graph. However, since I commonly draw all sorts of graphs with the same x-axis, I need a LOT of flexibility. So, I've decided that it's easier to just copy/paste/modify the code for each graph.

#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)

Below is the plot of the four graphs.