Align x-axis to plot for consistent use with grid

问题

I'm trying to build an histogram using data available from here. I'm using using the CSV version of this database to display the number of exoplantes discovered per year. A simple script would be

bulkdata <- read.csv('file.csv',head=1,sep=',')
pdf(file="yearcount.pdf",family="Times")
bins <- seq(min(bulkdata$discovered,na.rm=T),max(bulkdata$discovered,na.rm=T),by=1)
hist(bulkdata$discovered,breaks=bins,col='gray',ylab="Discovered",xlab="Year",main="",ylim=c(0,100),axes=FALSE)
axis(1, at=seq(1989,2012,by=1))
axis(2, at=seq(0,100,by=10))
grid(nx=10)
hist(bulkdata$discovered,breaks=bins,col='gray',ylab="Discovered",xlab="Year",main="", add=TRUE)
dev.off()

The problem is that the xaxis is not aligned with the 0 point of the yaxis. This is a problem because the lines drawn by grid() does not mean anything because they are not aligned with the ticks! I tried to add in axis(1, at=seq(1989,2012,by=1)) the option line=-1 to correct but this way the axis is correctly drawn but the grid start below the axis. Maybe a non standard package is needed?

回答1:

?grid says:

If more fine tuning is required, use ‘abline(h = ., v = .)’ directly.

So here's a suggestion:

par(las=1,bty="l")
h <- hist(bulkdata$discovered,breaks=bins,
     col='gray',ylab="Discovered",xlab="Year",main="",
     ylim=c(0,100),axes=FALSE)
yrs <- 1989:2012
yvals <- seq(0,100,by=10)
axis(1, at=yrs)
axis(2, at=yvals)
abline(h=yvals,v=yrs,col="gray",lty=3)
hist(bulkdata$discovered,breaks=bins,
     col='gray',ylab="Discovered",xlab="Year",main="", add=TRUE)

I would consider making the grid lines a little bit sparser (e.g. every 5 years?)

来源：https://stackoverflow.com/questions/14044066/align-x-axis-to-plot-for-consistent-use-with-grid

标签

csv

histogram