是否可以在基本图形中将轴标签分成2行？

Question

我试图让x轴标签分成两行。我还希望标签旋转45度。我怎么能这样做？

到目前为止我所拥有的：

N <- 10
dnow <- data.frame(x=1:N, y=runif(N), labels=paste("This is observation ",1:N))
with(dnow, plot(x,y, xaxt="n", xlab=""))
atn <- seq(1,N,3)
axis(1, at=atn, labels=labels[atn])

Answer 1

这是ggplot2包的一种可能性。

N <- 10
labs <- factor(1:N,labels=paste("This is \n observation",1:N))
dnow <- data.frame(x=1:N, y=runif(N), labels=labs)
qplot(labels,y,data=dnow) + 
      opts(axis.text.x=theme_text(angle=-45,hjust=0))

我期待看到基础包示例！

Answer 2

这是我在使用基本图形时（在ggplot2天之前）制作的内容：

## data
N <- 10
dnow <- data.frame(x=1:N, y=runif(N), labels=paste("This is \nobservation ",1:N))
## make margins wide
par(mfrow=c(1,1), mar=c(10,10,6,4))
## plot without axix labels or ticks
with(dnow, plot(x,y, xaxt="n", xlab=""))
## the positions we ant to plot
atn <- seq(1,N,3)
## the label for these positions
lab <- dnow$labels[atn]
## plot the axis, but do not plot labels
axis(1, at=atn, labels=FALSE)
## plot labels
text(atn, ## x position
     par("usr")[3]-.05, ## position of the low axis
     srt=45, ## angle
     labels=lab, ##labels
     xpd=TRUE, ## allows plotting outside the region 
     pos=2)
## par("usr")[3]