将水平图例包裹在多行中

Question

假设我有以下数据:

    lab <- "A really really long string!"
    dat <- data.frame(grp = paste(1:6,lab),x=1:6,y=runif(6))

当用字符串绘制这个漫长的传奇时,有时候让传说很合适可能是一个挑战.如果必须的话,我总是可以缩短字符串以缩短它们,但我想知道是否有可能(最有可能使用一些grid魔法)将图例"包裹"在多个行或列中.例如,假设我将图例水平放置在底部:

    ggplot(dat,aes(x=x,y=y,colour=grp)) + geom_point() + 
        opts(legend.position="bottom",legend.direction="horizontal")

是否有可能将此图例显示为两行三行,而不是一行六行？

Answer 1

试试这个.我为很长的标题写了这个,但它适用于任何长字符串.你仍然需要弄清楚你的实例的线长.

# splits title of plot if to long
splittitle=function(title,linelength=40)
{
    spltitle<-strsplit(title,' ')
    splt<-as.data.frame(spltitle)
    title2<-NULL
    title3<-NULL
    titlelength<-round(nchar(title)/round(nchar(title)/linelength))
    dimsplt<-dim(splt)
    n=1
    doonce2=0
    for(m in 1:round(nchar(title)/linelength)){
  doonce=0
    doonce2=0
    for(l in n:dimsplt[1]){
        if(doonce==0){title2<-title3}
        title2=paste(title2,splt[l,],sep=' ')
        if(doonce2==0){if(nchar(title2)>=(titlelength*m)){title3=paste(title2,'\n',sep='')
        n<-(l+1)
        doonce2=1}
        }
        doonce=1
    }
    }
    title2
}

lab <- "A really really long string!A really really long string!A really really long string!A really really long string!A really really long string!A really really long string!A really really long string!A really really long string!"
lab2<-splittitle(lab)
cat(lab)
cat(lab2)


library('ggplot2')

1个原件

dat <- data.frame(grp = paste(1:6,lab2),x=1:6,y=runif(6))

ggplot(dat,aes(x=x,y=y,colour=grp)) + geom_point() + 
    opts(legend.position="bottom",legend.direction="horizontal")

2使用splittitle

dat <- data.frame(grp = paste(1:6,lab2),x=1:6,y=runif(6))
ggplot(dat,aes(x=x,y=y,colour=grp)) + geom_point() + 
    opts(legend.position="bottom",legend.direction="horizontal")

Answer 2

要包装长字符串,请使用strwrap.

lipsum <- "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur ullamcorper tellus vitae libero placerat aliquet egestas tortor semper. Maecenas pellentesque euismod tristique. Donec semper interdum magna, commodo vehicula ante hendrerit vitae. Maecenas at diam sollicitudin magna mollis lobortis. In nibh elit, tincidunt eu lobortis ac, molestie a felis. Proin turpis leo, iaculis non commodo quis, venenatis at justo. Duis in magna vel erat fringilla gravida quis non nisl. Nunc lacus magna, varius eu luctus vel, luctus tristique sapien. Suspendisse mi dolor, vestibulum at facilisis elementum, lacinia vitae metus. Etiam ut nisl urna, vel tempus mi. In hac habitasse platea dictumst. Quisque pretium volutpat felis, nec tempor diam faucibus at. Praesent volutpat posuere sapien, eu vulputate risus molestie vitae. Proin iaculis quam non leo porttitor hendrerit."

strwrap(lipsum)
cat(strwrap(lipsum), sep = "\n")
# Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur ullamcorper tellus
# vitae libero placerat aliquet egestas tortor semper. Maecenas pellentesque euismod
# tristique. Donec semper interdum magna, commodo vehicula ante hendrerit vitae. Maecenas
# at diam sollicitudin magna mollis lobortis. In nibh elit, tincidunt eu lobortis ac,
# molestie a felis. Proin turpis leo, iaculis non commodo quis, venenatis at justo. Duis
# in magna vel erat fringilla gravida quis non nisl. Nunc lacus magna, varius eu luctus
# vel, luctus tristique sapien. Suspendisse mi dolor, vestibulum at facilisis elementum,
# lacinia vitae metus. Etiam ut nisl urna, vel tempus mi. In hac habitasse platea
# dictumst. Quisque pretium volutpat felis, nec tempor diam faucibus at. Praesent
# volutpat posuere sapien, eu vulputate risus molestie vitae. Proin iaculis quam non leo
# porttitor hendrerit.