r - 调整图例的宽度以进行连续变量

Question

我下面有一个脚本来说明我的问题：

temp.df <- data.frame(x=1:100,y=1:100,z=1:100,stringsAsFactors=FALSE)
chart <- ggplot(data=temp.df,aes(x=x,y=y))
chart <- chart + geom_line(aes(colour=z))
chart <- chart + scale_colour_continuous(low="blue",high="red")
chart <- chart + theme(legend.position="bottom")
# so far so good, but I think the legend positioned at bottom with such a small size is a waste of space, so I want to "widen" it using the line below...
chart <- chart + guides(colour=guide_legend(keywidth=5,label.position="bottom"))
# oops, it changed to legend for categorical variable

如何扩大位于底部的“连续变量”图例？

Answer 1

代替功能guides()，您应该使用功能theme()并设置legend.key.width=

temp.df <- data.frame(x=1:100,y=1:100,z=1:100,stringsAsFactors=FALSE)
chart <- ggplot(data=temp.df,aes(x=x,y=y))
chart <- chart + geom_line(aes(colour=z))
chart <- chart + scale_colour_continuous(low="blue",high="red")
chart <- chart + theme(legend.position="bottom")
chart <- chart + theme(legend.key.width=unit(3,"cm"))