如何使geom_text()在log-lin范围内与geom_segment()并行？

Question

需要在log-lin图中注释一行.如何使文本字符串(此处为"0000000000")与其注释的行平行？

require(ggplot2)
require(scales)
x=c(1:10)
y=2^x
data_line <- data.frame(x=3,xend=8,y=2^8,yend=2^9)
line <- geom_segment(data=data_line,aes(x=x,xend=xend,y=y,yend=yend),color="blue")
angle= atan((data_line$yend - data_line$y) / (data_line$xend - data_line$x))*(180/pi)
text <- annotate("text",x=data_line$x,y=data_line$y,label="0000000000",angle=angle)
qplot(x=x,y=y,geom="line") + line + text + scale_y_log10()

Answer 1

解决办法如下

require(ggplot2)
require(scales)
coord_ratio = ((1+sqrt(5))/2)^-1
data <- data.frame(x=c(1:10),y=10^(1:10))
line_coord <- data.frame(x=round(runif(5,1,5)),
                     y=round(runif(5,10^1,10^5)),
                     xend=round(runif(5,5,10)),
                     yend=round(runif(5,10^5,10^10)))
line_draw <- geom_segment(data=line_coord,aes(x=x,y=y,xend=xend,yend=yend),color="blue")
angle = atan((log10(line_coord$yend)*(coord_ratio)-log10(line_coord$y)*coord_ratio) / (line_coord$xend-line_coord$x))*(180/pi)
text <- annotate("text",x=line_coord$x,y=line_coord$y,label="LLLLLLLLLL",angle=angle,hjust=-0.1,vjust=-0.5)
qplot(data$x,data$y) + scale_y_log10() + coord_fixed(ratio=coord_ratio) + line_draw + text