Place text at a fixed distance from the chart

Question

Please help me find a universal way to place text at a constant distance from the right side of the plot, as shown below. Since the plot area is already on the right, unfortunately, the current location calculation positions the text too far to the left. Notice that the text is right justified.

My last thought: if we knew the distance in centimeters between the words x = 1 and x = 2, we could easily calculate the position. Unfortunately, this is apparently not so easy to get this distance.

FYI: I do not want to name the lines.

Full size image

library(ggplot2) library(reshape) library(gridExtra) df = data.frame(x =(1:3),One=c(12, 8, 13),Two=c(13, 7, 11),Three=c(11, 9, 11)) df.melt = melt(df, id.vars="x") xmax = max(df.melt$x); xmin = min(df.melt$x) ymax = max(df.melt$value); ymin = min(df.melt$value) dfa = data.frame(x=(xmax-xmin)*1.15+xmin, y=c(11,12,13.5), ann=c("10.1|","1.1|","Texttexttext|")) dfa.melt = melt(dfa, id.vars=c("x","ann")) p = ggplot() + geom_line(data=df.melt, aes(x=x, y=value, color=variable), show_guide=F) + geom_text(data=dfa.melt, aes(x=x, y=value, hjust = 1, label=ann), size=3) + coord_cartesian(xlim=c(xmin,xmax), ylim=c(ymin,ymax)) p1 = p + theme(plot.margin=unit(c(1,3,0,0),"cm"), axis.text.y=element_text(size=10)) p2 = p + theme(plot.margin=unit(c(1,3,0,3),"cm"), axis.text.y=element_text(size=35)) p1c <- ggplot_gtable(ggplot_build(p1)) p1c$layout$clip[p1c$layout$name=="panel"] <- "off" p2c <- ggplot_gtable(ggplot_build(p2)) p2c$layout$clip[p2c$layout$name=="panel"] <- "off" grid.arrange(p1c, p2c, ncol=2) 

Answer 1

Since everything is named, you can access any component of the chart using the grid .

The problem is that ggplot2 creates many viewports and grobs when drawing a graph. Therefore, making changes to this plot is not easy. I also notice that the name of the gnomes and viewports changes for each new run of the plot. So I tried to get viewports by some criteria (here depth = 4)

 #Get the viewports: scene.vps <- grid.ls(viewports=T,grobs=F) scene.flat <- as.data.frame(do.call('cbind',scene.vps)) vps <- subset(scene.flat ,vpDepth == '4')$name[1:2] vps <- as.character(vps) # modify the plot by grid.text depth <- downViewport(vps[1]) grid.text("1.1|",x=unit(1, "npc") - unit(1, "mm"), y=unit(1, "npc") - unit(20, "mm"), just=c("right", "top")) grid.text("10.1|",x=unit(1, "npc") - unit(1, "mm"), y=unit(1, "npc") - unit(60, "mm"), just=c("right", "top")) grid.text("Texttexttext|",x=unit(1, "npc") - unit(10, "mm"), y=unit(1, "npc") -unit(2,'mm'), just=c("right", "top")) upViewport(depth) # come back to the root viewport depth <- downViewport(vps[2]) grid.text(...