ggplot和轴号和标签

Question

我尝试构建以下示例图（有关CIELAB色轮的示例，请参阅here）。它已接近完成，但仍有一些小问题（见demo）： - 轴上的数字（数字，不确定它是如何用英语调用的）应该直接在x / y轴上（x = 0和y = 0）。目前我正在使用hline和vline来“添加”轴。有没有办法移动整个轴？ - 轴标签位于轴旁边，但应位于轴的末端，如样本图像中所示。我不确定是否有解决方案。试图在wickham和chang的书中找到解决方案，但失败了。不确定ggplot2是否可以使用这样的情节。

对不起链接，作为新用户我不允许发布图片:(

非常感谢 西蒙！

library(ggplot2)
circleFun <- function(center = c(0,0),diameter = 1, npoints = 100){
  r = diameter / 2
  tt <- seq(0,2*pi,length.out = npoints)
  xx <- center[1] + r * cos(tt)
  yy <- center[2] + r * sin(tt)
  return(data.frame(x = xx, y = yy))
}

# sample data for yellow
colorvals <- data.frame(file = 'Yellow.csv', L = 88.94026, a = -9.8599137, b=88.77139)

# build the circles for the plot
r20 <- circleFun(center = c(0, 0), diameter = 40, npoints = 100)
r40 <- circleFun(center = c(0, 0), diameter = 80, npoints = 100)
r60 <- circleFun(center = c(0, 0), diameter = 120, npoints = 100)
r80 <- circleFun(center = c(0, 0), diameter = 160, npoints = 100)
r100 <- circleFun(center = c(0, 0), diameter = 200, npoints = 100)
r120 <- circleFun(center = c(0, 0), diameter = 240, npoints = 100)
dat <- rbind(r20, r40, r60, r80, r100, r120)

# plot the data
ggplot(data = dat, aes(x, y)) +
  geom_path() +
  geom_hline() +
  geom_vline() +
  theme(legend.position = c(1,0), legend.justification=c(1,0)) +
  xlab("a* (Grün/Rot)") +
  ylab("b* (Gelb/Blau)") +
  labs(colour="L*") +
  geom_point(data = colorvals, aes(x = a, y = b), size=3) +
  geom_text(data = colorvals, aes(x = a, y = b, label = gsub(".csv", "", file)), size = 3, vjust=0,hjust=1.2)

Answer 1

在绘图面板内移动整个轴并不是直截了当的（可以说有充分的理由）。你可以这样做，

g <- ggplotGrob(p)

library(gtable)
# move the axis up in the gtable
g$layout[g$layout$name == "axis-b", c("t", "b")] <- 
  g$layout[g$layout$name == "panel", c("t", "b")] 
# extract the axis gTree and modify its viewport 
a <- g$grobs[[which(g$layout$name == "axis-b")]] 
a$vp <- modifyList(a$vp, list(y=unit(0.5, "npc")))
g$grobs[[which(g$layout$name == "axis-b")]] <- a


g$layout[g$layout$name == "axis-l", c("l", "r")] <- 
  g$layout[g$layout$name == "panel", c("l", "r")] 
# extract the axis gTree and modify its viewport 
b <- g$grobs[[which(g$layout$name == "axis-l")]] 
b$vp <- modifyList(b$vp, list(x=unit(0.5, "npc")))
g$grobs[[which(g$layout$name == "axis-l")]] <- b

#grid.newpage()
#grid.draw(g)


## remove all cells but panel
panel <- g$layout[g$layout$name == "panel",] 

gtrim <- g[panel$b, panel$r]
## add new stuff
gtrim <- gtable_add_rows(gtrim, unit(1,"line"), pos=0)
gtrim <- gtable_add_rows(gtrim, unit(1,"line"), pos=-1)
gtrim <- gtable_add_cols(gtrim, unit(1,"line"), pos=0)
gtrim <- gtable_add_cols(gtrim, unit(1,"line"), pos=-1)

gtrim <- gtable_add_grob(gtrim, list(textGrob("top"),
                                     textGrob("left", rot=90),
                                     textGrob("right", rot=90),
                                     textGrob("bottom")), 
                         t=c(1,2,2,3),
                         l=c(2,1,3,2))

grid.newpage()
grid.draw(gtrim)

Answer 2

除了使用theme(axis.text=element_blank(),axis.ticks=element_blank())删除旧轴和geom_text()添加新轴标签，手动创建文本之外，我不知道有什么方法可以做到这一点。我在下面修改了你的代码：

library(ggplot2)
circleFun <- function(center = c(0,0),diameter = 1, npoints = 100){
  r = diameter / 2
  tt <- seq(0,2*pi,length.out = npoints)
  xx <- center[1] + r * cos(tt)
  yy <- center[2] + r * sin(tt)
  return(data.frame(x = xx, y = yy))
}

# sample data for yellow
colorvals <- data.frame(file = 'Yellow.csv', L = 88.94026, a = -9.8599137, b=88.77139)

# build the circles for the plot
r20 <- circleFun(center = c(0, 0), diameter = 40, npoints = 100)
r40 <- circleFun(center = c(0, 0), diameter = 80, npoints = 100)
r60 <- circleFun(center = c(0, 0), diameter = 120, npoints = 100)
r80 <- circleFun(center = c(0, 0), diameter = 160, npoints = 100)
r100 <- circleFun(center = c(0, 0), diameter = 200, npoints = 100)
r120 <- circleFun(center = c(0, 0), diameter = 240, npoints = 100)
dat <- rbind(r20, r40, r60, r80, r100, r120)

# define labels and coordinates for axes
y.labs <- data.frame(x=rep(0,11),y=seq(-100,100,by=20))
y.text <- as.character(y.labs[,2])
y.text[6] <- ""
x.labs <- data.frame(x=seq(-100,100,by=20),y=rep(0,11))
x.text <- as.character(x.labs[,1])
x.text[6] <- ""

# plot the data
ggplot(data = dat, aes(x, y)) +
  geom_path() +
  geom_hline() +
  geom_vline() +
  theme(axis.text=element_blank(),axis.ticks=element_blank(),legend.position = c(1,0), legend.justification=c(1,0)) +
  xlab("a* (Grün/Rot)") +
  ylab("b* (Gelb/Blau)") +
  labs(colour="L*") +
  geom_point(data = colorvals, aes(x = a, y = b), size=3) +
  geom_text(data = colorvals, aes(x = a, y = b, label = gsub(".csv", "", file)), size = 3, vjust=0,hjust=1.2) +
  geom_text(data=x.labs, aes(x = x, y = y,label = x.text),vjust=0,hjust=.5) +
  geom_text(data=y.labs, aes(x = x, y = y,label = y.text),vjust=.5,hjust=1)