Question

我有以下代码：

df=data.frame(time=as.factor(rep(0.5:9.5,each=10)),
              roi=rep(1:10,10),
              area=runif(100, 5.0, 7.5))

df$time=factor(df$time, levels=rev(levels(df$time)))  

ggplot(data=df, aes(x=factor(roi), y=time, fill = area)) + 
   theme_minimal() + coord_fixed(ratio=1) + 
   geom_tile(colour = NA, width = 1.5, height = 1) + 
   scale_fill_gradient(low="black",high="white")

现在，我想删除x轴并添加一个新轴，以获得下面的预期图形。对于Seg 1，Seg 2，Seg 3，Seg 4，x轴将分为4个部分，分别为39％，23％，23％，15％的轴长度。任何人都有任何想法可以解决它。我很感谢所有的回应，并期待着你的回答。

非常感谢Mark Heckmann为我的问题提供了有用的答案。我想再问一件事。我还想通过＆＃34; scale_y_discrete＆＃34;来修改y轴，代码运行良好，但是y轴标签不符合我的期望。我运行的代码是：

ggplot(data=df, aes(x=factor(roi), y=time, fill = area)) + theme_minimal() +coord_fixed(ratio=1) +geom_tile(colour = NA, width = 1.5, height = 1)+scale_fill_gradient(low="black",high="white") +scale_y_discrete(name="Time (min)",expand =c(0.01,0.1),breaks=c(1,2.5,5.0,7.5,10.0),labels=c(0,15,30,45,60))

非常感谢！

Answer 1

这是我无法进入自定义注释grobs所能获得的。

library(ggplot2)
library(grid)
df=data.frame(time=as.factor(rep(0.5:9.5,each=10)),
              roi=rep(1:10,10),area=runif(100, 5.0, 7.5)) 
df$time=factor(df$time, levels=rev(levels(df$time)))
p1 <- ggplot(data=df, aes(x=factor(roi), y=time, fill = area)) + 
  theme_minimal() +coord_fixed(ratio=1) +
  geom_tile(colour = NA, width = 1.5, height = 1)+
  scale_fill_gradient(low="black",high="white") + 
  scale_x_discrete(breaks = c(4,6,8,10),
                   labels = paste0("Seg",1:4)) +
  theme(axis.title.x = element_blank(),
        axis.ticks.x = element_line(size =1),
        axis.text.x = element_text(hjust=c(2,1.5,1.5,1.5)),
        plot.margin = unit(c(2,0,2,0), "lines"))

如果您想查看自定义绘制轴标签和刻度标记，请参阅here。

Answer 2

您需要使用annotation_custom在绘图区域外绘制。

#### your plot

library(ggplot2)

g <- ggplot(data=df, aes(x=factor(roi), y=time, fill = area)) + 
  theme_minimal() + coord_fixed(ratio=1) +
  geom_tile(colour = NA, width = 1.5, height = 1) + 
  scale_fill_gradient(low="black",high="white")

额外代码：

library(grid)

# remove axis 
g <- g +  theme(axis.title.x=element_blank(),
             axis.text.x=element_blank(),
              axis.ticks.x=element_blank()) +
          scale_x_discrete(expand = c(0,0)) 

# calculate segment coordinates
segs <- c(.39, .23, .23, .15)
segs_center <- cumsum(segs) - segs/2
seg_ticks <- cumsum(segs)[1:3]
seg_labels <- paste("Seg", seq_along(segs))

# create graphicaal objects and gather as tree
grobs <- grobTree(linesGrob(c(0,1), c(.5,.5)),
                  segmentsGrob(x0=seg_ticks, x1=seg_ticks, y0=0, y1=1),
                  textGrob(x=segs_center, y=0, 
                           label = seg_labels, hjust = .5, gp = gpar(cex =.7)))

# insert grobsTree in as annotation
g <- g + annotation_custom( grob = grobs,  
                            ymin = -.2, ymax = .2, 
                            xmin = .25, xmax = 10.75)

# override clipping for plotting outside of plotting area
gt <- ggplot_gtable(ggplot_build(g))
gt$layout$clip[gt$layout$name == "panel"] <- "off"
grid.newpage()  
grid.draw(gt)

添加自定义的x轴以绘制ggplot2和y轴

2 个答案: