ggplot2偏移散点图

Question

我有两组带误差线的点.我想偏移第二个,所以它显示从第一个集稍微下降,所以它不会模糊原始.

这是一个模拟数据集:

x=runif(4,-2,2)
y=c("A","B","C","D")
upper=x+2
lower=x-2
x_1=runif(4,-1,3)
upper_1=x_1+1
lower_1=x_1-2

这是我用来制作情节的代码:

qplot(x,y)+
  geom_point(size=6)+
  geom_errorbarh(aes(xmax=upper,xmin=lower),size=1)+
  geom_point(aes(x_1,y),size=6,pch=8,vjust=-1,col="grey40")+
  geom_errorbarh(aes(xmax=upper_1,xmin=lower_1),size=1,col="grey40")

这是情节:

我希望将灰色星号和相关的误差条绘制在黑色圆圈和相关误差条下方的头发上.我会转换数据集,但Y轴是分类变量.

Answer 1

使用Richie重组您的数据,这也可以完全在其中ggplot,而不必弄乱轴:

dodge <- position_dodge(width=0.5)  
p <- ggplot(dfr,aes(x=y,y=x,colour=type)) + 
        geom_point(aes(shape=type),position=dodge) +
        geom_errorbar(aes(ymax=upper,ymin=lower),position = dodge) + 
        scale_colour_manual(values = c('gray','black')) +
        scale_shape_manual(values = c(8,19)) +
        coord_flip() + 
        opts(legend.position="none")

这给了我这个情节:

注意:由于版本0.9.2 opts已被替换为theme:

+ theme(legend.position = "none")

Answer 2

将数据重组为数据框.

x = runif(4,-2,2)
x_1 = runif(4,-1,3)
dfr <- data.frame(
  x = c(x, x_1),
  y = rep(c("A","B","C","D"), 2),
  upper = c(x+2, x_1+1),
  lower = c(x-2, x_1-2),
  type = rep(c("alpha", "beta"), each = 4)
)

添加一个作为因子的数字版本的列y.

dfr$y_numeric <- with(dfr, 
  as.numeric(y) - ifelse(type == "alpha", 0, 0.1)
)

           x y    upper       lower  type y_numeric
1 0.16694617 A 2.166946 -1.83305383 alpha       1.0
2 1.95060734 B 3.950607 -0.04939266 alpha       2.0
3 1.85516860 C 3.855169 -0.14483140 alpha       3.0
4 0.08773196 D 2.087732 -1.91226804 alpha       4.0
5 0.74837995 A 1.748380 -1.25162005  beta       0.9
6 0.61489655 B 1.614897 -1.38510345  beta       1.9
7 2.31641418 C 3.316414  0.31641418  beta       2.9
8 2.62842027 D 3.628420  0.62842027  beta       3.9

现在你的绘图代码更简单了.

ggplot(dfr, aes(x, y_numeric, colour = type)) +
  geom_point(size = 6) +
  geom_errorbarh(aes(xmax = upper,xmin = lower), size = 1) +
  scale_colour_grey()