由于类似的问题已经问过了（here），但我不能调整那里提供的解决方案，以我的具体问题。对于下面显示的每个图，应该有x轴和y轴。
数据：

df_nSubj <- data.frame(
  nSubj = rep(seq(10L, 50L, by = 10L), each = 24L),
  family = factor(rep(rep(c("AOV", "MLM1", "MLM2", "MLM3"), 5), each = 6L)),
  Spher = factor(rep(rep(c("met", "vio"), 20), each = 3L)),
  effSize = rep(c(0.2, 0.5, 0.8), 40),
  pow = c(
    0.12, 0.53, 0.84, 0.1, 0.4, 0.74, 0.13, 0.55, 0.84, 0.11, 0.44, 0.74, 0.12,
    0.5, 0.82, 0.1, 0.43, 0.76, 0.12, 0.49, 0.81, 0.1, 0.43, 0.76, 0.2, 0.84,
    0.99, 0.15, 0.72, 0.97, 0.21, 0.81, 0.98, 0.17, 0.69, 0.95, 0.2, 0.83, 0.99,
    0.17, 0.75, 0.97, 0.19, 0.82, 0.99, 0.17, 0.75, 0.97, 0.32, 0.95, 1, 0.23,
    0.87, 1, 0.32, 0.92, 1, 0.25, 0.83, 0.99, 0.3, 0.94, 1, 0.24, 0.89, 1, 0.3,
    0.94, 1, 0.24, 0.89, 1, 0.41, 0.99, 1, 0.29, 0.96, 1, 0.4, 0.97, 1, 0.3, 0.92,
    1, 0.38, 0.99, 1, 0.32, 0.97, 1, 0.37, 0.98, 1, 0.32, 0.97, 1, 0.5, 1, 1,
    0.36, 0.98, 1, 0.47, 0.99, 1, 0.36, 0.96, 1, 0.47, 1, 1, 0.4, 0.99, 1, 0.46,
    1, 1, 0.4, 0.99, 1
  )
)

图：

require(ggplot2)
require(grid)
    pl1 <- ggplot(data=df_nSubj,aes(x=nSubj,y=pow,group=family))+
      geom_point(aes(shape=family))+geom_line()+
      labs(x="Number of subjects",y="Power",shape="")+
      scale_y_continuous(limits=c(0.2,1),breaks=c(0.2,0.4,0.6,0.8,1))+
      guides(shape = guide_legend(ncol = 4))+
      facet_grid(Spher~effSize)+
      theme_bw()+
      theme(legend.position = "top",
            panel.margin = unit(2, "lines"),
            legend.key = element_blank(),
            strip.text.x = element_blank(),
            strip.text.y = element_blank(),
            strip.background = element_blank(),
            panel.border=element_blank(),
            axis.line=element_line(),
            axis.title.x = element_text(vjust=-0.5))

先谢谢你了