具有不同行数的格子图

Lattice plot with different count of rows

我想创建一个包含 4 个不同面板的格子图。其中 2 个面板应该是 2 个盒子,另外 2 个面板应该是 3 个盒子。 Lattice 会自动在前 2 个面板中绘制一个空行(见下图)。我怎样才能删除这个空 row/space,以便在前 2 个面板中只显示 line_a 和 line_b?

示例:

library("lattice")

set.seed(123)

N <- 2000
dat_a_b <- data.frame(x = rnorm(N),
                  lines = c(rep("line_a", N / 2), 
                            rep("line_b", N / 2)),
                  head1 = rep(c(rep("head1_a", N / 4),
                                rep("head1_b", N / 4)), 2),
                  head2 = rep(c(rep("head2_a", N / 8),
                                rep("head2_b", N / 8)), 4))

dat_c <- data.frame(x = rnorm(N / 2, 5),
                lines = rep("line_c", N / 2),
                head1 = rep(c(rep("head1_a", N / 8),
                              rep("head1_b", N / 8)), 2),
                head2 = rep("head2_a", N / 2))
dat_all <- rbind(dat_a_b, dat_c)

bwplot(x = lines ~ x | head1 * head2, data = dat_all)

当前图表:

非常感谢!

设置y轴的刻度为"free":

bwplot(x = lines ~ x | head1 * head2, data = dat_all,
       scales = list(y = "free"))