使用geom_segment和facet防止重叠标签

Question

我正在使用geom_segment()和facet_wrap()来显示不同类型和型号的估算值。 previous post帮我组织了一些事情，但是我很难弄清楚如何监督标签，使它们不重叠。一旦我添加更多模型以与更多数据点进行比较，事情就会变得混乱。我试过在没有分辨率的情况下改变宽高比。

我如何监管或展开标签，使其可读，同时保留y轴的比例，以便在模型和类型之间进行比较？

示例数据

dat <- structure(list(temp = c(1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 
4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 
5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 
1, 2, 3, 4, 5), rev = c(-5, -11, -20, -29, -40, -9, -20, -32, 
-45, -57, -12, -24, -37, -50, -62, -7, -20, -36, -52, -67, -5, 
-13, -23, -35, -47, -12, -24, -36, -48, -58, 0, 0, -3, -7, -12, 
0, 0, 0, 0, -1, -4, -9, -15, -21, -28, 2, 1, -1, -6, -13, -4, 
-7, -8, -8, -6, 8, 16, 23, 29, 34), type = c("Type 1", "Type 1", 
"Type 1", "Type 1", "Type 1", "Type 1", "Type 1", "Type 1", "Type 1", 
"Type 1", "Type 1", "Type 1", "Type 1", "Type 1", "Type 1", "Type 2", 
"Type 2", "Type 2", "Type 2", "Type 2", "Type 2", "Type 2", "Type 2", 
"Type 2", "Type 2", "Type 2", "Type 2", "Type 2", "Type 2", "Type 2", 
"Type 3", "Type 3", "Type 3", "Type 3", "Type 3", "Type 3", "Type 3", 
"Type 3", "Type 3", "Type 3", "Type 3", "Type 3", "Type 3", "Type 3", 
"Type 3", "Type 4", "Type 4", "Type 4", "Type 4", "Type 4", "Type 4", 
"Type 4", "Type 4", "Type 4", "Type 4", "Type 4", "Type 4", "Type 4", 
"Type 4", "Type 4"), model = c("A", "A", "A", "A", "A", "B", 
"B", "B", "B", "B", "C", "C", "C", "C", "C", "A", "A", "A", "A", 
"A", "B", "B", "B", "B", "B", "C", "C", "C", "C", "C", "A", "A", 
"A", "A", "A", "B", "B", "B", "B", "B", "C", "C", "C", "C", "C", 
"A", "A", "A", "A", "A", "B", "B", "B", "B", "B", "C", "C", "C", 
"C", "C")), .Names = c("temp", "rev", "type", "model"), row.names = c(NA, 
-60L), class = "data.frame")

剧情

df.labeled <- dat %>% 
  ungroup() %>% group_by(type, rev) %>% 
  mutate(label = c(rev[1], rep(NA, length(rev) - 1)))

ggplot(df.labeled, aes(temp, rev, color = model)) + 
  geom_segment(aes(xend = 0, yend = rev), linetype = "dashed", color = "grey") +
  geom_text(aes(label = label, x = -0.1), colour = "black", hjust = 1) +
  geom_vline(xintercept = 0) +
  geom_point() + geom_line() + facet_wrap(~type) + 
  scale_y_continuous(breaks = NULL) + 
  scale_x_continuous(limits = c(-0.5, NA)) +
  theme_bw() + theme(panel.grid = element_blank())

Answer 1

一种选择是错开价值观。但是，我认为直接标记要点更清晰，更少混淆。我在下面展示了两种方法。

交错的价值标签

# Set up staggered x-values for the value labels
df.labeled = df.labeled %>% 
  group_by(type, is.na(label)) %>% 
  arrange(rev) %>%
  mutate(xval = rep(c(-0.1,-0.35), ceiling(n()/2))[1:n()])

ggplot(df.labeled, aes(temp, rev, color = model)) + 
  geom_segment(aes(xend=xval - 0.08, yend=rev), linetype="11", color="grey70", size=0.3) +
  geom_text(aes(x=xval, label=label), colour="black", hjust=1, size=2.5) +
  geom_vline(xintercept = 0, colour="grey90", size=0.3) +
  geom_point() + geom_line() + facet_wrap(~type) + 
  scale_y_continuous(breaks = NULL) + 
  scale_x_continuous(limits = c(-0.5, NA)) +
  theme_bw() + theme(panel.grid = element_blank())

使用y值作为点标签

ggplot(df.labeled, aes(temp, rev, color = model)) + 
  geom_text(aes(label = rev), size=2.5, show.legend=FALSE) +
  geom_line(alpha=0.3, size=0.7) + 
  facet_wrap(~type) + 
  scale_x_continuous(limits = c(0, NA)) +
  theme_bw() + 
  theme(panel.grid = element_blank()) +
  guides(colour=guide_legend(override.aes=list(alpha=1, size=1)))