如何将几何标签应用到最后一个值数据点

Question

我想仅将几何标签应用于每个系列的最后一个值数据点。\n这是我的数据库：

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这是我的代码：

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paises <- c("Peru", "Brazil", "Colombia", "Ecuador", "Chile", "Argentina", "Uruguay", "Paraguay", "Bolivia")\n\ndata <- jhu_sitrep_import(source = "confirmed") %>%\n  jhu_sitrep_cleandb() %>%\n  filter(country_region %in% paises) %>%\n  filter(value>0) %>%\n  group_by(country_region) %>%\n  mutate(start = first(dates),\n         d_start = dates-start,\n         per = ifelse(country_region =="Peru","Per","Otros"),\n         max_cases = max(value)) %>%\n  filter(max_cases>30)\n\ndata %>%\n  filter(per =="Otros") %>%\n  ggplot(aes(x = d_start, y = value, group=country_region)) +\n  geom_line(aes(col = country_region)) +\n  geom_point(aes(col = country_region, shape = country_region)) +\n  geom_line(dat = data %>% filter(per=="Per"), col = "red") +\n  geom_label(aes(y = value, label =value), vjust = 0.5) +\n  geom_label(aes(y = value, label =value ), vjust = -0.5) +\n  geom_point(dat = data %>% filter(per=="Per"), col = "red") +\n  geom_text(data = data %>% slice(n()) %>% filter(country_region!="Peru"),\n            aes(y = value, label = country_region, col = country_region), vjust=-.5) +\n  geom_text(data = data %>% slice(n()) %>% filter(country_region=="Peru"),\n            aes(y = value, label = country_region), col = "red", vjust=-.5) +\n  scale_fill_discrete_qualitative(palette="Pastel 1", nmax = 14, order = 5:14) +\n  labs(color = "Paises", x = "D\xc3\xadas desde primer caso", y = "Numero de casos", shape = "Paises") +\n  scale_y_log10() + \n  theme(legend.position = "bottom")\n

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因此，通过我的代码，我可以获得每个值数据点的值。我只想要最后一个值的标签。

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这是我的情节

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Answer 1

您希望将数据过滤/子集到最后一点，然后将其传递到geom_label()usingdata参数中。

我在下面包含了一个 reprex（可重现的示例）。

library(tidyverse)

cars <- rownames_to_column(mtcars, var = "model")

ggplot(cars, aes(x = mpg, y = disp)) +
  geom_point() +
  geom_label(data = filter(cars, model == last(model)), aes(label = model))

^{由reprex 包(v0.3.0)于 2020-03-20 创建}