r - 通过 ggplot 中的多个方面进行一次回归

Question

我正在尝试通过具有 20 个面的图形来拟合线性回归(实际上有 9 个)。每次我拟合回归(使用 geom_smooth 使用 method = lm)时，它拟合 20 条线，每个面一条，但是我希望每个 ReefSpecies 组合的一条线穿过所有 20 个面。

这是我的图:

Similar Figure

这是我目前所拥有的:

Biomass <- c(20, 10, 5, 4, 5, 7, 8, 22, 13, 13, 15, 18, 2, 5, 7, 10)
Season <- c("Winter", "Spring", "Summer", "Fall")
Year <- c("1", "2", "3", "4")
ReefSpecies <- c("Admiral Ma", "Jaap Mf", "Grecian Ma", "Alligator Mf", "Jaap Mf", "Grecian Ma", "Alligator Mf", "Admiral Ma", "Grecian Ma", "Alligator Mf", "Admiral Ma", "Jaap Mf", "Alligator Mf", "Admiral Ma", "Jaap Mf","Grecian Ma")
Seasonal <- data.frame(Biomass, Season, Year, ReefSpecies)

testp <- ggplot(data = Seasonal, aes(x = Season, y = Biomass, group =        ReefSpecies, fill = ReefSpecies, colour = ReefSpecies))
testp <- testp + geom_point(stat = "identity", position="identity", inherit.aes = TRUE)
testp <- testp + facet_grid(. ~ Year, scales="fixed")
testp <- testp + theme(axis.text.x = element_text(angle = 90))
testp <- testp + theme(panel.margin.x = unit(0, "lines"))
testp <- testp + theme(legend.position = "top")
testp

Answer 1

根据评论，您不想想place an identical smooth on each facet of a ggplot (你可以通过 setting the faceting variable to NULL in the smooth 来完成。

您做想要的是对所有方面进行单一回归。我认为如果没有一些黑客攻击，这是不可能的 like that shown here .你可以试试看。

但相反，我建议退一步考虑您为什么要这样做以及顺利意味着什么。也许这意味着分面不是正确的选择？在这种情况下，您可能会考虑定义一个 Time 变量，该变量说明跨年的季节并对其进行回归(不带分面)。

一个示例(使用经过调整的数据，因为您的示例数据每年没有超过一次观察):

Year <- sort(rep(Year, 4))
Seasonal <- data.frame(Biomass, Season, Year, ReefSpecies)
Seasonal$Time <- interaction(Season, Year)

ggplot(Seasonal, aes( Time,  Biomass, color=ReefSpecies)) + 
  geom_point() +
  geom_smooth(aes(group=ReefSpecies), method="lm")