Legend ggplot figure doesn't show for means, errorbars and coloured rectangle

问题

I have been making this scatterplot of means in R and I know I should include all variables of interest as an aesthetic in the figure plot. However, in the figure that I created (see below), the legend doesn't show.

The variables that I'm interested in are the means, errorbars and the coloured rectangles. Anyone knows how to plot them in a smart or manual manner?

df <- data.frame(weeks = c(-1, 0, 1, 2, 3, 4),
             mean = c(64, 65, 66, 66, 66, 67),
             lowerCI = c(63.4, 64.9, 64.5, 63.8, 62.1, 66.8),
             upperCI = c(65.6, 65.1, 66.5, 67.2, 68.9, 67.2))

sp_ts <- ggplot(data = df,
            aes(x = weeks,
                y = mean))

sp_ts +
  geom_point(shape = 15,
         size = 4) +
  geom_errorbar(aes(ymin = lowerCI,
                ymax = upperCI),
            width = 0.05,
            size = 0.5) +
  labs(title = "Scatterplot of means",
   x = "Weeks",
   y = "Means") +
  scale_x_continuous(limits = c(-1, 4),
                 breaks = c(-1, 0, 1, 2, 3, 4)) +
  scale_y_continuous(limits = c(62, 69),
                 breaks = c(61, 62, 63, 64, 65, 66, 67, 68, 69)) +
  annotate("rect", xmin = -Inf, xmax = 2, ymin = -Inf, ymax = Inf, fill = "light blue", alpha = 0.2) +
  annotate("rect", xmin = 2, xmax = Inf, ymin = -Inf, ymax = Inf, fill = "blue", alpha = 0.2) +
  theme_bw() +
  theme(panel.grid.minor = element_blank())

回答1:

Here is one way to show the legend (taken from this answer)

library(ggplot2)

sp_ts1 <- sp_ts +
  geom_point(shape = 15, size = 4) +
  geom_errorbar(aes(ymin = lowerCI, ymax = upperCI),
            width = 0.05,
            size = 0.5) +
  labs(title = "Scatterplot of means",
   x = "Weeks",
   y = "Means") +
  scale_x_continuous(limits = c(-1, 4),
                 breaks = c(-1, 0, 1, 2, 3, 4)) +
  scale_y_continuous(limits = c(62, 69),
                 breaks = c(61, 62, 63, 64, 65, 66, 67, 68, 69)) +
  annotate("rect", xmin = -Inf, xmax = 2, ymin = -Inf, ymax = Inf, 
           fill = "light blue", alpha = 0.2) +
  annotate("rect", xmin = 2, xmax = Inf, ymin = -Inf, ymax = Inf, 
           fill = "blue", alpha = 0.2) +
  theme_bw() +
  theme(panel.grid.minor = element_blank())

sp_ts2 <- sp_ts1 +
  geom_point(aes(color = "Mean"), shape = 15, size = 4) +
    geom_errorbar(aes(ymin = lowerCI, ymax = upperCI,
                      color = "95% CI"),
            width = 0.05,
            size = 0.5) +
  scale_color_manual(name = "Legend", values = c("#666666", "#1B9E77")) +
  guides(colour = guide_legend(override.aes = list(linetype = c("solid", "blank"), 
                                                   shape = c(NA, 15))))
sp_ts2

To show 95% CI as a vertical line, use geom_linerange:

sp_ts3 <- sp_ts1 +
  geom_point(aes(color = "Mean"), shape = 15, size = 4) +
  geom_linerange(aes(ymin = lowerCI, ymax = upperCI, 
                       color = "95% CI")) +
  scale_color_manual(name = "Legend", values = c("#666666", "#1B9E77")) +
  guides(colour = guide_legend(override.aes = list(linetype = c("solid", "blank"), 
                                                   shape = c(NA, 15))))
sp_ts3

Edit: To show the filled rectangles, we need to use geom_rect instead of annotate

sp_ts3 + 
    geom_rect(aes(fill = "First"), xmin = -Inf, xmax = 2, ymin = -Inf, ymax = Inf, 
           alpha = 0.1) +
    geom_rect(aes(fill = "Second"), xmin = 2, xmax = Inf, ymin = -Inf, ymax = Inf, 
           alpha = 0.1) +
    scale_fill_manual(name = "Group", 
                      values = c(`First` = "bisque", `Second` = "cornflowerblue")) +
    guides(fill = guide_legend(override.aes= list(alpha = 0.6)))

Created on 2018-04-04 by the reprex package (v0.2.0).

来源：https://stackoverflow.com/questions/49644149/legend-ggplot-figure-doesnt-show-for-means-errorbars-and-coloured-rectangle

标签

ggplot2

legend