Odering of the items of a legend in ggplot2 and color them manually

Question

I am having troubles with the following piece of code

ggplot(entidad, aes(x=Año, y=promedio, group=Entidad, color=Entidad)) + 
    geom_point(aes(shape = Entidad), size = 3, position = position_dodge(0.2)) +
    geom_errorbar(aes(ymin=promedio-desviación, ymax=promedio+desviación, color = Entidad), width=0.4,
                  position=position_dodge(0.2)) +
    ylim(150,350) + xlim(2015.7,2019.3) +
    ylab("Promedio (desviación estándar)") +
    geom_text(data = entidad[entidad$Entidad=="ZIPAQUIRÁ",],aes(label = promedio, y = promedio), hjust = 1.8) +
    geom_text(data= entidad[entidad$Entidad=="Nacional",], aes(label = promedio, y = promedio), hjust = -0.9) +
    geom_text(data = entidad[entidad$Entidad=="ZIPAQUIRÁ",], aes(label = paste("(",desviación,")"), y = promedio), 
              hjust = 1.5, vjust = 2) +
    geom_text(data = entidad[entidad$Entidad=="Nacional",], aes(label = paste("(",desviación,")"), y = promedio), 
              hjust = -0.45, vjust = 2) +
    scale_color_manual(values=c(rgb(0,81,160, maxColorValue = 255), 
                                rgb(58, 170, 53, maxColorValue = 255)),
                       breaks = c("ZIPAQUIRÁ", "Nacional")) +
    #scale_fill_manual(values = c(rgb(116, 141, 199, maxColorValue = 255), 
    #                             Nacional = rgb(164, 200, 70, maxColorValue = 255)),
    #                  breaks = c("ZIPAQUIRÁ", "Nacional")) +
    theme(
      panel.background = element_rect(fill = "white", colour = rgb(198,
                                                                   198,
                                                                   198, 
                                                                   maxColorValue = 255),
                                      size = 1, linetype = "solid"),
      #panel.grid.major = element_line(size = 0.1, linetype = 'dashed',
      #                               colour = rgb(198,198,198,
      #                                             maxColorValue = 255)) 
      panel.grid.minor = element_line(size = 0.1, linetype = 'dashed',
                                      colour = rgb(198,198,198,
                                                   maxColorValue = 255))
    )

Which returns the plot:

I do not understand why is that I have two legends labelled "Entidad", I only want the bottom one to appear. My second concern is that I would like the item "ZIPAQUIRÁ" to be color blue, and "Nacional" to be color green.

Does anyone know how I can achieve this?

Answer 1

You have two legends for "Entidad" because you have it mapped to two aestetics - shape and color. To remove the legend for an aesthetic (in your case the upper legend is for shape) you can just add (with a +)

guides(shape = FALSE)

Colors in scale_color_manual follow the order of factors, so if you want "ZIPAQUIRÁ" (the second factor, they're alphabetic regardless of the order you specify for breaks) to be blue, make blue your second color like this:

  scale_color_manual(values=c(rgb(58, 170, 53, maxColorValue = 255), 
                              rgb(0,81,160, maxColorValue = 255)),
                     breaks = c("ZIPAQUIRÁ", "Nacional"))

Some simulated data to make this reproducible:

set.seed(123)
entidad <- data.frame(Año = c(2016, 2016, 2017, 2017, 2018, 2018, 2019, 2019),
                      promedio = as.integer(runif(8, 200, 300)),
                      desviación = as.integer(runif(8, 25, 50)),
                      Entidad = rep(c("ZIPAQUIRÁ", "Nacional"), 2))

ggplot(entidad, aes(
  x = Año,
  y = promedio,
  group = Entidad,
  color = Entidad
)) +
  geom_point(aes(shape = Entidad),
             size = 3,
             position = position_dodge(0.2)) +
  geom_errorbar(
    aes(
      ymin = promedio - desviación,
      ymax = promedio + desviación,
      color = Entidad
    ),
    width = 0.4,
    position = position_dodge(0.2)
  ) +
  ylim(150, 350) + xlim(2015.7, 2019.3) +
  geom_text(data = entidad[entidad$Entidad == "ZIPAQUIRÁ", ],
            aes(label = promedio, y = promedio),
            hjust = 1.8) +
  geom_text(data = entidad[entidad$Entidad == "Nacional", ],
            aes(label = promedio, y = promedio),
            hjust = -0.9) +
  geom_text(
    data = entidad[entidad$Entidad == "ZIPAQUIRÁ", ],
    aes(label = paste("(", desviación, ")"), y = promedio),
    hjust = 1.5,
    vjust = 2
  ) +
  geom_text(
    data = entidad[entidad$Entidad == "Nacional", ],
    aes(label = paste("(", desviación, ")"), y = promedio),
    hjust = -0.45,
    vjust = 2
  ) +
  scale_color_manual(values = c(
    rgb(58, 170, 53, maxColorValue = 255),
    rgb(0, 81, 160, maxColorValue = 255)
  ),
  breaks = c("ZIPAQUIRÁ", "Nacional")) +
  theme(
    panel.background = element_rect(
      fill = "white",
      colour = rgb(198,
                   198,
                   198,
                   maxColorValue = 255),
      size = 1,
      linetype = "solid"
    ),
    panel.grid.minor = element_line(
      size = 0.1,
      linetype = 'dashed',
      colour = rgb(198, 198, 198,
                   maxColorValue = 255)
    )
  ) +
  guides(shape = FALSE)