Confidence bands & set order in legend - ggplot

Confidence bands & legend - ggplot.R

# ======================================================================================
# Confidence bands and setting order of line types in legend - ggplot
# ======================================================================================

library(ggplot2)

# ==========  create some data
my.data <- data.frame(time     = rep(1:10,2),
                      means    = 2:21,
                      lowerCI  = 1:20,
                      upperCI  = 3:22,
                      scenario = rep(c("A","Z"), each=10))
my.data

# ========== plot
ggplot(data = my.data) +
    # plot CI-s as a ribbon arround each line;
    # initiate the filling (fill) with color/gray differently for each scenario and
    # also adjust alpha parameter for - opacity/transparency
    geom_ribbon(aes(x=time, ymin = lowerCI, ymax = upperCI, fill=scenario), alpha=0.6) +
    # set manually the fill color for ribbons
    scale_fill_manual(name = 'Scenario',
                      breaks = c("Z", "A"),
                      values = c("A" = "gray70",
                                 "Z" = "gray70")) +
    
    # add the average lines on top of CI ribbons
    geom_line(aes(x=time, y=means, linetype=scenario), lwd=.8) +
    
    # set manually the type of line
    scale_linetype_manual(name = 'Scenario',
                          breaks = c("Z", "A"),
                          values = c("Z"  = "solid",
                                     "A"  = "twodash")) +
    # NOTE: to set the order in legend as desired one needs to mention that in breaks=()
    
    # Final adjustments (optional)
    # set axis labels
    labs(x = "Time", 
         y = "Population growth") +
    # set number of axis ticks
    scale_x_continuous(breaks=pretty(my.data$time, 10)) +
    # eliminate default backgound
    theme_bw() + 
    theme(panel.grid.major = element_blank(), # eliminate major grids
          panel.grid.minor = element_blank(), # eliminate minor grids
          # set font family for all text within the plot ("serif" should work as "Times New Roman")
          # note that this can be overridden with other adjustment functions below
          text = element_text(family="serif"),
          # adjust text in X-axis title
          axis.title.x = element_text(size = 12, face = "bold"),
          # adjust text in Y-axis title
          axis.title.y = element_text(size = 12, face = "bold"),
          # adjust legend title appearance
          legend.title = element_text(size = 10, face = "bold"),
          # adjust legend label appearance
          legend.text = element_text(size = 10),
          # don't draw legend box (check element_rect() for borders and backgrounds)
          legend.background = element_blank(),
          # Put lower-right corner of legend box in lower-right corner of graph
          # Note that the numeric position in legend.position below is relative to the entire area, 
          # including titles and labels, not just the plotting area
          legend.justification = c(1,0),
          legend.position = c(1,0))

# save as pdf
ggsave("Confidence bands & legend - ggplot.pdf", width=10, height=9, units="cm")
# save as png
ggsave("Confidence bands & legend - ggplot.png", width=10, height=9, units="cm", dpi=300)