Error bars using ggplot

ggplot_error_bars

### ggplot ###
# Refs: http://learnr.wordpress.com/2010/02/25/ggplot2-plotting-dates-hours-and-minutes/
# http://had.co.nz/ggplot2/
# http://wiki.stdout.org/rcookbook/Graphs/Plotting%20means%20and%20error%20bars%20%28ggplot2%29
   
library(ggplot2)
 
ggplot(data = gCount, aes(x = date, y = count, group = trt)) + 
     #geom_point(aes(shape = factor(trt))) +
     geom_point(aes(colour = factor(trt), shape = factor(trt)), size = 3) +
     geom_errorbar(aes(ymin=count-se, ymax=count+se), width=.1) +
     # scale_shape_manual(values=c(24,21)) + # explicitly have sham=fillable triangle, ACCX=fillable circle
     #scale_fill_manual(values=c(“white”,”black”)) + # explicitly have sham=white, ACCX=black
     xlab(“Date”) +
     ylab(“Mean number of salamander captures per night”) + 
     scale_colour_hue(name=”Treatment”, # Legend label, use darker colors
                      l=40) +                  # Use darker colors, lightness=40
                      
                      
     theme_bw() + # make the theme black-and-white rather than grey (do this before font changes, or it overrides them)

     opts(legend.position=c(.2, .9), # Position legend inside This must go after theme_bw
           panel.grid.major = theme_blank(), # switch off major gridlines
           panel.grid.minor = theme_blank(), # switch off minor gridlines
          legend.title = theme_blank(), # switch off the legend title
          legend.key = theme_blank()) # switch off the rectangle around symbols in the legend