I'm creating a plot in ggplot from a 2 x 2 study design and would like to use 2 colors and 2 symbols to classify my 4 different treatment combinations. Currently I have 2 legends, one for the colors and one for the two shapes. How can I combine them into a single legend so I have one blue circle, one red circle, one blue triangle, and one read triangle?
Data & code for plot:
state1 <- c(rep(c(rep("N",7), rep("Y",7)),2))
year <- rep(c(2003:2009), 4)
group1 <- c(rep("C",14), rep("E", 14))
group2 <- paste(state1,group1, sep = "")
beta <-c(0.16,0.15,0.08,0.08,0.18,0.48,0.14,0.19,0.00,0.00,0.04,0.08,0.27,0.03,0.11,0.12,0.09,0.09,0.10,0.19,0.16,0.00,0.11,0.07,0.08,0.09,0.19,0.10)
lcl <-c(0.13,0.12,0.05,0.05,0.12,0.35,0.06,0.13,0.00,0.00,0.01,0.04,0.20,0.00,0.09,0.09,0.06,0.06,0.07,0.15,0.11,0.00,0.07,0.03,0.05,0.06,0.15,0.06)
ucl <-c(0.20,0.20,0.13,0.14,0.27,0.61,0.28,0.27,0.00,1.00,0.16,0.16,0.36,0.82,0.14,0.15,0.13,0.13,0.15,0.23,0.21,0.00,0.15,0.14,0.12,0.12,0.23,0.16)
data <- data.frame(state1,year,group1,group2,beta,lcl,ucl)
library(ggplot2)
pd <- position_dodge(.65)
ggplot(data =data,aes(x= year, y = estimatebeta, colour = state1, group = group2, shape = groupgroup1)) +
geom_point(position = pd, size = 4) +
geom_errorbar(aes(ymin = lcl, ymax = ucl),colour = "black", width = 0.5, position = pd) +
scale_colour_hue(name="Treatment & State", #Legend label, use darker colors
labels=c("Control", "Exclosure"),
l=40) + scale_shape(name="State", labels = c("Non-F", "Flwr"))
