R ggplot2 legend inside the figure
plot1 <- ggplot(data=df, aes(x=xval, y=yval, group=cond, colour=cond) ) + geom_smooth(aes(ymin = yval-se, ymax = yval+se, linetype=cond, colour=cond, fill=cond), stat="identity", size=1.1) + scale_colour_hue(l=25) + ylim(-0.1,1.3) + scale_linetype_manual(values = c('a' = 1,'b' = 2))plot1 + facet_grid(~ zval, scales="free_y") + theme(strip.text.x = element_blank(), strip.background = element_rect(colour="white", fill="white"), legend.position=c(.9,.75) )Tweak the legend.position values to suit your preference.