r - How to change the size of legend text in ggplot2? -

i got plot using data , code below

i want able change size of legend text (a, b, m1, ,m3). tried using

legend.text=element_text(size=0.5) 

but didn't change. suggestion how reduce size of legend.text?

code

library(xts) library(zoo) library(ggplot2) library(tidyr) cols <- c("a"="black", "b" = "black","m1"="red","m2"="blue", "m3" = "green") ggplot(df.trial1, aes(x=date, y= a, color="a"))+   geom_line(linetype=3, size=0.2)+   geom_point(aes(x=date, y=b, color="b"), shape = 16, size =1, alpha=0.5)+   geom_point(aes(x=date, y=value, color=method), size =1, alpha=0.5)+   scale_colour_manual(name=" ", values=cols,                   labels=c("a", "b", 'm1', "m2", "m3"))+   scale_linetype_manual(values = c("dashed")) +   scale_x_date(breaks = date_breaks("1 month"), labels = date_format("%d-%b-%y"))+   guides(color=guide_legend(override.aes=list(shape=c(na,16, 16, 16, 16),                                           linetype=c(3,0, 0, 0, 0)),                         direction = "vertical", title.position = "top",                         label.position="right", label.hjust = 0, label.vjust = 0.5,                         label.theme = element_text(angle = 0)))+   labs(x=expression(date), y=expression(value))+   theme(legend.text=element_text(size=0.5)) 

data

set.seed(123) date <- as.date(seq(as.date("2003-01-01"), as.date("2003-05-31"), = 1), format="%y-%m-%d") <- runif(151, 0.005, 2.3) df <- data.frame(date, a) rans<-sample(length(df$a), 30) df$a.rm <- df$a df[rans, 3]<-na df <- subset(df, select=c(1,3,2)) nats<-xts(df[,-1], as.posixct(df$date)) m1<-na.locf.default(nats[,1]) m2<-na.approx(nats[,1]) m3<-na.spline(nats[,1]) nats1 <- fortify(nats) m1.1 <- fortify(m1) m2.1 <- fortify(m2) m3.1 <- fortify(m3) nats1$b <- nats1$a nats1[-rans,4] <-na  m1.1[-rans,2] <- na m2.1[-rans,2] <- na m3.1[-rans,2] <- na nats1<- nats1[, c(1, 3, 4)] m1.1 <- m1.1[, 2] m2.1 <- m2.1[, 2] m3.1 <- m3.1[, 2] df.trial <- cbind(nats1,m1.1, m2.1,m3.1) names(df.trial) <- c("index", "a", "b", "m1", "m2", "m3") df.trial1 <- gather(df.trial, "method", "value", 4:6) df.trial1$date <- as.date(strptime(df.trial1$index, format="%y-%m-%d %h:%m:%s", tz="pacific/auckland")) df.trial1 <- subset(df.trial1, select=c(6,2,3,4,5)) 

remove label.theme = element_text(angle = 0) guides seems fix this.

guides(color=guide_legend(override.aes=list(shape=c(na,16, 16, 16, 16),                                         linetype=c(3,0, 0, 0, 0)),                       direction = "vertical", title.position = "top",                       label.position="right", label.hjust = 0, label.vjust = 0.5                       #,label.theme = element_text(angle = 0)                       )) + theme(legend.text=element_text(size=10))