How to change legend text in ggplot2

Question

I have a question about how to change the legend text, I tried a few answers from this site and non of them worked. Here is the example code:

counts <- c(18,17,15,20,10,20,25,13,12)
time <- c(1, 1.3, 1.11, 1, 1, 1, 1, 1.3, 1.1)
sex <- c("m","f","m","f","m","f","m","f","m")
print(myDF <- data.frame(sex, counts, time))

ggplot(myDF, aes(counts, time, color=sex)) +
  geom_point(size = 3)+geom_smooth(method="lm", se=F) +
  ggtitle("Long-Term Gain in Speech Rate")+
  xlab("Baseline Speech Rate") +
  ylab("Mean Speech Rate Gain")+
  theme(legend.position = "bottom")

The result is: As some answers suggested to use the scale_fill_manual() or scale_fill_discrete(). I tried these solutions but none of them changed the legend text, such as the code below:

counts <- c(18,17,15,20,10,20,25,13,12)
    time <- c(1, 1.3, 1.11, 1, 1, 1, 1, 1.3, 1.1)
    sex <- c("m","f","m","f","m","f","m","f","m")
    print(myDF <- data.frame(sex, counts, time))
    
    ggplot(myDF, aes(counts, time, color=sex)) +
      geom_point(size = 3)+geom_smooth(method="lm", se=F) +
      ggtitle("Long-Term Gain in Speech Rate")+
      xlab("Baseline Speech Rate") +
      ylab("Mean Speech Rate Gain")+
      theme(legend.position = "bottom")+
      scale_fill_discrete("", labels=c('women', 'men'))

Any suggestions?

Answer 1

You are using scale_fill_discrete, while you should use scale_colour_discrete... This should work:

counts <- c(18,17,15,20,10,20,25,13,12)
time <- c(1, 1.3, 1.11, 1, 1, 1, 1, 1.3, 1.1)
sex <- c("m","f","m","f","m","f","m","f","m")
print(myDF <- data.frame(sex, counts, time))

ggplot(myDF, aes(counts, time, colour = sex)) +
  geom_point(size = 3) +
  geom_smooth(method = "lm", se = FALSE) +
  ggtitle("Long-Term Gain in Speech Rate") +
  xlab("Baseline Speech Rate") +
  ylab("Mean Speech Rate Gain")+
  theme(legend.title = element_blank(),
        legend.position = "bottom") +
  scale_colour_discrete(labels = c('Women', 'Men'))

Here is the output: