How to manually change line size and alpha values for ggplot2 lines (separated by factor)?-CodePudding

I want to create a graph where I can change the line size for each line c(1,2,3) and the alpha values for each line c(0.5,0.6,0.7). I tried to use scale_size_manual but it didn't make any difference. Any ideas on how to proceed?

var <- c("T","T","T","M","M","M","A","A","A")
val <- rnorm(12,4,5)
x <- c(1:12)

df <- data.frame(var,val,x)

ggplot(aes(x= x , y = val, color = var, group = var), data = df)   
scale_color_manual(values = c("grey","blue","black"))    geom_smooth(aes(x = x, y = val), formula = "y ~ x", method = "loess",se = FALSE, size = 1)   scale_x_continuous(breaks=seq(1, 12, 1), limits=c(1, 12))   scale_size_manual(values = c(1,2,3))

CodePudding user response：

To set the size and alpha values for your lines you have to map on aesthetics. Otherwise scale_size_manual will have no effect:

library(ggplot2)

ggplot(aes(x = x, y = val, color = var, group = var), data = df)  
  scale_color_manual(values = c("grey", "blue", "black"))  
  geom_smooth(aes(x = x, y = val, size = var, alpha = var), formula = "y ~ x", method = "loess", se = FALSE)  
  scale_x_continuous(breaks = seq(1, 12, 1), limits = c(1, 12))  
  scale_size_manual(values = c(1, 2, 3))  
  scale_alpha_manual(values = c(.5, .6, .7))