[R] Choosing colours for lines in ggplot2

[Nick Wray]

Hello - I am trying to plot flows in a number of rivers within the same
plot, and need to colour the lines differently, using a colour-blind
palette.


Code beneath works but has colours assigned by the program I have made some
simple dummy data:
## code 1
cb8<- c("#000000", "#E69F00", "#56B4E9", "#009E73","#F0E442", "#0072B2",
"#D55E00", "#CC79A7")  ## this is the colour-blind palette
 set.seed(020823)
 df<-as.data.frame(cbind(rep(1980:1991,2),c(10*runif(12),10*runif(12)),c(rep(1,12),rep(2,12))))
 colnames(df)<-c("Year","Flow","Stat")
 df
 ggplot(df,aes(Year,Flow,group=Stat,colour=Stat))+
   coord_cartesian(ylim = c(0, 10)) +
   geom_line()+
   geom_point()
 ## this works

## BUT:
## code 2
col.2<-cb8[4:5]
 ggplot(df,aes(Year,Flow,group=Stat,colour=Stat))+
   coord_cartesian(ylim = c(0, 10)) +
   geom_line()+
   geom_point()+
 scale_color_manual(values =cb8[4:5])+
   theme_bw()
 ## this gives error message Error: Continuous value supplied to discrete
scale

## However this example using code from the net does work so I don't
understand why my ## second code doesn't work.
## code 3
 df.1 <- data.frame(store=c('A', 'A', 'A', 'B', 'B', 'B', 'C', 'C', 'C'),
                  week=c(1, 2, 3, 1, 2, 3, 1, 2, 3),
                  sales=c(9, 12, 15, 7, 9, 14, 10, 16, 19))
 ggplot(df.1, aes(x=week, y=sales, group=store, color=store)) +
   geom_line(size=2) +
   #scale_color_manual(values=c('orange', 'pink', 'red'))
   scale_color_manual(values=cb8[4:6])

Can anyone help? Thanks Nick Wray

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