How to draw 3 separate connecting lines in one graph?

[ducati]

This is the graph I'm working on:

I'd like to draw 3 separate black lines: 1 connecting the 6 red points, 1 connecting the 6 yellow points, and 1 connecting the 6 green points. Here's the code that produces the figure:

cr = as.factor(1:18)
ggplot(CRatio, aes(x = CR, y = Mean)) +
  geom_errorbar(show.legend = FALSE, aes(ymin = Mean - FLSD, ymax = Mean + FLSD), color = "black", width = 0.003, size = 1.5) +
  geom_errorbar(show.legend = FALSE, aes(ymin = Mean - FLSD, ymax = Mean + FLSD, color = cr), width = 0.003, size = 0.75) +
  geom_point(show.legend = FALSE, aes(shape = cr, fill = "black"), size = 4) +
  geom_point(show.legend = FALSE, aes(shape = cr, fill = cr, size = 3)) +
  geom_hline(show.legend = FALSE, yintercept = 100, color = "gray60") +
  theme(legend.position = c(0.92, 0.82)) +
  scale_fill_manual(values = c("1" = "firebrick1", "2" = "firebrick1", "3" = "firebrick1", "4" = "firebrick1", "5" = "firebrick1", "6" = "firebrick1", "7" = "gold", "8" = "green3", "9" =   "gold", "10" = "green3", "11" = "gold", "12" = "green3", "13" = "gold", "14" = "gold", "15" = "green3", "16" = "gold", "17" = "gold", "18" = "green3")) +
  scale_color_manual(values = c("1" = "firebrick1", "2" = "firebrick1", "3" = "firebrick1", "4" = "firebrick1", "5" = "firebrick1", "6" = "firebrick1", "7" = "gold", "8" = "green3", "9" =   "gold", "10" = "green3", "11" = "gold", "12" = "green3", "13" = "gold", "14" = "gold", "15" = "green3", "16" = "gold", "17" = "gold", "18" = "green3")) +
  scale_shape_manual(values = c(22, 22, 22, 22, 22, 22, 23, 21, 23, 21, 23, 21, 23, 23, 21, 23, 23, 21)) +
  scale_x_continuous(breaks = seq(1, 1.4, 0.02)) +
  scale_y_continuous(breaks = seq(-20, 120, 20)) +
  coord_cartesian(ylim = c(0, 120)) +
  xlab("Contrast Ratio") +
  ylab("Score")

The data frame I'm graphing is shown below. I expect I need to add a column to it that identifies the plot color, but I don't know how to get ggplot2 to draw connecting lines only between matching colors.

   CR      N     Mean        SD      FLSD
1.114545, 36, 68.08103, 28.461777, 4.918355
1.123529, 36, 88.43912, 16.905620, 4.918355
1.132000, 36, 97.53609,  5.414429, 4.918355
1.140000, 36, 97.87396,  6.445279, 4.918355
1.147568, 36, 98.27566,  5.394553, 4.918355
1.154737, 36, 98.52912,  4.188169, 4.918355
1.235887, 36, 66.51105, 30.614724, 4.918355
1.240000, 36, 25.77416, 30.007565, 4.918355
1.256579, 36, 84.82706, 22.994580, 4.918355
1.266667, 36, 27.95530, 30.950723, 4.918355
1.276418, 36, 93.89677, 15.541952, 4.918355
1.293333, 36, 47.70902, 34.625131, 4.918355
1.295455, 36, 95.78894, 15.429926, 4.918355
1.313738, 36, 97.65004, 11.511776, 4.918355
1.320000, 36, 78.12021, 22.704971, 4.918355
1.331311, 36, 98.35325,  5.426022, 4.918355
1.346667, 36, 94.35469, 10.343709, 4.918355
1.373333, 36, 97.75070,  6.704323, 4.918355

[FJCC]

Does this get you close to what you want? I made a new column to set a Grp identity for each row.

library(ggplot2)
CRatio <- read.csv("~/R/Play/Dummy.csv")
#cr = as.factor(1:18)
CRatio$Grp = c("A","A","A","A","A","A",
                "B","C","B","C","B","C","B","B","C","B","B","C")  


ggplot(CRatio, aes(x = CR, y = Mean)) +
  geom_errorbar(show.legend = FALSE, aes(ymin = Mean - FLSD, ymax = Mean + FLSD), color = "black", width = 0.003, size = 1.5) +
  geom_errorbar(show.legend = FALSE, aes(ymin = Mean - FLSD, ymax = Mean + FLSD, color = Grp), width = 0.003, size = 0.75) +
  geom_point(show.legend = FALSE, aes(shape = Grp, color = "black"), size = 4) +
  geom_point(show.legend = FALSE, aes(shape = Grp, fill = Grp, size = 3)) +
  geom_hline(show.legend = FALSE, yintercept = 100, color = "gray60") +
  geom_line(aes(group = Grp, color = Grp), linewidth = 1,show.legend = FALSE) +
  theme(legend.position = c(0.92, 0.82)) +
  scale_fill_manual(values = c("A" = "firebrick", "B" = "gold", "C"= "green3")) +
  scale_color_manual(values = c("A" = "firebrick1",  "B" = "gold", "C" = "green3")) +
  scale_shape_manual(values = c("A" = 22, "B"= 23,"C" = 21)) +
  scale_x_continuous(breaks = seq(1, 1.4, 0.02)) +
  scale_y_continuous(breaks = seq(-20, 120, 20)) +
  coord_cartesian(ylim = c(0, 120)) +
  xlab("Contrast Ratio") +
  ylab("Score")
#> Warning: Using `size` aesthetic for lines was deprecated in ggplot2 3.4.0.
#> ℹ Please use `linewidth` instead.
#> This warning is displayed once every 8 hours.
#> Call `lifecycle::last_lifecycle_warnings()` to see where this warning was
#> generated.

^{Created on 2023-07-20 with reprex v2.0.2}

[ducati]

Wow. I need to digest how you used grouping with geom_line to make what I need so easy.

Thanks also for demonstrating a more elegant way to map the colors to the points.

Your code's output:

: