Adding a subscript to the ggplo2 legend using scale_color_manual

Good evening,

I have been trying to add a subscript for (H20) to the legend using scale_color_manual. I had to create another aes mapping to see and manually alter the legend. However, I am unable so far to add a subscript. I have been using this code:

geom_point(aes(colour = "Blank (50 µM of dH20)"))+
  scale_color_manual(name = "Final concentrations and volumes",
                                              values = c(expression(paste( "Blank" ~ "(", 50 *µL* "of",  dH[2],0, ")" =  "#B2182B"))), 
                                expression(paste( "Vehicle - Vehicle"~ "(", 10 *µL*  "of",  dH[2],0 , "+",  10 *µL* "of",  dH[2],0, ")" = "#D6604D")), 
                                expression(paste( "Vehicle -Nicotinic Acid" ~ "(", 10 *µL*  "of",  dH[2],0 , "+",  10 *µL*  "of",  1 *mM* ")" = "#F4A582")),
                                expression(paste( "Sp-Vehicle" ~ "(", 10 *µL*  "of",  5 *µM* "+", 10 *µL*  "of", dH[2], 0, ")" = "#FDDBC7")),
                                expression(paste( "Sp-Nicotinic Acid" ~ "(", 10 *µL*  "of", 5 *µM*  "+", 10 *µL* "of",  1 *mM* ")" = "#D1E5F0")))+

But, I am encountering the following error:

I used "=" to order ggplot2 to produce the exact same colours as they are presented within the graph:

As I did previously:

scale_color_manual(name = "Final concentrations and volumes",
                     labels = c( "Blank (50 µL of dH20)", "Vehicle - Vehicle (10µL of dH20 + 10µL of dH20)", "Vehicle -Nicotinic Acid (10µL of dH20 + 10µL of 1mM)", "Sp-Vehicle (10µL of 5µM + 10µL of dH20)", "Sp-Nicotinic Acid( 10µL of 5µM + 10µL of 1mM)"),
                     values = c("Blank (50 µL of dH20)" =  "#B2182B", "Vehicle - Vehicle (10µL of dH20 + 10µL of dH20)" = "#D6604D", "Vehicle -Nicotinic Acid (10µL of dH20 + 10µL of 1mM)" = "#F4A582", "Sp-Vehicle (10µL of 5µM + 10µL of dH20)"= "#FDDBC7", "Sp-Nicotinic Acid(10µL of 5µM + 10µL of 1mM)"= "#D1E5F0"))+

I do not know where I am doing mistakes.

That is the entire code used to produce the above graph:

PhospholipaseA2NOPo1<-structure(list(Drug = structure(c(1L, 1L, 5L, 5L, 5L, 5L, 5L, 
                                       5L, 4L, 4L, 4L, 4L, 4L, 4L, 3L, 3L, 3L, 3L, 3L, 3L, 2L, 2L, 2L, 
                                       2L, 2L, 2L), .Label = c("Blank", "SP.N", "SP.V", "V.N", "V.V"
                                       ), class = "factor"), Absorbance = c(0.178155098, 0.281888047, 
                                                                            0.315468607, 0.395427286, 0.443773761, 0.274327232, 0.126408569, 
                                                                            0.160375886, 0.332019768, 0.328779358, 0.31918001, 0.202597307, 
                                                                            0.241052828, 0.332138474, 0.356656925, 0.329787758, 0.291912398, 
                                                                            0.264823437, 0.167194165, 0.176451481, 0.406376062, 0.28900749, 
                                                                            0.298281464, 0.181890255, 0.245723697, 0.350279692)), class = "data.frame", row.names = c(NA, 
                                                                                                                                                                      -26L))

library(tidyverse)
library(ggplot2)
library(ggpubr)
library(RColorBrewer)
library(tidyr)
library(readr)
library(cowplot)
ggplot(PhospholipaseA2NOPo1, aes( x = Drug, y = Absorbance))+
  labs(x = expression(paste("Treatment")))+
  ylab(expression(paste("Absrobance " ~ "(",   A[425], " - ", A[600] ~ nm, ")"))) +
  labs(title = "Comparison of the effect of Blank, Vehicle - Vehicle, Vehicle - Nicotinic Acid, SP - Vehicle, and SP - Nicotinic Acid on microglia ",
       caption = "Phospholipase A2 Assay")+
  geom_point(aes(colour = "Blank (50 µM of dH20)"))+
  scale_color_manual(name = "Final concentrations and volumes",
                     labels = c( "Blank (50 µL of dH20)", "Vehicle - Vehicle (10µL of dH20 + 10µL of dH20)", "Vehicle -Nicotinic Acid (10µL of dH20 + 10µL of 1mM)", "Sp-Vehicle (10µL of 5µM + 10µL of dH20)", "Sp-Nicotinic Acid( 10µL of 5µM + 10µL of 1mM)"),
                     values = c("Blank (50 µL of dH20)" =  "#B2182B", "Vehicle - Vehicle (10µL of dH20 + 10µL of dH20)" = "#D6604D", "Vehicle -Nicotinic Acid (10µL of dH20 + 10µL of 1mM)" = "#F4A582", "Sp-Vehicle (10µL of 5µM + 10µL of dH20)"= "#FDDBC7", "Sp-Nicotinic Acid(10µL of 5µM + 10µL of 1mM)"= "#D1E5F0"))+
  stat_compare_means(label.y = 0.80,
                     label.x = 4.25)+
  scale_x_discrete(labels = c("Blank", "Vehicle- Vehicle", "Vehicle - Nicotinic Acid", "SP - Vehicle", "SP - Nicotinic Acid"))+
  geom_boxplot(
               fill=c("#B2182B", "#D6604D", "#F4A582", "#FDDBC7", "#D1E5F0"),            
               width=0.2,notch = FALSE)+
  stat_summary(fun=mean, colour="black", geom="point", 
               shape=18, size=3) + 
  theme_bw() +
  theme(panel.grid.major = element_line(colour = "#d3d3d3"),
        panel.grid.minor = element_blank(),
        panel.border = element_blank(), panel.background = element_blank(),
        plot.title = element_text(size = 14, face = "bold"))+
  theme(axis.text.x = element_text(face="bold", color="#3142b0", 
                                   size=8.9, angle=0),
        axis.text.y = element_text(face="bold", color="#3142b0", 
                                   size=8.9, angle=0))+
  theme(
    plot.title = element_text(size = 12, face = "bold"),
    plot.caption = element_text(hjust = 0, size = 8, face = "italic")
  )+
   scale_linetype_manual('Legend',values='solid')+
  scale_shape_manual('',values = 18)+
  theme(legend.spacing.y = unit(0.01, "cm"))+
  theme(legend.position = c(0, .97),
        legend.justification = c("left", "top"),
        legend.background = element_rect(colour = NA, fill = NA))

And this is the : DataUsed

You can use bquote(). Below, I only modified the blank to demonstrate the use.

ggplot(PhospholipaseA2NOPo1, aes( x = Drug, y = Absorbance))+
  labs(x = expression(paste("Treatment")))+
  ylab(expression(paste("Absrobance " ~ "(",   A[425], " - ", A[600] ~ nm, ")"))) +
  labs(title = "Comparison of the effect of Blank, Vehicle - Vehicle, Vehicle - Nicotinic Acid, SP - Vehicle, and SP - Nicotinic Acid on microglia ",
       caption = "Phospholipase A2 Assay")+
  geom_point(aes(colour = "Blank (50 µM of dH20)"))+
  scale_color_manual(name = "Final concentrations and volumes",
                     labels = c(bquote("Blank (50 µL of"~H[2]*"O)"), "Vehicle - Vehicle (10µL of dH20 + 10µL of dH20)", "Vehicle -Nicotinic Acid (10µL of dH20 + 10µL of 1mM)", "Sp-Vehicle (10µL of 5µM + 10µL of dH20)", "Sp-Nicotinic Acid( 10µL of 5µM + 10µL of 1mM)"),
                     values = c("Blank (50 µL of dH20)" =  "#B2182B", "Vehicle - Vehicle (10µL of dH20 + 10µL of dH20)" = "#D6604D", "Vehicle -Nicotinic Acid (10µL of dH20 + 10µL of 1mM)" = "#F4A582", "Sp-Vehicle (10µL of 5µM + 10µL of dH20)"= "#FDDBC7", "Sp-Nicotinic Acid(10µL of 5µM + 10µL of 1mM)"= "#D1E5F0"))+
  stat_compare_means(label.y = 0.80,
                     label.x = 4.25)+
  scale_x_discrete(labels = c("Blank", "Vehicle- Vehicle", "Vehicle - Nicotinic Acid", "SP - Vehicle", "SP - Nicotinic Acid"))+
  geom_boxplot(
    fill=c("#B2182B", "#D6604D", "#F4A582", "#FDDBC7", "#D1E5F0"),            
    width=0.2,notch = FALSE)+
  stat_summary(fun=mean, colour="black", geom="point", 
               shape=18, size=3) + 
  theme_bw() +
  theme(panel.grid.major = element_line(colour = "#d3d3d3"),
        panel.grid.minor = element_blank(),
        panel.border = element_blank(), panel.background = element_blank(),
        plot.title = element_text(size = 14, face = "bold"))+
  theme(axis.text.x = element_text(face="bold", color="#3142b0", 
                                   size=8.9, angle=0),
        axis.text.y = element_text(face="bold", color="#3142b0", 
                                   size=8.9, angle=0))+
  theme(
    plot.title = element_text(size = 12, face = "bold"),
    plot.caption = element_text(hjust = 0, size = 8, face = "italic")
  )+
  scale_linetype_manual('Legend',values='solid')+
  scale_shape_manual('',values = 18)+
  theme(legend.spacing.y = unit(0.01, "cm"))+
  theme(legend.position = c(0, .97),
        legend.justification = c("left", "top"),
        legend.background = element_rect(colour = NA, fill = NA))

1 Like

Thank you so much. I had been trying to use bquote(), however, now I know where I was making a mistake. As I thought I was messing up with the "*". Thank you. This is the following outcome

Using the following code:

scale_color_manual(name = "Final concentrations and volumes",
                     labels = c(bquote("Blank (50 µL of"~dH[2]*"O)"), 
                                bquote("Vehicle - Vehicle (10µL of"~dH[2]*"O + 10µL of"~dH[2]*"O)"), 
                                bquote("Vehicle -Nicotinic Acid (10µL of"~dH[2]*"O + 10µL of 1mM)"), 
                                bquote("Sp-Vehicle (10µL of 5µM + 10µL of"~dH[2]*"O)"), 
                                bquote("Sp-Nicotinic Acid( 10µL of 5µM + 10µL of 1mM)")),
                     values = c("Blank (50 µL of dH20)" =  "#B2182B", "Vehicle - Vehicle (10µL of dH20 + 10µL of dH20)" = "#D6604D", "Vehicle -Nicotinic Acid (10µL of dH20 + 10µL of 1mM)" = "#F4A582", "Sp-Vehicle (10µL of 5µM + 10µL of dH20)"= "#FDDBC7", "Sp-Nicotinic Acid(10µL of 5µM + 10µL of 1mM)"= "#D1E5F0"))+

This topic was automatically closed 7 days after the last reply. New replies are no longer allowed.

If you have a query related to it or one of the replies, start a new topic and refer back with a link.