How to Add P-Values onto Horizontal GGPLOTS

library(ggpubr)
library(rstatix)
# Transform `dose` into factor variable
df <- ToothGrowth
df$dose <- as.factor(df$dose)
head(df, 3)
# Box plots
bxp <- ggboxplot(df, x = "dose", y = "len", fill = "dose", 
                 palette = c("#00AFBB", "#E7B800", "#FC4E07"))

# Bar plots showing mean +/- SD
bp <- ggbarplot(df, x = "dose", y = "len", add = "mean_sd", fill = "dose", 
                palette = c("#00AFBB", "#E7B800", "#FC4E07"))
stat.test <- df %>% t_test(len ~ dose)
# Box plot
stat.test <- stat.test %>% add_xy_position(x = "dose")
bxp + stat_pvalue_manual(stat.test, label = "p.adj.signif", tip.length = 0.01)

# Bar plot
stat.test <- stat.test %>% add_xy_position(fun = "mean_sd", x = "dose")
bp + stat_pvalue_manual(stat.test, label = "p.adj.signif", tip.length = 0.01)

library(ggpubr)
library(rstatix)
# Transform `dose` into factor variable
df <- ToothGrowth
df$dose <- as.factor(df$dose)
head(df, 3)
# Box plots
bxp <- ggboxplot(df, x = "dose", y = "len", fill = "dose", 
                 palette = c("#00AFBB", "#E7B800", "#FC4E07"))

# Bar plots showing mean +/- SD
bp <- ggbarplot(df, x = "dose", y = "len", add = "mean_sd", fill = "dose", 
                palette = c("#00AFBB", "#E7B800", "#FC4E07"))
stat.test <- stat.test %>% add_xy_position(x = "dose")
bxp + 
  stat_pvalue_manual(
    stat.test, label = "p.adj.signif", tip.length = 0.01,
    coord.flip = TRUE
  ) +
  coord_flip()

# Horizontal bar plot with p-values
stat.test <- stat.test %>% add_xy_position(fun = "mean_sd", x = "dose")
bp + stat_pvalue_manual(
  stat.test, label = "p.adj.signif", tip.length = 0.01,
  coord.flip = TRUE
) +
  coord_flip()

library(ggpubr)
library(rstatix)
# Transform `dose` into factor variable
df <- ToothGrowth
df$dose <- as.factor(df$dose)
head(df, 3)
# Box plots
bxp <- ggboxplot(df, x = "dose", y = "len", fill = "dose", 
                 palette = c("#00AFBB", "#E7B800", "#FC4E07"))

# Bar plots showing mean +/- SD
bp <- ggbarplot(df, x = "dose", y = "len", add = "mean_sd", fill = "dose", 
                palette = c("#00AFBB", "#E7B800", "#FC4E07"))
# Using `p.adj` as labels
stat.test <- stat.test %>% add_xy_position(x = "dose")
bxp + 
  stat_pvalue_manual(
    stat.test, label = "p.adj", tip.length = 0.01,
    coord.flip = TRUE
  ) +
  coord_flip()

library(ggpubr)
library(rstatix)
# Transform `dose` into factor variable
df <- ToothGrowth
df$dose <- as.factor(df$dose)
head(df, 3)
# Box plots
bxp <- ggboxplot(df, x = "dose", y = "len", fill = "dose", 
                 palette = c("#00AFBB", "#E7B800", "#FC4E07"))

# Bar plots showing mean +/- SD
bp <- ggbarplot(df, x = "dose", y = "len", add = "mean_sd", fill = "dose", 
                palette = c("#00AFBB", "#E7B800", "#FC4E07"))
stat.test <- df %>% t_test(len ~ dose, ref.group = "0.5") 
# Vertical box plot with p-values
stat.test <- stat.test %>% add_xy_position(x = "dose")
bxp + 
  stat_pvalue_manual(stat.test, label = "p.adj", tip.length = 0.01) +
  scale_y_continuous(expand = expansion(mult = c(0.05, 0.1)))

library(ggpubr)
library(rstatix)
# Transform `dose` into factor variable
df <- ToothGrowth
df$dose <- as.factor(df$dose)
head(df, 3)
# Box plots
bxp <- ggboxplot(df, x = "dose", y = "len", fill = "dose", 
                 palette = c("#00AFBB", "#E7B800", "#FC4E07"))

# Bar plots showing mean +/- SD
bp <- ggbarplot(df, x = "dose", y = "len", add = "mean_sd", fill = "dose", 
                palette = c("#00AFBB", "#E7B800", "#FC4E07"))
stat.test <- df %>% t_test(len ~ dose, ref.group = "0.5") 
# Vertical box plot with p-values

# Vertical bar plot with p-values
stat.test <- stat.test %>% add_xy_position(fun = "mean_sd", x = "dose")
bp + 
  stat_pvalue_manual(stat.test, label = "p.adj.signif", tip.length = 0.01) +
  scale_y_continuous(expand = expansion(mult = c(0.05, 0.1)))

library(ggpubr)
library(rstatix)
# Transform `dose` into factor variable
df <- ToothGrowth
df$dose <- as.factor(df$dose)
head(df, 3)
# Box plots
bxp <- ggboxplot(df, x = "dose", y = "len", fill = "dose", 
                 palette = c("#00AFBB", "#E7B800", "#FC4E07"))

# Bar plots showing mean +/- SD
bp <- ggbarplot(df, x = "dose", y = "len", add = "mean_sd", fill = "dose", 
                palette = c("#00AFBB", "#E7B800", "#FC4E07"))
# Horizontal box plot with p-values
stat.test <- stat.test %>% add_xy_position(x = "dose")
bxp + 
  stat_pvalue_manual(
    stat.test, label = "p.adj", tip.length = 0.01, 
    coord.flip = TRUE
  ) +
  scale_y_continuous(expand = expansion(mult = c(0.05, 0.1))) +
  coord_flip()

library(ggpubr)
library(rstatix)
# Transform `dose` into factor variable
df <- ToothGrowth
df$dose <- as.factor(df$dose)
head(df, 3)
# Box plots
bxp <- ggboxplot(df, x = "dose", y = "len", fill = "dose", 
                 palette = c("#00AFBB", "#E7B800", "#FC4E07"))

# Bar plots showing mean +/- SD
bp <- ggbarplot(df, x = "dose", y = "len", add = "mean_sd", fill = "dose", 
                palette = c("#00AFBB", "#E7B800", "#FC4E07"))

# Horizontal bar plot with p-values
stat.test <- stat.test %>% add_xy_position(fun = "mean_sd", x = "dose")
bp + 
  stat_pvalue_manual(
    stat.test, label = "p.adj", tip.length = 0.01,
    coord.flip = TRUE
  ) +
  scale_y_continuous(expand = expansion(mult = c(0.05, 0.1))) +
  coord_flip()

library(ggpubr)
library(rstatix)
# Transform `dose` into factor variable
df <- ToothGrowth
df$dose <- as.factor(df$dose)
head(df, 3)
# Box plots
bxp <- ggboxplot(df, x = "dose", y = "len", fill = "dose", 
                 palette = c("#00AFBB", "#E7B800", "#FC4E07"))

# Bar plots showing mean +/- SD
bp <- ggbarplot(df, x = "dose", y = "len", add = "mean_sd", fill = "dose", 
                palette = c("#00AFBB", "#E7B800", "#FC4E07"))

# Show p-values at x = "group2"
stat.test <- stat.test %>% add_xy_position(x = "dose")
bxp + 
  stat_pvalue_manual(
    stat.test, label = "p = {p.adj}", tip.length = 0.01, 
    coord.flip = TRUE, x = "group2", hjust = 0.4
  ) +
  scale_y_continuous(expand = expansion(mult = c(0.05, 0.2))) +
  coord_flip()

library(ggpubr)
library(rstatix)
# Transform `dose` into factor variable
df <- ToothGrowth
df$dose <- as.factor(df$dose)
head(df, 3)
# Box plots
bxp <- ggboxplot(df, x = "dose", y = "len", fill = "dose", 
                 palette = c("#00AFBB", "#E7B800", "#FC4E07"))

# Bar plots showing mean +/- SD
bp <- ggbarplot(df, x = "dose", y = "len", add = "mean_sd", fill = "dose", 
                palette = c("#00AFBB", "#E7B800", "#FC4E07"))


# Make the p-values horizontal using the option angle
stat.test <- stat.test %>% add_xy_position(x = "dose")
bxp + 
  stat_pvalue_manual(
    stat.test, label = "p = {p.adj}", tip.length = 0.01, 
    coord.flip = TRUE, x = "group2", angle = 90
  ) +
  scale_y_continuous(expand = expansion(mult = c(0.05, 0.1))) +
  scale_x_discrete(expand = expansion(mult = c(0.05, 0.3))) +
  coord_flip()