```r

# Distribution to plot:
# Number of groups:
k <- 2
#
# # Individuals in each group, assuming equal group sizes
n <- nValue
# #
df1 <- k - 1
df2 <- n - k

# df1 <- 1
# df2 <- 58

# df1 <- 1
# df2 <- 8

# Make a F distributuion
x.Ftest <- seq(0, 30, length=3000)
hx.Ftest <- df(x.Ftest, df1, df2)
df.Ftest <- data.frame(x.Ftest, hx.Ftest)

# qf(p=0.05, df1, df2, lower.tail=FALSE)

ggplot(df.Ftest, aes(x = x.Ftest, y = hx.Ftest)) +
  geom_line(col = MidRed) +

  geom_vline(xintercept = qf(p=0.05, df1, df2, lower.tail=FALSE), col = DarkRed, linetype = 2) +
  # annotate("text", x = qf(p=0.05, df1, df2, lower.tail=FALSE) + (distAnnot*6), y = 0.05, label = "Critical value for\n$\\alpha$ = 0.95", hjust=0, size = 3.5) +

  geom_ribbon(data=subset(df.Ftest, df.Ftest$x.Ftest > mars.anova.eye['F value'][1,1]), aes(x=x.Ftest,ymax=hx.Ftest),ymin=0,fill=MidRed) +

  geom_vline(xintercept = mars.anova.eye['F value'][1,1], col = "Black") +
  # annotate("text", x = mars.anova.eye['F value'][1,1] - (distAnnot*6), y = 0.05, label = "Observed\nF statistic", hjust=1, size = 3.5) +

  scale_x_continuous("F", expand = c(0,0), breaks = seq(0,30,2)) +
  scale_y_continuous("f(x)", expand = c(0,0), breaks = seq(0,0.1,0.025)) +
  coord_cartesian(xlim = c(0,30), ylim = c(0,0.1)) +

  ggtitle(paste("F-Distribution (df1 =",df1,", df = ",df2,")", sep ="")) +
  theme(axis.line = element_blank(),
        legend.position = c(0.8, 0.8),
        panel.background = element_blank(),
        panel.grid.major = element_blank(),
        panel.grid.minor = element_blank(),
        axis.ticks.x = element_line(colour = "black"),
        axis.ticks.y = element_line(colour = "black"),
        axis.text.x = element_text(colour = "black"),
        axis.text.y = element_text(colour = "black")
  )
```

<img src="figures/graphics-FMartianlinreg1-1.png" width="359.05536" style="display: block; margin: auto;" />