An example to use glht function in the multcomp package

glht.Rmd

---
title: "R Notebook"
output: html_notebook
---

## An example to use glht function in the multcomp package

```{r setup}
library(multcomp)
library(palmerpenguins)
```

### View data

plot bill_length_mm vs. species

```{r}
png("plot01.png", width = 480, height = 480, pointsize = 14)
boxplot(bill_length_mm ~ species, data = penguins)
dev.off()
```

### Multiple comparison

```{r}
bill_l.glht <- lm(bill_length_mm ~ species, data = penguins) |>
  glht(linfct = mcp("species" = "Tukey"))
summary(bill_l.glht)
```

### Plot the results

```{r}
png("plot02.png", width = 480, height = 520, pointsize = 14)
par(mai = c(1, 1, 1.25, 1))
cld(bill_l.glht ) |>
  plot()
dev.off()
```