# How to Adjust Line Thickness in Boxplots in ggplot2

You can use the following methods to adjust the thickness of the lines in a boxplot in ggplot2:

Method 1: Adjust Thickness of All Lines

```ggplot(df, aes(x=x, y=y)) +
geom_boxplot(lwd=2)
```

Method 2: Adjust Thickness of Median Line Only

```ggplot(df, aes(x=x, y=y)) +
geom_boxplot(fatten=4)```

The following examples show how to use each method in practice with the following data frame in R:

```#make this example reproducible
set.seed(1)

#create data frame
df <- data.frame(team=rep(c('A', 'B', 'C'), each=100),
points=c(rnorm(100, mean=10),
rnorm(100, mean=15),
rnorm(100, mean=20)))

team    points
1    A  9.373546
2    A 10.183643
3    A  9.164371
4    A 11.595281
5    A 10.329508
6    A  9.179532
```

Note: We used the set.seed() function to ensure that this example is reproducible.

## Example 1: Create Boxplot with Default Line Thickness

The following code shows how to create a boxplot to visualize the distribution of points grouped by team, using the default line thickness:

```library(ggplot2)

#create box plots to visualize distribution of points by team
ggplot(df, aes(x=team, y=points)) +
geom_boxplot()
``` ## Example 2: Create Boxplot with Increased Line Thickness

The following code shows how to create a boxplot to visualize the distribution of points grouped by team, using the lwd argument to increase the thickness of all lines in the boxplot:

```library(ggplot2)

#create box plots with increased line thickness
ggplot(df, aes(x=team, y=points)) +
geom_boxplot(lwd=2)``` Notice that the thickness of each of the lines in each boxplot has increased.

## Example 3: Create Boxplot with Increased Line Thickness of Median Line Only

The following code shows how to create a boxplot to visualize the distribution of points grouped by team, using the fatten argument to increase the thickness of the median line in each boxplot:

```library(ggplot2)

#create box plots with increased median line thickness
ggplot(df, aes(x=team, y=points)) +
geom_boxplot(fatten=4)``` Notice that only the thickness of the median line in each boxplot has increased.

Feel free to play around with both the lwd and fatten arguments in geom_boxplot() to create boxplots that have the exact line thickness you’d like.