Trying to make a boxplot with ggplot2 in R where the x-axis in continous but their are paired boxplots for each value of on the x-axis based on another factor

ggplot boxplot continuous x with groups

# ggplot boxplot groups of continuous x

### Daniel J. Hocking

I am trying to make a boxplot with ggplot2 in R where the x-axis in continous but their are paired boxplots for each value of on the x-axis based on another factor with two possible values. I want to make a plot where boxplots are arranged by number of survey years on the x-axis but paired by spatialTF (2 boxplots for every value of n_years) but n_years are not evenly spaced.

This plot gets the paired boxplots correct by year but the years on the x-axis are evenly spaced and don't reflect the actual (continuous) time between years.

```
ggplot(df_converged, aes(factor(n_years), mean_N_est)) + 
geom_boxplot(aes(fill = factor(spatialTF))) +
scale_fill_manual(values=c("#F8766D", "#619CFF"))
```

This next plot gets the spacing between years correct but only puts 1 boxplot for each year rather than having them paired (one for each of the 2 possible values of spatialTF).

```
ggplot(df_converged, aes(n_years, mean_N_est, group = n_years)) + 
geom_boxplot(aes(fill = factor(spatialTF))) + 
scale_fill_manual(values=c("#F8766D", "#619CFF"))
```

Is there anyway to combine these to make my desired plot?

df_converged <- data.frame(n_years = rep(c(1:3, 8), each = 30), mean_N_est = rnorm(120), spatialTF = rep(1:2, times = 60))

df_converged$n_years <- factor(df_converged$n_years, levels = c(1:8))

ggplot(df_converged, aes(factor(n_years), mean_N_est)) +
geom_boxplot(aes(fill = factor(spatialTF))) +
scale_fill_manual(values=c("#F8766D", "#619CFF")) +
scale_x_discrete(limits = levels(df_converged$n_years), drop = FALSE)