Need help making multiple superscripts in gplot legend title

[kaito]

Need help making the superscripts for grams of carbon per meter squared per year (g C m^[1] yr^[2]).

pp_plot <- gplot(ras.stack[[5]])+
geom_raster(aes(x=x,y=y,fill=value)) +
scale_fill_viridis_c(na.value="grey95", name = "Primary production (g C m^[3] yr^[4])") +
theme_bw()+
labs(tag = "D") +
theme(legend.position = "bottom",
legend.key.size = unit(0.5, 'cm'),
legend.key.height = unit(0.5, 'cm'),
legend.key.width = unit(0.5, 'cm'))

---

1. −2 ↩︎

2. −1 ↩︎

3. −2 ↩︎

4. −1 ↩︎

[DavoWW]

Hi @kaito,
Welcome to the RStudio Community Forum.
Try this:

x_name <- c(expression(paste( "Primary production (g C m"^{"-2"},".yr"^{"−1"},")"))) 
plot(1,1, xlab=x_name)

^{Created on 2022-09-11 with reprex v2.0.2}

Getting this to work correctly can be quite tricky. See help(plotmath).
I discovered that I needed to quote the "-2" and "-1" to get this example to work as required.

[kaito]

Great that worked. Thank you so much!