Generating predicted values

Start by generating model predictions, both at the population level and within-site.

As a reminder, your model was applied using:

random_int_slope <- lme(abundance ~ humidity,
                        random = ~1 + humidity | site,
                        data = orchids)

Note that the orchids data set, 'nlme' and ggplot2 libraries, and random_int_slope_model have been preloaded.

Use data.frame() to create a data frame containing 10 values of humidity between 40 and 75 that will be used to generate population level predictions.