Linear modelling

Machine Learning and Modeling
1

Hiya,

I'm using the Palmerpenguin dataset in R studio to fit a linear model. However, there are three species of penguin and my data is only showing the output for two of these. I'll try and explain better by showing my console below.

> speciesmass<- lm(penguins$body_mass_g ~ penguins$species)
> speciesmass

Call:
lm(formula = penguins$body_mass_g ~ penguins$species)

Coefficients:
              (Intercept)  penguins$speciesChinstrap     penguins$speciesGentoo  
                  3700.66                      32.43                                 1375.35

The output provides information on two species of penguin but not the Adelaide penguin. Any help would be greatly appreciated. Thanks!

2

The Adelaide penguin is being used as the baseline case. That is, the coefficients of the other two species are the change seen between them and the baseline.

3

If you want more information, there are discussions about this in Tidy Models with R as well as Feature Engineering and Selection