02-data-visualisation.Rmd line 187 wording

[thoughtfulbloke]

Line 187 of 02-data-visualisation.Rmd currently has the wording

Island is a categorical variable, in R we call it a factor. The colours get tagged with their factor in the legend, so we can interpret which colour belongs to which factor. year is a numerical variable, so the colour becomes a gradient colour bar, rather than showing fewer distinctly different colours. ggplot treats numerical and factors different in this way precisely.

Finishing with the adverb reads a little oddly, but also because island, in the data, is a character variable with recent version of R from being read in with read.csv with the default settings rather than explicitly a factor, while numeric variables can also be factors, possibly the whole paragraph could be better explained in terms of discrete and continious, rather than specific data types. Something like this (as a suggestion):

Island is categorical character variable with a discrete range of possible values. This, like the data type of factor, is represented with colours by assigning a specific colour to each member of the discrete set. year is a continuous numeric variable in which any number of potential values can exist between known values. To represent this, R uses a colour bar with a continuous gradient.

[drmowinckels]

I like this very much. Would you consider doing a suggestion directly int he document. If you dont have experience with that, I am happy to guide you.