Documentation not fully matching functionality

[jpiaskowski]

Hello,

I am trying to use the discrete color scales options for having different color scales based on the number of levels. It would appear that while this is possible using options:

options(
    ggplot2.discrete.colour = list(...)
)

This is apparently not possible in the superseded function of nesting color options under the theme:

theme(palette.colour.discrete = "...")

The documentation does not make this clear, so perhaps consider updating it so someone does not spend a few hours trying to troubleshoot functionality that does not exist.

Thank you.

[teunbrand]

Just to be clear, you're pointing out that the following option listed in the docs:

A list of character vectors of color codes. The minimum length vector that exceeds the number of data levels is chosen for the color scaling. This is useful if you want to change the color palette based on the number of levels.

Is not possible using the theme palette method (and this requires clarification)?

[jpiaskowski]

It's not possible to pass a list via the theme (but a list can be done with options()). I spent a few hours ascertaining this after fruitlessly trying to pass a list. The list functionality is for when a user wants a different palette based on the number of levels.

The documentation says this:

The preferred mechanism for setting the default palette is by using the theme. For example: theme(palette.colour.discrete = "Okabe-Ito"). One of the following:
A character vector of color codes. The codes are used for a 'manual' color scale as long as the number of codes exceeds the number of data levels (if there are more levels than codes, scale_colour_hue()/scale_fill_hue() are used to construct the default scale). If this is a named vector, then the color values will be matched to levels based on the names of the vectors. Data values that don't match will be set as na.value.
A list of character vectors of color codes. The minimum length vector that exceeds the number of data levels is chosen for the color scaling. This is useful if you want to change the color palette based on the number of levels.
A function that returns a discrete colour/fill scale (e.g., scale_fill_hue(), scale_fill_brewer(), etc).

All I am suggesting is that you make clear that for the superseded function, the list option is no longer possible. I had to look at the ggplot2 source code to determine this.

[teunbrand]

Thanks for the clarification. Right, so the confusion arose because it seemed like the three listed inputs would likewise apply to the theme palettes.
To be clear, the type argument is superseded, not the theme palettes.

I think the right thing to do here is just mark the type argument as superseded and point to the theme palettes, in other words remove the three inputs options from the documentation (as they are causing confusion).