This theme is designed to be a foundation from which to build new
themes, and not meant to be used directly. theme_foundation
is a complete theme with only minimal number of elements defined.
It is easier to create new themes by extending this one rather
than theme_gray or theme_bw, because those themes
those themes define elements deep in the hierarchy.
theme_foundation(base_size = 12, base_family = "")base font size
base font family
This theme takes theme_gray and sets all colour and fill
values to NULL, except for the top-level elements
(line, rect, and title), which have colour = "black",
and fill = "white". This leaves the spacing
and-non colour defaults of the default ggplot2 themes in place.
Other themes: theme_base,
theme_igray, theme_par,
theme_solid