Initial release. ggmemo adds two functions for annotating ggplot2 business charts without manual coordinate math.
annotate_callout() points at a specific data row
with an arrow and label. Supports four label positions, automatic or
explicit nudge, and ... pass-through for styling.
annotate_change() draws a color-coded arrow between
two data rows and labels the midpoint with the computed delta. Supports
four format options: "percent" (default),
"absolute", "points" (percentage points), and
"both". Custom colors via the colors argument;
label styling via ....
Both functions use tidy evaluation for row selection
(where, from, to) — the same
syntax as dplyr::filter().
The automatic nudge heuristic in annotate_callout()
guesses which columns are x and y from the data frame structure. On wide
data frames with many numeric columns, use the nudge
argument or pass a two-column subset of the data.
annotate_change() similarly guesses the x-axis
column. The heuristic prefers Date > numeric/factor > character,
but can pick wrong on wide data.
Both limitations are tracked for v0.2 (#1, #2).