NEWS

---

ggdiagram 2026-10-12

• Updates for compatibility with S7 > 0.2.2.

New features

• Color gradients for arrows. ob_segment, ob_path, ob_bezier, and ob_arc gain a gradient property: a vector of 2 or more colors (or a list of such vectors, one per object) that makes a smooth gradient from the arrow's fins to its head. Gradients are drawn as grid gradient fills, so they require a graphics device that supports them (e.g., ragg, svg, or pdf). For paths, beziers, and arcs, the gradient follows a straight line from start to end, not the curve.
• New functions geom_arrow_segment_gradient() and geom_arrow_gradient() apply the gradients in ordinary ggplot2 code (ggarrow does not accept gradient colors). The approach was inspired by ggforce::geom_link() and its color gradients along segments, by Thomas Lin Pedersen, the author of ggforce.
• Gradients are interpolated in the OKLab color space by default, which avoids the dull midpoints of RGB interpolation (e.g., blue to yellow no longer passes through gray). The gradient is sampled at many closely spaced stops, following the approach in Matt DesLauriers' post Perceptually Smooth Multi-Color Linear Gradients. Use the space argument of the gradient geoms, or options(ggdiagram.gradient_space = ...), to choose "oklab", "oklch", "lab", "lch", or "rgb".
• connect now uses a color gradient by default when the from and to objects have different colors. An object's color is its color, or its fill if color is NA, or black if both are NA. If the two colors are identical, no gradient is used and the connector has that color. Specifying color, gradient, or a style with a color overrides this behavior.
• ob_style and ob_segment gain distort (a ggarrow distortion, e.g., "sinewave") and force_arrow (draw the arrowhead even if the segment is too short). ob_path gains force_arrow.

Changes in behavior

• ob_segment now defaults to black when no color is specified (or inherited) unless color = NA is set explicitly. Objects derived from segments, such as @midpoint(), therefore carry color = "black".
• The connect color now comes from the from object. Previously the to object's color overrode it.
• ob_path@segment no longer carries arrowheads or fins, and each segment keeps the style of its own path.

Documentation and internal changes

• New "Color gradients" sections in the segments, paths, Bézier, and arc/wedge articles.
• Reorganized source files: generics moved to R/generics.R and helper functions to R/helpers.R.
• Minimum R version is now 4.4.0.
• Added copyright holder (cph) role to the maintainer in DESCRIPTION.

ggdiagram 2026-06-12

• Fixed bug in round_probability so that NA does not throw an error when digits are specified.

ggdiagram 2026-05-04

• Better documentation of objects (used Posit Assistant to identify undocumented properties).
• More complete set of tests (used Posit Assistant to generate many of them)
• ob_angle objects (i.e., degree, radian, and turn) gain an @upright slot useful for preventing angled text from being upside down.
• ob_reuleaux and ob_ngon gain additional function slots similar to those of ob_circle.
• ob_segment, ob_bezier, and connect can set label positions with equal x and y coordinates via the @set_label_x and @set_label_y property functions.
• Added map2_ob function to map over 2 ggdiagram objects
• Added rescale function to resize ggdiagram objects
• Made ob_intercept a special case of ob_ngon.
• Breaking change: Renamed all instances of @segments to @segment for the sake of consistency.

ggdiagram 2025-10-15

• 6 ggforce 0.5.0 or higher is now required

ggdiagram 2025-09-15

• Fix print method for class_color
• Fix bug in polygon slot for ob_ellipse

ggdiagram 2025-09-14

• ggplot2 4.0.0 broke ggdiagram 0.1.0. New version requires ggplot2 4.0.0 or higher.
• Fix print method for class_color
• Fix @tangent_at for ellipses when given a point

ggdiagram 2025-08-18

• Initial CRAN submission.