position_bluenoise() and
position_bluenoisedodge() scatter over-plotted points
across an elliptical field while keeping them evenly spaced, in the
pattern the eye’s own photoreceptors are laid out in. Jittering samples
uniformly, which clumps: in a draw of 250 points the closest pair
typically sits about a fifteenth of the median spacing apart, and a
reader cannot tell those knots from real structure. Blue noise looks
equally unstructured without the knots, so unlike
position_sunflower() there is no visible spiral for a
reader to misread as a finding.
position_honeycomb() and
position_honeycombdodge() arrange over-plotted points on a
hexagonal lattice, the densest packing of equal circles in the plane. At
a given density the footprint matches
position_sunflower(), so the two are interchangeable and
the choice between them is about looks: crystalline and countable, or
organic and without a preferred direction.
All five dodged position adjustments gain an
orientation argument, matching
ggplot2::position_dodge(). They were hard-wired to separate
groups side-to-side; orientation = "y" now separates them
up and down instead. ggplot2 has no height argument for
dodging, since width is the extent along whichever axis
orientation picks. The height spelling belongs
to the superseded ‘ggstance’ package, whose
position_dodgev() predates
orientation.
impute_extreme_values() prepares the extreme value
bounds figure for an experiment with attrition, imputing the logical
best case and worst case for the missing outcomes and flagging which
points are observed and which are imputed. It estimates nothing;
estimator_ev() in the ‘attrition’ package (https://github.com/acoppock/attrition) provides the
bounds themselves. The outcome’s logical range is required at the call
site rather than guessed from the data, because guessing narrows the
bounds.
Seven new datasets carry the worked examples from the chapter the
package implements: two_arm_trial,
blocked_experiment, clustered_experiment,
covariate_adjustment, continuous_interaction,
noncompliance_experiment, and
attrition_experiment. All are simulated, and all report
both potential outcomes and the probability of the assigned
condition.
A second vignette, vignette("design-based-graphs"),
reproduces the chapter’s seven worked examples, one per experimental
design, contrasting a strong graph with a weak one in each
case.
Every position adjustment now has behavioural tests covering the geometry it promises, which is how these were found.
Four of the fixes change where points are drawn, so a figure built
with 1.0.0 will not reproduce pixel for pixel under 1.1.0: the
lone-point sunflower, the row order, the seed = NULL
ellipse, and the centring of the circle pack. Estimates and models are
unaffected.
The position adjustments no longer require ggplot2
to be attached. They used resolution(),
transform_position(), and PositionDodge
unqualified, so position_jitter_ellipse(),
position_jitterdodge_ellipse(),
position_sunflowerdodge(), and
position_circlepackdodge() failed for anyone calling
ggplot2::ggplot() without library(ggplot2),
and for any package importing ‘vayr’.
position_jitterdodge_ellipse() gave every group the
same jitter, so one group’s cloud was an exact translation of the next.
Each group is now jittered independently.
position_jitter_ellipse() and
position_jitterdodge_ellipse() drew the radius and angle
separately for the x and y shifts, which placed points outside the
requested ellipse whenever seed = NULL. The two shifts now
share one draw.
sunflower() and position_sunflower()
moved a point that had nothing over-plotting it. A lone point now stays
at its own coordinates.
position_circlepack() and
position_circlepackdodge() displaced the cluster from the
point it stands for. circleProgressiveLayout() does not
centre what it returns: a lone circle lands at
(-radius, 0), and packs of three or five sit off-centre by
roughly a third of their radius. The layout is now centred, so a lone
point stays exactly where it is here too.
All four splitting position adjustments returned rows in a different order than they received them. Row order is now preserved.
position_circlepackdodge() ran the circle packing
twice per group and discarded the first result.
This first release of ‘vayr’ includes three position adjustments and their dodged counterparts: position_jitter_ellipse() and position_jitterdodge_ellipse(); position_sunflower() and position_sunflower_dodge(); position_circlepack() and position_circlepack_dodge().