erplots

• Added er_predict_survival(), a fourth model-interface generic (see ?er_model_interface) powering er_tte_add_model()'s S(t) overlay. The new companion package ertte (Suggests/Remotes-only, GitHub- only like erglm/emaxnls) implements it, alongside the existing er_predict()/er_simulate()/er_summary() methods.
• cut_quantile()/cut_exposure_quantile() gain a ties argument controlling how a value that sits exactly on an interior quantile break is assigned ("upward", the default and prior behaviour; "downward"; or "split-even", which randomly balances tied values between the two candidate bins), plus an opt-in seed argument for reproducing "split-even"'s random tie-break. The resolved rule is recorded as a "ties" attribute on the returned factor.
• cut_quantile()/cut_exposure_quantile() gain a quantile_type argument, passed straight through to [stats::quantile()]'s own type argument for computing the quantile break points. Defaults to 7 (unchanged prior behaviour) and is recorded as a "quantile_type" attribute on the returned factor.
• cut_quantile()/cut_exposure_quantile() gain a labeller argument for customising quantile-bin labels: a function called as labeller(n, breaks), or a character vector used directly. Defaults to NULL (unchanged "Q1"/"Q2"/... labelling); cut_exposure_quantile()'s separate "Placebo" level is untouched by labeller.
• er_plot_add_quantiles()/er_plot_add_groups() gain ties/ quantile_type/labeller arguments, forwarded to cut_exposure_quantile()/cut_quantile(). These are local to each call -- they aren't required to agree across different er_plot_add_groups() calls, or with er_plot_add_quantiles() -- except in one case: er_plot_build() now warns if er_plot_add_groups() bins *the exposure variable itself* differently than er_plot_add_quantiles() does, since the two panels would then show inconsistent quantile bins for the same variable.
• er_vpc() gains ties/quantile_type/labeller for plot_by, plus a seed argument for reproducing a "split-even" tie-break. Unlike the er_plot_add_quantiles()/er_plot_add_groups() arguments above, these live on er_vpc() itself rather than on er_vpc_add_observed()/er_vpc_add_simulated(), since the observed and simulated layers must always bin plot_by identically -- er_vpc_add_simulated()'s own seed argument now also seeds its independent "split-even" tie-break.
• er_vpc() gains an optional stratify_by for faceting a VPC into one panel per discrete stratum, mirroring er_plot()'s own stratification (facet-only here, since a VPC has no colour/fill precedence rule to reconcile). Errors if stratify_by resolves to the same variable as plot_by.
• er_style_tag() gains a label argument for registering a builder under a short string (e.g. label = "logrank"), so the corresponding _add_*() function's style argument can be given that string instead of the function itself (e.g. er_plot_add_model(mod, style = "spaghetti") in place of style = er_style_model_spaghetti). Every built-in builder across all three grammars is tagged with one; see er_style_labels() to list what's registered (optionally filtered to one layer), and ?er_style_tag for the full naming/lookup contract. label requires layer to also be set in the same call, since the registry is keyed by (layer, label), not label alone. A new overwrite argument (default FALSE) controls what happens when re-registering a (layer, label) pair already assigned to a *different* function: errors by default; overwrite = TRUE replaces it unconditionally. Re-registering the identical function is always a silent no-op regardless of overwrite.

Improvements

• er_style_vpc_observed_mean_errorbar()/er_style_vpc_simulated_mean_errorbar() gain an opt-in show_label/label_size pair that draws each bin's formatted rate/mean above its error bar, making er_vpc_theme()'s format_percent/format_number arguments actually visible (#22).
• er_style_tte_risktable_text() gains an opt-in show_percent argument that appends each break's number at risk as a percentage of its stratum's baseline size, using er_tte_theme()'s format_percent (#22).
• emaxnls is back in Suggests/Remotes (pinned to emaxnls (>= 0.1.1.9000), the GitHub development version), and its gated examples in ?erplots_data are reinstated, now that emaxnls registers the er_predict()/er_simulate()/er_summary() methods. It had been stripped for the 0.1.0 CRAN submission, ahead of that registration landing.

Breaking changes

• er_style_tag()'s zorder argument is renamed to draw_order (same "foreground"/"background" values); a builder tagged with the old name needs updating (e.g. er_style_tag(fn, draw_order = "background") in place of zorder = "background")). layout is split into two independent arguments: layout keeps its existing "overlay"/ "panel" meaning for a data-layer builder, while a VPC observed/ simulated builder's "categorical"/"continuous" distinction moves to a new vpc_layout argument -- the two had shared one argument and attribute despite meaning unrelated things. See ?er_style_tag.
• er_style_tag()'s layer values are renamed to be grammar-prefixed: "model"/"summary"/"quantile"/"data"/"group" (er_plot()) become "plot_model"/"plot_summary"/"plot_quantile"/"plot_data"/ "plot_group"; "observed"/"simulated" (er_vpc()) become "vpc_observed"/"vpc_simulated"; "curve"/"censor"/"risktable" (er_tte()) become "tte_curve"/"tte_censor"/"tte_risktable". "tte_model"/"tte_summary" are unchanged (already grammar-prefixed). A custom builder tagged with one of the old values needs updating; see ?er_style_tag.
• stratify_by must now name a discrete/categorical variable in er_vpc(); a numeric column errors instead of being automatically split into quantile bins, and the n_strata argument is removed. Bin a continuous covariate yourself first with cut_quantile()/ cut_exposure_quantile(), which also gives full control over bin count, tie-breaking, and labels -- see ?er_vpc. (er_tte()'s own stratify_by has the same discrete-only requirement from the outset, being new in this release.)
• style/keep_strata's argument position is standardised across every er_plot_add_*()/er_vpc_add_*()/er_tte_add_*() layer function: style now always comes immediately after object and any required model/grouping argument, and keep_strata (where the layer has one) always comes immediately after style. conf_level (where the layer has one) always comes immediately after keep_strata, ahead of any layer-specific argument such as er_plot_add_quantiles()'s bins or er_tte_add_model()'s time_grid. Calls that name these arguments (the documented usage) are unaffected; positional calls that relied on the previous ordering will need updating.
• er_vpc()'s stratify_by argument moves to immediately after response, matching where er_plot()/er_tte() already place their own stratify_by; it previously sat after plot_by's binning arguments (plot_by/n_bins/ties/quantile_type/labeller). Calls that name stratify_by (the documented usage) are unaffected.
• The position of ... relative to a builder's own named arguments is standardised to always come last, across every built-in er_style_*() builder: er_style_model_ribbonline()/_line()/ _spaghetti(), er_style_data_overlay()/_boxjitter()/_hex(), er_style_tte_curve_km(), er_style_tte_censor_ticks(), er_style_tte_risktable_text(), er_style_tte_model_line(), and er_style_tte_summary_logrank() previously placed ... immediately after theme, ahead of their own style-specific arguments, unlike every other built-in builder. Calls that name these arguments (the documented usage) are unaffected.
• The "number of quantile bins" argument is renamed to n_bins everywhere, matching er_vpc()'s existing name: bins in er_plot_add_quantiles()/er_plot_add_groups(), and n in cut_quantile()/cut_exposure_quantile(), all become n_bins. A custom labeller function is now called as labeller(n_bins, breaks) rather than labeller(n, breaks) -- since this call is positional, only the documentation changed; existing custom labeller functions keep working regardless of their own parameter names. er_style_data_hex()'s and er_style_group_histogram()'s own bins arguments (2D-hexbin/histogram bin counts, forwarded straight to the matching ggplot2 geom) are unrelated and unchanged.
• er_style_data_overlay()'s and er_style_tte_censor_ticks()'s size argument (a plotted point's size) is renamed to point_size, matching the quantile/VPC builder family's existing name for the same concept (er_style_quantile_errorbar(), er_style_vpc_observed/ simulated_mean_errorbar(), etc.) and the package's own <thing>_size convention (label_size, text_size, jitter_size).
• er_style_group_linerange()'s size argument is renamed to scale_factor, since it isn't a point size at all -- it's a single multiplier applied to three different elements (a dot and two line ranges) at three different ratios, so neither size nor point_size described it accurately.
• er_style_group_linerange()'s alpha_dot/alpha_inner/alpha_outer are renamed to dot_alpha/inner_alpha/outer_alpha, matching the <thing>_alpha suffix order used by every other alpha argument in the package (ribbon_alpha, box_alpha, jitter_alpha).

Bug fixes

• er_plot_add_model()'s curve/ribbon no longer goes stale after er_plot_theme(xlim = ...) narrows or widens the exposure axis once the model layer has already been added -- the prediction grid is now recomputed at build time rather than cached from add-layer time (#14).
• The data, quantile, and group layers now drop (and warn about) any observations falling outside er_plot_theme(xlim = )/ylim = ), instead of silently handing them to a geom that renders past the visible panel with no visual cue (#16).
• er_vpc_add_observed()/er_vpc_add_simulated() summary markers falling outside er_vpc_theme(xlim = )/ylim = ) are now dropped, with a warning, instead of silently drawn past the panel (#17).
• er_plot() now errors clearly when stratify_by names a numeric column, instead of silently mapping it to a continuous colour scale (which broke every stratified builder's discrete-groups assumption -- ribbons, per-stratum lines, dodging -- with no warning). stratify_by has always been documented as requiring a discrete variable; this was simply never validated.
• er_plot_add_groups()'s bins argument now actually controls the number of quantile bins used for a continuous grouping variable. Previously documented but silently ignored -- every continuous grouping variable was always split into cut_quantile()/cut_exposure_quantile()'s own default of 4 bins, regardless of what bins was set to.
• er_style_quantile_errorbar_vlines()/er_style_quantile_pointrange_vlines()'s bin-boundary lines/labels are now dropped (and warn), like every other layer's out-of-range markers, when they fall outside er_plot_theme(xlim = ), instead of silently landing off the visible panel with no cue (#16).

Documentation

• ?er_style_tag is rewritten to describe the mechanism as a whole -- the shared self-declaration system every built-in builder across er_plot()/er_vpc()/er_tte() carries -- rather than describing each argument in isolation.
• Added ?er_style_vpc/?er_style_tte, documenting the shared builder interface for er_vpc()/er_tte() builders, alongside the existing ?er_style for er_plot(). Previously this material was scattered across each builder family's own help page.
• Fixed several cross-reference links in the pkgdown articles that previously rendered as literal bracketed text instead of a hyperlink.
• Every layer-adding function (er_plot_add_model(), er_plot_add_summary(), er_plot_add_quantiles(), er_plot_add_data(), er_plot_add_groups(), er_vpc_add_observed(), er_vpc_add_simulated(), and all five er_tte_add_*() functions) now documents a "Styles" table listing every registered style label for that layer, linking straight to each builder's own help page.