Changes in version 0.2.1 (2026-10-27)                  

CRAN preparation.

  - The difference label is now drawn with plotmath (Delta ~ "= +4.2%")
    and an ASCII minus sign, so it renders on every graphics device
    including the pdf() device used by R CMD check. Previously the
    literal U+0394 and U+2212 glyphs failed with "conversion failure ...
    mbcsToSbcs" on devices with single-byte encodings.
  - Multi-line @importFrom tags joined; NAMESPACE is now generated by
    roxygen2.
  - dplyr, grid and magrittr removed from Imports (never used).
  - .Rbuildignore added; developer notes no longer ship in the tarball.

                        Changes in version 0.2.0                        

Publication-quality rendering refinements.

New features

  - mirror_slope_plot() gains y_percent (default TRUE) to format y-axis
    ticks and header statistics with a percent sign; set FALSE for
    absolute-scale outcomes.
  - mirror_slope_plot() gains jitter_points (default FALSE) to spread
    overlapping individual endpoints horizontally for readability,
    reproducible via seed.

Improvements

  - Directional "to " arrows now flow inward toward the centre on both
    arms, reinforcing that the horizontal axis is positional and not a
    time axis.
  - The baseline reference line at zero is now a clearer dashed line,
    and a dashed vertical guide marks the central convergence axis.
  - Footnotes with embedded line breaks render as multiple left-aligned
    lines.
  - Header statistics show a percent sign when y_percent = TRUE.
  - The between-group annotation is now drawn as a bracket sized to the
    treatment gap (with end serifs), rather than a rule sized to the
    text block, so the bracket measures the difference it labels.

Journal-quality refinements

  - Individual trajectory lines are now drawn from each subject's
    baseline to the central endpoint only, grouped by arm and subject,
    so no line crosses the centre or connects across arms. This removes
    the main source of visual clutter.

  - Mean-endpoint diamonds now sit on a small white halo so they read
    cleanly where the converging lines crowd the central knot.

  - Directional arrows are lighter and smaller, receding as chart
    furniture.

  - The difference bracket is now a thin hairline matching the axis
    weight, with short inward serifs and more space before the
    annotation text, for a cleaner measurement mark.

  - Chart furniture (axis lines, ticks, gridlines, reference lines,
    arrows) now uses a single coherent light hairline family so nothing
    competes with the data.

  - Slope echoes are shorter and more muted, reading as a subtle
    continuation hint rather than data.

  - theme_mirror() now sets a clean sans typeface, a clear
    title/subtitle/caption hierarchy, and refined spacing; base_family
    defaults to a Helvetica/Arial/sans stack and can be overridden.

  - Default mean-line width and marker size were reduced slightly for
    print.

  - save_path documents vector output (.pdf/.svg) for journal
    submission.

                        Changes in version 0.1.0                        

Initial release.

Features

  - prep_mirror_data() prepares a long analysis dataset into a
    mirror_data object: validates structure, applies population flags
    with AND logic, retains baseline and endpoint visits, assigns role
    columns, counts analysed N per arm, and records provenance metadata
    (schema version, filters, timestamp, call).
  - add_summary() attaches group-level estimates and the baseline each
    mean line is drawn from, supporting both change-from-baseline
    (baseline 0) and absolute-scale outcomes.
  - add_precision() attaches per-arm standard errors or confidence
    intervals.
  - add_difference() attaches the between-arm difference with optional
    standard error, confidence interval, and p-value; warns on sign
    inconsistency.
  - mirror_slope_plot() renders the figure as a standard ggplot object.
    Optional elements (individual trajectories, difference band,
    relative-benefit annotation, per-arm precision, N in the strip
    header) are off by default and shown only on request. The annotation
    zone auto-expands the x-axis without altering the data panel.
  - mirror_palette() provides "default", "colorblind" (Okabe-Ito), and
    "capricor" palettes.
  - theme_mirror() supplies a publication theme with proportional text
    scaling.
  - S3 methods print(), summary(), and as.data.frame() for mirror_data.

Design notes

  - The mirror_data structure conforms to a versioned specification
    (schema 1.0) shared with a companion SAS macro, so both tools
    produce equivalent figures from equivalent inputs.
  - direction describes the direction of numeric movement (endpoint
    versus baseline). For outcomes where the favourable direction is
    unusual, supply outcome_label and benefit_label explicitly.

Known limitations

  - Right-to-left and non-Latin arm labels in strip headers are not yet
    supported.
  - Multi-endpoint layouts are produced by combining plots with an
    external layout package such as patchwork rather than within
    mirrorslope.