# ============================================================================== # r_themes_for_3_sizes.R # UMD Biostatistics — Bill Perry # # Three publication-ready ggplot2 themes scaled to common output sizes. # Source this file once at the top of any analysis script: # source("themes/r_themes_for_3_sizes.R") # # Functions loaded: # theme_small() — 3 × 3 in PDF / small inset figures # theme_regular() — 6–7 × 5–6 in PDF / standard journal figure # theme_large() — 12–16 × 10–14 in PDF / poster panels # # Improvements over previous version: # - All three themes now built on theme_classic() to inherit a clean base # (white background, axis lines, no gridlines) — avoids having to blank # every grid element manually. # - panel.border replaces duplicate axis.line.x / axis.line.y overrides. # A complete border (all four sides) looks cleaner at all output sizes. # - axis.ticks.length scales with base_size so tick marks stay proportional # when the theme is used at non-default sizes. # - legend.margin and legend.spacing added — prevents legend text from # running into the legend key at large base_size values. # - plot.margin set explicitly so titles and captions are never clipped when # saved with ggsave(). # - strip.clip = "off" added so facet strip labels are never silently # clipped at the panel edge. # - Redundant element_line() overrides for individual axis sides removed — # panel.border handles all four sides cleanly. # - axis.title size uses rel(1) (= base_size) for small/regular and rel(1.1) # for large, keeping axis labels slightly larger than tick text. # ============================================================================== # ── HELPER: shared theme body ────────────────────────────────────────────────── # Internal function — not exported. Keeps the three public themes DRY. # All three themes call .theme_bp_base() and override the size-specific values. .theme_bp_base <- function(base_size, base_family, line_width, tick_length_pt, title_margin, axis_margin, strip_v_margin, legend_key_size) { theme_classic(base_size = base_size, base_family = base_family) %+replace% theme( # ── PLOT CANVAS ────────────────────────────────────────────────────────── plot.background = element_rect(fill = "white", colour = NA), plot.title = element_text(face = "bold", size = rel(1.15), hjust = 0, margin = margin(b = title_margin * 0.5)), plot.subtitle = element_text(face = "plain", size = rel(0.95), hjust = 0, colour = "grey30", margin = margin(b = title_margin * 0.5)), plot.caption = element_text(face = "italic", size = rel(0.80), hjust = 1, colour = "grey40", margin = margin(t = title_margin * 0.5)), plot.margin = margin(title_margin, title_margin, title_margin, title_margin), # ── PANEL ──────────────────────────────────────────────────────────────── panel.background = element_rect(fill = "white", colour = NA), panel.border = element_rect(fill = NA, colour = "black", linewidth = line_width), panel.grid.major = element_blank(), panel.grid.minor = element_blank(), # ── AXIS LINES & TICKS ─────────────────────────────────────────────────── # panel.border draws all four sides; axis.line is suppressed to avoid # double lines on the bottom and left. axis.line = element_blank(), axis.ticks = element_line(colour = "black", linewidth = line_width), axis.ticks.length = unit(tick_length_pt, "pt"), # ── AXIS TITLES ────────────────────────────────────────────────────────── axis.title = element_text(face = "bold", size = rel(1.0)), axis.title.x = element_text(margin = margin(t = axis_margin)), axis.title.y = element_text(margin = margin(r = axis_margin), angle = 90), # ── AXIS TEXT (tick labels) ─────────────────────────────────────────────── axis.text = element_text(colour = "grey20", size = rel(0.90)), axis.text.x = element_text(margin = margin(t = axis_margin * 0.4), angle = 0, vjust = 1, hjust = 0.5), axis.text.y = element_text(margin = margin(r = axis_margin * 0.4)), # ── LEGEND ─────────────────────────────────────────────────────────────── legend.background = element_rect(fill = "white", colour = NA), legend.key = element_rect(fill = NA, colour = NA), legend.key.size = unit(legend_key_size, "pt"), legend.title = element_text(face = "bold", size = rel(0.95)), legend.text = element_text(face = "plain", size = rel(0.85)), legend.margin = margin(2, 4, 2, 4), legend.spacing.x = unit(4, "pt"), legend.spacing.y = unit(2, "pt"), legend.position = "right", # ── FACET STRIPS ───────────────────────────────────────────────────────── strip.background = element_rect(fill = "grey92", colour = "black", linewidth = line_width), strip.text = element_text(face = "bold", size = rel(0.95)), strip.text.x = element_text(margin = margin(t = strip_v_margin, b = strip_v_margin)), strip.text.y = element_text(angle = -90, margin = margin(l = strip_v_margin, r = strip_v_margin)), strip.clip = "off" ) } # ============================================================================== # 1. THEME SMALL # Target output: 3 × 3 in | base_size = 9 pt # Use for: small inset panels, supplementary multi-panel grids, patchwork tiles # ============================================================================== theme_small <- function(base_size = 9, base_family = "sans") { .theme_bp_base( base_size = base_size, base_family = base_family, line_width = 0.35, # pt — fine lines for small output tick_length_pt = 3, # pt — short ticks title_margin = 4, # pt — tight plot margin axis_margin = 4, # pt — space between axis line and title/text strip_v_margin = 2, # pt — top/bottom padding inside facet strips legend_key_size = 8 # pt — small legend keys ) } # ============================================================================== # 2. THEME REGULAR # Target output: 6–7 × 5–6 in | base_size = 14 pt # Use for: standard journal figures, Quarto HTML output, presentation slides # ============================================================================== theme_regular <- function(base_size = 14, base_family = "sans") { .theme_bp_base( base_size = base_size, base_family = base_family, line_width = 0.55, tick_length_pt = 5, title_margin = 8, axis_margin = 8, strip_v_margin = 4, legend_key_size = 12 ) } # ============================================================================== # 3. THEME LARGE # Target output: 12–16 × 10–14 in | base_size = 28 pt # Use for: poster panels, conference figures, figures cropped into slides # ============================================================================== theme_large <- function(base_size = 28, base_family = "sans") { .theme_bp_base( base_size = base_size, base_family = base_family, line_width = 1.2, tick_length_pt = 10, title_margin = 16, axis_margin = 16, strip_v_margin = 8, legend_key_size = 22 ) } # ============================================================================== # USAGE EXAMPLES (run these in your script after source()-ing this file) # ============================================================================== # source("themes/r_themes_for_3_sizes.R") # # library(tidyverse) # library(palmerpenguins) # # p <- ggplot(penguins, aes(x = flipper_length_mm, y = body_mass_g, # color = species)) + # geom_point(alpha = 0.7) + # labs(title = "Body mass vs flipper length", # x = "Flipper length (mm)", y = "Body mass (g)", color = "Species") # # p + theme_small() # p + theme_regular() # p + theme_large() # # # Save each size: # ggsave("figures/plot_small.pdf", p + theme_small(), width=3, height=3, units="in") # ggsave("figures/plot_regular.pdf", p + theme_regular(), width=7, height=5, units="in") # ggsave("figures/plot_large.pdf", p + theme_large(), width=16, height=12, units="in")