Add Split Tables Around a Forest Plot — add_split

Compose split table blocks around a forest plot so that text columns appear on both sides of the plotting panel. This helper should generally be added last because it returns a patchwork composition. Split tables do not draw table grid lines, left-side columns are left-justified, right-side columns are right-justified, and the default widths are estimated from the displayed text to reduce clipping.

Usage

add_split_table(
  plot = NULL,
  show_terms = TRUE,
  show_n = NULL,
  show_estimate = TRUE,
  show_p = FALSE,
  left_columns = NULL,
  right_columns = NULL,
  term_header = "Term",
  n_header = "N",
  estimate_label = "Estimate",
  p_header = "P-value",
  digits = NULL,
  text_size = NULL,
  striped_rows = NULL,
  stripe_fill = NULL,
  stripe_colour = NULL,
  left_width = NULL,
  plot_width = NULL,
  right_width = NULL
)

Arguments

plot: A plot created by ggforestplot(). Leave as NULL to use + add_split_table(...) syntax.
show_terms: Whether to include the term column in the default left-side selection when left_columns is not supplied.
show_n: Whether to include the N column in the default left-side selection when left_columns is not supplied. Defaults to TRUE when the underlying plot data include an n column.
show_estimate: Whether to include the formatted estimate and confidence interval column in the default right-side selection when right_columns is not supplied.
show_p: Whether to include the p-value column in the default right-side selection when right_columns is not supplied.
left_columns: Optional explicit columns to place on the left side of the forest plot. Accepts names such as "term" and "n", or positions 1:4 corresponding to term, n, estimate, and p.
right_columns: Optional explicit columns to place on the right side of the forest plot. Accepts names such as "estimate" and "p", or positions 1:4 corresponding to term, n, estimate, and p.
term_header: Header text for the term column.
n_header: Header text for the N column.
estimate_label: Header label for the estimate column.
p_header: Header text for the p-value column.
digits: Number of digits used when formatting estimates and p-values. Defaults to 2.
text_size: Text size for table contents. Defaults to 3.2.
striped_rows: Whether to draw alternating row stripes behind the split table layout. Defaults to the stripe setting used in ggforestplot().
stripe_fill: Fill colour used for striped rows. Defaults to the stripe fill used in ggforestplot().
stripe_colour: Outline colour for striped rows. Defaults to the stripe outline used in ggforestplot().
left_width: Optional width allocated to the left table block. By default this is estimated from the displayed left-side text so long labels get more room.
plot_width: Optional width allocated to the forest plot panel. By default this is derived from the left and right table widths.
right_width: Optional width allocated to the right table block. By default this is estimated from the displayed right-side text.

Value

A patchwork-composed plot containing a left table, the forest plot, and a right table, or a ggplot add-on object when plot = NULL.

Examples

coefs <- data.frame(
  term = c("Age", "BMI", "Treatment"),
  estimate = c(0.3, -0.2, 0.4),
  conf.low = c(0.1, -0.4, 0.2),
  conf.high = c(0.5, 0.0, 0.6),
  sample_size = c(120, 115, 98),
  p_value = c(0.012, 0.031, 0.004)
)

p <- ggforestplot(coefs, n = "sample_size", p.value = "p_value")
add_split_table(
  p,
  left_columns = c("term", "n"),
  right_columns = c("estimate", "p"),
  estimate_label = "HR"
)


ggforestplot(coefs, n = "sample_size", p.value = "p_value") +
  add_split_table(left_columns = c(1, 2), right_columns = c(3, 4), estimate_label = "HR")