Create an Alluvial (Sankey) Plot

Shows co-occurrence and flow between categories across multiple columns. Each study traces a path through the strata. Requires the ggalluvial package.

Usage

reviewAlluvial(
  data,
  cols,
  sep = "\r\n",
  study_id = StudyID,
  colors = PALETTE,
  base_size = 12,
  na.rm = TRUE,
  na_label = "Not reported",
  labels = c("none", "prop", "count", "both"),
  flow_labels = FALSE,
  flow_alpha = 0.25,
  stratum_width = 0.5,
  axis_labels = NULL
)

Arguments

data

A data frame.

cols

Character vector of column names to use as axes (left to right).

sep

Character. Separator for multi-value cells. Defaults to "\r\n". When a column contains multi-value cells, each combination generates a separate alluvium.

study_id

Column containing study identifiers (quoted or unquoted). Defaults to StudyID.

colors

Character vector. Fill colors for strata, cycled or matched by name. Defaults to PALETTE.

base_size

Numeric. Base font size in points. Defaults to 12.

na.rm

Logical. Drop rows with missing values? Defaults to TRUE.

na_label

Character. Label for missing values when na.rm = FALSE. Defaults to "Not reported".

labels

Character. What to show on each stratum. One of "none" (default), "prop" (proportion within axis), "count", or "both" (count and proportion).

flow_labels

Logical. If TRUE, show counts on the flows between strata. Defaults to FALSE.

flow_alpha

Numeric. Transparency of flows (0–1). Defaults to 0.25.

stratum_width

Numeric. Width of stratum bars. Defaults to 0.5.

axis_labels

Character vector of custom axis labels (same length as cols), or NULL to use the column names. Defaults to NULL.

Value

A ggplot2::ggplot object.

Examples

if (FALSE) { # \dontrun{
df <- data.frame(
  StudyID  = paste0("S", 1:6),
  Design   = c("RCT", "Cohort", "RCT", "RCT", "Cohort", "RCT"),
  Quality  = c("High", "Low", "High", "Low", "Low", "High"),
  Outcome  = c("Positive", "Negative", "Positive", "Negative",
               "Positive", "Positive"),
  stringsAsFactors = FALSE
)
reviewAlluvial(df, c("Design", "Quality", "Outcome"))
} # }