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Create a Co-occurrence Heatmap

Source: R/review_overlap.R
reviewOverlap.Rd

Counts how many studies share each combination of values in two columns and displays the result as a tile heatmap. Returns a ggplot2::ggplot object.

Usage

reviewOverlap(
  data,
  col1,
  col2,
  sep = "\r\n",
  fill = "#7BB0D1",
  base_size = 12,
  na.rm = TRUE,
  na_label = "Not reported",
  studlabs = FALSE,
  study_id = StudyID,
  label_wrap = 15
)

Arguments

data

A data frame with at least the columns named by col1 and col2.

col1

First column (quoted or unquoted), mapped to the x-axis.

col2

Second column (quoted or unquoted), mapped to the y-axis.

sep

Character. Separator for multi-value cells. Defaults to "\r\n".

fill

Character. High-end color for the gradient. Defaults to "#7BB0D1".

base_size

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

na.rm

Logical. Drop missing values? Defaults to TRUE.

na_label

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

studlabs

Logical. If TRUE, show comma-separated study IDs inside each tile instead of (or below) the count. Defaults to FALSE.

study_id

Column containing study identifiers (quoted or unquoted). Used when studlabs = TRUE. Defaults to StudyID.

label_wrap

Integer. Wrap axis tick labels longer than this many characters onto multiple lines. Set to NULL or Inf to disable. Defaults to 15.

Value

A ggplot2::ggplot object.

Examples

df <- data.frame(
  StudyID = c("S1", "S2", "S3", "S4"),
  Design  = c("RCT", "Cohort", "RCT", "Case-control"),
  Country = c("UK", "UK", "Spain", "Spain"),
  stringsAsFactors = FALSE
)
reviewOverlap(df, Design, Country)

reviewOverlap(df, Design, Country, studlabs = TRUE)