Lollipop Chart — lollipop • jjstatsplot

Creates lollipop charts for categorical data visualization following R Graph Gallery best practices, with emphasis on clinical applications like patient timelines, treatment outcomes, and biomarker comparisons. Uses geom_segment() and geom_point() for optimal visual presentation.

Usage

lollipop(
  data,
  dep,
  group,
  useHighlight = FALSE,
  highlight,
  sortBy = "original",
  orientation = "vertical",
  showValues = FALSE,
  showMean = FALSE,
  colorScheme = "default",
  theme = "default",
  pointSize = 3,
  lineWidth = 1,
  lineType = "solid",
  baseline = 0,
  conditionalColor = FALSE,
  colorThreshold = 0,
  xlabel,
  ylabel,
  title,
  width = 800,
  height = 600
)

Arguments

data: The data as a data frame.
dep: The numeric variable for the values (lollipop heights/lengths).
group: The categorical variable for grouping (lollipop categories).
useHighlight: Enable or disable highlighting of specific levels in the plot.
highlight: Specific level to highlight in the plot with different color/style.
sortBy: How to sort the lollipops in the chart.
orientation: Chart orientation (vertical or horizontal lollipops).
showValues: Whether to display value labels on the lollipops.
showMean: Whether to display a reference line at the mean value.
colorScheme: Color scheme for the lollipops.
theme: Overall theme/appearance of the plot.
pointSize: Size of the lollipop points.
lineWidth: Width of the lollipop stems.
lineType: Type of line for lollipop stems.
baseline: Starting point for lollipop stems (default is 0).
conditionalColor: Enable coloring based on value thresholds.
colorThreshold: Threshold value for conditional coloring (values above/below get different colors).
xlabel: Custom label for the x-axis.
ylabel: Custom label for the y-axis.
title: Custom title for the plot.
width: Width of the plot in pixels.
height: Height of the plot in pixels.

Value

A results object containing:

`results$todo`					a html
`results$summary`					a table
`results$plot`					an image

Tables can be converted to data frames with asDF or as.data.frame. For example:

results$summary$asDF

as.data.frame(results$summary)

Examples

# Load clinical lab data
clinical_lab_data <- read.csv("clinical_lab_data.csv")
#> Warning: cannot open file 'clinical_lab_data.csv': No such file or directory
#> Error in file(file, "rt"): cannot open the connection
# Or load from package: data("clinical_lab_data", package = "ClinicoPath")

# Basic lollipop chart - Hemoglobin by treatment group
lollipop(
    data = clinical_lab_data,
    dep = "hemoglobin",
    group = "treatment_group",
    sortBy = "value_desc",
    title = "Hemoglobin Levels by Treatment"
)
#> Error: object 'clinical_lab_data' not found

# Highlighting severe disease cases - Albumin levels
lollipop(
    data = clinical_lab_data,
    dep = "albumin",
    group = "disease_severity",
    useHighlight = TRUE,
    highlight = "Severe",
    orientation = "horizontal",
    showValues = TRUE,
    colorScheme = "clinical",
    title = "Albumin Levels by Disease Severity"
)
#> Error: object 'clinical_lab_data' not found

# Conditional coloring for abnormal creatinine (>1.2 mg/dL)
lollipop(
    data = clinical_lab_data,
    dep = "creatinine",
    group = "age_group",
    conditionalColor = TRUE,
    colorThreshold = 1.2,
    lineType = "dashed",
    sortBy = "value_asc",
    title = "Creatinine by Age (Threshold: 1.2 mg/dL)"
)
#> Error: object 'clinical_lab_data' not found

# Advanced - Platelet count with clinical baseline
lollipop(
    data = clinical_lab_data,
    dep = "platelet_count",
    group = "hospital",
    baseline = 150,  # Lower normal limit
    useHighlight = TRUE,
    highlight = "Hospital A",
    lineType = "dotted",
    pointSize = 4,
    showMean = TRUE,
    colorScheme = "clinical",
    title = "Platelet Counts by Hospital (Normal >150)"
)
#> Error: object 'clinical_lab_data' not found

# Compare WBC across multiple factors
lollipop(
    data = clinical_lab_data,
    dep = "white_blood_cells",
    group = "treatment_group",
    conditionalColor = TRUE,
    colorThreshold = 11,  # Upper normal limit
    orientation = "horizontal",
    sortBy = "value_desc",
    lineWidth = 2,
    title = "WBC Count by Treatment (ULN: 11)"
)
#> Error: object 'clinical_lab_data' not found