bubblechart: Create an Interactive Bubble Chart

Description

Creates an interactive circle packing (bubble chart) visualization using the Nivo library. This function produces a hierarchical bubble chart that supports click and hover interactions in Shiny applications. Bubble size is determined by the value field in your data, and colors are fully customizable.

Usage

bubblechart(
  element_id,
  main_color,
  label_color,
  on_hover_title_color,
  data = NULL,
  width = NULL,
  isInteractive = TRUE,
  height = "400px",
  activeColor = "transparent",
  borderWidth = 3
)

Value

An htmlwidget object of class c("bubblechart", "htmlwidget") that can be:

Rendered directly in R console or RStudio Viewer
Included in R Markdown documents
Used in Shiny applications with bubblechartOutput and renderBubblechart
Saved to HTML with htmlwidgets::saveWidget()

Arguments

element_id

Character string specifying the Shiny input ID for click events. Click events will be accessible in Shiny as input$<element_id>_clicked. For example, if element_id = "my_chart", click events are available at input$my_chart_clicked.

main_color

Character string specifying the default color for bubbles (hex color code, e.g., "#ff5f56" for red, "#3498db" for blue). This color is used as the base color for the chart border and as a fallback.

label_color

Character string specifying the default label text color (hex color code). Use high-contrast colors for better readability (e.g., "#ffffff" for white text on dark bubbles, "#000000" for black text on light bubbles).

on_hover_title_color

Character string specifying the label color when hovering over a bubble (hex color code). This color is applied to the label text when the user hovers their mouse over a bubble, providing visual feedback.

data

A nested list representing hierarchical data. Must have a "name" field at the root and a "children" field containing child nodes. Each child should have:

name: Display name for the bubble (character)
value: Numeric value determining bubble size (must be positive)
color: Hex color code for the bubble fill (character, e.g., "#3498db")
labelColor: Hex color code for the label text (character, e.g., "#ffffff")

Use prepare_bubble_data to convert data frames to this format.

width

The width of the widget. Can be a valid CSS unit (e.g., "100 percent", "400px", "50vw") or NULL for automatic sizing. NULL is recommended for responsive layouts.

isInteractive

Logical. If TRUE (default), enables click and hover interactions. Set to FALSE for static charts in reports or presentations where interactivity is not needed.

height

The height of the widget. Can be a valid CSS unit (e.g., "400px", "600px", "50vh") or NULL. Default is "400px". Adjust based on your layout needs and the amount of data being displayed.

activeColor

Character string specifying the color of selected/active bubbles (hex color code). When a user clicks a bubble, it changes to this color. Default is "transparent", which makes the selected bubble see-through.

borderWidth

Numeric value specifying the border width of bubbles in pixels. Default is 3. Use larger values (e.g., 5) for prominent borders, smaller values (e.g., 1) for subtle borders, or 0 for no borders.

Details

The bubble chart (circle packing diagram) is a powerful way to visualize hierarchical data where the size of each circle represents a quantitative value. This implementation uses the Nivo visualization library to create responsive, interactive charts that work seamlessly in both static R documents and dynamic Shiny applications.

When used in Shiny, the chart generates click events that can be captured via input$<element_id>_clicked, where <element_id> is the ID you specify. Clicking a bubble returns its name, and clicking it again returns "DESELECT_EVENT".

Examples

Run this code

if (interactive()) {
library(nivo.bubblechart)

# Example 1: Basic bubble chart with manual data
sample_data <- list(
  name = "root",
  children = list(
    list(name = "Category A", color = "#ff5f56", labelColor = "#ffffff", value = 100),
    list(name = "Category B", color = "#ffbd2e", labelColor = "#ffffff", value = 200),
    list(name = "Category C", color = "#27c93f", labelColor = "#ffffff", value = 150)
  )
)

bubblechart(
  element_id = "my_chart",
  main_color = "#ff5f56",
  label_color = "#ffffff",
  on_hover_title_color = "#000000",
  data = sample_data,
  height = "500px"
)

# Example 2: Using prepare_bubble_data for data frame conversion
df <- data.frame(
  product = c("Laptop", "Phone", "Tablet"),
  sales = c(45000, 38000, 22000),
  category_color = c("#3498db", "#e74c3c", "#f39c12"),
  text_color = rep("#ffffff", 3)
)

chart_data <- prepare_bubble_data(
  df,
  name_col = "product",
  value_col = "sales",
  color_col = "category_color",
  label_color_col = "text_color"
)

bubblechart(
  element_id = "sales_chart",
  main_color = "#3498db",
  label_color = "#ffffff",
  on_hover_title_color = "#2c3e50",
  data = chart_data,
  height = "600px"
)

# Example 3: Customized appearance
bubblechart(
  element_id = "custom_chart",
  main_color = "#2c3e50",
  label_color = "#ecf0f1",
  on_hover_title_color = "#f39c12",
  activeColor = "#e74c3c",  # Red when selected
  borderWidth = 5,          # Thicker borders
  data = sample_data,
  isInteractive = TRUE
)
}