Welcome to ClientVPS Mirrors

Using JSON Format

Using JSON Format

Introduction

This vignette demonstrates how to define Mosaic visualizations using JSON format. JSON is useful when working with external specifications or generating specs programmatically.

Example: Voronoi Diagram with JSON

This is the same voronoi diagram from the getting-started vignette, but defined using JSON format:

library(rMosaic)

# Generate synthetic penguins dataset
set.seed(42)
penguins_df <- data.frame(
  bill_length = rnorm(150, mean = 40, sd = 5),
  bill_depth  = rnorm(150, mean = 18, sd = 3),
  species     = sample(c("Adelie", "Gentoo", "Chinstrap"), 150, replace = TRUE)
)

# Define YAML spec first (as R list)
voronoi_yaml <- list(
  params = list(
    mesh = 0,
    hull = 0
  ),
  vconcat = list(
    list(
      plot = list(
        list(
          mark = "voronoi",
          data = list(from = "penguins"),
          x = "bill_length",
          y = "bill_depth",
          stroke = "white",
          strokeWidth = 1,
          strokeOpacity = 0.5,
          fill = "species",
          fillOpacity = 0.2
        ),
        list(
          mark = "hull",
          data = list(from = "penguins"),
          x = "bill_length",
          y = "bill_depth",
          stroke = "species",
          strokeOpacity = "$hull",
          strokeWidth = 1.5
        ),
        list(
          mark = "delaunayMesh",
          data = list(from = "penguins"),
          x = "bill_length",
          y = "bill_depth",
          z = "species",
          stroke = "species",
          strokeOpacity = "$mesh",
          strokeWidth = 1
        ),
        list(
          mark = "dot",
          data = list(from = "penguins"),
          x = "bill_length",
          y = "bill_depth",
          fill = "species",
          r = 2
        ),
        list(mark = "frame")
      ),
      width  = 680,
      height = 480
    ),
    list(
      hconcat = list(
        list(
          input   = "menu",
          label   = "Delaunay Mesh",
          options = list(
            list(value = 0,   label = "Hide"),
            list(value = 0.5, label = "Show")
          ),
          as = "$mesh"
        ),
        list(hspace = 5),
        list(
          input   = "menu",
          label   = "Convex Hull",
          options = list(
            list(value = 0, label = "Hide"),
            list(value = 1, label = "Show")
          ),
          as = "$hull"
        )
      )
    )
  )
)

# Convert to JSON string
voronoi_json <- jsonlite::toJSON(voronoi_yaml, auto_unbox = TRUE, pretty = TRUE)

# Run the application with JSON spec
runMosaicApp(
  spec     = voronoi_json,
  specType = "json",
  data     = list(penguins = penguins_df),
  title    = "Voronoi Diagram (JSON)"
)

Working with JSON

You can also load JSON from a file:

# Save spec to file
writeLines(voronoi_json, "voronoi_spec.json")

# Load and use
json_spec <- readLines("voronoi_spec.json")
runMosaicApp(
  spec     = paste(json_spec, collapse = "\n"),
  specType = "json",
  data     = list(penguins = penguins_df),
  title    = "Voronoi from File"
)

When to Use JSON

Note: YAML format (R lists) is generally more convenient for defining specs directly in R code, as shown in the getting-started vignette.

Need a high-speed mirror for your open-source project?
Contact our mirror admin team at info@clientvps.com.

This archive is provided as a free public service to the community.
Proudly supported by infrastructure from VPSPulse , RxServers , BuyNumber , UnitVPS , OffshoreName and secure payment technology by ArionPay.