add_data: Add data to a Vega-Lite spec

In vegalite: Tools to Encode Visualizations with the 'Grammar of Graphics'-Like 'Vega-Lite' 'Spec'

Description

Vega-Lite is more lightweight than full Vega. However, the spec is flexible enough to support embedded data or using external sources that are in JSON, CSV or TSV format.

Usage

add_data(vl, source, format_type = NULL)

Arguments

vl	a Vega-Lite object
source	you can specify a (fully qualified) URL or an existing data.frame (or ts) object or a reference to a local file. For the URL case, the url component of data will be set. You can help Vega-Lite out by giving it a hint for the data type with format_type but it is not required. For the local data.frame case it will embed the data into the spec. For the case where a local file is specified, it will be read in (either a JSON file, CSV file or TSV file) and converted to a data.frame and embedded.
format_type	if source is a URL, this should be one of json, csv or tsv). It is not required and it is ignored if source is not a URL.

References

Vega-Lite Data spec

Examples

dat <- jsonlite::fromJSON('[
    {"a": "A","b": 28}, {"a": "B","b": 55}, {"a": "C","b": 43},
    {"a": "D","b": 91}, {"a": "E","b": 81}, {"a": "F","b": 53},
    {"a": "G","b": 19}, {"a": "H","b": 87}, {"a": "I","b": 52}
  ]')

vegalite() %>%
  add_data(dat) %>%
  encode_x("a", "ordinal") %>%
  encode_y("b", "quantitative") %>%
  mark_bar()

Example output

vegalite documentation built on May 2, 2019, 10:46 a.m.