Changes in version 5.2.0.9002                      

  - Update to use Altair 5.2.0 (#168).

  - Temporarily uses dev version of vegawidget (#174).

                 Changes in version 4.2.3 (2023-09-04)                  

  - Update URLs in documentation. (#164)

  - Update package-documentation to comport with Roxygen updates. (#165)

  - Update actions - note that for Altair 4.2.0, you must use
    Pandas<=1.5.3 (#163)

                 Changes in version 4.2.2 (2023-03-13)                  

  - Update case-study vignette to allow for more than 5000 rows. (#159)

  - Update signatures of repr_text() and repr_vegalite4() to align with
    signatures of their generics. (#158)

                 Changes in version 4.2.1 (2022-02-14)                  

  - Upgrade to vegawidget 0.4.1. (#150, #154)

  - Upgrade to Altair 4.2.0. (#148)

  - Bump version for development

                 Changes in version 4.1.1 (2021-01-14)                  

  - Upgrade to Altair 4.1.0

  - Re-export vegawidget::vw_set_base_url(), sets default base URL when
    rendering specs.

                 Changes in version 4.0.1 (2020-01-23)                  

  - Upgrade to Altair 4.0.0

  - Update repr methods to include top-level Altair class. (#127)

                 Changes in version 3.1.1 (2019-07-11)                  

  - Deprecate vw_as_json(), vegawidgetOutput(), renderVegawidget();
    these are available in the vegawidget package. (#117)

  - Remove references to r_to_py(), as reticulate manages this
    automatically. (#83)

  - Update the JupyterLab renderers to Vega-Lite 3

  - Upgrade to Altair 3.1.0

                       Changes in version 2.3.0.1                       

  - updates the image-functions from vegawidget

                        Changes in version 2.3.0                        

  - upgrades to Altair 2.3.0

                       Changes in version 2.2.2.2                       

  - updates exports from vegawidget

                       Changes in version 2.2.2.1                       

  - adds methods repr_text() and repr_vegalite2() methods for Altair
    chart objects, allowing them to be rendered natively in Jupyter
    notebooks using IRKernel (https://irkernel.github.io) (#91, with
    @flying-sheep).

  - imports vw_rename_datasets() from vegawidget

                       Changes in version 2.2.2.0                       

  - new versioning system: first three version numbers follow supported
    Altair (Python) version

  - updates to use Altair 2.2.2

                        Changes in version 0.0.6                        

  - adds altair_version(), returns list of versions used for Altair,
    Vega, Vega-Lite, etc.

  - adds as_chart(), to import a vegaspec as an Altair chart

  - removes rendering functions in favor of a separate package,
    vegawidget - vegawidget functions imported and exported using
    templating function vegawidget::use_vegawidget().

  - adds requirement to use reticulate (>=) 1.9, to avoid conflict
    between data-frame variable-names and python methods (#50,
    @aliciaschep) and to remove the need to use the r_to_py() function
    for data (#83)

  - updates to use Altair 2.1.0, which offers tooltips (#29, #46,
    @aliciaschep)

                        Changes in version 0.0.5                        

  - adds compiled option to only_actions() to conform with new option in
    vega-embed (#71)

  - incorporates remaining galleries

                        Changes in version 0.0.4                        

  - incorporates first gallery

                        Changes in version 0.0.3                        

  - adapts examples gallery from Altair (#24, @haleyjeppson)

  - updates articles and documentation (#32)

  - deprecates vegalite() in favor of vegawidget() (#48)

  - provides methods for knit_print() and print() generics (#8)

  - updates versions of JS libraries: vega 3.3.1, vega-lite 2.4.3,
    vega-embed 3.9.0 (#33)

  - removes tooltip functions (#45)

  - updates .onLoad() to run check_altair() on loading, and adds error
    handling (#43, with @aliciaschep)

  - updates travis.yml so that this package installs its supported
    version of Altair (#44)

  - adds function check_altair() to check installed version against
    supported version (#42, with @aliciaschep)

  - updates install_altair() (#41)

  - synchronizes with Altair v2.0.x (#36)

                     Changes in version 0.0.1.9000                      

  - new function to manage installation of Altair Python package:
    install_altair() (#1)

  - makes Vega datasets available through import_vega_data() (#25)

  - significant changes to the rendering function vegalite():
    
      - if the embed argument is NULL, vegalite() sets it to
        getOption("altair.embed_options") - if that is not defined, the
        vega-embed defaults are used
    
      - width and height arguments to vegalite() are used now to specify
        the total width and height of rendered charts - notes: (1) this
        is effective only for single-view charts, (2) width and height
        apply to the chart only, they do not take into account any
        action-links - if arguments are not set, the size of the chart
        is determined from the chart specification (#18)
    
      - vegalite() strips the style attribute from the <div/> for the
        htmlwidget - this has the effect of letting the rendered
        Vega-Lite chart determine the size of its container (#16, #18)

  - adds concatenation operators for charts: |, &, + (#22, @aliciaschep)

  - adds function vega_embed(), with friend only_actions(), to support
    embedding options in vegalite() (#16)

  - updates css for embedding, makes the action-links look much better
    (#20, @aliciaschep)

  - adds tooltip-capability to vegalite() renderer, with functions
    vega_tooltip(), add_fields(), and friends: vega_tooltip_encoding()
    and vega_tooltip_all() (#4, with @aliciaschep)

  - adds a NEWS.md file to track changes to the package

  - achieves minimal functionality