Support the creation of Vega-Lite visualizations in Haskell. This code is released under the BSD3 license.
It is an almost-direct copy of version 2.2.1 of the Elm Vega library, which is released under a BSD3 license by Jo Wood of the giCentre at the City University of London.
let cars = dataFromUrl "https://vega.github.io/vega-datasets/data/cars.json"  enc = encoding . position X [ PName "Horsepower", PmType Quantitative ] . position Y [ PName "Miles_per_Gallon", PmType Quantitative ] . color [ MName "Origin", MmType Nominal ] bkg = background "rgba(0, 0, 0, 0.05)" in toVegaLite [ bkg, cars, mark Circle , enc  ]
When viewed with a Vega-Lite aware viewer, the resultant plot is
The Elm Vega documentation can be used as a guide to using this module. The Vega-Lite Example Gallery has been converted to an IHaskell notebook Uunfortunately the plots created by VegaEmbed do not appear in the notebook when viewed with either GitHub’s viewer or ipynb viewer, but things seem much better when using Jupyter Lab (rather than notebook) to create the notebooks (since Vega is natively supported in this environment). The notebooks have been re-created using Jupyter Lab (thanks to Tweag I/O’s JupyterWith environment), which should make the plots appear on GitHub (you may need to reload the notebooks as I find they don’t display on the first try).
The notebooks directory contains a poorly-curated set of examples and experiments with hvega.
Differences to Elm Vega
The main changes to version 2.2.1 of Elm Vega are:
VLSpec(although both are synonyms for the underlying JSON representation).
Add a type for the output of
VegaLite) that is separate from
VLSpec, which is usefull for integration with IHaskell. The JSON specification is retrieved with
Take advantage of the lack of backwards compatibality requirements to remove or replace several symbols (such as add the
TimeUnit, remove the
binfunction, and use
(VLProperty, VLSpec)in function signatures).
In version 0.2.0.0, the constructors for the
LegendOrientationtype have gained a
LOprefix, which avoids clashing with the Prelude’s
For the latest version of this document, please see https://github.com/DougBurke/hvega/blob/master/hvega/CHANGELOG.md.
The minimum base version has been bumped from 4.7 to 4.9, which means ghc 8.0 or later. This is because the 0.2.0.1 release does not appear to build with ghc 7.10. If this restriction is a problem then please comment on the issues list.
There have been minor documentation updates, adding
Channel type has been extended to include
constructors and the
tooltips function allows you to provide
multiple tooltips for a channel. The schema version has been changed
from 2 to 3, but there has been limited checking to see if the API
correctly reflects the new schema.
This functionality was provided by Adam Massmann (massma) and BinderDavid.
This functionality was provided by Gregory Schwartz; apologies for taking so long to get it released.
The constructors for the LegendOrientation type have been renamed (by
adding the prefix
LO) which avoids the name clash with
seen in earlier releases. This is a breaking API change.
Clarify how to use the library in the main
Thanks to contributions from Nicolas Mattia (nmattia) and Marco Zocca (ocramz).
The only change is to the cabal file, where
cabal-version: >=1.18 has
been changed to
Updated the upper bounds of
aeson to really allow v1.4. This was not
released on Hackage.
Updated the upper bounds of
aeson from v1.2 to v1.4.
The cabal package now includes
the latter is not guaranteed to be correct), as well as a
change log and an extra image.
This is the initial version of
hvega, which is based on
version 2.2.1 of the
Elm Vega library.