Altair

Bug Fixes

- appropriate handling of InlineData in dataset consolidation (1092)

- fix admonition formatting in documentation page (1094)

Enhancements

- better handling of datetimes and timezones (1053)

- all inline datasets are now converted to named datasets and stored at the
top level of the chart. This behavior can be disabled by setting
``alt.data_transformers.consolidate_datasets = False`` (951 & 1046)

- more streamlined shorthand syntax for window transforms (957)

Maintenance

- update from Vega-Lite 2.4.3 to Vega-Lite 2.6.0; see vega-lite change-logs [2.5.0](https://github.com/vega/vega-lite/releases/tag/v2.5.0) [2.5.1](https://github.com/vega/vega-lite/releases/tag/v2.5.1) [2.5.2](https://github.com/vega/vega-lite/releases/tag/v2.5.2) [2.6.0](https://github.com/vega/vega-lite/releases/tag/v2.6.0)

Backward-incompatible changes

- ``alt.SortField`` renamed to ``alt.EncodingSortField`` and
``alt.WindowSortField`` renamed to ``alt.SortField`` (923)

Bug Fixes

- Fixed serialization of logical operands on selections within
``transform_filter()``: (1075)

- Fixed sphinx issue which embedded chart specs twice (1088)

- Avoid Selenium import until it is actually needed (982)

Enhancements

- add a ``scale_factor`` argument to ``chart.save()`` to allow the
size/resolution of saved figures to be adjusted. (918)

- add an ``add_selection()`` method to add selections to charts (832)

- add ``chart.serve()`` and ``chart.display()`` methods for more flexiblity
in displaying charts (831)

- allow multiple fields to be passed to encodings such as ``tooltip``
and ``detail`` (830)

- make ``timeUnit`` specifications more succinct, by parsing them in a manner
similar to aggregates (866)

- make ``to_json()`` and ``to_csv()`` have deterministic filenames, so in json
mode a single datasets will lead to a single on-disk serialization (862)

Breaking Changes

- make ``data`` the first argument for all compound chart types to match the
semantics of ``alt.Chart`` (this includes ``alt.FacetChart``,
``alt.LayerChart``, ``alt.RepeatChart``, ``alt.VConcatChart``, and
``alt.HConcatChart``) (895).

- update vega-lite to version 2.4.3 (836)

- Only API change is internal: ``alt.MarkProperties`` is now ``alt.MarkConfig``

Maintenance

- update vega to v3.3 & vega-embed to v3.11 in html output & colab renderer (838)

Complete rewrite of Altair, focused on supporting Vega-Lite 2.X

This version of Altair is based on Vega-Lite 1.2.1.

Major additions

- Support for JupyterLab/nteract through MIME based rendering. Enable this by calling `enable_mime_rendering()` before rendering visualizations (216).

- Change default import in all code and docs to `import altair as alt`

- Check for missing and misspelled column names upon exporting or rendering, and raise `FieldError` (399) if any problems are found. This can be disabled by setting `Chart.validated_columns=False`.

- Raise `MaxRowsExceeded` if the number of rows in the dataset is larger than `Chart.max_rows` to guard against sending large datasets to the browser.

- Move the Vega-Lite 1.x api into `altair.v1` to make it easier for us to migrate to Vega-Lite 2.x and continue to support 1.x. No import change are needed as `altair.v1` is aliased to `altair` in this release (377).

- Moved the example notebooks into a separate repository (https://github.com/altair-viz/altair_notebooks) that has Binder support (#391).

- Add `$schema` to top-level JSON spec (370).

- Minor documentation revisions.

Bug fixes

- Make sure default mark is a point (344).

Nov 7, 2016

Major additions
- Update to Vega-Lite 1.2 and make all its enhancements available to Altair
- Add `Chart.serve` method
([197](https://github.com/altair-viz/altair/pull/197))
- Add `altair.expr` machinery to specify transformations and filterings
([213](https://github.com/altair-viz/altair/pull/213))
- Add `Chart.savechart` method, which can output JSON, HTML, and (if Node
is installed) PNG and SVG. See https://altair-viz.github.io/documentation/displaying.html

Bug Fixes
- Countless minor bug fixes

Maintenance:
- Update to Vega-Lite 1.2.1 and add its supported features
- Create website: http://altair-viz.github.io/
- Set up Travis to run conda & pip; and to build documentation