Holoviews

**December 6, 2022**

This release contains a small number of important bug fixes and
adds support for Python 3.11. Many thanks to our maintainers
Hoxbro, maximlt and jlstevens.

Bug Fixes:

- Fix for empty opts warning and incorrect clearing semantics
([5496](https://github.com/holoviz/holoviews/pull/5496))
- Fix potential race condition in the Options system
([5535](https://github.com/holoviz/holoviews/pull/5535))

Enhancements:

- Add support to Python 3.11
([5513](https://github.com/holoviz/holoviews/pull/5513))
- Cleanup the top `__init__` module
([5516](https://github.com/holoviz/holoviews/pull/5516))

Documentation:

- Fixes to release notes and CHANGELOG
([5506](https://github.com/holoviz/holoviews/pull/5506))

**November 3, 2022**

This release contains a small number of important bug fixes. Many thanks
to stanwest for his contribution and thank you to our maintainers
Hoxbro, maximlt, jlstevens, jbednar, and philippjfr.

Bug fixes:

- Fix support for jupyterlite
([5502](https://github.com/holoviz/holoviews/pull/5502))
- Improve error message for `hv.opts` without a plotting backend
([5494](https://github.com/holoviz/holoviews/pull/5494))
- Fix warnings exposed in CI logs
([5470](https://github.com/holoviz/holoviews/pull/5470))
- Thanks to maximlt for various CI fixes
([5484](https://github.com/holoviz/holoviews/pull/5484),
[5498](https://github.com/holoviz/holoviews/pull/5498),
[5485](https://github.com/holoviz/holoviews/pull/5485))

Enhancement:

- Allow Dimension objects to accept a dictionary specification
([5333](https://github.com/holoviz/holoviews/pull/5333))
- Refactor to remove iterrows for loop from `connect_edges_pd`
([5473](https://github.com/holoviz/holoviews/pull/5473))

Deprecations:

Promoted `DeprecationWarning` to `FutureWarning` when using pandas
`DataFrame`s with non-string column names. This will not change any
functionality but will start warning users about functionality that will
be deprecated in future.

- Upgrade warning for invalid dataframe column names
([5472](https://github.com/holoviz/holoviews/pull/5472))

**October 4, 2022**

This release contains a small number of important bug fixes. Many thanks
to all our new contributors MarcSkovMadsen, j-svensmark, ceball,
droumis, ddrinka, Jhsmit and stanwest as well as a special thanks to
Hoxbro for his many bug fixes. An additional thank you goes out to
maximlt, philippjfr, jbednar and jlstevens.

Enhancements:

- Sort output of `decimate` operation so that it can be used with connected Elements
(Curve, Area, etc.) ([5452](https://github.com/holoviz/holoviews/pull/5452))
- Ensure HoloViews is importable from a pyodide webworker
([5410](https://github.com/holoviz/holoviews/pull/5410))
- Add support for stepwise Area plots
([5390](https://github.com/holoviz/holoviews/pull/5390))
- Better error message for `hv.Cycle` when incompatible backend activated
([5379](https://github.com/holoviz/holoviews/pull/5379))
- Improvements to VSCode notebook support
([5398](https://github.com/holoviz/holoviews/pull/5398))
- Protect matplotlib tests from global styles
([5311](https://github.com/holoviz/holoviews/pull/5311))
- Faster hashing for arrays and pandas objects
([5455](https://github.com/holoviz/holoviews/pull/5455))
- Add pre-commit hooks to CI actions and fixes to pytest configuration
([5385](https://github.com/holoviz/holoviews/pull/5385),
[5440](https://github.com/holoviz/holoviews/pull/5440))

Bug Fixes:

- Allow import of numpy 1.12
([5367](https://github.com/holoviz/holoviews/pull/5367))
- Fixes handling of iterables in Overlays
([5320](https://github.com/holoviz/holoviews/pull/5320))
- Always return a string when using `hv.Dimension.pprint_value`
([5383](https://github.com/holoviz/holoviews/pull/5383))
- Support widgets in slices for `loc` and `iloc`
([5352](https://github.com/holoviz/holoviews/pull/5352))
- Take account of labeled dimension in Bokeh plotting classes
([5404](https://github.com/holoviz/holoviews/pull/5404))
- Fix handling of pandas `Period` ranges
([5393](https://github.com/holoviz/holoviews/pull/5393))
- Fixed declaration of `Scatter` to `Selection1DExpr`
([5413](https://github.com/holoviz/holoviews/pull/5413))
- Ensure rangesupdate event fires on all plots with linked axes
([5465](https://github.com/holoviz/holoviews/pull/5465))
- Fixed fallback to shapely spatial select
([5468](https://github.com/holoviz/holoviews/pull/5468))
- Many thanks to Hoxbro for many miscellaneous plotting fixes,
including fixes to plotting of `BoxWhisker`, `VectorField` elements
([5397](https://github.com/holoviz/holoviews/pull/5397),
[5450](https://github.com/holoviz/holoviews/pull/5450),
[5400](https://github.com/holoviz/holoviews/pull/5400),
[5409](https://github.com/holoviz/holoviews/pull/5409),
[5460](https://github.com/holoviz/holoviews/pull/5460)))
- Fixes to documentation building GitHub Action
([5320](https://github.com/holoviz/holoviews/pull/5456),
([5320](https://github.com/holoviz/holoviews/pull/5467)))

Documentation:

- Introduced module documentation
([5362](https://github.com/holoviz/holoviews/pull/5362))
- Remove Python 2 references from README
([5365](https://github.com/holoviz/holoviews/pull/5365))
- Update call to panel add_periodic_callback in Bokeh gallery example
([5436](https://github.com/holoviz/holoviews/pull/5436))
- Added reference to example in `RangeToolLink`
([5435](https://github.com/holoviz/holoviews/pull/5435))

API:

In future, HoloViews will not allow non-string values for pandas
DataFrame column names. This deprecation cycle starts by
issuing a `DeprecationWarning` that should not be visible to users.

- Issue DeprecationWarning for invalid DataFrame column types
([5457](https://github.com/holoviz/holoviews/pull/5457))

**July 6, 2022**

This is a major release with a large number of new features and bug
fixes, as well as updates to Python and Panel compatibility.

Many thanks to the numerous users who filed bug reports, tested
development versions, and contributed a number of new features and bug
fixes, including special thanks to ablythed ahuang11
douglas-raillard-arm FloLangenfeld HoxBro ianthomas23 jenssss
pepijndevos peterroelants stas-sl Yura52 for their contributions. In
addition, thanks to the maintainers jbednar, maximlt, jlstevens and
philippjfr for contributing to this release.

Compatibility:

- Python 2 support has finally been dropped with 1.14.9 as the last
release supporting Python 2
- HoloViews now requires panel >0.13.1
([4329](https://github.com/holoviz/holoviews/pull/4329))
- Colormaps for the output of the datashade operation have changed to
address
[holoviz/datashader357](https://github.com/holoviz/datashader/issues/357);
see `rescale_discrete_levels` below. To revert to the old colorbar
behavior, set `ColorbarPlot.rescale_discrete_levels = False` in the
`bokeh` or `mpl` plotting modules as appropriate.
- Updated Sankey algorithm means that some users may need to update the
`node_padding` parameter for plots generated with earlier releases.

Major features:

After a long period of hotfix releases for the 1.14.9 series, many new
features on the main branch have been released. Features relating to
datashader support, linked selection and improvements to the Bokeh
plotting backend are called out in their own sections.

- Support constructor interface from a spatialpandas GeometryArray
([5281](https://github.com/holoviz/holoviews/pull/5281))
- Allow plotting anonymous pandas.Series
([5015](https://github.com/holoviz/holoviews/pull/5015))
- Add support for rendering in pyodide/pyscript
([5338](https://github.com/holoviz/holoviews/pull/5338),
[5321](https://github.com/holoviz/holoviews/pull/5321),
[5275](https://github.com/holoviz/holoviews/pull/5275))

Datashader features:

The following new features have been added to the datashader support in
HoloViews, mainly focused on Datashader's new support for antialiasing
lines as well as the new `rescale_discrete_levels` colormapping option.

- Add automatic categorical legend for datashaded plots
([4806](https://github.com/holoviz/holoviews/pull/4806))
- Implement `line_width` support when rasterizing spatialpandas paths
([5280](https://github.com/holoviz/holoviews/pull/5280))
- Expose `rescale_discrete_levels` in the Bokeh backend
([5312](https://github.com/holoviz/holoviews/pull/5312))
- Set `rescale_discrete_levels=True` by default
([5268](https://github.com/holoviz/holoviews/pull/5268))

New linked selection features:

- Implement `linked_selection.filter` method
([4999](https://github.com/holoviz/holoviews/pull/4999))
- Allow passing custom `selection_expr` to linked selections filter
([5012](https://github.com/holoviz/holoviews/pull/5012))
- Fix `AdjointLayout` in `link_selections`
([5030](https://github.com/holoviz/holoviews/pull/5030))

New features for the Bokeh plotting backend:

- Add `legend_labels` option to allow overriding legend labels
([5342](https://github.com/holoviz/holoviews/pull/5342))
- Updated sankey algorithm to `d3-sankey-v0.12.3`
([4707](https://github.com/holoviz/holoviews/pull/4707))

Other enhancements:

- Optimize and clean up options system
([4954](https://github.com/holoviz/holoviews/pull/4954))
- Optimize lasso selection by applying box-select first
([5061](https://github.com/holoviz/holoviews/pull/5061))
https://github.com/holoviz/holoviews/pull/5061
- Support ibis-framework version 3
([5292](https://github.com/holoviz/holoviews/pull/5292))
- Add `OpenTopoMap` as a tile source
([5052](https://github.com/holoviz/holoviews/pull/5052))
- Show all histograms of an `Overlay`
([5031](https://github.com/holoviz/holoviews/pull/5031))

Bug fixes:

- Fix batch watching and linking of parameters in Params stream
([4960](https://github.com/holoviz/holoviews/pull/4960),
[4956](https://github.com/holoviz/holoviews/pull/4956))
- Ensure `Plot.refresh` is dispatched immediately if possible
([5348](https://github.com/holoviz/holoviews/pull/5348))
- Fix datashader empty overlay aggregation
([5334](https://github.com/holoviz/holoviews/pull/5334))
- Fixed missing handling of nodata for count aggregator with column
([4951](https://github.com/holoviz/holoviews/pull/4951))
- Handle `pd.NA` as missing data in dtype=object column
([5323](https://github.com/holoviz/holoviews/pull/5323))
- Forward `DynamicMap.hist` dimension parameter to histogram creation
([5037](https://github.com/holoviz/holoviews/pull/5037))
- Remove numpy pin from examples
([5285](https://github.com/holoviz/holoviews/pull/5285))
- Fix vmin/vmax deprecation on matplotlib HeatMapPlot
([5300](https://github.com/holoviz/holoviews/pull/5300))
- Don't skip each renderer's `load_nb call` when multiple extension
calls are made in a single cell
([5302](https://github.com/holoviz/holoviews/pull/5302))
- Set plotly range correctly for log axis
([5272](https://github.com/holoviz/holoviews/pull/5272))
- Sanitize uses of `contextlib.contextmanager`
([5018](https://github.com/holoviz/holoviews/pull/5018))
- Ensure `overlay_aggregate` is not applied for anti-aliased lines
([5266](https://github.com/holoviz/holoviews/pull/5266))
- Switch to using bokeh `rangesupdate` event for `Range` streams
([5265](https://github.com/holoviz/holoviews/pull/5265))
- Fixes for bokeh `Callbacks`
([5040](https://github.com/holoviz/holoviews/pull/5040))
- Fix for attribute error in matplotlib `CompositePlot`
([4969](https://github.com/holoviz/holoviews/pull/4969))
- Silenced inappropriate deprecation warnings and updated deprecation
settings in options system
([5345](https://github.com/holoviz/holoviews/pull/5345),
[5346](https://github.com/holoviz/holoviews/pull/5346))

Documentation:

The following improvements to the documentation have been made:

- Fix `hv.help` when pattern is set
([5330](https://github.com/holoviz/holoviews/pull/5330))
- Added release dates to changelog and releases
([5027](https://github.com/holoviz/holoviews/pull/5027),
[5035](https://github.com/holoviz/holoviews/pull/5035))
- Removed unneeded list from dynamic map example
([4953](https://github.com/holoviz/holoviews/pull/4953))
- Added FAQ about sharing only a single axis
([5278](https://github.com/holoviz/holoviews/pull/5278))
- Miscellaneous fixes to Heatmap reference notebook and Continuous
Coordinates user guide
([5262](https://github.com/holoviz/holoviews/pull/5262))
- Added example of multiple RGB images as glyphs
([5172](https://github.com/holoviz/holoviews/pull/5172))
- Trim trailing whitespaces
([5019](https://github.com/holoviz/holoviews/pull/5019))
- Update outdated IOAM references
([4985](https://github.com/holoviz/holoviews/pull/4985))

Testing infrastructure:

Many thanks to maximlt for his work maintaining and fixing the testing
infrastructure across too many PRs to list here.

- Switch to pytest
([4949](https://github.com/holoviz/holoviews/pull/4949))
- Test suite clean up and fix for the pip build
([5326](https://github.com/holoviz/holoviews/pull/5326))

**May 6, 2022**

This release contains a small number of important bug fixes as well as
support for the newly added antialiasing option for line rendering in
datashader. Many thanks to andriyot, Hoxbro, pepijndevos, stas-sl,
TheoMathurin, maximlt, jlstevens, jbednar, and philippjfr.

Enhancements:

- Improvements to extension loading, improving visual appearance in
JupyterLab when no logo is used and a check to avoid loading
unnecessary JavaScript.
([5216](https://github.com/holoviz/holoviews/pull/5216),
[5249](https://github.com/holoviz/holoviews/pull/5249))
- Add support for setting antialiased line_width on datashader line
aggregation as well as pixel_ratio setting
([5264](https://github.com/holoviz/holoviews/pull/5264),
[5288](https://github.com/holoviz/holoviews/pull/5288))
- Added options to customize hover line\_(width|join|cap|dash) properties
([5211](https://github.com/holoviz/holoviews/pull/5211))
- Restored Python 2 compatibility that lapsed due to lack of CI testing
since 1.14.3. This is expected to be the last release with Python 2 support.
([5298](https://github.com/holoviz/holoviews/pull/5298))

Bug fixes:

- Fix to respect series order in stacked area plot
([5236](https://github.com/holoviz/holoviews/pull/5236))
- Support buffer streams of unspecified length (5247)
([5247](https://github.com/holoviz/holoviews/pull/5247))
- Fixed log axis lower bound when data minimum is <= 0
([5246](https://github.com/holoviz/holoviews/pull/5246))
- Declared GitHub project URL in setup.py
([5227](https://github.com/holoviz/holoviews/pull/5227))
- Fixed streaming Psutil example application
([5243](https://github.com/holoviz/holoviews/pull/5243))
- Respecting Renderer's center property for HoloViews pane
([5197](https://github.com/holoviz/holoviews/pull/5197))

Documentation:

- Updated Large data guide to reflect changes in Datashader and
antialiasing support
([5267](https://github.com/holoviz/holoviews/pull/5267),
[5290](https://github.com/holoviz/holoviews/pull/5290))