Holoviews

**March 20, 2020**

This release is packed full of features and includes a general
refactoring of how HoloViews renders widgets now built on top of the
Panel library. Many thanks to the many contributors to this release
either directly by submitting PRs or by reporting issues and making
suggestions. Specifically we would like to thank poplarShift,
jonmease, flothesof, julioasotodv, ltalirz, DancingQuanta, ahuang,
kcpevey, Jacob-Barkhak, nluetts, harmbuisman, ceball, mgsnuno,
srp3003, jsignell as well as the maintainers jbednar, jlstevens and
philippjfr for contributing to this release. This version includes the
addition of a large number of features, enhancements and bug fixes:

Major features:

- Add `link_selection` to make custom linked brushing simple
([3951](https://github.com/holoviz/holoviews/pull/3951))
- `link_selection` builds on new support for much more powerful
data-transform pipelines: new `Dataset.transform` method
([237](https://github.com/holoviz/holoviews/pull/237),
[3932](https://github.com/holoviz/holoviews/pull/3932)), `dim`
expressions in `Dataset.select`
([3920](https://github.com/holoviz/holoviews/pull/3920)), arbitrary
method calls on `dim` expressions
([4080](https://github.com/holoviz/holoviews/pull/4080)), and
`Dataset.pipeline` and `Dataset.dataset` properties to track
provenance of data
- Add Annotators to allow easily drawing, editing, and annotating visual
elements ([1185](https://github.com/holoviz/holoviews/pull/1185))
- Completely replaced custom Javascript widgets with Panel-based widgets
allowing for customizable layout
([84](https://github.com/holoviz/holoviews/pull/84),
[805](https://github.com/holoviz/holoviews/pull/805))
- Add `HSpan`, `VSpan`, `Slope`, `Segments` and `Rectangles` elements
([3510](https://github.com/holoviz/holoviews/pull/3510),
[3532](https://github.com/holoviz/holoviews/pull/3532),
[4000](https://github.com/holoviz/holoviews/pull/4000))
- Add support for cuDF GPU dataframes, cuPy backed xarrays, and GPU
datashading ([3982](https://github.com/holoviz/holoviews/pull/3982))

Other features

- Add spatialpandas support and redesigned geometry interfaces for
consistent roundtripping
([4120](https://github.com/holoviz/holoviews/pull/4120))
- Support GIF rendering with Bokeh and Plotly backends
([2956](https://github.com/holoviz/holoviews/pull/2956),
[4017](https://github.com/holoviz/holoviews/pull/4017))
- Support for Plotly `Bars`, `Bounds`, `Box`, `Ellipse`, `HLine`,
`Histogram`, `RGB`, `VLine` and `VSpan` plots
- Add `UniformNdMapping.collapse` to collapse nested datastructures
([4250](https://github.com/holoviz/holoviews/pull/4250))
- Add `CurveEdit` and `SelectionXY` streams
([4119](https://github.com/holoviz/holoviews/pull/4119),
[4167](https://github.com/holoviz/holoviews/pull/4167))
- Add `apply_when` helper to conditionally apply operations
([4289](https://github.com/holoviz/holoviews/pull/4289))
- Display Javascript callback errors in the notebook
([4119](https://github.com/holoviz/holoviews/pull/4119))
- Add support for linked streams in Plotly backend to enable rich
interactivity
([3880](https://github.com/holoviz/holoviews/pull/3880),
[3912](https://github.com/holoviz/holoviews/pull/3912))

Enhancements:

- Support for packed values dimensions, e.g. 3D `RGB`/`HSV` arrays
([550](https://github.com/holoviz/holoviews/pull/550),
[3983](https://github.com/holoviz/holoviews/pull/3983))
- Allow selecting/slicing datetimes with strings
([886](https://github.com/holoviz/holoviews/pull/886))
- Support for datashading `Area`, `Spikes`, `Segments` and `Polygons`
([4120](https://github.com/holoviz/holoviews/pull/4120))
- `HeatMap` now supports mixed categorical/numeric axes
([2128](https://github.com/holoviz/holoviews/pull/2128))
- Use `__signature__` to generate .opts tab completions
([4193](https://github.com/holoviz/holoviews/pull/4193))
- Allow passing element-specific keywords through `datashade` and
`rasterize` ([4077](https://github.com/holoviz/holoviews/pull/4077))
([3967](https://github.com/holoviz/holoviews/pull/3967))
- Add `per_element` flag to `.apply` accessor
([4119](https://github.com/holoviz/holoviews/pull/4119))
- Add `selected` plot option to control selected glyphs in bokeh
([4281](https://github.com/holoviz/holoviews/pull/4281))
- Improve default `Sankey` `node_padding` heuristic
([4253](https://github.com/holoviz/holoviews/pull/4253))
- Add `hooks` plot option for Plotly backend
([4157](https://github.com/holoviz/holoviews/pull/4157))
- Support for split `Violin` plots in bokeh
([4112](https://github.com/holoviz/holoviews/pull/4112))

Bug fixes:

- Fixed radial `HeatMap` sizing issues
([4162](https://github.com/holoviz/holoviews/pull/4162))
- Switched to Panel for rendering machinery fixing various export issues
([3683](https://github.com/holoviz/holoviews/pull/3683))
- Handle updating of user supplied `HoverTool` in bokeh
([4266](https://github.com/holoviz/holoviews/pull/4266))
- Fix issues with single value datashaded plots
([3673](https://github.com/holoviz/holoviews/pull/3673))
- Fix legend layout issues
([3786](https://github.com/holoviz/holoviews/pull/3786))
- Fix linked axes issues with mixed date, categorical and numeric axes
in bokeh ([3845](https://github.com/holoviz/holoviews/pull/3845))
- Fixed handling of repeated dimensions in `PandasInterface`
([4139](https://github.com/holoviz/holoviews/pull/4139))
- Fixed various issues related to widgets
([3868](https://github.com/holoviz/holoviews/pull/3868),
[2885](https://github.com/holoviz/holoviews/pull/2885),
[1677](https://github.com/holoviz/holoviews/pull/1677),
[3212](https://github.com/holoviz/holoviews/pull/3212),
[1059](https://github.com/holoviz/holoviews/pull/1059),
[3027](https://github.com/holoviz/holoviews/pull/3027),
[3777](https://github.com/holoviz/holoviews/pull/3777))

Library compatibility:

- Better support for Pandas 1.0
([4254](https://github.com/holoviz/holoviews/pull/4254))
- Compatibility with Bokeh 2.0
([4226](https://github.com/holoviz/holoviews/pull/4226))

Migration notes:

- Geometry `.iloc` now indexes by geometry instead of by
datapoint. Convert to dataframe or dictionary before using `.iloc` to
access individual datapoints
([4104](https://github.com/holoviz/holoviews/pull/4104))
- Padding around plot elements is now enabled by default, to revert set
`hv.config.node_padding = 0`
([1090](https://github.com/holoviz/holoviews/pull/1090))
- Removed Bars `group_index` and `stack_index` options, which are now
controlled using the `stacked` option
([3985](https://github.com/holoviz/holoviews/pull/3985))
- `.table` is deprecated; use `.collapse` method instead and cast to
`Table` ([3985](https://github.com/holoviz/holoviews/pull/3985))
- `HoloMap.split_overlays` is deprecated and is now a private method
([3985](https://github.com/holoviz/holoviews/pull/3985))
- `Histogram.edges` and `Histogram.values` properties are deprecated; use
`dimension_values`
([3985](https://github.com/holoviz/holoviews/pull/3985))
- `Element.collapse_data` is deprecated; use the container's `.collapse`
method instead
([3985](https://github.com/holoviz/holoviews/pull/3985))
- `hv.output` `filename` argument is deprecated; use `hv.save` instead
([3985](https://github.com/holoviz/holoviews/pull/3985))

**November 22, 2019**

This a very minor hotfix release fixing an important bug related to
axiswise normalization between plots. Many thanks to srp3003 and
philippjfr for contributing to this release.

Enhancements:

- Add styles attribute to PointDraw stream for consistency with other
drawing streams
([3819](https://github.com/holoviz/holoviews/issues/3819))

Bug fixes:

- Fixed shared_axes/axiswise regression
([4097](https://github.com/holoviz/holoviews/pull/4097))

**October 8, 2019**

This is a minor release containing a large number of bug fixes thanks
to the contributions from joelostblom, ahuang11, chbrandt,
randomstuff, jbednar and philippjfr. It also contains a number of
enhancements. This is the last planned release in the 1.12.x series.

Enhancements:

- Ensured that shared_axes option on layout plots is respected across backends
([3410](https://github.com/pyviz/holoviews/issues/3410))
- Allow plotting partially irregular (curvilinear) mesh
([3952](https://github.com/pyviz/holoviews/issues/3952))
- Add support for dependent functions in dynamic operations
([3975](https://github.com/pyviz/holoviews/issues/3975),
[3980](https://github.com/pyviz/holoviews/issues/3980))
- Add support for fast QuadMesh rasterization with datashader >= 0.8
([4020](https://github.com/pyviz/holoviews/issues/4020))
- Allow passing Panel widgets as operation parameter
([4028](https://github.com/pyviz/holoviews/issues/4028))

Bug fixes:

- Fixed issue rounding datetimes in Curve step interpolation
([3958](https://github.com/pyviz/holoviews/issues/3958))
- Fix resampling of categorical colorcet colormaps
([3977](https://github.com/pyviz/holoviews/issues/3977))
- Ensure that changing the Stream source deletes the old source
([3978](https://github.com/pyviz/holoviews/issues/3978))
- Ensure missing hover tool does not break plot
([3981](https://github.com/pyviz/holoviews/issues/3981))
- Ensure .apply work correctly on HoloMaps
([3989](https://github.com/pyviz/holoviews/issues/3989),
[4025](https://github.com/pyviz/holoviews/issues/4025))
- Ensure Grid axes are always aligned in bokeh
([3916](https://github.com/pyviz/holoviews/issues/3916))
- Fix hover tool on Image and Raster plots with inverted axis
([4010](https://github.com/pyviz/holoviews/issues/4010))
- Ensure that DynamicMaps are still linked to streams after groupby
([4012](https://github.com/pyviz/holoviews/issues/4012))
- Using hv.renderer no longer switches backends
([4013](https://github.com/pyviz/holoviews/issues/4013))
- Ensure that Points/Scatter categorizes data correctly when axes are inverted
([4014](https://github.com/pyviz/holoviews/issues/4014))
- Fixed error creating legend for matplotlib Image artists
([4031](https://github.com/pyviz/holoviews/issues/4031))
- Ensure that unqualified Options objects are supported
([4032](https://github.com/pyviz/holoviews/issues/4032))
- Fix bounds check when constructing Image with ImageInterface
([4035](https://github.com/pyviz/holoviews/issues/4035))
- Ensure elements cannot be constructed with wrong number of columns
([4040](https://github.com/pyviz/holoviews/issues/4040))
- Ensure streaming data works on bokeh server
([4041](https://github.com/pyviz/holoviews/issues/4041))

Compatibility:

- Ensure HoloViews is fully compatible with xarray 0.13.0
([3973](https://github.com/pyviz/holoviews/issues/3973))
- Ensure that deprecated matplotlib 3.1 rcparams do not warn
([4042](https://github.com/pyviz/holoviews/issues/4042))
- Ensure compatibility with new legend options in bokeh 1.4.0
([4036](https://github.com/pyviz/holoviews/issues/4036))

**August 14, 2019**

This is a very minor bug fix release ensuring compatibility with recent
releases of dask.

Compatibility:

- Ensure that HoloViews can be imported when dask is installed but
dask.dataframe is not.
([3900](https://github.com/pyviz/holoviews/issues/3900))
- Fix for rendering Scatter3D with matplotlib 3.1
([3898](https://github.com/pyviz/holoviews/issues/3898))

**August 4, 2019**

This is a minor release with a number of bug and compatibility fixes
as well as a number of enhancements.

Many thanks to recent henriqueribeiro, poplarShift, hojo590,
stuarteberg, justinbois, schumann-tim, ZuluPro and jonmmease for
their contributions and the many users filing issues.

Enhancements:

- Add numpy log to dim transforms
([3731](https://github.com/pyviz/holoviews/issues/3731))
- Make Buffer stream following behavior togglable
([3823](https://github.com/pyviz/holoviews/issues/3823))
- Added internal methods to access dask arrays and made histogram
operation operate on dask arrays
([3854](https://github.com/pyviz/holoviews/issues/3854))
- Optimized range finding if Dimension.range is set
([3860](https://github.com/pyviz/holoviews/issues/3860))
- Add ability to use functions annotated with param.depends as
DynamicMap callbacks
([3744](https://github.com/pyviz/holoviews/issues/3744))

Bug fixes:

- Fixed handling datetimes on Spikes elements
([3736](https://github.com/pyviz/holoviews/issues/3736))
- Fix graph plotting for unsigned integer node indices
([3773](https://github.com/pyviz/holoviews/issues/3773))
- Fix sort=False on GridSpace and GridMatrix
([3769](https://github.com/pyviz/holoviews/issues/3769))
- Fix extent scaling on VLine/HLine annotations
([3761](https://github.com/pyviz/holoviews/issues/3761))
- Fix BoxWhisker to match convention
([3755](https://github.com/pyviz/holoviews/issues/3755))
- Improved handling of custom array types
([3792](https://github.com/pyviz/holoviews/issues/3792))
- Allow setting cmap on HexTiles in matplotlib
([3803](https://github.com/pyviz/holoviews/issues/3803))
- Fixed handling of data_aspect in bokeh backend
([3848](https://github.com/pyviz/holoviews/issues/3848),
[3872](https://github.com/pyviz/holoviews/issues/3872))
- Fixed legends on bokeh Path plots
([3809](https://github.com/pyviz/holoviews/issues/3809))
- Ensure Bars respect xlim and ylim
([3853](https://github.com/pyviz/holoviews/issues/3853))
- Allow setting Chord edge colors using explicit colormapping
([3734](https://github.com/pyviz/holoviews/issues/3734))
- Fixed bug in decimate operation
([3875](https://github.com/pyviz/holoviews/issues/3875))

Compatibility:

- Improve compatibility with deprecated matplotlib rcparams
([3745](https://github.com/pyviz/holoviews/issues/3745),
[3804](https://github.com/pyviz/holoviews/issues/3804))

Backwards incompatible changes:

- Unfortunately due to a major mixup the data_aspect option added in
1.12.0 was not correctly implemented and fixing it changed its
behavior significantly (inverting it entirely in some cases).
- A mixup in the convention used to compute the whisker of a
box-whisker plots was fixed resulting in different results going
forward.

**May 20, 2019**

This is a minor release primarily focused on a number of important bug
fixes. Thanks to our users for reporting issues, and special thanks to
the internal developers philippjfr and jlstevens and external
developers including poplarShift, fedario and odoublewen for their
contributions.

Bug fixes:

- Fixed regression causing unhashable data to cause errors in streams
([3681](https://github.com/pyviz/holoviews/issues/3681)
- Ensure that hv.help handles non-HoloViews objects
([3689](https://github.com/pyviz/holoviews/issues/3689))
- Ensure that DataLink handles data containing NaNs
([3694](https://github.com/pyviz/holoviews/issues/3694))
- Ensure that bokeh backend handles Cycle of markers
([3706](https://github.com/pyviz/holoviews/issues/3706))
- Fix for using opts method on DynamicMap
([3691](https://github.com/pyviz/holoviews/issues/3691))
- Ensure that bokeh backend handles DynamicMaps with variable length
NdOverlay ([3696](https://github.com/pyviz/holoviews/issues/3696))
- Fix default width/height setting for HeatMap
([3703](https://github.com/pyviz/holoviews/issues/3703))
- Ensure that dask imports handle modularity
([3685](https://github.com/pyviz/holoviews/issues/3685))
- Fixed regression in xarray data interface
([3724](https://github.com/pyviz/holoviews/issues/3724))
- Ensure that RGB hover displays the integer RGB value
([3727](https://github.com/pyviz/holoviews/issues/3727))
- Ensure that param streams handle subobjects
([3728](https://github.com/pyviz/holoviews/pull/3728))