Datashader

---------------------------

This release contains an important bug fix to ensure that categorical column order in maintained across dask partitions. It also adds support for categorical inspection reductions such as ``by(max_n)``. The only missing functionality for inspection reductions is now antialiased lines, which in planned for the next release.

Thanks to contributors `ianthomas23 <https://github.com/ianthomas23>`_, `maximlt <https://github.com/maximlt>`_ and `philippjfr <https://github.com/philippjfr>`_.

Bug fixes:

- Fix single category reductions (`1231 <https://github.com/holoviz/datashader/pull/1231>`_)
- Ensure categorical column order is the same across dask partitions (`1239 <https://github.com/holoviz/datashader/pull/1239>`_)

Enhancements:

* Categorical inspection reductions:

- Support ``by(max_n)`` and ``by(min_n)`` (`1229 <https://github.com/holoviz/datashader/pull/1229>`_)
- Categorical ``max_row_index``, ``max_n_row_index`` and ``min`` equivalents (`1233 <https://github.com/holoviz/datashader/pull/1233>`_)
- Use enum for row index column rather than ``None`` (`1234 <https://github.com/holoviz/datashader/pull/1234>`_)
- Add support for categorical ``where`` reductions (`1237 <https://github.com/holoviz/datashader/pull/1237>`_)
- Add tests for handling of NaNs in ``where`` reductions (`1241 <https://github.com/holoviz/datashader/pull/1241>`_)

* General code improvements:

- Only check ``dask.DataFrame`` ``dtypes`` of columns actually used (`1236 <https://github.com/holoviz/datashader/pull/1236>`_)
- Remove all use of ``OrderedDict`` (`1242 <https://github.com/holoviz/datashader/pull/1242>`_)
- Separate out 3d and 4d combine functions (`1243 <https://github.com/holoviz/datashader/pull/1243>`_)
- Reorganise antialiasing code (`1245 <https://github.com/holoviz/datashader/pull/1245>`_)

Improvements to CI:

- Bump holoviz tasks (`1240 <https://github.com/holoviz/datashader/pull/1240>`_)
- Add image is close test helper (`1244 <https://github.com/holoviz/datashader/pull/1244>`_)

Improvements to documentation:

- Update to Google Analytics 4 (`1228 <https://github.com/holoviz/datashader/pull/1228>`_)
- Rename pyviz-dev as holoviz-dev (`1232 <https://github.com/holoviz/datashader/pull/1232>`_)

---------------------------

This release provides significant improvements for inspection reductions by adding new ``first_n``, ``last_n``, ``max_n`` and ``min_n`` reductions, and providing Dask and CUDA support for all existing and new inspection reductions including ``where``. It also provides support for Numba 0.57, NumPy 1.24 and Python 3.11, and drops support for Python 3.7.

Thanks to first-time contributors `danigm <https://github.com/danigm>`_ and `Jap8nted <https://github.com/Jap8nted>`_, and also regulars `Hoxbro <https://github.com/Hoxbro>`_, `philippjfr <https://github.com/philippjfr>`_ and `ianthomas23 <https://github.com/ianthomas23>`_

Enhancements:

* Inspection reductions:

- Reduction append functions return index not boolean (`1180 <https://github.com/holoviz/datashader/pull/1180>`_)
- ``first_n``, ``last_n``, ``max_n`` and ``min_n`` reductions (`1184 <https://github.com/holoviz/datashader/pull/1184>`_)
- Add ``cuda`` argument to ``_build_combine`` (`1194 <https://github.com/holoviz/datashader/pull/1194>`_)
- Support ``max_n`` and ``min_n`` reductions on GPU (`1196 <https://github.com/holoviz/datashader/pull/1196>`_)
- Use fast cuda mutex available in numba 0.57 (`1212 <https://github.com/holoviz/datashader/pull/1212>`_)
- Dask support for ``first``, ``last``, ``first_n`` and ``last_n`` reductions (`1214 <https://github.com/holoviz/datashader/pull/1214>`_)
- Wrap use of cuda mutex in ``where`` reductions (`1217 <https://github.com/holoviz/datashader/pull/1217>`_)
- Cuda and cuda-with-dask support for inspection reductions (`1219 <https://github.com/holoviz/datashader/pull/1219>`_)

* x and y range attributes on returned aggregations (`1198 <https://github.com/holoviz/datashader/pull/1198>`_)

* Make ``datashader.composite`` imports lazy for faster import time (`1222 <https://github.com/holoviz/datashader/pull/1222>`_)

* Improvements to CI:

- Cancel concurrent test workflows (`1208 <https://github.com/holoviz/datashader/pull/1208>`_)

* Improvements to documentation:

- Inspection reduction documentation (`1186 <https://github.com/holoviz/datashader/pull/1186>`_, `#1190 <https://github.com/holoviz/datashader/pull/1190>`_)
- Upgrade to latest nbsite and pydata-sphinx-theme (`1221 <https://github.com/holoviz/datashader/pull/1221>`_)
- Use geodatasets in example data

Bug fixes:

* Fix conversion from ``cupy`` in categorical ``rescale_discrete_levels`` (`1179 <https://github.com/holoviz/datashader/pull/1179>`_)
* Validate canvas ``width``, ``height`` (`1183 <https://github.com/holoviz/datashader/pull/1183>`_)
* Support antialiasing in pipeline API (`1213 <https://github.com/holoviz/datashader/pull/1213>`_)

Compatibility:

* NumPy 1.24 compatibility (`1176 <https://github.com/holoviz/datashader/pull/1176>`_, `#1185 <https://github.com/holoviz/datashader/pull/1185>`_, `#1218 <https://github.com/holoviz/datashader/pull/1218>`_)

* Numba 0.57 compatibility (`1205 <https://github.com/holoviz/datashader/pull/1205>`_)

---------------------------

This release adds a new ``where`` reduction that provides improved inspection capabilities and adds support for colormaps that are tuples of hex values. There are also various bug fixes and compatibility improvements.

Thanks to `ianthomas23 <https://github.com/ianthomas23>`_, `maximlt <https://github.com/maximlt>`_ and `Hoxbro <https://github.com/Hoxbro>`_.

Enhancements:

* New ``where`` reduction to provide improved inspection functionality:

- Add new where reduction (`1155 <https://github.com/holoviz/datashader/pull/1155>`_)
- Where reduction using dataframe row index (`1164 <https://github.com/holoviz/datashader/pull/1164>`_)
- CUDA support for where reduction (`1167 <https://github.com/holoviz/datashader/pull/1167>`_)
- User guide page for where reduction (`1172 <https://github.com/holoviz/datashader/pull/1172>`_)

* Support colormaps that are tuples of hex values (`1173 <https://github.com/holoviz/datashader/pull/1173>`_)

* Add governance docs (`1165 <https://github.com/holoviz/datashader/pull/1165>`_)

* Improve documentation build system (`1170 <https://github.com/holoviz/datashader/pull/1170>`_, `#1171 <https://github.com/holoviz/datashader/pull/1171>`_)

* Improvements to CI:

- Rename default branch from ``master`` to ``main`` (`1156 <https://github.com/holoviz/datashader/pull/1156>`_)
- Use holoviz_task install action (`1163 <https://github.com/holoviz/datashader/pull/1163>`_)

Bug fixes:

* Validate calculated log canvas range (`1154 <https://github.com/holoviz/datashader/pull/1154>`_)

* Better validate ``canvas.line()`` coordinate lengths (`1160 <https://github.com/holoviz/datashader/pull/1160>`_)

* Return early in ``eq_hist()`` if all data masked out (`1168 <https://github.com/holoviz/datashader/pull/1168>`_)

Compatibility:

* Follow recommended ``numba`` best practice.

- Ensure cuda functions are correctly jitted (`1153 <https://github.com/holoviz/datashader/pull/1153>`_)
- ``nopython=True`` everywhere (`1162 <https://github.com/holoviz/datashader/pull/1162>`_)

* Update dependencies:

- Pip ``pyarrow`` in tests dependencies (`1174 <https://github.com/holoviz/datashader/pull/1174>`_)

---------------------------

This release fixes a bug related to spatial indexing of ``spatialpandas.GeoDataFrames``, and introduces enhancements to antialiased lines, benchmarking and GPU support.

Thanks to first-time contributors `eriknw <https://github.com/eriknw>`_ and `raybellwaves <https://github.com/raybellwaves>`_, and also `ianthomas23 <https://github.com/ianthomas23>`_ and `maximlt <https://github.com/maximlt>`_.

Enhancements:

* Improvements to antialiased lines:

- Fit antialiased line code within usual numba/dask framework (`1142 <https://github.com/holoviz/datashader/pull/1142>`_)
- Refactor stage 2 aggregation for antialiased lines (`1145 <https://github.com/holoviz/datashader/pull/1145>`_)
- Support compound reductions for antialiased lines on the CPU (`1146 <https://github.com/holoviz/datashader/pull/1146>`_)

* New benchmark framework:

- Add benchmarking framework using ``asv`` (`1120 <https://github.com/holoviz/datashader/pull/1120>`_)
- Add ``cudf``, ``dask`` and ``dask-cudf`` ``Canvas.line`` benchmarks (`1140 <https://github.com/holoviz/datashader/pull/1140>`_)

* Improvements to GPU support:

- Cupy implementation of eq_hist (`1129 <https://github.com/holoviz/datashader/pull/1129>`_)

* Improvements to documentation:

- Fix markdown syntax for link (`1119 <https://github.com/holoviz/datashader/pull/1119>`_)
- DOC: add text link to https://examples.pyviz.org/datashader_dashboard (`#1123 <https://github.com/holoviz/datashader/pull/1123>`_)

* Improvements to dependency management (`1111 <https://github.com/holoviz/datashader/pull/1111>`_, `#1116 <https://github.com/holoviz/datashader/pull/1116>`_)

* Improvements to CI (`1132 <https://github.com/holoviz/datashader/pull/1132>`_, `#1135 <https://github.com/holoviz/datashader/pull/1135>`_, `#1136 <https://github.com/holoviz/datashader/pull/1136>`_, `#1137 <https://github.com/holoviz/datashader/pull/1137>`_, `#1143 <https://github.com/holoviz/datashader/pull/1143>`_)

Bug fixes:

* Ensure spatial index ``_sindex`` is retained on dataframe copy (`1122 <https://github.com/holoviz/datashader/pull/1122>`_)

---------------------------

This is a bug fix release to fix an important divide by zero bug in antialiased lines, along with improvements to documentation and handling of dependencies.

Thanks to `ianthomas23 <https://github.com/ianthomas23>`_ and `adamjhawley <https://github.com/adamjhawley>`_.

Enhancements:

* Improvements to documentation:

- Fix links in docs when viewed in browser (`1102 <https://github.com/holoviz/datashader/pull/1102>`_)
- Add release notes (`1108 <https://github.com/holoviz/datashader/pull/1108>`_)

* Improvements to handling of dependencies:

- Correct dask and bokeh dependencies (`1104 <https://github.com/holoviz/datashader/pull/1104>`_)
- Add requests as an install dependency (`1105 <https://github.com/holoviz/datashader/pull/1105>`_)
- Better handle returned dask npartitions in tests (`1107 <https://github.com/holoviz/datashader/pull/1107>`_)

Bug fixes:

* Fix antialiased line divide by zero bug (`1099 <https://github.com/holoviz/datashader/pull/1099>`_)

---------------------------

This release provides a number of important bug fixes and small enhancements from Ian Thomas along with infrastructure improvements from Maxime Liquet and new reductions from `tselea <https://github.com/tselea>`_.

Enhancements:

* Improvements to `antialiased lines <https://datashader.org/user_guide/Timeseries.html#antialiasing>`_:

- Support antialiased lines for categorical aggregates (`1081 <https://github.com/holoviz/datashader/pull/1081>`_, `#1083 <https://github.com/holoviz/datashader/pull/1083>`_)
- Correctly handle NaNs in antialiased line coordinates (`1097 <https://github.com/holoviz/datashader/pull/1097>`_)

* Improvements to ``rescale_discrete_levels`` for ``how='eq_hist'``:

- Correct implementation of ``rescale_discrete_levels`` (`1078 <https://github.com/holoviz/datashader/pull/1078>`_)
- Check before calling ``rescale_discrete_levels`` (`1085 <https://github.com/holoviz/datashader/pull/1085>`_)
- Remove empty histogram bins in ``eq_hist`` (`1094 <https://github.com/holoviz/datashader/pull/1094>`_)

* Implementation of first and last reduction (`1093 <https://github.com/holoviz/datashader/pull/1093>`_) for data types other than raster.

Bug fixes:

* Do not snap trimesh vertices to pixel grid (`1092 <https://github.com/holoviz/datashader/pull/1092>`_)
* Correctly orient (y, x) arrays for xarray (`1095 <https://github.com/holoviz/datashader/pull/1095>`_)
* Infrastructure/build fixes (`1080 <https://github.com/holoviz/datashader/pull/1080>`_, `#1089 <https://github.com/holoviz/datashader/pull/1089>`_, `#1096 <https://github.com/holoviz/datashader/pull/1096>`_)