.. doctest-skip-all

.. _whatsnew-4.1:

************************
What's New in sunpy 4.1?
************************
The SunPy project is pleased to announce the 4.1 release of the ``sunpy`` core package.

On this page, you can read about some of the big changes in this release.

.. contents::
    :local:
    :depth: 1

``sunpy`` 4.1 also includes a large number of smaller improvements and bug fixes, which are described in the :ref:`changelog`.

This release of ``sunpy`` contains 1408 commits in 191 merged pull requests closing 86 issues from 28 people, 18 of which are first-time contributors.

* 1408 commits have been added since 4.0
* 86 issues have been closed since 4.0
* 191 pull requests have been merged since 4.0
* 28 people have contributed since 4.0
* 18 of which are new contributors

The people who have contributed to the code for this release are:

-  Akash Verma  *
-  Alasdair Wilson
-  Albert Y. Shih
-  Alex Kaszynski  *
-  Alex W  *
-  Andy Tang  *
-  Chris Bard  *
-  Conor MacBride
-  Daniel Garcia Briseno  *
-  David Stansby
-  Jan Gieseler  *
-  Jia Qing  *
-  Karthikeyan Singaravelan  *
-  Krish Agrawal  *
-  Laura Hayes
-  Lazar Zivadinovic
-  Marius Giger  *
-  Matt Wentzel-Long  *
-  Nabil Freij
-  Naveen Srinivasan  *
-  Stuart Mumford
-  Timo Laitinen  *
-  Will Barnes
-  William Jamieson  *
-  William Russell  *
-  tal66  *

Where a * indicates that this release contains their first contribution to ``sunpy``.

Extracting map values along coordinate paths
============================================
It is now easy to extract data values from a `~sunpy.map.GenericMap` along a curve specified by set of coordinates using the new ``sunpy.map.extract_along_coord`` function.
This is done by applying `Bresenham's line algorithm <http://en.wikipedia.org/wiki/Bresenham%27s_line_algorithm>`__ between the consecutive coordinates, in pixel space, and then indexing the data array of the map at those points.

Easier reprojecting to Carrington and Stonyhurst coordinates
============================================================
``sunpy.map.header_helper`` has a new :func:`~sunpy.map.header_helper.make_heliographic_header` function that simplifies creating map headers that span the whole solar surface in Carrington or Stonyhurst coordinates.
When used in combination with :meth:`sunpy.map.GenericMap.reproject_to` this greatly simplifies reprojecting helioprojective maps into heliographic full-Sun maps.

.. minigallery:: sunpy.map.make_heliographic_header

Drawing the solar equator and prime meridian
============================================
The new `sunpy.visualization.drawing` module can be used to draw the solar equator and prime meridian (zero Carrington longitude) on a plot with Astropy WCS Axes.

.. minigallery:: sunpy.visualization.drawing.equator

Sample data downloaded on demand
================================
The sample data files provided through `sunpy.data.sample` are now downloaded individually on demand rather than being all downloaded upon import of that module.
All the sample data files can still be downloaded at once by calling :func:`sunpy.data.sample.download_all`.

``sunpy.database`` deprecation
==============================
The ``sunpy.database`` module is no longer actively maintained and has a number of outstanding issues.
It is anticipated that sunpy.database will be formally deprecated in sunpy 5.0 and removed in sunpy 6.0.
If you are using sunpy.database and would like to see a replacement, please join the discussion thread at https://community.openastronomy.org/t/deprecating-sunpy-database/495.

``sunpy.visualization.limb`` moved
==================================
``sunpy.visualization.limb.draw_limb`` has been moved into the `sunpy.visualization.drawing` module and renamed :func:`sunpy.visualization.drawing.limb`.
The ``sunpy.visualization.limb`` module will remain working, but is deprecated and will be removed in version 5.1.

``HelioviewerClient`` deprecated
================================
The Helioviewer Project now maintains a Python Wrapper called `hvpy <https://hvpy.readthedocs.io/en/latest/>`__.
As such, in consultation with the Helioviewer Project, the ``sunpy.net.helioviewer`` module is deprecated and will be removed in sunpy 5.1.

Changes to timeseries plotting
==============================
To make plotting a timeseries as source-independent as possible, a number of source-specific plot customisations in ``peek()`` and ``plot()`` methods have been removed.
See the changelog for full details on what has changed.

To harmonize different ``peek()`` and ``plot()`` signatures, all non-keyword arguments to these methods are deprecated.
To avoid a warning pass all arguments with keywords (e.g. ``plot(title='my plot title')``) instead.

Updated data downloader dependency
==================================
The package that handles downloading data from remote sources, ``parfive``, has had a recent major release to version 2.0.
This new version comes with major usability improvements: removal of incomplete files and major error reporting upgrades.

sunpy users are encouraged to upgrade ``parfive`` to benefit from these improvements.
To upgrade you can use pip:

.. code-block:: bash

    $ pip install -U parfive

or conda:

.. code-block:: bash

    $ conda update parfive
