.. comment: -*- fill-column: 72; mode: rst -*-

=========
 CHANGES
=========

.. _firstrelease:

0.1 (2018/01/11): initial release. Features:
--------------------------------------------

* The :ref:`\\poldef <poldef;>` parser itself,
* Differentiation and anti-differentiation,
* Euclidean division and GCDs,
* Various utilities such as :ref:`\\PolFromCSV <PolFromCSV>`,
  :ref:`\\PolMapCoeffs <PolMapCoeffs>`,
  :ref:`\\PolToCSV <PolToCSV>`, :ref:`\\PolToExpr <PolToExpr>`, ...

Only one-variable polynomials so far.

0.2 (2018/01/14)
----------------

* Fix: ``"README thinks \numexpr recognizes ^ operator"``.
* Convert README to reStructuredText markup.
* Move main documentation from README to separate ``polexpr.txt`` file.
* Provide ``polexpr.html`` as obtained via DocUtils_ ``rst2html.py``.
* Convert README to (CTAN compatible) Markdown markup.

Due to lack of available time the test suite might not be extensive
enough. Bug reports are very welcome!

0.3 (2018/01/17)
----------------

* Bug fixes:

  - The ``0.1`` :ref:`\\PolEval <PolEvalAt>` accepted expressions for its
    second argument, but this was removed by mistake at ``0.2``. Restored.

    **Attention**: at ``0.4`` this has been reverted again, and
    :ref:`\\PolEval{P}\\AtExpr{foo} <PolEvalAtExpr>` syntax is needed for
    using expressions in the second argument.
* Incompatible or breaking changes:

  - :ref:`\\PolToExpr <PolToExpr>` now by default uses *descending*
    powers (it also treats differently coefficients equal to 1 or -1.)
    Use :ref:`\\PolToExpr* <PolToExpr*>` for *ascending* powers.
  - :ref:`\\PolEval <PolEvalAt>` reduced the output to smallest terms,
    but as this is costly with big fractions and not needed if e.g.
    wrapped in an ``\xintRound`` or ``\xintFloat``, this step has been
    removed; the former meaning is available as 
    :ref:`\\PolEvalReduced <PolEvalReducedAt>`.
* New (or newly documented) macros:

  - :ref:`\\PolTypesetCmd <PolTypesetCmd>`
  - :ref:`\\PolTypesetCmdPrefix <PolTypesetCmdPrefix>`
  - :ref:`\\PolTypesetMonomialCmd <PolTypesetMonomialCmd>`
  - :ref:`\\PolEvalReducedAt <PolEvalReducedAt>`
  - :ref:`\\PolToFloatExpr <PolToFloatExpr>`
  - :ref:`\\PolToExprOneTerm <PolToExprOneTerm>`
  - :ref:`\\PolToFloatExprOneTerm <PolToFloatExprOneTerm>`
  - :ref:`\\PolToExprCmd <PolToExprCmd>`
  - :ref:`\\PolToFloatExprCmd <PolToFloatExprCmd>`
  - :ref:`\\PolToExprTermPrefix <PolToExprTermPrefix>`
  - :ref:`\\PolToExprVar <PolToExprVar>`
  - :ref:`\\PolToExprTimes <PolToExprTimes>`
* Improvements:

  - Documentation has a table of contents, internal hyperlinks,
    standardized signature notations and added explanations.
  - One can do ``\PolLet{g}={f}`` or ``\PolLet{g}{f}``.
  - ``\PolToExpr{f}`` is highly customizable.
  - :ref:`\\poldef <poldef;>` and other defining macros prepare the
    polynomial functions for usage within ``\xintthefloatexpr`` (or
    ``\xintdeffloatvar``). Coefficients are pre-rounded to the floating
    point precision. Indispensible for numerical algorithms, as exact
    fractions, even reduced, quickly become very big. See the documentation
    about how to use the exact polynomials also in floating point context.

    **Attention**: this has been reverted at ``0.4``. The macro
    :ref:`\\PolGenFloatVariant <PolGenFloatVariant>` must be used for
    generation floating point polynomial functions.

0.3.1 (2018/01/18)
------------------

Fixes two typos in example code included in the documentation.

0.4 (2018/02/16)
----------------

* Bug fixes:

  - When Euclidean division gave a zero remainder, the internal
    representation of this zero polynomial could be faulty; this
    could cause mysterious bugs in conjunction with other package
    macros such as :ref:`\\PolMapCoeffs <PolMapCoeffs>`.
  - :ref:`\\PolGCD <PolGCD>` was buggy in case of first polynomial being
    of lesser degree than the second one.
* Breaking changes:

  - Formerly :ref:`\\PolEval{P}\\At{foo} <PolEvalAt>` allowed ``foo`` to
    be an expression, which was transparently handled via
    ``\xinttheexpr``. Now, ``foo`` must be a fraction (or a macro
    expanding to such) in the format acceptable by ``xintfrac.sty``
    macros. Use :ref:`\\PolEval{P}\\AtExpr{foo} <PolEvalAtExpr>` for more
    general arguments using expression syntax. E.g., if ``foo`` is the
    name of a variable known to ``\xintexpr``.

    The same holds for :ref:`\\PolEvalReduced <PolEvalReducedAt>`
    and :ref:`\\PolFloatEval <PolFloatEvalAt>`.
  - The ``3.0`` automatic generation of floating point variants has
    been reverted. Not only do *not* the package macros automatically
    generate floating point variants of newly created polynomials,
    they actually make pre-existing such variant undefined.

    See :ref:`\\PolGenFloatVariant <PolGenFloatVariant>`.
* New non-expandable macros:

  - :ref:`\\PolGenFloatVariant <PolGenFloatVariant>`
  - :ref:`\\PolGlobalLet <PolGlobalLet>`
  - :ref:`\\PolTypesetOne <PolTypesetOne>`
  - :ref:`\\PolQuo <PolQuo>`
  - :ref:`\\PolRem <PolRem>`
  - :ref:`\\PolToSturm <PolToSturm>`
  - :ref:`\\PolToSturm\* <PolToSturm*>`
  - :ref:`\\PolSetToSturmChainSignChangesAt <PolSetToSturmChainSignChangesAt>`
  - :ref:`\\PolSetToNbOfZerosWithin <PolSetToNbOfZerosWithin>`
  - :ref:`\\PolSturmIsolateZeros <PolSturmIsolateZeros>`
  - :ref:`\\PolRefineInterval* <PolRefineInterval*>`
  - :ref:`\\PolRefineInterval[N] <PolRefineInterval[]>`
  - :ref:`\\PolEnsureIntervalLength <PolEnsureIntervalLength>`
  - :ref:`\\PolEnsureIntervalLengths <PolEnsureIntervalLengths>`
  - :ref:`\\PolPrintIntervals <PolPrintIntervals>`
  - :ref:`\\PolPrintIntervalsPrintExactZero <PolPrintIntervalsPrintExactZero>`
  - :ref:`\\PolPrintIntervalsPrintLeftEndPoint <PolPrintIntervalsPrintLeftEndPoint>`
  - :ref:`\\PolPrintIntervalsPrintRightEndPoint <PolPrintIntervalsPrintRightEndPoint>`
  - :ref:`\\PolReduceCoeffs* <PolReduceCoeffs*>`
  - :ref:`\\PolMakeMonic <PolMakeMonic>`
* New expandable macros:

  - :ref:`\\PolToExprOneTermStyleA <PolToExprOneTermStyleA>`
  - :ref:`\\PolIfCoeffIsPlusOrMinusOne <PolIfCoeffIsPlusOrMinusOne>`
  - :ref:`\\PolLeadingCoeff <PolLeadingCoeff>`
  - :ref:`\\PolSturmChainLength <PolSturmChainLength>`
  - :ref:`\\PolSturmNbOfIsolatedZeros <PolSturmNbOfIsolatedZeros>`
  - :ref:`\\PolSturmIfZeroExactlyKnown <PolSturmIfZeroExactlyKnown>`
  - :ref:`\\PolSturmIsolatedZeroLeft <PolSturmIsolatedZeroLeft>`
  - :ref:`\\PolSturmIsolatedZeroRight <PolSturmIsolatedZeroRight>`
  - ``\PolPrintIntervalsTheEndPoint`` (removed at 0.7)
  - :ref:`\\PolPrintIntervalsTheIndex <PolPrintIntervalsTheIndex>`
  - ``\PolIfEndPointIsPositive`` (removed at 0.7)
  - ``\PolIfEndPointIsNegative`` (removed at 0.7)
  - ``\PolIfEndPointIsZero`` (removed at 0.7)
  - :ref:`\\PolIntervalWidth <PolIntervalWidth>`
  - :ref:`\\PolDecToString <PolDecToString>`
* Improvements:

  The main new feature is implementation of the `Sturm algorithm`_
  for localization of the real roots of polynomials.

0.4.1 (2018/03/01)
------------------

Synced with xint 1.3.

0.4.2 (2018/03/03)
------------------

Documentation fix.

0.5 (2018/04/08)
----------------

* Bug fix:

  - :ref:`\\PolGet{polname}\\fromarray\\macro <PolGet>`
    crashed when ``\macro`` was
    an xinttools_ array macro with no items. It now produces the zero
    polynomial.
* Breaking changes:

  - :ref:`\\PolToSturm <PolToSturm>` creates primitive integer coefficients
    polynomials. This speeds up localization of roots via
    :ref:`\\PolSturmIsolateZeros <PolSturmIsolateZeros>`. In case of user
    protests the author will make available again the code producing the
    bona fide Sturm polynomials as used formerly.
  - Polynomials created from :ref:`\\PolFromCSV <PolFromCSV>` or 
    :ref:`\\PolGet <PolGet>`
    get their coefficients normalized via xintfrac_\ 's ``\xintRaw``.
* Experimental change:

  - Optional argument to :ref:`\\PolSturmIsolateZeros <PolSturmIsolateZeros>`
    (see ``The degree 41 polynomial with -2, -1.9, -1.8, ..., 0, 0.1, ...,
    1.9, 2 as roots`` in ``polexpr-examples.pdf``). It will presumably be
    replaced in future by an interval specification.
* New non-expandable macro:

  - :ref:`\\PolMakePrimitive <PolMakePrimitive>`
* New expandable macro:

  - :ref:`\\PolIContent <PolIContent>`
    
0.5.1 (2018/04/22)
------------------

* New feature:

  - The character ``'`` can be used in polynomial names.

0.6 (2018/11/20)
----------------

* Bug fixes:

  - The starred variant
    :ref:`\\PolToSturm*{\<polname\>}{\<sturmname\>} <PolToSturm*>`
    was broken. On the occasion of the fix, its meaning has
    been modified, see its documentation.

  - Using :ref:`\\PolToSturm <PolToSturm>` with a constant polynomial
    caused a division by zero error.

* New macro:

  - :ref:`\\PolSturmIsolateZeros* <PolSturmIsolateZeros*>`
    acts like the :ref:`non-starred variant
    <PolSturmIsolateZeros>` then computes all the multiplicities.

* New expandable macros:

  - :ref:`\\PolSturmIsolatedZeroMultiplicity{\<sturmname\>}{\<index\>} <PolSturmIsolatedZeroMultiplicity>`
  - :ref:`\\PolSturmNbOfRootsOf{\<sturmname\>}\\LessThanOrEqualTo{\<value\>} <PolSturmNbOfRootsOfLessThanOrEqualTo>`
  - :ref:`\\PolSturmNbOfRootsOf{\<sturmname\>}\\LessThanOrEqualToExpr{\<num. expr.\>} <PolSturmNbOfRootsOfLessThanOrEqualToExpr>`
  - :ref:`\\PolSturmNbWithMultOfRootsOf{\<sturmname\>}\\LessThanOrEqualTo{\<value\>} <PolSturmNbWithMultOfRootsOfLessThanOrEqualTo>`
  - :ref:`\\PolSturmNbWithMultOfRootsOf{\<sturmname\>}\\LessThanOrEqualToExpr{\<num. expr.\>} <PolSturmNbWithMultOfRootsOfLessThanOrEqualToExpr>`

0.7 (2018/12/08), 0.7.1 (bugfix), 0.7.2 (2nd bugfix) (2018/12/09)
-----------------------------------------------------------------

* Breaking changes:

  - Although :ref:`\\PolPrintIntervals[\<varname\>]{\<sturmname\>} <PolPrintIntervals>` default output
    remains the same, some auxiliary macros for user-customization
    have been removed: ``\PolPrintIntervalsTheEndPoint``,
    ``\PolIfEndPointIsPositive{T}{F}``,
    ``\PolIfEndPointIsNegative{T}{F}``, and
    ``\PolIfEndPointIsZero{T}{F}``.

* Bug fixes:

  - It could happen that, contrarily to documentation, an interval computed
    by :ref:`\\PolSturmIsolateZeros{\<sturmname\>} <PolSturmIsolateZeros>` had
    zero as an endpoint,
  - :ref:`\\PolEnsureIntervalLength{\<sturmname\>}{\<index\>}{\<exponent\>}
    <PolEnsureIntervalLength>` could under certain circumstances erroneously
    replace a non-zero root by zero,
  - :ref:`\\PolEnsureIntervalLengths{\<sturmname\>}{\<exponent\>}
    <PolEnsureIntervalLengths>` crashed when used with a polynomial with no
    real roots, hence for which no isolation intervals existed (thanks to
    Thomas Söll for report).

* New macros:

  - :ref:`\\PolSturmIsolateZeros**{\<sturmname\>} <PolSturmIsolateZeros**>`
  - :ref:`\\PolSturmIsolateZerosGetMultiplicitiesAndRationalRoots{\<sturmname\>} <PolSturmIsolateZerosGetMultiplicitiesAndRationalRoots>`
  - :ref:`\\PolSturmIsolateZerosAndFindRationalRoots{\<sturmname\>} <PolSturmIsolateZerosAndFindRationalRoots>`
  - :ref:`\\polexprsetup <polexprsetup>`
  - :ref:`\\PolPrintIntervals* <PolPrintIntervals*>`
  - :ref:`\\PolPrintIntervalsNoRealRoots <PolPrintIntervalsNoRealRoots>`
  - :ref:`\\PolPrintIntervalsBeginEnv <PolPrintIntervalsBeginEnv>`
  - :ref:`\\PolPrintIntervalsEndEnv <PolPrintIntervalsEndEnv>`
  - :ref:`\\PolPrintIntervalsKnownRoot <PolPrintIntervalsKnownRoot>`
  - :ref:`\\PolPrintIntervalsUnknownRoot <PolPrintIntervalsUnknownRoot>`
  - :ref:`\\PolPrintIntervalsPrintMultiplicity <PolPrintIntervalsPrintMultiplicity>`

* New expandable macros:

  - :ref:`\\PolSturmNbOfRationalRoots{\<sturmname\>} <PolSturmNbOfRationalRoots>`
  - :ref:`\\PolSturmNbOfRationalRootsWithMultiplicities{\<sturmname\>} <PolSturmNbOfRationalRootsWithMultiplicities>`
  - :ref:`\\PolSturmRationalRoot{\<sturmname\>}{\<k\>} <PolSturmRationalRoot>`
  - :ref:`\\PolSturmRationalRootIndex{\<sturmname\>}{\<k\>} <PolSturmRationalRootIndex>`
  - :ref:`\\PolSturmRationalRootMultiplicity{\<sturmname\>}{\<k\>} <PolSturmRationalRootMultiplicity>`
  - :ref:`\\PolPrintIntervalsTheVar <PolPrintIntervalsTheVar>`
  - :ref:`\\PolPrintIntervalsTheSturmName <PolPrintIntervalsTheSturmName>`
  - :ref:`\\PolPrintIntervalsTheMultiplicity <PolPrintIntervalsTheMultiplicity>`

0.7.3 (2019/02/04)
------------------

* Bug fixes:

  - Debugging information not destined to user showed in log if root
    finding was done under ``\xintverbosetrue`` regime.
  - :ref:`\\PolPrintIntervalsTheVar <PolPrintIntervalsTheVar>` remained
    defined after :ref:`\\PolPrintIntervals <PolPrintIntervals>` but was
    left undefined after :ref:`\\PolPrintIntervals* <PolPrintIntervals*>`
    (reported by Jürgen Gilg). Now remains defined in both cases, and
    :ref:`\\PolPrintIntervalsTheSturmName <PolPrintIntervalsTheSturmName>`
    also.
  - Polynomial names ending in digits caused errors (reported by Thomas
    Söll).

0.7.4 (2019/02/12)
------------------

* Bug fix:

  - 20000000000 is too big for ``\numexpr``, shouldn't I know that?
    Thanks to Jürgen Gilg for report.

0.7.5 (2020/01/31)
------------------

Synced with xintexpr 1.4. Requires it.

.. _polexpr08release:

0.8 (2021/03/29)
----------------

Synced with xintexpr 1.4d. Requires it.

* Breaking changes:

  - As the usability of character ``'`` in names has been extended
    from ``\poldef`` to also generally ``\xintexpr``, ``\xintdefvar``,
    and ``\xintdeffunc``, it means that the infix operators
    ``'and'``, ``'or'``, and ``'mod'`` must be replaced
    by ``&&``, ``||``, and ``/:`` if they
    follow immediately a variable name (similarly ``'xor'`` must
    be replaced by the ``xor()`` function in such case).

  - :ref:`\\PolToExpr <PolToExpr>` by default uses a catcode 12
    ``^``. See its documentation and the new configuration
    :ref:`\\PolToExprCaret <PolToExprCaret>`.

* Deprecated:

  - Usage of ``P/Q`` for the euclidean quotient of two polynomials is
    deprecated.  Start using ``quo(P,Q)`` in its place.

* Bug fixes:

  - The ``\xintglobaldefstrue`` setting was obeyed only partially
    by the polexpr macros defining polynomials.

  - The ``\xintexpr`` variables storing the values of the extremities of the
    intervals as found by :ref:`\\PolSturmIsolateZeros
    <PolSturmIsolateZeros>` were not updated at 0.7.5 to the xintexpr 1.4
    format and thus caused low-level TeX errors if used.

  - Attempting to use in ``\poldef`` a function previously declared
    via ``\xintdeffunc`` which made usage of the indexing or slicing
    "ople" syntax typically caused ``TeX capacity exceeded`` error.
    Indeed 0.7.5 only partially made polexpr able to cope with the
    extended possibilities for xintexpr 1.4 user-declared functions.
    Hopefully ``0.8`` achieves full functionality in this context.

* New macros:

  - :ref:`\\polnewpolverbosefalse <polnewpolverbosefalse>`
  - :ref:`\\PolToExprCaret <PolToExprCaret>`
  - :ref:`\\PolToExprInVar <PolToExprInVar>`
  - Alongside the major new functionalities described in the next item
    :ref:`\\PolTypeset <PolTypeset>` and :ref:`\\PolToExpr <PolToExpr>` have
    been enhanced to accept as argument a general expression and not
    only a pre-declared polynomial name.

* New features:

  - The package is usable under Plain and probably most any TeX format,
    and not only under LaTeX.

  - The core of the package has been rewritten entirely in order to
    start letting ``\xintexpr`` recognize a polynomial type as a genuine
    variable.  This has allowed:

    - to solve the reduced inter-operability problems between polexpr
      and xintexpr_ which arose as consequences to the deep xintexpr_ ``1.4``
      evolution,

    - to make available most of the functionality associated to
      expandable macros directly in the ``\xinteval`` syntax as
      operators or functions,

    - to provide (expandable) functional interface in ``\xinteval`` to
      features previously available only via (for some, non-expandable)
      macro interface such as gcd computations.

See the updated :ref:`Quick syntax overview <quick>` and then
:ref:`the extended syntax description <polexpr08>`.

0.8.1 (2021/04/12)
------------------

* Breaking changes:

  - Renamed 0.8's ``icontent()`` to :ref:`cont() <cont>`.
  - Renamed 0.8's ``lcoeff()`` to :ref:`lc() <lc>`.

* Bug fixes:

  - Sadly, ``diff1()``, ``diff2()``,  ``diffn()`` were broken
    for polynomials of degrees 8 or more, due to a typo and
    insufficient testing.

  - The package should have (as documented) required xintexpr_ 1.4d
    but in practice it accepted to work with xintexpr_ 1.4c, whose
    ``\xinteval`` does not know how to "output" a polynomial.

  - The definition of one of the two variants of 
    :ref:`\\PolSturmNbOfRootsOf... <PolSturmNbOfRootsOfLessThanOrEqualTo>`
    was broken by an end-of-line space, left-over
    from mass conversion from LaTeX to TeX syntax.

* Added:

  - :ref:`lpol() <lpol>`
  - :ref:`lcoeffs() <lcoeffs>`

0.8.2 (2021/05/05)
------------------

* Breaking change:

  - Usage of ``\xintPFloat`` in place of ``\xintFloat`` for
    :ref:`\\PolToFloatExprCmd <PolToFloatExprCmd>`.

* Improved:

  - Some xintexpr_ functions such as ``rseq()`` use the semi-colon,
    and it was mentioned in the documentation that :ref:`\\poldef <poldef;>`
    will be confused by this and that inner semi-colons could be
    set within braces ``{;}`` as a work-around.  It was not clear from
    this documentation that also :ref:`\\PolDef <PolDef>` required
    this work-around.  With this relase only :ref:`\\poldef <poldef;>` but
    not :ref:`\\PolDef <PolDef>` needs the work-around.

* Track xintexpr_ ``1.4e`` changes relative to powers.

0.8.3 (2021/05/27)
------------------

* Small internal update to track an xintexpr_ ``1.4h`` change
  regarding handling of exceptions.  Will require this version at
  least on loading.

0.8.4 (2021/11/01)
------------------

* Bug fix: :ref:`\\PolSturmIsolateZeros**{\<sturmname\>}
  <PolSturmIsolateZeros**>` did not declare the ``<sturmname>_norr`` and
  ``<sturmname>_sqf_norr`` polynomials if original polynomial had no real
  root!

0.8.5 (2021/11/30)
------------------

* Bug fix: support for the ``intfrom()`` function was in the code,
  but the declaration to the polynomial parser had not been done.

* Track (belatedly) upstream deprecation of ``\xintSignedFrac`` and
  ``\xintSignedFwOver`` at xintexpr_ ``1.4g``

0.8.6 (2022/01/09)
------------------

* Provide a separate ``polexpr-examples.pdf`` with examples formerly
  shown as part of the html documentation.

* Minor improvement to the computation of a priori bounds on real roots.

* Add :ref:`\\PolPrintIntervalsRowSeparator <PolPrintIntervalsRowSeparator>`
  and allow usage of ``amsmath`` environments in custom
  :ref:`\\PolPrintIntervalsBeginEnv <PolPrintIntervalsBeginEnv>` and
  :ref:`\\PolPrintIntervalsEndEnv <PolPrintIntervalsEndEnv>`.

0.8.7 (2022/05/14)
------------------

* Bug fix: catcode sanitization by :ref:`\\poldef <poldef;>` was minimal
  ever since ``0.1`` and handled only the semi-colon.  Thus e.g. the
  active ``!`` from babel-french caused errors and ``\string!`` was
  needed as work-around for factorials.  Now the same sanitization as
  for ``\xintdefvar`` and ``\xintdeffunc`` is applied.  This however can
  only work at locations where the catcodes are not yet frozen at the
  time ``\poldef`` expands.

* Split the html documentation into three files and enhance it via CSS
  styling.

0.8.7a (2022/05/19)
-------------------

* Documentation updates.


.. _xinttools:
.. _xintfrac:
.. _xint: https://www.ctan.org/pkg/xint

.. _xintexpr: https://www.ctan.org/pkg/xintexpr

.. _xintsession: https://www.ctan.org/pkg/xintsession

.. _Wilkinson polynomial: https://en.wikipedia.org/wiki/Wilkinson%27s_polynomial

.. _Sturm algorithm:
.. _Sturm Theorem: https://en.wikipedia.org/wiki/Sturm%27s_theorem

.. _DocUtils: http://docutils.sourceforge.net/docs/index.html


.. Local variables:
.. sentence-end-double-space: t;
.. End:
