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A small correction to my previous announcement:

*> Now FeynCalc is just one package and all its
*

*> objects live in the context HighEnergyPhysics`FeynCalc`.
*

should actually read

*> Now FeynCalc is just one package and all its
*

*> objects live in the context FeynCalc`.
*

Sorry for the confusion.

Cheers,

Vladyslav

Am 08.04.2015 um 15:03 schrieb Vladyslav Shtabovenko:

*> Dear FeynCalc users,
*

*>
*

*> the new commit
*

*>
*

*> <https://github.com/FeynCalc/feyncalc/commit/9365d4937c208d53d843568bb059f48e83cd3c26>
*

*>
*

*> to the git repository of FeynCalc introduces a lot of changes to the
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*> structure of FeynCalc that we would like to introduce in details here:
*

*>
*

*> 1) You might have been wondering, why FeynCalc must be installed to the
*

*> directory "HighEnergyPhysics" and not just "FeynCalc". Well, this used
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*> to be liked that for some legacy reasons but is actually not necessary
*

*> nowadays. From now on FeynCalc lives in "FeynCalc" and
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*> it is started simply via "<<FeynCalc`"
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*>
*

*> 2) The internal structure of FeynCalc got completely refactored to
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*> simplify the maintenance and avoid problems with Mathematica's
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*> autocompletion. Before that FeynCalc actually consisted of hundreds of
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*> separate packages (each .m file was a package). Loading that number of
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*> packages in one session was freezing Mathematica's auto-complete. This
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*> should not occur anymore. Now FeynCalc is just one package and all its
*

*> objects live in the context HighEnergyPhysics`FeynCalc`. This allows us
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*> to get rid of the (error-prone) tricks with MakeContext and CheckContext
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*> that we had in the source code before. Furthermoe, the directory
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*> structure was adjusted to be compatible with the standard layout in
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*> Wolfram Workbench, which is the state of the art tool to develop large
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*> Mathematica packages.
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*>
*

*> 3) Much of the source code (although not everything yet) is now nicely
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*> formatted.
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*>
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*> 4) The directory structure inside HighEnergyPhysics is now organized in
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*> the following way
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*> * "AddOns": small user addons for FeynCalc
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*> * "Database" : contains cached results for user's computations
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*> * "Dirac": tools for Dirac algebra
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*> * "Documentation": contains package documentation
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*> * "Examples": sample computations with FeynCalc that reproduce known
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*> results from the literature
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*> * "ExportImport": tools for exchanging results between FeynCalc and
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*> other tools
*

*> * "FeynArts": contains patched FeynArts
*

*> * "Feynman" : tools for dealing with S-matrix elements, including
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*> derivation of Feynman rules and computation of the matrix element squared
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*> * "Kernel": related to the way Mathematica loads packages
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*> * "LoopIntegral": tools for loop integrals
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*> * "Lorentz": tools for working with quantities that carry Lorentz
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*> indices and for dealing with the kinematics
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*> * "Misc" : for routines that don't fall into any other category.
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*> * "NonComAlgebra": general functions for non-commutative objects
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*> * "Phi": contains Frederik Orellana's PHI
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*> * "QCD" : tools for QCD OPE calculations (still poorly tested and
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*> documented)
*

*> * "Shared": general objects (e.g. Pair, DiracGamma, SUNF) and functions
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*> (e.g. FreeQ2, SelectFree, Factor2) that are widely used by other parts
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*> of the FeynCalc code.
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*> * "SUN": tools for SU(N) algebra
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*> * "Tables": database with various analytic expressions
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*> * "Phi": contains TARCER by Rolf Mertig and Rainer Scharf
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*>
*

*> 5) Since FeynCalc now always loads all its .m files, we squashed some
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*> (short) functions into common files. For example, Apart1, Apart2 and
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*> Apart3 now live in Apart.m. This is done to keep the time FeynCalc needs
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*> to load reasonably small.
*

*>
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*> 6) Options parsing in many functions have been improved to use the
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*> modern MMA's OptionsPattern - OptionValue paradigm.
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*>
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*> 7) The number of unit tests have been increased. Although we are still
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*> far away from the full code coverage, with more than 2700 unit test we
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*> are doing quite good.
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*>
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*> 8) FeynCalc tabulates many expressions that can be requested by the
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*> user, e.g. Lagrangians. To make it easy for the user to work with these
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*> expressions, FeynCalc returned them with indices and variables in the
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*> Global` context. However this also means that when FeynCalc is loaded,
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*> it puts a lot of objects into the Global` context where they may clash
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*> with user-defined functions. To solve this problem we introduced a new
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*> object: FCGV which is acronym for FeynCalc Global Variable. The syntax
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*> is FCGV[x_String]. From now on, variables that used to be returned as
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*> Global`VariableName will be outputted as FCGV["VariableName"]. You will
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*> nottice them in your expressions as having FCGV around them, i.e.
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*> FCGV["p"] will be displayed as FCGV(p). You can always convert such
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*> objects to "normal" variables via the replacement rule {FCGV[x_String]
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*> :>ToExpression[x]} We understand that this additional step may pose some
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*> inconveniences to you, but from the point of view of Mathematica
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*> programming and interoperability between different packages, this
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*> solution seems to be the cleanest way to avoid troubles in future.
*

*>
*

*> For example, Lagrangian["QCD"] now returns
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*>
*

*> -(1/4) FieldStrength[FCGV["\[Alpha]"], FCGV["\[Beta]"],
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*> FCGV["a"]].FieldStrength[FCGV["\[Alpha]"], FCGV["\[Beta]"],
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*> FCGV["a"]]
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*>
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*> instead of
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*>
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*> -(1/4) FieldStrength[\[Alpha], \[Beta],
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*> a].FieldStrength[\[Alpha], \[Beta], a]
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*>
*

*> as it used to be. Now suppose that before invoking Lagrangian["QCD"] you
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*> defined \[Alpha] = 1/137. With the new output using FCGV nothing
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*> changes. With the old output
*

*> you would have got
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*>
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*> -(1/4) FieldStrength[1/137, \[Beta], a].FieldStrength[1/137, \[Beta], a]
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*>
*

*> which is clearly not what you want.
*

*>
*

*> 9) To circumvent problems related to the patching of FeynArts, from now
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*> on FeynCalc will look for FeynArts only in the directory "FeynArts"
*

*> inside "HighEnergyPhysics". Nevertheless, it is still possible to
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*> specify an alternative directory by setting
*

*> FeynCalc`$FeynArtsDirectory="path" before loading FeynCalc. The patching
*

*> code was moved to FeynCalc, i.e. now it will run even when Phi is not
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*> loaded.
*

*>
*

*> 10) The TARCER notebook have been converted into a source file
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*> ("TARCER.m"). Furthermore, generated TARCER*.mx files are not
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*> distributed anymore with the source code. When you first try to load
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*> TARCER, a dialog will appear with the suggestion to generate the .mx
*

*> file now. This process has to be done only once and takes only a couple
*

*> of minutes. After that, the generated .mx will be automatically loaded
*

*> whenever you want to use TARCER.
*

*>
*

*> 11) Prior to this commit FeynCalc used to switch the format of output
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*> cells to TraditionalForm. Now it will only issue a
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*> warning message suggesting the user to do this by himself or herself.
*

*> Such messages can be disabled by setting $FCAdvice to False.
*

*> So if you despise all the fancy typesetting and prefer to work with
*

*> StandardForm, FeynCalc will respect your decision.
*

*>
*

*> 12) To avoid clashes with built-in functions of recent Mathematica
*

*> versions, we had to rename
*

*> some FeynCalc functions:
*

*>
*

*> PartialD -> FCPartialD
*

*> Symmetrize -> FCSymmetrize
*

*> AntiSymmetrize -> FCAntiSymmetrize
*

*>
*

*> Cheers,
*

*> Vladyslav
*

*>
*

**Next message:**Vladyslav Shtabovenko: "Re: DiracReduce"**Previous message:**Vladyslav Shtabovenko: "Great Unifying Refactoring"**In reply to:**Vladyslav Shtabovenko: "Great Unifying Refactoring"**Messages sorted by:**[ date ] [ thread ] [ subject ] [ author ]**Mail actions:**[ respond to this message ] [ mail a new topic ]

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