@teake teake released this Oct 30, 2014 · 2 commits to master since this release

Assets 3
  • Added RicciToRiemann.
  • Added KretschmannToRiemann.
  • ToRiemann also converts rank-2 curature tensors if the curvature relations are not enabled.
  • ToRicci also converts contractions of Riemann tensors to Ricci tensors even if the curvature relations are not enabled.

@teake teake released this Oct 20, 2014 · 7 commits to master since this release

Assets 3
  • IndexConfigurations gives correct results for expressions with more than one tangent bundle.
  • EulerDensity is faster, and takes the option Verbose.
  • xTras now needs xTensor 1.1.1.

@teake teake released this Sep 23, 2014 · 14 commits to master since this release

Assets 3
  • AllContractions automatically parallelizes on Mathematica 8 or newer.
  • AllContractions has an improved algorithm.
  • AllContractions directly calls the external xPerm executable, which makes it about 5x faster.
  • ConstantSymbolsOf now takes multiple arguments.
  • RiemannSimplification's error-message is more human-readable.

@teake teake released this Mar 31, 2014 · 32 commits to master since this release

Assets 3
  • xTras now requires xTensor 1.1.0.
  • Products of symmetrized derivatives that commutate are now fully canonicalized.
  • Improved speed of perturbations of symmetrized derivatives.
  • Fixed two PrintAs related issues.
  • FromIndexFree is now compatible with $AutoSymmetrizeCovDs = True.
  • CollectTensors is more verbose while simplifying coefficients.

@teake teake released this Mar 3, 2014 · 40 commits to master since this release

Assets 3
  • Symmetrized derivatives use the chain rule on scalar functions.
  • Improved speed of SymmetrizeCovDs in some situations.
  • SymmetrizeCovDs strips all dummy indices before caching.
  • VarD on symmetrized derivatives w.r.t. to another derivative works.
  • Symmetrized covariant derivatives pass Validate.
  • CollectTensors is faster on expressions that are (partially) collected.
  • TensorWrapper is much faster on large products (was exponential in the number of terms, is now linear).
  • Fixed warning message in SolveTensors.

@teake teake released this Feb 22, 2014 · 53 commits to master since this release

Assets 3
  • Added the function ConstantSymbolsOf.
  • Added possibility (controlled by the variable $AutoSymmetrizeCovDs)
    to automatically symmetrize covariant derivatives.
  • Added caching to SymmetrizeCovDs, controlled by the "UseCache" option.
  • Improved algorithm for symmetrizing covariant derivatives in the case
    when there is no torsion and the derivative is metric-compatible.
  • Perturbation no longer expands symmetrized covariant derivatives.

@teake teake released this Feb 10, 2014 · 69 commits to master since this release

Assets 3

Big changes:

  • Added functions for symmetrizing covariant derivatives (SymmetrizeCovDs and ExpandSymCovDs).
  • Added the symmetrized Riemann tensor.

Other changes:

  • Added the function ToRiemann.
  • RiemannYoungProject only projects if the Riemann tensor has its full symmetries; otherwise it does nothing.
  • RiemannYoungProject also projects Weyl and symmetrized Riemann tensors.
  • TableauSymmetric now inherits the value of its option ManifestSymmetry from YoungSymmetrize.

@teake teake released this Nov 22, 2013 · 87 commits to master since this release

Assets 3

This is a small point release, adding just one function:

  • Added GradChristoffelToRiemann, which converts partial derivatives of Christoffel symbols to Riemann tensors.

@teake teake released this Sep 29, 2013 · 93 commits to master since this release

Assets 3

Again a small bugfix release:

  • RemoveConstants, RemoveTensors, and TermsOf now also work on non-expanded sums.

@teake teake released this Aug 16, 2013 · 99 commits to master since this release

Assets 3

This is a small bugfix release. The changes are:

  • Defining a metric with PD as its Levi-Civita derivative is no longer broken.
  • Extra curvature tensors Schouten, SchoutenCC, and EinsteinCC tensors are defined only when there
    is curvature. Furthermore, they become non-symmetric when there is torsion, and are properly
    extended, projected, and orthogonalized when needed.
  • Added torsion to the RHS of the contracted Bianchi identities returned by CurvatureRelationsBianchi.