* Sat Feb 03 2018 jengelh@inai.de
- Update to new upstream release 4.6.1
* No user-visible changes (only pkg metadata)
* Mon Dec 25 2017 jengelh@inai.de
- Update to new upstream release 4.6.0
* Determining transitivity and computing transitivity
certificates has been made more efficient in some cases, and
an operation `SimplifiedCertificate' has been added.
* An operation `EpimorphismsUpToAutomorphisms' has been added,
together with a method which computes all epimorphisms from a
given finitely presented group to a given finite group up to
automorphisms of the latter.
* Lists 'redundant_generator', 'spheresizebound_4',
'spheresizebound_6', 'spheresizebound_12' and
'spheresizebound_24' have been added to the database of
groups generated by 3 class transpositions.
* Single-argument methods for `TransitionMatrix' and
`TransitionGraph' have been added.
* Sat Apr 29 2017 jengelh@inai.de
- Update to new upstream release 4.5.1
* RCWA now prints a warning if GAP is run in legacy 32-bit mode
due to the size of integers in ranges in 32-bit GAP which may
make some computations fail and trigger error messages.
* A further method for `EpimorphismFromFpGroup' has been added.
This method allows to limit the search space to elements with
not more than a given number of affine parts.
* Attributes
`DecompositionIntoPermutationalAndOrderPreservingElement' and
`SignInOddCTPZ' have been added.
* The following components have been added to the database of
groups generated by 3 class transpositions:
'minwordlengthnonbalanced', 'minwordlengthcoprimemultdiv',
'epifromfpgrouptocollatzgroup_c' and
'epifromfpgrouptocollatzgroup_t'.
* The method for `RestrictedBall' for computing restricted
balls in rcwa monoids does now interpret options
"boundaffineparts" and "boundnonidentityaffineparts". If set,
the specified bound is on the number of affine parts,
respectively, on the number of affine parts distinct from the
identity, rather than on the modulus of the mapping.
* An operation `HashValueOfRcwaMapping' has been added. The
purpose of the hash values is to allow faster searching of
rcwa mappings by algorithms.
* Now the operations `Support', `IncreasingOn', `DecreasingOn',
`ShiftsUpOn', `ShiftsDownOn',
`LargestSourcesOfAffineMappings' and `Multpk' return their
result in sparse representation if the argument is in sparse
representation.
* An operation `RefinementSequence' has been added.
* Mon Jun 20 2016 jengelh@inai.de
- Update to new upstream release 4.4.1
* A `Random` method for finitely generated rcwa groups and given
word length has been added.
* Many newly found subgroup relations have been added to the
database of groups generated by 3 class transpositions which
interchange residue classes with moduli <= 6.
* A new method for computing the order of an element of CT(Z) has
been added. Its use can be triggered by setting the option
"new_order" when calling the operation `Order`. This method is
sometimes faster and sometimes slower than the default method.
* The function `PrimeSwitch' has been turned into an operation,
and new methods PrimeSwitch(p,r,m) and PrimeSwitch(p,cl) to
construct "residue class specific" prime switches have been
added.
* The functions for loading the databases of rcwa groups and
- mappings do no longer return the content of the respective
database itself, but just the name of the variable which the
database record is assigned to. Hence forgetting the ';;' at
the end of the line when loading one of the databases does no
longer result in megabytes of data printed to the screen.
* Selector functions `All3CTs9Groups' and `All3CTs9Indices' have
been added to the database of groups generated by 3 class
transpositions interchanging residue classes with moduli <= 9.
* The meaning of CT(P,Integers) has been changed in that 2 is no
longer treated as a special case, and P is now the full prime
set of the constructed group. -- That means e.g. that the
former CT([],Integers) is now CT([2],Integers).
* There is now a generating set for CT([2,3],Integers) consisting
of only 6 class transpositions known, instead of 14 as before.
Also, a generating set for CT([3],Integers) has been added.
* A method for `ExtRepOfObj' for class transpositions has been
added. This method returns the 4-tuple [r1,m1,r2,m2]
corresponding to the interchanged residue classes r1(m1) and
r2(m2).
* Wed Jun 08 2016 jengelh@inai.de
- Update to new upstream release 4.3.1
* The propagation of the knowledge about bijectivity to inverses of
bijective rcwa mappings is now taken care of by RCWA. -- Until GAP
4.8.1, this was done by the GAP Library.
* Sat Mar 12 2016 jengelh@inai.de
- Update to new upstream release 4.0.0
* A database of groups generated by 3 class transpositions
intechanging residue classes with moduli <= 9 has been added. For
each of these 3031864 groups, the modulus and the order are
stored. Also, for all finite ones among these groups, the length
of the shortest respected partition is stored.
* The following data has been added to the database of groups
generated by 3 class transpositions:
* data on subgroup- and supergroup relations between the groups in
the database (lists 'subgroups' and 'supergroups'),
* data on the orbit growth functions (list 'orbitgrowthtype'),
* lists of lengths of short finite orbits of residue classes, and
* data on sphere size cycles for orbits with periodic growth
function.
* RCWA makes now use of the new sparse representation of residue
class unions implemented in ResClasses 4.0.0.
* Fri Dec 12 2014 jengelh@inai.de
- Update to new upstream release 3.7.0
* An operation "MergerExtension" has been added. This operation
constructs a certain infinite extension of a given transitive
finite permutation group.
* The manual section "Constructing residue-class-wise affine
groups" has been revised.
* The function "DrawOrbitPicture" has been improved, and in
particular been made more efficient. The meaning of one of its
arguments has changed.
* Functions "EncryptIntoBitmapPicture" and
"DecryptFromBitmapPicture" for steganography in bitmap pictures
have been added.
* A function "ShrinkMonochromePictureToGrayscalesPicture" has been added.
This function is for producing smaller greyscale pictures from large
monochrome pictures.
* Fri Feb 07 2014 jengelh@inai.de
- Update to new upstream release 3.6.1
* Considerable additions to the database of groups
generated by 3 class transpositions have been made
* A database of pairs of class transpositions interchanging residue
classes with moduli <= 12 sorted by the order of their product
has been added.
* A database similar to the one mentioned before up to modulus 32,
but restricted to orders 8, 24, 40, 42, 84, 120, 168 and 420 has
been added.
* There is now an operation `Mirrored' which applies the automorphism
conjugating with n |-> -n - 1 to an rcwa mapping of Z or an rcwa
group over Z. This interchanges the action on negative and
nonnegative integers.
* A basic method for `RepresentativeAction' has been added which
computes an rcwa permutation g such that G^g = H for given
conjugate rcwa groups G, H < RCWA(Z).
* A bug has been fixed which caused error messages when computing
with rcwa mappings of Z in sparse representation which were not
class-wise order-preserving.
* Fri May 10 2013 jengelh@inai.de
- Split rcwa (version 3.5.1) off the gap RPM package