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= Sage 3.4.1 Release Tour = Sage 3.4.1 was released on FIXME. For the official, comprehensive release note, please refer to [[http://www.sagemath.org/src/announce/sage-3.4.1.txt|sage-3.4.1.txt]]. A nicely formatted version of this release tour can be found at FIXME. The following points are some of the foci of this release: * Merging improvements during the Sage Days 13 coding sprint. * Other bug fixes post Sage 3.4. |
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== Algebra == * FIXME: summarize ticket #5535. * FIXME: summarize ticket #5658. * Speed-up in irreducibility test (Ryan Hinton) -- For polynomials over the finite field {{{GF(2)}}}, the test for irreducibility is now up to 40,000 times faster than previously. On a 64-bit Debian/squeeze machine with Core 2 Duo running at 2.33 GHz, one has the following timing improvements: {{{ # BEFORE sage: P.<x> = GF(2)[] sage: f = P.random_element(1000) sage: %timeit f.is_irreducible() 10 loops, best of 3: 948 ms per loop sage: sage: f = P.random_element(10000) sage: %time f.is_irreducible() # gave up because it took minutes! # AFTER sage: P.<x> = GF(2)[] sage: f = P.random_element(1000) sage: %timeit f.is_irreducible() 10000 loops, best of 3: 22.7 µs per loop sage: sage: f = P.random_element(10000) sage: %timeit f.is_irreducible() 1000 loops, best of 3: 394 µs per loop sage: sage: f = P.random_element(100000) sage: %timeit f.is_irreducible() 100 loops, best of 3: 10.4 ms per loop }}} Furthermore, on Debian 5.0 Lenny with kernel 2.6.24-1-686, an Intel(R) Celeron(R) CPU running at 2.00GHz with 1.0GB of RAM, one has the following timing statistics: {{{ # BEFORE sage: P.<x> = GF(2)[] sage: f = P.random_element(1000) sage: %timeit f.is_irreducible() 10 loops, best of 3: 1.14 s per loop sage: sage: f = P.random_element(10000) sage: %time f.is_irreducible() CPU times: user 4972.13 s, sys: 2.83 s, total: 4974.95 s Wall time: 5043.02 s False # AFTER sage: P.<x> = GF(2)[] sage: f = P.random_element(1000) sage: %timeit f.is_irreducible() 10000 loops, best of 3: 40.7 µs per loop sage: sage: f = P.random_element(10000) sage: %timeit f.is_irreducible() 1000 loops, best of 3: 930 µs per loop sage: sage: sage: f = P.random_element(100000) sage: %timeit f.is_irreducible() 10 loops, best of 3: 27.6 ms per loop }}} == Algebraic Geometry == * Refactor {{{dimension()}}} method for schemes (Alex Ghitza) -- Implement methods {{{dimension_absolute()}}} and {{{dimension_relative()}}}, where {{{dimension()}}} is an alias for {{{dimension_absolute()}}}. Here are some examples of using {{{dimension_absolute()}}} and {{{dimension()}}}: {{{ sage: A2Q = AffineSpace(2, QQ) sage: A2Q.dimension_absolute() 2 sage: A2Q.dimension() 2 }}} And here's an example demonstrating the use of {{{dimension_relative()}}}: {{{ sage: S = Spec(ZZ) sage: S.dimension_relative() 0 }}} * Plotting affine and projective curves (Alex Ghitza) -- Improving the plotting usability so it is now easier to plot affine and projective curves. For example, we can plot a [[attachment:5-nodal curve]] of degree 11: {{{ sage: R.<x, y> = ZZ[] sage: C = Curve(32*x^2 - 2097152*y^11 + 1441792*y^9 - 360448*y^7 + 39424*y^5 - 1760*y^3 + 22*y - 1) sage: C.plot((x, -1, 1), (y, -1, 1), plot_points=400) }}} Now we plot an [[attachment:elliptic curve]]: {{{ sage: E = EllipticCurve('101a') sage: C = Curve(E) sage: C.plot() }}} == Basic Arithmetic == * Speed-up in dividing a polynomial by an integer (Burcin Erocal) -- Dividing a polynomial by an integer is now up to 6x faster than previously. On Debian 5.0 Lenny with kernel 2.6.24-1-686, an Intel(R) Celeron(R) CPU running at 2.00GHz with 1.0GB of RAM, one has the following timing statistics: {{{ # BEFORE sage: R.<x> = ZZ["x"] sage: f = 389 * R.random_element(1000) sage: timeit("f//389") 625 loops, best of 3: 312 µs per loop # AFTER sage: R.<x> = ZZ["x"] sage: f = 389 * R.random_element(1000) sage: timeit("f//389") 625 loops, best of 3: 48.3 µs per loop }}} * New {{{fast_float}}} supports more datatypes with improved performance (Carl Witty) -- A rewrite of {{{fast_float}}} to support multiple types. Here, we get accelerated evaluation over {{{RealField(k)}}} as well as {{{RDF}}}, real double field. As compared with the previous {{{fast_float}}}, improved performance can range from 2% faster to more than 2x as fast. An extended list of benchmark details is available at [[http://trac.sagemath.org/sage_trac/ticket/5093|ticket 5093]]. * FIXME: summarize #5622 * FIXME: summarize #5735 * FIXME: summarize #5659 * FIXME: summarize #3309 * FIXME: summarize #5685 == Build == == Calculus == * Deprecate the calling of symbolic functions with unnamed arguments (Carl Witty, Michael Abshoff) -- Previous releases of Sage supported symbolic functions with "no arguments". This style of constructing symbolic functions is now deprecated. For example, previously Sage allowed for defining a symbolic function in the following way {{{ f2 = 5 - x^2 # bad; this is deprecated }}} But users are encouraged to explicitly declare the variables used in a symolic function. For instance, the following is encouraged: {{{ sage: x,y = var("x, y") # explicitly declare your variables sage: f(x, y) = x^2 + y^2 # this syntax is encouraged }}} == Coercion == == Combinatorics == * Enhancements to the {{{Subsets}}} and {{{Subwords}}} modules (Florent Hivert) -- Numerous enhancements to the modules {{{Subsets}}} and {{{Subwords}}} include: 1. An implementation of subsets for finite multisets, i.e. sets with repetitions. 1. Adding the method {{{__contains__}}} for {{{Subsets}}} and {{{Subwords}}}. Here's an example for working with multisets: {{{ sage: S = Subsets([1, 2, 2], submultiset=True); S SubMultiset of [1, 2, 2] sage: S.list() [[], [1], [2], [1, 2], [2, 2], [1, 2, 2]] sage: Set([1,2]) in S # this uses __contains__ in Subsets True sage: Set([]) in S True sage: Set([3]) in S False }}} And here's an example of using {{{__contains__}}} with {{{Subwords}}}: {{{ sage: [] in Subwords([1,2,3,4,3,4,4]) True sage: [2,3,3,4] in Subwords([1,2,3,4,3,4,4]) True sage: [2,3,3,1] in Subwords([1,2,3,4,3,4,4]) False }}} * Fix and Enhancements to permutations (Sebastien Labbe) -- Corrects the Robinson-Schensted algorithm on trivial permutations. Implements the inverse Robinson-Schensted algorithm: {{{ sage: Permutation((Tableau([[1,2,4],[3]]), Tableau([[1,3,4],[2]]))) [3, 1, 2, 4] sage: Permutation(([[1,2,4],[3]], [[1,3,4],[2]])) [3, 1, 2, 4] }}} It also works for arbitrary words (with semi-standard tableaux): {{{ sage: Permutation(([[1,2,2],[3]], [[1,3,4],[2]])) [3, 1, 2, 2] }}} * First pass of cleanup of the interface of combinatorial classes -- Florent Hivert Before the patch the interface of combinatorial classes had two problems: - there were two redundant ways to get the number of elements {{{len(C)}}} and {{{C.count()}}}. Moreover {{{len}}} must return a plain {{{int}}} where we want arbitrary large number and even {{{infinity}}}; - there were two redundant way to get an iterator for the elements {{{C.iterator()}}} and {{{iter(C)}}} (allowing for {{{for c in C: ...}}}) via {{{C.__iter__}}}. The patch standardize those to: - {{{C.cardinality()}}} which is more explicit and consistent with many other Sage libraries; - {{{iter(C)}}} / {{{for x in C:}}} via {{{C.__iter__}}} with is clearly more Pythonic. The functions {{{ iterator}}} and {{{count}}} are deprecated (with a warning) but still working for the moment (please fix your code). On the other hand, there was no way to keep backward compatibility for {{{len}}}. Indeed, many of function such as {{{list / filter / map}}} try silently to call {{{len}}}, which would have caused miriads of warnings to be issued in seemingly unrelated places. So it was decided to simply remove it, and issue an error, suggesting to call {{{cardinality}}} instead. * FIXME: summarize #4549 * FIXME: summarize #5729 * FIXME: summarize #5478 * FIXME: summarize #5721 == Commutative Algebra == * New function {{{weil_restriction()}}} on multivariate ideals (Martin Albrecht) -- The new function {{{weil_restriction()}}} computes the [[http://en.wikipedia.org/wiki/Weil_restriction|Weil restriction]] of a multivariate ideal over some extension field. A Weil restriction is also known as a restriction of scalars. Here's an example on computing a Weil restriction: {{{ sage: k.<a> = GF(2^2) sage: P.<x,y> = PolynomialRing(k, 2) sage: I = Ideal([x*y + 1, a*x + 1]) sage: I.variety() [{y: a, x: a + 1}] sage: J = I.weil_restriction() sage: J Ideal (x1*y0 + x0*y1 + x1*y1, x0*y0 + x1*y1 + 1, x0 + x1, x1 + 1) of Multivariate Polynomial Ring in x0, x1, y0, y1 over Finite Field of size 2 }}} * FIXME: summarize #5146 * FIXME: summarize #5353 * FIXME: summarize #3812 == Distribution == == Doctest == * FIXME: summarize #5318 == Documentation == == Geometry == * Improved enumeration of vertices and 0-dimensional faces of LatticePolytope's. There was an inconsistency between indicies of vertices, i.e. columns of the .vertices() matrix, and indicies of 0-dimensional faces, i.e. objects returned by .faces(dim=0). E.g. the 5-th 0-dimensional face could be generated by the 7-th vertex etc. Now the i-th 0-dimensional face is generated by the i-th vertex. (The reason for the old behaviour was the output of the underlying software package PALP, now there is extra sorting.) == Graph Theory == * FIXME: summarize #5623 == Graphics == * FIXME: summarize #5606 * FIXME: summarize #5450 == Group Theory == * Speed-up in comparing elements of a permutation group (Robert Bradshaw, John H. Palmieri, Rob Beezer) -- For elements of a permutation group, comparison between those elements is now up to 13x faster. On Mac OS X 10.4 with Intel Core 2 duo running at 2.33 GHz, one has the following improvement in timing statistics: {{{ # BEFORE sage: a = SymmetricGroup(20).random_element() sage: b = SymmetricGroup(10).random_element() sage: timeit("a == b") 625 loops, best of 3: 3.19 µs per loop # AFTER sage: a = SymmetricGroup(20).random_element() sage: b = SymmetricGroup(10).random_element() sage: time v = [a == b for _ in xrange(2000)] CPU times: user 0.00 s, sys: 0.00 s, total: 0.00 s Wall time: 0.00 s sage: timeit("a == b") 625 loops, best of 3: 240 ns per loop }}} * FIXME: summarize #5264 == Interfaces == == Linear Algebra == * Deprecate the function {{{invert()}}} (John H. Palmieri) -- The function {{{invert()}}} for calculating the inverse of a dense matrix with rational entries is now deprecated. Instead, users are now advised to use the function {{{inverse()}}}. Here's an example of using the function {{{inverse()}}}: {{{ sage: a = matrix(QQ, 2, [1, 5, 17, 3]) sage: a.inverse() [-3/82 5/82] [17/82 -1/82] }}} * Speed-up in calculating determinants of matrices (John H. Palmieri, William Stein) -- For matrices over {{{Z/nZ}}} with {{{n}}} composite, calculating their determinants is now up to 1500x faster. On Debian 5.0 Lenny with kernel 2.6.24-1-686, an Intel(R) Celeron(R) 2.00GHz CPU with 1.0GB of RAM, one has the following timing statistics: {{{ # BEFORE sage: time random_matrix(Integers(26), 10).determinant() CPU times: user 15.52 s, sys: 0.02 s, total: 15.54 s Wall time: 15.54 s 13 sage: time random_matrix(Integers(256), 10).determinant() CPU times: user 15.38 s, sys: 0.00 s, total: 15.38 s Wall time: 15.38 s 144 # AFTER sage: time random_matrix(Integers(26), 10).determinant() CPU times: user 0.01 s, sys: 0.00 s, total: 0.01 s Wall time: 0.01 s 23 sage: time random_matrix(Integers(256), 10).determinant() CPU times: user 0.00 s, sys: 0.00 s, total: 0.00 s Wall time: 0.00 s }}} * FIXME: summarize #5715 == Miscellaneous == * FIXME: summarize #5638 * FIXME: summarize #5386 == Modular Forms == * FIXME: summarize #5520 * FIXME: summarize #5648 * FIXME: summarize #5180 == Notebook == FIXME: A number of tickets related to UTF-8 text got merged and should definitely be mentioned! #4547, #5211; #2896 and #1477 got fixed by those tickets. There's also #5564, which may not get merged for 3.4.1 but should get in soon; it pulls together a whole bunch of UTF-8 fixes and improvements. * FIXME: summarize #5681 == Number Theory == * FIXME: summarize #5518 * FIXME: summarize #5508 * FIXME: summarize #793 * FIXME: summarize #4667 * FIXME: summarize #5159 * FIXME: summarize #4990 * FIXME: summarize #3081 * FIXME: summarize #4724 * FIXME: summarize #5673 == Numerical == == Packages == * FIXME: summarize #4987 * FIXME: summarize #4881 * FIXME: summarize #4880 * FIXME: summarize #4876 * FIXME: summarize #5672 * FIXME: summarize #5240 * FIXME: summarize #5738 * FIXME: summarize #5696 * FIXME: summarize #4987 * FIXME: summarize #5697 * FIXME: summarize #5823 == Quadratic Forms == == Symbolics == * FIXME: summarize #5737 == User Interface == == Website / Wiki == |
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