Richard Kreckel [Thu, 25 Mar 2010 22:08:54 +0000 (23:08 +0100)]
Really fixed the atan2(-Pi, 0) bug.
The problem was that atan2_eval assumed that if y is real and not
positive, it must be negative. But this neglects the fact that in
symbolic compution it may just not be possible to determine the
sign. Now, the expression is returned as it is. Ugly, but correct.
Jens Vollinga [Thu, 25 Mar 2010 09:36:41 +0000 (10:36 +0100)]
Fixed a bug in atan2. It gave a division by zero error for calls like
atan2(-Pi,0), because arguments like -Pi were not recognized (via
info_flags) as negative but as real nevertheless.
(cherry picked from commit 9e13d46552bb7852399867b9eb355732b9ded59e)
pgcd(): detect relatively prime polynomials properly...
... so pgcd() doesn't loop forever any more. Division test does not handle
relatively prime polynomials (because C = 1 divides any polynomial). So we
should stop interpolation (and return gcd of contents) if we got relatively
prime images (we should do that for efficiency reasons too).
But the ability to do so is important for a lot of practical uses. So soon
after the C++98 standard was approved, a language defect report was filed
on this topic, see
http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#195
The result is that compilers will be allowed to support reinterpret_cast
conversions of function pointers to other (pointers) types, and vice a versa.
Such conversions work with *current* compilers (GCC 4.x), but don't work
with older ones, hence this patch.
Richard Kreckel [Tue, 29 Sep 2009 20:28:47 +0000 (22:28 +0200)]
Remove debian/ directory.
The lifecycle of the Debian packaging files is better maintained in
the Debian pool's diff file. Removing these files makes the life of
the GiNaC releaser easier.
Richard Kreckel [Tue, 29 Sep 2009 20:08:11 +0000 (22:08 +0200)]
Properly document how to deal with libtool versioning.
The old description was referring to ginac_lt_age which should always
stay 0, because we promised to mark incompatible binary interfaces by
bumping ginac_minor_version (or even ginac_major_version). Let's get
rid of ginac_lt_age.
modular_matrix: don't use STL iterators in {mul, sub}_col and friends.
Not using STL iterators makes the code simpler and cleaner. Also we don't
have to argue whether the standard ([lib.random.access.iterators]) imposes
any pre/post-condictions on operator+=.
(cherry picked from commit 59ec13895c97ffd74979a0b811a7571f6de56386)
shaker_sort, permutation_sign: fix invalid use of STL iterators.
According to the standard incrementing end(), and decrementing begin()
are ill-defined operations (see [lib.forward.iterators],
[lib.bidirectional.iterators]).
(cherry picked from commit 694f839947982f5b12b6c629d5bab522c801630d)
check_parameter_G: fix pontential increment of end().
Incrementing past-the-end iterator is not permitted by the standard, see
[lib.input.iterators].
(cherry picked from commit 49a44f7d55ec0d6686d3c32c7081a07d10c93274)
According to [lib.bidirectional.iterators] it's not OK to decrement
an iterator pointing to the beginning of the sequence. Fortunately random
access iterators provided by (current versions of) gcc/libstdc++ don't have
this silly limitation, so the code which works with pointers works with
iterators without any changes at all. However,
- there's no guarantee that the current behavior won't change in the future
- some non-GNU compilers are not that smart (i.e. the program segfaults
upon when decrementing beginning-of-the-sequence iterator).
(cherry picked from commit dda45abd8a2c408f8b3eb7959a10dfb2468ecc3a)
Fix the compliation error *for real* ... and restore performance
Commit 8bf0597dde55e4c94a2ff39f1d8130902e3d7a9b (titled as 'Fixed the parser
such that it can read in user defined classes again.') made the parser a bit
slower, especially if the input contains many terms of user-defined type.
The reason for that is quite simple: we throw and catch an exception every
time we construct an object of user-defined type:
// dirty hack to distinguish between serial numbers of functions and real
// pointers.
GiNaC::function* f = NULL;
try {
unsigned serial = (unsigned)(unsigned long)(void *)(reader->second);
f = new GiNaC::function(serial, args);
}
catch ( std::runtime_error ) {
if ( f ) delete f;
ex ret = reader->second(args);
return ret;
}
Fortunately functions are aligned and we can use much more efficient
technique to distinguish between serial and pointers to functions.
This patch is an ugly hack that does the same as the commit f38cbcd651246fb5c1294705d29399f3cbfddaf5
but without changing the ABI (so it can be used in ginac_1-5).
Added include for cstdio header.
gcc 4.0 does not include cstdio as part of other headers like string
anymore. As a result, gcc 4.0 complained about EOF being undefined.
Due to the strange (although permitted by the standard) behaviour of C++
RTTI on woe32 calchash() returns different hash values for equal objects.
As a result automatic evaluation gets spectacularly broken:
examining clifford objects.....({1+t,2+x,3+y,4+z}) - ({1+t,2+x,3+y,4+z}) erroneously returned -{1+t,2+x,3+y,4+z}+{1+t,2+x,3+y,4+z} instead of 0
({1+t,2+x,3+y,4+z}) - ({1+t,2+x,3+y,4+z}) erroneously returned -{1+t,2+x,3+y,4+z}+{1+t,2+x,3+y,4+z} instead of 0
.({1+t,2+x,3+y,4+z}) - ({1+t,2+x,3+y,4+z}) erroneously returned -{1+t,2+x,3+y,4+z}+{1+t,2+x,3+y,4+z} instead of 0
({1+t,2+x,3+y,4+z}) - ({1+t,2+x,3+y,4+z}) erroneously returned {1+t,2+x,3+y,4+z}-{1+t,2+x,3+y,4+z} instead of 0
[skipped]
.......FAIL: exam_clifford.exe
This patch works around `features' of woe32 RTTI, so calchash() works
properly.
Univariate GCD timing: use sr_gcd when appropriate.
The benchmark consists of two parts:
1) timing of different GCD calculation methods (i.e. subresultant PRS,
heuristic, chinese remaindering).
2) timing of different implementations of the same method. The purpose
is to find out how (in)efficient GiNaC::ex is as a representation
of (univariate) polynomials (as a side note, the result is a bit
depressing -- using coefficient vector instead of GiNaC:ex makes
GCD calculation 50x -- 1000x faster).
Now GiNaC uses modular (chinese remaindering) GCD by default, so part 2)
got broken, i.e. instead of (intended) timings
a) (heuristic, GiNaC::ex) versus (heuristic, coefficient vector)
b) (PRS, GiNaC::ex) versus (PRS, coefficient vector)
one gets
a') (heuristic, GiNaC::ex) versus (heuristic, coefficient vector)
b') (chinese remaindering, GiNaC::ex) versus (PRS, coefficient vector)
Set the gcd_options::use_sr_gcd to restore the meaning of the benchmark.
Note: this patch does not affect the library proper.
Jens Vollinga [Fri, 6 Feb 2009 15:07:10 +0000 (16:07 +0100)]
Prettified source code.
- Added copyright and GPL licencing to new files.
- Increased year to 2009.
- Changed guarding macros in header to uniform pattern without leading or
trailing __ (double underscores).
- Put includes of system wide header consistently below own includes (help
a tiny bit to clarify dependencies).
Implement modular multivariate GCD (based on chinese remaindering algorithm).
Both algorithm and implementation are a bit inefficient:
* algorithm does not make use of sparseness of inputs (and most of
multivariate polynomials are quite sparse)
* GiNaC's expressions are essentially immutable. Thus some simple
operations (i.e. multiplying a polynomial by an element of the base ring)
are prohibitively expensive.
* All numbers (i.e. GiNaC::numeric objects) are heap allocated.
Still it's much faster (~5x on bivariate polynomials, ~100x on 3-variate
ones) than (subresultant) PRS algorithm, so gcd() uses modular algorithm
by default.
Jens Vollinga [Thu, 18 Dec 2008 10:10:50 +0000 (11:10 +0100)]
Fixed bug in multivariate factorization. Fractional numerical content was not
extracted and led to a not so finite running behavior. Added new checks for that
bug.
Added static keywords to hide debugging output operators.
The libtool naming scheme cannot guarantee that on all systems, the numbering
is consecutive. It only guarantees that it is increasing. This doesn't matter,
though: there is not incurred cost for numbers that are omitted, except for
shrinking the available space of leftover numbers. Not something we need to
worry about yet. ;-) On the other hand, tricks which we were using to make
version numbers consecutive on GNU/Linux break versioning on other OSes.
Jens Vollinga [Thu, 13 Nov 2008 10:13:05 +0000 (11:13 +0100)]
Fixed lots of bugs in factor_multivariate().
factor_univariate() takes now the content of the polynomial into accout when
choosing a prime. It also returns the chosen prime. This supports the
factor_multivariate() code.
Polynomials are expanded before calling factor_sqrfree(). This avoids problems
with some input polynomials.
Jens Vollinga [Mon, 10 Nov 2008 12:38:11 +0000 (13:38 +0100)]
Added modular square free factorization.
Completed distinct degree factorization.
Univariate polynomial factorization uses now upoly.
Merged class Partition and function split into class factor_partition.
Jens Vollinga [Wed, 5 Nov 2008 10:22:19 +0000 (11:22 +0100)]
Changed code from using cl_UP_MI to using umodpoly. The cl_UP_MI interface was
inconvenient to use and caused several very difficult bugs (some were still
unresolved before changing to umodpoly!).
Fixed severe bug in multivariate factorization. The condition that all modular
factors should be relatively prime in the base ring was violated. This caused
the factorization sometimes to go into an infinite loop.
symbol: remove return_type_tinfo() and return_type() (shrink symbol by 8 bytes)
Bloating symbol to the state sizeof(symbol) == 64 is not appreciated at all.
If someone needs/wants non-commutative symbols or other fancy stuff, please
derive from class symbol and do whatever you want.
return_type_tinfo() is used in order to distingish between non-commutative
objects of different type. However, often it's necessary to distingish
between non-commutative objects of the same type, for example, between
gamma matrices with different representation label. return_type_tinfo()
does not provide any clean way to do that. Hence, introduce return_type_t
type which holds representation label along with type information, and
use it for return_type_tinfo().
calchash(): use type_info::name() instead of tinfo().
Custom RTTI considered harmful, part 4.
The hash value of the object of different types should be different whenever
possible. Hence calcash() needs a unique per type number. Previously we used
tinfo_key for this. typeinfo::name() (a *pointer* to implementation dependent
string) is also unique for each class, so it's just as good as tinfo() is.
basic, expairseq: use standard C++ RTTI in compare(), is_equal(), match(), etc.
Custom RTTI considered harmful, part 2.
* basic.cpp: use standard C++ RTTI in compare(), is_equal(), operator=(),
match().
* expairseq.cpp: use standard C++ RTTI in match(), make_flat(),
construct_from_2_ex().
is_exactly_a: use typeid() to check the type of expression.
Custom RTTI considered harmful, part 1.
Custom run time type information (RTTI) system implemented in GiNaC have
several serious drawbacks, such as
1. It makes writing GiNaC classes unnecessary cumbersome.
2. It wastes sizeof(void *) bytes per object, for small objects like
symbol, numeric, etc. this overhead is considerable.
It turns out that GiNaC's RTTI is not any faster than the standard one
(at least on GNU/Linux and Solaris with GNU C++ library and compiler).
So, GiNaC RTTI have no reasons to exit any more.
ptr.h: use unsigned int to store reference counts (in order to save memory).
We'll hardly ever get more than 2^32 references to the same object. So using
size_t to store reference count only wastes 4 bytes per object (on 64-bit
architecture). Use unsigned int instead.
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