]> www.ginac.de Git - ginac.git/blobdiff - ginac/flags.h
- This helps mul::expand() and friends to recognize objects which have
[ginac.git] / ginac / flags.h
index 90f4e38d992960961613eba7d8d52f3ffd063552..39a2113a12fbcb4f87db0afe779222be6fea3a28 100644 (file)
@@ -3,7 +3,7 @@
  *  Collection of all flags used through the GiNaC framework. */
 
 /*
- *  GiNaC Copyright (C) 1999 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2007 Johannes Gutenberg University Mainz, Germany
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -17,7 +17,7 @@
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
 #ifndef __GINAC_FLAGS_H__
 
 namespace GiNaC {
 
+/** Flags to control the behavior of expand(). */
 class expand_options {
 public:
-    enum { expand_trigonometric      = 0x0001
-         };
+       enum {
+               expand_indexed = 0x0001,      ///< expands (a+b).i to a.i+b.i
+               expand_function_args = 0x0002, ///< expands the arguments of functions
+               expand_rename_idx = 0x0004 ///< used internally by mul::expand()
+       };
+};
+
+/** Flags to control the behavior of has(). */
+class has_options {
+public:
+       enum {
+               algebraic = 0x0001,              ///< enable algebraic matching
+       };
+};
+
+/** Flags to control the behavior of subs(). */
+class subs_options {
+public:
+       enum {
+               no_pattern = 0x0001,             ///< disable pattern matching
+               subs_no_pattern = 0x0001, // for backwards compatibility
+               algebraic = 0x0002,              ///< enable algebraic substitutions
+               subs_algebraic = 0x0002,  // for backwards compatibility
+               pattern_is_product = 0x0004,     ///< used internally by expairseq::subschildren()
+               pattern_is_not_product = 0x0008, ///< used internally by expairseq::subschildren()
+               no_index_renaming = 0x0010,
+               // To indicate that we want to substitue an index by something that is
+               // is not an index. Without this flag the index value would be
+               // substituted in that case.
+               really_subs_idx = 0x0020
+       };
+};
+
+/** Domain of an object */
+class domain {
+public:
+       enum {
+               complex,
+               real,
+               positive
+       };
+};
+
+/** Flags to control series expansion. */
+class series_options {
+public:
+       enum {
+               /** Suppress branch cuts in series expansion.  Branch cuts manifest
+                *  themselves as step functions, if this option is not passed.  If
+                *  it is passed and expansion at a point on a cut is performed, then
+                *  the analytic continuation of the function is expanded. */
+               suppress_branchcut = 0x0001
+       };
+};
+
+/** Switch to control algorithm for determinant computation. */
+class determinant_algo {
+public:
+       enum {
+               /** Let the system choose.  A heuristics is applied for automatic
+                *  determination of a suitable algorithm. */
+               automatic,
+               /** Gauss elimination.  If \f$m_{i,j}^{(0)}\f$ are the entries of the
+                *  original matrix, then the matrix is transformed into triangular
+                *  form by applying the rules
+                *  \f[
+                *      m_{i,j}^{(k+1)} = m_{i,j}^{(k)} - m_{i,k}^{(k)} m_{k,j}^{(k)} / m_{k,k}^{(k)}
+                *  \f]
+                *  The determinant is then just the product of diagonal elements.
+                *  Choose this algorithm only for purely numerical matrices. */
+               gauss,
+               /** Division-free elimination.  This is a modification of Gauss
+                *  elimination where the division by the pivot element is not
+                *  carried out.  If \f$m_{i,j}^{(0)}\f$ are the entries of the
+                *  original matrix, then the matrix is transformed into triangular
+                *  form by applying the rules
+                *  \f[
+                *      m_{i,j}^{(k+1)} = m_{i,j}^{(k)} m_{k,k}^{(k)} - m_{i,k}^{(k)} m_{k,j}^{(k)}
+                *  \f]
+                *  The determinant can later be computed by inspecting the diagonal
+                *  elements only.  This algorithm is only there for the purpose of
+                *  cross-checks.  It is never fast. */
+               divfree,
+               /** Laplace elimination.  This is plain recursive elimination along
+                *  minors although multiple minors are avoided by the algorithm.
+                *  Although the algorithm is exponential in complexity it is
+                *  frequently the fastest one when the matrix is populated by
+                *  complicated symbolic expressions. */
+               laplace,
+               /** Bareiss fraction-free elimination.  This is a modification of
+                *  Gauss elimination where the division by the pivot element is
+                *  <EM>delayed</EM> until it can be carried out without computing
+                *  GCDs.  If \f$m_{i,j}^{(0)}\f$ are the entries of the original
+                *  matrix, then the matrix is transformed into triangular form by
+                *  applying the rules
+                *  \f[
+                *      m_{i,j}^{(k+1)} = (m_{i,j}^{(k)} m_{k,k}^{(k)} - m_{i,k}^{(k)} m_{k,j}^{(k)}) / m_{k-1,k-1}^{(k-1)}
+                *  \f]
+                *  (We have set \f$m_{-1,-1}^{(-1)}=1\f$ in order to avoid a case
+                *  distinction in above formula.)  It can be shown that nothing more
+                *  than polynomial long division is needed for carrying out the
+                *  division.  The determinant can then be read of from the lower
+                *  right entry.  This algorithm is rarely fast for computing
+                *  determinants. */
+               bareiss
+       };
+};
+
+/** Switch to control algorithm for linear system solving. */
+class solve_algo {
+public:
+       enum {
+               /** Let the system choose.  A heuristics is applied for automatic
+                *  determination of a suitable algorithm. */
+               automatic,
+               /** Gauss elimination.  If \f$m_{i,j}^{(0)}\f$ are the entries of the
+                *  original matrix, then the matrix is transformed into triangular
+                *  form by applying the rules
+                *  \f[
+                *      m_{i,j}^{(k+1)} = m_{i,j}^{(k)} - m_{i,k}^{(k)} m_{k,j}^{(k)} / m_{k,k}^{(k)}
+                *  \f]
+                *  This algorithm is well-suited for numerical matrices but generally
+                *  suffers from the expensive division (and computation of GCDs) at
+                *  each step. */
+               gauss,
+               /** Division-free elimination.  This is a modification of Gauss
+                *  elimination where the division by the pivot element is not
+                *  carried out.  If \f$m_{i,j}^{(0)}\f$ are the entries of the
+                *  original matrix, then the matrix is transformed into triangular
+                *  form by applying the rules
+                *  \f[
+                *      m_{i,j}^{(k+1)} = m_{i,j}^{(k)} m_{k,k}^{(k)} - m_{i,k}^{(k)} m_{k,j}^{(k)}
+                *  \f]
+                *  This algorithm is only there for the purpose of cross-checks.
+                *  It suffers from exponential intermediate expression swell.  Use it
+                *  only for small systems. */
+               divfree,
+               /** Bareiss fraction-free elimination.  This is a modification of
+                *  Gauss elimination where the division by the pivot element is
+                *  <EM>delayed</EM> until it can be carried out without computing
+                *  GCDs.  If \f$m_{i,j}^{(0)}\f$ are the entries of the original
+                *  matrix, then the matrix is transformed into triangular form by
+                *  applying the rules
+                *  \f[
+                *      m_{i,j}^{(k+1)} = (m_{i,j}^{(k)} m_{k,k}^{(k)} - m_{i,k}^{(k)} m_{k,j}^{(k)}) / m_{k-1,k-1}^{(k-1)}
+                *  \f]
+                *  (We have set \f$m_{-1,-1}^{(-1)}=1\f$ in order to avoid a case
+                *  distinction in above formula.)  It can be shown that nothing more
+                *  than polynomial long division is needed for carrying out the
+                *  division.  This is generally the fastest algorithm for solving
+                *  linear systems.  In contrast to division-free elimination it only
+                *  has a linear expression swell.  For two-dimensional systems, the
+                *  two algorithms are equivalent, however. */
+               bareiss
+       };
 };
 
+/** Flags to store information about the state of an object.
+ *  @see basic::flags */
 class status_flags {
 public:
-    enum { dynallocated              = 0x0001,
-           evaluated                 = 0x0002,
-           expanded                  = 0x0004,
-           hash_calculated           = 0x0008
-         };
+       enum {
+               dynallocated    = 0x0001, ///< heap-allocated (i.e. created by new if we want to be clever and bypass the stack, @see ex::construct_from_basic() )
+               evaluated       = 0x0002, ///< .eval() has already done its job
+               expanded        = 0x0004, ///< .expand(0) has already done its job (other expand() options ignore this flag)
+               hash_calculated = 0x0008, ///< .calchash() has already done its job
+               not_shareable   = 0x0010, ///< don't share instances of this object between different expressions unless explicitly asked to (used by ex::compare())
+               has_indices     = 0x0020,
+               has_no_indices  = 0x0040  // ! (has_indices || has_no_indices) means "don't know"
+       };
 };
 
+/** Possible attributes an object can have. */
 class info_flags {
 public:
-    enum { 
-           // answered by class numeric
-           numeric,
-           real,
-           rational,
-           integer,
-           positive,
-           negative,
-           nonnegative,
-           posint,
-           negint,
-           nonnegint,
-           even,
-           odd,
-           prime,
-
-           // answered by class relation
-           relation,
-           relation_equal,
-           relation_not_equal,
-           relation_less,
-           relation_less_or_equal,
-           relation_greater,
-           relation_greater_or_equal,
-
-           // answered by class symbol
-           symbol,
-
-           // answered by class lst
-           list,
-
-           // answered by class exprseq
-           exprseq,
-
-           // answered by classes numeric, symbol, add, mul, power
-           polynomial,
-           integer_polynomial,
-           rational_polynomial,
-           rational_function,
-
-           // answered by class ex
-           normal_form,
-           
-           // answered by class indexed
-           indexed,      // class can carry indices
-           has_indices,  // object has at least one index
-
-           // answered by class idx
-           idx,
-
-           // answered by class coloridx
-           coloridx,
-
-           // answered by class lorentzidx
-           lorentzidx
-    };
+       enum {
+               // answered by class numeric and symbols/constants in particular domains
+               numeric,
+               real,
+               rational,
+               integer,
+               crational,
+               cinteger,
+               positive,
+               negative,
+               nonnegative,
+               posint,
+               negint,
+               nonnegint,
+               even,
+               odd,
+               prime,
+
+               // answered by class relation
+               relation,
+               relation_equal,
+               relation_not_equal,
+               relation_less,
+               relation_less_or_equal,
+               relation_greater,
+               relation_greater_or_equal,
+
+               // answered by class symbol
+               symbol,
+
+               // answered by class lst
+               list,
+
+               // answered by class exprseq
+               exprseq,
+
+               // answered by classes numeric, symbol, add, mul, power
+               polynomial,
+               integer_polynomial,
+               cinteger_polynomial,
+               rational_polynomial,
+               crational_polynomial,
+               rational_function,
+               algebraic,
+
+               // answered by class indexed
+               indexed,      // class can carry indices
+               has_indices,  // object has at least one index
+
+               // answered by class idx
+               idx,
+
+               // answered by classes numeric, symbol, add, mul, power
+               expanded
+       };
 };
 
 class return_types {
 public:
-    enum { commutative, noncommutative, noncommutative_composite};
+       enum {
+               commutative,
+               noncommutative,
+               noncommutative_composite
+       };
 };
 
-class csrc_types {
+/** Strategies how to clean up the function remember cache.
+ *  @see remember_table */
+class remember_strategies {
 public:
        enum {
-               ctype_float,
-               ctype_double,
-               ctype_cl_N
+               delete_never,   ///< Let table grow undefinitely
+               delete_lru,     ///< Least recently used
+               delete_lfu,     ///< Least frequently used
+               delete_cyclic   ///< First (oldest) one in list
        };
 };