A system of generators. More...
#include <ppl.hh>
Inherits Parma_Polyhedra_Library::Linear_System.
Inherited by Parma_Polyhedra_Library::Grid_Generator_System [private].
Classes | |
| class | const_iterator |
| An iterator over a system of generators. More... | |
Public Member Functions | |
| Generator_System () | |
| Default constructor: builds an empty system of generators. | |
| Generator_System (const Generator &g) | |
Builds the singleton system containing only generator g. | |
| Generator_System (const Generator_System &gs) | |
| Ordinary copy constructor. | |
| ~Generator_System () | |
| Destructor. | |
| Generator_System & | operator= (const Generator_System &y) |
| Assignment operator. | |
| dimension_type | space_dimension () const |
Returns the dimension of the vector space enclosing *this. | |
| void | clear () |
| Removes all the generators from the generator system and sets its space dimension to 0. | |
| void | insert (const Generator &g) |
Inserts in *this a copy of the generator g, increasing the number of space dimensions if needed. | |
| bool | empty () const |
Returns true if and only if *this has no generators. | |
| const_iterator | begin () const |
Returns the const_iterator pointing to the first generator, if *this is not empty; otherwise, returns the past-the-end const_iterator. | |
| const_iterator | end () const |
| Returns the past-the-end const_iterator. | |
| bool | OK () const |
| Checks if all the invariants are satisfied. | |
| void | ascii_dump () const |
Writes to std::cerr an ASCII representation of *this. | |
| void | ascii_dump (std::ostream &s) const |
Writes to s an ASCII representation of *this. | |
| void | print () const |
Prints *this to std::cerr using operator<<. | |
| bool | ascii_load (std::istream &s) |
Loads from s an ASCII representation (as produced by ascii_dump(std::ostream&) const) and sets *this accordingly. Returns true if successful, false otherwise. | |
| memory_size_type | total_memory_in_bytes () const |
Returns the total size in bytes of the memory occupied by *this. | |
| memory_size_type | external_memory_in_bytes () const |
Returns the size in bytes of the memory managed by *this. | |
| void | swap (Generator_System &y) |
Swaps *this with y. | |
Static Public Member Functions | |
| static dimension_type | max_space_dimension () |
| Returns the maximum space dimension a Generator_System can handle. | |
| static void | initialize () |
| Initializes the class. | |
| static void | finalize () |
| Finalizes the class. | |
| static const Generator_System & | zero_dim_univ () |
| Returns the singleton system containing only Generator::zero_dim_point(). | |
Related Functions | |
(Note that these are not member functions.) | |
| std::ostream & | operator<< (std::ostream &s, const Generator_System &gs) |
| Output operator. | |
| void | swap (Parma_Polyhedra_Library::Generator_System &x, Parma_Polyhedra_Library::Generator_System &y) |
Specializes std::swap. | |
A system of generators.
An object of the class Generator_System is a system of generators, i.e., a multiset of objects of the class Generator (lines, rays, points and closure points). When inserting generators in a system, space dimensions are automatically adjusted so that all the generators in the system are defined on the same vector space. A system of generators which is meant to define a non-empty polyhedron must include at least one point: the reason is that lines, rays and closure points need a supporting point (lines and rays only specify directions while closure points only specify points in the topological closure of the NNC polyhedron).
x and y are defined as follows: Variable x(0); Variable y(1);
axis (i.e., the first Cartesian axis) in
: Generator_System gs; gs.insert(line(x + 0*y));
axis, we can add the following code which inserts the origin of the space as a point: gs.insert(point(0*x + 0*y));
gs.insert(point(0*x));
axis through the point
. gs.insert(point(0*x + 1*y));
axis in
: Generator_System gs; gs.insert(ray(x + 0*y));
gs.insert(point(0*x + 0*y));
(the same as Example 1 for the system of constraints): Generator_System gs; gs.insert(point(0*x + 0*y)); gs.insert(point(0*x + 3*y)); gs.insert(point(3*x + 0*y)); gs.insert(point(3*x + 3*y));
Generator_System gs; gs.insert(point(x + y)); gs.insert(closure_point(0*x + 0*y)); gs.insert(closure_point(0*x + 3*y)); gs.insert(closure_point(3*x + 0*y)); gs.insert(closure_point(3*x + 3*y));
(the same as Example 2 for the system of constraints): Generator_System gs; gs.insert(point(0*x + 0*y)); gs.insert(point(0*x + 1*y)); gs.insert(ray(x - y));
| bool Parma_Polyhedra_Library::Generator_System::OK | ( | ) | const |
Checks if all the invariants are satisfied.
Returns true if and only if *this is a valid Linear_System and each row in the system is a valid Generator.
Reimplemented in Parma_Polyhedra_Library::Grid_Generator_System.
| bool Parma_Polyhedra_Library::Generator_System::ascii_load | ( | std::istream & | s | ) |
Loads from s an ASCII representation (as produced by ascii_dump(std::ostream&) const) and sets *this accordingly. Returns true if successful, false otherwise.
Resizes the matrix of generators using the numbers of rows and columns read from s, then initializes the coordinates of each generator and its type reading the contents from s.
Reimplemented in Parma_Polyhedra_Library::Grid_Generator_System.
| std::ostream & operator<< | ( | std::ostream & | s, | |
| const Generator_System & | gs | |||
| ) | [related] |
Output operator.
Writes false if gs is empty. Otherwise, writes on s the generators of gs, all in one row and separated by ", ".
| void swap | ( | Parma_Polyhedra_Library::Generator_System & | x, | |
| Parma_Polyhedra_Library::Generator_System & | y | |||
| ) | [related] |
Specializes std::swap.
1.6.3