svsample05.cpp
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/*
Copyright(c) 2002-2017 Anatoliy Kuznetsov(anatoliy_kuznetsov at yahoo.com)
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
For more information please visit: http://bitmagic.io
*/
/** \example svsample05.cpp
Example how to use for bvector re-mapping / transformation
based on sparse_vector as a translation table.
Example discusses how use of NULL (unassigned) sparse_vector<> semantics affects
behavior of image transformation algorithm.
\sa bm::sparse_vector<>
\sa bm::set2set_11_transform
*/
/*! \file svsample05.cpp
\brief Example: sparse_vector<> used for set 2 set remapping (theory of groups Image)
*/
#include <iostream>
#include <vector>
#include "bm.h"
#include "bmsparsevec.h"
#include "bmsparsevec_algo.h"
#include "bmundef.h" /* clear the pre-proc defines from BM */
using namespace std;
typedef bm::sparse_vector<bm::id_t, bm::bvector<> > sparse_vector_u32;
static
void print_svector(const sparse_vector_u32& sv)
{
if (sv.size() == 0)
{
cout << sv.size() << ": [ EMPTY ]" << endl;
return;
}
cout << sv.size() << ": [ ";
for (unsigned i = 0; i < sv.size(); ++i)
{
unsigned v = sv.at(i);
bool is_null = sv.is_null(i);
if (is_null)
cout << "NULL";
else
cout << v << "";
if (i == sv.size()-1)
cout << " ]";
else
cout << ", ";
}
cout << endl;
}
inline
void print_bvector(const bm::bvector<>& bv)
{
cout << "( count = " << bv.count() << ")" << ": [";
bm::bvector<>::enumerator en = bv.first();
for (; en.valid(); ++en)
{
cout << *en << ", ";
}
cout << "]" << endl;
}
int main(void)
{
try
{
// initialize sparse_vector as a binary relation (transform function)
// to translate from one set to another (please note it uses NULL values)
//
sparse_vector_u32 sv_transform(bm::use_null);
// transformation function defined as a table:
// 2 -> 25
// 3 -> 35
// 7 -> 75
// 1000 -> 2000
// 256 -> 2001
sv_transform.set(2, 25);
sv_transform.set(3, 35);
sv_transform.set(7, 75);
sv_transform.set(1000, 2000);
sv_transform.set(256, 2001);
print_svector(sv_transform);
// initialize input bit-vector
//
bm::bvector<> bv_in { 1, 2, 3, 1000, 256 };
bm::bvector<> bv_out;
bm::set2set_11_transform<sparse_vector_u32> func;
func.run(bv_in, sv_transform, bv_out);
std::cout << "re-mapped vector:" << endl;
print_bvector(bv_out); // ( count = 4): [25, 35, 2000, 2001, ]
// Please note, that remapping request for "1" cannot be satisfied
// as sv_transform vector did not assign this element so it has
// special unassigned, NULL value
bm::id_t from = 1;
bm::id_t to;
bool found = func.remap(1, sv_transform, to);
if (!found)
std::cout << from << " not mapped" << std::endl; // THIS works!
else
std::cout << from << " mapped to " << to << std::endl;
// now lets try another experiment here, construct image transform
// function as default NOT using NULL values
sparse_vector_u32 sv_transform2;
sv_transform2.set(2, 25);
sv_transform2.set(3, 35);
sv_transform2.set(7, 75);
sv_transform2.set(1000, 2000);
sv_transform2.set(256, 2001);
found = func.remap(1, sv_transform2, to);
if (!found)
std::cout << from << " not mapped" << std::endl;
else
std::cout << from << " mapped to " << to << std::endl; // Now THIS works!
// Please note that remapping for unassigned value - works and maps to 0
// because transformation sparse vector does not keep information about
// unassigned values, all unassigned are now implicitly assumed to be "0"
func.run(bv_in, sv_transform2, bv_out);
std::cout << "re-mapped vector2:" << endl;
print_bvector(bv_out); // ( count = 5): [0, 25, 35, 2000, 2001, ]
}
catch(std::exception& ex)
{
std::cerr << ex.what() << std::endl;
return 1;
}
return 0;
}
bm.h
Compressed bit-vector bvector<> container, set algebraic methods, traversal iterators.
bmsparsevec.h
Sparse constainer sparse_vector<> for integer types using bit-transposition transform.
bmsparsevec_algo.h
Algorithms for bm::sparse_vector.
bmundef.h
pre-processor un-defines to avoid global space pollution (internal)
bm::base_sparse_vector::is_null
bool is_null(size_type idx) const BMNOEXCEPT
test if specified element is NULL
Definition bmbmatrix.h:1830
bm::bvector::enumerator
Constant iterator designed to enumerate "ON" bits.
Definition bm.h:603
bm::bvector::iterator_base::valid
bool valid() const BMNOEXCEPT
Checks if iterator is still valid.
Definition bm.h:283
bm::bvector
Bitvector Bit-vector container with runtime compression of bits.
Definition bm.h:115
bm::bvector::count
size_type count() const BMNOEXCEPT
population count (count of ON bits)
Definition bm.h:2401
bm::bvector::first
enumerator first() const
Returns enumerator pointing on the first non-zero bit.
Definition bm.h:1871
bm::set2set_11_transform
Integer set to set transformation (functional image in groups theory) https://en.wikipedia....
Definition bmsparsevec_algo.h:1247
bm::set2set_11_transform::remap
void remap(const bvector_type &bv_in, bvector_type &bv_out)
Perform remapping (Image function) (based on attached translation table).
Definition bmsparsevec_algo.h:1458
bm::set2set_11_transform::run
void run(const bvector_type &bv_in, const SV &sv_brel, bvector_type &bv_out)
Run remap transformation.
Definition bmsparsevec_algo.h:1304
bm::sparse_vector
succinct sparse vector with runtime compression using bit-slicing / transposition method
Definition bmsparsevec.h:87
bm::sparse_vector::at
value_type at(size_type idx) const
access specified element with bounds checking
Definition bmsparsevec.h:1747
bm::sparse_vector::size
size_type size() const BMNOEXCEPT
return size of the vector
Definition bmsparsevec.h:729
bm::sparse_vector::set
void set(size_type idx, value_type v)
set specified element with bounds checking and automatic resize
Definition bmsparsevec.h:1849
bm::use_null
@ use_null
support "non-assigned" or "NULL" logic
Definition bmconst.h:230
bm::id_t
unsigned int id_t
Definition bmconst.h:38
main
int main(void)
Definition svsample05.cpp:87
print_bvector
void print_bvector(const bm::bvector<> &bv)
Definition svsample05.cpp:75
print_svector
static void print_svector(const sparse_vector_u32 &sv)
Definition svsample05.cpp:48
sparse_vector_u32
bm::sparse_vector< unsigned, bm::bvector<> > sparse_vector_u32
Definition xsample02.cpp:68