BitMagic-C++
svsample05.cpp
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1 /*
2 Copyright(c) 2002-2017 Anatoliy Kuznetsov(anatoliy_kuznetsov at yahoo.com)
3 
4 Licensed under the Apache License, Version 2.0 (the "License");
5 you may not use this file except in compliance with the License.
6 You may obtain a copy of the License at
7 
8  http://www.apache.org/licenses/LICENSE-2.0
9 
10 Unless required by applicable law or agreed to in writing, software
11 distributed under the License is distributed on an "AS IS" BASIS,
12 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 See the License for the specific language governing permissions and
14 limitations under the License.
15 
16 For more information please visit: http://bitmagic.io
17 */
18 
19 /** \example svsample05.cpp
20  Example how to use for bvector re-mapping / transformation
21  based on sparse_vector as a translation table.
22 
23  Example discusses how use of NULL (unassigned) sparse_vector<> semantics affects
24  behavior of image transformation algorithm.
25 
26  \sa bm::sparse_vector<>
27  \sa bm::set2set_11_transform
28 */
29 
30 /*! \file svsample05.cpp
31  \brief Example: sparse_vector<> used for set 2 set remapping (theory of groups Image)
32 */
33 
34 
35 #include <iostream>
36 #include <vector>
37 
38 #include "bm.h"
39 #include "bmsparsevec.h"
40 #include "bmsparsevec_algo.h"
41 
42 using namespace std;
43 
45 
46 static
48 {
49  if (sv.size() == 0)
50  {
51  cout << sv.size() << ": [ EMPTY ]" << endl;
52  return;
53  }
54  cout << sv.size() << ": [ ";
55  for (unsigned i = 0; i < sv.size(); ++i)
56  {
57  unsigned v = sv.at(i);
58  bool is_null = sv.is_null(i);
59 
60  if (is_null)
61  cout << "NULL";
62  else
63  cout << v << "";
64 
65  if (i == sv.size()-1)
66  cout << " ]";
67  else
68  cout << ", ";
69  }
70  cout << endl;
71 }
72 
73 inline
75 {
76  cout << "( count = " << bv.count() << ")" << ": [";
78  for (; en.valid(); ++en)
79  {
80  cout << *en << ", ";
81  }
82  cout << "]" << endl;
83 }
84 
85 
86 int main(void)
87 {
88  try
89  {
90  // initialize sparse_vector as a binary relation (transform function)
91  // to translate from one set to another (please note it uses NULL values)
92  //
93  sparse_vector_u32 sv_transform(bm::use_null);
94 
95  // transformation function defined as a table:
96  // 2 -> 25
97  // 3 -> 35
98  // 7 -> 75
99  // 1000 -> 2000
100  // 256 -> 2001
101 
102  sv_transform.set(2, 25);
103  sv_transform.set(3, 35);
104  sv_transform.set(7, 75);
105  sv_transform.set(1000, 2000);
106  sv_transform.set(256, 2001);
107 
108  print_svector(sv_transform);
109 
110  // initialize input bit-vector
111  //
112  bm::bvector<> bv_in { 1, 2, 3, 1000, 256 };
113 
114  bm::bvector<> bv_out;
115 
117  func.run(bv_in, sv_transform, bv_out);
118 
119  std::cout << "re-mapped vector:" << endl;
120  print_bvector(bv_out); // ( count = 4): [25, 35, 2000, 2001, ]
121 
122  // Please note, that remapping request for "1" cannot be satisfied
123  // as sv_transform vector did not assign this element so it has
124  // special unassigned, NULL value
125 
126  bm::id_t from = 1;
127  bm::id_t to;
128  bool found = func.remap(1, sv_transform, to);
129  if (!found)
130  std::cout << from << " not mapped" << std::endl; // THIS works!
131  else
132  std::cout << from << " mapped to " << to << std::endl;
133 
134 
135  // now lets try another experiment here, construct image transform
136  // function as default NOT using NULL values
137 
138  sparse_vector_u32 sv_transform2;
139 
140  sv_transform2.set(2, 25);
141  sv_transform2.set(3, 35);
142  sv_transform2.set(7, 75);
143  sv_transform2.set(1000, 2000);
144  sv_transform2.set(256, 2001);
145 
146  found = func.remap(1, sv_transform2, to);
147  if (!found)
148  std::cout << from << " not mapped" << std::endl;
149  else
150  std::cout << from << " mapped to " << to << std::endl; // Now THIS works!
151 
152  // Please note that remapping for unassigned value - works and maps to 0
153  // because transformation sparse vector does not keep information about
154  // unassigned values, all unassigned are now implicitly assumed to be "0"
155 
156  func.run(bv_in, sv_transform2, bv_out);
157 
158  std::cout << "re-mapped vector2:" << endl;
159  print_bvector(bv_out); // ( count = 5): [0, 25, 35, 2000, 2001, ]
160 
161  }
162  catch(std::exception& ex)
163  {
164  std::cerr << ex.what() << std::endl;
165  return 1;
166  }
167 
168  return 0;
169 }
170 
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:982
bmsparsevec_algo.h
Algorithms for bm::sparse_vector.
bm::sparse_vector
sparse vector with runtime compression using bit transposition method
Definition: bmsparsevec.h:81
bm::set2set_11_transform
Integer set to set transformation (functional image in groups theory) https://en.wikipedia....
Definition: bmsparsevec_algo.h:773
bmsparsevec.h
Sparse constainer sparse_vector<> for integer types using bit-transposition transform.
bm::bvector::enumerator
Constant iterator designed to enumerate "ON" bits.
Definition: bm.h:599
bm::bvector<>
bm::use_null
@ use_null
support "non-assigned" or "NULL" logic
Definition: bmconst.h:215
print_svector
static void print_svector(const sparse_vector_u32 &sv)
Definition: svsample05.cpp:47
bm::bvector::count
size_type count() const BMNOEXCEPT
population cout (count of ON bits)
Definition: bm.h:2208
print_bvector
void print_bvector(const bm::bvector<> &bv)
Definition: svsample05.cpp:74
bm::bvector::iterator_base::valid
bool valid() const BMNOEXCEPT
Checks if iterator is still valid. Analog of != 0 comparison for pointers.
Definition: bm.h:280
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:831
bm::sparse_vector::size
size_type size() const BMNOEXCEPT
return size of the vector
Definition: bmsparsevec.h:644
main
int main(void)
Definition: svsample05.cpp:86
bm::base_sparse_vector::is_null
bool is_null(size_type idx) const BMNOEXCEPT
test if specified element is NULL
Definition: bmbmatrix.h:1285
bm::id_t
unsigned int id_t
Definition: bmconst.h:37
sparse_vector_u32
bm::sparse_vector< bm::id_t, bm::bvector<> > sparse_vector_u32
Definition: svsample05.cpp:44
bm::sparse_vector::at
value_type at(size_type idx) const
access specified element with bounds checking
Definition: bmsparsevec.h:1440
bm::bvector::first
enumerator first() const
Returns enumerator pointing on the first non-zero bit.
Definition: bm.h:1784
bm.h
Compressed bit-vector bvector<> container, set algebraic methods, traversal iterators.
bm::sparse_vector::set
void set(size_type idx, value_type v)
set specified element with bounds checking and automatic resize
Definition: bmsparsevec.h:1475