sample9.cpp
Go to the documentation of this file.
/*
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 sample9.cpp
Example demonstrates binary distance metrics. BM library can compute
various distances without materializing a product set.
\sa bm::count_and
\sa bm::count_xor
\sa bm::count_sub
\sa bm::count_or
\sa bm::distance_operation
For more information please visit: http://bmagic.sourceforge.net
*/
/*! \file sample9.cpp
\brief Example: bvector<> binary similarity / distance algorithms
*/
#include <iostream>
#include "bm.h"
#include "bmalgo.h"
#include "bmundef.h" /* clear the pre-proc defines from BM */
using namespace std;
int main(void)
{
try
{
bm::bvector<> bv1;
bm::bvector<> bv2;
bv1[10] = true;
bv1[100] = true;
bv1[10000] = true;
bv2[10] = true;
bv2[100] = true;
bv2[20000] = true;
bv2[30000] = true;
// Hamming distance:
auto hamming = bm::count_xor(bv1, bv2);
cout << "Hamming distance = " << hamming << endl;
// Dice distance using basic distance functions
double dice =
double(2 * bm::count_and(bv1, bv2))/double(bv1.count() + bv2.count());
cout << "Dice distance = " << dice << endl;
// Dice distance, can be computed using "metric pipeline"
bm::distance_metric_descriptor dmd[3];
dmd[0].metric = bm::COUNT_AND;
dmd[1].metric = bm::COUNT_A;
dmd[2].metric = bm::COUNT_B;
bm::distance_operation(bv1, bv2, dmd, dmd+3);
double dice_p =
double(2 * dmd[0].result) / double(dmd[1].result + dmd[2].result);
cout << "Dice distance (pipeline) = " << dice_p << endl;
}
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.
bmalgo.h
Algorithms for bvector<> (main include).
bmundef.h
pre-processor un-defines to avoid global space pollution (internal)
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::distance_operation
void distance_operation(const BV &bv1, const BV &bv2, distance_metric_descriptor *dmit, distance_metric_descriptor *dmit_end) BMNOEXCEPT
Distance computing template function.
Definition bmalgo_impl.h:766
bm::COUNT_A
@ COUNT_A
A.count().
Definition bmalgo_impl.h:64
bm::COUNT_B
@ COUNT_B
B.count().
Definition bmalgo_impl.h:65
bm::COUNT_AND
@ COUNT_AND
(A & B).count()
Definition bmalgo_impl.h:59
bm::count_and
BV::size_type count_and(const BV &bv1, const BV &bv2) BMNOEXCEPT
Computes bitcount of AND operation of two bitsets.
Definition bmalgo.h:49
bm::count_xor
bm::distance_metric_descriptor::size_type count_xor(const BV &bv1, const BV &bv2) BMNOEXCEPT
Computes bitcount of XOR operation of two bitsets.
Definition bmalgo.h:81
main
int main(void)
Definition sample9.cpp:47
bm::distance_metric_descriptor
Distance metric descriptor, holds metric code and result.
Definition bmalgo_impl.h:87
bm::distance_metric_descriptor::metric
distance_metric metric
Definition bmalgo_impl.h:94