<html><!-- Created using the cpp_pretty_printer from the dlib C++ library. See http://dlib.net for updates. --><head><title>dlib C++ Library - random_subset_selector.h</title></head><body bgcolor='white'><pre>
<font color='#009900'>// Copyright (C) 2010 Davis E. King (davis@dlib.net)
</font><font color='#009900'>// License: Boost Software License See LICENSE.txt for the full license.
</font><font color='#0000FF'>#ifndef</font> DLIB_RANDOM_SUBSeT_SELECTOR_H_
<font color='#0000FF'>#define</font> DLIB_RANDOM_SUBSeT_SELECTOR_H_
<font color='#0000FF'>#include</font> "<a style='text-decoration:none' href='random_subset_selector_abstract.h.html'>random_subset_selector_abstract.h</a>"
<font color='#0000FF'>#include</font> "<a style='text-decoration:none' href='../rand.h.html'>../rand.h</a>"
<font color='#0000FF'>#include</font> <font color='#5555FF'><</font>vector<font color='#5555FF'>></font>
<font color='#0000FF'>#include</font> "<a style='text-decoration:none' href='../algs.h.html'>../algs.h</a>"
<font color='#0000FF'>#include</font> "<a style='text-decoration:none' href='../string.h.html'>../string.h</a>"
<font color='#0000FF'>#include</font> "<a style='text-decoration:none' href='../serialize.h.html'>../serialize.h</a>"
<font color='#0000FF'>#include</font> "<a style='text-decoration:none' href='../matrix/matrix_mat.h.html'>../matrix/matrix_mat.h</a>"
<font color='#0000FF'>#include</font> <font color='#5555FF'><</font>iostream<font color='#5555FF'>></font>
<font color='#0000FF'>namespace</font> dlib
<b>{</b>
<font color='#0000FF'>template</font> <font color='#5555FF'><</font>
<font color='#0000FF'>typename</font> T,
<font color='#0000FF'>typename</font> Rand_type <font color='#5555FF'>=</font> dlib::rand
<font color='#5555FF'>></font>
<font color='#0000FF'>class</font> <b><a name='random_subset_selector'></a>random_subset_selector</b>
<b>{</b>
<font color='#009900'>/*!
INITIAL VALUE
- _max_size == 0
- items.size() == 0
- count == 0
- _next_add_accepts == false
CONVENTION
- count == the number of times add() has been called since the last
time this object was empty.
- items.size() == size()
- max_size() == _max_size
- next_add_accepts() == _next_add_accepts
!*/</font>
<font color='#0000FF'>public</font>:
<font color='#0000FF'>typedef</font> T type;
<font color='#0000FF'>typedef</font> T value_type;
<font color='#0000FF'>typedef</font> default_memory_manager mem_manager_type;
<font color='#0000FF'>typedef</font> Rand_type rand_type;
<font color='#0000FF'>typedef</font> <font color='#0000FF'>typename</font> std::vector<font color='#5555FF'><</font>T<font color='#5555FF'>></font>::iterator iterator;
<font color='#0000FF'>typedef</font> <font color='#0000FF'>typename</font> std::vector<font color='#5555FF'><</font>T<font color='#5555FF'>></font>::const_iterator const_iterator;
<b><a name='random_subset_selector'></a>random_subset_selector</b> <font face='Lucida Console'>(</font>
<font face='Lucida Console'>)</font>
<b>{</b>
_max_size <font color='#5555FF'>=</font> <font color='#979000'>0</font>;
<font color='#BB00BB'>make_empty</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>;
<b>}</b>
<font color='#0000FF'><u>void</u></font> <b><a name='set_seed'></a>set_seed</b><font face='Lucida Console'>(</font><font color='#0000FF'>const</font> std::string<font color='#5555FF'>&</font> value<font face='Lucida Console'>)</font>
<b>{</b>
rnd.<font color='#BB00BB'>set_seed</font><font face='Lucida Console'>(</font>value<font face='Lucida Console'>)</font>;
<b>}</b>
<font color='#0000FF'><u>void</u></font> <b><a name='make_empty'></a>make_empty</b> <font face='Lucida Console'>(</font>
<font face='Lucida Console'>)</font>
<b>{</b>
items.<font color='#BB00BB'>resize</font><font face='Lucida Console'>(</font><font color='#979000'>0</font><font face='Lucida Console'>)</font>;
count <font color='#5555FF'>=</font> <font color='#979000'>0</font>;
<font color='#BB00BB'>update_next_add_accepts</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>;
<b>}</b>
<font color='#0000FF'>const</font> std::vector<font color='#5555FF'><</font>T<font color='#5555FF'>></font><font color='#5555FF'>&</font> <b><a name='to_std_vector'></a>to_std_vector</b><font face='Lucida Console'>(</font>
<font face='Lucida Console'>)</font> <font color='#0000FF'>const</font> <b>{</b> <font color='#0000FF'>return</font> items; <b>}</b>
<font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> <b><a name='size'></a>size</b> <font face='Lucida Console'>(</font>
<font face='Lucida Console'>)</font> <font color='#0000FF'>const</font>
<b>{</b>
<font color='#0000FF'>return</font> items.<font color='#BB00BB'>size</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>;
<b>}</b>
<font color='#0000FF'><u>void</u></font> <b><a name='set_max_size'></a>set_max_size</b> <font face='Lucida Console'>(</font>
<font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> new_max_size
<font face='Lucida Console'>)</font>
<b>{</b>
items.<font color='#BB00BB'>reserve</font><font face='Lucida Console'>(</font>new_max_size<font face='Lucida Console'>)</font>;
<font color='#BB00BB'>make_empty</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>;
_max_size <font color='#5555FF'>=</font> new_max_size;
<font color='#BB00BB'>update_next_add_accepts</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>;
<b>}</b>
<font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> <b><a name='max_size'></a>max_size</b> <font face='Lucida Console'>(</font>
<font face='Lucida Console'>)</font> <font color='#0000FF'>const</font>
<b>{</b>
<font color='#0000FF'>return</font> _max_size;
<b>}</b>
T<font color='#5555FF'>&</font> <b><a name='operator'></a>operator</b>[] <font face='Lucida Console'>(</font>
<font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> idx
<font face='Lucida Console'>)</font>
<b>{</b>
<font color='#009900'>// make sure requires clause is not broken
</font> <font color='#BB00BB'>DLIB_ASSERT</font><font face='Lucida Console'>(</font>idx <font color='#5555FF'><</font> <font color='#BB00BB'>size</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>,
"<font color='#CC0000'>\tvoid random_subset_selector::operator[]()</font>"
<font color='#5555FF'><</font><font color='#5555FF'><</font> "<font color='#CC0000'>\n\t idx is out of range</font>"
<font color='#5555FF'><</font><font color='#5555FF'><</font> "<font color='#CC0000'>\n\t idx: </font>" <font color='#5555FF'><</font><font color='#5555FF'><</font> idx
<font color='#5555FF'><</font><font color='#5555FF'><</font> "<font color='#CC0000'>\n\t size(): </font>" <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#BB00BB'>size</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>
<font color='#5555FF'><</font><font color='#5555FF'><</font> "<font color='#CC0000'>\n\t this: </font>" <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#0000FF'>this</font>
<font face='Lucida Console'>)</font>;
<font color='#0000FF'>return</font> items[idx];
<b>}</b>
<font color='#0000FF'>const</font> T<font color='#5555FF'>&</font> <b><a name='operator'></a>operator</b>[] <font face='Lucida Console'>(</font>
<font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> idx
<font face='Lucida Console'>)</font> <font color='#0000FF'>const</font>
<b>{</b>
<font color='#009900'>// make sure requires clause is not broken
</font> <font color='#BB00BB'>DLIB_ASSERT</font><font face='Lucida Console'>(</font>idx <font color='#5555FF'><</font> <font color='#BB00BB'>size</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>,
"<font color='#CC0000'>\tvoid random_subset_selector::operator[]()</font>"
<font color='#5555FF'><</font><font color='#5555FF'><</font> "<font color='#CC0000'>\n\t idx is out of range</font>"
<font color='#5555FF'><</font><font color='#5555FF'><</font> "<font color='#CC0000'>\n\t idx: </font>" <font color='#5555FF'><</font><font color='#5555FF'><</font> idx
<font color='#5555FF'><</font><font color='#5555FF'><</font> "<font color='#CC0000'>\n\t size(): </font>" <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#BB00BB'>size</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>
<font color='#5555FF'><</font><font color='#5555FF'><</font> "<font color='#CC0000'>\n\t this: </font>" <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#0000FF'>this</font>
<font face='Lucida Console'>)</font>;
<font color='#0000FF'>return</font> items[idx];
<b>}</b>
iterator <b><a name='begin'></a>begin</b><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font> <b>{</b> <font color='#0000FF'>return</font> items.<font color='#BB00BB'>begin</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>; <b>}</b>
const_iterator <b><a name='begin'></a>begin</b><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font> <font color='#0000FF'>const</font> <b>{</b> <font color='#0000FF'>return</font> items.<font color='#BB00BB'>begin</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>; <b>}</b>
iterator <b><a name='end'></a>end</b><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font> <b>{</b> <font color='#0000FF'>return</font> items.<font color='#BB00BB'>end</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>; <b>}</b>
const_iterator <b><a name='end'></a>end</b><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font> <font color='#0000FF'>const</font> <b>{</b> <font color='#0000FF'>return</font> items.<font color='#BB00BB'>end</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>; <b>}</b>
<font color='#0000FF'><u>bool</u></font> <b><a name='next_add_accepts'></a>next_add_accepts</b> <font face='Lucida Console'>(</font>
<font face='Lucida Console'>)</font> <font color='#0000FF'>const</font>
<b>{</b>
<font color='#0000FF'>return</font> _next_add_accepts;
<b>}</b>
<font color='#0000FF'><u>void</u></font> <b><a name='add'></a>add</b> <font face='Lucida Console'>(</font>
<font color='#0000FF'>const</font> T<font color='#5555FF'>&</font> new_item
<font face='Lucida Console'>)</font>
<b>{</b>
<font color='#0000FF'>if</font> <font face='Lucida Console'>(</font>items.<font color='#BB00BB'>size</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font> <font color='#5555FF'><</font> _max_size<font face='Lucida Console'>)</font>
<b>{</b>
items.<font color='#BB00BB'>push_back</font><font face='Lucida Console'>(</font>new_item<font face='Lucida Console'>)</font>;
<font color='#009900'>// swap into a random place
</font> <font color='#BB00BB'>exchange</font><font face='Lucida Console'>(</font>items[rnd.<font color='#BB00BB'>get_random_32bit_number</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font><font color='#5555FF'>%</font>items.<font color='#BB00BB'>size</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>], items.<font color='#BB00BB'>back</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font><font face='Lucida Console'>)</font>;
<b>}</b>
<font color='#0000FF'>else</font> <font color='#0000FF'>if</font> <font face='Lucida Console'>(</font>_next_add_accepts<font face='Lucida Console'>)</font>
<b>{</b>
<font color='#009900'>// pick a random element of items and replace it.
</font> items[rnd.<font color='#BB00BB'>get_random_32bit_number</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font><font color='#5555FF'>%</font>items.<font color='#BB00BB'>size</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>] <font color='#5555FF'>=</font> new_item;
<b>}</b>
<font color='#BB00BB'>update_next_add_accepts</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>;
<font color='#5555FF'>+</font><font color='#5555FF'>+</font>count;
<b>}</b>
<font color='#0000FF'><u>void</u></font> <b><a name='add'></a>add</b> <font face='Lucida Console'>(</font>
<font face='Lucida Console'>)</font>
<b>{</b>
<font color='#009900'>// make sure requires clause is not broken
</font> <font color='#BB00BB'>DLIB_ASSERT</font><font face='Lucida Console'>(</font><font color='#BB00BB'>next_add_accepts</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font> <font color='#5555FF'>=</font><font color='#5555FF'>=</font> <font color='#979000'>false</font>,
"<font color='#CC0000'>\tvoid random_subset_selector::add()</font>"
<font color='#5555FF'><</font><font color='#5555FF'><</font> "<font color='#CC0000'>\n\t You should be calling the version of add() that takes an argument</font>"
<font color='#5555FF'><</font><font color='#5555FF'><</font> "<font color='#CC0000'>\n\t this: </font>" <font color='#5555FF'><</font><font color='#5555FF'><</font> <font color='#0000FF'>this</font>
<font face='Lucida Console'>)</font>;
<font color='#BB00BB'>update_next_add_accepts</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>;
<font color='#5555FF'>+</font><font color='#5555FF'>+</font>count;
<b>}</b>
<font color='#0000FF'><u>void</u></font> <b><a name='swap'></a>swap</b> <font face='Lucida Console'>(</font>
random_subset_selector<font color='#5555FF'>&</font> a
<font face='Lucida Console'>)</font>
<b>{</b>
items.<font color='#BB00BB'>swap</font><font face='Lucida Console'>(</font>a.items<font face='Lucida Console'>)</font>;
std::<font color='#BB00BB'>swap</font><font face='Lucida Console'>(</font>_max_size, a._max_size<font face='Lucida Console'>)</font>;
std::<font color='#BB00BB'>swap</font><font face='Lucida Console'>(</font>count, a.count<font face='Lucida Console'>)</font>;
rnd.<font color='#BB00BB'>swap</font><font face='Lucida Console'>(</font>a.rnd<font face='Lucida Console'>)</font>;
std::<font color='#BB00BB'>swap</font><font face='Lucida Console'>(</font>_next_add_accepts, a._next_add_accepts<font face='Lucida Console'>)</font>;
<b>}</b>
<font color='#0000FF'>template</font> <font color='#5555FF'><</font><font color='#0000FF'>typename</font> T1, <font color='#0000FF'>typename</font> T2<font color='#5555FF'>></font>
<font color='#0000FF'>friend</font> <font color='#0000FF'><u>void</u></font> <b><a name='serialize'></a>serialize</b> <font face='Lucida Console'>(</font>
<font color='#0000FF'>const</font> random_subset_selector<font color='#5555FF'><</font>T1,T2<font color='#5555FF'>></font><font color='#5555FF'>&</font> item,
std::ostream<font color='#5555FF'>&</font> out
<font face='Lucida Console'>)</font>;
<font color='#0000FF'>template</font> <font color='#5555FF'><</font><font color='#0000FF'>typename</font> T1, <font color='#0000FF'>typename</font> T2<font color='#5555FF'>></font>
<font color='#0000FF'>friend</font> <font color='#0000FF'><u>void</u></font> <b><a name='deserialize'></a>deserialize</b> <font face='Lucida Console'>(</font>
random_subset_selector<font color='#5555FF'><</font>T1,T2<font color='#5555FF'>></font><font color='#5555FF'>&</font> item,
std::istream<font color='#5555FF'>&</font> in
<font face='Lucida Console'>)</font>;
<font color='#0000FF'>private</font>:
<font color='#0000FF'><u>void</u></font> <b><a name='update_next_add_accepts'></a>update_next_add_accepts</b> <font face='Lucida Console'>(</font>
<font face='Lucida Console'>)</font>
<b>{</b>
<font color='#0000FF'>if</font> <font face='Lucida Console'>(</font>items.<font color='#BB00BB'>size</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font> <font color='#5555FF'><</font> _max_size<font face='Lucida Console'>)</font>
<b>{</b>
_next_add_accepts <font color='#5555FF'>=</font> <font color='#979000'>true</font>;
<b>}</b>
<font color='#0000FF'>else</font> <font color='#0000FF'>if</font> <font face='Lucida Console'>(</font>_max_size <font color='#5555FF'>=</font><font color='#5555FF'>=</font> <font color='#979000'>0</font><font face='Lucida Console'>)</font>
<b>{</b>
_next_add_accepts <font color='#5555FF'>=</font> <font color='#979000'>false</font>;
<b>}</b>
<font color='#0000FF'>else</font>
<b>{</b>
<font color='#009900'>// At this point each element of items has had an equal chance of being in this object.
</font> <font color='#009900'>// In particular, the probability that each arrived here is currently items.size()/count.
</font> <font color='#009900'>// We need to be able to say that, after this function ends, the probability of any
</font> <font color='#009900'>// particular object ending up in items is items.size()/(count+1). So this means that
</font> <font color='#009900'>// we should decide to add a new item into items with this probability. Also, if we do
</font> <font color='#009900'>// so then we pick one of the current items and replace it at random with the new item.
</font>
<font color='#009900'>// Make me a random 64 bit number. This might seem excessive but I want this object
</font> <font color='#009900'>// to be able to handle an effectively infinite number of calls to add(). So count
</font> <font color='#009900'>// might get very large and we need to deal with that properly.
</font> <font color='#0000FF'>const</font> <font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> num1 <font color='#5555FF'>=</font> rnd.<font color='#BB00BB'>get_random_32bit_number</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>;
<font color='#0000FF'>const</font> <font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> num2 <font color='#5555FF'>=</font> rnd.<font color='#BB00BB'>get_random_32bit_number</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>;
uint64 num <font color='#5555FF'>=</font> num1;
num <font color='#5555FF'><</font><font color='#5555FF'><</font><font color='#5555FF'>=</font> <font color='#979000'>32</font>;
num <font color='#5555FF'>|</font><font color='#5555FF'>=</font> num2;
num <font color='#5555FF'>%</font><font color='#5555FF'>=</font> <font face='Lucida Console'>(</font>count<font color='#5555FF'>+</font><font color='#979000'>1</font><font face='Lucida Console'>)</font>;
_next_add_accepts <font color='#5555FF'>=</font> <font face='Lucida Console'>(</font>num <font color='#5555FF'><</font> items.<font color='#BB00BB'>size</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font><font face='Lucida Console'>)</font>;
<b>}</b>
<b>}</b>
std::vector<font color='#5555FF'><</font>T<font color='#5555FF'>></font> items;
<font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> _max_size;
uint64 count;
rand_type rnd;
<font color='#0000FF'><u>bool</u></font> _next_add_accepts;
<b>}</b>;
<font color='#0000FF'>template</font> <font color='#5555FF'><</font>
<font color='#0000FF'>typename</font> T,
<font color='#0000FF'>typename</font> rand_type
<font color='#5555FF'>></font>
<font color='#0000FF'><u>void</u></font> <b><a name='swap'></a>swap</b> <font face='Lucida Console'>(</font>
random_subset_selector<font color='#5555FF'><</font>T,rand_type<font color='#5555FF'>></font><font color='#5555FF'>&</font> a,
random_subset_selector<font color='#5555FF'><</font>T,rand_type<font color='#5555FF'>></font><font color='#5555FF'>&</font> b
<font face='Lucida Console'>)</font> <b>{</b> a.<font color='#BB00BB'>swap</font><font face='Lucida Console'>(</font>b<font face='Lucida Console'>)</font>; <b>}</b>
<font color='#009900'>// ----------------------------------------------------------------------------------------
</font>
<font color='#0000FF'>template</font> <font color='#5555FF'><</font><font color='#0000FF'>typename</font> T1, <font color='#0000FF'>typename</font> T2<font color='#5555FF'>></font>
<font color='#0000FF'><u>void</u></font> <b><a name='serialize'></a>serialize</b> <font face='Lucida Console'>(</font>
<font color='#0000FF'>const</font> random_subset_selector<font color='#5555FF'><</font>T1,T2<font color='#5555FF'>></font><font color='#5555FF'>&</font> item,
std::ostream<font color='#5555FF'>&</font> out
<font face='Lucida Console'>)</font>
<b>{</b>
<font color='#BB00BB'>serialize</font><font face='Lucida Console'>(</font>item.items, out<font face='Lucida Console'>)</font>;
<font color='#BB00BB'>serialize</font><font face='Lucida Console'>(</font>item._max_size, out<font face='Lucida Console'>)</font>;
<font color='#BB00BB'>serialize</font><font face='Lucida Console'>(</font>item.count, out<font face='Lucida Console'>)</font>;
<font color='#BB00BB'>serialize</font><font face='Lucida Console'>(</font>item.rnd, out<font face='Lucida Console'>)</font>;
<font color='#BB00BB'>serialize</font><font face='Lucida Console'>(</font>item._next_add_accepts, out<font face='Lucida Console'>)</font>;
<b>}</b>
<font color='#0000FF'>template</font> <font color='#5555FF'><</font><font color='#0000FF'>typename</font> T1, <font color='#0000FF'>typename</font> T2<font color='#5555FF'>></font>
<font color='#0000FF'><u>void</u></font> <b><a name='deserialize'></a>deserialize</b> <font face='Lucida Console'>(</font>
random_subset_selector<font color='#5555FF'><</font>T1,T2<font color='#5555FF'>></font><font color='#5555FF'>&</font> item,
std::istream<font color='#5555FF'>&</font> in
<font face='Lucida Console'>)</font>
<b>{</b>
<font color='#BB00BB'>deserialize</font><font face='Lucida Console'>(</font>item.items, in<font face='Lucida Console'>)</font>;
<font color='#BB00BB'>deserialize</font><font face='Lucida Console'>(</font>item._max_size, in<font face='Lucida Console'>)</font>;
<font color='#BB00BB'>deserialize</font><font face='Lucida Console'>(</font>item.count, in<font face='Lucida Console'>)</font>;
<font color='#BB00BB'>deserialize</font><font face='Lucida Console'>(</font>item.rnd, in<font face='Lucida Console'>)</font>;
<font color='#BB00BB'>deserialize</font><font face='Lucida Console'>(</font>item._next_add_accepts, in<font face='Lucida Console'>)</font>;
<b>}</b>
<font color='#009900'>// ----------------------------------------------------------------------------------------
</font>
<font color='#0000FF'>template</font> <font color='#5555FF'><</font>
<font color='#0000FF'>typename</font> T,
<font color='#0000FF'>typename</font> alloc
<font color='#5555FF'>></font>
random_subset_selector<font color='#5555FF'><</font>T<font color='#5555FF'>></font> <b><a name='randomly_subsample'></a>randomly_subsample</b> <font face='Lucida Console'>(</font>
<font color='#0000FF'>const</font> std::vector<font color='#5555FF'><</font>T,alloc<font color='#5555FF'>></font><font color='#5555FF'>&</font> samples,
<font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> num
<font face='Lucida Console'>)</font>
<b>{</b>
random_subset_selector<font color='#5555FF'><</font>T<font color='#5555FF'>></font> subset;
subset.<font color='#BB00BB'>set_max_size</font><font face='Lucida Console'>(</font>num<font face='Lucida Console'>)</font>;
<font color='#0000FF'>for</font> <font face='Lucida Console'>(</font><font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> i <font color='#5555FF'>=</font> <font color='#979000'>0</font>; i <font color='#5555FF'><</font> samples.<font color='#BB00BB'>size</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>; <font color='#5555FF'>+</font><font color='#5555FF'>+</font>i<font face='Lucida Console'>)</font>
subset.<font color='#BB00BB'>add</font><font face='Lucida Console'>(</font>samples[i]<font face='Lucida Console'>)</font>;
<font color='#0000FF'>return</font> subset;
<b>}</b>
<font color='#009900'>// ----------------------------------------------------------------------------------------
</font>
<font color='#0000FF'>template</font> <font color='#5555FF'><</font>
<font color='#0000FF'>typename</font> T,
<font color='#0000FF'>typename</font> alloc,
<font color='#0000FF'>typename</font> U
<font color='#5555FF'>></font>
random_subset_selector<font color='#5555FF'><</font>T<font color='#5555FF'>></font> <b><a name='randomly_subsample'></a>randomly_subsample</b> <font face='Lucida Console'>(</font>
<font color='#0000FF'>const</font> std::vector<font color='#5555FF'><</font>T,alloc<font color='#5555FF'>></font><font color='#5555FF'>&</font> samples,
<font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> num,
<font color='#0000FF'>const</font> U<font color='#5555FF'>&</font> random_seed
<font face='Lucida Console'>)</font>
<b>{</b>
random_subset_selector<font color='#5555FF'><</font>T<font color='#5555FF'>></font> subset;
subset.<font color='#BB00BB'>set_seed</font><font face='Lucida Console'>(</font><font color='#BB00BB'>cast_to_string</font><font face='Lucida Console'>(</font>random_seed<font face='Lucida Console'>)</font><font face='Lucida Console'>)</font>;
subset.<font color='#BB00BB'>set_max_size</font><font face='Lucida Console'>(</font>num<font face='Lucida Console'>)</font>;
<font color='#0000FF'>for</font> <font face='Lucida Console'>(</font><font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> i <font color='#5555FF'>=</font> <font color='#979000'>0</font>; i <font color='#5555FF'><</font> samples.<font color='#BB00BB'>size</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>; <font color='#5555FF'>+</font><font color='#5555FF'>+</font>i<font face='Lucida Console'>)</font>
subset.<font color='#BB00BB'>add</font><font face='Lucida Console'>(</font>samples[i]<font face='Lucida Console'>)</font>;
<font color='#0000FF'>return</font> subset;
<b>}</b>
<font color='#009900'>// ----------------------------------------------------------------------------------------
</font>
<font color='#0000FF'>template</font> <font color='#5555FF'><</font>
<font color='#0000FF'>typename</font> T
<font color='#5555FF'>></font>
random_subset_selector<font color='#5555FF'><</font>T<font color='#5555FF'>></font> <b><a name='randomly_subsample'></a>randomly_subsample</b> <font face='Lucida Console'>(</font>
<font color='#0000FF'>const</font> random_subset_selector<font color='#5555FF'><</font>T<font color='#5555FF'>></font><font color='#5555FF'>&</font> samples,
<font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> num
<font face='Lucida Console'>)</font>
<b>{</b>
random_subset_selector<font color='#5555FF'><</font>T<font color='#5555FF'>></font> subset;
subset.<font color='#BB00BB'>set_max_size</font><font face='Lucida Console'>(</font>num<font face='Lucida Console'>)</font>;
<font color='#0000FF'>for</font> <font face='Lucida Console'>(</font><font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> i <font color='#5555FF'>=</font> <font color='#979000'>0</font>; i <font color='#5555FF'><</font> samples.<font color='#BB00BB'>size</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>; <font color='#5555FF'>+</font><font color='#5555FF'>+</font>i<font face='Lucida Console'>)</font>
subset.<font color='#BB00BB'>add</font><font face='Lucida Console'>(</font>samples[i]<font face='Lucida Console'>)</font>;
<font color='#0000FF'>return</font> subset;
<b>}</b>
<font color='#009900'>// ----------------------------------------------------------------------------------------
</font>
<font color='#0000FF'>template</font> <font color='#5555FF'><</font>
<font color='#0000FF'>typename</font> T,
<font color='#0000FF'>typename</font> U
<font color='#5555FF'>></font>
random_subset_selector<font color='#5555FF'><</font>T<font color='#5555FF'>></font> <b><a name='randomly_subsample'></a>randomly_subsample</b> <font face='Lucida Console'>(</font>
<font color='#0000FF'>const</font> random_subset_selector<font color='#5555FF'><</font>T<font color='#5555FF'>></font><font color='#5555FF'>&</font> samples,
<font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> num,
<font color='#0000FF'>const</font> U<font color='#5555FF'>&</font> random_seed
<font face='Lucida Console'>)</font>
<b>{</b>
random_subset_selector<font color='#5555FF'><</font>T<font color='#5555FF'>></font> subset;
subset.<font color='#BB00BB'>set_seed</font><font face='Lucida Console'>(</font><font color='#BB00BB'>cast_to_string</font><font face='Lucida Console'>(</font>random_seed<font face='Lucida Console'>)</font><font face='Lucida Console'>)</font>;
subset.<font color='#BB00BB'>set_max_size</font><font face='Lucida Console'>(</font>num<font face='Lucida Console'>)</font>;
<font color='#0000FF'>for</font> <font face='Lucida Console'>(</font><font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> i <font color='#5555FF'>=</font> <font color='#979000'>0</font>; i <font color='#5555FF'><</font> samples.<font color='#BB00BB'>size</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>; <font color='#5555FF'>+</font><font color='#5555FF'>+</font>i<font face='Lucida Console'>)</font>
subset.<font color='#BB00BB'>add</font><font face='Lucida Console'>(</font>samples[i]<font face='Lucida Console'>)</font>;
<font color='#0000FF'>return</font> subset;
<b>}</b>
<font color='#009900'>// ----------------------------------------------------------------------------------------
</font>
<font color='#0000FF'>template</font> <font color='#5555FF'><</font>
<font color='#0000FF'>typename</font> T
<font color='#5555FF'>></font>
<font color='#0000FF'>const</font> matrix_op<font color='#5555FF'><</font>op_array_to_mat<font color='#5555FF'><</font>random_subset_selector<font color='#5555FF'><</font>T<font color='#5555FF'>></font> <font color='#5555FF'>></font> <font color='#5555FF'>></font> <b><a name='mat'></a>mat</b> <font face='Lucida Console'>(</font>
<font color='#0000FF'>const</font> random_subset_selector<font color='#5555FF'><</font>T<font color='#5555FF'>></font><font color='#5555FF'>&</font> m
<font face='Lucida Console'>)</font>
<b>{</b>
<font color='#0000FF'>typedef</font> op_array_to_mat<font color='#5555FF'><</font>random_subset_selector<font color='#5555FF'><</font>T<font color='#5555FF'>></font> <font color='#5555FF'>></font> op;
<font color='#0000FF'>return</font> matrix_op<font color='#5555FF'><</font>op<font color='#5555FF'>></font><font face='Lucida Console'>(</font><font color='#BB00BB'>op</font><font face='Lucida Console'>(</font>m<font face='Lucida Console'>)</font><font face='Lucida Console'>)</font>;
<b>}</b>
<font color='#009900'>// ----------------------------------------------------------------------------------------
</font>
<b>}</b>
<font color='#0000FF'>#endif</font> <font color='#009900'>// DLIB_RANDOM_SUBSeT_SELECTOR_H_
</font>
</pre></body></html>