Add uniform_inside_sphere_distribution
Ed Smith-Rowland
3dw4rd@verizon.net
Wed Nov 5 18:27:00 GMT 2014
This distribution has come in handy for me.
It relies on uniform_on_sphere_distribution and like it, min and max
have no real meaning.
Unlike uniform_on_sphere_distribution which really is a random
multidimensional unit vector users often want to pick the radius of the
distribution.
Unit radius is a good default and is provided but the user can specify
radius.
Like the uniform_on_sphere_distribution which is used inside, the
2-dimensional case uses rejection and higher dimensions use a transform.
Built and tested clean on x86_64-linux.
OK?
Ed
-------------- next part --------------
2014-09-05 Edward Smith-Rowland <3dw4rd@verizon.net>
* include/ext/random: Add uniform_inside_sphere_distribution.
* include/ext/random.tcc: Out-of-line implementation of
uniform_inside_sphere_distribution.
* testsuite/ext/random/uniform_inside_sphere_distribution/cons/
default.cc: New.
* testsuite/ext/random/uniform_inside_sphere_distribution/cons/
parms.cc: New.
* testsuite/ext/random/uniform_inside_sphere_distribution/operators/
equal.cc: New.
* testsuite/ext/random/uniform_inside_sphere_distribution/operators/
generate.cc: New.
* testsuite/ext/random/uniform_inside_sphere_distribution/operators/
inequal.cc: New.
* testsuite/ext/random/uniform_inside_sphere_distribution/operators/
serialize.cc: New.
-------------- next part --------------
Index: include/ext/random
===================================================================
--- include/ext/random (revision 216942)
+++ include/ext/random (working copy)
@@ -3487,6 +3487,218 @@
_RealType>& __d2)
{ return !(__d1 == __d2); }
+
+ /**
+ * @brief A distribution for random coordinates inside a unit sphere.
+ */
+ template<std::size_t _Dimen, typename _RealType = double>
+ class uniform_inside_sphere_distribution
+ {
+ static_assert(std::is_floating_point<_RealType>::value,
+ "template argument not a floating point type");
+ static_assert(_Dimen != 0, "dimension is zero");
+
+ public:
+ /** The type of the range of the distribution. */
+ using result_type = std::array<_RealType, _Dimen>;
+
+ /** Parameter type. */
+ struct param_type
+ {
+ using distribution_type
+ = uniform_inside_sphere_distribution<_Dimen, _RealType>;
+ friend class uniform_inside_sphere_distribution<_Dimen, _RealType>;
+
+ explicit
+ param_type(_RealType __radius = _RealType(1))
+ : _M_radius(__radius)
+ {
+ _GLIBCXX_DEBUG_ASSERT(_M_radius > _RealType(0));
+ }
+
+ _RealType
+ radius() const
+ { return _M_radius; }
+
+ friend bool
+ operator==(const param_type& __p1, const param_type& __p2)
+ { return __p1._M_radius == __p2._M_radius; }
+
+ private:
+ _RealType _M_radius;
+ };
+
+ /**
+ * @brief Constructors.
+ */
+ explicit
+ uniform_inside_sphere_distribution(_RealType __radius = _RealType(1))
+ : _M_param(__radius), _M_uosd()
+ { }
+
+ explicit
+ uniform_inside_sphere_distribution(const param_type& __p)
+ : _M_param(__p), _M_uosd()
+ { }
+
+ /**
+ * @brief Resets the distribution state.
+ */
+ void
+ reset()
+ { _M_uosd.reset(); }
+
+ /**
+ * @brief Returns the @f$radius@f$ of the distribution.
+ */
+ _RealType
+ radius() const
+ { return _M_param.radius(); }
+
+ /**
+ * @brief Returns the parameter set of the distribution.
+ */
+ param_type
+ param() const
+ { return _M_param; }
+
+ /**
+ * @brief Sets the parameter set of the distribution.
+ * @param __param The new parameter set of the distribution.
+ */
+ void
+ param(const param_type& __param)
+ { _M_param = __param; }
+
+ /**
+ * @brief Returns the greatest lower bound value of the distribution.
+ * This function makes no sense for this distribution.
+ */
+ result_type
+ min() const
+ {
+ result_type __res;
+ __res.fill(0);
+ return __res;
+ }
+
+ /**
+ * @brief Returns the least upper bound value of the distribution.
+ * This function makes no sense for this distribution.
+ */
+ result_type
+ max() const
+ {
+ result_type __res;
+ __res.fill(0);
+ return __res;
+ }
+
+ /**
+ * @brief Generating functions.
+ */
+ template<typename _UniformRandomNumberGenerator>
+ result_type
+ operator()(_UniformRandomNumberGenerator& __urng)
+ { return this->operator()(__urng, _M_param); }
+
+ template<typename _UniformRandomNumberGenerator>
+ result_type
+ operator()(_UniformRandomNumberGenerator& __urng,
+ const param_type& __p);
+
+ template<typename _ForwardIterator,
+ typename _UniformRandomNumberGenerator>
+ void
+ __generate(_ForwardIterator __f, _ForwardIterator __t,
+ _UniformRandomNumberGenerator& __urng)
+ { this->__generate(__f, __t, __urng, this->param()); }
+
+ template<typename _ForwardIterator,
+ typename _UniformRandomNumberGenerator>
+ void
+ __generate(_ForwardIterator __f, _ForwardIterator __t,
+ _UniformRandomNumberGenerator& __urng,
+ const param_type& __p)
+ { this->__generate_impl(__f, __t, __urng, __p); }
+
+ template<typename _UniformRandomNumberGenerator>
+ void
+ __generate(result_type* __f, result_type* __t,
+ _UniformRandomNumberGenerator& __urng,
+ const param_type& __p)
+ { this->__generate_impl(__f, __t, __urng, __p); }
+
+ /**
+ * @brief Return true if two uniform on sphere distributions have
+ * the same parameters and the sequences that would be
+ * generated are equal.
+ */
+ friend bool
+ operator==(const uniform_inside_sphere_distribution& __d1,
+ const uniform_inside_sphere_distribution& __d2)
+ { return __d1._M_param == __d2._M_param && __d1._M_uosd == __d2._M_uosd; }
+
+ /**
+ * @brief Inserts a %uniform_inside_sphere_distribution random number
+ * distribution @p __x into the output stream @p __os.
+ *
+ * @param __os An output stream.
+ * @param __x A %uniform_inside_sphere_distribution random number
+ * distribution.
+ *
+ * @returns The output stream with the state of @p __x inserted or in
+ * an error state.
+ */
+ template<size_t _Dimen1, typename _RealType1, typename _CharT,
+ typename _Traits>
+ friend std::basic_ostream<_CharT, _Traits>&
+ operator<<(std::basic_ostream<_CharT, _Traits>& __os,
+ const __gnu_cxx::uniform_inside_sphere_distribution<_Dimen1,
+ _RealType1>&
+ );
+
+ /**
+ * @brief Extracts a %uniform_inside_sphere_distribution random number
+ * distribution
+ * @p __x from the input stream @p __is.
+ *
+ * @param __is An input stream.
+ * @param __x A %uniform_inside_sphere_distribution random number
+ * generator engine.
+ *
+ * @returns The input stream with @p __x extracted or in an error state.
+ */
+ template<std::size_t _Dimen1, typename _RealType1, typename _CharT,
+ typename _Traits>
+ friend std::basic_istream<_CharT, _Traits>&
+ operator>>(std::basic_istream<_CharT, _Traits>& __is,
+ __gnu_cxx::uniform_inside_sphere_distribution<_Dimen1,
+ _RealType1>&);
+
+ private:
+ template<typename _ForwardIterator,
+ typename _UniformRandomNumberGenerator>
+ void
+ __generate_impl(_ForwardIterator __f, _ForwardIterator __t,
+ _UniformRandomNumberGenerator& __urng,
+ const param_type& __p);
+
+ param_type _M_param;
+ uniform_on_sphere_distribution<_Dimen, _RealType> _M_uosd;
+ };
+
+ /**
+ * @brief Return true if two uniform on sphere distributions are different.
+ */
+ template<std::size_t _Dimen, typename _RealType>
+ inline bool
+ operator!=(const __gnu_cxx::uniform_inside_sphere_distribution<_Dimen,
+ _RealType>& __d1,
+ const __gnu_cxx::uniform_inside_sphere_distribution<_Dimen,
+ _RealType>& __d2)
+ { return !(__d1 == __d2); }
+
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace __gnu_cxx
Index: include/ext/random.tcc
===================================================================
--- include/ext/random.tcc (revision 216942)
+++ include/ext/random.tcc (working copy)
@@ -1669,6 +1669,117 @@
return __is >> __x._M_nd;
}
+
+ namespace {
+
+ // Helper class for the uniform_inside_sphere_distribution generation
+ // function.
+ template<std::size_t _Dimen, typename _RealType>
+ class uniform_inside_sphere_helper
+ {
+ using result_type
+ = typename uniform_inside_sphere_distribution<_Dimen, _RealType>::
+ result_type;
+
+ public:
+ template<typename _UniformOnSphereDistribution,
+ typename _UniformRandomNumberGenerator>
+ result_type
+ operator()(_UniformOnSphereDistribution& __uosd,
+ _UniformRandomNumberGenerator& __urng,
+ _RealType __radius)
+ {
+ std::__detail::_Adaptor<_UniformRandomNumberGenerator,
+ _RealType> __aurng(__urng);
+
+ _RealType __pow = 1 / _RealType(_Dimen);
+ _RealType __urt = __radius * std::pow(__aurng(), __pow);
+ result_type __ret = __uosd(__aurng);
+
+ std::transform(__ret.begin(), __ret.end(), __ret.begin(),
+ [__urt](_RealType __val)
+ { return __val * __urt; });
+
+ return __ret;
+ }
+ };
+
+ }
+
+
+ template<std::size_t _Dimen, typename _RealType>
+ template<typename _UniformRandomNumberGenerator>
+ typename uniform_inside_sphere_distribution<_Dimen, _RealType>::result_type
+ uniform_inside_sphere_distribution<_Dimen, _RealType>::
+ operator()(_UniformRandomNumberGenerator& __urng,
+ const param_type& __p)
+ {
+ uniform_inside_sphere_helper<_Dimen, _RealType> __helper;
+ return __helper(_M_uosd, __urng, __p.radius());
+ }
+
+ template<std::size_t _Dimen, typename _RealType>
+ template<typename _OutputIterator,
+ typename _UniformRandomNumberGenerator>
+ void
+ uniform_inside_sphere_distribution<_Dimen, _RealType>::
+ __generate_impl(_OutputIterator __f, _OutputIterator __t,
+ _UniformRandomNumberGenerator& __urng,
+ const param_type& __param)
+ {
+ __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator>)
+
+ while (__f != __t)
+ *__f++ = this->operator()(__urng, __param);
+ }
+
+ template<std::size_t _Dimen, typename _RealType, typename _CharT,
+ typename _Traits>
+ std::basic_ostream<_CharT, _Traits>&
+ operator<<(std::basic_ostream<_CharT, _Traits>& __os,
+ const __gnu_cxx::uniform_inside_sphere_distribution<_Dimen,
+ _RealType>& __x)
+ {
+ typedef std::basic_ostream<_CharT, _Traits> __ostream_type;
+ typedef typename __ostream_type::ios_base __ios_base;
+
+ const typename __ios_base::fmtflags __flags = __os.flags();
+ const _CharT __fill = __os.fill();
+ const std::streamsize __precision = __os.precision();
+ const _CharT __space = __os.widen(' ');
+ __os.flags(__ios_base::scientific | __ios_base::left);
+ __os.fill(__space);
+ __os.precision(std::numeric_limits<_RealType>::max_digits10);
+
+ __os.flags(__flags);
+ __os.fill(__fill);
+ __os.precision(__precision);
+ return __os << __x.radius() << __space << __x._M_uosd;
+ }
+
+ template<std::size_t _Dimen, typename _RealType, typename _CharT,
+ typename _Traits>
+ std::basic_istream<_CharT, _Traits>&
+ operator>>(std::basic_istream<_CharT, _Traits>& __is,
+ __gnu_cxx::uniform_inside_sphere_distribution<_Dimen,
+ _RealType>& __x)
+ {
+ typedef std::basic_istream<_CharT, _Traits> __istream_type;
+ typedef typename __istream_type::ios_base __ios_base;
+
+ const typename __ios_base::fmtflags __flags = __is.flags();
+ __is.flags(__ios_base::dec | __ios_base::skipws);
+
+ _RealType __radius_val;
+ __is >> __radius_val;
+ __is >> __x._M_uosd;
+ __x.param(typename uniform_inside_sphere_distribution<_Dimen, _RealType>::
+ param_type(__radius_val));
+
+ __is.flags(__flags);
+ return __is;
+ }
+
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
Index: testsuite/ext/random/uniform_inside_sphere_distribution/cons/default.cc
===================================================================
--- testsuite/ext/random/uniform_inside_sphere_distribution/cons/default.cc (revision 0)
+++ testsuite/ext/random/uniform_inside_sphere_distribution/cons/default.cc (revision 0)
@@ -0,0 +1,43 @@
+// { dg-options "-std=gnu++11" }
+// { dg-require-cstdint "" }
+//
+// Copyright (C) 2014 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// Class template uniform_on_sphere
+// 26.5.1.6 Random number distribution requirements [rand.req.dist]
+
+#include <ext/random>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+ bool test [[gnu::unused]] = true;
+
+ __gnu_cxx::uniform_inside_sphere_distribution<2> u2;
+ __gnu_cxx::uniform_inside_sphere_distribution<3> u3;
+ __gnu_cxx::uniform_inside_sphere_distribution<4, double> u4;
+ __gnu_cxx::uniform_inside_sphere_distribution<5, float> u5;
+}
+
+int
+main()
+{
+ test01();
+ return 0;
+}
Index: testsuite/ext/random/uniform_inside_sphere_distribution/cons/parms.cc
===================================================================
--- testsuite/ext/random/uniform_inside_sphere_distribution/cons/parms.cc (revision 0)
+++ testsuite/ext/random/uniform_inside_sphere_distribution/cons/parms.cc (revision 0)
@@ -0,0 +1,44 @@
+// { dg-options "-std=gnu++11" }
+// { dg-require-cstdint "" }
+//
+// Copyright (C) 2014 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// Class template logistic_distribution
+// 26.5.1.6 Random number distribution requirements [rand.req.dist]
+
+#include <ext/random>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+ bool test [[gnu::unused]] = true;
+
+ __gnu_cxx::uniform_inside_sphere_distribution<2> u(1.5);
+ VERIFY( u.radius() == 1.5 );
+
+ __gnu_cxx::uniform_inside_sphere_distribution<3> v(3.0);
+ VERIFY( v.radius() == 3.0 );
+}
+
+int
+main()
+{
+ test01();
+ return 0;
+}
Index: testsuite/ext/random/uniform_inside_sphere_distribution/operators/equal.cc
===================================================================
--- testsuite/ext/random/uniform_inside_sphere_distribution/operators/equal.cc (revision 0)
+++ testsuite/ext/random/uniform_inside_sphere_distribution/operators/equal.cc (revision 0)
@@ -0,0 +1,41 @@
+// { dg-options "-std=gnu++11" }
+// { dg-require-cstdint "" }
+//
+// Copyright (C) 2014 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// Class template uniform_inside_sphere_distribution
+
+#include <ext/random>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+ bool test [[gnu::unused]] = true;
+
+ __gnu_cxx::uniform_inside_sphere_distribution<3> u(2.0), v(2.0);
+
+ VERIFY( u == v );
+}
+
+int
+main()
+{
+ test01();
+ return 0;
+}
Index: testsuite/ext/random/uniform_inside_sphere_distribution/operators/generate.cc
===================================================================
--- testsuite/ext/random/uniform_inside_sphere_distribution/operators/generate.cc (revision 0)
+++ testsuite/ext/random/uniform_inside_sphere_distribution/operators/generate.cc (revision 0)
@@ -0,0 +1,60 @@
+// { dg-options "-std=gnu++11" }
+// { dg-require-cstdint "" }
+//
+// Copyright (C) 2014 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// Class template uniform_inside_sphere_distribution
+// 26.5.1.6 Random number distribution requirements [rand.req.dist]
+
+#include <ext/random>
+#include <sstream>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+ bool test [[gnu::unused]] = true;
+ std::minstd_rand0 rng;
+
+ __gnu_cxx::uniform_inside_sphere_distribution<3> u3(2.0);
+
+ for (size_t n = 0; n < 1000; ++n)
+ {
+ auto r = u3(rng);
+
+ VERIFY (std::abs(r[0]) < 2.0
+ && std::abs(r[1]) < 2.0
+ && std::abs(r[2]) < 2.0);
+ }
+
+ __gnu_cxx::uniform_inside_sphere_distribution<2> u2(4000.0);
+
+ for (size_t n = 0; n < 1000; ++n)
+ {
+ auto r = u2(rng);
+
+ VERIFY (std::abs(r[0]) < 4000.0 && std::abs(r[1]) < 4000.0);
+ }
+}
+
+int
+main()
+{
+ test01();
+ return 0;
+}
Index: testsuite/ext/random/uniform_inside_sphere_distribution/operators/inequal.cc
===================================================================
--- testsuite/ext/random/uniform_inside_sphere_distribution/operators/inequal.cc (revision 0)
+++ testsuite/ext/random/uniform_inside_sphere_distribution/operators/inequal.cc (revision 0)
@@ -0,0 +1,41 @@
+// { dg-options "-std=gnu++11" }
+// { dg-require-cstdint "" }
+//
+// Copyright (C) 2014 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// Class template uniform_inside_sphere_distribution
+
+#include <ext/random>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+ bool test [[gnu::unused]] = true;
+
+ __gnu_cxx::uniform_inside_sphere_distribution<3> u(4.0), v(4.0);
+
+ VERIFY( !(u != v) );
+}
+
+int
+main()
+{
+ test01();
+ return 0;
+}
Index: testsuite/ext/random/uniform_inside_sphere_distribution/operators/serialize.cc
===================================================================
--- testsuite/ext/random/uniform_inside_sphere_distribution/operators/serialize.cc (revision 0)
+++ testsuite/ext/random/uniform_inside_sphere_distribution/operators/serialize.cc (revision 0)
@@ -0,0 +1,50 @@
+// { dg-options "-std=gnu++11" }
+// { dg-require-cstdint "" }
+//
+// Copyright (C) 2014 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// Class template uniform_inside_sphere_distribution
+// 26.5.1.6 Random number distribution requirements [rand.req.dist]
+
+#include <ext/random>
+#include <sstream>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+ bool test [[gnu::unused]] = true;
+
+ std::stringstream str;
+ __gnu_cxx::uniform_inside_sphere_distribution<3> u(8.0), v(8.0);
+ std::minstd_rand0 rng;
+
+ u(rng); // advance
+ str << u;
+
+ str >> v;
+
+ VERIFY( u == v );
+}
+
+int
+main()
+{
+ test01();
+ return 0;
+}
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