在 Thrust 仿函数中使用 CURAND
Using CURAND inside a Thrust functor
是否可以在设备仿函数中将 CURAND 与 Thrust 一起使用?最小代码示例可以是:
#include <thrust/device_vector.h>
struct Move
{
Move() {}
using Position = thrust::tuple<double, double>;
__host__ __device__
Position operator()(Position p)
{
thrust::get<0>(p) += 1.0; // use CURAND to add a random N(0,1)
thrust::get<1>(p) += 1.0; // use CURAND to add a random N(0,1)
return p;
}
};
int main()
{
// Create vectors on device
thrust::device_vector<double> p1(10, 0.0);
thrust::device_vector<double> p2(10, 0.0);
// Create zip iterators
auto pBeg = thrust::make_zip_iterator(thrust::make_tuple(p1.begin(), p2.begin()));
auto pEnd = thrust::make_zip_iterator(thrust::make_tuple(p1.end(), p2.end() ));
// Move points in the vectors
thrust::transform(pBeg, pEnd, pBeg, Move());
// Print result (just for debug)
thrust::copy(p1.begin(), p1.end(), std::ostream_iterator<double>(std::cout, "\n"));
thrust::copy(p2.begin(), p2.end(), std::ostream_iterator<double>(std::cout, "\n"));
return 0;
}
在运算符函数中创建随机数的正确方法是什么?
Is it possible to use CURAND together with Thrust inside a device functor?
是的,这是可能的。如@m.s 所示。你需要的大部分 curand 都可以从 curand device api example in the curand documentation. (In fact, there is even a full thrust/curand sample code in the documentation here)
我们可以通过推力算法调用来模拟那里指示的设置内核的行为,例如。 thrust::for_each_n
为每个设备向量元素设置初始 curand 状态变量。
之后,只需要通过 zip 迭代器中的附加迭代器将初始化的 curand 状态传递给 Move
仿函数,然后在仿函数中调用 curand_uniform
(例如) .
这是一个基于您的代码的完整示例:
$ cat t20.cu
#include <thrust/device_vector.h>
#include <curand_kernel.h>
#include <iostream>
#include <thrust/iterator/counting_iterator.h>
#include <thrust/transform.h>
#include <thrust/for_each.h>
const int seed = 1234;
const int ds = 10;
const int offset = 0;
struct Move
{
Move() {}
using Position = thrust::tuple<double, double, curandState>;
__device__
Position operator()(Position p)
{
curandState s = thrust::get<2>(p);
thrust::get<0>(p) += curand_uniform(&s); // use CURAND to add a random N(0,1)
thrust::get<1>(p) += curand_uniform(&s); // use CURAND to add a random N(0,1)
thrust::get<2>(p) = s;
return p;
}
};
struct curand_setup
{
using init_tuple = thrust::tuple<int, curandState &>;
__device__
void operator()(init_tuple t){
curandState s;
int id = thrust::get<0>(t);
curand_init(seed, id, offset, &s);
thrust::get<1>(t) = s;
}
};
int main()
{
// Create vectors on device
thrust::device_vector<double> p1(ds, 0.0);
thrust::device_vector<double> p2(ds, 0.0);
thrust::device_vector<curandState> s1(ds);
// Create zip iterators
auto pBeg = thrust::make_zip_iterator(thrust::make_tuple(p1.begin(), p2.begin(), s1.begin()));
auto pEnd = thrust::make_zip_iterator(thrust::make_tuple(p1.end(), p2.end(), s1.end() ));
auto pInit = thrust::make_zip_iterator(thrust::make_tuple(thrust::counting_iterator<int>(0), s1.begin()));
// initialize random generator
thrust::for_each_n(pInit, ds, curand_setup());
// Move points in the vectors
thrust::transform(pBeg, pEnd, pBeg, Move());
// Print result (just for debug)
thrust::copy(p1.begin(), p1.end(), std::ostream_iterator<double>(std::cout, "\n"));
thrust::copy(p2.begin(), p2.end(), std::ostream_iterator<double>(std::cout, "\n"));
return 0;
}
$ nvcc -arch=sm_61 -std=c++11 t20.cu -o t20 -lcurand
$ ./t20
0.145468
0.820181
0.550399
0.29483
0.914733
0.868979
0.321921
0.782857
0.0113023
0.28545
0.434899
0.926417
0.811845
0.308556
0.557235
0.501246
0.206681
0.123377
0.539587
0.198575
$
关于这个问题:
What is the right way to create random numbers inside the operator function?
在 thrust 中使用 curand 没有问题,但您可能还想知道 thrust 有一个内置的 RNG facility and there is a fully worked usage example here。
是否可以在设备仿函数中将 CURAND 与 Thrust 一起使用?最小代码示例可以是:
#include <thrust/device_vector.h>
struct Move
{
Move() {}
using Position = thrust::tuple<double, double>;
__host__ __device__
Position operator()(Position p)
{
thrust::get<0>(p) += 1.0; // use CURAND to add a random N(0,1)
thrust::get<1>(p) += 1.0; // use CURAND to add a random N(0,1)
return p;
}
};
int main()
{
// Create vectors on device
thrust::device_vector<double> p1(10, 0.0);
thrust::device_vector<double> p2(10, 0.0);
// Create zip iterators
auto pBeg = thrust::make_zip_iterator(thrust::make_tuple(p1.begin(), p2.begin()));
auto pEnd = thrust::make_zip_iterator(thrust::make_tuple(p1.end(), p2.end() ));
// Move points in the vectors
thrust::transform(pBeg, pEnd, pBeg, Move());
// Print result (just for debug)
thrust::copy(p1.begin(), p1.end(), std::ostream_iterator<double>(std::cout, "\n"));
thrust::copy(p2.begin(), p2.end(), std::ostream_iterator<double>(std::cout, "\n"));
return 0;
}
在运算符函数中创建随机数的正确方法是什么?
Is it possible to use CURAND together with Thrust inside a device functor?
是的,这是可能的。如@m.s 所示。你需要的大部分 curand 都可以从 curand device api example in the curand documentation. (In fact, there is even a full thrust/curand sample code in the documentation here)
我们可以通过推力算法调用来模拟那里指示的设置内核的行为,例如。 thrust::for_each_n
为每个设备向量元素设置初始 curand 状态变量。
之后,只需要通过 zip 迭代器中的附加迭代器将初始化的 curand 状态传递给 Move
仿函数,然后在仿函数中调用 curand_uniform
(例如) .
这是一个基于您的代码的完整示例:
$ cat t20.cu
#include <thrust/device_vector.h>
#include <curand_kernel.h>
#include <iostream>
#include <thrust/iterator/counting_iterator.h>
#include <thrust/transform.h>
#include <thrust/for_each.h>
const int seed = 1234;
const int ds = 10;
const int offset = 0;
struct Move
{
Move() {}
using Position = thrust::tuple<double, double, curandState>;
__device__
Position operator()(Position p)
{
curandState s = thrust::get<2>(p);
thrust::get<0>(p) += curand_uniform(&s); // use CURAND to add a random N(0,1)
thrust::get<1>(p) += curand_uniform(&s); // use CURAND to add a random N(0,1)
thrust::get<2>(p) = s;
return p;
}
};
struct curand_setup
{
using init_tuple = thrust::tuple<int, curandState &>;
__device__
void operator()(init_tuple t){
curandState s;
int id = thrust::get<0>(t);
curand_init(seed, id, offset, &s);
thrust::get<1>(t) = s;
}
};
int main()
{
// Create vectors on device
thrust::device_vector<double> p1(ds, 0.0);
thrust::device_vector<double> p2(ds, 0.0);
thrust::device_vector<curandState> s1(ds);
// Create zip iterators
auto pBeg = thrust::make_zip_iterator(thrust::make_tuple(p1.begin(), p2.begin(), s1.begin()));
auto pEnd = thrust::make_zip_iterator(thrust::make_tuple(p1.end(), p2.end(), s1.end() ));
auto pInit = thrust::make_zip_iterator(thrust::make_tuple(thrust::counting_iterator<int>(0), s1.begin()));
// initialize random generator
thrust::for_each_n(pInit, ds, curand_setup());
// Move points in the vectors
thrust::transform(pBeg, pEnd, pBeg, Move());
// Print result (just for debug)
thrust::copy(p1.begin(), p1.end(), std::ostream_iterator<double>(std::cout, "\n"));
thrust::copy(p2.begin(), p2.end(), std::ostream_iterator<double>(std::cout, "\n"));
return 0;
}
$ nvcc -arch=sm_61 -std=c++11 t20.cu -o t20 -lcurand
$ ./t20
0.145468
0.820181
0.550399
0.29483
0.914733
0.868979
0.321921
0.782857
0.0113023
0.28545
0.434899
0.926417
0.811845
0.308556
0.557235
0.501246
0.206681
0.123377
0.539587
0.198575
$
关于这个问题:
What is the right way to create random numbers inside the operator function?
在 thrust 中使用 curand 没有问题,但您可能还想知道 thrust 有一个内置的 RNG facility and there is a fully worked usage example here。