skip_ahead¶
Proceed state of engine by the skip-ahead method.
Description and Assumptions
oneapi::mkl::rng::skip_ahead function changes the current state of the engine so that with the further call of the generator the output subsequence begins with the specified offset see Figure “Block-Splitting Method”.
Block-Splitting Method
skip_ahead¶
Syntax
namespace oneapi::mkl::rng {
template<typename EngineType>
void oneapi::mkl::rng::skip_ahead(EngineType& engine, std::uint64_t num_to_skip);
}
Template Parameters
- EngineType
Type of engine. Note: may not be supported by all available engine classes.
Input Parameters
- engine
Engine which state would be skipped.
- num_to_skip
Number of elements to skip in the engine’s sequence.
Example
// Creating 3 identical engines
oneapi::mkl::rng::mcg31m1 engine_1(queue, seed);
oneapi::mkl::rng::mcg31m1 engine_2(engine_1);
oneapi::mkl::rng::mcg31m1 engine_3(engine_2);
// Skipping ahead by 7 elements the 2nd engine
oneapi::mkl::rng::skip_ahead(engine_2, 7);
// Skipping ahead by 14 elements the 3rd engine
oneapi::mkl::rng::skip_ahead(engine_3, 14);
skip_ahead (Interface with a partitioned number of skipped elements)¶
Syntax
namespace oneapi::mkl::rng {
template<typename EngineType>
void oneapi::mkl::rng::skip_ahead(EngineType& engine, std::initializer_list<std::uint64_t> num_to_skip);
}
Template Parameters
- EngineType
Type of engine. Note: may not be supported by all available engine classes.
Input Parameters
- engine
Engine which state would be skipped.
- num_to_skip
Partitioned number of elements to skip in the engine’s sequence. The total number of skipped elements would be: \(num\_to\_skip[0] + num\_to\_skip[1] \cdot 2^{64} + ... + num\_to\_skip[1] \cdot 2^{64 (n - 1)}\), where n is a number of elements in num_to_skip list.
Example with Partitioned Numer of Elements
// Creating the first engine
oneapi::mkl::rng::mrg32k3a engine_1(queue, seed);
// To skip 2^64 elements in the random stream number of skipped elements should be
/represented as num_to_skip = 2^64 = 0 + 1 * 2^64
std::initializer_list<std::uint64_t> num_to_skip = {0, 1};
// Creating the 2nd engine based on 1st. Skipping by 2^64
oneapi::mkl::rng::mrg32k3a engine_2(engine_1);
oneapi::mkl::rng::skip_ahead(engine_2, num_to_skip);
Parent topic: Service Routines