Intel® oneAPI Math Kernel Library (oneMKL) - Data Parallel C++ Developer Reference

Developer Reference

Contents

rotg

Computes the parameters for a Givens rotation.

Description

Given the Cartesian coordinates
(a, b)
 of a point, the
rotg
 routines return the parameters
c
,
s
,
r
, and
z
 associated with the Givens rotation. The parameters
c
 and
s
 define a unitary matrix such that:
LaTex Math image.
The parameter
z
 is defined such that if |
a
| > |
b
|,
z
 is
s
; otherwise if
c
 is not 0
z
 is 1/
c
; otherwise
z
 is 1.
rotg
 supports the following precisions:
T
T_real
float
float
double
double
std::complex<float>
float
std::complex<double>
double

rotg (Buffer Version)

Syntax
namespace oneapi::mkl::blas::column_major {
    void rotg(sycl::queue &queue,
              sycl::buffer<T,1> &a,
              sycl::buffer<T,1> &b,
              sycl::buffer<T_real,1> &c,
              sycl::buffer<T,1> &s)
}
namespace oneapi::mkl::blas::row_major {
    void rotg(sycl::queue &queue,
              sycl::buffer<T,1> &a,
              sycl::buffer<T,1> &b,
              sycl::buffer<T_real,1> &c,
              sycl::buffer<T,1> &s)
}
Input Parameters
queue
The queue where the routine should be executed
a
Buffer holding
x
-coordinate of the point.
b
Buffer holding
y
-coordinate of the point.
Output Parameters
a
Buffer holding parameter
r
 associated with the Givens rotation.
b
Buffer holding parameter
z
 associated with the Givens rotation.
c
Buffer holding parameter
c
 associated with the Givens rotation.
s
Buffer holding parameter
s
 associated with the Givens rotation.

rotg (USM Version)

Syntax
namespace oneapi::mkl::blas::column_major {
    sycl::event rotg(sycl::queue &queue,
                     T *a,
                     T *b,
                     T_real *c,
                     T *s,
                     const std::vector<sycl::event> &dependencies = {})
}
namespace oneapi::mkl::blas::row_major {
    sycl::event rotg(sycl::queue &queue,
                     T *a,
                     T *b,
                     T_real *c,
                     T *s,
                     const std::vector<sycl::event> &dependencies = {})
}
Input Parameters
queue
The queue where the routine should be executed
a
Pointer to
x
-coordinate of the point.
b
Pointer to
y
-coordinate of the point.
dependencies
List of events to wait for before starting computation, if any. If omitted, defaults to no dependencies.
Output Parameters
a
Pointer to parameter
r
 associated with the Givens rotation.
b
Pointer to parameter
z
 associated with the Givens rotation.
c
Pointer to parameter
c
 associated with the Givens rotation.
s
Pointer to parameter
s
 associated with the Givens rotation.
Return Values
Output event to wait on to ensure computation is complete.

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.