Developer Reference

Contents

cos

Computes the element-wise cosine of vector elements.

Description

The
cos(a)
function computes cosine of vector elements.
Note that arguments
abs(a[i]) ≤ 213
and
abs(a[i]) ≤ 216
for single and double precisions, respectively, are called fast computational path. These are trigonometric function arguments for which VM provides the best possible performance. Avoid arguments that do not belong to the fast computational path in the VM High Accuracy (HA) and Low Accuracy (LA) functions. Alternatively, you can use VM Enhanced Performance (EP) functions that are fast on the entire function domain. However, these functions provide less accuracy.
Argument
Result
VM Error Status
+0
+1
-0
+1
+LaTex Math image.
QNAN
status::errdom
-LaTex Math image.
QNAN
status::errdom
QNAN
QNAN
SNAN
QNAN
Specifications for special values of the complex functions are defined according to the following formula
Cos(z) = Cosh(i*z)
.
Product and Performance Information
Performance varies by use, configuration and other factors. Learn more at https://www.intel.com/PerformanceIndex. Notice revision #20201201

API

Syntax
Buffer API
namespace oneapi::mkl::vm { sycl::event cos(sycl::queue & exec_queue, std::int64_t n, sycl::buffer<T> & a, sycl::buffer<T> & y, oneapi::mkl::vm::mode mode = oneapi::mkl::vm::mode::not_defined, oneapi::mkl::vm::error_handler<T> errhandler = {}); }
namespace oneapi::mkl::vm { sycl::event cos(sycl::queue & exec_queue, sycl::buffer<T> & a, oneapi::mkl::slice sa, sycl::buffer<T> & y, oneapi::mkl::slice sy, oneapi::mkl::vm::mode mode = oneapi::mkl::vm::mode::not_defined, oneapi::mkl::vm::error_handler<T> errhandler = {}); }
USM API
namespace oneapi::mkl::vm { sycl::event cos(sycl::queue & exec_queue, std::int64_t n, T const * a, T * y, std::vector<cl::sycl::event> const & depends = {}, oneapi::mkl::vm::mode mode = oneapi::mkl::vm::mode::not_defined, oneapi::mkl::vm::error_handler<T> errhandler = {}); }
namespace oneapi::mkl::vm { sycl::event cos(sycl::queue & exec_queue, T const * a, oneapi::mkl::slice sa, T * y, oneapi::mkl::slice sy, std::vector<cl::sycl::event> const & depends = {}, oneapi::mkl::vm::mode mode = oneapi::mkl::vm::mode::not_defined, oneapi::mkl::vm::error_handler<T> errhandler = {}); }
cos
supports the following precisions and devices:
T
Devices supported
float
Host, CPU, and GPU
double
Host, CPU, and GPU
std::complex<float>
Host
std::complex<double>
Host
Input Parameters
Buffer API
exec_queue
The queue where the routine should be executed.
n
Specifies the number of elements to be calculated.
a
The buffer containing the input vector.
sa
Slice selector for
a
. See Data Types for a description of the oneMKL slice type.
sy
Slice selector for
y
. See Data Types for a description of the oneMKL slice type.
mode
Overrides the global VM mode setting for this function call. See set_mode function for possible values and their description. This is an optional parameter. The default value is
mode::not_defined
.
errhandler
Sets local error handling mode for this function call. See the create_error_handler function for arguments and their descriptions. This is an optional parameter. The local error handler is disabled by default.
USM API
exec_queue
The queue where the routine should be executed.
n
Specifies the number of elements to be calculated.
a
Pointer to the input vector.
sa
Slice selector for
a
. See Data Types for a description of the oneMKL slice type.
sy
Slice selector for
y
. See Data Types for a description of the oneMKL slice type.
depends
Vector of dependent events (to wait for input data to be ready). This is an optional parameter. The default is an empty vector.
mode
Overrides the global VM mode setting for this function call. See the set_mode function for possible values and their description. This is an optional parameter. The default value is
mode::not_defined
.
errhandler
Sets local error handling mode for this function call. See the create_error_handler function for arguments and their descriptions. This is an optional parameter. The local error handler is disabled by default.
Output Parameters
Buffer API
y
The buffer containing the output vector.
return value (event)
Computation end event.
USM API
y
Pointer to the output vector.
return value (event)
Computation end event.

Examples

An example of how to use
cos
can be found in the oneMKL installation directory, under:
examples/dpcpp/vml/source/vcos.cpp

Product and Performance Information

1

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