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atan2pi

Computes the element-wise four-quadrant arctangent of vector a elements divided by vector b elements, divided by pi.

Description

The atan2pi(a,b) function computes the four-quadrant inverse tangent of the ratios of the corresponding elements of two vectors divided by .

For the elements of the output vector y, the function computers the four-quadrant arctangent of a_i/b_i, with the result divided by .

Argument 1	Argument 2	Result	Error Code
-	-	-3/4
-	b < +0	-1/2
-	-0	+1/2
-	+0	-1/2
-	x > +0	-1/2
-	+	-1/4
a < +0	-	-1
a < +0	-0	-1/2
a < +0	+0	-1/2
a < +0	+	-0
-0	-	-1
-0	b < +0	-1
-0	-0	-1
-0	+0	-0
-0	b > +0	-0
-0	+	-0
+0	-	+1
+0	b < +0	+1
+0	-0	+1
+0	+0	+0
+0	b > +0	+0
+0	+	+0
a > +0	-	+1
a > +0	-0	+1/2
x > +0	+0	+1/2
a > +0	+	+1/4
+	-	+3/4
+	b < +0	+1/2
+	-0	+1/2
+	+0	+1/2
+	b > +0	+1/2
+	+	+1/4
a > +0	QNAN	QNAN
a > +0	SNAN	QNAN
QNAN	b > +0	QNAN
SNAN	x > +0	QNAN
QNAN	QNAN	QNAN
QNAN	SNAN	QNAN
SNAN	QNAN	QNAN
SNAN	SNAN	QNAN

The atan2pi(a,b) function does not generate any errors.

API

Syntax

Buffer API

namespace oneapi::mkl::vm {

sycl::event atan2pi(sycl::queue & exec_queue,
      std::int64_t n,
      sycl::buffer<T> & a,
      sycl::buffer<T> & b,
      sycl::buffer<T> & y,
      oneapi::mkl::vm::mode mode = oneapi::mkl::vm::mode::not_defined);

}

namespace oneapi::mkl::vm {

sycl::event atan2pi(sycl::queue & exec_queue,
      sycl::buffer<T> & a,
      oneapi::mkl::slice sa,
      sycl::buffer<T> & b,
      oneapi::mkl::slice sb,
      sycl::buffer<T> & y,
      oneapi::mkl::slice sy,
      oneapi::mkl::vm::mode mode = oneapi::mkl::vm::mode::not_defined);

}

USM API

namespace oneapi::mkl::vm {

sycl::event atan2pi(sycl::queue & exec_queue,
      std::int64_t n,
      T const * a,
      T const * b,
      T * y,
      std::vector<cl::sycl::event> const & depends = {},
      oneapi::mkl::vm::mode mode = oneapi::mkl::vm::mode::not_defined);

}

namespace oneapi::mkl::vm {

sycl::event atan2pi(sycl::queue & exec_queue,
      T const * a,
      oneapi::mkl::slice sa,
      T const * b,
      oneapi::mkl::slice sb,
      T * y,
      oneapi::mkl::slice sy,
      std::vector<cl::sycl::event> const & depends = {},
      oneapi::mkl::vm::mode mode = oneapi::mkl::vm::mode::not_defined);

}

atan2pi supports the following precisions and devices:

T	Devices supported
float	Host, CPU, and GPU
double	Host, CPU, and GPU

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 1st input vector.

sa

Slice selector for a. See Data Types for a description of the oneMKL slice type.

b

The buffer containing the 2nd input vector.

sb

Slice selector for b. 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.

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 1st input vector.

sa

Slice selector for a. See Data Types for a description of the oneMKL slice type.

b

Pointer to the 2nd input vector.

sb

Slice selector for b. 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.

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 atan2pi can be found in the oneMKL installation directory, under:

examples/dpcpp/vml/source/vatan2pi.cpp

atanpi cosd