atan2

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

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ID 772045

Date 12/16/2022

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atan2

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

Description
API
Examples

Description

The atan2(a,b) function computes four-quadrant inverse tangent of elements of two vectors.

The elements of the output vector y are computed as the four-quadrant arctangent of a[i] / b[i].

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

The atan2(a,b) function does not generate any errors.

API

Syntax

Buffer API

namespace oneapi::mkl::vm {

sycl::event atan2(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 atan2(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 atan2(sycl::queue & exec_queue,
      std::int64_t n,
      T const * a,
      T const * b,
      T * y,
      std::vector<sycl::event> const & depends = {},
      oneapi::mkl::vm::mode mode = oneapi::mkl::vm::mode::not_defined);

}

namespace oneapi::mkl::vm {

sycl::event atan2(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<sycl::event> const & depends = {},
      oneapi::mkl::vm::mode mode = oneapi::mkl::vm::mode::not_defined);

}

atan2 supports the following precisions and devices:

T	Devices supported
`float`	CPU and GPU
`double`	CPU and GPU

Description

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 atan2 can be found in the oneMKL installation directory, under:

examples/dpcpp/vml/source/vatan2.cpp

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

atan2

Description

API

Examples