atan2pi

Computes the four-quadrant inverse tangent of the ratios of the corresponding elements of two vectors divided by π.

Syntax

Buffer API:

void atan2pi(queue &exec_queue, int64_t n, buffer<T, 1> &a, buffer<T, 1> &b, buffer<T, 1> &y, uint64_t mode = mode::not_defined)

USM API:

event atan2pi(queue &exec_queue, int64_t n, T *a, T *b, T *y, vector_class<event> *depends, uint64_t mode = mode::not_defined)

atan2pi supports the following precisions.

T
float
double

Description

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

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 π.

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.

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 a containing 1st input vector of size n.

b

The buffer b containing 2nd input vector of size n.

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 a to the 1st input vector of size n.

b

Pointer b to the 2nd input vector of size n.

depends

Vector of dependent events (to wait for input data to be ready).

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 y containing the output vector of size n.

USM API:

y

Pointer y to the output vector of size n.

return value (event)

Function end event.

Example

An example of how to use atan2pi can be found in the oneMKL installation directory, under:

examples/sycl/vml/vatan2pi.cpp

Parent topic: Trigonometric Functions