Developer Reference for Intel® oneAPI Math Kernel Library - C

Developer Reference

Contents

v?Atan2

Computes four-quadrant inverse tangent of elements of two vectors.

Syntax

vsAtan2
(
n
,
a
,
b
,
y
)
;
vsAtan2I(n, a, inca, b, incb, y, incy);
vmsAtan2
(
n
,
a
,
b
,
y
,
mode
)
;
vmsAtan2I(n, a, inca, b, incb, y, incy, mode);
vdAtan2
(
n
,
a
,
b
,
y
)
;
vdAtan2I(n, a, inca, b, incb, y, incy);
vmdAtan2
(
n
,
a
,
b
,
y
,
mode
)
;
vmdAtan2I(n, a, inca, b, incb, y, incy, mode);
Include Files
  • mkl.h
Input Parameters
Name
Type
Description
n
const MKL_INT
Specifies the number of elements to be calculated.
a
,
b
const float*
 for
vsAtan2
,
vmsAtan2
const double*
 for
vdAtan2
,
vmdAtan2
Pointers to arrays that contain the input vectors
a
 and
b
.
inca
,
incb
,
incy
const MKL_INT
Specifies increments for the elements of
a
,
b
 and
y
.
mode
const MKL_INT64
Overrides global VM mode setting for this function call. See
vmlSetMode
 for possible values and their description.
Output Parameters
Name
Type
Description
y
float*
 for
vsAtan2
,
vmsAtan2
double*
 for
vdAtan2
,
vmdAtan2
Pointer to an array that contains the output vector
y
.
Description
The
v?Atan2
 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]
.
Special values for Real Function
v?Atan2(x)
Argument 1
Argument 2
Result
Exception
-
∞
-
∞
-3*
π
/4
 
-
∞
X < +0
-
π
/2
 
-
∞
-0
-
π
/2
 
-
∞
+0
-
π
/2
 
-
∞
X > +0
-
π
/2
 
-
∞
+
∞
-
π
/4
 
X < +0
-
∞
-
π
 
X < +0
-0
-
π
/2
 
X < +0
+0
-
π
/2
 
X < +0
+
∞
-0
 
-0
-
∞
-
π
 
-0
X < +0
-
π
 
-0
-0
-
π
 
-0
+0
-0
 
-0
X > +0
-0
 
-0
+
∞
-0
 
+0
-
∞
+
π
 
+0
X < +0
+
π
 
+0
-0
+
π
 
+0
+0
+0
 
+0
X > +0
+0
 
+0
+
∞
+0
 
X > +0
-
∞
+
π
 
X > +0
-0
+
π
/2
 
X > +0
+0
+
π
/2
 
X > +0
+
∞
+0
 
+
∞
-
∞
+3*
π
/4
 
+
∞
X < +0
+
π
/2
 
+
∞
-0
+
π
/2
 
+
∞
+0
+
π
/2
 
+
∞
X > +0
+
π
/2
 
+
∞
+
∞
+
π
/4
 
X > +0
QNAN
QNAN
 
X > +0
SNAN
QNAN
INVALID
QNAN
X > +0
QNAN
 
SNAN
X > +0
QNAN
INVALID
QNAN
QNAN
QNAN
 
QNAN
SNAN
QNAN
INVALID
SNAN
QNAN
QNAN
INVALID
SNAN
SNAN
QNAN
INVALID

Product and Performance Information

1

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