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

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804