Intel® Math Kernel Library 2019 Developer Reference - Fortran
Computes inverse cosine of vector elements.
call vsacos( n, a, y )
call vmsacos( n, a, y, mode )
call vdacos( n, a, y )
call vmdacos( n, a, y, mode )
call vcacos( n, a, y )
call vmcacos( n, a, y, mode )
call vzacos( n, a, y )
call vmzacos( n, a, y, mode )
Name |
Type |
Description |
|---|---|---|
n |
INTEGER, INTENT(IN) |
Specifies the number of elements to be calculated. |
a |
DOUBLE PRECISION for vdacos, vmdacos COMPLEX for vcacos, vmcacos DOUBLE COMPLEX for vzacos, vmzacos REAL, INTENT(IN) for vsacos, vmsacos DOUBLE PRECISION, INTENT(IN) for vdacos, vmdacos COMPLEX, INTENT(IN) for vcacos, vmcacos DOUBLE COMPLEX, INTENT(IN) for vzacos, vmzacos |
Array that specifies the input vector a. |
mode |
INTEGER(KIND=8), INTENT(IN) |
Overrides global VM mode setting for this function call. See vmlSetMode for possible values and their description. |
Name |
Type |
Description |
|---|---|---|
y |
DOUBLE PRECISION for vdacos, vmdacos COMPLEX for vcacos, vmcacos DOUBLE COMPLEX for vzacos, vmzacos REAL, INTENT(OUT) for vsacos, vmsacos DOUBLE PRECISION, INTENT(OUT) for vdacos, vmdacos COMPLEX, INTENT(OUT) for vcacos, vmcacos DOUBLE COMPLEX, INTENT(OUT) for vzacos, vmzacos |
Array that specifies the output vector y. |
The v?Acos function computes inverse cosine of vector elements.
| Argument | Result | VM Error Status | Exception |
|---|---|---|---|
| +0 | +π/2 | ||
| -0 | +π/2 | ||
| +1 | +0 | ||
| -1 | +π | ||
| |X| > 1 | QNAN | VML_STATUS_ERRDOM | INVALID |
| +∞ | QNAN | VML_STATUS_ERRDOM | INVALID |
| -∞ | QNAN | VML_STATUS_ERRDOM | INVALID |
| QNAN | QNAN | ||
| SNAN | QNAN | INVALID |
See Special Value Notations for the conventions used in the table below.
RE(z) i·IM(z) |
-∞
|
-X
|
-0
|
+0
|
+X
|
+∞
|
NAN
|
|---|---|---|---|---|---|---|---|
| +i·∞ | +3·π/4-i·∞ | +π/2-i·∞ | +π/2-i·∞ | +π/2-i·∞ | +π/2-i·∞ | +π/4-i·∞ | QNAN-i·∞ |
| +i·Y | +π-i·∞ | +0-i·∞ | QNAN+i·QNAN | ||||
| +i·0 | +π-i·∞ | +π/2-i·0 | +π/2-i·0 | +0-i·∞ | QNAN+i·QNAN | ||
| -i·0 | +π+i·∞ | +π/2+i·0 | +π/2+i·0 | +0+i·∞ | QNAN+i·QNAN | ||
| -i·Y | +π+i·∞ | +0+i·∞ | QNAN+i·QNAN | ||||
| -i·∞ | +3π/4+i·∞ | +π/2+i·∞ | +π/2+i·∞ | +π/2+i·∞ | +π/2+i·∞ | +π/4+i·∞ | QNAN+i·∞ |
| +i·NAN | QNAN+i·∞ | QNAN+i·QNAN | +π/2+i·QNAN | +π/2+i·QNAN | QNAN+i·QNAN | QNAN+i·∞ | QNAN+i·QNAN |
Notes:
raises INVALID exception when real or imaginary part of the argument is SNAN
Acos(CONJ(z))=CONJ(Acos(z)).