v?Arg

Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

Download PDF

ID 766686

Date 4/28/2026

Version

Public

vcArg vmcArg vzArg vmzArg Computes argument of vector elements.

call vcarg ( n , a , y )

call vcargi(n, a, inca, y, incy)

call vmcarg ( n , a , y , mode )

call vmcargi(n, a, inca, y, incy, mode)

call vzarg ( n , a , y )

call vzargi(n, a, inca, y, incy)

call vmzarg ( n , a , y , mode )

call vmzargi(n, a, inca, y, incy, mode)

Name	Type	Description
`n`	INTEGER , INTENT(IN)	Specifies the number of elements to be calculated.
`a`	Fortran 77: COMPLEX for `vcarg` , `vmcarg`Fortran 77: DOUBLE COMPLEX for `vzarg` , `vmzarg`Fortran 90: COMPLEX , INTENT(IN) for `vcarg` , `vmcarg`Fortran 90: DOUBLE COMPLEX , INTENT(IN) for `vzarg` , `vmzarg`	Array that specifies the input vector `a` .
`inca` , `incy`	INTEGER, INTENT(IN)	Specifies increments for the elements of `a` and `y` .
`mode`		Overrides global VM mode setting for this function call. See vmlSetMode (Sets a new mode for VM functions according to the mode parameter and stores the previous VM mode to oldmode.) for possible values and their description.

Name	Type	Description
`y`	Fortran 77: DOUBLE PRECISION for `vzarg` , `vmzarg`Fortran 90: REAL , INTENT(OUT) for `vcarg` , `vmcarg`Fortran 90: DOUBLE PRECISION , INTENT(OUT) for `vzarg` , `vmzarg`	Array that specifies the output vector `y` .

The v?Arg function computes argument of vector elements.

See Special Value Notations for the conventions used in the table below.

Special Values for Complex Function v?Arg(z)

RE(z) i · IM(z)	∞	-X	-0	+0	+X	∞	NAN
+i · ∞	+3 · `π` /4	`π` /2	`π` /2	`π` /2	`π` /2	`π` /4	NAN
+i · Y	`π`		`π` /2	`π` /2		+0	NAN
+i · 0	`π`	`π`	`π`	+0	+0	+0	NAN
-i · 0	`π`	`π`	`π`	-0	-0	-0	NAN
-i · Y	`π`		`π` /2	`π` /2		-0	NAN
-i · ∞	-3 · `π` /4	`π` /2	`π` /2	`π` /2	`π` /2	`π` /4	NAN
+i · NAN	NAN	NAN	NAN	NAN	NAN	NAN	NAN

Notes: