CARG
This function evaluates the argument of a complex number.
Function Return Value
CARG — Function value. (Output)
If z = x + iy, then arctan(y/x) is returned except when both x and y are zero. In this case, zero is returned.
Required Arguments
Z — Complex number for which the argument is to be evaluated. (Input)
FORTRAN 90 Interface
Generic: CARG (Z)
Specific: The specific interface names are S_CARG and D_CARG.
FORTRAN 77 Interface
Single: CARG (Z)
Double: The double precision function name is ZARG.
Description
Arg(
z) is the angle
θ in the polar representation
z =
∣z∣eiθ, where
.
If z = x + iy, then θ = tan‑1 (y/x) except when both x and y are zero. In this case, θ is defined to be zero
Example
In this example, Arg(1 + i) is computed and printed.
USE CARG_INT
USE UMACH_INT
IMPLICIT NONE
! Declare variables
INTEGER NOUT
REAL VALUE
COMPLEX Z
! Compute
Z = (1.0, 1.0)
VALUE = CARG(Z)
! Print the results
CALL UMACH (2, NOUT)
WRITE (NOUT,99999) Z, VALUE
99999 FORMAT (' CARG(', F6.3, ',', F6.3, ') = ', F6.3)
END
Output
CARG( 1.000, 1.000) = 0.785
