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Using and Porting GNU Fortran

10.5.2.33 DReal Intrinsic

DReal(A)

DReal: REAL(KIND=2) function.

A: INTEGER, REAL, or COMPLEX; scalar; INTENT(IN).

Intrinsic groups: vxt.

Description:

Converts A to REAL(KIND=2).

If A is type COMPLEX, its real part is converted (if necessary) to REAL(KIND=2), and its imaginary part is disregarded.

Although this intrinsic is not standard Fortran, it is a popular extension offered by many compilers that support DOUBLE COMPLEX, since it offers the easiest way to extract the real part of a DOUBLE COMPLEX value without using the Fortran 90 REAL() intrinsic in a way that produces a return value inconsistent with the way many FORTRAN 77 compilers handle REAL() of a DOUBLE COMPLEX value.

See section 8.11.9.212 RealPart Intrinsic, for information on a GNU Fortran intrinsic that avoids these areas of confusion.

See section 8.11.9.67 Dble Intrinsic, for information on the standard FORTRAN 77 replacement for DREAL().

See section 8.11.5 REAL() and AIMAG() of Complex, for more information on this issue.