Statement: Specifies the DOUBLE COMPLEX data type.
Syntax
DOUBLE COMPLEX
A COMPLEX(8) or DOUBLE COMPLEX constant is a pair of constants that represents a complex number. One of the pair must be a double-precision real constant, the other can be an integer, single-precision real, or double-precision real constant.
A COMPLEX(8) or DOUBLE COMPLEX constant occupies 16 bytes of memory and is interpreted as a complex number.
The rules for DOUBLE PRECISION (REAL(8)) constants also apply to the double precision portion of COMPLEX(KIND=8) or DOUBLE COMPLEX constants. (For more information, see REAL and DOUBLE PRECISION.)
The DOUBLE PRECISION constants in a COMPLEX(8) or DOUBLE COMPLEX constant have IEEE* T_floating format.
See Also
General Rules for Complex Constants, COMPLEX Statement, Complex Data Types, DOUBLE PRECISION, REAL
Examples
DOUBLE COMPLEX vector, arrays(7,29)
DOUBLE COMPLEX pi, pi2 /3.141592654,6.283185308/
The following examples demonstrate valid and invalid COMPLEX(KIND=8) or DOUBLE COMPLEX constants:
| Valid | |
| (1.7039,-1.7039D0) | |
| (547.3E0_8,-1.44_8) | |
| (1.7039E0,-1.7039D0) | |
| (+12739D3,0.D0) | |
| Invalid | Explanation |
| (1.23D0,) | Second constant missing. |
| (1D1,2H12) | Hollerith constants not allowed. |
| (1,1.2) | Neither constant is DOUBLE PRECISION; this is a valid single-precision real constant. |