The RBw.d format writes numeric data in the same way that SAS stores them. Because it requires no data conversion, RBw.d is the most efficient method for writing data with SAS.

Note: Different operating environments store real binary values in different ways. However, RBw.d writes real binary values with consistent results in the same type of operating environment that you use to run SAS.

CAUTION:

Using RB4. to write real binary data on equipment that conforms to the IEEE standard for floating-point numbers results in a truncated eight-byte (double-precision) number rather than a true four-byte (single-precision) floating-point number.

Comparisons

The following table compares the names of real binary notation in several programming languages:

Language	4 Bytes	8 Bytes
SAS	RB4.	RB8.
Fortran	REAL*4	REAL*8
C	float	double
COBOL	COMP-1	COMP-2
IBM 370 assembler	E	D

Example

y=put(x,rb8.);
put y $hex16.;

Value of `x`	Result 1
	----+---1----+----2
128	4280000000000000
1The result is a hexadecimal representation of an eight-byte real binary number as it looks on an IBM mainframe. Each byte occupies one column of the output field.