The PDw.d informat is useful because many programs write data in packed decimal format for storage efficiency, fitting two digits into each byte and using only a half byte for a sign.

Note: Different operating environments store packed decimal values in different ways. However, PDw.d reads packed decimal values with consistent results if the values are created on the same type of operating environment that you use to run SAS.

The PDw.d format writes missing numerical data as -0. When the PDw.d informat reads -0, it stores it as 0.

Comparisons

The following table compares packed decimal notation in several programming languages:

Language	Notation
SAS	PD4.
COBOL	COMP-3 PIC S9(7)
IBM 370 Assembler	PL4
PL/I	FIXED DEC

Examples

Example 1: Reading Packed Decimal Data

input @1 x pd4.;

Data Line 1	Result
----+----1
0000128C	128
1The data line is a hexadecimal representation of a binary number stored in packed decimal form. Each byte occupies one column of the input field.

Example 2: Creating a SAS Date with Packed Decimal Data

input x: $hex10.;
mnth=input(x, pd5.); 
date=input(put(mnth,8.),mmddyy6.);

Data Line 1	Result
----+----1
012252010C	18621
1The data line is a hexadecimal representation of a binary number that is stored in packed decimal form on an IBM mainframe operating environment. Each byte occupies one column of the input field. The result is a SAS date value that corresponds to December 25, 2010.