Reads integer binary (fixed-point) data
| Category |
numeric
|
| Width range: |
1--8
|
| Default width: |
4
|
| Decimal range: |
0--10
|
| Windows specifics: |
native floating-point representation
|
-
w
-
specifies the width of the input field.
-
d
-
optionally specifies the power of 10 by which to divide the input value. SAS uses the d value even if the input data contain decimal
points.
For integer binary data, the high-order bit is the value's sign: 0 for positive values, 1 for negative. Negative values are
represented in twos-complement notation. If the informat includes a d value, the data value is divided by
10d.
Using the IBw.d informat requires you to understand twos complements
and byte-swapped data format.
For more information about microcomputer fixed-point values, see Intel Corporation's i486 Microprocessor Programmer's Reference
Manual.
The IBw.d informat and the PIBw.d informat give you different results. The
IBw.d informat processes both positive and negative numbers and it uses the high-order bit as the sign bit. In contrast, the
PIBw.d informat is used only for positive numbers and it does
not look for a sign bit. As an example, suppose your data contain the following two-byte (byte-swapped) value:
01 80
When you read this value using the IB2. informat, the informat looks for the sign bit, sees that it is on, and reads the value as -32,767. However, if you read this
value with the PIB2. informat, no sign bit is used, and the result is 32,769.
Suppose that your data contain the following 6-byte (byte-swapped) value:
64 00 00 00 00 00
If you read this value using the IB6. informat, it is read as the fixed-point value 100.0. Now suppose that your data contain the following (byte-swapped) value:
01 80
Because the sign bit is set, the value is read as -32,767.
Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.
