Dictionary

HEX w . Informat

Converts hexadecimal positive binary values to fixed- or floating-point binary values

Category: Numeric

Width range: 1 to 16

Default width: 8

UNIX specifics: floating-point representation

See: HEXw. informat in SAS Language Reference: Dictionary

Details

The HEX w . informat converts the hexadecimal representation of positive binary numbers to real floating-point binary values. The width value of the HEXw. informat determines whether the input represents an integer (fixed-point) or real (floating-point) binary number. When you specify a width of 1 through 15, the informat interprets the input hexadecimal as an integer binary number. When your specify 16 for the width value, the informat interprets the input hexadecimal as a floating-point value.

For more details, see "Reading and Writing Binary Data in UNIX Environments" on page 198.

$HEX w . Informat

Converts hexadecimal data to character data

Category: Character

Width range: 1 to 32,767

Default width: 2

UNIX specifics: values are interpreted as ASCII values

See: $HEXw. informat in SAS Language Reference: Dictionary

Details

The $HEX w. informat converts every two digits of hexadecimal data into one byte of character data. Use the $HEX w. informat to encode hexadecimal values into a character variable when your input data is limited to printable characters . SAS under UNIX interprets values that are read with this informat as ASCII values.

IB w . d Informat

Reads integer binary (fixed-point) values

Category: Numeric

Width range: 1 to 8

Default width: 4

Decimal range: 0 to 10

UNIX specifics: byte values

See: IBw.d informat in SAS Language Reference: Dictionary

Details

The IB w.d informat reads fixed-point binary values. 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 two's-complement notation. If the informat includes a d value, the data value is divided by 10 ^d .

For more details, see "Reading and Writing Binary Data in UNIX Environments" on page 198.

PD w . d Informat

Reads packed decimal data

Category: Numeric

Width range: 1 to 16

Default width: 1

Decimal range: 0 to 31

UNIX specifics: data representation

See: PDw.d informat in SAS Language Reference: Dictionary

Details

The PD w.d informat reads packed decimal data. Although it is usually impossible to type in packed decimal data directly from a console, many programs write packed decimal data.

Each byte contains two digits in packed decimal data. The value's sign is the first byte. Because the entire first byte is used for the sign, you should specify at least a width of 2.

For more details, see "Reading and Writing Binary Data in UNIX Environments" on page 198.

PIB w . d Informat

Reads positive integer binary (fixed-point) values

Category: Numeric

Width range: 1 to 8

Default width: 1

Decimal range: 0 to 10

UNIX specifics: byte order

See: PIBw.d informat in SAS Language Reference: Dictionary

Details

The PIB w.d informat reads integer binary (fixed-point) values. Positive integer binary values are the same as integer binary (see "IB w.d Informat" on page 258), except that all values are treated as positive. Thus, the high-order bit is part of the value rather than the value's sign. If the informat includes a d value, the data value is divided by 10 ^d .

For more details, see "Reading and Writing Binary Data in UNIX Environments" on page 198.

RB w . d Informat

Reads real binary (floating-point) data

Category: Numeric

Width range: 2 to 8

Default width: 4

Decimal range: 0 to 10

UNIX specifics: floating-point representation; supports single-precision numbers only for those applications that truncate numeric data

See: RBw.d informat in SAS Language Reference: Dictionary

Details

The RB w.d informat reads numeric data that is stored in real binary (floating-point) notation. SAS stores all numeric values in floating-point.

It is usually impossible to type in floating-point binary data directly from a console, but many programs write floating-point binary data. Use caution if you are using the RB w.d informat to read floating-point data created by programs other than SAS because the RB w.d informat is designed to read only double-precision data.

All UNIX systems that are currently supported by SAS use the IEEE standard for floating-point representation. This representation supports both single-precision and double-precision floating-point numbers. Double-precision representation has more bytes of precision, and the data within the representation is interpreted differently. For example, for single-precision, the value of 1 in hexadecimal representation is 3F800000 . For double-precision, the hexadecimal representation of 1 is 3FF0000000000000 .

The RB w.d informat is designed to read only double-precision data. It supports widths less than 8 only for applications that truncate numeric data for space-saving purposes. RB4. does not expect a single-precision floating-point number; it expects a double-precision number truncated to four bytes. Using the example of 1 above, RB4. expects 3FF00000 to be the hexadecimal representation of the four bytes of data to be interpreted as 1. If given 3F800000 , the single-precision value of 1, a different number results.

External programs such as those written in C and FORTRAN can only produce single-or double-precision floating-point numbers. No length other than four or eight bytes is allowed. RB w.d allows a length of 3 through 8, depending on the storage you need to save.

The FLOAT4. informat has been created to read a single-precision floating-point number. If you read 3F800000 with FLOAT4., the result is a value of 1.

To read data created by a C or FORTRAN program, you need to decide on the proper informat to use. If the floating-point numbers require an eight-byte width, you should use the RB8. informat. If the floating point numbers require a four-byte width, you should use FLOAT4.

Consider this C example:

 #include <stdio.h>   main() {   FILE *fp;   float x[3];   fp = fopen("test.dat","wb");   x[0] = 1; x[1] = 2; x[2] = 3;   fwrite((char *)x,sizeof(float),3,fp);   fclose(fp);   } 

The file Test.dat contains 3f8000004000000040400000 in hexadecimal representation.

The following statements read Test.dat correctly:

 data _null_;        infile 'test.dat';        input (x y z) (float4.);     run; 

Also available is the IEEE w.d informat, which reads IEEE floating-point data. On UNIX systems, IEEE8. is equivalent to RB8., and IEEE4. is equivalent to FLOAT4. IEEE w.d can be used on any platform, as long as the original IEEE binary data originated on a platform that uses the IEEE representation.

For more details, see "Reading and Writing Binary Data in UNIX Environments" on page 198.

ZD w . d Informat

Reads zoned decimal data

Category: Numeric

Width range: 1 to 32

Default width: 1

UNIX specifics: last byte includes the sign; data representation

See: ZDw.d informat in SAS Language Reference: Dictionary

Details

The ZD w.d informat reads zoned decimal data; it is also known as overprint trailing numeric format. Under UNIX, the last byte of the field includes the sign along with the last digit. The conversion table for the last byte is as follows :

Digit	ASCII Character
	{
1	A
2	B
3	C
4	D
5	E
6	F
7	G
8	H
9	I
-0	}
-1	J
-2	K
-3	L
-4	M
-5	N
-6	O
-7	P
-8	Q
-9	R

For more details, see "ZD w.d Format" on page 234 and "Reading and Writing Binary Data in UNIX Environments" on page 198.