The G data edit descriptor generally transfers values of real type, but it can be used to transfer values of any intrinsic type. It takes the following form:
The value of d (the number of places after the decimal point) plus e (the number of digits in the exponent) must not exceed the value of w (the field width).
The specified I/O list item can be of any intrinsic type.
When used to specify I/O for integer, logical, or character data, the edit descriptor follows the same rules as Iw, Lw, and Aw, respectively, and d and e have no effect.
Rules for Real Input Processing
On input, the G data edit descriptor transfers w characters from an external field and assigns their real value to the corresponding I/O list item. The G descriptor interprets and assigns input data in the same way as the F data edit descriptor (see Section 11.2.4.1).
Rules for Real Output Processing
On output, the G data edit descriptor transfers the real value of the corresponding I/O list item, right-justified and rounded to d decimal positions, to an external field that is w characters long.
The form in which the value is written is a function of the magnitude of the value, as described in Table 11-2.
Table 11-2 Effect of Data Magnitude on G Format Conversions
| Data Magnitude | Equivalent Conversion |
|---|---|
| 0 < m < 0.1 - 0.5 x 10-d-1 | Ew.d[Ee] |
| m = 0 | F(w-n).(d-1), n('b') |
| 0.1 - 0.5 x 10-d-1 <= m < 1 - 0.5 x 10-d | F(w-n).d, n('b') |
| 1 - 0.5 x 10-d <= m < 10 - 0.5 x 10-d-1 | F(w-n).(d-1), n('b') |
| 10 - 0.5 x 10-d+1 <= m < 100 - 0.5 x 10-d+2 | F(w-n).(d-2), n('b') |
. | . |
. | . |
. | . |
| 10d-2 - 0.5 x 10-2 <= m < 10d-1 - 0.5 x 10-1 | F(w-n).1, n('b') |
| 10d-1 - 0.5 x 10-1 <= m < 10d - 0.5 | F(w-n).0, n('b') |
| m >= 10d - 0.5 | Ew.d[Ee] |
The 'b' is a blank following the numeric data representation. For Gw.d, n('b') is 4 blanks. For Gw.dEe, n('b' ) is e+2 blanks.
The w should be greater than or equal to d+7 to allow for the following:
If e is specified, the w should be greater than or equal to d+e+5.
The following shows output using the G edit descriptor and compares it to output using equivalent F editing (the symbol ^ represents a nonprinting blank character):
Value Format Output with G Format Output with F
0.01234567 G13.6 ^0.123457E-01 F13.6 ^^^^^0.012346
-0.12345678 G13.6 -0.123457^^^^ F13.6 ^^^^-0.123457
1.23456789 G13.6 ^^1.23457^^^^ F13.6 ^^^^^1.234568
12.34567890 G13.6 ^^12.3457^^^^ F13.6 ^^^^12.345679
123.45678901 G13.6 ^^123.457^^^^ F13.6 ^^^123.456789
-1234.56789012 G13.6 ^-1234.57^^^^ F13.6 ^-1234.567890
12345.67890123 G13.6 ^^12345.7^^^^ F13.6 ^12345.678901
123456.78901234 G13.6 ^^123457.^^^^ F13.6 123456.789012
-1234567.89012345 G13.6 -0.123457E+07 F13.6 *************
For More Information: