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:
Gw.d[Ee]
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.
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.
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 the following table:
Data Magnitude |
Effective 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 |
(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:
A sign (optional if the value is positive and descriptor SP is not in effect)
One digit to the left of the decimal point
The decimal point
The d digits to the right of the decimal point
The 4-digit or e+2-digit exponent
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 *************