The F data edit descriptor transfers real values. It takes the following form:
Fw.d
The value of d (the number of places after the decimal point) must not exceed the value of w (the field width).
The specified I/O list item must be of type real, or it must be the real or imaginary part of a complex type.
On input, the F data edit descriptor transfers w characters from an external field and assigns their real value to the corresponding I/O list item. The external field data must be an integer or real constant.
If the input field contains only an exponent letter or decimal point, it is treated as a zero value.
If the input field does not contain a decimal point or an exponent, it is treated as a real number of w digits, with d digits to the right of the decimal point. (Leading zeros are added, if necessary.)
If the input field contains a decimal point, the location of that decimal point overrides the location specified by the F descriptor.
If the field contains an exponent, that exponent is used to establish the magnitude of the value before it is assigned to the list element.
The following shows input using the F edit descriptor:
Format Input Value
F8.5 123456789 123.45678
F8.5 -1234.567 -1234.56
F8.5 24.77E+2 2477.0
F5.2 1234567.89 123.45
On output, the F 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 w must be greater than or equal to d+3 to allow for the following:
A sign (optional if the value is positive and descriptor SP is not in effect)
At least one digit to the left of the decimal point
The decimal point
The d digits to the right of the decimal point
The following shows output using the F edit descriptor (the symbol ^ represents a nonprinting blank character):
Format Value Output
F8.5 2.3547188 ^2.35472
F9.3 8789.7361 ^8789.736
F2.1 51.44 **
F10.4 -23.24352 ^^-23.2435
F5.2 325.013 ******
F5.2 -.2 -0.20