FORTRAN Reference Manual

Statements
FORTRAN Reference Manual—528615-001
7-46
Editing Numeric Data
The E and D Descriptors
The E descriptor specifies conversion between an internal real or double precision
value and an external floating point number with an exponent. The D descriptor
specifies conversion between an internal double precision value and an external
floating point number with an exponent.
The E descriptor uses one of the following forms:
E w. d
E w. dE e
The field occupies w positions, the fractional part of which consists of d digits, unless
the scale factor in effect is greater than one, and the exponent part consists of e digits.
The e has no effect on input.
The form of the input field for E editing is the same as previously described for F
editing.
The D descriptor uses the form D w. d and is processed exactly the same as the E w. d
edit descriptor for both input and output.
The form of the output field for E editing with a zero scale factor is:
sign 0 . x1 x2 ... xd exp
sign is a minus sign if the value is negative, or an optional plus sign otherwise. x1 x2
... xd are the d most significant digits of the value after rounding. exp is a decimal
exponent in one of the following forms (z is a digit):
If you specify a scale factor, k, to control decimal normalization:
•
If k is greater than - d and less than or equal to zero, the output field contains
exactly | k| leading zeros and d - | k| significant digits after the decimal point.
•
If k is greater than zero and less than d + 2, the output field contains exactly k
significant digits to the left of the decimal point and d - k + 1 significant digits to the
right of the decimal point. Other values of k are not permitted.
The B Descriptor
The B w and B w. m descriptors convert a data value to a binary (base two) external
representation. You can also produce binary conversion using an I w. m.2 descriptor.
The binary digits are 0 and 1. Each binary digit represents one bit of the internal data
value.
Edit Descriptor
Absolute Value of
Exponent Form of Exponent
E w. d | exp| £ 99 E ± z1z2 or ± 0z1z2
E w. dEe | exp| £ (10** e) - 1 E ± z1z2 ... z e
D w. d | exp| £ 99 D ± z1z2
or E ± z1z2 or ± Oz1z2