Data of any of the floating-point types (Real, Double Precision,
and Complex) may be transferred using any of the descriptors `E`,
`F,` or `G`. For each complex number two descriptors must be
provided, one for each component; these components may be
separated, if required, by control descriptors. On output numbers
are rounded to the specified number of digits. All floating-point
data transfers are affected by the setting of the scale-factor; this is
initially zero but can be altered by the `P` control descriptor, as
explained in the section 10.9.

Output using `Fw.d` produces a fixed-point value in a field of `w
characters with exactly ``d` digits after the decimal point. The
decimal point is present even if `w` is zero, so that if a sign is
produced there is only space for, at most, `w-2` digits before the
decimal point. If it is really important to suppress the decimal
point in numbers with no fractional part one way is to use a format
specification of the form `(F15.0,TL1`)... so that the next field
starts
one place to the left and over-writes the decimal point. Another
way is to copy the number to an integer variable and write it with
an I descriptor, but note the limited range of integers on most
systems. `F` format is especially convenient in tabular layouts since
the decimal points will line up in successive records, but it is not
suitable for very large or small numbers.

Output with `Ew.d` produces a number in exponential or ``scientific"
notation. The mantissa will be between 0.1 and 1 (if the scale-factor is
zero). The form `Ew.dEe` specifies that there should be exactly `
e` digits in the exponent. This form must be used if the exponent will
have more than three digits (although this problem does not arise on
machines on which the number range is too small). `E` format can be
used to handle numbers of any magnitude. The disadvantage is that
exceptionally large or small values do not stand out very well in the
resulting columns of figures.

`Gw.d` is the general-purpose descriptor: if the value is greater than
0.1 but not too large to fit it the field it will be written using a
fixed-point format with `d` digits in total and with 4 blanks at the
end of the field; otherwise it is equivalent to `Ew.d` format. The
form `Gw.dEe` allows you to specify the length of the exponent; if
a fixed-point format is chosen there are `e+2` blanks at the end.

The next example shows the different properties of these three formats on output:

X = 123.456789 Y = 0.09876543 WRITE(UNIT=*, FMT='(E12.5, F12.5, G12.5)') X,X,X, Y,Y,Yproduces two records (with representing the blank):

0.12346E+03 123.45679 123.46 0.98766E-01 0.09877 0.98766E-01On input all the