Section 10,19: G

 Gw.d[Ee] (General Floating Editing)

 On input, G performs the same as F format.

 On output, G transfers the value of the corresponding I/O list
 element, rounded to "d" decimal positions, and right-justified, 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 given below:

    Data Magnitude             Effective Conversion
    --------------             --------------------
           m < 0.1                 Ew.d[Ee]
    0.1 <= m < 1.0             F(w-4).d, n(' ')
    1.0 <= m < 10.0            F(w-4).(d-1), n(' ')
         .                          .
         .                          .
         .                          .
    10**d-2 <= m < 10**d-1     F(w-4).1, n(' ')
    10**d-1 <= m < 10**d       F(w-4).0, n(' ')
          m >= 10**d               Ew.d[Ee]

 The term "w" must be large enough to include all of the following:
 a minus sign (when necessary) or a plus sign (if SP editing is in
 effect), a decimal point, one digit to the left of the decimal
 point, "d" digits to the right of the decimal, and either a
 4-character or "e"+2-character exponent.

 Therefore, "w" must be greater than or equal to "d"+8.  If "e" is
 present, "w" must be greater than or equal to "d"+"e"+6.