Filter
Top Products
FORTRAN-80
Scale Factor (P)
Editing
A scale factor
is
established by
the'
kP'
edit descriptor,
where'
k'
represents the scale
factor.
It
is
used with the
'F'
and
'E'
descriptors
to
edit real numbers. No
comma
is
needed between the
'P'
descriptor and
an
immediately following
'F'
or
'E.'
1 PE8.6E2
A scale factor
of
zero
is
assumed at the beginning
of
an
110
statement. Once it has
been changed by
the'
kP'
edit descriptor, the new scale factor remains in effect until
the'
kP'
descriptor
is
issued again
or
until the end
of
the
110
statement.
On input, the scale factor has no effect
if
there
is
an exponent in the
'F'
or
'E'
edited
field.
Otherwise, the effect
of
the scale factor
is
that
the externally-represented
number
equals the internally represented
number
multiplied by
'10**k.'
The same
is
true
of
output
with
'F'
editing. On
output
with
'E'
editing, the basic real
constant
part
of
the quantity
to
be produced
is
multiplied by
'10**k'
and
the exponent
is
reduced by
'k.'
As
we
saw in the description
of
'E'
descriptor editing, the
output
range
of
a
multiplier printed in scientific
notation
with a scale factor
of
zero
is
0.1 to 1.0.
Changing the scale factor to one changes the multiplier range
to
1.0 - 10.0. Changing
the scale factor
is
useful for very large
or
very small
'E'
edited numbers,
but
is
generally not desirable for
'F'
edited numbers. Following specification
of
a nonzero
scale factor, the scale factor should probably be respecified as
'OP' before the next
occurrence
of
'F'
editing.
The following table
of
number
representations illustrates instances where
'E'
editing
and the use
of
the scale factor would be most applicable. The column headings show
the field descriptor used
to
produce each representation.
Real
Number
4.32
7255000.0
0.0065
FS.2
4.32
******
0.01
E10.5
0.43200E +
01
O.
72550E + 07
0.65000E-02
1 PE10.4
4.3200E+00
7.2550E+06
6.5000E-03
Clearly,
'F'
descriptor editing
is
preferable for simple numbers like
'4.32.'
Just
as
clearly,
'F'
descriptor editing
is
inadequate for very large
or
very small numbers like
'7255000'
or
'0.0065.'
'BN'
and
'BZ'
Editing
These two edit descriptors are used for
input
only
and
affect only numeric editing.
They can be used
to
specify the interpretation
of
blanks,
other
than
leading blanks.
If
'BN'
is
specified, blanks are ignored except
that
a field
of
all blanks
is
treated as
zero.
If
'BZ'
is
specified, blanks are regarded as zeros.
Until the
'BZ'
or
'BN'
descriptor
is
specified (or,
if
neither
is
specified), the BLANK
specifier in the
OPEN
statement (section 6.2.1.9) determines the interpretation
of
blanks.
Example:
READ (2,50) INTNUM, FPNUM
50
FORMAT
(BN,
15,
5X, F7.4)
Dollyt
Sigfjl$ijitrrrg·
Th¢
..•
~oll.~f
•••.
$~~·~
••••••
~.~.).···.·e~l~
.••.••
(J~~pti~t?f
..
·
•••
~.s·
....
·.~.~~~.
·.p~i~~t~l,~
•••.
f~r~~~~r~~ti,~~
.•
ilq
...
t~r?Mgp.·L.a
c()nsoletYFl1l~l\l~LJtlea~~s.~·~l\tYF~inalfnlrs~r~tr~~~~§~~~~n~m,tn~~i~tel~fCl)~19\Ving
the
I/Odataju~t
pr()ces$ed;·rathe:rthant>egil1nill,gan1tw~ine~Ifthe·f{)r.i)lat·c()l1tTlpl
Input/Output
6-21