SIMSCRIPT II.5 Programming Language

Programming Language Concepts
numbers are printed unsigned, while negative numbers have the sign printed to the left of the highest-order
digit. Leading zeros are suppressed.
3.4.2.2 D (Decimal) Descriptor
A descriptor of the form n D(a,b) is used for converting numbers from internal to external decimal
representation, and vice versa. The a field specifies the number of characters in the data field, including
the sign and decimal points. The b field specifies the number of digits to the right of the
decimal point; and the optional n field specifies the number of consecutive values of the format.
When used for input, the D format accepts numbers typed with or without decimal points. If a decimal
point is omitted, one is implied before the first digit in the b field. When a decimal point is
present, it overrides the location specified by b. Very large and very small numbers can be input in
scientific notation, for when used for input the D and E formats are equivalent.
Used in output statements, D formats describe the precision in which decimal numbers are displayed.
Numbers that cannot be printed exactly in the specified format are rounded. Every number
output by a D format is printed in a field of a columns: the first column is used for the sign, the next
a-b-2 columns are for digits, the next column is for the decimal point, and the remaining b columns
are for digits. The sign is printed if a number is negative; otherwise it remains blank. If the integer
part of a negative decimal number does not require all the a-b-2 positions allotted to it, the sign is
shifted to the right, next to the high-order digit. Leading zeros are suppressed. If a number has trailing
zeros, as in the number 10.0, the trailing zeros are printed. Trailing zeros are not printed for a
value of exactly zero.
3.4.2.3 E (Scientific) Descriptor
Extremely large and extremely small numbers, and numbers that vary widely in scale, can be read
and written in a constant field width by using an E format. This format is similar to the D format
in that it specifies a field width and a decimal point position by the numbers a and b in the form n
E(a,b), but it differs from the D format in having a scale factor field. The scale factor field appears
to the right of a decimal number and indicates the necessary number of places right or left that the
decimal point must be moved to convert the scaled number to its proper form.
The E format is thus equivalent to the D format, plus a scale factor. Numbers read under E format
control are of the general form:
±XXX.XXXE±XX
although some latitude is allowed in writing the scale factor. A positive scale factor, such as E+02
or E 7, raises the value of a printed number; 24.795E-04 represents an internally stored value of
.0024795.
The E format can be used for both input and output. When used for output, it aligns numbers according
to the format specification and prints a scale factor indicating the true value of the printed
number. All E formatted numbers are a print positions wide, with the first a-4 positions used for
107