A Code - Algebraic Functions

Overview

The A code is a function that uses an algebraic format. There are two forms of the A code:

A Uses only the integer parts of stored numbers unless a scaling factor is included.

AE Handles extended numbers, that is, it uses both the integer and fraction parts of stored numbers.

The A code has arithmetic, relational, logical, and concatenation operators. It allows data to be referenced by attribute names as well as by AMC. It gives you the capability to use other data definition items as functions that return a value. It also allows you to modify data by means of format codes.

In handling the A code, the processor changes it to F code format before performing the function. Some error messages that you might see reflect this.

Input/Output Conversion

Output conversion is valid.

Input conversion is not allowed: the processor displays an error message.

Syntax

A{n}{;expression}

or

AE;expression

Syntax Elements

n is a number (1-6) to specify a desired scaling factor.

expression consists of operands, operators, conditional statements, and special functions.

 Summary of A and AE Formats

You can use the A code in these formats:

A;expressionEvaluates the expression and compiles into an F;expression function.

AnConverts to a scaled integer.

An;expressionConverts to a scaled integer and compiles into an Fn;expression function.

AE;expressionEvaluates the expression and compiles into an FE;expression function.

The F code functions are described under the heading F Code - Mathematical Functions.

An Format: Embedded Decimals

The An format converts a value stored with an embedded decimal point (such as values generated by ALL) to a scaled integer for use by an English sentence. The stored value is multiplied by the power of 10 as specified by n (where n is a number, 1 to 6) and rounded to the nearest integer. If n = 0, ;expression cannot be specified.

Attribute 2 of the data definition item must contain the AMC of the attribute that contains the data to be processed.

An;expression... Format

The An;expression format performs the functions specified in expression on values stored with an embedded decimal (such as ALL-generated values). The resulting value is then converted to a scaled integer for use by an English sentence.

If this data definition item is to be referenced by name from another function, attribute 2 must contain a zero.

AE Format

The AE format uses stored numbers as they are, both integers and fractions. The function handles up to nine decimal places. Scaling of output must be done with format codes.

Examples

Each of the function codes below adds the contents of attribute 1 to the contents of attribute 2. The A code adds integers only; the An code scales up each operand before adding them; the AE code adds the fractional part as well as the integer part.

Attribute 1     Attribute 2     A;1+2     A3;1+2     AE;1+2
6               023             29        29000      29
-99                             -99       -99000     -99
0.34            45.09           45        45430      45.43
-3.123          -12.34          -15       -15463     -15.463
-3.123          123.45          120       120327     120.327

 Operators

The operators that you can use in A code expressions include arithmetic, relational and logical operators, the concatenation operator, and the IF statement.

Arithmetic Operators

+ Sum of operands.

- Difference of operands.

* Product of operands.

/ Quotient of operands.

Note

Division by zero returns the dividend.

Relational Operators

Relational operators specify logical relational operations. Two expressions are treated as operands and evaluated as true (1) or false (0). The following are valid relational operators:

= or EQEqual to.

< or LTLess than.

> or GTGreater than.

<= or =< or LELess than or equal to.

>= or => or GEGreater than or equal to.

# or NENot equal.

In the following example, the sum of attributes ACT and PRI is multiplied by .07. If the result is greater than 0, then the word CREDIT is output. Otherwise the word DEBIT is output:

A;IF N(ACT)+N(PRI)*".07">"0" THEN "CREDIT" ELSE "DEBIT"

Logical Operators

The logical operators AND and OR combine two expressions into one value, 0 or 1:

AND If both expressions are true, the AND operation yields 1; else, 0.

OR If at least one of the expressions is true, OR yields 1; else, 0.

The words AND and OR must be followed by at least one space.

The AND operator takes precedence over the OR unless you specify a different order by means of parentheses.

Concatenation Operator

A colon (:) concatenates the results of two expressions. For example, the following expression adds the values in attributes 5 and 6 and concatenates the result with the value in attribute 3:

A;5+6:3

 Summary of Operands

The operands that you can use in A code expressions are attribute numbers (AMC), attribute names, literals, operands that return system parameters, and special functions.

attribute-number{R{R}}
Value of the attribute.

D System date (internal format).

I(expression) Integer part of expression.

"literal" Literal value.

LPV Previous value transformed by a format code.

N(attribute-name){R{R}}
Value as defined by the data definition item.

NA Number of attributes in the item.

NB Current break level counter:

1 = lowest break level
255 = GRAND-TOTAL line.

ND Number of items (detail lines) since the last control break.

Note

On detail lines, this has a value of 1; on break lines, it is the number of detail lines since the last controlled-break; and on grand-total lines, it has the same value as the item counter.

NF{c} The file specifier. The third character, if present, specifies a particular part of the file specifier; see Operand System Parameters for details.

NI Item counter.

NL Item length.

NS Subvalue counter.

NT Time of last update (number of milliseconds since midnight).

NU Date of last update (number days since 31 December 1967).

NV Value counter.

R(exp1,exp2) Remainder of exp1/exp2.

Note

If exp2 evaluates to 0, the result is 0.

S(expression) Sums all values generated by expression.

string[s,n] Substring starting at character s of length n.

T System time (internal format).

V Previous value transformed by a format code.

@(exp1,exp2,exp3)
if exp1 evaluates to true, returns value of exp2; otherwise returns value of exp3.

Format Codes

You can format an operand by following it with parentheses enclosing one or more format codes separated by value marks:

operand(format-code{]format-code}...)

Refer to the Format Codes section later in this topic for more details.

 Operand Attribute Number (AMC)

An attribute number (AMC) specifies the attribute containing the value(s) to be used. Attribute numbers 0, 9998, and 9999 have special meanings.

Syntax

attribute-number{R{R}}

Special Attribute Numbers

The following attribute numbers have special meanings:

0 Item-id

9999 Item size in bytes

9998 Sequential item count

Repeat Characters

R An attribute reference followed by R specifies that a single value is to be used repeatedly when evaluating a multivalued attribute used elsewhere in the calculation.

RR An attribute reference followed by RR specifies that a single subvalue is to be used repeatedly when evaluating a subvalued attribute used elsewhere in the calculation.

Note

Refer to MultiValuesfor details of how to use R and RR.

Example with AMC

To reference attribute 6, enter

A;6

Example with Item-size

To reference the item-size, enter

A;9999

 Operand Attribute Name

An attribute defined in the same dictionary can be specified by name through the N function. The processor returns whatever value is generated by the named attribute. If the attribute has attribute 8 codes, they are processed before the value is returned.

Syntax

N(attribute-name){R{R}}

Nesting

If the data definition item of the specified attribute contains attribute 8 codes, these are applied before the values(s) are returned.

These codes may also contain an A code function that references another attribute, and so on. For example, if attribute 8 of dictionary item SVRPT contains A;1 + 2R  and attribute 8 of dictionary item NEST contains A;N(SVRPT), the result of listing item NEST will be the same as listing item SVRPT.

This nesting capability is an important advantage provided only by the A and F codes.

Repeat Characters

R An attribute reference followed by R specifies that a single value is to be used repeatedly when evaluating a multivalued attribute used elsewhere in the calculation.

RR An attribute reference followed by RR specifies that a single subvalue is to be used repeatedly when evaluating a subvalued attribute used elsewhere in the calculation.

Note

Refer to MultiValuesfor details of how to use R and RR.

Example

In the following the value of QTY is the result of processing any codes in attribute 8 of the QTY data definition item:

A;N(QTY)

 Operand Literals

You can specify a literal string or numeric constant by enclosing it in single or double quotes.

Syntax

"literal" or 'literal'

Note

A numeric constant not enclosed in double quotes is assumed to be an attribute number.

Example with Literal

In the following, "20" is a numeric constant:

A;"20"+N(QTY)

Example with Attribute Reference

In the following, the number 20 means use the contents of attribute 20 of the current item. It is not a literal:

A;20+N(QTY)

Go to top buttonOperand System Parameters

You can use certain mnemonics to reference system parameters like date, time, the current break level, or the number of the current item.

Syntax

{-}special-operand

Special Operands

The following special operands return the current values of system parameters:

D System date (internal format)

LPV Previous value transformed by a format code

NA Number of attributes

NB Current break level counter:

1 = lowest break level
255 = GRAND-TOTAL line

ND Number of items (detail lines) since the last control break

NF The file specifier in the format:

{DICT }{/account/}file-name{,section-name}

NFA The account name part (if any) of the entered file specifier, in the format:

/account/

If no account was entered, a null string is returned.

NFD The string "DICT " if a dictionary access; otherwise a null string.

NFF The entered file specifier in the format:

{/account/}file-name

That is, with the DICT and section name strings, if any, removed.

NFN The file name part of the entered file specifier - that is, with the DICT, account name and section name strings, if any, removed.

NFS The section name part of the entered file specifier, in the format:

,section-name

If no section name was entered, a null string is returned.

NI Item counter.

NL Item length.

NS Subvalue counter.

NT Time of last update (number of milliseconds since midnight).

NU Date of last update (number days since 31 December 1967).

NV Value counter.

T System time (internal format).

V Previous value transformed by a format code.

Negative Value

To change the default sign (+) of the value, enter a minus sign before the operand.

 Operand Special Functions

Integer Function

Returns the integer portion of a number.

I(expression)

expression An expression that evaluates to a numeric value.

In the following example, the Integer Function returns only the integer part of the value returned by the expression shown:

A;I(N(COST)+N(PI)/N(MC))

Remainder Function

Takes two numbers as operands and returns the remainder of the first divided by the second.

R(exp1,exp2)

exp1,exp2 Expressions that evaluate to numeric values.

In the following example, the value returned by attribute COST is divided by 5 and the result is the remainder:

A;R(N(COST),"5")

Summation Function

Evaluates an expression and then adds together all the values.

S(expression)

expression An expression that evaluates to a multivalued list of numeric values.

In the following example, the values returned by attribute HOURS are multiplied by the single value returned by RATE, which is repeated for each value. The multivalued results are then summed:

S(N(RATE)R*N(HOURS))

Substring Function

Extracts a specified number of characters from a string, starting at a specified character.

[start-char-number,number-of-chars]

start-char-number
An expression that evaluates to the number of the first character of the substring.

number-of-chars An expression that evaluates to the number of characters in the substring.

In the following example, a string of 5 characters starting at the second position is returned:

A;N(NAME)["2","5"]

In the following example, a string can only be retrieved if the starting position is found in attribute 2 and the length in attribute 5:

A;N(NAME)[2,5]

Conditional Function

Returns one of two values, depending on the value of a condition.

@(expression, value1, value2)

condition An expression that evaluates to true or false.

value1, value2 Expressions, the results of which are returned depending on the value of condition.

In the following example, the string "True" is returned if the contents of attribute 1 evaluates to true; otherwise, the string "False" is returned.

@(1, "True", "False")

Format Codes

You can follow an A code operand with one or more format codes enclosed in parentheses to convert values stored in internal format to an output format.

Syntax

operand(format-code{]format-code}...)

Syntax Elements

operand is one of the A Code operands.

format-code is one of the format codes described in this topic (any code except A, AE, D1, D2, F, FE, FS or U).

] represents the value mark (CTRL+]) that must separate the format-codes.

Format Codes Following an A Code

Using a format code within an A code is different from using a format code following an A code. In the latter case, the processor applies the format code to the result of the A code processing.

Example: Format Code In an A Code

To convert the value stored in 'PRICE' to an integer and eliminate the cents, use:

A3;N(PRICE)(MD3]G0.1)*N(QTY)

In this example, both the format codes MD3 and G0.1 are applied only to the value of the attribute PRICE. The result is then multiplied by the value of QTY.

Example: Format Code Following an A Code

An integer can be output with the embedded decimal point by following the A code with a format code as follows:

A3;N(PRICE)(MD3)*N(QTY)]MD3

where ]MD3  at the end of the A code statement is the format code.

In this example, the format code MD3 is applied twice: once to the value returned by attribute PRICE; and then to the the complete result after multiplying by the value of QTY.

 IF Statement

The IF statement gives the A code conditional capabilities.

Syntax

IF conditional_expression THEN expression ELSE expression

Syntax Elements

conditional_expression
must evaluate to true or false.

If true, execute the THEN statement.

If false, execute the ELSE statement.

expression is a string, numeric value or an expression which evaluates to a string or numeric value.

Rules

Each IF statement must have a THEN clause and a corresponding ELSE clause.

IF statements can be nested but the result of the statement must evaluate to a single value.

The words IF, THEN, ELSE, AND, and OR must be followed by at least one space.

OR is the default operation and need not be entered.

Examples

The following statement

IF 1 THEN IF 2 THEN 3 ELSE 4 ELSE 5

presented structurally would be

IF 1 THEN
    IF 2 THEN
        3
    ELSE
        4
ELSE
    5

In the following example, "VALID" is output if both parts of the IF statement are true. "NO COMMENT" is output if only one part is true or both are false.

A;IF N(OBJ)="4" AND N(PRED)="7" THEN "VALID" ELSE "NO COMMENT"

 Multivalues

One of the most powerful features of the A and AE codes is that they can handle multivalues. They normally combine multivalues one-by-one, but if you specify R or RR after an AMC, they repeat the first value and combine it with several multivalues.

Note

The F and FS codes handle multivalues in the same way as the A and AE codes. In the examples below, the equivalent F/FS syntax is shown in parentheses.

Attribute operands may be valued and subvalued. When mathematical operations are performed on two multivalued lists (vectors), the result is also multivalued. The result has as many values as the longer of the two lists. Zeros are substituted for null and missing values in the shorter list.

For example, if attributes 10 and 15 contain the following values:

010 5]10]15
015 20]30]40]50

and the data definition item contains the following code in attribute 8:

A;10+15; (or F;10;15;+;)

when the A code is processed, each value is added to the corresponding value in the other attribute. The result is therefore:

:LIST TEST VALUES

TEST......  Values.....
THING       25             (5 + 20)
            40             (10 + 30)
            55             (15 + 40)
            50             (0 + 50)

ONE ITEM LISTED

Repeat Operator

To repeat a value for combination with multivalues, follow the AMC with the R operator.

Attributes 10 and 20 of item THING contain:

010 1]2
020 3

Data definition item VALUES has the following code in attribute 8:

A;10 + 20R; (or F;10;20R;+)

The expression repeats the value in attribute 20 to match the number of values in attribute 10:

1]2
3 3  Repeated by the R

The two lists are then added and result in the following:

:LIST TEST VALUES

TEST......  Values.....
THING       4              (1 + 3)
            5              (2 + 3)

ONE ITEM LISTED

Note

If the attribute to which the repeat character is applied is mutlivalued, the first value is repeated, but is only used for values in the other attribute for which there is no corresponding value. For example, if attributes 10 and 20 contain the following:

010 1]2]3]4]5]6

020 10]20]]40

and data definition item has the following code in attribute 8:

A;10 + 20R (or F;10;20R;+)

the expression repeats the first value in attribute 20 (that is, 10) to match values in attribute 10 for which there is no value in attribute 20:

 1] 2] 3] 4] 5] 6

10 20  0 40 10 10

Note that the first value is only repeated for the missing values - in this case, values 5 and 6. The null in value 3 is treated as 0.

When the two lists are added the following is the result:

:LIST TEST VALUES

TEST......  Values.....
THING       11             (1 + 10)
            22             (2 + 20)
            3              (3 + 0)
            44             (4 + 40)
            15             (5 + 10)
            16             (6 + 10)

ONE ITEM LISTED

Example with Repeat Subvalue (RR)

To repeat a value for combination with subvalues, follow the AMC with the RR operator.

Attributes 5 and 20 of item THING contain:

005 1]2\5\7]2\2\9
020 3

Data definition item SUBVALS has the following code in attribute 8:

A;5 + 20RR (or F;5;20RR;+;)

The expression repeats the value in attribute 20 to match the number of subvalues in attribute 5:

1]2\5\7]2\2\9
3 3 3 3 3 3 3

The two lists are then added and result in the following:

:LIST TEST SUBVALS

TEST......  Subval......
THING       4              (1 + 3 - Valid subvalue = 3)
            6              (2 + 4 - Valid subvalue = 4)
            9              (5 + 4 - No subvalue; use subvalue 1 of this value = 4)
            11             (7 + 4 - No subvalue; use subvalue 1 of this value = 4)
            5              (2 + 3 - No value; use value 1 subvalue 1 = 3)
            5              (2 + 3 - No value; use value 1 subvalue 1 = 3)
            12             (9 + 3 - No value; use value 1 subvalue 1 = 3)

ONE ITEM LISTED

Note the difference between this and a single R character used with sub-valued data. With a single R character, the repeated value is used only with the first sub-value in each value. Applying the conversion code A;5 + 20R  (or F;5;20R;+;) to the same data therefore results in:

:LIST TEST SUBVALS

TEST......  Subval......
THING       4              (1 + 3)
            5              (2 + 4)
            5              (5 + 0)
            7              (7 + 0)
            5              (2 + 3)
            2              (2 + 0)
            9              (9 + 0)

ONE ITEM LISTED

 A Code Example

Assume a STOCK file with:

The dictionary has data definition items PRICE, QTY.A, QTY.B, a total quantity QTY, and VALUE. QTY adds QTY.A and QTY.B; VALUE multiplies QTY by PRICE.

The definition items are as follows:

     VALUE                PRICE          QTY
001  A                    A              A
002  0                    l              0
003  Value                Price          Qty
004
005
006
007  MD2.$                MD2.$
008  A;N(PRICE)*N(QTY)                   A;N(QTY.A)+N(QTY.B)
009  R                    R              R
010  10                   10              5
     QTY.A                QTY.B
001  A                    A
002  2                    3
003  Qty.A                Qty.B
004
005
006
007
008
009  R                    R
010  5                    5

Data Items are as follows:

     1125      1126      1127      1128
001  1269      157       2763      21165
002  12        0         3         5
003  6         9         17        2
.
.
.

Sample Report

:LIST STOCK QTY.A QTY.B QTY PRICE VALUE

PAGE 1
STOCK   Qty.A   Qty.B   Qty..   Price.....   Value.....
1125       12       6      18       $12.69      $228.42
1128        5       2       7      $211.65    $1,481.55
1126        0       9       9        $1.57       $14.13
1127        3      17      20       $27.63      $552.60
4 ITEMS LISTED