HP OpenVMS Systems Documentation

HP COBOL
Reference Manual

Description

The LOG function returns a numeric value that approximates the logarithm to the base e (natural log) of the argument.

num

is a positive numeric argument.

Rules

1. The type of this function is numeric.
2. The returned value is an approximation of the logarithm to the base e of the argument.

Example

COMPUTE RSULT = FUNCTION LOG (NUM).

Description

The LOG10 function returns a numeric value that approximates the logarithm to the base 10 of the argument.

num

is a positive numeric argument.

Rules

1. The type of this function is numeric.
2. The returned value is an approximation of the logarithm to the base 10 of the argument.

Example

COMPUTE RSULT = FUNCTION LOG10 (NUM).

Description

The LOWER-CASE function returns a character string that is the same length as the argument with each uppercase letter in the argument replaced by the corresponding lowercase letter.

string

is an alphabetic or alphanumeric argument at least one character in length.

Rules

1. The type of this function is alphanumeric.
2. The returned value is the same character string as the argument, except that each uppercase letter in the argument is replaced by the corresponding lowercase letter.

Example

MOVE FUNCTION LOWER-CASE (STR) TO LC-STR.

Description

The MAX function returns the contents of the argument that contains the maximum value.

argument

is an alphabetic, alphanumeric, integer, or numeric argument.

Rules

1. The arguments must be all alphabetic, all alphanumeric, all integer, or all numeric, except that integer and numeric arguments can be mixed and alphabetic and alphanumeric arguments can be mixed.
2. The type of the function depends on the arguments, as follows:

   Arguments	Function Type
   Alphabetic and/or alphanumeric	Alphanumeric
   Integer (all arguments)	Integer
   Numeric (some arguments might be integer)	Numeric

3. The returned value consists of the contents of the argument having the greatest value, as determined by comparisons made according to the rules for simple conditions. (See Chapter 6.)
4. If more than one argument has the same value, and that value is the maximum, the returned value consists of the contents of the leftmost of these arguments.
5. If there is only one argument, the returned value consists of the contents of that argument.
6. If the type of the function is alphanumeric, the size of the returned value is the same as the size of the argument selected as the maximum.

Examples

1. MOVE FUNCTION MAX ("A", "B", "C") TO MAX-LETTER-OUT. MOVE FUNCTION MAX (1, 2, 3) TO MAX-NUMBER-OUT.

   MAX-LETTER-OUT is alphabetic or alphanumeric, and receives the value "C"; MAX-NUMBER-OUT is integer and receives the value 3.

2. COMPUTE ITEMC = (ITEMA + FUNCTION MAX (ITEMB, 10)).

   If ITEM A and ITEMB both contain the value 1, this statement results in ITEMC having the value 11.

   IF FUNCTION MAX (A, B, C) > 100 ...

   This is equivalent to the following more complex code:

   IF A >= B IF A >= C MOVE A TO TMP ELSE MOVE C TO TMP ELSE IF B >= C MOVE B TO TMP ELSE MOVE C TO TMP. IF TMP > 100 ...

3. The following example shows generic subscripting with reference modification:

   05 TABLE1 PIC X(7) OCCURS 3 TIMES. . . . MOVE "XAAAAAQ" TO TABLE1(1). MOVE "XBBBBBQ" TO TABLE1(2). MOVE "XCCCCCQ" TO TABLE1(3). MOVE FUNCTION MAX(TABLE1(ALL)(2:5)) TO RSULT.

   
   The value "CCCCC" is returned and stored in RSULT, an alphanumeric data item. The reference modifier, (2:5), applies to each element implicitly specified by the ALL subscript. Thus,

   FUNCTION MAX(TABLE1(ALL)(2:5))

   is equivalent to

   FUNCTION MAX(TABLE1(1)(2:5), TABLE1(2)(2:5), TABLE1(3)(2:5))

Description

The MEAN function returns a numeric value that is the arithmetic mean (average) of its arguments.

arg

is a numeric argument.

Rules

1. The type of this function is numeric.
2. The return value is the arithmetic mean of the arguments in the argument list; that is, it is the sum of the arguments divided by the number of arguments.

Examples

1. COMPUTE AVERAGE-VALUE = FUNCTION MEAN (9, 2, 6, 7, 1).

   The value returned and stored in AVERAGE-VALUE (a numeric data item) is 5 (the sum of the arguments divided by the number of arguments).

2. COMPUTE MEAN-ANSWER = FUNCTION MEAN(A, B, C).

   MEAN-ANSWER, A, B, and C are numeric data items. This code is equivalent to

   COMPUTE MEAN-ANSWER = (A + B + C ) / 3.

Description

The MEDIAN function returns the median value of a list of numbers, represented by the arguments. This value is such that at least half of the values are greater than or equal to the returned value, and at least half are less than or equal.

num

is a numeric argument.

Rules

1. The type of this function is numeric.
2. If the number of arguments is odd, the returned value is the middle occurrence in the sorted list.
3. If the number of arguments is even, the returned value is the arithmetic mean of the values referenced by the two middle occurrences in the sorted list.
4. The comparisons used to arrange the argument values in sorted order are made according to the rules for simple conditions. (See Chapter 6.)

Examples

1. COMPUTE RSULT = FUNCTION MEDIAN (1, 1, 9, 2, 1).

   The value returned and stored in RSULT (a numeric data item) is 1.

2. COMPUTE RSULT = FUNCTION MEDIAN (1, 1, 9, 2).

   The value returned and stored in RSULT is 1.5.