Variables

Simple Variables

INTEGER*1 gender
REAL*8 total total1
STRING*25 name
DATE curdate ('DDIMMIYYYY')

Extended Variable Definitions

INTEGER*1 VAR1 TO VAR10
SET VAR1 TO VAR10(2,4,6,8,10,12,14,16,18,20)

Variables can be referenced in a TO list format. A TO list specifies a beginning and ending variable. The following example declares seven variables and assigns a value to NAME, ADDRESS, CITY, STATE and COUNTRY. REGION and ZIPCODE are not affected by the SET command because they are not part of the implied list of variables.

STRING*25 REGION NAME ADDRESS
STRING*10 CITY STATE COUNTRY ZIPCODE
SET NAME TO COUNTRY ( 'Unknown' )

An individual variable can be referenced by specifying an index value after the TO list which specifies the position of the variable in the list. Specify the index value immediate following the TO list specification, enclosed in parentheses. For example:

INTEGER*1 NUMA NUMB NUMC NUMD    | declare variables
SET NUMA TO NUMD (11,12,13,14)   | assign values to variables
COMPUTE NUMX = NUMA TO NUMD(3)   | put 3rd var into NUMX

type [* size] ARRAY array_list (dimension [,...] ) [ (format)]

type	Variable type: INTEGER, REAL, STRING, DATE or TIME
size	Size of the integer, real or string variables.
ARRAY	Keyword specifying that arrays are being declared
array list	A list of the names of the arrays. Do not use VisualPQL function names. Do not use names of other variables referenced in the routine.
dimension	The number of occurrences in a dimension. A dimension can be specified either as a single number which is the number of entries in the array with references starting at 1 or as a start and finish pair of references speparated by a colon ':' where the number of entries is the difference between these values plus 1. The number of entries must be a positive integer. e.g. INTEGER*4 ARRAY monthtot (12) INTEGER*4 ARRAY yeartot (1990:2009)

Arrays may be declared and used for any of the basic data types. Following is the syntax for each data type:

INTEGER [* {1 | 2 | 4} ] ARRAY name_list (dimension [,...])
STRING  [* num_le_254  ] ARRAY name_list (dimension [,...])
REAL    [* {4 | 8 }    ] ARRAY name_list (dimension [,...])
DATE                     ARRAY name_list (dimension [,...]) ('date format')
TIME                     ARRAY name_list (dimension [,...]) ('time format')

Variables are implicitly defined in VisualPQL in two ways:

Declaration by Assignment

COMPUTE A = B

Numeric variables are declared as REAL*8. String variables are STRING*w where w is the current value of STRING LENGTH - default 20. Assigning dates and times creates numeric variables. Variables defined by assignment have no definitions other than the variable name, type and length.

The CRWARN option on the routine definition command issues a warning message during compilation whenever a variable is created by assignment.

GET VARS

Date variables are four byte integers. A date is held as the number of days since the start of the Gregorian calendar where October 15, 1582 is day 1. Dates can be represented as formatted strings and translated according to the date format.

When a date is assigned to another variable either the integer value or the equivalent formatted value is moved. If the assigned variable is numeric or undefined, the integer value is assigned. If the assigned variable is a string variable, the formatted string value is assigned.

The date format defines the default format. That is the format that is expected on input, is written on output and is assigned to string variables. The date format on date variable declarations deals only with the significant information on day, month and year. To output dates that contain other characters such as the day of the week, commas or slashes, either use the date functions or the formatting options on the WRITE command.

The date format may contain the letters M, D, Y and I (Upper or lower case is irrelevant.)

Caution When comparing dates and strings remember that the date is converted to a string using its default format then compared with the string. For example (assuming the datemap for birthday is DDIMMIYYYY): IF (BIRTHDAY lt '01 01 1980') SET AGEGROUP (2) This is a comparison of strings does not classify dates correctly as any date string that has days of the month greater than 1 (i.e.'02 mm yyyy') is greater than the string '01 01 1980'. If the datemap for birthday is YYYYIMMIDD then: IF (BIRTHDAY lt '1980/01/31') SET AGEGROUP (2) This compares strings like '1980 12 31' with '1980/01/31'. Again this gives rise to errors because the former is less than the later because the character ' '(blank) has a lower ascii value to the slash. It is recommended that all date comparisons and processing are done with the numeric values: IF (BIRTHDAY lt CDATE('1980/01/31','YYYYIMMIDD')) SET AGEGROUP (2)

D	A D is a day character. This is numeric on both input and output. If no day characters appear in the format, input dates default to the first day of the month. One or two D's are the day of the month. If the format has more than two D's, and no month characters, the day digits are the day of the year in Julian format (e.g. day 057 is February 26). If the format has more than two D's, and also has month characters, extra leading D's are treated as ignore characters for input and are represented by the digit 0 (zero) for output.
M	An M is a month character. On input, numbers are month numbers (1 to 12), letters are the initial letters of the month names (in English). If there is any ambiguity when letters are used, the month is the first month to which the character(s) apply. For example, 'JU' is interpreted as June, not July. If no month characters and three or more day characters are specified, the day digits are the day of the year in Julian format (e.g. day 057 is February 26). Otherwise, if no month characters are specified, input dates default to January. Invalid input results in missing values stored. On output, two month characters are written as month number and more than two month characters are written as the initial letters of the month name.
Y	A Y is a year character which is the year number. It is numeric on both input and output. If the format specifies more than four Y's, extra leading Y's are treated as ignore characters for input and are represented by the digit 0 (zero) for output. If fewer than four Y's are specified, the following applies to input : With three Y's, the millennium is 1nnn for values above 583 and 2nnn for values below this: With two Y's, if the year is greater than the year specified in the CENY parameter, the century is the century specified in the parameter otherwise the century is one greater. With a single Y, the decade is this decade.
I	An I is the ignore character. Characters in this position are ignored on input and written as blanks on output.
Other Characters	Any other characters that appear in the format specification are treated as the Ignore character.

For example, the following program declares and uses date variables. The program expects a string such as 'Jan 30, 1990' as input for BIRTHDAY and a string like '01-30-90' for VISDATE. The input strings '01 30, 1990' and 'JA/30/90' would also be valid. Note that on output, the default separator characters are spaces not slashes or dashes. Use the format options on the write to output other characters.

PROGRAM
DATE  BIRTHDAY ('MMMiDDiiYYYY') /
      VISITDAT ('MMiDDiYY')
COMPUTE BIRTHDAY = 'Feb 26, 1950'
COMPUTE VISITDAT = '07/13/90'
WRITE 'Born on '        BIRTHDAY  ('WWW  DD/MMM/YYYY')
      'and visited on ' VISITDAT ('DD/MM/YYYY')
END PROGRAM

The M, D and Y strings cannot be split. The following is not allowed:

DATE BIRTHDAY ('YiMMiY')

The INTEGER command declares the listed variables as integers. Optionally specify the size of the variables as 1, 2 or 4 byte integers. If a size is not specified, the variables are 4 byte integers.

• INTEGER*1 has values from -128 to 123

• INTEGER*2 has values from -32,768 to 32,763

• INTEGER*4 has values from -2,147,483,648 to 2,147,483,643

Example:

PROGRAM
INTEGER*1 SCORE1 TO SCORE5 SEX
INTEGER*2 MONTHSAL
INTEGER*4 YEARSAL
SET SCORE1 TO SCORE5 (0)
SET SEX (1)
SET MONTHSAL (2500)
COMPUTE YEARSAL = MONTHSAL * 12
WRITE MONTHSAL ('99,999') 2X YEARSAL ('999,999')
END PROGRAM

MISSING VALUES specifies up to three values for a variable which are treated as missing. Missing values are excluded from statistical procedures and functions. A missing value is, by definition, a valid value for the variable and need not be re-specified.

The missing values can be constants or the keyword BLANK. If BLANK is not a missing value for a numeric variable, then blanks are stored as 0 (zero).

Missing values can be specified for string variables. Missing values for string, date and time variables are specified as strings. If the specified missing value matches the leftmost input characters, missing values are recorded.

Missing values can be specified for an array. Specify the array name in the command, not specific array elements.

For example, the following declares several variables and defines missing values for them. If the date 01/01/01 is assigned to TESTDATE, the value is treated as missing. If either a blank or the letters ZZ are assigned to STATE, they are considered missing. For the numeric array and numeric variables, the value 9 is treated as missing. If blanks are input with a READ command, they are treated as missing.

DATE TESTDATE ('MMiDDiYY')
STRING*2  STATE
INTEGER*1  ARRAY QUESTION (25)
INTEGER*1 MATHTEST READTEST
MISSING VALUES  STATE (BLANK ,'ZZ') /
                QUESTION MATHTEST READTEST (BLANK , 9) /
                TESTDATE ('01/01/01')

The REAL command declares the listed variables as double precision, real, floating point numbers. REAL*4 (single precision) and REAL*8 (double precision) are also allowed.

When assigning a value to real variables, integers can be used without a decimal point.

SCALED declares the integer variables are scaled to power n. N is a positive or negative number representing the power of ten to which the variable is scaled.

If the variable has not been defined previously, this defines an INTEGER*4 variable. To create a different length integer, define the variable before declaring the scaling factor. The full, unscaled number, including any decimal point, is used wherever this number is referenced.

STRING declares the listed variables as string of maximum length number. The maximum length of a string variable is 4094. If a length is not specified, it defaults to the current setting of STRING LENGTH, which by default is twenty characters. If more characters than the declared string length are assigned to a variable, the string is truncated to the declared length.

Time variables are four byte integers, the value of which is the number of seconds between the time and the previous midnight. Times can be represented as formatted strings and translated according to the time format.

When a time is assigned to another variable either the integer value or the equivalent formatted value is moved. If the assigned variable is numeric or undefined, the integer value is assigned. If the assigned variable is a string variable, the formatted string value is assigned.

The time format defines the default format. That is the format that is expected on input, is written on output and is assigned to string variables. The time format on time variable declarations deals only with the significant information on hours, minutes and seconds. Input times are in 24 hour time notation. To output times that contain other characters such as "AM/PM", commas or slashes, use the time functions and the formatting options on the WRITE command.

Caution When comparing times and strings remember that the time is converted to a string using its default format then compared with the string. eg (assuming the timemap for START is HHIMM): IF (START gt '09:00') SET LATE (1) is a comparison of strings and the string '09 59' is less than the string '09:00' because the character ' '(blank) has a lower ascii value to the colon. In these cases it is best to convert the string to a number for the comparison: IF (START gt CTIME('09:00','HHIMM')) SET LATE (1)

The time format may contain the letters H, M, S and I, representing digits of Hours, Minutes and Seconds and Ignore (Upper or lower case is irrelevant.)

H	Each H in the time format represents one digit of the hour. On input, VisualPQL interprets numbers as hours in a 24 hour day. Numbers greater than 24 set the variable to undefined. If hour digits are not specified in the time format, input times default to the first hour of the day.
M	Each M in the time format specifies a minute digit. Numbers greater than 60 on input set the variable to undefined. If no minute characters appear in the time format, input times default to the first minute of the hour.
S	Each S in the time format represents a seconds digit. Numbers greater than 60 on input set the variable to undefined. If no second characters appear in the time format, input times default to the first second of the minute.
I	Each I in the time format specification indicate characters that are ignored on input or are converted to semi-colons on output.
Other Characters	Any other characters that appear in the format specification are treated as the Ignore character.

The following example declares two time variables:

TIME    CALLTIME   ('HHiMM') /
        EXACTIME   ('HHiMMiSS')

The following program declares and uses time variables:

PROGRAM
TIME STARTIME ENDTIME ('HHiMM')
COMPUTE STARTIME = SREAD('Enter Starting Time (HH:MM)')
COMPUTE ENDTIME  = SREAD('Enter Quitting Time (HH:MM)')
COMPUTE TTIME = ENDTIME - STARTIME
WRITE 'You worked ' TTIME(TIME 'HH')
      ' hours and ' TTIME(TIME 'MM') 'minutes.'
END PROGRAM

The H, M and S strings cannot be split. The following example is invalid:

TIME START ('MiHHiM')

Specifies the set of specific valid values a numeric variable can assume. If both VAR RANGES and VALID VALUES are defined for a variable, both specifications must be satisfied. Attempting to store a value in the variable that is not either a valid Missing Value or a Valid Value results in undefined. When a variable is updated during the running of a program, data validation takes place in the following order:

1. Missing Values
   
2. Valid Values
   
3. Variable Ranges

Examples:

INTEGER * 1 VAR1 TO VAR5 SCOREA SCOREB SCOREC
VALID VALUES VAR1 TO VAR5     ( 1 , 2 ) /
             SCOREA TO SCOREC ( 1, 2, 3, 88, 99 )

VALUE LABELS varlist (value1 ) 'label text'
                   [ (value2 ) 'label text_2' [...]]
                   [/...]

Specify value labels for multiple values of a single variable as one continuous command. If a number of variables have the same value labels, specify a list of variables, followed by the values and labels. If specifying value labels for an array, specify the array name not individual array elements. Specify value labels for several variables on the same command by separating the set of labels for one variable from the next set with the slash ( / ).

For example, to declare a string variable, an integer variable and a 25 element array and define value labels for each:

PROGRAM
STRING*3 STATE
INTEGER*1 REGION
INTEGER*1 ARRAY QUESTION (25)
VALUE LABELS QUESTION (1) 'Yes'
                      (2) 'No'  /
             REGION   (1) 'North'
                      (2) 'South'
                      (3) 'East'
                      (4) 'West' /
             STATE ('NSW') 'New South Wales'
                   ('QLD') 'Queensland'
                   ('VIC') 'Victoria'
SET STATE REGION ('NSW',1)
SET QUESTION *   ( 1)
COMPUTE STATEV  = VALLAB(STATE)
COMPUTE REGIONV = VALLAB(REGION)
COMPUTE QUESTV  = VALLAB(QUESTION(1))
WRITE STATEV REGIONV QUESTV
END PROGRAM

VAR LABELS specifies descriptive labels for variables. Variable labels may be up to 40 characters in length. Additional lines of text may be specified as documentation. Labels for multiple variables may be specified on a single command in which case the specification for each variable must be separated by a slash ( / ).

Variables may be defined to have specific values that are considered missing. A variable SEX might have valid value of 1 and 2 for Male and Female, and a value 3, for Unknown, which is considered missing.

There are functions and procedures to get and use the actual value of the variable. In general, operations that result from evaluating a missing or undefined value yield an undefined value (e.g. adding a number to an undefined value yields an undefined value). Functions that calculate statistics on a set of values have special rules for dealing with undefined values.

The numeric value 0 (zero) is a normal numeric value and is different from undefined. A zero length string (a string with no characters) is also a valid value that is different from an undefined string.

Logical tests evaluate to true or false. A missing value or undefined in a logical test always evaluates to false which should be taken into account when specifying logical tests.

COMPUTE REGION = 'Western ' + 'Canada'
COMPUTE TOTAL = 10 + 17
Expressions have two main elements; other expressions and operators. Operators are a symbol that specifies an operation between two expressions. Parentheses () may be used to specify the precedence (order) of operations.

Simple expressions are:

• Variables

• String and Numeric Constants

• Functions

Variables

• a number

• one decimal character (the period)

• a leading plus or minus sign (the + or - )

• a trailing letter E to indicate exponentiation followed by a number (which may be signed)

Following are valid examples of the SET command using several forms of expressing numeric constants.

String Operators

PROGRAM
STRING*40 ADDRESS
INTEGER ZIPCODE
COMPUTE CITY    = 'Chicago'
COMPUTE STATE   = 'Illinois'
COMPUTE ZIPCODE =  60614
COMPUTE ADDRESS =  CITY + ', ' + STATE + ' ' + FORMAT(ZIPCODE)
WRITE ADDRESS
END PROGRAM

In this example, ADDRESS is computed from three types of simple value expressions; string constants in quotes, variable names and the FORMAT function which converts a number to a string.

• + the plus sign performs addition

• - the minus sign performs subtraction

• * the asterisk performs multiplication

• / the slash performs division

• ** the double asterisk performs exponentiation, a number raised to a power. A number raised to a reciprocal power yields the root

Enclose signed constants that follow an arithmetic operator in parentheses. For example:

COMPUTE NUM1 = 10 + 20 + 33
COMPUTE NUM2 = 100 - NUM1
COMPUTE NUM2 = NUM1 * 5
COMPUTE NUM1 = 2 / 3
COMPUTE NUM1 = 4**3        | 4 cubed
COMPUTE NUM2 = NUM1**(1/3) | cube root
COMPUTE NUM = 13 * (-2)

In arithmetic expressions, operations of equal precedence are done from left to right. The precedence of operations is:

1. expressions within parentheses
2. functions
3. exponentiation
4. multiplication and division
5. addition and subtraction

An arithmetic operation that involves an undefined or missing value returns an undefined value. A number divided by zero yields an undefined value.

Examples:

COMPUTE NUM = 6 + 3 / 3      | NUM is 7
COMPUTE NUM = ( 6 + 3 ) / 3  | NUM is 3
COMPUTE NUM = 16**1 / 2      | NUM is 8, 16 divided by 2
COMPUTE NUM = 16**(1/2)      | NUM is 4, square root of 16
MISSING VALUES NUM (1)
COMPUTE NUM  = 1             | NUM  is missing
COMPUTE NUM2 = NUM + 3       | NUM2 is undefined
COMPUTE NUM3 = 1 / 0         | NUM3 is undefined

GET VARS local_var_list = db_var_list	The values of local variables are assigned the values of the database or table variables. The two lists must be of equal length and the value assignments are performed listwise.
GET VARS db_varlist	There is an assumed left hand side list of local variables with the same names as the database or table variable list.
GET VARS ALL	The keyword ALL specifies all record or table variables are assigned to local variables of the same name.

This is the only command which accesses table variables for input. If the name of the table variable is not a valid local variable name, the first form of the command must be used.

For example: the GET VARS command is used three times to retrieve database and table data and copy it into local variables. The first form of the command is used in the CASE and RECORD block. The second form of the command is used inside the ROW block since the row variable names are not valid VisualPQL names.

RETRIEVAL
PROCESS CASES ALL
. GET VARS ID
. PROCESS RECORD EMPLOYEE
.  GET VARS NAME
.  PROCESS ROWS OCCTAB INDEXED BY OCCINDEX VIA  (ID )
.   GET VARS  POS  START = CURRENT_POSITION  START_DATE
.   PERFORM PROCS
.  END PROCESS ROWS
. END PROCESS REC
END PROCESS CASE
REPORT   FILENAME = TEST.LIS /
         PRINT = ID NAME POS START
END RETRIEVAL

PUT VARS db_varlist = local_var_list	The values of the database or table variables are assigned the values currently held by the local variables on the right side of the equals sign. The lists of variables must be of equal length. The value assignments are performed list wise; the first right side value is assigned to the first left hand variable, the second right to the second left, and so forth.
PUT VARS db_varlist	There is an assumed right side list that is identical to the database or table variable list. The referenced database or table variables must have the same name as local variables. Note that the PUT VARS takes local variables as the source and sets database variables to be the same as the local variables. As these have the same name, there is an opportunity for confusion if the variable values were set inside the database block. e.g. PROCESS REC EMPLOYEE GET VARS SALARY COMPUTE SALARY = SALARY * 1.1 PUT VARS SALARY END PROCESS REC Because this is in a record processing block, the database variable SALARY would be updated by the compute, not the local variable with the same name. Then the PUT VARS would restore the original value of salary because that is the current value in the local variable. If database variables are updated inside a record block, the PUT VARS is unnecessary.
PUT VARS ALL	Any record or table variables with the same names as local variables are updated.

Values of keyfields in records may not be updated. Values of keyfields of the index being used on table rows may not be updated.

For example: The program retrieves data from the database and creates a new row on a table, if one does not already exist for that employee in that position. The two forms of PUT VARS are used, one to move a local variable to a row variable of the same name, the other to set a row variable of a different name. Note that the index variables are set by the reference on the ROW IS and are not referenced by a PUT VARS.

RETRIEVAL  TUPDATE
PROCESS CASES ALL
.  GET VARS ID
.  PROCESS RECORD EMPLOYEE
.    GET VARS NAME  CURRPOS SALARY CURRDATE
.    NEW ROW IS OCCTAB INDEXED BY OCCINDEX (ID , CURRPOS)
.       PUT VARS  START_DATE = CURRDATE
.       PUT VARS  SALARY
.    END ROW IS
.  END PROCESS REC
END PROCESS CASE
END RETRIEVAL

RECODE  [ update_var = ] recode_var
             [ (value_list =  recode_value) [...]]

The values in the value list and the recode value are either constants or one of the value keywords documented below. (Expressions and variable names are not allowed as values.)

recode variable	The variable or array element with the initial value to recode. If an update variable is not specified, this variable is updated with the recoded value.
update variable	The variable or array element to receive the recoded value if the original recode variable is not updated. The update variable must be a data type compatible with the recode value.
recode value	The single value to which the values in the value list are converted. This value must be of the same type as the update variable. The keyword UNDEFINED may be used to specify that values are recoded to undefined.
value list	A list of original values to recode. A value list is specified for each single recode value. Any value in the list is recoded into the single recode value. If the value of the variable is not found in a value list, the value is not recoded and is assigned unaltered to the update variable. Specify a separate parenthesised recode value list for each recode value. In the following examples: In the first, if RVAR is 1, 2 or 3, UVAR is recoded to 0. If RVAR has any other value, RVAR is copied to UVAR. In the second example, UVAR is 0 if RVAR is 1, 2 or 3 and 1 (one) if RVAR is 4, 5 or 6 : RECODE UVAR = RVAR(1,2,3 = 0) RECODE UVAR = RVAR(1,2,3 = 0)(4,5,6 = 1)

A number of keywords may be used in the value list.

THRU	Specifies an inclusive range of values. For example: RECODE UVAR = RVAR (1 THRU 3 = 0)(4 THRU 6 = 1) The value lists can overlap avoiding the possibility that a value (such as 3.5) falls between two value lists and is not recoded. The first match determines the recode used. Multiple ranges and multiple values can be specified in a value list. For example: RECODE UVAR = RVAR (1 THRU 3,7 THRU 99 = 0)(3 THRU 7 = 1)
LOWEST,LO	Specifies the lowest possible value. For example: RECODE UVAR = RVAR (LO THRU 3 = 0)(3 THRU 6 = 1)
HIGHEST,HI	Specifies the highest possible value. For example: RECODE UVAR = RVAR (LO THRU 3 = 0)(3 THRU HI = 1)
UNDEFINED	Specifies an undefined value. For example: RECODE UVAR = RVAR (UNDEFINED,LO THRU 3 = 0)(3 THRU 6 = 1) UNDEFINED may also be used as the recode value. For example: RECODE UVAR = RVAR (LO THRU 3 = 0)(3 THRU HI = UNDEFINED)
MISSING(0) MISSING(1) MISSING(2) MISSING(3)	Specifies missing values. MISSING(0) is a synonym for UNDEFINED. MISSING(1) refers to the first missing value, MISSING(2) to the second, and MISSING(3) to the third. For example: PROGRAM INTEGER*1 RVAR MISSING VALUES RVAR (7,8,9) SET RVAR (9) RECODE UVAR = RVAR (MISSING(1)=4) (MISSING(2)=5) (MISSING(3)=6) WRITE UVAR END PROGRAM
BLANK	Specifies that the blank missing value is recoded. For example: RECODE UVAR = RVAR (BLANK,7 THRU HI = 0)
ELSE	Specifies a recode for all values not included in any previously defined value list. If ELSE is specified, no other values may be specified in the value list. This must be the last recode specification of a set. For example: RECODE UVAR = RVAR (1,2,3 = 1)(4,5,6 = 2)(ELSE = 0)

Mixed Data Type Recodes

PROGRAM
INTEGER*1  NUMVAR
STRING*1   STRVAR
SET     STRVAR ('A')
RECODE  NUMVAR = STRVAR('A' = 1)('B' = 2)(ELSE = 0)
WRITE   STRVAR NUMVAR
END PROGRAM

If the recode variable in a mixed data type recode has a value not referenced in a recode value list, the update variable is set to undefined.

Assigns explicit values to variables and array elements during execution. Values in the value list are assigned in list order to the variables in the variable list. If the value list is shorter than the variable list, VisualPQL cycles through the value list until a value has been assigned to each variable. If the value list is longer than the variable list, the excess values are ignored.

Value Keywords for Undefined Values

Repeat Values

SET varlist ( repeat_value * value [ value_list])

In the following example, the first four variables are set to 2, the next three are set to 12 and the last three are set to 7,8 and 9 respectively.

SET VAR1 TO VAR10 (4*2,3*12,7,8,9)

Setting Array Elements

PROGRAM
INTEGER*1 ARRAY A (3,2)  | declare two dimensional array A
SET A * ( 0 )            | set all elements to 0
SET A * ( 1,2,3,4,5,6 )  | set each element to unique value
WRITE A(1,1)
END PROGRAM

The second SET statement in the above example is equivalent to:

SET A(1,1) A(2,1) A(3,1) A(1,2) A(2,2) A(3,2) ( 1,2,3,4,5,6 )

EXTERNAL VARIABLE BLOCK member[:V]
       [ NOSAVE ] [ REPLACE ] [PUBLIC ] [ VARMAP ]
...
variable definitions ...
...
END EXTERNAL VARIABLE BLOCK

Includes the variables as local variables in the routine. Do not declare variables from the included block in the routine that includes the block.

member

Names a member with the :V suffix, which is a previously compiled and stored set of variable declarations.

Use this command anywhere that variable declaration or definition commands are legal (except within another EXTERNAL VARIABLE BLOCK). External variables that are updated in one routine are accessible in other routines that have included the block. External variables provide an alternative mechanism to passing values on the EXECUTE SUBROUTINE command.

DEFINE PROCEDURE VARIABLES [ { INCLUDE | EXCLUDE } (varlist)]
       [ NOARRAYS    | ARRAYS   ]
       [ NOEXTERNALS | EXTERNALS [
       (external_block_list) ] ]
       [ NOSIMPLE    | SIMPLE  ]