Re: %lookup

["Peter Vidal" <Peter_Vidal@xxxxxxxx>]

%LOOKUPxx (Look Up an Array Element)
%LOOKUP(arg : array {: startindex {: numelems}})
%LOOKUPLT(arg : array {: startindex {: numelems}})
%LOOKUPGE(arg : array {: startindex {: numelems}})
%LOOKUPGT(arg : array {: startindex {: numelems}})
%LOOKUPLE(arg : array {: startindex {: numelems}})

The following functions return the array index of the item in array that 
matches arg as follows: 

%LOOKUP 
An exact match. 

%LOOKUPLT 
The value that is closest to arg but less than arg. 

%LOOKUPLE 
An exact match, or the value that is closest to arg but less than arg. 

%LOOKUPGT 
The value that is closest to arg but greater than arg. 

%LOOKUPGE 
An exact match, or the value that is closest to arg but greater than arg. 
If no value matches the specified condition, zero is returned. 

The search starts at index startindex and continues for numelems elements. 
By default, the entire array is searched. 

The first two parameters can have any type but must have the same type. 
They do not need to have the same length or number of decimal positions. 
The third and fourth parameters must be non-float numeric values with zero 
decimal positions. 

For %LOOKUPLT, %LOOKUPLE, %LOOKUPGT, and %LOOKUPGE, the array must be 
defined with keyword ASCEND or DESCEND. The ALTSEQ table is used, unless 
arg or array is defined with ALTSEQ(*NONE). 

Built-in functions %FOUND and %EQUAL are not set following a %LOOKUP 
operation. 

Note:
Unlike the LOOKUP operation code, %LOOKUP applies only to arrays. To look 
up a value in a table, use the %TLOOKUP built-in function. 

Figure 197. %LOOKUPxx Example
 *..1....+....2....+....3....+....4....+....5....+....6....+....7...+....
 /FREE
   arr(1) = 'Cornwall';
   arr(2) = 'Kingston';
   arr(3) = 'London';
   arr(4) = 'Paris';
   arr(5) = 'Scarborough';
   arr(6) = 'York';
 
   n = %LOOKUP('Paris':arr);
   // n = 4
 
   n = %LOOKUP('Thunder Bay':arr);
   // n = 0 (not found)
 
   n = %LOOKUP('Kingston':arr:3);
   // n = 0 (not found after start index)
 
   n = %LOOKUPLE('Paris':arr);
   // n = 4
 
   n = %LOOKUPLE('Milton':arr);
   // n = 3
 
   n = %LOOKGT('Sudbury':arr);
   // n = 6
 
   n = %LOOKGT('Yorks':arr:2:4);
   // n = 0 (not found between elements 2 and 5)
 /END-FREE


Peter Vidal
PALL Aeropower Corporation
SR Programmer Analyst
5775 Rio Vista Drive
Clearwater, FL 33760-3137
(727)539-8448
www.pall.com

"My religion consists of a humble admiration of the illimitable superior 
spirit who reveals himself in the slight details we are able to perceive 
with our frail and feeble mind."
Albert Einstein