Random Selection

[Billw]

Hi All,

Need some ideas here. I am creating a customer selection routine as follows:

1) top 20 customer
2) all new customers
3) randomly select 10 customers not fitting 1) & 2)

need advice on 3). There may not always be 10 left to select.

Not sure on how to select the randoms and still be random. Keep in mind I don't wanr to use up the randoms too soon in the process. Then that wouldn't be very random.

a) some customer information compared to millisecond (portion of zip code)
b) the millisecond looked up on a alpha table if the customer's name begins
c) customer's contact bust size ......who knows

open to programmical random selections (can random really be programmed?)

Thnx
Bill

[itp]

Re: Random Selection

How is this?

X = total number of customers/10   

Do 10 times
  Y =   [random(X) records *2 ]   
  Do Y Times
     Read CustFile
  EndDo
  If customer is not already selected
     Write to selection Workfile
  EndIf
EndDo

This should give a somewhat random selection of customers assuming your file sort order is not on something important like credit rating or RMA frequency.


Use CEERAN0 to generate random intervals

http://www.as400pro.com/servlet/sql.tipView?key=193&category=RPG

[jamief]

Re: Random Selection

--or-- here

http://www.code400.com/forum/showthread.php?t=478&highlight=random

SQL

    ˆH Debug NoMain

      // *----------------------------------------------------------------*
      // *‚                   Precision Sytems, Inc.                    € *
      // *----------------------------------------------------------------*
      // *                                                                *
      // *  System name. . :‚ *Any                                      € *
      // *  Module/Program :‚ GETRANDNUM                                € *
      // *  Text . . . . . :‚ Generate a "Random" Number                € *
      // *  Author . . . . :‚ Randy Weber                               € *
      // *                  ‚ PrecisionSystems@comcast.net              € *
      // *                                                                *
      // *  Remarks  . . . :  This module uses SQL to retrieve a          *
      // *                    random number using the Microseconds        *
      // *                    portion of the current timestamp to         *
      // *                    seed the SQL RAND routine.                  *
      // *                                                                *
      // *                  €„Parameters:€                                *
      // *                    1. Random - Packed 9,8                      *
      // *                                                                *
      // *                  €„Sample Create Command€                      *
      // *                                                                *
      // *                    CRTSQLRPGI                                  *
      // *                        OBJ(MyLib/GETRANDNUM)                   *
      // *                         SRCFILE(MyLib/QRPGLESRC)               *
      // *                         SRCMBR(GETRANDNUM)                     *
      // *                         COMMIT(*NONE)                          *
      // *                         OBJTYPE(*MODULE)                       *
      // *                         REPLACE(*YES)                          *
      // *                         DBGVIEW(*SOURCE)                       *
      // *                                                                *
      // *                  €„Sample GETRANDNUM Usage€                    *
      // *                                                                *
      // *                     // ‚Random number interface€               *
      // *                    D GetRandNum      PR             9P 8       *
      // *                                                                *
      // *                    D Random          S              9P 8       *
      // *                                                                *
      // *                     // ‚Free-form calc specs€                  *
      // *                             Random = GetRandNum() ;            *
      // *                                                                *
      // *                                                                *
      // *----------------------------------------------------------------*

      //‚Module interface
     D GetRandNum      PR             9P 8


    ˆ /Title  Use SQL to Get a Random NumberŠ...€
      // ‚***********************************************************
     P GetRandNum      B                   Export
      // ‚***********************************************************

     D GetRandNum      PI             9P 8

      // ‚Stand Alone Fields
     D Random          S              9P 8

     C                   Eval      Random = *Zeros

       // ‚Run the SQL statement
     C/EXEC SQL
     C+
     C+   SELECT Dec(
     C+              Rand(
     C+                   Int(
     C+                       Substr(
     C+                              Char(Current_TimeStamp),21,6
     C+                             )
     C+                       )
     C+                  ),9,8
     C+             ) Into :Random
     C+     FROM QsqpTabl With NC
     C+
     C/END-EXEC

     C                   Eval      Random = %Abs(Random)
     C                   Return    Random

     P GetRandNum      E


   ˆˆ /Title  Generate a "Random" NumberŠ...€ 

UUID

*

     H Option( *NoSrcStmt )  BNDDIR('QC2LE')
     **
     D UUID_template   Ds
     D  UtBytPrv                     10u 0 Inz( %Size( UUID_template ))
     D  UtBytAvl                     10u 0
     D                                8a   Inz( *Allx'00' )
     D  UUID                         16a
     D  Reply                         1a
     **
     D GenUuid         PR                  ExtProc('_GENUUID')
     D  UUID_template                  *   Value
     **
     D ToHex           PR                  EXTPROC('cvthc')
     D  szHexVal                  65534A   OPTIONS(*VARSIZE)
     D  szCharVal                 32767A   Const OPTIONS(*VARSIZE)
     D  nSrcLen                      10I 0 VALUE
     **
     D pMemberName     s             10
     D  OutField       s          65534
     D  shorter        s             16
     c                   do        5
     C                   Callp     GenUuid( %Addr( UUID_template ))
     C                   Callp     ToHex(OutField : UUID :16)
     c                   eval      shorter = %subst(outfield:1:16)
     c     shorter       dsply                   Reply
     c                   enddo
     **
     C                   Eval      *INLR = *on