random function

Hi jerome,

the dITo 3gl toolbox provides (among others) this feature.

See www.uli-merkel.de/dito on SITEMAP look for:

"3TB 3GL Toolbox"

Success, Uli

An alternative to the solution offered by Uli is to program a so called "linear congruential generator" in Uniface proc. For example:

variables
   numeric Aa, Cee, Em, Xn, Pee
endvariables
Xn  = $clock[15:2] ;Random seed
Em  = $power(2,32)
Aa  = 22695477
Cee = 1

...
while (...)
   Xn = (Aa*Xn+Cee)%Em ;Linear Congruential Generator
   Pee  = Xn /(Em-1)     ;Uniformly distributed on [0,1]
   ...
endwhile

Hans de Vos, Grontmij

Hi Hans,

yes, implementing a complete random generator in uniface is an alternative.

Thanks for sharing your code with us.

Some functions have changed it's name in between, so
If one wants to code it in version 7:  use power instead of $power

Success, Uli

Hi Jérôme

Long time ago, I wrote this procedure on the algorithm by Park&Mille

Ingo

;
;ENTRY  GP_RANDOM
;
; Zufallszahlen von 0 bis unterhalb v_MAX  erzeuzgen
;
 params
   numeric v_MAX    :IN
   numeric v_VALUE    :OUT ; erzeugte Zufallszahl
 endparams
 variables
   numeric v_VALUE2
 endvariables
  call LP_RANDOM(v_VALUE2)
  v_VALUE=v_MAX*v_VALUE2
  v_VALUE=v_VALUE[trunc]
  IF (v_VALUE=v_MAX) v_VALUE=0; Falls $RANDOM$ genau auf 1 stehen sollte
  ;putmess "Zufall[%%v_MAX] = %%v_VALUE"
RETURN(0)

ENTRY LP_RANDOM
 ; Nach Park and Miller in ACM June 1988 v32 #6
 ; http://www.unix-ag.uni-kl.de/~conrad/krypto/misc/prng.html
 params
   numeric v_VALUE:OUT
 endparams
 IF($$X_RAND_SEED=""|$$X_RAND_SEED<1)
   call LP_RANDOM_INIT
 ENDIF
 call LP_RANDOM2(v_VALUE)
RETURN(0)
 
ENTRY LP_RANDOM2
  params
    numeric v_VALUE:OUT
  endparams
  variables
    numeric v_A
    numeric v_M
    numeric v_Q
    numeric v_R
    numeric v_HI
    numeric v_LO
    numeric v_TEST
  endvariables
  v_A=16807       ;a
  v_M=2147483647  ;m
  v_Q=127773      ;q v_M DIV v_A
  V_R=2836        ;r v_M MOD v_A

  IF ($$X_RAND_SEED<1) $$X_RAND_SEED=1
  $$X_RAND_SEED=$$X_RAND_SEED[trunc]
  v_HI= $$X_RAND_SEED/v_Q    ;hi
  v_LO= $$X_RAND_SEED%v_Q    ;lo
  v_TEST= v_A*v_LO-v_R*v_HI    ;test
  IF (v_TEST>0)
    $$X_RAND_SEED=v_TEST
  ELSE
    $$X_RAND_SEED=v_TEST+v_M
  ENDIF
   v_VALUE=$$X_RAND_SEED/v_M
RETURN(0);LP_RANDOM2


ENTRY LP_RANDOM_INIT
  variables
    numeric v_SEED
    numeric v_SEK
  endvariables
  v_SEED=$time ; Dummerweise nur auf Sekundenbasis
  v_SEED=v_SEED[fraction]
  v_SEED=v_SEED*1000000
  v_SEED=v_SEED[trunc]
  v_SEK=v_SEED%10
  v_SEED=v_SEED+v_SEK*100+v_SEK*10000
  $$X_RAND_SEED=v_SEED
  WHILE(v_SEK>0)
    v_SEK=v_SEK-1
    call LP_RANDOM2(0)
  ENDWHILE
RETURN(0)

Thanks to all, I have yet to implement the solution but I'll let you know ! Remains to convince the functional office ;-)

Thanks !

I would like to see this as well -- currently, I call an Oracle procedure to perform this function but would rather do a call native to Uniface.

Random ... so often needed and not available :)

Yes, i would like to see this too. Doing web demands some randomizing here and there (e.g. for download-codes, activation stuff and so on).

Nice features could be:

• Param for "numeric" or "alpha" with default alphanumeric
• length of string
• optional params : Chars has to be [UPPERCASE|LOWERCASE|WITHOUT CHAR XYZ]
• $proc in order to get the results directly (e.g. vRandom = $random('alpha',8,"UPPERCASE") )

Any other ideas!?

Cheers,

-GHAN-

The dIToBox provides a random functionality.

Please have a look at it.

Success, Uli