I'd be curious to know how the VESoft RANDOM function derives it's
Integer?
For entertainmnet purposes only. My EMPIRE machine sends VESoft
generated die rolls with MAILX.
Tracy Johnson
Office 1-757-766-4318
[log in to unmask]
> -----Original Message-----
> From: HP-3000 Systems Discussion
> [mailto:[log in to unmask]] On Behalf Of Michael
> Sent: Friday, September 17, 2010 1:37 AM
> To: [log in to unmask]
> Subject: Re: [HP3000-L] RANDOM NUMBER..
>
> Thanks Walter, I appreciate your opinion, you are one of the
> members on
> the "3000-l" that make this list a great resource for technical info.
>
> This conversation got me thinking, and reading the manuals, and doing
> some poking around on the web, and I found a random number service on
> the web. They don't use any standard computer algorithm, for their
> randomness they use atmospheric noise. Ironic actually, in signal
> processing or computing noise was always considered unwanted data
> without meaning, but now someone has brought meaning to it.
>
> RANDOM.ORG
>
> Cheers,
> Mike.
>
>
> Walter J. Murray wrote:
> > Michael and the group,
> >
> > Whether you use the Compiler Library procedure RAND or the COBOL
> > function RANDOM, you are faced with the question of how to seed the
> > pseudo-random number generator.
> >
> > The Compiler Library provides the procedure RAND1 as a
> convenience to
> > generate a reasonably unpredictable seed value, based on the system
> > timer. As you know, that timer has a resolution of one millisecond.
> >
> > COBOL does not provide anything equivalent to RAND1, so you
> have to be
> > creative. For my purposes, it is generally satisfactory to use the
> > CURRENT-DATE function to generate the seed. That gives you
> a resolution
> > of one second. Another method, which is nonstandard, would
> be to access
> > the MPE variable HPHHMMSSMMM, which has a resolution of 100
> > milliseconds. If you want something equivalent to RAND1,
> you could just
> > call the TIMER intrinsic, which has a resolution of one millisecond.
> > That's probably what RAND1 does, essentially.
> >
> > In my experience, the typical way to use a pseudo-random number
> > generator is to seed it once during program initialization,
> then use the
> > sequence determined by that seed value.
> >
> > Michael writes, "I'm going to guess that when you use
> > 'function random' with value 0, then the function (I would hope)
> > actually calls RAND1 to get a fresh seed to start a new generation."
> >
> > Sorry, that's not the way it works. Calling FUNCTION
> RANDOM with the
> > value 0, or calling it without passing an argument, always
> resets the
> > sequence of pseudo-random numbers to the same starting point. COBOL
> > II/iX does not access the system timer to seed the RANDOM function.
> >
> > Michael also writes, "This re-seeding is making the numbers more
> > random ...". Maybe, but "more random" is a slippery
> concept, and some
> > intuitive ideas about how to create a "better" sequence of
> pseudo-random
> > numbers turn out to be wrong.
> >
> > I'm no expert on random numbers. Everything I know comes from Knuth
> > (The Art of Computer Programming, Volume 2, Seminumerical
> Algorithms,
> > Second Edition, pages 1-177), whom I highly recommend.
> >
> > Walter
> >
> > Walter J. Murray
> >
> >
> > -----Original Message-----
> > From: HP-3000 Systems Discussion [mailto:[log in to unmask]] On
> > Behalf Of Michael
> > Sent: Thursday, September 16, 2010 9:38 AM
> > To: [log in to unmask]
> > Subject: Re: [HP3000-L] RANDOM NUMBER..
> >
> > Mr. Walter J. Murray,
> >
> > I've read many of your posts, and I've always considered
> you to be an
> > authority on HP3000 Cobol, and still do.
> > Shoot'in from the hip, I was not aware that you could pass
> the random
> > function a seed value, and I stand corrected! Thank you, really!
> > Thats probably why I preferred to use RAND1 and RAND.
> >
> > Now my ASCII is showing, I might as well run with it.
> > So, I'll need to look at the manual more often, because the
> generation
> > of random numbers is far too important to be left to chance.
> > ;-)
> >
> > As to the source of the random number I will still disagree
> with you,
> > and mostly because I use RAND1 and RAND, not the function..
> > When using RAND1, the value is derived from a quantity
> changed every
> > millisecond by the MPE system timer (Clock milliseconds).
> Additionally,
> > looking at my source example you'll see that each iteration
> of PLAY-LIST
> >
> > makes another call to RAND1. This re-seeding is making the
> numbers more
> > random, and the way it is written you will get the same results if
> > PLAY-LIST is performed twice within one millisecond, yes, now the
> > machines are faster, and I should change my ways.
> Furthermore, it is a
> > fact that calling RAND 100 times, starting with the same
> initial seed,
> > will generate the same list of 100 numbers, thats what I mean by
> > patterns, or a random set of related numbers, or a generation of
> > numbers. To start a new generation, I re-seed using RAND1.
> >
> > I agree that I have seriously misunderstood the Cobol
> function "random",
> >
> > and now actually looking in the manual, I find the Cobol
> function does
> > use RAND1 and RAND, not the other way around as you stated, when you
> > said:
> >
> > "The techniques Michael describes using RAND and RAND1, if I am
> > understanding him correctly, are quite possible using the standard
> > RANDOM function in COBOL."
> >
> > The Cobol manual states:
> > "For details on the RANDOM function, refer to the /Compiler Library
> > Reference Manual/."
> >
> > In the compiler library manual it refers to RAND1 & RAND
> procedures, and
> >
> > RAND1 does get it's value from the system timer.
> >
> > OK, shooting from the hip again, I'm going to guess that
> when you use
> > "function random" with value 0, then the function (I would hope)
> > actually calls RAND1 to get a fresh seed to start a new generation.
> >
> > Can I do this using the "function random"?
> > I know I can do it using RAND1 and RAND.
> >
> > Cheers,
> > Mike.
> >
> >
> > Walter J. Murray wrote:
> >
> >> Greetings,
> >>
> >> I'm afraid there are some inaccuracies in Michael's posting.
> >>
> >> First, the RANDOM function in COBOL II/iX does not use the "clock
> >> milliseconds" as the seed, or in any other way. You either specify
> >>
> > the
> >
> >> seed value yourself, or let it default. In COBOL II/iX,
> the default
> >> seed value is zero.
> >>
> >> The suggestion to use the return value from RANDOM to re-seed it is
> >> essentially what COBOL II/iX does for you automatically.
> >>
> >> The statement that you don't have control of the seed value is
> >> incorrect. You have the option of specifying an argument
> to RANDOM,
> >> which seeds it (or re-seeds it); or not specifying an
> argument, which
> >> causes it to return the next pseudo-random number in the sequence
> >> determined by the previous seed. If you never specify a seed, it's
> >>
> > the
> >
> >> same as specifying an initial seed value of zero.
> >>
> >> The techniques Michael describes using RAND and RAND1, if I am
> >> understanding him correctly, are quite possible using the standard
> >> RANDOM function in COBOL.
> >>
> >> The implication that you will get the same result if you
> call RANDOM
> >> twice within a millisecond is incorrect. As I said, the RANDOM
> >>
> > function
> >
> >> doesn't use any system timer value.
> >>
> >> If I want a reasonably unpredictable sequence of pseudo-random
> >>
> > numbers,
> >
> >> I will typically use a seed value derived from the return
> value from a
> >> call to FUNCTION CURRENT-DATE. This is what I do, for
> example, in a
> >> routine I wrote to generate a random strong password.
> >>
> >> Bottom line: Save yourself some trouble and use the
> RANDOM function
> >> provided by the COBOL language. It's standard, portable COBOL.
> >>
> >> Walter
> >>
> >> Walter J. Murray
> >>
> >>
> >> -----Original Message-----
> >> From: HP-3000 Systems Discussion [mailto:[log in to unmask]] On
> >> Behalf Of Michael Anderson
> >> Sent: Wednesday, September 15, 2010 4:53 PM
> >> To: [log in to unmask]
> >> Subject: Re: [HP3000-L] RANDOM NUMBER..
> >>
> >> Such library functions will repeat patterns using the clock
> >>
> > milliseconds
> >
> >> as the initial seed. This "ramdom" function may provide enough
> >> randomness
> >> for some, but not all.
> >>
> >> To achieve more randomness with the standard system clock algorithm
> >> you'll
> >> need to set the initial seed value first. Then use that
> seed value to
> >> generate your first random number, then push the first
> random number
> >> back
> >> into the seed, thus making the seed more random than just using the
> >> clock.
> >> Then generate another random number using the random seed.
> >> Correct me if I'm wrong. To the best of my knowledge, when
> using the
> >> single function, you do not have control of the seed
> value. So when a
> >> pattern begins to repeat you're just SOL.
> >>
> >> My point is: On MPE there are two intrinsic functions available to
> >>
> > give
> >
> >> you more control of your random number generator. They are
> RAND1 and
> >> RAND.
> >> You can use these two routines in various different ways
> to generate a
> >> random seed, which is then passed to RAND to generate the random
> >>
> > number.
> >
> >> Not only can you use the random number as a seed for the
> next random
> >> number, but to break any pattern you can use any three
> digits of the
> >> random number to pause for a random number of
> milliseconds, then get a
> >> new
> >> seed value from the system clock by calling RAND1, then continue in
> >>
> > the
> >
> >> loop. None of this is possible using the standard "random"
> function.
> >>
> >> Example:
> >> RAND1 returns the seed to be passed to the RAND intrinsic. RAND1 is
> >> based
> >> on the system timer (clock milliseconds). The random function works
> >>
> > the
> >
> >> same way, therefore you will in up with the same random
> number if call
> >> it
> >> twice within 1 millisecond. Worse, if you are generating
> many random
> >> numbers you will start to see a pattern.
> >>
> >> About 20 years ago I was asked to write a random employee
> list, using
> >> COBOL74 on 16 bit MPE V. I would initially call RAND1 to
> get the first
> >> seed. From that point on I used the result from RAND as
> the next seed,
> >> and
> >> so on.
> >>
> >> To test this routine and make sure it will work for a truly random
> >> subset
> >> of employees, I wrote a little program to gen lotto
> numbers, and here
> >>
> > it
> >
> >> is:
> >>
> >> ====================================
> >> IDENTIFICATION DIVISION.
> >> PROGRAM-ID. RANNUM.
> >> AUTHOR. MICHAEL ANDERSON.
> >> ****************************************************************
> >> * - RANNUM - is a program developed to test and display the *
> >> * unbiased selection of numbers, that the HP random *
> >> * number generator will produce. *
> >> * The original need for this was the random employee*
> >> * list. *
> >> ****************************************************************
> >>
> >> DATE-COMPILED.
> >> ENVIRONMENT DIVISION.
> >> CONFIGURATION SECTION.
> >> SOURCE-COMPUTER. HP3000.
> >> OBJECT-COMPUTER. HP3000.
> >> SPECIAL-NAMES.
> >> CONDITION-CODE IS CC.
> >> DATA DIVISION.
> >> WORKING-STORAGE SECTION.
> >> 01 RANDOM-SEED PIC S9(9) COMP VALUE 0.
> >> 01 RANDOM-RETURN PIC S9(9) COMP VALUE 0.
> >> 01 DISP-N PIC 9(9) VALUE ZERO.
> >> 01 FILLER REDEFINES DISP-N.
> >> 02 FILLER PIC 9.
> >> 02 FILLER PIC 99.
> >> 02 FILLER PIC 99.
> >> 02 FILLER PIC 99.
> >> 02 RANDOM-PICK PIC 99.
> >>
> >> 01 DISP-N18 PIC ZZZ,ZZZ,ZZZ,ZZZ,ZZZ,ZZ9.
> >> 01 TBL-IDX PIC S9(4) COMP VALUE 0.
> >> 01 IDX PIC S9(4) COMP VALUE 0.
> >> 01 X PIC S9(18) COMP VALUE 0.
> >> 01 DOLLARS PIC S9(18) COMP VALUE 0.
> >> 01 SIXFLAGS PIC S9(4) COMP VALUE 0.
> >> 01 PLAYS PIC 99 VALUE 0.
> >> 01 F PIC S9(4) COMP VALUE 0.
> >> 01 T PIC S9(4) COMP VALUE 0.
> >> 01 NUMF PIC 99 VALUE 0.
> >> 01 NUMT PIC 99 VALUE 0.
> >>
> >> 01 FROM-NUM-TABLE.
> >> 02 FROM-NUMBERS.
> >> 03 FROM-NUM OCCURS 6 TIMES PIC 99.
> >>
> >> 01 TO-NUM-TABLE.
> >> 02 TO-NUMBERS.
> >> 03 TO-NUM OCCURS 6 TIMES PIC 99.
> >>
> >> 01 NUMBER-TABLE.
> >> 02 RANDOM-NUMBERS.
> >> 03 RANDOM-NUMBER OCCURS 6 TIMES PIC 99.
> >>
> >> PROCEDURE DIVISION.
> >> 0000-RANNUM.
> >> DISPLAY "RANDOM NUMBERS.".
> >> DISPLAY "--------------------".
> >> MOVE ZERO TO PLAYS SIXFLAGS DOLLARS.
> >> PERFORM PLAY-LIST UNTIL DOLLARS > 10.
> >> GOBACK.
> >>
> >>
> >> PLAY-LIST.
> >> INITIALIZE RANDOM-NUMBERS.
> >> MOVE ZERO TO TBL-IDX.
> >> CALL INTRINSIC "RAND1" GIVING RANDOM-SEED.
> >> *
> >> * GET NUMBERS
> >> PERFORM VARYING X FROM 1 BY 1
> >> UNTIL TBL-IDX IS EQUAL TO 6
> >> IF DISP-N > 0
> >> MOVE DISP-N TO RANDOM-SEED
> >> END-IF
> >> CALL INTRINSIC "RAND" USING RANDOM-SEED
> >> GIVING RANDOM-RETURN
> >> MOVE RANDOM-RETURN TO DISP-N
> >>
> >> IF ( RANDOM-PICK > 0 AND < 55 ) AND
> >> ( RANDOM-PICK <> RANDOM-NUMBER(1) AND RANDOM-NUMBER(2)
> >> AND RANDOM-NUMBER(3) AND RANDOM-NUMBER(4)
> >> AND RANDOM-NUMBER(5) AND RANDOM-NUMBER(6) )
> >> ADD 1 TO TBL-IDX
> >> MOVE RANDOM-PICK TO RANDOM-NUMBER(TBL-IDX)
> >> END-IF
> >> END-PERFORM.
> >> *
> >> * SORT NUMBERS
> >> IF RANDOM-NUMBERS <> TO-NUMBERS
> >> ADD 1 TO DOLLARS
> >> MOVE RANDOM-NUMBERS TO FROM-NUMBERS
> >> INITIALIZE NUMF NUMT TO-NUMBERS X T F
> >> PERFORM VARYING X FROM 1 BY 1 UNTIL X > 54
> >> PERFORM VARYING F FROM 1 BY 1 UNTIL F > 6
> >> MOVE FROM-NUM(F) TO NUMF
> >> IF NUMF = X
> >> ADD 1 TO T
> >> MOVE FROM-NUM(F) TO TO-NUM(T)
> >> END-IF
> >> END-PERFORM
> >> END-PERFORM
> >> *
> >> * DISPLAY NUMBERS
> >> MOVE TO-NUMBERS TO RANDOM-NUMBERS
> >> DISPLAY RANDOM-NUMBER(1)
> >> ", " RANDOM-NUMBER(2)
> >> ", " RANDOM-NUMBER(3)
> >> ", " RANDOM-NUMBER(4)
> >> ", " RANDOM-NUMBER(5)
> >> ", " RANDOM-NUMBER(6).
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>> The manual shows the format to be:
> >>>
> >>> 77 my-random pic v99999.
> >>>
> >>> Compute my-random = function random (30).
> >>>
> >>> My problem.. I keep getting a compile error on the word
> 'function'.
> >>>
> >>> 00604 011010 32 356 Q UNDEFINED DATA NAME FUNCTION.
> >>>
> >>> I'm on the latest and greatest and LAST version of the operating
> >>>
> >>>
> >> system.
> >>
> >>
> >>> C.75.00.
> >>>
> >>> I've tried taking the word 'function' out, along with
> various other
> >>> things.
> >>>
> >>> From page 10-49/50 of the manual.
> >>>
> >>> Mr Kim Borgman
> >>> IT mgr, RNDC of Indiana.
> >>>
> >>> * To join/leave the list, search archives, change list settings, *
> >>> * etc., please visit http://raven.utc.edu/archives/hp3000-l.html *
> >>>
> >>>
> >>>
> >> * To join/leave the list, search archives, change list settings, *
> >> * etc., please visit http://raven.utc.edu/archives/hp3000-l.html *
> >>
> >> * To join/leave the list, search archives, change list settings, *
> >> * etc., please visit http://raven.utc.edu/archives/hp3000-l.html *
> >>
> >>
> >>
> >
> > * To join/leave the list, search archives, change list settings, *
> > * etc., please visit http://raven.utc.edu/archives/hp3000-l.html *
> >
> > * To join/leave the list, search archives, change list settings, *
> > * etc., please visit http://raven.utc.edu/archives/hp3000-l.html *
> >
> >
>
> * To join/leave the list, search archives, change list settings, *
> * etc., please visit http://raven.utc.edu/archives/hp3000-l.html *
>
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