Random Numbers

[Pete]

...And Schrodinger's cat is always alive in some other universe.

Pete

[madscijr]

Hi,
A few years ago, I needed to obtain a long series of truly randomized numbers; I used the tools offered by https://random.org. If you are not familiar with it, I encourage you to rush to their site.

Interesting site - who knew? You did! Thanks!

[madscijr]

...And Schrodinger's cat is always alive in some other universe.

Pete

Schrodinger's cat solved our rodent problem but then it peed outside the litter box! 
It giveth and it taketh away!

[Magdha]

Some time ago I thought that I would amuse myself by writing a program to generate quasi-random numbers.  And the interest would be to see if the 'randomness' would be anything like RND.  The attach code is what I came up with.  I knew that code-produced 'random number' generation had something to do with very large number manipulations.  Steve McNeill has shown how the QB64 RND function works.  The details of my attempt are not worth exploring here, and the only point of interest is how 'random' my numbers were.  The image shows a distribution of the output and the superficial analysis suggests the numbers are reasonably random, and the function worked well when replacing RND in an actual program.  A minor ( ) down-side is that this function is over 1000 times slower than RND - but I was pleased!  (And I suppose that we have all attempted something similar at some idle moment).

   

Code: (Select All)

' Attempt to create a quasi-random number sequence using huge number multiplication mathematics 15/11/23

' When used instead of RND in an actual program

' this function works properly but is much, much slower - completely as expected.

' A success!

' Obviously BigNumberRND1 is quicker than BigNumberRND



CONST False = 0, True = NOT False '!!! Remove this if used in a program which has this already



PRINT BigNumberRND, BigNumberRND1 '!!! Remove this if used in a program

END '!!! Remove this if used in a program



FUNCTION BigNumberRND

    'Function generates huge numbers (18-19 figures), selects one digit

    'And strings six sequential numbers

    'And divides by 1e6 to get a number 0 - 0.999999

    STATIC Initi%%, HugeNo~&&, RanNo%%

    IF NOT Initi%% THEN

        Initi%% = True

        Timely& = INT(100 * TIMER)

        T$ = _TRIM$(STR$(Timely&))

        RanNo%% = VAL(MID$(T$, 2, 1)) '9

        'Get Primes

        Index%% = 2

        N%% = 1

        Starter~&& = 1

        WHILE N%% <= 9

            Index%% = Index%% + 1

            IsPrime%% = True

            K%% = 2

            WHILE IsPrime%% AND K%% < Index%%

                IF Index%% / K%% = Index%% \ K%% THEN IsPrime%% = False

                K%% = K%% + 1

            WEND

            IF IsPrime%% THEN

                Starter~&& = Starter~&& * Index%%

                IF N%% = 8 THEN HugeNo~&& = Starter~&& + Timely&

                IF N%% = 9 THEN HugeNo~&& = HugeNo~&& * Starter~&&

                N%% = N%% + 1

            END IF

        WEND

    END IF

    RanChr$ = ""

    FOR N%% = 1 TO 6

        BigString$ = _TRIM$(STR$(HugeNo~&&))

        RanString$ = MID$(BigString$, 5 + RanNo%%, 1)

        RanChr$ = RanChr$ + RanString$

        RanNo%% = VAL(RanString$)

        Biggy%% = False

        J%% = 1

        WHILE NOT Biggy%%

            IF VAL(MID$(BigString$, J%%, 1)) >= 2 THEN

                FirstString$ = MID$(BigString$, J%%, 9)

                Biggy%% = True

            END IF

            J%% = J%% + 1

        WEND

        Biggy%% = False

        J%% = LEN(BigString$) - 9

        WHILE NOT Biggy%%

            IF VAL(MID$(BigString$, J%%, 1)) >= 2 THEN

                SecondString$ = MID$(BigString$, J%%, 9)

                Biggy%% = True

            END IF

            J%% = J%% - 1

        WEND

        HugeNo~&& = VAL(FirstString$) * VAL(SecondString$)

    NEXT N%%

    BigNumberRND = VAL(RanChr$) / 1E6

END FUNCTION



FUNCTION BigNumberRND1

    'Function generates huge numbers (18-19 figures), selects six sequential digits

    'And divides by 1e6 to get a number 0 - 0.999999

    STATIC Initi%%, HugeNo~&&, RanNo%%

    IF NOT Initi%% THEN

        Initi%% = True

        Timely& = INT(100 * TIMER)

        T$ = _TRIM$(STR$(Timely&))

        RanNo%% = VAL(MID$(T$, 2, 1)) '9

        'Get Primes

        Index%% = 2

        N%% = 1

        Starter~&& = 1

        WHILE N%% <= 9

            Index%% = Index%% + 1

            IsPrime%% = True

            K%% = 2

            WHILE IsPrime%% AND K%% < Index%%

                IF Index%% / K%% = Index%% \ K%% THEN IsPrime%% = False

                K%% = K%% + 1

            WEND

            IF IsPrime%% THEN

                Starter~&& = Starter~&& * Index%%

                IF N%% = 8 THEN HugeNo~&& = Starter~&& + Timely&

                IF N%% = 9 THEN HugeNo~&& = HugeNo~&& * Starter~&&

                N%% = N%% + 1

            END IF

        WEND

    END IF

    BigString$ = _TRIM$(STR$(HugeNo~&&))

    RanString$ = MID$(BigString$, 5 + RanNo%%, 1)

    RNDTemp! = VAL(MID$(BigString$, 1 + RanNo%%, 6)) / 1E6

    RanNo%% = VAL(RanString$)

    Biggy%% = False

    J%% = 1

    WHILE NOT Biggy%%

        IF VAL(MID$(BigString$, J%%, 1)) >= 2 THEN

            FirstString$ = MID$(BigString$, J%%, 9)

            Biggy%% = True

        END IF

        J%% = J%% + 1

    WEND

    Biggy%% = False

    J%% = LEN(BigString$) - 9

    WHILE NOT Biggy%%

        IF VAL(MID$(BigString$, J%%, 1)) >= 2 THEN

            SecondString$ = MID$(BigString$, J%%, 9)

            Biggy%% = True

        END IF

        J%% = J%% - 1

    WEND

    HugeNo~&& = VAL(FirstString$) * VAL(SecondString$)

    BigNumberRND1 = RNDTemp!

END FUNCTION

[hsiangch_ong]

i'm learning common lisp.

where i discovered something.  the great experts at programming.  don't know how to make "platform independent."

so be glad basic has randomize timer.  that's all folks.

[dano]

Cloudflare uses lava 100 lamps to generate random numbers for use in cryptogrophy:

https://blog.cloudflare.com/randomness-1...roduction/

Pretty neat stuff.

[Pete]

It only works because nobody would ever want to steal anything from anybody who who owned a lava lamp, least of all 100 of them!

Pete

- The 70's called and they say they're doing fine without me!