Le 13 nov. 08 à 19:35, Randall Reetz a écrit :
Thank you Francois,
Can statistics be rigorously derived from proability math? I hope so.
yes, that is the clean way, which is, by the way, the best suited
for academic teaching.
Both are heavily dependent on what appears to be statistics
Dave Cragg wrote:
...
The two scripts measure the number of repeated sequences that are
generated by the two methods. The first method has yet to produce a
repeated sequence here.
...
METHOD 1 (no resetting)
Bingo. The psuedo-random algo used in Rev is pretty good as it is.
--
Richard
On 17 Nov 2008, at 16:04, Richard Gaskin wrote:
Dave Cragg wrote:
...
The two scripts measure the number of repeated sequences that are
generated by the two methods. The first method has yet to produce a
repeated sequence here.
...
METHOD 1 (no resetting)
Bingo. The psuedo-random algo
Dave Cragg wrote:
On 17 Nov 2008, at 16:04, Richard Gaskin wrote:
Dave Cragg wrote:
...
The two scripts measure the number of repeated sequences that are
generated by the two methods. The first method has yet to produce a
repeated sequence here.
...
METHOD 1 (no resetting)
Bingo. The
On 13 Nov 2008, at 19:38, Richard Gaskin wrote:
So unless I'm missing something obvious (and it certainly wouldn't
be the first time), beginning with a fresh seed as Rev does and then
resetting it each time during the session seems a fair way to avoid
discernible reproducible patterns for
Interesting demonstration ! If I'm not wrong, the probablity to get
twice the same sequence with the first method is about 6.25E-32 for
really random numbers (equiprobability for each number from 1 to
1000), what's a quite satisfying zero for dirty statisticians !
Jacques
Le 15 nov. 2008
: Random algorithm
On 13 Nov 2008, at 19:38, Richard Gaskin wrote:
So unless I'm missing something obvious (and it certainly wouldn't
be the first time), beginning with a fresh seed as Rev does and then
resetting it each time during the session seems a fair way to avoid
discernible
Dave Cragg wrote:
On 13 Nov 2008, at 19:38, Richard Gaskin wrote:
Fortunately, it doesn't. Rev sets the randomSeed to some non-fixed
number (a truncated portion of the milliseconds?) each time it starts.
This implies that each session starts with a unique seed, so each
sequence derived
Richard-
Thursday, November 13, 2008, 11:38:35 AM, you wrote:
True, and I've used this to my advantage in some modest encryption
algorithms to arrive at non-obvious but reproducible patterns.
In my world of software testing it is also quite advantageous to be
able to craft random data streams
not appear to be upper limited at 2130706432. Given the
game writers perspective to this, I really like the way the random
algorithm the way it is implemented in Revolution, as a seeded
algorithm can be used in many ways in games. It prevents the ability
to cheat with undo systems in casual games
PROTECTED]
To: How to use Revolution use-revolution@lists.runrev.com
Sent: 11/12/2008 5:26 PM
Subject: Re: Random algorithm
It would seem that resetting the randomSeed each time you use the
random function would only have a 1-in-4,570,422 chance of getting
the same seed as the previous run, no?
Yes
On 13 Nov 2008, at 07:36, Malte Brill wrote:
on each run of the following script:
on mouseUp pMouseBtnNo
repeat with i= 2130706432 to 2130706442
set the randomseed to i
put random(34) cr after fld 1
end repeat
end mouseUp
Malte
It looks like the limit is 2^31 --
/2008 6:18 PM
Subject: RE: Random algorithm
There is a huge difference between random and unique. If you are
after unique then just use the counting numbers. If you need both
random and unique you will have to check each number generated
against a saved list of every previous number
-
From: Randall Reetz [EMAIL PROTECTED]
To: How to use Revolution use-revolution@lists.runrev.com
Sent: 11/12/2008 6:18 PM
Subject: RE: Random algorithm
There is a huge difference between random and unique. If you are
after unique then just use the counting numbers. If you need both
random
: Eric Chatonet [EMAIL PROTECTED]
To: How to use Revolution use-revolution@lists.runrev.com
Sent: 11/13/2008 9:51 AM
Subject: Re: Random algorithm
Bonsoir François,
Great post indeed :-)
I fully agree.
Le 13 nov. 08 à 18:47, François Chaplais a écrit :
Le 13 nov. 08 à 03:39, Randall Reetz a écrit
, Malte summed it up well:
I really like the way the random algorithm the way it is
implemented in Revolution, as a seeded algorithm can be
used in many ways in games. It prevents the ability to
cheat with undo systems in casual games, or even lets you
set up whole galaxies without stuffing
It looks like the limit is 2^31 -- 2147483648
Thanks for testing that Dave!
Somewhat related :)
http://web.archive.org/web/20011027002011/http://dilbert.com/comics/dilbert/archive/images/dilbert2001182781025.gif
http://xkcd.com/221/
Cheers,
Malte
On 13 Nov 2008, at 19:50, Malte Brill wrote:
Somewhat related :)
http://web.archive.org/web/20011027002011/http://dilbert.com/comics/dilbert/archive/images/dilbert2001182781025.gif
http://xkcd.com/221/
Love them!!
Dave
___
use-revolution mailing
On 13 Nov 2008, at 19:38, Richard Gaskin wrote:
Fortunately, it doesn't. Rev sets the randomSeed to some non-fixed
number (a truncated portion of the milliseconds?) each time it starts.
This implies that each session starts with a unique seed, so each
sequence derived from it will be
that include millions of
possibilities and use that to randomize the final outcome. I would always set a
new random seed before starting.
My two cents,
another; Mark
Message: 8
Date: Tue, 11 Nov 2008 22:16:18 +0100
From: Jacques Hausser [EMAIL PROTECTED]
Subject: Random algorithm
Hi,
Does somebody
would always set a new random seed before starting.
My two cents,
another; Mark
Message: 8
Date: Tue, 11 Nov 2008 22:16:18 +0100
From: Jacques Hausser [EMAIL PROTECTED]
Subject: Random algorithm
Hi,
Does somebody know which algorithm is hidden behind the random
function ? Native random
Very interesting ! I didn't know that... my information is slightly
obsolete.
Many thanks
Jacques
Le 12 nov. 2008 à 03:34, Mark Smith a écrit :
Interestingly, on OS X and Linux, you can read from /dev/random
and get crypto-quality random numbers:
put /dev/random into tFile
+0100
From: Jacques Hausser [EMAIL PROTECTED]
Subject: Random algorithm
Hi,
Does somebody know which algorithm is hidden behind the random
function ? Native random number generators have usually a poor
reputation, and I need trustable random numbers. I have translated
the
Mersenne twister algorithm
Mark Smith wrote:
One day, all people will be called Mark, unlike now, when it's only
most people
The rest of us are named Jacque.
Jacques
Jacque
--
Jacqueline Landman Gay | [EMAIL PROTECTED]
HyperActive Software | http://www.hyperactivesw.com
Splitter :)
On 12 Nov 2008, at 19:09, J. Landman Gay wrote:
Mark Smith wrote:
One day, all people will be called Mark, unlike now, when it's
only most people
The rest of us are named Jacque.
Jacques
Jacque
--
Jacqueline Landman Gay | [EMAIL PROTECTED]
HyperActive
Mark Brownell wrote:
I'm surprised that the random seed was not mentioned.
Me too. Wouldn't it suffice to do this before each run?:
set the randomSeed to random(4570422)
--
Richard Gaskin
Managing Editor, revJournal
___
Rev tips,
One day, all people will be called Mark, unlike now, when it's only
most people
Best,
Mark
On 12 Nov 2008, at 18:04, Jacques Hausser wrote:
Many thanks for your two cents !
I wonder if the first name of people answering my first question is
really random : Mark, Mark and Mark...
Although this is fit for 99% of people's purposes, I would be careful
about expecting randomSeed or multiple samples to actually improve the
underlying random algorithm.
For sake of a silly example, suppose you had a bad random algorithm
which only returns even numbers. No matter how many
--- Richard Gaskin [EMAIL PROTECTED] wrote:
Mark Brownell wrote:
I'm surprised that the random seed was not
mentioned.
Me too. Wouldn't it suffice to do this before each
run?:
set the randomSeed to random(4570422)
--
Richard Gaskin
In theory, that could result in the
Jan Schenkel wrote:
--- Richard Gaskin ambassador at fourthworld.com wrote:
Mark Brownell wrote:
I'm surprised that the random seed was not
mentioned.
Me too. Wouldn't it suffice to do this before each
run?:
set the randomSeed to random(4570422)
In theory, that could result in the
It all depends on what you need.
This wouldn't do for high quality cryptography, for instance, since a
brute-force trial of possible seeds would eventually produce the same
sequence of numbers.
For many other purposes, the fact that rev sets a new randomseed
every time it starts up is
It depends of what you use to reset the randomSeed. Some papers
(reference burried to deep in my memory to be retrieved) suggest to
generate an array of random numbers at start, and then to reset the
seed each time it's needed with one of these elements, the index being
randomly choosen.
Gentle Rev users,
If you have ever watched any of the History Channels exposés regarding
this topic, the Las Vegas gerús have come to the conclusion that there
is no such thing as a random number generator, or they would be using
it to foil us. Read all you want, but it is a waste of time
Jacques Hausser wrote:
--- Richard Gaskin ambassador at fourthworld.com wrote:
Me too. Wouldn't it suffice to do this before each
run?:
set the randomSeed to random(4570422)
...
It would seem that resetting the randomSeed each time you use the
random function would only have a
Joe Lewis Wilkins wrote:
In my personal use, I have followed the users mouse clicks, used the
last one to plug into a pretty exotic personal equation that spits out
a seed number for use. Since the mouse clicks of a user are pretty
much uncharted, except for being limited pretty much to the
Thank you Richard. My middle name. (smile)
Joe Wilkins
On Nov 12, 2008, at 2:44 PM, Richard Gaskin wrote:
Joe Lewis Wilkins wrote:
In my personal use, I have followed the users mouse clicks, used
the last one to plug into a pretty exotic personal equation that
spits out a seed number
Le 12 nov. 2008 à 23:41, Richard Gaskin a écrit (excerpts):
for pure science, probably not. But for getting work done in Rev,
maybe.
One not-so-marginal problem is the criticism of pernickery* referees
when you (try to) publish your results. They DO want pure science, and
usually ask
On 12 Nov 2008, at 21:21, Jan Schenkel wrote:
If memory serves me well (and I admit mine is
comparable to that of a goldfish) then the engine
initializes the randomseed to the value of the
milliseconds at startup.
I thought the same. But while playing just now (as a result of this
thread
Jacques Hausser wrote:
The application I'm developping presently is a general-purpose analyse
program of ecological data mostly designed for students training (but
it should be useful for serious work too). I don't want a good RNG
for THIS application only, it's to be used as a library for
It would seem that resetting the randomSeed each time you use the
random function would only have a 1-in-4,570,422 chance of getting
the same seed as the previous run, no?
Yes, but the chances of having the same seed as any of teh previous
runs becomes progressively larger. Is it not a bit
Hi Richard,
In the future, why not ? But I would be ashamed to show my quick-and-
dirty scripts in their present state...
Jacques
Le 13 nov. 2008 à 01:41, Richard Gaskin a écrit :
Any chance we'll see a screen shot or two of the output and/or input
UIs?
Simulations are an interest of
I came into this discussion late, so apologies if this has been mentioned.
Have you considered utilizing http://www.random.org ?
They might have something available that would work for a solution.
- Noel
At 04:58 PM 11/12/2008, you wrote:
Le 12 nov. 2008 à 23:41, Richard Gaskin a écrit
-revolution@lists.runrev.com
Sent: 11/12/2008 5:26 PM
Subject: Re: Random algorithm
It would seem that resetting the randomSeed each time you use the
random function would only have a 1-in-4,570,422 chance of getting
the same seed as the previous run, no?
Yes, but the chances of having the same
isnt a
good diagnosis of severe case of the geeks.
-Original Message-
From: Randall Reetz [EMAIL PROTECTED]
To: How to use Revolution use-revolution@lists.runrev.com
Sent: 11/12/2008 6:18 PM
Subject: RE: Random algorithm
There is a huge difference between random and unique. If you
All,
rant
This has bugged me for a long time (back to the days of the Apple //,
at least). All programming languages should *document* their RNGs, so
we have some idea of what they are, and, especially, how bad they are
(and most are very bad). LGN RNGs are not necessarily bad (a
random(upperLimit - lowerLimit + 1) + lowerLimit - 1
Gads, I've given myself a headache. The Vegas stuff is interesting. The modern
RNGs are safe up to a half a million spins for their one armed bandits. After
that an attack can find repeats of the random sequences. Before they fixed it
they
--- Richard Gaskin [EMAIL PROTECTED] wrote:
set the randomSeed to random(4570422)
In theory, that could result in the same series of
random numbers multiple times, as the first random
may
start with the same randomseed as another, thus
resulting in the same random first number,
repeat with i= 2130706432 to 2130706442
set the randomseed to i
put random(34) cr after fld 1
end repeat
end mouseUp
So it does not appear to be upper limited at 2130706432. Given the
game writers perspective to this, I really like the way the random
algorithm the way
Hi,
Does somebody know which algorithm is hidden behind the random
function ? Native random number generators have usually a poor
reputation, and I need trustable random numbers. I have translated the
Mersenne twister algorithm which works OK, but slowly (47 milliseconds
for 1000 numbers
Hi Jacques,
You can find a library for random.org here: http://economy-x-talk.com/developers.html
.
I have never seen any specific documention on the algorithm behind
Rev's built-in random function. I suspect it is a standard C++ function.
--
Best regards,
Mark Schonewille
Jacques, as you probably know, there are many measures of randomness...
Taking the 'r' correlation as a measure of it, I've done this test:
generate two series of 1000 numbers between 1 and 1 each, using
the random() function. Take the correlation between the two series,
and append it
Many thanks, Mark,
That's far better than an algorithm, (true random numbers, not pseudo
ones ! ). I'll use it for serious research simulation programs, but
not in the standalone I'll distribute to the students. I do not want
random.org to be drowned under simultaneous queries from 70
Hi Jacques,
Depending on the kind of project you are working on, you could
download a few thousand (or more) random numbers from the site at once
and simulate the random series for your students.
--
Best regards,
Mark Schonewille
Economy-x-Talk Consulting and Software Engineering
Hi Mark (and Mark),
For small series, sure, it is random enough. But I'm afraid that the
period is actually rather short for what I suppose is a linear
congruential generator (for instance Excel algorithm was famous for
its period of 32000 numbers only), not speaking of the pattern due to
Jaques, I wonder if it would be practical to do what some of the
crypto-quality RNGs do, and use the microphone input of the users
computer as a source of random bits.
Hmm..
Best,
Mark
On 11 Nov 2008, at 22:57, Jacques Hausser wrote:
Hi Mark (and Mark),
For small series, sure, it is
Interestingly, on OS X and Linux, you can read from /dev/random and
get crypto-quality random numbers:
put /dev/random into tFile
open file tFile for binary read
read from file tFile for 1000 uint4
put it into tRandNums
close file tFile
will get you a comma
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