Try searching on "subtractive cancellation" on google for information on
strategies to avoid this kind of thing. One is to treat (a-b) as
(a^2 - b^2)/(a+b), which can reduce the relative error in some cases.
Unfortunately the exact strategy often depends on the numbers used and the
hardware it run
> El 7/31/08 5:31 PM, "Timothy J Miller" <[EMAIL PROTECTED]> escribió:
>
>>
>> On Jul 31, 2008, at 2:54 PM, Edgar J. De Cleene wrote:
>>> But (2 raisedTo: 128) atRandom could genetate
>>> 49572205802560219958060582892667404289
>>>
>>> and
>>> 49572205802560219958060582892667404289 hex also is wron
The issue is almost certainly in atRandom:
Running
30 timesRepeat: [ | a |
a:= (2 raisedTo: 57) atRandom.
Transcript show: a ; show: ' ' ; show: a even ; cr ].
Gives me 30 falses.
The odds of that are less than one in a billion (assuming uniformly
distributed integers).
This doesn't
> Hi there,
>
> I'm trying to read from a named pipe. I'm on Linux (Ubuntu 8.04).
>
>- I created the pipe using mkfifo
>- I can write to it, and when I cat the pipe within another terminal I
>see the output.
>- I've tried using various combinations of FileStream,
>OSProcess-Ext
> Quoting [EMAIL PROTECTED]:
>
>> Hi Stan!
>
> Hi John, not confusing- an excellent response, thanks.
>
> With the memory option it also cruises on under Linux, until it freezes at
> 70
> million objects.
>
> While it's still loading vmstat shows:
>
> procs ---memory-- ---swap-- --
Hi Stan!
Have you tried using the -mmap option when starting Squeak? I notice that
according to the squeakvm man page:
squeak uses a dynamic heap by default with the maximum size set to
75% of the available virtual memory or 1 gigabyte, whichever is smaller.
Perhaps Windows doesn't have
Hi Sven,
Yes, I'm in Oz, on the Gold Coast. I'm not an expert on Squeak by any
means, but I'm using it in maths education, and thinking seriously about
using it for a PhD in Maths Education in a couple of years. I know of one
other guy (a PHP wizard) who was pretty wowed by Seaside and Squeak, I
>> I don't know what you are working on but if you use fractions for what
>> you are
>> doing it would be interesting to hear about how you use them and your
>> results.
>> Because fractions are kept as an integer numerator and an integer
>> denominator,
>> they probably take up more memory than fl
Hi Goran!
I just want to point out that the long links in your mail were broken for
me (although a little cut and paste fixed that). Perhaps a service like
tinyURL would be useful when sending long links from the dark and distant
past.
I have noticed in this thread an undertone of "#become is the
I studied and taught at Griffith University in Australia. At the time the
computing dept was a weird combination of Business Programmers and
Numerical Modelers. I wouldn't be surprised if this kind of fundamental
instruction has disappeared these days, given the tendency to expose
students to Jav
Cedric,
As a follow up, when doing high precision arithmetic (in engineering,
numerical integration, weather prediction and the like) you usually have a
setup routine that does things like:
BEGIN
let a = 0.5
let b = a /2.0
while ( (a+b) <> a ) do
epsilon = b
b = b/2
endwhile
then epsilon i
Cedric,
Part of the issue is that different architectures will have different
values for machine epsilon (1e-09 in your post). Machine epsilon is
defined to be the largest float such that
0.0 + epsilon = 0.0
Its value varies according to your machine though - typically a machine
with a much lar
Hi Blake!
I've yet to find a situation where I can't put the code that would be in a
constructor in C++ into #initialize. I suppose there are situations where
that would be a bad idea, but I just haven't met them, or else I'm doing
bad things (very likely).
Every time I get that kind of a warnin
Hi,
I think it's probably a vendor bug. I notice that Gemstone is getting a
SIGILL, this is usually either a bad opcode (data corruption) or an
attempt to do stupid tricks like overwrite the return address in the stack
(this is in breach of POSIX).
Possibly you might have a subtle issue with li
> On Dec 6, 2007, at 14:24 , [EMAIL PROTECTED] wrote:
>
>>> On Dec 1, 2007, at 20:34 , Pete wrote:
>>>
It's also not clear to me why this array is
size of 120, when we have an rectangular region of
40x40, and what is the difference of depth 1,2,4 ...
>>>
>>>
>>> Depth is the number o
>
> On Dec 1, 2007, at 20:34 , Pete wrote:
>
>> Hi, I'm new to Smalltalk, coming from C++ and Java.
>>
>> I find Squeak very interesting, especially the
>> features for rapid prototyping.
>>
>> I tried learning on the job, started with the
>> Games-Chess class category, as I'm was formerly
>> exper
ALSA is the sound drivers and associated support files. You won't get
sound to work without them. Have patience, sometimes getting sound
working in Linux is an exercise in being persistent and methodical.
John
> Offray,
>
>
> Thanks for your help. I tried the instructions on your website but
Gday Edgar,
What distribution (i.e. Redhat, Suse, Debian, Ubuntu etc) and version
(hamm, buzz, Hoary Hedghog, 7 etc) are you running? That information will
probably allow us to help you.
Yrs
John
> People:
>
> Still this old donkey could't figure how to have Squeak as server on
> Linux.
> I tr
Hi Ching!
I've been saving the form to a graphic file and then printing that. That
way I can use Paint Shop Pro to add all sorts of eye candy before
printing. This is in the context of maths problems for remedial teaching
- I have a set of classes that create a form and populate it with maths
pr
> The new XML based format may be easier to parse / write using YAXO
As someone who has done this stuff (though not from Squeak), Good Luck
with OOXML. It's very fragile, and appears to break for no apparent
reason. I suggest you either use a library (as others have suggested) or
use Oo.org as a
> Hi Michael,.
>>
>> Are you installing the package that
>> comes with your Linux distribution?
> Are there already such distributions? I wonder why SuSE does not have
> integrated Squeak yet.
>
Debian doesn't include Squeak in main because Squeak-L is not DFSG
compliant. According to a note a
> Hey, guys:
>
> (And who came up with that whole "improper" terminology? Some guys with
> small numerators, I'd bet)
>
> ===Blake===
I spent many years teaching remedial maths. The whole
proper/improper/mixed number concept messes with many kids learning
arithmetic with fractions
Thanks Dave.
I'd looked at #close, but already had the system in a pretty weird state
so it didn't seem to help.
#ensure: is the kind of thing I really needed - but never found.
Two more questions arise:
1) How do I get a password to edit the wiki? The page 'Recipe: Reading a
file' could use
Just as I was thinking I was getting a handle on this I'm terribly
confused...
a _ FileStream fileNamed: 'readme.txt'.
gives me a stream an the file.
b _ FileStream fileNamed: 'readme.txt'.
gives me nil
a _ nil.
a _ FileStream fileNamed: 'readme.txt'.
a is still nil
It seems that the only w
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