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why stuffit, not .zip....?
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dividend
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Apr 9, 2003, 07:08 PM
 
One question to those of you who know things...

On the Mac,Stuffit is pretty much standard, on the PC, .zip is standard. .Zip works for Mac as well, on the PC .zip-programmes are free, Stuffit for "stuffing" costs, unstuffing is of course free.

Is there any reason for why Stuffit is better (or used on macs) than .zip? I have now idea, but practise apart, I can think of the following reasons:

Stuffit makes things smaller
It is easier to use
It is faster to use
It has more formats to stuff (but does it matter whether you also can use .tar &c?)

Could anyone please tell me the advantages with stuffit over zip?

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a holck
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Apr 9, 2003, 07:22 PM
 
Macs (especially OS9) has a fileformat called HFS(+), which is a forked file format.
That means the file can exist of several "layers", mostly used are Data and ressource forks.

.Sit support forks.
.Zip does not.

Compressing a forked file with .zip will loose some data.
     
dividend  (op)
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Apr 9, 2003, 07:30 PM
 
ok, part of the mac-user interface. to turn the question around - why does not PC-users use stuffit instead?
     
Adam Betts
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Apr 9, 2003, 08:27 PM
 
Disk Copy format is getting more popular and popular on MacOS X. The file format end with this extensions: .dmg and .img

Personally, I prefer Disk Copy format over Stuffit and Zip because of its easiness of use and integrated into OSX (Safari make the best uses of DiskCopy in Download Window). You could have your own window setting, window background image, etc while zip and Stuffit cannot.

I hope Apple will either buy Stuffit or ditch it completely. Right now Stuffit is one of the worst Carbon apps. Badly written, poor multithreading, etc
     
dividend  (op)
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Apr 9, 2003, 08:35 PM
 
does disk copy shrink files? I thought disk copy was for mounting files and so on, didn't know it could shrink files... or?
     
CharlesS
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Apr 9, 2003, 09:10 PM
 
Originally posted by dividend:
does disk copy shrink files? I thought disk copy was for mounting files and so on, didn't know it could shrink files... or?
Yes, .dmg is a full-fledged distribution medium. A damned good one too.

You can even mount .dmg's remotely over the Internet without downloading them, for example to get just one file out of an archive without downloading the entire archive. You can do this in the Terminal, using the hdid command. Type 'man hdid' for details.

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headbirth
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Apr 9, 2003, 09:18 PM
 
StuffIt as far as I know still has the greatest amount of compression as compared to other programs and platforms.
     
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Apr 9, 2003, 09:23 PM
 
Originally posted by Adam Betts:
Personally, I prefer Disk Copy format over Stuffit and Zip because of its easiness of use and integrated into OSX (Safari make the best uses of DiskCopy in Download Window).
Stuffit and expecially the new Stuf it X format offer far better compression than disk images. Disk images are also not easy to use. You first have to create a disk image, drag everything into it, then create a compressed disk image etc.
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Guy Incognito 2
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Apr 9, 2003, 09:34 PM
 
Originally posted by Developer:
Stuffit and expecially the new Stuf it X format offer far better compression than disk images. Disk images are also not easy to use. You first have to create a disk image, drag everything into it, then create a compressed disk image etc.
To the end-user disk images are the easiest to use. It's not very relevant whether or not disk images are easy for the one creating it. Besides, there are good tools out there for creating disk images.

Better compression is almost becoming irrelevant. It's always good to get the best compression, obviously, but, on average, the space saved from better compression algorithms are almost insignificant for average size files. The world is also moving to high speed internet making 'better' compression almost irrelevant also.

For average size files, for the average internet user, the .dmg compression is good enough.
     
Adam Betts
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Apr 10, 2003, 01:42 AM
 
Originally posted by Developer:
Stuffit and expecially the new Stuf it X format offer far better compression than disk images. Disk images are also not easy to use. You first have to create a disk image, drag everything into it, then create a compressed disk image etc.
You may be right that Sit and SitX offer far better compression but the quality of compression is really terrible. It can break/degrade easily if you move it around too much. With .dmg, the file rarely break or degrade (excluding all .dmg and .img made by Aladdin's Shrinkwrap). I prefer quality over size.

You could also browse the files inside the .dmg via url without downloading it first. This is very nice feature but unfortunately the feature isn't well-documented yet. Seem like Apple is still experimenting on this.

BTW, you could use FileStorm from Mindvision if you want the easiest way to make .dmg and .img file.
     
Adam Betts
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Apr 10, 2003, 01:46 AM
 
Originally posted by dividend:
ok, part of the mac-user interface. to turn the question around - why does not PC-users use stuffit instead?
Last time I remembered, Microsoft bundled WinZip in Windows. That gave WinZip a big advantage over Stuffit.
     
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Apr 10, 2003, 02:03 AM
 
Originally posted by Adam Betts:
Last time I remembered, Microsoft bundled WinZip in Windows. That gave WinZip a big advantage over Stuffit.
They have built in zip compression as of WindowsXP. I dont know if they licensed it from Winzip though.

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CharlesS
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Apr 10, 2003, 03:06 AM
 
Here's a summary of compression formats, and another reason why DMG is best:

ZIP: Doesn't support resource forks, type/creator codes, HFS metadata, UNIX file permissions. It hoses all of these things. Does support long filenames, but only when compressed at the command line, not with Aladdin tools. Zip is probably the worst compression method on Mac OS X.

Tar and GZip: Supports UNIX file permissions and long filenames (unless you use Aladdin tools to make it). Hoses resource forks, type/creator, and HFS metadata. Useful for distributing UNIX and Cocoa apps, but the tar.gz causes two garbage files to be created when decompressing instead of just one.

Stuffit: Supports resource forks, HFS metadata, and type/creator. Doesn't support filenames longer than 32 characters or UNIX permissions, and can really cause some trouble if an app expects its permissions to be a certain way (this actually did cause problems for me with an Ambrosia game that was distributed in .sit format). This is really not a great way to distribute software in OS X.

Stuffit X: Supposed to fix the problems that are in StuffIt. However, requires users to have the latest StuffIt Expander, which most don't have.

DMG: Guaranteed to preserve all metadata about a file that can be stored in the HFS+ file system, because a DMG is essentially a compressed HFS+ disk. Can be mounted over the network without even downloading the file, resulting in zero garbage files. Can be browsed through without downloading, and individual files can be extracted over the network without having to download the whole archive. Support is built into OS X. Can be mounted via the Terminal if the Disk Copy app gets hosed. Is Apple's recommended format for distributing software.

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Apr 10, 2003, 04:05 AM
 
Originally posted by CharlesS:


DMG: Guaranteed to preserve all metadata about a file that can be stored in the HFS+ file system, because a DMG is essentially a compressed HFS+ disk. <snip>
but can DMGs be mounted in Windows?? I didn't think they could...
     
CharlesS
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Apr 10, 2003, 04:28 AM
 
Originally posted by dice:
but can DMGs be mounted in Windows?? I didn't think they could...
Good point. I should clarify a bit I guess. DMG's are the best for distributing software to Mac OS X users. Tar.gz is the best format for sending to UNIX or Windows users. StuffIt is probably what you want to use to send files to OS 9 users.

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Apr 10, 2003, 11:10 AM
 
Here is the thing you can get people to download the Stuffit Standard version for windows then you can send them .sit and .sitx files. As well as .zip files. I have this installed on my machine. I think all PC's should have this installed also since Stuffit Standard is MUCH MUCH better than Winzip and all the other zip apps for windows.
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nobitacu
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Apr 10, 2003, 11:45 AM
 
Yea, I use stuffit on my Mac only, but when it comes to PC, I only use .zip. I dont' know why... but that's just the way I've been doing it... so hard to change. it works, so I'll stick to it that way...

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Apr 10, 2003, 12:01 PM
 
Originally posted by Guy Incognito 2:
To the end-user disk images are the easiest to use. It's not very relevant whether or not disk images are easy for the one creating it. Besides, there are good tools out there for creating disk images.

Better compression is almost becoming irrelevant.
I assumed this was an end user question (since it wasn't asked in the Developer forum). For end users disk images are complicated to use. There are too many steps involved to compress it.
I agree that disk images are a good format to distribute Mac OS X software, yet it is still confusing to many. Mounting a virtual volume, copy the app, unmount the volume, then trash the disk image, is a weird process if you think about it from a non-geek perspective. Internet enabled disk images make things a little bit better.
I also dare to disagree that size doesn't matter, if you consider a) how many users are still on dial-up and b) you have to pay for bandwidth. That's why many disk images are compressed additionally, which complicates things even further.
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Apr 10, 2003, 12:20 PM
 
For end users disk images are complicated to use. There are too many steps involved to compress it.
I'd say (as an end user) that .dmg files are the easiest to create and use. The conceptualization of a self-contained compressed and mountable disc is easier to understand. And of course it's free.

Plus it doesn't hose my long filenames like StuffIt does.
     
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Apr 10, 2003, 12:35 PM
 
Originally posted by Eug:
I'd say (as an end user) that .dmg files are the easiest to create and use. The conceptualization of a self-contained compressed and mountable disc is easier to understand. And of course it's free.

Plus it doesn't hose my long filenames like StuffIt does.
Let's compare the steps involved:

a) Usual disk compression tool:

1) Drag files into tool window -> bang! get archive

b) Disk Copy:

1) Get Info on to compressed files to calculate minimum size for new disk image
2) Create disk image just larger than size of to compressed files
3) Copy files into disk image
4) Convert disk image in DiskCopy to compressed format
5) trash original image

I don't see how even a geek with 3000+ posts in a Mac forum could say b) is "easiest".

StuffIt X doesn't hose long file names. But I wasn't here claiming that Stuffit is best or easiest. It has many flaws. All I was saying was that disk image are not easy to use for casual compression of files (for e-mail etc.)
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Apr 10, 2003, 01:17 PM
 
Originally posted by typoon:
Here is the thing you can get people to download the Stuffit Standard version for windows then you can send them .sit and .sitx files. As well as .zip files. I have this installed on my machine. I think all PC's should have this installed also since Stuffit Standard is MUCH MUCH better than Winzip and all the other zip apps for windows.
Windows users hate StuffIt, and don't want to install it. The reason is because the Windows version of StuffIt is very buggy and ill-behaved. It's really not very good...

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Apr 10, 2003, 01:30 PM
 
Originally posted by Developer:
Let's compare the steps involved:

A) Usual disk compression tool:

1) Drag files into tool window -> bang! get archive

B) Disk Copy:

1)Select the "create a disk image out of a folder" -> bang! get DMG

Now I see how DMGs are the "easiest".


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Apr 10, 2003, 01:38 PM
 
Originally posted by Developer:
Let's compare the steps involved:

a) Usual disk compression tool:

1) Drag files into tool window -> bang! get archive

b) Disk Copy:

<snip>

I don't see how even a geek with 3000+ posts in a Mac forum could say b) is "easiest".
Because he probably doesn't do it this way. You're right, this is much longer and more complicated. But why use Disk Copy when you could use Drop DMG or DMG Maker? The step for creating a dmg from a folder with Drop DMG is just the same as creating a sitx archive: drag the item to the tool window. - "bang!" get dmg.
     
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Apr 10, 2003, 01:41 PM
 
Originally posted by Dace:
Select the "create a disk image out of a folder" -> bang! get DMG
Thanks. Didn't know about that.
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Art Vandelay
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Apr 10, 2003, 01:57 PM
 
Originally posted by Developer:

b) Disk Copy:

1) Get Info on to compressed files to calculate minimum size for new disk image
2) Create disk image just larger than size of to compressed files
3) Copy files into disk image
4) Convert disk image in DiskCopy to compressed format
5) trash original image
There's a much simpler way of doing this.

1) Launch Disk Copy.
2) Drag files, folder, or volume onto Disk Copy's Info window.
3) Choose name and image type in Save Dialog.
4) Click Save.
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Apr 10, 2003, 02:42 PM
 
You can also just drag a folder or volume onto Disk Copy's icon.

Probably one reason StuffIt hasn't caught on on other platforms despite being available is that it's proprietary. Anyone can write a Zip or GZip compressor/decompressor, but Aladdin keeps the sit and sitx specifications under lock and key -- if you want to make software that understands these formats, you have to pay to license their software.
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Art Vandelay
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Apr 10, 2003, 02:47 PM
 
Originally posted by Art Vandelay:
There's a much simpler way of doing this.

1) Launch Disk Copy.
2) Drag files, folder, or volume onto Disk Copy's Info window.
3) Choose name and image type in Save Dialog.
4) Click Save.
Thanks to the tip by Rick, it is even simpler.

1) Drag files, folder, or volume onto Disk Copy's icon.
2) Choose name, location and image type in Save Dialog.
3) Click Save.
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Apr 10, 2003, 03:17 PM
 
Originally posted by CharlesS:
Windows users hate StuffIt, and don't want to install it. The reason is because the Windows version of StuffIt is very buggy and ill-behaved. It's really not very good...
Even the Newer versions?
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Apr 10, 2003, 03:25 PM
 
Originally posted by typoon:
Even the Newer versions?
Yep.
     
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Apr 10, 2003, 06:18 PM
 
Disk images are also not easy to use. You first have to create a disk image, drag everything into it, then create a compressed disk image etc. [/B]
They are DEAD easy to create. Just have Disk Copy open. DRAG the folder you want to Disk Copy in the dock or in its window. Voila. Instant DMG.
     
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Apr 10, 2003, 06:33 PM
 
Just add water.
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headbirth
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Apr 10, 2003, 10:16 PM
 
Does anyone know how compression works? It seems that if a file is simply a series of numbers, can't it be reduced to a simple short equation? If so, compressed files should be only a few K.
     
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Apr 10, 2003, 11:21 PM
 
Originally posted by headbirth:
Does anyone know how compression works?
Compression works on the principle that certain data in a given file will appear more often than other data in that same file. So you replace this common data with a code which takes up less space but means the same thing.

Lempel-Ziv, the compression algorithm used in .zip and in GIF files (and also the cause of the whole patent-encumbrance bit in GIF's), works this way. When it finds repeated sequences of bytes, it replaces them with references to the first time that the sequence occurred. These references generally take up a lot less space than the repeated stuff, so the file gets smaller. On the downside, nothing can understand the compressed format, so you have to decompress it before it gets useful again.

This is also why HTML and XML compress so well. Tags make for a whole lot of repeated sequences of text.
It seems that if a file is simply a series of numbers, can't it be reduced to a simple short equation? If so, compressed files should be only a few K.
What you say is theoretically true. However, the problem is, as always, finding the equation.

In computer science, there are several types of problems. The two bigggest sets are called polynomial and non-polynomial, or simply P and NP for short. The name refers to how long it takes to solve a problem, proportionally to the size of your input. For problems in P, the increase is basically linear or roughly linear; If your data is 16K, it will take eight or so times as long to process as if your data were 2K. For NP, though, it can increase exponentially, factorially, or even worse; your 16K data may now take sixteen times as long or even worse. It's easy to check if an equation would yield that number, but doing the reverse -finding an equation which yields the number- cannot be done in any practical amount of time by today's technology.

What you've described, namely, finding an equation to yield that number, is one of those NP problems. In fact, it's pretty close to the most famous NP problem of all, known as the halting problem, but I won't go into detail about that here, because that gets way more into computer-science theory that you probably wanted to go.

Now, here's the interesting thing. It's possible that NP problems don't really exist, that the only reason we haven't been able to get a computer to solve them is that someone hasn't hit on the right solution yet. However, it's similarly possible that these problems may be truly impossible for a computer to solve. No one has ever been able to prove one way or the other; it's one of the Great Mysteries of computer science. You may hear this problem referred to as "proving that P = NP". There's a million-dollar prize out there, waiting for someone to prove the answer to this question, one way or the other. As a final note, the "halting problem" that I mentioned happens to be a special kind of problem called NP-Complete: if anyone can ever solve it, then that act in and of itself would prove that P = NP.

But anyway, that's probably more detail than you wanted to go into.
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Apr 10, 2003, 11:26 PM
 
Does anyone know how compression works? It seems that if a file is simply a series of numbers, can't it be reduced to a simple short equation? If so, compressed files should be only a few K.
When I was younger, I was told that any sequence of numbers you cared to name could be found in the digits of Pi if you looked far enough. I thought it would be cool to compress things by describing the digit in Pi where they first occurred.
Then I studied probability and realized it would take more space to describe the location of some non-trivial string of numbers than simply stating the string of numbers.

Compression is a somewhat complex topic with roots in probability and information theory. Get a good textbook if you really want to learn about it.
     
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Apr 10, 2003, 11:42 PM
 
Originally posted by headbirth:
Does anyone know how compression works? It seems that if a file is simply a series of numbers, can't it be reduced to a simple short equation? If so, compressed files should be only a few K.
The previous two posters have done a good job of answering this question, but I think it's an interesting one so I'm gonna be a windbag and answer you, too.

Your question has to do with Information Theory, which attempts to find the minimum amount of "information" needed to contain an entire "signal". For example, if your signal is "2, 4, 6, 8, 10, 12, ..., infinity", you can abstract this by saying that the information is "positive integer solutions to x^2".

The problem is this: the less self-correlation that there is in a signal, the more information it takes to describe that signal. What this means is that if your signal is pure random noise, the most efficient compression is most likely to be the original signal.

A couple of other quick notes: the "every possible sequence of numbers can be found in the digits of pi" thing has had a mathematical proof.

Also, some classes of N! ("N Factorial") problems can approach P ("Polynomial") using quantum computation. This happens because you can do many operations in parallel.
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Apr 11, 2003, 12:11 AM
 
Gee, from discussing the difference between .zip and .sit to Information Theory.

Where will we be when the thread hits page two?
     
Eug
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Apr 11, 2003, 12:22 AM
 
Originally posted by Developer:
StuffIt X doesn't hose long file names.
Well, DropStuff 6 for X (or whatever it's called) hosed my 32+ char filenames. (I haven't tried version 7 though.)

And the other posters have already explained why .dmg files are so simple to use.
( Last edited by Eug; Apr 11, 2003 at 12:28 AM. )
     
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Apr 11, 2003, 12:29 AM
 
Originally posted by Eug:
Well, DropStuff 6 for X does. It still doesn't support names over 32 chars. (I haven't tried version 7.)

And the other posters have already explained why .dmg files are so simple to use.
He means .sitx when he's saying Stuffit X, not Stuffit for OS X. So, only 7.x using .sitx is good for long files.
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Apr 11, 2003, 03:34 AM
 
Originally posted by Art Vandelay:
He means .sitx when he's saying Stuffit X, not Stuffit for OS X. So, only 7.x using .sitx is good for long files.
And .sitx can only be decompressed if your users have the latest StuffIt Expander. And it's still a proprietary format. And it can't be compressed or decompressed with anything but Aladdin tools. And the Aladdin tools to compress .sitx cost money. And they can be buggy sometimes. And you can't browse .sitx archives remotely like you can .dmg's.

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Apr 11, 2003, 07:25 AM
 
Thanks for the info on compression theory guys.....very interesting stuff.

Does anyone know of a CM that will browse compressed DMG files?
     
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Apr 11, 2003, 08:04 AM
 
And .sitx can only be decompressed if your users have the latest StuffIt Expander.
that is why you make it self extracting. It only adds 9K to file size
     
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Apr 11, 2003, 09:25 AM
 
There is no superior compression format. It all comes down to the right tool for the job.

DMG's are great for software distribution. SIT... well it's there and it's commonly used. SITX is a vast improvement, too bad the line of Stuffit 7 apps aren't. ZIP is the de-facto compression standard on Windows; i'm not going to waste someone's time by telling them to download some Windows Alladin app, nor will I waste my time downloading it onto public computers for my own usage. It actually saves space when you think about it since you don't actually NEED metadata or resource forks when the file is going to end up on a PC anyway.

And just to add to Guy's comments: It certainly damn well matters how well it's compressed! Like stated above, many are still on dialup, and when I can save files with .sitx that are half the size of regular sit's or dmg's, that's damned well impressive and time-saving.

Oh, and those were rather interesting posts on the theory behind compression. And I have a hunch that quantum computing will take care of the P = NP problem.
     
nickm
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Apr 11, 2003, 11:41 AM
 
In fact, it's pretty close to the most famous NP problem of all, known as the halting problem
The Halting Problem is not in NP. The Halting Problem is the problem of saying whether a given program will halt on a given input. It is known to not be computable by any algorithm.

Now, here's the interesting thing. It's possible that NP problems don't really exist, that the only reason we haven't been able to get a computer to solve them is that someone hasn't hit on the right solution yet.
NP is a class of computable problems. They do exist. What is unknown is whether there are any NP problems that are not also P problems (pretty much everyone in CS thinks that that there are). One famous NP problem is the Travelling Salesman Problem - given a set of cities, find a route through the cities that hits each one exactly once and has the shortest length. In general, the fastest solution to this problem is on the same order as checking each possible path. However, there is good reason to believe that the [em]on average[/em] NP problems aren't that hard, and it is the relatively rare ones that make the worst case so bad. Again, see a CS textbook for more.
     
smeger
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Apr 11, 2003, 03:34 PM
 
Originally posted by nickm:
The Halting Problem is not in NP. The Halting Problem is the problem of saying whether a given program will halt on a given input. It is known to not be computable by any algorithm.
I haven't followed the research on this, but I suspect that the proof you're referring to states that it can't be solved by a Turing machine, which is equivalent to saying that it's not computable by any algorithm, but does not rule out the possibility that it may be computable by some other, currently unknown and non-algorithmic means. Do you know whether this is the case?

The Travelling Salesman problem is one that a quantum computer could conceivably compute in polynomial time. Essentially, the QC can find the time needed to take each individual path by doing only a single path compution. That single computation does all of the paths in one go, on one piece of computing hardware.

You could even do this on an analog computer if people actually used such things. To use a bad analogy to music theory, you assign each "travelling salesman path" it's own musical frequency, making sure that the frequencies you assign aren't harmonic multiples of one another. Add each of these frequencies together to produce a horrible cacophony of noise, run that noise through your path-adding algorith, and separate the answer back into its component frequencies to get the answer for each path.

This is, of course, a bad analogy and I'm ignoring lots of issues. But that's the basic gist of turning that sort of NP into P for this particular class of problem.
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nickm
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Apr 11, 2003, 11:30 PM
 
I suspect that the proof you're referring to states that it can't be solved by a Turing machine, which is equivalent to saying that it's not computable by any algorithm, but does not rule out the possibility that it may be computable by some other, currently unknown and non-algorithmic means.
This is correct. However, at this point the question leaves the realm of mathematics for philosophy; no one has yet come up with a model of computation that is stronger than a Turing machine. That is, a model for a computer that can compute things that cannot be computed by a Turing machine.

Keep in mind that computability vs. noncomputability is different from P vs. NP. The Traveling Salesman problem is computable --- but different models of computing may be able to solve it in different orders of complexity. I'm not really sure about quantum computation or analog computation, but I think the current thinking is that they can solve this more efficiently than a digital computer.
     
nickm
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Apr 11, 2003, 11:34 PM
 
To use a bad analogy to music theory, you assign each "travelling salesman path" it's own musical frequency...
I must admit that I didn't follow this at all. If you have to enumerate the possible paths, then you are already in NP land.
     
kmkkid
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Apr 12, 2003, 03:42 AM
 
rar is quickly becomming the best method of compression on windows. I like it, I like it alot.


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moki
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Apr 12, 2003, 03:43 AM
 
Originally posted by Guy Incognito 2:
Better compression is almost becoming irrelevant. It's always good to get the best compression, obviously, but, on average, the space saved from better compression algorithms are almost insignificant for average size files. The world is also moving to high speed internet making 'better' compression almost irrelevant also.
When you're paying thousands of dollars a month for an Internet connection that is metered by usage or has a bandwidth cap (such as we are), reducing the size of a file that thousands of people will download does indeed matter.
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Mohammed Al-Sabah
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Apr 12, 2003, 12:07 PM
 
got me stuffit works fine for OSX and the only thing i will use on a PC is .ZIP cuz most pc users out there use .zip and not worth changing the formart and telling them to go to a curtain program aladin does stuffit for windows also and i did try it out also.. but ill stick with .zip till windows users switch to somthing else orhmm u never know SWITCH TO MAC
     
allformac
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Apr 12, 2003, 04:24 PM
 
Originally posted by Groovy:
that is why you make it self extracting. It only adds 9K to file size
Really?

I didn't know that. How can you do this?

Does this work on all the compression formats you use or is this only for .sitx?
     
 
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