Wikipedia:Reference desk/Archives/Computing/2010 May 17

= May 17 =

Three dimensional spreadsheets - do they exist? why aren't they more prevalent?
I was compiling some research data over the weekend that had a clear column-row relationship, but the project requirements then added monthly records to the requirements and it occurred to me that the simplest way to represent that would have been to push the 2D spreadsheet (x & y axes) into three dimensions (x, y, and adding z for time).

Such visual modeling is certainly within the capabilities of all but the most rudimentary hardware to be found in the home or workplace today - and seems to me upon initial examination to be a tremendously useful way of structuring data.

So - does a "3D excel" exist? Who uses it? Why doesn't everyone? 218.25.32.210 (talk) 00:56, 17 May 2010 (UTC)
 * Too complicated to use? If you want to add months, just add a new sheet for every month. In fact a quick search shows people have called spreadsheet programs 3D for that reason, e.g. 3D-Calc Nil Einne (talk) 01:32, 17 May 2010 (UTC)


 * Just add extra worksheets in Excel (each spreadsheet can have multiple worksheets within it, as separate tabs of data), call them your Z third dimension if you want... --Mr.98 (talk) 02:12, 17 May 2010 (UTC)


 * MS Excel does in fact have a handful of "3D" functions, where you can (for example) sum the values in one RnCn cell across multiple sheets; I am unfortunately not on the computer where I can cut-n-paste a working example. In Office 2003, which my office is still on, the available functions are "fairly rudimentary" -- maybe it's something that's been improved in newer versions. DaHorsesMouth (talk) 02:25, 17 May 2010 (UTC)


 * /is OP -- I know how to work around it - want I wanted to know was if anyone had taken this approach. A 3D structure suspended in space with auto-transparencies as one stepped "through" the data would - to me - be much more user-friendly than flipping between worksheets. 218.25.32.210 (talk) 02:26, 17 May 2010 (UTC)


 * 3D-Calc. Mitch Ames (talk) 06:45, 17 May 2010 (UTC)


 * I never used 3D-Calc, though I did use a dozen other early spreadsheets and none of them had true built-in navigation in 3-D. Is there any spreadsheet with true 3-D display and navigation?  (I don't count "sheet!" references and clicking a new sheet as true navigation.)    D b f i r s   09:28, 17 May 2010 (UTC)
 * Considering that nearly the entire userbase of spreadsheet software are people that have a hard time navigating the first two dimensions on a PC comfortably... I would predict that putting a 3D spreadsheet feature into something prominent like Excel would be a disaster. Do you really think it would help workflow even of someone completely proficient with it?  Just brainstorming, I would say keeping the 2d view is essential to ease of use, even of expert users.  If you want a third dimension and tabs aren't your thing, use a slider that can be configured as the Z axis, with graduations for each interval (such as time increments) you need to navigate, then expose the data for that interval when the slider is in that position.  Not that you want to be told what you want, but this is what you want. --Jmeden2000 (talk) 14:17, 17 May 2010 (UTC)
 * Agree. Any non-trivial spreadsheet is a sorry and unstructured excuse for a proper program, anyways. Lifting that to three dimensions will make it unusable for the target audience. --Stephan Schulz (talk) 14:26, 17 May 2010 (UTC)
 * Well, I think that's a little of an overstatement; I've also wanted to add a third dimension to my spreadsheets in order to view data over the months, particularly because I wanted to generate a 3D graph from the data. People can visualize 3D graphs well (though Jmeden2000 is probably right that the third dimension would make the sheet itself 10 times harder to use).  Comet Tuttle (talk) 16:36, 17 May 2010 (UTC)
 * Excel has PivotTables, which can to some extent be seen as N-dimensional, but then you can just view the data and not edit it. I've also occasionally wished for a 3D excel (where you could rotate the data at will; with multiple sheets you're kind of stuck) but I'm unsure if I'd actually use it. Jørgen (talk) 05:49, 18 May 2010 (UTC)

There are some multi-dimensional spreadsheet packages: there's a list right here on Wikipedia. I understand they typically are a mix of spreadsheet and database software, and something like Excel pivot tables is used as a central user interface component. Requiring basic data modelling and allowing multi-dimensional data goes a long way toward solving the major weaknesses of standard 2-D spreadsheet solutions, i.e. scalability and extensibility. Alas, it looks like we're going to be stuck with Excel and the like for a long time to come. 130.188.8.12 (talk) 08:25, 18 May 2010 (UTC)

exit server?
I have been watching Open proxy detection lately and i would like to know what they are. wiooiw (talk) 02:02, 17 May 2010 (UTC)


 * Open proxy detection/Explanation defines it as a distinct IP address that's used by an open proxy for outgoing connections. -- BenRG (talk) 03:07, 17 May 2010 (UTC)


 * I see where you found that. Thanks. wiooiw (talk) 03:59, 17 May 2010 (UTC)

Preventing practical jokers from accessing your files using a linux boot cd
Is there any way to prevent annoying but technically-savvy practical jokers from accessing files on a typical (password-protected) windows system? They can, apparently, bypass the password and access the file system by using a linux boot cd.

Are there any solutions other than encrypting everything or physically putting the computer into a locked box? —Preceding unsigned comment added by 157.193.175.207 (talk) 07:02, 17 May 2010 (UTC)


 * A CMOS password would prevent them from entering the boot cycle. It's easily set within the system's BIOS (usually F2 on startup to enter Setup) 218.25.32.210 (talk) 07:37, 17 May 2010 (UTC)


 * You can also encrypt either the entire filssytem or just the most important folders/files. --Andreas Rejbrand (talk) 07:45, 17 May 2010 (UTC)


 * You can bypass the login password with a Windows installation CD too (recovery mode), and you can bypass a CMOS password by removing the hard drive and plugging it into another machine. A hard disk password is very difficult to bypass, though. -- BenRG (talk) 08:42, 17 May 2010 (UTC)


 * Let's be reasonable - if they're willing to pop the cover it'd be far easier to just yank the CMOS battery off the motherboard and count to 20. If his "friends" are that serious, there's little to be done. 218.25.32.210 (talk) 08:54, 17 May 2010 (UTC)


 * "Little to be done"? How about 75 years of cryptography research!?  There has been a significant effort to develop a series of best practices and technology tools for exactly this problem - "how do we deny access to information when an attacker has physical access to the machine?"  The solution is to strongly encrypt your hard disk.  The practical jokers will be able to open up your files as much as they like, but the contents will be strongly-encrypted (they will see only meaningless binary that is impervious even to powerful software efforts to decrypt/decipher them).  See List of cryptographic file systems and encryption software.  Nimur (talk) 10:03, 17 May 2010 (UTC)
 * The article on strong cryptography says its use is legally restricted in certain countries, though. 212.219.39.146 (talk) 11:45, 17 May 2010 (UTC)
 * Which is an entirely different issue than the question of technical protection of data. --Mr.98 (talk) 16:09, 17 May 2010 (UTC)
 * In general, physical access to a machine gives someone complete access to the hard drive contents. After all, they could just take out a screwdriver and steal whatever part of the computer they want.  Or they could take out a sledgehammer and bash the hard drive to bits.  The only defense against the first problem is encrypting the hard drive contents so that it's gibberish without the passphrase.  The only defense against the second one is backups.  On the other hand, security should be matched to the value of contents and the motivation level of the attackers: you might know how crazy your practical jokers are, and whether a CMOS password will be enough to deter them.  Paul (Stansifer) 13:37, 17 May 2010 (UTC)
 * Agreed, and even the best cryptography systems can't prevent a user from destroying data - all it can do is prevent them from deciphering it. I recently attended an interesting lecture from a Los Alamos physics package designer.  The computer security that goes into the control of a physics package is "unique," to say the least.  Should the device fall into the wrong hands, it is desired that the control electronics actively deny physical access to themselves - to prevent their unauthorized use, and also to prevent physical access to everything else inside the box!  So long as the device remains "intact" and "operational," with the computer controller safely locked inside a very difficult-to-open case, all of your favorite cryptographic locking and securing methods are valid.  But I think it becomes immediately obvious how difficult this problem is; suppose that the electronics are turned off: then how can the electronics or software prevent somebody from opening up the device?  Or supposing that somebody uses a cutting torch to open the box?  (Can this even be detected?  Some kind of "is physical enclosure intact" sensor that is "impervious" to tampering? Such sensors exist, and one could design an "un-resettable" device, but that has its own set of very scary problems).  Again, the challenge of denying access becomes very hard.  There probably will never be complete solution to this problem.  Fortunately, the interiors of most people's computer cases are fairly uninteresting.  Encrypting the hard-disk should be sufficient.  In both the case of a warhead and a hard-disk, it is "acceptable risk" if the attacker is able to destroy the contents, but it is unacceptable for the attacker to be able to use them.  I should say, the lecture was hosted by none other than Martin Hellman, inventor of public key cryptography. You can read more about his recent efforts here: Nuclear Risk. Nimur (talk) 17:33, 17 May 2010 (UTC)
 * Remember that if you go the cryptography route, your data is only as safe as the key used to encrypt/decrypt it. If you expose the key (say, to a hardware/software keylogger, or someone shoulder-surfing, two things any tech-savvy coworker can accomplish with ease especially if you work in relatively close quarters) then the encryption is worthless.  --Jmeden2000 (talk) 20:32, 17 May 2010 (UTC)

Integer division (still) rounding up
Really sorry to bother you with this again, but I'm determined to find and fix the source of this problem. It's the same as before (this question). I thought maybe if I showed you exactly what I'd done you'd be able to find out what I'd done wrong...

Private Sub btnChange_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnChange.Click Dim pounds As Integer Dim fifties As Integer Dim twenties As Integer Dim tens As Integer Dim fives As Integer Dim twos As Integer Dim ones As Integer pounds = Credit \ 1 fifties = (100 * (Credit Mod 1)) \ 50 twenties = (100 * ((Credit Mod 1) Mod 0.5)) \ 20 tens = (100 * (((Credit Mod 1) Mod 0.5) Mod 0.2)) \ 10 fives = (100 * ((((Credit Mod 1) Mod 0.5) Mod 0.2) Mod 0.1)) \ 5 twos = (100 * (((((Credit Mod 1) Mod 0.5) Mod 0.2) Mod 0.1) Mod 0.05)) \ 2 ones = (100 * ((((((Credit Mod 1) Mod 0.5) Mod 0.2) Mod 0.1) Mod 0.05) Mod 0.02)) \ 1 MessageBox.Show("Your change is: " & FormatCurrency(Credit) & "." & vbNewLine & vbNewLine & "£1: " & pounds & vbNewLine & "50p: " & fifties & vbNewLine & "20p: " & twenties & vbNewLine & "10p: " & tens & vbNewLine & "5p: " & fives & vbNewLine & "2p: " & twos & vbNewLine & "1p: " & ones, "Change") Credit = 0 lblTotal.Text = FormatCurrency(Credit) End Sub

It's supposed to list all of the coins that the vending machine will spit out once the "change" button is clicked. The "credit" variable is a double that is modified by other buttons elsewhere in the program. It all works fine, perfectly fine - except if the credit value ends in anything from 0.51 to 0.99 it will round up instead of rounding down. For example, asking for change from 51 pence will give me one 50p coin and one £1 coin.

Does anything leap out as being the obvious reason?

I can provide the rest of the code if it's needed. Thanks in advance 212.219.39.146 (talk) 09:53, 17 May 2010 (UTC)
 * Hilariously, £1.20 returns £1, 20p, two 10p's, two 5p's, two 2p's and a 1p. 212.219.39.146 (talk) 11:03, 17 May 2010 (UTC)


 * I suspect that, because 'credit' is a float, all those 'mods' you do are subject to rounding and are causing the problem. So my first advice is to get rid of all floats; you do not need them.  Work with the number of pennies that make up your total, and do this completely with integers.


 * You already do an integer division with 'pounds', so you have the number of pounds that will be in the change. Now you need to know how much is left to make change for.  You can either multiply the number of pounds times 100 and subtract it from the total, or you can use the mod function; these will give the same result.

dim IntCredit as Integer dim remainder as Integer

IntCredit = credit * 100  ' convert the float to an integer number of pennies. pounds = IntCredit \ 100  ' calc the number of pound coins/bills they get back. remainder = IntCredit - (dollars * 100) ' or remainder = IntCredit mod 100 fifties = remainder \ 50  ' 50-cent pieces, I presume remainder = remainder - (fifties * 50) ' or remainder = remainder mod 50


 * And continue this through your pennies.


 * Hope that helps.


 * rc (talk) 12:34, 17 May 2010 (UTC)
 * And what is the exchange rate between pounds and dollars? -- SGBailey (talk) 17:52, 17 May 2010 (UTC)
 * (OP here) Thank you - in the end I scrapped the whole system and tried out using loops, which worked (to my surprise, since I didn't actually know how to use them). But your system should still be useful for me when I come to write it up, evaluate, discuss, etc. I'll test it out when I get back to college tomorrow (that's where the program is saved). Thanks! Vimescarrot (talk) 16:39, 17 May 2010 (UTC)


 * Most currency systems are designed so that you can use a "greedy algorithm" to make change in the optimal fashion (by dispensing the largest coin until it's too big, moving on to the next largest, etc.), but this is not guaranteed to be optimal for all currency systems. See Greedy_algorithm and Change-making_problem.  -- Coneslayer (talk) 16:51, 17 May 2010 (UTC)
 * Currency denominations are actually designed specifically to make these algorithms optimal? That's quite an interesting fact - is this well-known? Do you have a source? Vimescarrot (talk) 19:00, 17 May 2010 (UTC)
 * I didn't mean it quite that strongly... rephrase as "In most currency systems you can use...". It seems likely that if this property did not hold, the system would be re-designed out of convenience.  -- Coneslayer (talk) 19:07, 17 May 2010 (UTC)
 * Aha, fair enough - I did wonder if I'd misinterpreted after re-reading. Vimescarrot (talk) 19:36, 17 May 2010 (UTC)

Samsung PC Studio
I somehow don't seem to be able to find where you can download the Samsung PC Studio software that allows you to transfer files from a Samsung mobile phone to a PC. Should I keep trying with the Samsung website that keeps sending me round in circles, or should I go to a site unconnected with Samsung? UK based. Itsmejudith (talk) 11:40, 17 May 2010 (UTC)
 * You can download it here: --Andreas Rejbrand (talk) 12:27, 17 May 2010 (UTC)
 * That seems to be the manual rather than the software. There appears to be a link to "software" but when I click an end-user agreement for the manual comes up in a new window. I'd be grateful for any other help. Thanks. Itsmejudith (talk) 14:08, 17 May 2010 (UTC)
 * I would never go to a third-party site for the software unless there was a link on Samsung's official site pointing to it. Chevymontecarlo . 15:12, 17 May 2010 (UTC)


 * No, the link I provided is correct; I just downloaded the software. Simply click "Software", and click the download button for your operating system. In the popup (make sure that you have no popup-blocker), check the "I have read these terms ..." checkbox and click "Close". Then you will be able to download the software. Depending on your browser, you may need to click the download icon once again after having accepted the terms. --Andreas Rejbrand (talk) 15:49, 17 May 2010 (UTC)

Movies Subtitles and Translation
I have a question if some one help me i will be very thankful. My question is that how can i create subtitle of language in a movie if it is not by default. My second question is that how can i translate english movie into Hindi or Urdu.as there are many english movies available in Hindi.Any idea please! —Preceding unsigned comment added by 116.71.217.59 (talk) 14:17, 17 May 2010 (UTC)
 * You can use a Subtitle editor to create your own subtitles. If you have a DVD, you can use a program such as SubRip to extract the existing subtitles to a text file, preserving the timing information. Then all you have to do is translate the text.  (talk) 09:56, 18 May 2010 (UTC)

php
I have a php script (that someone here wrote for me <3) that displays entries from a text file. I need a way for the script to count how many entries are in the text file (they are each on a new line) and display the total. I am unsure how to do this. Please help :) Thanks 82.44.55.254 (talk) 20:28, 17 May 2010 (UTC)


 * Try something like this:


 * Does that make sense? If the script in question already reads the file into an array using the file function, then all you have to do is put a count function on that array. --Mr.98 (talk) 23:26, 17 May 2010 (UTC)
 * Awesome!! Thank you :D :D 82.44.55.254 (talk) 11:09, 18 May 2010 (UTC)

Checking driver versions
Here is something I've always wondered when checking driver versions in Windows (7): Why is it when I am looking for the version of my NVIDIA graphics driver, it shows 8.17.11.9745 in the Device Manager? I have the 197.45 drivers and I've learned recently to read the last few numbers to figure out the version, but what is the significance of the 8.17.1 before? —Preceding unsigned comment added by 70.129.40.191 (talk) 21:35, 17 May 2010 (UTC)


 * Could the build date be November 17th, 2008 ? StuRat (talk) 12:22, 19 May 2010 (UTC)