- 1 September 17
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- 3 September 19
- 4 September 20
- 5 September 21
- 6 September 22
MacOS question - What does a flashing folder with a question mark mean?
I bought a Mac a few weeks ago to do some iOS development. Today, in the middle of a TeamView session (from my Win8 PC to my MiniMac), the screen turned white and there's now a flashing folder icon in the middle of the screen with a question mark in the middle of the folder. What does this mean? A Quest For Knowledge (talk) 13:56, 17 September 2014 (UTC)
- Here is the startup sequence and error codes/symbols. It sounds like you're describing the icon for "no bootable media," although it seems unlikely this would occur while the system was already booted. Can you reboot in verbose mode?
- Here are some more troubleshooting steps. Nimur (talk) 15:05, 17 September 2014 (UTC)
Time Machine again
I have three backup drives, cleverly named TM1, TM2, TM3, which I rotate. A week or two ago I wiped TM1 because it appeared to be corrupt. Soon after that I jumped from Snow Leopard to Mavericks (or, as I like to call it, Mavérix le Gaulois).
Time Machine now does a funny thing: it persistently calls TM2 and TM3 by the same name, although Finder shows different names. Yesterday, having them both plugged in, I experimentally renamed TM3 to "Three", and Time Machine showed that name correctly. But on startup today, having only TM2 plugged in, Time Machine said something like "Warning: drive Three has changed its identity."
I guess this happens because, when I bought each drive, I loaded them with a copy of TM1 (as it was then) so as to have copies of the oldest backups on all three; it seems that Time Machine reads something in the disk's backup database to find its "name".
- There must be some registration file in the hard drive that contained file id for TM1, and it, now being on TM2 and Three, is fooling OSX into changing its ID. Unless you have the time and patience to find the file, I can't see the problem resolving itself. KonveyorBelt 03:05, 18 September 2014 (UTC)
Hello. kubuntu linux. I am used to the ritual "./configure ; make ; make install". Why is it that about 80% of software packages simply configure and make straight out of the box, while about 20% end up in a nightmare dependency hell? I don't have a bizarre set-up, just a bog-standard plain vanilla kubuntu box. I'm not a power user. I'm don't muck about about with obscure configuration files or recompile my kernel on the bleeding edge. Right now I'm trying to compile inkscape and have just about given up. Any insights appreciated, Robinh (talk) 08:28, 18 September 2014 (UTC)
- Is there any reason why you're building from the source, rather than using "apt-get install inkscape" to install the pre-built package? If ./configure says it needs libfoo, then you need to install both libfoo and libfoo-dev. The latter tells the compiler building the program how to use libfoo. However, installing libfoo-dev should autoinstall libfoo as well. CS Miller (talk) 10:17, 18 September 2014 (UTC)
- Agreed, a package manager is the easiest way to avoid dependency hell. IMO, the ease and ubiquity of these tools is one of the major improvements to the *nix world over the past decade or so. I don't think there really is a way to make "./configure ; make ; make install" work with 100% reliability on any *nix. Some of the reasons are outlined in the linked articles. SemanticMantis (talk) 14:43, 18 September 2014 (UTC)
(OP) thanks guys. I want to do this because there is no precompiled version of inkscape 91, AFAICS. But I was asking about why (whether?) there is such a severe split between the majority works-out-of-the box software and the install-a-billion-weird-libraries-and-eventually-give-up software. Best wishes, Robinh (talk) 20:16, 18 September 2014 (UTC)
- It depends on what development packages are installed by default on your machine, and which (un)common packages inkscape needs. As I noted above, you can install the dev packages that inkscape needs. You can also try "apt-get build-dep inkscape" to install the build dependencies for the version that kubuntu ships with; they might be the same as 91.CS Miller (talk) 20:28, 18 September 2014 (UTC)
Excluding in Search
For example I would like to google search about Mickey. But everytime results of Mickey Mouse comes out. Is there ^a way to specify to exclude results for Mickey Mouse? e.g. ONLY Mickey NOT Mickey Mouse? --Jondel (talk) 10:11, 18 September 2014 (UTC)
- Search for 'Mickey -"Mickey Mouse" '. This will (mainly) exclude the phrase "Mickey Mouse" from the results. If you search for 'Mickey -Mouse' instead, then it will exclude all pages that have "Mouse" in them, even if its no where near "Mickey". CS Miller (talk) 10:20, 18 September 2014 (UTC)
Java two-way conversion
In Java, what's the typical method of providing a polymorphic two-way conversion between sibling classes? An example would be where text was sometimes HTML-escaped and sometimes unescaped, with only the runtime type indicating which was which (e.g. in an e-mail or forum app that accepted multiple formats), but where functions required either one or the other. 11:53, 18 September 2014 (UTC)
- The standard way to provide such polymorphism is to define your requirement - e.g., "provide text in a specific format" - as a Java interface; and then ensure that both classes implement this interface. Design an interface that meets your needs - and any instance of any class implementing the interface will automatically be able to satisfy your requirement. This can be enforced at compile time.
- If you actually want to perform a conversion, the language doesn't force you into any specific design. You could convert the text, convert the object, or both. You could re-convert on demand, or you could cache the result anywhere you like. You could provide a copy constructor for each class that takes an instance of the other class as its argument; each time you needed an instance of the other class, you could regenerate it. If this operation occurs so frequently that it incurs a high CPU cost, you could generate the text in all necessary formats ahead of time, and store it for later use. If that implementation uses memory in such quantity that it scales poorly, you could re-think your utility functions so that they could handle text data in a more intelligent way.
- Nimur (talk) 14:31, 18 September 2014 (UTC)
I want to store 1000's of images on my computer and I want them to stay the same quality as when I downloaded them. What should I convert all the files to so that I ensure they will stay in perfect condition for later viewing? I was thinking about converting all the images to a PNG format but I wanted to know what the best idea would be before I do that. — Preceding unsigned comment added by 184.108.40.206 (talk) 21:47, 18 September 2014 (UTC)
- You can just store them in the format they were when you downloaded them, that's the way most digital storage works. Lossy compression may mean some data was lost from the originals (although with modern cameras the closest thing to the originals often are lossy), but that's already happened by the time you download the lossy compressed images. (If you are editing the images, you do have to consider generation loss.) Of course this doesn't protect against data loss on the storage medium (defective medium, malware, filesystem problems, accidental deletion etc), malicious or dumb software tampering with the images or anything of that sort, but choosing a specific format won't generally help with that (except for dumb software which modifies and rewrites lossy images). Use multiple backups in different geographical locations to cover that. There is a minor advantage to a format which stores its error detecting code for the image data since in some cases you could get corruption not easily detected, but it's far better you ensure your backup system has decent error detection. Of course, even if your backup system is robust enough, you have no guarantees of software capable of opening the images in 50 years, if that's a concern, it may be worth considering the storage format. Nil Einne (talk) 22:05, 18 September 2014 (UTC)
- I agree with Nil Einne. Converting to say, lossless, from the original files you have downloaded doesn't have any benefit, as it isn't going to improve the quality; it could even degrade it if done improperly. -- Tahlorz
- As long as you're talking about common, open standard image formats (JPEG, PNG, GIF) then I agree with Nil Einne - you'll surely be able to find programs to read or at least convert them in 10, 20, probably 50 years from now (getting the media to work even in 10 years is more of a challenge, ditto the filesystem the files are stored on). Previous common formats like TIFF, BMP, and TrueVision Targa which have fallen mostly out of use are still widely supported. But file formats that are used by only one program, like Adobe Photoshop or Coreldraw files, would probably mean you'd need some future incarnation of that program (or hope that some open-source project has successfully reverse engineered these complex, proprietary file types). It's not even a completely safe assumption that Photoshop 2025 will read a CS5 document properly. -- Finlay McWalterᚠTalk 16:28, 21 September 2014 (UTC)
- To be clear, my point was not that I believe the images could be opened in 50 or even 10 years by future system but rather that the condition of the images should generally remain the same, and if they didn't, that changing format wouldn't help. I do agree that if you want to ensure the images are viewable, you need to consider the storage format, hence my last comment. While it's useful to talk more about being able to open the format in the future, I concentrated on the other issues (images remaining the same and the need for good storage practices) because it's not clear to me the OP understands such basics but they seem essential and also because it's not that common to download stuff besides PNG, TIFF, JPEG. Admitedly as you hinted at, I also glossed over the backup issue somewhat. I thought of mentioning the need for regular refreshes to ensure both that the backups still work & are correct & also that you can still access them on a modern system, but decided not to further complicate my reply, partially because I'm not sure the OP is really concerned about keeping the images that long. But if their hard disk containing their only copy of the images dies tomorrow, whatever they store them in isn't likely to make much difference. Well unless it's only partially dead, in which case a format more easily detected is more likely to be recoverable. Of course the OPs reply is fairly unclear so I could easily be wrong. Nil Einne (talk) 14:37, 22 September 2014 (UTC)
Network Printer doenst recognise pcs
Here at work we have a ricoh 8000 printer, this printer is connected on the network, by a network cable.
Until yesterday we were able to print from this printer. But now the printer doenst recognise pcs.
If I ping to the printer ip using a pc, it doens nothing, the same happens if I try to ping to a pc ip using the printer (yes, this printer has a ping function).
What can be the problem? This problem came out of nowere.220.127.116.11 (talk) 12:46, 19 September 2014 (UTC)
- Someone might want to help you, but that's not really what we do here. You can use the free program Audacity_(audio_editor) to do it yourself. SemanticMantis (talk) 19:34, 19 September 2014 (UTC)
- If this is for use in a Wikipedia article, you could ask at commons:Commons:Village pump. -- BenRG (talk) 00:11, 20 September 2014 (UTC)
Confusion with printing sizes and DPI
I went for the first time to a printing company, because i would like to print out some computer designed images as "Digital Art". I explained that for starters, i would like to have some prints made at 12" x 12". We did a little talking and i mentioned i wanted these printed at the highest DPI they have to offer. I am not used to how printing works, and i told the person at this company that i mainly work with pixel resolution. I said to them that i can produce the image at literally any pixel dimension needed, and asked "What pixel resolution should i give you to get a 12" x 12" image at your highest DPI?" They told me i should shoot for about 750x750 pixels. They then showed me a 24" x 24" poster of some football stuff, printed on the same printer that does their highest DPI.
Wanting to know as much as i could about this, i looked up DPI conversion as soon as i got home. According to formula #1 here:
Pixels / DPI = Inches 750 / ? = 12
This means the DPI would need to be around 60 (to produce 12.5 inches), which is only the DPI of a CRT monitor! Choosing the option in the converter of this site of "300 DPI (Laser/InkJet)" gives that my image would only give a 2.5" square print! Worse yet, at "600 DPI (Hi-Res Inkjet)" the image would be 1.25" square! At the 300 DPI i would need an image (according to the SECOND converter on this website) of 3600 pixels, and at 600 DPI i would need 7.2k pixels.
Whats going on here?!? I didn't notice anything wrong with the poster i was shown, it appeared pretty good quality! Maybe i don't know it and their "best" printer has really poor quality?!? Or perhaps its specially made for posters, which for some reason have really low DPI? Was there miscommunication?
It is hard for me to understand this issue. I *generally* understand DPI but it seems we weren't talking the same language or something. On top of that, the Photo-quality printing article talks about DPI starting around 2,400 DPI for more professional prints.
The person i talked to said they didnt know what DPI the printer had. What type of DPI should i expect from a company, for decent grade art prints? I want them to look great, but know what demands are reasonable! Surely i need more than a 750x750 pixel image?!?! What went wrong in my conversation with this person? Should i look for another company?
Bewildered and confused,
- Me too. But 60 DPI gives you about 0.4 mm pixels - definitely visible up-close. The ancient Apple Laserwrite had 300 DPI B/W, and that's still quite ok. I'd suggest you go with that and get a galley proof to see if it meets your expectation. --Stephan Schulz (talk) 18:40, 19 September 2014 (UTC)
- According to a friend i just talked with, people working at printing companies often have no idea what a pixel is, because they don't necessarily work with DIGITAL images. (Really?!?!?!)
- What i really want to avoid is that my image is too big or small for 12" x 12", and the person resizes the image to fit. This will cause distortions in the image. When a normal image off a camera is resized **slightly**, there is little or no difference noticeable in the quality... probably because neighboring pixels have similar hues. In my situation, there are intricate details and edges, and also situations where a single orange pixel may be alone in a sea of black background. This detail could get screwed up badly if the image is resized, am i right? At least, i don't think it will be good at all, so i really don't want the image resized! ... But if these printer people know nothing of pixels, it feels awkward to pay them so i can help them do what i need.
- I suspect that whoever told you "750 pixels" was just plain wrong.
- I'm not too familiar with what's considered "high resolution" among mainstream commercial printers, but if I wanted "highest resolution", I'd be thinking of something more like 600 dpi, and for 12x12 inches that's 12 x 600 = 7200 x 7200 pixels. —Steve Summit (talk) 23:54, 19 September 2014 (UTC)
- When you said "pixel resolution", you seem to have meant "image dimensions in pixels". Your printing company may have interpreted "pixel resolution" to mean "pixels per inch". If so, the 750 × 750 figure probably means "750 pixels per inch in both horizontal and vertical dimensions", and a 12 inch × 12 inch printed image would use a source image that is 9000 pixels × 9000 pixels. Maybe you can have another conversation with your printing company to make sure you're talking about the same thing. You might confirm what "image size in pixels" you should give them for a 12 inch by 12 inch print.
- If you want to better understand the pixels and dots conversions, here's some more information I just found.
- The conversion website you used is assuming a dot is the same as a pixel. But this isn't always the case. Look at Wikipedia's Dots per inch article, section DPI measurement in printing, and look at the picture showing an image of a ball on a screen and on a printer. (Ignore the subsection "DPI or PPI in digital image files" for now. In that subsection, dot means the same as pixel, just like the conversion website you used.) To summarize the section and picture, for black or white images (no grayscale), 1 pixel needs 1 printed dot. But for color images, 1 pixel may need multiple printed dots. This is because printed dots will have a limited color palette, so each pixel needs to use more dots and dithering to match the source pixel colors.
- Once you understand that, you could ask your printing company about the highest DPI they can print, and how one color pixel ends up in how many horizontal dots by how many vertical dots, then do all the conversion math yourself. This might be helpful to confirm you understand everything correctly and they didn't give you bad information. But if you trust they're doing the conversions correctly, just ask what image size, width by height, in pixels by pixels, you need to give them and you won't need to do any conversion math yourself. --Bavi H (talk) 04:11, 20 September 2014 (UTC)
- 300dpi is standard. (ppi is the digital resolution, dpi is the printing resolution, though some folks/programs use them interchangeably) ...The image resolution can be adjusted a little higher or little lower, depending on image quality and printer quality. To get substantially higher, like the photo-quality you mentioned, takes a substantially better printer and thus cost. If you give them a 600dpi image and their printer can really only handle 300, the print may end up darker and possibly inferior to the 300 version. So I suggest that you either go back to that print shop and ask for someone else to help you understand it (that's part of their service, their job!) or else go somewhere else. You could even ask for the specifications ("specs") in writing, or where it's listed on their website, which is also standard in this business. And I'm not sure what your friend told you, but anyone working at a printing company should know the resolution details, and yes they do deal with digital images -- unless they are a specialty shop like screen printing or something else old-fashioned, yet even then they should still know about what you're trying to do. Good luck. And FYI the Adobe forums (e.g. ) are a good place to read up on all this stuff. El duderino (abides) 09:18, 20 September 2014 (UTC)
- I've had similar problems with print shops - and the bottom line seems to be that they simply can't guarantee 1 pixel on-disk == 1 dot on the paper. These large format printers seem to resize the image no matter what - and provide processing to sharpen the image, etc, etc. So all efforts to get exact reproduction in a large-format printer have (so far) failed. You'd hope that a large-format printer would be able to cope with at least 300dpi - and for the kind of fancy professional stuff those guys use, you'd hope it was more like 600 or 1000 dpi...but there is no way to be sure unless you can read the manual for the printer, muscle the print shop guy away from his PC and do it yourself!
- SteveBaker (talk) 16:09, 22 September 2014 (UTC)
- I agree with the earlier comments that many print shop workers simply don't understand pixels at all, and that you want to print at 100% or at least an integer fraction of that, like 50%, 25% or 20% (33 1/3 % could be tricky though). I'd ask to speak to somebody else, or find another print shop, until you find somebody who understands his job. StuRat (talk) 17:00, 22 September 2014 (UTC)
Make GRUB handle missing disk
I have GRUB and Windows installed on my SSD, and Ubuntu on my magnetic HDD. Unless a missing Downloads folder is enough to crash it, Windows should be bootable even without the HDD. But when I disconnect the HDD for troubleshooting purposes, GRUB gives an error message and enters rescue mode. How can I configure it to instead handle the error and display the menu minus Ubuntu? 21:23, 20 September 2014 (UTC)
Audio card to speaker connectivity
Would it be possible to connect this audio card: Xonar Essence STX with this speaker system: Creative T4? If so, in which ways: digital and/or analogue? Also, would it be possible to connect a 5.1 analogue(3.5mm-connection) speaker system with this audio card somehow? With an adapter maybe? — Preceding unsigned comment added by 18.104.22.168 (talk) 21:59, 20 September 2014 (UTC)
- This review says the Creative T4 contains its own sound card on the end of a USB connection. So you could just use a usb connection to your computer, and you wouldn't need the Xonar at all. -- Finlay McWalterᚠTalk 23:33, 20 September 2014 (UTC)
Purchasing New Hard Drives
Hello all, I have never purchased a new hard drive for my Windows 7 machine. I'm planning on buying these hard drives from Amazon. My question, does anything special need to be done to hard drives like this before using them? I know that when I set up some virtual hard drives in virtual machines of old OSes (such as 95/98/etc), I had to FDISK and FORMAT them. Is there the requirement to do that, or any other special step that needs to be done? In addition, do you think my choice of hard drive/company is a good one? Do you have any suggestions on better hard drives? Thanks! -- Tohler (talk) 14:23, 21 September 2014 (UTC)
- You will probably have to format the disk (which you do in the Disk Management screen, which is part of Control Panel). As to which manufacturer: the only large-scale study of consumer disks that I'm aware of which calls out brands is this one one from online storage company Backblaze: that doesn't make Seagate look good, but note that at the end they say they're still mostly buying Seagates (but their storage infrastructure is probably more used to the bother of swapping out a failing drive is an individual user like you or I). -- Finlay McWalterᚠTalk 16:09, 21 September 2014 (UTC)
- Before making your purchase, check to see if you have the necessary cables, since bare drives usually come without cabling. A typical system power supply will have several extra SATA power cables. The motherboard will typically have extra SATA data ports, but you will need a data cable. Your original system purchase may have included one, but if not, now is the time to add one to your order. -- Tom N talk/contrib 18:13, 21 September 2014 (UTC)
- There are a few problems specific to large disks: the normal partitioning scheme, MBR, can only address 2TB (or 2.2TB depending on the definition of TB), so you would not be able to use the full capacity of your 3 TB disk. To fix that you'll have to choose GPT; if you are adding a disk for extra storage, you won't have any problems. . If however the disk has to be bootable (if you are replacing your old disk and want to install windows on the new one) then your system has to be UEFI-capable; older systems only have BIOS, and BIOS can only boot from an MBR partition, not from GPT. One other requirement in that case: your Windows 7 must be a 64-bit version. (see http://support.microsoft.com/kb/2581408 for more details) If your system only supports BIOS, you can still boot from the disk and use the full capacity by installing Seagate's DiscWizard device driver: it will create a second MBR for the part above 2.2 TB, basically pretending to be two physical disks instead of one. (http://www.seagate.com/support/downloads/discwizard/). Ssscienccce (talk) 19:21, 21 September 2014 (UTC)
Calling DLLs From Ruby
I've been looking at how to use win32api objects to call functions from DLLs inside of Ruby. The basic idea makes sense, as does most of what I've seen. However, my stumbling point is on how exactly they pass data back and forth, none of the tutorials or examples I've found seem to go into this enough for me to do it on my own. Do I need to write my functions, in the DLL, in a specific way to interface with Ruby (I'm guessing not since it can call to libraries I know were not made with Ruby in mind)? For something concrete, supposing I had a function, in the DLL, that took two longs and returned their sum, if I wanted to call it from Ruby with args 3 and 4, what I would pass to the dll, what would be returned, and what would I do with it? Finally, from what I've read, it looks like you can return pointers to data back to Ruby, but what would you do with them once received? Or have I got this wrong? --related, but not essential, if my functions in the dll need to use data from a file, can it load the data into memory and have it stay there, or does it disappear after the function call? Essentially, is it like a second program running side by side and communicating, or is it more like something that starts fresh every time I ask it to do something? --I know I am asking a lot here, any help would be welcome; even some links to a few obvious examples. Thank you all:-)Phoenixia1177 (talk) 18:10, 21 September 2014 (UTC)
- Your options include Ruby FFI (which I think uses its own scheme for describing the Ruby<->native interface) and Fiddle, which is a Ruby wrapper over libffi. -- Finlay McWalterᚠTalk 19:34, 21 September 2014 (UTC)
- I don't know much of anything about Ruby but I can answer your question in a broader context. I'll use "Ruby" and "C" as the language names, but this applies to most interfaces between garbage-collected and non-garbage-collected languages.
- Normally the DLL will be loaded once and will stick around after that. Any heap objects you allocate on the C side will stick around between calls. They will remain even if there are no more references to them, because Ruby's garbage collector doesn't understand the C heap, so you need to explicitly free them somehow to avoid memory leaks. You can think of the Ruby and C code as parts of the same program. They don't run in parallel; the C code only runs if you call it from Ruby, and it uses the same call stack as Ruby.
- A foreign function interface will typically provide a way to wrap a C function in a Ruby function. You give it a C function pointer (or the name of a DLL and an export in it) and the parameter and return types, and it will return a Ruby function that, when called, will coerce its arguments into the appropriate C types and call the C function, then coerce the return type back to a Ruby object. It looks like Win32API will do this. The documentation is pretty anemic, but you might write something like Win32API.new("mydll", "myexport", ['L'] * 2, 'L') to wrap your function that adds two longs. Per this page, there's also an optional argument to specify the calling convention. C compilers normally use cdecl, but the default for this argument (and for Windows DLLs) is stdcall. You need to either make sure your C functions use stdcall or else pass :cdecl for this argument (I'm assuming that's the spelling; the documentation doesn't say.)
- Pointers (type 'P') can be passed and returned but are just magic cookies on the Ruby side; the only thing you should do with them is pass them back to C code. (Actually, an FFI might provide functions to directly read and write through pointers, but without loss of generality you can pretend that those are wrapped C functions.)
- A good FFI may provide a way to wrap pointers in Ruby objects that automatically call an appropriate C function to free the pointer when the Ruby object is garbage collected, to make C heap objects easier to manage. And it will provide a way to make C wrappers for Ruby functions, so that you can write C callbacks in Ruby. -- BenRG (talk) 20:17, 21 September 2014 (UTC)
- Thank you for the suggestion Finlay, unfortunately, I must use Ruby's basic win32api object for this. I worked out a very speedy pathfinding algorithm that operates off of using a small collection of previously calculated data points from the map geometry - whatever she is using this in requires using an old basic version of Ruby (I think it's something like rpg maker, maybe it is, she didn't say for some reason, oddly). BenRG: thank you for the perspective, it is very helpful and has clarified a few points I was finding a bit murky.Phoenixia1177 (talk) 21:40, 21 September 2014 (UTC)