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June 29

Distinguish USB 1/2/(3) cords?

How to distinguish USB cords USB 1 and 2? USB 3 has a blue marker in the plug which makes it easy to recognize. Is there a similar clear visible difference when it comes to USB 1 & 2? I have plenty of 1 & 2 cords and it would be a real great effort to check each of them out one by one by connecting and see what the system tells me. Is there any shortcut to this? Thanks, TMCk (talk) 01:36, 29 June 2013 (UTC)

As far as I know, USB 1 and 2 use the same cables. RudolfRed (talk) 01:45, 29 June 2013 (UTC)

Actually no. There can be a difference in quality and shielding which makes your USB 2 device run slow if connected with the old standard. Also found a page that shows how to distinguish (most) cords here.
Thanks anyway, TMCk (talk) 17:28, 29 June 2013 (UTC)

Actually that document appears to present a bunch of misleading or inaccurate claims, as unfortunately is common with unofficial documents claiming differences in cabling required by standards (e.g. you get the same nonsense about HDMI, these sources mention it and say why it's generally crap [1] [2] [3]).

It suggests shielding was not required by USB 1.1, in fact various sources suggest it only wasn't required under USB 1.0 e.g. [4] and if you ignore the insults and crap in this discussion from usenet [5]. It suggests 3m was the limit for USB1.1 in fact our article says it's only the limit for low speed devices, full speed devices supported 5m (this isn't sourced but I'm pretty sure I heard the 5m length limit before USB2 existed). The documents also makes a big deal about their cable construction including the use of twisted pair for the data portion but our article says this has always been required.

Perhaps the most relevant to your question, it suggests the cable shold have a plus, in fact this document from the USB forum says it's only intended for ports, hubs etc and says it's not recommended for cables edit: because unique cables are unneeded [6]. (None of my cables have the plus even ones for USB 2.0 HDs etc.) Edit: Forgot to mention, while I do not know if a recommendation that the symbol isn't needed for cables has always been given in documents and info from the USB forum to implementers, I strongly suspect the plus was never recommended for cables even if this wasn't explicit.

The only part of that document which may be mostly true is that USB 1.1 did not have any specs for the higher frequencies (edit: forgot to mention I didn't look for sources for this, I'm just assuming it's probably the case as it's fairly common with this sort of thing). You will note that requirements for the lower frequencies did not change. My understanding of cable design or for that matter the science behind transmission is limited but I believe it's likely possible a cable could comply with the lower frequency requirements but not the higher ones but I suspect given the specs and differences, it's probably not that likely. (Edit: To be clear, this would likely depend on the various parts of the spec which I haven't read and obviously don't know enough to be able to comment on. For example, it could be that the lower frequency attenuation requirements are completely irrelevant because the higher frequency ones will almost definitely mean lower attenuation for the lower frequencies. However it's fairly common in these sort of things that the tolerances the spec requires mean that any compliant cable particularly if it isn's at the extreme edges for example a 5m cable, will work even if it's closer to the borderline then would be ideal in a spec. This seems to be borne out by the various stuff coming from the USB forum and elsewhere.)

To be clear, I'm not suggesting that cable cannot make a difference, rather the most likely case is that a cable which does make a difference isn't USB1.1 compliant either (in other words, the number of cables which are USB1.1 compliant but cause problems for USB2 is small) and that there are undoutedly still some USB2 cables which do not comply and may make problems (although probably less likely both because the price difference is small and the it's more likely to be noticed). This discussion [7] quoting stuff coming from the USB forum seems to agree . And of course perhaps the key point, unless you have the equipement to test the cable and perhaps even enough of the same kind that you can afford to cut some open, and the ability to understand the spec, you can't check compliance with either spec. Definitely going by the plus seems a rather flawed idea if it was your intention.

Note that this is quite distinct from USB 3.0 which requires extra wires so a USB2.0 cable will never be capable of providing superspeed support.

Nil Einne (talk) 07:22, 30 June 2013 (UTC)

Yes, the link I gave is not a definite source and has it's flaws, even more than I thought in the first place. After reading your reply and diggin' further myself I found out that even with USB 3 cords there are some troubles when running a USB 3 devise. Seems to depend somehow on the quality and length of cable and also the systems motherboard in use.Information online, (especially in forums), are quite conflicting [That's why I posted here in the first place].>br>Summarizing your response and my own research/experience as a layman, there is no clear answer since even i one knows what cord they're using the result can wary anyway.
I myself will go from now on with cords made for USB 3, (even so I don't have it on my current main system), and thus get at least USB 2 devises run at maximum speed.. Some old USB 1 devises I still have and run once in a while are therefore of no concern anymore just as to distinguish between USB 1 & 2.
Thanks for your input which helped me make up my mind in making a decision for the/my future.TMCk (talk) 04:23, 2 July 2013 (UTC)

29 to 30 inch monitor for gaming

Any suggestions? Budget would be around 850$, however wouldn't mind bang for buck. — Preceding unsigned comment added by 184.151.114.192 (talk) 07:02, 29 June 2013 (UTC)

You might want to consider a dual monitor system instead. With a single monitor that big, the corners will be significantly farther from your eyes than the center, making the picture seem distorted. (This assumes you are sitting close to it, so you can read small text.) With a dual monitor system, or even 3 monitors, you can arrange them around you, to approximate a curved shape, and thus prevent this distortion. Many games and gaming PCs have support for multiple monitors. StuRat (talk) 07:33, 29 June 2013 (UTC)

As far as the price side you may wish to check out sites like NewEgg.com and TigerDirect.com for bargain basement pricing, they also have ways of free shipping & are pretty good at standing behind their products and selling quality goods new or refurbished. ^{Market St.⧏} _{⧐ Diamond Way} 08:01, 29 June 2013 (UTC)

I don't reaslly have space for dual monitors in my super-ergonomic college-student-living-with-parents room (http://i.imgur.com/XJx8NVN.jpg), and I'm kinda wary because not many games support dual monitors. Those sites are probably where I'm going to buy it, the new Quebec electronic recycling tax is like 50 $ for a frigging 700$ monitor. Eisenikov (talk) 10:58, 29 June 2013 (UTC)

Not a computer question nor answer here but I hear New Hampshire has no sales taxes so depending where in Quebec you are a FedEx or UPS store in NH may be much more cost effective for shipping. Please update us on what you decide, I am curious what you find as the best model, brand, product and website. ^{Market St.⧏} _{⧐ Diamond Way} 05:30, 30 June 2013 (UTC)

How about a HD TV with a VGA/HDMI input port. Plenty of 32" models available for around US$400 with 1920x1080 pixel resolution (seems to be a gap in the market between 27 and 32 inch, though). Astronaut (talk) 19:50, 1 July 2013 (UTC)

That's a good idea. Something like this (though that particular one I linked to is out of stock, there are many other options listed on that page - for a lot less than your original budget.) --Yellow1996 (talk) 01:11, 2 July 2013 (UTC)

With such limited space, watch out for viewing distance. If you sit too close to a larger screen you might notice pixellation especially with older generation models. Also, with gaming, ghosting might become an issue. This is where the refresh rate matters. Current generation monitors have not only higher refresh rates than older TV's but technology that can help to reduce ghosting. You can also consider a plasma TV which has the advantages of better refresh rates as well as true black, compared to LCD/LED, which is brighter and sharper. However, there are pros and cons and the decision is yours... good luck! Sandman30s (talk) 13:37, 3 July 2013 (UTC)

Video colorization

Specifically this Ana Trijox music video here, I know that the text moving feature is an online software program but I am wondering about the color ball things that seem to travel throughout the video and cast shadows change shades of different objects etc. Is that a publicly available web software app/program? Thanks in advance. ^{Market St.⧏} _{⧐ Diamond Way} 07:59, 29 June 2013 (UTC)

The video looks like it makes heavy use of blend modes, which are a device for combining images in fancy ways. I'm not familiar with their use in video editors, but they are commonly used to create fancy still images with programs like Adobe Photoshop or GIMP. Modes such as "overlay", "soft light", and "hard light" give effects resembling those. Looie496 (talk) 13:53, 29 June 2013 (UTC)

Thanks so much Looie496, I will check out your recommendations, also if any other editors have insights I am all ears ;-). ^{Market St.⧏} _{⧐ Diamond Way} 05:27, 30 June 2013 (UTC)

A little bit redundant on my part but those are definitely - as Looie points out - blend modes, particularily soft light. I recall working with photoshop a few years back and doing similar effects; though if you don't have PS already I would reccomend GIMP since it's free! :) --Yellow1996 (talk) 17:33, 30 June 2013 (UTC)

iPhone/iPad volume side design decision

Was it a conscious decision to have the volume on different sides between the iPhones and iPads? When held vertically with the home button at the bottom and the screen facing the user, for the phones the volume is on the user's left side, but for the tablets the volume is on the right side. I'm interested in documented statements by people actually involved in the design process. 75.75.42.89 (talk) 18:07, 29 June 2013 (UTC)

I can't tell you about documents (I guess you'd need to consult a Patent Office for them) but I'm pretty sure that the reason behind this would be functionality for right-handed people. With an iPhone, you hold it in your right hand and your fingers go round the back until the volume buttons are directly under your index and middle fingers or so. With an iPad, it's too big for that so your right hand will always be on the right hand side of the iPad, thus the volume key is under your right index finger by being there instead. Falastur2 ^Talk 19:37, 29 June 2013 (UTC)

I see now. Thanks. As a left-hander, I've always used my thumb on the phone which is why I noticed the difference. 75.75.42.89 (talk) 20:12, 29 June 2013 (UTC)

How left-handers do suffer !!85.211.134.120 (talk) 08:15, 30 June 2013 (UTC)

Yeah, especially for writing! I'm dominantly left handed so I hold the phone in my left hand and put it up to my left ear; though I'm quite ambidextrous so I could do either... --Yellow1996 (talk) 17:39, 30 June 2013 (UTC)

While I agree that it's likely due to right-handed dominance, I'm right handed and always hold my phone with my left hand. I don't know why but I've thought that it might be a sub-conscious choice in order to have my right hand free to do more complex tasks. It might be worth looking into what hand right-handed people hold their phones with. (Or I could just be a freak.) This leaves my thumb to do the volume adjusting on the rocker switch for the volume. Note: I have a Samsung cell phone and my wife has an HTC which both have their volume adjustments on the left side of the phone when looking at it in the same way as the OP's example. Dismas|^(talk) 09:11, 30 June 2013 (UTC)

Nope. Turns out I'm a bit of a freak. According to a study using your right hand to hold your cell phone to your right ear is dominant. And it indicates which side of the brain your speech center is on. There are a number of news articles about this but they all seem to lead back to this study. Dismas|^(talk) 09:22, 30 June 2013 (UTC)

Geolocating

If someone is using a handheld device to edit Wikipedia and you trace the IP address, would the trace give you the device or the internet provider? I'm curious because, when I'm reviewing articles, I sometimes like to trace the location of recurring unregistered editors who are being a nuisance and, lately, many of those traces have been leading to Comcast Cable locations on the East Coast.WQUlrich (talk) 22:53, 29 June 2013 (UTC)

Most likely just the provider and city, but probably not the device. StuRat (talk) 04:11, 30 June 2013 (UTC)

The internet service provider has access to the device location, but that information is not available to the geolocate services. Looie496 (talk) 05:00, 30 June 2013 (UTC)

If they were really causing trouble though you could call the provider and request the information; whether you'd get it or not is another story! --Yellow1996 (talk) 17:41, 30 June 2013 (UTC)

I've tried geolocating myself when I'm on a 3G connection - the closest I get is the mobile phone company's proxy server (about 1000km from my actual location). Roger (Dodger67) (talk) 07:37, 1 July 2013 (UTC)

Try this geolocation demo or similar ones, search the web for something like html5 geolocation demo. Depending on your browser and hardware, you might get as close as a few meters (GPS accuracy) - or not, there are lots of variables in how it is done. This is not done using IP addresses, so it is not applicable to the original question above. 88.112.41.6 (talk) 19:59, 1 July 2013 (UTC)

June 30

Copying to an iPad

How can I automatically copy a spreadsheet ('Numbers') from my Mac laptop to my iPad please? Thanks in anticipation.85.211.134.120 (talk) 08:13, 30 June 2013 (UTC)

One option is to use iTunes File Sharing to transfer your iWork documents. Another option is to save the document to iCloud, and the Mac and iPad will both automatically have the most current revision at all times. Here are setup instructions for iCloud. To use Documents in the Cloud, your Mac needs OS X 10.7.4 or newer. Nimur (talk) 15:27, 30 June 2013 (UTC)

Thanks for this but neither option works for my iPad but my wife's mini iPad gets the transfer without any action by me! What might be going on I wonder?85.211.134.120 (talk) 06:37, 1 July 2013 (UTC)

You might have to have the same iTunes account in use on the Mac and apple device for the iCloud to sync. Graeme Bartlett (talk) 10:49, 1 July 2013 (UTC)

Automatizing tasks or creating macros for web browsers

Is there something like Autohotkey but more suited towards web browser automation? Maybe JavaScript bookmarklets or Selenium? Thanks. --Immerhin (talk) 18:49, 30 June 2013 (UTC)

Greasemonkey -- Finlay McWalterჷTalk 23:17, 30 June 2013 (UTC)

July 1

Internet fax - per page charge, no monthly fee

Is there an Internet fax service that does not have a monthly charge, and charges only per page? All of the ones I found have a monthly fee, but I need this only a couple of times per year, so I don't want a monthly charge. Bubba73 ^{You talkin' to me?} 00:36, 1 July 2013 (UTC)

Check out this service. They claim no monthly charges, no hidden fees and no contracts; simply a per-page charge - exactly what you're looking for. --Yellow1996 (talk) 01:12, 1 July 2013 (UTC)

Resolved

thank you. Bubba73 ^{You talkin' to me?} 23:16, 1 July 2013 (UTC)

256th notes in MuseScore

Does anyone here have any ideas how I could "fake" beamed 256th notes (for printing, playback unnecessary but would be cool to have) in MuseScore? Double sharp (talk) 10:45, 1 July 2013 (UTC)

Ah, figured out a way:

1. Use a 4:2 tuplet so that they will playback correctly as 256th notes but look like 128th notes.
2. Use "Lines" to put a line between the first and second "256th notes".
3. Make the line thickness 0.55sp. It will then have the same width as a beam and you can put it in as such.

Are there any less kludgy ways? Double sharp (talk) 10:52, 1 July 2013 (UTC)

Also, is there a way to get 128th notes without using tuplets? Double sharp (talk) 10:53, 1 July 2013 (UTC)

You can rescore your music so that it does not need 1/256th notes. If you double the tempo, you can notate the same music with simpler measure division. Nimur (talk) 16:11, 1 July 2013 (UTC)

Tell that to Mozart :-) --Phil Holmes (talk) 20:01, 1 July 2013 (UTC)

That's exactly what I happen to be typesetting. ;-) Double sharp (talk) 13:56, 2 July 2013 (UTC)

I just rooted my Samsung Galaxy Victory with SuperSU, Odin, TWRP and BusyBox. How come I still can't transfer my apps to SD with AppMgr Pro III?

I got help from this video and an Android Forum post about how to root. I managed to create a successful root of the phone.

However, when I try to use AppMgr Pro III, Easy App2SD and Link2SD, they still won't let me transfer to my SD card. My SD card had 1.83 GB available, and my SD card has 29 GB available.

AppMgr Pro III still says "The device does not have a real primary external storage, or the primary external storage is emulated. Moving app to SD function cannot be supported by this device." How do I make it "change its mind" now that I've rooted?

Easy APP2SD still shows a pop-up that says "This device does not support APP2SD function." How would I change its mind?

On Link2SD, when I select all 90 movable applications, and press "Move to SD card," another popup gives: "Warning: App2SD is not supported by your device. Because your device has a primary external storage which is emulated from the internal storage. You can link the app in order to move its files to your SD card."

I don't feel sure enough about what Link2SD is asking me to do.

So since I've already rooted the phone, how else do I enable my phone and its app-moving apps to move apps to SD card and still let them operate like they would while still in the internal memory? I've hoped for a solution for a month, so thanks in advance. --70.179.161.230 (talk) 11:20, 1 July 2013 (UTC)

I don't know much about this topic, but maybe you can connect it to the computer and run the shell from there? Is it similar like the Android SDK emulator, where you can run the shell from the computer, maybe it is the same. 190.60.93.218 (talk) 16:43, 5 July 2013 (UTC)

July 2

interference to heart rate monitor

There is nothing wrong with my watch (forerunner 305). I am just wondering, will the heart rate monitor work when I am using the elliptical in the gym? It is a heart rate monitor that is worn below the chest, and pairs with the watch (it is not attached to the watch). The elliptical is about 2-2 1/2 feet from a television. — Preceding unsigned comment added by 99.146.124.35 (talk) 02:19, 2 July 2013 (UTC)

I think it's very unlikely that a TV monitor will generate strong enough electric fields to mess up a heart rate sensor that you wear on a strap that goes around your chest. Are you having problems? Looie496 (talk) 02:27, 2 July 2013 (UTC)

As to whether the sender in the chest strap will be understood by the receiver in the elliptical machine, the answer is "maybe". There's a variety of wireless protocols that such equipment uses - ANT+ seems to be the dominant (the closest there is to a standard), but other systems use other schemes, some of them proprietary. The Garmin Forerunner article suggests they all do ANT+; you'd have to see what the brand of elliptic machine uses. I have gotten a Target Fitness band working with a Life Fitness bike, but neither has markings as to how this worked. In that case, a Bluetooth-like "pairing" paradigm doesn't seem to hold, as my heartrate was shown in the two adjacent bikes too - so presumably each bike was picking the strongest radio signal, if any. Sensibly, the Life Fitness equipment would ignore the radio signal and use the signal from its contact heartbeat sensors (if there was one) - so the people riding those adjacent bikes could grab the handlebars and override the display of my heart rate with theirs. -- Finlay McWalterჷTalk 10:17, 2 July 2013 (UTC)

HP 9845C screenshots?

At the homepage about HP 9845C. There are some really nice pictures [8], [9], and at the demo [10], [11], etc. Is there any free versions of these? Electron9 (talk) 13:10, 2 July 2013 (UTC)

Wow those are pretty neat! So you mean free versions of those exact pictures? I don't think that would be possible - you would have to claim fair use. There might be similar images that are free but those, probably not. --Yellow1996 (talk) 16:10, 2 July 2013 (UTC)

⟍⟍⟍⟍⟍⟍⟍⟍⟍⟍⟍

What do we call this character? ⟍ is a redlink, as is Box (typography). 2001:18E8:2:1020:5DD6:98CF:4B3B:E815 (talk) 13:28, 2 July 2013 (UTC)

mathematical falling diagonal -- Finlay McWalterჷTalk 13:31, 2 July 2013 (UTC)

Hm. On my screen, it's a little rectangle, not the character that displays on your link; I guess I don't have the right font. I was meaning to ask: what's the "official" term for the little box that displays when you don't have the right font installed? 2001:18E8:2:1020:5DD6:98CF:4B3B:E815 (talk) 13:35, 2 July 2013 (UTC)

Exactly. More generally, if a page contains a unicode character that isn't represented by an available font, your browser will draw a placeholder box. Some browsers (e.g. Firefox) will show the hexadecimal value of the character's codepoint (27CD in this case) inside that box, so even if you can't see what the character is supposed to look like, and it's possible to search unicode info sites like the one I listed above for the character by its code. See fallback font and Unicode's "Display of Unsupported Characters" advice. It doesn't render correctly for me either, btw. -- Finlay McWalterჷTalk 13:43, 2 July 2013 (UTC)

So is the box image officially a "placeholder box", "missing glyph", a ".notdef glyph", or something else, or does it not have an official name? 2001:18E8:2:1020:5DD6:98CF:4B3B:E815 (talk) 13:47, 2 July 2013 (UTC)

Beyond those there's also "substitute character", and uncode suggests using U+FFFD � "replacement character" (see Specials (Unicode block)). -- Finlay McWalterჷTalk 13:50, 2 July 2013 (UTC)

Freezing on a Mac

I have a MacBook Pro and recently have experienced freezing when watching films with DVD player and when watching videos or listening to music in iTunes. With the music in iTunes, there is just silence for a few seconds, before the music eventually starts playing again, at the same point where it stopped. With the other two problems, the video freezes but the audio tends to continue. Can anyone suggest anything? A similar issue happened to me a while back with just iTunes and it was solved by repairing disk permissions but that hasn't helped this time. Thanks. meromorphic [talk to me] 20:43, 2 July 2013 (UTC)

Have you tried reinstalling your video drivers? --Yellow1996 (talk) 20:34, 3 July 2013 (UTC)

You really don't do that on a Mac ;-). Check if the Activity Monitor shows some unusual activity. Sometimes a rogue process uses too much system resources. --Stephan Schulz (talk) 20:44, 3 July 2013 (UTC)

Ah - I see! I was actually going to affix "I was hoping that an actual Mac user would respond, but..." to my answer; and luckily for the OP, one has! ;) --Yellow1996 (talk) 21:10, 3 July 2013 (UTC)

Well, I'm more of a UNIX head, but PowerBooks/MacBooks have for a while been the best UNIX laptops one could buy. Not modern Ultrabooks with Ubuntu come close, but not yet close enough... --Stephan Schulz (talk) 21:55, 3 July 2013 (UTC)

July 3

What are these computer games?

First was on an Atari, I think. You play this guy whose spaceship crashes on a planet. The very first scene involves swimming out of your wrecked spaceship before some tentacles grab you. Then you are up on the shore of the lake. You have to move fast or the tentacles will reach out of the water behind you and drag you back into the water. There are some kind of horrible snake/worm things in this first scene as well.

The second was on the Amiga. It is a vertical scrolling platform game. I think it is set on Mars and you play one of two little creatures who are searching for water. There are signs everywhere saying "H2O".

Any ideas? Horatio Snickers (talk) 10:59, 3 July 2013 (UTC)

I'm amazed that I'm stumped for the first one because I am really familiar with Atari games... and is the second one Flood? --Yellow1996 (talk) 17:54, 3 July 2013 (UTC)

The first one: Another World? (I had the Press Start for Game Over trope open some weeks ago, and searching for "tentacle" threw it up.) - ¡Ouch! (^{hurt me} / _{more pain}) 08:00, 4 July 2013 (UTC)

Another World - that's the one! I'm pretty sure the first one wasn't Flood, though. It doesn't look similar to me. If it helps, I think the version I played was a demo given away for free on an Amiga magazine but I have no idea when. Thanks! Horatio Snickers (talk) 15:28, 4 July 2013 (UTC)

Every Amiga game ever released - should be on there somewhere! :) Do you remember anything about the title of the second game? That might make finding it a lot easier than sifting through all those lists (they're in alphabetical order); either way, it's somewhere on that site. --Yellow1996 (talk) 16:30, 4 July 2013 (UTC)

Searching in Windows Explorer

Is it possible to limit searches in Windows Explorer (on Win7) to exact file-name matches? By default when searching for, say, file.ext, it seems to find anything that matches *file*.*ext* Rojomoke (talk) 16:16, 3 July 2013 (UTC)

Never mind. Double quotes are what I needed. Rojomoke (talk) 16:27, 3 July 2013 (UTC)

Speaking on the same subject, is there any way to get Windows 7's search to behave/imitate like Windows XP's search function? I find XP's to be much more powerful and requires little/no confusing syntax (since 7's is all in one search box). -- 140.202.10.134 (talk) 16:43, 3 July 2013 (UTC)

This tutorial may be of some help. --Yellow1996 (talk) 17:48, 3 July 2013 (UTC)

In my experience, the Win7 search is unreliable, even if you follow the above tutorial. I either use Super Finder XT (if I want a GUI) or Grep under Cygwin (seeing as I'm from a Unix background). --TrogWoolley (talk) 22:02, 3 July 2013 (UTC)

Need a complicated, but really cheap site.

A non-profit is looking for someone to create a rather complicated web site. My guess is that it would take an experienced programmer at least 3 months to create it. As the budget is really small (a few thousand dollars at most) I was wondering if there are reliable websites to find freelancers directly at "Bangalore rates", without having to pay for managers, etc. I could do the managing, but I don't have 3 months holiday at hand.. Any ideas? Joepnl (talk) 23:04, 3 July 2013 (UTC)

You can always have a look at guru.com - my brother really swears by them, but I'm rather skeptical, personally. I expect that any money you try to save by going the cheap route, you'll have to pay for later in trouble, and most likely it will require quite a bit of managing. 3 months to create a website sounds like a pretty damn complicated website, too - do you have any reasoning behind this estimate or did you just ballpark it? 64.201.173.145 (talk) 02:33, 4 July 2013 (UTC)

Perhaps if you can describe the complexities they want, we can suggest simpler and more economical ways of accomplishing the same thing. For example: Do they want a zoomable, rotating Earth as a way to zoom in to any of their sites ? How about a non-zoomable, pickable flat map instead ? StuRat (talk) 08:10, 4 July 2013 (UTC)

Thanks both, I'll have a look at guru.com. It's not technically complicated, but there are just al lot of tables, screens, buttons, etc. Joepnl (talk) 13:26, 4 July 2013 (UTC)

Downloading and editing portions of a NSA video on polygraphing

There is an NSA-produced video on the polygraphing process:

• Video: http://www.nsa.gov/media_center/careers/video/Polygraph/index.html
• Transcript: http://www.nsa.gov/media_center/careers/video/Polygraph/Transcript.html - http://www.webcitation.org/6Hqa0BJZZ - http://archive.is/CSpsI

While an NSA-produced video is public domain, it also uses very short excerpts of footage from copyrighted TV shows: Meet the Parents and The Simpsons So, does this mean, for it to be posted on the Commons, the footage of the TV shows has to be cut out (I assume yes, but just making sure)? How should I download the video and do the editing? WhisperToMe (talk) 23:36, 3 July 2013 (UTC)

IANAL, but I would assume your notion of having to cut out the copyrighted material would be correct. As for downloading the videos, I have gotten great use out of DownloadHelper for Firefox. For the editing (the cutting-out of the copyrighted material) any free movie making/editing software should do (though Windows Movie Maker generally doesn't play nice with the types of files you'll get from DownloadHelper and similar addons - you'll need a converter.) --Yellow1996 (talk) 16:38, 4 July 2013 (UTC)

July 4

Memory not entirely recognized by laptop

I have an eMachines E627 laptop, and I have two 2GB memory cards installed (which, according to the technical specifications of the system, is the maximum amount of memory permissible for this model). However, it seems that only the memory installed in the inner slot gets recognized by the system, whereas the memory installed in the outer slot does not. I experimented with the system and determined that each individual memory card works fine when installed in the inner slot. Is this problem common? How can I get the system to recognize all 4GB of memory installed? 24.47.141.254 (talk) 02:43, 4 July 2013 (UTC)

What operating system are you using, and how are you determining that it can't see all the memory? RudolfRed (talk) 03:04, 4 July 2013 (UTC)

Also, have you checked if all 4GB is visible to the BIOS? WegianWarrior (talk) 03:49, 4 July 2013 (UTC)

I am using Windows 7. When I run setup at the beginning, BIOS shows 2048 MB of memory (instead of the expected 4096 MB), and the "System" function from my Control Panel shows 2.00 GB of memory (not 4.00 GB). During my experiments, I tried inserting one memory card into the outer slot and leaving the inner slot empty, and surely enough, the screen did not display anything when I powered up. 24.47.141.254 (talk) 05:08, 4 July 2013 (UTC)

If your BIOS does not recognize more than 2GB, there is no way the OS will be able to see it either. Not sure how to fix though, sorry. WegianWarrior (talk) 06:49, 4 July 2013 (UTC)

Calculating Pearson correlation coefficient with Python

def pearson_correlation(a,b): # Python 3
    if len(a)!=len(b):
        raise ValueError('samples are of unequal size')
    mean_a=mean_b=0
    for i,j in zip(a,b):
        mean_a+=i
        mean_b+=j
    mean_a,mean_b=mean_a/len(a),mean_b/len(b)
    x=y=z=0
    for i,j in zip(a,b):
        x+=(i-mean_a)*(j-mean_b)
    for i in a:
        y+=(i-mean_a)**2
    for j in b:
        z+=(j-mean_b)**2
    return x/(y*z)**(1/2)

This function takes two samples as two lists and returns the Pearson correlation coefficient of them. Is there any thing wrong with it? Czech is Cyrillized (talk) 02:56, 4 July 2013 (UTC)

I see some possible problems:

1. The usual way to make multiple assignments on one line in Python is

mean_a, mean_b = 0,0

I think an expression like

mean_a = mean_b = 0

is assigning mean_a to the result of the expression "mean_b = 0" - although in this case that could be 0 anyway, so this might make no difference.

2. Be very careful with integer division in Python. One of the oddities of Python is that any arithmetic expression that includes only integers returns an integer value - so 1/2 will return 0, whereas 1./2 will return 0.5 because 1. is a float not an int. So your final line

return x/(y*z)**(1/2)

will always return 1 (I think) because the value of 1/2 is 0. You could try

return (float(x)/(y*z))**(0.5)

or you could use the sqrt function, but you have to import that from the math module. And if your lists a and b only contain integer values, there could be a similar integer division problem when you are calculating mean_a and mean_b. A good rule of thumb is that wherever you have a division expression that you expect to return a non-integer value, convert the numerator or denominator to a float to force the result to be a float.

3. Not a problem as such, but the loop where you sum the values in lists a and b is not necessary because Python has a built in sum function that returns the sum of values in a list.

Gandalf61 (talk) 11:40, 4 July 2013 (UTC)

If I understand your mean_a, mean_b calculations properly, and taking into account Gandalf61's wizardly advice about floats, the calculation of those two can be simplified to:

  mean_a = float(sum(a))/len(a)
  mean_b = float(sum(b))/len(b)

turning 5 lines into two (and to my mind being much clearer). edit yeah, I didn't read Gandalf's last point before posting.-- Finlay McWalterჷTalk 12:48, 4 July 2013 (UTC)

You can also change those calculations for x, y, z into sums on list comprehensions, like

x= sum([(i-mean_a)*(j-mean_b) for i,j in zip(a,b)])

- although that's not such an obviously clearer piece of code. -- Finlay McWalterჷTalk 13:01, 4 July 2013 (UTC)

Why cant Graphics processing units keep up with Central processing units?

"Top" GPUs like Tahiti XT in AMD "Radeon 7970" and "7990" series Videocards or as GPU from Nvidia (GK110) in "GeForce GTX 780" or "Titan" labled Videocards work on a frequencies of 900-1000 MHz. Same time "TOP" CPUs from Intel like "core i7 3770K" or "core i7 4770K" run at 3500 MHz and additionally are known to overclock to near 5000 MHz as are CPU from AMD like "AMD FX-4350" starting even from 4200 MHz. Same with "big professional" brands like SPARC T5 (3600 MHz). Why is it that customers willing to pay beyond $ 1000 for a Nvidia "Titan" Videocard only get a 900 MHz GPU and one buying a 3500-4500 MHz CPU like "core i7 4770K" only has to pay $ 300. Also why exactly are GPUs not also clock atleast near with maybe 3000 MHz? --Kharon (talk) 07:18, 4 July 2013 (UTC)

Roughly, because "clock speed" is a really bad measure of performance. See Megahertz myth. Graphics cards do different things per clock, and they can use massive parallelism. In fact, GPUs are much ahead of CPUs in pure processing power, and there is an increasing trend to tap into that performance for general purpose computing. See General-purpose computing on graphics processing units. The high end Radeon Sky 900 is rated at nearly 6 TeraFLOPS, while the best multi-core i7 CPUs are stuck more than an order of magnitude behind that. --Stephan Schulz (talk) 08:29, 4 July 2013 (UTC)

How does solar model works

Do all scientists use computer simulations and solar models to calculate future for the sun or only certain groups of astrophysics does that. Because I have problem think concrete details that is why I thought [12] when scientist do solar model all the variables are well-written. I cannot tell when they guess on the variable they don't know. When astrophysics create solar model do they have to fill out the data entry they are require to fill out all the variables? How can they guess on certain variables if they have to fill in variables on the solar model? If they don't know they can just leave that entry blank. Do solar model require all variables to be fill out in order to run the simulation? Can these two documents I linked above have alot of errors, I can't tell because I am not a concrete thinker--69.233.254.115 (talk) 20:20, 4 July 2013 (UTC)