I typed following command in vim to show white space characters, such as eol, tab, and space.  :set listchars=eol:$,nbsp:_,tab:&gt;-,trail:~,extends:&gt;,precedes:&lt;   This file was cloned from git repository.  Indentation is setup for tabs.  How do I convert indentation to space?   50 addtask listtasks$  51 do_listtasks[nostamp] = "1"$  52 python do_listtasks() {$  53 &gt;-import sys$  54   print('Hello World')$  55 &gt;-for e in bb.data.keys(d):$  56 &gt;-&gt;-if d.getVarFlag(e, 'task', False):$  57 &gt;-&gt;-&gt;-bb.plain("%s" % e)$  58 }$
I would like to convert tab to spaces in gVim. I added the following line to my _vimrc:  set tabstop=2   It works to stop at two spaces but it still looks like one tab key is inserted (I tried to use the h key to count spaces afterwards).  I'm not sure what should I do to make gVim convert tabs to spaces?
Recover EXT4 partition I was trying to resize my EXT4 partition and something went wrong. I lost it. The space in once consumed is now being represented as Unallocated. How do I recover the partition? What is the value of $i^{i^{i^\ldots}}$? What is the value of $i^{i^{i^\ldots}}$?   My effort is the following: If $z, \alpha \in \mathbb{C}$ with $z \neq 0$ then we can write $z^{\alpha}=e^{\alpha \log z} = e^{\alpha [ \log |z|+i \text{ Arg z} + 2 \pi i m]}$ where $ m=0, \pm 1, \pm 2, \ldots$  and Arg z is the principle argument of the complex number $z$. But in above expression we don't have the finite no of exponents, so I am not sure how should I use this formula to the solve above problem. Thanks and Regards! I get “signal out of range” displayed on screen after boot up from fresh Ubuntu installation, if flashes grup in corner for half a sec then it goes to “No Input Signal”, anyone got a clue how to get the grub to load in diffrent resolution with out have access to the file system?   if not i guess my only option is to boot from the cd and edit som files to get grub to load in diffrent resolution?   as it is now i cant get access to grub menu, and i cant get access to login screen, all will give me “No Input Signal”, anyone worked around this? It just struck me that Utility Companies world-wide supply domestic users at either 50/60Hz. It could have been selected to be 10 Hz, or 100 Hz ... whatever  Was 50/60 chosen at random? Is there some rationale involved (efficiency, easier to construct/control etc) in restricting domestic supply to either 50/60 Hz?  In other words, if I were designing a power system, why would I pick 50/60 Hz instead of some other frequency? Displaying and/or searching across thousands of contacts? The Need  Our application has a chat feature that allows our users to chat with other users within their database.   However, we're adding a feature that allows clients to share data between multiple databases as an "Enterprise" configuration, and we've been asked to update the design of the chat feature to allow users to chat with other users within any of those databases.   We've looked at the numbers of possible users in these scenarios, and the number of chat users in these shared database environments can be as many as 5,000.   Users need to be able find people they need to chat with out of these thousands of contacts. However, up til now, we've had a list of contacts the users can browse. Since that is a user expectation, we were hoping to still maintain a browse-able list of contacts. We have ruled out trying to display a list of 5,000 contacts, as this doesn't seem to be anywhere close to useful or usable.   We've come up with three approaches to solve the problem:  Option One  Show a list of contacts from the local database that user's can browse. Have a second tab that allows users to search the "Full Directory", returning results from multiple databases.     Pros:   Allows us to show a browse-able list of relevant contacts  Clearly indicates to users that another source of chat contacts are available   Cons:   Search would be limited to the current tab, meaning users would have to be in the right tab to return the right result Adds a possible source of user confusion: whats the difference between "contacts" and the "full directory"? Adds another tab to what should be a simple chat list     Option Two  Show a list of contacts from the user's local database, but if they search for a contact, include results from other databases as well.     Pros:   Maintains a list of contacts the user can browse Avoids adding adding another tab One search field searches all sources   Cons:   Searching a finite contact list and returning results that weren't in the contact list may defy user's mental model of how the search will work. Not clear that another source of contacts exist. May need to add explanatory text that says "Search to see contacts from the full directory".      Option Three  Add a dropdown that allows a user to select a what to search in: the local database, or the full directory.     Pros:    No additional tab required Indicates to users that another source of chat contacts are available, though not as clearly as option 1   Cons:    Search still isn't universal: the right search category must be selected to return the right result Users may not notice the dropdown or understand intuitively what its function is. May require explanatory text in search results, reminding the user they can expand the search to the full directory     Thoughts?  Right now I'm leaning towards option two, but is there another option I'm not considering here? Is there another alternative worth considering?   Thanks! How have Superman comics dealt with the Man of Steel, Woman of Kleenex problem? When I was a teen and Superman II came out, when Superman realized he and Lois were in love, he de-supered himself in the Fortress of Solitude so he could be with Lois.  Right after he emerged from the crystal cage that drained his powers, the first thing he does is take Lois' hand and escort her to a conveniently placed bed that we had never seen there before.  This implies it was necessary for him to lose his powers so he could have sex with Lois.  The problems involved in this situation are well covered in the wonderful essay by Larry Niven, .  But I also know that Superman has been in the comics for decades.  A friend of mine once said, "Oh, he tells her who he is a lot, but he always makes her forget it again later."  So how have the comic books (since this is Superman's primary medium) handled this?  Were there different ways it was handled, or was it always handled the same way?  Have they literally kept Superman and Lois from having sex for decades?  Or have there been times when they've ended up in bed together?  How do they deal with the issues of the Man of Steel having sex with, and not killing, a woman of Kleenex? Code in beamer presentation Good day! So, I need to present my disertation code to my thesis advisors, but I'm quite unsure how to actually do it in a proper way. I found  showing some ideas.  Is there a way of making the slides 48-67 in beamer without using tikz? Any ideas to implement the whole ideas the author propose?  Thanks in advance. Viruses in wine? The Story  I installed wine some time ago, and after trying out some versions of Cinema 4D that were "free", I looked in the comments of the videos, and saw some people complaining about viruses. I got worried, downloaded and installed MalwareBytes, and scanned my "system". Of course, since MalwareBytes was runnning through Wine, it only scanned ~/.wine/C:. It found many viruses/trojans and I opted to delete them. I did so.  Questions:   Assuming there is any malware left, can this malware spread into my OS? Tell me the entire truth on what can happen. I deleted my entire .wine directory and am planning to uninstall wine later. I am the only user out of the three on this system that runs wine programs, but wine is installed for all. Is that enough, or must I do more? Please be specific on what I should do because I want to be 100% sure that there are no viruses.   I am sure that many others have these questions too, so please answer this question to the point.   Additional information:  Wine was installed with sudo-apt get. The exact commands can be found here:   Commands:  sudo add-apt-repository ppa:ubuntu-wine/ppa -y sudo apt-get update sudo apt-get install wine1.6 -y   I did try to install a font that was a ttf font. I tried to convert it to otf with no success. Then, I placed it in the fonts directory directly. I then saw that some people said it was malicious, and I removed it.  This question was flagged as  a duplicate of this question:  It is not the same. This question is more precise, as it specifies two scenarios involving viruses, not risks of viruses. The other question talked about Internet Explorer; this one does not mention the installation of any programs.  Note: wine was installed with sudo privileges, so does that mean it runs with sudo privileges? I couldn't find anything about Ubuntu acting as a  receiver or sender.   Can it work at all? Are there hardware prerequisites? Is WiFi a requirement or can it work over LAN or another kind of network connection? WiFi direct seems to be a necessary requirement, is it a sufficient one? (i.e. if a system supports WiFi direct does that mean it supports Miracast?) Are there differences in support between receiving/sending? How is the latency? (compared to the competition, i.e. VNC, commercial Miracast devices, etc.) How do I actually use it, if it's difficult?   Specifically, I plan to use it together with an Android phone (4.x Jelly Bean). Responsive Web Design - what should happen when the mobile device is rotated? Currently, the standard behaviour for viewing web pages on a mobile is that:   If viewed in portrait the text is smaller because the width of the device is small and the whole page width needs to fit into view. If viewed in landscape the view 'zooms in' as the width is now wider so that the text is larger and more readable, but with less content on screen as a result.   So, this brings a dilemma. When creating a responsive website what should happen on device rotation? (Not on initial page load, I am referring to what should happen once the site is loaded and you decide to then rotate the screen)   When rotated from portrait to landscape should you:   a) Re-detect the device widths and map the contents according to the new dimensions (thereby retaining the same font / images sizes as when viewing portrait). b) Keep the same dimensions and on rotation just bring the content to fit the window (thereby zooming in the content to make it more readable for viewers if the portrait orientation text is too small).          &ndash; Wireframes created with   Bear in mind that with a traditional web-page viewed in the mobile you have the option of pinch-to-zoom the text, so if it's too small you can zoom in. With a responsive site this isn't an option because the site will fit the dimensions so there is nothing to zoom into.  (I guess there is a third option too - use responsive fonts so that the font sizes change according to the screen width. But that's probably a different question altogether). Ubuntu App Development. Unable to install Ubuntu SDK and buggy Ubuntu emulator How does $cos(x) = \frac{\vec{v} \cdot \vec{w}}{|\vec{v}| \cdot |\vec{w}|}$ make sense? In Multivariable Calculus, the professor said that in order to compute the angle $x$ between two vectors $v$ and $w$, we use the formula: $\cos(x) = \frac{\vec{v} \cdot \vec{w}}{|\vec{v}| \cdot |\vec{w}|}$  He also mentioned "Projection" but I didn't understand much of it. The only thing I got was that we can create a right triangle by drawing a perpendicular line from one vector to the head of the other and compute the angle like that using $\cos$, but I don't understand why we're multiplying vectors, or dividing by their magnitudes…how do those operations make sense?  Also, in the specific example, the result of $\cos(x) = \frac{\vec{v} \cdot \vec{w}}{|\vec{v}| \cdot |\vec{w}|}$ ended up being $1/2 = \pi/2$. Where does $\pi/2$ come from here? I can't understand how we go from $1/2$ to $\pi/2$. I really miss the graphical "Services" tool from older versions of Ubuntu, but I understand why it had to go. I always have terminals open anyway, so I use (because I have to now, I guess) service --status-all to see what services are running. This would be ok except that the command produces output like the following:   [ + ]  winbind  [ ? ]  wpa-ifupdown  [ - ]  x11-common   I'm guessing that those symbols mean something like listening, blocked, or stopped, but which is which? More importantly, why doesn't the man page say? Conversion Error setting value for 'null Converter' - Why do I need a Converter in JSF? Embedding $S_n$ into $A_{n+2}$ I understand that assuming light is quantized implies that if a lower energy interacts with  metal, it is possible that that quanta will not have enough energy to eject the electron. What prevents two quanta from interacting with the electron at the same time, though, and summing to have enough energy to release the particle. Indeed, what if two separate light rays of the same frequency impact the electron, why can't that free it? What are C++ functors and their uses? I keep hearing a lot about functors in C++. Can someone give me an overview as to what they are and in what cases they would be useful? I asked this question for many people/professors without getting a sufficient answer, why in QM Lebesgue spaces of second degree are assumed to be the one that corresponds to the Hilbert vector space of state functions, from where this arises? and why 2-order space that assumes the following inner product:  $\langle\phi|\psi\rangle =\int\phi^{*}\psi\,dx$  While there is many ways to define the inner product.  In Physics books, this always assumed as given, never explains it, also I tried to read some abstract math books on this things, and found some concepts like "Metric weight" that will be minimized in such spaces, even so I don't really understand what is behind that, so why $L_2$? what special about them? Who and how physicists understood that those are the one we need to use? Can I run CAT5/6 cables parallel to electrical cables? I am building a new house and am planning to hardwire network cables into each room.   Can I run CAT5/6 cables parallel to electrical wires without introducing any general safety issues or losing much in connection quality?  Wiring runs for up to 25 metres from patch panel and distribution board in garage to rooms.   My research indicates that is should be fine if they are in separate conduits or if the CAT cables are shielded. Can infinitely many primes lie over a prime?