Iterating through a ruby nested hash with nils?
How to avoid NoMethodError for nil elements when accessing nested hashes?
How do I transfer data and settings from one Apple Watch to another? I have an Apple Watch. I have had it for a while. I just bought a new Apple Watch. (Both are Series 1, just different sizes.)  I would like to transfer all my data and settings from my old Apple Watch to my new Apple Watch and then sell my old Apple Watch.  Is it possible to migrate my profile from one Apple Watch to another?  If so, what is the procedure?  All the search results I have found have to do with moving an Apple Watch to a new iPhone or restoring a backup to the same Apple Watch. Perhaps it is possible to restore a backup from an old Apple Watch onto a new one? I have a dataset with a large number of Yes/No responses. Can I use principal components (PCA) or any other data reduction analyses (such as factor analysis) for this type of data? Please advise how I go about doing this using SPSS. How to disable SMS notification during phone call? I call somebody, or somebody calls me, we are talking. Now, during the call I got SMS and I cannot hear anything because the SMS notification is playing.  So how to disable this notification when call is active? Thank you in advance.  Samsung Galaxy Ace 2, Android 2.3.  Note: I am interested in setting this once and for good. Not something I have to remember to switch off each time I make/get a call. If $\left(1+\sin \phi\right)\cdot \left(1+\cos \phi\right) = \frac{5}{4}\;,$ Then $\left(1-\sin \phi\right)\cdot \left(1-\cos \phi\right)$ If $\displaystyle \left(1+\sin \phi\right)\cdot \left(1+\cos \phi\right) = \frac{5}{4}\;,$ Then $\left(1-\sin \phi\right)\cdot \left(1-\cos \phi\right) = $  $\bf{My\; Try::}$ Given $\displaystyle \left(1+\sin \phi\right)\cdot \left(1+\cos \phi\right) = \frac{5}{4}\Rightarrow 1+\sin \phi\cdot \cos \phi+\sin \phi+\cos \phi = \frac{5}{4}.$  So $\displaystyle \sin \phi+\cos \phi+\sin \phi \cdot \cos \phi = \frac{1}{4}\Rightarrow \left(\sin \phi+\cos \phi\right) = \frac{1}{4}-\sin \phi \cdot \cos \phi.$  Now $\displaystyle \left(1-\sin \phi\right)\cdot \left(1-\cos \phi\right) = 1-\left(\sin \phi+\cos \phi\right)+\sin \phi \cdot \cos \phi =\frac{3}{4}+\sin 2\phi$  Now How can I calculate $\sin 2\phi.$  Help me, Thanks I'm not sure how to prove these basic theorems in propositional calculus. Instead of using the standard axioms, we're supposed to use:   Deduction Theorem (if $\Phi, \alpha \vdash \beta$ then $\Phi \vdash \alpha \to \beta$),  Reductio (if $\Phi, \alpha \vdash \, $, then $\Phi \vdash \lnot \alpha$), Cut Rule (if $\Phi \vdash \alpha$ and $\Psi, \alpha \vdash \beta$ then $\Phi \cup \Psi \vdash \beta$),  Inconsistency Effect (if $\Phi \vdash \, $, then $\Phi \vdash \beta$ for every formula $\beta$), and  the Principle of Indirect Proof (if $\Phi, \lnot \alpha \vdash \, $, then $\Phi \vdash \alpha$),    as all the axioms can be deduced using these theorems.  I don't really know how to start the proofs without using the axioms:  i) prove that $\lnot(\alpha \to \beta) ⊢ \alpha$  ii) prove that $\lnot\alpha \vdash \alpha \to \beta$  Any suggestions on how to start these proofs or any insight at all would be greatly appreciated!  Thanks! Is $\mathbb{R}^\omega$ endowed with the box topology completely normal (or hereditarily normal)? Did the Nazgûl retain their Rings of Power? In The Fellowship of the Rings, Frodo sees the true appearance of the Nazgûl:      He was able to see beneath their black wrappings. There were five tall figures: two standing on the lip of the dell, three advancing. In their white faces burned keen and merciless eyes; under their mantles were long grey robes; upon their grey hairs were helms of silver; in their haggard hands were swords of steel. Their eyes fell on him and pierced him, as they rushed towards him.   The Fellowship of the Ring - J.R.R. Tolkien - chapter 11, A Knife In the Dark   There's no mention of the Nazgûl wearing the rings of power that Sauron gave them, although their hands are referenced. Did the Nazgûl retain their rings of power once they became wraiths? Or did something else happen to the rings once the Nazgûl emerged?&#185;  &#185; As an FYI, I am currently re-reading The Lord of the Rings trilogy and am just pages from being done with The Fellowship of the Ring. I'm very familiar with the Peter Jackson movies. So that's where I'm coming from as far as canon knowledge goes. Let I and J be ideals of a ring R. Show by example that the set of products {xy | x ∈ I, y ∈ J} need not be an ideal Let I and J be ideals of a ring R. Show by example that the set of products {xy | x ∈ I, y ∈ J} need not be an ideal, but that the set of finite sums of products of elements of I and J is an ideal. This ideal is called the product ideal, and is denoted by IJ.   I want to check if my work on the first part makes any sense. I am not sure if I am picking the right example.  If I let R = Z and I = (2) and J = (3) then I has multiples of 2, and J has multiples of 3  6 will divide the product IJ if we add 2 and 3 though we get 5 in IJ, but I am not sure if 5 Divides IJ. Down arrow button for choosing the desired site When searching for the desired SE site, the down arrow key (down) should work in order to choose the site one is looking for and hit enter to visit it, instead of using the mouse point to choose it. Would be pretty convenient. Windows Backup & Restore: What to Keep from AppData? A couple years ago, my father made a backup of one of our computers using Windows Backup and Restore. It was either Windows Vista or Windows 7, not sure which. He backed up the entire computer, including Program Files, AppData, My Documents, everything, and now it is on .zip files on a WD Passport with 300GB, I'm not sure exactly what it is called. Now I am trying to decide which files to keep and which to delete. Most of what we would keep are files, as we would need CD's to use the programs, and I'm pretty sure they would install everything all over again. That pretty much leaves out Program Files, however, I'm not sure about AppData. For example, my mother used Greetings Workshop and wants some files from there, and she may want to keep some default settings she used. I am talking generally here, as I'm sure some programs have different ways of saving things in AppData.  What, if anything, should I keep from AppData, and what should I delete? How to clone/copy all file/directory attributes onto different file/directory? I want to copy the attributes (ownership, group, ACL, extended attributes, etc.) of one directory to another but not the directory contents itself.  This does not work:  cp -v --attributes-only A B cp: omitting directory `A'              Note: It does not have to be cp. What sequence of documents should I read to know "all of" TeX and then LaTeX? Python BeautifulSoup findAll by "class" attribute Tips for getting really good answers on SO The way the askers write questions is a factor in determining how good the answers we get are. Obviously, if you ask a clear, direct question it is easier for a someone to answer you.  But, sometimes I've done that and my questions have still been overlooked.  I've noticed some question-posting methods that aren't exactly obvious, but do help me get better answers.    Some tricks I've learned...   Even if my question is very complicated, I try to write a short question.  People get turned off by longer questions, probably because they think its not worth their time (relative to other questions with equal reputation potential).  After I get some traffic and votes on my question, and maybe some comments like "Can you post the code?" or "Clarify this..." I might post more, but by then I am already getting attention to my question.  So, in summary, even if I know the answer requires a long question, I don't make it long until I've already gotten people to look at it. I use more generic tags when possible.  People are more likely to have c# and linq as a favorite tag, than MethodCallExpression, and I tend to get more views if I use at least one or two general purpose tags along with my more specific tags. I've noticed that if I give my question the performance tag, then SO heavy-weights like Marc Gravell, Jon Skeet and Eric Lippert are more likely to answer my question (especially if I use it in conjunction with a C# tag).  Since having this realization, if I can think of a way to rephrase my question to sound like it is related to C# performance, I will word it as such and tag it accordingly.   "Be polite. SO Users HATE when people be impatient, rude or impolite." - Benny   So,  Does anyone else have any tips for getting better answers and question-recognition on SO?  I think it would be really helpful if everyone contributed their own observations and techniques here.  P.S. This question is probably too long. What is the motivation for including the compactness and semi-simplicity assumptions on the groups that one gauges to obtain Yang-Mills theories?  I'd think that these hypotheses lead to physically "nice" theories in some way, but I've never, even from a computational perspective. really given these assumptions much thought. The lines wrap so much on v1.0.85 that only a few items can be displayed.  Edit: This is on the world's most low end tablet, Azpen A727.  Screenshots of the old:    and new, showing loss of quality Connect to SQL Server with Windows Authentication in a different domain Are any of the alien languages in Star Wars real Earth languages? Are any of the alien languages (other than English and binary) in Star Wars movies or TV shows real Earth languages? On the meta home page I noticed the  is listed as doing something, but cannot figure out what it is.  There is nothing on the  or its , but the recent activity is listed with the same timestamp. How to pass command output as multiple arguments to another command