How to disable rotating to landscape mode?
How can I disable landscape mode in Android?
Multiplying by a $1\times 1$ matrix? For matrix multiplication to work, you have to multiply an $m \times n$ matrix by an $n \times p$ matrix, so we have $$\bigg(m \times n\bigg)\bigg(   n\times p \bigg).$$  But what about a $1 \times 1$ matrix? Is this just a scalar? But every matrix can be mulitplied by a scalar; so do $1 \times 1$ matrices break the rule? Deleted comments leave badge on iOS app When someone leaves a comment that involves you being notified, you get the notification both on the main toolbar on Stack Exchange and as a notification/badge on the iOS app.  If you read a comment on the website and cause the notification to be removed from the toolbar, the badge also gets removed from the iOS app.  However, when a comment that has previously caused a notification/badge to appear on iOS gets deleted, the badge remains on the iOS app while the notification gets removed from the website toolbar.  Could the badge also be removed from the iOS app in this situation? Using headset controls like a smart phone I have a generic pair of smartphone earphones that have the button (along with a microphone) and I would like to use the button as a pause/play key in Ubuntu, like I would on an Android phones music player.  Is there a way to enable this headset control in Ubuntu?  If the headset controls are a hardware feature of audio jacks used in Android phones, the name of that hardware (audio jack) would be appreciated. Take a look at this example schematic:  The chip in question is the  and as you can see power is provided on both sides (with a 100nF cap to smooth noise I guess). Is this strictly required or could you put power into one side and just ignore the other? I know that I have just put power in one side and everything still seems to work fine but I feel uneasy with doing that. I feel that they would not waste pins that could be doing something useful by having an extra pair of power in/out pins. For what purpose does this PIC MCU (and others like it) have multiple power pins? I have a point $(X,Y)$ on an elliptical curve $E(a,b)$ where $a=-3$ and $B$ is a large number that is in hexadecimal from -51BD. To compress this point oficially in a program, we know that every $X$ on the curve has two $Y$'s, one even and one odd. Therefore, we only need to store whether the corresponding $Y$ point we are storing is even or odd. So to store the point $(X,Y)$ now, we shift $X$ ridding of its most significant bit and add $1$ if the $Y$ point is odd. Therefore, one can think of the compressed point being $2 \cdot X+B$ ($B$ is the bit we added to tell if $Y$ was odd or even) since the multiplication by $2$ is implied because of the shift. I understand this completely. It's recovering the original point that has me confused.  Since a point on the curve is given by the equation $y^2=x^3+ax+b$, we can find square roots officially in $\mathrm{GF}(p)$. The following from my spec is what confuses me.  If $p$ is prime and congruent to $3$ mod $4$, one of its square roots is $z^{(p+1)/4} \bmod p$ and the other is $p-z^{(p+1)/4} \bmod p$. How would I solve this? What is $z$?  For example, I know how to extract the $x$ point so let's say I simplify the right side of the equation to be $7$ and $p$ is $11$. Would I be trying to solve for the square root that's equal to $7$ mod $11$? Is the harmonic oscillator potential unique in having equally spaced discrete energy levels? I was wondering if the good old quadratic potential was the only potential with equally spaced eigenvalues. Obviously you can construct others, such as a potential that is infinite in some places and quadratic in others, but that's only trivially different. I am not referring to equally spaced as a limiting behavior either, I mean truly integer spaced.  Any ideas? If not, is there a proof for its uniqueness?  If there are other potentials with equally spaced eigenvalues, can one use them as starting points for a free-field QFT? It would be interesting to know if there is a deeper mathematical relation between all of these potentials and whether they could be used to study interacting systems. Case field mapping with custom object fields? Add markdown toolbar to mobile web On the full site, there's that helpful Markdown toolbar above the post box:   This is conspicuously missing in the mobile site:   It's difficult just to get a bracket on my iPad. Backticks aren't even available. If there's a view that really needs it, i vote mobile. getResourceAsStream() is always returning null What HTML tags are allowed on Stack Exchange sites? Which is the correct tense to use with 'by'? I gave him the money by 6 PM.   I had given him the money by 6 PM.   I can't spot the difference between them and both seem right, but I was told the first one is wrong. Can anyone say, why?  Here is a another set of sentences with the same issue:     By 5 PM I gave him the book.   By 5 PM I had given him the book.   In both the sentences the book was given before 5 PM and no later than 5 PM. But I can't understand then what the difference between them is.   Is it right to use simple past with 'by' at all? If yes, then why and if not, then why is it incorrect to use simple past with 'by'? Projection is an open map Let $X$ and $Y$ be (any) topological spaces. Show that the projection  $\pi_1$ : $X\times Y\to X$   is an open map. How do I enable or disable Apport? The system crash dialog is annoying me, how can I turn it off? I'd also like to know how to turn it back on just in case I need it to report a problem. Decode escaped Url without using HttpUtility.UrlDecode Change font size of labels in figures to any font size I want to change the font size of the label of a figure environment to any font size. It's possible to use the package caption with the argument font=Large for example. But I found no way to choose any font size, e.g. fontsize=28pt.  Here an example code:  \documentclass{standalone} \usepackage{anyfontsize}  \usepackage[font=Large]{caption} %\usepackage[fontsize=28pt]{caption} % not implemented   \begin{document} \parbox[t]{20cm}{  \fontsize{28}{30} \selectfont  \begin{figure}     %\includegraphics{figure.eps}     \caption{\label{fig_req_osnr} \fontsize{28}{30} \selectfont My caption.} \end{figure}  }  \end{document}     Do you have any ideas? Omission of the indefinite article to eliminate ambiguity love between husband and wife   What is the reason that there is no article (e.g. "love between a husband and a wife") in the above? Has some kind of a rule been identified grammatically when it comes to such a case? If I were to guess I think it's because the indefinite article 'a', the purpose of that, is taking a generic sample (or 'instance') from a 'class' (the class of husbands), but in the above sentence you want to refer to the class itself... the husband class and the wife class... and not an 'instance' of them, because it just is more to the point. Do you think this is a fair reasoning? Also, a thought came to me that with the use of the indefinite article, you get a generic husband and a generic wife, which, may not necessarily love each other (for they are not a specific pair of a specific husband and a specific wife who in fact love each other). How to explain the different forms of the Hamilton-Jacobi equation? In Arnold's Mathematical Methods of Classical Mechanics, he derives the Hamilton-Jacobi equation (HJE) using a generating function $S_1(Q, q)$ to get  $$ H\left(\frac{\partial S_1(Q, q)}{\partial q}, q, t \right) ~=~ K(Q, t). $$  However, this is different from what I've seen in other physics texts. For example, Goldstein uses the generating function $S_2(q, P, t)$ to get the equation  $$ H\left(\frac{\partial S_2(q, P, t)}{\partial q}, q, t\right) ~=~ - \frac{\partial S_2(q, P, t)}{\partial t}. $$  Why is there this difference? Are the two equations saying the same thing? Suppose I have a 6 GB page file on an SSD and another 6 GB page file on a traditional mechanical 5400rpm SATA drive.  Does Windows take into account the difference in the performance characteristics between the two drives when deciding which page file to use?  If it matters, I'm asking about Windows 7 and higher.  I reviewed this  but it doesn't appear to factor in the case of dissimilar storage speeds. How can the speed of sound increase with an increase in temperature? How to import Illustrator swatch libraries into InDesign - Adobe Indesign Mac? I have a very reach swatch library in adobe-illustrator like food colors and.... But in adobe-indesign I don't have many colors. Why? Can I import them to indesign?