I need help to change the file system from ext4 to NTFS. I am using this command:  sudo mkfs.ntfs /dev/sda   But I get this output:  /dev/sda is entire device, not just one partition Refusing to make file system here!   I don't have any data on /dev/sda. What should I do?
The Ubuntu installer does not allow me to install on NTFS partitions, but certain circumstances requires me to do so. Is it possible?
After viewing episode 5 of season 6 of Game of Thrones, we have come to know that      the Children of the Forest created the White Walkers.   But it seems that the White Walkers attack the Children of Forest. My question is why they would do so, given their origin. center align equation in ‎\documentclass[11pt,twoside,fleqn]{book}‎ How do I disable notifications in my personal profile for activity on pages I am an admin of? I'm an admin of several pages on Facebook (for technical stuff like RSS imports, etc.), but neither do I contribute content nor do I care about their content.  Still, as an admin, I get notifications (upper left hand, the globe icon) about activity (someone liked this, someone posted that) on those pages in my personal (!) profile .  Does anyone have the same issue? Is there any way to explicitly disable notifications for certain pages?  (This behavior seems to be new, by the way; I'm only seeing those notifications for a few weeks now.) Change bounding box of math glyphs in LuaTeX I'm trying to use the Garamond-Math font in LuaTeX (despite the documentation saying I should use it with XeTeX only :-). It's working more or less OK with LuaTeX, except for some unfortunate glyph combinations, mostly at the end of inline math, such as “where $T$ is the period”.  I used \fbox to draw the bounding box of the glyph and noticed that the bounding boxes are different in LuaTeX:        and in XeTeX:        In XeTeX the glyph fits almost entirely in the bounding box, but in LuaTeX it overshoots far too much.  I'm not a font guy, so I have no idea why this happens. I thought the bounding box was a property of the font, so in my imagination the result should be the same. Thus the first question is: what actually happens that the bounding boxes are different?  The second question, in the title, is: can I change the bounding box of specific glyphs (using LuaTeX) so that the output looks more like XeTeX's?  I tried manually adding some spacing after the glyphs, but this looks hideous and will go down the drain if I happen to change the font or engine, so I'd really like not to do that. I also tried using the italic correction \/ but it seems to have no effect in math.  Here's the code to produce the pictures above:  \documentclass{standalone} \usepackage{unicode-math} \setmathfont{Garamond-Math.otf} \begin{document} \fboxrule=1sp \fboxsep=0pt In Lua\TeX{} this \fbox{$T$} looks horrible, but the \fbox{$X$} looks OK. \Huge\fbox{$T$}\quad. \end{document}   I'm using TL 2018:  This is LuaTeX, Version 1.07.0 (TeX Live 2018)  (format=lualatex 2019.3.29)  13 APR 2019 12:43  restricted system commands enabled. **test.tex (./test.tex LaTeX2e &lt;2018-12-01&gt; Lua module: luaotfload-main 2019-02-14 2.96 luaotfload entry point Include prior knowledge in regression model I've a classical dataset with real attributes and I want to perform a regression.  But, not all the entries in the training dataset are trustworthy; there is an attribute that I can turn into a confidence value (between 0 and 1) to say how much I can trust the label value. For example, if the confidence value is 0, I mustn't take the entry into consideration.  Is there a way to do this? Gauss law and electric flux Can you please explain me what is electric flux. I know it is $\int\mathbf{E}\cdot\mathrm{d}\mathbf{S}$, but in many place its given flux means to flow. But how does electric field "flow"? Also if we assume its the electric field lines (can you also specify what exactly are these) are "flowing" how does $\int\mathbf{E}\cdot\mathrm{d}\mathbf{S}$ give the total electric field lines passing through that area? (can you please elaborate when you explain?)  Pls. I know it shouldn't come here but there is no page for electric flux. Simulate limited bandwidth from within Chrome? Can you explain the "Axiom of choice" in simple terms? As I'm sure many of you do, I read the  webcomic regularly. The  involves a joke about the Axiom of Choice, which I didn't get.     I went to Wikipedia to see what the Axiom of Choice is, but as often happens with things like this, the Wikipedia entry is not in plain, simple, understandable language. Can someone give me a nice simple explanation of what this axiom is, and perhaps explain the XKCD joke as well? How do I prove that $$ a^3+b^3+c^3−3abc = 1 $$ if   $ a = 1+\frac{x^3}{3!}+\frac{x^6}{6!}......$ , $b=x+\frac{x^4}{4!}+\frac{x^7}{7!}....$ , $c=\frac{x^2}{2!}+\frac{x^5}{5!}+\frac{x^8}{8!}......$ ?  I have tried the following :-  I discovered that $a+b+c=e^x$ and that $a=\frac{d(b)}{dx}$, $b=\frac{d(c)}{dx}$, $c=\frac{d(a)}{dx}$ . But I am unable to proceed further with these information. I would like to transfer files between two remote hosts using on local shell, but it seems rsync doesn't support synchronisation if two remotes are specified as follow:  $ rsync -vuar host1:/var/www host2:/var/www The source and destination cannot both be remote.   What other workarounds/commands I could use to achieve similar results? I am trying to use netcat to send a simple message over TCP, e.g. I want to send the digit 1.  So I understood that I write the following in the terminal, after installing netcat  netcat [ip-address] [port]  But how do I specify the message to be sent? i.e. where to I write "1" ? Perl - Package/Module Issues Why do some AC adapters and power supplies generate a whining noise, and what can I do about it? I have an old Facebook account that I created, uploaded a couple of photos and simply ignored (i.e. no friends added). Now, I can't remember the email address associated with the account and I don't remember the password either. How can I find out which email address I had associated with that account?  P.S. I have created a new Facebook account and my picture can be used to identify me (if I can get someone at Facebook to take a look). Other than that, I'm willing to have that old account deleted altogether if recovery isn't possible.  Is there a way to resolve this issue? This is a canonical question and answer developed by the community to help address common questions. If you've been directed here, or your question has been closed as a duplicate, please look through the resources here and use them to shape more specific questions. To browse all canonical questions and answers, navigate to the  tag. This question and answer is owned by the community! If you can improve it and make it more useful, you're welcome to edit it. I am building a trigger, a unit test, or other Apex code. I'm working with sObject records, and trying to access related record information. For example, I might have a structure like this: Account a = new Account(Name = 'Test'); insert a;  Opportunity o = new Opportunity(Name = 'Donation', AccountId = a.Id); insert o;  System.assertEquals(o.Account.Name, 'Test', 'Correct Account associated'); // Assertion fails!  Or, in a trigger, I might be aiming for something like this: trigger ContactTrigger on Contact (after insert) {     for (Contact c : Trigger.new) {         if (c.Account.Name == 'Test') {             // Take some action here         }      } }  Why doesn't this work? Why am I getting null values, or NullPointerExceptions? How to prove $|\sum_{i=1}^n a_i|\le \sqrt{n} \sqrt{\sum_{i=1}^n a_i^2}$ Unique quadratic subfield of $\mathbb{Q}(\zeta_p)$ is $\mathbb{Q}(\sqrt{p})$ if $p \equiv 1$ $(4)$, and $\mathbb{Q}(\sqrt{-p})$ if $p \equiv 3$ $(4)$ I want to prove the assertion:      The unique quadratic subfield of $\mathbb{Q}(\zeta_p)$ is $\mathbb{Q}(\sqrt{p})$ when $p \equiv 1 \pmod{4}$, respectively $\mathbb{Q}(\sqrt{-p})$ when $p \equiv 3 \pmod{4}$.   My first attempt is this. In $\mathbb{Z}[\zeta_p]$, $1-\zeta_p$ is prime and $$ p = \epsilon^{-1} (1-\zeta_p)^{p-1} $$ where $\epsilon$ is a unit.  Since $p$ is an odd prime, $(p-1)/2$ is an integer and  $$ \sqrt{\epsilon p } = (1-\zeta_p)^{(p-1)/2} $$ makes sense and belongs to $\mathbb{Z}[\zeta_p]$.    How do I deal with the $\epsilon$ under the square root?  I guess the condition on the congruence class of $p$ comes from that.  Is this even the right way to proceed?  Uniqueness is not clear to me either.  I thought about looking at the valuation $v_p$ on $\mathbb{Q}$, extending it to two possible quadratic extensions beneath $\mathbb{Q}(\zeta_p)$, then seeing how those have to extend to common valuations on $\mathbb{Q}(\zeta_p)$, but I didn't see how to make it work.  I would appreciate some help. Removal of statistically significant intercept term increases $R^2$ in linear model In a simple linear model with a single explanatory variable,  $\alpha_i = \beta_0 + \beta_1 \delta_i + \epsilon_i$  I find that removing the intercept term improves the fit greatly (value of $R^2$ goes from 0.3 to 0.9). However, the intercept term appears to be statistically significant.  With intercept:   Call: lm(formula = alpha ~ delta, data = cf)  Residuals:      Min       1Q   Median       3Q      Max  -0.72138 -0.15619 -0.03744  0.14189  0.70305   Coefficients:             Estimate Std. Error t value Pr(&gt;|t|)     (Intercept)  0.48408    0.05397    8.97   &lt;2e-16 *** delta        0.46112    0.04595   10.04   &lt;2e-16 *** --- Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1   Residual standard error: 0.2435 on 218 degrees of freedom Multiple R-squared: 0.316,    Adjusted R-squared: 0.3129  F-statistic: 100.7 on 1 and 218 DF,  p-value: &lt; 2.2e-16    Without intercept:   Call: lm(formula = alpha ~ 0 + delta, data = cf)  Residuals:      Min       1Q   Median       3Q      Max  -0.92474 -0.15021  0.05114  0.21078  0.85480   Coefficients:       Estimate Std. Error t value Pr(&gt;|t|)     delta  0.85374    0.01632   52.33   &lt;2e-16 *** --- Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1   Residual standard error: 0.2842 on 219 degrees of freedom Multiple R-squared: 0.9259,   Adjusted R-squared: 0.9256  F-statistic:  2738 on 1 and 219 DF,  p-value: &lt; 2.2e-16    How would you interpret these results? Should an intercept term be included in the model or not?  Edit  Here's the residual sums of squares:  RSS(with intercept) = 12.92305 RSS(without intercept) = 17.69277 How to show that the cohomology of a Grassmannian has a basis consisting of the equivalent classes represented by Schubert cycles? Let $G(r, n)$ be the Grassmannian of the set of all $r$-planes in a $n$-dim vector space. How to show that the cohomology of a Grassmannian has a basis consisting of the equivalent classes represented by Schubert cycles? I am confused since I don't know how to compute the cohomology of a variety (how to construct the co-chain complex). I am really appreciate if you can compute the cohomology of, for example, $G(2,4)$ and show that it has a basis consisting of the equivalent classes represented by Schubert cycles. On googling I got     Random numbers are numbers that occur in a sequence such that two conditions are met: (1) the values are uniformly distributed over a defined interval or set, and (2) it is impossible to predict future values based on past or present ones. Random numbers are important in statistical analysis and probability theory.   What if I want to pick a random integer from the number line ? The number line consists of infinitely many integers. My favorable event is to get a number (random) and the number of events possible is the complete number line i.e. infinity. I won't be considering any limits here as our number line doesn't tend to infinity but does contain infinitely many elements.  Now the probability of getting a random number  P(E) = 1 / ∞ = 0   So I won't be able to get a random number, ever. This implies, never would I ever be able to get a random number.  That's absurd as many of our science topics do depends on things being random.