Am I technically allowed to look up cards during a Magic tournament match?

Am I allowed to look up a card during a game, if it's being played with serious Rules Enforcement? Either to read the full card from the Gatherer, or to try to find the exact card I'm vaguely thinking of.  Two possible scenarios:   An opponent has revealed a card previously, and I want to remember the exact details. (Something like the exact wording of a sorcery, mana cost, keywords on a creature, subtypes, etc. etc.) I have a "name a card and remove it from the opponent's deck" type card, and I want to, say, ask google for "Blue Gearhulk" to remember that it's that that one is called "Torrential Gearhulk".   Obviously, in casual or semi-casual games neither of these are a problem. Any reasonable opponent will just re-reveal the known card (assuming it IS still guaranteed to be known) or will accept "I name the Blue Gearhulk".  Also obviously, it seems unlikely that I (or anyone else) would get to the stage of playing at the REL without knowing the cards too thoroughly for this to be relevant.  But in principle... is it permitted? Or not? (and if not, is there a good reason, or just "we decided 'No'"?)


Change variables so that the following equation depends on one parameter only

I've got the following differential equation: $$\frac{dx}{dt}=rx(k-x) \quad \quad x(0)=x_0$$ I have to perform several changes of parameters/variables so that instead of depending on $x, k, x_0$ the differential equation depends on one parameter only. I've tried $$y=\frac{x}{k} \quad \quad \tau=rt$$ and this way my equation is (where $\dot{y}=\frac{dy}{d\tau}$): $$\dot{y}=\frac{1}{k}y(1-y) \quad \quad y(0)=\frac{x_0}{k}$$ Here I still have two parameters $(k,x_0)$ and I should have only one. Can someone help me continue? Edit: Just to clarify, my final equation should depend on one parameter and of course it will also depend on the variable


Please clarify confusion between chillies and pepper?

Chili and pepper are not the same thing however people just refer to chilies as peppers interchangeably.  As far as I'm aware the difference is that peppers contain pipirine coming from the piper plant(such as black pepper, long pepper) whereas chillies contain capsaicin coming from capsicum plant and this is mutually exclusive.    This scoville chart  shows bell peppers as containing no capsaicin so why is it in the list and is it considered a chili?  I'm confused Please clarify.


Can I use ajax to target multiple form elements from one input?

I'm trying to use ajax to update two different parts of a drupal form from just one form input blur.  I have the standard ajax stuff on my input:  $my_form['my_input']['#ajax'] = array(   'callback' => 'my_callback',   'wrapper' => 'my_target_div',   'event' => 'blur', );   This is working well, swapping out my div when the input is updated ... however I also want to update another form input elsewhere in the form with different code as a result of the blur on my original input.  Is this possible, any ideas?  Edit: For clarity, here's my real world example:   Content type 'movie' Added field 'primary_title' When 'primary_title' is updated my ajax callback checks for similar strings and returns html. The html from the callback is inserted into an empty div.  That part is working great!   I'm trying to also modify the standard node 'title' input, giving it the value of 'primary_title' after I have done some regex to tidy up the string (removing "The" or "A" from the start etc) The result will be two title fields, one with the complete title 'primary_title' and one trimmed 'title' that will be useful for sorting and displaying records.


Preventing SQL Injection: How do I make this query injection proof

New to php & MySQL. Followed a tutorial on Youtube but after messing around a bit I managed to bypass and access my site using admin'# as the username and a blank password.   My code (PHP):    <?php  $username = "***";  $password = "****";  $hostname = "mysql1.000webhost.com";  $database = "***_login";    $dbhandle = mysql_connect($hostname, $username, $password );      $selected = mysql_select_db("a7653250_login", $dbhandle)    or die("Could not connect to database");    $myusername = $_POST['user'];  $mypassword = $_POST['pass'];    $myusername = stripslashes($myusername);  $mypassword = stripslashes($mypassword);    $query = "SELECT * FROM Users WHERE Username='$myusername' and Password='$mypassword'";  $result = mysql_query ($query) or die(mysql_error());  $count = mysql_num_rows($result);    if($count==1){   $seconds = 186400 + time();  setcookie(loggedin, date("F jS - g:i a"), $seconds);   header("location:index.php");}  else{   header("location:loginfailed.php");  }    mysql_close() ?>     I've read about using some sort of parameters but I don't know where or how to use them.  Many thanks


What is the difference between macOS Sierra 10.12.2 Update and macOS Sierra 10.12.2 Combo Update?

According to , both pump up the version to 10.12.2, both have exactly the same changelog:   macOS Sierra 10.12.2  macOS Sierra 10.12.2    The only difference I was able to see was the file size (1.94 GB vs. 2.05 GB).  AppStore seems to mention only the "standard" update, not "combo".    Can somebody explain what are the differences? Thank you.


What is the difference between "kinematics" and "dynamics"?

I have noticed that authors in the literature sometimes divide characteristics of some phenomenon into "kinematics" and "dynamics".    I first encountered this in Jackson's E&M book, where, in section 7.3 of the third edition, he writes, on the reflection and refraction of waves at a plane interface:        Kinematic properties:   (a) Angle of reflection equals angle of incidence   (b) Snell's law   Dynamic properties   (a) Intensities of reflected and refracted radiation   (b) Phase changes and polarization      But this is by no means the only example.  A quick Google search reveals "dynamic and kinematic viscosity," "kinematic and dynamic performance,"  "fully dynamic and kinematic voronoi diagrams," "kinematic and reduced-dynamic precise orbit determination," and many other occurrences of this distinction.  What is the real distinction between  and ?


Checking validity of email in django/python

I have written a function for adding emails to newsletter base. Until I've added checking validity of sent email it was working flawlessly. Now each time I'm getting "Wrong email" in return. Can anybody see any errors here ? The regex used is :  \b[\w\.-]+@[\w\.-]+\.\w{2,4}\b and it is 100% valid (), but I may be using it wrong, or it may be some logic error :  def newsletter_add(request):     if request.method == "POST":            try:             e = NewsletterEmails.objects.get(email = request.POST['email'])             message = _(u"Email is already added.")             type = "error"         except NewsletterEmails.DoesNotExist:             if validateEmail(request.POST['email']):                 try:                     e = NewsletterEmails(email = request.POST['email'])                 except DoesNotExist:                     pass                 message = _(u"Email added.")                 type = "success"                 e.save()             else:                 message = _(u"Wrong email")                 type = "error"  import re  def validateEmail(email):     if len(email) > 6:         if re.match('\b[\w\.-]+@[\w\.-]+\.\w{2,4}\b', email) != None:             return 1     return 0


Irreducible Components of the Prime Spectrum of a Quotient Ring and Primary Decomposition

Recently I encountered a problem (the first exercise from chapter four of Atiyah & McDonald's Introduction to Commutative Algebra) stating that if $\mathfrak{a}$ is a decomposable ideal of $A$ (a commutative ring with unity), then the prime spectrum of $A/ \mathfrak{a}$ has finitely many irreducible components. This follows easily from the recognition that the maximal irreducible subspaces of $\textrm{ Spec } (A / \mathfrak{a})$ are precisely the "zero loci" of the minimal prime ideals of $A /\mathfrak{a}$.   I'm curious about the converse - the proof isn't easily reversed since the notion of minimal ideals of $\mathfrak{a} $ doesn't make sense before we know what we are trying to prove. My intuition says that it is false based on the general premise that images are badly-behaved (and the fact that it isn't part of the exercise.) However, I've had some difficulty constructing a counterexample, so that the main purpose of this post is to ask for a reasonable procedure or heuristic for doing so (or, of course, proof that my intuition is false.)   If it helps, if $\textrm{Spec }(A / \mathfrak{a})$ is irreducible then the nilradical $\mathcal{R}_{A /\mathfrak{a}}$ is prime so that $r(\mathfrak{a}) = \rho^{-1} ( \mathcal{R}_{A / \mathfrak{a}} ) = \displaystyle\cap_{i=1}^n \rho^{-1} (p_i),$ where $p_i$ are the minimal prime ideals of $A /\mathfrak{a}$ and $\rho $ is the associated projection, is also prime. Thanks!


Is there a way to access the Night Light setting in Ubuntu Studio? I could access in the GNOME install but can't fund it in STUDIO.


tail -f but suck in content of the file first (aka `cat -f`)

I need to display whole file before tracking it for a new changes, not only the last 10 lines (yep, I know it's not tail conceptually). In other words, something like cat -f would do, if it would ever existed. Tail's man doesn't give me any ideas. The only option I see right now is to somehow combine cat all but last 10 lines and tail -f output.  Any hints, please?


Operating System Not Found, Media Test Failure Check Cable, BIOS Shows 10GB HDD Size

I have a Dell Inspiron 1564 laptop. my harddisk partitions are not visible when i try to install OS.  In the BIOS the HDD size is 10GB only. But my laptop had 320GB.       on boot it shows:     PXE ROM "Media test Failure- Check cable"   Operating system not found.        on running dell diagnostics it shows:        Hard Drive DST Short Test - Test Results: Not Applicable.   Also, If i insert a live cd, the partitions i had are not visible. When i am trying to install a new copy of OS, there is no partition to select.


prove that $∃ c ∈ (0, 1)$ such that $c^2f(c) = 2\int_0^cxf(x) \,dx$ for a continuous function $f$

Let $f\colon [0, 1] → \mathbb{R}$ be a continuous function. Given, $f(0) = 0$ and $\int_0^1 f(x)\, dx = 0$, prove that $∃ c ∈ (0, 1)$ such that $c^2f(c) = 2\int_0^cxf(x) \,dx.$ I need some help on how to use the fundamental theorem to prove this result. My attempt: Let $F'(x)=f(x)$, the $\int_0^1 f(x)\, dx = 0$ implies that $F(1)=F(0)$. Now we take $H(x)=xf(x)$ and $\int_0^c xf(x)dx=\frac{c^2f(c)}{2}-\int_0^c\frac{x^2f'(x)}{2}dx$. This is where I'm stuck.


I have a masters degree in Physics and I have worked in Italian high school for 15 years. Now I'm 47 and I wish to have a bachelor or masters degree in Math, because I'd like to change job. How difficult might be for me to have a Phd after the degrees, considered my advanced age (even if I don't feel it)?


How to run .msi file in linux? (Ubuntu in my case)

I've been trying to run a .msi file in ubuntu. From what I've read, the .msi file can run on Windows natively, however, is it possible to run the .msi file in Linux(Ubuntu in my case)?


Trouble with executing my code: java.lang.NullPointerException

I just started learning Java required for my course. Everything seems fine, no syntax errors but when I run my code I have an error      Exception in thread "main" java.lang.NullPointerException     at Deck.<init>(Deck.java:18)     at MainDriver.main(MainDriver.java:17)   Here is my code.  Class Card      public abstract class Card {      public CardValue value;     public CardSuit suit;      CardValue [] cardvalue = CardValue.values();     CardSuit [] cardsuit = CardSuit.values();       public Card () {         value = cardvalue[0];         suit = cardsuit[0];      }      public String toString() {         return this.suit + " of " + this.value;     }      abstract boolean CardCompare(Card P1, Card P2);     }   Class Deck      import java.util.Random;  public class Deck  {      Card[] playingCards = new Card[52];      public Deck() {          int cardNumber = 0;          CardValue [] cardvalue = CardValue.values();         CardSuit [] cardsuit = CardSuit.values();           for (int i = 0; i < 4; i++)         {             for(int j = 0; j < 13; j++)    //Error here (Deck.java:18)             {                 playingCards[cardNumber].value = cardvalue[j];                 cardNumber++;             }             playingCards[cardNumber].suit = cardsuit[i];         }     }         public Card draw() {          Random rand = new Random();         int cardDraw = rand.nextInt(52);          return playingCards[cardDraw];      } }   Class Main  public class MainDriver extends Card{      static final int HANDS = 52;      boolean CardCompare(Card P1, Card P2)     {         if (P1.value.ordinal() > P2.value.ordinal())             return true;         else if (P1.suit.ordinal() > P2.suit.ordinal())             return true;         else return false;     }      public static void main(String[] args) {          Deck player1 = new Deck();    //Some reason there's a error here too (MainDriver.java:17)         Deck player2 = new Deck();          int player1Score = 0, player2Score = 0;         int CardCounter = 0;          while(CardCounter < 52)         {             player1.draw();             player2.draw();              System.out.println(player1 + " " + player2);              CardCounter++;         }         System.out.printf("Final score: Player 1--%d; Player 2--%d", player1Score, player2Score);     } }   I don't understand why the MainDriver.java:17 is having an error at all. I used abstract in Card because I will also extend it with other class(have not worked on yet) and I will define a different boolean through there. I also have trouble with comparing the cards in the main driver.  I did not include CardValue and CardSuit but they're public enums with suits(Clubs, Diamonds, Hearts, Spades) & values(Two, Three, all the way to Jack, Queen, King, Ace).


Movie with people on Mars, Mars atmosphere has a problem, and guy saves them all with putting hand on some Martian hand engraving on stone?

What's the movie with people living on Mars, the atmosphere I think having a problem, since in the end the atmosphere gets restored(?) cleaned(?) or something, by the guy placing his hand on a stone engraving of a hand of an alien/martian which is something with three fingers I think?  I watched this on HBO sometime 2007 I believe.


How to prove that convergence in MGF implies Convergence in Distribution?

I know that if the moment generating function of two distribution converges to the same function then the two distribution converges in CDF. But how can we prove this thing explicitly ?


I had this question in mind for long and I think this is the perfect spot to ask.  Consider the following sentences (Just for instance).     We are an equal opportunity employer. However when applying for this job he/she should also mention his/her gender.   So my question is, is there any other proper usage for he/she or his/her instead especially if the description is getting longer ?


Do multiple Gray Merchant of Asphodels trigger each others' enters-the-battlefield effects?

If there is a  on the battlefield and a second  enters, do both cards trigger and opponent loses x life where x is devotion times 2, or does just the one card entering the battlefield trigger?


I have this for loop used to fill html div using JQuery:  for (i = 0; i < count; i++) {                 //console.log(condizioniList[i]);                 var $pendenzaHTML = $("

  <input type='checkbox' name='my-checkbox'  class='checkbox' value=''>

");                  $pendenzaHTML.prop("id", "pendenza"+i);                 $pendenzaHTML.find(".col-80").prop("id", "colItem"+i);                 $pendenzaHTML.find(".col-80 > .titoloPendenza").text(condizioniList[i].descrTributo);                 $pendenzaHTML.find(".col-80 > .scadenza").text("Scadenza: " + condizioniList[i].scadenza);                 $pendenzaHTML.find(".col-80 > .importo").text(condizioniList[i].importo +"€");                 $( "#lista-pendenze" ).append($pendenzaHTML);                  $("#colItem"+i).on("click", function(){                     console.log('.picker-' + i);                     myApp.pickerModal('.picker-' + i);                     $(this).parent().css("background-color","#969696");                     $(".col-80").not(this).parent().css("background-color","#bfbfbf");                     //console.log('.picker-'+ condizioniList[i].pickerNumber);                 });             }       }   I would like to set different click events for each item with different id, like this: #colItem0 onclick will open modal with class .picker-0, #colItem1 will open .picker-1 and so on. In this way all divs will open .picker-3 (count = 3). How can i get this working?


Consider the hyperpower equation  $$x^{x^{x^{x...}}}=2$$  We will use the method that  Let $y=x^{x^{x^{x...}}}$ so $x^y=x^{x^{x^{x...}}}=2$ and $x^2=2$ to give the solution $x=\sqrt2$  However consider another equation such $x^{x^{x^{x...}}}=4$  Use the similar method so we have $y=x^{x^{x^{x...}}}$ to give $x^y=x^4=4$ , this also makes $x=\sqrt2$ as our solution  But the $\sqrt2^{\sqrt2^{\sqrt2^{\sqrt2...}}}$ have to equal to something, not 2 and 4 at the same time.  If there is only one solution $x=\sqrt2$, then what is wrong with the second equation?


How do I remove/delete a folder that is not empty?

I am getting an 'access is denied' error when I attempt to delete a folder that is not empty. I used the following command in my attempt: os.remove("/folder_name").   What is the most effective way of removing/deleting a folder/directory that is not empty?


Let $E$ be a metric $\mathbb R$-vector space, $I$ be a nonempty set and $(\mu_t)_{t\in I},(\nu_t)_{t\in I}$ be families of nonnegative finite measures on $\mathcal B(E)$.  that if $(\mu_t)_{t\in I}$ and $(\nu_t)_{t\in I}$ are tight$^1$ and bounded in total variation norm, then the family of convolutions $(\mu_t\ast\nu_t)_{t\in I}$ is tight and bounded in total variation norm as well.  Now I would like to show the converse: If $(\mu_t)_{t\in I}$ and $(\mu_t\ast\nu_t)_{t\in I}$ are tight, then $(\nu_t)_{t\in I}$ is tight. (Most probably we need to impose a boundedness assumption on $(\mu_t)_{t\in I}$ and on $(\mu_t\ast\nu_t)_{t\in I}$ or even a priori on $(\nu_t)_{t\in I}$.)  For the moment, I'm only able to prove the claim assuming that the $\mu_t,\nu_t$ are probability measures. Under this assumption, the proof goes as follows: Let $\varepsilon>0$. Since $(\mu_t)_{t\in I}$ and $(\mu_t\ast\nu_t)_{t\in I}$ are tight, there is a compact $K\subseteq E$ with $$\sup\left(\sup_{t\in I}\mu_t(K^c),\sup_{t\in I}(\mu_t\ast\nu_t)(K^c)\right)<\varepsilon\tag1.$$ Now $K-K$ is compact and \begin{equation}\begin{split}1-\varepsilon<(\mu_t\ast\nu_t)(K)&=\underbrace{\int_K\mu_t({\rm d}x)\nu_t(\underbrace{K-x}_{\subseteq\:K-K})}_{\le\:\nu_t(K-K)}+\underbrace{\int_{K^c}\mu_t({\rm d}x)\underbrace{\nu_t(K-x)}_{\le\:1}}_{<\:\varepsilon}\\&<\nu_t(K-K)+\varepsilon\end{split}\tag2\end{equation} for all $t\in I$, which immediately yields $$\nu_t(K-K)>1-2\varepsilon\;\;\;\text{for all }t\in I\tag3.$$  Can we drop the probability measure assumption?  EDIT I'm not able to obtain the claim, even with the help of the answer below. If $\varepsilon>0$, the goal is to show that $$\nu_t(E)-\nu_t(K-K)=\nu_t((K-K)^c)<\varepsilon\tag4.$$ If I'm choosing all the constants as generic as possible, we obtain $$\mu_t(E)\le c_1\tag5$$ $$\mu_t(K^c)\le k_1(\varepsilon)\tag6$$ $$(\mu_t\ast\nu_t)(K)<c_1\nu_t(K-K)+c_2k_1(\varepsilon)\tag6$$ $$\mu_t(E)\ge\alpha_1\tag7$$ $$(\mu_t\ast\nu_t)(E)\le c_3\tag8$$ $$\nu_t(E)\le\frac{c_3}{\alpha_1}=:c_2\tag9$$ $$(\mu_t\ast\nu_t)(E)\ge\alpha_3\tag{10}$$ $$\nu_t(E)\ge\frac{\alpha_3}{c_1}\tag{11}$$ $$(\mu_t\ast\nu_t)(K^c)<k_3(\varepsilon)$$ The assumptions that I'm imposing is that $(\mu_t)$ and $(\mu_t\ast\nu_t)$ are bounded above (by $c_1$ and $c_3$) and below (by $\alpha_1$ and $\alpha_3$) in total variation norm and are tight (so that we can find $K$ for arbitrary $k_1(\varepsilon)$ and $k_3(\varepsilon)$). In order to obtain the claim we need to choose $k_1(\varepsilon)$ and $k_3(\varepsilon)$ such that $(4)$ holds. From everything above, we obtain $$\nu_t(E)-\nu_t(K-K)<\frac{c_3}{\alpha_1}-\frac{\alpha_3}{c_1}+\frac{c_3}{\alpha_1c_1}k_1(\varepsilon)+\frac1{c_1}k_3.(\varepsilon)\tag{12}$$ Even if we simplify this by assuming $\alpha_1=\alpha_3$, $c_1=c_3$ and $k_1(\varepsilon)=k_3(\varepsilon)$, the equation $$\frac{c_3}{\alpha_1}-\frac{\alpha_3}{c_1}+\frac{c_3}{\alpha_1c_1}k_1(\varepsilon)+\frac1{c_1}k_3.(\varepsilon)=\varepsilon\tag{13}$$ doesn't seem to admit a solution $(k_1(\varepsilon),k_3(\varepsilon))$ with positive $k_1(\varepsilon)$ and $k_3(\varepsilon)$; unless $\frac{c_3}{\alpha_1}-\frac{\alpha_3}{c_1}\ge0$; which clearly doesn't need to be the case (it is clearly the case for probability measures though ...)  $^1$ Remember that a family $\mathcal F$ of finite signed measures on $\mathcal B(E)$ is called tight if for all $\varepsilon>0$, there is a compact $K\subseteq E$ such that $$\sup_{\mu\in\mathcal F}|\mu|(K^c)<\varepsilon.$$


Where would I be able to download/purchase stencilled background artwork?

What I mean by "stencilled" artwork is cartoonish glyphs for the background of a graphic, visible on  or in the  the  in the top banner.  More than willing to pay, just haven't come across something like this.


Duplicate my question by saying this question already answer

Recently I asked a question on this site and an expert marked my question duplicate, saying.. "This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question". But the mentioned duplicate question doesn't have any answer. So how could one say something like this which is complete invalid. Why they did this by giving invalid statements?  Here's my question


Creating polygons of area surrounded by roads / lines using PostGIS?

I'm currently trying to create polygons that represent the areas surrounded by roads. The roads are stored in PostGIS as points / lines so I have flexibility over what I can do with them.  I'm basically trying to turn the white areas of this example line output into polygons:    Any ideas?    Here is the PostGIS to achieve this (assuming you have a road table full of lines):  SELECT (ST_Dump(ST_Polygonize(roads.geom))).geom AS the_geom FROM (SELECT ST_Transform(ST_SetSRID(geom, 27700), 4326) AS geom FROM road_lines) AS roads


First of all, a disclamer, I am not a sys admin, I was just asked to check why a VM of ours is using a lot of the cpu. It turns out that this process is running for ever on 200% $top     PID   USER       PR NI    VIRT    RES    SHR S  %CPU %MEM     TIME+   COMMAND   11058 www-data  20   0  269564   5812    384 S  185.5     0.1  2:42.95   .resyslogd   After some research I figured out that this is a logger (actually I found that the logger is the rsyslog but i gess resyslog is the same thing. So i noticed that there are alot of connection attempts (from bots I am guessing) that was triggering the logger to write. So I decided to stop allowing passwords for loging in and switched to key authentication. That did nothing for the cpu usage, even though the records on the logger where now less than before. for the random IPs that i was seeing on the logger, I added them on /etc/hosts.deny. After all these the cpu usage has not droped at all. the same process is using more than 100% of the cpu core. I know that the www-data is a web server, assuming apache, and dont know if it actually used for any reason.  Any help is highly appreciated.


Does anyone know how you would type this in latex?  Thank you!


How to solve this and what is this number called?

What is the real number called to which the sequence $$\gamma_n =1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+\cdots+\frac{1}{n} - \log _e n$$ converges and what is the radius of convergence?


values = []          records =  contains two records of different person         values.extend((records.name, records.age , records.gender))  print values   This will print [some_name,age,gender , some_name,age,gender]     Expected output : [[some_name,age,gender] , [some_name,age,gender]]   How can I achieve this?


Can't find p-values in the output from lmer() in the lm4 package in R

I'm a new user of mixed models and through the material I've been reading there are always probability values (p>t) or (p>z) that estimate the importance of a level of a factor in the model. However, when using the lmer() function in R, which supposedly gives you those probabilities, I simply don't find them. Here is the output:   Linear mixed model fit by REML  Formula: Temp ~ depth + (1 | locality)     Data: qminmatrix     AIC   BIC logLik deviance REMLdev  561.3 581.3 -273.7    551.5   547.3 Random effects:  Groups   Name        Variance Std.Dev.  locality (Intercept) 4.7998   2.1909    Residual             4.0433   2.0108   Number of obs: 128, groups: locality, 4  Fixed effects:             Estimate Std. Error t value (Intercept)  22.0103     1.1500  19.140 depth1        1.9564     0.6832   2.864 depth10       2.6624     0.5756   4.625 depth5        3.0209     0.4932   6.125 depthWS      -2.2585     0.5444  -4.149  Correlation of Fixed Effects:         (Intr) depth1 dpth10 depth5 depth1  -0.157                      depth10 -0.175  0.189               depth5  -0.213  0.313  0.458        depthWS -0.191  0.334  0.373  0.441


Can I bring duty free liquids through LIM-CDG-LHR?

Similar to  regarding transit on a DUB-ORD-PDX route, can I make duty-free purchases (e.g. alcohol) in Lima, and return with it to London via Paris (LIM-CDG-LHR), and bring the liquids with me?  I also note that  is similar, though less specific about the intermediate airport.  I don't know whether that would make a difference (i.e. whether individual airports have different mechanisms which might specifically allow or preclude such a thing).   is vague on the subject, while  says that it simply can't be done without the liquids being confiscated.   The value of the drink is unlikely to be sufficient to make it worth buying a suitcase at CDG and checking that in, though a collapsible holdall might be one solution, if that's a possibility.  I just find it frustrating that something which should be easy is made so difficult.  [Edit] The return flights (AF483 and AF1080) both use terminal 2E at CDG, which (according the the easycdg site in DCTLib's answer) means I'll definitely be going through a security check.


Is it possible to run 64-bit software on a 32-bit operating system?

I have a program that is designed for a 64-bit OS, but I only have a 32-bit OS at the moment. Is there any way to convert the program to 32-bit or install the 64-bit program on a 32-bit OS?


Does wall of force allow heat through? Can it be used as insulation?

Wall of Force states      Nothing can physically pass through the wall.   Is thermal energy, heat, a "thing" that can pass through a wall? Could you use wall of force to insulate yourself from a very cold, or very warm, environment, assuming you don't suffocate?


If a creature with Multiattack is affected by Haste, can it make two Multiattacks?

It's a fairly straightforward question.   A creature has a Multiattack option, and it also can cast the Haste spell. While under the effect of Haste, can it use the second Action to take another Multiattack Action?  My main concern is the clause of the Haste spell that limits the number of attacks made from taking the Attack Action. This is a different Action, though.   Then there is the concern of being able to use Multiattack at all, because Haste says what kinds of Actions you can take.


Since  in titles, and there's not even a way  (or ) we all know users just get around that filter by typing various permutations of the word "problem".  The filter has . The bottom line there was:     "Hacking around" the filter is in fact very very rare.   I beg to disagree. I tried searching Stack Overflow for the following variations of the title:  problme probelm probeml probmle probmel prolbem prolbme prolebm prolemb prolmbe prolmeb proeblm proebml proelbm proelmb proembl proemlb   These are just a couple of permutations from 5040 possible ones. I also tried searching for variations with left out letters, like proble, or prblm. Here's just a graph of a subset from maybe 20 searches—but in reality, there might be more ways to get around the filter:    Was this ever intended? I know it saves a lot of bad titles from being created, but on the other hand it enforces even worse titles as well. 3% based on the  aren't much, but they're 3% crap the filter actively provokes.  Now, my questions up for discussion are:   What are we going to do about this large number of porblematic posts? It seems almost impossible to fix all those. We now have a really good review system that allows people to dig through low quality posts the entire day, so that'd be a way to address this of course. Are there any plans of getting rid of the filter again? This, at least, would give you a good indicator of poor quality. If a post title contains the word "problem" you instantly know something's off. Why not have it reviewed? I understand that some people will choose a better title after being blocked, but I don't even want to start looking at the number of those who merely did a s/problem/issue, or even worse, just used "problems" (because that's not blocked, just sayin').   In the end I'm just thinking if there was a way to clean up the back log on this, or how to prevent more posts of this sort in the future, even with a title filter in place if it has to be.


I want to determine $$\lim\limits_{(x,y) \to (0,0)} \frac{x^2·y^3}{x^4+y^6}$$  I'm sure the limit exists, it's zero because I tried to find other different limits in line and parabola points ($(x,mx)$ and $(x,mx^2)$) but every time I got zero. So, I have to use the definition or sequences to confirm.


Installing Ubuntu on a 32gb Notebook with a failed Windows 10 Installation

I tried to update Windows 10 on a Toshiba Notebook, but after formatting the main Partition it just keeps going into a loop and won't install. The notebook only has 32gb max storage, so have decided I would like to run Ubuntu instead. I have downloaded the Ubuntu ISO on may main Laptop. I have a 32gb SD Card. How do I install Ubuntu either from  the SD Card or a USB Stick. My notebook does not have a CD drive. Many Thanks


I'm a neophyte user trying to set my system up to program in PhP via Ubuntu. I have a cd with version 12.10 and would like to know how to upgrade after install and install packages for PHP... I'm guessing is what I need to do .... -- sooo I see that my version is no longer supported, how do I get the latest version


On every metric space $(T, d)$ metric $d:T^2 \to \mathbb{R}$ is continuous function? How to prove it?


Aptitude not asking for my consent when performing successive tasks

I am having this weird issue with aptitude: when I perform multiple successive tasks, it does not asks for my consent (i.e. type y or n to proceed) every time.   As an example, I was installing cuetools and it asked for my consent before proceeding (see the seventh line):  user@host:~$ sudo aptitude install cuetools  [sudo] password for user:  The following NEW packages will be installed:   cuetools flac{a} python-mutagen{a} vorbis-tools{a}  0 packages upgraded, 4 newly installed, 0 to remove and 4 not upgraded. Need to get 398 kB of archives. After unpacking 1.628 kB will be used. Do you want to continue? [Y/n/?] y Get: 1 http://co.archive.ubuntu.com/ubuntu xenial/universe i386 flac i386 1.3.1-4 [147 kB] Get: 2 http://co.archive.ubuntu.com/ubuntu xenial/universe i386 python-mutagen all 1.31-1ubuntu1 [102 kB]                                         Get: 3 http://co.archive.ubuntu.com/ubuntu xenial/universe i386 vorbis-tools i386 1.4.0-7ubuntu1 [105 kB]                                         Get: 4 http://co.archive.ubuntu.com/ubuntu xenial/universe i386 cuetools i386 1.4.0-2 [43,2 kB]                                                   Fetched 398 kB in 24s (16,4 kB/s)                                                                                Selecting previously unselected package flac. (Reading database ... 209720 files and directories currently installed.) Preparing to unpack .../archives/flac_1.3.1-4_i386.deb ... Unpacking flac (1.3.1-4) ... Selecting previously unselected package python-mutagen. Preparing to unpack .../python-mutagen_1.31-1ubuntu1_all.deb ... Unpacking python-mutagen (1.31-1ubuntu1) ... Selecting previously unselected package vorbis-tools. Preparing to unpack .../vorbis-tools_1.4.0-7ubuntu1_i386.deb ... Unpacking vorbis-tools (1.4.0-7ubuntu1) ... Selecting previously unselected package cuetools. Preparing to unpack .../cuetools_1.4.0-2_i386.deb ... Unpacking cuetools (1.4.0-2) ... Processing triggers for man-db (2.7.5-1) ... Processing triggers for mime-support (3.59ubuntu1) ... Setting up flac (1.3.1-4) ... Setting up python-mutagen (1.31-1ubuntu1) ... Setting up vorbis-tools (1.4.0-7ubuntu1) ... Setting up cuetools (1.4.0-2) ...   Almost immediately after that I installed shntool and wavpack but the system installed them without asking for my consent:  user@host:~$ sudo aptitude install shntool  [sudo] password for user:  The following NEW packages will be installed:   shntool  0 packages upgraded, 1 newly installed, 0 to remove and 4 not upgraded. Need to get 71,8 kB of archives. After unpacking 283 kB will be used. Get: 1 http://co.archive.ubuntu.com/ubuntu xenial/universe i386 shntool i386 3.0.10-1 [71,8 kB] Fetched 71,8 kB in 1s (59,9 kB/s) Selecting previously unselected package shntool. (Reading database ... 209823 files and directories currently installed.) Preparing to unpack .../shntool_3.0.10-1_i386.deb ... Unpacking shntool (3.0.10-1) ... Processing triggers for man-db (2.7.5-1) ... Setting up shntool (3.0.10-1) ...  user@host:~$ sudo aptitude install wavpack  [sudo] password for user:  The following NEW packages will be installed:   wavpack  0 packages upgraded, 1 newly installed, 0 to remove and 4 not upgraded. Need to get 57,2 kB of archives. After unpacking 165 kB will be used. Get: 1 http://co.archive.ubuntu.com/ubuntu xenial/universe i386 wavpack i386 4.75.2-2 [57,2 kB] Fetched 57,2 kB in 1s (43,6 kB/s) Selecting previously unselected package wavpack. (Reading database ... 209857 files and directories currently installed.) Preparing to unpack .../wavpack_4.75.2-2_i386.deb ... Unpacking wavpack (4.75.2-2) ... Processing triggers for man-db (2.7.5-1) ... Setting up wavpack (4.75.2-2) ...   So my question is: why is aptitude not asking for my consent every time and how can I make it do it?    NOTE:  Asking this question elsewhere I got the suggestion to make sudo ask for my password every time I invoke it. I did it (as can be seen in the logs) but clearly this is not the solution to my problem.


I have already successfully installed Arduino IDE 1.8.5 on Ubuntu 16.04. Now, I am having trouble getting programs to upload from my PC. I have a Mega 2560, I am using Arduino IDE 1.8.5, on Ubuntu 16.04. I read and tried he suggestions from other questions on Ask Ubuntu, but all of those seem to be more about getting the program installed. I have tried multiple times, and I am sure I have followed the install instructions to the T, but there is something else still in the way. My specific problem and question is about the upload process, once a program has been written.  I installed Arduino IDE in my /home directory  I can see /dev/ttyACM0 in Tools > Ports, which is selected, and Tools > Boards > Arduino/Genuino Mega or Mega 2560 is shown as the board.  The error I am getting is:  avrdude: stk500v2_ReceiveMessage(): timeout avrdude: stk500v2_ReceiveMessage(): timeout avrdude: stk500v2_ReceiveMessage(): timeout avrdude: stk500v2_ReceiveMessage(): timeout avrdude: stk500v2_ReceiveMessage(): timeout avrdude: stk500v2_ReceiveMessage(): timeout avrdude: stk500v2_getsync(): timeout communicating with programmer An error occurred while uploading the sketch   I already did sudo chmod a+rw /dev/ttyACM0, sudo usermod -a -G dialout icymike, and sudo adduser icymike tty which fixed a different issue, but did not help my case.  I am pretty sure it is Ubuntu, because I installed and used Arduino IDE 1.8.5 with no problem on a Mac. I am not finding much online, outside of "grayed out Ports menu", and changing USB permissions. I think I am missing some key point.   Does anyone happen to have the specific combination of Arduino IDE 1.8.5, with Ubuntu 16.04? How did you get it to work? Should I mess with the Programmer options?


Why do the Natural Earth shapefiles like ne_110m_countries_admin_0.shp have a geometry-type POLYGON, while it should be MULTIPOLYGON (at least when I understand  correct. E.g. USA48 + Alaska + Hawaii is Multipolygon)


Sharp interpolation inequality for Lebesgue spaces

Suppose $f\in L^{p}(\mathbb{R}^{n}) \cap L^{q}(\mathbb{R}^{n})$. How can I prove that for any $p \lt r \lt q$,  $$ \lVert f \rVert_{r} \leq (\lVert f \rVert_{p})^{(1/r-1/q)/(1/p-1/q)} (\lVert f \rVert_{q})^{(1/r-1/q)/(1/p-1/q)}\:? $$ I tried using Hölder to show that $f$ is in $L^{r}$ but I'm completely lost on how to go about it...


Make Textbox with Value of All Spaces Invalid

I have these scripts...   Name: <input type="text" id="inputName" onblur="verifyName(this.value)">   <script type="text/javascript">     function verifyName(nameInput)     {        if(nameInput=="")        {           // error           alert('please enter your name');        }        else        {           // accepted        }     }  </script>   This will display an error if the user don't want to enter his/her name on the textbox.  What if the user is lazy and he/she will enter " " (a space or more) as a name? This can be accepted by the JavaScript. It will return false on the if condition.  But I want the user not to enter only spaces. Is there any way to do that?  Note: Any number of spaces (without any letters) inputted are invalid.    If the user inputs one of the texts below, JavaScript should accepts/rejects the input as follows...  "John" --> valid "" --> invalid "John Doe" --> valid "    " --> invalid "John     Doe" --> valid (can be edited to remove too many spaces) "      Kim" --> valid (can be edited to remove too many spaces) " " --> invalid


using var foo = function() instead of function foo()

I was going through this code :  https://raw.githubusercontent.com/douglascrockford/JSON-js/master/json_parse.js   All functions in this file are defined as   var foo = function() {}   instead of   function foo(){}   I am quiet aware of what each style represents and how to use them. However I am yet to see a convincing answer on what the advantage of using the first pattern over the second one is.  Is it just because.. "functions are first class objects .. they can be assigned and tossed around.. so why not??"  or is there some solid reason behind this ?


how to make realistic water texture in blender 2.82

I am trying to get something vibrant but realistic for some gentle flowing water like if you were pouring it out of a glass on a table. this is what I got so far but it looks more like paint.


A lot of questions about this have unsatisfying answers that either argues how unsafe RSA is when $p=q$ or points out that $\phi(n) \neq (p-1)(q-1)$ for $p=q$.  However, I'd like to know why the RSA fails, i.e why the Decipher $R$ is not equal to the Message $M$ when $p=q$, regardless of safety concerns and assuming the public and private keys are just blindly computed in modulo $(p-1)(q-1)$.


Why the head of linked list in java is not getting changed (although objects in Java are passed as reference)?

The following code is supposed to increment the head pointer to the next node in linked list. However, it doesn't do so. But the value of head data is being changed.  The changeHead(Node head) method is changing the head of the linked list as the next node of the linked list.   Could anybody please help me out why only data value is getting changed but head pointer of the linked list is not getting changed ?  class Node { int data; Node next; Node(int data)   {    this.data=data;    this.next=null;   } }  class LinkedList {  Node head;   public LinkedList() //constructor for LinkedList class  {   this.head=null;    }   void insert(int data)  {   Node s=new Node(data);   if(head==null)   {     head=s;   }   else   {    Node t=head;    while(t.next!=null)        t=t.next;    t.next=s;   } } }  class Main {     public static void main(String[] args)      {        LinkedList ll=new LinkedList();        ll.insert(1);        ll.insert(2);        ll.insert(3);        ll.insert(4);        printList(ll.head); //calling method to print the list        changeHead(ll.head); //changing the head to the next node        printList(ll.head); //calling method to print the changed list      }    static void printList(Node head)     {        Node t=head;        while(t!=null)        {             System.out.print(t.data+" ");             t=t.next;        }        System.out.println();     }      static void changeHead(Node head)       {       head=head.next;      }    }   Output: 1 2 3 4  1 2 3 4  Expected output: 1 2 3 4 2 3 4  /*However if I change the function changeHead(Node head) as */ static void changeHead(Node head)  {   head.data=444;  }   then the output is as per expectations i.e.  1 2 3 4 444 2 3 4


Do I need an airport transit visa for layover in Germany?

I hold an Indian passport.  I'm travelling to Romania with a valid visa. I have a 5 hour layover at Munich international airport and 3 hour layover at Frankfurt international airport on the way back from Romania.  All the flights are of the same airline. Everywhere on the internet it says I need an airport transit visa.  However I met a person who said he didn't get a transit visa and still successfully went to Romania and back.


Cant find much documentation regarding over committing of memory for VM's on a KVM host

Most operating systems do not use 100% of the available RAM all the time, having said that I am unable to find an approximation for this over provisioning. CPU cores is not a constraint for me,  I have a 64 GB KVM host, I would like to provision multiple 8GB machines, the machines remain under utilized for most of the time but always in running state, I would like to know the maximum acceptable number of VM's that can be provisioned on this setup, without hitting any bottlenecks. The underlying storage is hard disk drives, with no SSD so there is little room for swap memory as it may impact performance


$X^{p^n} - a$ is irreducible if $a \in K$ has no $p$-th root?

Exercise from Lang.  I am trying to show that if $char K = p$ and $a \in K$ has no $p^{th}$ root (implying that K is an infinite field) then $X^{p^n} - a$ is irreducible for all positive integer $n.$ I am stumped.  First I tried $n = 1.$ If $X^p - a$ is reducible then $\prod f_i = X^p - a$ where $1 < deg(f_i) < p$ and $f_i$ irreducible. Clearly $deg(f_i) > 1 $ as otherwise it would mean $a$ has a $p^{th}$ root in $K.$ Now $X^p - a$ is not separable by the first derivative test. Yet each $f_i$ is separable by the first derivative test. Hence, two of these polynomials have a common zero which is a contradiction.   I cannot, however, generalize this method for $n > 1.$ Is there another way to approach this?


I've scoured the web, but I'm sick of reading "scan your computer for viruses" and "upgrade your RAM" on answers to similar questions to this. I understand that dwm.exe is for (simply put) caching bitmaps for things like Aero-peek and similar, but as far as I have read it shouldn't be using vast amounts of memory.  My colleague and I both have 4GB of RAM, Core 2 Duo, blah, blah -- essentially they're pretty capable. His dwm.exe is running at around 30mb, mine is currently running at about half a gig, though it does fluctuate quite a lot. This is the same while running the exact same applications (currently Zend studio, FireFox (with firemin - low memory usage), Outlook). Every so often I will get a notification asking me if I want to switch to Aero Basic because it's using too much memory, and sometimes it will just switch itself to basic and let me know why.  I know it's possible to stop it switching, but I want to know why it is using too much memory otherwise it's just papering over the cracks.  One thing to add is this seems to have started after a robbery on Monday, where two of my monitors were stolen, and I had to temporarily use a couple of alternative monitors. I am now using brand new monitors but the problem is the same. All drivers installed and working seemingly fine.  Any ideas why the usage is so high?  We are using windows 7 64-bit Professional.


I've been using sed for quite some time but here is a quirk I came around with, which I am not able to resolve.   Let me explain my problem with the actual case.    Scene#1  printf "ls" | xclip -selection clipboard echo "ls" | xclip -selection clipboard   In the first command, I pipe printf output to xclip so that it gets copied to the clipboard. Now, printf, unlike echo does not insert a new line at the end by default. So, if I paste this content into terminal, the ls command that is copied does not automatically run.   In the second, there is a new line at the end, so pasting the clipboard content also results in the running of the command in the clipboard.   This is undesirable for me. So, I wanted to remove the newline using sed, but it failed, as explained in the scene below.  Scene#2  echo "ls" | sed -r 's/\n//g' | xclip -selection clipboard   The content in the clipboard still contains new-line. When I paste it into terminal, the command automatically runs.   I also tried removing carriage return character \r. But nada. It seems I am missing something very crucial/basic here.


Consider this script:  \documentclass{article}                                                                                %\usepackage[latvian]{babel} \usepackage{listings} \begin{document}                                                                                \end{document}   I get an error   (/usr/local/texlive/2018/texmf-dist/tex/latex/listings/listings.cfg)) (./latvianpres.aux)  ! LaTeX Error: No counter 'chapter' defined.   if I uncomment the line  %\usepackage[latvian]{babel}   What is the problem and how to solve it?


Multiple on-the-fly filtering based on markers' features on leaflet

I would like to filter the markers on my (geojson) layer according to two features: year and type of event, ideally using both filters (year and eventType) as check-boxes without using layerGroup at all. I would like to be able to click on a checkbox and update dynamically the markers by filtering them according to feature.properties.eventType too, in addition to the year displayed, something like    <input type="checkbox" id="all" name="all" value="all">   All   <input type="checkbox" id="funfair" name="funfair" value="newsletter">   Funfair   <input type="checkbox" id="trade" name="trade" value="trade">   Trade   <input type="checkbox" id="exhibition" name="exhibition" value="exhibition">   Paid exhibition   etc... which would trigger a  filter: function(feature, layer) {   return feature.properties.eventType == value-of-checkbox; }   I have five types of eventType. So, for instance, if 1890 is checked, the map is showing all 1890 events, no matter what kind of event it is (because by default it would show all events). If the user checks the 'funfair' and the 'trade' checkbox, though, I want the map to show only the 1890 events of the funfair and trade kind, and not other kind of events.  This is my complete script, which so far is working fine with filtering by year.  var oldmap = L.tileLayer('address', {   maxZoom: 12 }),  var modernmap = L.tileLayer('https://api.tiles.mapbox.com/v4/{id}/{z}/{x}/{y}.png?access_token={accessToken}', {   maxZoom: 12,   id: 'mapbox.streets',   accessToken: 'mytoken' });  var map = L.map('map', {   center: [40.1857864,-4.5536861],   zoom: 7,   layers: [oldmap, modernmap] });  var baseMaps = {   "Old map": oldmap,   "Modern map": modernmap };  var jsontest = {"type": "FeatureCollection",   "features": [     {       "type": "Feature",       "geometry": {         "type": "Point",         "coordinates":  [ -16.5471268,28.4136726 ]       },       "properties": {         "Name":"Point1",         "year":'1892',         "eventType":"funfair",         "notes":""       }     },     {       "type": "Feature",       "geometry": {         "type": "Point",         "coordinates":  [ 2.1753895,41.3767925 ]       },       "properties": {         "Name":"Point2",         "year":'1890',         "eventType":"trade demonstration",         "notes":""       }     }   ]};  var mapLayerGroupsYear = [];  function onEachFeature(feature, layer) {   var year = mapLayerGroupsYear[feature.properties.year];   if (year === undefined) {     year = new L.layerGroup();      //add the layer to the map     year.addTo(map);      //store layer     mapLayerGroupsYear[feature.properties.year] = year;   }    //add the feature to the layer   year.addLayer(layer);    }   var myLayer = L.geoJSON(jsontest, {   onEachFeature: onEachFeature })  L.control.layers(baseMaps, mapLayerGroupsYear).addTo(map);   I am a beginner with leaflet so please forgive the dumb question, in case it is.


Can I prevent my full screen windows from being mixed around?

I use my Mac for personal, school, and work use and as you can imagine it's really easy to get cluttered up with a ton of windows. The solution I devised is separate desktops for home and work, separate full screen safari tabs, separate Xcode windows, etc. The only problem is macOS loves to jumble to ordering around. When I click links in mail they will open in safari, but then the safari window will move around in mission control. I don't want that. I want the work windows to stay together and the home windows to stay together. Is there any way to keep these windows in their place?


Step-by-Step Solution for $x^{1/x}=2^{1/2}$

I came across the equation $$x^{1/x}=2^{1/2}$$ where $x\in\mathbb R$. One can immediately see that $x=2$ is a solution, but it is easy to miss that $x=4$ satisfies the equation as well. Verfiying that $2,4$ are solutions is not hard, but how would one go about formally solving this equation, i.e. how could one solve for $x$? I am asking because if the equation was  say $x^{1/x}=2^{1/3}$ then the two solutions would not be obvious.  Basically, how to fill in the dots: $$x^{1/x}=2^{1/2} \iff \ldots\iff x=2 \text{ or } x=4$$


How to retrieve a file from a server via SFTP?

I'm trying to retrieve a file from a server using SFTP (as opposed to FTPS) using Java. How can I do this?


Natural number that has a remainder of $1, 2, 3, 4$ respectively after dividing...

A number when divided by 2 leaves a remainder of 1. When it is divided by 3 leaves a remainder 2. When it is divided by 4 it leaves a remainder of 3. And when it is divided by 5 it leaves remainder of 4. What should be the number ?  Note : I already formulated some formula but I think it might not work:  x = 2a + 1 x = 3b + 2 x = 4c + 3 x = 5d + 4


Any example of manifold without global trivialization of tangent bundle

It is said for most manifolds, there does not exist a global trivialization of the tangent bundle. I am not quite clear about it.  The tangent bundle is defined as $$TM=\bigsqcup_{p\in M}T_PM$$  So is the above statement saying that generally $$ \bigsqcup_{p\in M}T_PM\neq M\times\mathbb{R}^n? $$  But I think the tangent space is just attaching a $\mathbb{R}^n$ to every point on $M$, so I wonder what's the reason for it is not a product space?  Plus, when defining trivialization, we have a lot of constraint on the function $F:TM\rightarrow M\times V$, can anyone explain the necessity of those constraint?  At last, does $S^2$ has a global trivialization?    Update:  Following is my attempt to trivialize $S^2$, but meet some problem. I think it may reflect some aspect in the impossibility to trivialization of $S^2$, isn't it?  We want to define trivialization $F:TS^2\rightarrow S^2\times \mathbb{R}^2$. First of all, $F$ should be well-defined.   There are 3 different approach to define a tangent space, here I take the definition via chart.  So, an element in $TS^2$ is $\left[(p, v, (U,\varphi))\right]$, and of course I try to define its image to be $(p, v)$.  Then the problem comes. Because we need at least 2 chart to cover $S^2$, so when taking another representative $(p, w, (V,\phi))$ of the equivalent class $\left[(p, v, (U,\varphi))\right]$, we map it to $(p, w)$, which conflicts the previous image.  Of course it is only one attempt, but I think it may reflect some difficulty to define $F$ because it need to preserve coordinate transformation.  Right?  Eh.. I realized my attempt is too trivial. If I apply this method to any manifold, $F$ is never well-define...  Can anyone provide an manifold which can be trivialize? I think I may use it to get better understanding.


Sometimes I get an excellent throw when catching a Pokemon. What did I do? Did I hit the Pokemon on the head or is because of the catching circle?


How can I convert a string to boolean in JavaScript?

Can I convert a string representing a boolean value (e.g., 'true', 'false') into a intrinsic type in JavaScript?  I have a hidden form in HTML that is updated based upon a user's selection within a list. This form contains some fields which represent boolean values and are dynamically populated with an intrinsic boolean value. However, once this value is placed into the hidden input field it becomes a string.  The only way I could find to determine the field's boolean value, once it was converted into a string, was to depend upon the literal value of its string representation.  var myValue = document.myForm.IS_TRUE.value; var isTrueSet = myValue == 'true';   Is there a better way to accomplish this?


I am having an issue with a click listener for a choose file button.  This is the error.   Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener     I understand what a null pointer exception is and I have search thoroughly for an issue similar to mine. I tried a lot of solution for issue similar to mine but I get always an error  and this is my code :  public class Main2Activity extends AppCompatActivity {  Button btnChoiseFile; ImageView imgView; private static final int SELECT_PICTURE = 0; String filePath = "";  protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.activity_main);      if((Build.VERSION.SDK_INT >= Build.VERSION_CODES.M)) {         if (ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED ) {             ActivityCompat.requestPermissions((Activity) this, new String[]{ Manifest.permission.WRITE_EXTERNAL_STORAGE}, 300);         }     }      btnChoiseFile = (Button) findViewById(R.id.button2);     btnChoiseFile.setOnClickListener(listenerChoiceFile);     ImageView imgView = (ImageView) findViewById(R.id.img_view); }  @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) {     switch (requestCode) {         case SELECT_PICTURE:             if (data != null) {                   Uri selectedImage = data.getData();                 filePath = getPath(selectedImage);                 Log.d("path", filePath);                  imgView.setImageBitmap(BitmapFactory.decodeFile(filePath));              }             break;     }     super.onActivityResult(requestCode, resultCode, data); }  public String getPath(Uri uri) {     String[] projection = {MediaStore.Images.Media.DATA};     Cursor cursor = managedQuery(uri, projection, null, null, null);     int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);     cursor.moveToFirst();     return cursor.getString(column_index); }  View.OnClickListener listenerChoiceFile = new View.OnClickListener() {     @Override     public void onClick(View view) {         Intent intent = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);         startActivityForResult(intent, SELECT_PICTURE);         intent.setType("*/*");         startActivityForResult(intent, SELECT_PICTURE);     } };   }


Whats currently a good game to start on?

I used to do a lot of roleplaying in my youth, and would like to pass on the wonder and excitement I enjoyed to my Nephews and Nieces.  I have not played in a few years and so don't know what games are available anymore.  When I was playing I would have suggested to someone D&D or AD&D as a place to start.  Can anyone suggest where I should start with a 12,13,14 year old Nephew if I wanted to give a birthday present?


Which one is the longest anime ever created and how long is it hourwise?

Which one is the longest anime ever created?  Not just episodes, the duration of each episode is also important.


How can I make an overset symbol at the same size and height as \bar except with a different symbol?

Apologies for the cryptic title, but I was not sure how best to phrase the question in one sentence. I am essentially trying the create a vector symbol with \rightharpoonup as the top instead of the arrow.  The output to the following code will feature an overset harpoon over x, next to a simple \bar{x}. Observe that on the left, the top symbol is significantly higher and bigger than on the right one.  \documentclass{article}  \usepackage{amsmath,amsfonts,amsthm,amssymb}  \newcommand{\vect}[1]{\overset{\rightharpoonup}{#1}}  \begin{document} $$ \vect{x} \quad \bar{x} $$ \end{document}   I would like to create something that looks in every way like the right hand symbol, except using something that looks like \rightharpoonup at the top.  If this command sequence already exists in LaTeX, please use that as an answer, because I have searched for and failed to find it so far.


cannot install 16.04 - missing dependency

Ubuntu tells me there is an upgrade when I boot and starts the install process but then I get an error message -  The required dependency 'apt(>=1.0.1ubuntu2.13)' is not installed. How can Install or recover this and continue with the upgrade please? Thanks. Matt.


How can LyX create a pdf file that's suitable for Amazon Createspace publishing?

LyX by default creates documents in pdf file format version 1.5  Amazon Createspace says that it supports pdf submissions in pdf file format version 1.4 and below. They don't say they support this output of version 1.5 or above.  What adjustments need to be made in LyX or to PdfLaTeX to create files in a pdf file format version that Amazon Createspace supports?


How do I create a "day-night" scene in a photo?

I recently came upon the image below, and more like them on Stephen Wilke's , and was wondering how the image was made.     It really seems that there would be some form of post processing, but by the seemless flow of the image, it looks like the edits may have been very complex. Is there a simple way to recreate this style?


I would like to fill an arrow head with a color, but I have a problem with the fill command :    My code is :  \documentclass{article}  \usepackage{tikz} \usetikzlibrary{arrows}  \begin{document} \begin{tikzpicture}  \def \dx{10} \def \dy{5} \def \dz{5}  \draw  (0,\dy/4,\dz/2)--++(\dx/8,0,0)--++(0,1,0)[-open triangle 60 reversed]; \draw  (0,-\dy/4,\dz/2)--++(\dx/8,0,0)--++(0,1,0)[-open triangle 60 reversed, fill=blue];  \end{tikzpicture} \end{document}   but it's not working ... Any clue ?  EDIT :  I have modified my code to use the new library arrows.meta but there is a problem with specific arrow heads like reversed triangle to fill it with a color :    The code :  \documentclass{article} \usepackage{tikz} \usetikzlibrary{arrows.meta} \usetikzlibrary{arrows}  \tikzset{     antenne/.style={         -{open triangle 60 reversed[fill=blue]}                 },     ronde/.style={         -{Circle[fill=blue]}                 },         }  \begin{document} \begin{tikzpicture}     \draw[antenne] (0,0) -- (2,0) -- (2,2) ;     \draw[ronde] (5,0) -- (7,0) -- (7,2) ; \end{tikzpicture} \end{document}   RE-EDIT :  I found the problem, to fill the arrow head I had to replace open triangle 60 reversed[fill=blue] by triangle 60 reversed[fill=blue], the open prevents TikZ from filling the head with a color.


Double changes value after declare and after multiplication

I need some help here. I am trying to convert some numbers and running in to some weird things.   I declare a double to the value 264210.35. I then multiply it with 100, and in my opinion i get the wrong result.               double value = 264210.35;              double sum = value.Value*100;             //sum = 26421034.999999996              var longSum = (long) sum;             //longSum = 25421034   When i then multiply it with 100 i excpect to get the sum of 26421035, but i don't. I get 26421034.999999996. When i use a normal calculator and multiplies the value with 100 i get 25421035. How come i don't in this case?  And when i then cast it to a long, it ends up being 26421034. Which then makes it one didgit wrong.


Why don't Bounties give you reputation back automatically if you answer the question yourself?

I have surprisingly made the experience that you don't get back your reputation points if the bounty ends and no one has answered your question.   Even if you find an answer yourself before the bounty ends, and mark it as answer you're not getting your reputation points back.  Why is this so? Is it a bug or is it done intentionally? In my opinion, it would be good to redeem the credits to someone if he/she comes up with an answer finally.


Is there a risk of damaging a laptop with another charger?

Original charger: Input: 100-240V , 50-60Hz , 1.6A Output: 19V , 3.42A  New Charger: Input: 100-240V , 50-60Hz , 1.5A Output: 19V, 3.42A


Why does solid turn to liquid deep in the Earth?

Usually pressure decreases inter-molecular movement thereby keeping the substance in solid state.  Given this, why do the earth's crust and mantle, which are both solid, turn into a liquid outer core, despite the enormous pressure deep down in the Earth?


How can I change the default "ens33" network device to old "eth0" on Fedora 19?

I've just installed a Fedora 19 on VMware workstation 9. The default network device is "ens33" instead of "eth0" on RHEL.  The reason I have to use "eth0" is that the license component of one of our products has be to be linked with "eth0".  There are some posts discussing about similar issues, most of which are for older OS. I haven't found one that exactly match my situation.


The image of the circuit is shown below and it required to find \$V_0\$,  My first attempt at solving this problem is by changing the current source into a voltage source with 1-V and 2k\$\Omega\$ resistance. The fact that the inverting and non-inverting terminals aren't grounded make this problem look difficult.To the point which, I don't know how to proceed with this question or where to start. I would appreciate any help. Following some thought and another schematic from a hint suggested by Alfred, I produced a schematic representing our work.  And  my solution for the problem is below, Using node equation at nodes A and B we have, $$\frac{V_A-V_B}{1k}=-0.5 \text{mA}$$ $$\frac{V_B-(2+V_A)}{1k}=-0.5-x$$ where x is the current that is sent in the output of the op-amp. Using KCL, at the bottom node near the current source we see that the same current that goes through the op-amp also goes through the \$2\text{k}\Omega\$ resistor. Hence, we have, $$\frac{-V_A}{2k}=x$$ Replacing this in the second equation, $$\frac{V_B-(2+V_A)}{1k}=-0.5+\frac{V_A}{2k}$$ And and solving the equations yields \$V_A=-2 \text{-V}\$ and \$V_B=-1.5 \text{-V}\$


The ring $\mathbb Z[\sqrt{-2}]= \{a+b\sqrt{-2} ; a\in \mathbb Z,b\in \mathbb Z \}$ has a Euclidean algorithm

I need to prove that the ring $\mathbb Z[\sqrt{-2}]= \{a+b\sqrt{-2} ; a\in \mathbb Z,b\in \mathbb Z \}$ has a Euclidean algorithm, and to decide whether there are infinitely many primes in this ring.   How do I approach this kind of question?  Thank you.


The Three Princesses (distinguishing truth-teller with 1 question)

Is it possible to solve this problem:  A prince wish to marry a princess. There are 3 princesses, one is young, one is a little older and one is old. The prince is able to tell the princesses apart. One of the princesses always tells the truth, one never tells the truth and one sometimes tells the truth and sometimes not.  The prince only wish to marry a princess whom he can trust. Therefore it must be the princess that always tells the truth or the princess that never tells the truth (he can just negate her answers for the rest of their marriage).  Before he chooses the princess he wish to marry, he can ask one and only one princess a single question. She must only answer the question by yes or no.  Which question must he ask to be sure he marries one of the right princesses?  Edit: I was not expecting the question "who is more truthful", so consider this change of rules. Suppose we remove the "random princess", and instead insert an "evil princess". The evil princess can choose her strategy for answering, after she has seen which princess we are asking. So asking "Who is more truthful", does not make sense anymore, since the evil princess could choose to answer correct to every question.


Problems in Generating the Reference List with TexMaker

I have my .tex file as follows:  \documentclass[12pt]{article} \usepackage{natbib} % for the bibliography  \begin{document}  A much longer \LaTeXe{} example was written by Gil~\cite{label1}.  \bibliographystyle{unsrt} \newpage \bibliography{Weekly Report 10}  \end{document}   My Weekly Report 10.bib file is as follows:  @InProceedings{label1, author = {author}, title = {title}, booktitle = {booktitle}, OPTcrossref = {OPTcrossref}, OPTkey = {OPTkey}, OPTpages = {OPTpages}, OPTyear = {OPTyear}, OPTeditor = {OPTeditor}, OPTvolume = {OPTvolume}, OPTnumber = {OPTnumber}, OPTseries = {OPTseries}, OPTaddress = {OPTaddress}, OPTmonth = {OPTmonth}, OPTorganization = {OPTorganization}, OPTpublisher = {OPTpublisher}, OPTnote = {OPTnote}, OPTannote = {OPTannote} }   I have them together in one folder.  I have also run PDFLaTeX first, and then BibTeX, and then PDFLaTeX twice more.  However, my reference list is always empty. The error messages are as follows:    Where goes wrong?


How do I differentiate between decade and century in phrases like "the late 1600s"?

If I wanted to say something occurred occurred between 1627 and 1629, I would use "the late 1620s". However, if I wanted to say something occurred between 1607 and 1609, I couldn't use "the late 1600s" because that would imply it occurred between 1670 and 1699.


Book recommendations on geometrical methods for physicists (like Topology, Diff. Geometry)

I would like to obtain a book that has to do with geometrical methods/subjects for physicists. When I say geometrical methods/subjects I mean things like Topology, Differential Geometry, Lie derivative/groups, Manifolds, vector fields etc. Note: I do not want a book containing only Topology.


Is it possible to get a researcher position in a prestigious institute with a degree from a not very well-ranked university?

I'm currently in the 2nd year of my Ph.D. and I'm really interested in my future career options. I'm attending a double-degree study programme in two European universities, none of them being among the top ones. But, I'm employed as a researcher (not only a Ph.D. student) in a supercomputing center in one of them (member of PRACE, 3 years ago in top 40 from TOP500 list) since the beginning of my Master's degree, thanks to Dean's award for my Bachelor's thesis. Five years ago it was a top university in my country (slightly under 300 in QS WU rankings), but then the directorship changed and the ranking dropped drastically (to my shock completely out of QS WU rankings). The second university shares a pretty similar fate - from about 300th place to 520+ in the last 7 years (I have no idea, what happened), but still maintains at least 151-200 position in my field. In general, I feel, that while both of the labs I'm working in are good and productive, the problem lies in some other faculties who do not focus on research enough.  Is it possible to hope for admission into a researcher position in some well-ranked university in the future? I'm not talking only about post-doc now, but also in a long-time horizon. This situation makes me feel really inferior, so I'd like to now, if my researcher career direction is tightly bounded by this situation or if there is a possibility to overcome rankings with good research results over the years after Ph.D.


Is Stack Exchange experimenting with KaTeX?

is a new TeX-to-web renderer that is supposed to be faster and more lightweight than MathJax.  Normally, I would just dismiss it as an interesting technology that might not be ready for production use yet.  However, the example at the bottom of that page…    … caught my eye as something that looked !  I think that compatibility might be a concern, though, both in terms of browser support and fidelity when rendering existing content.


new member here with a question.  My Wine Enthusiast Wine Cooler (Model 254 60), bit the dust.  The new boards cost $297 each and there are three in the unit.  I want to remove all of the boards and use a 12 volt power supply on a timer.  The connections would be (3) Peltier's, (3) fans cooling side and (3) fans heating (exhaust side).  All connections wired in series.  What kind of 12 volt power supply would I need to complete the task?  Thanks in advance....


Calculate the general solution for this ODE: $x^2y''-3xy'+3y=0$

I'm trying to solve for the following ODE and would like the communities support on helping my figure it out: $x^2y''-3xy'+3y=0$ I have substituted $y = x^k$ into the equation and then taking the derivative until second-order.  $y' = kx^{k-1}$ $y'' = k(k-1)x^{k-2}$  After doing this I have placed this into the equation to get:  $$x^2k(k-1)x^{k-2}-3kxx^{k-1}+3x^k = 0$$ $$k(k-1)x^k-3kx^k+3x^k=0 \implies k(k-1)-3k+3=0$$  I'm not sure where to proceed from here. I have tried placing this into a quadratic formula and got: $$\frac{3k\pm\sqrt{(3k)^2-4(k(k-1))(3)}}{2(k(k-1))}$$ Though I'm not sure if this is the correct approach.


Homework gone wild : "Cannot create a generic array of AbstractChain"

So this is an exercice given by my teacher. We're creating a SkipList, aka a "LinkedList" with shortcuts. He gave us a class diagram with one interface (AbstractLink) and three class (StartLink and EndLink implement AbstractLink while Link extends StartLink). He also gave us a huge part of the code but i find it surprising that the interface is empty, i dont really understand why it is and he doesn't look like we need to fill it. Anyhow, in the StartLink, he told us to write the constructor.  So i tried to initialize nexts, which is an array of AbstractLink (???), with the parameter n. As far as I searched, it's impossible to do it because the type of the AbstractLink is not defined. But it leaves me clueless with what i have to change ...  public interface AbstractLink<T extends Comparable<T>> extends Comparable<AbstractLink<T>> {  }   public class StartLink<T extends Comparable<T>> implements AbstractLink<T> {      final AbstractLink<T>[] nexts;      public StartLink(int n){         this.nexts = new AbstractLink<T>[n];    //my line     }    And Eclipse gives me this : Cannot create a generic array of ChainonAbstrait  Thanks in advance


How can I extract a short part of characters from the string with Regular Expression in Python?

Here is my code:  s = '''I wish I may, I wish I might Have a dish of fish tonight.'''  import re m = re.search('w.*m', s) print(m.group())   and I got the result:  wish I may, I wish I m   If I want to get the result only the first half wish I m, how can I revise my code?  Thanks a lot!


Keep links to deleted posts in their authors' personal area

As I know, users here have links to their deleted posts only for a short time, under "recently deleted posts" on their page. That pages are still accessible by URL after that links are removed. I think that there aren't any cons in keeping those URLs, for authors. Additional explanations for an automatic quality check: that links would make it comfortable for authors to see their old content, for some reason. Authors may have lots of posts and may not even notice that their post is removed, so, this would help them to control their content.


Alternative to complex numbers - Study numbers $j^2=1$, $j \neq 1$

On p. 24 "Clifford Algebra and Spinors" (2.2 Double Ring of  $\:{}^2\mathbb{R}$ of $\mathbb{R}$) by Petri Lounesto the author mentions Study numbers as an equivalent alternative to complex numbers. The Study numbers are pair of two real numbers (a,b) $\in \mathcal{\mathbb{R}}^2$ such as $$a+jb, \quad j^2=1 ,\quad j \neq 1$$ He introduces Study conjugate as $(a+jb)^-=a-jb$, then they can be written in hyperbolic polar form e t c. It seems that the use of such numbers can be as powerful as the use of complex numbers then. My questions are  Why Study numbers are not widely known and used? Can someone point me to the reference to the Study numbers? I can not find it either in Wikipedia, neither in literature.  PS The mathematician is . He approached the dual quaternions with the dual numbers.


How do I know if I need AMD-64.deb or x86_64.rpm?

Is there a simple command (like uname -r to know my kernel version) to know if I need to download a AMD-64.deb package or a x86_64.rpm one ?  For example, for downloading printer drivers, I need to decide which one to take.  Sorry, if this is a dupe, I've seen many questions around this matter, but didn't find how to know what is my processor.


Does a monk's Unarmored Movement speed increase apply to the fly speed gained from a Fly spell?

A monk's Unarmored Movement class feature increases the monks speed by 10 feet at level 2, and further at higher levels. According to , this stacks with an Aarakocra monk's fly speed, because that fly speed is innate to the race. However, how does this interact with fly speeds gained from other sources, such as the Fly spell? That spell specifically states that "the target gains a flying speed of 60 feet for the duration." Can this gained flying speed then be improved by a monk's Unarmored Movement, giving a level 2 monk a flying speed of 70 feet while the Fly spell is active on them?


Why doesn't c++/c give an incorrect values when a negative int is divided by a sizeof(int) or sizeof(long)

This is the problem:  int num = -16; int div = num / sizeof(int);   The value of div is incorrect (Some big garbage value). But if I do,  int num = -16; int intSize = sizeof(int); int div = num / intSize;   Then it gives the correct answer. What I need to know is, why does this happen?


How to solve the equation $\phi(n) = k$?

Let $\phi(n) $ is the numbers of number that are relatively prime to n.   Then, how could we solve the equation $\phi(n) = k, k > 0?$   For example:    $\phi(n) = 8 $  I can use computer program to check all numbers that are relatively prime to $n$, but I think there must be an easier way to approach this problem.    Base on this formula: $$\prod_{i=0}^{k} p_{i}a^{a_i} $$ The only thing I can see is n must not have a prime factor > 9, otherwise $\phi(n) > 8 $. I really don't know where to start :( ? A hint would be greatly appreciated.


Find limit $\lim_{n\to \infty}\frac{\sum_{k=1}^n k^n}{n^n}$.

Now I want to find the limit   $$\lim_{n\to\infty}\frac{\sum\limits_{k=1}^n k^n}{n^n}.$$ I try to use the Stolz theorem as follows: $$\lim_{n\to \infty}\frac{\sum_{k=1}^n k^n}{n^n}=   \lim_{n\to \infty}\frac{\sum_{k=1}^{n+1} k^{n+1}-\sum_{k=1}^n k^n}{(n+1)^{n+1}-n^n}$$ $$=\lim_{n\to\infty}\frac{(n+1)^{n+1}+\sum_{k=1}^n(k^{n+1}-k^n)}{(n+1)^{n+1}-n^n}$$ $$=1+\lim_{n\to\infty}\frac{\sum_{k=1}^n(k^{n+1}-k^n)}{(n+1)^{n+1}}.$$ It seems to deal with the summation like this form: $$\sum_{k=1}^{n}k^p,\text{with}\ p=n,n+1.$$ I have no way to deal this summation, any help and hint will welcome!


Brand new to blender, and I'm trying to make a metallic object that is reflective.  There are lots of tutorials on youtube, however none of them are compatible with blender 2.71 with the cycles render.   Here are the tutorials I have tried:        All of these tutorials have a 'transparency' and a 'mirror' option in the outliner menu that I just don't seem to have.   How can I make this object reflective? Am I missing plugins or some other menu?


I want to upgrade from 12.10 to 16.0.4 LTS

I would like to upgrade (can do gradually to 13, 14, 15 etc) but none of the site are available.  Tried:  sudo apt-get upgrade  sudo apt-get dist-upgrade  sudo update-manager -d   Nothing works. I cannot even install aptitude. I am stuck for good?


Search over Stack Overflow and Server Fault at the same time?

As there is heated discussion as to where some edge case questions should end up, there is similar confusion on my part as to where I should search for answers to particular problems.   Is there any thought being put to have an integrated search that will pull results from whichever one of the trilogy the question has been asked?   This may also be useful to drive knowledge of the various strands of SuperStackFault to people that don't follow the place that closely.


Finding sum of the power series and the sum of the series

(1) Find the sum of the power series    $$\sum_{n=1}^{\infty} nx^n$$  (2) Find the sum of the series  $$\sum_{n=1}^{\infty} \frac{n}{3^n}$$  Any tips on solving the sum of series/power series?


Anvil tutorial. Subdivisions Surfice modifier creates a face where it should be a hole

I wanted to make an anvil with a tutorial. But as I added the subsurf Modifier it started looking weird. I wanted to make a"Hole" but it fills it up. How can i get it right?


A question has two solutions when I'm asked to prove one of them

So the question is   Prove that  $$\cot^{-1}{\sqrt{1+\sin x}+\sqrt{1-\sin x}\over\sqrt{1+\sin x}-\sqrt{1-\sin x}}={x\over 2};$$  $x$ belongs to $(0,π/4)$.  I simplified using $\sin x=2\sin(x/2)\cos(x/2)$ and $1=\sin^2(x/2)+\cos^2(x/2)$ and I get two answers because the second term in the numerator and denominator can be considered as either $(\sin x-\cos x)^{2}$ or $(\cos x-\sin x)^2$ leading to:   (I) the correct answer $x/2$;  (II) another solution $\cot^{-1}(\tan(x/2))$.  Am I missing something?


What is the usual boot time on Ubuntu 16.04 LTS?

I've been using Ubuntu 16.04 LTS (Xenial Xerus) on my Thinkpad E450 for almost a year. My device usually takes over two minutes to boot.   I ran systemd-analyze blame, and the total boot time is 126.741 seconds with the following output:  21.159s dev-sda1.device 14.846s apparmor.service 10.659s snapd.service 8.515s plymouth-read-write.service 6.842s grub-common.service 6.698s NetworkManager-wait-online.service 5.585s networking.service 5.579s systemd-logind.service 5.369s gpu-manager.service 5.110s NetworkManager.service 4.961s bluetooth.service 4.533s ufw.service 4.198s console-setup.service 3.965s systemd-udevd.service 2.724s systemd-tmpfiles-setup.service 2.522s thermald.service 2.304s ModemManager.service 2.254s accounts-daemon.service 2.209s systemd-tmpfiles-setup-dev.service 2.044s binfmt-support.service 1.718s lightdm.service 1.696s keyboard-setup.service 1.251s systemd-modules-load.service   Is this normal?


Is "from whence" correct? Or should it be "whence"?

I just saw a , where one of the characters says:     it must be cast back in the fire from whence it came!   This struck me as odd, since I expected them to say "whence it came"; but now I find that "from whence" seems to occur as well.  Does anybody know whether this is correct, or whether it has been correct at some point and subsequently fell into disgrace (or vice versa)?


Should Luke's lightsaber have given away his plan?

During Luke's confrontation of Kylo Ren toward the end of The Last Jedi we see that       the lightsaber Luke uses a blue lightsaber (which I thought was his original one but that really doesn't matter), not the green one of his own construction.   Given that Kylo Ren  and Rey has just     fought over and broken the blue lightsaber   Why did Kylo Ren not notice this "inconsistency" and realize that      Luke's physical body was not there?


Is there something like "common Linux commands"?

I come from the windows world trying to switch to Linux. Sorry for the naïve question but is there something like "common Linux commands"?  For example in Windows, the command line is pretty limited, but it is common between all windows. So if you know what the dir or mkdir command does and what switches it takes, you can use any version of Windows and be sure that your BATCH files work.  In Linux however, if I understand correctly there are many ways to do the same thing. For example for editing files you may use EMACS or VIM. Even the shells have a wide variety (is bash the de facto standard?)  From what I understand so far, the command line is way more flexible (and versatile) than Windows CMD. Something like Busybox promises to pack a whole lot of commands in one project. Anyway, this is all too overwhelming, so I was wondering if there is a small set of Linux commands that are common between all systems and I can carry on my daily tasks on every Linux machine regardless of its distro.


What is the linux-image-extra package for and do I need it?

I occasionally update my kernel from this web site    I have been always downloading 3 deb files for installing  linux header all, linux image and linux headers. I noticed one more deb file recently for 64 bit kernel called Linux-image-extra.  I would like to know what does kernel file Linux-image-extra do and should I also install it?


I am trying to install older version of Google Chrome. I am able to install older versions on my machine, but as soon as installation processes are getting completed, it will start updating the latest version automatically. This stops me to do my work.  Can anyone suggest me how to stop this auto updating process in chrome.  Thanks, Sourabh


im trying to understand preprocessor.  why one of the bellow preprocessor macro doesn't work while the other does  what is the difference between #pragma and _Pragma  why do we wrap STRINGZ with ASTRINGZ?    #define STRINGZ(x)                                #x #define ASTRINGZ(x)                               STRINGZ(x)  #define DO_PRAGMA(x) _Pragma (#x) #define TODO(x) DO_PRAGMA(message ("TODO - " #x)) #define msg(s) TODO( s " - @ - " ASTRINGZ(__FILE__))  msg ("This doesnt work") #pragma message "but this does: " ASTRINGZ(__FILE__)      sources:


Using the environment example from the collect package results in an error

I am writing a manual and I want to include tips and tricks trough out the chapters. A last chapter will collect all the tips and tricks that I included in the book. So I found the package collect. It does give instruction for a custom environment, so I decided to make a box with that so tips and tricks are clearly seperated from the regular text (using tcolorbox).  I applied the example from the :  \documentclass{book} \usepackage{collect}  \definecollection{gra} \newenvironment{grammarpart}[1]{% \@nameuse{collect*}{gra}{% \emph{Start of grammar ‘#1’}\par% }{% \par\emph{End of grammar}\par% }{% \subsection{#1}% }{% \par See some section in the text. }% }{% \@nameuse{endcollect*}% }  \begin{document} \chapter{Foo} \begin{grammarpart} bar \end{grammarpart} \end{document}   Typesetting this resulted in the following error, tried this with pdfLaTeX and XeLaTeX:  ! You can't use `\spacefactor' in vertical mode. \@->\spacefactor                   \@m {} l.10 b       ar ?   I also experimented with \grammarpart{test} instead of begin/end arguments. However, that did gave me the same error as well.  I searched on \spacefactor and the use of \@. But to be fair, at that point it became black magic for me. So how do I get this example to work? Or is there a package that allows me to collect environments for a later chapter?


How do I get flat texture projection on a object without distortion?

I tried using Window Texture coordinate, but it changes scale if I zoom in or out. The Camera Texture coordinate works in with orthographic camera but gets distorted if I use perspective camera.   I want the texture to have a fixed scale and not be distorted like on orthographic mode.


Every closed subset $E\subseteq \mathbb{R}^n$ is the zero point set of a smooth function

In Walter Rudin's Principles of mathematical analysis Exercise 5.21, it is proved that for any closed subset $E\subseteq \mathbb{R}$, there exists a smooth function $f$ on $\mathbb{R}$ such that $E=\{x\in \mathbb{R}\mid f(x)=0\}$.   Since $E^c$ is open in $\mathbb{R}$, $E^c$ is a countable disjoint union of open intervals $(a_i,b_i)$. On an interval $(a,b)$, if we let $f(x)=\exp(\frac{1}{(x-a)(x-b)})$, $x\in(a,b)$; $f(x)=0$, $x\notin(a,b)$, ($f(x)=\exp(\frac{1}{(x-a)})$ or $f(x)=\exp(\frac{1}{(x-b)})$ on $(a,\infty)$ and $(-\infty,b)$ resp.), then $f$ is smooth. Hence we can get a smooth function on $\mathbb{R}$ such that $E$ is the zero point sets of $f$.  (1). How about a closed subset $E$ of $\mathbb{R}^n$? is it true that for any closed subset $E\subseteq \mathbb{R}^n$, there exists a smooth function $f$ on $\mathbb{R}^n$ such that $E=\{x\in \mathbb{R}^n\mid f(x)=0\}$?  An open set in $\mathbb{R}^n$ cannot be written as a disjoint union of countable open balls hence the proof above is not valid. The partition of unity only claims that for an  open set $U$, there exists open $V$ in $U$ such that $\bar V\subseteq U$ and a smooth function $f$ on $\mathbb{R}^n$ such that $supp f\subseteq U$, $f|_V=1$.   (2). The taylor series of $f(x)=\exp(\frac{1}{(x-a)(x-b)})$ does not converge around points $a,b$ hence $f$ is not analytic at $a,b$. Is it true that for any closed subset $E\subseteq \mathbb{R}$, there exists an analytic function $f$ on $\mathbb{R}$ such that $E=\{x\in \mathbb{R}\mid f(x)=0\}$?


How do you theme a content type's create/edit form?

Like it says -- I've got a D7 content type whose editing form needs to be themed.  I did this all the time in D6 by registering theme functions in template.php and writing the associated theming functions, but things seem to have changed in D7, especially regarding what goes into template.php, or if D7 has shifted to using .tpl.php files for this, or whatever.  Is there any advice out there?


Drawing outline of point cloud using QGIS?

I want to know if there is a plugin in QGIS, which will allow me to draw the outline a point cloud. I know there Points2One the plugin, but it makes an outline with all points, even with the data found in the middle of the point cloud.  I give you an example ;  x       y       ID      order 3.3     43.2625 353293  1 3.13334 43.3458 353293  2 3.21667 43.3458 353293  3 2.88334 43.4292 353293  4 2.96667 43.4292 353293  5 3.05    43.4292 353293  6 3.13334 43.4292 353293  7 2.71667 43.5125 353293  8 2.8     43.5125 353293  9 2.88334 43.5125 353293  10 2.96667 43.5125 353293  11 3.05    43.5125 353293  12 3.13334 43.5125 353293  13 2.88334 43.5958 353293  14 2.96667 43.5958 353293  15 3.05    43.5958 353293  16 3.13334 43.5958 353293  17 2.96667 43.6792 353293  18 3.05    43.6792 353293  19 3.13334 43.6792 353293  20 3.21667 43.6792 353293  21 3.05    43.7625 353293  22 3.13334 43.7625 353293  23 3.21667 43.7625 353293  24 3.13334 43.8458 353293  25 3.21667 43.8458 353293  26   With the tool suggested by @ArMoraer I can only draw a polygon with the outer points that are more extreme. The polygon has touched just 5 points (see map of Convex hull below) but normally it should pass on 20 points (all points of the contour).     Each point has a pixel, actually the outline should not touch the points but it must pass through the outer limit of these pixels. In the end I want to have an outline like this map (see map below : desired contour)


Nvidia prime intel mode malfunction, Ubuntu GNOME 17.04, GTX 1050

I have a Dell XPS 15 9560 (2017) with a GTX 1050 and I'm using Ubuntu with it. I've been trying to get hybrid graphics working lately to no avail. I have Nvidia proprietary drivers installed successfully but when I try to switch to Intel and log out, my screen will freeze when I try to log back in.  Some information:    BIOS: 1.3.1 Ubuntu: GNOME 17.04 - up to date nvidia drivers: 375 kernel: 4.11.2-041102-generic   Do I need to install a specific Intel driver? I've seen others post about the same issue with success on KDE (), is this an issue with gnome?


How do I get rid of weird pockmarks on the surface of my object?

I had been making some icing for a donut when I started to notice these evenly spaced out indentations in the texture of my object. I'm not sure if it's the result of adding a subsurf modifier to my mesh or a bad sculpting job. It looks like the pockmarks are directly related to my mesh though.


Do other animals have similar blood types to humans?

I am interested to know if there are any animals having blood groups similar to human blood groups? Is it possible to transfuse blood between humans and those animals?


How to replace ${} placeholders in a text file?

I want to pipe the output of a "template" file into MySQL, the file having variables like ${dbName} interspersed. What is the command line utility to replace these instances and dump the output to standard output?


Traced reason behind Nullpointerexception. But how do I solve it?

I have a NullPointerException, I have debugged the code and was able to trace the problem but how do I solve it?   Minimal test case:      ExecutorService theExecutor = Executors.newFixedThreadPool(10000); //Skapar nya Threads, samt begränsar antalet.     ServerSocket quizSocket = new ServerSocket(serverPort);      try {         while (true) {  //Skriver ut While True             Socket connection = quizSocket.accept();             theExecutor.execute(new Broadcaster(connection));         }     } finally {         quizSocket.close();     } }   Broadcaster class. where the problem occurs:   public static class Broadcaster extends Thread {      String quizFile = "src/qa.txt";  // Format of text: Vad heter äventyrets hjälte?/Frodo     private Socket connection;     private PrintStream write;     private String qString;     private String answer;     private String question;   // (Debug message) question: null     int points = 0;      public Broadcaster(Socket connection) {         this.connection = connection;     }      @Override     public void run() {         try {             write = new PrintStream(connection.getOutputStream());             //Skriva till klienten.             List<String> questionsList = new ArrayList<>();              try (Stream<String> questionsStream = Files.lines(Paths.get(quizFile))) {  //Reading from text file                 questionsList = questionsStream                         .parallel()                         .collect(Collectors.toList());                 Collections.shuffle(questionsList);  //Randomizing the Strings.                while (true) {      for (String qString : questionsList) {     String[] questions = qString.split("/");  //Splitting to question[0] and [1]     write.println(questions[0]);  //Printing out [0]. Has a valid value      question = questions[1].toLowerCase(); //question = null. question[1] "Sam"   The string question is still null, even though question[1] is not. The NullPointerException is a fact! Which means that this variable sets a null value to the getter later on:      public void setQuestion(String question) {    this.question = question;   I want to declare a variable, with the value of question[1].toLowerCasewithout causing a NullPointerException. Then I want to generate a setter with this variable. But how do I do this? In a previous post, I received a duplicate warning and was suggested to follow this . Now I have done that, and this is what I came up with. Still need advice how to solve the actual problem! Where do I go from here?   For more information, visit this !


When Bayesian estimator coincides with MLE

Assume that $\theta$ is an unknown parameter with prior belief $p(\theta)$ and that $X_1,...,X_n$ is an iid sample from $p(x|\theta)$.  What does it say about our prior distribution $p(\theta)$ when the Bayesian estimator $E[\theta|X=x]$ coincides with the maximum likelihood estimator $\hat{\theta}$? My professor posed this question in his notes and I don't know the answer.  Edit: The question was posed following an example where the prior distribution was improper, but not uniform.


I am not a programmer at all, but I need to get an OLD Joomla site up and running long enough for me to scrape the content out of the site (articles and navigation headings) and start a new WordPress site. Currently, the site (www.muellerfamilylaw.com) shows the following error:     jtablesession::Store Failed   DB function failed with error number 145   Table './tempmu5_muellerfamilylaw/jos_session' is marked as crashed and should be repaired SQL=INSERT INTO jos_session ( session_id,time,username,gid,guest,client_id ) VALUES ( '7f0d46db0c41fddae0302015fc529d2e','1491314393','','0','1','0' )   If anyone can help me repair this enough to just get the old site up long enough for me to gleen all the page content, I would be very grateful.


Leaving the US with a foreign passport and entering with a US passport

I will be traveling to Europe and Asia with my Hong Kong passport (tickets were booked with my previous legal name) and coming back with my US passport (I will be booking the ticket with my Hong Kong passport, since it has my previous legal name).  Will I get into trouble with US immigration when coming back? Since the US doesn't check passports going out of the country, how do they know who went out? Or doesn't it matter?


I made a glass and have some fluid falling into it.  I applied the fluid, smoothed it out, re sized the glass, added some ice cubes....   The glass renders and so do the ice cubes... just not the fluid!  Here are some screenshots.  Preview Render:   And a sample of the final render (also taken at low quality):


Why does the coefficient of a categorical variable (coded 0,1) change when we exclude an intercept in linear regression?

lm(mpg~hp+wt+am+cyl-1, mtcars) Call: lm(formula = mpg ~ hp + wt + am + cyl - 1, data = mtcars) Coefficients:  hp        wt       am0       am1      cyl6      cyl8   -0.03211  -2.49683  33.70832  35.51754  -3.03134  -2.16368        lm(mpg~hp+wt+am+cyl, mtcars) Call: lm(formula = mpg ~ hp + wt + am + cyl, data = mtcars) Coefficients: (Intercept)           hp           wt          am1         cyl6         cyl8  33.70832         -0.03211     -2.49683      1.80921     -3.03134    -2.16368     When I excluded the intercept, I am getting a coefficient for am0. And when the intercept is included, I am only getting a coefficient for am1 an not for am0, why is it so??


Purpose of the questions in the Visa Waiver ESTA Application Guide

What's the point of asking:  “Do you seek to engage in or have you ever engaged in terrorist activities, espionage, sabotage, or genocide?”  Do they expect to catch many honest terrorists, war criminals and spies with that?


Object won't show in render. None of the suggested solves I've found have helped

I've tried to render my scene but there's an object that won't show up. I've checked the camera, I've checked the visibility, it isn't hidden and it's showing in the viewport. I feel like I've opened every setting and have achieved nothing. I’m trying to render a book with a cover, flipping pages and stacks of pages. I have no idea how to fix the fact that the book cover doesn’t render. If I create a plane and select both the book cover and the plane and join them with Ctrl+J, the render contains a book cover but it doesn’t turn as it’s rigged to do so because it’s now linked to the plane and loses all the animated properties. As soon as I unjoin them the book cover stops rendering and everything appears as you see it there, a book with binding, pages, but no cover. For the life of me I cannot figure out what’s going on. There's a link to the file here:


How can I add a direct link to the edit account settings page in a menu?

Ok, I must be missing something obvious, but I'm having trouble adding a link to user/%/edit to the main menu.  In the Menu UI, I clicked "add link," set the title to "Account settings," and then was at a loss about what to put for the path.  I know how to generate a link to the account edit page using views, which is what I've always done before, but this time I actually need to add the link to the "Main Menu."


I want to change the host name - is it enough to edit the /etc/hosts file?

Short version  Can I just edit the /etc/hosts file, meaning can I login as user@<hostname I wish to change> without unintentionally breaking something? Would this be enough or is there something else to do?     Long version  I'm trying to create an Ubuntu 16 guest OS in VirtualBox on a Windows 10 host. I have downloaded the Ubuntu 16 .vdi from , but I don't like the fact that I have to login as osboxes@osboxes. Ultimately I want to login as ab@ab.  First I changed the user name using usermod as described  in @ValentinUveges answer. This worked and so I can now at least login as ab@osboxes. To change @osboxes to @ab I have tried groupmod -n ab osboxes, but this failed.   But at least I think what I really need to change is the /etc/hosts file, which currently contains    cat /etc/hosts   127.0.0.1   localhost   127.0.1.1   osboxes   So can I just edit /etc/hosts and change osboxes to ab in order to allow me to login as ab@ab without unintentionally breaking some parts of the OS? Would this be enough or is there something else to do?   Apart from the steps I mentioned before, this is a "fresh" osboxes.vdi virtual operating system file.


Find the limit of $(\sqrt2-\root3\of2 )(\sqrt2 -\root4\of2 )...(\sqrt 2-\root{n}\of2 )$ without using the squeezing principle

$$\mathop {\lim }\limits_{n \to \infty } (\sqrt 2  - \root 3 \of 2 )(\sqrt 2  - \root 4 \of 2 )...(\sqrt 2  - \root n \of 2 )$$  I was able easily to find the limit of this series using the squeezing principle, but how can you find it without it? I'm guessing it's an algebra trick :)