Whenever I travel around the world Google always assumes I want to use the region I am in as the search engine.  I just want to always search Google.co.uk wherever I am in the world. I don't want to see foreign results and foreign languages and foreign countries results.  How do I default Google and Chrome to this?

I look for information about Tour de Pologne, the problem is that I want to know what foreign services say about it. I want to watch their videos with their comments but because I live in Poland I get a few pages of Polish websites.  How to force Google to treat my search phrase as I would be in UK for example?


Basically I want the my web-app users to be able to find the link for my website log in page, like we have in facebook:    I would really appreciate if you could tell where is it done and/or if you could redirect me to a tutorial where it shows how its being made.

My website used to have sitelinks and now it doesn't. It's very possible that it's due to changing the website to a sidebar design instead of having an "interstitial" type landing page which limited the number of choices, but I'm not sure.  Here is how sitelinks might look for a site:    What are some things that I can do to improve my chances of getting sitelinks?


I am wondering: After I rotate an element in Illustrator to an un-even angle, is there a simple way to rotate it back to an even angle later?  Whenever I try to get a shape back to 0 degrees or 90 degrees, it always seems to be off by a smidgen.  Any solution?

Let's say I have a shape that I rotated at an awkward angle of let's say 34°. I close the document, return a few hours later, and want to straighten the it back to its original 90° or 0° angle. The problem is I don't remember the angle I originally rotated it at. Shift + Rotating nor resetting its bounding box does the trick. Any shortcuts/options I'm overlooking here? For example how would I rotate this quadrilateral so that it sits horizontally straight and looks like a box.


I'm writing a program for my grandpa, who's not exactly tech savvy. I want to make it easy for him to always have the latest version of my program (which consists of one Python script, by the way). He can just download it from an email to his desktop, but I had to set the default download location and if it gets messed up he's out of luck.  I want to be able to have a folder on my computer with my script in it, and when I update the program, I want the changes/new program to appear on his desktop. It would be even better if it only works one way, in case he accidentally deletes it on his machine.  So all the files in my folder go on his desktop, but all the files on his desktop don't go into my folder. I don't believe GDrive or Dropbox (my first ideas) can do that.  I have Windows 8.1, and he has 7.  EDIT: I'm starting to get into GitHub. Is there a way to use GitHub to automatically update his local repository?

I want to synchronise two folders in real time under Windows 7.  Basically, I want to monitor a folder and synchronise each change (new files, changed files, deleted files) to another drive. It has to be in real time, so it gets synchronised instantly when a change happens. A one-direction synchronisation is enough.  I tried Microsoft's , but it does only syncing by hand or scheduled (thus not satisfying the "real-time" requirement).  Can this be achieved with Windows 7 itself? If not, are there other methods of doing this?


I'm reading about the  concerning digital signatures and I can't understand whether RSA is more secure than El Gamal digital signature. Well, they are both prone to forgery, but I don't see which signature is better in terms of security.

If i am not wrong in cryptography there are 2 basic cryptographic schemes for public key cryptography.  encryption whose security is based on the infeasibility of solving the factoring of big primes problem and the  encryption which is as secure as the discrete logarithmic problem. The question is whether or not there are specific circumstances where you must use ElGamal instead RSA and vice versa. What are the weak and the strong points of each?  To sum up is it harder under the same attacking model to solve the factoring problem or the discrete logarithmic problem?


I can't get my objects... which at the moment is the cube to move along the x,y, z axis using my mouse. If I left click, all I seem to do is move the crosshairs.   I am using Blender 2.72.  The only way I can move along those axis' is if I click "G" for grab then which ever I would like either x,y, or z.  if I try to get the trackball to move... I cant do anything with it.  IS this a bug?  Ive been looking for answers on youtube in tutorals but, everyone just left clicks and moves along the choice axis... I feel like im lost until I can get this working.   HELP!

I am trying to select the cube that in the middle of the scene. How can I select it? All I see is a crosshair appearing everywhere I click. Is this a bug?


I have a road lines data in a table with field  roads(id SERIAL ,the_line geometry(LineString,4326))  suppose an accident occurs in a middle or at any location in that waterline i want to stop the entire waterline so, given a location or coordinates(POINT(350205.805 148722.56)),  I need to find a roadline which is closest to that point. and return its start point and endpoint   "SELECT id, ST_AsText(ST_StartPoint(the_line )) AS startpoint,ST_AsText(ST_EndPoint(the_line )) AS endpoint from roadlines where (some condition to get the closest roadline) close to 'POINT(350205.805 148722.56)'"   POINT(350205.805 148722.56) WILL BE THE INPUT

I have a table of roads and a table of points. I'd like for each point to have the ID of the closest road, as well as the distance to that road.  The line data has both the path type and the geometry type for its coordinates. The points have XY coordinates. What would be the best way to go about finding the closest road using PostGIS?


I'm going to The Netherlands (as usual) and was wondering if the times overlapped. For example, I went for about a month in December and am planning to go again this May.   Assuming my 180 days began when I went in December, I will be okay to go again in June?    If I'm already there, will my 180 days reset or will they count my second vacation as going over the amount of days I'm able to stay there?

I have searched the web a lot and could not find an answer that fits my situation. Here are two links that are quite contradictory:       My situation:  I've visited Portugal in December 2012 for 29 days on a Schengen visa valid from December 1st, 2012 to February 1st, 2013 for research purposes (I am a Ph.D. student). I want to visit Sweden from February 10th, 2013 to May 10th, 2013 (89 days). I have applied for a Schengen visa again (for research). How will the 90/180 rule work in my situation?


I am facing problem on understanding this problem---  You have 12 coins and a balance scale, one of which is fake. All the real coins weigh the same, but the fake coin weighs less than the rest. All the coins visually appear the same, and the difference in weight is imperceptible to your senses. In at most 3 weighings, give a strategy that detects the fake coin. (Note: the scale in this problem is a scale with two dishes, which tips toward the side that is heavier. For clarification, do an image search for “balance scale”).

I have 12 rocks, all have the same weight except for one rock, but I don‘t know which rock is. How do I know which rock is different from other, and also know that rock heavier or lighter, with maximum 3 comparating steps. My only tool is just a balance that can only compare the weight between the rocks.


I use the glossaries package to define and use acronyms in my text. I use \newacronym{} to define my acronyms. In the text I use \gls{} to refer to these acronyms.  In order to improve readibility of my text, I only want a link from the acronym to the glossary-entry on first use. For some acronyms which are used extensively in my text, it would not look nice, if at each use of the acronym a hyperlink appears in the PDF.  Hence, I would like to know how I can achieve this behavior: link to the glossary only for the first use of an acronym.  In the user manual of the glossaries package, there seems to be a parameter doing exactly that: hyperfirst. However, if I set it to true (default is true anyway), I still have link at all acronym usages (i.e. \gls{}) throughout the document.  EDIT:  Ohps, just found the solution here:   should we delete or mark as duplicate?

By default, the glossaries package creates a link to the glossary for each occurrence of an entry (e.g. each time I use \gls{entry}). With the links visualized (e.g. using hyperref colorlinks). This becomes really cluttered if an entry is used many times.  I would rather prefer that only the first occurrence of an entry is hyperlinked. Is this possible?


I'd recommend adding notifications for when users comment back/write back in a chat. I tend to close the link or end up doing other things making me totally forget about the current Chat I'm having with someone about a  question. It would be nice if we could be notified when user replies.   Otherwise, if we don't want to be notified we can just leave the chat.

This is regarding the feature where we can chat regarding a question on SO. There is an automated process for creating the room from comments. It's a very useful feature in case the OP is not able to understand an answer and needs more clarification.  What I don't see is a notification system for chats where there has been an extended period of time between communication.   Let's say someone replied to my chat after a few days, in that case I do not receive any notification.   This happened to me only a few hours ago, where in I had replied to one question but the OP was not available at that point and he replied to me after some days. As I didn't check that chat I had no way of noticing if someone replied to my message and the 48h window after my last activity in that chat, during which I would have received the @ convention ping notification, had already expired.  We receive notification on posts, upvotes that we receive, so why not the chat rooms?   Should there be a notification center like the one for posts (or may be include this in the same center as posts)?


This problem was came to a Facebook post of mathigon ......the problem seems trickier than I expected...can you help me to find the distance??

Two unit circles overlap in such a way that exactly half the area of each circle is within the overlap. How far apart are the centers of the two circles?


Hello is there any way to view the history of all the remote connections made by the built-in application called Destkop Sharing ?  i would like to make sure myself that there was not connection made between me and anyone else.  Im looking for some log files which if there was a connection made will contain time and ip or atleast the information that somebody has connected... thanks

Hello is there any way to view the history of all the remote connections made by the built-in application called Desktop Sharing ?  i would like to make sure myself that there was not connection made between me and anyone else.


\begin{cases} T(1) = 1 \\ T(n) = 2T(n-1)-4 \end{cases} Solve this recursion using summation factor method or iterative method. Could someone solve for me this recursion and explain all steps?

I got such recurrence equation which I cannot solve, I tried with mathematical induction, but I've got information, that this one is not linear and cannot be solve like that. And really have no idea how to do it.  $ \begin{cases} T(1)=1 \\ T(n)=2T(n-1)-4 \end{cases}$


earners,  I thought Friday was a good excuse to do a very basic question, which still makes me wonder. Why do we need the centering part in standard normalization? Assuming normalization means here, centering plus scaling to the standard deviation.  If we want  fairness in the influence of the variables, eg distances, scaling has intuitive meaning. But why the centering matters? I have not found a satisfying answer 'in general'. That is, I am putting aside the cases the the actual algorithm requires such centering; I rather wonder whether centering, by itself, has a generic justification which applies to all or many scenarios. I presume such justification exists somewhere, as we all seem to follow the mantra of doing this standard normalization 'by-default'.  Thanks for sharing in advance, and have a great weekend.

My understanding is that when some features have different ranges in their values (for example, imagine one feature being the age of a person and another one being their salary in USD) will affect negatively algorithms because the feature with bigger values will take more influence, is it a good practice to simply ALWAYS scale/normalize the data?  It looks to me that if the values are already similar among then, then normalizing them will have little effect, but if the values are very different normalization will help, however it feels too simple to be true :)  Am I missing something? Are there situations/algorithms were actually it is desirable to let some features to deliberately outweigh others?


I'm trying to solve a problem with a content that I'm putting in a page with an iframe, the problem is: I want the SEO of that iframe but in the principal page, I wrote a collapse with JavaScript but it put the content in with display:none and I know that google has SEO penalties with no content displayed, so, I really don't know what to do, any solutions? here the code I'm trying to implement:  HTML <button type="button" class="collapsible">+</button>     Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.  CSS .collapsible {   background-color: #777;   color: white;   cursor: pointer;   padding: 0px 3px;   width: auto;   border: none;   text-align: left;   outline: none;   font-size: 15px; }  .active, .collapsible:hover {   background-color: #555; }  .content {   padding: 0 18px;   display: none;   overflow: hidden;   background-color: #f1f1f1; }  JAVASCRIPT var coll = document.getElementsByClassName("collapsible"); var i;  for (i = 0; i < coll.length; i++) {   coll[i].addEventListener("click", function() {     this.classList.toggle("active");     var content = this.nextElementSibling;     if (content.style.display === "block") {       content.style.display = "none";     } else {       content.style.display = "block";     }   }); }

I've heard many times that it's bad to use display: none for SEO reasons, as it could be an attempt to push in irrelevant popular keywords. A few questions:   Is that still received wisdom? Does it make a difference if you're only hiding a single word, or perhaps a single character? If you should avoid any use of it, what are the preferred techniques for hiding (in situations where you need it to become visible again on certain conditions)?   Some references I've found so far:       If you're straight-out using CSS to hide text, don't be surprised if that is called spam. I'm not saying that mouseovers or DHTML text or have-a-logo-but-also-have-text is spam; I answered that last one at a conference when I said "imagine how it would look to a visitor, a competitor, or someone checking out a spam report. If you show your company's name and it's Expo Markers instead of an Expo Markers logo, you should be fine. If the text you decide to show is 'Expo Markers cheap online discount buy online Expo Markers sale ...' then I would be more cautious, because that can look bad."   And  on the same article     We can flag text that appears to be hidden using CSS at Google. To date we have not algorithmically removed sites for doing that. We try hard to avoid throwing babies out with bathwater.   Eric Enge      The legitimate use of this technique is so prevalent that I would rarely expect search engines to penalize a site for using the display: none attribute. It’s just very difficult to implement an algorithm that could truly ferret out whether the particular use of display: none is meant to deceive the search engines or not.


I am currently employed as a Graphic designer in an IT company and want to switch to a company that is more focused on brand or design.   I plan to make a new portfolio. What types of work are relevant to the following topics 1. design, 2. brand or 3. marketing?

I am a relatively recent graphic design graduate. I have been working at a small printing house for about two years, but will soon be interviewing for a different position in another city.  My question is about what to include in my design portfolio. When I was in school, my professors all insisted that work included in a portfolio should be 100% original: my original photography, my original logos, my original layout, my original written content etc. However, at my current office, we rely heavily on client-supplied logos, type content, and photography—and stock photography (shutterstock, etc).  What do other designers include in their portfolios? Has anyone else had this issue and can I reasonable include these more recent projects in my portfolio if I label them appropriately (something like "layout design")?


Is there is a non-constant real-valued function on $\mathbb{R}$ such that each point is its local minimum, i.e. its value at any point is no greater than any other value in a sufficiently small neighborhood of the point. The answer is no if continuity is assumed, see .  If there is such a function, is its range necessarily a countable set or not?

What are the functions $f:\mathbb R\to\mathbb R$ such that every point is a local maximum?  Certainly, $f(x)=c$ works for every constant. So does $\lfloor x\rfloor$, as does $I_{\{0\}}(x)=\begin{cases}1&x=0\\0&x\ne0\end{cases}$. Another example is the oddly beautiful $e^{-\lfloor1/\lvert x\rvert\rfloor^{-2}}$. Question is, are step functions such as these the only ones? Are there any examples where every point is a strict local maximum?  (Thomae's function is a near-miss, since the condition doesn't hold on irrational points. Although, most points are irrational, so I guess the term "near-miss" doesn't quite fit.)  EDIT: My definition of step-function is the sum of countably many indicator functions of intervals, $\sum_{n=0}^\infty a_nI_{A_n}(x)$. If it were uncountable, any function would be step, as $\{\alpha\}$ is an interval ($[\alpha,\alpha]$).     This arose when I was thinking about the topological space with basis $\{(-\infty,a]:a\in\mathbb R\}$. If you call that space $X$, then the continuous functions $f:\mathbb R\to X$ are precisely these. I don't have a formal proof but I'm pretty sure (and this would belong in a different question anyway).   Contrast with:


Hi so after removing old seasoning on my wok with vinegar baking powder and a lot of scrubbing, i tried to season it again. But i could not get any good results (  ) As you can see the oil did not act as a layer but like some drops dripping.. I am sure i didnt use too much (it was really a thin layer) but once starting to burn, the oil grouped in these weird lines. Could that be the patterns of my towel showing off? I am really confused... I am doing it over the gas stove because i dont have any oven. If anyone can help it is really annoying because its the only pan i have right now and the small seasoning i made still peeled when cooking... Thanks!!

I have a carbon steel wok but it became rusty recently when I forgot something in it for a day.  I decided to scrub everything off and re-season it. The problem is I can't get the center of the wok to be seasoned. No matter how much oil I add, it burns and disappears leaving the center as bare metal...  My method is applying a very thin layer of oil and making it burn on the gas, then when it's dry (and not seasoned...) I rub more oil. It worked for everywhere except the middle.  Should I scrub off everything again and start over? If not, what should I do?


In ZF(C), is $C_S =\{X: \#X = \#S\}$, for some set $S\neq \emptyset$ a set? No, because then we would have an element of $C_S$ that contains $\{C_S\}$ and we get an infinite chain $\{C_S\} \in C_S \in \{C_S\} \in$ ..., which contradicts axiom of regularity. But if we exclude the axiom of regularity, can such a set exist?

How to show that the class of all sets of a particular cardinality ,say $h$ is not a set.   My argument:  I assume that I've shown the following lemma.  Lemma: If $X$ is an infinite set of cardinality $h$ , $a\ne x$ for every $x\in X$ then $\{a\}\cup X$ is of cardinality $h$ too i.e. adding new element to an infinite set doesn't change cardinality.  Let $h$ be an infinite cardinal number. Let $T_h=\{x:\text{x is a set of cardinality h}\}$. Suppose $T_h$ is a set.   Let $a$ be any set and consider any $t\in T_h$. Let $R=t\cup \{a\}$. Using the above lemma, $R\in T_h$.   So, $a\in R\subset \bigcup T_h$. As $T_h$ is a set then $\bigcup T_h$ is also a set.  As $a$ was arbitrary set then we have, $a\in\bigcup T_h$ for every set $a$. Hence, the set $\bigcup T_h$ contains all sets which meas that the collection of all sets is a set, contradiction.    If $h$ is non-zero finite cardinal number. Define $T_h$ the same way as above. Let $a$ be any set, Let $A_1=a, A_{n+1}=A_n\times a$. Consider $A=\{A_1,A_2,...,A_h\}$. So, $A\in T_k$. Hence, $a=A_1\in \bigcup T_h=K$. So K is a set containing all sets $a$ since $a$ was arbitary,contradiction.  My main question is, Is there any flaws in my argument? If yes, point it out please.   If the argument is valid, Is there any standard proof to show the same fact?


I have a code that should read the mouse coordinates, but it only works in ArcMap, can I somehow translate it into code for ArcGlobe, otherwise it gives an error: CreateObject cannot open map document. def onMouseDownMap(self, x, y, button, shift):         mxd = arcpy.mapping.MapDocument("CURRENT")         df = mxd.activeDataFrame         sr = df.spatialReference         point = arcpy.Point(X=x, Y=y)         pointGeometry = arcpy.PointGeometry(point,sr).projecntAs(arcpy.SpatialReference(4326))         X=pointGeometry.firstPoint.X         Y=pointGeometry.firstPoint.Y         pythonaddins.MessageBox("Your mouse clicked at " + str(X) + " , " + str(Y),"My Coordinates:")

Work in ArcGlobe and I want to calculate the coordinates of the globe latitude and longitude, but the coordinates from the mouse click is read from the screen, not the globe, because when I clicked on the corner of the screen it shows me the coordinates 0,0. How can I make it so that coordinates read with globe and not with the screen? import arcpy import pythonaddins  class ToolClass2(object):     """Implementation for coord_addin.tool (Tool)"""     def __init__(self):         self.enabled = True         self.shape = "NONE" # Can set to "Line", "Circle" or "Rectangle" for interactive shape drawing and to activate the onLine/Polygon/Circle event sinks.     def onMouseDown(self, x, y, button, shift):         pythonaddins.MessageBox("Long" + " " + str(x) + '\n'+ "Lat"+ " " + str(y), 'Coordinates', 0)         pass     def onMouseDownMap(self, x, y, button, shift):         #pythonaddins.MessageBox("Long" + " " + str(x) + '\n'+ "Lat"+ " " + str(y), 'Coordinates', 0)         pass     def onMouseUp(self, x, y, button, shift):         pass     def onMouseUpMap(self, x, y, button, shift):         pass     def onMouseMove(self, x, y, button, shift):         pass     def onMouseMoveMap(self, x, y, button, shift):         pass     def onDblClick(self):         pass     def onKeyDown(self, keycode, shift):         pass     def onKeyUp(self, keycode, shift):         pass     def deactivate(self):         pass     def onCircle(self, circle_geometry):         pass     def onLine(self, line_geometry):         pass     def onRectangle(self, rectangle_geometry):         pass


I remember reading a series when I was around 7th or 8th grade about aliens who had taken over Earth by putting metal caps on people when they were "entering adulthood" to control them (not direct control, but it would keep them from rebelling). There was a faction of people who able to escape and had fake caps and would save teens who were about to be capped.  The main protagonist was a teen boy who was a boxer (or training to be a boxer or something). The aliens would hold tournaments for the humans and whoever won would be "worthy" to serve as personal slaves to the aliens.     The protagonist won and was able to get inside to try and learn more about the aliens from the inside.

The story takes place in an undefined future where society has reverted to a pre-industrial stage. The world is ruled by huge three-legged robots. At a certain age every child gets an implant that removes all its creativity, curiosity and passion, turning them into compliant, mellow sheep.  Before he receives his implant the hero of the story escapes with his friend (a Samweis Gamdschie-like sidekick). On their journey through the in-fact post-apocalyptic world they discover that the world was once way more advanced and that the robots are alien oppressors.


I'll hit save on a comma and/or tab delimited file - Prompt: "Do you want to keep using this format?" Me: "Yes."  Then when closing the window and without making any changes, a prompt asks me, "Do you want to save?".... "Do you want to keep using this format?" Whether one hits yes or no here, the file will open just as it was saved a moment before.  Anyone know why this is and if there's a config to make it stop?

Every CSV I've ever tried to save from Excel (2010, anyway) says filename.csv may contain features that are not compatible with CSV (Comma delimited). Do you want to keep the workbook in this format?. Why is this? Is there any way to save CSV files from excel that do not contain this message?  Even the following file (saved as a .csv) will cause this to happen, if you try to save it:  test1,test2 test3,test4   I've even just created a new spreadsheet in excel and tried to save it, and it still shows this message.   I wouldn't care, but I have someone telling me that I'm not formatting CSV files properly because excel shows that warning message, and I'm looking for ammunition to prove it's Excel and not my format (or if it actually is my format, to fix it).


I am reading  to understand the Eigenface approach but I can't follow the derivation of the PCA as presented on the paper.  In the algorithm it is necessary to do a PCA using a covariance matrix $AA^T$. However, $A$ is of size $N^2\times M$ where $N$ is the dimension of the image and $M$ is the number of images. This means $N^2$ is a very large number and finding the eigenvectors of $AA^T$ is therefore computationally intensive.  Then it is said that for PCA it's enough to find the eigenvectors of $A^TA$ instead of $AA^T$, and it turns out this is a lot easier because $M \ll N^2$ . The reasoning is the following:   Eigenvectors of $A^TA$ are the vectors $\vec{v}_i$ that for some number $\lambda_i$ it holds that   \begin{equation} A^TA\vec{v}_i = \lambda_i\vec{v}_i \end{equation}  and once we left multiply with $A$ we get  \begin{equation} AA^TA\vec{v}_i = \lambda_iA\vec{v}_i \end{equation} from which we see that $A\vec{v}_i$ are the eigenvectors of $AA^T$.  The authors then proceed to use these eigenvectors in the algorithm, but why can we use those? These are not the original eigenvectors $\vec{v}_i$ we were looking for, but $A\vec{v}_i$, different vectors of a different matrix.  So the question is: why can we use eigenvectors of $A^TA$ instead of $AA^T$? Is this something specific to the Eigenfaces algorithm?

I have a $20\times100$ matrix $X$, containing my $N=20$ samples in the $D=100$-dimensional space. I now wish to code up my own principal component analysis (PCA) in Matlab. I demean $X$ to $X_0$ first.  I read from someone's code that in such scenarios where we have more dimensions than observations, we no longer eigen-decompose the $X_0$'s covariance matrix. Instead, we eigen-decompose $\frac{1}{N-1}X_0X_0^T$. Why is it correct?  The normal covariance matrix is of size $D\times D$, each element of which tells us the covariance between two dimensions. To me, $\frac{1}{N-1}X_0X_0^T$ is not even of the correct dimensions! It is $N\times N$ matrix, so what would it tell us? Covariance between two observations?!


The crux of GR is the action  $$ S=\int _\mathcal M d^n x \sqrt{|g|}\,R $$  Varying this and setting $\delta S=0$ gives you the Einstein field equations. However, that only determines the metric, not the manifold, and a metric doesn't uniquely determine a manifold. For instance,   $$ ds^2 = du^2 + dv^2 $$  can be the metric of flat 2D space or the metric of a 2D cylinder of radius 1.  It seems that the manifold isn't determined by GR. In particular, you have an indeterminate topology—you don't if the manifold is open, closed, etc. This is problematic because if your manifold has a boundary, the action is modified to include a boundary term:  $$ S=\int _\mathcal M d^n x \sqrt{|g|}\,R + \frac{1}{2} \int_{\partial \mathcal M} d^{n-1}x \sqrt{|h|}\,K $$  where $h$ is the induced metric on the boundary and $K$ the extrinsic curvature.  Does that mean you have to know the topology of the universe before you start doing any physics? Shouldn't there be "equations" of motion to determine the topology, just like there are for the metric?

General relativity says that spacetime is a Lorentzian 4-manifold $M$ whose metric satisfies Einstein's field equations.  I have two questions:   What topological restrictions do Einstein's equations put on the manifold?  For instance, the existence of a Lorentz metric implies some topological things, like the Euler characteristic vanishing. Are there any experiments being done or even any hypothetical experiments that can give information on the topology?  E.g. is there a group of graduate students out there trying to contract loops to discover the fundamental group of the universe?


How should I read from a file if there is one given as a command line argument, if not I would like to read from std::cin. I tried to solve this with pointers to istrem, but is there a better way.

I want to open a file for reading, the C++ way. I need to be able to do it for:   text files, which would involve some sort of read line function. binary files, which would provide a way to read raw data into a char* buffer.


What is the difference between Workflow, Sequential Workflow and State Machine Workflow Templates in Visual Studio 2013 for SharePoint 2013? This doesn't seem to be clearly documented. Which one allows code? Which can be used only in On-Premise? Which one can be used only in the Cloud? Can anyone explain in layman's terms, the difference between Sequential and State Machine workflows? I am unable to understand it from the MSDN documentation. Can anyone explain it in simple language with some good examples?

What is the difference between Sequential Workflow and Stater machine workflow? What context should I take account to when choosing one of them?


I know there are tons of examples of music driven LED circuits out there, but they mainly control just one LED or one string of them. I want to make a circuit that will control quite a few LEDs, with each LED at a different range of frequencies.  To do this, I am planning on making an array of band pass filters. Each filter would drive a different LED (or string, or something else)... through a BJT perhaps? Here is a quick sketch of what I am thinking.  I might add in a high and low pass filter in the end, but I'll decide that later.  Anyway, would this work? I am wondering if you have advice for me, or maybe some different tricks that could reduce the complexity of this project. Are there certain things to watch out for, such as my source not being able to supply enough power to my filters, ect?  Thanks in advance! I really appreciate any help!

I want to create a circuit that can detect audio frequencies and flash RGB LEDs different colors depending on the detected frequency. The frequency range will be from 20 Hz to 12 kHz, after looking at the chart below.   (source: )    So my question is: what circuit design should I choose to make a good frequency detector? I suppose I would need    Preamp for the microphone (is it necessary for the ADC?) Band pass filters (active or passive?) A microcontroller with an onboard ADC that has a sampling rate of at least 24 kHz.   Before I get too excited, are there any circuits out there that already do this?


Recently I realized the automatic time doesn't work.   I guess the battery that keeps the time in my computer is bad, so I need the system to take the right time from Internet.  I'm testing changing the year and it is not automatically fixed. I'm using Compiz.    I'm pretty sure the problem is caused by Dual Boot (Windows/Ubuntu).  But in this moment I'm telling Ubuntu to take the time from Internet.  Why it doesn't work?  I think this must have a fix inside Ubuntu regardless of the dual boot.

Dual boot system Windows XP Pro and Ubuntu 12.04.  I have the bios set for the correct time and Ubuntu set for US Eastern time.  Ubuntu will boot up and the time will be off by -4 hours.  If I correct the time in Ubuntu then when I boot up in Windows XP the time will be off by + 4 hours.  This is a fresh install of 12.04. I did not have this problem before reinstalling Ubuntu.


Noob Here,  Making a Beast Master Ranger for 5e, from the Revised Unearthed Arcana...thing. I have an ape and it says in the monster manual that he has   2 attacks both with a   Hit: 6(1d6+3) bludgeoning damage.  So math, I assume this means I roll a 1 D6, say I roll a 4, so the equation looks like 6(4+3) so that would equal 42 right?   Now because he's my pal he gets my +2 prof bonus.   so does that mean I  take that 42+2= 44? Or is it then 6(4+3+2) which would be 54?  OR!  does the original equation mean I roll a 1d6, 6 times and add 3 to each roll? And then add 2 to that?   Sorry if this seems a really dumb question, but I wanna get this right.

My friends and I are very new to D&D, played like 3 times. In a monster's stats next to weapon damage it says stuff like "+11 to hit" and "Hit: 5 (1d8+1)". For the premade characters it just says things like "+4, 2d6 + 2 slashing", though. Why are there two "hit" numbers for monsters? Which do I use for the d20 roll to hit against a target's AC?  I mean for example like in the Ogre entry in the "" article on monsters.


"I'd the house to myself."  Since "I'd" can be a contraction of I had, would it work in this case for "I had the house to myself?"

I feel uncomfortable saying sentences like the following:    "I've a car" instead of "I have a car" "They've a great time" instead of "They have a great time" "He's a pen" instead of "He has a pen" etc   I ask this because I read this sort of thing in a book.  Are they correct? And what is the rule? Can you use such forms in a formal setting?


The 2nd level spell Hold Person can affect multiple targets when upcast with a higher level slot.  Suppose a wizard uses a 6th level slot and successfully holds 5 humanoid king's guards with the spell.  The Dispel Magic spell simply works automatically if it targets any spell 3rd level and below. The caster needs to make an ability check to ends spells of a higher level with a DC of 10+spell level.  If the king's adviser wished to dispel the spell on one of the guards, would a check be unnecessary because he is attempting to end a 2nd level spell that affects multiple targets or does he need to attempt a DC16 ability check?

As the title says: Is a 1st-level spell cast using a 4th-level slot a 1st-level spell, or a 4th-level spell?


As has been established in another question, although the four champions had to face really difficult challenges,    The first task makes the most sense to me. It seems to be quite entertaining for the audience. They could see the fights of the champions with their dragons but the second task had the audience watching the Black Lake for one full hour. Since Dumbledore had to question one of the merpeople about what happened, I don't believe that anybody was able to witness anything except when each of the champions reappeared on the surface.   The same goes for the third task. The audience watched the walls of the maze for the most time. Mrs Weasley and Bill came to the castle specially to watch the third task, but I don't think that there was anything interesting to watch at all.   So, if no-one could see anything, in what way was the Triwizard Tournament meant to be entertaining for the audience?

If you're a contestant, away you go and do your things - good luck. But what could the students of Hogwarts watch? The first task seems ace - dragons and brooms, but task two happens under a lake, and task three is in a maze.  I wonder if somehow the students could see the action on a screen (a magic screen) but then the chapter after the lake we hear that everyone's hassling Harry and trying to find out what went on, because for them it was just an hour of lake.   What do you think? Do they do something in the films to imply what the audience gets to see?


Does using debian with systemd type will result in only one runlevel?

Does systemd still have the concept of runlevels? For example is it pointless to use telinit <number>?


In Joker (2019) while the Joker character was assaulted by the 3 men in the train/subway, he pulls out the revolver gun and shoots and kills the men. Some of them are shot 2 or 3 times. We don't see the Joker reloading the gun at any point, but I counted at least 8 bullets fired. Was this a mistake?

In the movie Joker, when killing three white collars in a subway, Arthur fires eight rounds out of his 38 revolver that holds five or six bullets without reloading.   I doubt it is a mistake, why does this happen?


This is a follow-up question to .  Does there exist an example of a bounded and continuous but not necessarily uniformly continuous function defined on all of $\mathbb{R}$, which is not H\"{o}lder continuous?

Can someone give me an example of a function $f: I\to \mathbb R$ which is uniform continuous but not Hölder continuous (for any $\alpha$)? Here $I$ is an interval. If $I$ is closed and bounded then we are essentially assuming that $f$ is merely continuous.   By saying that $f$ is not Hölder continuous for any $\alpha$, I mean for all $\alpha >0$,   $$\sup_{x,y\in I, x\neq y} \frac{|f(x) - f(y)|}{|x-y|^\alpha} = \infty.$$  That is, I need to find a function $f$ so that for all $\alpha$ and $M>0$, there are $x, y\in I$ so that   $$ \frac{|f(x) - f(y)|}{|x-y|^\alpha} \ge M.$$  I know that $f(x) = x^\alpha$ are $\alpha$-Hölder continuous. Thus, in some sense, I am looking for $f$ which are worst than the functions $x^\alpha$ for all $\alpha >0$.


I have a header file where I have declared a structure and declared it as  static Test_t = TESTID;  Have multiple files in the project and files has multiple functions. And want to update these variables from different files and functions. So have tried to get the address of this static variable inside each function like    Test_t *info = &TESTID;   Update it as info-> ...  But the address of info are different in functions?  What could be the reason?

If I have a source.c file with a struct:  struct a {      int i;     struct b {         int j;     } };   How can this struct be used in another file (i.e. func.c)?  Should I create a new header file, declare the struct there and include that header in func.c?  Or should I define the whole struct in a header file and include that in both source.c and func.c?  How can the struct be declared extern in both files?  Should I typedef it? If so, how?


I have one function that refreshes the div but the then the jquery function won't work any more. I've seen answers where I have to use the about it losing the bindings but I can't get it to work.  refresh div code working fine   $(document).on('click', '#reload', function () {     //Load next question     $("#new_sen").load(" #new_sen");    });   My code that won't work after div refresh   $(".card_flip").on('click', function() {     $(this).toggleClass('flipped');   })   Thanks for any help.

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


How can the area of a map from OpenStreetMap be determined in the form of Xkm x Ykm, given the following information:         Left Longitude  = 103.554879 Right Longitude = 103.740497  Top Latitude    = 1.585770 Bottom Latitude = 1.490873   Any ideas?

In my daily work, I am constantly asked to calculate areas of global raster datasets in geographic projection at 30 arc second resolution. These datasets are normally the result of a Combine operation (a typical example is a vegetation classes combined with country layer). To do this, our unit created a raster dataset with the area of each pixel in geographic projection at 30 arc second. With this area grid, a zonalstat is performed to sum the areas for each class. Since I am not sure how this area grid was created, I always wondered whether this approach is more accurate of just reprojecting the raster in a equal-area projection (from simple tests the results of the two methods are similar). Does anybody experienced a similar situation?


Sequence: $a_n=2^n-1$   I want to prove that $a_m|a_n$ whenever $m|n$.   I started by approaching with induction, base/trivial cases being $m=n$, $n=0$, and $m=1$, but I'm not sure where to go from there or if there is a more straightforward method.  Note:  $m|n$ means for some $x$, $mx = n$  $a_m|a_n$ means for some $y$, $a_my=a_n$  Other similar questions appeal to laws beyond basic arithmetic and the definitions of divisibility and the sequence.

How to prove $x^a-1\mid x^b-1 \iff a \mid b$, where $x \ge 2$ and $a,b,x \in \Bbb Z$.  I've tried the following in attempting to solve this:  $$a\mid b \Rightarrow aq=b \Rightarrow x^{aq}=x^b \Rightarrow x^ax^q=x^b$$  Because $x^q \in \Bbb Z$, it follows that $x^a\mid x^b$.  This is as far as I have gotten; any help getting further is appreciated.  Note: It may be that this identity is not true at all?


How would I go about showing that $\int_0^1x^{-x}dx = \sum_{n=1}^\infty n^{-n}$  Right now my numerical analysis class is covering gaussian quadrature but we have also covered interpolation. I'm not sure how to prove this equality without using an estimation for the lefthand integral

I need help with this exercise.  I need to prove $$\int_{0}^{1}x^{-x}\ dx=\sum_{n=1}^{\infty}n^{-n}$$  I think I should use some convergence theorem, but I'm stuck.  Thanks a lot!


I came across the result that $(x^a+1)|(x^b+1)$ if and only if $\frac{b}{a}$ is odd. Any intuitive reason why, though? What about $\frac{b}{a}$ being odd makes this true?

I read somewhere that     $(a^n - b^n)$         It is always divisible by $a-b$.   When $n$ is even it is also divisible by $a+b$.   When $n$ is odd it is not divisible by $a+b$.      and     $(a^n + b^n)$         It is never divisible by $a-b$.   When $n$ is odd it is divisible by $a+b$.   When $n$ is even it is not divisible by $a+b$.      I wonder what's the proof for this.  First postulate is clear. $(a-b)$ would or would not be a factor. Any light on others?


How to take ScreenShot & save it with different filenames by using Selenium & Java?

How to take screen shot on both test cases "Positive and Negative" results?  NOTE: Currently, I am working in selenium webdriver (junit) and I did not have an idea about how to code for adding methods to take screen shots.


Question Consider the intervals of real numbers (0,1) = {x | 0 < x < 1} and (0,1] = {x | 0 < x ≤ 1}.  Show that |(0,1)| = |(0,1]|  Work I stated that since both intervals are uncountably infinite then they have the same cardinality, but this was marked as wrong. How do I actually prove this?

How to define a bijection between $(0,1)$ and $(0,1]$?   Or any other open and closed intervals?   If the intervals are both open like $(-1,2)\text{ and }(-5,4)$ I do a cheap trick (don't know if that's how you're supposed to do it): I make a function $f : (-1, 2)\rightarrow (-5, 4)$ of the form $f(x)=mx+b$ by \begin{align*} -5 = f(-1) &= m(-1)+b \\ 4 = f(2) &= m(2) + b \end{align*} Solving for $m$ and $b$ I find $m=3\text{ and }b=-2$ so then $f(x)=3x-2.$  Then I show that $f$ is a bijection by showing that it is injective and surjective.


Is it correct to say e.g. "I like your way of wearing" or "the way you wear looks perfect"?  Is it politely? Is it in use or not?  Thank you for your suggestions in advance.

Is it correct to say e.g. "I like your way of wearing" or "the way you wear looks perfect"?  Is it politely? Is it in use or not? May I use "the way you wear" referring to whole wearings including dress, scarf, hat, bracelet. jewellery, etc?  Thank you for your suggestions in advance.


I heard some one talked about the instantaneous and average velocities.  He was using $\Delta t$ to denote a time frame, $dt$ denote a time point.  average velocities $\bar{v} = \dfrac{\Delta s}{\Delta t}$  the $\Delta t$ part is indeed common. my concern is about the $dt$ part   use the notation  instantaneous velocities $v = \dfrac{ds}{dt}$  Is it reasonable and common to interpret this way?

I have read the thread regarding , but it does not answer my question.  I am confused about the notation for change in Physics. In Mathematics, $\delta$ and $\Delta$ essentially refer to the same thing, i.e., change. This means that $\Delta x = x_1 - x_2 = \delta x$. The difference between $\delta$ and $d$ is also clear and distinct in differential calculus. We know that $\frac{dy}{dx}$ is always an operator and not a fraction, whereas $\frac{\delta y}{\delta x}$ is an infinitesimal change.   In Physics, however, the distinction is not as clear. Can anyone offer a clearer picture?


I multiply 2 numbers using their polynomial representation and addition via XOR. Do I need to find the remainder of the division by $x ^ 8 + x ^ 4 + x ^ 3 + x + 1$, using the operator "%" or by division, using the rules of finite fields?

I am working on AES and I am stuck on multiplication in $GF(2^{8})$ field.   In terms of polynomial it is easy; I just have to multiply polynomials modulo $(x^{8} + x^{4} + x^{3} + x + 1)$. But I do not understand multiplication with $x$, following an example given in NIST specification:     {57} • {13} = {fe}   solution:     {57} • {02} = xtime({57}) = {ae}   {57} • {04} = xtime({ae}) = {47}   {57} • {08} = xtime({47}) = {8e}   {57} • {10} = xtime({8e}) = {07},   thus     {57} • {13} = {57} • ({01} $XOR$ {02} $XOR$ {10})    = {57} $XOR$ {ae} $XOR$ {07}   = {fe}   I am unable to understand a single step in this, please also explain the x_time() function too.  Also, how is $x^{i}$ calculated? I need this for the $rcon[i]$ matrix.  Edit: this question has been marked as a possible duplicate of . I have already read this but the explanation is not sufficient, I am unable to understand the concept hence I have posted this question, because I need a somewhat detailed answer.Thanks.


. Trying to "directly add member" John Doexyz@gmail (< before xyz and> after mail, but don't show in the draft). I get back Member                email xyz                   xyz@gmail  I don't see any replies to Trent.

I'm a manager on Google Groups for a group that has about 100 members.  I want to be able to edit the display name so I can identify who my users are, instead of "JKL6" for example, which is the prefix for an email address.  First, I can't seem to edit the "Display Name" and second, I have deleted the list of email addresses when I was fooling around with the identity tool.  I was trying to change the settings about display name vs. Google name, and now my "Members" list does not have ANY email addresses showing.


Is there a simple way of getting windows7 file explorer back to a nice, clean, simple, consistent explorer like it was in winXP?  I'm fed up with adjusting folder columns et al. and clicking on "apply to all folders" for nothing to happen. I just want a list of files with the columns I select and I don't want the column order to be continually reset.  Why do microsoft always tamper with things for the worse then take away the options to get it back :(

I like the folder-tree behavior of Windows XP, that is, clicking on any folder on the left pane will automatically expand the folder-tree. Unfortunately this is not how Explorer works in Windows 7.  Does anyone know how I can get Windows 7’s Explorer to behave like the one in XP?


I'm using this JS regex text.match(/|(https:.+?path.+?)|/)[1] to get a regex of a URL that is in between pipe | characters but it's not working.  The text is ||https://url.com/path/value|| but I can't seem to extract the URL from it. I need to have path in the middle to identify this particular URL since there are other URLs in the file.  It doesn't have to be a URL that I'm extracting. I mainly would like to know how to extract something from between a pair of characters (| in this case).

I am trying to find all matches in a string that begins with | |.    I have tried: if ($line =~ m/^\\\|\s\\\|/) which didn't work.   Any ideas?


I am using HP Pavilion G series Model. I've been trying to install the AMD Catalyst driver on my laptop but it's not working.   Please give me a step-by-step procedure to install the AMD driver.

I have 14.04.5/16.04 or newer and an AMD GPU. I'm not getting the performance I want, and some programs say they need things like OpenCL.  I've heard about fglrx, but if I try to install it on my machine, it breaks and I have no GUI.  Is there anything I can do to get my AMD card working to its full potential?


I am sorry. I should change my question. I have the following code std::vector<int> v = {10, 20, 30}; auto it = v.begin();  std::cout << *it++ << std::endl;    // 1. no parenthesis  std::cout << *(it++) << std::endl;  // 2. with parenthesis  it++;                               // 3. post-increment first std::cout << *it << std::endl;   std::cout << *(it + 1) << std::endl;// 4. increment index  What is the difference between the above 4 statements? Is the parenthesis matter in post increment? All outputs are the same as my expectations except 2(with parenthesis).

In C, what is the difference between using ++i and i++, and which should be used in the incrementation block of a for loop?


Both are actually ioc containers. But what is the actual difference between them? Which one is better to use?

I'm pretty new to the Spring Framework, I've been playing around with it and putting a few samples apps together for the purposes of evaluating Spring MVC for use in an upcoming company project. So far I really like what I see in Spring MVC, seems very easy to use and encourages you to write classes that are very unit test-friendly.  Just as an exercise, I'm writing a main method for one of my sample/test projects. One thing I'm unclear about is the exact differences between BeanFactory and ApplicationContext - which is appropriate to use in which conditions?  I understand that ApplicationContext extends BeanFactory, but if I'm just writing a simple main method, do I need the extra functionality that ApplicationContext provides? And just exactly what kind of extra functionality does ApplicationContext provide?  In addition to answering "which should I use in a main() method", are there any standards or guidelines as far as which implementation I should use in such a scenario? Should my main() method be written to depend on the bean/application configuration to be in XML format - is that a safe assumption, or am I locking the user into something specific?  And does this answer change in a web environment - if any of my classes needed to be aware of Spring, are they more likely to need ApplicationContext?  Thanks for any help. I know a lot of these questions are probably answered in the reference manual, but I'm having a hard time finding a clear breakdown of these two interfaces and the pros/cons of each without reading thru the manual with a fine-tooth comb.


I'm running an app in kiosk mode. Currently swiping up triggers the Ubuntu on-screen keyboard.  How can I completely disable this keyboard? I will never want it in this instance

I'm in 17.10. Whenever I touch the screen, whether to change windows/apps, scroll within a browser, or press a button, the stupid little keyboard pops up in the bottom left corner.  I have never left Screen Keyboard enabled in Universal Access, but if I toggle it on, that's the same keyboard popping up in the bottom left corner.    In this screenshot, I'm simply touching the screen in a full-screen youtube video. You can see the menu pop up on the right, under the point where I'm touching.  I don't have a before pic, but it was similar look/color keyboard, but it was smaller, maybe half as wide, and only in the bottom left section of the screen, as opposed to stretching across the entire width. This change from little left-hand keyboard to full-width keyboard happened after following @pomsky 's advice below.    This is a . You can mark yourself affected by it to hopefully increase its received attention.


I have string with umlauts in utf-8 and it displayed ok:   var_dump($content);   It return me "höst lanseras". But when I try this:  for ($i = 0; $i < strlen($content) - 1; $i++) {     var_dump($content[$i]); }   I have this:   string(1) "h" string(1) "o" string(1) "�" string(1) "�" string(1) "s" string(1) "t" string(1) " " string(1) "l" string(1) "a" string(1) "n" string(1) "s" string(1) "e" string(1) "r" string(1) "a" string(1) "s"   How to get umlaut symbol as element of array?

I'm setting up a new server and want to support UTF-8 fully in my web application. I have tried this in the past on existing servers and always seem to end up having to fall back to ISO-8859-1.  Where exactly do I need to set the encoding/charsets? I'm aware that I need to configure Apache, MySQL, and PHP to do this — is there some standard checklist I can follow, or perhaps troubleshoot where the mismatches occur?  This is for a new Linux server, running MySQL 5, PHP, 5 and Apache 2.


I made a group of different objects with different set of modifiers for each one. I wanted to add a lattice modifiers to this group to be able shape its form... it is possible? I tried with no sucess... It seems something very useful, i'm impressed something like this isn't implemented in blender yet...

Is it possible to array a group of objects?   For example, if I have three objects in a group, (I want to keep them as separate objects) is it possible to easily duplicate them as if I pressed AltD for every single one?


I have a .smi file. When i open with notepad++ i had:  - °øµ¿¹ø¿ªÀÌ´Ùº¸´Ï Áö¸í°ú ÀÌ¸§ÀÌ ¾à°£¾¿ Æ²¸±¼ö ÀÖ½À´Ï´Ù.-   Then i set Character sets > Korean > UEC-KR:  - 공동번역이다보니 지명과 이름이 약간씩 틀릴수 있습니다.  -   So, what can i do it in C#? I want when i open a file, app can detect Character sets and display in a richtextbox. I used:  System.IO.StreamReader sr = new System.IO.StreamReader(openFile.FileName); inputText.Text = sr.ReadToEnd(); inputText.SelectAll(); inputText.SelectionFont = new Font("Arial Unicode MS",9,FontStyle.Regular);   Result in inputText:  - ���������̴ٺ��� ����� �̸��� �ణ�� Ʋ���� �ֽ��ϴ�.  -

In our application, we receive text files (.txt, .csv, etc.) from diverse sources. When reading, these files sometimes contain garbage, because the files where created in a different/unknown codepage.  Is there a way to (automatically) detect the codepage of a text file?   The detectEncodingFromByteOrderMarks, on the StreamReader constructor, works for UTF8  and other unicode marked files, but I'm looking for a way to detect code pages, like ibm850, windows1252.     Thanks for your answers, this is what I've done.  The files we receive are from end-users, they do not have a clue about codepages. The receivers are also end-users, by now this is what they know about codepages: Codepages exist, and are annoying.  Solution:    Open the received file in Notepad, look at a garbled piece of text. If somebody is called François or something, with your human intelligence you can guess this. I've created a small app that the user can use to open the file with, and enter a text that user knows it will appear in the file, when the correct codepage is used.  Loop through all codepages, and display the ones that give a solution with the user provided text.  If more as one codepage pops up, ask the user to specify more text.


TL;DR  What is the best way to change a page's <title> tag when a link is clicked but page content is not re-loaded (simply shown/hidden via CSS)? Some JavaScript, I would assume?    On this page () I have two methods for viewing individual magazines. Clicking on the magazine cover on the right completely re-loads the page with a query string (e.g. ?mag=1) appended to the URL and we have set the <title> tag to change then, but this was additional functionality we added via PHP. The framework's original method of changing content was simply to change shown/hidden content via CSS (basic JavaScript to add and remove an active class) by clicking on the left-hand tabs.  However, I would like for the page title to change when these left-hand tabs are clicked, also. The HTML code for the tabs is as follows:

Electric &amp; Hybrid Marine

Marine Catering

Marine Maintenance

Shipping Port

ALL TITLES

   And for their content:

   I tried investigating, and I think something needs to happen in the DOM, but my JavaScript knowledge is unfortunately, almost completely non-existent. Can anyone kindly help?  EDIT:  I've tried changing my  tags to the following, but this doesn't seem to do anything:  <a onclick="window.document.title='<?=$title?> | UKIP Media &amp; Events'" href="#" class="skip" gumby-goto="#top_of_page" gumby-offset="-60">   ($title is a PHP variable set on page load)  SECOND EDIT @MGA  My link now looks like so:     With this script at the bottom of the page:     But still nothing happens?

I have a webpage that implements a set of tabs each showing different content. The tab clicks do not refresh the page but hide/unhide contents at the client side.  Now there is a requirement to change the page title according to the tab selected on the page ( for SEO reasons ). Is this possible? Can someone suggest a solution to dynamically alter the page title via javascript without reloading the page?


When i download a data uri(this works in chrome/FF),using  url1 = "data:attachment/plain;base64,encodeuri(<base64data-xyz>)"   Here using attachment mime type forces it to download, using any other mime type like(text/html) will open the content of file in new tab, since i wanted to download ,i used attachment/plain-xyz [MIME type].  I tried the download attribute, but everytime,the file name downloaded is "download", and there is no extension, so it gets appeneded in my downloads folder as ".FILE", whereas i need to store it using "variable.txt"  Please do guide me how you are able to change "download.FILE" to some "variable.txt", i have tried all attributes of data, download, data-downloadurl, contentdisposition,even tried setting pom attributes etc..  Please help in converting the downloaded file content to a file with some filename and .txt as extension

If for example you follow the link:  data:application/octet-stream;base64,SGVsbG8=  The browser will prompt you to download a file consisting of the data held as base64 in the hyperlink itself.  Is there any way of suggesting a default name in the markup?  If not, is there a JavaScript solution?


When I visit recently-active but old questions, I often find that the activity consists of a new answer which duplicates, in briefer form, a long-existing answer. Such answers are often from new users and are generally reasonably accurate, but entirely duplicative of another answer long since posted.  What should I do in this case, as a <10k user?  Should I downvote it? Should I flag it? Should I comment on it?

I've been seeing this for a while now, especially on the  tag.  A user will ask a question (usually very simple, and mostly a duplicate of older questions. But that's for another day).  The user will get one or more answers that successfully answer the question. A little bit later, usually around 5-10 minutes but can be more, another user or users will come along (mostly low rep users) and post the exact same solution, sometimes changing the wording a bit, but sometimes being lifted word for word from the other answer(s).  This is slightly different from the Fastest gun in the west problem. I have nothing against answers posted in very quick succession that solve the problem. The ones I'm talking about are answers posted long after the first correct solution, that say the same thing.  A good example of this is available . All three answers say the same thing. One offers code + explanation (first answer), the second one (three minutes later) offers only code and the third one (a full eighteen minutes later) offers only a text answer.  How should answers like this be dealt with? They are adding nothing of value to the community, as the problem has already been answered. The person posting the answer could not have run into the "The other and I posted the answer so close to each other we didn't know about duplicates until after posting" problem, as there is an eighteen minute gap.   is another example.


Let $I$ and $J$ be ideals of a commutative ring $R,$ considered as $R$-modules. The product ideal $$IJ=\left\{\sum_{i=1}^{n}a_{i}b_{j}:n\in\mathbb{N},a_{i}\in I,b_{j}\in J\right\}$$ is also an $R$-module. Question: Is it true that $I\otimes_{R}J\cong IJ?$ This seems intuitive to me, since I like to think of the tensor product $M\otimes_{R}N$ as "sums of things of the form $m\otimes n$ where $m\in M$ and $n\in N,$" and this sounds a lot like a description of $IJ.$ I came up with the following (now seen to be incorrect) argument, which originally I had posted as an answer:  Let $f\colon I\times J\to IJ$ be given by $(a,b)\mapsto ab.$ This is an $R$-bilinear map, so there exists a (unique) corresponding $R$-linear map $h\colon I\otimes_{R} J\to IJ$ with $h(a\otimes b)=ab.$ We would like to prove that this map $h$ is bijective. To prove that $h$ is surjective: the element $\sum_{i=1}^{n}a_{i}b_{j}\in IJ$ is mapped to by $\sum_{i=1}^{n}a_{i}\otimes b_{j}.$ To prove that $h$ is injective, we consider its kernel. Suppose $x=\sum_{i=1}^{n}a_{i}\otimes b_{j}\in I\otimes_{R}J$ is such that $h(x)=0.$ Letting $y=\sum_{i=1}^{n}a_{i}b_{j}\in IJ,$ we see that $$x = \sum_{i=1}^{n}(a_{i}b_{j}\otimes1) = \left(\sum_{i=1}^{n}a_{i}b_{j}\right)\otimes1 = y\otimes 1.$$ Therefore $h(y\otimes1) = 0.$ But by the defining property of $h$ we have $h(y\otimes 1)=y\cdot1=y,$ whence $y = h(x) =0.$ Therefore we must have had $x=0\otimes 1=0$ all along, so the kernel of $h$ is trivial and this completes the proof.  However, the above argument does not work, as pointed out to my by @xyzzyz, since we don't know that $1\in J$ (and indeed this is true if and only if $J=R,$ which changes the nature of the question).

Ok, I'm reading some thesis of some former students, and come up with this proof, but it doesn't really look good to me. So I guess it should be wrong somewhere. So, here it goes:     Let $R$ be a unitary commutative ring, and $I$ be an ideal, and $N$ is an $R$-module. I'll now show that $$I \otimes_R N \cong IN\,.$$   First, since $1 \in R$, and $I$ is an ideal of $R$, we must have that $I = RI$. So then $$I \otimes_R N = RI \otimes_R N = R \otimes_R IN \cong IN\,.$$  But this must be so wrong, since if this proof is true, I could prove that any $R$-module is flat. So how come this proof is wrong?


The tagging system doesn't support (as far as I know) a tag to be "separated" into two tags. For example, the  currently has questions on  and . I'm sure there are more tags that have this problem. How would you suggest splitting tags in this case?

If tag "foo" refers to two or more different technologies or concepts is it better to retag the less common usages or is it better to add additional tags to disambiguate?  My particular issue is with the  tag which mostly refers to the  but could also refer to the  programming language & software platform. Is it better to retag the Curl language questions as  (any other suggestions?) or add some other tag such as "language"?


How to solve differential equations of the following form:   $\frac{df}{dx} = f(x+1)$

I was toying with equations of the type $f(x+\alpha)=f'(x)$ where $f$ is a real function. For example if $\alpha=\frac{\pi}{2}$ then the solutions include the function $f_{\lambda,\mu}(x)=\lambda cos(x+\mu)$. Are there more solutions?  On the other hand, if I want to solve the equation for any $\alpha$, I can assume a solution of the form $f(x)=e^{\lambda x}$, and find $\lambda$ as a complex number that enables me to solve the equation...   I was wondering: is the set of the solutions of dimension 2 because the derivative operator creates one dimension and the operator $\phi: f(x)\mapsto f(x+1)$ adds another one? Is there some litterature about this kind of equations?  Please satisfy my curiosity if you can... Thanks!


On the , if you scroll down a bit, you'll encounter a site with a very long title: . A title this long messes up the formatting of the list (at least in the latest Firefox and Safari on macOS Mojave):

The long name pushes the stats to a weird place. And what's with the "Stack Exchange" at the end anyway?


Anyone know how to edit the y tick? I want it in decimal form but the output gives tick in scientific notation. Thanks.       \documentclass[margin=5mm]{standalone}     \usepackage{tikz}     \usepackage{pgfplots}     \pgfplotsset{compat=1.13}     \begin{document}     \begin{tikzpicture} \begin{axis}[     ymin=0,ymax=0.12,     xtick={30,50,100,150,200,250,300},     ytick={0,0.02,0.04,0.06,0.08,0.10,0.12},     legend pos=north east,     x tick label style={rotate=90,anchor=east}     ]     \addplot[mark=*,mark options={fill=white}] coordinates {(30,0.018)(50,0.015)(100,0.0205)(150,0.0145)(200,0.016)(250,0.017)(300,0.014)};     \addlegendentry{a}     \addplot[dashed,mark=square*,mark options={solid,fill=white}] coordinates {(30,0.0165)(50,0.031)(100,0.0305)(150,0.0315)(200,0.0365)(250,0.0425)(300,0.043)};     \addlegendentry{b}     \addplot[dashdotted,mark=triangle*,mark options={solid,fill=white}] coordinates {(30,0.025)(50,0.025)(100,0.025)(150,0.025)(200,0.025)(250,0.025)(300,0.025)};     \addlegendentry{c}     \end{axis}     \end{tikzpicture}     \end{document}

the y-axis of my diagram uses small numbers like 0,005. I don't want to use a multiplier like 10^-3 which appears by default. If I remove it with   scaled x ticks = false, x tick label style={/pgf/number format/fixed},  the tick labels are not accurate enough and show ony 0 or 0,1:    Code used:  \begin{tikzpicture} \begin{axis}[% scaled x ticks = false, x tick label style={/pgf/number format/fixed}, scaled y ticks = false, scale only axis, width=6cm, height=5cm, xmin=0, xmax=30000, ymin=-0.001, ymax=0.006, ymajorgrids, axis on top]   How can i get this right?


Gaussian wave packets spread as the time passes, which means that as we go backwards in time they get more localized. Therefore, Gaussian wave packets introduce less uncertainty in the position as the we go backwards in time.  Are there wave functions (not necessarily Gaussian) in Nature that don't behave like this, i.e that don't get localized as we go backwards in time? If so, I think this would mean that the uncertainty they introduce in position doesn't necessarily increase with time (or decrease as we go backwards in time) as it does in the case of a typical Gaussian wave packet.

Consider any wave packet describing a free particle (so no potential or other forces acting on it). Then it can be shown that $\Delta p$ does not change in time. However, my question is what happens with $\Delta x$ as we go forward in time? Does it have to increase at all times? Or is there a counter-example where the uncertainty in position is decreasing, if even for a short time period?  My initial guess is $\Delta x$ must always increase, because $p \neq 0$, so that $\Delta p \neq0$ and hence $\Delta v = \frac{\Delta p}{m} \neq 0$. But if there's a spread in velocities, then the wave packet must also spread. Is this logic correct? Or could we have a wave packet where the back of it would move forward faster than the front, and for a certain period until that back end catches up with the front one, it would actually be narrower than at the outset, i.e. reducing $\Delta x$? If yes, how would one describe such a free particle (wave packet)?  So it does seem to me that every wave packet describing a free particle will eventually spread, but the question is whether there can be a time period in its evolution when it is actually becoming narrower.  edit: In particular, if it does not have to increase at all times, can this be shown without appealing to time reversal?


I am having trouble with bash. I am trying to put a command in an if statement and then compare it to a string.  This works perfectly.  echo $(ipcs | grep Shared | awk '{print $2}')   When I put it in an if statement I get some problems.  $ if [ "$(ipcs | grep Shared | awk '{print $2}')" -eq "Shared"]; then   echo expression evaluated as true; else   echo expression evaluated as false; fi bash: [: missing `]' expression evaluated as false  $ if [ "$(ipcs | grep Shared | awk '{print $2}')" = "Shared"]; then   echo expression evaluated as true; else   echo expression evaluated as false; fi bash: [: missing `]' expression evaluated as false  $ if [ "$(ipcs | grep Shared | awk '{print $2}')" == "Shared"]; then   echo expression evaluated as true; else   echo expression evaluated as false; fi bash: [: missing `]' expression evaluated as false   I tried ==, =, and -eq because I wasn't sure which one to use.

I am using the below script to move two days back when script runs at starting two days of the year and also check first and second days of every month and move two days back. if [$month="01"] && [$day="01"]; then         date="$last_month/$yes_day/$last_year"         fulldate="$last_month/$yes_day/$last_year" else         if [$month="01"] && [$day="02"]; then                 date="$last_month/$yes_day/$last_year"                 fulldate="$last_month/$yes_day/$last_year"         else                 if [ $day = "01" ]; then                         date="$last_month/$yes_day/$year"                         fulldate="$year$last_month$yes_day"                 else                         if [ $day = "02" ]; then                                 date="$last_month/$yes_day/$year"                                 fulldate="$year$last_month$yes_day"                         else                                 date="$month/$yes_day/$year"                                 fulldate="$year$month$yes_day"                         fi                 fi         fi fi  But my bad am getting the below error message Etime_script.sh: line 19: [06=01]: command not found Etime_script.sh: line 24: [06=01]: command not found


I have created a block named 'xyz'. I also created a form whose id is 'form-type-node-form' and i want this form to display in that block. How can i do this? please help me to get solution.

I just wanted to know how to add "create node form" in a block  when i  copy the source code and make a block out of that code, only public could post from that. when i am posting as a user it says timeout and tells us to refresh the page. plz someone give me solution.  SO i tried to add the following code in page.tpl.php  $form = node_add('nodetype'); print drupal_render($form);


I'm trying to run a random intercept model in R on an adolescent dataset with >100 schools (the school being the intercept).  The data include a survey weight value for each observation, however lme and lmer seem to only take frequency weights, not survey weights.  Anyone know how to incorporate survey weights with lme or lmer?

I'm looking for advice on how to analyze complex survey data with multilevel models in R. I've used the survey package to weight for unequal probabilities of selection in one-level models, but this package does not have functions for multilevel modeling. The lme4 package is great for multilevel modeling, but there is not a way that I know to include weights at different levels of clustering.  sets up the problem:  Multilevel models are frequently used to analyze data from cluster sampling designs. Such sampling designs however often use unequal probability of selection at the cluster level and at the individual level. Sampling weights are assigned at one or both levels to reflect these probabilities. If the sampling weights are ignored at either level the parameter estimates can be substantially biased.  One approach for two-level models is the multilevel pseudo maximum likelihood (MPML) estimator that is implemented in MPLUS ().  reviews major software packages and makes a few recommendations about how to proceed:  To properly conduct MLM with complex survey data and design weights, analysts need software that can include weights scaled outside of the program and include the "new" scaled weights without automatic program modification. Currently, three of the major MLM software programs allow this: Mplus (5.2), MLwiN (2.02), and GLLAMM. Unfortunately, neither HLM nor SAS can do this.   give a more updated review, and I'll quote the relevant passage at length:  Occasionally, analysts wish to fit LMMs to survey data sets collected from samples with complex designs (see Heeringa et al, 2010, Chapter 12). Complex sample designs are generally characterized by division of the population into strata, multi-stage selection of clusters of individuals from within the strata, and unequal probabilities of selection for both clusters and the ultimate individuals sampled. These unequal probabilities of selection generally lead to the construction of sampling weights for individuals, which ensure unbiased estimation of descriptive parameters when incorporated into an analysis. These weights might be further adjusted for survey nonresponse and calibrated to known population totals. Traditionally, analysts might consider a design-based approach to incorporating these complex sampling features when estimating regression models (Heeringa et al., 2010). More recently, statisticians have started to explore model-based approaches to analyzing these data, using LMMs to incorporate fixed effects of sampling strata and random effects of sampled clusters. The primary difficulty with the development of model-based approaches to analyzing these data has been choosing appropriate methods for incorporating the sampling weights (see Gelman, 2007 for a summary of the issues). Pfeffermann et al. (1998), Asparouhov and Muthen (2006), and Rabe-Hesketh and Skrondal (2006) have developed theory for estimating multilevel models in a way that incorporates the survey weights, and Rabe-Hesketh and Skrondal (2006), Carle (2009) and Heeringa et al. (2010, Chapter 12) have presented applications using current software procedures, but this continues to be an active area of statistical research. Software procedures capable of fitting LMMs are at various stages of implementing the approaches that have been proposed in the literature thus far for incorporating complex design features, and analysts need to consider this when fitting LMMs to complex sample survey data. Analysts interested in fitting LMMs to data collected from complex sample surveys will be attracted to procedures that are capable of correctly incorporating the survey weights into the estimation procedures (HLM, MLwiN, Mplus, xtmixed, and gllamm), consistent with the present literature in this area.  This brings me to my question: does anyone have best practice recommendations for fitting LMMs to complex survey data in R?


The most precious thing for me was .... a) my brother-in-law guitar b) my brother’s-in-law guitar c) my brother-in-law’s guitar d) my brother’-in-law guitar e) my brother’s-in-law’s guitar

I need a bit of help with this.      She is a photographer but that camera is her brother's-in-law     or:        She is a photographer but that camera is her brother-in-law's   I am aware that I could change the construction to make things easier, like:      She is a photographer but that camera belongs to her brother-in-law       However, I would really like to find out what's the correct way to write the sentence.


I get email notifications when someone answers or comments on one of my questions, but not when one of my questions is put on hold.  That's an event I'd like to know about!  Why am I not notified?

I think it would really help if you get notified that a question of yours was closed.  Especially for the multi-site power user, usually (at least for me) a question is asked and then left alone for while. I rely on the network-wide inbox to tell me when someone has commented or answered, but if I don't receive any messages then I tend to assume that the question wasn't answered or even noticed. It's only when I check the question a day or two later to see what I can add do I find out it was closed.  This would be especially helpful for duplicates, where the answers you need are already there. A message to the effect of, "Closed as duplicate of question" is just like notifying me that a new answer has been added!  Unfortunately, question closures can remain unnoticed by their askers until months have passed. By then, the questions may either be too old to migrate to the correct site, or may , depending on the specific closing reason. We should notify users of these question closures so that they can improve them and learn from their mistakes.  Could closed questions get added to the inbox?


I have Weil-McLain gas boiler for hot water heat and going to install WiFi thermostat that requires common 24V 'C' wire. I do have a free wire in the cable but cannot figure out where should I connect it on the boiler, there's no any terminal, marked as 'C', 'common' or similar. The system includes hot water boiler and central AC. Currently I use thermostat with battaries that has 5 wires going in.

How do I identify the C terminal on an HVAC, furnace, or boiler? If the terminals don't have a screw labeled C what should I look for on the wiring diagram? What steps should I take if a wiring diagram cannot be found or if it indicates that a C terminal doesn't exist?  Note: This is an extension to  which asks about running the wires through the wall. This question is about where to connect the wire at the HVAC.


What would happen if I put a 2400mhz ram on a E5 2620 v3 which supports only a maximum of 1866 MHz?! I read that that would work but CPU could only reach its maximum, but is there any exception?

Looking at the  CPU, under Memory types it says "DDR3-1333/1600". My question is, in what way does the CPU limit the RAM speed? What would happen if I put in a DDR3-2133 RAM chip together with the CPU, if the motherboard supports the faster RAM speed? Would it be better to get a RAM chip that is DDR3-1600 so it matches the CPU's listed frequency?


this is my first post on tex exchange , i am using latex for the first time for my internship report . I read that lateX is very useful and professionnal especially for writing equation . I've found a lot of Books about it but i'm not fan of them ... i was wondering if there is a method , steps or structure to follow to make a good report  thanks

Which book (free or otherwise) was the most useful to you when you started learning LaTeX?  I am frequently asked this question by friends who want to learn LaTeX, and I recommend the book which got me started, , but I feel that there might be better options around.  Also see .


I requested from Google Webmaster to remove an URL called example.com/demo some months ago and the URL was removed from the search engine and now the status is expired.  Today I want to reindex the demo page  and have it appear in the search engine again but Google Webmaster is showing "301 Redurect html is corrupted" in the index request  .

This is a general, community wiki  question and answer pair intended to address any questions   concerning the reasons a site or specific site contents do not appear   in search engine results.      If your question was closed as a duplicate of this question and you   feel that the information provided here does not provide a sufficient   answer, please open a discussion on .   My site (or specific pages on my site) is not appearing in search engine results.  Why isn't my content indexed and what can I do about it?


Suppose I have this dictionary: {"A":3,"B":4,"H":1,"K":8,"T":0}  I want to get the keys of the highest 3 values. So in this case I will get the keys: K, B and A

I have a dictionary of values read from two fields in a database: a string field and a numeric field. The string field is unique, so that is the key of the dictionary.  I can sort on the keys, but how can I sort based on the values?  Note: I have read Stack Overflow question here  and probably could change my code to have a list of dictionaries, but since I do not really need a list of dictionaries I wanted to know if there is a simpler solution to sort either in ascending or descending order.


I'm running Ubuntu 18.04 LTS, and I can't install from new PPA's.  It gives me a 404 error every time I try to update the package lists.  curtice@linuxloverpc:~$ sudo apt update [sudo] password for curtice:  Hit:1 http://security.ubuntu.com/ubuntu bionic-security InRelease Hit:2 http://us.archive.ubuntu.com/ubuntu bionic InRelease                Hit:3 http://us.archive.ubuntu.com/ubuntu bionic-updates InRelease        Hit:4 http://ppa.launchpad.net/bartbes/love-stable/ubuntu bionic InRelease Ign:5 http://ppa.launchpad.net/gnome-shell-extensions/ppa/ubuntu bionic InRelease Hit:6 http://ppa.launchpad.net/obsproject/obs-studio/ubuntu bionic InRelease   Hit:7 http://ppa.launchpad.net/papirus/papirus/ubuntu bionic InRelease         Err:8 http://ppa.launchpad.net/gnome-shell-extensions/ppa/ubuntu bionic Release   404  Not Found [IP: 91.189.95.83 80] Reading package lists... Done E: The repository 'http://ppa.launchpad.net/gnome-shell-extensions/ppa/ubuntu bionic Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.   I did not re-enable repositories after a distro upgrade, I did not incorrectly type the repo name, and the repository obviously exists at   How do I fix this?

PPA seems to be constantly offline. Whenever I use sudo apt-get update, this error is shown:  W: Failed to fetch http://ppa.launchpad.net/ 404  Not Found   How do I fix these errors?


I have got a list called words_list that has around 28352 elements (words). Now I want to split this list into 29 different lists each having 1000 elements i.e, the first list would contain first 1000 words and the next list would contain next 1000 words from the words_list and so on. I implemented this in the following manner,  split=[] start=0 end=1000 for i in range(0,29):     temp=words_list[start:end]     split.append(temp)     start=start+1000     end=end+1000    The code is serving the purpose. I just want to know, is there any way to reduce the steps?

I have a list of arbitrary length, and I need to split it up into equal size chunks and operate on it. There are some obvious ways to do this, like keeping a counter and two lists, and when the second list fills up, add it to the first list and empty the second list for the next round of data, but this is potentially extremely expensive.  I was wondering if anyone had a good solution to this for lists of any length, e.g. using generators.  I was looking for something useful in itertools but I couldn't find anything obviously useful. Might've missed it, though.  Related question:


Let $\,A,B\,$ be two finite subgroups of a group $\,G.\,$ We define $\,AB=\left\{ab \mid a\in A,b\in B\right\}$. Prove that $\;\left\lvert AB\right\rvert=\dfrac{\left\lvert A\right\rvert\cdot\left\lvert B\right\rvert}{\left\lvert A\cap B\right\rvert}$. I want a complete proof plz.

Let $A,B < G$ be two subgroups of some group $G$, then I have a question on the proof of the following: $$  |AB| = \frac{|A||B|}{|A \cap B|}. $$ Proof: Let $D = A \cap B$, arrange $A$ and $B$ in left cosets and right cosets regarding $D$ (which is also a subgroup) $$  A = D \cup s_2 D \cup s_3 D \cup \ldots \cup s_n D, \quad   B = D \cup D t_2 \cup D t_3 \cup \ldots \cup D t_m $$ Now the fact that $\frac{|A||B|}{|D|}$ are distinct results from the following equations: If $$  s_{\alpha}D D t_{\beta} = s_{\alpha_1} D D t_{\beta_1} $$ then $$  s_{\alpha_1}^{-1} s_{\alpha} D = D t_{\beta} t_{\beta}^{-1} $$ As the first member of the last equation represents an element of $A$ while the second member represents an element of $B$, it results that the last equation implies $\alpha_1 = \alpha$ and $\beta_1 = \beta$.  The last step is not clear to me, why does $\alpha_1 = \alpha$ and $\beta_1 = \beta$ follows? Is it the case that if $aD = Db$ for $a \in A$ and $b \in B$ that $a=b=1$ follows? I don't believe this and cannot prove it either? Could someone please explain the last step?


Brightness control button is changing brightness value in file /sys/class/backlight/acpi_video0/brightness, but screen brightness is not changing.

I edited the xconf file, and added this line to device section:  Enable brightness control=1   Now I am able to adjust brightness, but after every restart the brightness setting change back to 100%.  Is there any solution for this?


I'm sure I've missed a step somewhere in configuring my machine to run Virtualbox, but when trying to boot a new VM (Ubuntu MATE) my host machine completely locks up. No GUI, no terminal, no SSH. My only recourse is a hard restart.  The host machine is running 16.04 LTS on a Gen 10 HP Proliant server and all packages should be up to date.  I've checked the MD5 hash on the iso. I've given the VM 2 gigs of memory, made sure it's using the correct type of pointing device and that it's booting from the .iso first.  I've reviewed several guides on installing Virtualbox and setting up VMs and I don't feel like I'm doing anything wrong, but obviously something is amiss. I'm just not sure where.

Ubuntu 16.04 LTS Virtualbox 5.0.40 ubuntu r 115130  Today after upgrading to kernel 4.13.0-26 guest vbox machines started to crash whole ubuntu. just hard poweroff is working.  If I startup with kernel 4.10.0-42 everything works fine.  what may be the problem ?


The inequality I am having a problem with is as follows:  Let $1\leq k\leq n$, where $n,k$ are natural numbers. Prove that $\binom{n}{k}\geq(\frac{n}{k})^k$  I have proven already the inequality $\binom{n}{k}\leq\frac{n^k}{k!}\leq(\frac{en}{k})^k$, but cannot seem to prove my lower bound. I have been told that differentiating may be of use, though I am unsure how to approach this. Any help is greatly appreciated.

What is the best way of proving inequalities including binomial coefficients in general? Lets look at this example:     $$\frac{n^k}{k^k}\leq\binom{n}{k}\leq\frac{n^k}{k!}$$   What I started with is:  $$\binom{n}{k}\frac{1}{n^k}\leq\frac{1}{k!}$$ $$\frac{n!}{k!(n-k)!}\frac{1}{n^k}\leq\frac{1}{k!}$$ $$\frac{(n-1)!}{(n-k)!n^{k-1}}\leq1$$ This is where I got stuck. How can I prove that is is lower than or equal to 1? Could you give me a hint?


Find⠀the⠀average⠀distance⠀of two⠀randomly-selected⠀points⠀in⠀a⠀circle⠀of⠀Radius $=R$. This⠀is⠀my⠀approach: Consider a function $I(R)$ that is given an input (the radius $R$ of the circle) and outputs the average distance between two randomly-selected points inside that circle. The size of the radius seems like it would only scale the answer, so we can say that $I(R)=R\cdot I(1)$. This reduces the problem to merely considering the case when $R=1$. One’s first instinct might be to consider two random variables, $r\in [0,1]$ and $\theta \in [0,2\pi]$, and considering $x=r\cos\theta$ and $y=r\sin\theta$, but a closer inspection shows us that these won’t correspond to random points, and the points would cluster more around the center of the circle than they would closer to the edges (notice to that $dA=r\cdot dr\cdot d\theta$, not just "⠀$dr\cdot d\theta$ "). The correct transformation is $x=r\sqrt{\cos\theta}$ and $y=r\sqrt{\sin\theta}$ (when I first considered this problem myself, I understood that the first approach wouldn’t work, and the points would cluster around the center, but even now I couldn’t exactly tell you why the correct transformation requires taking precisely the $\sqrt{r}$ ; this is evidence for the question’s conceptual difficulty). Considering this transformation and integrating each variable with respect to its PDF, taking (without loss of generality) the first point to be $(r_1,0)$ and the second to be $(r_2,θ)$, and noticing that $\theta$ only needs to range from $0$ to $\pi$ yields the integral⠀: \begin{align}I(1)&=\frac{\int_{0}^{1}\int_{0}^{1}\int_{0}^{\pi}\sqrt{(\sqrt{r_1}-\sqrt{r_2}\cos\theta)^2+(\sqrt{r_2}\sin\theta)^2}⠀d\theta dr_1 dr_2}{\int_{0}^{1}\int_{0}^{1}\int_{0}^{\pi}d\theta dr_1 dr_2}\\&=\frac{1}{\pi}\int_{0}^{1}\int_{0}^{1}\int_{0}^{\pi}\sqrt{r_1+r_2+\sqrt{r_1r_2}\cos\theta}⠀d\theta dr_1 dr_2 \end{align} It took me 2hr to type the question and 1hr to type this integral. This took me really Long, So without showing the steps to anti-differentiate, This equals to : $⠀I(R)=\frac{128}{45\pi}R $ Is my answer is correct?⠀ Kindly provide⠀your⠀solution⠀too.

Question: What is the expected distance between two points inside a unit circle?    I know the expected distance on the unit circle is $\dfrac 4\pi$.  The expected distance $E$ must equal the integral $$E=\frac1{\pi^2} I=\frac1{\pi^2}\iint_{x^2+y^2\le 1}\iint_{z^2+w^2\le 1} \sqrt{(x-w)^2+(y-z)^2}\,\mathrm d x\,\mathrm d y\,\mathrm d z\,\mathrm d w.$$  Someone gives the beautiful answer $E=\dfrac1{\pi^2}I=\dfrac{128}{45\pi}$.  Polar coordinates seems complicated here. Any ideas to simplify the integral?


In fact, I don't know how to write this expression on LaTeX:     And thanks in advance.

What LaTeX markup would one have to write to produce a result similar to the image below?    Please excuse my Paint-and-mouse drawing skills. :-)


When preparing a presentation for a coding camp, I would like to display my directory structure as the following     Could anyone suggest any existing templates may help, or the correct latex package that does the job?

I'm trying to make a simple directory tree representation in LaTeX. Something like:  spam  |  +-- ham  +-- eggs      |      +-- more spam      +-- dead parrots   The tree won't be that long (say, 10--15 entries or so), with three or so levels, and is a one-off thing. So, quick-and-dirty solutions are welcome. When recommending tikz, please note that I have almost no experience with it, so I'd appreciate a clean simple solution, even if it doesn't look quite perfect.   On Tex.SE tikz is almost like the jquery recurring joke on StackOverflow..    Edit: As per Thorsten's suggestion,  is a nice and easy-to-use solution. The example from above could be written as:  \usepackage{dirtree} ... \dirtree{% .1 spam. .2 ham. .2 eggs. .3 more spam. .3 dead parrots. }


I couldn't find Karliah in the Ragged Flagon so I went to Snow Veil Sanctum and she was stuck trying to open a door. When I opened it she didn't do anything and she's not coming to the Ragged Flagon. I went back after a few days (in game) and she is just standing there.  Why is this happening, and what should I do to make her move to Ragged Flagon?

During the 'Hard Answers' Thieves Guild quest, Karliah asked me to meet her at the Ragged Flagon.  However, it seems that she doesn't show up at the rendezvous point.  Where do I find her?


I need to move the graph in the third page slide in the second page and make everything fit.     \documentclass{beamer}  %\setbeamercolor{titlelike}{parent=structure,bg=cyan} %background color %\setbeamercolor{titlelike}{parent=structure,fg=blue} %colore titoli %\setbeamercolor{titlelike}{parent=structure,fg=yellow,bg=cyan} %colore e background in un comando  \usepackage{tikz} \usepgflibrary{arrows.meta} \usetikzlibrary{calc,quotes,angles}  \usepackage{pgfplots} \pgfplotsset{compat=1.16}  \usepgfplotslibrary{groupplots}  \usetikzlibrary{calc}    \usepackage{xcolor}  \definecolor{cobalt}{rgb}{0.0, 0.28, 0.67}  \setbeamercolor{titlelike}{parent=structure,fg=cobalt}    \usepackage{tikz} \usepackage{subcaption} \usepgflibrary{arrows.meta} \usetikzlibrary{calc,quotes,angles}  \usepackage{pgfplots} \pgfplotsset{compat=1.16}  \usepgfplotslibrary{groupplots}  \usetikzlibrary{calc} %rido  \setbeamercolor{itemize item}{fg=cobalt} % all frames will have cobalt bullets  \setbeamersize{text margin left=5mm,text margin right=5mm} %margini  %\usebackgroundtemplate{\includegraphics[width=\paperwidth]{logo.jpeg}} \title{\textbf{title }} \author{name}  \institute[VFU] % (optional) {   \inst{1}%   thesis\\   uni   \and   \inst{2}%   prof1\\   pro2 }  \date[VLC 2013] % (optional) {Lmarch}  \titlegraphic{\includegraphics[height=1.5cm]{logo.jpeg}}  \begin{document}  \maketitle    \begin{frame} \frametitle{Title}  \begin{figure}[h]     \centering     \begin{tikzpicture}     \begin{axis}[name=plot,      xmin=-0.2,      xmax=0.8,      ymin=0,     ymax=3,     yticklabels={,,},      xticklabels={,,},       ytick=\empty,      xtick=\empty,      axis line style={draw=none},     tick style={draw=none}     ]          \addplot[black,mark=.] table{capitoli/capitolo_02/data/dati_polinomio_Greitzer_esempio.txt};     \coordinate (A) at (0,1.862);     \coordinate (B) at (0,0);     \coordinate (C) at (0.212,2.275);     \coordinate (D) at (0.212,1.862);          \draw[<->] (-0.05,1.862) -- (-0.05,0);     \draw[dashed] (B) -- (-0.01,0);     \draw[<->] (C) -- (D);     \draw[<->] (A) -- (D);     \draw[->] (0,0) -- (0,3);     \draw[->] (0,0) -- (0.7,0);          \node[text width=2cm] at (0.37,2.1) {2H};     \node[text width=2cm] at (0.212,1.7) {2W};     \node[text width=2cm] at (-0.05,0.9) {$\psi_{c0}$};     \node[text width=2cm] at (0.55,1) {$\Psi_c$};          \end{axis}          \end{tikzpicture}     %\caption{\textit{Definizione dei parametri del polinomio cubico}}   \label{fig:polinomio cubico} \end{figure}  \begin{equation} \Psi_c(m,N)=\psi_{c0}+H(N)\left[+\frac{1}{3}\left(\frac{\phi}{W(N)}-1\right)-\left(\frac{1}{2}\frac{\phi}{W(N)}\right)^3\right] \label{eq:polinomio cubico} \nonumber \end{equation}  \end{frame}  \begin{frame} \frametitle{Title}  \begin{figure}[h]     \centering     \begin{tikzpicture}     \begin{axis}[name=plot,     xmin=-0.1,      xmax=0.4,      ymin=1,     ymax=2.8,      xlabel={$[kg/s]$},      ylabel={Rapporto di compressione},     width = \textwidth,     height = 0.57\textwidth,     %yticklabel style={/pgf/number format/.cd,fixed zerofill,precision=5},     xticklabel style={rotate=-90,/pgf/number format/.cd,fixed zerofill,precision=2},     legend style={at={(0.5,-0.25)},anchor=north,legend cell align=left},     legend columns=-1     ]          \addplot[blue,mark=.,very thick] table{capitoli/capitolo_02/data/dati_polinomio_Greitzer_esempio.txt};     \addplot[red,mark=.,very thick] table{capitoli/capitolo_02/data/fisico.txt};          %\legend{$40000 rpm$,$45000 rpm$,$50000 rpm$,$55000 rpm$}             \end{axis}          \end{tikzpicture}     %\caption{\textit{Scostamento del polinomio cubico}}   \label{fig:spostamento_surge} \end{figure} \end{frame}  \end{document}

I have searched the stackexchange for a resolution of this problem, but I am still getting an error message when I put in the following (for now neglecting other things in my document, such as documentclass, begin{document}, etc.):  \begin{frame} \frametitle{explanation} \begin{columns} \begin{column}{width=0.5\textwidth}    some text here \end{column} \begin{column}     \begin{center}      \includegraphics[width=0.5\textwidth]{image1.jpg}            \end{center} \end{column} \end{columns} \end{frame}   When compiled, I get the error: Missing number, treated as zero. I should appreciate any help.


Here are the contents of my /etc/sudoers file  $ sudo cat /etc/sudoers # # This file MUST be edited with the 'visudo' command as root. # # Please consider adding local content in /etc/sudoers.d/ instead of # directly modifying this file. # # See the man page for details on how to write a sudoers file. # Defaults    env_reset Defaults    mail_badpass Defaults    secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin"  # Host alias specification  # User alias specification  # Cmnd alias specification  # User privilege specification root    ALL=(ALL:ALL) ALL  pkaramol ALL=(ALL:ALL) NOPASSWD:ALL # Members of the admin group may gain root privileges %admin ALL=(ALL) ALL  # Allow members of group sudo to execute any command %sudo   ALL=(ALL:ALL) ALL  # See sudoers(5) for more information on "#include" directives:  #includedir /etc/sudoers.d   And here is what's inside /etc/sudoers.d  /home/pkaramol $ sudo ls /etc/sudoers.d/ README   However, still no password-less sudo:  /home/pkaramol $ sudo -k /home/pkaramol $ sudo -i [sudo] password for pkaramol:    Why is that?

I have a NOPASSWD line in /etc/sudoers (edited with visudo)  gatoatigrado    ALL=(ALL) NOPASSWD: /bin/set-slow-cpufreq   However, the output is,  gatoatigrado@coral:~> sudo -n /bin/set-slow-cpufreq sudo: sorry, a password is required to run sudo   This kind of command works on an OpenSuSE machine, but not on Ubuntu 11.10. What am I doing wrong?  Note: I cannot find any relevant system log messages, e.g. via tail -f /var/log/syslog.  edit  Here is /etc/sudoers.  Defaults    env_reset  # things I've tried copying from an opensuse machine Defaults always_set_home Defaults env_keep = "LANG LC_ADDRESS LC_CTYPE LC_COLLATE LC_IDENTIFICATION LC_MEASUREMENT LC_MESSAGES LC_MONETARY LC_NAME LC_NUMERIC LC_PAPER LC_TELEPHONE LC_TIME LC_ALL LANGUAGE LINGUAS XDG_SESSION_COOKIE"  root    ALL=(ALL:ALL) ALL gatoatigrado ALL=NOPASSWD: /bin/set-slow-cpufreq %admin ALL=(ALL) ALL %sudo   ALL=(ALL:ALL) ALL