Is there a way to access one database from another in Postgresql?

I have recently switched from MySQL to Postgres and am still is discovery mode. In MySQL I could be connected to radius_db and still run a query against main_db. However in Postgresql this doesn't seem possible. radius_db=# SELECT COALESCE((SELECT UNIX_TIMESTAMP(expires_at) FROM main_db.device d WHERE d.id='123'), 0); ERROR:  relation "main_db.device" does not exist LINE 1: ... COALESCE((SELECT UNIX_TIMESTAMP(expires_at) FROM main_db.de...                                                              ^ radius_db=#  Both radius_db and main_db belong to the same Schema (public). Is there a way to achieve this? Thank you


What can be done with a question & bounty where single answer is already part of the question?

question of mine has a bounty of 50 points and received a single answer so far. However the answer is already part of the original quesiton. Additionally the answer also does not solve the question at all and does not include a jsfiddle as outlined in the bounty description.  What can be done now? Left a comment on the answer explaining why the answer is not valid. So far no reaction from the person that posted the answer.      Dont mind loosing the bounty, however I come here to learn form great answers, hence I thought putting a bounty might give me an answer that solves the problem and teaches me how to solve such a problem applicable to similar scenarios in the future.   Should I close the question altogether and go back to study this myself?     Is the question too specific?     What happens if the question does not receive another answer or an edit after 7 days, meaning will the bounty automatically be given to the single answer despite not being valid?


What is "magic" about the combination of addition and multiplication in formal arithmetic?

Goedel's incompleteness tells us that any system containing Robinson arithmetic is incomplete.  OTOH, Presburger Arithmetic, which contains only the successor and addition, is complete.  I'm pretty sure that I have read that it possible to define a complete arithmetic with only sucessor and multiplication axioms.  So, this raises the question about what is special about the combination of addition and multiplication.  In reviewing the proof of Goedel's theorem, I thought I had located the key point: the $\beta$-function involves both addition and mutliplication.  Without that, we cannot get to the primitive recursive functions, which means we cannot arithmetize syntax, so you cannot form the Goedel sentence, and there is nothing that says it cannot be proved.  This isn't a 100% satisfying, but it makes a certain amount of sense.  But then I learned that there are  which can arithmetize syntax despite being much weaker than Robinson arithmetic.  So that cannot be right.  Is there, then a simple explanation of why the combination of addition and multiplication is necessary for incompleteness to kick in?


Given an infinite set $A$ -  does the cardinality of $A$ equal to the cardinality of $A^2$?


Show that a metric space $(X,d)$ is totally bounded(ball compact) if and only if every sequence in X has a Cauchy subsequence.  I already proved that if $(X,d)$ is ball compact, then every sequence in X has a Cauchy subsequence. But I have no idea how to the other part.


Red items in HTML sudo lshw -html > ~/hardware.html

I am checking list of devices installed in my system  I used the following   sudo lshw -html > ~/hardware.html   Many items come in red in that list, others come in a yellow color.  Does red mean there's something wrong with them?


Add high-resolution-graphics and / or .svg-icons

I think that Stack Exchange could optimize the Stack Overflow logo on top of the page for high-resolution displays.  Moreover I think that svg-Files are a better solution for simple icons like upvote or down vote, which will look sharp on all devices and often have even a smaller size than png-files.


Proof via Group Theory : $\mathrm{lcm}(a,b) \cdot \gcd(a,b) = |ab|$

Recently, I was informed that we can verify the famous formula about $\mathrm{lcm}(a,b)$ and $\gcd(a,b)$ which is $$\mathrm{lcm}(a,b)=\frac{|ab|}{\gcd(a,b)} $$ via group theory.   The least common multiple of two integers $a$ and $b$, usually denoted by $\mathrm{lcm}(a,b)$, is the smallest positive integer that is a multiple of both $a$ and $b$ and the greatest common divisor ($\gcd$), of two or more non-zero integers, is the largest positive integer that divides the numbers without a remainder.  I do not know if we can prove this equation by using the groups or not, but if we can I am eager to know the way someone face it. Thanks.


I was wondering which is the fastest for general use. So instead of push_back() we could use the following code for arrays. I thought arrays are faster but I am not sure of that.    int *p;  p = new int[5];  for(int i=0;i<5;i++)     *(p+i)=i;   // realloc  int* temp = new int[6];  std::copy(p, p + 5, temp);   delete [] p;  p = temp;


Creating and executing shell scripts to run XAMPP on double click

Basic Specs - Ubuntu 13.10, Gnome 3 (session fallback), Ambiance theme, Faenza icons.  I recently installed , now everytime i want to use the program i have to run the sudo /opt/lampp/lampp start command, im quite new at ubuntu but i know my way around some things and i knew i can make a shell script to start the program when i double click on it, so, i open nano in the terminal and write:  #!/bin/bash/ sudo /opt/lampp/lampp start   I save it as "lampp.sh" at my home dir and give it the proper permissions chmod +x lampp.sh and chmod +775 lampp.sh. When i double click on it absolutely nothing happens, in order for it to work i have to open a terminal and run the the script there ./lampp.sh.  If i have to open the terminal each time i want to run the script then the script it self is worthless (specially when runing the sudo /opt/lampp/lampp start is 1 line of code), is there anyway i can run it on double click?  Thanks in advance, i love this community.


I am trying to read the RGB values at certain locations on my map which is a .tif-file I brought into QGIS. Goal: match species presence points on my map to certain RGB values on the .tif-file. from PIL import Image img = PIL.Image.open(iface.layerTreeView().selectedLayers()) col = img.convert("RGB") val = col.getpixel((0,0)) #tried to read value at center print (val)  And getting the error: AttributeError: 'list' object has no attribute 'read'


Update value in a list of dictionaries in Python

I create a list of identical dictionaries and I would like to update only the value of one specific key of one of the dictionaries of the list, but I don't get what I expect.  Would you know how to do that?


Suspension seatpost for mountain biking?

I've seen several seatposts on the market with suspension built into them such as the Thudbuster, Redshift, and Kinect and was wondering if anyone is using one for mountain biking?  Is it worth the money and does it improve the ride quality?  Let me know your thoughts. Thanks!


Can you deliver it [when,after] it [is | will be] assembled?

Right now we are assembling a device. I am asking another person if he is can deliver it [after/when] we finish. What question construction is the most correct?  Can you deliver it after it is assembled?  Can you deliver it after it will be assembled?  Can you deliver it when it will be assembled?  Can you deliver it when it is assembled?


I have setup y ubuntu with all kind of my setting  now I want to duplicate it to 9 more computers (so I will have 10 exactly the same computers - with all the software\users\setting.....) how I create an image and how do I install it on a new computer? also if something happand to the computer I will be able to full restore it ? Thanks ,


After Cloning my 80gb hdd to a 1tb hdd, ubunutu reads it as the 80gb.

The 80gb is not in the computer. How do I make it read and use the full tb?


in a dotnet core application that uses pinvoke and runs on linux, when c++ throws - for example - std::runtime_error - we get:  terminate called recursively terminate called after throwing an instance of 'terminate called after throwing an instance of 'std::runtime_error*' Aborted (core dumped)   even though the invocation of the externed c++ method is wrapped in a try catch block in the managed code.  how can this be caught and treated in the dotnet core managed code?


What is the easiest and/or fastest way to find players?

You have just arrived to a new town, you do not even know where the tavern is but an incessant need to form a group and start playing invades you.  What do you do? How to detect the ones who are the same as you or where they meet ?


What is the difference between topological and metric spaces?

What is the difference between a topological and a metric space?


How do I number equations only if they are referred to in the text?

I have a paper where all equations are numbered, but I want to number equations only if they are actually referred to in the .tex file using \ref{}. How can I make that happen? Alternatively, how can I make all equations that have no \label next to them (because then I know I don't refer to them) not have a number? Do I have to use \nonumber separately for each such equation?


How to remove old robots.txt from google as old file block the whole site

I have a website which still shows old robots.txt  in the google webmaster tools.  User-agent: * Disallow: /   Which is blocking Googlebot. I have removed old file updated new robots.txt file with almost full access & uploaded it yesterday but it is still showing me the old version of robots.txt Latest updated copy contents are below  User-agent: * Disallow: /flipbook/ Disallow: /SliderImage/ Disallow: /UserControls/ Disallow: /Scripts/ Disallow: /PDF/ Disallow: /dropdown/   I submitted request to remove this file using Google webmaster tools but my request was denied  I would appreciate if someone can tell me how i can clear it from the google cache and make google read the latest version of robots.txt file.


Is it more efficient for Java to import java.math.* or java.math.BigInteger and java.math.BigDecimal?

I was in the middle of creating a project that involved Java's math package.  import java.math.BigDecimal; import java.math.BigInteger;   And just as I was about to delete the second line and insert the * character in the first line:  import java.math.*;   I began to question if this method really is the better option. I imagine it makes very little difference in the overall scheme of the project, and it's very possible the compile would treat both versions of this import as being the same. If this isn't the case, however, then which is faster/more efficient?


It was he who messed up everything.  It was him who messed up everything.  What is the difference between these two sentences?


Create a simple TWO dimensional array in JavaScript. I am not just trying to append value in an array

var a = ["1", "2"]; var b = ["a", "b"]; var c = [];   //Can someone suggest how do i push a and b into c such that c is a 2-dimensional array? (By using JavaScript)  //c should look like [["1","2"],["a","b"]]


From Star Trek to the Newest iterations, the Enterprise moves through a starfield in a way that seems to defy physics.

Watching many space fictions on tv and in films, the effect of moving through a starfield seems to be out of proportion. Given the vast distances between stars, wouldn't the stars be immobile? Instead of zooming past the ships like the classic screen saver?                                 I considered this may attributed to a warp field in the story, but it happens with slow moving ships too. The obvious answer is , it looks cool. And it does, until you see seeming impossibility of such an effect is considered. Watch the STNG opening,                               the stars appear to be mere  kilometers of the ship as they pass.


let $f:[0,1]\longrightarrow [0,1]$ be a continuous function such that $f(0)=f(1)$, show that : if the number $l$ is not of the form $\dfrac{1}{n}$ there exsits a function of this form on whose graph one cannot inscrible a horizontal chord of length $l$  This problem is from $Mathematical Analysis (Zorich) P170,problem 7(2),Thank you evryone


About the additive group and the multiplicative group of a field

Let $F$ be a field. When happens that the additive group of $F$ is isomorphic to the multiplicative group?  It is easily to work out that $F$ must have characteristic $0$, but then what?


I am preparing a new application for a Family Visa in UK after a refusal I stay at my brother's house in Birmingham for a week of my leave limit  My salary is £420 and I started my current job on June 4, 2017.  Question: that it's just questions I made in attached picture


Can 3rd-party package repositories be trusted? (Are there criteria to test if they're trustworthy?)

(Note: no disrespect whatever to the hard work people that people who run 3rd-party repositories put in.)  I came across a package repository, a ppa, that was suggested for getting php5.5 on Ubuntu 12.04. This has to be added to the list of repositories that Ubuntu knows to download software.  In general, can such 3rd-party repositories be trusted?   In this particular case, the ppa seems to be well regarded - and I would certainly want to support this and recommend it.  Is there a checklist or criteria one can follow to arrive at a decision to trust a 3rd-party repository?  The aim here is to avoid downloading malware or anything else that may damage the computer.


Multiple disks vs single disk on virtualized environment

We're planning to install a SQL Server on this physical architecture:  A hyper-v cluster based on windows server 2019 A cluster shared volume where all VMs live A full-flash SAN that contains the CSV  I've always read that is a common best practice to have multiple disks for data files, log files, temp db files ect... But that best practice is referred to a bare-bone installation. So, what I'm asking is: what are the actual benefits of doing so on the above described architecture (if any)?


Proportional Editing is not working, object is moving

Have a question about Proportional editing. When I choose the vertice, then press O, and press G - as result my object is moving completely unstead of editing. Please advise what can be wrong?


How can get I get the PID of the "firefox" process in C?  In this code, system only returns 0, indicating success. How can I get the PID?  int x = system("pidof -s firefox"); printf("%d\n", x);


Any concrete example of ''right identity and left inverse do not imply a group''?

In the abstract algebra class, we have proved the fact that right identity and right inverse imply a group, while right identity and left inverse do not. My question: Are there any good examples of sets (with operations on) with right identity and left inverse, not being a group?  To be specific, suppose $(X,\cdot)$ is a set with a binary operation satisfies the following conditions: (i) $(a\cdot b)\cdot c=a\cdot (b\cdot c)$ for any $a,b,c\in X$; (ii) There exists $e\in X$ such that for every $a\in X$, $a\cdot e=a$; (iii) For any $a\in X$, there exists $b\in X$ such that $b\cdot a=e$. I want an example of $(X,\cdot)$ which is not a group.


What can be done against abuse of edits?

Today I saw that someone revised one of my answers, but at first I couldn't see any changes. After switching to side-by-side markdown I saw that he only adds a single space at the end.    Therefore I examined the activity/revisions of the user and saw that he edits hundreds or thousands  of posts in this way.  I had hoped, that this sort of abuse should be detected by some automatism, but there seems no such system.  But how to stop users like him and what can be done to detect this before so many posts are changed without any good reason?


Error saving image in an ImageView object with JavaFX and sceneBuilder

I'm making a simple graphical desktop application for image management and, I'm using JavaFX, in addition to its sceneBuilder. The idea is, at pushing a button  a FileChooser appears, to choose the image and to show a new window with all the background image on it. The problem is that in doing it. I get an error that I can not identify. Edit: I discovered that if I open the image in the same window there is no error. My code:    public void OpenWindow(ActionEvent event) throws IOException {         Parent root = FXMLLoader.load(getClass().getResource("Window2.fxml"));         Scene secondScene = new Scene(root,800,800);         Stage newWindow = new Stage();         newWindow.setTitle("Imagen");         newWindow.setScene(secondScene);         newWindow.setX(100);         newWindow.setY(100);         newWindow.show();         /////// Open Window //////         FileChooser fileChooser = new FileChooser();         FileChooser.ExtensionFilter extFilterJPG = new FileChooser.ExtensionFilter(" JPG", "*.JPG");         fileChooser.getExtensionFilters().addAll(extFilterJPG);         File file = fileChooser.showOpenDialog(null);          try {             BufferedImage bufferedImage = ImageIO.read(file);             Image image = SwingFXUtils.toFXImage(bufferedImage, null);             myImageView.setImage(image);          }catch(IOException ex) {             System.out.println(ex.getMessage());         }       }   Edit: (SOLUTION WAS CREATE A NEW FMXL LOADER) `      FXMLLoader loader = new FXMLLoader(getClass().getResource("SecondController.fxml"));     Parent root = (Parent) loader.load();     SecondController secController = loader.getController();     secController.nuevaImagen(imagen);     secController.mostrarInfo(imagen); // Hacer que el controlador de la imagen muestre la info     secController.addMainController(this);     Stage stage = new Stage();     stage.setScene(new Scene(root));     stage.setTitle(datosImagenActiva.titulo);     stage.show();`


What the live streaming of a time traveler will look like?

Consider a hypothetical situation: In which a time traveler travels in a spaceplane at close to speed of light circling the earth and I get a live telecast of inside of that plane to my television. How time dilation will effect him and what will I observe sitting next to the tv seeing him live. Considering time runs slower at speed of light, will he be looking like a slow motion video? (Or let he also watching live streaming of us at earth, what it will look to him) P.S. I'm not sure if it even makes some sense but if it does kindly explain in logical details. Sorry for the the bad english, I'm not a native speaker.


What does this construction mean in java?

I found the following code. But I can't undestand what it is. Looks like inner class. But seems very strange. What is is? How can we define class and create it? As I know here must be inheritance from  DefaultHandler, but where is it?  DefaultHandler handler = new DefaultHandler() { boolean bfname = false; ...  public void startElement(String uri, String localName,String qName,      Attributes attributes) throws SAXException { ... }  public void endElement(String uri, String localName,    String qName) throws SAXException { ...  }  ...  };


How can I shut down the system from command line without sudo?

I'm not the administrator, so I'm not in the sudo list. How can I shut down the computer from command line without sudo?  As I can shut down the computer from GUI, I must be able to get the privilege from somewhere... Thanks.


What set of properties does a matrix have to have in order for all its pairs of distinct eigenvectors $x$ and $y$ to have $x^Ty=0?$

I've often seen this property used when dealing with covariance matrices, which have just have every desirable property imaginable (e.g. they are symmetric, contain only real numbers, and are positive semi-definite), but I don't recall every seeing any use of this property outside of this context. Is it just a useful property of covariance matrices? Or is it a result of some of their non-unique properties, and if so, which properties?


Method for determining irreducibles and factorising in $\mathbb Z[\sqrt{d}]$

I know that $\mathbb Z[\sqrt{7}]$ is a UFD, and I can write the equation $(2 + \sqrt{7})(3 - 2\sqrt{7}) = (5 - 2\sqrt{7})(18 + 7\sqrt{7}) $. So clearly these are not all irreducibles. How do I determine which of these aren't irreducible? How do I factor those into irreducibles?  It seems difficult when dealing with $\mathbb Z [\sqrt{d}] $ with $d$ positive, since the norm map isn't as nice (it's not always positive).  Thanks


as we speak my disk space is lowering, ubuntu 16.04. What should i do to stop that? and maybe delete these huge files that are created?   4,0K    /srv 13M /bin 16K /lost+found 432K    /tmp 4,6M    /libx32 1,1T    /var 4,0K    /ptions 4,0K    /mnt 1,2G    /lib 8,0K    /snap 518G    /home 15M /sbin 311M    /opt 4,0K    /lib64 3,9M    /lib32 8,0K    /media 21M /etc 13G /usr 1,4G    /root 4,0K    /cdrom 1,6T    /   Using ncdu   -- /var/log/cups -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------                          /..                                                                                704,0 GiB [##########]  error_log   321,2 GiB [####      ]  error_log.1     2,4 GiB [          ]  error_log.7.gz     1,6 GiB [          ]  error_log.4.gz     1,6 GiB [          ]  error_log.3.gz     1,5 GiB [          ]  error_log.5.gz     1,3 GiB [          ]  error_log.2.gz     1,2 GiB [          ]  error_log.6.gz   570,5 MiB [          ]  error_log.1.gz   410,9 MiB [          ]  error_log.1.gz-2019042212.backup     4,0 KiB [          ]  access_log.1     4,0 KiB [          ]  access_log.4.gz     4,0 KiB [          ]  access_log.2.gz     4,0 KiB [          ]  access_log.7.gz     4,0 KiB [          ]  access_log.5.gz     4,0 KiB [          ]  access_log.6.gz     4,0 KiB [          ]  access_log.3.gz     0,0   B [          ]  page_log     0,0   B [          ]  access_log   edit, using tail to error_log  E [08/Feb/2020:12:07:33 +0200] Directory \"/usr/lib/cups/notifier\" has insecure permissions (040777/uid=0/gid=0). W [08/Feb/2020:12:07:33 +0200] Notifier for subscription 1695 (dbus://) went away, retrying! E [08/Feb/2020:12:07:33 +0200] Directory \"/usr/lib/cups/notifier\" has insecure permissions (040777/uid=0/gid=0). W [08/Feb/2020:12:07:33 +0200] Notifier for subscription 1695 (dbus://) went away, retrying! E [08/Feb/2020:12:07:33 +0200] Directory \"/usr/lib/cups/notifier\" has insecure permissions (040777/uid=0/gid=0). W [08/Feb/2020:12:07:33 +0200] Notifier for subscription 1695 (dbus://) went away, retrying! E [08/Feb/2020:12:07:33 +0200] Directory \"/usr/lib/cups/notifier\" has insecure permissions (040777/uid=0/gid=0). W [08/Feb/2020:12:07:33 +0200] Notifier for subscription 1695 (dbus://) went away, retrying! E [08/Feb/2020:12:07:33 +0200] Directory \"/usr/lib/cups/notifier\" has insecure permissions (040777/uid=0/gid=0). W [08/Feb/2020:12:07:33 +0200] Notifier for subscription 1695 (dbus://) went away, retrying!   so i did, and it stopped the on-growing file:  sudo chmod 755  /usr/lib/cups/notifier sudo service cups restart   and then  sudo rm   all error_log files


Here's initialization I just found in somebody else's question.  my_data data[]={     { .name = "Peter" },     { .name = "James" },     { .name = "John" },     { .name = "Mike" } };   I never saw something like this before and can't find explanation how is .name possible to be correct. What I'm looking for is how step by step this process goes.  It looks like it gets:  1) data; 2) *data; 3) (*data).name; 4) (*data).name="Peter";   Or am I totally wrong?


Appropriateness of a Big Bad with player class levels

I'm running a 5th ed campaign that's getting close to finishing out a big story arc where the PCs are hunting down a vampire lord trying to take over the city they're based in. The group should be level 15 once they get into the big showdown with the vampire.  My players are pretty clever and I'm hoping to present them with a challenging fight to make the Big Bad in question memorable. But I'm concerned that the base vampire stats won't be a huge challenge. I'm designing the encounter to make for some fun along the way, but I'm hoping to make the vampire himself stand out. Storyline wise, he's one of the most powerful vampires in the campaign world, so I hope to make him seem special.  Toward that end, I've rolled up a level 15 elf sorcerer and given him the vampire powers on top of his stats. I can't get a sense if this is too much or too little, though, and I was hoping someone can give some insight on this, particularly if you've tried this approach yourself, with Fifth Edition.   Also, I may be blind; if there's a place in the DMG that talks about this particularly, I've missed it (and my DMG is currently in a box because I just moved).


Find all values of z for which $z^6 = (z+1)^6$.


Using pgfplots, add vertical/horizontal spacing between plots?

I once already asked a very similar question; . But this is some what different.  I have the following code;  \documentclass{standalone} \usepackage{graphics} \usepackage{tikz,pgfplots} \pgfplotsset{compat=1.6} \begin{document} \begin{tikzpicture}  \begin{axis}[% width=3cm, height=3cm, scale only axis, every x tick label/.append style={font=\scriptsize\color{gray!80!black}}, xmin=0, xmax=20000, xlabel={$t$}, xmajorgrids, xminorgrids, every y tick label/.append style={font=\scriptsize\color{gray!80!black}}, ymin=0.0004, ymax=0.0012, ylabel={$\phi_{\mathrm{i}}(t)$}, ymajorgrids, yminorgrids, name=plot1]  \end{axis}  \begin{axis}[% width=3cm, height=3cm, scale only axis, every x tick label/.append style={font=\scriptsize\color{gray!80!black}}, xmin=0, xmax=20000, xlabel={$t$}, xmajorgrids, xminorgrids, every y tick label/.append style={font=\scriptsize\color{gray!80!black}}, ymin=0.2, ymax=1.2, ylabel={$h(t)$}, ymajorgrids, yminorgrids, name=plot2, at=(plot1.right of north east), anchor=left of north west]  \end{axis}  \begin{axis}[% width=3cm, height=3cm, scale only axis, every x tick label/.append style={font=\scriptsize\color{gray!80!black}}, xmin=0, xmax=20000, xlabel={$t$}, xmajorgrids, xminorgrids, every y tick label/.append style={font=\scriptsize\color{gray!80!black}}, ymin=0.0004, ymax=0.0012, ylabel={$\phi_{\mathrm{o}}(t)$}, ymajorgrids, yminorgrids, name=plot4, at=(plot1.below south west), anchor=above north west]  \end{axis}  \begin{axis}[% width=3cm, height=3cm, scale only axis, every x tick label/.append style={font=\scriptsize\color{gray!80!black}}, xmin=0, xmax=20000, xlabel={$t$}, xmajorgrids, xminorgrids, every y tick label/.append style={font=\scriptsize\color{gray!80!black}}, ymin=2000, ymax=12000, ylabel={$p_{\mathrm{i}}(t)$}, ymajorgrids, yminorgrids, name=plot5, at=(plot4.right of north east), anchor=left of north west]  \end{axis}  \end{tikzpicture} \end{document}   This creates the following plot:    I think there is to few vertical/horizontal spacing between the plots. I want to increase this. Currently I use x- yshift, this gives the following result:  \documentclass{standalone} \usepackage{graphics} \usepackage{tikz,pgfplots} \pgfplotsset{compat=1.6} \begin{document} \begin{tikzpicture}  \begin{axis}[% width=3cm, height=3cm, scale only axis, every x tick label/.append style={font=\scriptsize\color{gray!80!black}}, xmin=0, xmax=20000, xlabel={$t$}, xmajorgrids, xminorgrids, every y tick label/.append style={font=\scriptsize\color{gray!80!black}}, ymin=0.0004, ymax=0.0012, ylabel={$\phi_{\mathrm{i}}(t)$}, ymajorgrids, yminorgrids, name=plot1]  \end{axis}  \begin{axis}[% xshift=1cm, width=3cm, height=3cm, scale only axis, every x tick label/.append style={font=\scriptsize\color{gray!80!black}}, xmin=0, xmax=20000, xlabel={$t$}, xmajorgrids, xminorgrids, every y tick label/.append style={font=\scriptsize\color{gray!80!black}}, ymin=0.2, ymax=1.2, ylabel={$h(t)$}, ymajorgrids, yminorgrids, name=plot2, at=(plot1.right of north east), anchor=left of north west]  \end{axis}  \begin{axis}[% yshift=-1cm, width=3cm, height=3cm, scale only axis, every x tick label/.append style={font=\scriptsize\color{gray!80!black}}, xmin=0, xmax=20000, xlabel={$t$}, xmajorgrids, xminorgrids, every y tick label/.append style={font=\scriptsize\color{gray!80!black}}, ymin=0.0004, ymax=0.0012, ylabel={$\phi_{\mathrm{o}}(t)$}, ymajorgrids, yminorgrids, name=plot4, at=(plot1.below south west), anchor=above north west]  \end{axis}  \begin{axis}[% xshift=1cm, width=3cm, height=3cm, scale only axis, every x tick label/.append style={font=\scriptsize\color{gray!80!black}}, xmin=0, xmax=20000, xlabel={$t$}, xmajorgrids, xminorgrids, every y tick label/.append style={font=\scriptsize\color{gray!80!black}}, ymin=2000, ymax=12000, ylabel={$p_{\mathrm{i}}(t)$}, ymajorgrids, yminorgrids, name=plot5, at=(plot4.right of north east), anchor=left of north west]  \end{axis}  \end{tikzpicture} \end{document}     I want to know if there is a more consistent manner to do this.


Prove that if a linear operator is continuous, then it is bounded.

I'm trying to prove that if a linear operator is continuous, then it is bounded.   Let $T:V\to W$. Let us assume it is continuous. Then for any $\epsilon>0$, $\|T(x-x_0)\|<\epsilon$ if $\|x-x_0\|<\delta$ for some $\delta\in \Bbb{R}$.   If $T$ is bounded, then $\sup \frac{\|T(x-x_0)\|}{\|x-x_0\|}$ exists, where $x$ and $x_0$ may be any vectors in $V$.   The proof in my book "Functional Analaysis" by Kreyszig (pg.97) proceeds by stating      Let $x=x_0+\delta\frac{y}{\|y\|}$, where $y$ is any vector in $V$   Aren't we artificially restricting the possible values of $x$ in comparison with $x_0$?  Thanks in advance!


I need change browser shortcut url adware

I have an adware my PC and I need change my all browser shortcuts URL to google. I try manually remove but adware soft set URL again. I need batch file this operation or vbs script or C# code?


When using the command \Rightarrow is there any way to put text above it? I have tried \overbrace but is there a way to do it without this?


Why the default eth0 interface is down by default on CentOS?

I am already a little bit familiar with Linux distros like Debian or Ubuntu (yeah, very similar) but I wanted to try Red Hat based - CentOS 6.2. I have installed it on my Windows 7 host in VirtualBox and tried to play with it a little. I have come across a small problem, namely: the default eth0 interface is down by default. I use the option with NAT (the virtual machine is 'behind' the host). Even if I bring the interface up with ifconfig eth0 up, it does not work right away. I get this after bringing the interface up: eth0      Link encap:Ethernet  HWaddr 08:00:27:0F:00:8A           inet6 addr: fe80::a00:27ff:fe0f:8a/64 Scope:Link           UP BROADCAST RUNNNING MULTICAST MTU:1500 Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:6 errors:0 dropped:0 overruns:0 carriers:0           collisions:0 txqueuelen:1000           RX bytes:0 (0.0 b)  TX bytes:468 (468.0 b)           Interrupt:19 Base address:0xd020  lo        Link encap:Local Loopback           inet addr:127.0.0.1  Mask:255.0.0.0           inet6 addr: ::1/128 Scope:Host           UP LOOPBACK RUNNING  MTU:16436  Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:0           RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)  virbr0    Link encap:Ethernet  HWaddr 52:54:00:75:C2:9B           inet addr:192.168.122.1  Bcast:192.168.122.255  Mask:255.255.255.0           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:0 [root@centos ~]# _  What should be done more to configure the network on CentOS machine?


How to delete all my progress in Fruit Ninja?

I would like to reset all my progress, achievements and objects from Fruit Ninja. I've tried deleting it and then reinstalling it again, but I still have all my stuff.   So, how could I reset the game so that it's like I've never played before?


I am have a database that is running fine on website, but when I run it on my xampp for wordpress it is showing single quote ' as â€™ . While database also has â€™ in table, and there is smooth mysql_fetch_array is using to display data, but my xampp and wordpress not showing â€™ as ' single quote, please let me know how can I solve this issue. ?


Ubuntu login loop lightdm-session errors

I have been trying to solve this problem for over a month now, so of course I have tried all the 3 common solutions which are all over the internet. I think I am getting close and my problem resembles this particular problem:   This is my .xsession-errors file:  /usr/sbin/lightdm-session: line 24: mktemp: command not found /usr/sbin/lightdm-session: line 29: : No such file or directory /usr/sbin/lightdm-session: line 33: cat: command not found /usr/sbin/lightdm-session: line 34: truncate: command not found /usr/sbin/lightdm-session: line 29: : No such file or directory /usr/sbin/lightdm-session: line 33: cat: command not found /usr/sbin/lightdm-session: line 34: truncate: command not found /usr/sbin/lightdm-session: line 106: ls: command not found   Following is the output of grep -H PATH ~/.profile ~/.bash_profile ~/.bash_login and echo $PATH and type gnome-session:    notice: no such file or directory for bash_profile and bash_login.  I think the problem has got something to do with my path variable? I am just not sure.  Also, I just started seeing this new error after a recent reboot:   /usr/sbin/lightdm-session: line 117: exec: gnome-session: not found


Is JavaScript validation necessary alongside PHP?

When validating forms with javascript and php, why do we need to include the same validation rules (ie correct format, checking fields are filled in, values within bounds) on both the server and browser? I understand that javascript can be turned off, so why not just have everything on the server and save checking it twice?


Does the alchemist artificer casting cure wounds through his spell storing feature benefit from the alchemical savant feature?

Related:  Alchemical Savant reads:  You develop masterful command of magical chemicals, enhancing the healing and damage you create through them. Whenever you cast a spell using your alchemist’s supplies as the spellcasting focus, you gain a bonus to one roll of the spell. That roll must restore hit points or be a damage roll that deals acid, fire, necrotic, or poison damage, and the bonus equals your Intelligence modifier (minimum of +1).  Spell-Storing Item reads:  At 11th level, you learn how to store a spell in an object. Whenever you finish a long rest, you can touch one simple or martial weapon or one item that you can use as a spellcasting focus, and you store a spell in it, choosing a 1st- or 2nd-level spell from the artificer spell list that requires 1 action to cast (you needn’t have it prepared). While holding the object, a creature can take an action to produce the spell’s effect from it, using your spellcasting ability modifier. If the spell requires concentration, the creature must concentrate. The spell stays in the object until it’s been used a number of times equal to twice your Intelligence modifier (minimum of twice) or until you use this feature again to store a spell in an object.  So does a cure wounds cast using the spell-storing feature, and using the alchemist's supplies to store the spell, benefit from alchemical savant? I think to answer this question a few sub questions need to be answered: Does producing the spell's effect from the spell-storing item count as casting a spell? Because casting the spell is requisite for the alchemical savant feature to take effect. Another requirement for benefiting from alchemical savant is that you cast the spell using your alchemist's supplies as the spellcasting focus. In spell-storing item's case, you would be casting the spell using your alchemist's supplies as the 'spellcasting focus used to store the spell', according to the requirements set forth by the spell-storing item feature. However, does alchemical savant require that you cast the spell using your alchemist's supplies as the 'spellcasting focus used in place of material components'? because being cast from an item means that there are no material components.  Some magic items allow you to cast a spell from the item. The spell is cast at the lowest possible spell level, doesn't expend any spell slots, and requires no components, unless the item's description says otherwise.


Prove that when performing long division for 2 integers, the resulting decimal fraction is always repeating.

Here is the exact proof I must solve:  Prove that when the process of long division is used for 2 integers, say m and n, then the resulting decimal fraction is always a repeating one, i.e. m/n=an*an−1...a1*a0 [decimal point] b1...bkc1...cpc1...cpc1...cp... = anan−1... a1*a0 [decimal point] b1...bk(c1...cp).  I don't know where to begin. If m=5 and n=8, then 5/8=0.625 which is terminating. The wording of the question is confusing me.


Is speed of gravitational waves constant?

Is the speed of gravitational waves constant in all inertial frames? If so, why isn't this included as one of the postulates of special relativity?


Open muiltiple(100+) files in `gvim` - not in tabs, not in vim

I'm analyzing a regression of thousands of test cases in linux. So I want to open many files(failed) in gvim at once.  I have a file as mention in below with 100+ lines specifying 100+ files in a directory. I want to open all these files in gvim(in single gvim).  ./Linux2/Lint/case1/DIFF ./Linux2/Lint/case4/DIFF ./Linux2/Lint/case10/DIFF ./Linux2/range/case1/DIFF ./Linux2/operator/case7/DIFF   100+ lines like this.  Is there any way to open files in all these files in gvim with some navigation mechanism.   I know it is possible to use,  gvim file1 file2 .....   But it is not easy with 100+ files.  I need to do this in gvim, not in vim.


This is what I think is best for making an object in js      function obj(){         var x = "hi";         this.getX(){return x;}     }     var y = new obj()     console.log(y.x); //this returns undefined   But from what I have seen, using this.variable is used more often in object creation.   I am thinking in java where things should be "private" in a class (note I have read about closures), does that apply in js?  What is considered the best way of object creation?


why my render not showing anything in image?

Why is my render not working?  I have tried setting camera, render setting in EEVEE or cycle also render progression in 0%


Size of a natural transformation and the Yoneda Lemma

Appearing on the second page (under the section Digression: Size worries) of the following paper about the Yoneda Lemma:     It says that $a$ $priori$ $[\mathcal C^{op},Set](H_A,X))$ is a class. I don't understand why this is the case.  My understanding is that $a$ $priori$ each member of $[\mathcal C^{op},Set](H_A,X))$ is a class.  So it seems to me that $[\mathcal C^{op},Set](H_A,X))$ could be a collection of proper classes.  I've looked at this , but it hasn't helped me much.  Any help is appreciated -Thanks


I have a linux OS with OpenJdk version "1.8.0_262". while generating the jasper pdf letter from web based application, i am getting error as below. Caused by: java.lang.NoClassDefFoundError: Could not initialize class net.sf.jasperreports.engine.util.JRStyledTextParser at net.sf.jasperreports.engine.fill.JRBaseFiller.(JRBaseFiller.java:116) [jasperreports-6.13.0.jar:6.13.0-46ada4d1be8f3c5985fd0b6146f3ed44caed6f05] at net.sf.jasperreports.engine.fill.JRVerticalFiller.(JRVerticalFiller.java:79) [jasperreports-6.13.0.jar:6.13.0-46ada4d1be8f3c5985fd0b6146f3ed44caed6f05] at net.sf.jasperreports.engine.fill.JRFiller.createBandReportFiller(JRFiller.java:251) [jasperreports-6.13.0.jar:6.13.0-46ada4d1be8f3c5985fd0b6146f3ed44caed6f05] at net.sf.jasperreports.engine.fill.JRFiller.createReportFiller(JRFiller.java:272) [jasperreports-6.13.0.jar:6.13.0-46ada4d1be8f3c5985fd0b6146f3ed44caed6f05] at net.sf.jasperreports.engine.fill.JRFiller.fill(JRFiller.java:156) [jasperreports-6.13.0.jar:6.13.0-46ada4d1be8f3c5985fd0b6146f3ed44caed6f05] at net.sf.jasperreports.engine.fill.JRFiller.fill(JRFiller.java:145) [jasperreports-6.13.0.jar:6.13.0-46ada4d1be8f3c5985fd0b6146f3ed44caed6f05] at net.sf.jasperreports.engine.JasperFillManager.fill(JasperFillManager.java:758) [jasperreports-6.13.0.jar:6.13.0-46ada4d1be8f3c5985fd0b6146f3ed44caed6f05] at net.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:1074) [jasperreports-6.13.0.jar:6.13.0-46ada4d1be8f3c5985fd0b6146f3ed44caed6f05] at net.atos.wlp.lgs.provider.formatter.AbstractPrintFormatter.generatePrintData(AbstractPrintFormatter.java:52) [wlp-lgs-provider-IBO-21Q2-1.0.jar:IBO-21Q2-1.0] at net.atos.wlp.lgs.provider.formatter.SemiDynamicPrintFormatter.getPrintData(SemiDynamicPrintFormatter.java:74) [wlp-lgs-provider-IBO-21Q2-1.0.jar:IBO-21Q2-1.0] at net.atos.wlp.lgs.provider.controller.ServiceController.generateJasterLetter(ServiceController.java:78) [wlp-lgs-provider-IBO-21Q2-1.0.jar:IBO-21Q2-1.0] at net.atos.wlp.lgs.provider.controller.ServiceController.generateLetter(ServiceController.java:62) [wlp-lgs-provider-IBO-21Q2-1.0.jar:IBO-21Q2-1.0] at net.atos.wlp.lgs.provider.LetterGenerationServiceImpl.generateLetter(LetterGenerationServiceImpl.java:132) [wlp-lgs-provider-IBO-21Q2-1.0.jar:IBO-21Q2-1.0] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [rt.jar:1.8.0_282] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) [rt.jar:1.8.0_282] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [rt.jar:1.8.0_282] at java.lang.reflect.Method.invoke(Method.java:498) [rt.jar:1.8.0_282] at org.jboss.as.ee.component.ManagedReferenceMethodInterceptor.processInvocation(ManagedReferenceMethodInterceptor.java:52) As part of troubleshooting, i have verified below points  standalone.conf (JBOSS EAP-7.3) file has below value Djava.awt.headless=true  There were no different versions of “jasperreports” jar in ../WEB-INF/lib . Only jasperreports-6.13.0.jar is existing.  In order to check the font installed in linux OS, "fc-list" command was not recognised , perhaps because fonts are not installed in Operating system?   Any help to troubleshoot this issue is appreciated. I checked existing smilar topics, but haven't got much help.


"May" & "Might": What's the right context?

I may not be coming in tomorrow...    I might not be coming in tomorrow...       When should I use "may" and "might"?


Number of discontuinity Two to one functions from $\mathbb{R}$ to $\mathbb{R}$

Let's call a function $ f: \mathbb{R} \rightarrow \mathbb{R} $ Two to one if for any $y \in Im(f)$ there is exactly two distinct $x_1,x_2 \in \mathbb{R}$ such that $f(x_1)=f(x_2)=y$  Is it true that every Two to one function with domain $\mathbb{R}$ must have infinite number of discontinuity?  P.S: As answered before  it must be discontinous but can it have finite number?


How to fix corrupted QGIS project file that causes Windows to freeze?

I'm running QGIS 2.14.9 on Windows 7 SP1. I have a project that contains PostGIS layers from a remote server, as well as some (local) shapefiles that I've been doing some development on in the Python Console. I have reached a point, however, where when I try to open this project the entire computer freezes, requiring a hard reboot. My colleague tried opening the project on their computer and suffered a BSOD.   I can open other projects OK. So would like to try removing layers from this project to see if that fixes loading issues, but how can I do that without opening it in QGIS?


Create a block matrix with four quadrants

I want to create a block matrix of this form:    But Block A should be a diagonal matrix with 1 on the diagonal, the other blocks should be B, C and D like in the picture. But the size of each block should be equal.


How to expand environment variables from variable names in Python

At work we use .pam_environment to hold some of our paths to commonly used folders. For example:  PROJECTS DEFAULT=${HOME}/projects APP_DIR = ${PROJECTS}/app_name   When I want to get that information with Python, I use the following code:  >>> import os >>> app_dir = os.environ['APP_DIR'] ${PROJECTS}/app_name   What I want to do is get the absolute path to app_name so I can run it with subprocess. However this is what happens when I attempt to do that:  >>> os.path.abspath('${PROJECTS}/app_name') '/current_working_directory/${PROJECTS}/app_name'   This is an invalid path and the subprocess call will fail. I know I can set subprocess's shell=True to make it work, but I was hoping there was a way to get a valid path without doing that in case I need that path for other work in the application.   Note: We use Python 2.7 at work.


writting xml file & storing on local disk

I was following on the above mentioned topic since long & finally got to see this link "  ". But, unfortunately, following this method on chrome i got the error saying : " Uncaught ReferenceError: XMLWriter is not defined" I tried to reply on that blog itself but i think it is no longer available & hence i choose to write here.  can anyone hekp me out with this please.


I've been searching for this and many answers came out but it just wasn't the solution I was looking for so I came here and try to ask help to you guys...  I want to create a .txt file in the same folder where the JAR file is located  (dist folder)...  I tried using System.getProperty("user.dir") it works fine when I run it on windows and using netbeans the file created is always in the same folder where the jar file is but when I run it on LINUX it saves the file in root... but the folder where the jar file is on the desktop  it creates in the same folder when I use the terminal to open the jar file  private static String directory=System.getProperty("user.dir"); private final String sample=directory+File.separator+"sample.txt";   public void createFile() {      File file=new File(sample);     try(FileWriter fw=new FileWriter(file))     {         fw.write("INSERT ME WHERE MY JAR IS");         fw.flush();         fw.close();     }catch(IOException ex)     {         ex.printStackTrace();     } }


i can't install wine on my linux(xUbuntu 14.04 x64)  The following packages have unmet dependencies:  wine1.6 : Depends: wine1.6-amd64 (= 1:1.6.2-0ubuntu4)            Depends: wine1.6-i386 (= 1:1.6.2-0ubuntu4) E: Unable to correct problems, you have held broken packages.   what to do?


Export Wavefront .mtl file -- Where is the reflectance coefficient?

It seems that when exporting a model, the output .mtl file does not include reflectance coefficient, which in blender is set using under "Mirror" in "Material".    The .mtl file is as follow:  # Blender MTL File: 'None' # Material Count: 1  newmtl Material Ns 96.078431 Ka 0.000000 0.000000 0.000000 Kd 0.640000 0.640000 0.640000 Ks 0.500000 0.500000 0.500000 Ni 1.000000 d 1.000000 illum 2   Is there a way to include reflectance in this file?  Thanks in advance!


Yesterday I saw a documentary where some showed software that predicts developments in airfares. Similar to weather and traffic predictions a user would get a prediction of price developments when airfares for a specific connection are searched. Based on these prediction you could make an educated guess if you need to buy now, or better wait some time.   Since watching that documentary I have been searching for a booking site that uses this prediction feature. In the documentary they mention that such a webservice is not yet available in Europe, but since the Internet is more then Europe only, I expect to find a working example. No luck so far.  The documentary was a Dutch , where they explored the actual costs of flying an airplane from Amsterdam to London. The objective was to find a reason for the fluctuating real airfares asked.


What over-arching narrative is told during Phase 2 of the Marvel Cinematic Universe?

Or "Why is Ant-Man the last movie of Phase 2, rather than Avengers 2?"  The Marvel Cinematic Universe is the series of movies involving characters from Marvel comics and produced by Marvel Studio/Disney Studio. The series of movies is decomposed into phases, that are different steps in the studios' production plan.   Phase 1, entitled Avengers Assembled, is composed of all movies from Iron Man (2008) to The Avengers (2012). This phase relates the origins of each Avenger and how these mighty superheroes came to fight as a team.   The narrative purpose of Phase 2 is less clear to me. At first, I thought it was about Thanos' story arc but Thanos doesn't seem to appear in Ant-Man, the last movie of the Phase 2. Actually, Thanos will most likely be the main antagonist of Infinity War, which is a part of Phase 3.   Therefore, what story arc will be concluded at the end of Ant-Man? I believe it can be answered before the movie is released, as the purpose of Phase 1 was clear before the release of The Avengers. Marvel Studio may also have commented about the organization of the movies. In other words, what narrative elements unify the movie of Phase 2?


I've been looking for questions about dark matter, and I've read some very interesting answers. However, I desire too look into it deeply.   This is not actually a question. I'm asking the community to recommend interesting references to understanding dark matter and dark energy.   I accept all sort of references: notes, books, scientific papers etc.  Let us assume some background on classical physics, thermodynamics and basics about quantum theory.


Interpretation of Linear SVM Coefficients

I’m building a model using Linear SVM from the Scikit-learn package in Python. I have found that Linear SVM performs much better on my training set than Logistic Regression.   My question is, is there a way to interpret the coefficients from my linear SVM in a similar way as we would interpret logistic regression coefficients? I can output the coefficient of each feature in my model using coef_.   I’m trying to figure out if there is a way to measure how effective each feature in my dataset is in regards to predicting an outcome. For example, a completely hypothetical situation, using logistic regression to predict whether a student is in an honors class or not, given the student’s test scores. Using Logistic Regression it’s possible to calculate an output along the lines of “a one-unit increase in the test score leads to an expected 10% increase in odds of the student being in the honors class”. Is it possible to calculate something similar using Linear SVM?   As you can probably tell, I’m a complete newbie when it comes to this and any help would be greatly appreciated! Thanks


Are there any airlines which refund fare (including economy class) fully in case you don't get visa?

I'm an Indian. I'm planning to book a journey from Mumbai to Johannesburg, South Africa and back (conference visa). I looked at refundable tickets, while they are priced higher, they give you half your money back, for instance if the to and fro flight costs INR 40,000 they give you INR 20,000 . But this is if you are cancelling for some reason.   What if you have to cancel because your visa application or the transit visa application got rejected. As far as I understand the procedure is :-  a. Buy airline tickets   b. Apply for Visa   c. Wait between 1-6 weeks to get update about your visa application, for both visa and transit visa (although transit visa should be shorter I guess.)  d. If visa is granted then move on to planning other things about the trip.   Now in case, if the visa application fails (for whatever reason ) what recourse does the traveler have ?  Are there any airlines who are better understanding than others about this situation ?  In non-refundable tickets, I guess that all is lost or is there some way to save money there too.   Lastly, I read travel insurance can help in this case. How does travel insurance help in the above scenario ?  Edit :- One of the pre-conditions of getting the visa is   Proof of a Valid Return or onward ticket or purchase of ticket. This is from   and


Are 'per second' Performance Counters measured over a certain period of time?

This may be a very silly question, but when I'm looking at the current value of a 'per second' counter in PerfMon, for example SQL Statistics\Batch Requests/sec - how is that value actually measured?  Let's say I use PowerShell's Get-Counter method to return a result for a specific server, as follows:  (Get-Counter -ComputerName $server -counter $countername -SampleInterval 1 -MaxSamples 1).CounterSamples.CookedValue   And this returns: 32  How can that value actually be contextualized? Is it an "average of 32 batch requests per second in the last x minutes"? Or is it "in the last second there were 32 batch requests"


How can I extend a hard disk in Ubuntu logical volume

When I installed Ubuntu 16.04 I selected logical volume management. I created a virtual machine with 40GB Hard disk.  The I cloned that to a new machine with Hard disk 100. but when I check df -h it still shows 40GB.  Is there any way to increase it?


Lubuntu freezes less frequently than Xubuntu, which freezes less frequently than Ubuntu

I am very new to Linux. Ubuntu would freeze so I installed Xubuntu. That would freeze less frequently, but still so. Now, I am on Lubuntu, and it still freezes although least frequently. My system is a Lenovo Thinkpad 11e. Celeron N2940 @ 1.83GHz and 8GB.  The computer freezes in day to day tasks: watching videos, browsing the web, etc. Also, the default word editor was AbiWord. I started a document on AbiWord and saved it. But after my computer froze and I restarted it, it was not able to open that document.


Can existence of aleph one be proved without the power set axiom?

Cantor's construction of $\aleph_1$ is to notice that all ordinals constructed after $\omega$ are countable, take the union of all countable ordinals, and then show that this union can not be countable. However, in ZFC the union can only be taken over a set. I can see how to relate countable ordinals to elements of $2^{\aleph_0}$ proving that their collection is a set by specification, but that requires the power set axiom. The "slicker" modern way, declaring $\aleph_1$ to be the least uncountable cardinal, already presupposes the existence of uncountable cardinals. That's even worse since in addition to power set one needs choice to prove that $2^{\aleph_0}$ is an aleph, and then it is greater by the diagonal argument.  It wouldn't surprise me that some voodoo with collection or replacemnt schemas does the trick, but then my question is what does it translate to in "naive" terms of Cantor? What reason do we have for the collection of countable ordinals to be a set (without invoking formulas in the first order logic and definable functions)? If power set isn't required why can't Cantor's argument be reproduced to create inaccessible cardinals by noticing that all cardinals produced after $\aleph_0$ are, by construction, accessible?


The \G modifier:     \G forces the pattern to only return matches that are part of a continuous chain of matches. From the first match each subsequent match must be preceded by a match.   However, in the python standard re module, \G is not an available anchor. Is there a way to convert what might have been done with a \G into a python-friendly regex? What would be an example of a regex containing a \G flag that could be re-written in a regex that would compile in python?


php socket flow error 10054. when trying to connect with ssh

I'm using a Bitvise SSH to connect with the server of digital ocean it was working good till yesterday but accidentally I fire the command "sudo chmod -R 0777 /" after that I am not able to connect using SSH. when I am trying to connect get the error as below.     Reason:FlowSocketReader: Error receiving bytes. Windows error 10054: An existing connection was forcibly closed by the remote host.   How can I solve this?


I've been doing proofreading on a beta site and there appears to be a typo. Is there any usage of "many a times" that is correct, or is it always wrong to apply a singular "a" to a plural noun?


I see this statement: (20, 30, 50)  When I cout << (20, 30, 50); it prints 50.  When I rewrite it (a, b, c) — a, b, c can be char* or int — it always prints c. Does anybody explain for me? Please.


Consider the series:  $$a) \sum_{n=1}^\infty \frac{a^n}{ \prod_{k=1}^n \ (1+\sin\frac{1}{2k})}$$ $$b) \sum_{n=1}^\infty \frac{a^n}{ \prod_{k=1}^n \ (1+\tan\frac{3}{2k})}$$  Showing that these two are convergent (and absolutely convergent) it's no big deal for  $a\in R^*$. But I couldn't figure out how to solve it when $a=1$. My guess is that the general term has to be brought to another form. And that is my question: how to prove convergence when $a=1$.  Thanks for helping with this!


Can I see only mail I have archived in Gmail?

In Gmail, the inbox view only contains mail which has not been archived. I'm looking for a particular conversation I had with someone a while ago to find a quote, but I can't remember the exact topic or person I was emailing. I know it has been archived but I cannot find a way of viewing only archived email—it appears I have to browse through many months of All Mail in order to find that particular conversation.  Is there a more effective way of viewing only archived mail?


Windows won't let me install Ubuntu Studio

This is my first time getting Linux. I burned Linux to my disk. Every time i reset my computer it says "Windows could not install (or something like that). It says like something is missing. It worked when I installed it on  Virtual Box. But it won't let me install on my laptop. Please help.


The sentence \hl{Upphängningsmetoden visade att masscentrumet låg i punkten (10,5;7,30) i centimeter medan den algebraiska metoden visade på att tyngdpunkten låg i $(10,5;7,34)$}  gives 5 errors and I don't know how to fix it. Here is a sample of the doc. \documentclass[12pt]{article}  \usepackage[margin=1in]{geometry} \usepackage{amsmath} \usepackage{units} \usepackage{tikz} \usepackage{cite} \usepackage{soul} \usepackage[nottoc]{tocbibind} \usepackage{xurl} \usepackage{graphicx} \usepackage{caption} \usepackage{hyperref} \usepackage{refstyle} \usetikzlibrary{intersections} \usepackage[swedish]{babel}  \usepackage{parskip} \usepackage[T1]{fontenc} \usepackage[utf8]{inputenc} \usetikzlibrary{patterns}  \begin{document} \section*{Sammanfattning} Denna rapport kommer att undersöka masscentrumet hos en pappersfigur med två metoder - en algebraisk och en experimentbetonad metod. Därefter ställs dessa metoder mot varandra och jämförs. \\ Den algebraiska metoden utfördes genom att rita in figuren i första kvadranten i ett koordinatsystem och figuren var mätt i SI-enheten centimeter. Sedan användes bland annat arean för två områden i figuren samt beräknades tyngdpunkten för dessa områden för att sedan kunna utreda hela figurens masscentrum. Den experimentbetonade metoden utfördes genom att hänga figurskivan i tre punkter, dra tre lodlinjer från desssa punkter och bestämma masscentrum genom konstruktion. Båda metoderna gav givande resultat då båda fick samma tyngdpunkt men den algebraiska metoden var mest effektiv. \\ Resultatet besvarade alla tre frågeställningar som ställdes i rapporten och innehållet följde syftet.\hl{Upphängningsmetoden visade att masscentrumet låg i punkten (10,5;7,30) i centimeter medan den algebraiska metoden visade på att tyngdpunkten låg i $(10,5;7,34)$}. Skillnaden mellan dessa metoders resultat är knappast stor men den algebraiska metoden ses som mest trovärdig på grund av att metoden hade en högre noggranhet än upphängningsmetoden. Upphängningsmetoden hade vissa brister men det påverkade knappast resultatet. Dock kan det påverka andra mer komplicerade föremål där upphängningsmetoden kan vara svår att genomföra med. \end{document}


When quoting a speaker of another English dialect, should you spell things his way?

I realize (or realise?) I may be splitting hairs here, but I find this question interesting, and I’ve never heard or seen it discussed before.  I was about to post a quote from Rich Hickey outside my cubicle, taken from  with him, in which the writer uses the traditional British spelling of realize.  Hickey is an American, as am I, so I changed it back to the American spelling.    However, it got me thinking: if Hickey were British, should I spell it his way?  The question then is whether I should do so only if quoting something he wrote, or even if I were quoting something he spoke — and thus something he did not actually spell.    Tangentially: should I think of this as quoting Hickey himself, or quoting the author who quoted him?  My gut instinct is that if you’re quoting something written, then you should maintain whatever spelling the author used, and if something spoken then it’s debatable, and using the spelling of your dialect (or of your audience’s dialect) is probably okay.   But I’d like to know: do any conventions exist on this matter?


Why do people pronounce "f***ing" like "f***en"?

I'm not a native English speaker so I might not be exactly accurate with this, but whenever people (e.g. in films) say fucking, it sounds something like fucken.  There's no "g" at the end and instead of "i", I hear "e" (like in the word men).  Why is that? Am I that deaf or is the pronunciation really different from what the spelling would suggest?   If it is, why do people pronounce it this way? Why is it different than any other word ending with -ing (e.g.looking)?


Professional interests continue to expand, Virgo, and you're managing to keep very busy. Your income is rising, and you could be achieving a certain prominence in your field. Nonetheless, you could be looking for new opportunities. The field you're in now may not be one that you want to continue for the next 20 years. This is therefore a good day to put out a few feelers and test the waters. You might be surprised at the opportunities out there.    I think it should be "are continuing to expand."


Here is a very simple code:    public class Test2 {  public static void main(String[] args)  {         String a = "hello2";          final String b = "hello";         String d = "hello";         String c = b + 2;          String e = d + 2;         System.out.println((a));         System.out.println((c));         System.out.println((e));         System.out.println((a == c));         System.out.println((a == e));      } }   And the output is:  hello2 hello2 hello2 true false   Please tell me why the last one is 'false'??Thanks


Last year, the United Nations security council adopted four sanctions solutions seeking to deprive North Korea of key sources...   I was taught that “attributive noun” can only be in a single form not plural.   Could you please tell me how this works?         when could we make (the attributive noun) plural?


How can I Change the color of a bunch of symbols in Illustrator

I have a set of flat objects and they are independent, they are all in one single .AI file.  How can I Change the colors of those objects while they are in symbol panel and are not yet in my artboard?


Unable to install .NET 3.5 on Windows 8.1

I am trying to install .NET 3.5 to work on few legacy applications and this has been burning my head for past few weeks.   During installation a pop up window requests me to install .NET 3.5 and when i hit download it fails stating issues with internet connection. But internet works just fine Tried enabling .NET 3.5 from Control panel it redirects to " Download from Windows update " and the download goes on forever ( best try 6 hours on 18mbps wifi keeps loading..) Using Dism with and without /LimitAccess the process gets stuck at 65.8% and then throws a  Downloaded offline package 253 MB from microsoft when i tried to install it again asks me download 3.5 to launch dotfx35.exe which is the setup file :( Tried everything from  no luck   Please help.. :(


If $\gcd(p,q+Ar)>1$ for all $A\in \mathbb{Z}$, then $\gcd(p,q,r)>1$

Prove that if $\gcd(p,q+Ar)>1$ for all integers $A$, then $\gcd(p,q,r)>1$.  I let $A=0$ to get that $\gcd(p,q)>1$. Then I noticed that $\gcd(p,q,r)=\gcd(\gcd(p,q),r)$.  Another way to say it:  Prove that if $\gcd(ag,bg+Ar)>1$ for all integers $A$ ($\gcd(a,b)=1$), then $\gcd(g,r)>1$.


Question about set notation: what does $]a,b[$ mean?

In the following question  the notation $c\in ]a,b[$ is used. What does this mean? I have never seen it before.


Simple past or present perfect? (in unknown point in time in the past)

Describing the typical Twitter user:     I criticize what you wrote/have written and then I block you, without   waiting for your reply.   Which one is correct? Thank you.


I was reading a book of linear algebra and started the chapter of isomorphisms. The book describes them as linear maps that are injective and surjective. Then I realised that that condition is the same as invertibility of the matrix of the linear map, but I don't know how to prove it. So, my idea is: Given a linear map $f: E\to F$ (with $dim(F) = dim(E)$ and basis $B$ of $E$ and $B'$ of $F$, I want to proof that $f$ is an isomorphism if and only if it is invertible. That is, I want to prove they are equivalent. In some way I kind of "feel" it, but don't know how to proceed. Here is my attempt for the right-to-left implication: we assume $f$ is invertible. Then we want to show it is injective and surjective. Let $u,v \in E$, and $f(u) = f(v)$, then $u = f^{-1}(f(u)) = f^{-1}(f(v)) = v$, therefore $f$ is injective. To prove it is surjective we want to prove that $range(f) = F$. Let $w \in F$, then take $v = f^{-1}(w)$, the existance and uniqueness of this element is guaranteed by the invertibility of the inverse of $f$. Then $f(v) = f(f^{-1}(w)) = w$. So $range(f) = F$. However, for the other direction I don't know how to do it. Can somebody help me?


A fair die is rolled 1,000 times. What is the probability of rolling the same number 5 times in a row? How do you solve this type of question for variable number of throws and number of repeats?


Typesetting with different values of a boolean

In my document I have defined a few booleans (like etu in order to hide some parts of the document for the students, or mono which activates the monochrome option of xcolor).  My aim is now to provide different versions of the pdf, with just one typesetting, depending on the booleans etu and mono. Unfortunately I don't know how I can do this.


How to understand this sentence correctly: "He shambled off down the corridor."

"Off down the corridor"?  "off" and "down"?  I can't get the picture of this sentence,because I don't know where the man was and where he was going in the sentence.  What position did the speaker think "he" was in then?


Linux partition deleted by windows 10 installer

So, my configuration is with 2 separate physical drives. One with Linux one with Windows. Boot selection I am doing from bios (Linux was installed without the windows SSD plugged in). Everything was sugar and nice until I need it to reinstall windows and from Windows 10 installer by mistake I deleted also the SSD with linux. I immediately realized and did nothing over it hoping that there will be a queue of events that will be triggered by a "apply changes to disk" but this was not the case.  Is there any way how I can recover my partition? thank you!


Assign triggered code to multiple images - Excel VBA

I wanted to assign some specific actions when clicking on one of the images I have inserted in my Excel sheet. The problem is, I got 52 images (Poker cards for those wondering). So, my question is, is there any way to avoid writing code for 52 cases, and find a way like below:    Private Sub Image(x)_Click()    Call common_subroutine(x) End Sub   , instead of writing the same thing 52 times, one for each different image name? Since I use the same subroutine to do the work with a variable according to the case, the load of work won't be that big if there's no way to do it, but it surely bothers me whether this obviously silly way is the only one possible.


How to get display code that are modified code using git

I have project which is committed in locally, now I want to see the changes made in the project with the modified code, I want output like as follows :    commit 54576760f3437ta3s457999d3ef606   Author: Rajesh   Date:   Tue Nov 13 1:40:55 2012 +0100     class myFile {       ....       //modified code should getdisplayed    }   What is the command can i use for it ?


I am trying to edit a list of lists by   s[0][0]=1   but instead of just the first number in the first row changing to 1, the first number in all the rows are changing to 1.  I was first taught python using 2.7, but the class I'm taking now requires 3.4. Was there a change in syntax between the two versions? Otherwise, what am I doing incorrectly?   Thanks in advance


Whenever I try to launch Minecraft the launcher loads perfectly but, once I hit play, the launcher disappears for a second and then reappears with the following error message:   Minecraft Version: 16w40a     Operating System: Windows 10 (amd64) version 10.0     Java Version: 1.8.0_25, Oracle Corporation     Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation     Memory: 52833096 bytes (50 MB) / 151068672 bytes (144 MB) up to 1060372480 bytes (1011 MB)     JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M     IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0     Launched Version: 16w40a     LWJGL: 2.9.4     OpenGL: ~~ERROR~~ RuntimeException: No OpenGL context found in the current thread.     GL Caps:      Using VBOs: Yes     Is Modded: Probably not. Jar signature remains and client brand is untouched.     Type: Client (map_client.txt)     Resource Packs:      Current Language: ~~ERROR~~ NullPointerException: null     Profiler Position: N/A (disabled)     CPU: <unknown>    I have tried deleting minecraft and reinstalling, repairing minecraft, etc. but nothing will work.


If every $x\in X$ is uniquely $x=y+z$ then $\|z\|+\|y\|\leq C\|x\|$

Problem Statement  Let $(X,\|\cdot \|)$ be a Banach space and $Y$, $Z$ closed subspaces of $X$. If every $x \in X$ can be uniquely represented as $x=y+z$ for $y \in Y$ and $z \in Z$ then show that there exists $c$ such that $\|y\|\leq C\|x\|$ and $\|z\| \leq C\|x\|$  Attempt  If $L:X \rightarrow Y$ given by $L(x)=L(y+z)=y,$ then we will be done if we can show that $L$ is a bounded linear operator. Alternatively, by adding the two inequalities, we can show that the norm $\|\cdot\|$ is equivalent to $\| \cdot \|_{Y\times Z}$, where $\|(y,z)\|=\|y\|+\|z\|$. I attempted the first approach via the closed graph theorem but I am unable to make any headway.


Proof of the superposition theorem in linear circuit analysis

I couldn't find a proof of the superposition theorem from circuit analysis anywhere online.  I thought it might be helpful to ask and provide my proposed proof as an answer to gather feedback and improvements.


Quoting  :  "elastic net is a regularized regression method that linearly combines the L1 and L2 penalties of the lasso and ridge methods."  L1-regularised learning corresponds to a MAP estimate with a Laplacian prior on the weights: p(w) ~ Laplace(0, b)  L2-regularised learning corresponds to a MAP estimate with a normal prior on the weights: p(w) ~ N(0, sigma^2)  I'm struggling to recognise the prior that gives rise to L1 + L2: p(w) ~ e^(a|w| + bw^2). Insight appreciated!


President Nixon declared, "I am not a crook." President Nixon declared: "I am not a crook." President Nixon declared "I am not a crook."  Do you agree that using the comma and the colon in the sentece above is "completly pointless" as one of the many manuals dedicated to the problem of quotation marks asserts? According to this manual the first two sentences are the examples of "bad style".


I am new to Python and QGIS, and I want to automate a process so I want to learn how to use the QGIS Pyhton API to make our own code and do the job. If anyone knows any tutorial about this then please share, it will be of great help.


I've executed Wireshark and I tried to capture packets.  I got the following error which shows up after clicking "start capturing":


JAVA linked list delete node NullPointerException

I was working on this code to take in a target String and search the linked list for the target and delete all instances of it. I feel like I have most of the logic down but I am getting a NullPointerException and was needing some help. here is the code:  public class LinkedStringLog implements StringLog {   private LLStringNode head;   private int numOfEntries;     public LinkedStringLog() {//constructor     head = null;     numOfEntries = 0;     }     public void delete(String target){//deletes all entries of target      LLStringNode current = head;     LLStringNode prev = head;      for (int i = 0; i < numOfEntries; i++) {         prev = current;         current = current.getNext();          if (target.equals(current.getValue())){             prev.setNext(current.getNext());             current.setNext(null);             numOfEntries--;          }     }   }


I wrote a windows application using C# .Net 2.0 and i want to do something which hide the source code, so when any one use refactor tool can't see the source code. I used dotfuscator but it just changed the function names but not all the source code.  UPDATE: I want to hide the source code, not because of hiding the key, but to hide how the code is working.  Thanks,


Use PROMPT_COMMAND to echo to custom bash history file

I executed the command below in a BASH shell.  export PROMPT_COMMAND='echo "$BASH_COMMAND" >> $HOME/my_bash_history'   but everytime I type something in the shell and hit return, I just get one more line my_bash_history file which fills up with:  echo "$BASH_COMMAND" >> $HOME/my_bash_history echo "$BASH_COMMAND" >> $HOME/my_bash_history echo "$BASH_COMMAND" >> $HOME/my_bash_history echo "$BASH_COMMAND" >> $HOME/my_bash_history echo "$BASH_COMMAND" >> $HOME/my_bash_history echo "$BASH_COMMAND" >> $HOME/my_bash_history   anybody know why that's happening?


Set of unordered $n$-tuples of points of $\mathbb{CP}^1$ can be identified with $\mathbb{CP}^n$?

This is a followup question to .  Fix $n \in \mathbb{N}$. What is the easiest way to see that the set of unordered $n$-tuples of points of $\mathbb{CP}^1$ can be identified with $\mathbb{CP}^n$?


Can you execute your ready action in the same turn it was readied?

Is it possible for a spellcaster to ready a fireball when he is out of view, move into line of sight and release it in the same turn , without giving the opposing spellcaster the chance to counterspell it since he didn't see it being cast?


Is it possible to add the time of editing to the table of a shapefile?

I would like to automatically track the time when a point is created or edited. I first thought about virtual fields and the now() function. However, that field always contains the current time. So maybe it would be possible to only update the virtual field one time, but I have no clue how. Is there a way or any other possibility to automatically track the time?  In contrast to the question  or rather the answers I don't think it is reasonable to select a field or save the shapefile every time after editing a new feature. So yes the quesions may be similar, but the answers of the other question don't answer my question.


What specifically determines output if I printf an integer without a matching argument?

For example, when my code is as shown below, I get -1301113336 for a = 0 and -1266657529 for a = 1 to 99.  #include <stdio.h>  int main() {     int a;     for (a = 0; a < 100; a++)     {         printf("\n%i");     } }   Is this some kind of undefined case when behaviour varies by compiler? If I use gcc, where do these numbers come from and why does it not change for each iteration?


Constant case CRT: $\,x\equiv a\pmod{\! 2},\ x\equiv a\pmod{\! 5}\iff x\equiv a\pmod{\!10}$

Problem: Find the units digit of $3^{100}$ using Fermat's Little Theorem (FLT).  My Attempt: By FLT we have $$3^1\equiv 1\pmod2\Rightarrow 3^4\equiv1\pmod 2$$ and $$3^4\equiv 1\pmod 5.$$ Since $\gcd(2,5)=1$ we can multiply the moduli and thus, $3^4\equiv 1\pmod {10}\Rightarrow3^{4*25}\equiv 1\pmod{10}.$ So the units digit is $1.$


How can I write my profile in multiple languages on Careers?

I just accepted an invitation to , and thought that it would be just great if there was any possibility to write my profile in multiple languages.  I know English is kind of vernacular in Programming languages, but I have the habit to write CV, list of publications, etc., in both my native language (a.k.a. French) and English, and think this is an excellent practice.  Could it be possible to write a profile in several languages, and depending on the recruiter's profile, to display such or such language ?


Diff Between Call By Reference And Call By Pointer

Can any one tell me the exact diff between call by pointer and call by reference. Actually what is happening on both case?  Eg:   Call By Reference:  void swap(int &x, int &y) {    int temp;    temp = x; /* save the value at address x */    x = y;    /* put y into x */    y = temp; /* put x into y */     return; }  swap(a, b);   Call By Pointer:  void swap(int *x, int *y) {    int temp;    temp = *x; /* save the value at address x */    *x = *y; /* put y into x */    *y = temp; /* put x into y */     return; }    swap(&a, &b);


Create row for each entry in a table (ideally without script)

I have a table of number entries. Say, for each Product (rows) a number of purchases on each Date (columns).      Date Date     Product 150 200   Product 350 400     I'd like to turn this into one entry for each number on the 2D table. Example:            Product Date 200   Product Date 200   Product Date 350   Product Date 400     Is there a way to do this with formulas, without having to dive into a script to run each time I update the data?


Do foxes count as one of the "Free Peoples?"

In Middle-earth, Elves are bound to the world and will live as long as it lasts. Men are of course mortal, as are Dwarves, Hobbits, Eagles, Trolls, Orcs, Ainur (so it would seem), and, most importantly, foxes. In the early stages of the Ringbearer's Quest, one fox comes across the sleeping Hobbits far from where Hobbits tend to sleep. He finds it rather odd, and we get a peek inside his head for a short monologue.  My question is, do Foxes count as sentient beings of Middle-earth? Are they something more akin to the Eagles, being a representative of a Vala in the wide world?


Site Navigation using Managed Metadata Term Store using SharePoint 2013

There are multiple lists in my site collection. And for these lists, there are multiple SharePoint Groups who can access the lists depending on the list permissions.  Depending on the Logged In user I want the Lists to be accessed. How is this possible using Managed Metadata Term store?


Comparing binomial outcomes from prediction algorithms in R

I've written a simple model to predict the outcome of soccer games based on some input. The outcome is either "H","D",or "A", short for home team, away team, or draw. I'm comparing the results of this model to predictions made by a popular betting site (meaning both are being compared to the actual outcomes as well).   My question is: what's the best way to check wether my model is performing better/worse than the betting site, and to quantify the amount?   I figured a better way is to compare each model to the actual outcome and replace the outcomes with binary ones just saying true or false based on wether the prediction was correct and then compare this binomial data. I've seen  and  question, that say a paired t-test isn't the ideal choice, suggesting either McNemar's test or a regular z-test. However, I'm not sure it translates to my situation as well, because I'm not familiar enough with the intricacies of each method.   I'm doing all of this in R, so here's some reproducible code for the data:  myTable <- data.frame(outcome=c("H","H","D","A","H"), betsite=c("H","A","A","H","H"), predmodel=c("A","H","D","A","H"), betsitebin=c(TRUE, FALSE, FALSE, FALSE, TRUE), predmodelbin=c(FALSE, TRUE, TRUE, TRUE, TRUE))  Which looks like this:       outcome betsite predmodel betsitebin predmodelbin 1       H       H         A       TRUE        FALSE 2       H       A         H      FALSE         TRUE 3       D       A         D      FALSE         TRUE 4       A       H         A      FALSE         TRUE 5       H       H         H       TRUE         TRUE


If $f\colon \mathbb{R} \to \mathbb{R}$ is such that $f (x + y) = f (x) f (y)$ and continuous at $0$, then continuous everywhere

Prove that if $f\colon\mathbb{R}\to\mathbb{R}$ is such that $f(x+y)=f(x)f(y)$ for all $x,y$, and $f$ is continuous at $0$, then it is continuous everywhere.   If there exists $c \in \mathbb{R}$ such that $f(c) = 0$, then $$f(x + c) = f(x)f(c) = 0.$$ As every real number $y$ can be written as $y = x + c$ for some real $x$, this function is either everywhere zero or nowhere zero. The latter case is the interesting one. So let's consider the case that $f$ is not the constant function $f = 0$.  To prove continuity in this case, note that for any $x \in \mathbb{R}$ $$f(x) = f(x + 0) = f(x)f(0) \implies f(0) = 1.$$  Continuity at $0$ tells us that given any $\varepsilon_0 > 0$, we can find $\delta_0 > 0$ such that $|x| < \delta_0$ implies $$|f(x) - 1| < \varepsilon_0.$$  Okay, so let $c \in \mathbb{R}$ be fixed arbitrarily (recall that $f(c)$ is nonzero). Let $\varepsilon > 0$. By continuity of $f$ at $0$, we can choose $\delta > 0$ such that $$|x - c| < \delta\implies |f(x - c) - 1| < \frac{\varepsilon}{|f(c)|}.$$  Now notice that for all $x$ such that $|x - c| < \delta$, we have $$\begin{align*} |f(x) - f(c)| &= |f(x - c + c) - f(c)|\\  &= |f(x - c)f(c) - f(c)|\\  &= |f(c)| |f(x - c) - 1|\\  &\lt |f(c)| \frac{\varepsilon}{|f(c)|}\\   &= \varepsilon. \end{align*}$$ Hence $f$ is continuous at $c$. Since $c$ was arbitrary, $f$ is continuous on all of $\mathbb{R}$.  Is my procedure correct?


I get spam texts from a certain number (five digit number). Does anyone know how to block texts from specified numbers? I am on a nexus 5 android 4.4.3.


Sci-fi book series featuring insectoid aliens, motorized armor and main character in anabiosis

I remember not too much about this book series, but I know exactly:  It was written before 2000 (70-80's maybe). Series includes at least 3 books, maybe more. Space opera. Main character is a male soldier, fighting in some kind of motorized armor (exoskeleton?). Soldier was in suspended animation during flight to one of the fights, but something on his ship broke and he slept for too long and was the last survivor of his squad. In one of the books hero starts to think that his armor has its own mind. Humanity has settled in galaxy, but is at war with bug-kind insectoid race. In one of the books, main character meets ambassador of these bugs. Main character saves a girl from slavery or something like that, later she falls in love with him.  This book is not Armor by John Steakley, and not Starship Troopers.


How to use variables between different python tkinter button event actions?

I'm writing a python program to take user input for input file and output directory and then take a dd image of the input file using the subprocess module. I have written the following code. I am not able to use the variables i use in one def, in some other def part. Please help me out with this as i'm new to Python.  def open_dir():     o_file = subprocess.call(["zenity","--file-selection","--directory","--title=Select Destination Directory"])     o_var = StringVar()      o_var.set(o_file)     def quit_root():     root.destroy()   def get_input():     msg1 = subprocess.call(["df","-h"])     msg2 = StringVar()     msg2.set(msg1)     msg = Message(labelframe, textvariable=msg1)     msg.pack()       in_file=subprocess.check_output(["zenity","--entry"])     var=StringVar()     var.set(in_file)   def dev_img():     global var     global o_var     input_file=var     output_file=o_var+"device.img"     out = subprocess.check_output(["dd","if="+input_file,"|pv|","of="+output_file,"bs=1024"], stderr=subprocess.STDOUT)     var1 = StringVar()     var1.set(out)     label1 = Message(labelframe, textvariable=var1)     label1.pack()   Please suggest me some way so that i can use the 'var' and 'o_var' variables from open_dir() and get_input() and use those varibales in dev_img().


When can you get up again after falling on the ground?

I had always thought that when the ball carrier was on the ground, they were down and the play was over. Recently I have seen a fair number of plays such as interceptions or fumble recoveries where the player intercepted (or recovered) the ball and fell on the ground, and then immediately got up and ran for as many yards as possible.  How does this work? Is there a time limit for getting up to resume play?


Can the photoelectric effect be explained without photons?

Lamb 1969 states,     A misconception which most physicists acquire in their formative years is that the photoelectric effect requires the quantization of the electromagnetic field for its explanation. [...] In fact we shall see that the photoelectric effect may be completely explained without invoking the concept of "light quanta."   The paper gives a description in which an atom is ionized by light, with the atom being treated quantum-mechanically but the light being treated as a classical wave.  Is it true that all the standard treatments in textbooks are getting this wrong?  Lamb and Scully "The photoelectric effect without photons," in "Polarization, Matière et Rayonnement," Volume in Honour of A. Kastler (Presses Universitaires de France, Paris, 1969) -- can be found online by googling


Why is $\pi r^2$ the surface of a circle?   I have learned this formula ages ago and I'm just using it like most people do, but I don't think I truly understand how circles work until I understand why this formula works.   So I want to understand why it works and not just how.  Please don't use complicated symbols.


Screen tearing and audio jitter when play videos on google chrome

Using 16.04  and only seems to happen in chrome.the other question seems to have fixed the flickering problem but i still have like small screen delay when i switch tabs and i still seem to have the sound jitter randomly


What's the best way to ask that my question be moved to Stack Overflow?

I asked  which received the feedback:     You can integrate Laravel functionality into WordPress, it's just PHP, but this question is way to open ended, voting to close unless you have a specific example your trying to get to work.   I took this on board, read a couple of entries on meta about improving questions, and reworked my question.    The rewrite was major: I have aimed for simpler goals to achieve my problem, but now the question is less relevant to the WordPress community, and the question is mothballing - not too many views, no answers, and a total of 2 comments.  I think the question is a better fit in its current form for Stack Overflow, but I don't have the 250 required to vote for a move...  What are my options?   Ask here? Ask in the comments of the question?   Any recommendations?  PS. the only  I saw like this one regards: "why can I not do this for myself", and does not answer my question


I have a bunch of formulas in a column that I wish to duplicate exactly into another column, where I will go through and tweak them so that a different function is run on the same parameters.  When I do a copy/paste, the cell addresses are all altered to be one higher, which is not desired.  The only way that I have found is to move the cells using cut/paste, but then I destroy the source cells, leaving me without the duplicate cells.  If you want more detail, I have a column full of CORREL() calculations, and I want to duplicate them to another column where I will do SLOPE() calculations.


How to evaluate the quotient of Dedekind eta function in Pari/Gp

This expression I found in some research paper, which connects quotient of Dedekind eta function and ray class field of conductor N, which in turn gives the value of j-invariants.  For $K=\mathbb Q(i)$ and $N=3$ (conductor), the discriminant of the order is -36. Now,$$j_{1,3}(\tau)=\frac{\eta(\tau)^{12}}{\eta(3\tau)^{12}}$$ where $\tau=i$.  I evaluated this expression in Pari/Gp, and I got the answer in decimals which I found wrong, if some one knows how to evaluate the above quotient,  their reply will be of great help


What is an example of Gâteaux differentiable but not Fréchet differentiable at a point in a finite-dimensional space?

Let $V,W$ be nonzero normed spaces over $\mathbb{K}$ such that $V$ is finite-dimensional.  Let $E$ open in $\mathbb{K}$ and $p\in E$.  Let $f:E\rightarrow W$ be Gâteaux-differentiable at $p$.  Is $f$ necessarily Fréchet-differentiable at $p$ in this case?  I think this is not true in general, but cannot find a counterexample. What would be a counterexample?


There's someone much like Crazy Earl in Oasis behind a locked door. He tells me to leave until I've killed a seraph guardian or I get some sort of guardian crystal.  I just beat the DLC and did many of the sidequests and I'm still stumped as to how to get such a crystal. I assumed there would be Guardian foes just like in Borderlands 1, and they'd drop this item. After completing the story...there were no such enemies. So what do I do?


How do you get parent and grandparent categories

I'm wondering how you can receive a categories parent name and link for a breadcrumb I've written.  I basically want to have the following structure  if child category blog > parent_category  else if grandchild category blog > grand_parent_category > parent_category


Object not visible in Render Blender 2.8

worked for some time on modeling shoe laces and as I rendered the image the laces are not being rendered in blender 2.8  In blender 2.78 it does render all the objects.  What am I doing wrong?


How can I detect a power outage with a microcontroller?

I have the following power supply configuration: AC MAINS -> UPS -> 24V POWER SUPPLY -> 5V VOLTAGE REGULATOR -> PCB (microcontroller). What's the best solution to detect the power outage on the mains with the microcontroller? I also need to detect the zero-crossing so that I can control the speed of an AC motor.


What's the quickest way to get a graphic on the clipboard saved to disk?

I have a graphic on the clipboard on OS X.  What's the quickest way to get it onto disk as a png or jpg?


Suppose a charged capacitor (parallel plates), the negative and positive charges on two plates attract each other. Which force cause the negative charge carriers (electrons) move through the circuit to the other plate if we connect two plates (from outer sides) with a wire?


Receiving $30k from mother for house down payment

My wife and I are planning on buying a house in the near future. My mother has offered to give us $30,000 to put towards our down payment. I am interested to know what method to receive the money would be best and to avoid as much hassle/taxes from the government.   Our real estate agent has said that there is a law that any money we use for the down payment must be "seasoned" for a minimum of two months in our account before we are allowed to use it, so a protracted solution is not desirable but understandable if unavoidable.


How to calculate stays against 90/180 visa rules?

Some destinations have a "90/180 rule" which says you can come and go but you must not spend over 90 days out of any 180 days in the area.  concerns this rule.  At least Schengen and Turkey have this rule, probably depending on where the traveller is from and what kind of visa they apply for.  Maybe I'm a dummy but I've always had a lot of trouble trying to add up how many days I've spent in such places when I've entered and left several times over recent months.  Is there an easy way to do this I'm missing or is it difficult for everybody? I'm guessing something based on counting backwards from the end date might be the trick?  Maybe you know of an app or website that can do this for you.


I need to use JARs in my maven project. But these JARs are located on hdd disc, like d:\MyJar.jar. I need use it in my project to resolve dependencies.  I know that I can install it in local maven repository, and use it. But my client doesn't want this for some reasons (scared of some licence agreements or something, it doesn't matter, he insists).  In Intellij Idea I can go to Project Structure and add libraries there, but I need to compile it from command line with - mvn package command.  So, I need to add myjar.jar to classpath without installing it in maven repository, using only maven.   How can I do this?


Why do we say that a system with mass gap has correlation function which decays exponentially and one without a mass gap has a slower power law decay?


Questions with opinion-based answers put on hold

I have seen related questions been asked on this forum, but none of them actually reached the point I would like to be clarified. From my perspective, every single non-math/logic question is opinion-based. In some cases, that opinion will be strongly backed by evidence. In others, it will be an intuition with not too much justification. However, there is always a chance of every answer being wrong (the only verifiable truth is, as Descartes put it "cogito, ergo sum")  My question would then be "where's the barrier?"? How certain does science have to be about an answer in order to stop being opinion-based. Let's show a few examples:  First, our all time favourite: a code question I posted myself on stackoverflow:  In this thread, I am asking for a way of writing a "Python list with labels", this means, a "Python dictionary", but there are other ways to achieve the same goal. Most people would not say this should be put on hold as opinion-based, but in that case... Why should the following question?   This question was posted on the chess forum. For those who may not be familiar with chess, the asker wants to build an "opening repertoire", so, he wants other users to help him find the most adequate answers to the opponent's first moves. But there is no such thing as the most adequqate answer! There are many possible ways to reach a good position, just as in my previous question. So, yes, the answers to this question are purely opinion-based and it was put on hold.  However,  this quedstion is asking basically the same thing, except it a different position. As before, there is no final answer, and indeed we see different people giving different pieces of advice. The question was not put on hold and it even received 4 upward votes.  Just in case you know nothing about either Python or chess, here are a few examples of questions that could be opinion-based (or not)                  In short, my point is that opinion-based judgements are purely a matter of opinion and this should not be a reason to put on hold so many questions,at least, not in every community. I understand I could be wrong and that's why I ask you: "Where is, in the Stack Exchange world, the border between a fact and an opinion?" Please don't put on hold as opinion-based!


Why is the action dimensionless in natural units?

As I understand it, a natural system of units is one in which the numerical values of $c$ and $\hbar$ are unity, i.e. $c=\hbar =1$.   What I find confusing is that they are still dimensionful, i.e. $[c]=LT^{-1}$ and $[\hbar]=ML^{2}T^{-1}$. So, how can the action be dimensionless, $[S]=1$, when it has the same dimensions as $\hbar$?


Make Google stop sending 'new sign in from ...' emails

I get at least two emails from Google every time I sign in to my account and I want it to stop.  I tried changing the notification settings in Gmail, but they're still coming and they're useless.  How can I stop this?


This is a reworking of a previous question  which was marked as a duplicate. Some nice folks have referred me to solutions to similar problems. I still have a couple of questions, since one of the solutions used the Poisson kernel, which is not the desired solution in the text, because the Poisson kernel has not been introduced yet. The other solutions were for problems that were similar, but whose solutions were only partially applicable, as I understand them.  I'm working on a problem from p. 166 of Lars Ahlfors' Complex Analysis:     If $u$ is harmonic and bounded in $0 < |z| < \rho$, show that the origin is a removable singularity in the sense that $u$ becomes harmonic in $|z|<\rho$ when $u(0)$ is properly defined.   My Solution So Far:   Here's what I've got for a non-Poisson kernel solution: We want to find a harmonic conjugate for $u$ in the punctured disk, and then we can apply big Picard to show that $0$ is a removable singularity. The problem is that the punctured disc is not simply connected.   If we take $\sigma = (u \circ \exp)(z): L \to \mathbb{C}$, where $L$ is the left half-plane, now we have $\sigma$ harmonic, and defined in a simply connected set $L$, so it has a harmonic conjugate $\tau$. Now we wish to take $v = (\tau \circ \log):\{0 < |z| < \rho\}\to \mathbb{C}$, but in order to do so we need $\tau$ to be $2\pi i$-periodic. This is where my proof breaks down.  One of the similar problems which readers referred me to used the following strategy: note that since $\sigma$ is $2\pi i$-periodic, and $\sigma, \tau$ satisfy the Cauchy-Riemann equations, we have that $\nabla\tau(z) = \nabla\tau(z + 2 \pi i)$ for all $z\in L$, or in other words, $\tau(z) - \tau(z+2\pi i)$ is a constant function, say, equal to $\alpha \in \mathbb{R}$. Then, the solution suggests, we can set $$g(z) = u + iv - \frac{c}{2\pi}z,$$  in order to make $g$ $2\pi i$-periodic, and then we can use $(g\circ \log)$ on $\{0 < |z| < \rho\}$. But the reason why this won't work for my purposes is: now we have changed $u$! On the other hand, we can't simply subtract $\frac{c}{2\pi}\Im{(z)}$, and try to leave $u$ untouched, because now $g$ is not analytic. How can we get around this?  Another strategy entirely might be to try to use the mean-value property. Ahlfors discusses that a lot in the preceding section, and his main example is the punctured disc. Since $u$ is harmonic, we know that the average over circles centered at zero is a constant...


Is there a dense set in $\Bbb{R^2}$ that every vertical line or horizontal line intersect in finite points. I think that we can consider $\Bbb{Q} ×\Bbb{Q}$ but every vertical line or horizontal line don't intersect in finite points.