I'm attempting to compute the value of an arbitrarily large matrix (order $n$). In simplifying the determinant, I was able to express its value in terms of the determinants of smaller matrices of the same form. Specifically, $$ D_n = 2 \cos \theta D_{n-1} - D_{n-2}, $$ where $D_n$ is the determinant of the original order $n$ matrix. The form of the original matrix isn't critical to this question (just the recursive relationship), but if you're curious $$ D_n = \begin{vmatrix}     \cos \theta & 1             & 0             & 0             &        &               & 0             \\     1           & 2 \cos \theta & 1             & 0             & \dots  & \dots         & 0             \\     0           & 1             & 2 \cos \theta & 1             &        &               & 0             \\     0           & 0             & 1             & 2 \cos \theta &        &               & 0             \\                 &               & \vdots        &               & \ddots &               & \vdots        \\                 &               & \vdots        &               &        & 2 \cos \theta & 1             \\     0           & 0             & 0             & 0             & \dots  & 1             & 2 \cos \theta \\ \end{vmatrix}. $$ I've defined $D_{n-1}$ in terms of $D_n$ by removing the last row and column from $D_n$. My question is: where does this recursive relationship end? In Mathematical Methods in the Physical Sciences by boas, section 3.3, Boas states:  The value of det A if A is a 1 by 1 matrix is just the value of the single element  So, $D_1=\cos\theta$. But, what about the 0x0 matrix $D_0$? Is this just 0? Is it defined at all?


Dong as in ding-dong is clearly onomatopoetic as confirmed by :     ding dong        imitative of the sound of a bell, c.1560.   and similarly for :     ding (v.)       1819, "to sound as metal when struck," possibly abstracted from ding-dong, of imitative origin. The meaning "to deal heavy blows" is c.1300, probably from Old Norse dengja "to hammer," perhaps also imitative. Meaning "dent" is 1960s. Related: Dinged; dinging.   What, then, is the origin of dong to mean penis? Etymonline.com is  here:     dong (n.)        "penis," 1891, of unknown origin.   We also have a much more recent word, dongle, which has no entry at etymonline.com but  claims it is:     Apparently from dangle.   This leads me to the theory that the anatomical and onomatopoetic dongs  are not related and that the former usage, like dongle, derives from dangle. So, my questions are:   Is that so? Does dong (penis) derive from dangle? Sounds reasonable enough but I have found no definitive sources for it. Does dongle derive from dangle? It makes perfect descriptive sense for dong but the USB devices called dongles do not dangle but instead protrude quite rigidly, so I feel that dongle being derived from the cruder meaning of dong makes more sense.


gpedit.msc command doesn't exist on windows 10 home premium

I tried to execute the command gpedit.msc through the "run program" window, but when i do it i get an error that says the command doesn't exist. I tried to execute the command from the administrator user. My pc has windows 10 Home premium x64


Server Folder Permission Security Standards

I'm a hapless newbie front end dev who has inherited a tangled nightmare of a website that has been cowboy coded for several years. The web host found an infected PHP file which has been removed and so I've been asked to look into security and to "go through the folders and ensure that none have overly generous permissions". The only experience I have with this is a month long process of destroying my local apache permissions on my linux laptop so I'm quite hesitant to mess with this. Forgive me if this question is not specific enough but unfortunately I'm so out of my league that I dont even know what to ask google so I am hoping some of you can either . . .  1 ) provide me with a checklist of things to look for regarding folder permission security   2 ) point me to an article or phrase that will help me do more precise research  3 ) point me to a tool that scans this for me  or  4 ) tell me I'm in over my head and that I'm not going to be able to ensure that our site is secure with a couple days of googling   Thanks!


Why is a world line's proper time the age of an observer moving along this world line?

We define "world line" in Minkowski Space to be a curve whose velocity is time-like. Then we define "proper time" to be its arc length (with respect to the metric). The given question is     "why is proper time between two events of the curve the time between these events as measured by an observer moving along that curve?".    The answer found in some books is that you can approximate the time as measured by a non-inertial observer by the sum of n inertial ones and then take the limit as n approaches infinity.The hypothesis required is Statement (1): "an instantaneous change in velocity results in an instantaneous change in time at max proportional to the square of the change in velocity", so their sum tends to zero as n gets arbitrarily large. Other books state the Clock Hypothesis straight ahead, claiming that the answer to the given question is "yes" by experimental facts.Another equivalent statement is Statement (2): "the rate of a clock does not depend on its acceleration but only on its instantaneous velocity".   Statement (2) and the Clock Hypothesis can be proven equivalent. Statement (1) implies the Clock Hypothesis for smooth world lines and the Clock Hypothesis implies a much stronger version of statement (1), that is that under the conditions of statement (1), the change in time is zero. What are equivalent statements resulting to the Clock Hypothesis? Is there a statement as fundamental as statement (1) but in the same time avoiding the introduction of discontinuities in proper time?


Object becoming null outside return statements

this may be a simple problem, but I've looked for an answer and I'm just not finding it anywhere. I'm trying to use a method to check if an inputted answer is correct compared to the actual answer. The actual answer is defined by a setter, and the getter works also. But in the method where it's compared it becomes null. This isn't a question about why comparing them returns null, but why correctAnswer is null in the first place. I'm confused because getCorrectAnswer() works as intended.   Here is the code:  public class MultipleChoiceQuestion implements Question {  String question; String correctAnswer;  public String getQuestion()  {     return question; }  public boolean isCorrectAnswer(String answer)  {     if (answer != correctAnswer)     {         return false;     }     return true; }  public String getCorrectAnswer()  {     return correctAnswer; }  public void setQuestion(String questionText){     question = questionText; }  public void setAnswer(String answer){     correctAnswer = answer; }   }  "answer != correctAnswer" doesn't work because correctAnswer is null in that method.


Ubuntu 19.04 is stuck at the ubuntu logo on the boot sequence. I installed it on a Dell Latitude E6540 as the main operating system (not in VirtualBox). It worked normally for few days, and since last night the computer never boots up and gets stuck at this screen.    Please help to recover it.


How to highlight important parts (with a gray background)

In the below link        the author highlights anything which is important using a greyish color background. For example, if you see Equation 1.5.3 (which on page 22 of the book) it is highlighted in grey. I would like to know the TeX commands for producing similar output.


Why isn't temperature measured in Joules?

If we set the  to $1$, then entropy would just be $\ln \Omega$, temperature would be measured in , and average kinetic energy would be an integer times $\frac{T}{2}$. Why do we need separate units for temperature and energy?


Using author description for resources listing blog

I'm working on a new blog that collects resources for web developers like lists of available CMS, Frameworks, Libraries and other plugins. I want to use the author description for every item as is from its website and telling that this is the author description and of course with a link back to that site where it will be available for download (not on my site).  Will I be infringing copyright or will my SEO be penalized for duplicating content maybe?  Here is an example of what a post will look like:


Question about strings (as a variable from cs50) in C

If you have some string (as a variable type from ), let`s assume it is string S that is "AAA". You can change individual chars freely. Like:  for(int i=0; i<3; i++) {     S[i]++ }   which as i guess will make it "BBB". So, in cs50 course lection we got that string function is just like char * and here is this code:  #include <cs50.h> #include <ctype.h> #include <stdio.h> #include <string.h>  int main(void) {     // Get a string     char *s = get_string("s: ");      // Allocate memory for another string     char *t = malloc(strlen(s) + 1);      // Copy string into memory     for (int i = 0, n = strlen(s); i <= n; i++)     {         t[i] = s[i];     }      // Capitalize copy     t[0] = toupper(t[0]);      // Print strings     printf("s: %s\n", s);     printf("t: %s\n", t); }   which effectively is copying one string to another, not just making another copy of link to starting character of string, but making another string with same filling just with the difference we are capitilizing first letter. SO, I've got a thought, why should I even use this new malloc(strlen(s) + 1). If I need another string to appear in means of just creating some memory jar, why can't I just make new string with any filling. Like this:  #include <cs50.h> #include <ctype.h> #include <stdio.h> #include <string.h>  int main(void) {     // Get a string     string s = get_string("s: ");      // Let`s consider we know exact size of s we are getting, so we are creating the string of same size, just for question purposes     string t = "qooq";      // Copy string into memory     for (int i = 0, n = strlen(s); i <= n; i++)     {         t[i] = s[i];     }      // Capitalize copy     t[0] = toupper(t[0]);      // Print strings     printf("s: %s\n", s);     printf("t: %s\n", t); }   And at this point it does not work, it compiles, but shows some cryptic errors when it goes into for loop. So where am I basically wrong? Am I missing something? I can do whatever I want with characters in a string, so why can`t I just give to characters the valuse of another character in this t[i] = s[i] ???


Looks like a material problem, but I can't find anything to remove?

Really sorry as I'm a beginner and I don't know enough to characterize, or accurately search for what the problem may be. I've taken a picture of what I'm seeing, where it appears the faces have different textures, but nothing shows up under materials, and it's currently causing the solidify modifier to thicken differently along the edges and inside the areas.   I appreciate any help you all may give!


Why do I get a NullPointerException from the read.split(",") method when reading in from a text file?

Here is my code to read a text file line per line.       ArrayList<Student> studentCollection = new ArrayList<Student>();     BufferedReader in = null;     try {         in = new BufferedReader(new FileReader("StudentAnswers2.txt"));         String read = null;         while ((read = in.readLine()) != null)          {             read = in.readLine();             String[] splited = read.split(",");             int[] answersTrans = new int[20];              for(int i = 0; i < 20; i++)             {                 answersTrans[i] = Integer.parseInt(splited[i+3]);              }                        studentCollection.add(new Student(splited[0], splited[1], splited[2], answersTrans));                           }   Context: I am trying to set each comma separated value as fields of a List of Student objects ( one line per Student). The first 3 values need to go in as String parameters, and the following 20 values go in as one int[] array.  Here's the content of the txt file:        C97288501,Byrne,John,0,3,3,0,2,4,0,1,4,5,0,3,3,1,2,4,2,0,4,5   D11255403,Smith,Eileen,1,3,2,0,4,3,1,4,5,0,3,3,1,3,4,5,0,5,4,0   C06623662,Doyle,Mary,1,4,3,3,2,2,1,1,4,5,3,3,3,5,2,4,2,5,4,5   C02887223,Radecki,Jason,2,4,3,0,2,2,4,1,0,2,3,3,5,0,4,4,0,4,0,5   D11123581,Hanley,Nora,1,0,2,2,3,0,0,1,5,4,3,3,0,3,2,4,0,5,4,4


I hope this is the right word to use.  To me, these forces seem kind of fanciful (except for General Relativity and Gravity, which have a geometric interpretation).  For example, how do two charged particles know that they are to move apart from each other?  Do they communicate with each other somehow through some means?  I've heard some people tell me that they bounce together messenger photons.  So does one electron receive a messenger photon, go, "Oh hey, I should move in the direction opposite of where this came from, due to the data in it", and then move?  Aren't photons also associated with energy, as well?  Does this type of mediation imply that electrons give off energy in order to exert force on other electrons?  Every electron is repelled by every other electron in the universe, right?  How does it know where to send its force mediators?  Does it just know what direction to point it in?  Does it simply send it in all directions in a continuum?  Does that mean it's always giving off photons/energy?  I'm just not sure how to view "how" it is that electrons know they are to move away from each other.  These questions have always bugged me when studying forces.  I'm sure the Standard Model has something to shed some light on it.


My understanding is that $R^2$ cannot be negative as it is the square of R. However I ran a simple linear regression in SPSS with a single independent variable and a dependent variable. My SPSS output give me a negative value for $R^2$. If I was to calculate this by hand from R then $R^2$ would be  positive. What has SPSS done to calculate this as negative?   R=-.395 R squared =-.156 B (un-standardized)=-1261.611   Code I've used:  DATASET ACTIVATE DataSet1.  REGRESSION /MISSING LISTWISE /STATISTICS COEFF OUTS R ANOVA             /CRITERIA=PIN(.05) POUT(.10) /NOORIGIN             /DEPENDENT valueP /METHOD=ENTER ageP   I get a negative value. Can anyone explain what this means?


I have a C# .exe program that I wish to run every time when USB flash drive is inserted that opens welcome screen.    I know about autorun.inf files and similar stuff that show option in autorun "menu" but I need to start program automatically (plug and play).   How can I achieve this without using any additional programs that user needs to install in it's computer.


Best technique for taking sharp photos with only a few auto focus points?

I have some Canon APS-C cameras which only have 9 or 11 AF points and I find the focus points are mostly in the center of the view finder. I work around it by finding the closest point, half-pressing the shutter to focus, then reframing and taking the shot. Sometimes the movement or 1/8 second delay costs the photo.  Is this the best technique for taking sharp photos with only a few auto focus points? I'm mostly interested in shooting people during events/weddings or on the street.


Leaving the States on Visa Waiver and coming back

I'm travelling on the ESTA visa waiver, I'm now in the States but would like to go to Costa Rica for a bit (say three weeks) then come back to the States. All will be within my 90 day limit.  Is that allowed?  (I have my onward ticket home.)


Where can I find the points per game throughout many NBA seasons?

Where can I find the points per game (of both teams) throughout many NBA seasons?  To illustrate my point, what I mean is something like:   2000/01 average points per NBA game: 200; 2001/02 average points per NBA game: 210; 2002/03 average points per NBA game: 205;   so on...


Find the Cauchy-Riemann equations in polar form. In other words, if $f(re^{i\theta}) = u(r,\theta)+iv(r, \theta)$, then find the relations for the partial derivatives of $u$ and $v$ with respect to $f$ and $\theta$ if $f$ is complex differentiable.      Hint: the following version of the chain rule for partial derivatives may be useful:   $$\frac{\partial u}{\partial r}=\frac{\partial u}{\partial x}\frac{\partial x}{\partial r}+\frac{\partial u}{\partial y}\frac{\partial y}{\partial r}$$   Further, Use the polar version of the Cauchy-Riemann equations to verify that $f(z)=z^n$ is analytic in $\mathbb{C}$ for any $n \in \mathbb{N}$, and that the principal logarithm is analytic in $\mathbb{C} \setminus \{ z \leq 0\}$.  I'm pretty unsure of where to start on this one. Thanks for your help!


unable to associate .txt file with listed Visual Studio Code on Windows 10

I just installed Visual Studio Code 1.28.1, but I'm unable to associate it with the .txt extension on Windows 10.  I'm well aware how to associate an extension with an application on Windows. I can right-click in Explorer, select, "Open As...", select the application, and make sure "Always open with this app" is checked. Or I can go in to the properties of a file in Explorer, look at "Opens with", and click on "Change". Or I can go to "Choose default apps by file type …", etc. The problem is that none of this is working with VS Code.  Currently my .txt files are associated with EmEditor. I change the association to Notepad. No problem. I change the association back to EmEditor. That works.  But if I select the blue "Visual Studio Code" option that appears in the list of applications, nothing changes. The old association remains.  I even tried ignoring the blue icon in the selection list, and manually browsed and selected %LocalAppData%\Programs\Microsoft VS Code\Code.exe as the default editor. That doesn't work, either. Nor did manually selecting %LocalAppData%\Programs\Microsoft VS Code\bin\code.cmd.  In case you think this might be related to EmEditor, I tried to associate .tidyconfig files (which on my system are currently not associated with any editor at all) with VS Code. It did nothing.  What's going on? Associating VS Code with my text files should be the most basic of basic Windows integration. Why won't it work?  (I filed this as , but I had no responses. I'm filing it here in case the "bug" is some sort of user error.)


Can only search social network messages in the Dash after 13.10 upgrade

After upgrading to Ubuntu 13.10, when I click on the Dash icon I can only see social media search results. I can't type in applications or see a list of applications to launch.


How can I view gzipped files in less without having to type zless?

I am using Ubuntu, and I would like to be able to type less compressed_text_file.gz and page the contents of the text file in uncompressed form. Is there a way to do this?


What is the proper association measure of a variable with a PCA component (on a biplot / loading plot)?


how can i fix my code in order to get rid of the error that says that the object I want to instantiate is null?

using System.Collections; using System.Collections.Generic; using UnityEngine; using UnityEngine.UI;  public class replicate : MonoBehaviour {      public void replicateCube(InputField T)     {         int H = int.Parse(T.text);           for (int i = 0; i < H; i++)         {              GameObject prefab = Resources.Load("Cube") as GameObject;             GameObject go = Instantiate(prefab) as GameObject;             go.transform.position = new Vector3(0, i*5, 0);          }     } }


How to set a different theme when the site is on maintenaince mode?

Hi i am searching for a way to change the active theme when the site is on maintenaince mode (Drupal 7), can you help me? thanks in advice


Is Sobolev space $H^{s}(\mathbb R),$ for $s>\frac{1}{2},$ closed under point wise multiplication?

We note that, $L^{2}(\mathbb R)$ is not closed under point wise multiplication.  Let $s>\frac{1}{2};$ and we define Sobolev space, as follows: $H^{s}(\mathbb R)=\{f\in L^{2}(\mathbb R):[\int_{\mathbb R} |\hat{f}(\xi)|^{2}(1+|\xi|^{2})^{s}d\xi]^{1/2}<\infty \}.$     My Question is: Is Sobolev space $H^{s}(\mathbb R),$ for $s>\frac{1}{2},$ closed under point wise multiplication, that is, if $f,g \in H^{s}(\mathbb R),$ can we expect $fg\in H^{s}(\mathbb R)$ ?   Thanks,


I have a task. Prove that $(\cos(n\alpha), \sin(n\alpha))$, with $n\in\mathbb{N}$ is dense on unit circle.($\alpha$ chosen such that our set is infinite ) We want to show, that for every element's neighbourhood there is an element of that that is in the neighborhood. We know that there all points are different (there is no cycle on the circle). But why can we use pigeonhole principle to prove that if we divide the circle in $k$ arcs then there exists two elements which a closer than $\frac{2\pi}{k}$?  EDIT: Thanks everyone. Now everything is clear. This question is [SOLVED]


Does increasing epochs really cause overfitting?

I have a simple 2 hidden layer feed forward neural network. As I increase the number of epochs, I am getting a much better F1 score for the test dataset. Overfitting means that model is performing too well on training data, but my model performs well for the unseen test data (20% of dataset). Is the only cost of more epochs more computation time in my case?


What does it mean: A utility hookup or work order dated within 60 days before registration?

Does it mean any day in a timeframe of 60 days max to the action, in other words: it could be 1 day or 59 days before?


Ending of DoFP with Wolverine (spoliers)

I'm trying to understand the ending of DoFP.      Wolverine wakes up in the future at the Xavier school, obviously not knowing anything that has transpired since he was flung into the Potomac river in the battle with Magento.  He approaches the Professor and Xavier says something like "I've been waiting for you to return."  How is it that this Wolverine remembers what happened?


I ran Windows on Mac using Bootcamp, but apparently I'm having so many compatibility issues, especially with this .  So I was thinking to manually install Windows on my MacBook Pro 13" 2019, and check if this would allow my eGPU to work. Apparently the eGPU works fine on both Windows and MacOS, but it does NOT work on BootCamp.  The problem must be with Bootcamp drivers, in fact the eGPU works fine in Windows. Instead it specifically says the eGPU does not work on Bootcamp (not on Windows, but on Bootcamp). So I am thinking installing Windows on a partition myself, with another boot loader rather than bootcamp, might help.  I have found  but the solution there is for a block size of 512. I need a solution for a block size of 4096.  Not looking for Virtual Machines solutions.


Fitting a UIDatePicker into a UIActionSheet

I'm trying to get a UIDatePicker with a UIButton to show up in a UIActionSheet. Unfortunately it gets cropped off and the entire Date Picker is not visible. I have not even attempted to add the UIButton yet. Can anyone suggest on getting the entire view to fit properly? I'm not sure how to add the proper dimensions as UIActionSheet seems to lack an -initWithFrame: type constructor.  UIActionSheet *menu = [[UIActionSheet alloc] initWithTitle:@"Date Picker"                                                    delegate:self                                          cancelButtonTitle:@"Cancel"                                     destructiveButtonTitle:nil                                          otherButtonTitles:nil];  // Add the picker UIDatePicker *pickerView = [[UIDatePicker alloc] init]; pickerView.datePickerMode = UIDatePickerModeDate; [menu addSubview:pickerView]; [menu showInView:self.view];  [pickerView release]; [menu release];   I've also tried with something similar to:  UIActionSheet *menu = [[UIActionSheet alloc] initWithFrame:CGRectMake(200.0, 200.0, 100.0f, 100.0f)];   The coords are ofcourse not realistic, but they don't seem to affect the position/size of the UIActionSheet.


Unordered sampling with replacement with minimum and maximum bounds

Suppose we have $R$ containers ($x_1,x_2,\ldots,x_R$) and we have $N$ balls. How many possible distributions we have assuming that $x_{min}\leq x_r\leq x_{max}$ $\forall r\in\{1,2,\ldots,R\}$?  The following is my current work to solve this problem:  Dropping the minimum and maximum constraint, we have  $x_1+x_2+\ldots+x_R=N$  with $x_r\geq0$. We have $\binom {N+R-1}{R-1}$ possible combinations   For the minimum constraint, we can define $y_r=x_r-x_{min}$. Therefore, we have  $y_1+y_2+\ldots+y_R=N-R*x_{min}$   with $y_r\geq0$ meaning that $x_r-x_{min}\geq0$ meaning that $x_r\geq x_{min}$. Therefore, we have $\binom {N-R*x_{min}+R-1}{R-1}$ possible combinations.  I am stuck at applying the maximum constraint. Can someone help with applying the maximum constraint?  I do appreciate your help. Thank you


If you True Polymorph a zombie you create via Finger of Death, does it remain under your command?

When you kill a humanoid with Finger of Death, it creates a zombie that is permanently under your command.  If you then True Polymorph that zombie, replacing its statistics with another creature's, does the creature remain under your control?  Related:


static void Main(string[] args)     {         int numberOfTheWords = 1;         string[] words = new string[numberOfTheWords];          Console.WriteLine("You can exit from program by writing EXIT ");         Console.WriteLine("Enter the word: ");         for(int i = 0; i < numberOfTheWords; i++)         {             words[i] = Console.ReadLine();               if (words[i] == "EXIT")                 break;             else                numberOfTheWords++;         }     }   Guys I am trying to expand the lengt of the array but "numberOfTheWords" variable is in the "for loop' scope" so it does not effect the global "numberOfTheWord" variable and i cannot expand the array length. What I am trying to achieve is to make dynamic array. I do not want to declare the length of the array. When the user input a word, the length of the array will be increased automatically. Can you help me about how to do this?


Citations in Texmaker using Mendeley to form a bibtex database

I'm fairly new to LaTeX and having trouble with citations when using texmaker.   I have used Mendeley to produce what i believe is the .bib file containing all relevant references. (File produced = library & Filetype = BibTex Database, when double clicked "library" is opening in TEXworks). The bibtex file (library) seems to be in the correct format i.e.  @report{refname, abstract = {}, author = {}, doi = {}, file = {}, issn = {}, journal = {}, keywords = {}, month = , number = {}, pages = {}, pmid = {}, title = {{}}, url = {}, volume = {}, year = {} }   Within Texmaker i have the generic Latex source saved as testdoc.tex  \documentclass[a4paper,12pt]{report} \begin{document} Blahblah \cite{refname} \bibliographystyle{plain} \bibliography{library} \end{document}   however within the PDF my citations do not appear to work and have the warning message   LaTeX Warning: Citation `refname' on page X undefined on input line XX. No file testdoc.bbl.


Does this probability paradox have a name?

I stumbled over a probability paradox on the internet:  If you choose an answer to this question at random, what is the chance that you will be correct? A) 25% B) 50% C) 60% D) 25%  Given that "at random" means choosing each option with equal probability, each option had a chance of 25% to be correct. But since there are 2 options with 25% as the solution, we get 50% of being correct. In this case, B) would be correct. But then again, the probability of choosing B) at random would be 25%. And so on. Does this paradox have a name? Is there something I can read on it?


For the TikZ grid command, I am wondering why the leftmost line is missing from the second grid that I am drawing below when I specify a step and do not start at (0,0).  \documentclass{article} \usepackage{tikz} \begin{document}  \begin{tikzpicture}   \draw[blue] (0,0) grid[step=5mm] (3,3);   \draw[red] (4,0) grid[step=5mm] (7,3);   \draw[green!50!black, xshift=8cm]  grid[step=5mm] (3,3); \end{tikzpicture}  \smallskip \begin{tikzpicture}   \draw[blue] (0,0) grid (3,3);   \draw[red] (4,0) grid (7,3);   \draw[green!50!black, xshift=8cm]  grid (3,3); \end{tikzpicture}  \end{document}


Can't read text in web forms since firefox uses dark theme by default

Since a couple of years, I have the dark desktop theme by default. Since I upgraded to Ubuntu Gnome 16.04 a week ago, firefox upgraded with it, and it now uses a dark theme as well. That's okay with me, except for the fact that a fair number of web forms now have become unreadable: the text is white, but the form fields are white as well, so you can't see what you're typing.  Workaround: select the text after you've typed it, then it becomes visible and you can inspect it.  Other workaround: type everything in gedit and copy-paste it from there.  Sure, there are workarounds, but this is very annoying. I like the dark theme so I prefer to keep using it, but for web forms it's just not a good idea.  Is it possible to keep the dark theme but fix its behavior in web forms such that they are always readable?


Is there a way to disable a non-dynamic class constructor?

Imagine a class which can be constructed only with the new operator. Is it possible to achieve this in the c++17 standard without deleting its destructor?  class Foo {     Foo(){}     ~Foo(){}     // delete non-dynamic constructor...? }  // ... Foo A; // compiling error Foo* B = new Foo(); // ok


Can i use grep to search words on the content that i already have in terminal

I am new here and in the Linux world. So i am wondering if it is possible to search for a word in the content that i already have in my terminal.  Thanks in advance


failed to get D-Bus connection: Operation not permitted

I'm trying to list services on my CentOS image running in Docker using  systemctl list-units     but I get this error message:  Failed to get D-Bus connection: Operation not permitted   Any suggestions what the problem might be?


Why aren't there any common words for 'defecating' and 'urinating'?

Besides 'poo(p)ing' and 'peeing/weeing' used by and to children,  besides 'shitting/crapping' and 'pissing' which are spoken, not polite, says the Longman Dictionary of Contemporary English,  besides 'defecating/excreting' and 'urinating/micturating' which are technical and formal,  besides a long list of euphemistic terms,  why aren't there any common/standard verbs for these actions?


I have two polygon layers, Land-use and Mesh.  I had this mesh layer in specific geometric way. Anyways, I want the mesh layer to have the landuse value of the maximum area it contains. Lets say that a polygon in the mesh contains three land use types (40% urban, 30% roads, 30% green areas). I want it to assign the value of urban because it has the biggest area.   I tried Spatial Join tool, but it did not give me what I was looking for. I used the (mode) as a Field Map of Join Features which should Use the value with the highest frequency but it did not work.


I recently rendered a project i was working on and found that the main object was missing in the final render. I checked older versions of the file and it was all the same. What could it be?  the render is on the right.  this is the most recent state. There are some pyramids on top. I wondered if it has something to do with textures i added, but i removed them and nothing changed.  this is an older version, before i tinkered with textures...


How to get/suppress french spacing before punctuation in `\href`

Attention I have already a possible answer and will add it soon. I thought it would be useful to have a solution about it on the site. (Other answers are naturally welcome too).  Question How to activate or suppress the french spacing before some punctuations like a colon in the text argument of \href locally (for one specific \href) and globally? Switching the language is not an answer!  Minimal examples for tests (the argument of \href should normally be a valid url, so it is a bit unfair to add an example without a colon in the link):  pdflatex  With pdflatex it depends on the link how the argument of \href is printed:  \documentclass{article} \usepackage[french]{babel}  \usepackage{hyperref}  \begin{document} With pdflatex no french spacing in links with colons:   \href{link}{a:b}  \href{link:colon}{a:b}  \end{document}     lualatex  With lualatex the spaces are always there:  \documentclass{article} \usepackage[french]{babel}  \usepackage{hyperref}  \begin{document} With lualatex always spaces:  \href{link}{a:b}  \href{link:colon}{a:b}  \end{document}


NullPointerException when I try to select a view

I'm very new to working with SQL stuff in Java, I'm trying to select a view I made in Oracle and print off it's contents, but I get a nullpointerexception  try {             conn = DriverManager.getConnection(dbURL, user, password);             conn.clearWarnings();             System.out.println("Connection opened! for driver ==>Oracle 11XE");             while (!option.equalsIgnoreCase("X"))             {                 System.out.print("What to do Q1 (1) Q2 (2) or (X) exit: ");                 option = s.nextLine();                 System.out.println("");                  if (option.equalsIgnoreCase("1"))                 {                     System.out.println("ID      Product Name          Price");                     System.out.println("==      ============          =====");                     ResultSet rs = stmt.executeQuery("select * from VQ1");                      while (rs.next()){                         System.out.println(rs.getString("PRODUCTID") + "     " + rs.getString("PRODUCTNAME") + "          " + rs.getString("UNITPRICE"));                     }                     rs.close();                 }             }   The exception occurs at ResultSet rs = stmt.executeQuery("select * from VQ1")   Like I said, I'm really new to working with this kinda stuff, so it could be something extremely small and simple.


ArcGIS crashes when trying category symbology?

I'm facing an issue with ArcGIS 10.3. When I try to use symbology type "category" the program crashes. It seems that is not a matter of data because I used the data before and nothing happened. The problem started yesterday after a windows 10 update so I consider something relate do this update (may 10).   I tried the complete uninstall and reinstall and didn't solve the problem.  I tried also save the MXD with another name in other location.   So my question is related to the possibility of a problem caused by an windows update.   Any ideas?


Time complexity for nested for different loop structures

I have a piece of code which executes three nested for loops in the following way (written as language agnostic as possible):  for i = 0 to n - 1     for j = 0 to n - 1         for k = 0 to n - 1             [do computation in linear time]   My intuition says that this should result in N^3 complexity. I'd like to compare its complexity to the following nested loops:  for i = 0 to n - 1     for j = i + 1 to n - 1         for k = j + 1 to n - 1             [do computation in linear time]   Logically, it should be faster, because as i increases, the inner loops should compute faster; however, having seen countless other threads on the site explaining that the latter of those is also N^3 is confusing.  Is my assumption of N^3 for both correct, and if so, how do I quantify the differences, assuming there are any?


mysql connect in PDO (xss and inject secure)

At the moment I'm using;       <form name="frmSearch" method="get" action="<?=$_SERVER['SCRIPT_NAME'];?>">

       Keyword         <input name="txtKeyword" type="text" id="txtKeyword" value="<?=$_GET["txtKeyword"];?>">         <input type="submit" value="Search">

 </form> <? if($_GET["txtKeyword"] != "")     {       $objConnect = mysql_connect("XXXXX","XXXX","XXXX") or die(mysql_error());     $objDB = mysql_select_db("XXXX");     // Search By Name or Email     $strSQL = "SELECT * FROM blogs WHERE (title LIKE '%".$_GET["txtKeyword"]."%' or metadescription LIKE '%".$_GET["txtKeyword"]."%')";     $objQuery = mysql_query($strSQL) or die ("Error Query [".$strSQL."]");     $Num_Rows = mysql_num_rows($objQuery);       $Per_Page = 2;   // Per Page      $Page = $_GET["Page"];     if(!$_GET["Page"])     {         $Page=1;     }      $Prev_Page = $Page-1;     $Next_Page = $Page+1;      $Page_Start = (($Per_Page*$Page)-$Per_Page);     if($Num_Rows<=$Per_Page)     {         $Num_Pages =1;     }     else if(($Num_Rows % $Per_Page)==0)     {         $Num_Pages =($Num_Rows/$Per_Page) ;     }     else     {         $Num_Pages =($Num_Rows/$Per_Page)+1;         $Num_Pages = (int)$Num_Pages;     }       $strSQL .=" order  by id ASC LIMIT $Page_Start , $Per_Page";     $objQuery  = mysql_query($strSQL);      ?>

CustomerID

Name

Email

   <?     while($objResult = mysql_fetch_array($objQuery))     {     ?>

         <?=$objResult["id"];?>
	     <?=$objResult["title"];?>	     <?=$objResult["metadescription"];?>
   <?     }     ?>

 Total <?= $Num_Rows;?> Record : <?=$Num_Pages;?> Page : <?     if($Prev_Page)     {         echo " << Back ";     }      for($i=1; $i<=$Num_Pages; $i++){         if($i != $Page)         {             echo "[ $i ]";         }         else         {             echo " $i ";         }     }     if($Page!=$Num_Pages)     {         echo " Next>> ";     }      mysql_close($objConnect);      }    ?>     This works fine but I'd like to make it more secure so it can withstand injection and xss attacks etc. Basically I need to make it 100% secure.  I'm trying to change it to PDO and I have got the following so far;  $stmt = $pdo->prepare('SELECT * FROM blogs WHERE title LIKE = ?'); $stmt->execute($_POST['txtKeyword']);   Which I think is correct and as its two separate interactions with the DB it should be secure from injections (i think?)  problem is; 1) I'm not sure how to implement this and 2) what else is needed to make sure the search is secure   I'd really appreciate any help


I am about to submit a paper in which I present a new algorithm. There are many algorithms that are named after the author in my field, but I am not sure whether the authors themselves named those after themselves, or whether others named those algorithms after the authors post-pbulication (so in other papers). Is it appropriate to name the algorithm after myself?


Choose the word or set of words that, when inserted in the sentence, best fits the meaning of the sentence as a whole      It was advised that ____ inside until the storm passed our area.      1) we are staying        2) we stay      3) we may      4) we stayed   I believe that the answer is 2. But, I also think 4 is equally correct because I know most subjunctive structures can be replaced by "should + infinitive" or ordinary present and past tenses. Am I right?


Find the number of vertices that belong to all the maximum matchings of a general connected graph

The given graph is connected but not necessarily bipartite. Please describe the complete approach with useful links , I read stuff related to augmenting paths but could not comprehend well. An O(VE) approach will be good for me . Though i would prefer O(V^2) approach (if it is known)


how to make footer stay at the end of scroll

I have html      <head>      </head>       <body>       </body>       <footer>        </footer>   now what I want is the footer stay at the very end of the page and the user should scroll to see it. would you help me please?  I tried :  footer{     position: fixed;     bottom:-100px;     height: 100px;     left: 0;     width:100%;     text-align: center; }   but setting height:100px and bottom:-100px get it hidden while I want the user to be able to scroll down to see it


I'd like to know if someone has a better word than , for both creating and updating something.  Context: I'm a software developer and I'm trying to think of a clever way to name the function that will initially create an object, and if it's already created, update it.


Other than having the Haste spell cast on you and using the action provided to use something that requires a bonus action are there any other ways to gain additional bonus actions in 5e?


Is it possible with JDeveloper to debug an executing JAR file on my PC?

I have a JAR file that is executed with "javaw ..." and it works fine.  Is there a way with JDeveloper, or any other tool, to debug that executing file? The answers found on this board focus on Eclipse whcih I do not have.


What happens if the explanatory and response variables are sorted independently before regression?

Suppose we have data set $(X_i,Y_i)$ with $n$ points. We want to perform a linear regression, but first we sort the $X_i$ values and the $Y_i$ values independently of each other, forming data set $(X_i,Y_j)$. Is there any meaningful interpretation of the regression on the new data set? Does this have a name?  I imagine this is a silly question so I apologize, I'm not formally trained in statistics. In my mind this completely destroys our data and the regression is meaningless. But my manager says he gets "better regressions most of the time" when he does this (here "better" means more predictive). I have a feeling he is deceiving himself.  EDIT: Thank you for all of your nice and patient examples. I showed him the examples by @RUser4512 and @gung and he remains staunch. He's becoming irritated and I'm becoming exhausted. I feel crestfallen. I will probably begin looking for other jobs soon.


In what kind of system, relativistic effect is non-negligible?

For electron with large kinetic energy, one needs to introduce Dirac equation for relativistic correction. In what type of systems these relativistic effects is non-negligible?


If Z|Y ~ Bin(p, y) and Y ~ Poisson(L) then Z ~ Poisson(p*L)?

I checked whether this question was answered before but because of notation, it's hard to see. I am a reading a paper that defines the following two RVs $$ z \mid y \sim Binomial(\pi, y) \\ y \sim Poisson(\lambda) $$ then concludes (by integration and Bayes Rule) that $$  z \sim Poisson(\pi \cdot \lambda) \\ y - z \sim Poisson( (1 - \pi)\cdot \lambda) $$ I tried working it out on paper but since I am not a trained statistician, I am not sure where I am going wrong. If I want to derive $z \sim Poisson(\pi\lambda)$, then I use the conditional probability i.e. $$ p(z) = \int_y p(z, y) \,\, dy $$ where $p(z, y)$ is the joint probability. Expanding this out, I have $$p(z) = \int_y {y\choose z} \pi^z (1 - \pi)^{(y - z)} \frac{e^\lambda \lambda^y}{y!} \, \, dy $$ but I am guessing I have to get to the following equation somehow $$p(z) = \frac{e^{\pi\lambda} (\pi\lambda)^{z}}{z!}$$ but I was not able to manipulate the integral above to get this form. Not sure if that's even possible.


Is there a way to automatically split the output into different PDF files?  The reason is that I want to generate a document "paper.pdf" and a different document "supplementarymaterial.pdf", with shared macros, cross references, and even having some theorems from "paper.pdf" restated (using the restatable package) in the supplementarymaterial.pdf file.  The other immediate option (using different source files) has these pros/cons:   shared macros is easy (common \input file with macro definitions) cross references is a pain (xr package, never used it) restating theorems across different source files seems impossible   Basically I am looking for a latex-native alternative to Acrobat->Tools->split document (or wherever that option is)


Why does Hume raise the Missing Shade of Blue?

From reading this  on Hume, having read the first seven sections of the Enquiry Concerning Human Understanding (which covers the relevant section), a further question hit me. Hume dismisses the occurrence as "singular ... scarcely worth our observing", yet he brings the counter example up instead of others. Why does he bring up a counterexample which he himself dismisses as trivial? Is it to bolster his argument by suggesting that the only counterexample so important as to be worth mentioned is itself highly trivial? Or is it merely because its the only concrete, simple counterexample Hume conceived of? Responses with links to Hume scholars would be appreciated.


I have a LINUX machine (remote), and a MAC machine (local). Our system administrator set up an "SSH" method, whereby I can ssh from my MAC, to my LINUX machine, via this command on my MAC:  ssh marcus@gateway.highlabs.co -p 12345   When I do this, I am prompted to put in the password for my LINUX machine, and when I do, I have access, which is great.   What I want to do now though, is be able to scp from my MAC machine, to my LINUX machine, so that I can transfer files over. How do I do that? I have googled around but I am not sure what to do.   Thank you


What does "@" signify in unix file permissions?

I have a file with the following permissions on my MacBook Pro:  -rwxr-xr-x@  1 root  wheel   101K Feb 29 17:09 apachectl  What does the @ stand for?  I can't execute the file and this is the only thing that's standing out to me.  How can I get rid of it?    Just as some background, I copied this from a Time Machine backup.


Yeah, simple as that.  Why do most of the people use a plane which emits light (in most cases) and not a lamp? What's the difference between them? When do I use a lamp and when the emission node?  Thanks in advance.


Given a space $X$, the topological cone $CX$ is defined as the quotient $X\times I/(X\times \{1\})$.  If $X$ is a subset of $\mathbb R^n$, choose a point in $\mathbb R^{n+1}$ that does not lie in $\mathbb R^n$. The geometrical cone $aX$ is defined as $\{ta+(1-t)x|x\in X, t\in I\}$ equipped with subspace topology.     Proposition: If $X\subset \mathbb R^n$ is compact, then $CX$ is homeomorphic to $aX$.   Question: I wonder if it is possible to drop the assumption that $X$ is compact.  My teacher guessed that the conclusion remains to be true if $X$ is merely bounded, but didn’t provide any proof or counterexample.


Cognito Form disabled due to suspicious content

This appears:     Our apologies, this form has been disabled due to suspicious content. If you believe you have received this message in error, please contact the original form author.     How can I make my form code work?


Can Windows use headsets that have a single audio jack with 4 rings?

As you guys may know, for several years now, Apple uses 4-ring headphone jacks instead of 3-ring headphone jacks, and the fourth ring is dedicated to microphone input. This is what lets you have headphones that also serve as a microphone on the iPhone (and probably most competing phones nowadays, too).    Also for several years now, these jacks have been recognized by MacBook Pros so that you can connect this kind of headset on your computer and use its microphone.  However, even though my MacBook Pro on Mac OS X recognizes the microphone built into my headset (that has one of those 4-ring jacks), it seems that Windows 8.1 on Boot Camp doesn't register my headset as a microphone and instead insists on using only the built-in microphone. This is an issue when I'm playing games because the fan kicks in and annoys everyone voice chatting with me.  Is there a way to make Windows aware of the microphone integrated to my headset and using the fourth ring of the jack?  The device manager says that the headset is advertised by the 'Cirrus Logic CS4206A (AB 11)' audio controller.


Null Pointer Exception Java GUI Application SQL Query

I am trying to run a simple sql query but am getting a Null pointer exception. I tried to change everything possible but could not figure out the reason for this exception.  My part of code :  String sql = "Insert into CG (Date,Day,Pre,Sub) values (?,?,?,?)";         try{         pst = conn.prepareStatement(sql);         pst.setString(1, "date");//4 value taken as input         pst.setString(2, "day");         pst.setString(3, "1");         pst.setString(4, "0");         pst.execute();     }catch (Exception ex) {         JOptionPane.showMessageDialog(null, ex);     }   Edit : I am getting NPE at line pst = conn.prepareStatement(sql)         My connection is : Connection conn = DriverManager.getConnection("jdbc:sqlite:E:\\NetBeansProject\\At\\At.sqlite");


How can I change the encoding of a subtitle file?

I have a subtitle .srt file. Is there an app which can change the encoding of this file. (I guess it's encoding is Arabic(windows-1256) but vlc and MXPlayer didn't open it.) The link of subtitle is .


How can I tell which app is trying to access my thumb drive? It is locked and an Access is Denied error is being displayed multiple times

How can I tell which application is trying to access my thumb drive? The drive happens to be locked and an Access is Denied notification keeps popping up again and again. The PC has Windows 10 Pro installed on it.


Blender 2.8 - Sprinkles particle are not visible when rendered

I just started learning Blender, so I'm following the donuts tutorial from Blender Guru. Unfortunately, I'm stuck at part 7 on rendering Sprinkles.  My problem is, the Sprinkles is visible in my viewport :    However, when I render it, the sprinkles are gone :    My Blender file can be downloaded .  Any help is appreciated. Thank you.


Finding descendants and potential relatives of immigrant to USA from Spain through Cuba?

I am trying to find an almost certainly dead relative that emigrated from Spain to Cuba before finally moving to USA.  I have in my hands the complete name with Spanish conventions (name + 2 surnames) and will have the birth date in Spain (around 1920s).  I have a parallel investigation to get information about the emigration to Cuba and later on to USA.  What I am trying to do is to find details about this person, specially descendents and potential relatives. How can I achieve this without direct contact with the person?


How to highlight few sentences in a paragraph?

I would like to get a simple result, as the following    Is it possible?


Let $X$ and $Y$ be sets with $n$ and $m$ elements, respectively. Prove that if $X\cap Y=\emptyset$, then $X\cup Y$ has $n+m$ elements.  It's clear to me intuitively how this is true. I understand that if two sets have no elements in common, then there is no 'repetition' in the union and the number of elements of the union is the sum of the number of elements in each set. How could I formalize this? Is there a way to do it by induction? I am not sure.


A proverb that means "using big measures/actions for small things"

In Vietnamese we have a proverb that would translate as "you dont kill a chicken with a blade that you would use to hack a buffalo".  It's been in my mind for some work-related stuff and i cant think of an equivalent proverb or phrase in English. Any idea? Thanks!


Is there any proof that Euclid's fifth postulate cannot be proven?

I've read many times that a plethora of people have tried to prove Euclid's parallel postulate but to no avail. However, I do not know of any proof of how it cannot be proven. Is it because modifying it leads to different and consistent geometries and you can just state such a thing? How do you know your geometry is consistent?


Recursive bash script to collect information about each file in a directory structure

How do I work recursively through a directory tree and execute a specific command on each file, and output the path, filename, extension, filesize and some other specific text to a single file in bash.


"Exception in thread "main" java.lang.NullPointerException" - CSV to Arff

I'm trying to convert a CSV file to Arff format following this guide. (link below)  This is for practice purposes, I just want to know how to convert this properly before building a bigger dataset.   CSV file  Name,points,rebounds,steals,assists Lebron James,17,10,1,7 Lebron James,29,5,2,8 Lebron James,30,4,0,8 Lebron James,24,4,1,3 Lebron James,25,1,0,11 Lebron James,22,4,2,9 Lebron James,21,3,2,2 Lebron James,27,7,1,14 Lebron James,41,5,0,5 Lebron James,35,2,2,2 Lebron James,18,4,3,4   Java file - Working off this site tutorial   import weka.core.Instances; import weka.core.converters.CSVLoader; import weka.core.converters.ArffSaver;  import java.io.File;  public class arffBBALL{     public static void main(String[] args) throws Exception{            //load CSV         CSVLoader loader = new CSVLoader();         loader.setSource(new File("Users/myname/Desktop/bball.csv"));         Instances data = loader.getDataSet();           //save ARFF         ArffSaver saver = new ArffSaver();         saver.setInstances(data); // set the dataset we want to convert         // save as ARFF         saver.setFile(new File("Users/myname/Desktop/nbball.arff"));         saver.writeBatch();     } }   This is the error I'm getting in Java  Exception in thread "main" java.lang.NullPointerException     at java.io.StreamTokenizer.<init>(StreamTokenizer.java:248)     at weka.core.converters.CSVLoader.getStructure(CSVLoader.java:593)     at weka.core.converters.CSVLoader.getDataSet(CSVLoader.java:628)     at arffBBALL.main(arffBBALL.java:15)   I loaded the Weka.jar file into the referenced Library, but I can't seem to convert the CSV file to arff.  I have the CSV file on my Desktop on my Mac.    Any help would be appreciated.  Thanks  EDIT:  Latest errors after adding absolute path:  ---Registering Weka Editors--- Trying to add database driver (JDBC): jdbc.idbDriver - Error, not in CLASSPATH? Exception in thread "main" java.io.IOException: wrong number of values. Read 2, expected 1, read Token[EOL], line 4     at weka.core.converters.ConverterUtils.errms(ConverterUtils.java:912)     at weka.core.converters.CSVLoader.getInstance(CSVLoader.java:824)     at weka.core.converters.CSVLoader.getDataSet(CSVLoader.java:646)     at arffBBALL.main(arffBBALL.java:15)


I have a math formula, having three underbraces, enclosing three expressions, with explanations below each brace, explaining what that quantity is. Since these expressions, as well as their explanations, have different widths and heights, LaTeX automatically adjusts the math font sizes. I want to prevent this so that the expressions above each brace have the same size, regardless of how big the brace is extended.  How can I ensure a consistent math font size in a formula?  \documentclass{standalone}  \usepackage{tikz,amsmath} \usetikzlibrary{positioning}   \begin{document}  \begin{tikzpicture}[>=stealth]   \node (a) at (0,0) {$\frac{\partial y}{\partial t}=\underbrace{\frac{AAA}{BB}}_{ Text 1}+ \underbrace{YYY}_{Text 2}+\underbrace{ZZZ}_{Text 3}$ };   \end{tikzpicture}  \end{document}


java.lang.NullPointerException..for JDBC SQLite connection

Using JDBC for a local sqlite database. Everytime I click login i get the java.lang.NullPointerException.   Things I have tried :  1.Verified the path to the database. (As the connection sucessfull window pops after running)  2.Verified the table name as well.  3.Tried moving the Database and updating the path.  4.Tried other method as well e.g(username='"+username.getText()"')  The Login code:  import java.net.URL; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.util.ResourceBundle; import javafx.event.ActionEvent; import javafx.fxml.FXML; import javafx.fxml.Initializable; import javafx.scene.control.Button; import javafx.scene.control.Hyperlink; import javafx.scene.control.Label; import javafx.scene.control.PasswordField; import javafx.scene.control.TextField; import javafx.scene.text.Text; import javafx.stage.Stage; import javax.swing.JOptionPane;   public class FXMLDocumentController implements Initializable { Connection connection=null; @FXML private Label label;  @FXML private TextField username;  @FXML private PasswordField password; @FXML private Button login; @FXML private Button signup;  @FXML private Button close;    public FXMLDocumentController() {      connection=SQLconnection.dbConnector(); } public void close(ActionEvent event) {    System.exit(0); } public void login(ActionEvent event) {      try     {          String query="select * from user where username=? and password=?";         PreparedStatement pst=connection.prepareStatement(query);         String uname=username.getText();         String pass=password.getText();         pst.setString(1, uname);         pst.setString(2, pass);            ResultSet rs=pst.executeQuery();         int count=0;         while(rs.next())         {             count++;         }         if(count==1)         {             System.out.print("Username password correct");         }         else         {             JOptionPane.showMessageDialog(null, "Incorrect Username and              password");         }         rs.close();         pst.close();     }     catch(Exception e)     {         JOptionPane.showMessageDialog(null, e);     }   }  @Override public void initialize(URL url, ResourceBundle rb) {     // TODO }      }   The Connection :  import java.sql.*; import javax.swing.*; public class SQLconnection {   Connection conn=null; public static Connection dbConnector() {   try   {       Class.forName("org.sqlite.JDBC");       Connection conn=DriverManager.getConnection("jdbc:sqlite:C:\\Users\\Pushkar\\Documents\\NetBeansProjects\\Traveler\\traveler.db");       JOptionPane.showMessageDialog(null, "Connection Sucessfull");       return conn;   }catch(Exception e)   {       JOptionPane.showMessageDialog(null, e);       return null;   } } }   Here is a screenshot :


How do you have your group meet, besides the age old, tried and true method of, "You all meet in a tavern"?


How to mark a package to prevent from being installed

I've detected some packages that breaks my configuration (like light-locker, evince, etc...)   How can I prevent these packages to be able to install via apt-get install in my system (Debian) with the provided error reason?


How to determine which .bash_profile .profile .bashrc .zshrc to use?

I've been creating a project for managing my complete terminal environment. One of the things I manage are the dotFiles. So I have separate dotfiles for e.g.   ivonet-alias.sh ivonet-docker.sh ivonet-functions.sh etc.   When I run setup.sh from my project I install symlinks (ln) to my ivonet-*.sh files in my HOME folder. Now to activate them I do the following (once):  prefix="ivonet" resource="${HOME}/.zshrc" echo "" >>${resource} echo "# Personal dotFile resources:" >>${resource} echo "for f in \${HOME}/.${prefix}-*.sh; do source \${f}; done" >>${resource}   On my own machine I use oh-my-zsh shell and I make it so that that file is changed so that when I open a new terminal session all my dotfiles are sourced in. This works fine but now a couple of colleagues asked to use my setup for dotfiles too and I gave them my repo and it didn't work as I had hoped. The were not using zsh but bash, but even that was not uniform.  When I changed the setup to write to .bashrc it worked for one colleague but not for the other. So in the end I had to do it multiple ways.    once in .profile twice in .bash_profile once in .bashrc   Can anyone help me on how I can determine where to make the changes?  I would like to be able to check this from a script something like:  check=$(which bash) if [[ -z "${check}" ]]; then    #do stuff here fi   but I have no idea how to do this. I know it looks like this  but I'm more interested on how I can automatically determine which file is loaded.


Could you help me solve this: For projective coordinate system on the line $l$ are given points $A (2,1)$, $B (1,1)$, $C (0,1)$, $A_1 (0,1)$, $B_1 (1,5)$ and $C_1 (2,1 )$. Find a linear transformation where the points $A, B$ and $C$ go respectively at  $A_1$, $B_1$, and $C_1$.  I tryed to solve it but I dont know what to do.  Here is what I tryed:  \begin{equation} ρ_1 * \begin{pmatrix}0 \\ 1 \\ \end{pmatrix} = \begin{pmatrix}m & n \\ p & q \\ \end{pmatrix}* \begin{pmatrix} 2 \\ 1 \\ \end{pmatrix} \end{equation} \begin{equation} ρ_2 * \begin{pmatrix}1 \\ 5 \\ \end{pmatrix} = \begin{pmatrix}m & n \\ p & q \\ \end{pmatrix}* \begin{pmatrix} 1 \\ 1 \\ \end{pmatrix} \end{equation} \begin{equation} ρ_3 * \begin{pmatrix}2 \\ 1 \\ \end{pmatrix} = \begin{pmatrix}m & n \\ p & q \\ \end{pmatrix}* \begin{pmatrix} 0 \\ 1 \\ \end{pmatrix} \end{equation}  2m + n = 0 2p + q = $ρ_1$  m + n = $ρ_2$ p + q = 5*$ρ_2$  n = 2*$ρ_3$ q = $ρ_3$  Is that the right way ? I got some equations for m, n, p, q but I dont think they are right. What should I do now ?


As you can see in the picture in the camera the red bordered rectangle is what the camera sees. How can I zoom in to this rectangle without changing the camera viewport/settings.


How to solve this : $ \prod^{\infty}_{n=2}(1-\frac{1}{n^2}) $

How to  solve this :   $$ \prod^{\infty}_{n=2}(1-\frac{1}{n^2}) $$  We  can write it as follows :   $$ \prod^{\infty}_{n=2}\frac{(n-1)(n+1)}{n^2} $$  How can we proceed further please guide.. thanks..


In WoT 13, Towers of Midnight, Tam is with Perrin and Rand at the same time. He goes to Rand, talks with him. At the same time, it is told him speaking with Perrin and crew. No mention of him being taken from Perrin's side by Aes Sedai. Because then Perrin would know all about what was happening in Tear from the Aes Sedai. No mention of Tam coming back either. It says Rand sent Tam back to Two Rivers.  How was Tam in both places at the same time?


Caller property of JS for "foo = function()" style of coding

I want to use the property of "caller" for a function which is defined   It works fine for this style of function declaration      function g() {       alert(g.caller.name) // f }     function f() {       alert(f.caller.name) // undefined       g() }  f()     But then my function declaration is something like       g = function() {       alert(g.caller.name) // expected f, getting undefined     }      f = function() {      alert("calling f")      alert(f.caller.name) // undefined      g()    }   f()   and I am getting undefined (basically not getting anything)     Is there any way that I can use the caller property without having to rewrite my code? Also, I hope I have not made any mistakes in usage and function declaration since I am quite new to using JS.


Is there any way in the code below to replace (Color) to standard Color. (with dot) in getting a color from UserData?   This line  rect.setFill((Color) group.getSelectedToggle().getUserData()   Wider code fragment based on Oracle doc about ToggleButton   tb1.setUserData(Color.LIGHTGREEN); tb2.setUserData(Color.LIGHTBLUE); tb3.setUserData(Color.SALMON);  final Rectangle rect = new Rectangle(145, 50);  final ToggleGroup group = new ToggleGroup(); group.selectedToggleProperty().addListener(new ChangeListener<Toggle>(){      public void changed(ObservableValue<? extends Toggle> ov,         Toggle toggle, Toggle new_toggle) {             if (new_toggle == null)                 rect.setFill(Color.WHITE);             else                 rect.setFill(                     (Color) group.getSelectedToggle().getUserData()                 );          }     });


If an allrounder takes highest wickets and scores highest runs then which cap he will be awarded with?

In IPL, Orange and Purple caps are awarded to the highest run scorer and highest wicket taker.  My question is, if an all-rounder takes highest wickets and scores highest runs then which cap he will be awarded with?


Complete first order theory with finite model is categorical

I am trying to prove that if $T$ is a complete first order theory that has a finite model then it has exactly one model up to isomorphism. To this end, I assumed that $T$ is complete with a finite model $M_n$. Then I assumed that $M_m$ was another model of size $m \geq n$. We know that if a theory has two finite models with different cardinalities then the theory is incomplete hence $m = n$. Now two things remain to be shown: one is that any two models of finite size $n$ are isomorphic and the other is that every infinite model is also isomorphic to this finite model (is this even possible? but we clearly need to do something about the infinite case)  Thanks for helping me finish this proof. For the record: this is an exercise in Just/Weese, page 84.  Edit  I'm looking for a sentence $\varphi$ such that if $M_n \models \varphi$ then $M_n \cong M_m$. There are no assumptions on the language. But I think it's not possible to have a finite model for an infinite language so the language must be finite.   Edit 2  After some more thinking, if there is a finite model $M$ of size $n$, let $$ \varphi = \exists v_1, \dots , v_n ((v_1 \neq v_2) \land \dots \land (v_{n-1} \neq v_n)) \land \lnot \exists v_{n+1} ((v_{n+1} \neq v_1) \land \dots \land (v_{n+1} \neq v_n))$$ that is, $\varphi$ says that the model has exactly $n$ elements. Since $T$ is complete, either $\varphi$ or $\lnot \varphi$ is provable from $T$. Since we have a model in which $\varphi$ is true we therefore know that $T \vdash \varphi$. Hence any model of $T$ must have exactly $n$ elements.   Now the question is, how do I show that any two $n$-element models of $T$ must be isomorphic?


I can't make symbols with Ctrl+Alt+(key) and my keyboard doesn't have an Alt Gr key – what do I do?

I'm on a laptop with a bluetooth keyboard connected. When I changed from Windows 7 to Xubuntu 14.04 (now using KDE 4 with it) I could no more use Ctrl+Alt+(key) to make symbols as  @£$½¥{[]}   I instead have to use Alt Gr+(key) to make them, which becomes irritating because my bluetooth keyboard has NO Alt Gr key.  How can I do so Ctrl+Alt acts the same as Alt Gr?  I am using the danish keyboard (default) layout on a German keyboard.


Repeated elements following an “and”: Use ’em or Lose ’em?

Here is a sentence:     You have to be nice to alleviate the social anxiety and start a healthy relationship.   Should it be like that or like this:     You have to be nice to alleviate the social anxiety and to start a healthy relationship."   The first does not have a to, but the second does.  Which should I use, and why?  Or doesn’t it matter?


Google Chrome: Remove all 'Other Search Engines'

Google Chrome saves lots of Other Search Engines from websites I visit, under Settings > Search; Manage search engines. I believe this is called ‘OpenSearch’.  Clicking the remove icon ❌ on each one would be very cumbersome.  Is there a way to delete all of them, without having to do it manually?     NB: This  supposedly prevents Chrome from adding custom search engines.


Is there a site that covers questions about developer behavior?

I recently found an article about a kind of 'sickness' under   developers that they don't Google before they ask a question but just   ask the question without trying to do research. I'm in a Facebook   group about PHP and 9/10 of all the questions could've been solved by   just searching on Google.      Anyway, I was saying that he should Google it first and then he said   that 'I should chill'. So now I want him to read the article but I   can't find it anymore.      Does anybody know which article I'm talking about?   Where should I post this question?


How can I obtain a command block without using any minecraft plugins? I want to do this on a vanilla server and I'm not too sure how.


Which graphics formats can be included in documents processed by latex or pdflatex?

There several types of graphics files. In no particular order .jpeg .eps .pdf .png .tif .jif (and no doubt others). Some work with latex, dvips and some work with pdflatex. How am I supposed to know which?  Just to confuse matters, metapost produces .eps but I can use these with pdflatex as long as I put in a four line incantation.  Can anyone explain this?


I've been using this pan for a while, and have somehow scorched the bottom of the pan. Can someone tell me how I should clean it? Thanks!


How much more RAM can I add to my Mid 2007 24" iMac?

I have a "vintage" iMac with the spec below:    This is going to sound like a real beginners question but can I up the RAM anymore? At the time, I upped it to as far as I could but could I put say 2 4gb RAM in?


My desktop has a fast wired connection and I would like to set up a sort of "wifi hotspot" that allows mobile devices to connect to my pc and share this fast connection. How would I go about doing this?


How is reflection of light possible at all?

If a photon cannot be accelerated or decelerated, how is reflecting them possible at all?


Why is my USB Flash Drive Now Read-Only?

Suddenly my USB Flash Drive (8gb Corsaire Voyager) is suddenly read-only, and I'm not sure why.    There is no "read-only" switch on the drive. All of the data is still there. But nothing can be written to it anymore. There are 2gb free on the drive. The OS is Windows7 Pro x64. It wasn't this way yesterday.  In FreeCommander, if I try to create a new folder on the drive, it tells me the drive is write-protected.  I plugged it into a different computer and it is read-only there, too.  What could cause that, and how can I get it back to read/write mode like it ought to be? I know I can fix it by reformatting it, but I don't want to do it that way.  I have found several solutions to do this, but haven't solved it yet:   Safely Eject Flash Drive  Make a registry edit (the key doesn't exist, however)  Add the registry key (that didn't exist) and set the value to 0 (HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\StorageDevicePolicies set WriteProtect to 0) Reassign the drive letter "Scan and Fix" (check disk dialogue appears when you plug it in) - write-protection prevents this, however.


Is my StackExchange-Description written correctly?

This is my profile-description of the StackExchange-Site:     "Dösbaddel" is a (North-)German word for "Dummkopf" which probably means "fool" in English.   Is it written properly or do I need to insert a comma right after "Dummkopf"?     "Dösbaddel" is a (North-)German word for "Dummkopf", which probably means "fool" in English.   If you find more things one could/should change, I would be glad if you would inform me about that.


Removing Array Records with Repeated Value

Within an array, how can I remove records with a repeated value? For example, I have:  container_array (     [0] => sub_array         (             [order_id] => 14539972             [name] => Desiree         )      [1] => sub_array         (             [order_id] => 14570621             [name] => Jana         )      [2] => sub_array         (             [order_id] => 14574112             [name] => Debra         )      [3] => sub_array         (             [order_id] => 14570621             [name] => Jana         )      [4] => sub_array         (             [order_id] => 14570621             [name] => Jana         ) )   Order ID 14570621 is repeated multiple times. How can I remove the duplicates so that only one remains? The resulting array should be:  container_array (     [0] => sub_array         (             [order_id] => 14539972             [name] => Desiree         )      [1] => sub_array         (             [order_id] => 14570621             [name] => Jana         )      [2] => sub_array         (             [order_id] => 14574112             [name] => Debra         ) )


the type of movement in electron jump between levels?

what's the type of movement when the electron jump from level to another when gaining or losing a quantum of energy is it actually jump or move in a specific movement?


Is there any way to run a RoR app as a 'portbale app'?   For instance, can you put an app including the ruby on rails stack, web server et all, on a stick and then just run it on a windows machine? Without installing?  There was project called Instant Rails that provided this more or less, but it's not maintained. (http://rubyforge.org/projects/instantrails/)  Also, there is RubyStack from Bitnami (http://bitnami.org/stack/rubystack#nativeInstaller) but it needs to be installed (I can go with that, but rather not).  So, the question is, can Ruby on Rails, including a specific app, be made to run on any computer (well, let's start with Win) from a stick, CD or DVD, without having to install anything first?


What's the fastest way to find mineshafts?

, and one place I'm fairly sure I can find them is a mineshaft.  Which leaves me back at square one, how do I find a mine shaft?  It seems they were made substantially harder to find between 1.8 and 1.0.  What's the fastest way to find a mineshaft?


$A, B, C, D$ are sets, where $A \not = \emptyset$ and $B \not = \emptyset$. Equation $(A \times B) \cup (B \times A) = C \times D$ is true.  Prove that $A = B = C = D$.  I tried to find $A, B, C, D$ separately, but that didn't get me anywhere. Any ideas how to solve it?


How do I upgrade from 17.04 to 18.04 using intel processor

I have ubuntu 17.04 running on my Lenovo desktop with an Intel processor. My attempts to update to a newer version have all failed to load current registry. I have not used this software in a few years, and want to refamiliarize myself with ubuntu.


I need some help with understanding damage types and damage added to damage dice

I’m super new to DnD and I was hoping to get some clarification on a few things.  My character has a long bow and a short sword. For the longbow it has an ATK bonus of +5 and damage/type of 1d8 +3 piercing... my question is how do I calculate that? Do I role the d8 then add +5 and +3? Or what do?


Participate in Meta privilege on Meta S.E

The privileges page for Meta.Stackexchange.com (MSE) lists "Participate In Meta" as a privilege. I think that it should be removed as a privilege on MSE (unless we get a meta.meta.stackexchange.com per site child meta, which would be awesome ;-).


I have two website. first one is in wordpress and second one is in corephp. My Question is that i am connection database by $wpdb.  /* Core php database */  $newwpdb = new wpdb( 'username', 'password', 'database', 'localhost' );  Database connection is done. Now i am fetching some data using second database. After fetching i want to close the connection of core php database.  I have checked but not found any solution of it.    So anybody knows than please help me for solution.  Thanking in advance


Proof that a strictly diagonally dominant matrix is invertible

Let $A$ be a strictly diagonally dominant matrix of dimensions $n \times n$. ("Strictly diagonally dominant" means that $\left|a_{i,i}\right| > \sum\limits_{j \neq i} \left|a_{i,j}\right|$ for all $i \in \left\{1,2,\ldots,n\right\}$, where $a_{u,v}$ denotes the $\left(u,v\right)$-th entry of $A$.) Prove that $A$ is invertible.  My attempt builds on the proof of Gershgorin's circle theorem, given in the Wikipedia article  Let $\lambda$ be an eigenvalue of $A$, and scale its corresponding eigenvector $x$ so that $x_{i} = 1$ and $|x_{j}| \leq 1$ for $j \neq i$ Then $Ax = \lambda x$, and in particular $\sum_{i\neq j}a_{i,j}x_{j} = \lambda - a_{ii}$ (1) Now because $A$ is strictly diagonally dominant it holds for every $i$ that, $\sum_{j \neq i}|a_{i,j}| < |a_{i,i}|$ and since $|x_{i}| \leq 1$ the following should hold: $\sum_{i\neq j}|a_{i,j}x_{j}| \leq \sum_{j \neq i}|a_{i,j}| < |a_{i,i}|$ But here I get stuck, feel like I want to use (1) in some way to complete the proof and put $\lambda = 0$ to get a contradiction, thus proving that if $A$ is strictly diagonally dominant, it has non-zero eigenvalues which should imply invertibility.. Am I in the right direction?


"bibs and bobs" - what does it mean and where does it come from?

Just exactly what is a bibs and a bobs? And where the heck did that expression come from, anyway?


Possible Duplicate:          What will be the answer if zero$(0)$ divided by zero$(0)$ Why It is un answerable?   $$\frac 00=\space ?$$ Thanks in Advance, Vicky


Let $A$ be an n×n matrix with eigenvalues $\lambda_i, i=1,2,\dots,n$. Then $\lambda_1^k,\dots,\lambda_n^k$ are eigenvalues of $A^k$.   I was wondering if $\lambda_1^k,\dots,\lambda_n^k$ are all the eigenvalues of $A^k$? Are the algebraic and geometric multiplicities of $\lambda_i^k$ for $A^k$ same as those of $\lambda_i$ for $A$ respectively?   Thanks!


Is there a better alternative to ambiguous for a word with a wide range of meanings, difficult to find, because they become different in connection with person's opinion.


Fitting exponential (regression) model by MLE?

Let's say I have an outcome that is exponentially distributed, so $p(y|\lambda_i) = \lambda_i e^{-\lambda_i y}$. However, we also know that $\log{\lambda_i} = \beta_0+\beta_1x_i$. If we want to estimate the MLE's for $\beta_0$ and $\beta_1$, what's the best way to do it given data?  I was thinking of using the following code:  summary(glm(y~x,family=Gamma(link="log")))   Not 100% sure what the various arguments are going though.


Outside of Order 66, does a blaster ever beat a lightsaber?

There is a scene in The Clone Wars where Ahsoka is in the middle of hallway, deflecting blaster fire from two directions while carrying on a conversation (, I think) and it got me wondering... In the original trilogy, lightsabers are mostly used for dueling - but we see Luke successfully ward off blaster fire with 100% success (amended: see ... nearly 100%).  He never gets hit. In The Clone Wars, there are many examples like Ahsoka's where the Jedi are defending against an amazing amount of blaster fire.  Often from multiple angles.  Usually while talking. But in the prequels, we see the defense effective - with the notable exception being when Sidious starts speed dialing Clone Troopers to murder Jedi:                                Even then:  Master Mundi is clearly shocked at the betrayal and not defending himself fully Secura is shot in the back while she is unarmed.  Repeatedly. Plo Koon is shot down while in a Starfighter A Jedi is killed by speeder bike cannon fire (no lightsaber involved)  Obi Wan and Yoda make dramatic escapes.  We basically see one lone nameless Jedi get gunned down in what looks like a fair fight.  While conjecture might assume there were many more... what we see onscreen is that the best chance you have to beat a Jedi that is ready and armed with a lightsaber is to bring a cannon. Are there other notable times when a blaster beats a lightsaber?


Just starting out, wondering exactly what the darker shading means:   Is it simply shadowing based on the current dimensions?  Is it also an indicator that front and side rigging are somehow not correspondent with each other?   Thanks a bunch.


Android setTime() throwing NullPointer Exception

I'm trying to set a Date (highestNumber) with a long (highest) but it throws a NullPointer exception, I can't figure out why.  public static Date highestNumber = null;  long highest = 0;     for (int x = 0;x <numberofData - 2;x++){         long first = Array.Stop.get(x).getTime();         long next = Array.Stop.get(x+1).getTime();         if(x==0){highest = first;}         if (highest < next){             highest = next;         }     }     highestNumber.setTime(highest);   Exception is being thrown on the setTime() line. highest gets a valid value of 1523328768914   Error: java.lang.NullPointerException: Attempt to invoke virtual method 'void java.util.Date.setTime(long)' on a null object reference  Edit: I don't feel like this is a duplicate of "What is a nullpointerexception since i didn't realise a Date had to be initiaized. I thought it was just a variable like a string.


How can we remove the "Not a real question" close reason from SO?

Somebody has to stop this, now.  I've been seeing questions getting closed for this nonsense reason. They aren't my questions but it bothers me a lot.  I searched MSO on the matter. The explanation given by the community so far is "vagueness". I saw some examples where people said "your question was too vague to be answered". Somebody on MSO even used the word "unanswerable".   First I find these arguments ridiculous. If a question is vague, the answers would naturally be vague, or none. The question would get downvotes, critical comments and would evolve into a better question over time, or simply be ignored, this is a Wiki after all, or isn't it?   Second, the application of this rule has been extremely biased. Take the famous "what's your most controversial programming opinion?" and "what's the funniest programming joke have you heard?". They are still open as wide as possible. Oh I hear you're saying "they are specific because they didn't omit to add first person in the sentence". So you're closing questions because it doesn't start with "What's your opinion on..." ? What kind of Gulliver's land are you from?  Third, I don't think the learning process is simply a matter of a question and the right answer. You can learn from opinions, incorrect answers and build your experience upon them. In the end you gain better knowledge on the matter or society itself. Such an open community is supposed to evolve, supposed to be open to opinions on the matter rather than specific answers.  I think the reasoning behind that rule is "to keep helpful content only and remove noise in site traffic". I already explained it's not noise, it's helpful. And I already explained it can simply be ignored by community if it's not found worthwhile.  The only justification I can give credit for is "insufficient server resources to hold vague questions in" and I don't believe in such nonsense either. I don't think "vague questions" would grow faster than specific questions.  One might argue that one can always reopen a question and correct the wrong. That's presenting release after a day as a solution to an wrongful arrest. "Correctability of wrong" doesn't make wrong less-wrong.   Currently the moderation is being hypocrite by applying rules inconsistently. It's not their fault, it's the fault of the rule itself. It prevents valuable information to be shared and synthesized by allowing blocks to be put on the flow of information. That's incredibly discomforting.  Here is my specific question: I see an unjust process in SO that I believe hurts the community and the future of SO. How can I convince "The SO guy" at the top to stop this besides yelling, or throwing in a single Meta Stack Overflow request among thousands? Because I think this has high priority, I think this has been doing serious damage.


I know the program launchy from Windows (and it is also available in Ubuntu) in which I can simply enter 100/9.14 and get the result without opening a calculator. But I don't want to install the whole program just to do that...  Is there a simple command line tool I can use?


how to disconnect main service drop at service panel

when upgrading to a 200 amp service panel with service drop coming from bottom underground do I need southern California Edison to come disconnect and then reconnect or can I just do it on my own. I do have a permit.


Can SG teams travel to different galaxies without extra power or an 8th chevron?

In the tie-in of SG-1 and Atlantis, they had to use a ZPM to power the gate, and use an eighth chevron to travel to the Pegasus Galaxy. It was (so I thought) common knowledge that they could only travel to gates within our own galaxy unless they had met those requirements.   Now, I recently rewatched the movie, in which the probe traveled to the Kaliam Galaxy, or as Catherine put it, "the other side of the known universe." So, why the limitation on the TV show? And why were they able to travel back to that planet in the first episodes?


Default Enum type, why this code does not compile?

I defined an Enum. I also have 2 methods:   method 1 -  will get the enum type - enum default type is int so it will print System.Int32  method 2 - will have switch case that compare the enum type with simple number - so in case the enum is int the switch case need to be compile with not problem and without any casting.    But this code does not compile and I get two errors ( the error point on the case 1 and case 2 in the switch case )      Cannot implicitly convert type 'int' to 'Color'. An explicit conversion exists (are you missing a cast?)      Someone can explain why I get an error even if the Color type is int ?  To compile this code I need to make casting to the Color to int.  The code:  public enum Color {     RED,            // 0     BLUE,           // 1     GREEN           // 2 };  Color color = Color.BLUE;  private void boo(object sender, EventArgs e) {     string str = Enum.GetUnderlyingType( color.GetType() ).ToString();      // it will print 'System.Int32'     System.Console.WriteLine(str); }  // the switch case make the compile error - but the color is int  private void foo() {     switch( color )     {         case 0:         {          }         break;          case 1:         {          }         break;          case 2:         {          }         break;     } }


Find the limit $\lim_\limits{n\to{\infty}}n^2(\sqrt[n]{x}-\sqrt[{n + 1}]{x})$ and my inquiry about Stolz-Cesàro theorem

Let $x>0$, find the limit $$\lim_\limits{n\to{\infty}}{n^2\left(\sqrt[n]{x}-\sqrt[{n + 1}]{x}\right)}$$  I use Maclaurin series and find out that the limit is $\ln x$. And this is the answer I get from a math forum:  "Let $x_n=\sqrt[n]{x}-1$, $y_n=\dfrac{1}{n}$, then $(x_n)\to0,(y_n)\to0,(y_n)\downarrow$ when $n\to\infty$.  Use Stolz-Cesaro theorem, we have:  $$\mathop {\lim }\limits_{n \to \infty } \dfrac{{\sqrt[n]{x} - \sqrt[{n + 1}]{x}}}{{\frac{1}{n} - \frac{1}{{n + 1}}}} = \mathop {\lim }\limits_{n \to \infty } \dfrac{{\sqrt[n]{x} - 1}}{{\frac{1}{n}}} = \ln x$$ Then $\mathop {\lim }\limits_{n \to \infty } {n^2}\left( {\sqrt[n]{x} - \sqrt[{n + 1}]{x}} \right) = \mathop {\lim }\limits_{n \to \infty } \dfrac{{{n^2}}}{{n\left( {n + 1} \right)}}\cdot\dfrac{{\sqrt[n]{x} - \sqrt[{n + 1}]{x}}}{{\frac{1}{n} - \frac{1}{{n + 1}}}} = \ln x$.  /END"  I just wonder what form Stolz-Cesaro theorem that he used, because I just learn Stolz-Cesaro theorem when $(y_n)\to\infty$.  Could anyone help me to get this? Thank you in advance.     This is "another form of Stolz theorem" in the forum that I mentioned: Let $(x_n),(y_n)$     be two sequences of real numbers. Assume $\mathop {\lim }\limits_{n \to \infty } {x_n} = \mathop {\lim }\limits_{n \to \infty } {y_n} = 0$; $y_n>0$, $(y_n)$ is strictly decreasing  and the following limit exist $\mathop {\lim }\limits_{n \to \infty } \dfrac{{{x_{n + 1}} - {x_n}}}{{{y_{n + 1}} - {y_n}}} = L$. Then $\mathop {\lim }\limits_{n \to \infty } \dfrac{{{x_n}}}{{{y_n}}} = L$. Is this correct?


Do monthly payments decrease on a mortgage later in the loan?

I am planning to purchase a home and all calculations and the banks say principal, interest, property tax, plus mortgage insurance will be close to $1000 per month.  The calculator show that if I increase my down payment by $10,000, then my monthly payment goes down by $200 per month. Based on that, if I suddenly were to come into $10,000, and apply that to the home loan, would the monthly payment similarly reduce my monthly payment by $200 per month. Over time, would the monthly payment amount slowly reach $0 per month?


What is the difference between a vector and the transpose of the vector

I would like to understand what the transpose of a vector represents different from the vector itself.  I am not looking for a proof, just an explanation with some examples. I understand how the transpose can be used to follow the rules needed for matrix multiplication in linear algebra. But do the individual meanings of each element of a column vector have a different meaning when transposed to a row vector. For example, I have a good "feel" of what a vector in 2D Real coordinate space means, for example, when I see v =(2,5) I can think of this as a vector with a size of 2 units in the X direction and a size of 5 units in the Y direction. Do I change how I think of those values (2 and 5) when I take the transpose of v ?


I understand that  of a function, but while I can easily see how to apply this convention to work with functions instead of numbers in some circumstances, e.g.,  $$\sin(x)\text{ becomes } \sin\text{,}$$ $$\cos(x)\text{ becomes } \cos\text{, and}$$ $$g(x)\text{ becomes } g\text{,}$$ it isn't clear to me how to to express the functions corresponding to the numbers $$x^{2}\text{, or}$$ $$2\cdot x\text{.}$$  Short of defining new symbols, like $S$ or $I$ (which I've seen for the function corresponding to $x \mapsto x$), can one say things like $$\left(\cdot\right)^{2}\text{ for }x^{2}\text{, or}$$ $$2\cdot \left(\cdot\right)\text{ or }2\left(\cdot\right)\text{ or }2\cdot\text{ for }2\cdot x\text{?}$$  What is the general idiom for expressing such functions concisely?


Per-site-meta questions not showing up on network profile Top Questions

I was looking at  to find his posts on each pre-graduation meta site about the design choices. However, his Top Questions section includes no meta posts. His activity tab showed some meta activity, but I believe that may also be incomplete. Where can I access his top Meta posts?


Download Xcode 10.2.1 in macOS High Sierra (10.13.6)

I use MacBook pro with macOS High Sierra (10.13.6). The version of Xcode am using is 10.1 and I see the updated Xcode in AppStore is 10.3 which is not compatible with my environment since it expects macOS Mojave 10.14.6.  How can I get Xcode 10.2.1 which got released after Xcode 10.1 release. Also will  MacBook pro with macOS High Sierra (10.13.6) get macOS Mojave 10.14.6 update ? Thanks


Is the classification of particles into matter and anti-matter arbitrary?

It is well known that every fundamental particle has a corresponding antiparticle, and that  – except for particles which are their own antiparticle – for practically every pair of particles and antiparticles, one type of particle predominates. We call this particle matter, and its antiparticle is considered to be antimatter.  However, is there any intrinsic difference between matter and antimatter, or are these terms defined based on nothing more than the balance that we so happened to end up with? For example, is there any reason that we should place an up quark and a charm quark in the same category, and not an up quark and a charm antiquark? Is there any reason we should group together up quarks and electrons rather than up quarks and positrons?


How do I remove a configuration object from the active configuration?

I'm writing a custom module for Drupal 8. It defines a field storage configuration object, in a file called modules/mymod/config/install/field.storage.bloom_stem.bs_twitter_ac.yml.  The problem is that this is not removed when I uninstall the module; it is apparently left behind because, when I re-install the module, I get a crash.   drush -y pm-uninstall mymod drush cr drush -y en mymod      exception 'Drupal\Core\Config\PreExistingConfigException' with message 'Configuration objects (field.storage.bloom_stem.bs_twitter_ac) provided by mymod already exist in active configuration'   So it seems I need to some how manually remove this configuration object. Do I need to provide some more code that deletes it when the module is uninstalled?


Having the following data in a table:  ID     Category   Value 1234   Cat01      V001 1234   Cat02      V002 1234   Cat03      V003 1234   Cat03      V004 1234   Cat03      V005   I want to have the following output:  ID     Cat01  Cat02   Cat03 1234   V001   V002    V003 1234   V001   V002    V004 1234   V001   V002    V005   The output I want to achieve is a kind of pivot table where I have all the values vertically in a table and I want to have those values, horizontally, having the category as a column. But there are some categories that have multiples values, in that case, I need to repeat the values of all other categories and create a row per each repeated value  How can it be done in PostgreSQL?


What is the difference between the pronunciation of "horse" and "whores"?

Cambridge dictionary lists the pronunciation of horse as /hɔːrs/ and that of whore as /hɔːr/. What exactly is the way to pronounce both of them?


I'm using classic asp. I've got   <% If question = "where" Then %><!-- OTHER STINGING THINGS --> <!-- #INCLUDE FILE="sting.asp" --> <% End If %>   so I can get to my site with www.mysite.com/?question=where  I can add queries e.g.   <% If question = "when" Then %><!-- OTHER STINGING THINGS --> <!-- #INCLUDE FILE="sting.asp" --> <% End If %>   But I can't seem to add a different query e.g.  <% If answer = "now" Then %><!-- OTHER STINGING THINGS --> <!-- #INCLUDE FILE="sting.asp" --> <% End If %>   to get to www.mysite.com/?answer=now  What am I missing?


Is it possible to set DNS for mobile network

I live in Canada and use an unblocking service to access US Netflix content, Pandora and Hulu. I would like to be able to use this service while not on my WiFi is there a way to set the DNS server to the ones i need for my unblocker to work for the mobile network


How to find out where the "grub" is installed

My Ubuntu Server 12.04 LTS is asking me during "apt-get dist-upgrade" where to install "GRUB" update.How can I simply find out which partition/disc is the proper answer? How to find out where GRUB is currently installed? I found similar question and answer but how to do it without installing additional script? I will be grateful for your advice.  Similar question:   Cheers :)


So I was told to do last > lastloggedin which creates a file that shows the classes last login since the last system reboot, and now I am asked to write an Awk script which is named myawk that counts/determines how many lines of  lastloggedin contain the string CFS264.   I've done grep -c CFS264 lastloggedin


Creating heat map or density map from stacked polygons in ArcMap?

I have a polygon shape file that has many overlapping features. Each feature represents an area used by polar bears. So some of the polygons overlap and some don't, and there are separate clusters of overlapping areas.   I would like to get a measure of how much overlap there is in a particular area. But I have no clue how to do this. I'm pretty new to GIS and am still learning the ropes, it just seems I can't find an answer.


why kernel methods are called kernel ? where is the intuition?

One thing i never really understand is why kernel trick is called 'kernel'.  Kernel means:   the central or most important part of something.  synonyms:   essence, core, heart, essentials, quintessence, fundamentals, basics, nub, gist, substance;   what's the connection between above definition and 'make low dimension samples repeatable in high dimension'?  does anyone have any insights here?


When I read about past events in the universe (i.e. big bang, formation of the sun and planets, etc) future events (i.e. sun becoming a red giant) and distant objects (black holes, nebulas, galaxies, etc), it appears to me that a big assumption is always made:  The laws of physics observed from earth today are the same throughout the universe, and throughout time.  My question is: do we have any evidence that supports this assumption? Or do we make this assumption simply  because we have never seen evidence to the contrary?


This screenshot is from Windows app called MyRadar by ACME AtronOmatic LLC. I found their wind direction animation to be very visually appealing and was wondering if anyone knew how to create this animation?      I prefer Java, Python, C++, or MATLAB answers for the code for creating this animation if possible.  Edit: So I know MATLAB and Python already have libraries for creating vector fields. However, I only found the ones that only change the direction and magnitude of the arrow. In this animation, the vector field arrow moves along the vector field.


Creating a tool that can break certain blocks as a command in Bedrock 1.14

I've been trying to figure out a way to create a tool that can only break certain blocks, but I found nothing for bedrock 1.14 update? I looked at other questions but none seem to work, since they reference Java Edition, or potentially that the command has changed for the new update (1.14) so is there an updated version?


Continue operator doesn't continue the for loop

Trying to continue iterating if (str1Number == str2Number), but the loop stops after incrementing the i variable  String getOldestVersion (String str1, String str2) {     String[] str1Arr = str1.split("\\.");     String[] str2Arr = str2.split("\\.");     String result = "";     int str1Number = 0;     int str2Number = 0;      for (int i = 0; i < str1Arr.length-1; i++) {         str1Number = Integer.valueOf(str1Arr[i]);         str2Number = Integer.valueOf(str2Arr[i]);         if (str1Number > str2Number) {             result = str1;             break;         } else if (str1Number == str2Number) {             i++;             continue;         } else {             result = str2;             break;         }     }      return (result); }


What is quickest way to find hackers entrance to computer?

I have a hacker in computer, what steps to remove, block entrance to computer programs.  I tried going to basics, reloading windows...I do not know what steps to take.  Please advise.


If you go through security at the airport with a paper boarding pass, the TSA will look at your ID and then sign the pass with a pen, but if you use a mobile boarding pass, there is nothing for them to sign (At least as I understand it. Maybe I'm wrong.) Why is the signing necessary in the one case and not the other? Where is the security compensated for in the mobile case? Or what purpose does signing the paper pass serve?


How can I play Pokémon GO without Internet?

I downloaded Pokémon GO on my Samsung Galaxy Express and I can play it at home, but when I go outside I can't play because there is no Internet.  How can I play Pokémon GO without Internet outside?


Poor battery life on recent Ubuntu installation

I've just started using Ubuntu (or any Linux distro, for that matter). I just bought this computer (), and I've installed the latest Canonical LTS version of Ubuntu (20.04). My battery life is, quite frankly, abysmal. I was told the battery should be lasting 7-8 hours, but it's barely lasting 3. I assumed it might be a driver issue with the NVIDIA GPU, and, as per the instructions , I examined the "Additional Drivers" tab, where I saw that the "Using NVIDIA driver metapackage from nvidia-driver-440 (proprietary, tested)" radio button was already selected:  So now I'm at a bit of a loss as to what's going on. Again, I'm new to Ubuntu and to Linux, even though I do have some rudimentary knowledge of the command line--does anyone have any recommendations of next-step diagnostics?


How did Worf pay for Yridian's information?

In the begining of "" episode (Star Trek Next Generation 6x16) an Yridian tells Worf, that he has a certain information,      that Worf's father is still alive (apparently not killed in ) and is held in a prison camp on Carraya IV.   Yridian is an information broker and agrees to reveal details (i.e. location) only for a price.      Worf agrees.   How or with what Worf would pay for this? There is no economic factor inside the Federation (no money is being used) and I don't recall anything, Worf would have on board Enterprise, that would have enough value for an information this kind.