On my Toshiba Satellite E45t-A4100, the keyboard is not working. No matter what I press nothing responds. The touch screen is still working, and everything seems to be working properly, but I have zero keyboard function! When I went into the device manager and looked at the error message it say that windows can't start this hardware because its configuration in the registry is incomplete or damaged. I've tried all of the trouble shooting basics and I'm in the registry now I just don't know what to do. Any suggestions? I was up a few nights ago using my laptop and everything worked fine, the next morning when I woke up I opened it and turned it back on from sleep mode and none of my keys, nor mouse worked. Really strange to me, I did not add anything to my laptop or do anything, just simply used it one night woke up the next morning and can not use my key board for the last 3 days now.

On my Toshiba Satellite E45t-A4100, the keyboard is not working. No matter what I press nothing responds. The touch screen is still working, and everything seems to be working properly, but I have zero keyboard function! Any suggestions? I was up a few nights ago using my laptop and everything worked fine, the next morning when I woke up I opened it and turned it back on from sleep mode and none of my keys, nor mouse worked. Really strange to me, I did not add anything to my laptop or do anything, just simply used it one night woke up the next morning and can not use my key board for the last 3 days now.


Which one is correct?        He is one of the boys who play football.   He is one of the boys who plays football.      Please state the reason as well.

In the construction "one of the [plural noun] who ...", should the verb agree with "one" or "[plural noun]"?   For example, which of the two following sentences is grammatically correct? Or are both acceptable?        She was one of the several children who was sold at the auction    She was one of the several children who were sold at the auction.


In Field Theory I have always seen the Euler-Lagrange equation written as $$ \dfrac{\delta\mathcal{L}}{\delta \phi_s}-\partial_\mu\dfrac{\delta\mathcal{L}}{\delta\partial_\mu\phi_s}=0 $$ My doubt is about the partial derivative that appears in the second addend. Do I have to "interpret" this partial derivative as a total derivative? Let's suppose that Lagrangian density doesn't depend on $x$ directly, so $\mathcal{L}=\mathcal{L}(\phi_s,\partial\phi_s)$, where $\phi_s$ and $\partial\phi_s$ depend on $x$ of course. If I compute the functional variation of $\mathcal{L}$ with respect to $\partial\phi_s$, I do not have any reason to suppose that the result depend on $x$ directly, that is $$ \dfrac{\delta \mathcal{L}(\phi_s,\partial\phi_s)}{\delta\partial\phi_s}=G(\phi_s,\partial\phi_s) $$ Then, if I compute the partial derivative of $G$ with respect to $x^\mu$, the result should be $0$, while the total derivative of $G$ with respect to $x^\mu$ should be what I really want in the E-L equation $$ \partial_\mu\dfrac{\delta \mathcal{L}(\phi_s,\partial\phi_s)}{\delta\partial_\mu\phi_s}=\partial_\mu G(\phi_s,\partial\phi_s)=0\\ \dfrac{d}{dx^\mu}\dfrac{\delta \mathcal{L}(\phi_s,\partial\phi_s)}{\delta\partial_\mu\phi_s}=\dfrac{d}{dx^\mu}G(\phi_s,\partial\phi_s)=\dfrac{\delta G}{\delta \phi_s}\partial_\mu\phi_s+\dfrac{\delta G}{\delta\partial_\nu\phi_s}\partial_\mu\partial_\nu\phi_s $$ Example: Let's consider the Lagrangian density $$ {\mathcal L} = {1 \over 2} \partial_{\mu} \phi \partial^{\mu} \phi - {1 \over 2} m^2 \phi^2 $$ Using E-L equation I get $$ \dfrac{\delta\mathcal{L}}{\delta\phi}=-m^2\phi\\ \dfrac{\delta \mathcal{L}}{\delta \partial_\mu\phi}=\partial^\mu\phi=\eta^{\mu\nu}\partial_\nu\phi\equiv G(\phi,\partial\phi)$$ So formally if I compute $\partial_\mu G=0$, while I can get the result that I want (Klein-Gordon equation) if I compute $$ \dfrac{d G}{dx^\mu}=\dfrac{d}{dx^\mu}(\eta^{\mu\nu}\partial_\nu\phi)=\dfrac{\delta G}{\delta\partial_\alpha\phi}\partial_\mu\partial_\alpha\phi=\eta^{\mu\nu}\delta_\nu^\alpha\partial_\mu\partial_\alpha\phi=\partial_\mu\partial^\mu\phi $$ Is this correct? If it is, then why is it often used the partial derivative symbol, which leads to some misunderstanding (for example in the demonstration of the E-L equation you use the "partial derivative" as an actual partial derivative [i.e. if the Lagrangian density doesn't have a direct dependency on $x$, you say that this "partial derivative" on $\mathcal{L}$ is $0$] but at the end it appears in the final equation and, if my reasoning is correct, it is not an actual partial derivative)?

The Euler-Lagrange equation for particles is given by   $$ \frac{d}{dt}\frac{\partial L}{\partial \dot{q}} = \frac{\partial L}{\partial q},\tag{1}$$  and for fields  it is   $$ \partial_{\mu} \frac{\partial \mathcal{L}}{\partial (\partial_{\mu}\phi)} = \frac{\partial \mathcal{L}}{\partial \phi}.\tag{2} $$  Comparing the two equations, the first one has a total time derivative $\frac{d}{dt}$ but the other one appears to have partial derivatives $\partial_{\mu}$. These derivatives come from integration by parts in the derivation of the EL equation. I was wondering why the field version has partial derivatives and the particle version has total derivatives?   I have also seen for the specific example (in Quantum Field Theory for the gifted amateur) of 1 dimensional waves on a string, the corresponding Euler-Lagrange equation is  $$ \frac{d}{dt} \frac{\partial \mathcal{L}}{\partial \left(\frac{d\phi}{dt}\right)} + \frac{d}{dx} \frac{\partial \mathcal{L}}{\partial \left(\frac{d\phi}{dx}\right)} = \frac{\partial \mathcal{L}}{\partial \phi}, \tag{3}$$  which uses total derivatives, so I am a bit confused.


Hi I am trying to run the below code with TestNG but all it gives me is java.lang.NullPointerException error. The Before method gets worked. After that, it shows the below error .What's going wrong. Please help!   ERROR :  java.lang.NullPointerException at lokbo.Login.afterMethod(Login.java:50) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)     at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)     at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)     at java.base/java.lang.reflect.Method.invoke(Unknown Source)     at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:108)     at org.testng.internal.Invoker.invokeConfigurationMethod(Invoker.java:523)     at org.testng.internal.Invoker.invokeConfigurations(Invoker.java:224)     at org.testng.internal.Invoker.invokeMethod(Invoker.java:731)     at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:877)     at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1201)     at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:125)     at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:109)     at org.testng.TestRunner.privateRun(TestRunner.java:776)     at org.testng.TestRunner.run(TestRunner.java:634)     at org.testng.SuiteRunner.runTest(SuiteRunner.java:425)     at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:420)     at org.testng.SuiteRunner.privateRun(SuiteRunner.java:385)     at org.testng.SuiteRunner.run(SuiteRunner.java:334)     at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)     at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)     at org.testng.TestNG.runSuitesSequentially(TestNG.java:1318)     at org.testng.TestNG.runSuitesLocally(TestNG.java:1243)     at org.testng.TestNG.runSuites(TestNG.java:1161)     at org.testng.TestNG.run(TestNG.java:1129)     at org.testng.remote.AbstractRemoteTestNG.run(AbstractRemoteTestNG.java:114)     at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:251)     at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:77)   Code :    package lokbo;  import java.util.concurrent.TimeUnit;  import org.testng.annotations.Test;   import org.openqa.selenium.By;  import org.openqa.selenium.WebDriver;  import org.openqa.selenium.chrome.ChromeDriver;  import org.testng.annotations.AfterMethod;   import org.testng.annotations.BeforeMethod;     public class Login  {   public  WebDriver driver;   @BeforeMethod  public void beforeMethod()  {  System.setProperty("webdriver.chrome.driver", "E:\\RF   AUTOMATION\\chromedriver_win32\\chromedriver.exe");     WebDriver driver=new ChromeDriver();     String baseurl= "http://dev.idrottonline.se/";     driver.get(baseurl);     driver.manage().timeouts().implicitlyWait(300, TimeUnit.SECONDS);       String expectedTitle = "Idrottonline2 - Svenskidrott";     String actualTitle="";     actualTitle=driver.getTitle();     if(actualTitle.contentEquals(expectedTitle))     //if(expectedTitle.isDisplayed())        {         System.out.println("Test pass");     }     else     {         System.out.println("Test Fail");     } }   @Test   public void login() {    driver.findElement(By.id("IdrottOnline-LoginBoxTarget")).click();     driver.findElement(By.id("ioui-access-username")).sendKeys("lagorf01");     driver.findElement(By.id("ioui-access-password")).sendKeys("Dumbo753");     driver.findElement(By.xpath(".//*[@id='ioui-access-login']/fieldset/div[5]/div/button")).click();  }  @AfterMethod  public void afterMethod() {   driver.manage().deleteAllCookies();   driver.quit(); }  }

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


I'm planning on riding the bus to my friends house tomorrow (so i would like answers asap please) and i'm planning on taking my bike so we can ride together but im worried the bike rack on the bus is gonna be full and i have no idea how to handle that situation so if anyone could tell me what to do asap that would be fantastic.

Sometimes I take commute via bike, other times on the bus, but I rarely plan on doing both because I worry about the possibility of waiting for a bus only to find that its bike rack is full and having to wait for the next bus, which may also have a full bike rack.  What do you do in this case? I asked a bus driver today on the way home and I couldn't really understand what he was saying, but he said something about a bike rack in the back and I think he was saying that were he not driving the rapid bus and were his schedule different, he would put any extra bikes in the back. Not sure though, he could have said something completely different.


I want to write a^b in latex where ^ is not a power symbol. If I just write b^a in latex, the latter obliged me to put $. But in fact I don't want to write a to the power b, but just a^b. How can I solve this issue? Any help will be very appreciated!

I need to output the below text but since \ is a special character, I cannot:  [RegularExpression(@"\d+")]   Also sometimes I need use dollar sign $ as well but it seems to be a special char, too.  What is the way to escape those in LaTeX?  UPDATE:  I used \verb as suggested but I am unable to run commands inside it. Also, in the output the font and the opacity of the text is different than the default one:  \verb|[RegularExpression(\newline @"\d+")]|


I am currently banned from giving answers on Stack Overflow, and I want to know if there will be some kind of notification after the ban will get removed?

It would be nice if we could see somehow that someone is getting the infamous "Sorry, we are no longer accepting questions from this account" message when trying to ask new question, same way that we can see when someone is suspended when viewing the user profile.  It can appear as the same red bar as in the suspended account, or something else.. maybe only via the moderation tools for 10K+ members.  Right now when someone ask  we can only assume this is the case but can't know for sure.  Edit: as we can all clearly see, there is a steady rise in programming questions posted here on Meta by users who are getting banned from asking questions on the main site. While we can handle this easily, it would still be useful to show some indication that the user is question banned on the main site even if just so that people won't waste time trying to offer guidance to those users.


I'm having a problem with my Dell Inspiron 1564,   I am getting this error:  problem Kernel panic - not syncing: fatal exception in interrupt drm_kms_helper:: panic occurred, switching back to text console   I've found that it is probably due to the Broadcomm STA wireless driver.  But I am not sure how to solve the issue, does anyone know what I should do/try ?

These errors occur while starting Ubuntu. I am dual booting Windows 8.1 with Ubuntu.  kernel panic - not syncing : fatal exception in interrupt. shutting down cpus with NMI drm_kms_helper : panic occurred, switching back to text console.  Nothing happens and Ubuntu freezes.


Im not exactly from the EE field and I would happy for guidance. long question a head: Im trying to build a circuit for keep running Raspberry Pi using solar panel + rechargeable battery. I came across this nice . on the bottom of it, there is section of Power Sharing which seems like good and working design. but the thing is that this design talking about two scenarios: 1. what happens when power source connected (both load and battery getting current) 2. what happens when power source disconnected (load getting current only from battery)  Now, I thought to use that design and add the solar panel so it will feed both the load and the battery. On sunny day, we have no problem, both the load and the battery getting current:  The issue is what happens on bit cloudy day. the solar panel could output much smaller voltage than 6v so it will be necessary to detach the solar panel from the P-Channel-Mosfet, so the load will get its current only from the battery. If I keep the wiring like this:  The voltage could be not low enough for influence the Gate and feed the load only from battery + the DC-DC will not react good to 3v\2v\1v because it minimum voltage is ~6v. So I understand that there is a need to disconnect the solar panel , so the gate will 'turn on' the mosfet and current will flow from Drain to Source and feed the load + disconnect the charge controller. so we have two options: option 1:  option 2:  So, I guess my questions are:  The main question- How can I disconnect the solar panel (option 1 \ option 2) when the voltage gets under threshold voltage (for example 4v)? there is a need with another power source of that threshold for comparison (less preferred option)? if there is a way implementing it without chips \ minimum waist of current from solar panel (I guess with mosfets) it will be very helpful.  The values on this example are not set yet (solar panel + DC-DC conv + pull down resistor), Im looking for DC-DC that can get as input range of ~3v to >15v and output 5v but couldnt find one, minimum input is about 6v.. is there unit that can implement that? (the rest of the values will be set according to DC-DC input volatage)   Sorry for the long question :) Thank you all!

I have a simple circuit that runs off of a 9V battery. I'm re-designing it so that it can also run off of an external 12V DC source (ie: a wall adapter). I want to design the circuit so that if both the battery and the wall adapter are connected simultaneously, the wall adapter is used, and the battery is effectively disconnected from the circuit.   I've found a , but they , and since it could be a non-rechargeable (ie: alkaline) cell, this could be disastrous.   I've considered the using a , but I'm not quite sure how to start. How would I go about designing such a circuit?


With the recent change in the moderator privilege distribution among staff members, not everyone gets an immediately visible diamond symbol next to their name.  Hovering over a user card is not the best solution. Not everyone knows that this feature exists, and sometimes employees don't fill out their descriptions, there's gotta be a better way.  I think this might be a good time to think of a new visual indicator, perhaps something like the "New contributor" undersign, but which says "Staff, {job title}", or just the title, like so:

Starting today, all staff member accounts will have "Staff" next to their name on their user profile.  It looks like this:    For reference, it used to look like this:    We took our cue from the existing design of the "top n% overall" label which we've actually inverted for everyone (not just staff) to stand out from the others. Additionally, we've updated the moderator label from "(moderator)" to an actual label, so it's easier to see and stands out. Staff with diamonds will have both of the indicators.    Clearing up confusion to improve interactions  We've noticed a shared point of friction for users and staff alike - staff often need to post answers on meta sites to explain how a tool or feature works or to respond to bugs. This is a great opportunity for them to interact with the people asking the questions but, sometimes, not having an indicator for every employee makes these interactions more challenging than they already are.  You might say "But what about diamonds, that's used for staff"... and you'd be right, in some cases. The primary purpose of the diamond is to indicate the moderators on a site. These are non-staff users who have extra tools at their disposal and special access to information. While we gave these to staff in the past, we now only grant them to specific types of staff members who need access to these tools - generally community managers and developers.  As such, for the rest of our cohort, we have relied on them mentioning their status in their "about me" sections. This simply isn't a sustainable option both because it's easy to forget but also because it's not actually proof. Anyone can edit their profile to state they're staff.  Adding an indicator like this isn't an original idea. Y'all have been asking for a way to recognize us for years and we're so excited to be able to deliver this change:        Fortunately, we already indicate staff status at the account level, so we can use that information to add a marker to staff profile pages that anyone can see. So this update makes most of these requests !  We'll still encourage our staff to be more specific about their job title in their "about me" but this marker will let y'all quickly and easily know if the person supporting a feature or answering a bug report is staff.  I'm really excited about this change and I hope it helps smooth out interactions across the network a bit. Questions? Ask them in the answers.


I'm rewriting a C code to python but it seems I've stuck.  I have the function in C:    double GetArrival()   /* ---------------------------------------------   * generate the next arrival time, with rate 1/2   * ---------------------------------------------   */    {   static double arrival = START;    SelectStream(0);    arrival += Exponential(2.0);   return (arrival);   }   This function is called from a main() function. As you can see every time it is called, an exponential random rate of 2.0 is added to arrival. All you have to know is that it's a custom function that returns a random variable.  After consulting ddd on the C file which works as it should, I realized that in the following python "equivalent" the variable arrival gets initialized to START = 0 everytime the function GetArrival() is called. This for some reason doesn't happen in the C, except the first time the function is called.  def GetArrival():      arrival = START      SelectStream(0)      arrival += Exponential(2.0)      return arrival   So I thought I should omit this evil initialization and that should do it. Did not, because in that case I get the following error:  UnboundLocalError: local variable 'arrival' referenced before assignment   Which kinda makes sense.  So my question is how can I make the python code work like the one in C, without having the variable arrival initialize to zero every time?  Thanks.

What is the idiomatic Python equivalent of this C/C++ code?  void foo() {     static int counter = 0;     counter++;     printf("counter is %d\n", counter); }   specifically, how does one implement the static member at the function level, as opposed to the class level? And does placing the function into a class change anything?


I would like to ask to allow CTRL + K in in comments. However, I found I would create    How can I bump it to get it resolved/accepted/declined?      Editor's Note: The procedure for getting attention for issues and requests on meta sites is different, so this is not a duplicate of other general questions that ask how to get attention for questions.

I posted a question here on Meta Stack Exchange, or on a per-site meta, regarding a bug I found in the system. I got no comments, or a few comments stating that this is a legitimate bug (and not by design). However, it's been quite a long time, and no official response was ever posted there.  Or, I had an idea for a new feature, but realized it's already requested, either by searching or posting a request myself only to have it closed as a duplicate of the existing one. It's been a while since the original request was filed, but no official response has been made.   I'm aware that staff members are , but either my post isn't about one of the indicated topic areas for which they're accepting escalation requests for that month, or I already flagged to request escalation but it was declined, so the instructions there don't apply for my post.  What can I do to draw attention to meta questions for the SE team, so they can give an official response, and possibly implement the bug fix or feature?  Note: This is different from other general questions which ask for how to get attention for unanswered questions, since the procedures on meta sites are different, and getting an official response isn't necessarily the same as getting a good answer.


Here is the story .. My friend bought an iphone 5S .. Later he found that it's linked to icloud account and it wasn't verified .. So, he asked me to help him remove the account .. And i couldn't .. So, i told him that there is nothing i can do for him and he should use the device in this condition till someone find a solution .. Next day i met him .. And his iphone has no icloud !! He told me that he found a guy in a mobile shop who did it for him .. That guy didn't just removed the account .. He also gave it's password to my friend !! And i've tested the account myself .. !! My friend also told me that he did it in just 15 min .. !!  I know you can extract account password from an encrypted backup .. But it's not that simple .. And not everyone can do it !!  So, have someone here knows about getting icloud password from activated device .. Or can explain what that dude did to my friend's iphone ??  Thx in advance.

I bought my iPhone 5s about 3 days ago.Once i bought it i activated the phone from one of my friend's AppleID and password , because i needed to check if the phone functions well, before i leave the shop.but then after when i got back home i made a new apple account and used the phone with that account.  But since my phone is activated from my friend's iCloud i logged into account from his appleID and password. then i removed the device from his account. Then i erased the phone then rebooted it and setup a new i phone  with my AppleID and iCloud but still my phone is NOT Activated in my new account??  can someone please help me to activate my phone from my new account????


How to calculate the following determinant: $\begin{vmatrix}  a & b & b & ... & b \\   b & a & b &  ... & b \\   . & . & . & . ... & .\\  b & b & b & ... & a\\  \end{vmatrix}$ I don't have idea from where to start. Any help is welcome. Thanks in advance.

Compute the determinant of the nun matrix: $$ \begin{pmatrix} 2 &  1  & \ldots & 1 \\ 1  &  2 & \ldots & 1\\ \vdots & \vdots & \ddots & \vdots\\ 1  &   1       &\ldots & 2 \end{pmatrix} $$  For $n=2$, I have$$ \begin{pmatrix} 2 &  1   \\ 1  &  2  \end{pmatrix} $$   Then $det = 3$.  For $n=3$, we have $$ \begin{pmatrix} 2 &  1 & 1\\ 1  &  2 & 1\\ 1 & 1 & 2 \\ \end{pmatrix} $$  Then $det = 4$.  For $n=4$ again we have  $$ \begin{pmatrix} 2 &  1  & 1 & 1 \\ 1  &  2 & 1 & 1\\ 1 & 1 & 2 & 1\\ 1  &   1  & 1 & 2 \end{pmatrix} $$ Then $det = 5$  How can I prove that the determinant of nun matrix is $n+1$.


$\sum\limits_{n=1}^{\infty}  \dfrac{1}{n^{1+1/n}}  $  I believe it diverges. But I am having trouble comparing it to another series which also diverges and whose terms are less than the original series. If need to show that the series diverges

Does $$\sum_{n=1}^{\infty} \frac{1}{n^{1 + 1/n}}$$ converge? If yes, to where?  I searched this specific series but couldn't find a solution.


When I test the following code with #define N 100  , there's no error accures. But I change it into #define N 1000, error show's that fish: “./file” terminated by signal SIGSEGV (Address boundary error). Can somebody help? I'v tried to find answers from google, but I can't understand other's solutions which since to be same error different problem.... I know that multiply two matrix can work in a large amount such as 1000*1000 matrix. But I'm new to learn this multiply matrix. #include <stdio.h> #include <stdlib.h> #include <omp.h> #include <time.h> #define N 2000  int main(){    struct timespec t_start, t_end;    double elapsedTime;    int i, j, k;    int a[N][N], b[N][N], c[N][N], cc[N][N];        for( i=0; i<N; i++ )     for( j=0; j<N; j++ ) {         a[i][j] = rand();         b[i][j] = rand();         c[i][j] = 0;         cc[i][j] = 0;     }     // start time     clock_gettime( CLOCK_REALTIME, &t_start);       for( i=0; i<N; i++ ){         for( j=0; j<N; j++ ) {             for( k=0; k<N; k++ ){                 c[i][j] += a[i][k]*b[k][j];             }         }     }     // stop time    clock_gettime( CLOCK_REALTIME, &t_end);     // compute and print the elapsed time in millisec    elapsedTime = (t_end.tv_sec - t_start.tv_sec) * 1000.0;    elapsedTime += (t_end.tv_nsec - t_start.tv_nsec) / 1000000.0;    printf("Sequential elapsedTime: %lf ms\n", elapsedTime);       // start time    clock_gettime( CLOCK_REALTIME, &t_start);      #pragma omp parallel for private(i, j, k)      for( i=0; i<N; i++ )     for( j=0; j<N; j++ ) {         cc[i][j] = 0;         for( k=0; k<N; k++ )             cc[i][j] += a[i][k]*b[k][j];     }     // stop time    clock_gettime( CLOCK_REALTIME, &t_end);     // compute and print the elapsed time in millisec    elapsedTime = (t_end.tv_sec - t_start.tv_sec) * 1000.0;    elapsedTime += (t_end.tv_nsec - t_start.tv_nsec) / 1000000.0;    printf("Parallel elapsedTime: %lf ms\n", elapsedTime);      for(i=0; i<N; i++){         for(j=0; j<N; j++){             if(cc[i][j] != c[i][j])                 break;         }     }         if(i==N && j==N)         printf("Test pass!!!\n");      else         printf("Test failed!!!\n");    return 0; }     Tried to google SIGSEGV but couldn't found what's wrong?

The following code is generating a stack overflow error for me  int main(int argc, char* argv[]) {     int sieve[2000000];     return 0; }   How do I get around this? I am using Turbo C++ but would like to keep my code in C  EDIT:  Thanks for the advice.  The code above was only for example, I actually declare the array in a function and not in sub main.  Also, I needed the array to be initialized to zeros, so when I googled malloc, I discovered that calloc was perfect for my purposes.  Malloc/calloc also has the advantage over allocating on the stack of allowing me to declare the size using a variable.


Will the total work done by friction on a system be always zero if friction is static and internal to the system? Explain if possible by man boat problem as system and no friction is being provided by water to boat.  Friction only exists between man and boat and man is walking without skidding to the other end.

As I am seeing this,  the man and boat will have different displacement from ground frame,  so there should be a net work done by friction .  The books says,  total work done by friction is zero when friction is static and internal to system. Please explain..


Are there any organisms that do not want to reproduce?  As humans, there are people who do not want to reproduce with the opposite sex. Do any other organisms replicate this behavior? Also, why does this behavior exist? If the end goal of an organism is to reproduce, why has evolution allowed organisms that do not want to reproduce to exist?

I would imagine that the answer to this question would be population control, especially since even if one sibling is homosexual this does not necessarily mean that the other siblings will be too.


I have heard that temperature in space is very cold or near to -200 degree celsius in the side opposite to sun.How is this possible?If there are no or negligible amount of molecules in space,how can the term temperature be defined.I have been taught that temperature is just the vibration of molecules.If there are no molecules in space,is it plausible to say that space is neither hot nor cold,when you are exposed to space you feel neither hot nor cold?Please help me in simplest language.

My understanding is that heat is essentially atomic vibrations. If there are almost no atoms, how can there be residual heat?  Also, as I understand in space there is no heat transfer via convection and it is mainly through EM radiation. In this case, why is it that if i were to go into space with no suit and just an airtight helmet through which I could breathe, I would still freeze to death very quickly?


... as described by these two wikipedia pages:     In the former, the predicted value for the variable of interest is given by (in the simplest case) the mean of a few lagged values.  In the latter, the predicted value is given by some weighted 'error' terms. Is that error supposed to be the model's prediction subtracted from the actual value that obtained?  Are they similar things or totally different?

When I read "moving average" in relation to a time series, I think something like $\frac{(x_{t-1} + x_{t-2} + x_{t-3})}3$, or perhaps a weighted average like $0.5x_{t-1} + 0.3x_{t-2} + 0.2x_{t-3}$. (I realize these are actually AR(3) models, but these are what my brain jumps to.) Why are MA(q) models formulas of error terms, or "innovations"?  What does $\{\epsilon\}$ have to do with a moving average? I feel like I'm missing some obvious intuition.


E: Some index files failed to download. They have been ignored, or old ones used instead. E: Could not open lock file /var/lib/dpkg/lock - open (21: Is a directory) E: Unable to lock the administration directory (/var/lib/dpkg/), are you root?

I get this error whenever I try to install programs using the terminal:  home@ubuntu:~$ apt-get install myunity E: Could not open lock file /var/lib/dpkg/lock - open (13: Permission denied) E: Unable to lock the administration directory (/var/lib/dpkg/), are you root?   Also I'm unable to install updates using the terminal.


I'm using mvc 5 and wanna define extension method FindMessageAsync in class Queryable (namespace System.Linq).  I usually use this way to get some records in database:  public void GetMessage(string id) {   using (var db = new MyDbContext())   {         var message = db.Message.FirstOrDefault(x => x.Id == id);     //or     var _message = db.Message.Where(x => x.Id == id).ToList();      //do stuff   } }   I wanna improve the method to:  public async Task<MessageViewModels> GetMessage(string id) {   using (var db = new MyDbContext())   {         var message = await db.Message.FindMessageAsync(x => x.Id == id);      if (message != null)     {       //string id = message.Id;       //string fromUser = message.FromUser;       //string toUser = message.ToUser;       //string content = message.Content;       //bool isRead = message.IsRead;     }      //do stuff   } }   My question is: How to define extension method FindMessageAsync?  UPDATE:  The answers of  don't solve my problem.

I'm a fan of extension methods in C#, but haven't had any success adding an extension method to a static class, such as Console.  For example, if I want to add an extension to Console, called 'WriteBlueLine', so that I can go:  Console.WriteBlueLine("This text is blue");   I tried this by adding a local, public static method, with Console as a 'this' parameter... but no dice!      public static class Helpers {     public static void WriteBlueLine(this Console c, string text)     {         Console.ForegroundColor = ConsoleColor.Blue;         Console.WriteLine(text);         Console.ResetColor();     } }   This didn't add a 'WriteBlueLine' method to Console... am I doing it wrong? Or asking for the impossible?


I tried to write ajax with jquery to fetch data from database butajax doesn't return any data. I put that code in header and it return the whole html content in response. What is the code need to write in admin-ajax.php to use ajax?

I'm wondering what the preferred method is for dealing with AJAX calls. Should one use the same plugin php file to process the POST or a separate one? Which is cleaner or safer?


I am using a simple LaTeX file main.tex where am including a bib file and referring to its references, but reference numbers and references are not displayed, instead there is symbol ?. I want to print references whom I have referred to under the section Bibliography and reference number such as [1]. How can I make this code work as I want? Am using Windows 8, Texmaker 4.0.4 and MiKTeX 2.9. Here is the code. main.tex  \documentclass[11pt]{article} \usepackage{cite} \usepackage[german, english]{babel}  \begin{document}  \title{My Article} \author{Nobody Jr.} \date{Today} \maketitle  Blablabla said Nobody ~\cite{Nobody06}.  \bibliographystyle{plain}  \bibliography{local}  \end{document}   local.bib  @misc{ Nobody06,        author = "Nobody Jr",        title = "My Article",        year = "2006" }

I've browsed the forums and found a number of posts that have addressed this issue, but none of the solutions seem to work for me. I have the following script that I just copied from the bibtex home page to get familiar with it. Instead of the citation number I get a question mark. I compile using Latex+Bibtex+Latex+Latex+PDFLatex+ViewPDF just as has been previously suggested and the problem persists.   \documentclass[11pt]{article} \usepackage{cite}  \begin{document}  \title{My Article} \author{Nobody Jr.} \date{Today} \maketitle  Blablabla said Nobody ~\cite{Nobody06}.  \bibliography{mybib} \bibliographystyle{plain} \end{document}   My bibliography (Bib.bbl)  @misc{ Nobody06, author = "Nobody Jr", title = "My Article", year = "2006" }    Looking at previous posts one thing that is concerning is that my .bbl looks empty as shown below. Further, I don't have a .blg  \begin{thebibliography}{}  \end{thebibliography}


In plain zsh, when I press Enter, it runs the command I've typed. Hooray! This includes performing any necessary event designator substitutions all in one go, though it prints them out along the way: ~ % echo a b c # ^M a b c ~ % echo !$ # ^M echo c c ~ % echo !-2:2 # ^M echo b b ~ %   I've decorated the above block with # ^M to indicate where I pressed the Enter key. In contrast, with Oh My Zsh, when I hit Enter, it runs the command immediately but only if there are no event designator substitutions to be made. Other types of substitutions happen inline, but if I've used an event designator, instead of actually running the command, it gives me a new line with a new prompt and the substitution having been made. Example, same # ^M business as above: ~ % echo a b c # ^M a b c ~ % echo !$ # ^M ~ % echo c # ^M c ~ % echo !-2:2 # ^M ~ % echo b # ^M b ~ % echo $(echo a b) c # ^M a b c ~ %   Note that I have to hit Enter twice to make most of the commands run, though the final one with the $() substitution runs in a single go. How do I configure OMZ to use the normal zsh behavior here, or otherwise just configure zsh to go back to normal after OMZ has performed its dark magic? I can't seem to find any documentation on how to make zsh do this in the first place. (I know that I can use the Tab key to have the substitution performed immediately. That's fine, but I know I typed the thing correctly and I just want it to run without seeing it again first.)

In zsh with oh-my-zsh you can enter a history expansion command and press either space, tab, or enter, and it will expand out. For example:  ls /path/to/some/directory cd !$<enter>   would expand to  cd /path/to/some/directory   But it does not actually execute the command. It remains on the prompt for further editing and you need to press enter a second time to actually run the command.  I was installing arch linux last night and found that the zsh settings the install shell comes with has history expansion on tab and space, but pressing enter runs the expanded command immediately without requiring the user to press enter again.  This is what I want because it saves me a key press. If I want to edit the expansion, I could press tab. If I want to run the command immediately I could press enter.  I think it's something to do with magic-space, and I see the following line in .oh-my-zsh/lib/key-bindings.zsh  bindkey ' ' magic-space        # [Space] - do history expansion   But I can't find where enter and tab are also bound to expansion or if there's some option to run the command immediately on enter.


My glossary looks like this:  \renewcommand{\glsgroupskip}{} \renewcommand*{\arraystretch}{1.5} \renewcommand*{\glsnamefont}[1]{\bfseries #1} \renewcommand*{\entryname}{Hitza} \renewcommand*{\descriptionname}{Deskribapena} \renewcommand*{\pagelistname}{Orrialdeak\\}  \newglossaryentry{glos:entry1}{name=entry1, description={blablabla.}}  ...  \newglossaryentry{glos:entryN}{name=entryN, description={blablabla.}}   I need to add a figure (an image) after each glossary entry, so that I can show an image of the entry I just explained.  I guess I'll need to modify the newglossaryentry command, but I don't know how to do that.

I'm using the Glossaries package, which is fantastic, but I'd like to put in pictures which explain the term better than words would. Is there a way for me to do this?


I have an FSA and I used it to buy my contact lenses recently.  The contacts come with an offer for a rebate if you buy a whole year supply, which I did.  Is the money I get from the rebate tax-free, like the FSA money?

I used an HSA to buy some contact lenses.  They came with a rebate form that I can send in to get a refund of about 1/5 of the purchase price.  Is it okay to send away for the refund after using the HSA to buy the contact lenses?  If I get the refund, do I have to deposit they money back into the HSA, or can I spend it any way I wish without having to pay any tax penalty on it?  If I get the rebate, do I need to declare it when I do my (USA) taxes next year?


What is the exact difference between null, 0, false, and an empty string in PHP? Is null similar to None in python?

I am told that good developers can spot/utilize the difference between Null and False and 0 and all the other good "nothing" entities. What is the difference, specifically in PHP?  Does it have something to do with ===?


In Ubuntu I tried to play with the permission of NTFS drive. I installed an app from the Ubuntu Software Center named NTFS Configuration Tool. After using it a few times, the app started to close and wasn't responding. So I removed the app.  The next day I opened my PC, started the torrent client Transmission. That was a huge file so I downloaded that to my NTFS drive. So I resumed the torrent, but it said Permission denied to write. :( It seems like all of my NTFS drives have become read-only. I can't write anything.  How can I fix this permanently?   (I've run Transmission using sudo command. It's working, but using sudo command everywhere isn't the solution, I need it back like it was before. Please help.)  Here are my fstab contents:

I have in my /etc/fstab file this line in order to mount my Windows ntfs partition: /dev/sdb1 /media/sdb1  ntfs rw,noauto,users,permissions 0 2  I've changed the owner using chown and set the permissions to 777 using chmod. If I make an ls -lt it shows the owner and the permissions properly changed. However I still don't have permissions for writing there, if I execute mkdir test it says:  mkdir: cannot create directory `test': Permission denied  Any suggestions? UPDATE I found the solution, these are the steps I followed:  Type sudo blkid  Get the UUID related to your ntfs partition.  Change the /etc/fstab file adding this line: UUID="your UUID" /media/"any name" ntfs users,defaults 0 0


What is the literary device for giving a human un-human attributes? For example, a picture of a woman driving a car really quickly saying "She's flying down that road!". What is that literary device?  Also, if this isn't actually a literary device, please let me know what it would be.

I want a word that means the opposite of personification.  What is the correct word for describing people with the characteristics of an object/as if they are objects?  I found the word chremamorphism on some forums, but it doesn't seem to be included in the two online dictionaries I searched.


Running 14.04. Prompted to upgrade to 16.04, when I agree it asks for an Authentication password. What's this, and where is it?

I'm working on a Ubuntu system, and my client has completely forgotten his administrative password. He doesn't even remember entering one; however it is there.  I've tried the suggestions on the website, and I have been unsuccessful in deleting the password so that I can download applets required for running some files. Is there a solution?


I am unable to install WinUSB in Ubuntu 14.04 using command:  sudo apt-get install winusb  What is the correct way to install WinUSB in Ubuntu 14.04? Or is there any other application available to create Windows bootable USB in Ubuntu 14.04?

I'd like to create a Windows bootable USB stick, but I don't have a Windows machine with me at the moment to do so. How could I achieve the same using Ubuntu?


INSERT INTO EMP (EMPNO,ENAME,JOB,MGR,HIREDATE,SAL,COMM,DEPTNO) VALUES  (7499,'ALLEN','SALESMAN',7698,'20-Feb-81',1600,300,30)       , (7521,'WARD','SALESMAN',7698,'22-Feb-81',1250,500,30);   Tried to insert two rows at the same time. but failed saying "SQL command not properly ended". Can someone please correct the query?  Error:     Error at Command Line : 18 Column : 125 Error report - SQL Error: ORA-00933: SQL command not properly ended 00933. 00000 - "SQL command not properly ended" *Cause: *Action:


We see in the Battle of Geonosis in Attack of the Clones that the clone army had Acclamator-Class assault ships, but how did they get them? How did Kuat Drive Yards design and produce a warship so fast without any notice?

So we've determined that there wasn't a  and that . We know that Yoda went and gathered the clones from Kamino. But where did they get all of the ships/supplies to transport and equip an entire army? We know they'd been working on a motion in the Senate, but I doubt they could've gotten funding to build all of those ships let alone had time to do so.


I cannot understand why I am receiving the following error:  Too many query rows: 50001  The first two queries work perfectly when using COUNT( id), but the last two Contacts_Reached_TR_120_Query and Accounts_Reached_TR_120_Query receive this error. Is there something wrong with using COUNT_DISTINCT. I also would like to note that the Aggregate Result is only returning six rows.  String Contacts_Created_TR_120_Query = 'SELECT CreatedByID SDR_ID, COUNT( id ) result FROM Contact Where CreatedDate = LAST_N_DAYS:120 AND CreatedById in :ListOfIDs GROUP BY CreatedById'; DynamicBatchApexAR batch1_TR120      =   new DynamicBatchApexAR('SDR_ID', 'result', 'Contacts_Created_TR_120__c', Contacts_Created_TR_120_Query, SDR_IDs);  String Accounts_Created_TR_120_Query = 'SELECT CreatedByID SDR_ID, COUNT( id ) result FROM Account Where CreatedDate = LAST_N_DAYS:120 AND CreatedById in :ListOfIDs GROUP BY CreatedById'; DynamicBatchApexAR batch2_TR120      =   new DynamicBatchApexAR('SDR_ID', 'result', 'Accounts_Created_TR_120__c', Accounts_Created_TR_120_Query, SDR_IDs);  String Contacts_Reached_TR_120_Query = 'SELECT Ownerid SDR_ID, COUNT_DISTINCT( whoid ) result FROM Task Where ActivityDate = LAST_N_DAYS:120 AND OwnerId in :ListOfIDs GROUP BY Ownerid'; DynamicBatchApexAR batch3_TR120      =   new DynamicBatchApexAR('SDR_ID', 'result', 'Contacts_Reached_TR_120__c', Contacts_Reached_TR_120_Query, SDR_IDs);  String Accounts_Reached_TR_120_Query = 'SELECT Ownerid SDR_ID, COUNT_DISTINCT( accountid ) result FROM Task Where ActivityDate = LAST_N_DAYS:120 AND OwnerId in :ListOfIDs GROUP BY Ownerid'; DynamicBatchApexAR batch4_TR120      =   new DynamicBatchApexAR('SDR_ID', 'result', 'Accounts_Reached_TR_120__c', Accounts_Reached_TR_120_Query, SDR_IDs);

So I have the following query that I am running through Batch Apex. I get the error:  System.LimitException: Too many query rows: 50001  I am receiving this because COUNT_DISTINCT() is subject to the same governor limits as other SOQL Queries. Basically I cannot think of a solution here, which is why I am posting this. The goal of the query is to see how many unique accounts an SDR is in contact with over a given time period. In this case, it is over a 120 day period. Would love some advice on how to achieve this.  String Contacts_Reached_TR_120_Query = 'SELECT Ownerid SDR_ID, COUNT_DISTINCT( whoid ) result FROM Task Where ActivityDate = LAST_N_DAYS:120 AND OwnerId in :ListOfIDs GROUP BY Ownerid';  DynamicBatchApexAR batch3_TR120      =   new DynamicBatchApexAR('SDR_ID', 'result', 'Contacts_Reached_TR_120__c', Contacts_Reached_TR_120_Query, SDR_IDs);   Then here is the batch class  global class DynamicBatchApexAR implements Database.Batchable<AggregateResult> {  public String sObjectIdKey; public String sObjectResultKey; public String sObjectFieldToUpdate; public String query; public List<Id> ListOfIDs;   global DynamicBatchApexAR(String arIdKey, String arResultKey, String fieldToUpdate, String soqlQuery, List<Id> whereInClause )  {       sObjectIdKey            = arIdKey;     sObjectResultKey        = arResultKey;     sObjectFieldToUpdate    = fieldToUpdate;     query                   = soqlQuery;     ListOfIDs               = whereInClause; }  global DynamicBatchApexAR(String arIdKey, String arResultKey, String fieldToUpdate, String soqlQuery )  {       sObjectIdKey            = arIdKey;     sObjectResultKey        = arResultKey;     sObjectFieldToUpdate    = fieldToUpdate;     query                   = soqlQuery; }  global Iterable<AggregateResult> start(Database.BatchableContext BC)  {     return ListOfIDs == null ? new BulkIterable(query) : new BulkIterable(query, ListOfIDs); }  global void execute(Database.BatchableContext BC, List<sObject> scope)  {     DynamicSObjectUpdater sObjectUpdater = new DynamicSObjectUpdater();      for(sObject sObj: scope)     {          AggregateResult ar      = (AggregateResult)sObj;         ID sObjectId            = (ID)ar.get(sObjectIdKey);         Decimal arResult        = (Decimal)ar.get(sObjectResultKey);         Map<String, Object> sObjectFieldsToUpdate = new Map<String, Object>{             sObjectFieldToUpdate => arResult         };          sObjectUpdater.getUpdateSObject(sObjectId, sObjectFieldsToUpdate);     }      sObjectUpdater.updateSObjects();   } global void finish(Database.BatchableContext BC)  {  }   }  Here is the iterable    global with sharing class BulkIterable implements Iterable<AggregateResult> {         String query;         List<Id>   ListOfIDs;      global BulkIterable(String soql, List<Id> WhereInClause)     {         query = soql;         ListOfIDs = WhereInClause;     }      global BulkIterable(String soql)     {         query = soql;     }      global Iterator<AggregateResult> Iterator(){         return ListOfIDs == null ? new BulkIterator(query) :  new BulkIterator(query, ListOfIDs);     }  }   Here is the iterator      global class BulkIterator implements Iterator<AggregateResult> {        AggregateResult[] results { get;set; }       Integer index { get;set; }   List<Id> ListOfIDs;      global BulkIterator(String query, List<Id> WhereInClause)      {     index = 0;     ListOfIDs = WhereInClause;     results = Database.query(query);        }    global BulkIterator(String query) {     index = 0;     results = Database.query(query);      }    global Boolean hasNext(){     return results != null && !results.isEmpty() && index < results.size();    }        global AggregateResult next() {      return results[index++];   }      }   Is the error because I am running too many batches?


How do you earn reputation when trying to start on Stack Overflow? Typically, I'm programming in C# at work, using and consuming SO threads several times a day.  I'd be able to up/down many answers each time I use SO but can't without reputation. Unfortunately I won't ask new questions since almost anything I wonder has been answered already. And I won't answer questions since almost anything I would answer has been told already.  I really want to participate but don't really know how. Please tell me how to do it, old lads!

Is there any way of getting to the first 15 reputation (at which point you can actually do something) on Stack Overflow other than by asking questions?  My problem is this: if I see a good answer that works, I can't vote for it (not enough reputation).  I have been programming for many years and often see a question I could contribute, but I can't (not enough reputation).  I so far have never needed to ask a question (I know how to use a search facility, and so can find an already existing answer).    Therefore asking questions can't possibly be the only mechanism to get enough reputation to get started, can it?  Because if it is then as more and more questions get asked on Stack Overflow, the need to ask new ones will diminish, so if this is the only mechanism of gaining those first few reputation, soon all new joiners will never be able to contribute, or will need to re-ask already answered questions (not good for anyone).  Advice on how to get those first few reputation gratefully received.


As per our current scientific knowledge the earth rotates on its axis and it rotates at a speed of 1670 kilometers/hour. This decreases by the cosine of your latitude so that at a latitude of 45 degrees, cos(45) = .707 and the speed is .707 x 1670 = 1180 kilometers/hr  Earth atmosphere has 5 distinct layers :   First there is the troposphere, which contains more than half of the overall atmosphere. Near the poles, it starts at the Earth’s surface and stretches more than 30,000 ft (9 km), and about 56,000 ft (17 km) at the Equator The Second layer is the stratosphere ,it begins where the troposphere ends, extending above 31 miles (50 km) above that. This is where many airplanes fly, due to the stability of this layer. Going onward up, there is the mesosphere — the area in which meteors generally burn up Just above the mesosphere is the thermosphere Exosphere is the area where earth atmosphere ultimately merges with space. Space starts at 188 KM above the earth surface.   Keeping all the above in perspective, Let’s say that a space craft reaches an altitude of 800 KM above the earth surface and is well outside the earth’s atmosphere. Now since the earth below is rotating, would the space craft be able to land in different places by just hovering above and making a straight vertical descent. This would eliminate all horizontal travel distance as done by the airplanes when traveling from one point to another. Once we are at 800 km above the earth surface, all that is needed is to wait for the appropriate time when as a result of rotation of the earth, your destination point passes right under you and you descent your space craft to your destination. Do you think that this could revolutionize travelling? Less fuel and less time by just taking advantage of the rotation of the earth?  I am also attaching a diagram to clarify my question. The Diagram shows the various layers of earth’ atmosphere. The Orange tube just shows the vertical descent I am talking about from Point A in outer space (say at 800 km above the surface of earth). The Yellow line is the Imaginary karman line at distance of 110 km which serves the boundary between the earth’s atmosphere and the region where the space begings.  Please comment if the idea is feasible and the areas where you see flaws in this theory. One possible argument that people can give in the opposition of the idea is :  “Motion is relative and that the earth’s atmosphere rotates with the same velocity as the earth itself and therefore our spacecraft in question would also be in  same motion as the atmosphere” - Relative Motion Concept Please note that the relative motion concept would not apply in the case presented above because my assumption is that the space craft is no longer in earth’s atmosphere and is way beyond the karman line and cannot be considered as inside the earth’s atmosphere. The Space craft is 800 KM above the surface of the earth. Do you think that this idea of vertical travelling taking advantage of earth’s rotation is possible? Please comment.  Your feedback would be greatly appreciated.

I saw a video some days ago () of a schoolgirl successfully launching a balloon into space which later popped and landed ~47 km from launch site.  If I vertically launch an object (say via balloon or rotors) from the surface of a spinning planet with an atmosphere like ours, then as it rises, will the planet's surface move away below it, or will the object rotate with the earth? (Assume that there are no local strong winds relative to the atmosphere, and it is completely calm.) The latter would mean the atmosphere, being itself a collection of such objects (air molecules), also spins with the planet.  Related SE question:   It seems from common sense that since at launch the object shares the motion of the surface it would keep rotating with the planet, and hence would later land at the launch site. However, as it ascends, the lateral speed required to maintain the same angular velocity with the planet rises linearly. Where would it get this extra momentum/energy from? From the rotating atmosphere? How did the atmosphere get moving in the first place then?  It might seem a lot of questions for a single SE post, but they're all connected, so a single explanatory answer should suffice.


How long will canned cooked clams last after can has been opened- and been refrigerated? OK to eat after 7 days? (No weird smell detected)

How do I know if a given food or ingredient I have is still good, or if I should discard it?  How can I best preserve a food or ingredient?     This broad question is intended as a "general reference" question to quickly answer many how long will food keep for? questions. Please feel free to edit this question to expand and clarify as needed.


Given a solid ball with density $\rho$ and radius $R$, we dig a "thin tunnel" through its center and place an object with mass $m$ at distance $r$ from the center.  Computing the gravitational force, how come can we ignore all the mass further away than $r$? All answers I found rely on Gauss' Law for gravity, which although I know I don't want to use. My main problem is setting up the explicit integral we need to calculate.

It is quite easy to derive the gravitational field intensity at a point within a hollow sphere. However, the result is quite surprising. The field intensity at any point within a hollow sphere is zero.   What exactly is the reason behind this? Except for, of course, the mathematics behind it. Is there any logic why the field intensity should be zero within a sphere? For example, it is logical to say that the field intensity would be zero at the center, as all the intensities cancel out. However, this cannot be the case for any point within the sphere.


I appear to have lost some hats: At the beginning I got 5 or 6 secret hats (obviously I have no idea for what) but that count suddenly went down to 4. I might have thought that I mis-remembered if I wasn't currently wearing one of the lost ones:  As you see that Disciple hat is not in the collection. Furthermore, the "You earned this hat on" list for it is empty. Thus, ... are hats sometimes denied after earning them by design or is this a glitch?

Till a couple of hours back I was having a collection of 20 odd colorful hats. All of a sudden now it seems a gust of wind made me lose a couple of my hats. I am aware about :  I fixed a bug in the secret definition of Vexillologist, removed the hat from all users (since a good number who earned it should not have, based on a bug in the sql) and reawarded to all users who should earn it. Anyone who is earning it now will get a new WB inbox notification. So if you are trying to figure out the hat, just look at hats awarded from [now - 5 minutes] and on.  Were there more similar incidences?  PS: I've managed to hide my Vexillologist hats within my cupboard up till now


Before anyone says this has been answered elsewhere I don't think it has.   The likelihood is given by:  $$ L(θ;x_1,\cdots, x_n) = \prod^n_i f(x_i\mid\theta)$$  where $f$ is the probability density function for a continuous function or probability mass function if discrete.   For a discrete probability distribution, the individual $f$ terms are probabilities so I understand the need to form a product.   For a continuous probability distribution such as the normal distribution, the probability is the area, not the height. Why can we multiply the heights for a pdf when computing the likelihood since the height itself isn't a probability?

In general we maximize a function   $$ L(\theta; x_1, \ldots, x_n) =  \prod_{i=1}^n f(x_i \mid \theta) $$  where $f$ is probability density function if the underlying distribution is continuous, and a probability mass function (with summation instead of product) if the distribution is discrete.  How do we specify the likelihood function if the underlying distribution is a mixture between a continuous and a discrete distribution, with the weights on each depending on $\theta$ ?


Okay so here is the deal: My mother-in-law's ex boyfriend installed Ubuntu on her computer, due to the fact that she isn't very good with computers, I now have to install windows 7 on it. I started the install after a long time trying to get the damn thing to boot from the disc. Halfway through something went wrong and it told me to retry. Now it pops up with whenever i try to boot from the CD again:  Error: unknown filesystem entering rescue mode... grub rescue>  I have formatted the drives, but somehow grub is still there (no idea how?) Now how do I delete this stuff and install windows?

I have absolutely no experience with Linux, and I desperately need to get my computer back up and running again with Windows.  How do I remove Ubuntu and reinstall Windows?    Editor's note: many of the answers are about removing Ubuntu from dual-boot but keeping Windows (which is a bit complicated), while other answers are about removing Ubuntu from single-boot (which is easy: basically just format the disk while installing Windows). The question as written is ambiguous between dual-boot or single-boot.


We installed ubuntu linux in windows 10 machine. However, we are not getting dual booting option to run ubuntu after rebooting the laptop. After rebooting, windows 10 always shows up, never ubuntu linux. Please help us to fix this problem.

I installed Ubuntu on a Dell XPS 13 laptop that had Windows 10 preinstalled on it. I installed it from a USB flash drive on a partition. When I boot my computer I can only boot into Windows 10 and Ubuntu is nowhere to be seen.  If I boot into my USB then I can see that Ubuntu is installed, but I can't get to it from the BIOS boot menu.


I think there is an error in the  physics profile page. The about me section does not fit. I already tried to zoom, but that didn't help. Please see the picture below for clarification.

Odd CSS link colors have appeared again on at least some of the sites without the CSS update, specifically including Science Fiction & Fantasy and Mi Yodeya, and likely others.  User profile pages also have broken layouts.  I believe it's related to this previous bug report:    This time, Seasoned Advice is not affected as they've had the CSS redone.


Can someone explain how the milliseconds works and some documentation. I am trying to work out, given two dates, what is the years, days and months difference between the two dates. Ideally I would want to round off the number so no decimals. Is this possible in JavaScript without any libraries?  This is my code so far. I have tried doing 1000 * 60 / 365 and a few combinations but I do not know what those represent - I may try hours too.          var date1 = new Date(a); // 01/03/2008         var date2 = new Date(b); // 22/03/2016         var timeDiff = Math.abs(date2.getTime() - date1.getTime());         var diffDays = Math.ceil(timeDiff / (1000 * 3600 * 24));          var diffMonths = Math.ceil(timeDiff / (12));          var diffYears = Math.ceil(timeDiff / (365));          console.log(diffDays);         console.log(diffMonths);         console.log(diffYears);   I managed to work out days difference but I still do not understand it fully.

I'm creating an application which lets you define events with a time frame.  I want to automatically fill in the end date when the user selects or changes the start date.  I can't quite figure out, however, how to get the difference between the two times, and then how to create a new end Date using that difference.


How do I take the default off of my secondary Google Drive account, so my primary account shows up first in Google Drive?

After I enable multiple sign-in, and login to multiple accounts, I see that one of them says "(Default)". How do I change which of the accounts is the default one?


Compare two variables named target and guess when one is an integer, and one is a string using Python 3.  import random import sys target = random.randint(1, 20) name = input ('Hello, what is your name?') print ('Hello, %s. I am thinking of a number from 1 to 20. You will have 3 tries, and after each try, I will tell you if the number that I am thinking of is lower or higher. Try to guess it!' % name)  guess = input ('What number do you think I am thinking of?') if guess == target:     print ('Congratulations! You won! Please play again!')     sys.exit() else:     print ('You did not guess the number correctly.')     if target < guess:         print ('The number that I am thinking of is smaller than your guess. Try again')     else:         print ('The number that I am thinking of is larger than your guess. Try again!')

I have a tuple of tuples from a MySQL query like this:  T1 = (('13', '17', '18', '21', '32'),       ('07', '11', '13', '14', '28'),       ('01', '05', '06', '08', '15', '16'))   I'd like to convert all the string elements into integers and put them back into a list of lists:  T2 = [[13, 17, 18, 21, 32], [7, 11, 13, 14, 28], [1, 5, 6, 8, 15, 16]]   I tried to achieve it with eval but didn't get any decent result yet.


If Quicksilver runs at speeds faster than the speed of sound then how come the song he's listening to on headphones is playing at a normal rate?

In Days Of Future Past, Quicksilver spends a lot of time playing with electronics.  In his famous tour de force scene in the Pentagon, he specifically puts his headphones on before running around the kitchen.  But why?  Does the music on his Walkman speed up with him as he uses it, or is it still operating at "normal" speed? Or indeed, does any electronic device that he touches speed up?


Hi i wanted to know if it is possible to remove the swap partition and merge it with home partition. I'm dual booting with mac os using refind, and tried to boot gpartedlive from refind, but it wont boot and gets stuck on a terminal-like black screen.   Edit : I forgot to ask how come I have two recovery hd partitions? is it safe to delete one? maybe it's because I did a fresh reinstall of the whole osx system?

I have 4GB of RAM and I want to install Ubuntu. Do I need a to have a swap partition? Because my computer has 4GB RAM, I do not think it is necessary to have a swap partition. If I do need to have a swap partition, should it be a 4GB or an 8GB partition?


There is probably a duplicate or a simple question but I would just like to do this so I can add my game to a .zip directory so it takes up less space.

If I have a Java source file (*.java) or a class file (*.class), how can I convert it to a .exe file?  I also need an installer for my program.


Let $T: V \rightarrow V $ be a linear mapping such that $T^2=T$. If $M = Image(T)$ and N = $Ker(T)$,   I want to show that $V = M \oplus N$. Not sure how to proceed.

I got the following question as my homework.     Given $V$ is a vector space with $P \in \operatorname{End} V$. $P \circ P = P$ ("P is idempotent"). Show that $V = \operatorname{Ker} P \oplus \operatorname{Im} P$.   One $P$ I can imagine is a projection from 3d-space to plane, that just sets some coordinates to zero. For example $\begin{pmatrix} x \\ y \\ z\end{pmatrix} \mapsto \begin{pmatrix}x \\ y \\ 0\end{pmatrix}$. Then $\operatorname{Ker} P$ would give the line $\begin{pmatrix} 0 \\ 0 \\ z\end{pmatrix}$ and $\operatorname{Im} P$ would contain all $\begin{pmatrix}x \\ y \\ 0\end{pmatrix}$. So the result of $\operatorname{Ker} P \oplus \operatorname{Im} P$ is of course $V$.  But how do I prove that in a mathematical way?


I have a 140GB partition I would like to merge into an existing partition. Both are APFS formatted. How can I merge these two containers ?   Container Disk2 is my MacMini OS Mojave 115.9GB Container Disk1 is 140GB empty that I want to merge to Disk2

Using the latest Macbook Pro with currently High Sierra 10.13.1, I was using bootcamp for a year, and I decided to get rid of the Bootcamp partition this morning. The Bootcamp utility would not let me erase this partition, so I decided to do it through Disk Utility.  I did everything I could to "erase" it, but I can't find any way to merge this 58GB partition with my primary Macintosh HD one.    In Disk Utility, if I want to erase the container Disk2, it tells me that an internal error occured... The BOOTCAMP partition is actually formatted as APFS...    $ diskutil list     How can I merge those two partitions ?  EDIT : The BOOTCAMP partition is now gone but I can't extend the primary one ...


I am absolutely brand new to Ubuntu, having tried it a few years ago and didn't continue with it because my often used software would not work on it.  I still need to use Windows from time to time and I have a dual boot system on a Dell Inspiron n5010 laptop.  This morning when using Windows, Skype tried and failed to update.  I shut down restarted and booted to Ubuntu.  Trying to access the files in the windows partition gave this message:  Error mounting /dev/sda3 at /media/nick/426268B36268AD7B: Command-line `mount -t "ntfs" -o "uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000" "/dev/sda3" "/media/nick/426268B36268AD7B"' exited with non-zero exit status 14: Windows is hibernated, refused to mount. Failed to mount '/dev/sda3': Operation not permitted The NTFS partition is in an unsafe state. Please resume and shutdown Windows fully (no hibernation or fast restarting), or mount the volume read-only with the 'ro' mount option.   I shutdown Widows fully but still get the same error.  At this stage I don't know enough to or mount the volume read-only with the 'ro' mount option.  Since posting this question I have found that restarting rather than shutting down after using windows cured the problem.  I have no hibernate option in my windows 10

Whenever I boot Ubuntu, I get a message that it cannot mount my windows partition, and I can choose to either wait, skip or manually mount.  When I try to enter my Windows partition through Nautilus I get a message saying that this partition is hibernated and that I need to enter the file system and properly close it, something I have done with no problem so I don't know why this happens.    Here's my partition table, if any more data is needed please let me know.     Device Boot      Start         End      Blocks   Id  System /dev/sda1            2048    20000767     9999360   83  Linux /dev/sda2        20002814   478001151   228999169    5  Extended /dev/sda3   *   478001152   622532607    72265728    7  HPFS/NTFS/exFAT /dev/sda4       622532608   625141759     1304576   82  Linux swap / Solaris /dev/sda5        20002816   478001151   228999168   83  Linux


Suppose we have a Fourier pair of  $f(t)={1\over 2\pi}\int_{-\infty}^{\infty}F(w)e^{-iwt}dw$ and $F(w)=\int_{-\infty}^{\infty}f(t)e^{iwt}dt.$  How can we prove the following pair? $f(t)=\int_{-\infty}^t g(\tau) d\tau $ and $F(w)=G(w)/iw+\pi G(0)\delta(w),$ where $\delta$ is a delta function.

How to prove   that      $$\mathcal{F}\left\{\int_{-\infty}^{t}f(\tau)\, d\tau\right\}=\frac{1}{i\omega}F(\omega)+\pi F(0)\delta(\omega),$$   where $F(\omega)$ is Fourier transform of $f(t)$.  Could anyone explain to me how to prove this?  thanks.


Say you have 2 functions:  void func(int x,int y,...) {  //do stuff } void func2(int x,...) {  func(x,123,...); }   How can you make this work, e.g pass the arg-list to the other function?  EDIT: this is a , can someone merge them or whatever?

Say I have a C function which takes a variable number of arguments: How can I call another function which expects a variable number of arguments from inside of it, passing all the arguments that got into the first function?  Example:  void format_string(char *fmt, ...);  void debug_print(int dbg_lvl, char *fmt, ...) {     format_string(fmt, /* how do I pass all the arguments from '...'? */);     fprintf(stdout, fmt);  }


I was following the "" tutorial to verify the ubuntu-18.04.5-desktop-amd64.iso download. After the following command gpg --keyid-format long --verify SHA256SUMS.gpg SHA256SUMS  I receive the following message: gpg: Signature made Thu 13 avg 2020 17:02:20 CEST  gpg:                using RSA key 843938DF228D22F7B3742BC0D94AA3F0EFE21092  gpg: BAD signature from "Ubuntu CD Image Automatic Signing Key (2012) <cdimage@ubuntu.com>" [unknown]  I've downloaded all the files (SHA256SUMS.gpg, SHA256SUMS, iso file) from the  page. I've been told that there is a similar question answered . I acknowledge this. But (1) the question is rather old, maybe in the meantime the files SHA256SUMS and SHA256SUMS.gpg have changed and (2) the answers in that question do not answer my problem. I have downloaded the files with Save Link As... from Firefox browser. It would help me if I get confirmation that the files are ok; then the problem is on my side. Then any help what the problem might be would be useful. Edit: it seems . So there may be something wrong with the signature.

I am attempting to verify my download of Bionic Beaver on Windows 7.  I feel like I am missing something very obvious.  I went to  and clicked on both SHA256SUMS and SHA256SUMS.gpg  It seems like this does not download the files, but opens the text in the files in new tabs.  I used Ctrl-A and then copied the text into Notepad, naming the files SHA256SUMS and SHA256SUMS.gpg.  I made sure that windows didn't add any weird extensions when saving.  I manually downloaded both keys I used from https://keyserver.ubuntu.com, one with fingerprint  C598 6B4F 1257 FFA8 6632 CBA7 4618 1433 FBB7 5451   and the other with fingerprint  8439 38DF 228D 22F7 B374 2BC0 D94A A3F0 EFE2 1092   After I downloaded both keys I certified them with my personal key using Kleopatra, after verifying the key fingerprint with those at .  When I ran   gpg --verify SHA256SUMS.gpg SHA256SUMS   I got   gpg: Signature made 11/29/18 16:27:43 US Mountain Standard Time gpg:                using DSA key 46181433FBB75451 gpg: BAD signature from "Ubuntu CD Image Automatic Signing Key <cdimage@ubuntu.c om>" [full] gpg: Signature made 11/29/18 16:27:43 US Mountain Standard Time gpg:                using RSA key D94AA3F0EFE21092 gpg: BAD signature from "Ubuntu CD Image Automatic Signing Key (2012) <cdimage@u buntu.com>" [full]   When I ran   gpg --verbose --verify SHA256SUMS.gpg SHA256SUMS   I got  gpg: armor header: Version: GnuPG v1 gpg: Signature made 11/29/18 16:27:43 US Mountain Standard Time gpg:                using DSA key 46181433FBB75451 gpg: using pgp trust model gpg: BAD signature from "Ubuntu CD Image Automatic Signing Key <cdimage@ubuntu.c om>" [full] gpg: binary signature, digest algorithm SHA512, key algorithm dsa1024 gpg: Signature made 11/29/18 16:27:43 US Mountain Standard Time gpg:                using RSA key D94AA3F0EFE21092 gpg: BAD signature from "Ubuntu CD Image Automatic Signing Key (2012) <cdimage@u buntu.com>" [full] gpg: binary signature, digest algorithm SHA512, key algorithm rsa4096   I tried copying the data from SHA256SUMS and SHA256SUMS.gpg tabs over TOR instead, in case it was a local network problem, but no dice either.  What am I missing here? Is there some way to download the SHA256SUMS and SHA256SUMS.gpg files directly, as opposed to copying the data into a text editor and saving it?  Any help would be very appreciated. I am very confused and frustrated at this point.


In python I'm having a unicode escape sequence that is originally a part of chinease text. I'm trying to display it properly (to convert into Unicode string). Searching SO I've tried several proposed ways but none of them work. Here's what I got:  import re import codecs import urllib  ESCAPE_SEQUENCE_RE = re.compile(r'''     ( \\U........      # 8-digit hex escapes     | \\u....          # 4-digit hex escapes     | \\x..            # 2-digit hex escapes     | \\[0-7]{1,3}     # Octal escapes     | \\N\{[^}]+\}     # Unicode characters by name     | \\[\\'"abfnrtv]  # Single-character escapes     )''', re.UNICODE | re.VERBOSE)  def decode_escapes(s):     def decode_match(match):         return codecs.decode(match.group(0), 'unicode-escape')      return ESCAPE_SEQUENCE_RE.sub(decode_match, s)   print(decode_escapes('\u6240\u8BF7\u6C42\u7684\u8FD4\u7A0B\u65E5'))   Trying to execute this code will fail with this error:  Traceback (most recent call last):   File "Test.py", line 21, in <module>     print(decode_escapes('\u6240\u8BF7\u6C42\u7684\u8FD4\u7A0B\u65E5'))   File "C:\Python27\lib\encodings\cp437.py", line 12, in encode     return codecs.charmap_encode(input,errors,encoding_map) UnicodeEncodeError: 'charmap' codec can't encode characters in position 0-6: character maps to <undefined>   Finally it should be like this:  所请求的返程日   Could you suggest what I can do to see correct string?

When I try to print a Unicode string in a Windows console, I get an error . UnicodeEncodeError: 'charmap' codec can't encode character .... I assume this is because the Windows console does not accept Unicode-only characters. What's the best way around this? Is there any way I can make Python automatically print a ? instead of failing in this situation? Edit:  I'm using Python 2.5.  Note: @LasseV.Karlsen answer with the checkmark is sort of outdated (from 2008). Please use the solutions/answers/suggestions below with care!!  is more relevant as of today (6 Jan 2016).


I am a 67 years old Canadian Citizen who came to US to visit my son on Feb 29th, 2020. Can't go back due to Covid19, how can I get insulin?

My wife takes a prescription medication that cannot be stopped. Her supply is running out while in the US and we've tried faxing her foreign doctor's prescription to Walmart but they wouldn't accept it. What options do we have for getting a prescription quickly? We've thought of going to a walk-in clinic or urgent care but fear a lengthy diagnosis with costly lab tests.


I need to download  file. Being on cellular internet I should know the size of the file before downloading it - it there any way know that in OS X?  I saw a , but I cannot realise how to use the asnwer there.

How can I know the file size of the downloaded file before downloading it?


I've noticed that on Stack Overflow, some posts are highlighted yellow, while others aren't. Is there a reason for this?

On SO, when I'm scrolling through "questions" some have a yellow background.  Is this intuitive to everyone but me?  What is the yellow background trying to tell me about this particular question?


I have one remote server with MySQL databases running on it and I would like to move one database I have on my personal computer in this remote MySQL server to centralize everything.  Global configurations:   Personal Computer (origin): MySQL 5.7 and Ubuntu 16.04 Server (target): macOS El Capitan + MySQL 5.7   If I move only the database file to the new computer (using secure copy) I’m running into an error saying tables doesn’t exit but I’m still able to select the database name in the list:   ERROR 1146 (42S02): Table ´database_name.table_name´ doesn´t exist   If I also move configurations files, I will erase existing configuration for currently running databases.   How can I merge MySQL configuration files to merge all those databases on the same device without loosing any data?

What is a good way to sync two MySQL databases?   I would like to sync the data in my production website's database to my local development database. Right now, I am just using the PHPMyAdmin interface to export it from one, and then I import it into the other.  These would be user-initiated sync's, not necessarily periodic or automated (something like a one-click sync).


I'm a bit worried because one of my papers have been more than 2 months "with editor" status. It's a science journal (field: drug residue, food), from a famous editorial and impact factor 3.3. I'm used to 48h desk reject and I was wondering about the options of being so long with this status 1) very busy editor 2) my paper was forgotten 3) there is a mistake on the website  Oh, normally we have the option to send an e-mail to the assigned editor, but in this case there is only "view your submission".  Edit:  At the end it took 2 months but... We are under review!

I have submitted a paper to a journal 2 and a half months ago. Its status remains "With editor". From your experience, is this normal? If not, how should I deal with that?


I experienced the reset bug several times and my decorated levels were stripped (including when I had about 29 levels done ..so close!!!) so I was unable to unlock panna city meds.   Does anyone know if it will be possible to unlock this level some other way? I have special boba fett, but no level to match him with :,(

The Holiday Decoration Event may have started a month ago, but, it only showed up yesterday in my game.  And, it says there are 0 days left. The app was updated as soon as it was released, but there was no sign of it in-game. Is this a bug? If so, are there any fixes that I can apply?


I encountered a  for a question without tags.      A question without tags? Suspicious... Aha - a review audit!

I have found another indicator that reveals a post to be an audit in the review queue. The question did not show the tags, although they are normally shown. Here is the image(the image is after I passed, but it didn't show the tags before either):  Review with no tags:    Proof it has tags:    And here is an image of a real review on a question that showed the tags (even though they weren't being changed), which I believe is normal:  Non-audit review with tags:    Obviously, things that indicate that the review is an audit is bad (I have found several, check my previous posts). If someone can please confirm that this is a bug so that it can be fixed?  EDIT: This appears to not be a "known-good audit".


If someone is performing music with an instrument, I'd say that they're playing the instrument.  If someone is performing music with their voice, I'd say that they're singing.  Is there a word that combines both of these connotations?  "In the band, there are pianists, drummers, flautists, and singers; they _____ together."  I wouldn't use perform in this context, because they're not performing in front of an audience. Practice also doesn't have the right connotation, and playing to me connotes strictly playing an instrument and wouldn't be used in the context of singing. Jamming is a relevant word, but to me connotes only certain types of musical styles. Is there a single word that would encapsulate both singing and playing an instrument?

I'm looking for a word that means "to make music" without regard to how the music is made (vocal or instrumental), like "to sing" means to make music by passing air over the vocal chords. Example sentences:  I am going to ____. Let's ____.  I would like it to not require an object( for example "play" would work, but the meaning is unclear without stating what is being played). EDIT: To clarify, I am looking for a single word meaning to play music, not a word meaning to write music, although it should be able to apply to improvising(playing and composing music simultaneously). EDIT2: "Make Music" does not work because it is unclear (it could mean to compose or to play music) and sounds too formal for common use.


I wish to add the same thing which is 'select service' by clicking the add button and want to have the same functionality. I've been trying this..I also add the 'select service' by clicking the add button which is obtained through the cloning of the individual div(s). But I found that, through cloning I can't get the job done as the functionality won't work for the clone(i.e I can't get the div(s) for shirt,pant,suit by clicking the buttons). I also attach the cloning part coding but it commented. So, rather than cloning, is there any possible way to do this with the help of jquery?    $(function() {   $('#selectService').change(function() {     $('.hidden-fields').hide();     var $target = $(this).val();     $('#' + $target).show();   });   $("#add").click(function() {      var $orderClone  = $("#orderClone:last");      var $clone = $orderClone.clone();      $clone.find('*').val('');      $orderClone.after($clone);    });  }); .hidden-fields {   display: none; }

         Service

                    <select id="selectService" name="service[]" class="form-controlservice">             <option disabled="" selected="">Select Service</option>             <option id="one" value="shirt">Shirt</option>             <option value="pant">Pant</option>             <option value="suit">Suit</option>           </select>

Shirt

 Body     <input type="text" class="form-control" name="body" />

     Shoulder     <input type="text" class="form-control" name="shoulder" />

     Neck     <input type="text" class="form-control" name="neck" />

Pant

 Length     <input type="text" class="form-control" name="length" />

     Thigh     <input type="text" class="form-control" name="thigh" />

Suit

 Name     <input type="text" class="form-control" name="length" />

     Name     <input type="text" class="form-control" name="thigh" />

 <button type="button" id="add" name="add" class="btn btn-success" >Add</button>

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


Suppose $\lim_{j\to\infty} a_j=L$  then show that   $$\lim_{j \rightarrow \infty}\frac{a_1+a_2+a_3+\cdots+a_j}{j}=L$$  How would you show this I am entirely certain.  Is this because when you add up all your terms in the sequence and divide by how many you have you have an average, and the limit goes to this "average"

Prove that if $\lim_{n \to \infty}z_{n}=A$ then:  $$\lim_{n \to \infty}\frac{z_{1}+z_{2}+\cdots + z_{n}}{n}=A$$ I was thinking spliting it in: $$(z_{1}+z_{2}+\cdots+z_{N-1})+(z_{N}+z_{N+1}+\cdots+z_{n})$$ where $N$ is value of $n$ for which $|A-z_{n}|<\epsilon$ then taking the limit of this sum devided by $n$ , and noting that the second sum is as close as you wish to $nA$ while the first is as close as you wish to $0$. Not sure if this helps....


I've been reading the  in the US about a court order for Apple to help the FBI bypass the security check present on devices running iOS8+. Since iOS8, Apple has stopped storing encryption keys on the cloud.  I'm just wondering how does this apply to Android. I believe Nexus devices that came with Marshmallow out of the box (6P and 5x) have full disk encryption thus these will have the same security as iOS8+ devices.  How about those that were upgrade to Marshmallow? I know my G3 was upgraded to Marshmallow but encryption is turned off. Also, does turning it on make a difference? Or perhaps the 6P and 5x has extra hardware so encryption keys aren't stored in the cloud?  Thanks for reading and your replies :)

Apple recently made waves within the tech community by refusing to comply with law enforcement in regards to accessing encrypted user data.  Their statement was that they do not have the technical ability to decrypt this data.   As an Android user, is there any similar possibility (preferably built in to the OS instead of third party) that I can use to achieve similar protection from even Google and my device manufacturer? I know there is the "Full Device Encryption" in my settings, but does this prevent Google etc. from accessing it?   For reference, my device runs Android Lollipop and is a OnePlus Two. If other versions like Marshmallow would allow me to do this that's fine.


I would like to know why new users can't flag comments or answers on their own questions as "rude or offensive" unless they've got 15 points.   I'm pretty sure that especially when someone is new to SO and doesn't know exactly how the questions should be formalized - and let's be honest how many of us did read the FAQ right after registration - some comments to those newbie questions can be considered offensive. I also don't think that anyone should need to "earn" the right to report such comments.   For sure someone else might report them - but is it really necessary to expect someone else to "defend" you?

Something that has always bothered us about the new user experience was the amount of guidance we've got out there telling folks to flag rude or abusive comments, but not allowing new users to do it, because .. . Let's un-complicate it and let new users flag any comment on any post that they own. Or, essentially, if you're allowed to comment on a post, you're allowed to flag comments on that post, too. There are some caveats to get around because:  We gate the feature for a reason, and that reason is it takes a little experience to know how flagging works. We're different, it's just a fact of life. Duplicate close votes leave comments that shouldn't be flagged, which new users will probably want to dispute, and a 'flag' dialog seems like a reasonable place to start to most We're not sure how big of a tide the current restrictions are holding back.  So, here's what we propose: New users see a modified flag UI on comments they can flag: Options:  Rude or abusive This is not a duplicate (as-appropriate) (probably churns back through the close vote queue) Other  But here's the thing, we'd let moderators actually see who flagged in these instances, so moderators could gain context and know what else to look for in the situation. Theorized outcome (isn't theory great? everything works there!) Any of the following would indicate success:  More rude comments surface faster Engagement from new users (going past 1 - 2 questions) goes up Frequency of people contacting us to report snark they could have easily flagged if they had a bit of rep goes down  Any of the following would indicate more work is needed, or possibly a general failing of the idea:  Moderators note an increase in noise they can't really act on from 'other' flags Engagement goes down Nothing really happens, at all  The third item in the second list is actually a distinct possibility, because the flag feature is (as it stands) a little difficult to find. We'll be making it more obvious in the future, as well as mentioning it when we launch our revised code of conduct for new users to accept, but there's a strong chance new users just won't notice the feature. We're thinking about putting this out for testing soon and wanted to get any feedback folks might have. This isn't a permanent implementation (yet), but we really do need to let new users raise flags if they encounter snark / condescension / overt rudeness - we've found too many instances of it that just evaded other folks with privileges seeing and flagging it. Thoughts? What we hadn't thought of yet are rate limits, and probably a few other things. Shog is working on some research and I suspect he'll post a pretty comprehensive reply, but we want your take early so we know much sooner than later if we're not seeing obvious problems.


I have a Philippine passport. I'm traveling from Guam to LAX (have a US tourist visa) and returning Houston to Guam. Both flights stopover in Narita, for 4 hours and 8 hours. Do I need a transit visa?   Thanks!

I will be transferring between two international flights at Tokyo Narita airport. I'm scheduled to depart the same day I arrive. I am planning to stay within the airport during the layover. Does anyone know if I will require a transit visa at Narita?


In an autocomplete field only the title of the entity reference is displayed to select it. I would like to display more fields to be more accurate in the selection, but after many research and try different modules I still don't know how to do that :-(  Can someone help me please?

I'll like to add this functionality to the autocomplete widget in Entityreference field to show node ID next to the titles in the dropdown list. The reason behind the idea is to differentiate between multiple nodes with same title.  Example:    This is a title (3) This is a title (2) This is a title (1)   I know the node ID is shown once a selection is made but I like to show it in the dropdown list in order to pick the right node quickly based on the node ID.


I love being as far as possible from the plane path. And sometimes, the couple of houses I want to go to are just a little too far.  So what are techniques to optimize how far you go when freefalling/using the parachute?

When jumping from the aircraft how do I ensure I travel the maximum amount away from the plane? Should I use a steep angle during free fall or a shallow one?   Should I remain in free fall as long as possible, or use the parachute early, and when using the parachute should I lean forward or not?


So I have created a Fragment for my app. In the fragment, I have an EditText field created through the xml file (whose id is myText). Now in my Java class of this fragment, I am creating a reference to this text field by using the command:  EditText myText = (EditText) getView().findViewById(R.id.myText);   However, I get a warning on this statement saying:  Method invocation `getView().findViewById(R.id.myText)' may produce 'java.lang.NullPointerException'.   Also, when I run the app, it terminates prematurely due to the same NullPointerException. I did the exact same thing except without using a fragment (that is, I created an EditText field in the xml file of my main activity) and created a reference to it in the Java file using the command:  EditText myText = (EditText) findViewById(R.id.myText);   and it works perfectly.  So my question is, why does this work in the second case and not in the first? How do I make it work in the first case?

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


I am trying to read some data from firebase database, and when i try to open the activity to see the result i get this error:  Caused by: java.lang.NullPointerException: Can't pass null for argument 'pathString' in child() The error is poiting me to the first line of this code  reference = FirebaseDatabase.getInstance().getReference("Users").child(userid);         reference.addValueEventListener(new ValueEventListener() {             @Override             public void onDataChange(@NonNull DataSnapshot dataSnapshot) {                 User user = dataSnapshot.getValue(User.class);                 username.setText(user.getUsername());             }              @Override             public void onCancelled(@NonNull DatabaseError databaseError) {              }


As you saw in the title, parentheses inside parentheses don't look too good. But, gramatically speaking, is it correct to do this? For example:     Go to this site (you should probably check it out, it's great (in case you didn't already notice) and gives you great information) to find out more about the solar system.

Is it acceptable to nest parentheses (for example, if I (meaning myself) write like this)?


Source:      Many of the summer facilities aren't winterized, so they will have to move come autumn, but they don't know where.   Is this just a fancier way of saying if autumn comes?

From NPR, transcript .     Michelle Scott is reading from the Common Core math standards for   fifth-graders. She'll be teaching fifth next year, along with John   Gries. And together, they're writing—and rewriting—lessons   they'll need come September.   For the last sentence, did he want to say, “they're re-writing lessons they'll need if September comes”? He inverted the last part, put the verb “come” in the front and omitted “if”, right?   As far as I could determine, it seems only “if” with subjunctive voice could be used in this way. I don't think it's a subjunctive voice. In my impression, the subjunctive voice stands for those occasions when you're not sure whether it will happen or not, such as “If it were to rain, I'd pick you up.”   September will come sooner or later (it's not in limbo), so I'm wondering how to explain the sentence.


Packages seem to be downloaded over http from the Ubuntu main repository, so I was wondering whether the client's OS verifies the packages once downloaded? If so please could someone outline the different steps in this process? Would be much obliged if you could use apt-get flac as an example! When exploring -  I can see that there is a DSC file for each version of the package. Within this are the hashes of the XZ archives for the release, which is then in turn signed by one of the maintainers.

I couldn't find much info on the security of Ubuntu (and Linux in general) update verification/security.  The connection appears to be plain ftp. but the packages are signed using a private key and the corresponding public key is stored in the system as a trusted key.  So what are the details? Is the package itself signed or just the hash? Is it an RSA 4096 bit key? What are the chances of a malicious entity being able to mess with the updates and who owns the private key?


I have been asked this question recently in an interview:  You are given an fair Randon5() function, which return numbers between 1-5 with same probability. Now you need to write a fair Random7() function using Random5() which will return numbers between 1-7, nothing else to use.  Thanks in Advance.

Given a function which produces a random integer in the range 1 to 5, write a function which produces a random integer in the range 1 to 7.   What is a simple solution? What is an effective solution to reduce memory usage or run on a slower CPU?


I'm stuck on which is the correct grammar to use in my ad copy. The first sentence is "99% of patients have to wait." which is followed by (one of the following):   "Be the 1% that do not." "Be the 1% that does not." "Be the 1% who does not." "Be the 1% who do not."

Does a percentage require a singular or plural verb, for example, do we say ten percent "go" or "goes"?


Hello I have a JSF Java application that Im working on, Im a beginner only working for two months and I have an error and I dont know how to solve it.  This is the line that the error occurs:  public long getId_l() {     return Long.parseLong(obj.getIdl());  //This is the line with the error. }   An this is the error :   java.lang.NullPointerException     at com.spv.raport.Info.getId_l(Info.java:58)  How can I solve it, or do i have to post more code to get help ?


This is the title of a Hallmark movie: A Wish Come True.  Unfortunately I can't speculate anything as why it is come and not comes.  Thank you for your help.

I was confused by a company slogan I saw, and that made me wonder: Is it correct to write "a dream come true"?  If I was the one writing it I would use "a dream comes true" but is the initial form wrong?


I would like to change the spacing between the sections of a document. Changing the margins values seem to have no effect. What can I do ? Thanks,

I know this subject has been mentioned before, but I'm still having a problem in creating a space under a section title. I used the titlesec package and then tried using the command \titlespacing{\section}...  This is my code. Can anybody help?  \documentclass[10pt]{book} \usepackage[utf8]{inputenc} \usepackage{fullpage} \usepackage[compact]{titlesec} \usepackage{setspace} \usepackage{sectsty} \chapterfont{\huge} \sectionfont{\Huge} \begin{document} \chapter*{Kapitel 1} \section*{Einleitung} \begin{large} \subsection*{1.1 Motivation}