Computing double limit of $\lim_{n\to\infty} \lim_{m\to\infty} \cos^m(n!2\pi x)$

Compute, for every real value $x$, the double limit:   $$\lim_{n \to \infty} \lim_{m \to \infty} \cos^m(n!2\pi x)$$  How do i go about solving the above problem? Note that this is a problem from a real analysis course, not calculus.  Thanks for looking at my question.


hi guys, is there any possibilities to change these mirror ball reflections to my interior scene reflections. as you can see this doesn't looks very good... thanks


Using Gauss's law when point charges lie exactly on the Gaussian surface

Suppose you place a point charge $+Q$ at the corner of an imaginary cube.  Since electric field lines are radial, there is no flux through the three adjacent (adjacent to the charge) sides of the cube. However there is some amount of flux passing through the other three sides of the cube (flowing out of the cube).  We can estimate that the flux through these three surfaces combined is equal to $Q/(8\epsilon)$. As, if you consider $7$ other cubes having the charge at the corner, each of them would have equal flux flowing out by symmetry and since the total flux through the $8$ cubes is $Q/\epsilon$, each cube would have a flux of $Q/(8\epsilon)$.  Now apply Gauss' law to the cube, and we find that the cube encloses a charge of $Q/8$.  This means that 1/8th of the charge belongs to this cube.   But the charge we placed was a point charge with no dimensions. It cannot be split into parts.  What is wrong?


How to find $\zeta(s)$ for $\text{Re}(s)\leq 1$?

I was trying to build animation to show How $\zeta(1/2+it)$ would look as $t$ changes. If the $\text{Re}(s)$ were greater than $1$, I could simply use the definition of the zeta function. $$\zeta(s)=\sum_{n=0}^\infty \frac{1}{n^s}$$ But as the above sum doesn't converge for $\text{Re}(s)\leq 1$, I'm in trouble. I don't know if I can use analytic continuation for it. So I'm asking if there is some trivial way to find $\zeta(1/2+it)$  for  $\text{Re}(s)\leq 1$.


If for a discrete distribution we can say that its PDF answers a question of something like "How possible is exactly this  value?", then what would a be similar "human" interpretation of a PDF for a continuous distribution?  And in R, how in some kind of "practical" terms can an illiterate like me interpret something like dnorm(0.2, 0, 1)? What exactly is '0.2'?  Besides, if dnorm reports a probability for a value in an interval, then is it in any way related to pnorm, which kinda also reports probability for a value in an interval (probability for a value in an upper or in a lower tails)? Can dnorm be expressed via two pnorms? Like, Probability(x1 < X < x2) = F(x2) - F(x1) or something like that?


When scaling or extruding a Gear's Edges, the edges  seem to scale down on the Z axis, in a way that is not level with the origin point of the edges:    Any other "default" Blender object will scale or extrude without scaling down on the Z axis:      How do I scale or extrude these edges without them moving to the center on the Z axis? I don't think it has to do with applying scale/location because all three GIFs in this question were produced at default size for each object.


A finite group of even order, whose $2$-Sylow subgroups are cyclic, is not simple.

Let $G$ be a finite group of even order, whose $2$-Sylow subgroups are cyclic. Show that $G$ is not simple.   I was trying to use Cayley theoem, place $G$ in some $S_m$ and get a contradiction with $A_n$ being simple but I couldn't get to anything...  Moreover I'm not sure how does it help that the $2$-Sylow subgroups are cyclic?


I want to download windows 10 on by Ubuntu 16.04 to dual boot. There are so many ways to download Ubuntu after Windows, but I have no idea of downloading Windows After Ubuntu. Can anyone help?


Should a public site store the language in cookies/handle the Accept-Language header?

There's an idea that if one user sends somebody a link, it most likely wants the other user to see the same content in that specific language. And that coincides with the  . Does that mean that it's best to avoid storing language in cookies and handling the Accept-Language header? From user's perspective and for better indexing.


A word for "untranslatable" words from other languages

Speakers of many languages treat as a cultural good that their language possesses words which are "untranslatable". Of course, that can be challenged or qualified, but this phenomenon is common enough that it deserves a word or phrase in English to describe it: a semantic equivalent of "shibboleth".  Does anyone know of such a word to collectively describe these assertions?  Examples of such claimed words include   Sehnsucht Heimat Gwybodaeth   What these words share, beyond difficulty in translating, is that they are often claimed to be a cultural lodestone for the source language.


Square of a second derivative is the fourth derivative

I have a simple question for you guys, if I have this:  $$\left(\frac{d^2}{{dx}^2}\right)^2$$  Is it equal to this:  $$\frac{d^4}{{dx}^4}$$  Such that if I have an arbitrary function $f(x)$ I can get:  $$\left(\frac{d^2 f(x)}{{dx}^2}\right)^2 = \frac{d^4 f(x)}{{dx}^4}$$  Sorry if it's a pretty simple question, but I was trying to simplify something like this:  $$\left(a \cdot \frac{d^2}{{dx}^2} - f(x)\right)^2 g(x)$$ that's where it came up.


Where is the log of used commands in Linux?

In Linux, generally we use a lot of commands and it is difficult to remember all of them.    history   command provides the list of commands we used previously but its limit is less. New commands are overwritten on old commands then old commands are missing. I think somewhere the log of the commands is stored in the system.  Is that log available to open and read? If possible can we change the maximum size of log that it can handle?  Is the output of history command depends upon the login-user?


How to deal with different resolutions in a 2D game?

For example, you have a sprite of mario with a size of 20px x 20px.  This sprite however was made for a game resolution of 1000px x 1000px. What if you want to provide a different game resolution as an in-game option? You could offer to change the game resolution to 2000px x 2000px, but then Mario should be drawn again for this particular resolution. And if you offer many resolutions, this can be very much to draw and the amount of space the image files will take, are going to get too big.  So, my question, what's the trick here?


Has Tolkien's estate ever sold the rights to adaptations of any Tolkien works?

Inspired by the comments on  question. J.R.R. Tolkien   to United Artists in 1968 or .   Although he retained enough creative control at first to veto  of The Lord of the Rings in the late 60's, it seems that he (and later, his estate) had little or no input in further attempts to make movies based on these two properties. Since Tolkien died in 1973, his estate has done what it could to protect its property, even  for making casino machines and video games using the likenesses of Tolkien characters. And in Tolkien's will, he named his son Christopher as his "sole literary executor", with authority to revise, edit, and publish J.R.R.'s other works. He has done so, releasing several previously unpublished books written by his father - The Silmarillion, Unfinished Tales, and The History of Middle-earth, to name a few.  But I'm asking about adaptations of J.R.R. Tolkien's writing, not Christopher's publication of his father's previously unreleased writing. Has the Tolkien Estate - as opposed to Tolkien himself - sold any sort of rights to adaptations of any of Tolkien's works?


Ubuntu 20.4 virtualbox Kernel driver not installed (rc=-1908)

The VirtualBox Linux kernel driver is either not loaded or not set up correctly. Please reinstall virtualbox-dkms package and load the kernel module by executing'modprobe vboxdrv' as root.If your system has EFI Secure Boot enabled you may also need to sign the kernel modules (vboxdrv, vboxnetflt, vboxnetadp, vboxpci) before you can load them. Please see your Linux system's documentation for more information.where: suplibOsInit what: 3 VERR_VM_DRIVER_NOT_INSTALLED (-1908)  - The support driver is not installed. On linux, open returned ENOENT.  I tried certain commands like sudo modprobe vboxdrv  showing this error Could not insert 'vboxdrv': Operation not permitted  How can I solve this?


How do I use chmod to make .sh files executable?

My touch overlay is failing to respond in portrait but in landscape I got to a page where I am able to rotate touch input so that it can work in portrait (using ), so I have to make the .sh scripts and run them. I am working with shell scripts for the first time and I am using the ones on this page and it asked me not to forget to set chmod to execute for .sh files using this code:  chmod 777 *.sh


Can a character use "provoke" repeatedly to defeat monsters?

In FATE Core there are two types of combat: physical and mental. The mechanics are more or less the same: the physical combat uses fight or shoot against fight or athletics, while mental combat uses provoke against will.  Most monsters are stronger in physical combat than mental combat. So, if a character is strong in "provoke", it seems that he can use that to simply scare away every enemy or monster in his way.  Is that true? Am I missing something?


slow boot boot 19.10 (tried almost everything)

I previously had Ubuntu 18.04 along with Windows 10, after having many problems I decided to install Ubuntu 19.10, but one of the main problems (boot time) was still happening, I have tried almost everything with no solutions. It's really weird since my laptop is new and shouldn't have any troubles. systemd-analyze time Startup finished in 3.449s (firmware) + 48.782s (loader) + 5.522s (kernel) + 52.274s (userspace) = 1min 50.028s  graphical.target reached after 52.206s in userspace   systemd-analyze blame      29.319s plymouth-quit-wait.service       8.752s NetworkManager-wait-online.service       8.734s snapd.service       8.325s dev-sda5.device       8.277s systemd-journal-flush.service       6.499s networkd-dispatcher.service       6.000s ModemManager.service       5.693s udisks2.service       4.703s accounts-daemon.service       4.134s NetworkManager.service       3.867s e2scrub_reap.service       3.645s systemd-fsck@dev-disk-by\x2duuid-86D3\x2dF64F.service       3.387s secureboot-db.service       3.344s grub-common.service       3.257s dev-loop2.device       ...  EDIT I: Things I have tried so far: fresh installs many times, edited grub file with "quiet splash noresume", disabled some processes that were taking a long time, and most of the common solutions that somebody could find on internet. Results of: cat /proc/swaps && free -m Filename                Type        Size    Used    Priority /swapfile               file        947128  0       -2                total        used        free      shared  buff/cache   available Mem:          10969        1603        8030         124        1336        8958 Swap:           924           0         924  Result of systemd-analyze critical-chain graphical.target @52.206s └─multi-user.target @52.206s   └─kerneloops.service @31.766s +1.015s     └─network-online.target @31.601s       └─NetworkManager-wait-online.service @22.848s +8.752s         └─NetworkManager.service @18.711s +4.134s           └─dbus.service @18.704s             └─basic.target @18.474s               └─sockets.target @18.474s                 └─snapd.socket @18.310s +163ms                   └─sysinit.target @18.286s                     └─apparmor.service @15.427s +2.858s                       └─local-fs.target @15.423s                         └─boot-efi.mount @14.946s +477ms                           └─systemd-fsck@dev-disk-by\x2duuid-86D3\x2dF64F.service @10.828s +3.645s                             └─dev-disk-by\x2duuid-86D3\x2dF64F.device @10.826s  EDIT II: Outputs after sudo systemctl disable NetworkManager-wait-online.service systemd-analyze time Startup finished in 4.261s (firmware) + 12.044s (loader) + 4.338s (kernel) + 40.317s (userspace) = 1min 962ms  graphical.target reached after 40.276s in userspace   systemd-analyze blame      18.691s plymouth-quit-wait.service      10.686s dev-sda5.device       9.799s snapd.service       9.379s configure-printer@usb-001-002.service       6.580s systemd-journal-flush.service       5.879s udisks2.service       5.620s networkd-dispatcher.service       4.928s ModemManager.service       3.954s NetworkManager.service       3.906s accounts-daemon.service       3.855s e2scrub_reap.service       2.898s apport.service       ...  I know nothing about Ubuntu but I need it running properly for many courses. I really hope for someone to help me, thanks.


Inverting logarithmic output from VAR model

I'm working on a VAR model and am doing a log transformation of the raw data.   x = log(x)   After differencing, running various tests and running a VAR(2) model, I add the predicted differences cumulatively to the original time series (logged) like this:  prd.diffs <- as.ts(prd$mean$d.x1) U <- tail(undiff,2) cumu <- cumsum(prd.diffs) + U[1]   However, while the output now looks as it should, it is still in logged values.  My question is as follows:  How does one return the logged output to original values? I'm under the impression that using exp() will not give the correct results, and having tried some variations it hasn't worked for me.   Does the fact that it is a VAR($p$) model (and possibly what lag it has) influence the method, and how should that be implemented to get the correct output?  P.S. I realise that the above code does not constitute a replicable example as I didn't deem that necessary for the question, but should that be desired I can add some more code.


Healthy Boy Black Soy Sauce vs Healthy Boy Black Sweet Soy Sauce

Could someone please tell me whether these two soy sauces are different?  Thank you.


How do I read in the contents of a directory in Perl?

How do I get Perl to read the contents of a given directory into an array?   can do it, but is there some method using 'scandir' or a similar term?


Button.onClick.AddListener(() => ItemButton(i)) Applies the same i value

So, I worked on my shop system and I wanted to make it so that when the player presses the button, that button was selected (I need to know the id of button that I press) void Awake() {     //Cycle through all the ShopItems     for (int i = 0; i < shopItemsList.Count; i++)     {         go = Instantiate(ItemTemplate, ShopScrollView);         go.GetComponent<Button>().onClick.AddListener(() => ItemButton(i));         go.transform.GetChild(0).GetComponent<TextMeshProUGUI>().text = shopItemsList[i].itemName;          if (!shopItemsList[i].isPurchased)         {             go.transform.GetChild(1).gameObject.SetActive(true);         }         else if (shopItemsList[i].isChosen)         {             go.GetComponent<Image>().color = new Color32(164, 0, 0, 255);         }             go.transform.GetChild(1).GetChild(0).GetComponent<TextMeshProUGUI>().txt = shopItemsList[i].price.ToString() + "$";         }     }       void ItemButton(int itemName)     {         Debug.Log(itemName);     } }  So when I Press Play button in Unity all works fine (every item has its stats) but all buttons have the same value that equals to 12 (the last iteration of "for" cycle)


Windows 10 Doesn't Detect Hard Drive Anymore - How to Recover

My computer has an SSD and a HD. SSD contains Windows 10 while my HD has my programs and documents. When I turn on my computer, it takes about 5 minutes to load into Windows where it then freezes. I am unable to perform any tasks in Windows. Previously, CrystalDiskInfo has reported that my HD has bad sectors. I unplugged my HD and I am able to successfully load Windows 10.  My problem is that I need the data and applications from my failed HD. I would like to clone my failing HD onto a new HD, then plug it into my computer so Windows will function normally as before (ie - my applications will still be stored, settings and documents will remain the same). What sort of steps can I take to clone my drive?  UPDATE:  I have taken a look at the linked resource () but I don't think it helps me in my situation. I do not think I have a mechanical issue as I do not hear any weird noises coming from my hard drive. Furthermore, CrystalDiskInfo has reported that I have bad sectors. To recover from corruption or bad sectors, the linked resource says to get direct access to the data. Right now Windows freezes when I plug in my hard drive. How do I gain direct access to the data?  Looks like EaseUS allows to clone failing HDD/SSD that has bad sectors. My question is how do I gain access to the data in my failed HDD?


How long should I keep the bag tag and its receipt?

When you check in luggage on a flight you get a receipt and also there is a tag dangling from your luggage. Assuming that you received your luggage at your destination, what reasons are there to not throw away the tag and its receipt immediately (maybe even in the baggage claim area)?


$E$ is a splitting field of $f(x)=x^3-3x+1$ over $\mathbb Q$.Then determine the group $G(\frac {E}{\mathbb Q})$  MY try : Actually I don't Know how to relate splitting field to group,But I found something like $Gal(E/\mathbb{Q}) \simeq S_3$


I'm writing a small article on humanly readable alternatives to Guids/UIDs, for example those used on TinyURL for the url hashes (which are often printed in magazines, so need to be short).  The simple uid I'm generating is - 6 characters: either a lowercase letter (a-z) or 0-9.   "According to my calculations captain", that's 6 mutually exclusive events, although calculating the probability of a clash gets a little harder than P(A or B) = P(A) + P(B), as obviously it includes numbers and from the code below, you can see it works out whether to use a number or letter using 50/50.  I'm interested in the clash rate and if the code below is a realistic simulation of anticipated clash rate you'd get from generating a hash. On average I get 40-50 clashes per million, however bare in mind the uid wouldn't be generated a million times at once, but probably only around 10-1000 times a minute.  What is the probability of a clash each time, and can anyone suggest a better way of doing it?  static Random _random = new Random();  public static void main() {     // Size of the key, 6     HashSet<string> set = new HashSet<string>();     int clashes = 0;     for (int n=0;n < 1000000;n++)     {         StringBuilder builder = new StringBuilder();          for (int i =0;i < 7;i++)         {             if (_random.NextDouble() > 0.5)             {                 builder.Append((char)_random.Next(97,123));             }             else             {                 builder.Append(_random.Next(0,9).ToString());             }         }          if (set.Contains(builder.ToString()))         {             clashes++;             Console.WriteLine("clash: (" +n+ ")" +builder.ToString());         }          set.Add(builder.ToString());         _random.Next();         //Console.Write(builder.ToString());     }      Console.WriteLine("Clashes: " +clashes);     Console.ReadLine(); }   UPDATE:   from this question  I really asked two questions here so I was cheating. The answer I was after was rcar's, however Sklivvz's is also the answer to the 2nd part (an alternative). Is it possible to make a custom unique id generator in a database, or would it be client side (which would be 2 possible reads first)?  The general idea I was after was using Ids in databases or other stores that can be used by phone or printed material, not a giant 16 byte guid.  UPDATE 2: I put the formula for two mutually exclusive events above instead of 2 independent ones (as getting an 'a' the first time doesn't mean you can't get an 'a' the second time). Should've been P(A and B) = P(A) x P(B)


How to close JavaScript driven HTML Popup Box by clcking outside the Popup Box?

I make a JavaScript driven html popup box . The code work perfectly for me ,but now I need to press the close link to close the popup box. How can I modify the below code so that I can also close the popup box by clicking outside the popup box.    function toggle_visibility(id) {   var e = document.getElementById(id);   if (e.style.display == 'block')     e.style.display = 'none';   else     e.style.display = 'block'; } #popupBoxOnePosition {   top: 0;   left: 0;   position: fixed;   width: 100%;   height: 120%;   background-color: rgba(0, 0, 0, 0.7);   display: none; } .popupBoxWrapper {   width: 550px;   margin: 50px auto;   text-align: left; } .popupBoxContent {   background-color: #FFF;   padding: 15px; }

Popup Box 1

You are currently viewing popup box 1.

Click here to close popup box one.

Click here to see popup box one.
     Please note I try below code but it doesn't work for me   $('#popupBoxOnePosition').click(function(event){                          event.stopPropagation();  });


To show that ${x_n}$ is convergent where $|x_{n+1} - x_n|< \frac{1}{n^2}$

Let ${x_n}$ be a sequence in $R$ such that $|x_{n+1} - x_n|< \frac{1}{n^2}$ for all $n \in N$.  Show that the sequence is convergent.  If it were $|x_{n+1} - x_n|= \frac{1}{n^2}$, could take help of the fact $\sum \frac{1}{n^2}$ is convergent and of triangular inequality.  But what to do here? Please help. Thanks in advance.


What does "it" refer to in "it's raining"?

I wanted to leave the question title as is so as not to take away from my amusement :).  Anyway,     It's raining.   What is raining? Is it the sky? The clouds? The weather? The rain? What is "it"? Any historical insights on the statement?


Example for path connected subspace of $\Bbb{R}^2$ that is not locally path connected at any point

I'm looking for an example for path connected subspace of   $\Bbb{R}^2$ (euclidean topology) that is not locally path connected at any point. Will appreciate any help


RAW, is there anything that explicitly states what happens to a creature (either PC or monster) when a weight that exceeds their carry capacity is suddenly dropped on them?  EDIT: The intent is to find out the mechanics, if any exist, of what would happen if a Goliath Barbearian PC unceremoniously dropped, say, a 1000 lb. iron ball on a wolf. How would damage and other things be handled? If existing mechanics can't fully describe this situation, how would you handle it at your table?


I saw this sentence in comments     I would recommend going through the Help Center   What is the difference between 'I recommend' vs 'I would recommend'? Is that only for making sentence more polite?  It can be seen as very easy one to people whose first language is English but in my country, there is no exact elucidations for this.  Many thanks.


Why is sound reflected and not transmitted through a wall?

We know that speed of sound is higher in a denser medium. So when a sound wave strikes a wall, why does it echo instead of passing through it with a speed faster than the speed of sound in air?


I can't figure out how to place the brace on the opposite side, that is on the left of the group of equations, when following the answer in this link:    What should be changed in the solution?


ListView.setAdapter(android.widget.ListAdapter)' on a null object reference in android

Hi in the below where click on this fragment my list view getting null pointer.  If it is normal activity it is working fine.it is crashing my app  can any one please help me where i did the mistake.  public class HomeFragement extends Fragment {      EditText et_building;     TextView Add;     ListView lv;     ArrayList<String> arrayList;     ArrayAdapter<String> adapter;        public HomeFragement() {     }      @Override     public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {          ((NavigationViewActivity) getActivity()).setActionBarTitle("ADD BUILDING");          View rootView = inflater.inflate(R.layout.activity_building, container, false);          init();          return rootView;     }      private void clickListener() {         Add.setOnClickListener (new View.OnClickListener ( ) {             @Override             public void onClick(View v) {                 String result=et_building.getText ().toString ();                 arrayList.add (result);                 adapter.notifyDataSetChanged ();              }         });     }      private void init() {         et_building=(EditText)getActivity ().findViewById (R.id.build_name);         Add=(TextView)getActivity ().findViewById (R.id.addbuild);         lv=(ListView)getActivity ().findViewById (R.id.list_building);         arrayList=new ArrayList<String> ();         adapter=new ArrayAdapter<String> (getActivity (),android.R.layout.simple_list_item_1,arrayList);         lv.setAdapter(adapter);         clickListener();     }


Checking the maximality of a principal ideal in $R[x]$

Let $R = \mathbb{Z}_{(2)}$ be the localization of $\mathbb{Z}$ at the prime ideal generated by $2$ in $\mathbb{Z}$. Then prove that the ideal generated by $(2x-1)$ is maximal in $R[x]$.


How to create a custom Linux distro that runs just one program and nothing else?

How I could go about creating my own "custom" Linux distro that will run just one program, pretty much exactly the same way as .


Printer says "Idle- rendering complete" Ubuntu 20.04

My hp printer got detected, printed two pages. then suddenly it started saying "processing - rendering complete" then "Idle- rendering complete" Ubuntu 20.04


How does final keyword work with string immutability?

I have the following code. I understand the concept of java string immutability and string constant pool. I don't understand why 'name1 == name2' results false and 'name2 == name3' results true in the following program. How are the string variables name1, name2, and name3 placed in the string constant pool? public class Test {     public static void main(String[] args) {         final String firstName = "John";         String lastName = "Smith";         String name1 = firstName + lastName;         String name2 = firstName + "Smith";         String name3 = "John" + "Smith";         System.out.println(name1 == name2);         System.out.println(name2 == name3);    } }  Output: false true


Let g be an entire function such that   $2g(z)=g(\frac{z}{2}) + g(\frac{z+1}{2})$ holds $\forall z\in \mathbb{C}$   the I want to prove that $ g $ is constant.  Hint: Apply maximum modulus principle on $cl(B_r (0))=${$ |z| \leq r $}$ $  also   if $g$ has no zeros and  $cg(z)=g(\frac{z}{2}) g(\frac{z+1}{2})$  holds $\forall z\in \mathbb{C}$ and for some $c\in \mathbb{C}$ prove that $g(z)=ce^{\frac{-b}{2}}e^{bz}$ for some $b\in \mathbb{C}$   I have no idea how to prove this statement . Any Hints leading to solutions  are appreciable


Goal: Show the button "Candy Candy candy" after pressing the button text "Test2"     Problem: It doesn't show the text and what part am I missing in order to complete it?    I have tried using on() and live() but it still doesn't work.    Info: *I'm using jQuery and its ajax    Thank you!    $('#test1').click(function() {   document.getElementById("data1").innerHTML = "<button id='test2' type='button'>Test 2</button>"; });  $('#test2').click(function() {   document.getElementById("data2").innerHTML = "Candy candy candy !"; });  <!DOCTYPE html>      <meta charset="utf-8">   <meta name="viewport" content="width=device-width">   <title>JS Bin</title>         <button id="test1" type="button">Test 1</button>


why we are using 1 = 1 in SQL select Query

Can anyone please explain Why we are using where 1=1 in SQL select query?  Select * from <TableName> Where 1=1 <cfif isdefined('Something)> AND  columnName = value </cfif>


what do you call someone performing below their potential

What do you call someone who doesn't know their worth or is under-performing their potential?


How to use exclamation marks in Minecraft commands?

I know that you can use exclamation marks in Minecraft commands to check for an entity that does not have a specific tag. For example, you can use /kill @e[type=!Player] to kill all entities except for the player. I have, however, encountered two problems with using exclamation marks that I can't find a solution for.  For my first problem, I've set up a series of command blocks to summon shootable fireballs above the player’s head when a certain item is being held;  /scoreboard players add @a Fireball 1 {SelectedItem:{tag:{display:{Name:"Summon Fireball"}}}} /execute @a[score_Fireball_min=1,score_Fireball=1] ~ ~ ~ /summon Fireball ~ ~2.5 ~ {direction:[0.0,0.0,0.0]} /scoreboard players set @a Fireball 0   I used a comparator and a redstone torch so that the last command would activate when the first command would deactivate, that is, when the player is not holding the item.  The problem is, that when I move far away from the setup, the redstone stops working, leaving me unable to summon any new fireballs. Instead, I'm trying to use a command block to check when anything except for item is being held;  /scoreboard players set @a Fireball 0 {SelectedItem:{tag:{display:{Name:!"Summon Fireball"}}}}   I’ve either put it at the wrong place, or you simply can’t use exclamation marks in NBT tags. Could someone tell me where I should put the exclamation mark, or in the latter case, how I can check for anything except for a specific item?  Further, I’ve tried using exclamation marks to set the score of all entities, including the ones with a blank score, but except for the ones with a score of 2 or higher, to 0;  /scoreboard players set @e[score_arrows_min!=2] Arrows 0 /scoreboard players set @a Arrows 1 {SelectedItem:{tag:{display:{Name:"Rain of Arrows"}}}} /scoreboard players set @e[type=Arrow] Arrows 2 {inGround:1b}   The code does change the scores of entities without scores to 0, but it doesn’t exclude the arrows with a score of 2. Could anyone tell me what I’m doing wrong here?


Calculate the area covered by spectral end members in Google Earth Engine?

3 down vote favorite I am doing a project on calculating the growth of urban areas in different cities located in different parts of India. I have been able to classify the area into urban, vegetation and water. Now the problem is I cannot calculate the area covered by each pixel. I searched on Google and the available methods uses band values, what I need is to find the area covered by urban/water/vegetation based on spectral end member values that is been defined. If anyone has idea on how to perform it please share and if possible suggest an idea to export it into a graph. What I need is to find the area covered by the different spectral endmembers (urban,veg,water) values which has been defined.  Here is a link to the script:    I'm fairly new to Earth Engine so my knowledge is quite limited, please excuse


The  (or conjecture), suggests that black holes can be entirely described by their mass, angular momentum and charge. All other details of the BH formation are lost.  Is there a simple way of understanding why you would be able to tell the difference between a BH made from protons and one made from electrons, but not between one made from matter rather than anti-matter?  i.e. What is special about charge, and why aren't lepton number, baryon number, strangeness etc, also black hole properties?


why render of jquery datatable does not execute?

i have the following jquery datatable column 'DOB' associated with a function  columns:[ {     'data': 'DOB',     'visible': false,     'render': function (jsonDate) {         var date = new Date(parseInt(jsonDate.substr(6)));         var month = date.getMonth() + 1;         return month + '/' + date.getDate() + '/' + date.getFullYear();      } }, ]   but when i retrieve the value it retrieves as Json date /Date(-133335000000)/ why this happens and how do i fix this?


Constructor Dependency injection in asp.net core 2

I have read this official documentation: .  There is something i do not understand in constructor injection:  Let's have a look to my code, which works fine:  public class HomeController : Controller {     private readonly UserManager<Utilisateurs> _userManager;     private readonly SignInManager<Utilisateurs> _signInManager;     private readonly RoleManager<IdentityRole> _roleManager;      public HomeController(         SignInManager<Utilisateurs> signInManager,         UserManager<Utilisateurs> userManager,         RoleManager<IdentityRole> roleManager)     {         _userManager = userManager;         _signInManager = signInManager;         _roleManager = roleManager;     }   It works fine too if change constructor parameter orders or if i remove some parameters like this:  public class HomeController : Controller {     private readonly UserManager<Utilisateurs> _userManager;     private readonly SignInManager<Utilisateurs> _signInManager;      public HomeController(         UserManager<Utilisateurs> userManager         SignInManager<Utilisateurs> signInManager,         )     {         _userManager = userManager;         _signInManager = signInManager;     }   I have understood the concept of DI. What i do not understand is how does it works in C# to have something dynamic in constructor parameters ? Is there a set of all kind of overload constructors ?  Thanks


how to calculate the bounding square of an ellipse?

I'm trying to find the formula of a bounding square of an ellipse. So in other words: I want a formula that gives the size (length of one side of a the square) that bounds a given ellipse with width $a$ and length $b$.   I know that the formula of an ellipse is given by: $$\frac{x^2}{a^2}+\frac{y^2}{b^2}=1$$ but I just cant figure out what the length of one side of a bounding square is.


I felt as if it "was" or "were" grinning at me?

A wicked aura around it, I felt as if it was grinning at me   or     A wicked aura around it, I felt as if it were grinning at me   ?


How can undo checked-in files and nuget package updates from Team Foundation Server?

I update my mvc project nuget packages and some related files, unfortunately I had checked-in my solution to TFS source control. but I understand this update damaged my project functionality, Now I decide to rollback changes. How I can do it? It is possible to use get specific version by change set to undo nuget updated packages?


If $(a_n)$ is a null sequence and $(b_n)$ is bounded, then $(a_nb_n)$ is a null sequence

How can you prove that $(a_nb_n)$ is a null sequence given that $(a_n)$ is a null sequence that converges to zero and $(b_n)$ is bounded above by $A$?  The conditions of $(a_n)$ are: For every $\varepsilon > 0$ there exists an $N$ in Natural numbers such that $|a_n| < \varepsilon$ for all $n \ge N$.  The conditions of $(b_n)$ are: $b_n$ is a function natural numbers -> reals such that there exists $A$ with $|b_n| \le A$ for all $n$ in natural numbers.


My documents language is Persian and I am using xepersian package for the matter. The font I defined for my document which is an MS thesis is B nazanin, we are told to use the font and can't change it. Apparently it does not support the bold font. Since I cannot use other fonts, what can be done about it?  \documentclass[a4paper,12pt]{report} %\setlist[itemize,1]{label={\fontfamily{cmr}\fontencoding{T1}\selectfont\textbullet}} \usepackage{pifont} \usepackage{xepersian} \settextfont[Scale=1.1]{B Nazanin} \defpersianfont\nastaliq[Scale=2]{IranNastaliq} \defpersianfont\titr[Scale=1]{B Titr} \defpersianfont\traffic[Scale=1]{B Traffic} \deflatinfont\calibri{Calibri}  \begin{document} \chapter{مقدمه} \section{پیشگفتار}   در دنیای امروزی با حجم وسیعی از اطلاعات روبرو هستیم که بوسیله‌ی سنسورهای طبیعی و مصنوعی گرفته و ثبت شده‌اند. این اطلاعات عموماً یا تکراری هستند و شامل چندین نسخه از جهان فیزیکی مشابه هستند و یا شامل چیزی فراتر از اطلاعات مورد نظر ما و آنچه ما به دنبال آن هستیم می‌شوند. اطلاعات مرتبط و مورد نظر ما معمولاً در ابعاد بسیار پایین‌تر قرار دارند. استخراج این اطلاعات به یکی از دغدغه‌های امروز دنیای فناوری اطلاعات بدل شده است، اینکه بتوان تشخیص داد که داده‌ی مطلوب و مورد نظر ما در کجای داده‌ی مشاهده شده قرار دارد.  نمایش تنک داده‌ها ابزاری قدرتمند است که در زمینه‌های نمایش و فشرده‌سازی داده‌ها در ابعاد بالا مورد استفاده قرار می‌گیرد. \end{document}


Post-apocalyptic movie about matriarchal society

This post-apocalyptic movie was probably made in the 80's.  It plays in a matriarchal society, where men are slaves. I remember only one scene, where the main guy escapes a camp of women (the women are like Amazons) and by accident he falls into a cave (the scenery is similar to Grand Canyon). It turns out that the cave is a long lost, hidden fort, and he is in a control room. He sees monitors and computers, and a recording starts where he sees how the human civilization was before the apocalypse, skyscrapers, and such stuff. I think that before that, nobody knew what happened, and how the old world was at all.


PDFLATEX : Cover Page Image with No Margin

I'm creating exam paper using exam class as mentioned below:   \documentclass[a4paper,addpoints,answers,10pt]{exam} \usepackage{tikz} \usepackage{graphicx} \usepackage{wallpaper} \TileWallPaper{\paperwidth}{1\paperheight}{QPborder} \begin{document} \thispagestyle{empty} \begin{figure} \includegraphics[width=1.25\linewidth, height=1.15\textheight, keepaspectratio=true]{Std3Qpcover} \end{figure} \end{document}   Before Starting questions, I want to add image on the first page occupying full size of A4 page (without margin & wallpaper background).  I tried many options already mentioned on the forum, but somehow nothing is working. Can you please suggest, how can I add full page Image without margin & border & background image?


ext4 to btrfs conversion: how many times the whole volume will be read during the process?

I want to convert the 3TB 80% full ext4 block device into btrfs and I want to estimate the time it will take. I understand that this process is disk-bound rather then cpu- or memory-bound. So can anyone explain me how long it will take in units of time it takes to read/write the whole volume?


Wifi enabled on 13.04 but cannot connect. Tried Recommended solution but does not work

I recently upgraded to Ubuntu 13.04 from Ubuntu 12.10. However, since then although my wireless network is detected, I cannot connect to it.  Ubuntu keeps on trying to reconnect with the network but is not successful. Same machine on Windows 8 I am able to connect to the same wireless network.  Also, Ethernet is working fine as I am able to connect to the same network through Ethernet on Ubuntu.  My lspci -nn output is   12:00.0 Network controller [0280]: Broadcom Corporation BCM4313 802.11b/g/n Wireless LAN Controller [14e4:4727] (rev 01) 13:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd.                RTL8101E/RTL8102E PCI Express Fast Ethernet controller [10ec:8136] (rev 02)   I already tried the solution in this post  but it not solving my problem. The situation is the same.  Please help me. I do not want to switch to using Windows again.


If a function is uniformly continuous on $(-\infty,-1]$ and $[-1,\infty)$ is it uniformly continuous on $\mathbb{R}$

Is it correct to say that if $f(x)$ is uniformly continuous on $(-\infty,-1]$ and $[-1,\infty)$, then it is uniformly continuous on $\mathbb{R}$?  I don't think this is true but cannot think of a counterexample. Below there is an example of where I want to use this.  Thanks for any help     Prove that $f(x)=|x|^{\frac{1}{2}}$ is uniformly continuous on $\mathbb{R}$   Proof. As $|x|^{\frac 12}$ is differentiable on $(-\infty,-1]$ and $[1,\infty)$ with the derivatives bounded then it is uniformly continuous on these intervals.  It is also continuous on $[-1,1]$ and so it is uniformly continuous.   It is therefore continuous on $\mathbb{R}$.


How do new posts on Stack Overflow appear almost instantly on Google?

Are there API calls for sites to invoke when new content is submitted?   I see that new posts on Stack Overflow appear almost instantly on Google.


Is autocorrelation and stationarity in the residuals related?

Or are they completely independent? Can you have autocorrelation and non-stationarity and vice versa? Or not?


Show that $ab \mod m = ((a \bmod m)(b \bmod m)) \bmod m.$

With modular definition in mind that two integers $a,b \in \mathbb{Z}$, are congruent module $m$ meaning that $a\equiv b \pmod{m}$, where $m$ is a positive integer. Details:  $x \equiv y \pmod{m}$ is by definition equivalent to  $m|(x−y)$. $x \equiv y \pmod{m}$ , $x,y\in \mathbb{Z}, m \in \mathbb{Z^+}$ iff $a \pmod {m} = b \pmod{m}$. if $a | b$ and $a|c$, then $a|(b+c)$. if $a | b$ and $b|c$, then $a|c$. if $a | b$ then $a|bc$, for all integers $c$.  Question: Show that $ab \pmod{m} = ((a \pmod{m} )(b \pmod{m})) \mod m.$


I tried to install gnome-shell on Ubuntu 16.04 and when configuring I choose gdm as my default desktop but after I reboot I didn't see the login screen , only the black screen with Ubuntu  logo and the red dots, so I have reinstall Ubuntu again.  My question How can I install gnome-shell on Ubuntu 16.04?


Why do I get an Exception when pushing objects to Stack?

I've been debugging my solution to . I'm still debugging the code, but my main concern is regarding the NullPointerException I get when I try to push Integers to a Stack in a static HashMap.  Here's my code:  import java.util.Stack; import java.util.HashMap; import java.util.HashSet; public class Twitter {  private static HashMap<Integer, Stack<Integer>> newsFeed; private HashMap<Integer, HashSet<Integer>> followList; /** Initialize your data structure here. */ public Twitter() {     //Holds a userId as a key, with a Stack of tweets acting as a newfeed.     newsFeed = new HashMap<Integer, Stack<Integer>>();     //Holds a userId as a key, with a HashSet of userIds in the user's follow list     followList = new HashMap<Integer, HashSet<Integer>>(); }  /** Compose a new tweet. */ public void postTweet(int userId, int tweetId) {     /** When a user tweets, the tweet is seen by the user and all the user's followers; therefore, each tweet posted requires an update to the newsfeed Stack of the user and all their followers. */     Stack<Integer> userFeed = newsFeed.get(userId);     userFeed.push(new Integer(tweetId));     newsFeed.put(userId, userFeed);     postToAllFollowers(userId, tweetId); }  private void postToAllFollowers(int userId, int tweetId){     HashSet<Integer> set = followList.get(userId);      for(Integer followerId : set){         Stack<Integer> followerFeed = newsFeed.get(followerId);         followerFeed.push(new Integer(tweetId));         newsFeed.put(followerId, followerFeed);     } }  /** Retrieve the 10 most recent tweet ids in the user's news feed. Each item in the news feed must be posted by users who the user followed or by the user herself. Tweets must be ordered from most recent to least recent. */ public List<Integer> getNewsFeed(int userId) {     if(!newsFeed.containsKey(userId)){         return null;     }     Stack<Integer> stack = newsFeed.get(userId);     return stackToListIn10(stack); }  private List<Integer> stackToListIn10(Stack<Integer> stack){     List<Integer> timeLine = new ArrayList<Integer>();     while((timeLine.size() != 10) || (!stack.isEmpty())){         timeLine.add(stack.pop());     }     return timeLine; }  /** Follower follows a followee. If the operation is invalid, it should be a no-op. */ public void follow(int followerId, int followeeId) {     HashSet<Integer> set = followList.get(followerId);     set.add(followeeId);     followList.put(followerId, set); }  /** Follower unfollows a followee. If the operation is invalid, it should be a no-op. */ public void unfollow(int followerId, int followeeId) {     HashSet<Integer> set = followList.get(followerId);     set.remove(followeeId);     followList.put(followerId, set); } }  /**  * Your Twitter object will be instantiated and called as such:  * Twitter obj = new Twitter();  * obj.postTweet(userId,tweetId);  * List<Integer> param_2 = obj.getNewsFeed(userId);  * obj.follow(followerId,followeeId);  * obj.unfollow(followerId,followeeId);  */   LeetCode gives me the following error: Line 20: java.lang.NullPointerException  Any insight on this? I haven't seen this problem on StackOverflow, so I don't think it's a duplicate


querySelectorAll selects only selects the first element

I'm using the code below, written by Niels Reijnders on this thread  to wrap each line of a paragraph in span. function splitLines(container, opentag, closingtag) {   var spans = container.children,     top = 0,     tmp = '';   container.innerHTML = container.textContent.replace(/\S+/g, '<n>$&</n>');   for (let i = 0; i < spans.length; i++) {     var rect = spans[i].getBoundingClientRect().top;     if (top < rect) tmp += closingtag + opentag;     top = rect;     tmp += spans[i].textContent + ' ';   }   container.innerHTML = tmp += closingtag; }  splitLines(document.querySelectorAll('p')[0], '<span>', '</span>')  It works great and accomplishes what I needed, but only selects the first paragraph of the DOM, not the others. It seems like adding forEach method might solve what I'm looking for, but I don't know how to implement it within this code. Any help would be very appreciated. Thanks


I have a series of photos captures with care to make up into a panorama photo. Can anyone suggest a good software which can stitch them in sequence without much manual intervention and providing good results.  Thanks.


What is the difference between a Framework, a Toolkit and a Library?


How to detect if JavaScript is disabled?

There was a post this morning asking about how many people disable JavaScript. Then I began to wonder what techniques might be used to determine if the user has it disabled.   Does anyone know of some short/simple ways to detect if JavaScript is disabled? My intention is to give a warning that the site is not able to function properly without the browser having JS enabled.   Eventually I would want to redirect them to content that is able to work in the absence of JS, but I need this detection as a placeholder to start.


Package pgfplots Error: "sorry, plot file could not be opened"

I was met with this unpleasant surprise when trying to compile this file:  \documentclass{standalone}  \usepackage{pgfplots}  \pgfplotsset{compat=1.13}  \begin{document}  \begin{tikzpicture}      \begin{axis}[view={0}{90}]     \addplot3[domain=-10:10,         contour gnuplot={labels=false,levels={1}}     ]{(x+1)^2/4-(y-2)^2/9};     \end{axis}  \end{tikzpicture}  \end{document}   The file produces this error:  ! Package pgfplots Error: sorry, plot file{test_contourtmp0.table} could not be opened.   I did some digging and found out that my file is trying to borrow gnuplot functionality. Well, I installed gnuplot on my system, added --shell-escape and --enable-write18 to my pdflatex configuration, but the error persisted.  I'm completely out of ideas. Please, help me.


What does a Terminator do after its mission is accomplished?

A Terminator is essentially given a mission or an objective ("Go back in time and kill Sarah Connor" or something of the like).  What does a Terminator do once its mission is accomplished?  We see in Terminator 2: Judgment Day (the live-action movie) that the  (played by Arnold Terminator Schwarzenegger) completed its mission of protecting the Connors, and then sort-of just melted itself into nothingness (presumably to protect the world from discovering Terminators again).  But what would the  or the  (in Terminator 3) have done?   Are they given multiple directives ("Go kill Sarah Connor, then go kill Robert Baratheon, and then have a nice hot bath; you've earned it")?  This question is related, but not a dupe:


how to echo text into a file from the CLI to ammend a variable in the file?

using Centos7  e.g  vi test.txt    test.txt contains the following information  x=100 y=200 z=300   I want to put a command into the CLI such as echo x=250 >> test.txt but instead of x=250 being added to the bottom of the file, I want it to replace x=100 with x=250  any help on hwo to tackle this is much appreciated!  Thanks.


Does the Spirit Guardians spell stack with multiple casters?

Recently played with a group, where 3 of their clerics would cast spirit guardians, claiming monsters in the area had to make 3 wisdom saves for 3d8 damage each, potentially adding up to 9d8 damage per round.  Is this any different then trying to have two casters cast insect plague or cloudkill on the same area, or bless on the same individual?


Is it possible to reclassify rasters manually?

Is it possible to change raster cell values individually or as a group?     Currently, I am digitizing around cells I want to change and then doing a polygon to raster conversion and then a merge to new raster.   I'm using ArcGIS 10.3 for Desktop.


Email goes to spam using by PHP Mailer and wp_mail

Duplicate question. I found some answers but no one works.  I want to send email using Php Mailer or wp_mail with attachment PDF file in WordPress. In both techniques PHP Mailer or wp_mail, Email goes with attachment but every time in spam.  Code using PHP Mailer 1  $mail->From = "from email"; $mail->FromName = "name"; $mail->AddAddress("to email"); //$mail->AddReplyTo( 'from email', 'name' ); //Line add or not doesn't effect. $mail->AddAttachment("filename.pdf");     $mail->Subject = "Email Subject";                   $mail->Body = "Email Body"; if(!$mail->Send()) {    echo "Message could not be sent. <p>";    echo "Mailer Error: " . $mail->ErrorInfo; } else {    echo "Message sent"; }   Code using PHP Mailer2  $mail->isSMTP();                                       $mail->Host = 'smtp.gmail.com';   $mail->SMTPAuth = true;                              $mail->Username = 'email user name';                  $mail->Password = 'password';                                           $mail->Port = 587; //587 or 25   $mail->From = "from email"; $mail->FromName = "name"; $mail->AddAddress("to email"); //$mail->AddReplyTo( 'from email', 'name' ); //Line add or not doesn't effect. $mail->AddAttachment("filename.pdf");     $mail->Subject = "Email Subject";                   $mail->Body = "Email Body"; if(!$mail->Send()) {    echo "Message could not be sent. <p>";    echo "Mailer Error: " . $mail->ErrorInfo; } else {    echo "Message sent"; }   Code using wp_mail  global $wpdb; $to = 'to email';  $from = 'from email';  $name = 'name'; $headers = 'From: name <from email>' . "\r\n";  $subject = 'SUBJECT';  $msg = 'CONTENT';  $mail_attachment = array('filename.pdf');    wp_mail($to, $subject, $msg, $headers, $mail_attachment);


In the context of mathematics, What is the difference between equation and formula?

Equation and formula, these 2 terms are used alternatively in "Introduction to Linear Algebra 4th edition" without giving a clear definition, so, what is the difference?  Can any one provide some concrete examples like following, to distinguish these 2 terms, especially a case is a formula rather than an equation.     Even a supercomputer doesn't want the inverse matrix: too slow.   Inverses give the simplest formula $x = A^{-1}$ b but not the top speed.   And everyone must know that determinants are even slower-there is no   way a linear algebra course should begin with formulas for the   determinant of an n by n matrix. Those formulas have a place, but not   first place.      The equation Ax = b uses the language of linear combinations right   away.   This question is different to this , which gives a lot of non-math examples without giving a clear comparison between the 2 terms in the context of mathematics.


Since I started playing, I have seen this icon in the bottom right of my screen. Clicking it does nothing.  What does this icon represent?  I'll add a PC tag, as I'm playing on PC, and it could be related to that.


I always interpret "expletive you" as an imperative statement with an implicit subject of "I", although the (less than intelligent) speaker clearly doesn't think of it in this light.  Is there any basis for considering it otherwise?  P.S. - It seems to me that it would be so much easier for the submitter to type relevant tags in rather than this bizarre system - that I'm still struggling to decipher.


Not able to apply jquery to appended elements

I am adding #show_data button dynamically, but not able to use jQuery on that button. Hi! data is never logged How do I add Scripts to dynamic elements?        <button id="show_fields">Show Fields</button>


Sci-fi book from the 80’s or 90’s; aliens control humans using a cap

Does anyone remember a book about Aliens that invaded earth and controlled people with a cap. The main character had a defective cap so he was able to think for himself. He went on an adventure to find freedom from the aliens. Does anyone remember anything like this?


I'm trying to sculpt this hand and I came up with this extrude big thumb but when I create a bridge to smooth it out, it gets like that. How can I fix it? If I 'subdivision surface' it gets weirder... :/


about "by" followed by a number or amount of change

Which of the following sentence is correct ? If both are correct, do they have the same meaning ? The company's sales grew by 70% year-on-year to US$100 m. The company's sales grew 70% year-on-year to US$100 m.


Wordpress generates  for each tag.  I read a discussion where someone says these urls are "not important" and they negatively affect SEO. Is this true?


T-test equal variances, unequal sample sizes

I have two groups with equal variances and unequal sample size (28 and 8) and I want to run a Student t-test. Can I use Mann-Whitney considering that the variances are equal? Do you think if there is a better test to compare the samples?


How to prove inequality similar to that of Minkowski

I am struggling with this problem. How to prove the below inequality  $|x+y|^r$ $\leq$ $|x|^r+|y|^r$ for $0<r\leq1$.  A little guidance please.


I want to use the command "\angle". I have the "amsmath" package included im my document, and I can use any other math commands, but not this. What I need to do? It requires a different package?  Thank you!


How to change/remove paste on middle click?

Question:  How to remove the "paste" feature of the middle button?  I am not asking to remove the middle button from the device (as many pages show as a solution) because I use this middle button for several operations like opening a tab on firefox, or whatever else.  Just to remove the "paste" operation by default.  Background:  Middle button is easy to press by mistake, and for a programmer, this kind of error could easily carry 2h looking for strange bugs, or worse, a crash 2 weeks later, or even worse, a comment in code with personal information, etc..  I am pretty fast to use Ctrl+V, so I do not need this dangerous feature.  Additional information:  I am currently using Linux OpenSuse with KDE. The version does not seem important, but I could provide it if requested.


Granted there are already quite a few badges for community service on this site, I thought, how about some more!  The theme is merging enthusiast/fanatic with suffrage/vox populi. Something like this (names and numbers open to suggestions)  Enthusiastic Voter - Voted 20 times per day consecutively for 30 days ????? - Voted 30 times per day consecutively for 50 days Fanatic Vox - Use the maximum number of 40 votes consecutively for 100 days


Compare two strings by ignoring certain characters

I wonder if there is an easy way to check if two strings match by excluding certain characters in the strings. See example below.  I can easily write such a method by writing a regular expression to find the "wild card" characters, and replace them with a common character. Then compare the two strings str1 and str2. I am not looking for such implementations, but like to know whether there are any .Net framework classes that can take care of this. Seems like a common need, but I couldn't find any such method.  For example:  string str1 = "ABC-EFG";     string str2 = "ABC*EFG";   The two strings must be declared equal.  Thanks!


Can't Connect to LAN from Mac to Windows

If I start a LAN from my Mac, my son can connect to it but if he creates a LAN on his Windows machine I can't connect and the "Scanning for games.." message just stays there. Any ideas what we should do? Is it a firewall rule?


HD bad blocks: is there a way to repair them?

During the last month Ubuntu starts having some problems: it shuts down suddenly without any apparent reason.. I figured out that the problem is in the hard disk, if I run this command:  $ sudo badblocks -sv -b 512 /dev/sda   I get 24 bad blocks all in the Linux partition (I have Windows in another one and it does not have the same problem). The question is if there is a way (different from changing the disk) for avoiding this shutting down. Maybe isolating the bad blocks?


Trying to zoom towards object for more detail, but zooming through object instead

I'm a Noob. I was working through a tutorial when I hit some keys causing the problem below (I was creating faces between vertices... holding shift & right clicking the vertices to select, then clicking F to create the faces)  Before I was able to zoom (scroll) toward the object to see the the mesh in finer detail without going through the mesh. Now I just zoom straight through the mesh. So I start to see the mesh in more detail as I zoom, then with 1 more turn of the mouse scroll wheel, I zoom straight through my mesh. It appears to be zooming by the same increments.  Anyone know what I have done & how to sort this?  Image 1: What is see before scrolling my mouse forward.  [![enter image description here][2]][2]  Image 2: What I see after scrolling my mouse forward (It goes through the object). See my clipping values to the right.  [![enter image description here][3]][3]  Iv'e also just noticed that my background image has disappeared (I only mention this as I assume this is caused by the same problem). 'Background Images' is ticked in the properties region! (I can't show this image as apparently I can't show more than 2 links since my 'reputation' is below 10)  Edit: I just solved my problem & feel like a complete idiot! I was in perspective view, I just pushed '5' on the number pad to change to orthographic view & it solved both my problems above :)


I'm new to java and trying to make a simple Banking class. My do while loop has a switch statement that checks the user input. Everything works fine, but the loop never ends. The loop should terminate once 6 is entered, but it doesnt.         String answer = "";         do{             System.out.println("Would you like to do?");             answer = scan.nextLine();             switch (answer){                 //get balance                 case "1":                     System.out.println("Your balance is: $" + getBalance());                     break;                 //make a transaction                 case "2":                     System.out.println("Enter deposit amount: ");                     double depositAmount = scan.nextDouble();                     makeDeposit(depositAmount);                     break;                 //make a withdrawal                 case "3":                     System.out.println("Enter withdrawal amount: ");                     double withdrawalAmount = scan.nextDouble();                     makeWithdrawal(withdrawalAmount);                     scan.nextLine();                     break;                 //show previous transaction                 case "4":                     System.out.println("Your previous transaction was: $" + getPreviousTransaction());                     break;                 //return to menu                 case "5":                     showMenu();                     break;                 //exit application                 case "6":                     break;                 //for invalid input                 default:                     System.out.println("Invalid option.");                     break;             }         }         while(answer != "6");             System.out.println("Goodbye.");     }


I'm struggling with this problem of proof by induction:     For any natural number $k\geq 5$, prove that  $k^2<2^k$.   I assumed that $k^2<2^k$  I want to show that $(k+1)^2<2^{k+1}$  The final statement is $k^2+2k+1$  Am I missing something ?


In light of the discovered vulnerabilities in SSL/TLS, is legacy RDP encryption or SSL more secure?

Windows offers the option of using either RDP encryption or SSL (TLS 1.0) to secure a remote desktop connection. Which option is more secure?  Given the recent discoveries, is TLS 1.0 still secure in this use case?  This is the description Microsoft provides   RDP: The RDP method uses native RDP encryption to secure communications between the client and RD Session Host server. If you select this setting, the RD Session Host server is not authenticated. SSL (TLS 1.0): The SSL method requires the use of TLS 1.0 to authenticate the RD Session Host server. If TLS is not supported, the connection fails.   UPDATE: I'm referring to the POODLE vulnerability discovered recently that TLS 1.0 is no longer secure


Is a Canon 1300D with 18-55mm lens good for portrait shots?

I want to shoot amazing portraits like the ones I see in magazines or model shots. Can it be done with my  EF-S 18-55mm IS 2? If not, please give names of affordable cheap lenses I can buy for this.


Prove that there exists a monotone nondecreasing function $f:[0,1] \rightarrow \mathbb{R}$ discontinuous in rationals of $[0,1]$   I tried to test functions of the type  $$ f(x)=\begin{cases} \frac{1}{q} & \text{if } x=\frac{p}{q} \mid p,q \in \mathbb{Z}^+ \,\,\, \text{and} \,\,\, \gcd(p,q)=1  \\ x & \text{if } x \not\in \mathbb{Q} \end{cases}$$ which is discontinuous in all rationals, but is not monotone.


We are developing an MMO using Smartfox Server. The targeted audience is kids from 7 -12 years.  There is a global chat option in this MMO. Whatever the user types in a textbox get displayed next to users avatar after he/she hits enter.  We would like to filter abusive language / profanities from this chat. We could capture the chat and read the text. The problem is getting the list of profanities itself.  Our questions are   Where will one get exhaustive list of all profanities? What method is adopted in similar scenario to filter out these?


On this click doesn't work for the + button

When you click on the + button you get a new option. When you click on the new + button created it doesn't work, why?

     Ask your question here:
     <textarea id="questionInput"></textarea>

     <button id="save">Save</button>     <button id="refresh" style="display:none">Amend question</button>

       Option 1

       <textarea class="opt" id="option1"></textarea>	       <button type="button" class="plus btn btn-default">  </button>         <button type="button" class="minus btn btn-default">  </button>

     <button id="doThis">Decide</button>

You should:

   $(document).ready(function() {     //Write question     //Save question, replace over input     $("#save").on("click", function() {         //get value of question         var question = $("#questionInput").val();         //replace over label         $("#replace").text(question);         //hide input         $("#questionInput").hide();         //hide save button         $("#save").hide();         //show refresh button         $("#refresh").show();         //on click of refresh re-enable input field and save button     });     //Onclick of refresh button enable amend question     $("#refresh").on("click", function() {         $("#replace").text("Ask your question here:");         $("#questionInput").show();         $("#save").show();         $("#refresh").hide();     });     //Decide on number of answers     $(function() {         var counter = 1;         $('.plus').on("click", function(event) {             event.preventDefault();             counter++;             var firstRow = $('
Option' +' '+counter+'
' +             '
<textarea class="opt" id="option1"></textarea>	' +       '<button type="button" class="plus btn btn-default">  </button>'+         '<button type="button" class="minus btn btn-default">  </button>	'+     '
');              $('table.options').append(firstRow);         });     });          //delete an answer option         $('.minus').click(function(event) {             event.preventDefault();             $(this).destroy(firstRow);         });             //On click, get values of answers & choose random answer         $("#doThis").bind("click", function() {             var optionone = $("#option1").val();             var optiontwo = $("#option2").val();             var optionthree = $("#option3").val();             var optionfour = $("#option4").val();             var optionfive = $("#option5").val();             var arrayList = [optionone, optiontwo, optionthree,                 optionfour, optionfive             ];             var decide = arrayList[Math.floor(Math.random() *                 arrayList.length)];             $("#verdict").text(decide);         }); // end of dothis click event }); // end of ready   It will be easier to view this on the js fiddle


Switching motherboard without new install?

I need to replace my current motherboard with a new one, no other parts are changed.   Must I format my harddrive and reinstall windows, or can I use the old installation and let windows install the right drivers?  I realize, there might be a performance hit, but I'll probably need the new one just for a week and would like to replace it with the old motherboard again.


Some shadows are too sharp in the render

do you know what is causing this type of shadows? Does it have something to do with the way the mesh is?


Currently i am using an instance on Google cloud platform and in Ubuntu 16.04 I am able to install p7zip to extract .7z files, but on Ubuntu 18.04 I get the following error:  Package p7zip-full is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source  E: Package 'p7zip-full' has no installation candidate   Bearing in mind that I do not have a GUI, do I have any other option to extract .7z archives in Ubuntu 18.04?  I tried to install it using this command   sudo apt-get install p7zip-full   But it does not work for 18.04.


Convergence of $\sum (\log k)^{- \log k}$

I can fairly easily work out that $\sum (\log k)^{-k}$ does converge using the ratio test, and I think I could use that somehow to work out whether $\sum (\log k)^{- \log k}$ converges. The ratio test and the root test don't give any result on this series, so I think there might be a clever comparison test I could do, but I don't see it.


How to interpret the constraints on Poisson's ratio values, physically?

If I'm not mistaken, a Young's modulus $E$ can theoretically take on any positive value without bound.   Physically, I interpret this as though a solid can have any arbitrary "stiffness" (within the limits of its linear stress-strain region, of course).  On the other hand, the range of possible Poisson's ratios is constrained to $[-1,0.5]$ for stable, isotropic, linearly elastic materials.  I'm not quite sure how to interpret this physically.  Why must the Poisson's ratio necessarily be constrained?


Prove that $\frac{\xi}{n} \to 0$ , where $\xi = \max(f_1 \dots f_n)$

Consider $\xi = \max(f_1 \dots f_n)$ , where $f_i$ are i.r.v. with $\operatorname{E}(f_i) \ < +\infty$ and $f_i \stackrel{d}{=} f_j$. We want to determine $\dfrac{\xi}{n} \to 0$ a.s. I thought about continuous mapping theorems for $\bar{f_i} = \dfrac{f_i}{n}$. $\bar{f}_i \to 0$ and hence $\max(\bar{f_1} \dots \bar{f_n}) \to 0$. But I guess this idea is quite incorrect. Any hints?


WiFi not working on Lubuntu 18.10 running on a 2008 imac with 1gb DDR2 RAM

I wiped a 2008 imac and installed Lubuntu 18.10. My WiFi network doesn't show up although i have tried many things. It has a Broadcom BCM94321MC WiFi card and Ethernet works fine. when i run rfkill it only shows Bluetooth. I don't know much in terminal so please bear with me. TIA


Does this have a closed form $\lim_{n\to \infty}\left(\prod_{r=0}^{n/2} \left(\frac{mn+1-mr}{mn+3-mr}\right)\right)$?

$$\lim_{n \to \infty}\left(\prod_{r=0}^{n/2}{\left(\frac{mn+1-mr}{mn+3-mr}\right)}\right)$$  Of course if we check out cases where it should telescope like $ m = 1, 2, \frac{2}{3}, \cdots$, we get closed forms - $\frac{1}{4}, \frac{1}{2}, \frac{1}{8}, \cdots$.  So, I was thinking if it has a closed form.   One can reduce it to   $\displaystyle \lim_{n \to \infty} \dfrac{\prod_{r=0}^n{\frac{r + p/m}{r+q/m}}}{\prod_{r=0}^{n/2}{\frac{r + p/m}{r+q/m}}}$, where $p,q$ are $1,3$ in the above problem     $$\displaystyle  = \lim_{n \to \infty}{\dfrac{\Gamma\left(\frac{p}{m}+n+1\right) \Gamma\left(\frac{q}{m} + \frac{n}{2} + 1\right)}{\Gamma\left(\frac{q}{m}+n+1\right) \Gamma\left(\frac{p}{m} + \frac{n}{2} + 1\right)}}$$   Now, how to find this limit? Wolfram Alpha now can find the limit quite fast for example for $(p,q) = (1,3)$, and $m=3$ it gives the limit $\frac{\sqrt[3]{2}}{2}$.


How to resolve Skill Checks that can be repeated with no consequence?

As a newbie GM, I wonder what happens when a PC fails on a Skill Check, but nothing stops them from rerolling it.  E.g. In the starter set, after defeating a goblin ambush, the players can spot a trail by succeeding on a DC 10 Wisdom(Survival) check.   If a player fails to notice it, couldn't they reroll the check or let another player try with the excuse that they're keep looking for clues?


i am working on imageSlider,i have taken div and setting background-image of div. on Page load background page takes lots of time to load image. is there any way to load all background image first in cache and once loaded i can show main Div ..    i am reading xml file and then setting background-image of div one by one .   $('#myImageFlow').append('

'+frontDiv[k]+'

');   Any suggestion .


TV series: girl becomes a mermaid by rubbing a gel on her legs, brother grows into a man in one day

I remember watching a TV show where there's a family consisting of a father, mother, elder daughter and a son. The intro of the show is like any other intro just showing them and their names and some scenes from the show like some alien/robot shoots some green stuff at him and he jumps behind the couch. I watched it between 2002-2005.   I remember only two scenarios from the show:   Where the girl becomes a mermaid, she just applies some gel on her legs and it turns her into a mermaid and then she participates in a show. Where her brother grows up into a man in a day and he has this robot, which looks exactly like him. In one scene, the robot goes to the fridge, has a drink and it all leaks from under his shoes (that's how it was shown).   I think it was from Disney, but I'm not sure.  In the intro the show name pops out with mostly green colour with some cartoon characters on top or something (vague).  It was a real show, not reality show. I think it might have the Micky Mouse and Goofy on its name logo. Not sure.


Appending elements and replaceWith() - jQuery

i'm trying to give the user the possibility to update the values of some fields concerning him by clicking on a container named #info-client Here I append the input areas after the click and once the #finish button is clicked the infos will then be updated. The problem i got is that the infos were updated yet they were showed more than once ( 2 times or even 3 .. )  $("#info-client").one('click', function() {   $("#info-client").children().hide();    // liste des champs   var c1 = $(' Nom : <input type="text id="identifiant">
');   var c2 = $(' Adresse : <input type="text" id="adresse">
');   var c3 = $(' Ville : <input type="text" id="ville">
');   var c4 = $(' Tel : <input type="text" id="tel">
');   var c5 = $(' Fax : <input type="text" id="fax">
')   var button = $('<input type="button" id="finish" value="Mettre à jour">');    $("#info-client").append(c1);   $("#info-client").append(c2);   $("#info-client").append(c3);   $("#info-client").append(c4);   $("#info-client").append(c5);   $("#info-client").append(button);    $("#finish").one('click', function() {     var identifiant = $('#identifiant').val();     var adresse = $('#adresse').val();     var ville = $('#ville').val();     var tel = $('#tel').val();     var fax = $('#fax').val();      c1.replaceWith("
" + identifiant + "
");     c2.replaceWith("
 Adresse : " + adresse + "
");     c3.replaceWith("
" + ville + "
");     c4.replaceWith("
Fax : " + tel + "
");     c5.replaceWith("
 Tel :" + fax + "
");    }); });


Cyberpunk/Post-Apocalyptic Sci-Fi series from the 90s or 00s based in Manhattan

A friend and I are trying to find an old book series, probably by a Christian author, that we read in the late 90s or early 2000s. It takes place after the "Water Wars," and fresh water is super scarce.  Manhattan has been turned into a giant prison/slum, all the metal has been stripped from crumbling buildings and they get a very small ration of water from the main land.  A guy convinces a board of trustees on the mainland to take a guy from the island to determine if they should continue to get water by testing his virtue and bravery.  He gets stuck in this cyber-world where he relives events in history from Egypt, Rome, the Crusades, etc. and eventually encounters Jesus or God (in the machine, literally).  We have no idea what the name of these books are except that we're pretty sure that the name "Cyber-" is in the title.  Also, if I remember rightly, each individual book is pretty thin (just a couple hundred pages) but the anthology is a pretty decent-sized novel.  Anyone have any thoughts?  EDIT: I am 28 (was 15 in 2000), but tend to read genre fic from above and below my reading level.  I feel like this series was about at my intended level (even though I was reading above it).


If $g:V \rightarrow V$ is an injective linear transformation. Prove if $V$ is finite dimensional then $g$ is surjective.

I am asked to prove this without the rank nullity theorem   My Attempt at a Proof  For the $\implies$; If $g:V \rightarrow V$  is injective then the dimension of the kernel is 0, and so as ($im$) and ($ker$) are both subspaces of $V$, $dim(im)=dim(v)$ which implies $g$ is surjective.    For the $\impliedby$ ; If $g:V \rightarrow V$  is surjective, then $dim(v)=dim(im)$ and $dim(ker)$ must be 0, so $g$ is injective.    It seems to me that i have indirectly used the  rank nullity theorem, would there be a more suitable proof that doesn't incorporate it?


How to evaluate $\int_0^{\frac{\pi}{2}}\frac{dx}{1+\tan^{2013}x}$

How to evaluate the integral  $$\int_0^{\frac{\pi}{2}}\frac{\mathrm dx}{1+\tan^{2013}x}$$  It is almost impossible to calculate the antiderivative of this function by hand. Are there any tricks?


Search engine and words with accent doesn't match

I'm trying to make a search engine for my site. It works unless there are accents in a word.  For example, if I have the title: "Musée Baudouin", if I write "Musee Baudouin" or "Musée Baudouin", it does not display anything. If I write just "Baudouin", it's work.  I can't find my articles if they have accents in the title.  How to do ?  public function searchNav(Request $request)   {     $search = $request->get('search');      $buildings = Building::where('title', 'LIKE', '%' . $search . '%')->orWhere('city', 'LIKE', '%' . $search . '%')->published()->get();     $events = Event::where('title', 'LIKE', '%' . $search . '%')->orWhere('city', 'LIKE', '%' . $search . '%')->published()->get();      // Create a new collection and merge elements     $all = new Collection();     $all = $all->merge($buildings);     $all = $all->merge($events);     $all = $all->sortByDesc('updated_at');     $this->data['items'] = $all->all();      return view('pages.search-nav-results', $this->data);   }   Thanks


How would we calculate the dipole moment of a charge combination (of 3 or more charges) whose magnitudes are different but net charge is zero? As a special case, what if the net charge is not zero? How would we calculate the dipole moment then?


Is a monk's Slow Fall ability considered magical? That is if a monk were to enter an antimagic field whilst falling, would their slow fall ability be negated by the antimagic field, the same way some Ki abilities would be?


When, I try to cat the speed file, in /sys/class/net I get the following error  $ cat /sys/class/net/wlan0/speed  cat: /sys/class/net/wlan0/speed: Invalid argument #throws error   Whereas, for eth0 it shows  $ cat /sys/class/net/eth0/speed 1000   Can I know the reason for the error for wlan alone. Also the duplex is unkown for wlan0 but the carrier is set to 1?


Independent Events- $P(\text{neither/exactly/at least one})$

I'm working on some problems from Pitman's Probability.  Let events $A$ and $B$ be independent, with $P(A)=0.1$ and $P(B)=0.3$. Find: $(a)$ Neither of the events occur $(b)$ At least one of the events occur $(c)$ Exactly one of the events occur  Attempt: $(a)$ If neither of the events occur, this is the complement of both events occurring. Hence $1-P(A\cap B)=1-P(A)P(B)=1-\frac{1}{30}=\frac{29}{30}$ $(b)$ At least one of the events can be represented as the union of the two events. Hence $P(A\cup B)=P(A)+P(B)-P(A\cap B)=P(A)+P(B)-P(A)P(B)=\frac{4}{10}-\frac{1}{30}=\frac{11}{30}.$ $(c)$ Not sure what this would be. Maybe $P(A^c\;\cap\;B)+P(A\cap B)$?


UEFI boot up file for Ubuntu? (Toshiba P840t-ST3N01)

I am trying to install Ubuntu on my Toshiba P840t-ST3N01 and I keep getting the following message: Reboot and select proper Boot device or Insert boot media in selected boot device and press a key.  I want to install 14.10 Ubuntu from a USB I have. It boots up fine, but when I install, it says it is installed, but can't boot up. Also tried boot-repair. It tells me to boot from the file sda1/EFI/ubuntu/shimx64.efi though, so how do I do it?  1 terabyte hard drive, windows 8 deleted. UEFI mode enabled.


Using Apple's Screen Sharing, can I redirect gestures and keys for controlling Spaces to the shared machine?

I'm using the built in Screen Sharing tool in El Capitan to control an iMac from a Macbook Pro in full screen mode. Everything works beautifully except that many special keys and gestures are intercepted by the local Mac and not sent to the shared Mac. Specifically:   Ctrl-Arrow (Desktops and Mission Control) F3 (Mission Control) F4 (LaunchPad) Three finger swipe (Switch between Desktops, Mission Control, Exposé) Two finger swipe from left side (Notification Center) Pinch with four fingers (Launchpad)   I can't find any way to switch between desktops on the remote machine other than manually opening the Mission Control app from the Finder or Dock. Disabling the gestures on the local machine doesn't help; they still don't get sent to the remote machine.  Is there any way to get special keys and gestures passed to the shared machine?


Show that for any reals $a; b; x; y \ge 0, (ax + by)^2 \le (a^2 + b^2)(x^2 + y^2)$. (Hint: Use Cauchy-Schwarz inequality in $\mathbb{R}^{2}$.)

Having a little trouble with this. The Cauchy-Schwatrz inequality for vectors $u$ and $v$ is generally   $$|(u,v)^2|\le (u,u)\cdot(v,v).$$    Then for a two dimensional space its   $$|(u,v)^2|= (\|u\| \|v\|\cos(\theta))^2\le \|u\|^2\|v\|^2.$$  What I did was set two vectors $u$ and $v$ with the values $u=(a,b), v=(x,y).$  Then I used the inequality to plug in the values.   $$||u||=(a^2+b^2),\qquad ||v||=(x^2+y^2),$$   \begin{align*} \cos(\theta)&= (u\cdot v)/(||u||\cdot||v||)\\ &= (ax+by)/((a^2+b^2)\cdot(x^2+y^2)) \end{align*}  $$((a^2+b^2)\cdot (x^2+y^2)\cdot(ax+by)/((a^2+b^2)\cdot(x^2+y^2)))^2\le (a^2+b^2)^2\cdot(x^2+y^2)^2$$  after canceling becomes $$(ax+by)^2\le(a^2+b^2)^2\cdot(x^2+y^2)^2.$$  How could I get rid of the square on the terms on the right side of the inequality?  Edited: Looks like a duplicate but when I searched it did not come up on SE as the inequality was rearranged in the previous question.  Thanks DcMcMor for the editing.


on-topic page of a help center of a site contains the following sentence:     Please look around to see if your question has been asked before.   look around in above sentence links to the /search page where you'll find search bar is missing if you're using mobile theme.


Ubuntu is stuck at a blinking cursor while starting in Oracle VM

I have been logging into Ubuntu VM for about a month or more with no problem. Now the Ubuntu logo appears and it does not finish starting. After some time the rotating ring of Ubuntu disappears and after some time Ubuntu written at the time of starting as well. After some time my screen completely goes blank and only a blinking cursor appears on my screen. I have virtualization already enabled for my system.


What is the meaning of "a straight line"?

The book "The Dancing Wu Li Masters" page 189 talking about General Relativity says "A geodesic is not always a straight line".  Is that true? What is a definition of "straight line" that makes sense in this context?   The naive definition of "straight" is a three dimensional Euclidean sense. However, that is problematic. You'd need to project our four dimensional universe onto a "flat" three dimensional space. Presumable this would be done by choosing a pretty big inertial frame of reference and setting the Time axis to a constant. But choose a different frame, or different constant, and suddenly "straight" means something different.  Perhaps it makes more sense to define "straight" by projecting our four dimensional universe onto a four dimensional Euclidean space. But I think this will not work. Consider how difficult it is to project a curved 2D space onto a flat 2D space, such as making a map of the Earth. Except in special cases, the "straight lines" on the map do not correspond to any useful concept of "straight" on the globe. So I think in 4D the result will be not any better.  I am starting to think that the statement "A geodesic is not always a straight line" is simply nonsense, because there is no concept of "straight" except for the geodesic itself.  Perhaps five dimensions? Is there a projection of our four dimensional universe onto a five dimensional Euclidean space that would give us a sensible definition of "straight"?  Sorry if this is off-topic or too "philosophical".


Segmentation fault and core dumped when trying to declare a big array

In my C program, when I try to assign this array value:  double sample[200000][2];   I get a segmentation fault error. But when I use:  double sample[20000][2]   it works!! Is there a limit to these index values?


How can I calculate this integral? $\int_{-\infty}^{\infty} \Phi (a + bX) \phi (c + eX) dx$

Suppose we have the density and distribution of the standard normal. How can one calculate the integral:  $\int_{-\infty}^{\infty} \Phi (a + bX) \phi (c + eX) dx$  Note this is not included in the Wikipedia .  Further, this is not the same as  because that solution only works for a standard normal second term, i.e. $\phi (X)$ whereas this problem includes a coefficient and additional term. One cannot put into the same form as that case because $c$ and $e$ cannot be brought out of the normal density due to their involvement in the exponential component.


Can very strong gravitational wave collapse into a black hole?

Can a beam of very focused gravitational wave collapse into a black hole as ordinary matter(particle or radiation) does?   Alternative question: can a black hole grow by absorbing gravitational wave as well as absorbing ordinary matter?  It has been puzzling me that whether gravitational wave is "real matter", since gravitational wave can possess energy and momentum, but it has no well defined stress tensor. That's how I came up with this question. If the answer is negative, that means gravitational wave still cannot be unified with matter, otherwise there may be a potencial theory to explain the energy and momentum of gravitational wave.  I have read the answers to a similar question. But I was concerned that the result of numerical calculation may be unreliable because of the error. I want a more rigorous proof. (I will check the articles later)


I recently purchased an ASUS VivoTab Windows 8.1 tablet and, being the Linux enthusiast that I am, decided to install Ubuntu on it. Unfortunately, there are no USB or DVD drives, so I don't know what I'm supposed to install Ubuntu off of. I've already tried to format a MicroSD like an Ubuntu Live USB, but I can't seem to get the BIOS to let me boot off of the MicroSD. Any suggestions? I just need to install Ubuntu without using any kind of external drives. Alternately, I'm up for suggestions on the possibility of creating a Live MicroSD. Thanks.


Is it legal for users to make their SE posts native?

If a site uses content originating from a Stack Exchange site, is the user who owns the content legally permitted to make his post "native" to the non-SE site?    Here's what I mean. Some non-Stack Exchange site uses a post originating from an SE site, with all required attribution. The post was posted on SE by user X. If user X registers on the non-SE site, is the user allowed to remove the attribution and make it native to that site?   It should be, because it is the user's original content, but I just wanted to verify that this is legal.


Java - Adding a 0 in the minutes of the current time (GMT)

when I output the following code (taken from dr. Liang Introduction to Java, 10th ed., chapter 03 - selections)   /* (Current time) Listing 2.7, ShowCurrentTime.java, gives a program that displays the current time in GMT. Revise the program so that it prompts the user to enter the time zone offset to GMT and displays the time in the specified time zone. */   import java.util.Scanner;  public class Ex_03_08 {     public static void main(String[] args) {         Scanner input = new Scanner(System.in);           System.out.print("Enter the time zone (GMT): ");         int gmt = input.nextInt();           long totalMilliseconds = System.currentTimeMillis();           long totalSeconds = totalMilliseconds / 1000;           long currentSecond = totalSeconds % 60;           long totalMinutes = totalSeconds / 60;           long currentMinute = totalMinutes % 60;           long totalHours = totalMinutes / 60;           long currentHour = totalHours % 24;         currentHour = currentHour + gmt;           System.out.println("The current time is " + currentHour + ":"                 + currentMinute + ":" + currentSecond);          input.close();     } }   the output is   Enter the time zone (GMT): 1 The current time is 11:2:31   How can I let display instead 11:02:31?  Thank you.


Can a topological manifold be non-connected and each component with different dimension?

These are two definitions in page 48 of the book an introduction to manifolds by Loring Tu.  Definition 5.1. A topological space $M$ is locally Euclidean of dimension $n$ if every point $p$ in $M$ has a neighborhood $U$ such that there is a homeomorphism $\phi$ from $U$ onto an open subset of $\mathbb R^n$.  Definition 5.2. A topological manifold is a Hausdorff, second countable, locally Euclidean space. It is said to be of dimension $n$ if it is locally Euclidean of dimension $n$.  In the last lines of page 48, we reed,  Of course, if a topological manifold has several connected components, it is possible for each component to have a different dimension.  But this is a bit strange for me. If a topological manifold has several connected components and each component has different dimension, then how this manifold can be locally Euclidean space, say for example of dimension $n$? That is, by the above definition of topological manifolad, can a non-connected toplogical space be a topological manifold?


$c_n = 1 + \frac{1}{1!} + \frac{1}{2!} +...+\frac{1}{n!}$, so $e - c_n \le \frac{1}{n! * n}$  I absolutely have no idea how to solve it, could anyone tell me the approach?


I launch script.sh and inside it i want to know what is his name   Is there a standard procedure to know the scripts name ? the idea is to be able to extract the name from teh full path + name contained in $0  Thanks


I'm having some trouble with plain old JavaScript (no frameworks) in referencing my object in a callback function.  function foo(id) {     this.dom = document.getElementById(id);     this.bar = 5;     var self = this;     this.dom.addEventListener("click", self.onclick, false); }  foo.prototype = {     onclick : function() {         this.bar = 7;     } };   Now when I create a new object (after the DOM has loaded, with a span#test)  var x = new foo('test');   The 'this' inside the onclick function points to the span#test and not the foo object.  How do I get a reference to my foo object inside the onclick function?


Let $X$ be a noetherian integral separated scheme which is regular in codimension one. Then the proposition states that $\operatorname{Cl}(X)\cong\operatorname{Cl}(X\times\mathbb{A}^1_\mathbb{Z})$, where $\operatorname{Cl}$ denotes the divisor class group. In the proof, the author defines a homomorphism $\operatorname{Cl}(X)\to\operatorname{Cl}(X\times\mathbb{A}^1_\mathbb{Z})$ by sending a prime divisor $Y$ on $X$ to $\pi^{-1}(Y)$ on $X\times\mathbb{A}^1_\mathbb{Z}$.  Why is $\pi^{-1}(Y)$ a prime divisor?  Reducing to affine open sets, it suffices to prove that if $A$ is a noetherian integral domain (regular in codimension one) and $\mathfrak{p}$ is a prime ideal of $A$ with height $1$, then $\mathfrak{p}[t]$ is a prime ideal of $A[t]$ with height $1$. How do I prove this? Why can't there be a prime $\mathfrak{q}$ of $A[t]$ with $0\subsetneq\mathfrak{q}\subsetneq\mathfrak{p}[t]$ and $\mathfrak{q}\cap A=0$?


Will leaving corpses lying around upset my prisoners?

I see questions/information online about how to get rid of corpses but I'm not sure what the consequences to having them lying around are.  I know that I can use a morgue to store them and that they will eventually be taken away in a hearse. However, I've always just left them lying around. This doesn't seem to have any obvious consequences.  Do they upset prisoners or staff (e.g. increasing the danger level beyond what death normally does)? Make them sick? Slow down pathing? Is this something that's not implemented yet or is leaving dead bodies all over the place meant to be completely fine?  The wiki's pages for  and  don't shed any light on this. All I'm finding is the how of getting rid of corpses/glitches related to it but not why it matters in the first place. All I've seen that's related is that apparently prisoners can loot guard corpses for keys, but there's no obvious consequences for prisoner corpses which are what I tend to end up with.  So why not just leave them in the corridors?


How do I find the coordinates of the centre / centroid of a raster?   I have tried Zonal Geometry but this does not give me the coordinates.  I need to find the centroids of two rasters and create points and measure the distance and bearings between them. i.e. distance and direction between two raster centroids.  I am using ArcGIS Desktop 10.2.


How to find the last two digits of $237^{222222212202}$?

Problem  Finding the last two digits of a base with a large exponent: $237^{222222212202}$.  Method   If the number ends on 1:   the the second last digit is the second last base digit times the last exponent digit the last digit is 1  If the number ends on odd:   rewrite it until it is a number that ends on one and the first rule can be used $((n^4)^{e/4})$  If the number ends on an even number:   $..76^{n} = ..76$ $..24^{n} = $ ..76 for even $n$ and 24 for uneven $n$ $..2^{10} = ..24$    Solution  $$(7^4)^{55555553050}\cdot 7^2 = (2401)^{..0} \cdot 7^2 = ..01 \cdot 7^2 = 49$$  Question   Is this method correct / could it be improved? Is there an easier method? Can someone please take my example and demonstrate it with Euler and explain it?   Thank you so much!


Between which two consecutive integer numbers is $\sqrt{2}+\sqrt{3}$? My thoughts: $\sqrt{2}$ is $\approx1,4$ and $\sqrt{3}$ is $\approx{1,7}$ so their sum must be of the interval $(3;4)$. Any more strict approaches? Thank you in advance!


Java: return the actual object vs. returning a reference

Pass by value and by reference - I do this all the time in C++. But I'm wondering the behavior of java.  I'm writing a BST and conjured the following method:  private Node<T> get_node(T data) {     Node<T> tmp = null;     if (isEmpty())     {         return null;     }     tmp = root;     while (tmp != null)     {         //System.out.println("tmp is " + tmp.getData());         if (compare(tmp.getData(), data) < 0) //data is greater         {             System.out.println("get right");             tmp = tmp.getRight();         }         else if (compare(tmp.getData(), data) < 0) //tmp is greater         {             System.out.println("get left");             tmp = tmp.getLeft();         }         else if (compare(tmp.getData(), data) == 0) //we found it         {             System.out.println("get left");             return tmp;         }     }     return null; }    This is in the BST class itself - I am using this helper function to construct a new BST in "this".  The problem is, I don't think this method is actually returning the ACTUAL Node in this. I think it is returning a copy or something likewise useless to me. I really want this to return the ACTUAL Node in this.  How is this done? Is this done at all?


C++ : How differs type* varName from type *varName?

I am purely new to C++, I did Java 10 years ago and between this I used mainly R and Perl. Now I have to extend the code written by someone and I am confused with the using of the pointer operator"*". Is there a difference between writing it at the end of the type (f.e. "unsigned char* thing"), or writing it at the beginning of the variables name (f.e. "unsigned char *thing")? Even in books the "grammar" seems to differ, what leads me to a "should not differ" meaning, but I want to be sure, so I ask you...


Differentiability of $f(x+y) = \frac{f(x)+f(y)}{1-f(x)f(y)}$

let $f$ be a function defined on the interval $(-1, 1)$ such that for all $x, y \in (-1, 1)$,  $$f(x+y) = \frac{f(x)+f(y)}{1-f(x)f(y)}$$  Suppose that $f$ is differentiable at $x = 0$  (i) Show that $f$ is differentiable on $(-1, 1)$.  (ii) If $f'(0) = \pi/2$, find the explicit expression of $f(x)$.


How to add a link to answer / question or a comment that opens in new tab?

Whenever I add a link to an answer it doesn't gives me any option to open it in new tab ("target='_blank'") all links open in the same tab.. or may be I don't know the way to do this.  SO, is there anyway to do this??  Many Thanks.


Using a primed sum operator in display and text mode

I would like to define a primed sum command \sump such that \sump_{x \in X} produces:   a prime at the top right corner and the x \in X below the sigma in display mode, and a prime in the top right corner and the x \in X at the bottom right of the sigma in text mode.   I've tried combinations of \mathchoice and \sideset to get this right, but have not succeeded so far.  If it makes any difference, I'd like to do this not only with sums, but also to define primed \prod, \min and \max commands.  Of course, one could define \sump to take the x \in X as an argument, and then place it correctly using \mathchoice and \sideset, but for writing code that is more readable and includes normal (non-primed) sums I'd prefer not to do this. Help?  If one follows the most accepted answer in the suggested , then when using \sump_{x \in X} in text mode there is an unnecessary space before the x \in X lower limit; the prime pushes the right boundary of the operator out, so that the lower limit doesn't start right next to the Sigma.


Ubuntu Wi-fi driver not working on my Acer Aspire V15 Nitro?? (Qualcomm Atheros QC6174a

How do I install my wifi drivers? There is no option to "Enable Wi-fi" on my toolbar except for "Enable Networking".  Any help would be appreciated,.  Thanks.


Prove that $\frac{1+\sin\theta + i\cos\theta}{1+\sin\theta-i\cos\theta}=\sin\theta+i\cos\theta.$

Prove that $$\frac{1+\sin\theta + i\cos\theta}{1+\sin\theta-i\cos\theta}=\sin\theta+i\cos\theta.$$  Hence, show that $$(1+\sin\frac{\pi}{5}+i\cos\frac{\pi}{5})^5+i(1+\sin\frac{\pi}{5}-i\cos\frac{\pi}{5})^5=0.$$  In the first part, I tried realising LHS so I got $$LHS=\frac{(1+\sin\theta+i\cos\theta)^2}{(1+\sin\theta)^2+\cos^2\theta}=\frac{1+2\sin\theta+2i\cos\theta+2i\cos\theta\sin\theta+\sin^2\theta+i^2\cos^2\theta}{2+2\sin\theta}.$$  but now I am stuck :( . Any help would be greatly appreciated, thanks!


Commenting is one of the unsung heroes of Stack Exchange. :   Request clarification from the author; Leave constructive criticism that guides the author in improving the post; Add relevant but minor or transient information to a post (e.g. a link to a related question, or an alert to the author that the question has been updated).   These are all essential for coordinating the creation of useful questions and answers, but originally comments were not part of the design for this system! During the beta period, it was observed that, without a way to annotate or discuss specific posts, answers became noisy and tangential. Therefore, a separate space was carved out for this purpose below each post, leaving answers free for content that, y'know, actually tries to answer the question. This created a problem, however: how do we expose useful comments inline with answers without adding back the same amount of noise comments were created to alleviate? . This simple strategy proved to be quite durable, working admirably in most common cases - but it suffers from a few drawbacks:  Comments can become obsolete, addressing issues or concerns long ago addressed via edits to the post itself. Those one-liner contests Jeff alluded to don't always produce results as  as one might like. With the addition of comment replies and real-time notifications, comments can be used for casual conversation and debate - fun and perhaps even enlightening for those involved, noise for those just looking for an answer.  Thus the need for comment moderation. This involves three groups of people:  The authors of the comments themselves can clean up after they're done, if they so desire.  can flag comments in response to the issues noted above, bringing them to the attention of the moderators. (They can also vote on comments, controlling to a degree which ones are shown)  can remove individual comments or entire comment threads, , and even  posts if comments are getting unruly.  This raises several questions, which I'll try to address below:        These guidelines are based on the authors' experience moderating comments on various sites. Individual communities, particularly on meta sites, may benefit from additional guidelines - this guide is intended as a baseline.