the $R^2$ is the amount of variation of the dependend variable $Y$ explained by linear regression. It can take values between 0 and 1.  If I use the adjusted $R^2$ instead, what is the interpretation of this value?


How do I chmod or chown a file so that anybody in the world can access it?

.I have a font file which I created using a python script from Github. The owner and group are root. I don't actually know what this means... I can guess what owner means, and I can guess that a group is a group permission that can be used to determine access but I'm not entirely clear on the difference between the group being root and the owner being root. Or how one even creates a group.   Anyway the permissions for "Other" is read only, and when I try to install the font using the font viewer I am denied based on permissions.   I also want to transfer this file to my windows machine and to other friends etc, so I want to take away all permissions from this file. Or give all permissions on this file? I'm not clear on the semantics there... basically I want to make it so that anyone can read, write, execute, use, install, whatever this file.   I tried running chmod o+rx {{font name}} but that didn't do anything it seems. I then tried `chown o+rx {{font name}}' and that threw an error because I didn't write a user name.   But if I don't want to write a specific user name, I just want to make it that anyone can do anything with this file, what would I do. and why would I do it that way?   I also realize that I could just use the CLI to sudo install the font but I want to understand why permissions work this way and what exactly I'm doing.   When I download a picture from the internet, anyone can edit, delete, move, or use the file etc. So having never really dealt with permissions I'm not really clear on how a picture from the internet differs from files one has set permissions for. I get conceptually that it's a security thing but the exact logic is not clear to me.   EDIT:  The top answer to this question essentially answered my question:   I'm still not clear on the full limits or theory about permissions, but in order to make it so that a file can be used by anyone I just have to change the permissions while under root using this command: chmod a+rwX {{filename}}  I know what rwx means. It means read, write, execute. And plus means to give those permissions. But what do a mean? I read to use o which is other, but I'm guessing that a is anyone?   I know how to give anyone permission, but how can I make anyone owner? That's probably the more specific question I'm asking.


Bad password after upgrading from 17.10 to 18.04 with full disk encryption

I upgraded from 17.10 to 18.04 today and after a reboot, I noticed my password no longer works. I'm certain the password is correct, but I keep getting "bad passphrase or options". How can I fix this?


Binomial coefficients with sums $\sum_{i=0}^ni^2{n\choose i} $

I need help solvinf this task, if anyone had a similar problrm it would help me. The task is: Calculate : $\sum_{i=0}^ni^2{n\choose i}  $ I tried this: $ \sum_{i=0}^ni^2{n\choose i}\\ \sum_{i=0}^ni^2\frac{n!}{i!(n-i)!}\\ \sum_{i=0}^ni\frac{n!}{(i-1)!(n-i)!}\\ n!\sum_{i=0}^ni\frac{1}{(i-1)!(n-i)!}\\ \frac{n!}{(n-1)!}\sum_{i=0}^ni\frac{(n-1)!}{(i-1)!(n-i)!}\\ n\sum_{i=0}^ni{n-1\choose i-1}  $ And now, i have no idea how to get solution $2^{n-2}n(n+1)   $ Thanks in advance !


Using round function in QGIS expression?

I created a grid of rectangular polygons with the Create Grid function, from the Vector Creation group of the Processing Toolbox in QGIS 3.4.2. The rectangles measure half a degree of longitude by half a degree of latitude.    When I want to label the polygons, I write an expression that rounds the values of latitude and longitude attributes to 2 decimal places, since the attributes created in the grid brings many decimal places.    But the round function rounds the values badly.    I know that I can create new attributes that express the coordinates with fewer decimal places and label the entities based on those attributes, but I was struck by the behavior of the function. I expected it to round to the nearest value.    Does anyone know what the problem is that the round function wrongly rounds off the decimal number?    Attached screenshots of Source Fields and the Attribute Table.


Preventing duplication on a Postgres table with 2 columns

I am currently implementing a simple database schema (in PostgreSQL 11.1 (Debian)), with two int columns (say col1, col2).  My goal is to prevent duplicates appearing in any of the two columns.  If (1,2) already existed, then (1,2) or (2,1) would cause a "duplicate key value violates unique constraint" error.  For a practical example.  I have created a table someTable, with col1, col2, with a unique constraint (col1, col2).  Everything is fine when I insert (1,2) a second time:  CREATE TABLE someTable (  col1 int NOT NULL,  col2 int NOT NULL,  unique (col1, col2));  - CREATE TABLE  INSERT INTO someTable (col1, col2) VALUES (1,2); - INSERT 0 1  INSERT INTO someTable (col1, col2) VALUES (1,2); - ERROR:  duplicate key value violates unique constraint "sometable_col1_col2_key" DETAIL:  Key (col1, col2)=(1, 2) already exists.  INSERT INTO someTable (col1, col2) VALUES (2,1); - INSERT 0 1   I would like the (col1, col2) unique constraint to work for swapped values (for example 2,1 is treated the same as 1,2).


Extracted from  (see the bottom section):     Some roller-coasters have loop-the-loop sections, where you travel in a vertical circle, so that you're upside-down at the top. To do this without falling off the track, you have to be traveling at least a particular minimum speed at the top. The critical factor in determining whether you make it completely around is the normal force; if the track has to exert a downward normal force at the top of the track to keep you moving in a circle, you're fine, but if the normal force drops to zero you're in trouble.   I've been told the normal force is a contrapositive force. I mean, when I'm at the top of the loop, the weight already points down so how can there be a normal force, if I'm not exerting a force to the road?


Why can't this virtual method be inlined?

I read that, in simplified terms, if the C++ compiler can prove that a variable is of a certain type, it can inline virtual functions. Why can't it do it in this case (tested with MSVC 2017, clang 4.0, gcc 7.2 and icc 17):  #include <iostream>  class Callable { public:     virtual int sq(int n) const; };  class Square : public Callable { public:     inline int sq(int n) const override final  {         return n*n;     } };  class Call { public:         const Callable caller; };  class Methods { public:     constexpr static const Call c {Square()}; };  int main() {     using std::cout;     cout << Methods().c.caller.sq(5); }   I noticed that clang's optimization output in godbolt (link below) says that Callable::sq will not be inlined because its definition is unavailable. However, Methods::c is static and const. Call::caller is also const. Also, Square::sq is final. As far as I know, there is no way they'll change at runtime. Or am I missing something?  On the other hand, the compiler is able to inline the function in this version:  #include <iostream>  class Callable { public:     virtual int sq(int n) const; };  class Square : public Callable { public:     inline int sq(int n) const override final  {         return n*n;     } };  class Call { public:         Callable const* caller; };  class Methods { public:     Call c {new Square()}; };  int main() {     using std::cout;         cout << Methods().c.caller->sq(5); }   Why is that so?  for godbolt for easy checking.


Cron Job Issue - Centos 7 ( Centos Webpanel)

The following cronjob don´t work in my server and I don´t understand the reason  Cron:  `curl https://app.codexbot.co/cron_job/background_scanning_update_subscriber_info/1-NmZTjQk1575844678nNCBzwb >/dev/null 2>&1`


In the movie, Newt reveals that the beast attacking New York was actually an Obscurus, which he explains is      a burst of dark power that manifests in witch or wizard that represses their magical power.   Now, he goes on to explain that      The oldest known Obscurial was 10 years old, but they're usually younger.   If this is true, why then      did Harry Potter or Hermione Granger not develop an Obscurus? They were not even aware magic existed until they were 11. My only thought would be that they didn't actively repress their magic, just didn't know what it was.   I don't know if there was any more detail given in a companion novel, Pottermore or the book itself, but on the wiki it made no mention of details other than was given in the movie. Are there any additional rules that would explain why this doesn't happen more often?


Why do I need energy quantization to explain the blackbody spectrum?

I don't understand why the postulate of "Energy Quantization" is needed to explain the black body energy spectrum.   I think it suffices to say that Energy is proportional to frequency. That statement alone, taken together with Boltzmann distribution, implies that there will be less energy present at higher frequency. And this explains why the black body radiation spectrum dies away at higher frequencies. Why do I need to invoke quantization?


Sinking and Sourcing Current to and from a PIC24F Output Pin

Sinking and sourcing current refers to current going into and out of the MCU (respectively), right? If you configure a GPIO pin as an output, why would current ever go into the pin (since it's configured as an OUTPUT)? I suppose it depends what the output circuit looks like, if it's tied to the voltage supply rail or ground... maybe I just answered my own question...?


Why does a perpendicular force not change speed?

I have been taught that a perpendicular force acting on an object will only change the direction of its velocity, not its magnitude. The explanation that was provided to me is that because there no force in the direction of its velocity, there must be no work done and thus change in the object's kinetic energy. However, I have also studied the vectorial form of the equations of motion   $$\vec v_f = \vec v_i + \vec a\cdot t$$   So I assume that the velocity after a constant force has acted on it for a period of time is simply the vector sum of $\vec v_i $ and  $\vec a \cdot t$, which I just assume is the acceleration vector (determined by the force) scaled up by a factor of the time the force acts.Diagrammatically, I took the sum as    It is obviously clear from the diagram that the new speed (which is the length of the $\vec v_f$ vector) is bigger than the previous speed.  This can be confirmed by Pythagoras's theorem, the magnitude of the $\vec v_f$ vector is   $$ |\vec v_f|=\sqrt{|\vec v_i|^2 + |\vec a|^2 \cdot t^2}  $$  which is very clearly not equal to $|\vec v_i| $  So, I conclude that the speed of the object has changed even though the force acting on it was perpendicular to its velocity. So my question is, what have I missed?  Is my assumption that the final velocity is the vector sum of the initial velocity and the product of acceleration and time incorrect? Or have I made a mistake somewhere else?  Thank you in advance for your help.


How to use Android in Wi-Fi repeater mode by bridging Wi-Fi with Access Point?

I would like to extend a WiFi signal. I could buy a WiFi repeater, but a much cheaper solution would be using an older Android 4 device, which I own and don't use. The Android device is capable of creating a WiFi AP. So if I bought an external WiFi USB adapter for it, with a large antenna used as the receiver and the Android device itself as the AP, I could bridge the network.  The hardware should be possible. But how about the Android software? Will there be any issues, or any considerations I need to take note of?


I am trying to restart my Apache but I keep getting this error:  Jan 28 20:34:05 localhost systemd[1]: apache2.service: Failed with result 'resources'. Jan 28 20:36:22 localhost systemd[1]: apache2.service: Failed to run 'start' task: No space left on device Jan 28 20:36:22 localhost systemd[1]: Failed to start The Apache HTTP Server. Jan 28 20:36:22 localhost systemd[1]: apache2.service: Failed with result 'resources'. Jan 28 20:37:37 localhost systemd[1]: apache2.service: Failed to run 'start' task: No space left on device Jan 28 20:37:37 localhost systemd[1]: Failed to start The Apache HTTP Server. Jan 28 20:37:37 localhost systemd[1]: apache2.service: Failed with result 'resources'. Jan 28 20:45:03 localhost systemd[1]: apache2.service: Failed to run 'start' task: No space left on device Jan 28 20:45:03 localhost systemd[1]: Failed to start The Apache HTTP Server. Jan 28 20:45:03 localhost systemd[1]: apache2.service: Failed with result 'resources'.   I have tried this  but it does not work:     fs.inotify.max_user_watches = 262144 (Add this to /etc/sysctl.conf and   then run sysctl -p.)   This is some more info if it helps?  sudo df -h Filesystem      Size  Used Avail Use% Mounted on /dev/root        20G   20G     0 100% / devtmpfs        488M     0  488M   0% /dev tmpfs           490M     0  490M   0% /dev/shm tmpfs           490M   51M  440M  11% /run tmpfs           5.0M     0  5.0M   0% /run/lock tmpfs           490M     0  490M   0% /sys/fs/cgroup tmpfs            98M     0   98M   0% /run/user/0   Any ideas what I can do?  EDIT:  There is no solution from this . How is this duplicated?


Let $f:X \rightarrow Y$ be a continuous map of topological spaces, such that it is closed immersion. Let $\mathfrak{F}$ and $\mathfrak{G}$ be sheafs on $X$ and $Y$ respectively. How to show, that canonical morphisms $$ \mathfrak{G} \rightarrow f_* f^{-1} \mathfrak{G}, \; f^{-1} f_* \mathfrak{F} \rightarrow \mathfrak{F} $$ are isomorphisms?  Is it true, that taking stalk doesn't commute with direct image, but commutes with inverse image?


How do I recover files from an USB flash drive?

Possible Duplicate:          I have a USB flash drive that claims it needs to be formatted every time I put it into my computer (Windows).  Yesterday the drive was healthy and had data on it.  The data is probalby still there.  Are there any free tools to restore the drive?  If not free, what tools are known to work in this situation?


Review queue showing wrong review today number

When going onto recent views on Safari Mobile I saw it says there were 5 reviews in the suggested edit queue.  Yet. In the users reviews today list there were only two:    Also for close votes:    And low quality posts:


Is it feasible to build an index of prime factors?

Would it be possible to break an RSA key, in for example 1 week of time, if the cracker have already spent X number of years building an index of primes by performing every permutation of existing prime keys up to $2^{2048}$?  I understand this would take an immense amount of time to do, but it would only be done once. Obviously, computing such an index would take a considerable amount of time and would have to be done with someone having the right amount of resource. Given the public key, you would be able to look up what the two primes are, and hence retrieve the private key instantly.  Breaking an 256 AES would then be easier, as AES keys are often generated using the RSA private key.  Would it be possible to build such an index? How long would that take in permutations and perhaps with the fastest computer in the world?


How can I delete all my personal files on my Mac so they are not recoverable

I have to return my work laptop soon and would like to delete all my personal files so they are not recoverable at all.  I was thinking of using the terminal command rm –rf / but I'm not sure if this would leave the computer in a state that my company could recover it from.


What are the integers $n$ such that $\mathbb{Z}[\sqrt{n}]$ is integrally closed?

I was recently reading about integral ring extensions. One of the first examples given is that $\mathbb{Z}$ is integrally closed in its quotient field $\mathbb{Q}$. Another is that $\mathbb{Z}[\sqrt{5}]$ is not integrally closed in $\mathbb{Q}(\sqrt{5})$ since for example $(1+\sqrt{5})/2\in\mathbb{Q}[\sqrt{5}]$ is integral over $\mathbb{Z}$ as a root of $X^2-X-1$, but $(1+\sqrt{5})/2\notin\mathbb{Z}[\sqrt{5}]$.     Now I'm  curious, can we find what are all integers $n$ such that $\mathbb{Z}[\sqrt{n}]$ is integrally closed (equal to its integral closure in its quotient field)?   One thing I do know is that unique factorization domains are integrally closed, so I think rings like $\mathbb{Z}[\sqrt{-1}]$, $\mathbb{Z}[\sqrt{-2}]$, $\mathbb{Z}[\sqrt{2}]$ and $\mathbb{Z}[\sqrt{3}]$ are integrally closed, as they are Euclidean domains, and thus are UFDs. But can we say what all integers $n$ are such that $\mathbb{Z}[\sqrt{n}]$ is integrally closed? Thanks!


"The software on this computer is up to date" while upgrading 12.10 to 13.04

Before you guys close this question as duplicate, I did go through  and nothing solves my problem there.  When I try to upgrade my ubuntu 12.10 installation it says      The software on this computer is up to date.      There are no upgrades available for your system. The upgrade will now   be canceled.   Here's a snapshot:    Question: how to fix this issue and upgrade 12.10 to 13.04?  Update  I tried @montazeri's command and cated release file. Here's the output:


Undefined reference to static constexpr char[][]

I tried to init char[][] static public field in class but in another function this field is undefined. How I use consexpr  or exists another method to init static (dictionary) array?  class A {     public:         constexpr static char dict[][3] = {             "a",             "bb"         };          void print() {             printf(A::dict[1]);         } };  int main() {     A a;     a.print();     return 0; }   10  undefined reference to `A::dict'


Can $A[x]$ be isomorphic to $A$ if $A$ is noetherian?

Let $A$ be a nonzero noetherian commutative ring with one, and let $x$ be an indeterminate.   Can the rings $A[x]$ and $A$ be isomorphic?  Of course such a ring would have infinite Krull dimension, but noetherian rings of infinite Krull dimension are well known to exist: see .


Are or is? May be a simple question but I am confused

Which of the following sentences are grammatical?     Being egocentric and selfish are dangerous in a world where karma is always with you.      Being egocentric and selfish is dangerous in a world where karma is always with you.   According to the top answer on this thread:      I can use either: it depends on whether 'X and Y' are considered like a single thing or individually. However, one of the comments below says that for the other question this is true, but in this case I do NOT have a choice. The grammar here is different.


Tourist Visa (30 days) Dubai valid until date

Today I was informed by VFS that my tourist visa for UAE got approved. I'm travelling to UAE on 16th December 2014 and returning on 7th Jan 2015. But when I checked the "valid until" date on the visa it states 30 December 2014.    Does this date mean I should return before December 30th? Should I get it corrected from VFS?


Imagine I have an infinite source of numbered apples and a box of an infinite size. I take two apples from the source, put them in the box, then take one apple out: Step $1$: apples $1$ and $2$ in - apple $1$ out Step $2$: apples $3$ and $4$ in - apple $2$ out Step $3$: apples $5$ and $6$ in - apple $3$ out ... Step $N$: apples $(2N-1)$ and $2N$ in - apple $N$ out ... With each step the number of apples $S$ in the box increases, so: $$ \lim_{N\to\infty}S=\infty  $$ However, once I have gone though the infinite number of steps, the box ends up empty: $$ S_{N=\infty}=0 $$ Proof: If the box is not empty, it must contain at least one apple numbered $N$. This is impossible, because I removed this apple in the step number $N$ according to the above procedure. Where is a flaw in this logic and how is this apparent paradox resolved?


Probability of picking an odd number from the set of naturals?

I know there's no uniform distribution for a countably infinite set, but I'm wondering if there's still a way to determine the probability of picking from a subset of a countably infinite set.  For example, what's the probability that I pick an odd number from the set of naturals, assuming I'm picking randomly? Is this even a coherent question? If so, is there a textbook approach to this problem in measure theory/probability theory/probability measure?  Thanks!


Show  $$1+\cosθ+\cos(2θ)+\cdots+\cos(nθ)=\frac12+\frac{\sin\left(\left(n+\frac12\right)θ\right)}{2\sin\left(\frac\theta2\right)}$$ I want to use De Moivre's formula and $$1+z+z^2+\cdots+z^n=\frac{z^{n+1}-1}{z-1}.$$  I set $z=x+yi$, but couldn't get it.


I have this string in php  $tagged   and I want to put it in my javacript script inside the ' '  tagName: '',   how do I do this


What is the shortest fingerprint of a Curve25519 public key that is secure

My clients have to exchange public keys. To ensure security they are exchanging fingerprints and typing them into the computer by hands.  I want the fingerprints to be as short as possible.  I am using libsodium for encryption, which uses Curve25519. What is the shortest fingerprint I can generate which would still ensure security?


Replacing tech reports: can we put good undergrad dissertations in arxiv?

My department requires dissertations from all honours students (being England, that's basically all of them).  Some of these are extremely good, even though they are written by undergraduates.  My department for some years created a tech report series, which included undergraduate dissertations with high enough marks and the agreement of the supervisor, but now this system has gotten lost in a morass of web redesigns etc.  Is there any new norm for archiving good undergraduate dissertations?  We were thinking of just putting it in arxiv.org, is that considered acceptable?  We are writing an article and want to cite the dissertation for the full implementation details.


bevel shader not appearing in 2.79 on Mac

I have seen tutorials showing the bevel shader in Blender 2.79b. I cannot get it to show up in the shader menu even after doing a fresh install of Blender. I wonder if it is a Mac issue. I am running Mac OS high sierra 10.13.6, AmD FirePro D700 graphics cards. In the shader node editor I am going Add:Input... bevel shader should appear between Attribute and CameraData but it doesn't.


Ubuntu 16.10 Dual Boot error - 'grub-efi-amd64-signed' package failed to install

I'm currently trying to dual boot Ubuntu 16.10 alongside Windows 10 on a Dell XPS 13 (series 7).  I've basically followed this guide! which involves:    Changing from IDE to AHCI mode Enabling 'UEFI Network Stack' via the BIOS Booting via USB - (with Ubuntu Boot disk created via Rufus or Etcher) Installing Ubuntu via USB   Install hums along as per usual until it comes to installing Grub where it shows an error:   "The 'grub-efi-amd64-signed' package failed to install into /target/. Without the GRUB boot load, the installed system will not boot."   This is a new laptop so I haven't installed Ubuntu on the machine yet, but I have installed it on old laptops and am reasonably familiar with the setup process so I've tried a number of alternative solutions including:  - ensuring updates are downloaded during the install - specifying the install partitions for the root, swap and boot - Installing via DVD instead of USB - Making a sandwich   Anyway, I haven't had any luck and would be grateful for suggestions/ideas as after a lot of googling I'm out of them.   EDIT:   Okay, so I've managed to get it working after a lot of trial and error.   Unfortunately I'm not sure if it provides useful information for others who might experience the same issue.   Here are the steps I took:   Suspecting it may be an issue with Ubuntu 16.10, I undertook the painful process of downloading 16.04 (LTS). - painful due to my slow internet - I updated my BIOS and Hard drive (Toshiba NVMe) firmware from the Dell website (Dell XPS 13 9360).  Delete the old ubuntu EFI entries via Windows (in case it was causing the error). Installing Ubuntu 16.04 via USB (UEFI mode) - made it past previous GRUB error above, but received error "'grub-install /dev/nvme failed. This is a fatal error.'". Installation halted.  Launched live-usb and repaired grub via 'Boot Repair' with 'secure-boot' unchecked in the 'advanced' option.    This worked.   No idea if my computer is likely to explode, but everything seems fine.   Btw, this has been reported by a number of other users eg  and   EDIT 2:   One other thing I had to do (possibly as the install halted early) was check and replace/repair missing files via instructions below:


Jquery Validation for Two Dropdown Boxes

I have Two dropdown boxes, if i select 4 from first select box, the value of the second dropdown value must be less than the first dropdown. if it fails show a custom error message, like that.  <select name="t_dropdown" id="t_dropdown" class="form-control required">   <option value="">Select Value</option>   <option value="1">1</option>   <option value="2">2</option>   <option value="3">3</option>   <option value="4">4</option>   <option value="5">5</option> </select>  <select name="p_dropdown" id="p_dropdown" class="form-control required">   <option value="">Select Value</option>   <option value="1">1</option>   <option value="2">2</option>   <option value="3">3</option>   <option value="4">4</option>   <option value="5">5</option>   <option value="6">6</option>   <option value=">6">>6</option> </select>   Please let me know, how to do it using jquery validations.


How to change permissions to writable of local disk partitions created in windows 10?

I installed windows 10 and then dual booted my laptop by Ubuntu 18.04 Now I can't copy files (while using ubuntu) to the partitions which were created using windows as the partitions are Read-only. Properties show that the filesystem are of fuse type. I have tried solutions given


$f(x+1)-f(x)$ converges $\Rightarrow\frac{f(x)}x$ converges

Let $f:\mathbb{R}\to\mathbb{R}$ continuous such that $\lim_{x\to\infty}f(x+1)-f(x)=l$.  How can I prove that $\dfrac{f(x)}x$ converges for $x\to+\infty$ ?  I am just trying to prove the convergence, not that it converges to $l$ (that part be deduced immediately by Stolz-Cesaro and the sequential characterization of limits)


How can I run Windows applications on a MacBook Pro?

I have a friend that wants to buy a Mac Book Pro and he has some windows applications that he needs to run. He doesn't want to buy the applications again.  Can he run the Windows applications on his MacBook Pro? What ways to accomplish this are available?


What's the difference between these two sentences?        This movie is hardly as interesting as that one.     That movie is almost more interesting than this one.      I would like a native speaker's opinion on this.


Virus causing multiple explorer.exe instances using high memory

To begin, yes, there are similar questions out there, even on this site. However, none of them seem to off a solution outside of format the computer.  Story time! (Or the background to this whole ordeal)  Pretty sure this one has been looming for at least a month, since it was about a month ago when I tried to update AVG 2014 -> 2015. It failed, and in the meantime I installed AdAware until I could mess with it more. The other day I finally realized after some help on AVG's forum that several things were missing, such as Windows Firewall. I finally found  which allowed me to get things going and AVG reinstalled. It did find a couple viruses, which were removed, but then I noticed that explorer had multiple instances running, some of which were near to well above 1,000,000 K memory usage. AVG hasn't found anything else. AdAware obviously didn't find anything, and MalwareByes didn't find anything either, though it is constantly blocking internet requests from explorer.exe. I even corrupted explorer.exe so that sfc could fix it, and still the issue persists.   I had a thought that perhaps a driver was to blame, based on a previous experience with the Google redirect virus, however, nothing looks overly suspicious in the device manager or in the drivers folder.   Any hints or suggestions are welcome. I'm really trying to avoid having to do a refresh on this computer, as reinstalling everything takes a good 10+ hours if things go well.


Suppose $f(0) = f(2 \pi)$. Show there is a number $c \in [0, \pi]$ such that $f(c)=f(c + \pi)$

I'm a student taking a real analysis course at university. I'm working down my problem sheet and have been asked the following (which is the full version of the shortened question in the title).  Q:Suppose $f:[0,2 \pi] \rightarrow \mathbb{R}$ is a continuous function satisfying $f(0) = f(2 \pi)$. Show that there is a number $c \in [0,\pi]$ such that $f(c) = f(c+ \pi)$.  The question seems to be referencing $\sin(x)$. A solution I know exists in the range $[0, \pi]$ is $c=0$, therefore $\sin(0)= \sin(\pi)$. However $\sin(x)$ doesn't appear to be directly referenced and I am not sure how to show a value for $c$ only knowing $f(0) = f(2 \pi)$.  If anyone can help it would be much appreciated!


Early Modern English: Shakespearean Insult

I think many are familiar with the famous line from Shakespeare:     Shall I compare thee to a summer's day? Thou art more lovely and more   temperate.   What I seek to do is keep the analogy but change the second sentence to an insult. I also want to keep the  style and a few words of the original phrasing so the parody is clear. However, if I use nearly all the original words from the second sentence, it sounds too contrived:     Shall I compare thee to a summer's day? Nay, thou art much less   lovely, let alone temperate.   Question: Can someone give me a suitable, slightly less contrived,  insult using "Thou art more lovely and more temperate" as inspiration?


What--is the Ultimate Limit of heat based off c?

As heat goes up, molecules start moving at a faster rate. A gas molecule, if unhindered, could speed across the United States in three hours. I don't even want to know about plasma. But if heat consists of the speed of the molecule (which is an if) then shouldn't there be an Absolute Infinity as well as an Absolute Zero? And if so, why isn't this mentioned in textbooks? Shouldn't "Absolute Infinity" be important in thermodynamics? And are there quantum repercussions if some plasma approaches the speed of light through the individual speeds of its molecules? Does this also mean that the process of heating objects up is not linear anymore (because as you approach c, it becomes harder to accelerate the molecules)?  Thanks guys! More questions coming :)  EDIT: In light of the fact that there are many contending theories for the Ultimate Heat Limit (Hagedorn temperature, Planck temperature, even 0 K) I will leave this open to a wide variety of answers. :)


Suppose we have 'n' Stars and 'k' bins. We have to distribute 'n' stars in 'k' bins (using k-1 bars) such that bins can be empty. We can do this in $\binom {n+k-1}{k-1}$ = $\binom {n+k-1}{n}$ ways. But Sometimes we use another notation $\left({{k}\choose {n}}\right)$ to represent $\binom {n+k-1}{k-1}$, Which says 'k multichoose n'. But normally as n > k, then how can we choose more objects from less objects i.e. n from k. So, I think It has to be like this $\left({{n}\choose {k}}\right)$.


New Rep indicator stops when having negative score

Today I gave a .  This results of course in a negative score for today.   Since then I don't get any more notifications for new rep in the new top-bar on meta.    Only after resetting the rep indicator by clicking on it I get new notifications.


Regex to one letter and character without special chars

I'm trying to write a regex to validate below conditions in a password string   Atleast one number and a letter Should not contain any special characters   Tried this regex  [a-zA-Z]+[0-9]+[a-zA-Z0-9]*|[0-9]+[a-zA-Z][a-zA-Z0-9]*   But it allows special characters.  Any help would be appreciated!  Example   aaaa - Not accepted  11111 - Not accepted aaaa1 - Accepted aaaa1* - Not accepted


Seeking shapefiles of global climate/climatic zones

Have been looking around a bit for a shapefile/kml/etc file of global climatic zones (as listed here: ) -- temperature, subtropical, tropical, etcetera.  Also would be very pleased to find gis overlays detailing photoperiod areas, that sort of thing?   An online GIS service would be fine for this as well for this, as long as its a real GIS with aerial overlays etc, not a plane paper PDF deal, which is about all I can find.  One promising (but dead link) source I found before posting question:


the limit of Poisson CDF with diverging rate parameter

The CDF of a Poisson distribution with rate parameter $\lambda$ is $$ P(n;\lambda)=\sum_{k=0}^n \frac{\lambda^ke^{-\lambda}}{k!}. $$ As $n$ goes to infinity, the CDF would certainly approach 1. Now, consider the case when the rate parameter is $\xi n$ with $\xi\in(0,1)$ being a given constant. According to the last answer in , the following limit should be 1: $$ \lim_{n\to\infty}P(n;\xi n)=\lim_{n\to\infty} \sum_{k=0}^n\frac{(n\xi)^ke^{-n\xi}}{k!}=1. $$ Is it possible to check the convergence rate of the above limit? More specifically, I wonder whether the convergence rate is faster than $n$, i.e., whether $n[1-P(n;\xi n)]=O(1)$? I checked using software that the convergence rate is faster than $n$, but I don't know how to show it rigorously. Can anyone provide some hints and insights? Thanks!


Proof of the inequality $e^x\le e^{x^2} + x$

The question is to prove the inequality $e^x\le e^{x^2} + x$. I tried the Taylor expansion like ${e^x} = 1 + x + \frac{{{x^2}}}{{2!}} + \frac{{{x^3}}}{{3!}} + ...$ and $x + {e^{{x^2}}} = 1 + x + \frac{{{x^4}}}{{2!}} + \frac{{{x^6}}}{{3!}} + ...$ but cannot see anything useful out of this. Anyone can provide some help? Thank you.


Do we have $(z^r)^s=(z^s)^r$ for all $z\in\mathbb{C}-\{0\}$?

Over the reals, I know this is true: $$(x^r)^s=(x^s)^r$$ for $x>0$ and $r,s\in\mathbb{Q}$.  Does the same equation hold over $\mathbb{C}$? I.e., $$(z^r)^s=(z^s)^r,$$ for $z\in\mathbb{C}-\{0\}$ and $r,s\in\mathbb{Q}$?


Prove that $E(X^n)^{1/n}$ is non-decreasing for non-negative random variables

For a nonnegative random variable $X$, how to prove that $E(X^n)^{\frac1n}$ is nondecreasing  in $n$?


A reference request for real world experimental data

I always use to wonder how the experimental physicists discover new particles every now and then whose dimensions/properties/mass/charge several order of magnitudes below that of anything that is visible/perceptible. So as engineers do, I guess they also set up a extremely complicated equipment and do some pretty complicated experiments and measure some physical quantity, say (pardon me if my example is poor) an voltage or a magnetic field intensity or could be anything depending on the experimental setup. Now they compare this measured voltage variation with that of what is expected theoretically and then go on to prove the hypothesis. ( This is the hardest thing I could imagine).  Now my request is where can i find a set of data (preferable a continuous variation of a physical parameter with respect to another... may be sampled at sufficient sampling frequency) along with the context of experiment (as minimal as possible but sufficient) so that i can carry out some processing of data in my own way so that i can verify the hypothesis or any such a thing. Simply put i need some really cool real world data ( in the form of signal).  Is any such thing available on the internet or where could I find one? Please suggest me something which involves signal processing.


From :     BIOS software is stored on a non-volatile ROM chip on the motherboard. ... In modern computer systems, the BIOS contents are stored on a flash memory chip so that the contents can be rewritten without removing the chip from the motherboard. This allows BIOS software to be easily upgraded to add new features or fix bugs, but can make the computer vulnerable to BIOS rootkits.   Since ROM means Read-Only Memory,  why can the BIOS contents be rewritten?  Does the "flash memory chip"  mean the same as the "non-volatile ROM", both meaning where BIOS is stored?


Why float += operator leaves out integer?

Hey there I'm using libGDX and I have following problem, just can't see what I'm doing wrong:  I have   float generatingTime = 0;  if (generatingTime < 1.0f){    generatingTime =+ 0.01f)    }  if (generatingTime == 1.0f){    objectState.state = objectState.GENERATED;    }   Somehow my float generatingTime never is exactly "1.0f". What am I doing wrong?  Thank you for helping guys!


Number of subgroups of $S_6$ isomorphic to $C_3\times C_3$

I have a doubt, I do not know if my method of solving this problem is correct. I have to count how many isomorphic subgroups to $ \mathbb{Z}_3\times \mathbb{Z}_3$ there are in $ S_6 $. being abelian I have to find two generators that switch between them, so I think you can choose a three cycle and then I have 40 choices, having the second generator forced (the other three cycle, and its power) then in all 80 choices, dividing by the number of elements of order 3 I have that ultimately there are 20 in the subgroups searched for.


Cooking Small White Navy's giving me issues

how long must I cook small white navy beans in my soup to get soft?  Seems like it is taking too long. So far I have cooked 4 hours!


I have a world that has just transitioned into hard-mode. Stripes of Hallow and Corruption have both appeared in the world (as I expected), but the Hallow appeared right in the middle of my jungle biome (it even surrounds the Jungle Temple!).  Will the Hallow eventually destroy the jungle? I'm concerned that I won't be able to fight Plantera if it takes over the underground jungle quickly enough.


what does sudo apt install (linux) install from?

I recently used sudo apt install on my Linux Virtual Machine to get funny commands like cowsay and Telnet Star Wars and, I was wondering, what does the command actually install from? What does it take the code from?


Mathematical definition of the word "generic" as in "generic" singularity or "generic" map?

I've been trying to work out what generic means but I'm not making much progress.   You can find an example of the usage of the word generic for example : "School on Generic Singularities in Geometry" or :  "Rigidity of generic singularities of mean curvature flow"  Here is what I have so far:  I found  which mentions   "... "generic" singularities, i.e., singularities that appear for almost all maps ..."  Just after that he mentions "generic maps" but does not elaborate on what it means. He mentions it later (kind of) by saying  "...The precise definition of a generic map is very delicate; for the moment, we say only that any map may be approached by a generic map (up to an approximation on the derivatives of order r), and that any map that is sufficiently close to a generic map, in the preceding sense, is itself generic. ..."  and later  on he gives a definition of "generic singularity of a singular set":  "... A critical point $x$ of $S_r$ will be called transversally critical, or, furthermore, generic, if the tangent planes to $ \overline{f}(\mathbb R^n) $ and $F_r$ are in general position at the point $\overline{f} (x)$ of the Grassmannian, which is assumed to be ordinary on $F_r$ . ..."  Does this mean that generic and transversally critical are synonyms?  I feel I still don't understand what generic means even after reading this definition and part of the article.      Please could someone help me understand what generic means?


A word for the heart-wrenching pain of wanting someone you can't have

There is a phrase in French that exactly means this: "la douleur exquise"  It literally means "the exquisite pain" and expresses the  pain of wanting the affection of someone unattainable. I think it is not used as a loan phrase in English and the translation does not make much sense.  Is there an equivalent word or phrase in English?    Note I:      Sometimes, platonic love is used in this sense (though not exactly for the pain) but it is actually an emotional relationship without sexual desires. I'm not sure if there is a semantic shift in the meaning though.     Note II:     “Unrequited love” describes a relationship state, but not a state of mind. Unrequited love encompasses the lover who isn’t reciprocating, as well as the lover who desires. La douleur exquise gets at the emotional heartache, specifically, of being the one whose love is unreciprocated.   Source:


How to force a RazorPage RedirectToPage to perform a POST instead of a GET

For .net core RazorPages there it is common to put code in the OnGet() or OnPost() functions that do some work and then redirect the user to another RazorPage with some data (eg. an anonymous object):  public async Task<IActionResult> OnPost() {    // do some work     // redirect the user to another page    return RedirectToPage("NextPage", new { user = _user, isComplete = _isComplete }); }   The problem is the RedirectToPage always redirects with the arguments in the object as a GET, with the arguments visible in the browser address bar:    How can I force the RazorPage to send the redirect request as a POST instead of a get?


Prove that $A^n=0$ if and only if $A^2=0$

Let $A$ be a $2×2$ matrix and $n$ be an integer exceeding $2$. Show that $A^n=0$ if and only if $A^2=0$ where $0$ denotes null matrix of second order.   Proving the 'if part' is easy.  Given, $A^2=0$  Then, pre-multiplying(or post-multiplying) both sides by $A$ for $n-2$ times consecutively, we get  $A^n=0$.  But I cannot prove the 'only if' part, i.e., given $A^n=0$, how can I show that $A^2=0$?   Please anyone help me solve it. Thanks in advance.


Why do quarks tend to bond in groups of three?   I understand why they might in bond in groups of three to create a net charge of zero (i.e. neutrons), but I don't understand why they form protons and not, for example, commonly form in groups of four. I have done background research on this question, and did not find any information. The wikipedia article on baryons () was not helpful either.  To summarize, why are mesons and baryons more common than other hadrons?


Bash: Escaping double quotes in $() command substitution

I am having trouble wrapping my head around how command substitution works when part of the command's parameters come from a variable.  To illustrate, I'll just present a series of commands:  I'll first create a directory A B C in my tmp directory, in the new directory I'll create a new file abcfile:  user@desktop /tmp $ pwd /tmp  user@desktop /tmp $ mkdir "A B C"  user@desktop /tmp $ ls 'A B C'  user@desktop /tmp $ touch "A B C"/abcfile  user@desktop /tmp $ ls "A B C"/ abcfile   I'll new assign the value A B C to a variable $DIR and attempt to call ls to list the contents of this directory using various ways of calling the command  user@desktop /tmp $ DIR="A B C"   With the variable unquoted, the command fails as expected  user@desktop /tmp $ ls $DIR ls: cannot access 'A': No such file or directory ls: cannot access 'B': No such file or directory ls: cannot access 'C': No such file or directory   With the variable quoted, it works as expected  user@desktop /tmp $ ls "$DIR" abcfile   If I want the output of the command as a string  user@desktop /tmp $ echo $(ls "$DIR") abcfile   This command works, but why does it work? According to shellcheck this is actually not correct, the variable should be outside of double quotes  user@desktop /tmp $ echo "$(ls "$DIR")" abcfile   If the inner variable is not double quoted, the command fails  user@desktop /tmp $ echo "$(ls $DIR)" ls: cannot access 'A': No such file or directory ls: cannot access 'B': No such file or directory ls: cannot access 'C': No such file or directory


How to convert itertools.chain into numpy array?

My code  import math import itertools  with open('/home/milenko/OCCAM2DMT_V3.0/13042/ITER04.iter') as f:     lines_after_19 = f.readlines()[19:]     p = []     for line in lines_after_19:         line = line.split()                  line = [float(i) for i in line]         p.extend(line)      a1=p[1:81] for i in a1:     b1=math.pow(10, i)    a2=p[83:163] for i in a2:     b2=math.pow(10,i) a3=p[165:245]    for i in a3:     b3=math.pow(10,i) a4=p[247:327] for i in a4:     b4=math.pow(10,i) a5=p[329:409]  for i in a5:     b5=math.pow(10,i) a6=p[411:491] for i in a6:     b6=math.pow(10,i)  c = itertools.chain(b1, b2, b3, b4, b5, b6)  print type(c)   I need to convert c to numpy array,for reshape and then further calculations.


Converting a String object into an array using whitespace as separators [Java]

I'm trying to create a program in Java that takes user input and converts it into Pig Latin. To do this, I am planning to get the user input, store it as a String, and somehow convert it to an array so I am able to work with each individual word in there.  How should I go about this?


How is multiplication faster than addition

I wanted to get some numbers on how fast is multiplication over addition. I wrote a simple code where I am multiplying 2 numbers, finding the time taken. Then I am adding the 2 numbers and find the time taken. The results are a bit disturbing. Before I show the results, here is the code  package com.np.fun;  import java.util.Scanner;  import org.apache.commons.lang3.time.StopWatch;  public class HowSlowIsMultiplication {  public static void main(String[] args) {     Scanner scanner = new Scanner(System.in);     int x = scanner.nextInt();     int y = scanner.nextInt();     long z;     StopWatch stopWatchMultipy = new StopWatch();     stopWatchMultipy.start();     z = x*y;     stopWatchMultipy.stop();     System.out.println("Time taken for multiplication is : " + stopWatchMultipy.getNanoTime());     StopWatch stopWatchAdd_1 = new StopWatch();     stopWatchAdd_1.start();     for(int i =0 ;i <Math.min(x, y); i++){         z = z + Math.max(x, y);     }     stopWatchAdd_1.stop();     System.out.println("Time taken for adding in less for loops is : " + stopWatchAdd_1.getNanoTime());     StopWatch stopWatchAdd_2 = new StopWatch();     stopWatchAdd_2.start();     for(int i =0 ;i <Math.max(x, y); i++){         z = z + Math.min(x, y);     }     stopWatchAdd_2.stop();     System.out.println("Time taken for adding in more for loops is : " + stopWatchAdd_1.getNanoTime()); }   }  I tried this with varying values of x & y. Here is the output for x=10000 and y=5000 (all times are in naoseconds) Time taken for multiplication is : 61593 Time taken for adding in less for loops is : 1622599 Time taken for adding in more for loops is : 1622599  As you can see, multiplication is several orders of magnitude faster than addition.  Any reasons for this?


How current induced when magnet moves in coil?

How is current induced when a magnet moves through a coil? How does it work? I would like to know how it works and how to explain it in a somewhat simple language.


Shell - check if file contains string with newlines inside

I've declared a string with two newlines inside of string     somestring=$'\n##### Branch FREEZE enable/disable\nRelease:'   I have a $file with a text inside like this  ###############################  ##### Branch RELEASE enable/disable Release: disable  ##### Branch FREEZE enable/disable Freeze: disable  ##### Mail list #####   I am trying to figure out, if there is a string inside with both of the newlines with a command     if grep -q "$somestring" "$file"; then   echo "found the string"   But the result is always positive, when there is a newline inside of string.  How can I make it work correct with newlines inside?


Is a user deleted in one Stack Exchange deleted in all of them?

I'm considering deleting my profile on one site, but want to know something before I proceed. Is a user deleted in one Stack Exchange site deleted in all of them? Can I delete only the one profile?


TikZ: convenient way to draw Metcalfe's law network diagrams

Metcalfe's law is a simple principle that says a network with n nodes has n(n-1)/2 possible undirected connections between nodes. It is often illustrated thus (wikipedia):    Is there an easy way to replicate this in TikZ. Ideal would be an approach that allows the user to specify the number, n, of nodes and then draws n nodes symmetrically positioned around a circle with all of the possible n(n-1)/2 connections between them.


iCloud Drive keeps re-downloading a 40GB file

I am running the macOS Big Sur Beta. Every little while, iCloud Drive will randomly start to download 50GB of files I don't need. I have a ~40GB zip file full of photos that I do not need stored on my laptop and this keeps downloading. This is wasting a lot of data. How can I fix this?


How are the protons for collisions in the LHC made?

I heard that the LHC smashes two protons together to research the universe.  But how does it create the protons for collision? If we strip off the electrons won't there be neutrons along with protons?  A  is used by the LHC, it ionises atoms into negative or positive ions but how is the proton separated from that?


Why div DOM object does not have height and width properties

I am a beginner coder. It is probably very simple, but I tried to find the answer and have not succeeded. My question is why do width and height properties of div object return undefined while they are apparently 100px both?   is explained how to get .offsetWidth property. But as I understand it is not 100% the same as .width.    window.onload = function() {    var test = document.getElementById("test");   test.addEventListener("click", select);     function select(e) {     var elementID = e.target.id;     var element = document.getElementById(elementID);     var width = element.width;     console.log(element);     console.log(width);   }  } div#test {   position: absolute;   height: 100px;   width: 100px;   background-color: black; }

     My answer  Thank you all guys for your answers. They pushed me to find my own simple solution which I hope will be helpful for such beginners as me. The answer is: div DOM object does not have .width and .height property even if you assign them in CSS and they work well. For this purpose it has .style.width and .style.height respectively. But even if you assign them through CSS they will not appear in  element.style until you do it purposefully using Java Script. So to get width or height of the div element through JS first of all remove these properties from CSS. You will not need them anymore. Then assign width through element.style.width command and then you can easily get it whenever you want using element.style.width.  CSS  div {     position: absolute;     background-color: black; }   JavaScript  window.onload = function() {      var test = document.getElementById("test");     test.addEventListener("click", select);     test.style.width = "100px";     test.style.height = "100px";       function select(e) {                                           var elementID = e.target.id;         var element = document.getElementById(elementID);         var width = element.style.width;         console.log(element);         console.log(width);     }  }


Is there anyway to snap to vertices while using Edge Slide with Clamp Off?

I am a precision modeler, which means I like to be exact instead of "eyeballing" things when I model. I am very happy to see the option to Edge Slide with Clamping Off in v2.75a, but I don't seem to be able to snap the edge slide destination to a vertex point elsewhere on the model. Is this possible and I am just missing something?


CSS - Child height relative to viewport if parent has position:fixed

I need to make the child height relative to the viewport. Using HTML:
My divider
       Inside the div

   and CSS:  .t1 {     background:#f00;     color:#fff; }  .t2 {   background:#212121;   height:100vh; }     As you can see from the example, There's always this small gap, because it takes into account the overall height of the parent. However, I only need the child to fill "the rest" of the viewport from parent.  How should I proceed? I've tried many other things, but without sufficient result


Is there a term for the moment when a lot of users visit/log onto your website at the same time?


can not find element or element id that is added with php

using jquery i am adding new elements to a div element i also have set id of new added element but still javascript can not find that newly added elements.  $.ajax({  //ajax call     type: "POST",            url: "ajax/ajax.php",      data: { users: values } }).done(function( msg ) {     //do something with msg which is response     //this line will put the response to item with id `#txtHint`.     $("#divselect").html(msg)     //alert(msg); }); });   new elements added successfully but on button click javascript can not find that new element id. is there any way to reload only javascript or what should i do ?       $("#validator").click(function (){//validator is my submit button id       var value = document.getElementById('select_division'); //select_division is id of my new added element      alert(value);  }   then comes reference error. on this.


Is this form of Bernoulli's inequality for n variables correct?

Somewhere I found the following inequality (see below), named as an alternative form of . I could not find it in wikipedia or other math books. Is this inequality always true? Provided that both 1 and 2 hold simultaneously  $x_n > -1$  all $x_n$ have same sign The below is true:   $$ (1+x_1)(1+x_2)(1+x_3)...(1+x_n) \ge 1 + x_1+x_2+x_3+...+x_n $$


How to use regular expression in subject name field in same code

$(function () {  $("#course_outline").validate({      rules: {          ignore: [],          errorClass: "",          course_code: {required: true},          subject_name: {required: true},          time_allocation: {required: true},          lecturer: {required: true},          subject_status: {required: true},          agree: "required"      },      messages: {          course_code: {required: "Course Code Mandatory"},          subject_name: {required: "Subject Name Is Mandatory"},          time_allocation: {required: "Time  is mandatory" },          lecturer: { required: "Lecturer is mandatory" },          subject_status: {required: "Subject Status is mandatory"},          agree: "policy are acccept"     } });   });  i don't know to how to use regular expression in same code anybody help me soon.  accept: "[a-zA-Z]+".This method also i use but not working my script.


Properly setting up a "default" nginx server for https

I have several servers running on the same machine, some with http only, some with both http and https.  There are several server blocks defined in separate files which are included from the main config file.  I have set up a "default" server for http which will serve a generic "maintenance page" to requests that don't match any of the other server_names in the other config files.  The http default server works as expected, it uses the server_name "_" and it appears first in the list of includes (because I have observed that in the case of duplicate server_names across servers, the one appearing first is used).  This works great.  I would expect the same exact server block (only switching "listen 80 default_server" to "listen 443 default_server" and also instead of serving page "return 444") however it does not.  Instead, it appears that the new default https server is actually grabbing all incoming https connections and causing them to fail, although the other server blocks have more appropriate server_names for the incoming requests.  Removing the new default https server will cause semi-correct behavior to resume: the websites with https will all load correctly; but the websites without https will all be routed to the first https server in the include files (which according to the docs, if no "default_server" appears, then the first server block to appear will be "default").  So my question is, what is the correct way to define a "default server" in nginx for ssl connections?  Why is it that when I explicitly set a "default_server" it gets greedy and grabs all connections whereas when I implicitly let nginx decide the "default server" it works like I would expect (with the incorrect server set as default and the other real servers behaving correctly)?  Here are my "default servers".  Http works without breaking other servers.  Https breaks other servers and consumes all.  server {     listen 443 ssl default_server;     server_name _;      access_log /var/log/nginx/maintenance.access.log;     error_log /var/log/nginx/maintenance.error.log error;      return 444; }  server {     listen *:80 default_server;     server_name _;     charset utf-8;      access_log /var/log/nginx/maintenance.access.log;     error_log /var/log/nginx/maintenance.error.log error;      root /home/path/to/templates;      location / {         return 503;     }      error_page 503 @maintenance;      location @maintenance {         rewrite ^(.*)$ /maintenance.html break;     } }   Any of you see what might be wrong here?


I have an invocation target exception issue. I am having one object(window) which i am calling on a click of a button, now using that common button on two different User Interfaces. The problem is that when i click on it on one UI it shows me the data but when i click it on other UI it returns invocation target exception.   Code is:  @Override public void buttonClick(ClickEvent event) {      // This if block will be called when user clicks on list of      // document button      if(event.getButton() == mlistButton) {         try {             listButtonButtonClicked();         } catch (RequestDetailTableException | InvocationTargetException e) {             e.printStackTrace();         }     }      // this if block will be called when user clicks on Tracking button     if(event.getButton() == mtrackingButton) {         trackingButtonClicked();     }  }  /**  * This function will be called when user clicks on list of  * document button.  * @throws Exception   */ protected void listButtonButtonClicked() throws RequestDetailTableException {      DocumentListLayout ldocumentList = null;     try {         ldocumentList = new DocumentListLayout(mrequestInfoBean,mdetailRequestLayout.getGeoAISUI());     } catch (DocumentListLayoutException e) {         throw new RequestDetailTableException(e);     }     mdetailRequestLayout.getGeoAISUI().addWindow(ldocumentList); }    Stack Trace:  java.lang.NullPointerException  at org.ids.geoais.common.RequestDetailTable.listButtonButtonClicked(RequestDetailTable.java:306)  at org.ids.geoais.common.RequestDetailTable.buttonClick(RequestDetailTable.java:275)  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)  at java.lang.reflect.Method.invoke(Method.java:606)  at com.vaadin.event.ListenerMethod.receiveEvent(ListenerMethod.java:508)  at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:198)  at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:161)  at com.vaadin.server.AbstractClientConnector.fireEvent(AbstractClientConnector.java:995)  at com.vaadin.ui.Button.fireClick(Button.java:393)  at com.vaadin.ui.Button$1.click(Button.java:61)  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)  at java.lang.reflect.Method.invoke(Method.java:606)  at com.vaadin.server.ServerRpcManager.applyInvocation(ServerRpcManager.java:158)  at com.vaadin.server.ServerRpcManager.applyInvocation(ServerRpcManager.java:118)  at com.vaadin.server.communication.ServerRpcHandler.handleInvocations(ServerRpcHandler.java:313)  at com.vaadin.server.communication.ServerRpcHandler.handleRpc(ServerRpcHandler.java:202)  at com.vaadin.server.communication.UidlRequestHandler.synchronizedHandleRequest(UidlRequestHandler.java:95)  at com.vaadin.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:41)  at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1408)  at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:350)  at org.ids.geoais.Servlet.service(Servlet.java:160)  at javax.servlet.http.HttpSer   The compiler moves to this:      /**      * Constructs a InvocationTargetException with a target exception.      *      * @param target the target exception      */     public InvocationTargetException(Throwable target) {         super((Throwable)null);  // Disallow initCause         this.target = target;     }


How to recover money from old closed/dormant bank accounts in the U.S.?

Can anyone answer how to recover cash from (old) closed bank accounts from banks in usa?


Let it be $$(1+x+x^2+x^3+x^4)^{496}=a_0+a_1x+a_2x^2+...+a_{1984}x^{1984}.$$ Find $$\gcd(a_3,a_8,...,a_{1983})$$ I know the Leibniz Theorem, so all coefficients are of the form $$\frac{496!}{a!b!c!d!e!}1^a\cdot x^b\cdot x^{2c}\cdot x^{3d}\cdot x^{4e}$$ and $a+b+c+d+e=496$, $a,b,c,d,e\in\mathbb N$ So, if $d$ is the $\gcd$ of these numbers, $$d\mid\sum_{i=3}^{1983}a_i,$$ but I couldn't found the value of $d$.  Can someone help me?  Thanks for attention!


$p$-adic field with infinite residue field.

I am reading J M Fontaine's  where on page 7 the following definition is made:     A local field($K$) is a complete discrete valuation field whose reside field($k$) is a perfect field of characteristic $p > 0$.   A $p$-adic field is a local field of characteristic $0$.   Immediately afterwards he makes the remark that finite extensions of $\mathbb Q_p$ are the only $p$-adic fields with finite residue field. So I tried to find an example of a $p$-adic field $K$ which has infinite residue field.  $K$ has to be of zero characteristic, so it contains $\mathbb Q$. I am not sure of the next claim, and it is vague. Since $K$ is a complete field w.r.t. a norm, by Ostrowski it has to be a $\mathbb Q_p$ or $\mathbb R$ and extensions thereof. Since we want to have infinite residue field, we are left with $\mathbb R$ and its extensions. I tried $\mathbb R((x))$ and $\mathbb C((x))$ (with $x$ indeteminate, and valuation being measured by the power of $x$) since we are in search of a discrete valuation field. But they fail to produce residue fields of positive characteristic. Since local fields are necessarily non-archimedean, will considering valuation subrings of $\mathbb R$ or $\mathbb C$ help? Are there any such subrings? Somebody kindly help. Thank you!!


Expression for $ \sum\limits_{i=1}^\mathbb{n}(-1)^{i-1}i^2 $

How to find an expression for the below summation series? $ \sum\limits_{i=1}^\mathbb{n}(-1)^{i-1}i^2 $


How to deal with 2 almost identical constructors

If I have 2 constructors in my custom class and one of them takes an extra argument and does everything the first one does but with just one additional line of code (and this extra line utilises the extra argument), how best to deal with this without having to duplicate all the code in the first constructor?  Example code  public myConstuctor(int number, int number2){      int result = (number + number2);     int result2 = (number2 - number1)      //Etc     //Etc     //Etc     //Etc  }  public myConstructor(int number1, int number2, int number 3){      int result = (number + number2);     int result2 = (number2 - number1)      //Etc     //Etc     //Etc     //Etc      int result3 = (result + result2 + number3)   }


Could anyone help me with it? I don`t know how to write by Latex, so I have update a picture of the problem.      thankyou very much!


MathJax half-broken in suggested edit diffs

In a suggested edit I just reviewed, about a third of the MathJax renders properly, but the rest doesn't. Note that the delimiters on puzzling are \$, so that doesn't escape it.    Related:  Don't render MathJax when viewing source:   Render MathJax when viewing rendered output:


How to recover files, after Windows partition deleted (installing Ubuntu)

Was running Windows 7 (64-bit). Downloaded Ubuntu, and booted it from USB Started installing Ubuntu OS. I chose the last option, do not replace Windows, do something else.  However, when I had to choose a partition, I ticked and formatted the one in which my Windows 7 was on.  After formatting, I cancelled installation.  So, I now have neither have windows nor Ubuntu.  When I switch it on, I just get the System Recovery options.   I cannot do that as I still have important files: pictures and videos (I am a photographer.)  Please tell me there is a way to get them back!


Uncaught PDOException: Condition Expected

When clicking a button my faktura.php script fires. What is supposed to happen is getting data from my database with SQL and echoing that data. But on the Execute function of PDO the error "An expression of non-boolean type specified in a context where a condition is expected, near 'AND'." occurs.  I have tried running my query in SQL and it works but inside the script it does not.  Also to specify I'm using database.php once before when logging in to the site with another script.  faktura.php <?php  session_start(); require("config/database.php"); $fakturaView = "myView";  if(isset($_POST['fakturaBtn'])){      $fakturaNr = 50163;     $userID = 144;      $stmt = $pdo->prepare('SELECT * FROM :fakturaView WHERE :fakturaNr AND :userID');     $stmt->execute(['fakturaView' => $fakturaView, 'fakturaNr' =>  $fakturaNr, 'userID' => $userID]); //Where the exception occurs     $faktura = $stmt->fetch();      echo $faktura['userID'];     echo $faktura['fakturaNr']; } ?>   database.php <?php $host = 'myhost'; $db   = 'mydb'; $user = 'myuser'; $pass = 'mypass';  $dsn = "sqlsrv:Server=$host;Database=$db"; //$dsn = "sqlserv:host=$host;dbname=$db;charset=$charset"; $options = [     PDO::ATTR_ERRMODE              => PDO::ERRMODE_EXCEPTION,     PDO::ATTR_DEFAULT_FETCH_MODE   => PDO::FETCH_ASSOC,     PDO::SQLSRV_ATTR_ENCODING      => PDO::SQLSRV_ENCODING_UTF8, ]; try {      $pdo = new PDO($dsn, $user, $pass, $options); } catch (\PDOException $e) {      throw new \PDOException($e->getMessage(), (int)$e->getCode()); } ?>


502 Bad Gateway/ failed (111: Connection refused) while connecting to upstream

I have the following docker-compose xml  web:   build: nginx/.   container_name: nginx   ports:     - "80:80"   links:     - "openchain"   restart: always wallet:   build: wallet/.   container_name: wallet   ports:     - "81:81"   restart: always   read_only: false   volumes:     - ./www:/usr/share/nginx/html:rw   working_dir: /user/share/nginx/html openchain:   build: openchain/.   ports:     - "8080"   volumes:     - ./data:/openchain/data   restart: always   And the following conf for web and wallet respectively  worker_processes 4;  events { worker_connections 1024; }  http {     server {         listen 80;          location / {             proxy_pass http://127.0.0.1:8080/;              proxy_http_version 1.1;             proxy_set_header Upgrade $http_upgrade;             proxy_set_header Connection "upgrade";         }     } }   and  worker_processes 4;  events { worker_connections 1024; }  http {  server {     listen 81;      location / {         root /usr/share/nginx/html;     } }   }  when I run docker ps I get      05e351c8f8db        openchain_web         "nginx -g 'daemon off"   5 seconds ago       Up 5 seconds        0.0.0.0:80->80/tcp, 443/tcp    nginx     e7401ea7c5bc        openchain_wallet      "nginx -g 'daemon off"   5 seconds ago       Up 5 seconds        80/tcp, 443/tcp, 0.0.0.0:81->81/tcp   wallet     40439fdb1c69        openchain_openchain   "dotnet openchain.dll"   5 seconds ago       Up 5 seconds        0.0.0.0:32774->8080/tcp        openchain_openchain_1   But when I try to access the port openchain_openchain via proxy openchain_web I get the subject error  I'm new to docker so I'm not sure I'm proxying correctly with the nginx  Can you tell me what I did wrong?  P.S. I can access wallet just fine


I have just installed Ubuntu 16.04. I tried installing terminator from https://apps.ubuntu.com/cat/applications/precise/terminator (The link is redirecting somewhere else now) but I am unable to install it. I am getting following message     This software comes from a 3rd party and may contain non-free components   How can I install terminator by command line?


How do I create an automated SQL Server restore script for multiple backups?

I basically have 6 daily SQL Server backups (.bak) that need a restore everyday. I want to automate this process by having the SQL Agent run the script daily. I have the following restore script written, and I know it's not completely correct, that is why I'm here to ask for any pointers is much appreciated!  use master; go  set nocount on  -- 1 - variable declaration  declare @dbname nvarchar(max) --database to restore  declare @backuppath nvarchar(max) --backup location declare @filelisttable --list the table to populate  declare @sql nvarchar(max) --dynamic sql  declare @mdf nvarchar(max) --logical primary data file declare @ndf nvarchar(max) --logical 2nd data file declare @ldf nvarchar(max) --logical log data file declare @dp nvarchar(200) --data file path declare @lp nvarchar(200) --log file path declare @backupfile nvarchar(500)  -- 2 - initialize variables set @dbname = 'test' set @backuppath = '\\mybackuppath\c$\test'  -- 3 - get list of files insert into @filelisttable exec('restore filelistonly from disk = ''' +@backuppath+'''') --temptable to retrieve all back up files   -- 4 - retrieve top 6 recent data extracts  select  @backuppath  = max(backupfile) from @filelist where backupfile like '%.bak' --how to pick up most recent 6 back up files w/timestamp on trails?  set @sql = ('use [master])     restore database @dbname ['+@dbname+']         from disk = N'''+@backuppath+'''             with replace,             move N'''+@mdf+''' to N'''+@mdf+'''             move N'''+@ndf+''' to N'''+@ndf+'''             move N'''+@ldf+''' to N'''+@ldf+''''  -- 5- the 6 backup files that need to be restored daily  /** I have to run this manually everyday, and I want to automate this. RESTORE DATABASE test FROM     DISK = 'C:\test\test_Customer_20160518_1.bak',     DISK = 'C:\test\test_Customer_20160518_2.bak',     DISK = 'C:\test\test_Customer_20160518_3.bak',     DISK = 'C:\test\test_Customer_20160518_4.bak',     DISK = 'C:\test\test_Customer_20160518_5.bak',     DISK = 'C:\test\test_Customer_20160518_6.bak'     WITH REPLACE,     MOVE 'test_Data1' TO 'E:\Program Files\Microsoft SQL Server\MSSQL10.MSSQLSERVER\MSSQL\DATA\test_CUSTOMER.mdf',     MOVE 'test_Data2' TO 'E:\Program Files\Microsoft SQL Server\MSSQL10.MSSQLSERVER\MSSQL\DATA\test_CUSTOMER_1.ndf',     MOVE 'test_Log' TO 'E:\Program Files\Microsoft SQL Server\MSSQL10.MSSQLSERVER\MSSQL\DATA\test_CUSTOMER_2.ldf'     GO **/  use master  alter database test set multi_user with rollback immediate;  go  return   The goal of this script is to automate a restore with the variables declared, restore the 'test' database from the backup path where 6 files sit, create a temp filelist table to be used for restore, pick it up from there, and restore the test database everyday based on the latest date stamped files.  Currently, there are old and new files in there. I need a WHERE statement to only use current ones.


Bullet train from Tokyo to Osaka (with stopovers)

I am planning a trip from Tokyo to Osaka, with a stopover at Nagoya for 2 nights to travel to Takayama, and continue to Osaka. Should I do one more stopover at Kyoto or is a day trip better? Also, can I book a single trip from Tokyo to Osaka and hop on and off at Nagoya and Kyoto?


Rep in User Dropdown doesn't match rep in User Profile sometimes

I've noticed this a few times where the reputation in the user dropdown    doesn't match the reputation in the user profile    It doesn't appear to be a caching issue, and I've refreshed plenty of times.  There have been similar problems brought up on Meta before, but this seems different.  Edit: The -30 difference appears to be because in the User Profile some rep that was marked removed is subtracted out, but it's not subtracted out of the dropdown reputation.


systemd-resolve high cpu usage after update to 17.04

I have recently upgrade my Xubuntu from 16.10 to 17.04.  Every things works well except systemd-resolve. some times it makes cpu usage too high and I don't know why this issue has been happend.  And here is the top command output:    PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND                                  1114 systemd+  20   0   51532   6744   4504 R   100  0.0   9:51.67 systemd-resolve                          1152 dnsmasq   20   0   64360   2892   2480 R  38.9  0.0   4:05.53 dnsmasq                                  1245 root      20   0  376644  89644  64436 S   1.7  0.5   0:35.69 Xorg                                     1624 asus      20   0  370160  45820  28488 S   0.7  0.3   0:00.90 python2                                  2238 asus      20   0 2562816 553112 128492 S   0.7  3.4   2:41.20 firefox                                    16 root      20   0       0      0      0 S   0.3  0.0   0:01.05 ksoftirqd/1                               708 root     -51   0       0      0      0 S   0.3  0.0   0:01.20 irq/95-ELAN1000                          1302 root     -51   0       0      0      0 S   0.3  0.0   0:03.68 irq/142-nvidia                           1734 asus      20   0  483388  11060   8560 S   0.3  0.1   0:05.45 conky                                    2820 root      20   0       0      0      0 S   0.3  0.0   0:00.14 kworker/5:1                              3420 asus      20   0   53384   3932   3200 R   0.3  0.0   0:00.76 top                                      I don't know why this issue has been happend but usually it's occured when run some commands like sudo apt update .  (I'm using tor and obfs4proxy,  It's may be helpful for answer)


In  a number of 'magic links' were added.  These translate things such as [help/on-topic] into  in the comments (rendered as "help center").  With the loss of the privileges link from the header it can be (slightly) harder to instruct people where to find this information.  Could [help/privileges] be made to link to  (as appropriate for the site) when used in comments?


Applying curve using ArcGIS API for JavaScript?

In desktop, there is  to create arc and curves, but I can't find any tutorial about how to make and create arc or curves on ArcGIS API for Javascript.  Is there any way to do that?


A uniformly continuous function is bounded

Suppose that the function $f:[0,1)\rightarrow \mathbb{R}$ is uniformly continuous on $[0,1).$ Prove that the function $f$ is bounded. (i.e. that the range$(f)$ is a bounded set)


I am calling a webservice from lightning web component and it respond with a value. This value is appended in the URL. However, when the page start loading I can see the value but it vanishes as soon as page load completes and I cannot see the parameter in the console.log as well. sCurrentURL is page URL  connectedCallback(){         //get the parameters of the URL         let sTempURL = new URL(this.sCurrentURL).searchParams;         if(this.sCompleteURL == ''){             this.sCompleteURL = sTempURL.get('code');         }         console.log(this.sCompleteURL);         if(sTempURL.get('code') != null && sTempURL.get('code') != ''){             this.sAuthCode = sTempURL.get('code');             getToken({                 sAuthCode : this.sAuthCode             }).then( () => {refreshApex(this.retreiveTokens)});         }else{             //do nothing         }     }  When trying to use the traditional ways to capture the parameter from url, I get undefined. I also tried using an api property with same name as the url parameter, but nothing is captured in that too.


fall-back BibTeX(8) backend: (biblatex)functionality may be reduced/unavailable

/usr/share/texlive/texmf-dist/tex/latex/biblatex/blx-bibtex.def: Package biblatex Warning: Using fall-back BibTeX(8) backend: (biblatex)                functionality may be reduced/unavailable.   EXAMPLE:   \usepackage[backend=bibtex,style=authoryear,natbib=true]{biblatex}   \addbibresource{Elyssesbib.bib}  \usepackage[autostyle=true]{csquotes}   \begin{document} \...... rest of doc.


Can I freeze stew made from leftover roast beef?

I bought a large joint of beef which I roasted on Sunday. On Monday I made a stew from leftovers.   From a food hygiene/bacterial growth perspective am I ok to reheat the stew after freezing/refrigeration? I wouldn't do this with ordinary leftovers but I wonder if the boiling for 1.5Hrs kills any bacteria in the leftovers.  Thanks


Can vegetable juices stop bread from rising?

I used vegetables juice for the additional liquid ingredients in milk bread, and it didn't rise. I think there is something in vegetables juice that killed the fermentation of dough.  This is a study, a food experiment. I used radish, mustard green, ginger, onion, garlic, beans, tomato, squash, eggplant, winged beans, winter melon, bitter melon, mexican turnip, and sponge gourd juice. The first step that we did was, we mixed first the yeast, milk and the juice. After mixing all the ingredients the dough become sticky, and it didn't rise.  In our first trial, we have done it right by using the extract of vegetables. And in our 2nd trial, we used the process of juicing, we actually use a juicer to get all the juice. and after all, the juice had an effect in our dough.


gallery - size is thumbnail by default change it to medium

In wordpress gallery(through add media) when i create a gallery it default shows the thumbnail size image.   Instead of it i want to set to show the medium size image by default.  It is not good and takes lot of time to edit the old post for the tag manually: [gallery size="medium"]  So i want to show the medium size by default. It can be through functions.php


I have just started with Linux Ubuntu 16.04 (Novice) Looking for PDF Reader for said OS.


In Tikz, how to make the text on an edge have the same direction as the edge's?

I have created a simple node-edge graph in which I would like to have the texts on each edge aligned to the direction of the edge.  \documentclass[class=minimal,border=0pt]{standalone} \usepackage{pgf} \usepackage{tikz} \usetikzlibrary{arrows,automata} \usepackage[latin1]{inputenc} \begin{document}  \begin{tikzpicture}[->,>=stealth',shorten >=1pt,auto,node distance=2.8cm,                     semithick]   \tikzstyle{every state}=[fill=red,draw=none,text=white]    \node[state]         (D)                     {$D$};   \node[state]         (C) [below right of=D]  {$C$};   \node[state]         (B) [above right of=D]  {$B$};   \node[state]         (A) [below right of=B]  {$A$};    \path (D) edge              node {tdc} (C)                     (B) edge              node {tbc} (C)         (C) edge              node {tca} (A); \end{tikzpicture}  \end{document}   For example, I would like the text tbc rotates -90 degrees automatically to be aligned to the direction of the edge connects the node B to the node C. Is that possible?


How to know how much of a file is downloaded from Javascript

I have a big data file of size 8 MB. Now while my page is downloading it from the server, I would like to present a status update on how much is downloaded, e.g. 56% is downloaded. The data file in itself is a .js file!  I would like to do it from my javascript. I was thinking of the below option.  1) First measure network speed. 2) Then do a linear interpolation as I know the size of the file.  But measuring netspeed in JS is not very reliable given connection timing, caching, rendering etc etc.  Is there any direct approach, where I can straightway get the size of the partially downloaded file and calculate how much is downloaded so far.  Thanks for your help!


How do I attach a database in SQL Server?

Some common questions relating to attaching databases in SQL Server:        What does it mean to attach or detach a database?    How do I detach a database?    How do I attach a database?       What does it mean to attach and rebuild the log?      How do I do it in SQL Server Express?    When might I consider detaching and attaching?   Are there any risks or warnings?   What about attaching between versions and editions of SQL Server? (Standard to Enterprise? 2000 to 2008? 2012 to 2008?)


I really need to get permanent token or dynamic generator. We set job in the server and this service will come to salesforce and get the data. To provide this, I created connected app, got the token from postman by myself and gave it. After a while (approximately 1 day), we faced with session id problem.   What can I do?


Why Macbuntu pack always corrupts my system?

Are noobslab repositories safe to add to my repository lists?  I am asking this because Macbuntu transformation pack corrupted my system many times. My system would have missing icons. Sometimes it didn't even boot and I had to perform a re installation.


How get the best threshold value by ROC curve

I'm working with unbalanced class databases and I'm wondering what's the best practice to retrieve the best threshold cutoff value using roc curve ?  I want the best cutoff to maximize my F1 score.      I already have a roc curve I'm wondering what the best practice to   generate the best threshold cutoff.


"Come over" and etymology of other idioms

Can someone explain the etymology of using over in expressions like come over to and go over to as in "pay a casual visit"?  Is there a source for the etymology of idiomatic expressions somewhere?


Problem obtaining a marginal from the joint distribution

Suppose $X_1$ and $X_2$ have the joint pdf  $$f_{X_1,X_2}\left(x_1,x_2 \right)=4x_1 x_2,\quad\text{for}\quad 0<x_1<1, 0<x_2<1$$  From that I found the joint pdf of $Y_1=\frac{X_1}{X_2}$ and $Y_2=X_1 X_2$ to be  $$f_{Y_1,Y_2} \left(y_1,y_2 \right)=2 \frac{y_2}{y_1}\quad \text{for}\quad \left(y_1,y_2 \right) \in \mathcal{T}$$  where $\mathcal{T}=\{ \left(y_1,y_2 \right): y_1,y_2>0,y_2<\frac{1}{y_1},y_2<y_1 \}$  That is, in the $ \left(y_1, y_2 \right)$ plane, the area of the pdf is bounded by the 45 degree line and the hyperbola $\frac{1}{y_1}$. Based on that I can easily derive the marginal of $Y_1$ for the two cases   $0<y_1<1$ $1<y_1<\infty$   But what about the marginal of $Y_2$? $Y_1$ is not bounded above and is bounded below by zero, right? How can I integrate out $Y_1$ if the integral from 0 to infinity diverges? Which begs the question, have I done something wrong in the above?


What is the integral of $\int e^x\,\sin x\,\,dx$?

I'm trying to solve the integral of $\left(\int e^x\,\sin x\,\,dx\right)$ (My solution):  $\int e^x\sin\left(x\right)\,\,dx=$  $\int \sin\left(x\right) \,e^x\,\,dx=$  $\left(\sin(x)\,\int e^x\right)-\left(\int\sin^{'}(x)\,\left(\int e^x\right)\right)$  $\left(\sin(x)\,e^x\right)-\left(\int\cos(x)\,e^x\right)$  $\left(\sin(x)\,e^x\right)-\left(\cos(x)\,e^x-\left(\int-\sin\left(x\right)\,e^x\right)\right)$  $\left(\sin(x)\,e^x\right)-\left(\cos(x)\,e^x-\left(-\sin\left(x\right)\,e^x-\int-\cos\left(x\right)\,e^x\right)\right)$  I don't know how to complete because the solution gonna be very complicated.


Installing ubuntu touch on meizu MX4 flyme edition

I would like to know if its possible to install ubuntu on meizu mx4 android version? Also can someone tell me the steps to unlock the phone and install it ? Thanks


Given n points drawn randomly on the circumference of a circle, what is the probability they will all be within any common semicircle?


I've taken multiple gps waypoints and I'm hoping to put them into some sort of GIS program (atm I have GQIS as that was recommended to me) to look at them in map form, but how do I get them there?   I am using GDA94 points and a Garmin GPSMAP 64s.  I have no clue what I'm doing.


Computer won't boot, possible causes? Motherboard or CPU

I have a old setup that I haven't used in a while. When I plug it in and turn it on, I see it light up for a second before dying.  So far I have tested the paperclip method with the psu and it works fine. I have also removed all the ram.   My motherboard has a few Leds and a start/reset button (Asus M6E Motherboard). They all light up. I have tried taking out the cpu and putting it back again.  Is it possible my cpu failed or my motherboard failed? I don't have any other 1150 cpu around to check. Since this is one of my old setups, I want to make it to work again, but I'm not sure if I have to buy a motherboard or cpu.


Suppose $M$ is a closed $k-$manifold in $\mathbb R^n$ without boundary, can we always find a smooth function $f:\mathbb R^n\to\mathbb R^{n-k}$ such that $M$ is the level set where $f=0$?


How to avoid null pointer exception in java

I am curious to know proper way to avoid NullPointerExceptions.  try {     String name = null;     System.out.println("name=" + name.toString()); } catch(Exception e) {     System.out.println("Exception Occured" + e.getMessage()); }   Here I am just catching and showing the exception message. I want to know proper way to handle this or avoiding such situations.


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I'm running a binary logistic regression on 15 independent variables for 180 observations in Stata (version 11). This I do for four different groups, i.e. four dependent variables. For three, it works fine, but the fourth gives me the warning message that one IV "predicts success perfectly" and that the IV is "dropped and 96 obs not used". This IV is a dummy (and considered important for this one out of the four groups).  This leaves me with 84 observations. In comparison with the other three estimations, the SE seem to be a bit inflated, but p-values are fine (if I drop the problematic IV, the SE go down, but the p-values go up). The LR chi squared shows significance at the 10% level and the pseudo R squared is 0.191.  I suppose this is a case of (quasi-)complete separation. My questions are   if I can still use the regression estimates after such a warning, because Stata dropped the problematic cases (=all of the 84 the observations, for which the dummy exists or is coded 1). or if I should drop the problematic IV (which would be unfortunate, even though I would have a the original sample size of 180 then) and if neither 1. or 2., how I can deal with this problem.    I know that 180 observations are not much for a model with 15 IVs. However, I'm hoping for some advice on how to solve the problem other than reducing an overfitted model - especially specific Stata knowledge would be of great help.


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I am taking a flight from Amsterdam to Delhi via London Heathrow Airport. I have a British Airways flight to London and a Virgin Atlantic flight from London to Delhi. The customer care on British Airways has confirmed that I can do a through check-in, meaning I don't have to collect my baggage at London and check it in again. I have a layover of about 6 hours in London, and the next flight is on the same calendar day. I am an Indian national.   Can anyone who has been through the same situation clarify if I would need a transit visa for London? Also, I don't hold any other visas right now (USA, Australia etc). I am traveling to Europe on a tourist (type C) visa, and this is my flight back to India. Drop a comment if you'd need additional information!  According to the UK website, I would need a transit visa, but is there any possibility that people have traveled along the same route and it wouldn't be required if I'm not leaving the airport? My flights are non-refundable and Virgin Atlantic has declined to refund any partial amount as well.


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Sometimes my SD card gets "corrupted" and this leads to many read/write errors. Usually, connecting the SD card to the windows 7 and selecting the "Error Checking" (Right click the drive > Tools > Error Checking) option finds the corruption and fixes it.  Is there any tool or app for checking SD cards for drive errors and fixing the same from within the android itself?  I'd also like to mention that I'm on rooted froyo with busybox installed.


How do I prove that $\sum _{n=1}^{\infty }\:\ln\left(1+\frac{1}{n^2}\right)$ converges without applying the series integral test?

I am at a loss as to how I can prove that the sum $\sum_{n=1}^{\infty }\:\ln\left(1+\frac{1}{n^2}\right)$ converges. At first I tried the ratio test, but that came out inconclusive. Then I tried it by showing that the sequence of partial sums is bounded, to no avail. If anyone could give me a hint on this, it would be much appreciated!


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Letting $a_{1}=2$ I have a recursive sequence defined as follows: $$ a_{n+1} = \frac{a_{n}}{2} + \frac{5}{a_{n}} \ \  \forall n \geq1$$  How can I prove that the sequence {$a_{n}$} converges and also find the limit of this sequence? I plugged in first few terms and get something like:  2,  3.5,   3.179,   3.162,   3.162,   ...  The textbook example showed an example of a recursive sequence that was monotone, but this sequence I have here does not appear as such. However, this sequence looks like a Cauchy sequence though. I am completely lost and not sure how to proceed. Any help is much appreciated! Thank you.


Which one is correct ? Explain me. a  ( or )  b  a/ Walking is good exercise. b/ Walking is a good exercise.


how can I please write this? I can't find the right name to find it in instructions. Thank you.


tkinter, message box close program on click "ok"

How do I close the entire program once the user hits OK in the message box?   Here is the portion of the script that contains the button and command:  class Application(tk.Tk):     def create_options(self):          tk.Button(self,                   text = "Begin search", command=self.pop_up1                   ).place(x=465, y=285)      def pop_up1(self):         """shows submitted box"""         tkMessageBox.showinfo(title="Finished", message="Query Submitted")


Given $a_1 =1, a_{n+1}=a_n+e^{-a_n}$. Prove that $b_n:=a_n-\ln(n)$ converges

Given the sequence $a_1 =1, a_{n+1}=a_n+e^{-a_n}$.   Prove that $b_n:=a_n-\ln(n)$ converges.   I have just known $\lim a_n =\infty$. I have tried to prove $b_{n+1} \leq b_n$ but I didn't make it. Help me, thank you so much


Is there a simple, elegant way to define singletons?

There seem to be many ways to define  in Python. Is there a consensus opinion on Stack Overflow?


Is it really going to damage a bike to wash it with a hose?

I was chatting to the guys at my LBS the other day about how they get my bike so clean when I take it in for a service. They said they use compressed air to clean it.   They warned I shouldn't use any high pressure water because it can get into the sealed bearings and cause damage. I also noted on the  (right at the end) that you should "Never spray your bicycle with water under pressure".  How much of an issue is this? Rinsing the bike with the hose is such a convenient way to wash off loose grit and then the soap after washing. How do you clean your bikes?


Getting cors error when trying to refresh parent page in an embedded VF page

I was trying to refresh a page from an embedded VF page. Since it is an iframe in the big page, so I have tried:   window.parent.location.reload();   and  parent.location.href = parent.location.href;   For both of them, I got the same error message:      Uncaught DOMException: Blocked a frame with origin   "" from accessing a cross-origin frame.   It seems weird to me that I am getting a CORS error here. Is there a way I can walkaround this issue?


Polynomial $p(z)$ in $\mathbb{C}$ has no zero whose modulus does not exceed $1$

For $n>1$ consider real numbers $c_0>c_1>.....>c_n>0$. Prove that the polynomial $$p(z) = c_0+c_1z+.....+c_nz^n$$ in $\mathbb{C}$ has no zero whose modulus does not exceed $1$.


Intel Corporation Device [8086:0d4f] is not supported on Ubuntu 18.04.3

I am currently unable to install ubuntu server 18.04.03 LTS on the latest intel NUC10i7FNH.  Ubuntu always states both network adapters as unclaimed. The previous version (NUC8i7BEH) has the same network controller I219-V and worked like a charm.  *-network:0 UNCLAIMED      description:  Network controller      product: Intel Corporation      vendor: Intel Corporation      physical id: 14.3      ...   Without network it is not even possible to follow most suggestions how to get it enabled, because it is impossible to fetch new packages from internet.  Here are some more information as requested:  The output from: modprobe -v e1000e && dmesg | grep e10   [ 3447.889394] e1000e: Intel(R) PRO/1000 Network Driver - 3.2.6-k [ 3447.889395] e1000e: Copyright(c) 1999 - 2015 Intel Corporation.   The output from: sudo lspci -knn  00:1f.6 Ethernet controller [0200]: Intel Corporation Device [8086:0d4f]     Subsystem: Intel Corporation Device [8086:2081] 01:00.0 PCI bridge [0604]: Intel Corporation JHL7540 Thunderbolt 3 Bridge [Titan Ridge 2C 2018] [8086:15e7] (rev 06)    For me this looks somehow, as the kernal driver would not be in use :-/  Here are a few more information i got from playiung around with 19.10 desktop version.  [    0.000000] Linux version 5.3.0-29-generic (buildd@lcy01-amd64-024) (gcc version 9.2.1 20191008 (Ubuntu 9.2.1-9ubuntu2)) #31-Ubuntu SMP Fri Jan 17 17:27:26 UTC 2020 (Ubuntu 5.3.0-29.31-generic 5.3.13)   output from lshw:    *-network:0        Beschreibung: Kabellose Verbindung        Produkt: Intel Corporation        Hersteller: Intel Corporation        Physische ID: 14.3        Bus-Informationen: pci@0000:00:14.3        Logischer Name: wlp0s20f3        Version: 00        Seriennummer: c8:09:a8:9c:cd:e0        Breite: 64 bits        Takt: 33MHz        Fähigkeiten: pm msi pciexpress msix bus_master cap_list ethernet physical wireless        Konfiguration: broadcast=yes driver=iwlwifi driverversion=5.3.0-29-generic firmware=48.4fa0041f.0 ip=192.168.178.109 latency=0 link=yes multicast=yes wireless=IEEE 802.11        Ressourcen: iomemory:600-5ff irq:16 memory:6023114000-6023117fff   The output from: modprobe -v e1000e && dmesg | grep e10  [    2.357430] e1000e: Intel(R) PRO/1000 Network Driver - 3.2.6-k [    2.357430] e1000e: Copyright(c) 1999 - 2015 Intel Corporation. [    2.357616] e1000e 0000:00:1f.6: Interrupt Throttling Rate (ints/sec) set to dynamic conservative mode [    2.562796] e1000e 0000:00:1f.6 0000:00:1f.6 (uninitialized): registered PHC clock [    2.634139] e1000e 0000:00:1f.6 eth0: (PCI Express:2.5GT/s:Width x1) 1c:69:7a:60:44:f0 [    2.634140] e1000e 0000:00:1f.6 eth0: Intel(R) PRO/1000 Network Connection [    2.634258] e1000e 0000:00:1f.6 eth0: MAC: 13, PHY: 12, PBA No: FFFFFF-0FF [    2.634991] e1000e 0000:00:1f.6 eno1: renamed from eth0 [    5.103285] checking generic (4000000000 e10000) vs hw (4000000000 10000000) [   15.806697] e1000e: eno1 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: None    output from lspci:  00:1f.6 Ethernet controller [0200]: Intel Corporation Ethernet Connection (10) I219-V [8086:0d4f]     DeviceName:  LAN     Subsystem: Intel Corporation Ethernet Connection (10) I219-V [8086:2081]     Kernel driver in use: e1000e     Kernel modules: e1000e


alias for date-stamping to create a directory(in .bashrc)

I am trying to create an alias in .bashrc to time-stamp a directory. Obviously, it's not working out too well for me. For example:  under .bashrc  alias testit="export testor=$(date +%d);mkdir ~/Desktop/$testor"   result:  ~> testit mkdir: cannot create directory ‘/home/SJL/Desktop/’: File exists   now if I run in command instead  ~> export testor=$(date +%d) ~> mkdir ~/Desktop/$testor   directory created, no problem.  Now if I run instead:  ~> export testor=$(date +%d);mkdir ~/Desktop/$testor   again, no problem.  going back to using the alias stated in .bashrc it does not work.  It's really curious because I've done similar things many many many times, but it seems that there's something going on/wrong with the date formatting.  I would really appreciate your input.


How can I run a function when an App Engine Datastore record is created?

Using Python/Django on App Engine, is it possible for the creation of a Datastore record to cause a function to run?  I have more than one function that creates a record.  What I want is for every time any function creates a record of a certain Model, another function is run, without the function needing to be called from the code that originally created the record.


What will be the query in MS Sql Server to concatenate my rows in one string , delimited by comma (Like shown below)


I am talking about events taking place in the known future:     Would it be okay if I'll confirm around 3 pm?   or should it be      Would it be okay if I'd confirm around 3 pm?   What is the difference and which one is correct? Why?


I'd appreciate some help identifying these three corvids I photographed in Austria during the Summer:    I know identifying corvids can be difficult and I'm not an ornithologist -- just an amateur bird watcher. After looking through many images of various crow species and their hybrids, I've tentatively identified these as:   Carrion crow (Corvus corone) Carrion crow × Hooded crow (Corvus corone × Corvus cornix) Carrion crow × Hooded crow (Corvus corone × Corvus cornix) I initially believed this to be a Hooded crow (Corvus cornix), but the broken coloration on the wings made me think it might actually be a hybrid as well.   Can someone here either confirm my identification or provide a more informed identification?


show that $\int_{0}^{\infty}\frac{x\cos ax}{\sinh x}dx=\frac{\pi^2}{4} \operatorname{sech}^2 \left(\frac{a\pi}{2}\right) $

Show that $$\int_{0}^{\infty}\frac{x\cos ax}{\sinh x}dx=\frac{\pi^2}{4} \operatorname{sech}^2\left(\frac{a\pi}{2}\right) $$   I think we can solve it by contour integration, but how? and it would be better if there were two ways, the first with real analysis and the second with complex analysis.


How do I bake my final Cycles render into a texture?

I'm new to blender and I would like to know  if there's any way I could bake my final render, with the shadows, the bump map etc. to one single texture that includes everything that I've done.


Where is the folder that contains contents of the Applications overview?

I might've messed some stuff up and I have icons which lead to a non-existent path in the "Show Applications", I am using Ubuntu 18.04.2 LTS if that helps.  More specifically I tried running Steam through wine, didn't work but made an icon in the "Show Applications" menu. Even when the path is correct it says it's wrong.