I want to use famous 741 ic to amplify the voltage from a sensor which is in the range 0-50 mV to 0-5V but the problem is all the circuits I found on web use +/- supply but i want to use only 5V supply from arduino so no negative voltage. Which configuration i need to use for a gain of 100?  When input is 0, output should be zero when input is .1mV output be 10 mV...if 741 is not feasible, suggest alternate ICs with single supply that accept such low voltages

I have a CO2 sensor that output signal values 30-50 mV. I need to translate these voltages to 0-5 V for my microcontroller with the highest resolution. I understand that I can amplify the voltage using a non-inverting op-amp circuit, as shown, to a range of 3-5 V, but is it possible to expand that range to 0-5 V in order to get better resolution of sensor values?


I have plenty of near-miss incidents. Most of the time I just awkwardly cycling along with the 'near-miss' driver* (urban, so plenty of traffic lights). And it truly feels awkward!   This time I tried to approach the driver, just to say if he/she ok. The problem with near-miss is that I am usually shaken, for obvious reason. I believe the driver would feel the same. So I thought it would be best for both to stop and talked about it, make sure that both of us is OK to continue the journey, rather than keep thinking about the incident.  One time, the male yells at me I shouldn't be on the road, albeit he was in the wrong?? Another time, the female driver bursts into tears saying sorry??  Is approaching driver after near-miss is a bad idea??  *'Near-miss' drivers in my area are usually considerate, but they are human and prone to making mistakes. If he/she is inconsiderate, I would just shrug it off. This question is not about angry driver at all.

Fortunately, I have very few strongly negative interactions with cars (most people generally seem to respect the way I ride), but those that do stick with me for a while.  The scenario is almost always the same. Rude driver approaches, does their rude thing (obscenities, "get off the road," unsafe passing, etc...), then speeds off to annoy the next bicyclist (or more than likely arrives at the next red light).  While this is generally a short interaction, I find that I just don't have a good rest of the ride. I find myself angry at the driver, thinking about what I could have done differently, and just generally being pissed off. Clearly I realize that it is possible I'm a jerk, but given the relative infrequency of these events I'm hoping that's not the case and I'm just riding defensively and this driver is having a bad day.  What can I do to get over (or mitigate) my anger at inconsiderate drivers?


I have the same problem. but after succelsfull logging in with ctr+alt+F1 I can't use sudo. I got the message:  owner of /usr/bin/sudo must be user number 0 and the setuid bit must be set. Can anyone tel me how i should do this?

I have run following command accidentally   sudo chown [username] -hR /   Now sudo su getting error:  sudo: /usr/bin/sudo must be owned by uid 0 and have the setuid bit set   How to Solve This?


How can i make my iPhone 7 play all sound through the earpiece?  I want to listen to music privately without headphones thought this would be an easy way to do it, pointing bottom of phone low-volume to head is awkward and doesn't work v well.

My company utilizes a voicemail system which sends audio files as email attachments. These audio files playback via QuickTime in iOS which pushes the audio out via the phone's speaker. Which is great for a Mumford and Sons song, not so great for voicemail. I can hook up headphones for private listening, but when I am without headphones wanted to use the phone's ear speaker instead.  Using an iPhone 5 and iOS 6 is it possible to play audio files played back via QuickTime with the ear speaker? If not via QuickTime is there an app for that?


How to make a bootable USB. I am using UBUNTU 13.04 LTS and want to make a bootable usb to install windows  Suggest any Ubuntu based usb creators to make a bootable Windows Flash drive.

How do I make an Bootable Ubuntu USB containing the the latest version of Ubuntu?  For completeness, how would I be able to do this on Ubuntu, Windows, OS X or another Linux distro?


I need your helping to find all the $a$ numbers,which follow the next rules:  there is prime number $ 2\lt n\in \mathbb N$ and $ 5\neq q\in \mathbb N$ so that the digits of $n\times q$ are only $a$.  for example:$n\times q=aaaaaaa$  if $n=7$,$a=1, 7\times 15873=111111$   and also if $2\lt n\in \mathbb N$ is odd and not divided by $5$,  $q\in \mathbb N$* , so $n\times q$ are only $a$ digits.  I need to find all the $a$ numbers which follow this rule , except $1$.

I need your helping to prove that there is a prime number $ 2\lt n\in \mathbb N$ and $ 5\neq q\in \mathbb N$ so that the digits of $n\times q$ are only $1$.  for example:if $n=3$ then $3\times 37=111$  if $n=7$ then $7\times 15873=111111 $  also if $2<n\in \mathbb N$ is odd and not divisible by $5$,  $q\in \mathbb N$* , so $n\times q$ are only $1$ digits.


1) Recently I've decided to replace multiple components in my computer because my hard drive is failing and my motherboard and such need an upgrade. Since the pc was built for me, I have a retail version of Windows 7. Is there any way to deactivate Windows 7 on my old computer and use the same disk and license key on the new computer I plan on building? Or will I just get "Windows errors"?   2) I'm assuming if I format my old computer I should be able to reuse the product key, correct? How does one go about formatting the computer?  3) My copy of Windows 7 is for a 32-bit processor, will it work if I get a 64-bit cpu and then upgrade to Windows 10 (the 64-bit version)? (I used the Windows Media Creation tool to dl Windows 10 to a flash drive so I'll have the upgrade even after July 29th)  Sorry for so many questions, all the forums I've looked at have confused me even more

I'm now a Mac user, but used to have a Windows laptop that I upgraded from Vista to 7 quite a while back (2 years now). I've not used the machine since I got my Mac, and wondered if there is any way of deactivating the license so it can be used on another Windows box (desktop) that I'd like to do some experimental stuff with, to save me purchasing anew?  It was an upgrade only license, but there is Vista on the box I want to upgrade, too.


I've conducted a multiple linear regression on a particular outcome variable with one covariate (block 1) and five related but independent predictors (block 2). The ANOVAs for both models are significant (P=0.01, P=0.026), and the covariate in the first model is significant (P=0.01). However, in the second model, even though there is an R-squared change of 21.9%, the covariate becomes non-significant (P=0.197) and none of the five predictors are significant either (0.07  I've been searching the web to try and figure out why this might have happened, and it seems like multicollinearity is the most common reason. So I ran collinearity diagnostics, and there isn't any evidence of multicollinearity - tolerance for predictors are all comfortably above 0.1, and VIF way below 10. Correlations between predictors are <0.504.   So can anyone explain what my problem is here, and how best to continue my analysis and report the data? Also, if possible, could it be explained in laymans terms? I'm just a lowly psychology student and I get confused by statistical jargon. I actually aced all regression questions on my statistics exams and have never found it difficult until now - using real-world data makes things much trickier apparently! Thanks in advance!

My multiple regression analysis model has a statistically significant F value however all beta values are statistically non-significant.   All the regression assumptions are met. No multicollinearity was found. Correlations among all predictors are all less than 0.60.   What else might be the cause of the insignificant predictors?


Here is my problem. I have a lot of partitions for different systems and I just copied my entire hard disc to a bigger one. So I find myself in this situation:  PRIMARY-1 PRIMARY-2 PRIMARY-3 [EXTENDED-1 EXTENDED-2 etc etc] -free space-  I want to make PRIMARY-3 bigger so the idea is to free up EXTENDED-1 and then make that space appear as a gap before the extended partition. But I think that is the hard part - it effectively means moving the base of the extended partition up while moving all the contents of the extended area down by the same amount.  Is there an easy/safe way to do this?

How can I expand/resize my extended partition (sda3) with unallocated free space to the left of it? I want this to be able to expand my / partition (sda5).


I'm trying to think of a word that basically communicates something in between a single and a double.   Is there such a thing as half of a ?  How would you communicate something that is in between a single and a double?

Sometimes when writing I find myself looking for a word to describe something in the “³⁄₂th” place — exactly between first and second.  I would like to ask, does there exist an easy expression for this?  If so, does it generalise to other “in-between” places as well?  (I mostly encounter this problem when writing mathematics, where I wish to write the “³⁄₂” order derivative, and normally have to endure clumsy or imprecise expressions (“Taking the fractional derivative. . . .”).)


I was studying sequence and series and used the formula many times $$1+2+3+\cdots +n=\frac{n(n+1)}{2}$$ I want its proof.  Thanks for any help.

Apparently $1+2+3+4+\ldots+n = \dfrac{n\times(n+1)}2$.  How? What's the proof? Or maybe it is self apparent just looking at the above?   PS: This problem is known as "The sum of the first $n$ positive integers".


Gluing the Mobius strip with a disk altogether along their boundaries gives $\mathbb RP^2$.   Please give me some hint or explanation how to solve it, why it is true. And give a topology on this space.

I spent some time trying to understand that the projective plane, $\Bbb RP^2$, can be viewed as the union of a Möbius band and a disc. I consider this using Homogeneous coordinates. But I still hope to really 'see' this fact in some way.


I have no idea what to do. How do i fix this eye sore?        Answer: The Problem was my start clipping distance was at the lowest setting. Increase the setting and everything will be good.

I was following  on creating a watch and noticed that when I rendered the watch, some pieces were messed up.  I'm new to 3D modeling and I've just learned Blender, I can't explain it well, so here's a picture:    Other examples:     I don't know if it's a problem with my World texture, the object, or the object's texture/material, so I can't even guess how to fix it. What causes this? Is it possible to fix it?


I think I know that there were times in the past when it was convenient to look at a number $1$ as a prime number, and, as far as I can remember, even then it was dependent on who we ask is it prime or not?  This question is primarily here because in some of the questions I posted in the last few days I wanted that we for the purpose of the question consider $1$ as prime, or because of some similar reason.  So, let us see why, in my opinion, we should take $1$ as prime, and why we should not.  First, the definition of prime numbers as seen on Wikipedia:     A prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself.   If we interpret here this greater as $n \in \mathbb N \setminus \{1\}$, in other words, as strictly greater, then clearly $1$ cannot be prime because it is, by definition, not taken into consideration.  If we change the definition and remove part of the sentence, the part greater than 1, then we have this definition:     A prime number (or a prime) is a natural number that has no positive divisors other than 1 and itself.   Then we could say that $1$ is prime, because he has no other positive divisors other than 1 and itself, and he has two divisors which coincide and are both equal to $1$ (1 and itself).  But do we stumble upon some problem if we declare $1$ as prime?  Yes we do, but all these problems (that I know of) are not so serious.  First, we should rephrase fundamental theorem of arithmetic which says that:     Every positive integer $n>1$ can be represented in exactly one way as a product of prime powers.   If we would take $1$ as prime then the fundamental theorem of arithmetic could be stated as:     Every positive integer $n>1$ can be represented in exactly one way as a product of prime powers in such a way that in the factorization of $n$ powers of number $1$ are absent.   This is because we have $1^a=1^b$ for $a \neq b$ so if we want unique factorization then powers of $1$ must be absent from the factorization.  But do we gain something positive if we declare $1$ as prime number?  I think we do.  For example, the Goldbach conjecture states:     Every even integer greater than 2 can be expressed as the sum of two primes.   If we would declare $1$ as prime we could shorten the Goldbach conjecture:     Every even natural number can be expressed as the sum of two primes.   Of course, this is because $1+1=2$ so now even two has a representation as a sum of two primes.  But in this case we would gain even more. Now, when $1$ is taken as a prime number, then we have slightly greater chance that every even natural number can be expressed as a sum of two primes because now we can consider sums of the form $2n=(2n-1)+1$ and we cannot consider them when we do not take $1$ as a prime.  It seems (but I could be wrong), that it is the matter of agreement between mathematicians should we or should we not take $1$ as a prime number.  So, I have a few questions:     1)  Is there any serious problem or inconsistency inside of mathematics if we take $1$ as a prime number (other than just re-writing the theorems/lemmas/conjectures/definitions in a different way)?      2)  Should we or should we not take $1$ as a prime number?      3)  Can you give some other examples of conjectures for which it would be better to take $1$ as a prime?      4)  What are your thoughts on this?

Why is $1$ not considered a prime number?  Or, why is the definition of prime numbers given for integers greater than $1$?


That question of mine was closed a long time ago (relatively, to me at least).  However, from time to time I still get downvotes for it.  That got me thinking: is there any reason to still downvote closed questions?

In seeing some of the potential solutions and problems related to this  I noticed something. Why are closed questions allowed to obtain more reputation for a user?   So my recommendation(even though it's a pain to implement probably) is this(note, this includes all close votes except for migrations)   When a question gets closed, only the question gets retroactively marked as community wiki. By retroactive, I mean all upvotes on the question before closing are undone.  Also note, downvotes are kept. This means a closed question with downvotes will always have a net negative reputation.  When a question is reopened, it gets retroactively assigned to the user instead of the community user. This just undoes point #1.   Details:  Point one solves these problems:   User asks a popular, but "bikeshed" subjective question. Even if the question is closed an hour later, they may accumulate 15 upvotes. With this system, those 15 upvotes won't matter. Downvotes are kept to the user while being closed. This deals with low-quality questions that people should get a negative reputation affect for. However, after being closed downvotes should be assigned to the community user to prevent the downward spiral affect, especially since pitty upvotes won't be able to save them. People can still upvote as a method of suggesting that a question should be reopened. The upvote just won't count for the author of the question until reopened.   I see no actual point in closed questions being capable of acquiring reputation, except for maybe duplicates(but only barely).  So, here is my feature-request. :)  Also, to solve the  you could apply the same thing toward the answers of closed questions. This isn't a big problem with any close reasons other than Not A Real Question, where many low quality answers fall but with users who try to answer them anyway with the small amount of information given. I think those users should not be discredited for their attempts.


I removed Python 3 from my computer now I don't have a desktop (posting this from work PC). I can only access the terminal via Ctrl+Alt+F1. I've tried just about everything I've seen on the forums, but   sudo apt-get update   results in a lot of:  W: Failed to fetch http://repo.org/dists/.... Could not resolve repo.org   I'm worried about losing some critical work, so I tried to push one of my Git repos to my Github account via the terminal and I get:  Could not resolve Github.com   Even  ping google.com   returns the Could not resolve error. So, first, how can save my files somehow? Either by pushing them to the Github repo or transferring them to another PC?

I am a new Ubuntu user running Ubuntu 13.04.  I've been trying to install and use a DeDRM tool, but I've been having problems doing so. I was following some directions that said I needed a version of Python 2.7, but not anything Python 3.0 or later (because 3.0 versions are missing some necessary libraries?). I tried to install Python 2.7.5.6, but it didn't work. I thought it was probably because I had the later version of Python, so I went through terminal and removed Python 3.3, so I could install the earlier version of Python.  Now that I've uninstalled Python 3.3, a lot of applications no longer work, including the terminal and the Ubuntu Software Center. I have no idea how to fix this problem now.


Every time I do a pdf build, TeXnic center opens my Adobe Acrobat Reader DC (version 2019.010.20098), but does not actually open the document in the Reader; I have to do that manually from the File menu or from recently opened files. If my reader is already open, then TeXnic center does not build the file at all, but runs into a fatal error when I try to build. Worst of all, after each successful build, TeXnic center completely freezes for something like two full minutes, finally popping up an error message (see attached image).    Here is a picture from my TeXnic Center settings that might also be helpful to see:     This is extremely frustrating, and I would be grateful if anyone can help me troubleshoot this problem. If there is more information I need to provide, please just let me know. Thanks in advance for any help anyone is able to offer.

How to configure TeXnicCenter to work with Adobe Reader DC? When I building and view current file .tex the following error "Can not execute the command" shows up and the PDF is not generated.    If there are any related post, could help. Thanks a lot!


This happened to me on the ELU stack exchange, though I figure perhaps this could happen on the other sites.   The review tab has a red dot on the left of the first post review tab, however it's usually grey. I clicked to review the first posts, however nothing seemed to be out of the ordinary.   What does the red dot mean?  This is a screenshot of what happened.

One of the more common bits of feedback when we  was that some sites would prefer to have an indication when there are any outstanding reviews available. So we are trying an experiment with an "inbox zero" review indicator. This would mean:  The review indicator lights up whenever there is at least one item in any queue.  There's no concept of the "danger threshold"; if there's even one item in a queue, it's marked with a red dot.    Clearly, this logic would be annoying for , so we've made it a site setting. We're going to test it out on a handful of sites to see how people respond to it:            One final thing: you will be notified even when you cannot complete a review task (for anyone who can see the review queue - 500+ reputation). In particular, people who do not have enough reputation to handle items all the queues will be notified of items in queues they can't access. This is the next thing we are working to fix. If too many people are frustrated by this situation, we'll pause the test until that problem is fixed. It'll also light up even after you've finished all the review tasks available to you, which is a much harder problem for us to fix. The goal of this experiment is to test whether aggressively notifying users can make "inbox zero" a possibility for sites that are close.


$f(x)$ is continuous for $x \geq 0$, and $\lim_{x \to \infty} f(x) = \ell.$   How do I show that for any $a, b > 0$, we have $$\int_0^\infty \frac{f(ax)-f(bx)} x \, dx = (f(0) - \ell)\log\frac{b}{a}$$  I was thinking something along the lines of we can express it in the form $$\lim _{m \to 0}\int_m^1 \frac{f(ax)-f(bx)}{x} \, dx +  \lim _{n \to \infty}\int_1^n\frac{f(ax)-f(bx)}{x} \, dx$$ but then I'm stuck and don't know how to proceed.

How can I prove the Theorem of Frullani? I did not even know all the hypothesis that $f$ must satisfy, but I think that this are  Let $\,f:\left[ {0,\infty } \right) \to \mathbb R$ be a a continuously differentiable function such that $$ \mathop {\lim }\limits_{x \to \infty } f\left( x \right) = 0, $$ and let $ a,b \in \left( {0,\infty } \right)$. Prove that $$ \int\limits_0^{\infty}  {\frac{{f\left( {ax} \right) - f\left( {bx} \right)}} {x}}dx  = f\left( 0 \right)\left[ {\ln \frac{b} {a}} \right] $$  If you know a more general version please give it to me )= I can´t prove it.


“-goer” is labelled as a suffix by the Cambridge dictionary () (UK and US English). In particular, the example it uses is “moviegoer”.   Merriam-Webster doesn’t return a result for “-goer” – instead, the query returns with the verb “go”.   Google Dictionary (yes, I know – not to best source), says both forms (hyphenated and unhyphenated) are correct. For instance:   churchgoer or church-goer  moviegoer or movie-goer   I can’t find any explanation, apart from an unanswered forum post, on the Chicago Manual of Style website regarding this question. I found a tweet by the AP Style Book (struggling to find the link) that says no hyphen should be used with “-goer”.  What makes it more confusing is that certain “-goer” compounds (unhyphenated) in MS Word are marked as spelling mistakes when others are not.  What is considered best practice when you’re trying to construct a “-goer” compound when the noun is not usually used with such a construction? For instance:   seagoer / sea-goer (unhyphenated is incorrect in MS Word) restaurantgoer / restaurant-goer (unhyphenated is incorrect in MS Word)   Additionally, is it correct in any situation to write “goer” without a hyphen (for example, “theater goer”)?

Some compound words are written without hyphens (nonaggression, nonbeliever), some with hyphens (well-intentioned), and others with spaces (post office).  Is there a rule or good guide as to which option should be used?


I want to add a key binding that allows me to use it even when the application is not in the foreground. Specifically how would I add play/skip/previous key bindings to Spotify?  I'm not looking for the media key bindings. They can stay as is. I would like to add custom ones with keys of my choosing.

Is it possible to set Spotify as the default program when the "media" keys (play, pause, previous, next, etc) are pressed on the Mac keyboard?   For the most part when Spotify is open, the "media" keys work fine. But every once and a while iTunes will pop up when you hit them. It'd be a lot nicer if you could just specify that Spotify is the default program when these keys are triggered, as oppose to iTunes.  If it matters, I'm using Mountain Lion.


I want to obtain the path of a Bash script, is when it’s executed through a symlink. In this case, $0 is -bash, while BASH_SOURCE is the symlink’s path. Can I obtain the script’s path through some shell variable, built-in shell command, or external command? Will BASH_SOURCE always holds the initial symlink’s path, even if the script is executed through several levels of indirection (multiple symlinks)? Could I use ls with BASH_SOURCE to always retrieve the script’s path?

I have a utility consisting of a couple of directories with some bash scripts and supporting files that will be deployed to several machines,  possibly in a different directory on each machine. The scripts need to be able to reference paths relative to themselves, so I need to be able to get the path to the file that's currently being executed. I am aware of the dirname $0 idiom which works perfectly when my script is called directly. Unfortunately there is a desire to be able to create symlinks to these scripts from a totally different directory and still have the relative pathing logic work. An example of the overall directory structure is as follows: /  |-usr/local/lib  |  |-foo  |  |  |-bin  |  |  |  |-script.sh  |  |  |-res  |  |  |  |-resource_file.txt  |-home/mike/bin  |  |-link_to_script (symlink to /usr/local/lib/foo/bin/script.sh)  How can I reliably reference /usr/local/lib/foo/res/resource_file.txt from script.sh whether it is invoked by /usr/local/lib/foo/bin/script.sh or ~mike/bin/link_to_script?


I have recently come across a picture that is a theory of Malfoy attempting to warn the trio of the Basilisk in the second film. It has a few exceptionally good points that seem genuine, and I couldn't helping thinking it to be possible.  Malfoy could just being his old self, and granted wished Hermione dead, however, how would she have gotten the page on basilisks from?     It looks typed as if from a Library book (but as explained from the theory, Hermione has an ever ending love for books), but was it? I understand that certain circumstances permit different actions of a human, but this was a hunch from Hermione, no?   The following picture contains mild, vulgar language.     I am looking for the authenticity of this theory, via J.K Rowling herself, or hard, canonical evidence.  Could this theory be linked with the page that Hermione had?   Not my photo - .

I was recently watching the movie Harry Potter and the Chamber of Secrets.  In the beginning you can see Draco Malfoy ripping out a page from a book in the bookstore Flourish and Blotts.  For what reason does he need this page?  I've already heard some theories about helping Hermione and Ron  with the basilisk but this sounds sort of implausible.  Could someone please explain this scene to me? AFAIK it has not been told in the books.  Note: I am searching for canon answers such as quotes from J.K. Rowling.


Some years ago, if I remember correctly, I was looking for sci-fi TV shows on Youtube, so I caught some snippets/inserts on Youtube, which were apparently from a German sci-fi TV show. It had rather minimalistic/noisy music, and there was a sort of a brutalist architecture vibe in the show. Unfortunately, I'm not a German speaker, so I didn't understand the story, nor did I remember the title. But as far as I can remember, it was in color, and the fashion/graininess of picture suggested it was from the late 70s or early 80s (so it would have been either East or West German production).  So now when I look for German sci-fi TV shows, all I can find are shows like "Alpha Alpha" (                               -> similar picture quality to what I remember, so probably close in period, but way too funky music in this trailer), or "Alpha 0.7 - Der Feind in dir" (that one is way too new).  I'm guessing the show was sci-fi due to some unseen computers or something (or maybe time travel), as there were no obvious "future technologies" (such as  lasers, holograms, or even computers), I think the architecture and interior design was (and the minimalist electronic music) was what mostly gave the association of "future" in that show.  I am aware this is quite vague description, but if anyone recognizes anything from this description, I'd love to hear a hint!  EDIT: I also remember the clothing was basically "normal" from the period, nothing (extremely) sci-fi-ish...

In this movie there are scientists who (spoilers ahead)       ...are creating a simulation. One scientist starts seeing odd looking characters but no one else sees them. He asks around and more and more characters are missing or don't know about the characters in the story he knows about.  He finds out that he is part of a simulation. He finds out that the characters only he remembers have been deleted. He also finds out that there are characters from his own simulation that have broken free of his simulation and are in his world.    Hints: I remember this being an older film (70's?); it might have been foreign film possibly with subtitles (not Hollywood); it might have been part of the Criterion collection; I'm pretty sure I streamed it from Hulu. Sorry, I can't remember more details.


problem is i havent been able to delete it. I dont remember how I installed it but now I would just like to get rid of it. FYI. Im using a laptop with Ubuntu 14.04

I want make my installed Ubuntu as light as possible to launch only on 256MB RAM machine (VirtualBox)?  So I'm thinking about removing GNOME and related components completely. How can I do that?  This link does not help me:


I have tried everything. Looked into every single thread, nothing is working.  I tried pressing e in GRUB and adding "nomodeset"  I tried "nouveau.modeset=0"  Recovery mode doesn't help because when I open the root shell, the files are read-only.  I can't boot into tty  The screen is blank, nothing is responsive.

I recently installed Ubuntu. Everything was working just fine until I wanted to change the selected driver for my laptop (Lenovo Y50) under the Additional Drivers tab in settings.   I added the ppa: graphics-drivers software source and then I selected the latest available driver. I don't remember the version. Then I proceeded to restart my computer, but now it just gets stuck at a black screen with the message /dev/sda2: clean, 290961/14106624 files, 4246276/56401920 blocks.   I can't use the CTRL + ALT + F1 (or F2...etc) shortcut, literally nothing happens when I try.


Is there a SCP Client like WinSCP just for Linux?  it has to support SCP and not SFTP as the other questions suggested  as the Server I have to connect to, only understands ssh and scp no sftp  its a embedded device with limited capabilities based on some busybox installation

I need a program that can manage files on a remote device running Linux using SCP. The remote device runs OpenWrt. On Windows there is a perfect one WinSCP. it is weird that there is no native program that can be used. The program should be able to:  list files copy and move files to/from the device and within the device. delete files on the device view and edit files change file permissions  I have found only one alternative, except using CLI and installing WinSCP with wine. It is Midnight Commander with fish. It works really poor. The problems are:  It mixes up ~ on a remote device and on the computer. It can't edit files. I can open and edit, but they are saved to a wrong place.  There is a lot of other annoying problems that makes it almost unusable. I gave up using mc and now I am using pure shell on the remote device. Please do not tell me that Nautilus, etc support these features. They don't!!! Linux native file managers require SFTP that is not available on the remote device. Maybe it is possible to get nautilus use SCP, but I did not find a way of doing it without changing sources. THIS IS NOT A DUPLICATE !!! I have a specific requirement that is not covered in the duplicate question. If it is not possible on Ubuntu, then this could be an answer.


Every time I hit play on the launcher it tries to open then crashes.  I am using Windows 10 professional 64 bit; I have uninstalled and reinstalled both Java and Minecraft.  Here is the error log:     ---- Minecraft Crash Report ---- // Hi. I'm Minecraft, and I'm a   crashaholic.      Time: 29/03/19 09:57 م Description: Initializing game      java.lang.IllegalStateException: GLFW error 65542: WGL: The driver   does not appear to support OpenGL     at cgd.b(SourceFile:218)    at   cgd$$Lambda$853/1962688455.invoke(Unknown Source)     at   org.lwjgl.glfw.GLFWErrorCallbackI.callback(GLFWErrorCallbackI.java:36)     at org.lwjgl.system.JNI.invokePPPP(Native Method)   at   org.lwjgl.glfw.GLFW.nglfwCreateWindow(GLFW.java:1649)     at   org.lwjgl.glfw.GLFW.glfwCreateWindow(GLFW.java:1827)  at   cgd.(SourceFile:99)     at cgc.a(SourceFile:79)     at   cft.am(SourceFile:439)    at cft.a(SourceFile:380)    at   net.minecraft.client.main.Main.main(SourceFile:144)      A detailed walkthrough of the error, its code path and all known      details is as follows:      -- Head -- Thread: Client thread Stacktrace:  at cgd.b(SourceFile:218)    at cgd$$Lambda$853/1962688455.invoke(Unknown Source)    at   org.lwjgl.glfw.GLFWErrorCallbackI.callback(GLFWErrorCallbackI.java:36)     at org.lwjgl.system.JNI.invokePPPP(Native Method)   at   org.lwjgl.glfw.GLFW.nglfwCreateWindow(GLFW.java:1649)     at   org.lwjgl.glfw.GLFW.glfwCreateWindow(GLFW.java:1827)  at   cgd.(SourceFile:99)     at cgc.a(SourceFile:79)     at   cft.am(SourceFile:439)      -- Initialization -- Details: Stacktrace:     at cft.a(SourceFile:380)    at net.minecraft.client.main.Main.main(SourceFile:144)      -- System Details -- Details:     Minecraft Version: 1.13.2   Operating System: Windows 10 (amd64) version 10.0   Java Version: 1.8.0_51,   Oracle Corporation    Java VM Version: Java HotSpot(TM) 64-Bit Server VM   (mixed mode), Oracle Corporation  Memory: 641696776 bytes (611 MB) /   805306368 bytes (768 MB) up to 2147483648 bytes (2048 MB)     JVM Flags:   9 total;   -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump   -Xss1M -Xmx2G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M  Launched Version: 1.13.2    LWJGL: 3.1.6 build 14   OpenGL: NO CONTEXT  GL Caps:    Using VBOs: No  Is Modded: Probably not. Jar signature remains and client   brand is untouched.   Type: Client (map_client.txt)   Resource Packs:   Faithful+1.12.2-rv4   Current Language: ~~ERROR~~ NullPointerException:   null  Profiler Position: N/A (disabled)   CPU:

I recently got Minecraft but not from the website, I paid for a code and everything seemed ok. When I tried to play the game a thing came up saying it crashed and then a message popped up saying The game crashed whilst initializing game     Error: java.lang.IllegalStateException: GLFW error 65542: WGL: The driver does not appear to support OpenGL.


I have hundreds of pairs of instrumental/vocal MP3 files. The instrumental version has music played with instruments. The vocal version does too, but it also has a vocal track overlaid.  I don't know what all processing went into creating these MP3 files, but I do know that the instrumental and vocal versions often do not have the same length, and they often start with a different length of silence.  I need to figure out what the offset is between each pair of MP3 files. Because there are so many of them, I would prefer a command line solution.  I don't know anything about signal processing, I'm hoping for some existing tool that can easily do this. Any ideas?

I've backed up some audio files up in 2 places and added ID3 tags into one backup but not the other, since time has passed my own memory has faded on whether the backups are actually the same, but now one has ID3 data and the other doesn't, basic binary compare will fail and inspection will be cumbersome.   Is there a tool to compare just the audio data (not the header, ID3) in mp3s, flac files, and other files using header data such as ID3.  started a thread on beyond compare here:   would consider other comparison software that does this task


How to prove that $a^2+ab+b^2\ge 0$?  Obviously the squares are positive, but how can I be sure that $ab$ doesn't become too negative with a certain combination of $a$ and $b$?

I want to prove that $x^2+y^2+xy\ge 0$ for all $x,y\in \mathbb{R}$.  My "proof":  Suppose wlog that $x\ge y$, so $x^2\cdot x\ge x^2\cdot y\ge y^2\cdot y=y^3$ (because $x^2\ge 0$ so we can multiply both sides by it without changing the inequality sign) giving $x^3\ge y^3$. Substracting we have $x^3-y^3\ge 0$ or $(x-y)(x^2+xy+y^2)\ge 0$. Since $x\ge y$ we can divide by $x-y$ to get $x^2+xy+y^2\ge 0$.  Is it right?  Thanks for your help!


Very simple question, I'm new to Linux  I have a command run on startup (Elementary OS) command is:  /home/zachary/Documents/Server108/Server108.sh   When I turn my laptop on the command runs in the background, and this is great, but I can't issue a "Stop" command because the terminal never opens. So, my question is this;  How do I force the terminal to open, run the script and then stay open? Do I need to add a line to the .sh file, or add arguments to the startup command?

I have a Python script which I would like to execute at every startup. I can run it by adding this to the startup applications:  python3 /path/to/script.py   That works, but it doesn't open a terminal window, so I can't see the program's output. How could I make it open a terminal window and execute the script in there?  Note: I get the window to stay open with input(' ') at the end of the Python script. Thanks!


I want to get a iso file, i just want to get the iso file but it keeps downloading this folder, I just want the iso file not entire folder with 2 gb of content

I have downloaded Ubuntu 16.04.1 LTS from .  In order to create a bootable DVD it is asking for an ISO image which I haven't found in the download folder.  Where is the .iso file?


Basically the character is posed and rendered with various props. At random, suddenly, the lines are "sticking" among multiple frames despite the fact that the object has been moved.   What could be the cause of this, and how can I fix it?  This only started happening recently - I had done many renders with this file / model and suddenly this has started.   The magnifying glass frame is two or three frames down from the hammer one.

When rendering my scene as an animation, on particular frames (in this instance, 17), I often get a delay in the outlining, like it's trying to outline the next/previous frame.    This doesn't happen when rendering the frame normally - as in not an animation.  It looks like this:           It's like the actual render is delayed by a frame, but only when animated. Is this a known bug?


i'm making a request to my db.    When i change "Canuelas" to "Cañuelas", the response it's empty, i tried to change the db, table and row collation but no results.  Here it's an image of the empty response:    Here it's the php code i use to the request:  <?php include "_db.php"; $con = crearConexion();  if ($con->connect_error) {     die("Connection failed: " . $con->connect_error); }  $postdata = file_get_contents("php://input"); $request = json_decode($postdata,true);  $action = $request['action'];  if ($action === "get_propiedades") {      $consulta_propiedades = "SELECT * FROM propiedades WHERE quitado = ''";     $result_propiedades = mysqli_query($con, $consulta_propiedades);      $row_container_propiedades = array();      while($row_propiedades = mysqli_fetch_array($result_propiedades)){         array_push($row_container_propiedades, $row_propiedades);     }      $row_container_propiedades = json_encode($row_container_propiedades);      echo $row_container_propiedades; }else if ($action === "get_filtros") {      $consulta_filtros = "SELECT * FROM filtros";     $result_filtros = mysqli_query($con, $consulta_filtros);      $row_container_filtros = array();      while($row_filtros = mysqli_fetch_array($result_filtros)){         array_push($row_container_filtros, $row_filtros);     }      $row_container_filtros = json_encode($row_container_filtros);      echo $row_container_filtros; }  $con->close(); ?>   Note: The problem it's in "get_filtros". "get_propiedades" it's retrieved correctly.  Sorry for my bad english!  EDIT: The set_charset('utf8mb4'); did the magic, all i needed to do was adding that line to the db connection, here it's the db connection file if someone need it.  <?php function crearConexion(){     //Datos para la conexión con el servidor     $servidor   = "localhost";     $nombreBD   = "dbname";     $usuario    = "dbuser";     $contrasena = "dbpass";     //Creando la conexión, nuevo objeto mysqli     $conexion = new mysqli($servidor,$usuario,$contrasena,$nombreBD);     $conexion->set_charset('utf8mb4');      //Si sucede algún error la función muere e imprimir el error     if($conexion->connect_error){         die("Error en la conexion : ".$conexion->connect_errno.                                   "-".$conexion->connect_error);     }     //Si nada sucede retornamos la conexión     return $conexion; } ?>

I'm setting up a new server and want to support UTF-8 fully in my web application. I have tried this in the past on existing servers and always seem to end up having to fall back to ISO-8859-1.  Where exactly do I need to set the encoding/charsets? I'm aware that I need to configure Apache, MySQL, and PHP to do this — is there some standard checklist I can follow, or perhaps troubleshoot where the mismatches occur?  This is for a new Linux server, running MySQL 5, PHP, 5 and Apache 2.


I rolled back a major edit to  today, but I found no place to put the reason I thought the edit was not appropriate.   In this case, I thought the edits would have been better if they we put into an answer, along with an explanation of why the suggestions make sense. I might even have offered to provide a bounty to the editor for providing a more up to date answer. But i have no way to communicate this in my rollback.  Or did I overlook something in the editor?

I just had an occasion where someone reformatted the code in my question, not because it was ill-formatted, but to match his preferred style. I would have liked to be able to type a reason for rolling back the edits when I did so - could the ability to do that be added?


I am totally new to Blender and I came upon an issue I can't solve by myself. I tried some solutions for a similar problem but seems not to work in my case. I was following a blender tutorial and everything was good until the last step when I wanted to render my last view. In my object mode, I have all elements but while rendering an image some of them are missing. Do you have any idea what is happening here because I am lost? I am using Blender Version 2.81 on Macbook Pro.  Here is a view from my Object Mode    and here is rendered result ...    Would really appreciate advise how to fix this problem ;))

I've been following BlenderGuru's tutorials on making a donut and cup.    I've gotten right to the end and now when I click 'Render Image', I don't get the icing:    The particles (sprinkles) are displaying, but not the pink icing.  I cannot figure out why.  The blender file is here:   And a screenshot of Blender:   Can anyone help me figure out why?


What is the difference between function and method ? Can any one say with suitable example say what are the differences? Where we say some routines are called function and where it is called method?

Can someone provide a simple explanation of methods vs. functions in OOP context?


I am programming  using UnityEngine;  public class playermove : MonoBehaviour {     public float moveSpeed=5f;      // Update is called once per frame     void Update()     {         jump();         Vector3 movment = new Vector3(Input.GetAxis("Horizontal"),0f ,0f);         transform.position += movment * Time.deltaTime * moveSpeed;      }      void jump()      {         if (Input.GetButtonDown("jump"))          {             GameObject.GetComponent("RigidBody2D")().AddForce(new Vector2(0f,5f),ForceMode2D.Impulse);         }     } }   and I am getting this problem:  (15,1): error CS0120: An object reference is required for the non-static field, method, or property 'GameObject.GetComponent(string)'

Consider:  namespace WindowsApplication1 {     public partial class Form1 : Form     {         public Form1()         {             InitializeComponent();         }          private void button1_Click(object sender, EventArgs e)         {             //int[] val = { 0, 0};             int val;             if (textBox1.Text == "")             {                 MessageBox.Show("Input any no");             }             else             {                 val = Convert.ToInt32(textBox1.Text);                 Thread ot1 = new Thread(new ParameterizedThreadStart(SumData));                 ot1.Start(val);             }         }          private static void ReadData(object state)         {             System.Windows.Forms.Application.Run();         }          void setTextboxText(int result)         {             if (this.InvokeRequired)             {                 this.Invoke(new IntDelegate(SetTextboxTextSafe), new object[] { result });             }             else             {                 SetTextboxTextSafe(result);             }         }          void SetTextboxTextSafe(int result)         {             label1.Text = result.ToString();         }          private static void SumData(object state)         {             int result;             //int[] icount = (int[])state;             int icount = (int)state;              for (int i = icount; i > 0; i--)             {                 result += i;                 System.Threading.Thread.Sleep(1000);             }             setTextboxText(result);         }          delegate void IntDelegate(int result);          private void button2_Click(object sender, EventArgs e)         {             Application.Exit();         }     } }   Why is this error occurring?     An object reference is required for the nonstatic field, method, or property 'WindowsApplication1.Form1.setTextboxText(int)


Just wanting to know what a Dirty Read is. If anyone could sum it up shortly and briefly that'd help. Looked online and nothing is really clicking to me. Appreciate the help, thanks.  Can you also give a simple clear example? Thank You.

Why should I or shouldn't I use dirty reads:  set transaction isolation level read uncommitted   in SQL Server?


I'm using QGIS and am trying to import coordinates pulled from Google Maps as CSV but they are displaying in the wrong location. They should be showing up in CA, however they are only displaying in the ocean off the west coast of Africa. I have tried changing projections and CRS but nothing so far has worked.

I'm new to QGIS and tried importing  (stops.txt). The project CRS, base map CRS and GTFS CRS have all been set to Google Mercator, but the points that are supposed to appear in Boston is now plotted in the middle of the ocean.  Did I miss out on something that messed up the import/plotting?


In C, we can convert void* to any other pointers.  But C++ forbids it.   int *a = malloc(4);   leads to this error:   invalid conversion from ‘void*’ to ‘int*’ [-fpermissive]   Are there any latent dangers here in c++?  Are there any examples of c++?

In , someone suggested in a  that I should not cast the result of malloc. i.e., I should do this: int *sieve = malloc(sizeof(int) * length);  rather than: int *sieve = (int *) malloc(sizeof(int) * length);  Why would this be the case?


I am trying to duplicate the qqnorm plot here  x=  c(1,2,3,4,5,6,7,8,9,10,11) y = c(10,45,39,50,77,20,28,14,25,23,33) length(x) length(y) l = lm(x~y) plot(l) #### PRESS ENTER 3 times to see the QQNORM plot below     How would you manually reproduce that with the standardized residuals from the regression model  StbdardizedRediduals = rstandard(l)

I am programmer developing a Software that features the display of a probability plot. As far as I know there are 2 different ways to display a probability plot (please correct me if I say something wrong):   A Percent / Percent Chart A Quantile / Quantile Chart   My customers want a Percent / Percent Chart. That brings some problems.  There is no charting control I know that features a probability plot chart.    That's why I have to calculate the positions of the data points by hand. Are there any formulas or calculations to place the data points and Y-axis values in a normal coordinate system?


Can anyone tell the way how to animate a rolling cube? Without bones. In Maya, for example, its quite easy to animate pivot point (origin) or use locators (empties), but in blender it seems to be a problem. There is a Pivot constraint, but besides that snaping doesn't work, it works in a weird way on its own. here is example scene -

Hi I'm in desperate need of help, I'm creating an animation for a Magic Cube.     This video shows what I need to create  So far I have been able to move the pivot of a cube one way and then again another by using an armature and an empty, however because these are now linked up I cannot figure out how to move the cube another turn     here demonstrates the point i'm at, I have place empty cubes to show where I need the actual cubes to be, however if I attempt to link them the original position has changed. Is there anyway I can animate these cubes rotating with the one above them?  I'm new to Blender and have had to learn after using 3Ds max for a while I'm struggling a lot would really appreciate the help please! Also I hope this makes sense...


We have to prove that $a^{2^n} +1\mid a^{2^m}-1$ when $m>n$.  What I've done: I considered the two cases when $a= 2k$ and when $a= 2k+1$.

I've been struggling with this all day today. I imagine it's not very hard, but my algebra skills are terrible. So, how can I show that if $m>n$ and $a$ is a positive integer, then $$a^{2^n}+1 \mid a^{2^m}-1.$$ I just can't get a coherent picture of what I'm supposed to do. If this too (see yesterday's question) boils down to the Unique Factorization Theorem, I would be very grateful for any intuition on how to think about this!


Why can't we print a number in binary like other in C programming.   Example:  int a=9;   printf("%b",a);      like we can print in other form:   octal       printf("%o",a);     decimal     printf("%d",a);        hexadecimal    printf("%x",a);

I can print with printf as a hex or octal number.  Is there a format tag to print as binary, or arbitrary base? I am running gcc. printf("%d %x %o\n", 10, 10, 10); //prints "10 A 12\n" print("%b\n", 10); // prints "%b\n"


It's been noted that the Stack Overflow close vote queue has a few questions in it. More generally, it appears as though the Stack Overflow community cannot keep up with the volume of questions that need closing. Community  after 30 days if they are negatively voted and have 0 answers. Closed questions that are 9 days old are also deleted if they have a score less than or equal to 0 and no answer with a score greater than 0 (and a whole lot of other minor stuff). I propose adding an automated closing process between these two. A question would be automatically closed by Community if all of the following are true:  There is at least one close vote that is at least 9 days old The question has a score of 0 or less There are no answers with a score greater than 0  There are  (this will be slightly out due to )  Close Votes # Questions -ve Answer 0 Answer No Answer  ----------- ----------- ---------- -------- ---------  1           10130       69         5649     4412       2           5094        50         3135     1909       3           2566        29         1639     898        4           723         13         495      215        5           3           0          2        1         This means that if a question starts to be closed then there's 9 days to either get an upvote, an answer with an upvote or 100 views. Due to the automatic deletion there would then be another 9 days to get some redeeming feature (re-open vote, edit etc) before the question was deleted. I would add similar conditions to closing so if a question with a close vote got edited it would get an additional 9 days grace period. I imagine the main objection to this is that a single person can auto-close and then delete a question. It is already possible for a single person to delete a question and there are currently  where a single person can delete without oversight. This suggestion will actually give those questions a greater chance of survival whilst at the same time helping the site to stay "clean" better. 1. Whether it's time of day or summat this query was really difficult to run so sorry if there are problems.

Today, the size of the close-votes queue is 55k questions and growing. Is that a problem?   Which action could be taken to clean it up? It seems to be growing faster than Stack Overflow members are capable to handle it.


I've been trying to build a docker image using Ubuntu:16.04 as the base image. I want to install python so I use   RUN \ apt-get -y update && \ apt-get -y install python python-dev python-pip   on a single RUN command to avoid layer caching. I also have tried using the --no-cache flag in my build command, but it does not prevent the error  Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/m/manpages/manpages-dev_4.04-2_all.deb  Writing more data than expected (2078445 > 2047608) Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?   I looked at other , and as this is a docker image I can't access /etc/apt/sources.list.

when trying to update package listings via apt update or apt-get update I receive the following error:  E: Failed to fetch http://lt.archive.ubuntu.com/ubuntu/dists/xenial/universe/dep11/Components-amd64.yml.gz  Hash Sum mismatch E: Failed to fetch http://lt.archive.ubuntu.com/ubuntu/dists/xenial/universe/dep11/icons-64x64.tar  Writing more data than expected (7468511 > 7467723) [IP: 193.219.61.87 80]   Is this somehow related to localised package distributor or is me all along? I am running beta2 release, that I've successfully installed and updated (without any error prompts) yesterday. Previously I used a 14.04 derivative which also did not bring up any errors. What can be the reason for this error?  EDIT: to duplicate markers, the topic name tackles a different problem rather than the hash sum problem, which is being referenced.


I have an image from an external url and I want to use it my visualforce page and render the page as pdf. However when I add the keyword renderAs="pdf" to the top of the page I showed below. The image looks perfectly fine in the visual force page. The images are only broken in pdf. I have whitelisted the url I am getting the image from and using the images as statis resources is not an option for me. Any help is appreciated. <apex:page standardStylesheets="false" standardController="Quote" renderAs="pdf" applyHtmlTag="false" showHeader="false" title="Teklif Çıktısı" language="TR" extensions="KsQuoteDomesticPdfController">

When referencing an external image in a Visualforce PDF rendered image, the image is displaying a broken link.  It works perfectly without the renderAs="PDF".


I'm wanting to do an incremental backup from my Linux computer to server. I've made the ssh link and I can at least get RSYNC to load the files incrementally, which I plan to do daily using cron.daily, but I want the server (Synology 213j) to take care of tarring the file, though - in my mind - I think it would be fine for my computer to tell the server to TAR the file every week and then put it in weekly, then tar it every month, and finally every two months.  The code I found that sounded somewhat like it might work is this example.  ssh root@192.168.1.105 "tar cvpfz - / --exclude="tmpl" | ssh regx@192.168.1.102 "cat > /media/shared/backup/iphone/iphone_bak_$today.tgz"   However, this looks like it's piping an iPhone to a server backup and it's probably much more complicated than I'll actually need.  Bonus question: would I be better off trying to run the TAR code on the server itself?

stdout on one CentOS server needs to be piped to stdin on another CentOS server. Is this possible?  Update  ScottPack, MikeyB and jofel all have valid answers. I awarded the answer to Scott because, even though my question didn't specify security as a requirement, it's always nice to be safe. However, the other two fellows' suggestions will also work.


I created a bootable USB for Ubuntu 17.10 (with Rufus), and when I boot on it, then select "Install" or "Try without installing", I got this error :  [Firmware Bug]: TSC_DEADLINE disabled due to Errata; please update microcode to version: 0x52 (or later)   I've seen on some other posts that I could try to update my BIOS. I did this, but didn't work.  It also happens when I try to install Ubuntu, Kali or Fedora 27 on a virtual machine (host is Windows 10 professional, with VirtualBox).  I guess it could be useful to give my CPU references, which are as follows :      Intel(R) Core(TM) i5-7300HQ CPU @ 2.50GHz, 2501 MHz, 4 core(s), 4 thread(s)   Thanks a lot ! Gaël

I saw several bugs and error messages when I was looking by chance into the tool called "logs".  Being a newbie in Ubuntu I have no idea how to deal with these bugs, where to report them or how to fix them.  Any help to guide me here?  The bug I have (which is listed under important) reads:  [Firmware Bug]: TSC_DEADLINE disabled due to Errata; please update microcode to version: 0x52 (or later)


I want to find all of the unusual gems for the thieves guild but I can't find any, I only have 3, are they in dungeons or where?

I can't seem to find a few of the Stones, so, is there a list available with the location of all the stones?


I'm going to travel to Europe in 11 days. I'm going to UK, Austria, Czech Republic and Hungary, and here in Chile I can exchange Chilean pesos to sterling pounds, dollars and euros. I'm particularly interested in the Czech crown. Do they accept euros or dollars in Czech Republic? What do you recommend, euros or dollars? I'm going to use my credit cards (all contactless), but it's always necessary to carry some cash. I'll be in Czech Republic for two days and a half.  Thank you in advance.

Recently my wife and I traveled to Italy and before we left we got about 85% of our money in travelers checks and the other 15% we carried on in cash. When we arrived there, no one would take our travelers checks and many places did not accept credit cards. Eventually, we found some currency exchange places that would take the travelers checks and give us Euro's, but at a 7-15% fee, which was not really a very fun surprise.   While I was under the impression that it is safer to use travelers checks, it seems that they were not really accepted (the usual explanation being fraud). So the question is, is it best to just exchange your currency at home and carry all of it with you when you travel or are there other alternatives to carrying cash that are safer and cost effective?


How to give a direct proof of the following result?     Let $A$ be a subset of $\mathbb{R}$ such that $A$ is both open and closed. Then $A$ is either empty or all of $\mathbb{R}$?   My work:   If $A$ is not empty, let $u \in A$. Then there is some open interval $(a,b)$ such that $$u \in (a,b) \subset A.$$  Now if $\mathbb{R} - A$ is not empty either, then let $v \in \mathbb{R} - A$. Then there is some open interval $(c,d)$ such that  $$v \in (c,d) \subset \mathbb{R} - A.$$  Suppose that $u < v$.   Since $$\emptyset \subset (a,b) \cap (c,d) \subset A \cap (\mathbb{R} - A) = \emptyset,$$ we must have $$(a,b) \cap (c,d) = \emptyset.$$ So we can conlclude that $$b \leq c.$$ But $b \in A$ and $c \in \mathbb{R} - A$. So we must have $$b < c.$$  What next? Can anybody here please help complete the proof from here on?  An edit based on a comment by Marc Paul:   Let us assume that the set $A$ is a non-trivial clopen set in $\mathbb{R}$. Let us define a function $f \colon \mathbb{R} \to \mathbb{R}$ as follows:  $$f(x) \colon= \begin{cases} 1 \ \mbox{ for } \ x \in A; \\ 0 \ \mbox{ for } \ x \in \mathbb{R} - A. \end{cases}$$   Let $V$ be an open set in the range space $\mathbb{R}$. We show that the inverse image set $f^{-1}(V)$ is open in the domain space $\mathbb{R}$.   The following cases arise:   If $0, 1 \in V$, then $f^{-1}(V) = \mathbb{R}$.   If $0 \in V$ but $1 \not\in V$, then $f^{-1}(V) = \mathbb{R} - A$.   If $1 \in V$ but $0 \not\in V$, then $f^{-1}(V) = A$.   And, if $0 \not\in V$ and $1 \not\in V$, then $f^{-1}(V) = \emptyset$.   Thus, $f^{-1}(V)$ is open in the domain space $\mathbb{R}$.   Hence the function $f$ is continuous.   What next? How does this lead to our desired conclusion?   [Yet another edit, again based on valuable comments from Marc Paul: ]  So if both $A$ and $\mathbb{R} - A$ were non-empty, then let's suppose $a \in A$ and $b \in \mathbb{R} - A$, and we can assume without any loss of generality that $a < b$.   Then $f(a) = 1$ and $f(b) = 0$. So by the intermediate value theorem there is a real number $c \in (a,b)$ such that $f(c) = 1/2$, which is a contradiction because the image set of $f$ does not contain $1/2$.

In other words, are $\emptyset$ and $\mathbb{R}$ the only open and closed sets in $\mathbb{R}$? Why/Why not?  I tried by assuming a set is equal to its interior points and contains its limit points.  A bounded set will not do since stuff like $[1,4]$ and $\{5\}$ will not work, though that is not really proof. Help please?  Anyway, it must then be unbounded.  If $a$ is a real number then $(a,\infty)$, $(-\infty,a)$, $[a,\infty)$ and $(-\infty,a]$ don't seem to cut it so it must be $\mathbb{R}$.


Split from:     I want to run a campaign "from the book" for a group of new players (played RPGs before, but stuff much much lighter then D&D, and I've not DMed this edition before. I DMed D&D 4e once: over prepared in some areas, under prepared in others, so the pacing was horrible and off putting. I didn't run it again (although the players seemed happy to try again).  My concern: by trying to run it "from the book" I might accidentally railroad them too much, That changing events too far from the module will cause errors in continuity, that will force me to improvise too much for my first game.  I've flicked through both the Tomb of Annihilation where this could be fun with the hex-crawl random encounter portion without too much continuity problems, as well as Waterdeep: Dragon Heist which seems more reliant on knowing the lore of the town, and even though it's modular, certain events still unfolding in a given manner.  What happens if avoiding a direct fight or encounter runs counter to the published adventures? i.e. making friends with the goblins throws out a future plot point of the adventure that I'm not yet familiar with? Or they completely miss and don't find a clue.

I'm DM'ing a play-by-post campaign and I'm at a point in the adventure where the group all meets for the first time. They've all had something stolen from them at the same time and saw a creature that took something run into a nearby alley (there's three separate parties within the play group currently, as they've only just started, so there's three separate robbers running into alleys in the marketplace).  Ideally, I want the players to have their PCs all give chase so they end up in the same part of town, all looking for the same thing. However, I don't want to railroad my players into doing this. I know I'm not supposed to take away player agency or narrate their actions for them, but the only way I could think of was to tell them that they start giving chase.  So how would you deal with this situation? And more broadly, how can I stop something like this happening again?  If it matters, we're currently playing D&D 5e.


I am trying to have the Python 3 console tab of QGIS 3 complete my file system.   I've tried import sys but this does not allow me to do it.

I would like to use Ipython in the console to perform tasks more easily.   How can I do that?   I want to use Ipython because I prefer to program with it. I would like to have TAB-completion because the attribute of QGIS module made me crazy.


I want to apply a texture to my object, but my window to view my object has disappeared when in shading mode. It has worked in the past, I'm not sure how to get the view back up.

Whenever I download a .blend from someone all of the windows and settings are the way they have left them as it is saved in the file. It takes way to long to rearrange every window and toolbar to the way it is by default. Is there any tool or shortcut that can reset the UI to blenders default and just leave the actual contents of the file? The only way I could do this is by creating a new file and using link/append but this is not the best option.


I am having a bit of difficulty showing that the set $A=\{a+b\sqrt{-7},a,b\in\mathbb{Z}/2\}$ (i.e. using integers+half integers) is a euclidean domain.  I see how a lot of the proofs work, like for $\mathbb{Z}[i]$ and $\mathbb{Z}[\sqrt{-2}]$.  However, I am a bit confused, as it seems that the trick that happens doesn't work for me.  In those proofs, you show that some remainder $r$ and elements $z,w$ such that $z=qw+r$.  With this, you can show that $N(r)\leq\frac{3}{4}N(z)$.  I am not getting this $\frac{3}{4}$, I am getting $\frac{8}{4}$, or just some constant that isn't less than 1.  Furthermore, I've looked at some of the other posts when your $d=1$mod$4$, but it looks like they're using the same norm, so I don't know.  Here's my work: Let the norm of an element in $A$ be $N(a+b\sqrt{-7})=4(a^2+7b^2).$ Now I am not entirely sure about multiplying this by 4, but it seems that the norm function has to map into $\mathbb{N}\cup{0}$, so in order to guarantee that this happens I need the 4 to account for the half integers being squared (does it matter that $\mathbb{N}$ has a bijection with $\frac{\mathbb{N}}{4}$?  Let $z,w\in A$.  Then there are real numbers $c,d$ such that $\frac{w}{z}=c+d\sqrt{-7}$.  Let $q_1,q_2\in\frac{\mathbb{Z}}{2}$ be the closest elements to $c,d$ respectively.  Then we have $|q_1-c|\leq\frac{1}{4}$ and $|q_2-d|\leq\frac{1}{4}$.  Setting $q=q_1+q_2\sqrt{-7}$ and $r=\frac{w}{z}-q$, so $w=qz+rz$.  Now it remains to show that $N(rz)=N(r)N(z)\leq N(z)$, and this is where my problem is.  For $N(r)$, my first question is why in the world can I even apply the norm to $r$ since it must not even belong to my set $A$.  Ignoring that technicality, we have that $r=(q_1-c)+(q_2-d)\sqrt{-7}$, so $N(r)=4[|q_1-c|^2+7|q_2-d|]\leq 4[(1/4)^2+7(1/4)^2=2.$  If my 4 from the norm wasn't part of my norm function, then I would be good to go, but I've explained why I'm not sure that works.  Can someone help me figure out where I'm going wrong?  Thanks.

Is the ring $\displaystyle A=\mathbb{Z} \left[ \frac{1+i \sqrt{7}}{2} \right]$ euclidean?  If $N : z \mapsto z \overline{z}$, then for all $z \in \mathbb{C}$ there exists $a \in A$ such that $N(z-a)<1$, except when $z$ has the form $\displaystyle \left(n+\frac{1}{2} \right)+ \left(m+ \frac{1}{2} \right) \frac{1+i \sqrt{7}}{2}$; in this case, you can only find a large inequality. So $A$ is "almost" euclidean, but is it actually euclidean?


I have a CSV file that I'm editing in Excel 2013. In the file there is a column that contains numbers e.g 688087123456789. Everytime I open the CSV file in Excel, it converts the number to scientific notation 6.88087E+14. I can revert the number back to its original format by right-clicking the cell > Format Cells > Custom and then selecting 0.   However, I do not want to do this process everytime I open teh CSV file. How can I do this?

I would like to prevent Excel behavior that any large number I enter is stored as a number, then abbreviated to scientific notation. Is it possible to tell Excel 2007 to stop doing this?


In the feed you get a scrolling entry for comments and one for answers. Both are labelled as "replies". I think they should be labelled as comments and answers.  As it is it looks particularly odd when you have answers and comments to the same question, where it shows two rows of "replies".

In the inbox of the app, there is no way to differentiate between comments and answers as is in the global inbox of the website.  Could this be added?


I have a class which is used to hold a bunch of python static methods which will return a string from an environment variable. class GitLabCiEnv():     """     Gitlab CI Environment variables.     """     @staticmethod     def CHAT_CHANNEL() -> str:         """         Source chat channel which triggered the ChatOps command.          Added in GitLab 10.6         Available in GitLab Runner all         """         return os.environ["CHAT_CHANNEL"]      @staticmethod     def CHAT_INPUT() -> str:         """         Additional arguments passed in the ChatOps command.          Added in GitLab 10.6         Available in GitLab Runner all         """         return os.environ["CHAT_INPUT"]  With this class I can just call GitLabCiEnv.CHAT_CHANNEL() to get the value of the environment variable. The "ugly" is, that I have to use paranthesis for each those @staticmethod. What I would do is GitLabCiEnv.CHAT_CHANNEL without paranthesis. I do not want to instantiate an object of this class, there is, in my opinion no benefit of having an object. I tried different implementations, using class variables, but then each variable will be initialized if the class is imported, this is not what i want. Maybe someone has a solution for me. Thank you very much!

I have a class with two class methods (using the classmethod() function) for getting and setting what is essentially a static variable.  I tried to use the property() function with these, but it results in an error.  I was able to reproduce the error with the following in the interpreter: class Foo(object):     _var = 5     @classmethod     def getvar(cls):         return cls._var     @classmethod     def setvar(cls, value):         cls._var = value     var = property(getvar, setvar)  I can demonstrate the class methods, but they don't work as properties: >>> f = Foo() >>> f.getvar() 5 >>> f.setvar(4) >>> f.getvar() 4 >>> f.var Traceback (most recent call last):   File "<stdin>", line 1, in ? TypeError: 'classmethod' object is not callable >>> f.var=5 Traceback (most recent call last):   File "<stdin>", line 1, in ? TypeError: 'classmethod' object is not callable  Is it possible to use the property() function with @classmethod decorated functions?


here's my problem:  Let's say I build a 3x4 matrix:   The first way :  M = [] k=1; while k<12: M.append([k,k+1,k+2,k+3]) k=k+4   I get this in output:  0 -> [1, 2, 3, 4]                                                                                1 -> [5, 6, 7, 8]                                                                                2 -> [9, 10, 11, 12]   Ok great now let's assign some element withM[2][1]=0  0 -> [1, 2, 3, 4]                                                                                1 -> [5, 6, 7, 8]                                                                                2 -> [9, 0, 11, 12]    OK it works. Now here's the issue with the second way :      lst1=[]      T=[]      for k in range(0,3):         lst1.append(0)     for j in range(0,4):         T.append(lst1)   output: [[0, 0, 0], [0, 0, 0], [0, 0, 0], [0, 0, 0]] note: The code I have to do is a transpose function hence the dimensions of this matrix  Now let's (try to) assign T[3][0]=4:  output :  0 -> [4, 0, 0]                                                                                1 -> [4, 0, 0]                                                                                2 -> [4, 0, 0]                                                                                3 -> [4, 0, 0]   Nope it changes all the colum instead of the element. Is there a way to make it work properly on the second option ?  I don't understand why it does that. I use python3  Thanks ! A python newbie

I needed to create a list of lists in Python, so I typed the following: my_list = [[1] * 4] * 3  The list looked like this: [[1, 1, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1]]    Then I changed one of the innermost values: my_list[0][0] = 5  Now my list looks like this: [[5, 1, 1, 1], [5, 1, 1, 1], [5, 1, 1, 1]]    which is not what I wanted or expected. Can someone please explain what's going on, and how to get around it?


I need someone to review the following proof to find the range of tan $\theta$, whether it is acceptable or not: Starting with |cos$\theta|\le$ 1 Square both sides: |cos$\theta|^2\le 1^2$ Simplify:  $cos^2\theta\le 1$ Use reciprocal property for inequality: $\frac{1}{cos^2\theta}\ge\frac{1}{1}$  Use reciprocal identity: $sec^2\theta\ge1$  Use Pythagorean identity: $1+tan^2\theta\ge1$  Simplify:  $tan^2\theta\ge 0$ Since the square of any real number is always greater or equal to 0, it follows that the range of tan $\theta$ is the set of all real numbers.  *************************************************************************** I need someone to review the following proof whether it is acceptable or not. Using the rectangular coordinates definition of $\tan \theta=\frac{y}{x}$ where $\theta$ is in standard  position and (x,y) is a point on the terminal side, tan $\theta=\frac{y}{x}$   =$\frac{y-0}{x-0}$    = Slope of the terminal side (The terminal side starts from the origin) Since the slope of a straight line is the set of all real numbers, it follows that the range of tan θ is the set of all real numbers.

I'm struggling to understand why the range of tangent function is equals to all real numbers. Because tangent = opposite/adjacent right? But the sum of the opposite^2 + adjacent ^2 must be equal to the hypotenuse^2. So doesn't that put a limit on the value of denominator (and the numerator) of the ratio/tangent, therefore putting a limit on the range of the function?   Also, I don't get how the tangent function is able to produce every single real number. Because doesn't the fact that opposite^2 + adjacent ^2 must be equal to the hypotenuse^2 prevent the tangent function from producing certain numbers? Because for any given opposite value, the adjacent value can't just be any integer. It's square must add up with the square of the opposite to equal hypotenuse squared. Doesn't that prevent the tangent function from producing certain numbers, because there are only so many combinations of opposite values and adjacent values that can occur?   Can you please explain to me why all possible real numbers can by formed by the tangent, even with these limits? Can you please explain why this is not the case as simply as possible, without using calculus (because I haven't learnt it)? I realize when you plot it, it will go up to infinity. But I want to understand why this is the case, without using calculus


As far  as I know there are amdgpu and fglrx AMD drivers and foss radeon driver. Where can I find a list what driver supports which card, which X.Org server, which Ubuntu vesion (16.04 and 16.10)?   Is there a new proprietary AMD driver instead of fglrx?  *Although my question has been identified as a possible duplicate and I foud there a partial answer to my question, it didn't give me a list of supported amdgpu-pro models and also amdgpu supported models. I think this list should exist so we can buy compatible Ubuntu hardware.

I have 14.04.5/16.04 or newer and an AMD GPU. I'm not getting the performance I want, and some programs say they need things like OpenCL.  I've heard about fglrx, but if I try to install it on my machine, it breaks and I have no GUI.  Is there anything I can do to get my AMD card working to its full potential?


I am trying to run the constructor/default initializer of a class on a specific memory location.  I am trying to use pooling so I have allocated memory (with malloc) for the object and I have the address of where I would like to go.  I just don’t know how to run the constructor of the object on that void* location.  Is this possible?

Has anyone here ever used C++'s "placement new"? If so, what for? It looks to me like it would only be useful on memory-mapped hardware.


I have recently received the Investor badge for offering a bounty on question , but i have not got any notifications about it and it is missing under Achievements.

Why is it that whenever I get a badge or some comment from Stack Overflow or the DSP Stack Exchange, I get notified by the red balloon, but when I get a similar response on some other branch like ComputerScience then there is no notification?  I don't get many notifications other than from Stack Overflow though.  Example a vote-up .


def my_function(fname):     print(fname + " Refsnes")  my_function("Emil") my_function("Tobias") my_function("Linus")  def my_greeting(*fname):     print(fname + " Smith")  my_greeting("Don")   The first part runs fine the second part crashes. Here are the results.  Emil Refsnes Tobias Refsnes Linus Refsnes  Traceback (most recent call last):   File "C:/Data/Python/turtleFun/kikiFunction.py", line 19, in <module>     my_greeting("Don")   File "C:/Data/Python/turtleFun/kikiFunction.py", line 17, in my_greeting     print(fname + " Smith")  TypeError: can only concatenate tuple (not "str") to tuple   I haven't created a tuple, I'm not trying to concatenate. The structures are the same but one runs and the other crashes. Why does Python 3.8.3 think I have a tuple? How do I fix? Tuples would be   myTuple = ("Don", "Fred", "George", "Paul", "John", "Ringo")

In the following method definitions, what does the * and ** do for param2?  def foo(param1, *param2): def bar(param1, **param2):


According to the theory, when quantum fluctuations occur near the event horizon, one is absorbed and the other is emitted as hawking radiation But in order to conserve the energy the fallen particle must've been of negative mass We know that negative mass particles move in the opposite direction of the acceleration applied to it, so how can that negative mass particle fall into the black hole in the first place?

Could someone please provide an explanation for the origin of ? (Ideally someone who I have been speaking with on the h-bar)  Any advanced maths beyond basic calculus will most probably leave me at a loss, though I do not mind a challenge! Please assume little prior knowledge, as over the past few days I have discovered that much of my understanding surrounding the process as virtual particle pairs is completely wrong.


I have declared a method that return Class, but i don't know if it is the right way or not . When i pass int, float, double or String as parameter, i want to return int.class, float.class or double.class.     How can i do that?     Class<?> analyseType(String nameType) throws ClassNotFoundException {         Class<?> classe = Class.forName(nameType);         return classe;      }

I need to make some reflective method calls in Java. Those calls will include methods that have arguments that are primitive types (int, double, etc.). The way to specify such types when looking up the method reflectively is int.class, double.class, etc.  The challenge is that I am accepting input from an outside source that will specify the types dynamically. Therefore, I need to come up with these Class references dynamically as well. Imagine a delimited file a list of method names with lists of parameter types:  doSomething int double doSomethingElse java.lang.String boolean   If the input was something like java.lang.String, I know I could use Class.forName("java.lang.String") to that Class instance back. Is there any way to use that method, or another, to get the primitive type Classes back?  Edit: Thanks to all the respondents. It seems clear that there is no built-in way to cleanly do what I want, so I will settle for reusing the ClassUtils class from the Spring framework. It seems to contain a replacement for Class.forName() that will work with my requirements.


I am trying to get a long range lens for taking pictures of animals.  I have read many questions and realize I need at least a 300 mm and I know they all depend on price...I'm not to go crazy with price but I would like a very good for wildlife even if it cost more. My question is what brand and I saw some quotes say fast what does that mean? I have a nikon d3000

I am looking at trying to buy a long range lens for shooting animals and nature. I'm kinda new to photography and am not sure which brand or size I should be looking for. What features are important and what will I get from different price points? I also would like to get a macro lens for really close shots — is that possible with the same lens?  I have a nikon d3000.


I am looking at a valid question with 4 votes to close on a site. I think the collective conscious has edited the question to make it appropriate, and there are answers for that question now.  With one more vote that question will be closed, creating cognitive dissonance about acceptable questions on that site.  The current recourse is to wait for the question to be closed, and then begin voting to reopen.  Instead there should also be a way to negate a vote to close, with a vote to keep open.  Thoughts?

Sometimes you vote to close something and the OP then changes it to fix the issue or issues. You can't take a close vote back though. It would be nice if you could.    With the new Duplicate close changes and the review queues, it's even more important to be able to remove accidental or erroneous close votes: close votes now place a banner on the question (for dupes) or put the question into a queue for other users to look over.  An easy "undo" button could save a bunch of people some time and grief for these accidental/no longer desired close votes.


Given a finite group $G$ of order an even number, prove that $G$ contains a non-identity element of order $2$.  Proof: For every non-idenity element $g \in G:g^2 \ne e \iff g \ne g^{-1}$ If such $g$'s exist then the number of them is an even number, since every one of them can be paired with its inverse, follows the number of elements in $G$ that are their own inverse in even, clearly $e=e^{-1}$, so the number of non-identity elements in $G$ that are their own inverse is odd, implies at least $1$ such element does exist.  Another way I tried is as follows: $G$ has an even order iff $\text{ord}(G)=2n$ for some $n \in \mathbb N^+$ iff $ g^{2n} =e$ for $\langle g \rangle = G$ and $e$ the identity element of the given group.Every element is in the group generated by itself and so $g \in \langle g \rangle$,$G$ is a group and so $g^n \in \langle g \rangle$. On the other hand $(g^n)^2=g^{2n}=e$. Then I figured out that this just implies that $\text{ord}(g^n)$ divides $2$ and is not necessarily equal to $2$. Is my conclusion true? besides is it possible to finish the proof using the second way?

I am working on the following problem from group theory:     If $G$ is a group of order $2n$, show that the number of elements of $G$ of order $2$ is odd.   That is, for some integer $k$, there are $2k+1$ elements $a$ such that $a \in G,\;\; a*a = e$, where $e$ is the identity element of $G$.


I am finding that the VBA Round function returns the wrong result. I found a working alternative which is to use the Application.Round instead.  Why doesn't the VBA Round function work as expected?  Sub roundingResults()     Range("A1") = 123456.705     Debug.Print "Approach #1 " & Round(Range("A1").Value, 2)     Debug.Print "Approach #2 " & Application.Round(Range("A1").Value, 2)     End Sub   Output  Approach #1 123456.7 Approach #2 123456.71

I had an application for returning closest matches to certain values in a large  cluster of values( as in my earlier )   and I chose a VBA solution. While in the course of using the said application, I observed that the results for the value of 0.5 were not correct. I had been using the VBA Round function which I found to be returning 0 for 0.5 rounded to integer whereas the worksheet round function returns 1. Strangely, the VBA round function returns 2 for 1.5. I had to substitute the worksheet function in place of the VBA one.  Am I missing something?


I have a Samsung Galaxy S4 Mini and when I go to download certain apps and it will not let me because 'it is not available in my country', however other people within my country have these certain apps and I am confused.

I'm travelling to country X. I want to install an application which isn't available in my country, but is available in country X; but I prefer to download and install it in advance, while the data connection is still cheap.  Unfortunately, the Play Stores does not allow me to install this app. Is there any way to circumvent this limitation?


Inaccurate visit count for referring sites.  Example from     Also saw some 441 on  and

The analytics for the beta site I moderate (Lego Answers) provides unreliable search keywords.  The first ten or so results are unique, but every search keyword after has 41 views, and there are hundreds of results with supposedly '41' views. Some of the referring sites also have 41 views.  Something doesn't seem right. I can understand each search keyword having one or two visits each.  See Also:


This is not a question about method synchronisation, only to statement synchronisation. Please do not incorrectly mark as duplicate.  Is this code:  synchronized (this) if (something) {     somecode();     somemorecode(); }   equivalent to this code:  if (something) {     synchronized (this)     {         somecode();         somemorecode();     } }

Can any one tell me the advantage of synchronized method over synchronized block with an example?


If I have only one front door, and only one back door, and they are both red.  Which is correct:         The front and back door are red;   The front and back doors are red.      I feel that (1) looks wrong and that (2) indicates that there are a plurality of both front and back doors.

I wonder which of the two is correct:        I have a red and a blue car.   I have a red and a blue cars.      or        Everyone has a left and a right arms.   Everyone has a left and a right arm.      My (non-native) inclination would be for option 1, as it sounds better.  On the other hand, in the following examples, the plural sounds better to me.    Everyone has left and right arms. I have old and new cars. (when I only have only one old car and one new car) The left and the right arms are...   But are they correct?


I am trying to make a Custom Trade on a villager. I need to make him buy 8 gold nuggets and sell a Cow Spawn Egg.  basically you pay 8 nuggets for a Cow Spawner.  The ID of the Cow Spawn Egg is 92 but I don't know where to put it in the command /summon Villager ~ ~2 ~ {Invulnerable:1,CustomName:Spawner_Vendor,Profession:2,Career:1,Offers:{Recipes:[{buy:{id:gold_nugget,Count:8},sell:{id:spawn_egg,Count:1}}]}}

Recently I have been working on a mini-game that gives a few players custom spawn eggs. I want the mob to simply have a name and be on a team. I'm attempting to use this command:   /give @p[x=-102,y=48,z=81,distance=..1] shulker_spawn_egg{Team:PurpleTeam,CustomName:"\"Purple Turret\""}   It does give the player a spawn egg, but the resulting shulker spawn does not have a team or a name. Any ideas why this isn't working?


I have an API i want to deploy to OpenShift, everything works locally, but when trying to use it online i get some problems. When trying to connect to the database, using PDO, i get this error:  Failed to connect to the database: SQLSTATE[HY000] [2002] Connection refused  i have the database set up correctly, and i have the correct details for the connection (im pretty sure). heres some code:  $username = "myuser";  $password = "lmnop";  $host = "127.0.0.1";  $dbname = "loginapi";  $port = "3306";  $db = new PDO("mysql:host={$host};port={$port};dbname={$dbname};charset=utf8", $username, $password, $options);   what could be wrong that OpenShift is not allowing the connection? considering that this works on my local machine?  thanks!

This is a  about Connection Refused    We see a lot of questions to the effect      When I try to connect to a system I get a message      Connection refused      Why is this ?


I need to  click on one of many links which are similar the only difference is the number. Can somebody help me with that? (using Java)       I tried these didnt work:  driver.findElement(By.xpath("//a[@href='/edit-files.php?i=26']")).click(); driver.findElement(By.cssSelector("a[href*='/edit-files.php?i=26']")).click();

This site contains many questions that are about finding the right locator expression (XPath, CSS, etc) for an object in WebPage or about troubleshooting problems related in invalid or dynamic locators. For instance: .    How one can find a good locator expression? What tools can generate expressions matching a certain element automatically? How to troubleshoot such issues when element does not match expression?


I run a local apahe2 and PHP set up on my Ubuntu desktop to test stuff. Mainly so I can avoid uploading utter garbage when I am creating new code.  However after a particularly problematic upgrade it seems Apache is no longer running. When I try to start or restart it I get this:    * Restarting web server apache2 AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1. Set the 'ServerName' directive globally to suppress this message (13)Permission denied: AH00072: make_sock: could not bind to address [::]:80 (13)Permission denied: AH00072: make_sock: could not bind to address 0.0.0.0:80 no listening sockets available, shutting down AH00015: Unable to open logs Action 'start' failed. The Apache error log may have more information.                                                                          [fail]  * The apache2 instance did not start within 20 seconds. Please read the log files to discover problems    I couldn't rember where the error logs might be found (it has beena  long while) but I googled it:   However /var/log/apache2/error.log is empty  How can I figure out what is wrong and fix it?  Notes: I am aware of the whole cannot determine FQDN thing and as I am running it only for me I've never been that bothered so long as it actually worked and I could test what I had written.

I can stop it using  /etc/init.d/apache2 stop   But when I want to start it again using:  /etc/init.d/apache2 start   I get this error:  Starting web server apache2                                                  /usr/sbin/apache2ctl: 87: ulimit: error setting limit (Operation not permitted) apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1 for ServerName (13)Permission denied: make_sock: could not bind to address [::]:80 (13)Permission denied: make_sock: could not bind to address 0.0.0.0:80 no listening sockets available, shutting down Unable to open logs Action 'start' failed. The Apache error log may have more information.                                                                          [fail]


I am trying to use the \filename@parse like this:  \filename@parse{\lstname}   but I get this error:  ! Undefined control sequence. l.22 \filename               @parse{\lstname} ?    Am I missing some package?

I am using the following code in my beamer document to make the frame title's appear in the table of contents:  \documentclass{beamer} \usetheme{default} \usepackage{bookmark} \usepackage{etoolbox} \usepackage{graphicx}  \makeatletter \apptocmd{\beamer@@frametitle}{   \addtocontents{toc} {\protect\beamer@subsectionintoc{\the\c@section}{0}{#1}     {\the\c@page}{\the\c@part}     {\the\beamer@tocsectionnumber}}     \bookmark[page=\the\c@page,level=3]{#1}}   {\message{** patching of \string\beamer@@frametitle succeeded **}}%   {\message{** patching of \string\beamer@@frametitle failed **}}% \makeatother  \begin{document} \begin{frame}[label=toc]{Table of Contents}     \tableofcontents     \end{frame} \section{First Section}   \begin{frame}{One}      content \end{frame}  \section{Second Section} \begin{frame}{Two}      Content  \end{frame}      \section{Third Section}     \begin{frame}{Three}      Content      \end{frame} \end{document}   What I am trying to do is understand what the solution does because I now want to add block titles to the table of contents as well as frame titles and I imagine that would be an easy function to add if I understood the code. Please help by re-writing the code (if possible) without the \makeatletter substitution command, using other latex commands.   Here are some related posts:


Are questions which are basically the same sites allowed on on two Stack Exchange sites?    For example take a look at these two questions from Server Fault and Super User.   Server Fault   Super User    If yes, then is there a way to link them or for the search box to look across multiple sites?

What's the right course of action for cross-site duplicates?  There are two flavors:   A question is posted which belongs on another site and ends up already having been asked there. I can't find an example right now, but it's bound to happen soon if it hasn't already. The same question is posted in two places at the same time. Take  for example, which is a duplicate of , posted within a half hour of each other by the same user.   Possible actions:   Move it to the proper site and close it once it gets there as a duplicate. Provide a way to close it right away as a cross-site duplicate, without moving it first. Flag it and let a moderator merge them. Close it as "no longer relevant" or something else.   Additionally, flavor 2 is a bit of a special case; perhaps the question really spans both sites in terms of content and intended audience. Should multiple-postings in this case be allowed? If so, should they somehow be linked to each other? If not, how do we avoid a migration war?


I am using Ubuntu 16.04 in HP Envy-15 laptop and want the touch-pad to disable automatically whenever I connect my mouse. Is there any particular setting available in Ubuntu?  I have seen many answers which tells how to manually disable the touchpad but I want something that automatically disables it whenever I plug in my mouse. I want to use it as a feature of Ubuntu, not to write some specific script and run on my system only (if any feature is there).

I want my touchpad to be disabled when I use my mouse. How can I do that? touchpad-indicator has stopped working on 11.10. It used to work on 11.04. Gnome3 is not a solution as I don't like it and find it buggy.


As seen from  question, the following command gives the IP address of the system. ip route get 8.8.8.8 | awk '{print $NF; exit}'  I wanted to make use of this command to create an alias so that I do not have to type such a long command everytime. So, I added the following line into .bashrc  alias ipconfig="ip route get 8.8.8.8 | awk '{print $NF; exit}'"   But I am facing an issue with the awk command when I use it with the alias (specifically, I think the $NF variable is not set. I have provided three versions of the output using the commandline and the set alias for better understanding.  dennis@dennis-HP:~$ ip route get 8.8.8.8 | awk '{print $NF; exit}' 192.168.0.X   dennis@dennis-HP:~$ ipconfig 8.8.8.8 via 192.168.0.Y dev wlx9d5d8eae8f64  src 192.168.0.X  dennis@dennis-HP:~$ ip route get 8.8.8.8 8.8.8.8 via 192.168.0.Y dev wlx9d5d8eae8f64  src 192.168.0.X      cache    How can I get it to produce the same output?

If I use single quotes to enclose awk's action statement, it works as expected:  $ dpkg -l | grep "linux\-[a-z]*\-" | awk {'print $2'} linux-headers-3.13.0-27 linux-headers-3.13.0-27-generic linux-headers-3.14.4-031404 linux-headers-3.14.4-031404-generic linux-headers-generic linux-image-3.13.0-27-generic linux-image-3.14.4-031404-generic linux-image-extra-3.13.0-27-generic linux-image-generic linux-libc-dev:i386 linux-sound-base   But if I use double quotes to enclose them, it prints the whole line instead of the particular column/field:  $ dpkg -l | grep "linux\-[a-z]*\-" | awk {"print $2"} ii  linux-headers-3.13.0-27                    3.13.0-27.50                                           all          Header files related to Linux kernel version 3.13.0 ii  linux-headers-3.13.0-27-generic            3.13.0-27.50                                           i386         Linux kernel headers for version 3.13.0 on 32 bit x86 SMP ii  linux-headers-3.14.4-031404                3.14.4-031404.201405130853                             all          Header files related to Linux kernel version 3.14.4 ii  linux-headers-3.14.4-031404-generic        3.14.4-031404.201405130853                             i386         Linux kernel headers for version 3.14.4 on 32 bit x86 SMP ii  linux-headers-generic                      3.13.0.27.33                                           i386         Generic Linux kernel headers ii  linux-image-3.13.0-27-generic              3.13.0-27.50                                           i386         Linux kernel image for version 3.13.0 on 32 bit x86 SMP ii  linux-image-3.14.4-031404-generic          3.14.4-031404.201405130853                             i386         Linux kernel image for version 3.14.4 on 32 bit x86 SMP ii  linux-image-extra-3.13.0-27-generic        3.13.0-27.50                                           i386         Linux kernel extra modules for version 3.13.0 on 32 bit x86 SMP ii  linux-image-generic                        3.13.0.27.33                                           i386         Generic Linux kernel image ii  linux-libc-dev:i386                        3.13.0-27.50                                           i386         Linux Kernel Headers for development ii  linux-sound-base                           1.0.25+dfsg-0ubuntu4                                   all          base package for ALSA and OSS sound systems   Why is it so? Why does using double quotes to enclose awk's action statements produce different results than when using single quotes to enclose them? Can I do something so that enclosing using double quotes works like enclosing using single quotes?