How to complain about being bullied by moderator?

Is there any channel for us to complain when we are bullied by a moderator? I really hope that Stack Overflow can be a place which is fully transparant. If we were being bullied by a  moderator, the evidence should not be wiped off (edited or deleted) by the big bully (moderator). Also, I hope there is a tool for us to vote on the moderator that likes bullying so that everyone knows about his real face.


How should I determine whether a deck is legal in a particular format?

I have a list of cards for a deck I want to build or buy. What should I do to check whether that deck is legal in a particular format (Standard, for example)?


GeoServer behind a reverse proxy with CORS problems using buttons

I've set up a simple GeoServer on a Ubuntu server, behind an NGINX reverse proxy. The proxy is at map.mydomain.com and passes incoming port 80 requests on a subdomain to another internal port. I can access the web interface all no problems, log in etc. But whenever I try to use most buttons (save/apply/etc) I get a CORS error: "Origin does not correspond to request". This is a snapshot of the request on clicking one of these buttons:  I have followed the below to enable CORS, but no luck. This is the default GeoServer 2.18.0 install, so it is using Jetty.  All I can figure is somewhere, some bits of Jetty may be expecting 127.0.0.1 rather than maps.ourdomain.com but for the life of me I can't figure out how or why it's only on button clicks! proxy config:     proxy_pass http://127.0.0.1:3201/$1$is_args$args;     proxy_http_version 1.1;     proxy_set_header Host $host;     proxy_set_header X-Real-IP $remote_addr;     proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;


A proof about the optimal values and extreme points

Show that if the optimal value of the objective function of a linear programming problem is attained at several extreme points, then it is also attained at any convex combination of these extreme points.     Definition. convex combination  A point $x\in\mathbb{R}^n$ is a convex combination of the points $x_1,x_2\dots x_r$ in $\mathbb{R}^n$ if for some real number $c_1,c_2,\dots,c^r$ which satisfy$$\sum_{i=1}^rc_i=1\text{ and }c_i\ge0,\space1\le i\le r$$have$$x=\sum_{i=1}^rc_ix_i$$    Proof.  let $f:\mathbb{R}^m\to\mathbb{R}$ be the objective function, $M$ be the optimal value, $c_1,\dots,c_n\ge0$ and $\sum_{i=1}^nc_i=1$  Assume $x_1,\dots,x_n$ are optimized solutions which are on the extreme points  $$f(x_1),\dots,f(x_n)=M$$  Show any convex combination of $x_1,\dots,x_n,s.t.$  $$x=c_1x_1+\dots+c_nx_n$$ is also a optimized solution$$\text{WTS } f(c_1x_1+\dots+c_nx_n)=M$$  Since $f$ is linear, have the following:  $$f(c_1x_1+\dots+c_nx_n)=c_1f(x_1)+\dots+c_nf(x_n)$$  $$=c_1M+\dots+c_nM=(c_1+\dots+c_n)M=M$$  Therefore convex combination of also also has a optimized value  Now show them are all feasible solutions  Since $x_1,\dots x_n$ are feasible we have  $$Ax_1,\dots,Ax_n\le b\wedge x_1,\dots,x_n\ge0$$  $$\text{WTS }A(c_1x_1+\dots+c_nx_n)\le b\wedge c_1x_1+\dots c_nx_n\ge0$$  Since $Ax_1,\dots,Ax_n\le b$ that   $$c_1Ax_1\le c_1b\wedge\dots\wedge c_nAx_n\le c_nb$$  $$\Rightarrow c_1Ax_1+\dots+c_nAx_n\le b(c_1+\dots+c_n)$$  Since A is a linear transformation, have the following:  $$\boxed{A(c_1x_1+\dots+c_nx_n)\le b}$$  Second part that $$\boxed{c_1x_1+\dots+c_nx_n\ge0}\text{ is trivial}$$  This proves any convex combination of these extreme points are optimized feasible solution.$\tag*{$\square$}$  Is my proof correct, any suggestions$?$


"I will not" or "I don't" as an answer for negative orders?

She: "Don't forget to bring washing powder.      I: Okay, I don't. (or I will not?)   I know the rule of thumb that in interrogative sentences we always have to answer in the same tense that we were asked. (For example: Are you there? Yes, I am.  or "Do you like it? Yes, I do.) But in this case which is not interrogative sentence but an order, I'm not sure what would be correct.


I'd like to install libjbig-dev on Ubuntu 14.04 LTS. So I run  sudo apt-get install libjbig-dev   which returns  Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  libjbig-dev : Depends: libjbig0 (= 2.0-2ubuntu4) but 2.0-2ubuntu4.1 is to be installed E: Unable to correct problems, you have held broken packages.   So I do  sudo apt-get install libjbig0   which returns  Reading package lists... Done Building dependency tree        Reading state information... Done libjbig0 is already the newest version. 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.   Now what? How can I install libjbig-dev? Thanks.


If I'm looking for a tool or set of tools (software, mostly) to do something that I'm clearly not knowledgeable enough to create on my own, how can I get that without asking an off-topic shopping question on SE?  In other words, if I were to create my own tools, I could ask about all the details in multiple questions, and all of them would be perfectly legitimate.  But what if I want to just use a tool that someone else probably made already?  How do I find that?  I'm sure there are lots of people on the SE network that would know.  The only problem is that it's not allowed to ask here as far as I can tell.


Is there a possibility to send a email notification when gitlab backup is done? I run the backups automatically with a cronjob


Prove that for $n>1$,the non-bounded function $u=\ln\ln\left(1+\frac{1}{|x|}\right)\in W^{1,n}(\Omega)$,Here $\Omega=B(0,1)\subset \mathbb{R}^{n}$  I think we have to prove that $$ \int_{B(0,1)}\left|\ln\ln\left(1+\frac{1}{|x|}\right)\right|^{n} dx<\infty,$$  and  $$ \int_{B(0,1)}\left|D\ln\ln\left(1+\frac{1}{|x|}\right)\right|^{n} dx<\infty,$$ but it hard for me to compute these integrates.


RAM: which one is more better 2x2GB or 4GB?

Is this better to have 2x2gb DDR3 RAM in both of the slot or single 4GB DDR3 RAM in single slot in laptop? Which way is right to increase my laptop perfromances, what should I do for best and fast performances?


Even though SELinux, firewalld, iptables are disabled on my VPS "curl: (7) Failed connect to ... Connection refused error"

I rented a KWM VPS storage server (CentOS 7) and I can access it via SSH and SFTP. But I can't do anything with it because it refuses everything. I didn't install anything on it, didn't change any config, havent done anything. Fresh OS install. (except for deactivating firewall and selinux which were automatically on) curl # curl xx.xx.xxx.xxx curl: (7) Failed connect to xx.xx.xxx.xxx:80; Connection refused  netstat # netstat -plnt Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name     tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      1226/sshd            tcp        0      0 127.0.0.1:25            0.0.0.0:*               LISTEN      1148/master          tcp6       0      0 :::22                   :::*                    LISTEN      1226/sshd            tcp6       0      0 ::1:25                  :::*                    LISTEN      1148/master  SELinux setsebool -P httpd_can_network_connect on setsebool:  SELinux is disabled.  Firewalld systemctl status firewalld â— firewalld.service - firewalld - dynamic firewall daemon    Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)    Active: inactive (dead)      Docs: man:firewalld(1)  iptables # iptables -L Chain INPUT (policy ACCEPT) target     prot opt source               destination           Chain FORWARD (policy ACCEPT) target     prot opt source               destination           Chain OUTPUT (policy ACCEPT) target     prot opt source               destination       I don't know what else to check on? VPS support says they didn't block any port and that it is a problem from "inside the KWM". From literally 3 days of googling, the only other 2 options might be maybe that my IP runs twice and maybe it is a NAS server? But I wouldn't know how to check on these things and it is just a guess. Or maybe some SSL stuff? Or vhost things? I don't know. I have not much clue about servers, so please help me, if you have the time. Much appreciated, thank you.


Prove that the area of a Pythagoras triple is divisible by 2, 3 and then 6.  I know that in the Pythagoras triple (x,y,z) area is equal to 1/2(xy). But I am unsure how to prove this statement.


Why do Python built-ins interact differently with the "is" keyword?

Here is something odd that I came across while experimenting with the 'is' keyword. When I use Python built-ins to create identical objects, Python assigns the same id to them:  >>> a = str() >>> b = str() >>> id(a), id(b) (29857888 29857888) >>> a is b True   Creating the string explicitly works the same way:  >>> a = '' >>> b = '' >>> id(a), id(b) (29857888 29857888) >>> a is b True    However, when I make my own classes, Python assigns different ids.  >>> class MyClass: ...    pass >>> c = MyClass() >>> d = MyClass() >>> id(c), id(d) (16566256 16566800) >>> c is d False   How/why does Python do this? Is there a way to implement this "id matching" functionality for my own classes?


I have recently been encountering sentences like "I have a bed that needs made." "You have a face that needs punched."  Is this proper grammar, and if so; is there a name for this construction?


Transparency of solids using bandgaps and relation to conduction and valence bands

I think I understand how a solid can appear transparent as long as the energy of the photons travelling through it are not absorbed in the material's bandgap. But how does this band gap relate to conduction and valence bands which explain insulators, semconductors, and conductors as described in the 'band theory for solids' (say) here:  ?  Specifically I wish to use answers to this question to construct a useful visualisation of this aspect - trying to explain to lay people why some solids are transparent and some are semiconductors (or both) and using the bandgap to do so. See a basic, perhaps rushed, explanation of transparency started here:   There are two good reference questions here:  and followup here:   So of course its not just about bandgap but also how classical waves are built up from a quantum substrate and materials with structures smaller than the wavelength of light. That's my visualisation challenge...  I intend to show:   high energy X-rays make many solids appear to be transparent because they are not absorbed vs the energies in IR, visible, and UV light for some materials. photons vs electrons being fired into a material glass structure vs crystal lattics or random structure solids opaque thin carbon vs transparent thick diamond and glass - why is paper opaque at visible light frequencies QED to classical wave showing how one leads to the other and how each model explains transparency Conduction, semiconduction, insulation and bandgaps and their relation to visible light energy transparency and probably some other aspects.   To reiterate my question: How does the bandgap theory of solids link transparency to conduction and valence bands (or other bands) ?  Feel free to suggest mechanisms for visualisation or any other contributing factors to explain this property of QED.


Why does my model turn into a mess when in object mode

Why does it do that when being in object mode?


$\lim_{h\to 0}\int \frac{f(x+h)-f(x)}{h}\,\mathrm{d}x = f(b)-f(a)$

Let $f:[a,b]\to  R$ be integrable and continuous on $(a,b)$. Prove that: $$\lim_{h\to 0} \int_a^b\frac{f(x+h)-f(x)}{h} \,\mathrm{d}x = f(b)-f(a).$$  What I've tried so far: make a change of variables, which didn't help. I also thought of using the intermediate value theorem inside the integral, but the function being differentiable is not specified. Any help, tips? Thanks in advance!


Please limit the number of PPCG questions which can appear on the HNQ

Programming Puzzles and Code Golf is a great site, it's fun to take part and there are some super inventive questions and answers.  That said, too much code golf can be a bad thing. And as I write this, there are 10 PPCG questions on the HNQ. Out of 100:    10% of the HNQ is devoted to a niche site which doesn't really represent what this network is about (Q&A, not puzzles set to the community).  A lot of people here might not browse the HNQ list that often. For anyone on iOS mobile, there is a widget to show you HNQs, and the homepage (Feed) shows them. It's also the homepage of Stack Exchange.  Please add an artificial limit to the HNQ formula to either make it harder for PPCG questions to get on the list, or limit it to (say) 3 on the list. 10% of the list devoted to one site is excessive.


Definition. A subset of $\mathbb{R}$ is called open if it is a union of open intervals.  Example. Show that $\mathbb{Q}$ is not open.  How can I show to use the definition? Can you give a hint?


Is there a physical connection between Lagrangian mechanics and Hamilton mechanics

I know that the Hamilton's equations results from the Legendre transformation of the Lagrange equation.  It's also well-known that the Hamiltonian is equal to the energy of a system if the system is time independent but that is caused by the symmetry of $H$, not because of  the fact that the Lagrange function is given by the kinetic energy plus the potential energy. So is there a concret physical relationship between $H$ and $L$?


Any weakness when performing SHA-256 repeatedly?

Is it significantly easier to reverse a SHA-256 hash if you know that the input was a 32 byte output of SHA-256?  I assume for most outputs of SHA-256 there will be zero, one or two possible 32 byte inputs.  Mapping and storing all of the values is infeasible, but I am still worried that constraining the input to being exactly 32 bytes may weaken SHA-256.  Is this a valid concern?


Only latest value of dictionary getting added to list

Creating a list of dictionaries via a for loop  I've been trying to create a list of dictionaries via a for loop, code shown below  a=["x","y","z"] b=[1,2,3] dict1={} superlist=[] for i in range(0,len(a)):     dict1['name']=a[i]     dict1['values']=b[i]     superlist.append(dict1)   What I'm expecting as my output is  [{'name':'x', 'values':1},{'name':'y', 'values':2},{'name':'z', 'values':3}],   instead I get  [{'name':'z', 'values':3},{'name':'z', 'values':3},{'name':'z', 'values':3}].   I'm not really sure what's going on here and it'd be great if someone can explain and help me get my desired result.


Test whether the endpoints of the interval of convergence should be included in the interval of convergence

Find the interval of convergence including endpoints of $$\sum_{n=1}^{\infty}  \frac{n(x+3)^n}{2^n(n^2+1)}.$$ I can find the interval of convergence but I don't know how to test endpoints $x=-5$ and $x=-1$. I don't know whether the series convergences at $x$ = $-5$ and $x$=$-1$ and need help. I don't think the series converges at $x= -5$ and  $x= -1$.


How can I make vfill to work without adding any text before?

Using \vfill between two texts works:  \newpage bla \vfill blabla   but it doesn't work if there is no text before it:  \newpage \vfill blabla   How can this be achieved?


I tried to apply a Subdivision Surface on a part of my object. I can't keep the angles sharp, they all turn into rounded angles.  The angle before applying the Subdivision surface...   ...And after


How much would it cost in U.S. dollars to brute force a 256 bit key in a year?

I am often told that any key can be broken and that it is only a matter of time and resources for any key to be broken. I know that this is technically true. However, I think that there is probably a point where it makes sense to say a key is uncrackable (for example, if it would cost 100 times the world GDP to crack it, it is essentially uncrackable without the help of an advanced alien civilization, etc.).  How much would it cost in U.S. dollars to brute force a 256-bit key using a strong algorithm such as AES or Twofish in a year?  I would also be curious to know what it would cost to crack a 128 bit key in a year.  I am asking this mostly out of curiosity. I do not know very much about cryptography, so please feel free to pick the algorithm of your choice if that matters. I am interested in how one would project the cost (assume you have to buy the hardware but you get to choose what hardware you buy).


How are two unequal applied forces at the end of a massless string result in a constant tension throughout?

Even when we apply two different forces $(F_1 > F_2)$ at the ends of an ideal rope, the tension produced in the rope is constant throughout the length of the string rather than being a function of its length. I can't understand this concept, I mean taking any arbitrary element in the rope the element would be experiencing two unequal forces at its two ends so how does that make a common tension? Why is tension not equal to the net resultant force $(F_1 - F_2)$? Is tension different than a force?


With new patch(2.0) you have different difficulties and despite which difficulty you are on, you are guaranteed a legendary drop when you finish the quest for the first time. And you can reset quests to get this first-time reward. Also, it seems that all legendaries can roll a lvl 60 stats(got a few low level legendaries with 400-500 stats).  So the question is: which difficulty should I play for the most/best legendaries? Does Torment give you better drops? I can farm Torment without many problems, but it seems that Normal is much more rewarding in terms of legendary drops because I can just fly through it.  EDIT  It also seems that you can reset quests any number of times. So a small addition: Will I get more/better legendaries if I finish the game 2-3 times on Normal than if I would finish it once on Torment difficulty?


Can I install Ubuntu on major OEM systems?

I want to buy a laptop and install Ubuntu on it. Most laptops these days are Windows 10 based, which require a UEFI secure boot, but don't require it to be unlocked.  So I can imagine that most OEMs don't turn it off.  Would I be able to install Ubuntu on a Dell/HP/Lenova computer and (at least) have it boot?


For continuous function $ f:\mathbb S^1 \to \mathbb R$ there exists uncountably many distinct points $x,y$ such that $f(x)=f(y)$

Let $\mathbb S^1$ denote the unit circle in $\mathbb R^2$.      Then prove that for every  continuous function $f:\mathbb S^1 \to \mathbb R$, there exist uncountably many pairs of distinct points $x, y$ in $S^1$, such that $f(x)=f(y)$.


Neutrons have no charge so they would not, I think, interact with photons.  Would a neutron star be transparent?


Let $A,B$ be $m\times m$ matrices such that $AB$ is invertible. Show $A,B$ invertible.   Here is what I have attempted:  We have $AB$ invertible so there exists an $m\times m$ matrix $C$ such that $C(AB)=(AB)C=I_{m}$. Since matrix multiplication is associative we immediately have a right and left inverse respectively: $(CA)B=A(BC)=I_{m}$. I know the fact that I have square matrices needs to play a roll and gaurentees me that the product will be, in general, defined. I have tried to multiply $CA$ and $BC$ on other sides but that didn't get me anywhere.   I've asked myself what would happen if they weren't square and its obvious, by definition, that they would not be invertible but I am not seeing a way to use the fact that they are to gaurentee ourselves a general inverse.


Proving $r^{k}$ is the only nonidentity element of $D_{2n}$ that commutes with all elements for even $n$

I am working on proving that $z = r^{k}$ is the only nonidentity element of $D_{2n}$ ($n = 2k$) which commutes with all elements of $D_{2n}$. I have been able to show that any other power of $r$ cannot commute with $s$. To do this I showed that $$r^j s = sr^{n-j}$$ I understand that $r^j \neq r^{n-j}$, but how can it be assured that $r^j s \neq sr^{n-j}$? I have been reading a solution of this problem that claims from here it suffices to show that $sr^j$ does not commute with $r$ for any integer $j$. Why is this sufficient? How did they choose $sr^j$?


Roulette wheel spins. That is I made it spin (sorry don't know how to say this)  Was the wheel spinned or spined?  How do I say what happened to the wheel once I spin it?


This has been something that I've wanted to ask for quite a while, but I just haven't.   When Ubuntu is being installed there is an option where swap space can be assigned, at least in the custom partition option (in the other options whether it is or isn't, I really don't know). So what is the role of the swap space?   Additionally, in the System Monitor, there is an icon indicating the amount of swap that has been used. Is it the same?


A bob hanging in an accelerating train moves backward. What is the force moving it backward?

When the train accelerates, the bob would also accelerate with the same magnitude and direction as the train. From the free body diagram, only tension and weight are exerted on the bob. I understand how to relate the "horizontal component" of the tension to the acceleration of the bob. It moves "backward" and in fact its vertical position is different from when the train is not accelerating.  I am not sure whether inertia could explain this situation. What is the force moving it backward/ lifting with the height?


Proving orthogonality of vectors in a complex vector space

I'm taking a course in Real Analysis and have come across the following question which I initially thought looked quite simple:  Let $X$ be an inner product space over $\mathbb{K}$ ($\mathbb{K} = \mathbb{C}$ or $\mathbb{R}$) Show that x and y are orthogonal if and only if $||\lambda x  + \mu y||^2 = ||\lambda x||^2 + ||\mu y||^2$ for all $\mu, \lambda \in \mathbb{K}$.  I have proven the statement in one direction (starting with orthogonality and ending up with $||\lambda x  + \mu y||^2 = ||\lambda x||^2 + ||\mu y||^2$). However, I seem to be getting stuck trying to go in the other direction. The following is what I have so far:  $||\lambda x  + \mu y||^2 = ||\lambda x||^2 + 2\bar{\lambda}\mu Re<x,y> + ||\mu y||^2$  Then we must have 2$\bar{\lambda}\mu Re<x,y> = 0$ for the desired equality to hold, and so $Re<x,y> = 0$.   However, for orthogonality I want $<x,y> = 0$ and can't see how I can make this next step.  Any help would be greatly appreciated.


I'm looking for a way to make the D figure in LaTeX. Please help :)


OLS in R with linear inequality constraints on coefficients

What is best way to run OLS in R with linear inequality constraints, e.g.  $$y(x)= ax + b,$$ where $0<a<1$?


"E:Type '<!DOCTYPE' is not known on line 1 in source list" how to fix?

I have recently installed PlayOnLinux on my Ubuntu 13.04, but I am getting a system error:  E:Type '<!DOCTYPE' is not known on line 1 in source list /etc/apt/sources.list.d /playonlinux.list   Please tell me how to fix it.  Here is the html file :  <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org /TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html> <head> <meta http-equiv="refresh" content="0;url=http://airtelforum.com/main?InterceptSource=0& ClientLocation=in&ParticipantID=kk7rp2jf3dkl4v52nla5u7676ej8r6uf&FailureMode=1& SearchQuery=&FailedURI=http%3A%2F%2Fdeb.playonlinux_jaunty.list%2F&AddInType=4& Version=2.1.8-1.90base&Referer=&Implementation=0"/> <script type="text/javascript">url="http://airtelforum.com/main?InterceptSource=0& ClientLocation=in&ParticipantID=kk7rp2jf3dkl4v52nla5u7676ej8r6uf&FailureMode=1& SearchQuery=&FailedURI=http%3A%2F%2Fdeb.playonlinux_jaunty.list%2F&AddInType=4& Version=2.1.8-1.90base&Referer=&Implementation=0";if(top.location!=location){var  w=window,d=document,e=d.documentElement,b=d.body,x=w.innerWidth||e.clientWidth||b.clientW idth,y=w.innerHeight||e.clientHeight||b.clientHeight;url+="&w="+x+"& h="+y;}window.location.replace(url); </script> </head><body> </body> </html>


Most of the time, it should be really easy to determine who is my ally and who is not. The people who try to kill me are most likely my foes, whereas the people who entered the dungeon with me are probably my allies.   But sometimes it’s not that simple. What if one of my party members got replaced by an evil doppelganger, who plans to kill me in the near future? What if one of my allies infiltrated the court of the evil king and I accidentally have to fight her, while she is (unbeknownst to me) under the effect of a  spell? What if a character fell in love with the BBEG and just wants to save him from himself, while the BBEG hates the character and actively tries to murder him?  Most spells and abilities that affect others specify the targets as “creatures” or “willing creatures”. Some explicitly affect allies only. That’s why I want to know, how to determine who’s allied with whom. Do I have to think that someone is my ally for someone to count as my ally? Does someone else have to believe to be my ally in order to count? Do both of us have to agree on being allies? Is there an objective observer who determines who’s allied? Can Person A be the ally of Person B, while Person B is not the ally of Person A?  There are many examples for spells/abilities that care about allies, among others:   the Exalted Champion feature from the  (SCAG, p. 132-133), that grants allies within 30 feet advantage on Wisdom saving throws. the Inspiring Surge feature from the  (SCAG, p. 128), that allows one or two allies within 60 feet to make a melee weapon attack as a reaction.   With features like this, you could accidentally affect someone who’s not actually your ally. You could fail to affect someone who is actually your ally, but you don’t know it (yet). Or you could affect someone who doesn’t want to be affected (because they don’t want to be allied with you). This all depends on the interpretation of the word “ally”. I’m not sure if "ally" is a defined game term (but I don’t think so), or if I have to rely on the dictionary definition. That’s why I want to ask:  How do I determine who’s allied with whom?


How to output string completions to stdout?

Some of the git commands have many options, and it would often be useful to search through them for the one I need - I was just looking for the option which controls the TAB width in git-gui, but there are about 200 completions for git config. An obvious workaround is to copy all the completions into an editor and search through them, but I'd rather do  [something] | grep tab   There are no man or info pages for compgen, help compgen doesn't even explain its own options, and there's no auto-complete for compgen (how's that for irony?).  PS:  doesn't work.  PPS: This is not a question about git-gui - The  was elsewhere.  PPPS: This is not about auto-completing commands, only command parameters.


I have some figures like this:  I want to use one caption for each pair like the figure. Note: I can not use the subfigure and subcaption package. Best


Is associativity implicated by commutativity

I definitely feel like an idiot because of the fact that I have to ask you the following question, but anyway I just don't know any other option. If just proven two things which are the opposites of each other, so at least one of my proofs have to be wrong. I tried to solve the following problem:       Definition: $a \boxplus b = 2a+2b$. $\boxplus$ is commutative.   Is $\boxplus$ assosiativ?   So I found two ways to solve the problem: 1. per definition We want to show $(a \boxplus b) \boxplus c = a \boxplus (b \boxplus c)$. $(a \boxplus b) \boxplus c = (2a+2b)*2+2c = 4a+4b+2c.$ And on the other side $a \boxplus (b \boxplus c) = 2a+2(2b+2c)= 2a+4b+4c$ $4a+4b+2c \neq 2a+4b+4c$. So $\boxplus$ is not assosiative.    2. Show that commutativity implicates associativity We want to proof $ (a \circ b) \circ c = a \circ (b \circ c)$ [$\circ$ shall be commutative] $ (a \circ b) \circ c = a \circ b \circ c = b \circ a \circ c = b \circ c \circ a = (b \circ c) \circ a. $    I know that my mistake have to look stupid and obvious, but I just can't see where I'm wrong. Thank you all for helping me!


How likely are Primordial Black Holes to form in the early universe?

In the very early universe, tiny fluctuations created slight over- and under-densities in mass/energy. As far as I understand, if a region becomes sufficiently over-dense, a primordial black hole (PBH) would form. This might be very very unlikely, but it should have some non-zero probability everywhere in space.  So my question is:  A) Do we have any sense of how many of these PBHs to expect?  B) The power spectrum was essentially flat back then, which I believe means that the size of fluctuations were scale-invariant (the average over-densities on one scale are twice as big as those at half the scale). Does this mean that PBHs are equally likely to form of any size ??  C) Does inflation have anything to say about this?


What EXACTLY happens when I ask to delete my account?

I have meticulously read through similar questions, answers and their comments but I still do not understand how the deletion is done. From what I understand I email the customer service and then they do what exactly?     1) They disable my account so that I can no longer use it?      2) They reassign all of my questions and answers to some other   account? To which one?      3) They delete all my questions and answers so that they go away from   public view?   What is the flexibility (if it exists) of the deletion procedure? Is it possible to erase the traces of my former association with the site. Can I request any of the following be done?     4) All of my questions and answers be deleted from public view?      5) Some of my questions and answers be deleted? If yes what criteria?      6) Can I have all of my contributions be assigned to some other   account which runs as sort of a "collective account" and already has   tons of content so that it doesn't happen like my contributions just   move to some other url but still stay grouped under that location and   therefore that location can be discovered as representing my account?      7) Can I have my contributions dispersed through several "collective   accounts?      8) Can my current public name be removed from any comments to my posts   so that my posts cannot be identified later as once belonging to me?   Please be polite with me. I wouldn't have asked if I have found the answer in the other questions. The other questions are also old and it is not clear what the situation is as per 05/2012.  UPDATE (for those interested):  I asked the Stackoverflow team about the procedure. Apparently none of the points 2-8 I asked above are possible, only 1 will take place. The link to my user page from my contributions is going to be removed and replaced with non-clickable text of an anonymized user name like "user1234". Whether this number is the same as my current user_id is not clear. That's all the information I got.  I'm going now to rename myself to "Anonymous" then request the account deletion. Those interested in the procedure will witness the exact result on this page.  Farewell.


Front page is not loading - tag search error

The front page of  wasn't loading yesterday for a good five minutes with the following error message:     It was not possible to perform this tag search at this time due to an unexpected error.  What's that about?


How do I disable automatic remote printer installation?

In Raring, everytime I connect to the network, Cups installs all the printers in the network automatically, some more than once.  Furthermore, I connect a USB printer to the laptop every now and then. Even though the printer is configured already, another printer is added to the list.  I wish to disable this feature and allow only manual installation of printers. How do I go about it?


Is 'fsck error on boot' hardware related or a bug?

I bought a Razer Blade Stealth a week ago, took windows off and installed Ubuntu 17.10. Used until today when it started saying that my hard disk was write protected while I tried to save simple files. Then I reboot and this happens:  fsck error on boot: /dev/...: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY   for my root partition. I found several answers here telling me to run fsck. I did and it fixed for some time, but then the error happened again.   I just want to know if this is hardware or software related, and if I should worry, or if this is just a bug in the 17.10 version. I'm downloading 17.04 now.


connected subspaces need to lie in one separated component

Let ($X,\tau)$ be a top space. Suppose $Y \subset X$ is a connected subspace given the subspace topology. If $A \cup B$ is a separation of the space $X$ then $Y$ lies entirely in $A$ or $B$. I just want a verification: Suppose other wise then $\exists a \in Y$ such that $a \in A$ and $\exists b \in Y$ such that $b \in B$. I claim that $$Y \cap X = Y \cap (A \cup B) = (Y \cap A) \cup (Y \cap B)$$ Forms a separation of $Y$. As $Y$ inherits the subspace topology, the topology on $Y$ can be given by $$\tau_Y = \{Y \cap U \mid U \in \tau\}$$ Then since $A,B \in \tau$ we have that $Y \cap A,Y \cap B \in \tau_Y$, i.e., are both open in $Y$. Clearly both are nonempty by existence of $a,b$ up top. Lastly for disjointness, suppose $\exists \alpha \in (Y \cap A) \cap (Y \cap B)$, then $\alpha \in A \cap B$ contradicting $A,B$ being disjoint (since they were assumed to form a separation of our parent space) and thus $$(Y \cap A) \cap (Y \cap B) = \emptyset$$ hence $$Y = (Y \cap A) \cup (Y \cap B)$$ forms a separation of $Y$ contradicting it being a connected subspace $\blacksquare$


Can I claim a route longer than the number of trains I have left?

On the last move, after only 2 train pieces remains, is it possible to claim a 3-carriage route, if you have the 3 required color cards but only 2 plastic trains left to place on the board?


What is the relation between potential energy & electric field?


The preimage of convergent bounded linear functional images

I have a question that could be trivial:  Let $X$ be a Banach space, with a sequence $\{x_n\} \subset X$. If $\forall f \in X^*, f(x_n) \to 0$, is it true that $x_n \to 0$ in $X$?  My idea is to first prove that $x_n$ should be convergent, and then use contradiction to prove that $x_n \to 0$. But I don't know what should be the whole picture of the proof. Thanks in advance!


How do I prevent/stop Gmail's right-click opening a New Message panel?

, is the same issue I've been having.  What happens is when I right click an email address within an email message, Gmail opens a new message. I want to disable this. How do I do that?   NOTE:  this is using Gmail in Chrome.  I opened Gmail in Firefox and I don't have the problem. Here are some screenshots:  Email in Chrome:    Email in Firefox:     While I can just use Firefox, I'd REALLY like to figure how to disable this in Chrome.


s3unichrome 3D gpu 256mb of ram can upgrade to 512mb AMD sempron 3100+ @ 1.8ghz  100gb hhd  emachine  t3104   The computer runs Windows XP but slowly and it crashes. It is about 13 years old and has the original Windows install.


Giving server-role to login breaks stored procedures

I have a login called user1. user1 can execute stored procedure [Test].[SP1]  EXEC [Test].[TestSortation] EXEC [TestSortation]   Both of the above commands work.  Now if I give the user1 the server role of sysadmin in addition to public. the later of the 2 statements above fails, and throws this error:     Could not find stored procedure 'TestSortation'.   I don't want to have to change every stored procedure in the database to have the schema name included with EXECute commands manually. Can someone explain to my why this is happening. Also, is there a way to get around this, automatically fix my stored procedures, have the schema default to [Test]?


The following code should find the appropriate project tag and remove it from the XmlDocument, however when I test it, it says:  The node to be removed is not a child of this node.  Does anyone know the proper way to do this?  public void DeleteProject (string projectName) {     string ccConfigPath = ConfigurationManager.AppSettings["ConfigPath"];      XmlDocument configDoc = new XmlDocument();      configDoc.Load(ccConfigPath);      XmlNodeList projectNodes = configDoc.GetElementsByTagName("project");      for (int i = 0; i < projectNodes.Count; i++)     {         if (projectNodes[i].Attributes["name"] != null)         {             if (projectName == projectNodes[i].Attributes["name"].InnerText)             {                                                                 configDoc.RemoveChild(projectNodes[i]);                 configDoc.Save(ccConfigPath);             }         }     } }   UPDATE  Fixed. I did two things:  XmlNode project = configDoc.SelectSingleNode("//project[@name='" + projectName + "']");   Replaced the For loop with an XPath query, which wasn't for fixing it, just because it was a better approach.  The actual fix was:  project.ParentNode.RemoveChild(project);   Thanks Pat and Chuck for this suggestion.


Build pre-signed AWS S3 URLs with Named Credentials

I'm building an integration with S3 and I want to create a pre-signed URL so I can access S3 from SF with a single user. I use the method below to generate a URL: public static string getSignedURL(string file, String bucketName, String accessKey, String secretKey, String state) {     String filename = EncodingUtil.urlEncode(file, 'UTF-8');     Datetime now = DateTime.now();     Datetime expireson = now.AddSeconds(60);     Long Lexpires = expireson.getTime() / 1000;      String stringtosign = 'GET\n\n\n' + Lexpires + '\n/' + BucketName + '/' + filename;     Blob mac = Crypto.generateMac('HMacSHA1', blob.valueof(stringtosign), blob.valueof(SecretKey));     String signed = EncodingUtil.base64Encode(mac);     String url = 'https://' + BucketName + '.s3.us-east-1.amazonaws.com/' + filename + '?AWSAccessKeyId=' + AccessKey + '&Expires=' + Lexpires + '&Signature=' + signed;     return url;  }  The method works, but the downside as you can see is that I need to send my accessKey and secretKey and I wish to avoid that. So I want to use a Named Credential to authenticate, and then I want to call my method getSignedURL(). But I don't know how I can pass the secret and key to the getSignedURL() method using a Named Credential. I didn't find a merge field related to AWS Signature Version 4 in the . I was hoping to find something like: {!$Credential.acessKey} {!$Credential.secretKey}


g++ Undefined reference in templated class

I am puzzled...  This is the *.h-file:  #include <string> #include <vector>  template<typename T> class pvector { private:     std::string filename;     std::vector<T> v;     void readvector();  public:     pvector(std::string fname) : filename(fname) { readvector(); }     void push_back(const T &el) { v.push_back(el); }     void pop_back() { v.pop_back(); } };   And this is the *.cpp:  #include <fstream> #include <string> #include "pvector.h"  using namespace std;  template<typename T> void pvector<T>::readvector() {     ifstream ifs(filename);     for(;;)     {         T x; ifs >> x; if(!ifs.good()) break;         v.push_back(x);     } }       If I want to generate the following object:  pvector<string> myVec("testfile.txt");   ... i get:      pvector.h:24: undefined reference to `pvector::readvector()'   Why???


Mapping R ARIMA parameters to coefficient symbols

I'm trying to map the information R prints for an ARIMA model to the coefficients in the formulas that I'm familiar with. Here's what I have so far   ar1 = $\varphi_1$, ar2 = $\varphi_2$, ... intercept = $c + \varepsilon_t$ ??? ma1 = $\theta_1$, ma2 = $\theta_2$, ... mean = $\mu + \varepsilon_t$ ??????   where an AR(p) model is defined as  $X_t = c + \sum_{i=1}^p \varphi_i X_{t-i}+ \varepsilon_t$  and an MA(q) model is given by  $X_t = \mu + \varepsilon_t + \sum_{i=1}^q \theta_i \varepsilon_{t-i}$  Note: I have read , but it doesn't discuss the "intercept" and "mean" parameters.


Are there tools for importing from CSV to BibTeX?

I'm seeking a way to get my books database, stored on , into BibTeX form. As near as I can tell, Goodreads provides no support for this directly, but does provide for  (on the right). Are there tools I could used to import from the CSV file into BibTeX?    FWIW, the fields exported by goodreads are  Book Id,Title,Author,Author l-f,Additional Authors,ISBN,ISBN13,My Rating,Average Rating,Publisher,Binding,Number of Pages,Year Published,Original Publication Year,Date Read,Date Added,Bookshelves,Bookshelves with positions,Exclusive Shelf,My Review,Spoiler,Private Notes,Read Count,Recommended For,Recommended By,Owned Copies,Original Purchase Date,Original Purchase Location,Condition,Condition Description,BCID   and I can, of course, easily rearrange their order or convert to other delimiters.


How do I use another partition as home post-installation?

I have a home partition from a previous installation that I grew out of (zorin os, really slow boot time) and now I have a kubuntu install that I just recently created. My question is: How do I both transfer the packages from the previous installation (all applications) and use the users from the old home for the new installation? In the past, simply mounting the partition as home has not created the new users, it has simply created a new user during install, and when I've tried creating a second user, deleting the home folder of that user and putting a shortcut to the other folder renamed to the same name, it has not gotten past the logon screen for that user. Is there something that I'm missing here?


How can I deep copy an irregularly shaped 2D array in Java?  Ie.  int[][] nums =  {{5},                  {9,4},                  {1,7,8},                  {8,3,2,10}}   I'm unable to use Arrays.arrayCopy() for some reason (versioning?)


How to call Apex REST API from Javascript?

I have two different developer orgs. One contains apex REST web service, and I want to call that REST service from my second org. I have tried to call that REST service using normal ajax post request and forcetk.js, But I got following error     XMLHttpRequest cannot load   . Origin    is not allowed by   Access-Control-Allow-Origin.   I searched about this problem then I got to know that Salesforce never allows CORS (Cross-Origin-Resource-Sharing).  Initially I was using apex to call that REST web service, that time I was able to post data from apex. But as we have callout limitation in salesforce, I want to use javascript.  Can anybody please help me?


How do subatomic particles have mass, velocity, spin etc if they are waves?

I don't think I understand the concept of sub-atomic particles very well. How can an electron or any sub-atomic particle have mass and spin if they are waves?


So I'm creating an animation and I've faced a serious problem. There's a moving object and I want a rope to be attached to this object while its moving, and the other end of the rope should be connected to somewhere else offscreen. I've used some techniques I've seen on youtube. But none of them were good for my case. Some tips would be appreciated.


I want to travel to Berlin several times in the next few months. I want to avoid the busiest times, when there are big events like IFA or Berlin Marathon because hotels get more expensive then.  Is there a reliable and comprehensive list of (only) big events that influence hotel availability and prices considerably?    Sure I can find lists of all events, but then I don`t know which are the dangerous ones...


Are duplicate questions acceptable across sites?

I am still pretty new to Stack Exchange. I have posted a couple of questions that have not gotten very good answers. If I post an question on one site, and it does not a good solution, is it acceptable to post a duplicate question on another community?  Example:  I posted an issue I was having with the OS X terminal and finding the right port on Stack Overflow. I got a few answers, but nothing that good. The problem was with an Arduino port, so is it acceptable to post a duplicate answer on the  or  since they would know more about Arduinos and terminal issues?


proof that on a compact manifold a vector field is complete

I would like to know if my proof of the following statement is correct     If $M$ is a compact manifold, then every vector field $X$ over $M$ is complete.   Proof:  I take $p\in M$ and $(\gamma_p,I_p)$ a maximal integral curve through $p$. $I_p$ is open and non empty so if $I_p$ is closed, it is equal to $\mathbb{R}$.  So take $s\in \text{Adh}(I_p)$. There exists $t_i\rightarrow s, t_i\in I_p$. Define $q$ as $\text{lim}(\gamma_p(t_i))$ and take a maximal integral curve passing by $q$ as $(\gamma_q,I_q)$. Then since the vector fields are $C^\infty$, $\gamma_q(I_q)\cap\gamma_p(I_p)$ is nonempty (intuitively, this is clear but don't really know how to show it).  On the intersection, $\gamma_p$ and $\gamma_q$ coincide. So we can extend the maximal curve $\gamma_p$ to include $\gamma_q$. This implies that $q\in\gamma_p(I_p)$ and is actually equal to $\gamma_p(s)$  I think the main idea is there even though it probably lacks a bit of rigour.


Construction of an infinite hierarchy of sets using types.

This is not a duplicate of , because the linked question asks about the existence of a something larger than class. My question is about a construction of an infinite series of $\mathrm{Class}_1, \mathrm{Class}_2, \mathrm{Class}_3, \dots$ by a specific repeatable method using types.    The collection of all sets is a class. I think we can collect classes and continue this process as follows:   The collection of all sets is $\mathrm{Class}_1$. The collection of all $\mathrm{Class}_1$ is $\mathrm{Class}_2$. The collection of all $\mathrm{Class}_2$ is $\mathrm{Class}_3$.   ...    First, let's look at how to construct natural numbers.   Let $\mathrm{N}$ be the type of natural numbers. $1:\mathrm{N}$ . If $n:\mathrm{N}$, then $\mathrm{suc}(n):\mathrm{N}$ . All terms of $\mathrm{N}$ are constructed by repeating rules 2 and 3 finitely.   In addition to this, we need to define propositions and axioms of them:   $a:\mathrm{N}, b:\mathrm{N}\vdash a=b:\mathrm{Prop}$ . $\forall n:\mathrm{N}. [\mathrm{suc}(n)\neq 1]$ is true. $\forall m:\mathrm{N}. \forall n:\mathrm{N}. [a\neq b\Rightarrow \mathrm{suc}(a)\neq \mathrm{suc}(b)]$ is true. If $\varphi(1)$ and $\varphi(n)\Rightarrow \varphi(n+1)$ are true, then $\forall n:\mathrm{N}. [\varphi(n)]$ is true.   In summary, the above process has 6 parts:   Define a type $T$. Define initial terms of $T$. Define construction rules of $T$. The extension of type $T$ is the closure of 2 and 3. Define the propositions of $T$. Define the axioms of $T$.     Let's construct $\mathrm{Class}_1$.  The initial term of $\mathrm{Class}_1$ is $\emptyset$.  The construction rules are    $A:\mathrm{Class}_1\vdash \mathcal{P}(A):\mathrm{Class}_1$ $A:\mathrm{Class}_1, B:\mathrm{Class}_1\vdash A\cup B, A\cap B, A\times B, A\coprod B:\mathrm{Class}_1$ $A:\mathrm{Class}_1, (x:A(\varphi(x)):\mathrm{PropositionInContext}_1\vdash \{x\in A| \varphi(x)\}:\mathrm{Class}_1$   etc.  The axioms are something like this:   $A:\mathrm{Class}_1, B:\mathrm{Class}_1\vdash \forall x: \mathrm{Class}_1 (x\in A\cap B\Leftrightarrow x\in A \wedge x\in B)$ $A:\mathrm{Class}_1, B:\mathrm{Class}_1\vdash \forall x: \mathrm{Class}_1 (x\in A\cup B\Leftrightarrow x\in A \vee x\in B)$ $A:\mathrm{Class}_1, (x:A(\varphi(x)):\mathrm{PropositionInContext}_1\vdash \forall x:\mathrm{Class}_1(x\in \{x\in A| \varphi(x)\}\Leftrightarrow x\in  A \wedge\varphi(x))$   etc.  The extension of $\mathrm{Class}_1$ is the closure of above rules. Let $\mathrm{Ext}(\mathrm{Class}_1)$ be this set. $\mathrm{Class}_2$ is constructed similarly but its initial term is $\mathrm{Ext}(\mathrm{Class}_1)$. Generally, the initial term of $\mathrm{Class}_{n+1}$ is $\mathrm{Ext}(\mathrm{Class}_n)$.    Is it possible to construct an infinite series of classes this way?


I was reading a book on C programming language where I found:  #define cat(x,y) x##y #define xcat(x,y) cat(x,y)   calling cat(cat(1,2),3) produces error whereas calling xcat(xcat(1,2),3) produces expected result 123.  How are both working differently ?


What does a "well ordering on $\Bbb R$" mean?

A well order is a poset such that every non empty subset of this set has a least element. Does "well ordering on $\Bbb R$" mean that every non empty subset of $\Bbb R$ (which is a poset) has a least element?


Our Professor said that : "A, an and the can all be used to indicate that a noun refers to the whole class which individual countable nouns belong"  which I didn't quite understood. doest that mean I can use a for example with the plural noun people if I'm talking about people in general? or what exactly?


Deleting Lines Containing a Specified String in Different Files

Suppose there are two files in web/ named foo.php and bar.php. The 1st line of foo.php is "sdajgeSTRINGdsad" and the 10th line of bar.php is "gdfhu98324STRING". The task is to first locate these two files, then delete 1st line of foo.php and 10th line of bar.php given that the specified string is "STRING".


Assuming I have a hollow shell with total mass $M$ and radius $r$. On the surface, the gravitational time dilation would be  $$\tau=t \cdot \sqrt{1-\frac{v_{esc}^2}{c^2}}$$  where  $$v_{esc} = \sqrt{\frac{2 \cdot G \cdot M}{r}}$$  but inside the shell there would be no gravitational field (Newton's shell theorem and Birkhoff's theorem).  But still, the escape velocity required to escape to infinity would be the same as on the surface, since inside the shell you could move without any accelerating or decelerating forces acting on you until you reach the surface, from where you would get pulled backwards.  So is the time dilation inside the hollow shell relative to a field free observer at infinity    zero (I assume it's not) or  the same as on the surface (my best guess), or something completely different?   I found some not really duplicate but related threads on the interior of black holes which did not really focus on the math, but I am more behind the calculations in terms of $M$ and $r$.


why all constant functions are continuous.$?$

I have read that if we let $(X, \tau_x)$ and $(Y, \tau_y)$ be topological spaces, and  $f: X \rightarrow Y$ is constant, then f is continuous. Can anyone please explain why? I assume we must look at the preimage of the open sets in $(Y, \tau_y)$..?  Thanks in advance


If $(I-T)^{-1}$ exists, can it always be written in a series representation?

If $X$ is a Banach space, and $T:X \to X$ is a bounded linear operator with norm < $1$, then $I-T$ has a bounded inverse defined by $(I-T)^{-1} = \sum_{n=0}^\infty T^n$.   Thinking in terms of a converse, if $T$ is any bounded linear operator defined on $X$, then does the existence of a bounded inverse $S=(I-T)^{-1}$ imply that $S$ can be represented as $S=\sum_{n=0}^\infty T^n$?


I edit e-books in e-pub format. I use CSS to do the book layout. I am confronted with a table column alignment problem, and I have no cue as to how to deal with it. The table has text headings for each column, and then numerical content of the cells. The column width is set by the heading, which makes in some cases the column very wide as compared to the cells contents.  I want to right-align the numbers in the column to their last digit. But I would like them to be placed more to the center of the column. The "text-align: right" command aligns the numbers at the right side of the cell. Is there a way to shift all the numbers towards the center while keeping them all right-aligned to the last digit?


In physics text books, it has only stated that Earth cooled down and so, water vapour condense and other life form develop and et cetera. But, why did Earth cooled down in the first place? What caused it to cool down?   In addition, when the Earth cooled down, did the water vapour condense to possible 'raw' magma/lava and then, creating the tectonic plates?


WordPress site hacked, recovered but Google still has hacked page description

My website got hacked recently and recovered it. It was populating casino ads on my website. There were virtually made URLs where casino pages were displayed.  I suspected the code came through a plugin and by taking help from the communities I was able to recover my website. But Google still has the pages (a lot of them) indexed. I resubmitted a request to crawl the full site a few weeks back, but still those are there. A site: search with casino keyword still displays the URLs. I am worried that my website's reputation will go down. Already a fall in traffic is noticeable.  I have removed everything from the database tables, disavowed links etc. But there are lots of links and I really do not want the contents to be removed from Google. To make you clear, the contents of the pages are there, the bug only changed the description and the title of the pages.


Problem regarding isometric isomorphisms

I need help regarding the following two exercises:     a) Show that $(\mathbb R^2, d_2)$ and $(\mathbb R,d_1)$ $d_2,d_1$ being the respective euclidean metrics, are not isometric isomorphic, i.e. there is no bijective isometric map between those metric spaces.   b) Let d be the restriction of the euclidean metric of $\mathbb R$ on $(-1,1) \times (-1,1)$. Find a metric $d':\mathbb R \times \mathbb R\to \mathbb R$ such that the spaces $((-1,1),d)$ and $(\mathbb R,d')$ are isometric isomorphic.   For a) I think I have solution but I am not really sure: Does it suffice to say that for every possible candidate $f$ for an isomorphism it can't be injective since it must be norm preserving, i.e. $$||f(x)||_2 = ||x||_2, \quad ||f(-x)||_2 = ||-x||_2 = ||x||_2$$ with $||\cdot||_2$ being the respetive euclidean norm?   For b) I don't really know how to start.


How does shyvana's q proc on-hit item effects

Twin Bite - Shyvana strikes twice on her next attack.  Dragon Form: Twin Bite cleaves all units in front Shyvana. Shyvana strikes twice on her next attack, dealing (+0.8/0.85/0.9/0.95/1.0) physical   damage on the second attack.  The bonus damage is equal to 80/85/90/95/100% of Shyvana's Attack Damage.`  Dragon Form: Twin Bite cleaves all units in front Shyvana. Cost No Cost Range 0   does this mean, Wit's End or other on-hit items will proc twice?  To Mind jumps: Black Cleaver Wit's End Executioners Calling BotRK    and the list goes on...


Can virus and bacteria move on the surface?

Do viruses/bacteria have some motive mechanism? I mean if the virus/bacteria reach some surface by touching, can it move on that surface?    Life example: suppose the cooler is not so clean and has some viruses on his surface. My cup came into contact with the cooler in some little area, so virus migrated to that little area of my cup. Can the virus eventually move to another area of my cup's surface? Or can I be sure that it remained at the point of contact? If yes, is this also true for bacteria?  P.S. obviously parasites can move, but I can't figure out are the viruses and bacteria can..


Where can I check what version of the Linux Kernel is released for 12.04?

Well I am using a newer kernel on my Ubuntu 11.10 as the stable 3.0.0-14 version was causing laggy sound on my PC. After upgrading my kernel to the latest version for the 12.04 Alpha (3.2.0-8) the sound issue was solved. I upgraded by temporarily changing my sources to 12.04 ones, upgrading kernel, then switching back. I would like to know how to check which is the latest version of kernel for 12.04 so I can know when I should upgrade.


I am just curious: Are there any 64 bit Linux systems, which support a 32 bit version of Apache? As far as I know, a 64 bit Linux system supports only an Apache 64 bit and a 32 bit Linux system supports only an Apache 32 bit.  Edit  My motivation was just to know, if and which Linux distribution also provide 32 bit packages for applications and / or libraries.


I am writing a pig latin converter that takes a string as a command line argument and converts each word in the sentence into pig latin. I am trying to break up the string into individual words by finding spaces, but the output I get with the below code... honestly makes no sense.   It works for the first word, but then doesn't convert any subsequent words. So "test this string" becomes "esttay this ay string ay."  At this point we haven't covered vectors, so the solution has to be relatively simple.  Any ideas?  #include <iostream> #include <string>  using namespace std;  void convertSentence(string sentence); string pigLatinWord(string input); bool isVowel(string input);  int main(int argc, char* argv[]) {      if(argc != 2) {         cout << "USAGE: " << argv[0] << " \"[sentence]\"" << endl;     } else {         string sentence(argv[1]);         convertSentence(sentence);     }      return 0; }  void convertSentence(string sentence) {     string word = "", remainder = sentence, pigLatin = "";      for(int i = sentence.find(" ",0); i != string::npos; i = sentence.find(" ",i)) {         word = sentence.substr(0,i);         pigLatin += pigLatinWord(word) + " ";         sentence = sentence.erase(0,i);         i++;     }      pigLatin += pigLatinWord(sentence);     cout << pigLatin << endl; }   string pigLatinWord(string input) {      string word = "";  // If the first letter is a vowel, simply add "yay" to the end of it.        if (isVowel(input)) {             word = input + "yay";  //If the first letter is a consonant, add the first letter to the end, //delete the first letter, then add "ay." - Credit to Tyler Sorrels //CString/String solution post on Piazza. I had issues working with //substrings, and this ended up being easier to read. //But I did add a check for words that start with two consonants //to cover all cases.     } else {         input += input.at(0);         input = input.erase(0,1);         word = input + "ay";     }      return word; }  // Checks if the first letter of the word is a vowel. // Returns true if yes, false if no. bool isVowel(string input) {      return ((input[0] == 'a') || (input[0] == 'e') || (input[0] == 'i') || (input[0]      == 'o') || (input[0] == 'a')); }


How can I use TikZ (+ LuaTeX), PSTricks, MetaPost, Asymptote, etc. to draw the convex hull of a set of points specified in no particular order?  Here's an example where the convex hull was computed by hand:  \documentclass[png]{standalone} \usepackage{tikz} \begin{document} \begin{tikzpicture}   % doesn't work:   %\draw[mark=*] convex hull[points={(0,0),(1,1),(2,2),(0,1),(2,0)}];    %should produce something similar to the following:   \draw (0,0) -- (0,1) -- (2,2) -- (2,0) -- cycle;   \foreach \point in {(0,0),(1,1),(2,2),(0,1),(2,0)} {     \fill[black] \point circle[radius=1pt];   } \end{tikzpicture} \end{document}


How to prove $|x − y| ≤ |x| + |y|$, proof and reasoning

Prove that, for all $x, y ∈ \mathbb{R}$, we have $|x − y| ≤ |x| + |y|$. Can I say . $|x − y|^2 ≤ (x − y)^2$, and work from there? Thank you


How do I replace a video on YouTube and keep the same URL?

I want to replace it with a version that has better quality. I do not care about the  view count, comments or ratings.


How to set the transparency for multiple layers or add a global transparancy preference?

How can I set the transparency to 27 % for all 245 layers in QGIS? The only way I know of is by right clicking on the layer name, selecting Properties, then Transparency and then moving the transparency slider left or right.    This is simple enough. But this is only good for up to 10 layers maybe. What if you have 245 layers like I do? Do you just keep on repeating the process? Now surely, there there must be a way to apply this to all 245 layers at once!?    Alternatively, is there a global transparency preference setting I can add in so that when I add new layers they automatically get 27 % transparency?  The QGIS online  mentions something about exporting your transparency setting to a file for a later use.     As you can see this is quite easy to set custom transparency, but it   can be quite a lot of work. Therefore you can use the button Export to   file to save your transparency list to a file. The button Import from   file loads your transparency settings and applies them to the current   raster layer.   This seems like a useful feature. But I don't think this is what I'm looking for.  I tried selecting multiple layers in the table of contents and then right click and select Properties and set the transparency level, apply changes and click OK. It applied the changes, but only to the last layer in the selection, the one I right clicked on. None of the other layers in the selection were affected. (This could be a bug actually.)


generate random num thats less than or greater than “x”

i am mking a program where the computer guesses your number. and it has to guess a random num. but how do i make the random line be lower or higher num than the perviously num guessed?  package compguse; import java.util.*;  public class Compguse {   public static void main(String[] args) {     Scanner scan = new Scanner (System.in);     String a;     String b;           String c;     String ans;     String d;             int input =1;     System.out.println("do u have your number?");     a = scan.nextLine();     while (a.equalsIgnoreCase("yes"))     {     int ran = (int) Math.floor(Math.random()*100)+1;         System.out.println(" is" +ran +" your num?");           a = scan.nextLine();         if(a.equalsIgnoreCase("no"))         {             System.out.println("Was i too high or low?");             b = scan.nextLine();             if(b.equalsIgnoreCase("high"))             {             int ran1 = (int) Math.floor(Math.random() < (int) ran);              }             }            } }


Transfer Function of Active Notch Filter

I have rigged up a notch filter from . See below: -     Its the first circuit. Now I am trying to calculate its transfer function. I have calculated two equations, but I need the third one:   (Vin-V2)/(1/SC1) = V2/R3 (Vin-V1)/R1 = (V1-Vo)/(R2+(1/SC2))   V1 and V2 are the potentials at the input of the op-Amp.


How to add a database index to a base field

Goal:  Add a database index to a 'created' field.  Given:  There is a custom entity with a base field created. The field is stored the entity table.  Field source code of the created field:  $fields['created'] = BaseFieldDefinition::create('created')   ->setLabel(t('Created'))   ->setDescription(t('The time that the entity was created.'))   ->setDisplayOptions('view', [     'label' => 'hidden',     'type' => 'timestamp',     'weight' => 3,     'settings' => [       'date_format' => 'medium',       'custom_date_format' => '',       'timezone' => '',     ],   ])   ->setDisplayConfigurable('view', TRUE);   What I researched:  I have not found a way to add index using the \Drupal\Core\Field\BaseFieldDefinition().  As I understand indexes are defined in a @FieldType plugin. The created field is implemented via the \Drupal\Core\Field\Plugin\Field\FieldType\TimestampItem() plugin and obviously does not have have indexes there.  P.S. I know, that I can write an updatescript to add an index to the table manually.


My Windows 10 search box is black! It doesn't search anything.  I remember that shortly before this happened, I was annoyed with Cortana and toyed with the idea of disabling it. I didn't actually disable it and am not sure I changed anything. So I'm not sure if this is related or not.  I've tried using System Restore to back up to a time before the problem started. It didn't help. I've also found a lot of material online about blank search boxes. Judging by the images with that material, it seems to be a different problem. In any case, I've tried a lot of the suggestions for that problem. But they don't help either.  How can I fix this?


Received Notification of my server be involved in "DNS amplification attack". How can I stop?

I just received an email from my website internet provider that my server has been "involved as open resolvers in DDoS attacks (DNS Reflection) over the past few weeks."  Here is the full email:     Subject: DNS amplification attack  Dear Sir or Madam,      We have received spam/abuse notification. Please take the necessary   steps to prevent this from happening again in future.      Furthermore, we would request that you provide both ourselves and the   person who has submitted this complaint with a short statement within   24 hours. This tatement should include details of the events leading   up to the incident and the steps you are taking to deal with it.      Next steps:   - Solve the problem   - Send your statement to us   - Send your statement to the person making the complaint per email      The details will then be checked by a colleague, who will coordinate   further proceedings. In the event of several complaints, this may lead   to the server being locked.   ----- attachment -----      Dear Sir or Madam,      We have been informed that IP addresses from your network range have   been involved as open resolvers in DDoS attacks (DNS Reflection) over   the past few weeks.      Please see the attachment to this message for the IP addresses of the   open DNS servers in your network range.      ----- log file -----      Affected IP: 176.9.1.67      Thank you,   What can I do to confirm this and to identify the origin of this attack?  Thanks Eco


Say I have a list/array:  list=(a b c)   how can I echo each element to xargs? Something like:  for v in list; do echo v; done; | xargs   is there a less verbose way?


How do "environment variables" work when executing them in the same line with a command?

I can supply an environment variable to a Python script and immediately print it with: $ FOO="bar" python -c "import os; print(os.environ.get('FOO'))" bar  However the same does not work with echo: $ FOO="bar" echo $FOO   $ echo $PWD /home/nntin  First question: How come it did not print bar?  When running multiple commands the environment variable is only applied to the first command. $ FOO="bar" python -c "import os; print(os.environ.get('FOO'))" && python -c "import os; print(os.environ.get('FOO'))" bar None  I could solve it with: $ FOO="bar" python -c "import os; print(os.environ.get('FOO'))" && FOO="bar" python -c "import os; print(os.environ.get('FOO'))" bar bar  but it gets clunky fast when I am passing a lot of environment variables. Second question: How can I apply it to both? I want to execute two commands one after another with e.g. && but I only want to define the environment variable once in the command line and not twice. I prefer setting the environment variables within the same command line because the environment variables may change and it is easier for me to execute a single line of command then multiple commands sequentially. I would prefer if I only need to change a single value. PS: Excuse me for the confusing title. I didn't know what it is called and where to search it under. When I execute my code like this the environment variable is not permanently set as in the next command line does not have that environment variable. But within the code it acts like a set environment variable. Feel free to change the title and description.


I'm trying to reverse and return a StringBuilder result but I get the following errors for trying all variations in order of return sb.Reverse().ToString():   Cannot implicitly convert type 'System.Collections.Generic.IEnumerable' to 'string'. 'StringBuilder' does not contain a definition for 'Reverse' and no extension method 'Reverse' accepting a first argument of type 'StringBuilder' could be found   What is the proper format for returning the stringbuilder result in reverse order?  public static string Reverse( string s ) {     char[] charArray = s.ToCharArray();     Array.Reverse( charArray );     return new string( charArray ); }   This bit of code unfortunately doesn't do it one line  Please vote to delete this post so I can get rep back XD


I have two systems, a Ubuntu PC and a Ubuntu laptop. I wonder if there is any way (wireless) to use my laptop as a second display? Because my laptop is too slow nowadays.


Method to get answers accepted if OP is unregistered

On many of the Stack Exchange sites, a significant proportion of questions are asked by unregistered users who are then unable to accept an answer to their question as correct. This is a massive disincentive to answering questions from unregistered users, given that the probability of reputation gain from that answer is significantly lower.  I have  that has been left un-accepted despite receiving 35 upvotes (and 0 downvotes) because the OP is unregistered and thus has no means of accepting it.   Could there be a way to automatically accept answers to unregistered users' questions once they reach, say, +5 votes? This rule would remove the disincentive of answering many of the posted questions, and get users well-earned reputation points.


In order to index my collection of tweets I have written this code but an error appears I do not know is what I should initialize a few things, thank you.  public static void main (String args []) throws IOException{         String line;         Gson gson = new GsonBuilder().create();         File f = new File(Constante.DATA);         BufferedReader reader;         Indexer indexer = new Indexer(Constante.INDEX);         int nbrtweet =0, i=0;                 for(File file : f.listFiles())         {                 System.out.println(file.getName());         reader = new BufferedReader( new FileReader(file));         while((line = reader.readLine())!=null){         Tweet tweet;                 try{            tweet = gson.fromJson(line, Tweet.class);            }catch( JsonSyntaxException e){             i++;             continue;                 }         nbrtweet++;         indexer.indexTweet(tweet);                 }   The error shows up on this line:   for(File file : f.listFiles())   and prints  Exception in thread "main" java.lang.NullPointerException     at ApprocheTwitter.src.Indexer.IndexationThematiqueTwits.main(IndexationThematiqueTwits.java:26)


Troubleshooting "Windows cannot be installed to this disk. The selected disk has an MBR partition table"

I recently bought a desktop computer with Windows 7 Home Premium x64 preloaded (OEM). I tried to install Windows 7 Ultimate x64 on this computer but I was presented with the following error message:     Windows cannot be installed to this disk. The selected disk has an MBR   partition table. On EFI systems, Windows can only be installed to GPT   disks.   The 1TB HDD on this computer has three partitions:   SYSTEM 100 NTFS - Healthy (System, Active Primary Partition)  OS (C:) 9148.04 GB NTFS - Healthy (Boot, Page File, Crash Dump, Primary Partition)  HP_RECOVERY (D:) 13.37 GB NTFS - Healthy (PrimarynPartition)   I'm trying to install a clean copy of Windows.


The set of all nilpotent elements is an ideal

Given that R is commutative ring with unity, I want show that set of all nilpotent elements is an ideal of R.    I know how to show ideal if set is given but here set is not given to me. Can anyone help me?


How was Harry going to kill Sirius Black?

In "The Prisoner of Azkaban", chapter 17, "Cat, Rat, and Dog":     Harry raised the wand.  Now was the moment to do it.  Now was the moment to avenge his mother and father.  He was going to kill Black.  He had to kill Black.  This was his chance...   How was Harry going to kill him, had he tried to go through with it?  It's only his third year, and I don't think he knows any killing curses yet.


Is stealing a WiFi password possible using Spectre/Meltdown

I have an un-patched 32-bit PC (no microcode is available) running Ubuntu 16.04.  If I will use just the guest account (not the administrator account) for browsing, would it be possible to steal the WiFi password?  Would it be possible to steal the administrator password of the PC?


Plurality of verb depending on plurality of list elements

This question is also open on EL&U:   Considering the amount of controversy it aroused, I believe it's past "Learners'" level.    An edit was suggested to my sentence.     There was were an orange, some grapes, two apples and a small pile of cherries on the plate.   In my native language plurality of the verb always follows plurality of the first element on the list. There were an orange,... sounds awkward to me, no matter what follows up. My simple solution was reordering:     There were some grapes, an orange, two apples and a small pile of cherries on the plate.   But that's not the first time I faced this situation and I'd like to know what the rules of grammar say about that — was my editor overzealous or am I trying to copy rules of my language that don't apply in English?


import sqlite3 conn = sqlite3.connect('ProcessPower.db')  c = conn.cursor() user_input = (input("Enter a Type: "))  c.execute("SELECT * FROM Instrumentation WHERE Type = ?", user_input) rows = c.fetchall() for row in rows:     print(row) conn.close()


Did Rose die at the end of Titanic, or was she dreaming?

At the end of , the camera pans across a group of pictures that showed Rose had lived a rich, full life (some of which was suggested to her by Jack - e.g. learning how to ride 'like a man').  It then settles on a very peaceful looking Rose in her bed.    Then the scene segues to drop down into the inky depths of the ocean to traverse one of the upper decks of the wreck, then that transforms back to the original ship as it had looked in its splendor, turns a corner into an area of people (all of whom, I'm guessing, died during the night it sank), and up a staircase to where Jack is waiting for her in front of a clock.  She takes his hand, and they embrace.  Was that to signify that she was dreaming of Jack and all those that had been lost, or had she died and joined them?


output neighbouring lines with line numbers while grepping

Is there a way to output the neighbouring lines along with the line numbers while grepping the contents of a file? I'm trying to get outputs of the form:  $ ~/myscript.sh download file # 'download' being the pattern here 121: # and downloads with wget/curl, whichever is available. 122: download_file () { 123:  if which wget &>/dev/null; then ---------- 356: # Since the prerequisites are already installed, we may proceed 357: download_urls=("http://example.com/foo/bar.bz2" 358:                "http://d1.example.com/xyz/abc.tar.gz"   Of course, I know that I can get grep my pattern with the -n option and show some of the neighbouring lines from the obtained line number (say, by using any of the methods ), but is there a better way to do this?


Article in "A George Lukas film" and its absence in "John's brother"

I'm sure about the 1st sentence, since I always see it at the opening credits of almost every film (a somebody's film).  But I'm not sure about the 2nd one, just it doesn't even look correct if I write it "A John's brother".  So, my question is as follows:  Is there any rule regulating usage of article before names like in my examples?  Thank you in advance!


Special Characters (InDesign) Total pages marker?

Is there a special character marker for Total Pages? I can use a marker on my master page for current page where it will say A, but if I want it to say A of 3 (3 being the total number of pages) is there a marker to count all the pages in your document?   I know I could type 3 in there but if I add pages I have to go back and re-edit the master page. Seeing if there is a smarter way to go about this.   Thank you in advance!


How move user data onto "Data" disk, while leaving boot disk for OS only

At the risk of asking a duplicate question (a few searches yielded no good question/answer),  and after messing this up royally myself () I am going to ask:  What is a least-trouble some but still effective way to move my user data onto a separate drive.  Goals:   OS/boot drive is used pretty much for booting and OS and Programs only Data disk is for all conceivable user data (Photos, Videos, etc) If I by change remove "Data" drive, have Windows still be fully operational   What I did in the linked question, was me using a hard link/junction to point C:\Users to D:\Users.  It worked perfectly for me, until I removed drive D and booted Windows, causing Windows to not be able to load User Profile.  And reattaching drive D, it did not fix my User Profile service issue and I did an OS reinstall to fix it.  So I am looking for a safer option, where my Data is still on another drive, but I can remove and replug drives as needed, with Windows breaking and still having a "Data" drive when I plug it back, with minimal recovery procedures (in case Windows complains about it missing)


I have no clue really, I know that $x$ can be written as $\ln (e^x)$ and that's it.


Building where clause based upon parameters

In PostgreSQL I am trying to build a where clause in a function that uses an inbound parameter to determine the contents of the IN  For example:   select fld1, count(fld1) from xyz where fld1 in (     case $1         when 1 then 'Value1'         when 2 then 'Value2'         when 3 then '''Value1'',''Value2'''         when 4 then '''Value4'',''Value5'',''Value6'''     else NULL ) group by fld1   Value 1 works fine as does Value2, Values 3 and 4 fail not syntactically but no rows are returned.


It is bugging me quite a long time already, so I decided to ask.   There are two possible strategies:   Use only relevant tags Just tag your question with all the tags you can think of.   My common sense is telling me the first one should be preferred. But occasionally I am coming into argument with people whose questions I am retagging and who want to keep an irrelevant tag.   The question is - which tag is relevant and which is not?   Let's take an example. Imagine a question in Travel@SE, like "I am traveling from Berlin to Amsterdam on my brand new Aston-Martin. Where would be the best place to stop to eat?" Should be this question tagged with "aston-martin" tag? In my opinion - no. Although car of this brand is indeed involved in both trip and question, it is irrelevant to the question matter. And it will be of no help to anyone who will either in the same trip or in the need of help with such a car.   Am I right?  Taking more closely to Stack Overflow, there is a question, say, on a PHP syntax error. It is tagged with PHP and mysql.  Although there is indeed some SQL in the question, but syntax error doesn't belong to it, but to some PHP code. And such error can happen in any PHP code, no matter what database it's interacting with. Should be this question tagged with MySQL?


($n$-dimensional) Inverse Fourier transform of $\frac{1}{\| \mathbf{\omega} \|^{2\alpha}}$

I'd like to find the $n$-dimensional inverse Fourier transform of $\frac{1}{\| \mathbf{\omega} \|^{2\alpha}}$ i.e. $$ \int_{\mathbb{R}^n} \frac{1}{ \| \mathbf{\omega} \|^{2\alpha}} e^{2 \pi i \mathbf{\omega}\cdot \mathbf{x} } d \mathbf{\omega} $$ where $\mathbf{x} = ( x_0 , x_1 , \cdots , x_n )$ is a spatial parameter in $\mathbb{R}^n$, $\mathbf{\omega} = ( \omega_0 , \omega_1 , \cdots , \omega_n )$, and $$ \| \omega\| = \omega_0^2 + \omega_1^2 + \cdots + \omega_n^2 $$ All I've been able to come up with in the one-dimensional case is that the integral $$ \int_{-\infty}^{+\infty} \frac{1}{ \| \omega \|^{2\alpha}} e^{2 \pi i \omega x } d \mathbf{\omega} $$ diverges because the lower power terms $\omega^p$ terms, for which $p < 2\alpha$, in expansion of the exponential $$ e^{2 \pi i \omega x } = \sum_{p = 0}^{\infty} \frac{(2 \pi i \omega x)^p}{p!} $$ do not prevent $\frac{1}{\| \omega \|^{2\alpha}}$ from blowing up at the origin.   I know that one possible way of regularizing this integral is to include a test function and consider the limit of the resulting integral, but I don't quite know how to do so. I've tried reading Gelfand and Shilov's Gneralized Functions vol 1 and while I understand bits of it on the whole its a bit heavy for me.    Based on the papers that I've read I know that there are two cases (the latter of which appears to me more general) and two solutions in each.   Case 1: 2$\alpha$ is an odd/even integer Case 2: 2$\alpha$ is integer or otherwise   I'd appreciate help, if possible, coming up with both solutions.


Given $\lim_{x \rightarrow a}f(x)+\frac1{\left|f(x)\right|}=0$, what is $\lim_{x \rightarrow a}f(x)$?

Another question I am struggling with:  Let $f:\mathbb{R} \rightarrow \mathbb{R}$ be defined in a neighborhood of $a$ (except maybe $a$ itself) and suppose that, $\lim_{x \rightarrow a}\left(f(x)+\dfrac{1}{\left|f(x)\right|}\right)=0$. Find $\lim_{x \rightarrow a}f(x)$, and prove by definition, that this is indeed the limit.    Thank you all for your answers!!  But.. How can I prove by definition that this is indeed the limit? take $\epsilon>0$, I have to show that there exists a $\delta>0$ such that, $|x-a| \leq \delta$ implies $|f(x)+1| \leq \epsilon$. now, I do know that there exists an $\delta_1>0$, such that $|f(x)+\frac{1}{|f(x)|}|< \epsilon$.Or, $\frac{\epsilon}{k}$ for some constant $k$ But, how can I continue from there?


Shell not handling escape character spaces

Recently it seems that shell has changed how it handles spaces in parameters. It used to handle them properly (Or at least as I intended it to), but now it recognises it as a bunch of different parameters and completely misses the escape character.  An example of a small script that used to work very well:  #!/bin/sh  exec /home/evan/.applications/Sublime\ Text\ 2/sublime_text $1   So I would give it some filepath with spaces and it used to open the proper file eg, /home/evan/Document/My\ File\ Path/file.txt would open that file.txt. Now it opens "My", "File", "Path", and some unknown "file.txt" Obviously, that won't be the file.txt that I am looking for.  Any help would be appreciated. Thank you in advance.  OS: Ubuntu 13.04 GNOME edition with latest updates  EDIT: I forgot to mention that the command executes perfect. The parameter does not.


Why are sudo su and bash root script paths different?

Admin note: This question is different then why is sudo path different then su because the environmental variables in a bash script ran from cron do not appear to carry over from environmental variables set for either users as sudo or as su. (See everything after the BUT.)  When running sudo su and showing paths, I have /usr/local/bin in my path. I have several custom apps I put in that folder in the intent of making them available system wide. In etc/sudoers, /usr/local/bin is in the secure_path.   BUT  When running a bash script executed as root via a cron job, /usr/local/bin is apparently not preserved in the path as I get command not found when attempting to run apps that are installed there, despite the fact they are in /etc/sudoers.  How do I get these apps to be available to root?  Ubuntu 16.10


Find a set of complex numbers for equation $2|z|<|1+z^2|$ and draw it.  That's as far as I got: $$4x^2+4y^2<(x^2+y^2+1)^2+x^2y^2\\ \vdots\\ x^4+y^4-6x^2-2y^2+1>0\\ (x^2-3)^2+(y^2-1)^2>9$$  Now I have no idea how to draw this.


Which equals operator (== vs ===) should be used in JavaScript comparisons?

I'm using  to go through JavaScript, and it's returning many suggestions to replace == (two equals signs) with === (three equals signs) when doing things like comparing idSele_UNVEHtype.value.length == 0 inside of an if statement.  Is there a performance benefit to replacing == with ===?   Any performance improvement would be welcomed as many comparison operators exist.  If no type conversion takes place, would there be a performance gain over ==?


how $\pi$ is irrational if it is a ratio

How can $\pi$ be an irrational number if it is a ratio of the circumference over the diameter?    Thanks!


I'm considering re-designing my personal website to promote my web services in my local area.  My issue is whether to do a one page website with a scroll-to navigation system. What effect does this have on SEO. As i understand it, you set stuff like h1's and meta description on specific page content. How does this work when all of your different content is on one page?


We are a South African couple with 5-year multi entry visas expiring in February 2024. For how long do we need to be out of the UK before we can return again? We intend spending the maximum of 6 months there on each visit if possible. We intend buying our own property there.


What problem does oversampling, undersampling, and SMOTE solve?

In a recent, well recieved, question, Tim asks ?  The premise of the question is that there is a lot of machine learning literature discussing class balance and the problem of imbalanced classes.  The idea is that datasets with an imbalance between the positive and negative class cause problems for some machine learning classification (I'm including probabilistic models here) algorithms, and methods should be sought to "balance" the dataset, restoring the perfect 50/50 split between positive and negative classes.  The general sense of the upvoted answers is that "it's not, at least if you are thoughtful in your modeling".  M. Henry L., in an up-voted comment to an accepted answer, states     [...] there isn't a low level problem with using unbalanced data. In my experience, the advice to "avoid unbalanced data" is either algorithm-specific, or inherited wisdom. I agree with AdamO that in general, unbalanced data poses no conceptual problem to a well-specified model.   AdamO argues that the "problem" with class balance is really one of class rarity     Therefore, at least in regression (but I suspect in all circumstances), the only problem with imbalanced data is that you effectively have small sample size. If any method is suitable for the number of people in the rarer class, there should be no issue if their proportion membership is imbalanced.   If this is the true issue at hand, it leaves an open question: what is the purpose of all the resampling methods intended to balance the dataset: oversampling, undersampling, SMOTE, etc?  Clearly they don't address the problem of implicitly having a small sample size, you can't create information out of nothing!


How to use (exclamation mark) color mix with \definecolor?

I need to use  blue!50   with  \definecolor   but they do not seem to be compatible. A workaround would be appreciated.


question on identity of sums with exponent.

I want to show that for $x>0$:  $$\sum_{n=-\infty}^\infty e^{-n^2\pi x}= \frac{1}{\sqrt{x}}\sum_{n=-\infty}^\infty e^{-n^2\pi / x}$$  It doesn't seem that a simple change of variables will do, like $n\mapsto n^2 x$, so how to show this identity?


Two-column bibliography in one-column document

I'd like to have a two-column bibliography in a one-column scrartcl. I'm using  with backend . To obtain a two-column table of contents where the header doesn't "fall" into the columns, I use the  commands  \BeforeStartingTOC[toc]{\begin{multicols}{2}} \AfterStartingTOC[toc]{\end{multicols}}   Is there something similar for the bibliography in ? Right now I'm using  \begin{multicols}{2}[\section*{References}]     \printbibliography[heading=none] \end{multicols}   It looks fine but it's not very semantic.


Word "Fella" will indicate the gender "Male". Can anyone say the word like "fella" for the gender "female"?.


When I try to apt-get update, I have this error:  W: The repository 'http://ppa.launchpad.net/upubuntu-com/flareget-amd64/ubuntu xenial Release' does not have a Release file. N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use. N: See apt-secure(8) manpage for repository creation and user configuration details. . . . E: Le téléchargement de quelques fichiers d'index a échoué, ils ont été ignorés, ou les anciens ont été utilisés à la place.


14.04: How to ssh/scp as root with NO password prompting?

We upgraded from 12.04 to 14.04. We have a dozens of processes that perform automation tasks for us and we use root with ssh/scp. After the upgrade root couldn't ssh/scp into the servers at all. We fixed that issue however no matter what we set the servers always prompts root for a password.  How do you configure ssh/scp so that root is NOT prompted for a password when executing ssh/scp?


i downloaded install_flash_player_11_linux.x86_64.tar.gz from adobe flash website.   tried  tar -zxvf install_flash_player_11_linux.x86_64.tar.gz   this error popped up  tar (child): install-flash-player-11-linux.x86-64.tar.gz: Cannot open: No such file or directory tar (child): Error is not recoverable: exiting now tar: Child returned status 2 tar: Error is not recoverable: exiting now   i need help on how to install it. do i have the correct file?


Currently a friend and I are arguing about what the sides of the force are called. What I want to know is if the opposite of the dark side is called the light side or the good side.


I saw a sentence like:     Maximum number of minutes are 60   but I feel like it must be "is 60" not "are" as we are describing about the word number here which is singular.  and after search I came across two different questions with two different answers ( , ) and I don't know what exactly is the correct behavior here and if I'm able to use both of them or not.


TL;DR: I have a Micro-SD card that has a primary partition that isn't formatted and can't be selected and I have tried:   DBAN nuke (wiped) Windows formatting 3rd party program formatting diskpart.exe Windows partition manager   I can't get it to work, please help.  I bought a micro-SD card which I had Kali Linux on and later wiped it as I wanted to use the card in my phone instead. The card failed and I think I messed up with the format of the card or my phone is too bad to work properly with an SD (cheap Chinese android). I am trying to re use it again to put Kali back on it but I am having problems.  When I try to connect it, it detects and no damage that I can recall reader is working too, Windows says I need to format it before I can use it. It just tries to and says Windows could not do it. I tried to check if there was maybe an issue with the partitions in it so I tried to select it in diskpart.exe and it recognizes the card but when I try to select the "primary" part, it just spits out: "There is no partition selected". The primary partition is active and I can't delete it because it won't select it and I can't create a new partition because the primary partition is there is taking the full size of the SD card but can't be selected.  I have also tried a DBAN nuke to clear any and all data off, it and, it just plain won't work. Formatting, partitioning and wiping it have all failed and it has no clear damage on it (bought this year). Anyone have something else I could try?


As far as we know, the particles of dark matter can interact with each other only by gravitation.  No electromagnetics, no weak force, no strong force.  So, let's suppose a local slight concentration of dark matter comes about by chance motions and begins to gravitate.  The particles would fall "inward" towards the center of the concentration. However, with no interaction to dissipate angular momentum, they would just orbit the center of the concentration and fly right back out to the vicinity of where they started resulting in no increase in density.  Random motions would eventually wipe out the slight local concentration and we are left with a uniform distribution again.     How does dark matter form lumps?


The appropriate match ratio between case and controls: the obsession with 1:5

My intention with this question is to collect relevant references or literature for a recurrent methodological approach commonly applied in health research.   The main question is: what is the appropriate ratio between case and controls?   Within my research field (primarily neurosurgery), it seems that almost every paper I've read exclusively match one case with five controls; however, I've never seen a reference to literature that actually investigated or argued this ratio.   Hence, I am seeking methodic literautre - preferable published papers, but not necessarily - that actively discuss or investigate the appropriate matching ratio between case and controls.       The main question yields a subsequent question: should researchers apply different case:control-ratios to different study designs? Eg., do a RCT require similar ratios compared to the methodic requirements of an epidemiological study, that match cases to the controls in the general population (through Health Registries)?   Open Discussion is encouraged.


How fast should internet speed be to host a webserver?

We host our own linux webserver in house. The company's Internet connection speed is 100MB, and the server runs no problem with it. We are planning to have another webserver located in another place, where there's no internet connection yet. My question is, how fast should the internet speed be in order to host a webserver that has about 3000 visitors daily?  Our webserver is specified as this:   Linux + PHP + mysql it's a webshop, with many database transactions. about 3000 visitors daily. we have experienced appr. 100 people online at the same time.


If $m$ and $n$ are relatively prime then the set $\{xm + ny : x,y \in Z^+\}$ contains all but a finite number of the positive integers.  What I tried : We know that there exist integers $x,y$ such that $mx+ny=1$. But both can't be negative/positive. So, we need to separate the positive and negative part of each coefficient. Let $a_1 =x^+$ and $b_1=x^-$ and $a_2 =y^+$ and $b_2=y^-$. Then $ma_1 + na_2 = 1 + mb_1 + nb_2$. So, I have got two consecutive integers. Stuck after that.


How to escape braces (curly brackets) in a format string in .NET

How can brackets be escaped in using string.Format? For example: String val = "1,2,3" String.Format(" foo {{0}}", val);  This example doesn't throw an exception, but it outputs the string foo {0}. Is there a way to escape the brackets?


Why java.lang.NoSuchMethodError occure very specific to environment or class loader?

I am currently working on a project where we have the log4j-over-slf4j.jar file. In all of the environment, this jar was working. But all of a sudden I have a WebSphere application server. Our product works on tomcat server and all of the sudden our application was not able to create any logs whereas it was creating in another environment. If I try to remove that jar from the project then I am able to generate logs.  But I am not able to identify why should i do it only specific to this particular environment.  Or what should  i do  in order to identify  the class loader information at server runtime to identify which class is loaded or which method is loaded?  My jdk version is: "1.7.0_71"  My application contains these libraries:  antlr-2.7.7.jar aopalliance-1.0.jar asm-1.5.3.jar asm-attrs-1.5.3.jar axiom-api-1.2.12.jar axiom-impl-1.2.12.jar axis2-1.6.2.jar axis2-kernel-1.6.1.jar axis2-transport-http-1.6.1.jar axis2-transport-local-1.6.1.jar c3p0-0.9.2.1.jar cglib-2.1_3.jar com.ibm.jbatch-tck-spi-1.0.jar commons-codec-1.6.jar commons-collections-3.1.jar commons-fileupload-1.2.jar commons-httpclient-3.1.jar commons-logging-1.1.3.jar dom4j-1.6.1.jar ehcache-1.2.3.jar geronimo-activation_1.1_spec-1.0.2.jar geronimo-javamail_1.4_spec-1.6.jar geronimo-jta_1.1_spec-1.1.jar geronimo-stax-api_1.0_spec-1.0.1.jar geronimo-ws-metadata_2.0_spec-1.1.2.jar hibernate-3.2.4.ga.jar hibernate-annotations-3.3.0.ga.jar hibernate-commons-annotations-3.1.0.GA.jar hibernate-core-3.3.0.CR2.jar hibernate-ehcache-3.3.0.CR2.jar hibernate-entitymanager-3.3.1.ga.jar hibernate-jpa-2.0-api-1.0.0.Final.jar hibernate-validator-3.1.0.CR2.jar httpcore-4.0.jar javaetmoi-spring4-vfs2-support-1.4.0.jar javassist-3.18.1-GA.jar javassist-3.3.GA.jar javax.batch-api-1.0.jar javax.servlet-api-3.0.1.jar jaxen-1.1.1.jar jboss-common-core-2.0.4.GA.jar jboss-logging-3.3.0.Final.jar jettison-1.2.jar jsr311-api-1.0.jar jta-1.1.jar log4j-1.2.17.jar log4j-api-2.0.jar logkit-1.0.1.jar mchange-commons-java-0.2.3.4.jar neethi-3.0.1.jar oracle-ojdbc6-11.2.0.3.0.jar persistence-api-1.0.jar poi-3.9.jar slf4j-api-1.7.11.jar slf4j-simple-1.6.4.jar spring-aop-3.2.13.RELEASE.jar spring-batch-core-3.0.1.RELEASE.jar spring-batch-infrastructure-3.0.1.RELEASE.jar spring-beans-3.2.13.RELEASE.jar spring-context-3.2.13.RELEASE.jar spring-core-3.2.13.RELEASE.jar spring-expression-3.2.13.RELEASE.jar spring-jdbc-3.2.13.RELEASE.jar spring-orm-3.2.13.RELEASE.jar spring-retry-1.0.3.RELEASE.jar spring-tx-3.2.13.RELEASE.jar spring-web-4.0.3.RELEASE.jar stax-api-1.0.1.jar woden-api-1.0M9.jar woden-impl-commons-1.0M9.jar woden-impl-dom-1.0M9.jar wsdl4j-1.6.2.jar wstx-asl-3.2.9.jar xmlbeans-2.5.0.jar xmlpull-1.1.3.1.jar XmlSchema-1.4.7.jar xpp3_min-1.1.4c.jar xstream-1.4.7.jar   My tomcat lib directory contains:  annotations-api.jar catalina-ant.jar catalina-ha.jar catalina.jar catalina-storeconfig.jar catalina-tribes.jar ecj-4.5.jar el-api.jar jasper-el.jar jasper.jar jsp-api.jar ojdbc6-11.2.0.3.jar servlet-api.jar sqljdbc4-11.1.0.7.0.jar tomcat-api.jar tomcat-coyote.jar tomcat-dbcp.jar tomcat-i18n-es.jar tomcat-i18n-fr.jar tomcat-i18n-ja.jar tomcat-jdbc.jar tomcat-jni.jar tomcat-juli.jar tomcat-util.jar tomcat-util-scan.jar tomcat-websocket.jar websocket-api.jar


Entering Germany while having a visa issued by a different country?

I believe this question was asked before but I think my case is a little bit different. My father works at the French embassy and so I have a Schengen visa issued for me from the French Embassy. Now I never visited France before and I plan to go Germany next week. Is it ok to go straight to Berlin with a visa issued by France. Again I will not be landing or visitng France at all.