Book about a traveling gypsy woman who makes potions and has visions

I've been trying to remember this book for years. I read it around 2003. It was a fantasy book set in a historical 1800s England type setting. (I think it was England but I'm not sure).  The gypsy inherited her wagon from her grandmother. I believe she made potions and traveled with a group but I don't think she was closely related to the family. The group performed somehow (I'm thinking circus-like but not sure).  She could see visions, I think in fire, a mirror, and possibly dreams. At one point she leaves the group for safety (hers and theirs). She is being hunted for what she sees; I think magic is outlawed and she's trying to keep the group safe as well as escape herself.  I also remember her having to choose a road to travel, I think she was going to the capital city, which is also where the most witch hunters were.  I also think one of her visions was of a couple being attacked by either wolves being controlled by someone else or wolves that are actually demons (or something similar).


If $F=m\dfrac{dv}{dt}$ why is it incorrect to write $F\,dt=m\,dv$?

My university lecturer told me that:     If $$F=m\dfrac{dv}{dt}$$ it's incorrect to write $$F\,dt=m\,dv\tag{1}$$ but it is okay to write $$\int F\,dt=\int m\,dv$$ for Newtons' second law.     But never explained why $(1)$ is mathematically incorrect.  My high school teacher told me that:      Derivatives with respect to one independent variable can be treated as fractions.    So this implies that $(1)$ is valid.  This is clearly a contradiction as my high school teacher and university lecturer cannot both be correct. Or can they?  Another example of this misuse of derivatives uses the specific heat capacity $c$ which is defined to be $$c=\frac{1}{m}\frac{\delta Q}{dT}\tag{2}$$  Now in the same vain another lecturer wrote that $$\delta Q=mc\,dT$$ by rearranging $(2)$.  Another contraction to the first lecturer. I this really allowed or if it's invalid then which mathematical 'rule' has been violated here?    EDIT:  In my question here I have used formulae that belong to Physics but these were just simple examples to illustrate the point. My question is much more general and applies to any differential equation in mathematics involving the treatment of derivatives with respect to one independent variable as fractions.   Specifically; Why is it 'strictly' incorrect to rearrange them without taking the integral of both sides?


A bag of carrots and half a tomato "was/were" sitting on the kitchen counter.  A bag of carrots and half a tomato was sitting on the kitchen counter.  Is this correct?  I was informed that the main subject is "bag," so I should be using the singular verb. Also, is "of carrots and half a tomato" the prepositional phrase? or is it just "of carrots"?  Is this correct as well?  Please advise.


Do Traits Have to be Adaptive in Order to Survive?

I'm reading Michael Pollan's book 'How to Change Your Mind', which is largely about psychedelic mushrooms. In discussing the biology of the mushrooms, he writes:  'Even if psilocybin in mushrooms began as 'an accident of a metabolic pathway', the fact that it wasn't discarded during the course of the species' evolution suggests it must have offered some benefit.'  I'm wondering if this is actually true. In general, I'm wondering if it is true that traits that do not confer advantage will eventually be weeded out.   Being ignorant of the finer points of evolution/natural selection, I can make arguments both ways. On the one hand, it seems that the intense competition would make investing any resources at all in a trait that was not beneficial a totally losing proposition. Therefore no traits that weren't positively adaptive would survive. On the other hand, there seem to be all kinds of traits that are 'neutral' in fitness terms but which survive anyway. E.g. coccyx, male nipples, appendix, whale legs, etc.   I am not talking about information encoded in the genome, which can be present but not expressed. I am talking about phenotypes, i.e. traits that get expressed in interactions with the environment, such as the psilocybin chemicals in these mushrooms. (Though I suppose unexpressed genetic info could never be selected for or against by natural selection by definition.)  So to put a very fine point on my question: Is it possible/likely that psilocybin mushrooms produce a chemical that happens to engender hallucinations, not because doing so is adaptive, but just incidentally? So that this property would be something like the redness of blood, i.e. not adaptive in itself but just a matter of happenstance?


Unix tools: what if a file is named minus something?

I'm always wondering: most GNU/Unix tools take options in the form "minus something", sometimes followed by an argument. What if you got a file named minus something?  $ ls -f $ rm -f $ ls -f $ mv -f abc mv: missing destination file operand after `abc' Try `mv --help' for more information. $ cat -f cat: invalid option -- 'f' Try `cat --help' for more information.   or  $ ls -ohello.c $ gcc -ohello -ohello.c gcc: fatal error: no input files compilation terminated.   This is just out of curiosity; I don't have a use case for this.


Find the non negative continuous function defined over $[0,1]$ and satisfy given equations

Find the non negative continuous function defined over $[0,1]$ such that $$\int_0^1 x^kf(x){\rm d}x=a^k,$$ where $k=0,1,2$ and $a\in[0,1]$  solution i try  from $$\int^{1}_{0}f(x)dx=1\cdots (1)\times a^2$$  and $$\int^{1}_{0}x\cdot f(x)dx=a\cdots (2)\times 2a$$  and $$\int^{1}_{0}x^2\cdot f(x)dx=a^2\cdots (3)$$  getting $$\int^{1}_{0}(x-a)^2f(x)dx=0$$  how i get functions which satisfy given equation, help required


I understand the derivation process of the least square estimator of B  𝑏=(𝑋′𝑋)-1  𝑋′𝑦  However, I am not seeing what I am doing wrong here, because I feel this can be further simplified like    𝑏 = (𝑋′𝑋)-1 𝑋′𝑦 = (𝑋)-1 (𝑋′)-1 𝑋′𝑦 = (𝑋)-1 Y  where am I doing wrong, please point out. Thank You!  Ok! I see , it has to be sqaure matrix to clearly define the inverse, I am just confused with derivation of the following:  Not sure how it gets from first red line to the second redline.. Thank you! Any help be will appreacited!


Can the "proves consistent" relation be proven antisymmetric?  By antisymmetric I mean there is not some chain of theories in which some theory proves other theories consistent which in turn prove it consistent.  If $\succ$ is the "proves consistent" relation:  $A\succ B\iff (A\models Con(B))\quad\forall A\forall B $  then I think antisymmetry is usually written as follows:   $A\succ B\land B\succ A\implies A=B\quad\forall A\forall B$  Can this be proven?  This is an inquiry motivated in part by learning that  is neither weaker nor stronger than PA, which suggests an ordering may not necessarily be implied by proving consistency.  It would seem to me that by Godel's imcompleteness theorem we're denied reflexivity:  $A\succ B\implies A\neq B$  which denies us the usual antisymmetry rule.  But it seems this doesn't necessarily rule out antisymmetry provided we have transitivity.  Because if $\succ$ were both transitive and symmetric, we might have the following contradiction:  $A\succ C\succ A \implies A\succ A\implies A\neq A$  $\therefore\nexists C\mid A\succ C\succ A$  Which fulfils the purpose of antisymmetry when we're denied reflexivity.  So the limit of what I can prove is that "proves consistent" is antisymmetric provided it is also transitive - which I have, as yet, no reason to believe it is.


Wrong result applying boolean modifier to an object

I'm new to Blender, I have the object shown on the first image (the one that is NOT selected) and I would like to create on it some holes using the boolean modifier. So I created the eight cylinders shown in yellow always on the first image to subtract them from my object.    Now if I select the object, add to it the boolean modifier and make the difference with those cylinders the surface of my object is not correctly modified. See the image below and compare it with the previous one.   Is it a problem of Blender or am I applying the boolean modifier in a wrong manner? What is the correct way to use the boolean difference between two objects? Thanks in advance.


Alice has 2 kids and one of them is a girl. What is the probability that the other child is also a girl? (Apply Bayes' Theorem)

I am aware that The outcomes for two kids can be {BB, BG, GB, GG}, and given that there's one girl, the answer would be 1/3. But, when I put the question into a context of Bayesian Theorem, I seem to struggle.  My equation is as follows: P(2G|1G)=[P(1G|2G)*P(2G)]/P(1G)  where P(1G|2G) = 1 as given there are two girls, the probability of having 1 girl would be 1, P(2G)=0.5*0.5, P(1G)=0.5 .   Where, in my equation, did I get wrong?


Wrapper classes and call by reference in java

Below is my code:  class Demo{ public static void main(String[] args) {     Integer i = new Integer(12);      System.out.println(i);      modify(i);      System.out.println(i);  } private static void modify(Integer i) {      i= i + 1;     System.out.println(i); }   }  The OUTPUT of the above CODE is  12 12 but as  I know, we are passing the wrapper object "i", it means it should be "Call by reference",Then the value should change to 13.but its 12. Any one has proper explanation for this?


I wrote the word "old" on my passport main page, by mistake. Do I need to get a new passport?

I wrote the word "old" on my passport main page, thinking it was my old outdated passport. (I looked at the issued date and thought it was the expired date.) The added word doesn't overlap with any passport information. It's on a blank part of the page. However I'm wondering if I should now get a new passport? Will I be denied entry because of that word written in? Thanks!


Entanglement and the relativity of simultaneity: an experiment

Setting of the experiment: Triplets Alice, Bob, and Carla have plenty of entangled electrons when they depart from Earth. Alice stays behind, Bob goes to Zeta Reticuli, and Carla goes to Andromeda. All three continuously make a video of everything around them, assuming they could even see each others clocks. Because of time dilation (including relativistic Doppler-shift) they all see each others clock running slow. However, if Bob returns to Alice she will be older because he accelerated. In Carla her reference frame, she thought that Bob was travelling anti-parallel to the motion of the Milky Way when he was on his way to Zeta Reticuli. The velocity of Alice was greater than Bob's according to Carla, concluding Alice her clock was running slowest. Outside the lightcones of certain events, Carla might even see a different sequence of events than Alice or Bob would. The experiment: The triplets have distributed entangled pairs of electrons among them so that each pair is separated after departure. They have agreed to make a position measurement at the end of every week (7 days of exactly 24 hours on their own clock). The "collapse of the wavefunction" happens instantaneously, while relativity denies the notions of absolute time: there is no "now-moment". The question is: when does the other electron collapse, "after" the position measurement? Could the triplets carry out this experiment, and see regularities in the wavefunction collapses caused by their siblings? I know it's correlation rather than causation, but what if the triplets agreed to a secret code? Since they might be able to predict each others clocks, they could agree that a postion measurement between 0-30 min of some hour represents 0 while 30-60 min represents 1.


I reset my all my settings on my iPhone and it messed up my notifications.  The problem is when I tap on my notification it slides to the left and makes me tap the open button. Before I could just tap on the notification itself once and it'd open right away.


I want to plot a function containing a (converging) series. To plot this function I changed the series to a finite sum.  \documentclass{standalone} \usepackage[utf8]{inputenc} \usepackage{tikz} \usepackage{pgfplots} \pgfplotsset{compat=1.8} \begin{document}    \begin{tikzpicture}   \begin{axis}[            domain = 0:1,            samples = 501,            ]   \addplot+[mark = none] gnuplot[raw gnuplot] {%     set samples 501;     dist(x) =  x - floor(x) < 0.5 ? x - floor(x) : 1 - (x - floor(x));     plot[0:1] sum [k=0:5] (2^(-k) * dist(2^(2^k) * x))   };   \end{axis} \end{tikzpicture} \end{document}   If I do k=0:4, it works fine. But the example above I tried k=0:5 and although a plot is created this plot has nothing do to with my function.  If this question should not be asked on this stackexchange, please tell me where to open a new question.


Suppose $V_1$ and $V_2$ are $k$-vector spaces with bases $(e_i)_{i \in I}$ and $(f_j)_{j \in J}$, respectively. I've seen the claim that the collection of elements of the form $e_i \otimes f_j$ (with $\left(i,j\right) \in I \times J$) forms a basis for $V_1 \otimes V_2$. But I seem to get stuck with the proof.  My question: What's the easiest way to see that the above set is indeed linearly independent?


Clock speed vs. number of cores for parallelized computer simulation

My question is similar to some "speed vs. cores"-questions that have already been asked on this website. However, I am interested in some very specific and technical points. So I hope that my question will be eligible for an "answer" instead of being solely opinion-based.  At my workplace, we frequently approach certain statistical problems using computer simulation. The software we use is largely meant for single cores, but we run it in parallel using multiple instances of these programs. The simulations are computationally intensive, and one iteration may take up to one hour to complete.  To enhance the speed of these calculations, I have been asked to propose a few models that would be best suited. However, I am unsure if, at this point, the computations would benefit from higher clock speed more than they would from more parallelized processes.  The computers we currently use are server-scale solutions that contain multiple CPUs at relatively high speed (16 physical cores, 2.9GHz each, and no GPU). So the decision cooks down to two options:   investing in similar machines with slightly higher clock speed (e.g., 3.2GHz) and the same number of cores (say 16), or alternatively... stepping down on the clock speed (e.g., 2.6GHz) and going for a larger number of cores (say 20 or 24).   I am unsure if increased clock speed would pay off even in computationally intensive applications because I assume that the performance does not increase linearly with clock speed. Strictly speaking, I could simply approach the problem like this:   3.2GHz * 16 cores = 51.2GHz, or alternatively... 2.5GHz * 24 cores = 60.0GHz   However, I am pretty sure this calculation is flawed in a number of ways. But in what way exactly? Money is not really an issue in this paarticular case, and computation using GPUs must be ruled out, unfortunately.  The machines will run Windows Server 2012 R2 and will be used exclusively for this kind of calculations. All programs involved are optimized for 64bit, but occasionally 32bit software programs be involved as well. Memory and HDD should not be a huge factor to consider.  Cheers!


Multi-Question Questions: How Best to Handle Them?

Sometimes I come across a question on SO that is actually a number of questions all in one. If these "sub-questions" are closely related, it's not a problem. But if they are only weakly related (or not at all) it gets ugly. I'm now (ironically or hypocritically) going to ask a few questions of my own for the community to respond to:  Do you consider a question made up of a number of weakly-related sub-questions "inappropriate"? Why or why not? How many is too many sub-questions? What do you think is the best way to deal with such questions?  As an example,  I had some discussion about with another user. I will add a more complete version of my response in an answer below, but in short I felt that this question should be closed and many of the questions asked separately.


Do a Brazilian and a Filipino citizen need an airport transit visa to wait for 2h30m in Seoul to fly to Addis Ababa?

It's hard to find a concrete information because everything is related to having a US visa, coming from or going to the US, which is not the case. We are leaving from Manila to Seoul, then to Addis Ababa and then to São Paulo, Brazil. Our layover length in Seoul is only 2 hours and 30 minutes. Is one of us required to have an airport transit visa?


The sound icon from the top menu bar is missing. It does however appear on the login screen and the guest account. I can still adjust my volume using keyboard keys but I liked the sound icon because it let me control Rhythmbox.  I noticed there are a lot of questions about this issue but all of the answers say to run $gnome-sound-applet & which does not seem to work. Does anybody know how I can fix this?  Edit: running "gsettings reset com.canonical.indicator.sound visible" fixed the problem


In some papers or documents, "linear times series" seems to refer to a time series that can be modeled as a linear AR (auto-regressive) model.   In other places, "linear time series" seems to refer to a time series with a linear trend.   When someone just drops "linear time series" out of the blue without any context, what do they mean usually?


$E$ Lebesgue measurable implies $E^2$ Lebesgue measurable?

Suppose $E \subset \mathbb{R}$ is Lebesgue measurable. Define $$ E^2 = \{x^2 : x \in E\}. $$ Is $E^2$ Lebesgue measurable as well?  I believe the answer is yes, but I am struggling to prove it. I tried forming interval covers of $E$ for which the sum of the lengths of the intervals is very close to $m(E)$, then considering the square of these intervals. However, if $E$ is unbounded, there is no guarantee these intervals will remain "small".


If $0 \le f(x) \le M$, prove $\lim\limits_{n \to \infty} \left[ \int_0^1 f(t)^n \, dt \right]^{1/n} = M$

Q: Suppose that $f$ is a continuous, nonnegative function on the interval $[0,1]$. Let $M$ be the maximum of $f$ on the interval. Prove that:  \begin{align*}   \lim\limits_{n \to \infty} \left[ \int_0^1 f(t)^n \, dt \right]^{1/n} &= M \\ \end{align*}  My attempt:  The upper/lower Darboux integrals of $f(t)^n$ are:  \begin{align*}   U_{f^n,\mathcal{P}} &= \sum\limits_{j=1}^k M_j \Delta_j \\   U_{f^n} &\le M^n \\   L_{f^n,\mathcal{P}} &= \sum\limits_{j=1}^k m_j \Delta_j \\   L_{f^n} &\ge 0 \\ \end{align*}  \begin{align*}   0 \le L_{f^n} \le \int_0^1 f(t)^n \, dt \le U_{f^n} \le M^n \\   0 \le \int_0^1 f(t)^n \, dt \le M^n \\ \end{align*}  I suspect that this is the wrong direction. I also believe that it is not necessarily true that $\int_0^1 f(t)^n = M^n$ for finite $n$.


Why do SSRI antidepressants cause a reduction in sex drive?

Drugs in this class are Prozac(fluoxetine), Zoloft (setraline), Lexapro (escitalopram) and many more. I've had the experience of using Prozac and Zoloft. I found that within two weeks, my ability to get an erection was nearly gone. I've heard that other indidivuals who tried to have sex/masturbate on these drugs found that their orgasms were 'dulled' and just not as pleasant as when not on the drug. There is a theory I've read about of serotonin being the "breaks" in sexual drive, and dopamine being the "gas/accelerator". Could someone explain if this is the reason?


After format exact double with decimal value not return

Decimal format issues:  DecimalFormat format = new DecimalFormat("###.#####"); Double d = new Double(122433423424.59696D); System.out.println(format.format(d));   Output:      122433423424.59695   but need exact value like:     122433423424.59696


I have created a usb flash drive in Ubuntu 16.04 using Startup disk creator, unetbootin, dd and the restore disk image in Disks. I have used the ubuntu 17.04 image and the Kubuntu 17.04 image. The MD5 hashes are correct. And my PC just sits there and nothing happens. With different usb sticks.  If I use the Lubuntu 17.04 image then everything works normally. Same usb stick.  I have tried on a second PC - also does not even reach the POST.  How is this a duplicate question? I can make a bootable USB but it will not boot if I use a 64 bit image even though the PC currently uses 64bit Ubuntu?  All I want to do is install Ubuntu 17.04


What is Reflection in Java Can anyone explain?

Can anyone explain me this question that I have.  What is reflection? I tired find answer in here, but I couldn't find it.  Thanks in advance.


Why is $[\mathfrak{q}, \mathfrak{g}]$ the smallest ideal $\mathfrak{a}$ of $\mathfrak{g}$ such that $\mathfrak{g}/\mathfrak{a}$ is reductive.

Does anyone know how I would go about answering this question? Any feedback is appreciated. I'm not too sure where to start. Thanks.  Let $\mathfrak{g}$ be a Lie algebra over $k$ and $\mathfrak{q}$ its radical. Prove that $[\mathfrak{q}, \mathfrak{g}]$ is the smallest of the ideals $\mathfrak{a}$ such that $\mathfrak{g}/\mathfrak{a}$ is reductive.  For this problem I am using the following definition of reductive Lie algebra: A Lie algebra is called reductive if its radical coincide with its center (from Varadarajan, "Lie Groups, Lie Algebras, and Their Representations").


sed : Ignore line starting whitespace for match

I want to replace the default listening port of httpd to 9090. I can edit the line in httpd.conf file using below  sed -i "/^Listen/c\Listen 9090" /etc/httpd/conf/httpd.conf   But the line   Listen 80   may have white space before it.  How do I ignore this white space to match this line?


How do I prove that powers of 5 are the sum of two squares using mathematical induction

Using mathematical induction I need to prove $$5^n=a_n^2 +b_n^2$$  What I've tried  P(1): $$5^1 = 1^2 +2^2$$ Which is true  P(2): $$5^2 = 3^2 +4^2$$ Which is also true  Now for the induction hypothesis  P(k): $$5^k=a_k^2+b_k^2$$  Then the question suggests to prove for (k+2) which I guess still makes sense.  P(k+2): $$5^{k+2} = 5^2 . 5^k$$ $$=(3^2 +4^2)(a_k^2+b_k^2)$$  This is where I get stuck. Apologies for formatting I'm fairly new to the site


Prove that there exists a linear transformation $T: \mathbb R^2 \rightarrow \mathbb R^3$ such that $T(1,1)=(1,0,2)$ and $T(2,3)=(1,-1,4)$  I know how to prove that a map is linear if I'm given the general rule the map is defined by. But that's not given here and I don't know how to find it from the two particular values given. Please help!


Error with managed C++ calling C# function : While having "out" type

I have C++/CLI code that needs to call a C# method.  The C# code is something like this:  class Coordinates { double latitude; double longitude; }  class ErorWarningData { string errorWarning; }   The C# method signature is like this :     Coordinates GetInfo(string custNum, out ErrorWarningData);  How can I specify the ErrorWarningData object to be "out" from my C++/CLI code and call the C# method ??


USB install will not work with i386 or amd64 iso

Having trouble installing ubuntu. I downloaded the 12.04.3 desktop i386 iso image, used the universal installer to put it on a USB drive (the netbook does not have a CD drive). netbook- acer aspire one with amd arm c-60 processor 1mhz with 4GB ram.  I changed the boot order to USB and I get:  SYSLINUX 4.06 EDD 2012-10-23 Copyright 1994-2012 H.Peter Anvin et al  _ and cursor flashing but you cant write anything, no buttons work you have to do a hard shutdown to leave.   I tried the same procedure with the amd64 iso and get same results.   why did it not boot?


Importing photos without using the OS X Photos app

I would like to import my photos off my camera without using the OS X Photos app and locate my photos direct in the Finder so I can store them in folders, edit them in Photoshop etc. (i.e. do whatever I like with my files without getting involved with the Photos app)  This app automatically recognises my camera and offers to import but I can't work out how to import them to a folder or seperate hardrive where I can sort through the files.  Does anyone know how to import to a folder? or even access the individual files in finder if photos has to be used for import?   …or is there a free import software I can use to avoid "photos " completely  (Theres no camera software available for Yosemite from the company that made my camera)


What are virtual objects, Reflection of light?

While studying reflection through a plane mirror, I have been told that when the object is real the image will be virtual and the image will be real while the object is virtual.  What are virtual objects? Do they really exist in nature?


How can I calculate how long it will take to transfer a file over LAN?

I want to know about the method with which we can calculate data transfer speed.   If I am sending a 1 GB file through a 1 Gb/s LAN connection, from one computer to another, how much time will it take to transfer that file?


Django Admin's "view on site" points to example.com instead of my domain

I added a get_absolute_url function to one of my models.  def get_absolute_url(self):     return '/foo/bar'    The admin site picks it up and adds a "view on site" link to the detail page for that object (when I put a real URL there instead of "/foo/bar").  The problem is instead of going to http://localhost:8000/foo/bar, it goes to http://example.com/foo/bar.  What am I doing wrong?


Quantum field theory is a broad subject and has the reputation of using methods which are mathematically desiring. For example working with and subtracting infinities or the use of path integrals, which in general have no mathematical meaning (at least not yet) ect. My question is a little vague, but i am interested in hearing what is the status of rigor in QFT. What is known to be mathematically rigorous and consistent, what is known to be not rigorous? Any examples and references are welcome.   Added: Just to clarify by rigorous I meant anything that a mathematician would find satisfactory. Also my question wasn't for books with rigorous (in some sense) approach, although that was welcomed. It was about specific examples of what is considered mathematically satisfactory and what not. For example the quantization of free fields satisfying the Klein-Gordon equation can be done rigorously. There is no mathematical definition in general of the Feynman path integral and so on.


Program to draw pinouts (and easily visualize pin's multiplexed functions)

Documenting an electronics project is also an important task if it will be used by someone else other than the hardware designer(s). Right now I need to draw a diagram for a breakout board in order to show what functions are available on each pin. Something like the following diagram (of mbed):    Can someone recommends me a program that allows me to easily draw such diagrams?


Beamer only includes part of the references in bibtex file

I have a file call mybib.bib. In my beamer presentation, I do this:     \usepackage[backend=bibtex,style=numeric]{biblatex}    \addbibresource{mybib.bib}   Then in the frame that I want the references to appear, I did:  \begin{frame}    \printbibliography  \end{frame}   This only prints out like 2 references in mybib.bib.  I have more than 20 references.  How do I get beamer to print out all references?


How to add item to right-click menu when NOT selecting a folder or file?

How do I add a menu item to my context menu to open up powershell (or any other arbitary application) when I right-click inside Windows Explorer?  I found tons of links on how to add menu items when doing this: (selecting a folder; )    ...but couldn't find any instructions on how to add menu items when doing this: (not selecting a folder or file)    I did find  and tried adding powershell to HKEY_CLASSES_ROOT\Directory\Background\shell\, (loosely based on the  and linked above) but it didn't work for me.  I'm running Windows 7, by the way.  Also, I'm currently interested in adding only PowerShell, but I'd prefer a general solution I can apply to add any program to the context menu.


What is a word to describe a response to a question that is evasive but not untrue

I'm looking for a single word synonym of evasion, fudging or dodging the question that does not imply deceit in the answer (apart from possible awareness of the respondent that they are not actually answering the question, and perhaps an intent to divert the questioner to other topics).  Answers could be verbose or blunt non-sequiturs.  This is similar but not identical to "What do you call a response which does not address the question?" There answers have other connotations, such as a word or phrase for an inappropriate response (such as a "non sequitur"). This is a new question, which differs particularly in that I'm looking for a word that does not imply an intention to deceive.


How to change the Postgres hostname in pgadmin 4?

By default, the database hostname is localhost after the Postgres has been installed. Can the hostname be changed to something else like localhost\\abc? If yes, how can I do it in Windows/pgadmin? Thanks


Windows 8.1 Upgrade fails with error code 0x80070652

I have a Thinkpad T530 running Windows 8 and Ubuntu 12.04 from a MBR-partitioned disk, with GRUB being the installed boot loader. I can see that the Windows 8.1 upgrade is offered to me in the Market, but I receive the 0x80070652 error code when I try to install the upgrade. It downloads fine, but fails during preparation.  More (may be too much) details about my setup:   I initially upgraded to Windows 8 Pro with Media Center 64-Bit via upgrade offer from Windows 7 64-Bit without keeping any data. Latest Intel graphics drivers from Windows Update are already installed. My laptop has only integrated Intel graphics, no AMD or Nvidia. I have 4 partitions on the drive, with all of them being primary partitions.   The table looks like this: Ubuntu LTS Swap, Ubuntu LTS root filesystem, Ubuntu LTS /home partition, Windows 8.  I also have a GPT-partitioned mSATA SSD running the latest Ubuntu non-LTS-release, but I removed that to do the upgrade.   As I said, I already tried removing the GPT partitioned SSD and tried only booting legacy/MBR style, leaving me with error code 0x80070652 during (attempt to install/prepare) the Windows 8.1 upgrade.  I also tried:   Looking up the error code. I remember reading a knowledge base article that suggested moving/deleting the contents of C:\Windows\SoftwareDistribution\Download. I did that, but no luck. Executed "Disk Cleanup" as well as "Clean up system files". Freed up more than 30 GiB of available diskspace on the Windows partition. Disabled swap file and hibernation and also deleting the corresponding files. Not luck, enabled them again. Runnning WindowsUpgradeAssistant.exe and removing all incompatible applications (it gave me only 3).


How can prove or disprove the following statement that is a commutative group? If G is a commutative group, then Z(G) = {b ∈ G| ab = ba for all a ∈ G} is G.  I was tried as follows, Since 𝑎𝑒 = 𝑎 = 𝑒𝑎 for all 𝑎 ∈ 𝐺,𝑒 ∈ 𝑍(𝐺) and so 𝑍(𝐺) ≠ 0  Let 𝑎, 𝑏 ∈ 𝑍(𝐺). Then 𝑏𝑐 = 𝑐𝑏 for all 𝑐 ∈ 𝐺.  𝑏𝑐 = 𝑐b b^-1 bc = b^-1 cb cb^-1 = b^-1 cb b^-1 cb^-1 = b^-1 c 𝑓𝑜𝑟 𝑎𝑙𝑙 𝑐 ∈ 𝐺  Hence 𝑏^−1 ∈ 𝑍(𝐺)  Now (𝑎𝑏^−1)𝑐 = 𝑎(𝑏^−1𝑐) = 𝑎(𝑐𝑏^−1) = (𝑎𝑐)𝑏^−1 = (𝑐𝑎)𝑏^−1 = 𝑐(𝑎𝑏^−1) for all 𝑎 ∈ g 𝑎𝑏^−1 ∈ 𝑍(𝐺)  Hence 𝑍(𝐺) ≤ 𝐺. By definition 𝑍(𝐺) is commutative, 𝑍(𝐺) is called the centre of g ```


I'm using Ubuntu 12.04 on an Amazon EC2 instance and new to the sysadmin side of things. I'm working on a little project of my own and I'm already starting to get targeted by bots (at least I hope they're bots).   I'm using PHP and in my error logs I noticed w00tw00t romanian anti-sec and /w00tw00t.at.blackhats.romanian.anti-sec:.  I googled and I found several results such as  and  which both state it's most likely just some bots. They were looking for variations of PHPMyAdmin, PMA, MyAdmin. From what I can tell, they did not find anything and only got some 404 errors. As far as PHPMyAdmin goes, I'm using an alias and I have access restricted to a couple of IP addresses.   Currently I'm running UFW and I have these rules  To                         Action      From --                         ------      ---- 80                         ALLOW       Anywhere 443                        ALLOW       Anywhere 22                         ALLOW       MY.IP.ADDRESS1 22                         ALLOW       MY.IP.ADDRESS2 22                         ALLOW       MY.IP.ADDRESS3 80                         ALLOW       Anywhere (v6) 443                        ALLOW       Anywhere (v6)   All of the tutorials I've seen on UFW just say how to set it up, not suggestions on the configuration itself. Basically I use SFTP and SSH (with a key pair) to work on my server. Are there any rules that are a must have that I am missing?


I want to take a string (for example,"jeff") and find the bit equivalent in the string. I tried with the dictionary but I couldn't able to find how to do it. How can I solve that problem please help me. (and sorry my English is not good :) )      static void Main(string[] args)     {         Dictionary<string, int> alfabe = new Dictionary<string, int>()         {             {"a",00000 },             {"b",00001 },             {"c",00010 },             {"d",00011 },             { "e",00100},             { "f",00101},             { "g",00110},             { "h",00111},             { "i",01000},             { "j",01001},             { "k",01010},             { "l",01011},             { "m",01100},             { "n",01101},             { "o",01110},             { "p",01111},             { "r",10000},             { "s",10001},             { "t",10010},             { "u",10011},             { "v",10100},             { "y",10101},             { "z",10110}          };         Console.Write("String gir: ");         string yazi = Console.ReadLine();         char[] harflistem = yazi.ToCharArray();         for (int [i] = 0; i < harflistem.Length; i++)             foreach (KeyValuePair<string,Int16> char[i] in alfabe)              {              }          {          }          Console.WriteLine("I want to show binary );     } }   }


This is the formatting I want. I enter text in this way   but it shows in this way   The first line of my text was indented in four spaces, so it was show as a line of code, how to set it to normal text? And the spaces between numbers are collapsed, how to solve it?


I've got the following entry in /etc/sudoers to allow me to run any command after asking for my password  %sudo   ALL=(ALL:ALL) ALL   I also want to run a specific command with no password as part of a script. I've tried putting the following line in /etc/sudoers, but it always asks for a password when I run it.  gmc ALL = NOPASSWD: /sbin/hdparm -C /dev/sdc   Is there a way to have sudo use the specific command before using the general entry?


Checkbox function to automatically add to total

I'm doing my club's accounting in a Google spreadsheet. I am looking for a way to put a checkbox at the beginning of a line in order to tick off the members who paid their dues and then have a function that will automatically add the amount of the "dues paid" cell to a "total dues paid" cell, elsewhere in the sheet.  Right now I'm doing it with a function of the type SUM(A1:A600)-A3-A20-A120 etc.—not very elegant…  If anyone could point me to a solution or a resource to learn how to implement this, I would appreciate it!


How do I get fireworks at the end of a Super Mario Bros level?

Every once and a while, I hear a game- like tune different from the usual end level tune and then there are fireworks.


How to get dark menu bar and dock in Mojave light mode?

I prefer light windows with dark menu bar as in High Sierra. However, it seems I can only choose all-dark or all-light in Mojave now. Are there any way to hybrid or customize it?


Issues with sequential feature selection

I am trying to do some feature selection in gene expression data with 22215 features. I followed the tutorial .  I initially applied filter method(ttest) to select the features having the best p values. I selected 100 features from them initially. Then I tried to apply sequential feature selection method on them with SVM classifier. However, when I do  [fs1, history] = sequentialfs(@SVM_class_fun, reducedL, yS1, 'cv', c);   it always returned me the 1st feature only. I mean in fs1 every other feature except the first one is 0. If I try to force it to give me 10 features with   [fs1, history] = sequentialfs(@SVM_class_fun, reducedL, yS1, 'cv', c, 'nfeatures', 10);   Here is my SVM_class_fun  function err = SVM_class_fun(xTrain, yTrain, xTest, yTest)   model = svmtrain(xTrain, yTrain, 'Kernel_Function', 'rbf', 'boxconstraint', 10);   err = sum(svmclassify(model, xTest) ~= yTest); end   it will give me the first 10 selected by the filter method having lowest p values.  So this mean using sequentialfs is not helpful in this case.  To let you know I have just 12 examples. So my data matrix is of dimension 12x22215. Might this be the issue?  Can anyone provide some insights?


why does plugging into a new USB port often solve USB problems?

I have 4 USB ports on the front of my computer and 6 in the back.  I have about 8 USB devices: external drives, sticks, cell phones, cameras.  It is often the case (40% of the time) that I plug something in (usually the external hard drive or cell phone) and it is not recognized or doesn't work correctly. My solution is to just plug it into another USB port (usually switching back-to-front or front-to-back works). I've found that this solves the problem 100% of the time.  Am I doing something wrong or is there just something "not quite baked" with USB (2.0) technology? It seems that e.g. the external hard drive "tires of its USB port" after while and needs a new one to be recognized again, i.e. there seems to be some kind of caching or ID recording that is going on.  This has happened on the last two computers that I had and still on the new one I just bought. The last two computers have USB 2.0 ports.  Can anyone explain what is going on with USB that would cause this phenomenon and perhaps what I could do so I dont' have to keep unplugging and replugging my USB devices to get them to work?


Why didn’t James Potter and the rest of the Marauders register as Animagi?

James Potter and co became un-registered Animagi in their school years. Presumably they didn't say anything about it for 2 reasons: first, it would prevent them from spending full moons with Moony; and second, it went against their rebel-without-a-cluecause nature.  It seems that being an unregistered Animagus is dangerous (Hermione implied in OotP that Rita Skeeter would go to Azkaban, as her blackmail).     "Otherwise, as you very well know, I will inform the authorities that you are an unregistered Animagus. Of course, the Prophet might give you rather a lot for an insider’s account of life in Azkaban.”   So, why didn't they register as Animagi after graduation, when James went "respectable" under Lily's influence and they no longer needed to hide their spending time with Lupin?   They could simply say they JUST learned to become Animagi; to avoid being accused of being unregistered during their school years.


Will an introduction to number theory help clear concepts of base conversion

I am having a hard time understanding why the division algorithm works during base conversion even after reading some of the answers given on this site.  Obviously I am missing a formal introduction to these topics hence the difficulty. So I am asking if introductory books on number theory like - "A Friendly Introduction to Number theory" or "A Gentle Introduction to Number Theory" would solve this problem?


Transaction log reported full but is not

Batch jobs error emails report:      The transaction log for database 'WebDB' is full.   No, it isn't. Its 90% free. The transaction log backups run normally. My hardware guy tells me the hardware is running perfectly, with plenty of space. SQL Server 2008 SP3, but not R2.  I'm a developer, we no longer have a DBA. So it falls to me to try and fix this.


How do I evaluate this function for given $s$?  $$\zeta(s) = \sum_{n=1}^\infty \frac1{n^s} = \frac{1}{1^s} + \frac{1}{2^s} + \frac{1}{3^s} + \cdots$$


what is the best email type to request for Phd position

Recently I have found a great PHD position which on some aspect exactly fit with my CV.  I am looking for the best email type to introduce my self to the professor? what information are necessary on my email.   Do you show me any examples or links?


The ancients undoubtedly discovered the ideal shape of a water clock by trial and error. In examining some ancient water clocks I notice the shape is different depending on the size. For example, a 9-inch water clock will have a different shape than a 5-inch water clock. Obviously the size of the orifice is very important also, and for that reason water clocks were made from metal, even gold, or from hardened ceramic, so that the orifice could be sized very exactly.  Should a modern person wish to make a water clock without going through the agony of many hundreds of hours of experimentation, what theory could be used to determine the ideal shape using the principles of physics alone?  The type of clepsydra I am envision is one that would provide the height of the water as a linear function of time.


I have the following code:  while (true) {     in = new BufferedReader(new InputStreamReader(socket.getInputStream()));     out = new PrintWriter(socket.getOutputStream());      String result = null;     while (result != "string") {         out.println("string one");         out.flush();          String var = null;               if ((var = in.readLine()) != null) {             var2 = function(login);             out.println(var2);             out.flush();         }     }            }   The flushing is not working correctly, mainly the first iteration of the outer while loop will print both outputs, but then after that there is an odd delay and everything is messed up ("string one" is not printing to the output).   What am I doing wrong?


Can anyone explain to me why light is not dispersed into a spectrum through a parallel glass slide, but only through a prism?

The question pretty much sums up what I need to know. Why is it that light only gets dispersed into a spectrum when travelling through two non-parallel sides(like a prism) and not through something like a glass slide with parallel slides.  And how does this experiment(an experiment conducted by Newton) explain this? Because this is what is in my school textbook.


How can I acknowledge, thank, or otherwise approve of an edit?

Possible Duplicate:    Sometimes I get an edit that greatly improves a question or answer I have submitted.  I'd like to acknowledge an edit like this, so that readers can know that the revision was approved of by the OP (me!). I was thinking of comments on edit, or a checkbox noting that OP vouches for the edit.  Sometimes I would like to add a comment to the question or answer, but those don't make a lot of sense in that context. Any suggestions about the best way to do this?  Consider this a feature request, as it seems useful to know that a particular edit was endorsed/vetted by the OP.


I'm changing the default setting for arp_ignore on an ubuntu 16.04 server, from it's default value 0 to 1.  My understanding of the /proc/sys/net/ipv4/conf/ directory is that files under all will affect all interfaces, and default will affect newly created interfaces.  After changing the value of /proc/sys/net/ipv4/conf/all/arp_ignore to 1, the other files are still set to 0:  cat /proc/sys/net/ipv4/conf/*/arp_ignore 1 0 0 0   Does the value of /proc/sys/net/ipv4/conf/all/arp_ignore just override the interface specific files rather than changing their values?


Time between connecting flights (separate tickets) at CDG

I am flying to CDG with WOW. The airplane arrives at Terminal 1 at 11:30 AM (stats say that usually not later than 12:15 PM). Assuming it will land no later than that, what is the earliest time I can take a domestic flight from terminal 2F on a separate ticket? Do I have to get completely out of the airport? I guess I have to enter EU first. Is there automatic passport control at CDG (like the one in FRA)?  Thanks!


When should I not use .com as a generic top-level domain? (.com vs .net, .org, etc.)

I've noticed .com is the standard top-level domain, but when should I not use .com? What are the most common alternatives? If someone has foo.com registered, should I choose a different domain or register foo.somethingelse?


I am learning how multithreading is supported by Spring. I found that Spring docs say that JdbcTemplate is  once configured. People suggest to use one instance of JdbcTemplate for the whole app as it is thread-safe (meaning there is no need to create a new instance for each class).  But when i look at the JdbcTemplate code i do not see any synchronized methods, locks or volatile variables. Also it contains a lot of instance variables. My question is how the JdbcTemplate can be thread-safe in this case?


Parameterized Queries with LIKE and IN conditions

Parameterized Queries in .Net always look like this in the examples:  SqlCommand comm = new SqlCommand(@"    SELECT *     FROM   Products     WHERE  Category_ID = @categoryid ",     conn); comm.Parameters.Add("@categoryid", SqlDbType.Int); comm.Parameters["@categoryid"].Value = CategoryID;   But I'm running into a brick wall trying to do the following:  SqlCommand comm = new SqlCommand(@"    SELECT *     FROM   Products     WHERE  Category_ID IN (@categoryids)        OR  name LIKE '%@name%' ",     conn); comm.Parameters.Add("@categoryids", SqlDbType.Int); comm.Parameters["@categoryids"].Value = CategoryIDs; comm.Parameters.Add("@name", SqlDbType.Int); comm.Parameters["@name"].Value = Name;   Where   CategoryIDs is a comma separated list of numbers "123,456,789" (without quotes) Name is a string, possibly with single quotes and other bad characters   What's the right syntax for this?


Short story about aliens who want to trade items for information, stories, jokes etc

So the aliens sent down pods, maybe they were phones, requesting info and would give you things in return. I remember a guy asked for a device that could make anything you want using nanotechnology. It would make it by disassembling items near by. He was wanted I think and made guns or a ship or something like that. I'm pretty sure it was in a book of short stories I read like 3 or 4 years ago.


Possible Duplicate:          I need to know why Euler's formula is true? I mean why is the following true: $$ e^{ix}  = \cos(x) + i\sin(x) $$


Integration of a multiplied weibull distribution

I am having trouble integrating a weibull function multiplied with a production function. The expression shortened for integration is as follows:  $$v^{k+2}e^{-\left(\frac{v}{y}\right)^k}$$  I hope you can read the expression and help with the question.


I have this issue . To solve it, I have to use terminal using Alt+F2. However it demands login and password to take actions in terminal. I forgot my login. Any ideas?


Cursor movement in comment edit-boxes broken

Trying to move the editing cursor while editing a comment on android using the screen keyboard's arrow keys results in incorrect behavior.  Moving right or left causes the cursor to move in that direction, and jump back to the first/highest line of the comment on the screen.  Moving up works as intended. Moving down does nothing at all.  Using latest SE app on Android 4.2


Who is run out if both batsmen are out of their grounds?

See following image. Who is Run-out?    A is crossed the crease and B is crossed half of the pitch. Run-out happening in B's side. Then who is out? A or B?


how do i put address between author's name and abstract in amsart?

\documentclass{amsart}  \usepackage{graphicx}    %and others  \begin{document}  \title[short title]{Title}  %how to make the title^*  \author[Nguyen Thi Hong]{ Nguyen Thi Hong \textsuperscript{1**}}  \address{\textsuperscript{1}Faculty of Mathematics and Physics, Charles University. Prague, Czech Republic.}  \email{nguyenhonglove@gmail.com}  % i'd like to have the address placed here  \keywords{keyword1, keyword2, keyword3, ...}  \begin{abstract} Abstract..... \end{abstract}  \maketitle   %prints out Title, Author and Abstract (all in smallcaps)  %here is the contents, several pages of text  %introduction, main part, conclusion %in the first page, in footnotes I want to have before ** Email: nguyenhonglove@gmail.com  \begin{thebibliography}{99} %references \end{thebibliography}   \newpage \begin{appendix} %lots of figures \end{appendix} \end{document}


FileObserver works fine for the most part but sometimes the following exception occurs:  FileObserver: Unhandled exception occurs   When a new file is added to the folder the FileObserver observes. But this error does not occur every time a new file is added to the folder, but happens randomly, and I don't know how to fix it. I have attached the code to the FileObserver and the method that are using it.   (CallLatestReceiptData) just calls a different method which calls the addNewReceipt method with the file path of the new added file in the folder. Here is the code:  private void initializeFileObserver() {     observer = new FileObserver(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES).toString() + "/" + "Receipt Manager" + "/") {         @Override         public void onEvent(int event, String file) {             switch (event) {                 case FileObserver.CREATE:                     callLatestReceiptData(file);                     Log.d(OBSERVER_LOG, "File created 1 [" + Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES).toString() + file + "]");                     break;             }         }     };     observer.startWatching(); }  private void addNewReceipt(String path) {      Log.d(RECEIPT_SERVICE_LOG, "Called Database AddNewReceipt");     String picturePath = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES).toString() + "/" + "Receipt Manager" + "/" + path;     Log.d(RECEIPT_SERVICE_LOG, "Set PicturePath AddNewReceipt");     Log.d(RECEIPT_SERVICE_LOG, picturePath);      Bitmap rotatedBitmap = createRotateAndScaleBitmap(picturePath);     Log.d(RECEIPT_SERVICE_LOG, "Rotated Bitmap AddNewReceipt");     byte[] byteArrayPicture = convertBitmapToByteArray(rotatedBitmap);     Log.d(RECEIPT_SERVICE_LOG, "Rotated Bitmap AddNewReceipt");      String date = picturePath.replace(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES).toString() + "/" + "Receipt Manager" + "/", "").replace(".jpg", "");     Log.d(RECEIPT_SERVICE_LOG, "Set Date AddNewReceipt");     final Receipts receipts = new Receipts("", "", date, "", "", 0, byteArrayPicture, 1);     Log.d(RECEIPT_SERVICE_LOG, "Created New Receipt AddNewReceipt");      receiptDatabase.daoAccessReceipt().insertOnlySingleReceipt(receipts);     Log.d(RECEIPT_SERVICE_LOG, "Inserted In Database AddNewReceipt");     fetchReceiptData(receipts);     Log.d(RECEIPT_SERVICE_LOG, "Fetch Data To List AddNewReceipt");      isDone = true;     Log.d(RECEIPT_SERVICE_LOG, "ISDONE IS TRUE - ADD_NEW_RECEIPT"); }     private Bitmap createRotateAndScaleBitmap(String filePath) {      Matrix matrix = new Matrix();     Log.d(RECEIPT_SERVICE_LOG, "Matrix Called");     matrix.postRotate(90);     Log.d(RECEIPT_SERVICE_LOG, "Matrix Rotated");     Bitmap receiptBitmap = BitmapFactory.decodeFile(filePath);     Log.d(RECEIPT_SERVICE_LOG, "File Decoded");     Bitmap scaledBitmap = Bitmap.createScaledBitmap(receiptBitmap, 1280, 960, false);     Log.d(RECEIPT_SERVICE_LOG, "Bitmap Scaled");     Bitmap rotatedBitmap = Bitmap.createBitmap(scaledBitmap, 0, 0, scaledBitmap.getWidth(), scaledBitmap.getHeight(), matrix, false);     Log.d(RECEIPT_SERVICE_LOG, "Bitmap Rotated");      return rotatedBitmap; }


A basic question on convergence in prob. and a.s. convergence

If random variables $X_n$ are dominated by an integrable random variable then $E[X_n]\to E[X]$ follows if $X_n$ converges to $X$ in probability.  Proof: Take any subsequence $\{E[X_{n_k}]\}$. I need to show that it converges to $E[X]$. Now I know that $X_{n_k}$ contains a further subsequence $X_{n_k(i)} $where almost sure convergence is guranteed. and so, $E[X_{n_k(i)}]\to E[X]$. We can say upto this much. But, I have to prove $\{E[X_{n_k}]\} \to E[X]$ . How to proceed from here.


I have following text chunk:  \colorbox{gray}{[862401.693536] sd 2:0:0:0: [sdb] Write Protect is off\hfill \break [862401.693548] sd 2:0:0:0: [sdb] Mode Sense: 45 00 00 08\hfill \break [862401.700884]  sdb: sdb1\hfill \break [862401.705538] sd 2:0:0:0: [sdb] No Caching mode page present\hfill \break [862401.705551] sd 2:0:0:0: [sdb] Assuming drive cache: write through\hfill \break [862401.705562] sd 2:0:0:0: [sdb] Attached SCSI removable disk}   The output is visible in attached screenshot. Why \hfill and \break combo does not work?


I want to see all output even if it is huge. For example, running systeminfo via regular command line prompt in Windows will show everything with vertical scrolling. But when I'm invoking the same command in Far 3 I'm able to see just the end of information that fit in one screen.


Here's the code where I should fill the square with different colors using menuBar  import java.awt.*; import java.awt.event.*; import java.awt.font.TextAttribute; import java.text.AttributedString; import javax.swing.*;  public class Hot {     public static void main(String[] args) {         MenuScribble frame;         frame = new MenuScribble("Square");         frame.setVisible(true);     } } class MenuScribble extends JFrame {      public MenuScribble(String s) {          super(s);         //setSize(500,500);         setVisible(true);         //pane.setSize(300, 300);         //add(pane, BorderLayout.CENTER);         MenuBar mb = new MenuBar();         setMenuBar(mb);         Menu menu = new Menu("Options");         mb.add(menu);          MenuShortcut keyYellow = new MenuShortcut(KeyEvent.VK_B);         MenuShortcut keyRed = new MenuShortcut(KeyEvent.VK_N);         MenuShortcut keyLabel = new MenuShortcut(KeyEvent.VK_M);          MenuItem yellow = new MenuItem("Fill with yellow", keyYellow);         MenuItem red = new MenuItem("Fill with red", keyRed);         MenuItem label = new MenuItem("Add a label", keyLabel);          yellow.addActionListener(new ActionListener() {              @Override             public void actionPerformed(ActionEvent e) {                 Pan obj = new Pan();                 obj.draw(1);                 }             });          red.addActionListener(new ActionListener() {              @Override             public void actionPerformed(ActionEvent e) {                 Pan obj = new Pan();                 obj.draw(2);             }         });         label.addActionListener(new ActionListener() {              @Override             public void actionPerformed(ActionEvent e) {                 Pan obj = new Pan();                 obj.draw(3);             }         });          Pan p = new Pan();          menu.add(yellow);         menu.add(red);         menu.add(label);         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);         setSize(840, 500);         add(p);         p.setBounds(0, 0, 840, 370);         p.setBackground(Color.BLACK);     }  }   Wnen I'm trying to click on menu items I got that errors:   Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException     at Pan.draw(Hot.java:85)     at MenuScribble$1.actionPerformed(Hot.java:41)     at java.awt.MenuItem.processActionEvent(Unknown Source)     at java.awt.MenuItem.processEvent(Unknown Source)     at java.awt.MenuComponent.dispatchEventImpl(Unknown Source)   What should I change in the code to avoid errors? ................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................


Where do I find the "official" rules for D&D 5e?

I play D&D 5e and sometimes come here with questions. But sometimes I see things referenced here as sources that I don't have or aren't aware of....  Which are the "official rules" for D&D 5e, and where do I find them?


multiple git repositories cloned into the same directory

I've got a standard repository for my project    /home/repo/.git     this is the repository i clone to get the base code for new websites i.e. i cloned this to   /var/www/site1   i also have several modules that i've created as repositories, some websites will be using these modules and some will not.     /home/modules/mod1/.git   /home/modules/mod2/.git   is there a way that i can clone those modules into the same site folder?    /var/www/site1     the module directories are set up with the same folder structure as the master repo, when i clone them on top of the master repo clone they should merge/replace existing files. (rarely any file overlap)  my optimal solution would be naming the repo's in some way so that when i deploy a new site I do something like:  cd /var/www/newsite   git clone /home/repo/.git   git clone /home/modules/mod1/.git   git clone /home/moudles/mod2/.git     and when I have updates to make to the site I could do a pull like:  git pull origin master   git pull mod1   git pull mod2     or  preferably:  git pull origin master    would also call the pulls on mod1 and mod2.  I've been looking at git submodules and branches but can't figure out if they are what I need.


Is there any paper analyzing the validity of Relativity in expanding space?

Big Bang models result from applying Relativity equations to expanding space; however, as Einstein noted, Relativity was not established in expanding space. A basic question arises: is Relativity valid in expanding space? Its validity in expanding space has implications on the properties of space, matter, time, light speed? Has anyone analyzed this? Or the validity of Relativity in expanding space is irrelevant because Big Bang models are just mathematical models and the only thing that matters is to obtain equations that fit cosmic data?


PERL : Unicode string : Permission denied

I program using Perl and need to install Unicode String. But make install tells me:      Files found in blib/arch: installing files in blib/lib into   architecture dependent library tree   !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!   ERROR: Can't create   '/Library/Perl/5.16/darwin-thread-multi-2level/Unicode' mkdir   /Library/Perl/5.16/darwin-thread-multi-2level/Unicode: Permission   denied at /System/Library/Perl/5.16/ExtUtils/Install.pm line 494.      !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!   at -e line 1. make: *** [pure_site_install] Error 13   Does anyone ever encountered this problem?


How to maintain current zoom level when panning to a new feature?

I want to speed up my work. How could I get ArcMap to stay at my current zoom level when panning to a new feature?  What I am currently doing is using Ctrl+Enter to move through my attribute table and Ctrl+= to zoom to my point. However, ArcMap will not maintain my current zoom level and no amount of messing around in scale settings has kept it where I need it to be. Even if I have only the scales I want in the drop down it will still put me at 1:7534 anytime I zoom to a new point.


Show that $\int_0^1 {\sin \left( {\pi x} \right)} x^x \left( {1 - x} \right)^{1 - x} \mathrm dx = \frac{{\pi e}}{{24}}$

While going through a  (Problem $17$) of interesting integrals I have come across this one     $$\int_0^1 {\sin \left( {\pi x} \right)} x^x \left( {1 - x} \right)^{1 - x} \mathrm dx = \frac{{\pi e}}{{24}}$$   I have tried integration by parts with $u=x^x \left( {1 - x} \right)^{1 - x}$ and $\mathrm dv=\sin \left( {\pi x} \right)$ but this ended up in and even more complicated integral. To use the series representation of $e^{x\ln(x)}$ and respectively $e^{(1-x)\ln(1-x)}$ does not appeared to be helpful at all even after reshaping it all in the form $(1-x)\left(\frac{x}{1-x}\right)^x$. Then I thought about using Euler's Reflection Formula to get rid of the $\sin(\pi x)$ and work in terms of the Gamma Function instead. Hence this formula only holds for $x\notin\mathbb{Z}$ $-$ and the limits are given by $0$ and $1$ $-$ I guess this is not possible here. My last try was to use the Weierstrass Expansion of the sine function but I guess this is not the right approach either.     Could someone please provide a whole solution since I have no further idea how to deal with this integral? I have searched here on MSE but it does not seem like someone hast asked something like this before. Nevertheless tell me when I have overseen something or when you can link a former question which is helpful for understanding the process of evaluating this definite integral.   Thanks in advance!


Let's suppose I have the following loop:  for i in {1..3} do  mkdir $i  done   Since I have many other loops in the main code and I am going to change regularly the size of the sequence, I would like to define the start and end of the loop and use these variables in the for loop(s).  I tried this without success:  start=1; end=1;  for i in {$start..$end} do  mkdir $i  done   Any suggestion?


getting error while trying to install unity-lens-applications

I'm trying to install unity-lens-applications because my dash doesn't show application when I search something and It returned these errors:  The following packages have unmet dependencies: unity-lens-applications:i386 : Depends: libxapian22:i386 but it is not going to be installed Depends: unity-common-7.0:i386 or unity-common:i386 (>= 7.0.0) E: Unable to correct problems, you have held broken packages.   but when I search for broken packages in my package manager it shows that there is no broken package !  Any Idea to solve this problem ?


I cannot navigate back to question from Image page

When there is an attached image in a question on any SE site, clicking on it opens it in a full screen mode. There is no way to redirect back to the question unless you press browser's back button. Keyboard's escape key does not work, neither there is explicit close button. Is there any different key combination to escape out from that page, or shall I be using back button of the browser?  Attached screenshot:   From the comment: "Because it's a link to another site. It's not being opened in a lightbox or anything. Notice that the address bar says imgur.com" - So is it possible to prevent this redirection and open image as popup or something, or using back button is fine?


I am an algebraic geometer and I fell in love with the font they use in mathematical articles published by the IHES (for instance EGA, which I assume is the most famous of all time). How would I proceed to do that?   P.S. : I don't just want to know what to write in the code (which I assume is quite obvious), I'd also like to know what font it is.   EDIT : Actually I realized it only changed the font, not the math font. In EGA the math symbols are not slanted as in the standard math font... what about that? (Please don't close!)


Can I travel around the EU with an Italian resident permit (humanity), without a passport?

I have an Italian resident permit (for humanity reasons).   Can I travel around the EU with this resident permit, without a passport?


I have to prove the  by tomorrow and I am really unconfident about what I did:  $$\sum_{n=1}^\infty a_n\text{ converges } \iff \sum_{n=1}^\infty 2^n a_{2^n}\text{ converges}$$  I did the following:  Let $(b_n)$ be a sequence as follow: $b_{2^k+m}:=a_{2^k}$ with $k\in\mathbb N_0$ and $0\leq m<2^k$.  It's $a_{n+1}\leq a_n$ and so $0\leq a_{n+p}\leq a_n$ for all $n,p\in\mathbb N$.  So $\sum\limits_{n=1}^\infty b_n$ converges by the majorizing series $\sum\limits_{n=1}^\infty a_n$. And it's $\sum\limits_{n=0}^\infty b_n=\sum\limits_{n=0}^\infty\sum\limits_{m=0}^{2^n-1}a_{2^{n+1}}=\sum\limits_{n=1}^\infty 2^{n-1}a_{2^n}$ so $\Rightarrow$ is done.  For $\Leftarrow$ consider $c_{2^k+m}:=a_{2^k}$ with $k\in\mathbb N_0$ and $0\leq m<2^k$.  It's $|a_n|\leq c_n$ and $\sum\limits_{n=0}^\infty c_n=\sum\limits_{n=0}^\infty\sum\limits_{m=0}^{2^n-1}a_{2^{n}}=\sum\limits_{n=1}^\infty 2^{n}a_{2^n}$ and so $\sum\limits_{n=1}^\infty a_n$ converges by the majorizing series $\sum\limits_{n=0}^\infty c_n$.  Is this in form and content correct?


Reason for inertia of motion of Earth orbiting the Sun

We all know the following universal truth since childhood.     Earth (and other planets) orbits around the Sun.   And, while I was reading , I found that the reason behind Earth revolution is chiefly due to one force:   Gravitational pull   Some physicists explains the movement of Earth around the Sun on the basis of the following image:       As we can see, the initial state of rock is rest. And when we apply a force, it starts moving in a circular path.   Now my question is from where the Earth had got the inertia of motion? As the rock in the above example was initially at rest and so the Earth should also be in state of rest (without any force applied on it).


I have been trying to figure out what is going on when I run apt-get update. I've tried going through the sources file and also using the Ubuntu Tweak to clean the sources list, but nothing is working.   When I run apt-get update I get this:  Reading package lists... Done N: Skipping acquire of configured file 'main/binary-i386/Packages' as repository 'https://packages.microsoft.com/repos/vscode stable InRelease' doesn't support architecture 'i386' W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://download.opensuse.org/repositories/home:/Horst3180/xUbuntu_16.04  Release: The following signatures were invalid: KEYEXPIRED 1496576244 W: The repository 'http://ppa.launchpad.net/tualatrix/ppa/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. W: Failed to fetch http://download.opensuse.org/repositories/home:/Horst3180/xUbuntu_16.04/Release.gpg  The following signatures were invalid: KEYEXPIRED 1496576244 E: Failed to fetch http://ppa.launchpad.net/tualatrix/ppa/ubuntu/dists/xenial/main/binary-amd64/Packages  404  Not Found W: Some index files failed to download. They have been ignored, or old ones used instead. W: Duplicate sources.list entry http://packages.microsoft.com/repos/vscode stable Release


Is heat transfer really just work at the microscopic scale?

I am having trouble understanding why a division is made between heat and work. The units for energy is $\text{kg} \, \text{m}^2 \, \text{s}^{-2}$. The only way to obtain this unit is if you exert a force over a distance - that is, if you do work. In other words, the only way to change the energy of something is if you do work on it. However, in thermodynamics, we are taught that there are two ways of changing the energy of a system: (1) heat transfer and (2) work. This got me thinking about how something other than work can change the energy of a system. But, given that heat transfer is just a transfer of energy through collisions at the microscopic scale, can we go as far as to say that heat is just work done at a microscopic level?


How to fully install Ubuntu on USB Flashdrive?

Rather than to install dual-OS on my laptop, I would like to install Ubuntu on my flashdrive (USB flash memory, or whatever you call it). So, whenever I want to run my Ubuntu, I will just plug my flashdrive to the USB port and run it from there by change the boot sequence in BIOS.  Is it possible?


How to reset sequence if the table is empty?

I am using Oracle SQL. There is a sequence and trigger used for id that increments from 1 every time a new record is added in the table. However if all the records are deleted and new records to be added this table, the id doesn't starts from 1 whilst it starts from the last maximum number of records recorded in the sequence.   Therefore is there a way in TRIGGER statement where I can reset the sequence if the table is empty and new records get imported.   OR do I have to do stored_procedure way, if that then how can i call this using myBatis mapper?   Table (customer_info)  customer_id customer_name customer_location 1           Arbin         USA 2           Tim           Canada 3           Rachel        Australia   Sequence  CREATE sequence customer_id_seq START WITH 1 INCREMENT BY 1 NOCACHE NOCYCLE;    Trigger  CREATE OR REPLACE TRIGGER customer_id  BEFORE INSERT ON customer_info  FOR EACH ROW  BEGIN  SELECT customer_id_seq.NEXTVAL  INTO   :new.customer_id  FROM   dual; END; /   Thank you.


Setting filename using encodeURIComponent() to let user download data file

Alright, so I have this webpage page that gets its data using AJAX requests (in javascript using JQuery). Once the data has been loaded on to the users browser I want to let them download said data without having to request it from the server again.  To do this, I found this little bit of code (in Javascript):  window.location = 'data:text/csv;charset=utf8,' + encodeURIComponent(someCSVtext);   This does what I want it to do, but it always names the file "download.csv"  Is there a way I can preset the filename assuming the user has an "always download file" option set in their browser (thus don't get a chance to rename the file)?


The length of a rectangle is $4$ m longer than its width. If the area is $8$ m$^2$, find the rectangle's dimensions.

The length of the rectangle is $4$ m longer than its width.  If the area is $8~\text{m}^2$, find the rectangle's dimensions. Round to the nearest $10$th of a meter.  I have absolutely no clue how to begin with this.


Force spaces to convert to %20 from HTML input field using js or jQuery

Hello I have an input field on my site which people can enter search terms.  I am taking the value of the users input and spitting it out onto a url string.    jQuery("#searchButton").click(function(){     var simpleSearchTermLocal = jQuery('#searchField').val();     var urlString = "www.mysite.com/" + simpleSearchTermLocal;     alert(urlString); }); <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <input type="text" id="searchField" /> <button id="searchButton">search</button>     So when someone inputs something like "ABC" into the search field, the value of variable urlString becomes www.mysite.com/ABC which is fine.  But when entering a space in the input field, like "ABC 123", urlString becomes www.mysite.com/ABC 123 which isnt fine. I would like it to turn into www.mysite.com/ABC%20123  Any suggestions?  Thanks


Integrate $\int\sqrt{x+\sqrt{x^{2}+2}} dx$ .

Q)  $\int\sqrt{x+\sqrt{x^{2}+2}} dx$ .  Tried rationalising the numerator twice to get Numerator =-2 but not able to simplify denominator   The question reduces to (as per my rationalising)  $$\int \frac{-2}{\bigl(x - \sqrt{x^2+2}\bigr)\sqrt{x + \sqrt{x^2+2}}}\,dx$$


I need to get position marked as green X. I have the helicopter's world position and the player's world position. I want X to always have an angle of 90 degrees. Player heading is ignored. How can I obtain the position X.


45 Minute Layover in Frankfurt on a flight from the US to India. Do I need to rebook?

I booked a flight from the US to India which has a 45 minute layover in Frankfurt. I'm a decently experienced flier and I've handled one hour layovers in Abu Dhabi or half an hour layovers domestically, but this one is freaking me out quite a bit.  The tickets are on one booking from Lufthansa and both flights arrive and take off from the same Terminal - Terminal 1. My one concern is that any outbound flights from Frankfurt to India would require me to have a Schengen visa, which I don't. Re-booking the flight would probably double the flight time.  Do you think I will be able to make my flight? Has anyone experienced this before?  Also, I'm flying in a from a non-Schengen zone area to another. I believe there are other implications as a result.


If $f \in D[x]$ has $f` a=0=f` b$ for $a \neq b$ in $D$, show that $f$ is divisible by $(x-a)(x-b)$

I'm doing Exercise 14 in textbook Algebra by Saunders MacLane and Garrett Birkhoff.   For $f \in D[x]$, $f` \in D^D$ is the polynomial function induced by $f$. If $f` a=0=f` b$ for $a \neq b$ in $D$, show that $f$ is divisible by $(x-a)(x-b)$.  My proof is very short that I suspect if I made any subtle mistakes. Could you please verify if my understanding is correct? Thank you so much for your help!  Our convention is that $\deg 0 = -\infty$. It follows from $f`a=0$ and division algorithm for commutative ring that $f = (x-a)g$ for some $g \in D[x]$ where $\deg g < \deg f$. Because $D[x] \to D^D, f \to f`$ is a homomorphism of rings, $f` = (x-a)`g`$ and thus $f`b = (b-a)g`b$. Then $f`b = 0 \iff (b-a)g`b= 0$. It follows from $b-a\neq 0$ and $D$ has no zero divisors that $g`b = 0$. Again, we get $g = (x-b)h$ for some $h \in D[x]$ where $\deg h < \deg g$. This completes the proof.


Why is gksu no longer installed by default?

I have always recommended pressing ALT+F2 and typing for example gksu nautilus or gksudo nautilus both are equivalent; to run graphical programs with root privileges.  However, I have just installed raring on a test system and this no longer works.  gksu and gksudo are not installed as part of a default raring install; though they are in the repositories. In 12.04 at least gksudo was just a symbolic link to gksu  The reasons I have always done this are because while it is often safe to use sudo under some circumstances it can cause problems with graphical applications because gksu has you running the program as root while with sudo you are running as yourself but with elevated privileges.  This can mean you inadvertently change the owner of critical system files.  This can cause problems.  This reasoning is explained better here:         Why was command removed from a fresh install and what should we be using instead?


I need to downgrade my PHP from 5.6 to 5.5  Here is what I've done so far  sudo aptitude purge `dpkg -l | grep php| awk '{print $2}' |tr "\n" " "`   Then   sudo apt-get install python-software-properties sudo add-apt-repository ppa:ondrej/php5 sudo apt-get update sudo apt-get install -y php5   Then I tried  sudo apt-get install php5   and  sudo apt-get install php5=5.5.26+dfsg-1+deb.sury.org~vivid+1   This is what I get when I run apt-cache policy php5  php5:   Installé : (aucun)   Candidat : 5.6.4+dfsg-4ubuntu6.2  Table de version :      5.6.4+dfsg-4ubuntu6.2 0         500 http://fr.archive.ubuntu.com/ubuntu/ vivid-updates/main amd64 Packages         500 http://security.ubuntu.com/ubuntu/ vivid-security/main amd64 Packages      5.6.4+dfsg-4ubuntu6 0         500 http://fr.archive.ubuntu.com/ubuntu/ vivid/main amd64 Packages      5.5.26+dfsg-1+deb.sury.org~vivid+1 0         500 http://ppa.launchpad.net/ondrej/php5/ubuntu/ vivid/main amd64 Packages   No matter what I do, PHP 5.6 is installed. I even tried with Synaptic, without success.  Any idea ?


Is there any way to determine a file's size without having to open it, as provided in the Java platform API (no 3rd party libs)? Also, I need the 64-bit size (which I assume Java would provide to begin with).


i found this relation whilst trying to evaluate the norm (over $\mathbb{Q}$) of $1-\zeta$ for $\zeta$ a primitive $p$-th root of unity ($p$ supposed prime) $$ \prod_{k=1}^{p-1} \sin(\frac{\pi k}{p}) = \frac{p}{2^{p-1}} $$ as yet i have no means of proving it. any suggestions?


Stack Egg - Force restart only if restart gains majority vote (at least 66% of total votes)

Tested this out on several sites with little activity/progress in the StackEgg game, so no harm done.  Restarting can occur as long as you have either majority vote on second vote or top vote (even if tie).  Make it so that a restart REQUIRES a majority vote. Meaning 50-50 will not restart.  Hell, even on the stackegg sites that have a lot of users, making it 2/3rds majority can easily root out the bots auto casting restart votes.  Simplest way to deal with the "Restart" abusers.


move Windows 7 OS from one SSD (128GB) drive to another (256GB)

I have Windows 7 Home Premium 64 bit installed on a 128GB SSD drive. Recently, I've purchased a new 500GB SSD drive and wish to move the entire OS over there, in order not to be forced to install everything all over again. I have tried a few things I've found in various guides online, and even tried it with EaseUS TODO Backup software, but at best all I got is that when I start the PC from the new drive, I get a message to insert a bootable disk... Any help in this matter will be greatly appreciated.


Creating the best possible home made milk chocolate bar

Assuming I am a total newbie in "patisserie", what are the best ingredients and steps to be used/taken to deliver a top quality home made milk chocolate bar? I mean, those that really make a difference from low-quality/average and finest/top-quality. For instance, cocoa quality and selection, cocoa butter (or butter?), powder milk. Are there any well-known tips or techniques? Any suggestions?


Is it true that a matrix is always positive semi-definite if it is positive definite?  I think it is not true since I saw a counter-example somewhere.  But the terminology 'semi-definite' and 'definite' seems to imply that 'definite' has strong condition, thus being sufficient condition for semi-definiteness.  So I want to know more detailed mathematical explanation for this proposition.


I am a Nigerian doctor working in Saudi Arabia. I am married with 2 children but my family resides in Nigeria. I was denied a plab 2 visa recently (see picture) and I am planning to reapply. I have also been denied 2 years ago for a visit visa due to lack of funds/fund parking. What are changes I could make to improve my chances?  By changes I mean:  1 Should I reduce my proposed length of stay to 3 days? This I already plan to do.  2 The only evidence that I have booked for this exam is the confirmation email usually sent after paying. How do I go about getting it certified like the ECO hinted? Should I include other things like a receipt generated from the GMC website? Also include all the email communication I have had with the GMC?  3 I stated I wanted to familiarize myself with the UK healthcare system. This was interpreted by the ECO to mean I wanted to do a clinical attachment. Should I explain this in my cover letter, on the application website or totally ignore it?  4 I applied for a PLAB visa. However I was assessed under the clinical attachment category. Should I point it out or keep quiet?  5 This last application was in Nigeria during my leave, now I plan to apply in Saudi Arabia. Does this affect my outcome positively or otherwise?


Do flags to close expire like votes to close?

Votes to close are known to expire, for the reasons explained eg in answers to this question:   Does something like this happen to flags to close cast by users lacking ?  Side note - related question makes one feel that it's unlikely the case:     I ask because per  flags like that are no longer targeted to moderators only, but instead, go to same  as votes to close. This makes one wonder if the reasoning for votes expiration can now be applied to flags.


Where does $PATH get set in OS X 10.6 Snow Leopard?

I type echo $PATH on the command line and get  /opt/local/bin:/opt/local/sbin:/Users/andrew/bin:/usr/local/bin:/usr/local/mysql/bin:/usr/local/pear/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin:/opt/local/bin:/usr/local/git/bin  I'm wondering where this is getting set since my .bash_login file is empty.  I'm particularly concerned that, after installing MacPorts, it installed a bunch of junk in /opt. I don't think that directory even exists in a normal Mac OS X install.  Update: Thanks to  for correcting my echo $PATH statement


I am trying to uninstall Skype and Skype for Business.  The major problem that I am having is that neither app is showing up on the uninstall screen of control panel.  Any suggestions?


Difference between static with and without public

I have a Class RequestHelper where I store methods for http-Requests to initiate Requests from different Activities.  E.g. there is this one:   class RequestHelper {     static void loginUser(String email, String password, final Context activityContext) {     // do request stuff     } }   Is there any difference if I put a public in front of it like in the following example or is it just nonsense to do so?  class RequestHelper {     public static void loginUser(String email, String password, final Context activityContext) {     // do request stuff     } }   Both versions do work as planned, so is there any difference at all?


Splitting text files based on a regular expression

I have a text file which I want to split into 64 unequal parts, according to the 64 hexagrams of the Yi Jing. Since the passage for each hexagram begins with some digit(s), a period, and two newlines, the regex should be pretty easy to write.  But how do I actually split the text file into 64 new files according to this regex? It seems like more of a task for perl. But maybe there's a more obvious way that I'm just totally missing.


The combination for select all (Ctrl+A) doesn't work in a browser (either if we speak about firefox or chromium). It doesn't work if I try to clik in to the adress bar nor if I try to use it to select what I've written in google search bar at google.com. When I press Ctrl+A it simply takes the cursor before the first letter.  This doesn't happen when I use a text editor software like Libre Office. There the shortcut does what's supposed to do, selecting all the text.  What could be the problem?


Unable to install packages with pip (ubuntu 15.10)

I am trying to install packages via pip. Here some information:  OS = Ubuntu 15.10 python --version = 2.7.10 pip --version = pip 8.0.2 from /usr/local/lib/python2.7/dist-packages (python 2.7)   So far I have tried with scikit-learn, pyqrcode, and numpy using pip command, none of them was successfully installed. For example with numpy:  pip install numpy   The output is:  Collecting numpy   Downloading numpy-1.10.4.tar.gz (4.1MB)     100% |████████████████████████████████| 4.1MB 137kB/s  Building wheels for collected packages: numpy Running setup.py bdist_wheel for numpy ... done Stored in directory: /home/diego/.cache/pip/wheels/66/f5    /d7/f6ddd78b61037fcb51a3e32c9cd276e292343cdd62d5384efd Successfully built numpy Installing collected packages: numpy Exception: Traceback (most recent call last): File "/usr/local/lib/python2.7/dist-packages/pip/basecommand.py", line 209, in main status = self.run(options, args) File "/usr/local/lib/python2.7/dist-packages/pip/commands/install.py", line 317, in run prefix=options.prefix_path, File "/usr/local/lib/python2.7/dist-packages/pip/req/req_set.py", line 731, in install     **kwargs File "/usr/local/lib/python2.7/dist-packages/pip/req/req_install.py", line 841, in install self.move_wheel_files(self.source_dir, root=root, prefix=prefix) File "/usr/local/lib/python2.7/dist-packages/pip/req/req_install.py", line 1040, in move_wheel_files isolated=self.isolated, File "/usr/local/lib/python2.7/dist-packages/pip/wheel.py", line 343, in move_wheel_files     clobber(source, lib_dir, True) File "/usr/local/lib/python2.7/dist-packages/pip/wheel.py", line 314, in clobber ensure_dir(destdir) File "/usr/local/lib/python2.7/dist-packages/pip/utils/__init__.py", line 82, in ensure_dir os.makedirs(path) File "/usr/lib/python2.7/os.py", line 157, in makedirs     mkdir(name, mode) OSError: [Errno 13] Permission denied: '/usr/local/lib/python2.7/dist-packages/numpy-1.10.4.dist-info'   Any help? thank you


Why aren't you automatically warned when a comment of your is deleted as offensive?

Recently I caustically commented a just-do-it-for-me question by an old user with "More than 7000 (!) reputation points without trying to do something by yourself and adding an MWE?"  My comment was deleted as offensive, but I realized it only by chance.  Since I used the same comment many times in the past for similar situations, I would have continued to use it in the future if I hadn't known it was considered offensive.  Why is there no sort of warning when a comment of yours is deleted for that reason?


Find the eigenvalues of an identity matrix minus a rank 1 matrix

This problem comes from Linear Algebra and its Applications by David C Lay and Steven R Lay.  Let $c$ be a unit vector in $\mathbb{R}^3$. Consider the matrix $A = I - 2cc^T$   a ) What are the eigenvalues of $A$?   b) Find an easily computable eigenvector of $A$  My attempt: Firstly we can see that $cc^T$ is a symmetric $rank\ 1$ matrix. Let $v_i$ be a eigenvector of $A$ for $i = 1, 2, 3$ $$Av_i = \lambda_iv_i = (I - 2cc^T)v_i \\ = Iv_i - 2cc^Tv_i \\ = v_i  - 2cc^Tv_i$$ I'm stumped on where to go next. Is there something I'm missing? Any pointers would be greatly appreciated :)


If you have a TRULY random key (in binary) and you have a text (in binary) that you want to encrypt.  Can you simple XOR the key and the text?  Is that secure?  How secure?


The prime elements of the ring $ \mathbb{Z} \! \left[ \dfrac{i \sqrt{3} - 1}{2} \right] $.

I have to study the prime elements of the ring $ \mathbb{Z} \! \left[ \dfrac{i \sqrt{3} - 1}{2} \right] $. For the moment, I cannot find the general form of such elements. Can you help me?  Thanks! :)


What device has high inductance? For example >1000mH (for 220Vrms 50-60Hz output)

What devices have high inductance values (for example >1000mH?) What I found in a real device (for example induction motor) datasheet is just near <1000mH (on rotor and stator.) Is there anything that has high inductance value besides filters and chokes?


Can a non EEA spouse have two Schengen visas (family and tourist)?

I went to Italy with my husband last year (he is British and I am Indian and we live in the UK). I got a free spouse of an EU national visa for a year with multiple entries allowed, this was issued by the Italian consulate. So technically, I have a valid Schengen visa but in the annotations, it says 'free visa, EU family' (in Italian).  Now I'm going to Spain with my sister in July and my husband can't join us. I know that according to EU law, I should apply for a new tourist visa. But will my existing Schengen Type C tourist visa cause any issues? I have read that you cannot have two Schengen visas at the same time.   I am dreading the thought of getting visas canceled and chasing consulates for a short weekend trip.  My questions are:    If I apply for a Schengen visa with the Spanish consulate, will they ask me to cancel my existing Schengen (EU family)? Or should I go to Spain without my husband?    It would help to know if anyone in this situation has been successful at changing their visa types or simply visiting the Schengen area without their spouse.


Prove that for each natural number $n$, with $n \geq 3$: $(1+(1/n)^n < n$.  I did the base step, (4/3)^3 < 3 so it holds, but I am confused about the inductive step.  The inductive hypothesis is (1+(1/k)^k < k, and the inductive conclusion is (1+(1/(k+1)))^k+1 < k+1. I can't figure out how to reach the IC from the IH.  I tried multiplying both sides by (1+(1/k), but that just gives (1+(1/k))^k+1 < k+1. Idk what I am supposed to do here?


Cocos2d-x supporting multi-resolution using density independent pixels

Is there a way to use Density Independent pixels(dp) in cocos2d-x?  I am developing an Android game using Cocos2d-x 3.0.  The Android reference  tells me not to use pixels in code but use dp when supporting multi-resolution support. It also tells me to provide different images for different screen size groups and different density groups.  However, cocos2d-x tutorials use pixels for multi-resolution support. If I were to use pixels, I think it means I need to have images for all these different resolutions:  240x320, 240x400, 240x432 320x480 480x640, 480x800, 480x854 600x1024 640x960 1024x600, 1024x768 1280x768, 1280x800 1536x1152 1920x1152, 1920x1200 2048x1536 2560x1536, 2560x1600  Even if I don't support every screen resolutions, I think this requires more work than following the Android reference's best practice.  Am I missing something on how supporting multi-resolution works or do I indeed do need to do much more work using cocos2d-x?


What's the word (or phrase) for the phenomenon that something suddenly works when you try to show an error

As the title describes, I'm looking for a word or phrase that describes the phenomenon that a bug/error/etc. disappears when you want to show it to someone.  Example: Your Internet connection does not work properly. You try everything to fix it, but it won't work. You call an expert but then when you want to show the issue to them, your Internet connection seems to be fine. Obviously, once your expert left, your Internet connection is broken again. Bad luck.  So, what would you call it?


Error during program installation using Synaptic Package manager

I tried to download and install the Pixillion Image Converter Software from the Synaptic Package Manager. It downloaded and started to install. Then the message below appeared.     W: Download is performed unsandboxed as root as file ‘/var/cache/apt/archives/partial/python3-problem-report_2.20.4-0ubuntu4.8_all.deb’ couldn’t be accessed by user ‘_apt’. - pkgAcquire::Run (13: Permission denied)   I am using Lubuntu 17.04 and Mozilla Fiefox


Run two commands on one argument (without scripting)

How can I perform two commands on one input, without typing that input twice?  For example, the stat command tells a lot about a file, but doesn't indicate its file type:  stat fileName   The file command, tells what type a file is:  file fileName   You can perform this in one line this way:  stat fileName ; file fileName   However, you have to type the fileName twice.  How can you execute both commands on the same input (without typing the input or a variable of the input twice)?  In Linux, I know how to pipe outputs, but how do you pipe inputs?


Why do we weigh less on equator when centrifugal force isn't a force at all?

Why would we weigh less on equator as the weighing machine measures the force by which we push ground and that should not change if are on equator or poles?


Proof that Radius of Convergence Extend to Nearest Singularity

Can someone provide a proof for the fact that the radius of convergence of the power series of an analytic function is the distance to the nearest singularity? I've read the identity theorem, but I don't see how it implies that the two functions must be equal everywhere.


Kind of converse of Kolmogorov maximal inequality

Let $S_n=\zeta_1+...+\zeta_n$ where $\zeta_i$ are independent with $E\zeta_i=0, E\zeta_i^2=\sigma_i^2<\infty, |\zeta_i|<K$.  Then, $P(\max_{1 \leq m  \leq n}|S_m| \leq x) \leq (x+K)^2/\operatorname{var}(S_n)$.  How do we show this?  The hint says that I should use the fact that $S_n^2-\sum_{m \leq n}\sigma_m^2$ is a martingale. But I am totally clueless....  Any hint would be appreciated! Thanks and regards.


I've been experiencing some problems with trying to get a callback to work. It constantly gives me this error:  java.lang.NullPointerException at Networking.JRNetworking.JRNet_Receiver.onReceive(JRNet_Receiver.java:89) at Networking.JRNetworking.JRNet_Receiver.run(JRNet_Receiver.java:63) at java.lang.Thread.run(Unknown Source)   here is the relevant code:  package Networking.JRNetworking;  public interface CallBack {     public void printId();     public void onReceive(String message, String IP); }   The caller (object):  public CallBack callBack ; public JRNet_Receiver(){} public JRNet_Receiver(CallBack callback) {     setCallBack(callback);     callBack.printId();     System.out.println("class: " + callback.getClass().toString()); } public void setCallBack(CallBack call) {     System.out.println("setCallBack has been called!");     callBack = call; }   and the void that calls:  private void onReceive(String ReceivedString, String senderIp) {     try{     System.out.println(senderIp + "     " + ReceivedString);      //THIS IS THE TROUBLING PART     System.out.println("callBack: " + callBack); //<<<<<<<<<<      //PC Version!     callBack.onReceive( //<<<<<             ReceivedString,              senderIp);     }catch(Exception E)     {         E.printStackTrace();     } }   and the instantiator and called:  JRNet_Receiver receiver ;  public int Id; @Override public void initialize(URL location, ResourceBundle resources) {     Id= new Random().nextInt(1000);     System.out.println(Id);      receiver = new JRNet_Receiver(this);     System.out.println("Current class: " + this);     receivePlayers(); }  public void onReceive(String message, String IP) {     System.out.println("I have been called in PlayerlistController!" + message + "    " + IP); }   I hope you can help me!


The order of a conjugacy class is bounded by the index of the center

If the center of a group $G$ is of index $n$, prove that every conjugacy class has at most $n$ elements. (This question is from Dummit and Foote, page 130, 3rd edition.)  Here is my attempt: we have  $|G| =|C_G (g_i)| | G : C_G (g_i)| $  $|C_G (g_i)| =|Z(G)| \cdot  |C_G (g_i):Z(G)| $.  Then   $|G|= |Z(G)|\cdot |C_G (g_i):Z(G)|\cdot | G : C_G (g_i)| $.  Then  $n = |C_G (g_i):Z(G)|\cdot  | G : C_G (g_i)| $.  But $|C_G (g_i):Z(G)|$ is positive integar as  $ Z(G)$ is   subgroup of  $C_G (g_i)$.  If $| G : C_G (g_i)|$ bigger than $n$, then $|C_G (g_i):Z(G)|\cdot | G : C_G (g_i)|$ is bigger than $n $.  But   $|C_G (g_i):Z(G)|\cdot | G : C_G (g_i)|=n$, contradiction.  Then $| G : C_G (g_i)|\le n$ and this completes the proof.   Is this proof right or not ??!!!


What is the difference between http://archive.ubuntu.com/ubuntu/dists/bionic-security and http://security.ubuntu.com/ubuntu/dists/bionic-security

I am trying to understand how security updates work for the ubuntu package mirror. I see  that the recommendation is to set up security.ubuntu.com as the apt source for the security pocket, and to set archive.ubuntu.com as the apt source for all other pockets. I assume that these correspond to the bionic-security dist and bionic, bionic-updates, bionic-backports, and bionic-proposed apt sources present in my apt config file. Further, it looks like the config file correspondes to these dists directories seen  However, it looks like archive.ubuntu.com has the bionic-security dist present as well. How is this different than the dist of the same name present on security.ubuntu.com? As far as I can tell these are updated at the same cadence. Are these effectively the same? If so, why is it recommended to use security.ubuntu.com for the -security source?


I'm trying to generate a apex class from WSDL actually i am importing some Web Services which are in the RPC/Encoded style.  i am having this issue while generate apex code from WSDL  Error : Unsupported WSDL style 'rpc'. Only supports Dcoument/literal/wrapped services.  Is it possible to develop Apex Code by hand which will talk with these Web Services? Some how i really want to create this class, if you have any suggestion would be helpful for me, thanks in Advance


From my understanding if the integrand is 1, then it gives you the volume of the region defined by the bounds. But what does the value of a triple integral represent if the integrand is a function for a surface in space?


Can I feed two circuits from one breaker?

I'm running out of slots in my old electrical panel. All of my breakers have a single wire plugged in. Can I free one up by feeding my doorbell low voltage converter into the same circuit breaker that I use for my ceiling lights?


Extract certain area of contours/satellite images

I have 2 satellite images (jpeg2000 format) and 2 xyz-files from the same area. I am trying to extract certain region from the area including contour lines and the satellite image in order to import these into Google Sketchup for terrain modeling.    I have been able to create contour lines from xyz-files. Anyway, I would like to first merge contours and then satellite pictures and finally extract only certain part of the data (both contours and satellite pictures). Is there some kind of instruction available that would help in a problem like this?


suppose we have the free field lagrangian: $$L=-\frac{1}{4}F_{\mu \nu} ^2$$ then its just $$L=-\frac{1}{4}(\partial_\mu A_\nu -\partial_\nu A_\mu)^2$$ what I don't understand is how its equal to: $$L=-\frac{1}{2}(\partial_\mu A_\nu)^2 +\frac{1}{2}(\partial_\mu A_\mu)^2$$  I appreciate any help. Thank you.


In the 1972 paper Some Graphic and Semigraphic Displays, Tukey says that “[w]e all ought to be aware of $h^2 / 12$, the approximate increase in variance due to grouping in cells of width $h$. This reaches $2\%$ of the initial variance when $h=\sigma/2$, thus supporting the classical suggestion that frequency distributions with $10$ to $20$ occupied cells are adequate for most purposes”. I am uncertain of how these figures were derived. Preferably an answer would show the variance before and after grouping and then showing how the numbers above fit in.


Here is an image of my current model:  Now I must smooth everything a little bit...But I don't want to use subdivision surface. Then I get this result:   If you need to see how it should look like, here is a reference image:


Inquiring about PhD status and mentioning standing offers

I have a PhD few admission offers from some universities. My first choice school didn't make its decision yet, or maybe didn't post it online yet.  Is it OK to send an email asking about application status and explaining that I have other standing offers which I have to make decisions about quickly?  Would this have any negative impact on my application?


I just managed to change font (thanks!) but now I have a problem... The text, once written in traditional asian form (top to bottom, right to left on pdflatex) is now normal.   So my question now is - can I have both? Changed font and traditional asian writing layout?