I calculated RMS value of trapezoidal fourier series but the numerical results are not same with its normal formula. $b_n = \frac{8\cdot A}{\pi \cdot u \cdot n^2}\cdot sin(\frac{n \cdot u}{ 2})$ $f_{rms} = \sqrt{ a_0^2 + \frac{a_1^2 + a_2^2 +a_3^2+..... + b_1^2 + b_2^2 + b_3^2}{2}}$ $V_{rms,f} = \sqrt{\frac{8 \cdot A }{\pi \cdot u \cdot 2}(\frac{1}{1^2} + \frac{1}{2^2} + \frac{1}{3^2}.... \frac{1}{(2n-1)^2})}$ $\sum(2n-1)^2 = \frac{\pi^2}{8}$ $V_{rms,f} = \sqrt{\frac{A \cdot \pi}{u \cdot 2}}$ if $A = 12$ and $u = pi/6$, $V_{rms,f} = 6$ Normal RMS formula $V_{rms} = A \cdot \sqrt{1-\frac{2 \cdot u}{3 \cdot \pi}}$ if $A = 12$ and $u = pi/6$, $V_{rms,f} = 11.313$ Where did I mistake ?


What is the system timezone in Marketing Cloud and does it consider DST?

My understanding is that the system timezone is CST. Is this correct? When Day Light Saving time occurs does this change to CDT?


Why are all prime numbers are congruent to 1 or 5 (mod6)?

I understand that any natural number congruent to 2 or 4 (mod6) is even and that 3 is the only prime congruent to 3(mod6). Thus, any prime, p > 3, must be congruent to either 1 or 5 (mod 6). I just don't understand the reasoning behind why any natural number congruent to 2 or 4 (mod6) is even and that any natural number congruent to 3(mod6) is a multiple of 3. Could someone explain why this is true?


Does anybody know how to make the following symbol in LaTeX? I think it is some calligraphic \mathcal{E}.     It is not anywhere in  and online font recognizers do not recognize it.   The general font in the book I got this symbol from, Introduction to Quantum Optics by Grynberg, is not very extraordinary: this is a formula containing the strange symbol:


Consider United States of America or United Kindgom. While using these, it is customary to add the before it. Eg. I'm travelling to the United Kingdom    However, when I use the abbreviation, it doesn't seem right to add the before UK. It will usually be sans the the, like, I'm travelling to UK.    Is it because when I use UK, I treat it as a proper noun, and in case of United Kingdom, it is mainly used to denote a cluster of kingdoms, and not treated a proper noun? Is skipping the the correct usage?


Is it appropriate to ask professors at which schools their recommendation letters have more power?

Usually in United States, three letters of recommendation are required by graduate schools but some applicants might ask more than more than three professors (say five) for letters. In this situation, there might be an issue of choosing whose-letter-to-which-school.   I wonder whether it is appropriate to ask each referee at which schools or departments they are relatively more well-known (having connections or interactions with professors in there) so that their letters are more powerful in there.   If it is not appropriate to do so, are there any efficient ways for students to determine to which schools should they send a certain professor's letter?  I am a little awkward with my grammar in this question (including the title). Please feel free to edit my question if you are a native speaker of English. Thank you very much!


While updating the ubuntu 16.04 does not have a Release file Error

I updated my ubuntu 16.04 by sudo apt update and encountered this problem .  suraj@UTM-600001420:~$ sudo apt update Hit:1 http://ppa.launchpad.net/gerardpuig/ppa/ubuntu xenial InRelease                               Hit:2 http://in.archive.ubuntu.com/ubuntu xenial InRelease                                                                     Ign:3 http://ppa.launchpad.net/linuxgndu/adt-raring/ubuntu xenial InRelease                                                    Hit:4 http://in.archive.ubuntu.com/ubuntu xenial-updates InRelease                                  Hit:5 http://ppa.launchpad.net/sunab/kdenlive-release/ubuntu xenial InRelease                  Hit:6 http://in.archive.ubuntu.com/ubuntu xenial-backports InRelease Hit:7 http://archive.canonical.com/ubuntu xenial InRelease                                      Hit:8 http://in.archive.ubuntu.com/ubuntu xenial-security InRelease                             Hit:9 http://ppa.launchpad.net/teejee2008/ppa/ubuntu xenial InRelease Hit:10 http://ppa.launchpad.net/webupd8team/java/ubuntu xenial InRelease Err:11 http://ppa.launchpad.net/linuxgndu/adt-raring/ubuntu xenial Release   404  Not Found Reading package lists... Done E: The repository 'http://ppa.launchpad.net/linuxgndu/adt-raring/ubuntu xenial Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.   How to fix this.?


Two mice: change primary button of just *one* of them?

I have two mice connected to my computer, one on each side of the keyboard.  Both mice are working: they move the pointer, and both buttons work (one is a DeathAdder, one is a Sensei, if that matters).  When opening the mouse section, I would have expected to see two configurations, but I only see one. It seems to be shared, as changing "Primary Button" changes primary button for both mice.  However, I would like the left mouse to have the primary button on the right and the right mouse to have its primary button on the left.  How can I accomplish that?


What should I do when I see copyright violations posted on Stack Overflow?

As prompted by , I'd like to try get a definitive moderator view on what is the appropriate action when a user spots an obvious copyright violation on Stack Overflow. To be clear, I have a reasonable understanding of fair use and am myself not averse to posting small extracts of code to which I do hold rights. What I am talking about is when large extracts of code are posted in clear and obvious violation of rights holders. This issue has been prompted by a couple of recent questions.  This question was flagged (not by me) as containing copyright code and then deleted by a moderator who stated:  I was the one that deleted the question, and answer, and the reason was that all the code is lifted from source code copyrighted by Embarcadero.  [Aside: I am as sure as I can be that none of the deleted code is copyrighted by Embarcadero.] However, another moderator, not involved with the voting and deletion on the disputed question has stated:  In order for a moderator to remove infringing content from Stack Overflow, the moderator must be able to verify that copy-pasting took place. In the absence of that verification, a better course of action is for the copyright holder to provide SE corporate with a DMCA take-down notice. Moderators make every effort to remove copy-pasted material when they can, but they cannot get involved in copyright disputes, for a number of reasons:  Mods cannot always verify that copyright infringement is taking place. Mods don't have the power or the authority to fully act on copyright issues. Mods do not know the intent of the copyright holder.  .... Before flagging such questions, consider raise the issue with the OP first by posting a comment on his question. It's possible they will voluntarily comply. .... But the only persons/entities that can raise a copyright claim are the copyright owners themselves, and the only way they can legally do that is by issuing a DMCA takedown notice to SE corporate.   I flagged this question:  The code posted here is copyrighted by Embarcadero and comprises key chunks of the TApplication class from Forms.pas  This flag was declined: a moderator reviewed your flag, but found no evidence to support it. I don't think there can be any debate that the code in this question is copied from the Delphi VCL source. The user asking the question states this! [Aside: Perhaps the reason for declining the flag should have been more informative.] Another question, which I cannot locate Recently I raised in comments what I believed to be an unattributed lift of a P/invoke declaration from pinvoke.net (the two declarations were identical character for character) in a Stack Overflow answer. This is pretty benign and I just suggested to the answerer that the original source should be credited. This rapidly descended into a comment war which I should have exited much sooner than I did. A moderator told me off for this (justifiably) and I asked how I should have handled it. I was told that I should not have used comments since this would inevitably be provocative and instead should have flagged. Summary It seems to me that there is a deal of confusion around this issue and its treatment by moderators. I would like to ask how a member of the Stack Overflow community should handle obvious copyright infringements. I am hoping that this question can result in definitive guidance. One final point, and this is a bit of a gripe. I find the inconsistency of moderation disconcerting. The two questions I linked to had exceedingly different responses. The first had no copyright issue yet the question was deleted and a very forceful message left by a moderator. The second had as clear a violation as ever there could be, and yet the flag was declined. This does not encourage community members to contribute to the running of the site.


I have site named janvhitravels.in. On Google Search when we type janvhi travels it show search result for jahnavi travels.  Google thinks that janvhi is wrong spelling and jahnavi is wrong. So my site not appers in the list.  If I click on "Search instead for janvhi travels" then my site shows up.  Can we stop Google think like that? Is there any solution for this?


I am a master's student in physics trying to learn maths on my own. My classes workload is heavy and the schedule is very hectic due to which I don't get time to do mathematics.   I have done Linear algebra and differential geometry to the beginners level and now currently I am trying to learn topology from Munkres and I plan to learn Differential geometry,Real and Complex Analysis, Groups and fields and Functional Analysis.  I know this is quite a lot of work in front of me considering I am in master's and I would never finish it of along with physics but what I really need is consistency which I have found could only be gained if I follow some video lectures because reading only from books makes me feel I am in a dense forest all alone.  Are there any good video lectures or notes on the beginners to intermediate level on these topics?  Due to my inexperience any advice given would be highly appreciated.


Solve $\cos x +\cos y - \cos(x+y)=\frac 3 2$ where $x,y\in [0,\pi]$.  I am trying to  solve this but I am stuck. I know that $x=y=\pi/3$ is a solution but how do I show this is the only one? I think there are no others! Hints would be appreciated


When should or shouldn't you use pasta water?

Every sauced pasta dish recipe I ever read calls for using the water in which the pasta was cooked for the purpose of thickening the sauce, as the water contains a lot of starch which helps the pasta adhere to the sauce  In  recipe, this step is skipped and the pasta is added without any water/starch  What was the reason for not using the pasta water? Or in other words, when should you not want to add pasta water? (other than in cold pasta dishes like salads)


Why does re.Match object return an end index higher than expected?

I'm trying to understand regular expression operations, string slicing, and strings in Python. String slicing using .start() and .end() results in the expected substring, and if I go for a single character from a string using .start() the resulting character is as expected, but if I go for a single character from a string using the .end() index, it doesn't result in the expected character. I understand that lists (including strings) begin with element zero, but why are exceptions to this rule the stop index of a string slice and the re Match .end() index? >>> import re >>> m = re.search("bake","123bake456") >>> m <re.Match object; span=(3, 7), match='bake'> >>> m.span() (3, 7) >>> m.start() 3 >>> m.end() 7 >>> "123bake456"[m.start():m.end()] 'bake' >>> "123bake456"[m.start()] 'b' >>> "123bake456"[m.end()] '4'


How many objects are created in inheritance?

If only one then how Parent class constructor gets executed when sub class object is create    class Parent {  Parent()  {   System.out.println("Parent class construcor");  } } class Child extends Parent  {  Child()  {   System.out.println("Child class construcor");  }   }  class Test  {   public static void main(String a[])   {    Child obj = new Child();   }  }


Is it possible to prove the converse of the Pythagoras theorem with out a geometric proof?.That is from $a^2+b^2=c^2$ to $\Theta=90^\circ$


How much play time to complete Legend of Zelda: Twilight Princess

Simple question: about how many hours of gameplay are required to complete Legend of Zelda: Twilight Princess?  I know that it depends upon skill and how thoroughly one explores the game, but can I please have a ballpark estimate of how long I should expect to take to finish the game?


How can I revert SE appearance on mobile?

The appearance/ look of English Language & Usage SE has changed in my mobile phone and it was completely unexpected. It wasn't like this before. I use SE on Chrome in my mobile phone (Android).  It was like how it looks on PC.  Also, lots of options are missing in this version. The old version was way better than this one and had many options.   For example, I'm unable to view history of the post, no options while editing or posting.  How do I revert it? Here's a screenshot of the new version (bluish one).


The rich get richer phenomenon in stackexchange communities

I've noticed that when two or more answers are provided to a question, people's votes tend to gravitate toward the answer posted by the person with higher reputation. I've observed this "rich get richer" phenomenon in nearly every community I am a part of. This even happens in cases where the lower reputation user posts their answer long before the higher reputation user comes along.  I feel like this unnaturally causes people to flock toward one idea/answer, discounting the opinions/views of people with lower reputation.   I understand how reputation is meant to signal one's knowledge of the subject area and the site in general; however, I think these reputation effects prevent people from judging the correctness of the answers themselves.   I would like to hear other's opinions on this. One suggestion I have is to hide the answerer's identity and reputation score for the first 24 hours after a question is asked. I think this would go a long way to resolving this issue.  Edits:    Supporting evidence:       The fact that this is  deserves discussion in itself.  The post linked by rene is certainly relevant:  however, it was posted nearly 9 years ago (is there no statute of limitations on posts marked as duplicate?). I'm sure it is no longer in anyone's mind, perhaps it deserves to be revisited? It seems I have caused a sufficient amount of controversy to prevent that objective from being met here, though.


Looping over list of lists, but if statement does not seem to work correctly

def drawme_five(n):      a = [['.']*n]*n     for i in range(len(a)):         for j in range(len(a[i])):             if i == 0 or i == len(a)-1 or i == int(len(a)/2):                 a[i][j] = '*'             if i < int(len(a)/2):                 a[i][0] = '*'             elif i > int(len(a)/2):                 a[i][len(a)-1]='*'      return a  I expected this code to give an output of a list of lists, where it with '.' and '*' in the form of number 5, but it gives me an output of all asterics. I don't know why the if statements don't work. If it works correctly, and we print one list each line, the output would be in a form of 5, for example if n = 5   . . . .   . . . . *


Configuring RAID1 on HP Proliant Microserver N54L / Ubuntu 14.04.1 LTS

I've bought a N54L and fitted two 3GB drives. Keen to get set up with RAID1.   BIOS: SATA controller mode set to "RAID" RAID Option ROM utility: both physical drives set up as one logical drive   When I came to install Ubuntu (14.04.1), both drives appeared during the setup process. I was only expecting to see the logical drive, although I'm a complete novice with RAID.  I've read that the HP Proliant Microservers don't have "proper" RAID support, and require some kind of driver to be installed. I've tried a few HP utilities from the following apt repo:  deb http://downloads.linux.hp.com/SDR/repo/mcp wheezy/current non-free   On installation, most say "server not supported"  Would appreciate your advice.


I have got really far in my second profile in Skyrim, level 41. It took a long time to get back to that level, because I had got a game-breaking bug on my last profile and I erased it by accident as well as my other messed up profile.  Is there anyway to get my saved data back on the Xbox 360? If there isn't, I will not play Skyrim again for a very long time and I have no other option. Please help.


Where is the best place to practice parrying?

I am well informed in how to parry, but I haven't mastered parrying with all weapons. I would like to find a area that spawns slow moving, slowly attacking monsters in low numbers (I would also appreciate you telling me the nearest bonfire).


I'd wish to visit Dubai with my girlfriend, but after reading  and  I started to get a little worried about it. How should I book an hotel? Must I book two singles? Could it be a problem if we walk together in the city and go together to restaurants and malls without being married?


Q: Using Grep to find a word that contains each of the vowels in the correct order

I'm trying to find out on how to use grep command to find the number of vowels in each word in the correct order in the word file on the root user. I've tried grep -Ew "*[aeiou]*" words But, it never gave me the number of how many such words are there.


Multiple-entry Bulgaria visa to enter to Romania

I got the Bulgaria multiple entry visa, can I enter Bucharest then pass the border to Bulgaria ?  If yes, what other document I have to prepare to show to the Romanian immigration?


How to order alphabetically the items in the itemize environment?

I have a really long list in an itemize environment and I want to order it in alphabetical order. My code is the following:  \documentclass[letterpaper,openright,12pt]{article} %\usepackage[spanish]{babel} %Defino idioma como español \usepackage{graphicx} % Para Añadir imagenes \usepackage{subfigure} %Para las subfiguras \usepackage{caption} \usepackage{enumitem} \usepackage{multicol} \usepackage{float} \usepackage{caption} \usepackage{adjustbox} \usepackage{xcolor} \usepackage{setspace} \usepackage{rotating} \usepackage[spanish,onelanguage]{algorithm2e} \usepackage{algorithm2e} \usepackage{lscape}  \usepackage{tikz} \begin{document} \section*{Glosario} \begin{itemize}[leftmargin=*] \setlength\itemsep{0.00em} %\small \item \textbf{DD.HH:} Derechos Humanos \item \textbf{LH:} Logística Humanitaria \item \textbf{OMS:} Organización Mundial de la Salud \item \textbf{ONU:} Organización de las Naciones Unidas \item \textbf{WFP:} \textit{World Food Programme} \item \textbf{FIDA:} Fondo Internacional de Desarrollo Agrícola \item \textbf{ECHO:} \textit{European Civil Protection and Humanitarian Aid Operations} \item \textbf{CICR:} Comité Internacional de la Cruz Roja \item \textbf{ONEMI:} Oficina Nacional de Emergencias del Ministerio del Interior \item \textbf{IO:} Investigación de Operaciones \item \textbf{OFDA:} Oficina de Asistencia para Desastres del Gobierno de los Estados Unidos, América Latina y el Caribe. \item \textbf{CRED:} Centro de Investigación sobre la Epidemiología de los Desastres \item \textbf{NSGA:} \textit{Non-dominated Sorting Genetic Algorithm} \item \textbf{SPEA:} \textit{Strength Pareto Evolutionary Algorithm} \item \textbf{ONU:} Organización de las Naciones Unidas \item \textbf{ACNUR:} Alto Comisionado de las Naciones Unidas para los Refugiados \item \textbf{AG:} Algoritmos Genéticos \item \textbf{CONAF:} Corporación Nacional Forestal \item \textbf{CONASET:} Comisión Nacional de Seguridad de Tránsito \item \textbf{SNPC:} Servicio Nacional del Patrimonio Cultural \item \textbf{SIDCO:} Sistema de Información Digital para Control de Desastres \item \textbf{PIB:} Producto Interno Bruto \item \textbf{MINSAL:} Ministerio de Salud \item \textbf{SRT:} \textit{Standar Relief Time} \item \textbf{CAL:} Centro de Acopio Local \item \textbf{LS:}  Logística de Socorro \item \textbf{LD:}  Logística de Desarrollo \item \textbf{UNISDR:} \textit{United Nations Office for Disaster Risk Reduction} \item \textbf{ONG:} Organización no Gubernamental \item \textbf{VRP:} \textit{Vehicle routing problem} \item \textbf{PDSTSP:} \textit{Parallel Drone Scheduling Traveling Salesman Problem} \item \textbf{TSP:} \textit{Traveling Salesman Problem} \item \textbf{VIH:} Virus de Inmunodeficiencia Humana \item \textbf{SIDA:} Síndrome de Inmunodeficiencia Adquirida \item \textbf{ACO:} \textit{Ant Colony Optimization} \item \textbf{MPE:} Métodos de Programación Entera \item \textbf{VNS:} \textit{Variable Neighborhood Search} \item \textbf{MTZ-SEC's:} Miller-Tucker-Zemlin Subtour Elimination Constraints \item \textbf{CLT:} Costo Logístico Total \item \textbf{CTT:} Costo de Transporte Total \item \textbf{CIT:} Costo de Instalación Total \item \textbf{CAT:} Costo de Asignación Total \item \textbf{CDIT:} Costo por Demanda Insatisfecha Total \item \textbf{C:} Camiones \item \textbf{H:} Helicópteros \item \textbf{m-p:} Múltiples productos \item \textbf{m-v:} Múltiples vehículos \item \textbf{m-d:} Múltiples depósitos \item \textbf{s-d:} \textit{Split Delivery} \item \textbf{t-l:} Tiempo de circulación limitado \item \textbf{MO:} Múltiples Objetivos \item \textbf{TPDRO:} \textit{Transportation Problem in Disaster Response Operations}  \end{itemize} \thispagestyle{empty} \newpage  \end{document}    How can I do this? any ideas?. Thanks and advance and greetings.


Is the Cartesian product of sets associative?

Is it associative? In general sense, if we compare $A \times (B \times C)$ and $(A \times B) \times C$, then $(a,(b,c))$ does not equal $((a,b),c)$, but both of those pairs may be interpreted as one triplet $(a,b,c)$. Is it correct to do that and can we use associativity of Cartesian product in set theory problems?


Minipage/framebox text is not justified and throws several Underfull \hbox (badness 10000)

How can I make the minipage/framebox page justified, so it stop the badness underfull warnings?    The warnings are:  Bad Boxes:  D:\test2.tex:23: Underfull \hbox (badness 10000) in paragraph at lines 23--23[]\OT1/cmtt/m/n/10 Lembre-se: a ficha de identificao da obra elaborada D:\test2.tex:23: Underfull \hbox (badness 10000) in paragraph at lines 23--23\OT1/cmtt/m/n/10 pelo autor deve constar no verso da folha de rosto D:\test2.tex:23: Underfull \hbox (badness 10000) in paragraph at lines 23--23\OT1/cmtt/m/n/10 de teses e dissertaes de modo a possibilitar sua D:\test2.tex:23: Underfull \hbox (badness 10000) in paragraph at lines 23--23\OT1/cmtt/m/n/10 representao precisa pelas informaes de autor, ttulo,   For the sample code:  \documentclass[10pt,openright,twoside,a5paper]{memoir} \usepackage[showframe]{geometry} \usepackage[brazil]{babel}  \begin{document}  \begin{center}  \hspace*{1cm} {Catalogação na fonte pela Biblioteca Universitária da Universidade Universitária da Universidade.}  \framebox[\textwidth] {     \begin{minipage}{\textwidth}          \ttfamily          Lembre-se: a ficha de identificação da obra elaborada pelo autor deve constar no         verso da folha de rosto de teses e dissertações de modo a possibilitar sua         representação precisa pelas informações de autor, título, local, data, número de         folhas, assunto, etc.      \end{minipage} }  \end{center}  \end{document}


Euler equation with single state variables

I want to simulate a flow using the Euler equations. For this reason I'm wondering if there's a modified version of the Euler equations.  At the moment my formula looks like this:  $$ \frac{\partial}{\partial t} \begin{pmatrix} \rho \\ \rho v_1 \\ \rho v_2 \\ \rho v_3 \\ \rho E \end{pmatrix} = -\mathrm{div} \begin{pmatrix} \rho v_1 & \rho v_2 & \rho v_3 \\  \rho v_1^2 + p & \rho v_1 v_2 & \rho v_1 v_3 \\  \rho v_2 v_1 & \rho v_2^2 + p & \rho v_2 v_3 \\  \rho v_3 v_1 & \rho v_3 v_2 & \rho v_3^2 + p \\  (\rho E + p) v_1 & (\rho E + p) v_2 & (\rho E + p) v_3 \end{pmatrix} $$  Since the state variables are all in combination with the density, I need a division to calculate the flow. So what I actually would like to get is something like this:  $$ \frac{\partial}{\partial t} \begin{pmatrix} \rho \\ v_1 \\ v_2 \\ v_3 \\ E \end{pmatrix} $$   Can someone help?


In the terminal, it tells me  The following packages have unmet dependencies:  playonlinux : Depends: curl E: Unable to correct problems, you have held broken packages.


Difference between [0-9], [[:digit:]] and \d

In , it seems that [[:digit:]] = [0-9] = \d.    What are the circumstances where they do not equal? What is the difference?  After some research, I think one difference is that bracket expression [:expr:] is locale dependent.


Chi-squared Test and Data Representation

I have a question with applying Chi-squared tests to a given set of data. Let's say that my data is numbers of different-colored MM's in a bag.   Suppose there are 6 red, 4 blue, 8 orange, 2 green, 10 purple, and 6 brown for a total of 36, while the expected value is 6 for each.  The chi-squared test for this data, after calculating $\sum\frac{(O-E)^2}{E}$, gives 6.67.  However, if I converted the discrete numbers into percentages/decimals such that the total is 1 (e.g. blue is 0.111 and expected is 0.167), the chi-squared value is different: 0.185.  I think this has to do with the fact that when the numbers are effectively scaled down, the numerator, which reflects the square of the differences between observed and expected, decreases more than the denominator, which is merely the single power of expected. But which way of performing the chi-squared test is correct?


How to make Latest Ubuntu look like Windows 7

For a talk about Linux I will be using Ubuntu to show off how flexible Open Source is, but one of the things I want to do is show Ubuntu with a Windows 7 Theme, which I will then change when a friend just happens to ask "But you are using Windows 7 to talk about Open Source", at that moment I will change the whole theme back to the default Ubuntu theme (Unity) which should have a impact on users that have not yet moved to Ubuntu.  Since I will be doing this on 13.04 (Examples for 11.04 up to 12.10 do not work in 13.04) I need a solution for this version. I have tried the following links and between not working and making the whole system unstable (Had to install from scratch) they did not solve my question:      So how can I change Ubuntu to a Windows 7 theme in 13.04?


How to prove this binomial identity $\sum_{r=0}^n {r {n \choose r}} = n2^{n-1}$?

I am trying to prove this binomial identity $\sum_{r=0}^n {r {n \choose r}} = n2^{n-1}$ but am not able to think something except induction,which is of-course not necessary (I think) here, so I am inquisitive to prove this in a more general way.  The left side of an identity occurs while solving another problem (concerning binomial theorem) so I am more interested in deriving the right side from the left side, else I have to remember it now onward.  EDIT: I am more interested in an algebraic proof rather than combinatorial argument or something involving calculus (however I liked  and  solution), hence I am removing the combinatorics tag.


In the Pottermore article on  it's mentioned that other fractional platforms exist (7 1/2, for instance). Is it ever stated elsewhere where these platforms lead? Perhaps you could get a connection from your hometown by accessing one of these platforms?


What's the sanest way to present a Ctools modal to the user while bypassing the normal AJAX workflow? For example, how could I show a completely JavaScript-generated "Are you sure you want to log out?" confirmation prompt to the user in a Ctools modal after the user clicks the "log out" link?  I know I can probably fake a box which would get the same styling as the Ctools modal, but I'd rather avoid silly hacks if not strictly necessary.


Assume that $f\in C^1([0,\infty))$, $f'$ is monotonic on $[0,\infty)$ and $\lim\limits_{x\to\infty} f(x)=l$ is finite. If $a,b>0$, prove that; $$\displaystyle\int_0^\infty\frac{f(bx)-f(ax)}{x}dx=(l-f(0))\ln\frac{b}{a}$$   The trick is clear for me, I have to write is as double integral, i.e. the function $\frac{f(bx)-f(ax)}{x}$ as an integral, obviously with limits $a$ and $b$. For example   $\displaystyle\int_a^bf'(xy)dy$$\quad$(Here is $f$ differentiated with respect to $y$)  works.   Now if I assume that, $\displaystyle\int_0^\infty\Big(\displaystyle\int_a^bf'(xy)dy\Big)dx=\displaystyle\int_a^b\Big(\displaystyle\int_0^\infty f'(xy)dx\Big)dy$  and $\displaystyle\int_0^\infty f'(xy)dx=\frac{l-f(0)}{y}$ $(\bigstar)$  then $\displaystyle\int_a^b\frac{l-f(0)}{y}=(l-f(0))\ln\frac{b}{a}$ gives the correct result.  MY QUESTIONS  1)Why is the line with $(\bigstar)$ correct ? Because $f'(xy)$ is differentiated w.r. to $y$ but if we integrate w.r.to $x$ why do we get $f$ again ?  2)Why can we change the order of integration, We have to make use of the monotonicity of $f'$, I guess $\lim\limits_{x\to\infty}f'(x)=0$, but this is not sufficient.


How do you beat frost dragons in Skyrim?

I find these types of Dragons really difficult to face. One strike with their frost breath wipes out most of my health. I have beaten some before, but I need easier ways, so feel free to tell me anything-Thanks     I am a Dumner or the Dark Elf btw and I use all magic, but mostly destruction.


The question is #$14$ from Chapter $2$ in Stein and Shakarchi's text Complex Analysis:     Suppose that $f$ is holomorphic in an open set containing the closed unit disc, except for a pole at $z_0$ on the unit circle. Show that if $$\sum_{n=0}^\infty a_nz^n$$ denotes the power series expansion $f$ in the open unit disc, then $$\lim_{n\to\infty}\frac{a_n}{a_{n+1}}=z_0.$$   I've shown that we can take $z_0=1$ without a loss of generality, but I'm having trouble showing the proof otherwise. One of the problems I'm having is because we aren't told the definition of a pole except that it is a place where the function isn't holomorphic. Disregarding this fact, the other problem I'm running into is that I don't know the order of the pole.  Making some additional assumptions, including that the pole is simple so we can write $F(z)=(z-1)f(z)$ as a holomorphic function, we see that $$F(z)=-a_0+z(a_0-a_1)+z^2(a_1-a_2)+\cdots$$ This almost gets me to the end with these added assumptions, but I don't think it's quite enough (why do we know some of the $a_i$'s aren't $0$, for example).  On another note, if we know $\lim_{n\to\infty}\frac{a_n}{a_{n+1}}$ exists, then it is easy to see that $\lim_{n\to\infty}\frac{|a_n|}{|a_{n+1}|}=1=|z_0|$; I, however, do not see why the limit must exist.  Are there any hints that someone can provide? Even a solution would be nice, especially if one can avoid making any assumptions about what a pole is or is not.  EDIT: So there isn't any confusion, I know the definition of a pole and I'm inclined to believe that the problem, as stated, necessarily has a pole at $z_0$. The problem is that the exercise is in Chapter $2$, and poles are introduced in Chapter $3$.


Is there a way to list all known pgfkeys (i.e., those that are currently set)?  Concretely, I'm looking for a way to get the value of the tikz scale option. I was hoping there would be a pgfkey for that. But it seems more useful to ask the general question of listing all pgfkeys.


What is the microscopic equation to calculate sound speed in an ideal gas?

The common equations to calculate the sound speed in an ideal gas use macroscopic quantities, e.g.:  $$c = \sqrt{\frac{\gamma RT}{M}}$$  What I am interested in is an equation that determines the sound speed in an ideal gas from a microscopic perspective. My reasoning is as follows: Sound propagates through an ideal gas by means of collisions between molecules. Since molecular movement is random, information that propagates from point A to point B via molecular collisions does not travel in a straight line but with an average angle of 45°.  The sound speed in an ideal gas should then be given by:  $$c = v_{rms} \space \sin{45°}$$ where $v_{rms}$ is the root-mean-square speed of molecules.  This equation gives results that are very close to the results given by the above formula (approx. 3% difference). Is my reasoning solid or what is a correct microscopic equation for sound speed in an ideal gas?


how to display osd_cat on a remote HDMI Screen

i have installed xosd an used osd_cat to display text in my screen. the problem is that i cant do it on the remote station on the remote screen through SSH.  I want to execute osd_cat on the remote HDMI Screen connected to the raspberry pi, not on my SSH screen  i tried    export DISPLAY=:0.0   and  adding DISPLAY=:0.0 before the command  but it didn't work  FIY:  when i use xrandr it gives me this:  xrandr: Failed to get size of gamma for output default Screen 0: minimum 1027 X 768, current 1024 x 768, maximum 1024 x 768 default connected 1024x768+0+0 0mm x 0mm    1024x768     0.0*


Is the pushforward of the sheaf of differentials on an elliptic curve over a scheme necessarily trivial?

If $f:E\rightarrow S$ is an elliptic curve over a scheme $S$ (so $f$ is proper and smooth of relative dimension one with geometrically connected fibers of genus one, equipped with a section $0:S\rightarrow E$), then is the sheaf $\underline{\omega}_{E/S}:=f_*\Omega_{E/S}^1$ actually free of rank one? According to the statement of Grothendieck-Serre duality in Hida's book Geometric Modular Forms and Elliptic Curves, there should be a canonical isomorphism $\underline{\omega}_{E/S}\cong\mathcal{Hom}_{\mathscr{O}_S}(R^1f_*\mathscr{O}_E,\mathscr{O}_S)$, and the first result on elliptic curves in this book is that $R^1f_*\mathscr{O}_E\cong\mathscr{O}_S$. It's also not clear to me whether $S$ is being assumed (locally) Noetherian, but if that's necessary for Grothendieck-Serre duality to hold, then I'm fine with assuming it. I can't find another reference with a statement of Grothendieck-Serre duality in this generality which does not use the language of derived categories (which I unfortunately don't understand).  The reason I'm kind of skeptical about this is that in Hida's book, as well as in Katz-Mazur, it is said that $\underline{\omega}_{E/S}$ is invertible, so that an $\mathscr{O}_S$-basis $\omega$ for $\underline{\omega}_{E/S}$ can be found locally on $S$. If the invertible sheaf in question were really trivial then one would be able to choose a global $\mathscr{O}_S$-basis for $\underline{\omega}_{E/S}$, and there would be no reason to talk about doing so locally. Hida goes on to say that, choosing an $\mathscr{O}_S$-basis $\omega$ locally on $S$ allows one to regard $(\Omega_{E/S}^1,\omega)$ as a relative effective Cartier divisor in $E/S$, which also doesn't make complete sense to me because if we can only find $\omega$ locally, how are we getting a global section $\omega\in H^0(E,\Omega_{E/S}^1)=H^0(S,\underline{\omega}_{E/S})$ (unless $\underline{\omega}_{E/S}$ really is trivial)?


Is it better to declare variables inside or outside the prototype property?

Which of the following cases is better for performance or proper techniques?  CASE #1  function SomeClass () {     this.someVar = null;     this.someFunc = function () {} }   CASE #2  function SomeClass () {} SomeClass.prototype.someVar = null; SomeClass.prototype.someFunc = function () {}


If I move out of range after a spell is cast, but before a spell hits me, does it miss?

Does a reaction that causes me to move out of range after the spell is cast but before the spell hits cause it to miss?  A couple ways this can be done are   Readied action to move with a trigger: target casts the spell Mage Slayer feat with a melee weapon attack that moves the caster


coming from panel to a double gang with two gfci nec approved?

Everyone has been so nice but never answered my questioned. Can I have a double gfci coming from a panel to a double gang box in a laundry room using line side only nec approved? Why? Because I want both to be independent in case one shuts down and doesn't affect the other.


How can I get my spawners to work when they are far away?

I am playing a custom map and I have 2 mob spawners in which I have set up traps for. These traps lead to the same place, however both spawners are considerably far away from each other and therefore only one spawns at a time (when I am near).   I was wondering if there was some sort of way to "mimic" a player position without a player actually being there. What I would usually do is start up another computer and simply open it to LAN and have another account be somewhere next to the spawner, however I was wondering if there was a way to not have to do this? Is this possible? Are there any mods that allow this?


I read this story in the 1990s or early 2000s, I believe. It was about a world with three layers or zones, and in order to travel from one zone to the next, travellers could only do so naked, otherwise a force field in the tunnel would prevent their passage. The second layer had many voice-activated "magic" devices, such as flying chairs, and put an emphasis on the number 6. The third layer had demons, and placed an emphasis on the number 5. The end of the story is that the system was devised to trap demons in the third layer, and the technology and numerology of the second layer was supposed to make it inhospitable and/or its population unsusceptible to the demons.


Formal Title for Someone with a Masters Degree?

We all know that someone with a doctorate is called a Doctor (or abbreviated as Dr.), is there a formal title for someone with a Masters degree? I've never heard someone refer to a person with a masters as "Master". I've also heard that Esquire is sometimes used as a formal title for someone with a masters, is this correct or is there another title?


Inverse bibliography: Print all works that aren't cited

Assume that I have a large bibliography file and a large document with a lot of citations. Now I want to know which works collected in the bibliography file aren't cited in my document.  Is there a way to achieve this?  P.S. I am aware of a recent article in Die TeXnische Kommödie where a partial solution of this problem is presented (basically, use an unsorted bibliography, use a sentinel for the last citation, and use \nocite{*}—all bibliography entries coming after the sentinel are not cited). There must be something better than that.


feature-request tag shown at the end of tag list. [feature-request] tag was replaced with itself

I saw this  and see that it has  in the end of tag list (it should in the beginning).    If I go to revision history I'm also facing some oddities:  was replaced by itself two times!    How is that possible?


Attach eventListener on dynamically created input text

i would like to attach eventListener to dynamically created input Text or other objects. Since the objects are not yet present in the DOM or the objects are not visible, attaching an event to these object fails. There's a proper way in plain Javascript or JQuery to avoid this problem?  Thank you


Upgrade 2011, 64 GB, iPad 2 (GSM model) running 5.1.1 to iOS 6 or 7 only - not jailbroken

I know this is similar to another question, but I think it's a different situation.  I hope it's okay to start a new thread.  I want to upgrade, but to nothing higher than iOS 6 or 7. The performance on our other iPad2 on iOS 8 is horrible.  I don't dare try iOS 9.  I've downloaded an IPSW file from osxdaily.com (iPad2,2_6.0.1_10A523_Restore.ipsw) but neither iTunes nor redsn0w will let me install it.  ITunes comes back with "This device isn‘t eligible for the requested build" and redsn0w says "That IPSW isn't supported by this version of redsn0w."  I do not have the SHSH blobs from iOS 4.  Can you tell me what I'm doing wrong?  Will iTunes not install the IPSW because Apple isn't signing it anymore?  If so, is there another route I can take?  Thanks.


I was invited to the private beta for the new Puzzling.SE site. I clicked the link in the email and created my account on one computer. But when I go to the site on another computer, there is no way to log in without going back to my email and clicking the link again.  Why can't I just log in to the site since I'm already there?


How can I control the vertical space before an environment, e.g., tabular or minipage?   Here is an example that reproduces my problem:   \documentclass{article} \begin{document}     \noindent TEXT-A\vspace{5pt}\\   TEXT-B\\TEXT-C     \\[2em]     \noindent TEXT-D\vspace{5pt}\\   \begin{tabular}{@{}l}TEXT-E\\TEXT-F \end{tabular} \end{document}   The spacing between TEXT-A and TEXT-B is different from the spacing between TEXT-D and TEXT-E:    I have learned so far that the space between TEXT-D and TEXT-E is normal if I delete \\TEXT-F:    Any help would be appreciated!


Character Translation using Python (like the tr command)

Is there a way to do character translation / transliteration (kind of like the tr command) using Python?  Some examples in Perl would be:  my $string = "some fields"; $string =~ tr/dies/eaid/; print $string;  # domi failed  $string = 'the cat sat on the mat.'; $string =~ tr/a-z/b/d; print "$string\n";  # b b   b.  (because option "d" is used to delete characters not replaced)


Subdivision surface modifier creates pinching at corners

I've only been 3D modelling for a few days now, so this may just be a newbie mistake:  However, because this model is for use in a game I am trying to stay away from proximity loops for performance reasons. Instead, I have used edge creases to maintain the structure of the model. It has led to certain vertices not being affected by the subsurf modifier, causing undesirable lighting at high subsurf levels.  Manually moving each point in a bit seems kind of sloppy but I'm not too sure what the best way to go about this is.  If any more information is needed I'll give what I can, thanks in advance :)


Hide Symbol if the label name not display / rendered in exported file

I am using QGIS 3.14. I downloaded world cities name kml, which has markers symbol on every label. I want to display the symbol only on every name which rendered / displayed on exported file. Currently, all symbol are displayed even though the cities name are not displayed, so it will only show empty marker without label on it. How do I filter or hide, so the symbol without names will be hidden in exported file? As you can see all the symbol which its name not displayed are also displayed on the exported file.


Why doesn't Volumetric follow the shape of Mesh in Eevee?

So I was in the middle of making a ball-shaped smoke, but the volumetric effect didn't work following the basic shape. It remains cube in Eevee Blender 2.8; while in Cycle it works, but in Cycle it takes thousands of years for Render.


What's the equivalent of VB's Asc() and Chr() functions in C#?

VB has a couple of native functions for converting a char to an ASCII value and vice versa  - Asc() and Chr().  Now I need to get the equivalent functionality in C#.  What's the best way?


Is there a way to find $\min\{E|X-c|, \:c \in \mathbb{R}\}$

Suppose X is a random variable. Is there a way to find $\min\{E|X-c|, c \in \mathbb{R}\}$?  What have I attempted to do so far:$\DeclareMathOperator{\Pr}{Pr}$ $$\Pr(|X - c| \leq t) = \begin{cases} 0 &  \text{if } \;t \leq 0\newline\Pr(X \leq t + c) - \Pr(X \leq c - t)& \text{if } t > 0 \end{cases}$$ That results in the probability density function of $|X - c|$ being  $$P_{|X - c|}(t) =  \begin{cases} 0 &  \text{if } t \leq 0,\cr P_{X}(t + c) + P_{X}(c - t)&   \text{if } t > 0,\end{cases}$$ where $P_X$ is the probability density function of $X$. That means, that $$E|X-c| = \int_0^\infty t(P(t + c) + P(c - t))\,dt.$$ However this gives me nothing, as finding $\min\{\int_0^\infty t(P_X(t + c) + P_X(c - t))\,dt,\; c \in \mathbb{R}\}$ does not seem to be any easier.  Any help will be appreciated.


WCF - Faults / Exceptions versus Messages

We're currently having a debate whether it's better to throw faults over a WCF channel, versus passing a message indicating the status or the response from a service.  Faults come with built-in support from WCF where by you can use the built-in error handlers and react accordingly. This, however, carries overhead as throwing exceptions in .NET can be quite costly.  Messages can contain the necessary information to determine what happened with your service call without the overhead of throwing an exception. It does however need several lines of repetitive code to analyze the message and determine actions following its contents.  We took a stab at creating a generic message object we could utilize in our services, and this is what we came up with:  public class ReturnItemDTO<T> {     [DataMember]     public bool Success { get; set; }      [DataMember]     public string ErrorMessage { get; set; }      [DataMember]     public T Item { get; set; } }   If all my service calls return this item, I can consistently check the "Success" property to determine if all went well. I then have an error message string in the event indicating something went wrong, and a generic item containing a Dto if needed.  The exception information will have to be logged away to a central logging service and not passed back from the service.  Thoughts? Comments? Ideas? Suggestions?  Some further clarification on my question  An issue I'm having with fault contracts is communicating business rules.  Like, if someone logs in, and their account is locked, how do I communicate that? Their login obviously fails, but it fails due to the reason "Account Locked".  So do I:  A) use a boolean, throw Fault with message account locked  B) return AuthenticatedDTO with relevant information


How many ways are there to pick r objects from n objects when each object appears an odd number of times?

So this is my first time encountering this type of problem, and I'm at quite a beginner level. If you could help me get on the right track I'd appreciate it.  Now if i'm picking r objects from n objects that's going to be  $n\choose r$   now there would be $\frac {n!}{(n-r)! r!}$ combinations (i think)  if we just wanted  to know ways where each object appears an odd number of times, wouldn't that be half of the total possibilities?   My logic and math may be way off here, but I'm just a beginner. I feel like this makes sense because all the odd possibilities would be half the amount of all possible possibilities right?  So if you were to pick r objects from n objects, how many ways are there to pick so that each r object appears an odd number of times. Is what the question is asking


Big Bang Theory prop on Sheldon's bedroom wall

is full of interesting props. It's a pastime of mine to try to identify odd props in shows and movies.  This one has me stymied. It is in the rarely seen set of Sheldon's bedroom. I've seen it on at least two different episodes. Can anyone help?


I've just written a quick algorithm that tests if a random number (decimal or whole) between -million and +million is divisible by 2. It iterated a million numbers. The sum of even numbers was ~50% every time.  I've read mixed opinions about if 'half of all numbers are even/odd'. My test shows it is true. But I feel I maybe missing something. Is there a mathematical explanation behind why this seems to be true?


Error LNK 2019 on Qt while linking a function from another file

I am working at a university project with Qt version 4.7.2(I am using an old version because our teacher will use this version to review the project) on a Windows x86 machine but I have some problems while linking some function from the class Container to the class QListModelAdapter.  I've already tried running qmake again, clean and rebuild the project and deleting the build folder for building it from scratch but nothing of this worked, also checked my .pro file but seems like nothing wrong there.  qlistmodeladapter.h  #ifndef QLISTMODELADAPTER_H #define QLISTMODELADAPTER_H  #include <QAbstractListModel> #include "container.h"  class AddLayout;  class QListModelAdapter : public QAbstractListModel { private:     Container<articolo>* model;     const AddLayout* insert; public:     QListModelAdapter(QObject* = nullptr, const AddLayout* = nullptr);     ~QListModelAdapter() override;     bool insertRows(int, int = 1, const QModelIndex& = QModelIndex()) override;     bool removeRows(int, int = 1, const QModelIndex& = QModelIndex()) override; }; #endif   qlistmodeladapter.cpp  #include "qlistmodeladapter.h" #include "container.h" #include "addlayout.h" #include <QFont>  QListModelAdapter::QListModelAdapter(QObject* parent, const AddLayout* ins) :     QAbstractListModel(parent),     model(new Container<articolo>()), insert(ins) {}  bool QListModelAdapter::removeRows(int begin, int count, const QModelIndex& parent) {     beginRemoveRows(parent, begin, begin + count - 1);     model->removeEl(begin);     endRemoveRows();     return true; }  bool QListModelAdapter::insertRows(int begin, int count, const QModelIndex& parent) {     beginInsertRows(parent, begin, begin + count - 1);     articolo art = articolo(new Computer(insert->getNome()));     model->insertEl(art);     endInsertRows();     return true; }   container.cpp  #include "container.h" template<class T> void Container<T>::insertEl(T& p) {     if (maxSize == size)     {         increaseSize();     }     iteratore it = end();     *(it) = p;     size++; } template<class T> void Container<T>::removeEl(int j) {     if (j <= size)     {         iteratore it = begin();         for(int i = 0; i <= (j-1); i++)         {             it++;         }         delete it.punt;         iteratore aux = it;         it++;         for(int i = j; i < size-2; i++)         {             aux = it;             aux++;             it++;         }         size--;     } }   container.h  #ifndef CONTAINER_H #define CONTAINER_H #include "items.h"  template<class T> class Container {     friend class iteratore; private:     T* vector;     int size;     int maxSize; public:     class iteratore { // is defined correctly     };     Container(T* p = nullptr, int s = 0);//it is defined but not included     void removeEl(int);     void insertEl(T&); }; #endif // CONTAINER_H    The incriminated function is removeEl and is where is get this error:  qlistmodeladapter.obj:-1: error: LNK2019: riferimento al simbolo esterno "public: void __cdecl Container<class articolo>::removeEl(int)" (?removeEl@?$Container@Varticolo@@@@QEAAXH@Z) non risolto nella funzione "public: virtual bool __cdecl QListModelAdapter::removeRows(int,int,class QModelIndex const &)" (?removeRows@QListModelAdapter@@UEAA_NHHAEBVQModelIndex@@@Z)   sorry but the language is set on Italian, the strange thing is that it works properly with insertEl so i don't know what to think.  I've already checked the .pro file so I'm not including it right now because there is a lot of code already.  Every help will be really appreciated, thank you a lot.


Prove that a set $A$ is infinite if and only if $A$ contains a countable subset $C$. I know I have to build a sequence and then I'll get a countable subset, but I don't know how to build that sequence from a infinite set.


Does this advertisement violate the ban on Fake UI ads?

I see some "ads" that show the title of a current StackExchange hot network question, with the relevant SE site name and logo below it.  There is a policy against .  But I'm not sure if this is an ad or not.  Is this an ad?   The URL points to "engine.adzerk.net/..." but if I click on it, it routes the browser back to stackexchange with no obvious ill-effect.  But it looks fishy...


Is there any ways to count number of character in NVARCHAR column in SQL Server?

For example, I have 100001,100002, stored in a NVARCHAR column.   I want to count the number of occurrences of , in this column.


why add a resistor parallel to voltage source?

Sometimes I see a resistor parallel to voltage source (such as image below), isn't it completely useless ?  Edit: I see the other similar question now, but I think it doesn't have the right keyword for this topic (I didn't find it when I searched)


I have Sql table called EmpTBL , Where it consist of data as:  ID  Emp_ID  Dept    Role_ID Status   82  E00004  D1       3        1         82  E00004  D2       3        1 83  E00034  E2       1        1  84  E00043  G1       2        1  84  E00043  G2       2        1  84  E00043  G3       2        1  76  E01053  A1       1        1    I need to write a query that groups up Emp_ID and display Dept as  ID  Emp_ID  Dept       Role_ID  Status 82  E00004  D1, D2      3        1 83  E00034  E2          1        1 84  E00043  G1, G2, G3  2        1 76  E01053  A1          1        1


Bash script not handling npm commands correctly

I have a script that runs some git and npm commands based on a user like  #!/bin/sh /bin/su someuser -c " cd /opt/app1/; env -i git remote update; env -i git pull origin dev; cd /opt/app1/client/; npm run build; "   The git commands run correctly. The npm command runs and builds the files but throws lots of errors about   Node Sass could not find a binding for your current environment: Linux 64-bit with Node.js 8.x  Found bindings for the following environments:   - Linux 64-bit with Node.js 9.x  This usually happens because your environment has changed since running `npm install`. Run `npm rebuild node-sass --force` to build the binding for your current environment.   If I run npm run build as the user from terminal, everything builds fine. I even tried env -i npm run build in the script and that just says env: ‘npm’: No such file or directory. So i then tried env -i /usr/local/bin/npm run build and oddly that returned /usr/bin/env: 'node': No such file or directory.  I though that the user -c would set me up with all env like the user was logged in and that env -i would give me clean env without the parent.  also tried:  #!/bin/sh /bin/su someuser - -c " cd /opt/app1/; git remote update; git pull origin dev; cd /opt/app1/client/; npm run build; "   That last attempt returns same as first: git commands work, build throws errors about sass and environment as if something is different than when i run the command as the user from the terminal.  Any idea why this command is not working correctly?


Couldn't load PyQGIS in QGIS 2.2 on Ubuntu 14.04

This issue appears to be occurring with some frequency to folks in some shape or form. I upgraded from ubuntu 12.04 to 14.04, with loss of python functionality.   My QGIS version is 2.2 from the official repository (not ubuntugis).  I have anaconda installed as my main python release, and I also used anaconda to install sip, since I received that error message earlier on.  conda install sip  Which left me with version 4.15.5. After installing that, the sip dependency was no longer an issue, and now it is "just" the pyQGIS and qgis.core dependencies causing problems.  I tried switching to the nightly build, but to no avail--still no python support.   I am not sure where the qgis package should be located--it may be just a pythonpath issue, but it may be an API version issue with underlying dependencies, although sip does seem to be fine now.  Tips?


Can I run my CPU at 100% usage for a long time?

I have a Dell XPS 15 9570, 32 GB ram, 2.2 ghz and 6 cores. When i use an application (The parsim command on MATLAB) ()  then my fan starts running fast , during this my PC doesn't seem to be heating but it never got this noisy in the past so it got me worried. In my task manager , the CPU usage shows 100% when this application is running.   Is it a problem for the life of laptop, if I run the PC at CPU 100% for like 4 hours in a day? Do I need to be worried about the noisy fan during the application?


Prove that circumcentre of $ABH,BCH,CAH$ are the vertices of a triangle congruent to $ABC$

Let $H$ be the orthocentre of an acute triangle $ABC$. Consider the circumcenters of triangle $ABH,BCH,CAH$ .Prove that they are the vertices of a triangle that is congruent to $ABC$.   My Work:   Observe that $AH$ is perpendicular to $BC$ & $O_BO_C$. (Let $O_B$ be the circumcentre of $AHC$ and the others are defined same).  Clearly,$AH\perp BC$ & $AH\perp O_BO_C$. Therefore $BC||O_BO_C$  Similarly $AC||O_AO_C$ & $AB||O_AO_B$  But, I failed to show $O_BO_C=BC$  You may also show that  $AO_C=AO_B$


Strategies for navigating directories quickly?

In general, I tend to prefer the command line to mousing around in Windows, but one aspect of the command line that I do not like is directory traversal. I seem to spend a lot of time cd-ing around for one reason or another.  Are there any strategies for making it easier to jump around from place to place in the directory structure?


Short circuit or disconnect to bypass a compressor

I have an Altec Lansing ATP3 2.1 audio system PCB which I reverse-engineered, and I would like to bypass the JFET compressor that's on it. Its active components are a JFET and four op-amps. I will connect the input to the output so it gets forwarded to the next stage.  My question is: should I disconnect the input and output from the compressor (in that case should I remove power supply as well, which would be very annoying), or can I leave it connected but short-circuited?  The block I want to short-circuit is the pink one on the left.    I realize the image is very small. The sound comes in on the right, in the green box. In the middle yellow box there's some trebble/volume/bass control. The small green box on its left merges the left and right channels to forward it to the subwoofer section, which is the complete left half of this diagram (except the red box on the left, which is just power). Signal then goes through a low-pass, a small equalizer and a compressor (the big purple box). It finally gets amplified in the brown power amp.


I have just installed Ubuntu 12.04 and I added some repo, and when I did apt-get update, I got missing gpg key.  Following command seems to doesn't work for me:  apt-get update 2> /tmp/keymissing; for key in $(grep "NO_PUBKEY" /tmp/keymissing |sed "s/.*NO_PUBKEY //"); do echo -e "\nProcessing key: $key"; gpg --keyserver subkeys.pgp.net --recv $key && sudo gpg --export --armor $key | apt-key add -; done   How to fix this problem?


I repost with a simplified question (my previous post was closed).  I need to output all combination of a list of length N.  I already know that combinations will do this with, as example, the actual input list: ['A, 'B'] ==> output: ['A', 'A'], ['A', 'B'], ['B', 'B']  But I need this: ['A', 'A'], ['A', 'B'], ['B', 'A'], ['B', 'B'].  Is there a way to do it with combinations()?


Initial particle configuration of a spiral galaxy for $N$-Body simulation

I coded an $N$-Body tree algorithm. Now I want to test the code for a particle configuration which represents at the beginning a sphere with radius $R=1$. All $N$ particles are randomly distributed inside the sphere. For the mass I chose $m_i=\frac{1}{N}$.   Now the difficult part to me, the right velocity: I want the sphere to rotate around its own axis in such a way that the sphere neither explodes (centrifugal force > gravitational force) nor implodes (centrifugal force < gravitational force). As a result for large simulation time $T_{MAX}$ I would expect a formation as known from a spiral galaxy.  So, I know what I have to consider, but I do not know how to get the right velocities for such a particle distribution. How should I possibly start? I would really appreciate any help.


Steam, missing 32bit libs but it won't install

Steam needs to install these additional packages: libgl1-mesa-dri:i386, libgl1-mesa-glx:i386, libc6:i386  [sudo] password for user: E: The method driver /usr/lib/apt/methods/https could not be found.  Reading package lists... Done Building dependency tree       Reading state information... Done Package libc6:i386 is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source However the following packages replace it:   tzdata libdb1-compat locales libc-bin initscripts  Package libgl1-mesa-glx:i386 is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source  Package libgl1-mesa-dri:i386 is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source However the following packages replace it:   libgl1-mesa-glx  W: Duplicate sources.list entry http://dl.google.com/linux/chrome/deb/ stable/main amd64 Packages (/var/lib/apt/lists/dl.google.com_linux_chrome_deb_dists_stable_main_binary-amd64_Packages) W: You may want to run apt-get update to correct these problems E: Package 'libgl1-mesa-dri:i386' has no installation candidate E: Package 'libgl1-mesa-glx:i386' has no installation candidate E: Package 'libc6:i386' has no installation candidate Press return to continue:   When I type in sudo apt-get update:   user@chrubuntu:~$ sudo apt-get update [sudo] password for user: E: The method driver /usr/lib/apt/methods/https could not be found.  When I type in sudo apt-get install ia32-libs user@chrubuntu:~$ sudo apt-get install ia32-libs Reading package lists... Done Building dependency tree        Reading state information... Done Package ia32-libs is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source However the following packages replace it:   lib32z1 lib32ncurses5 lib32bz2-1.0  W: Duplicate sources.list entry http://dl.google.com/linux/chrome/deb/ stable/main amd64 Packages (/var/lib/apt/lists/dl.google.com_linux_chrome_deb_dists_stable_main_binary-amd64_Packages) W: You may want to run apt-get update to correct these problems E: Package 'ia32-libs' has no installation candidate user@chrubuntu:~$    P.S. I'm a total newbie at ubuntu/linux


Awk compare 2 files, print match together with non match lines filled with 0

I have two files.  I want to match the 1st column of first file to 1st column of second file. If there is a match I'd like to print the 2st column of second file, if not 0.  I have tried awk (awk 'FNR==NR{a[$1]=$0;next} {print a[$1]}' 2.txt 1.txt) but it is not working.  F1.txt  A B C D E F G H I J   F2.txt  A  0.5 E   1 H   0.5 J    1   Desired_output  A    0.5 B    0 C    0 D    0 E    1 F    0 G    0 H    0.5 I    0 J   1


Is full wave rectifier better than half wave one?

I am curious if there are practical differences between a DC power supply based on a half wave rectifier or a full wave rectifier.  I mean I have a few small DC power supply units which should give 12V 0.1A each. They all have a transformer 240V->18V, then 1 diode or 4 diodes, then 78L12 (0.1A regulator) and one or two capacitors (typically 220uF or 470uF).  My question is if the power supply can give a good quality DC voltage with just a half wave rectifier (a single diode) when a 470uF capacitor and 78L12 is added, or if bridge rectifier (4 diodes) is better.  I also have one old 12V 0.2A power supply based on a Zener diode instead of 7812 regulator. It also has 18V going to just a single diode, then 33R resistor which limits current to 0.2 Amp, then Zener diode parallel with a 1000uF capacitor. Again: Would it be better to have 4 diodes there, or is the half wave rectification good enough here thanks to the 1000uF capacitor?  (All my power supplies work well, I am just curious "why" and "how" these things work.)  Update:  I found two more interesting information:   Capacitor should be approximately 500 uF for each .1 Amper of output (or more). This applies to full wave rectifier. Since I saw the same values in half wave rectifiers, it isn't enough and they are bad design. 4-diode rectification cannot be used when we want to have a combined 5V/12V output (or any other two voltages) with a simple transformer, because it can't provide a common ground for two different circuits. (A more complicated real example: I have got a power supply with four output wires from transformer -7/0/+7/+18 Volt. Then it uses 2-diode rectification to get full wave 7V output, and 1-diode rectification to get half wave 18V output. The 18V line can't be "upgraded" to 4-diode rectification here.)


Cannot rename abstractname when using babel (UKenglish)

I tried both redefinitions I found on tex.stackexchange, they have no effect:  \documentclass[11pt,a4paper]{article} \usepackage[UKenglish]{babel} \renewcommand{\abstractname}{Executive Summary} \addto{\captionsenglish}{\renewcommand{\abstractname}{Executive Summary}}  \begin{document} \begin{abstract} This work is an \ldots \end{abstract} \end{document}   Still renders as 'abstract':


Dual nationality, EU and Australian. Does it matter which passport is "travelled on"

I plan to visit Australia from the UK, I am an Australian national with dual nationality - I also hold a Greek passport.  I have all the correct documentation and everything is fine.  However, if I leave the UK and present my Australian passport to immigration control on exit from Heathrow, will this then pose problems when I return back to the UK and present my Greek passport. I will be carrying both passports.


Is this a Matlab bug? Do you have the same issue?

My Matlab version is R2012a Why in Matlab 1.1-0.2 is not equal to 0.9!!!!!?  This is awful!     >>1.1-0.2 == 0.9      ans =   0


Numbers of draws on a modified Bernouilli process

Here is the setup: Bob runs an experiment: he flips a coin N times (between 0 and +$\infty$). The coin has a probability p of landing on heads. Bob starts with zero points. For each head, Bob scores a point. Now, Bob goes to Alice and tells her p and that the score is zero, and ask her the probability that he flipped the coin N=n times. The case that make it special for me is the addition of the possibility of zero draws, and I'm stuck with it. Here is my attempt at solving this: N is the random variable counting the number of flips, S is the random variable counting the score. We want to know $P(N=n|S=0)$. $$ P(N=n|S=0) = \frac{P(S=0|N=n) \cdot P(N=n)}{P(S=0)} $$ Now $P(S=0|N=n)= (1-p)^{n}$ so that's good. Also, $P(S=0) = P(N=0) + \sum\limits_{n=1}^\infty (1-p)^{n}P(N=n) $ But now I'm stuck since I don't know what do with that $P(N=n)$. Now you could argue that since we know nothing about the distribution of N, the most reasonable assumption is that they are all equally likely. Then the substitution occurs as: $$ P(N=n|S=0) = \frac{P(S=0|N=n) \cdot P(N)}{\frac{1}{p}\cdot P(N)} = p(1-p)^{n} $$ This feels like cheating. Not because of the limit, this looks legit cf replace $\infty$ with $N_{max}$ and take the limit at the end, but because of the assumption on $P(N)$ being uniform. While keeping $N_{max}$ this is good, but it seems shady when taking the limit. Also, what do I know if it is uniform ? Am I doing something wrong here ?


Let $K$ be a field and $A$ a square matrix with entries in $K$. Then A and $A^\top$ have the same characteristic polynomial. What do we know about similarity? Do you have an example where $A$ and $A^\top$ are not similar?


What did we learn about Snoke in The Last Jedi?

Did The Last Jedi (or any script, novelization once that becomes available, etc) shed any new light on Snoke?    I do mean that in a pretty general sense in that I'm not after a particular piece of information, but rather, what were his goals, where was he from, who actually was he, etc...    After the events at the end of the movie, it seems a little strange to me that        they would just kill off Snoke like that, basically just being a means for Ren to draw even further to the dark side and becoming the new Supreme Leader (which in itself is a fine reason, but still... I [wrongly] expected him to play a further role in the SW universe).


Trouble creating 3TB ext4 partition due to msdos-partition-table-imposed error

I just bought a 3TB WD green drive, but when I try to partition in in gparted I get an error like:  ====================== libparted : 2.3 ====================== partition length of 5860530176 sectors exceeds the msdos-partition-table-imposed maximum of 4294967295   And when I try with Ubuntu "Disk Utility" I get a similar error like:  Error creating partition: helper exited with exit code 1: In part_add_partition: device_file=/dev/sdc, start=0, size=3000592982016, type=0x83 Entering MS-DOS parser (offset=0, size=3000592982016) MSDOS_MAGIC found looking at part 0 (offset 0, size 0, type 0x00) new part entry looking at part 1 (offset 0, size 0, type 0x00) new part entry looking at part 2 (offset 0, size 0, type 0x00) new part entry looking at part 3 (offset 0, size 0, type 0x00) new part entry Exiting MS-DOS parser MSDOS partition table detected containing partition table scheme = 0 got it got disk new partition Error: partition length of 5860528002 sectors exceeds the msdos-partition-table-imposed maximum of 4294967295 ped_disk_add_partition() failed


Reinterpreting bytes of a vector at memory level

I have a vector aVector. It starts at some memory address, let it be 0x00cff87f in this case.  I also have a double D.  Now, when the program accesses the D above, it accesses some other address, of course.  What I need is that when the program accesses D above, to be pointed to address 0x00cff87f, the start of that array, and take the first sizeof(double) bytes as a double.  I tried passing pointer to D to a function and switch it, but that just changed where that pointer was pointing at, once I exited the function, D remained unchanged.  Basically, I need some way to tell the program that four bytes of memory starting at 0x00cff87f are a double and that when I ask for a double named D to get me the number at that address.  I have an array in memory that needs to be decomposed to basic types, but instead of copying everything unnecessarily, I'd rather just tell the program where it already is.  How do I do that?  EDIT:  I have a vector of unsigned chars that I want to read into other types. Something that C# BinaryReader would do with MemoryStream. I don't know how to do it in c++. There are only fstreams, there isn't one that deals with (binary) files already in memory.


Pushing updates to 100 clients from 1 'YUM Server' (RHEL/CentOS)

We have a network of around 100 clients running RHEL and one machine hosting a mirror of RedHat's official repository (via rsync).  The clients point to the server to get their updates (via .repo file), but currently I have to manually go into each one and execute   $yum check-update $yum list updates $yum clean all $yum update  The idea is to have the server do a sort of "push updates" and all the clients receive and apply the corresponding updates on their own.


How to convert XML to a custom object in c#

XML File below.  Looking to be able to read from and write to the below file.  Using the below code I am able to SEARCH for a specific pagename node  `XDocument xmldoc = XDocument.Load(path);   metadata m = new metadata();  XElement emp = xmldoc.Descendants("data").FirstOrDefault(p => p.Element("pagename").Value == pagename);          if (emp != null)         {            //How to populate each child node            // dctermscreator.en = this            // dctermscreator.fr = this             //so on         }`   `<?xml version="1.0" encoding="UTF-8" ?>  <root>  <data>   <pagename>default</pagename>   <metadata>     <desc>       <en>eng desc</en>       <fr>desc fra</fr>     </desc>     <dctermscreator>       <en>eng desc</en>       <fr>desc fra</fr>     </dctermscreator>     <dctermssubject>       <en>eng desc</en>       <fr>desc fra</fr>     </dctermssubject>   </metadata>  </data>  </root>`


Derivation of Equation of Reducible and Irreducible Error

I am currently reading  by James, Witten, Hastie, and Tibshirani, and I am stuck on one of the leaps they take when defining reducible and irreducible error. They state that for a given set of input and output variable $X$ and $Y$, respectively, there is a function $f$ which we estimate, defined as $\hat f$. Using $\hat f$ we then obtain the our predictions of $Y$ which is called $\hat{Y}$ such that $\hat Y = \hat f(X)$. On page 19, equation 2.3, they give the following equation:  $$E(Y - \hat Y)^2 = E[f(X) + \epsilon - \hat f(X)]^2$$ $$ = [f(X) - \hat f(X)]^2 + Var(\epsilon)$$  They then go on to say that $[f(X) - \hat f(X)]^2$ is the reducible error while $Var(\epsilon)$ is the irreducible error.  I am by no means a mathematician and have tried some derivations but cannot reach that conclusion on my own, particularly in deriving $Var(\epsilon)$. Thank you.


get vf page to open up in parent window?

I have a vf page that is a custom button. That's it.  this VF page is on a STD Page Layout. When the user clicks on the VF page, the parent window needs to be redirected to the new URL.  The way this is working, is that the new page is opening in the vf section of the page layout.   <apex:page standardController="Opportunity"  standardStylesheets="true" extensions="OpportunityController" > <base target="_parent" /> <body style="background:#f3f3ec" > <apex:form > <center>  <apex:commandButton action="{!redirect}"  value="Change Record Type" rendered="{!render}"/> </center>   </apex:form>    </body> </apex:page>


Is there a mechanic to let me limit SSH and telnet logins to the root account based on IP address? I have 3 nets used for different things locally all in the 192.168.x ranges, I need to login from those and banned from anywhere else.  I know having root active is frowned on... but like a bad admin I live in my root account.


Ubuntu 17.10 Screen lock not working and grey

The screen lock is not working, it does not lock the screen (no password required).  I would like it to prompt for a password every time the screen locks (clock screen).  All instructions tells me to enable this in privacy but I can not enable or disable as it's grey (gray).  Ubuntu 17.10 upgraded from Ubuntu 17.04, upgraded from Ubuntu 16.10.    Any help or advise would be great as I already tried many setting and installs and removes suggested on online.


Convert lead in salesforce without creating an account?

Once a lead is converted it automatically creates an account, contact and one opportunity. But in my case i want to display the result without creating an Account. Please provide me with a sample code.  Any help will be appreciated...


I would like to use some code block for a report. The only problem : I didn't find inside listings for the language I used (Nodejs).  Can you help me ?  PS: I check inside the listings package :


Can anyone explain this? I'm new to this topic. Prove that for all integers a, b, c , if a | c and b | c , then ab | c² .


How to change the output color of the ls command in terminal in OS X and iTerm2?

I know that a similar question has been asked in:        although I didn't really understand the answer and couldn't really make it work.  However, I have tried something different. I decided to read the manual page for ls and it mentions different environment variables that can be set when dealing with the ls command. If one goes to the -G option it says to look at the CLICOLOR environment variables. I did and that one links you to documentation for the LSCOLORS environment variable. I went to it and it mentions:     "The value of this variable describes what color to use for which attribute when colors are enabled with CLICOLOR. This string is a concatenation of pairs of the format fb, where f is the foreground color and b is the background color. "   It also mentions that the default value of LSCOLORS is "exfxcxdxbxegedabagacad" and that each part specifies the color of some specific thing in the ls command. For example, the first pair ex in example specifies the color of directories. the second fx the color of symbolic links etc... e means blue and x means default "foreground".  1) First what does this mean: "when colors are enabled with CLICOLOR"?  2) What does "foreground" mean?  What must environment variables be for the ls command to color the output however I desire?    I also tried:  ls --color   But it threw me the following error:  ls: illegal option -- - usage: ls [-ABCFGHLOPRSTUWabcdefghiklmnopqrstuwx1] [file ...]   The same error happened when I did ls --color=auto: it alone also throws an error. I have no idea why, and am not sure if it was due to iTerm2 or OS X or why that happened. It seems it works on other systems...


software suggestion for drawing software diagrams

i am new to Ubuntu. need a suggestion for software to making **ERD,class & level diagrams in Final year project


If Riemann integrable, then it has finite number of discontinuities

I know that any bounded function with a finite number of discontinuities is Riemann integrable over some interval. Is vice versa i.e.,  If a bounded function is Riemann integrable, then it has a finite number of discontinuities?  Thanks.


Why did I get suspended for 6 days with all my votes reversed?

So in Chemistry and Math Stack Exchange I got suspended for six days and got my votes reversed. I believe that is because the moderators thought that I voted for myself.  So basically what was happening was that this account, John Rawls, had this other account Nick Bostrom voting for John Rawls. But rather I know Nick Bostrom so I kept on facebooking him the links to my questions so that I can get an answer.  I was wondering whether I am going to get my points back for Math.SE and Chem.SE after six days. If not, I was wondering if I could get it reversed because I don't understand why this is happening and I believe that this is unfair.  This question is specific and should not be marked as duplicate because this is a scenario where someone is voting for me


How to convert a column number (e.g. 127) into an Excel column (e.g. AA)

How do you convert a numerical number to an Excel column name in C# without using automation getting the value directly from Excel.  Excel 2007 has a possible range of 1 to 16384, which is the number of columns that it supports. The resulting values should be in the form of excel column names, e.g. A, AA, AAA etc.


If $a$ is an element of some ring and $\{a^n; n=0,1,\dots\}$ is finite, then $a$ is invertible or a zero divisor

I'm supposed to prove that, in a ring, if $a$ is an element such that the set $\{a^n; n=0,1,...\}$ is finite, then $a$ is either invertible or a zero divisor. I don't understand how $a$ can not be invertible, since if the set is finite then there has to be an $i$ such that $a^i=1$.


Can anyone explain the concept of a Vitali set? I am not able to understand the construction of the set.


What is the point of stacking favorite notifications?

I noticed I have more notifications than favorites, which means that the notifications are stacked (in other words, there can be more than 1 notification per question).    Here is my reasoning:   Why do they add up?, I don't know where is the benefit of knowing that some of the questions had multiple changes if we are not able to see which questions had how many changes   Since we don't know what questions had what amount of changes, the amount of notifications is just a meaningless number that don't help us too much. Here are some possible solutions:   Add a max of 1 notification per question Keep the same number, but allow us to see how many new changes there were on every question


some important proofs about adjoint operators

I was told that the formal adjoint of the gradient is the negative divergence.   Let $A : H\to H$ be a bounded, linear operator, The adjoint of $A$, i.e. $A^*: H\to H$ satisfies \begin{equation*}  (Au,v)=(u,A^*v) \end{equation*} for all $u, v\in H$. Moreover, $A$ is symmetric if $A^*=A$.  Could anyone help me to verify the claim:  what would be the adjoint of the gradient in the space $L^2(\mathbb{R}^d)$?


Bizarre reference behavior in Tree implementation

I've been completely perplexed by a bug in a larger system. Consider this class (each node maintains a pointer to its parent and a list of its children):  class Node:     children = []      def __init__(self, parent):         self.contents = dict()         self.parent = parent          if parent is not None:             print self.children             print parent == self             parent.children.append(self)             print self.children   Running this:  foo1 = Node(None) foo2 = Node(foo1)   Mysteriously returns this:  [] False [<__main__.Node instance at 0x10051f128>]   How does this make any sense whatsoever? Why is the second node's children not empty? Perhaps I'm missing a basic understanding of a concept related to how Python passes references around.


Moving data files from SSD to HDD, Ubuntu 16.04

My setup:   Ubuntu 16.04 SSD with 256 GB of space HDD with 2 TB of space   My SSD is filling up with saved numpy arrays from all my Python code. I am hoping to move those data files onto my HDD to clear up space. Unfortunately I don't know how to do that since it doesn't look like a straightforward mv command will work.  Here is some information: after typing in gksu baobab, I get a pop-up where I can see memory usage. Here, you can see that my home drive (name is blacked out for privacy reasons) is almost filling up to 177.9 GB (say, why is it not 256GB? I thought this was my SSD?):  My disk usage:   Here is df -h:  $ df -h Filesystem      Size  Used Avail Use% Mounted on udev             32G     0   32G   0% /dev tmpfs           6.3G  706M  5.6G  11% /run /dev/sda2       166G  128G   30G  82% / tmpfs            32G   60M   32G   1% /dev/shm tmpfs           5.0M  4.0K  5.0M   1% /run/lock tmpfs            32G     0   32G   0% /sys/fs/cgroup /dev/sda1       511M  3.6M  508M   1% /boot/efi tmpfs           6.3G  156K  6.3G   1% /run/user/1000 none             32G  2.8M   32G   1% /tmp/guest-3qjkgk tmpfs           6.3G  108K  6.3G   1% /run/user/999   I think dev/sda2 corresponds to my default usage on my computer, so if I move stuff and make new files, it will be here. I tested this by creating and removing temporary files,and the dev/sda2 memory usage changed. Unfortunately it seems like my 2 TB hard disk is not visible here.  Here is fdisk -l:  Disk /dev/ram0: 64 MiB, 67108864 bytes, 131072 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes  // // ram1 through ram14 omitted for clarity on askubuntu.com ... //  Disk /dev/ram15: 64 MiB, 67108864 bytes, 131072 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes  Disk /dev/sda: 232.9 GiB, 250059350016 bytes, 488397168 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: gpt Disk identifier: 23607B86-A307-4986-9B20-6E4403223EF3  Device         Start       End   Sectors   Size Type /dev/sda1       2048   1050623   1048576   512M EFI System /dev/sda2    1050624 354359295 353308672 168.5G Linux filesystem /dev/sda3  354359296 488396799 134037504  63.9G Linux swap   Disk /dev/sdb: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes   Now, here I can see my hard disk, which is in dev/sdb. However, again I can't figure out how to simply move a bunch of numpy arrays over to this drive.  From looking online, the typical procedure seems to be related to mounting the dev/sdb. But from looking at descriptions (e.g. ) it seems like mounting the hard disk would give me access to the files within the hard disk, but I wouldn't be able to access the previous files in the SSD that I'm trying to dump over to the HDD. My logic is probably wrong somewhere... and also, that tutorial mentions some things about moving file systems around, but it then says:     no data is copied or removed, it is merely displayed in a different place   and the main reason why I need to move the files is indeed to free memory on the SSD.  I am a beginner with Ubuntu 16.04 so I am happy to provide more information that would be useful about my computer.  Note: the most closely related question here seems to be , since I too share that poster's concern:     I thought that the best way to solve this is simply to move everything from the SSD to the HDD? But I am not entirely sure how to accomplish that correctly!   But there is only one answer there which doesn't seem like it answered the question (and I'm not moving everything, I just want to dump some numpy arrays over).


Weird behaviour when assigning material to specific faces

I'm following a guitar tutorial, and I created a material for the sides of the guitar. I assigned it to the sides, but in rendered view I get a band of the other material above and below the side material.    Any Idea why this is happening? Any help is appreciated!  EDIT:


Did Harry ever have classes with Ravenclaws?

Listening to the books with audible and I realized the Gryffindors never had classes with Ravenclaws. The only Ravenclaw in Harry's year mentioned seems to be Padma Patil. The Gryffindors seems to have a lot of classes with Hufflepuff (Ernie and Hannah often mentioned) and obviously Slytherin.  But how come they never have class with Ravenclaws? Did Ravenclaws even have more than 1 student for Harry's year?


I am using a shared pc and someone keeps uninstalling Chrome.  I have tried all the different versions and even the standalone installs.  Is there a way to only install Chrome on my user account not across everyone that uses the computer.


I am facing extremely slow wireless connection on Ubuntu 14.04. Also the connection is sporadic. Please help me with this. Also, if there is any more information needed do let me know.


How to make a field blank using dataloader

I have an email field having some values. I want to make this field blank. The problem is I have to make this field blank for 1000 records. When I try to update the email with blank in data loader it does not update.  Please help


I would like to write a Software and this Software have to save files in /usr/share/xy/. The Software would write and read this data with fprintf() and fscanf(). The owner of the directory /xy/ is root and the group too. Now i start the Software with sudo in the .desktop file.   Now my question is it possible to start them without an password. How big Software do this to save data in the background?  Thank you Bye Nick


Fill color and outline color with the same value

I made a categorized symbology on a shapefile, but the color value of outline (stroke color) is different than the color of fill color option. How can I ensure that both colors are the same for fill color and outline color using categorized symbology? See an example below.


I know that SQL Server 2000 doesn't support PIVOT table.   Let me tell you all about my issue and maybe you can help me with a solution.  I have a table with clients and projects.  client    project  ------    -------- A         1111 A         1112 B         2222 B         2223 C         1234 D         1235   I would like to swap rows with columns. So the output table will be:  A      B       C       D --------------------------- 1111   2222    1234    1235 1112   2223    NULL    NULL   It's possible in SQL Server 2008 simply using PIVOT table, but the server we need to use is 2000.  The clients and projects are dynamic of course.   Is there anything to get this result?   UPDATE:  I know that there are many questions in here about pivot in SQL Server. I read almost everything.  One solution is to do many case statements, but this doesn't return  what I need.  It will return:   A       B       C       D ---------------------------- 1111    NULL    NULL    NULL  1112    NULL    NULL    NULL NULL    2222    NULL    NULL NULL    2223    NULL    NULL NULL    NULL    1234    NULL NULL    NULL    NULL    1235   Which is not what I want since I will be exporting it to EXCEL with drop-down lists and it will create a lot of empty strings in the lists.


etc/apt/sources.list file for Ubuntu 17.10

I am unable to upgrade to Ubuntu 18.04 as due to wrong links in sources.list file. I am able to update successfully as only some of the links are wrong. As Ubuntu 17.10 repositories are not yet moved to old-release, I am unable to update when i replace archive to old-release. And with unchanged sources.list file, some of the links are not working-  Get:16 http://archive.ubuntu.com/ubuntu bionic/universe i386 Packages [8,531 kB]  Err http://archive.ubuntu.com/ubuntu bionic/universe i386 Packages Connection failed [IP: 91.189.88.161 80] Err http://archive.ubuntu.com/ubuntu bionic/universe amd64 Packages Connection failed [IP: 91.189.88.152 80]   Can someone tell the solution, or post their sources.list file to check the difference?


Let $Y_{(n)}=\max(Y_{1},Y_{2},\ldots,Y_{n})$, where $Y_{1},Y_{2},\ldots,Y_{n}$ is a sample uniform distribution in $(0,\theta)$. Find the MVUE for $\theta$.  My approach:  I know that $U=Y_{(n)}$ is a sufficient statistic for $\theta$. I could prove this using the factorization theorem by Neymann. I know that $\displaystyle h(U)=\left(\frac{n+1}{n}\right)U$ satisfy that $\mathbb{E}[h(U)]=\theta$.  So, $$\left(\frac{n+1}{n}\right)Y_{(n)}$$ is a (or the?) MVUE for $\theta$.  My approach is correct? Can I find other MVUE for $\theta$?


If $\langle Tv,v\rangle\in\mathbb{R}$, prove that $T$ is self-adjoint

Let $V$ be a finite-dimensional vector space over $\mathbb{C}$, together with a Hermitian inner product $\langle\cdot\,,\cdot\rangle$. Let $T:V\to V$ be a linear function. Prove that $T$ is self-adjoint if $\langle Tv,v\rangle\in\mathbb{R}$.  I know that since $\langle Tv, v\rangle \in\mathbb{R}$, $\langle Tv,v\rangle=\langle v, Tv\rangle $ ... I'm not sure where to go from here.


What does SE use to calculate reputations? SQL aggregate functions? A manual method?

I want to implement something similar to Stack Exchange's reputation system. What would be the better practice: using an SQL aggregate function to recalculate every time it changes, or storing reputations in a table and manually altering it every time reputation goes up or comes down? How does Stack Exchange's implementation work?


string[] arr1 = new string[] { "one", "two", "three" }; string[] arr2 = new string[] { "two", "three" };   I have to know if arr1 contains all string of arr2.  How to do it by coding faster?If there is a way by using lambda?  Thank you.


Reading the book called "The great design particles fields and creation" one finds the following paragraph  In a universe like ours, constructed of electrically charged elements, magnetism and the magnetic field can be considered a relativistic consequence of the electric field. If the speed of light were infinite, or if all charges moved very slowly, there would be no magnetic field and no magnetism. But in the universe we live in, where the speed of light is finite and electrical charges do move, magnetic fields accompany electric fields. The other vector fields associated with weak and strong nuclear forces have similar magnetic counterparts that derive from relativistic effects  Questions   Does gravity have such a counter part?  if not why, if yes what is it called?  The book does not explain why such a speed limit produces magnetic fields, can some one explain?


Gerund: Usage and meaning of "preposition +Being+past participle"

I've read in BBC that we use use "being" as a verb-ing. BBC has listed two kinds of usage. What I want to learn here is about the "preposition+verb-ing" form of usage. It has been said that "being+past particle" here is functioning as a noun. But I don't know what kind of meanings it would convey. So, the following are two examples from BBC:        I look forward to being interviewed on the current affairs programme. (What does "being interviewed" mean?)   She was afraid of being accused of a crime which she did not commit.   (Does it mean: She was afraid of that she was accused of a crime,...)        I think the following are also the examples of "preposition+verb-ing":     John talks about being helped by a stranger.   (Does it mean: john talks about that he was helped by a stranger.)      Before being moved to an apartment, he lived in a hostel.   (Does it mean: "Before he was moved to...")      Despite being helped by nurse, he slipped and fell.   (Does it mean: despite he was helped by nurse ,...)      What is the risk of being killed in war?   (Does it mean: what is the risk of killing in a war?)      What are the chances of being killed by a falling tree?   (Does it mean: what are the chances of killing in a war?)   Share your experiences of being helped by a teacher.      (Does it mean: share your experiences when you were helped by a stranger?)   Please explain to me the meaning and usage of "being+past particle" when we use it with a "preposition".


What is the difference between a desktop environment and a window manager?

I'm having a really hard time trying to understand what the differences between a desktop environment and a window manager are?  EDIT: From this :  There are basically three layers that can be included in the Linux desktop: X Windows – This is the foundation that allows for graphic elements to be drawn on the display.  builds the primitive framework that allows moving of windows, interactions with keyboard and mouse, and draws windows. This is required for any graphical desktop. Window Manager – The Window Manager is the piece of the puzzle that controls the placement and appearance of windows. Window Managers include: , , , , , etc. Requires X Windows but not a desktop environment. Desktop Environment – This is where it begins to get a little fuzzy for some. A Desktop Environment includes a Window Manager but builds upon it. The Desktop Environment typically is a far more fully integrated system than a Window Manager. Requires both X Windows and a Window Manager.  Examples of desktop environments are , , ,  among others)


How to name a written guide which grants you expert knowledge about a certain topic (after reading it). Is it an  expert guide experts guide experts' guide expert's guide expert' guide experts's guide   Also knowing why that's the case would be nice. (what would be other tags but apostrophe?)


Should I answer my own question in this particular case?

A while ago, I asked  then kept on searching in the meantime, and found out there was a bug with API and it would be fixed. I stated this in one of my comments. Should I make it an answer?


What is the limit $\lim\limits_{n \to \infty} \frac{n^{\sqrt{n}}}{2^n}$?

The question is rather:      Prove the following:   $$  \lim_{x \to \infty} \frac{x ^ {\sqrt x} }{ 2 ^ x} = 0. $$   I was thinking of using the Squeeze Theorem (might not be the right way to go), but finding an upper-bound function proved to be quite tricky.


Why is dimensionality reduction always done before clustering?

I learned that it's common to do dimensionality reduction before clustering. But, is there any situation that it is better to do clustering first, and then do dimensionality reduction?


Functional Equation (no. of solutions): $f(x+y) + f(x-y) = 2f(x) + 2f(y)$

Find all the functions $f\colon\mathbb{Q} \to \mathbb{Q}$ such that $f(x+y) + f(x-y) = 2f(x) + 2f(y)$, for all rationals $x,y$.


Did any Star Trek actor play both a Starfleet crewmember and one of the encountered aliens?

Is there any actor who has played, in different Star Trek episodes, both a Starfleet crewmember (of the Enterprise, Voyager, etc.) and one of the alien strangers encountered by the crew?  Clarifications:   All series (TOS, TNG, DS9, etc.), plus the stand-alone films, are included in the scope of this question. (I'd be most interested in an actor who's appeared in both these roles in the same series, but also in whether anyone's been e.g. a crewmember in TOS and an alien in TNG.) Neither of the roles in question needs to be a recurring role; either or both could be a one-off appearance. The crewmember role needs to be that of one of the primary vessels (the Enterprise, the DS9 space station, etc.)


Why is the company email still "at stackoverflow"

I got a mail from the Stack Exchange Travel Site that I am one of the top users this month.  In the email, I saw:     Email us directly at team@stackoverflow.com any time   Why are they putting @stackoverflow.com there instead of @stackexchange.com?


When migrating, moderators should be notified if a post with an identical title exists on the target site

if exact duplicates already exist on the target site. Shog9 says that moderators can override this. The implication is that they need to take some extra action to override it, but the actual behaviour seems to be that the check is simply bypassed for moderators. , and the response was that mods should coordinate with mods on the target site.  Recently, a mod migrated a question from meta to main that OP had posted to both (possibly accidentally). (That's to say, the migrating mod was a mod on the target site.) At the time of the migration, the titles were identical, but one of the bodies had been edited. I VTC'd the migrated post as a dupe, the mod saw that later, and closed and deleted it, as they would have done in the first place had they known. Of course, the mod thinks that they should have checked OP's posting history, but IMHO with identical titles some indication should have been given to them.