Find the maximum likelihood estimator for $\theta$ when $f(x)=2\theta^{-2}x, 0\leq x \leq \theta$

Find the maximum likelihood estimator for $\theta$ when $f(x)=\frac{2x}{\theta^2}, 0\leq x \leq \theta$.  This should be a really easy question but I somehow cannot seem to get the right answer. My likelihood function is $\prod\limits_{i=1}^n \frac{2x_i}{\theta^2}$ which gives me after some simplification $n\ln(2\theta^{-2}) + \sum\limits_{i=1}^n ln(x_i)$ as my log-likelihood function. Then the derivative becomes $\frac{-2n}{\theta}$. If I equate this to $0$ to obtain the maximum I obtain $\hat{\theta}\rightarrow\infty$. However, this answer does not seem plausible. What did I do wrong?


I need to decompress an archive and I need this application. How do I install it?


How to monitor traffic passing through my Wi-Fi access point

I know how to monitor the network interfaces on my local computer with Wireshark. But, how do I monitor the traffic flowing through my wireless access point from connected computers?  It seems like this might not be possible without some kind of special software on the wireless access point itself.


Is Harry's Trunk Magical or (where is Harry's broom during the summer)?

Is Harry's trunk magically oversized (like Hermione's bag in book 7, or the Weasley car in book 2) to allow him to store his Firebolt in it? Is Harry able to hide, pack his broom so the Dursley's can't see it? the broom, almost more than anything, would repulse the Dursleys.   I don't recall there being a mention of his broom specifically being at the Dursely's or being transported to Platform 9 3/4, specifically in book 4 when the Weasley's come to collect Harry from the Dursleys. One of the twins climbs into the fireplace with Harry's trunk, but no mention of the Firebolt is made, yet, Harry has it at the Burrow after the World Cup.


Are products of powers of 2 and powers of 3 dense in the nonnegative reals?

Is the set  $$ \left\{ 2^a \cdot 3^b \; : \; a, b \in \mathbb{Z} \right\} $$  dense in $[0, \infty)$? Seems like the answer is yes, but what's a simple proof?


How can I know if the set -e option is enabled or not?

I'm writing a shell function that will be called from many different places and I want to ignore all errors occurring inside the function disabling the (possibly enabled) set -e shell option, executing set +e.  The problem is that I don't know if that option was set or not, so I don't know if it's really needed to disable it, and more important, if I need to set it again at the end.  So, how do I know if it is set or not? Is there any way to ignore errors of all commands inside a shell function ignoring the -e shell option if is set?


How to check a date value according to yyyy-mm-dd pattern in bash?

In my bash script I want to check that date values provided via command line arguments by the user, have yyyy-mm-dd format. So for example, the date August 10th 2020 has to be written as 2020-08-10. Here is the test that I've written for pattern matching via a regular expression: #!/usr/bin/bash  dateval="2020-08-10" regexp="^[0-9]{4}-[0-9]{2}-[0-9]{2}$"  if [[ ! "${dateval}" =~ "${regexp}" ]] then     echo "Date format is not valid" else     echo "Date format is valid" fi  This prints "Date format is not valid" and I don't understand why as the date value being tested is indeed in good format. Could you kindly make some clarification and indicated what I misunderstand?


How to disable window move with alt + left mouse button?

I have problem with this function because i work in Maya and other 3D applications that use this key combination... This option on Ubuntu 11.04 was in "window" section so i could change it to something else to avoid conflicts... where is this located in Ubuntu 11.10?


How to get Mac to give Ethernet connection priority?

I have the following issues / question. I use WIFI and Ethernet through each other like most people probably.  Certain things like ripping a blu ray I want to do through the Ethernet connection so that is when I plug it on.  However, I first have to turn WIFI off to "force" the mac to choose to route the data through the Ethernet connection.  In system settings under network / priorities I have the proper order, so Thunderbolt Ethernet above WIFI.  Any idea how I can make the Mac use the Ethernet cable without turning off the WIFI? THANKS!


How to add two hexadecimal numbers in a bash script

I want to add two hexadecimal variables in a bash script.  I want them to start as hex and end in hex, not decimal.    What I've come up with so far is a bit of a round about hack. Is there a better or more elegant solution?  BASE=0xA000  OFFSET=0x1000  NEW_BASE=$(( $BASE + $OFFSET ))  NEW_BASE=`printf "0x%X\n" $NEW_BASE`  echo $NEW_BASE  0xB000


It had been him and Nina that had decided years ago. Now it was her who had to clean up their mess.   or     It had been he and Nina that had decided years ago. Now it was she who had to clean up their mess.   Which is correct


Reviewing suggested edits which add one or two not so important tags

During reviewing some of the suggested edits, I encountered with lots of questions which were edited to add just one tag or sometimes two.  I approved/rejected the edits on the basis of the severity of the tags added. But then I came to know that this type of editing was done by  the same user.   Some of the questions about this type of editing are           I found that almost all of the edits were approved. You can have a look at the  who have generated lot of reputation with such edits. I just have the doubt that if it is okay to approve this type of  editing. I have also asked for moderator attention for this.


Is minimizing Koenker-Bassett error the only optimization problem that gives sample quantile?

Sample quantile can be estimated by solving $\min_\theta \sum_{x \in X}f_\alpha(x-\theta)$ $f_\alpha = \alpha |x|$ when $x>0$, $f_\alpha = (1-\alpha) |x|$ when $x\leq0$. Sample expectile can be estimated by solving $\min_\theta \sum_{x \in X}f_\alpha(x-\theta)$ $f_\alpha = \alpha x^2$ when $x>0$, $f_\alpha = (1-\alpha) x^2$ when $x\leq0$, Are they unique? Are there other optimization problems that give sample quantile/expectile?


When using See for example figure \ref{fig:example}., it outputs something like See for example figure 2.4.1. when the ref is in section 2.4.1. Why does it not link to the figure? The figure is defined like this:  \begin{figure}[H]     \label{fig:example}     \caption{Example figure.}     \includegraphics[width=\textwidth]{img/example.png} \end{figure}   The figure itself does get a proper label, e.g. Figure 3: Example figure. but the reference references and links to the chapter it's in, which is completely useless. If I intentionally break the label, for example by using \label{example} without fig:, it puts ?? instead of the section, so it apparently can resolve it.


nginx: no permission to bind port 8090 but it binds to 80 and 8080

I'm struggling with some strange permission related behavior: when I configure nginx to listen to port 8080 everything works as expected, but when I use any other port I get something like  2014/01/10 09:20:02 [emerg] 30181#0: bind() to 0.0.0.0:8090 failed (13: Permission denied)   in /var/log/nginx/error.log  I have no clue where to look at so I don't really know what parts of the configuration might be interesting.  in nginx.conf nginx is configured to run as nginx:  user  nginx;   Also user nginx is in another group 'git'  in the site-config I tried to listen like this:  server {     listen 8090; #does not work     #listen 8080; #works     #listen 9090; #does not work     #listen 9090 default; #does not work neighter     #listen 80; #works!     server_name <some IP>;     ... }   I have only one more listener which serves port 443.  When I start some other service e.g. a SimpleHTTPServer on port 8090 etc. as non-root everything works fine:  $ python -m SimpleHTTPServer 8090 Serving HTTP on 0.0.0.0 port 8090 ... localhost.localdomain - - [10/Jan/2014 09:34:19] "GET / HTTP/1.1" 200 -   What can the reasons be for denied permissions in general?  System is Fedora 18 ngnix is stock fedora 1.2.9


single column footnote in two column layout

I want to print my affiliation in the bottom of the chapter opening page as a footnote, I am using a two-column layout.  Is it possible to get a single-column footnote in the two-column layout?


can we have a REAL terminal connected to an Ubuntu PC now-days

and how do we deal with it since we only have virtual terminals?? btw what are virtual terminals for? apart from logging into them when your GUI freezes?


Getting notifications from other Stack Exchange websites

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


I have recently gone back to a project I have been working on and the materials I have previously used no longer render properly. When I select the materials preview in the viewport I am treated to a weird disco light show.  Rendering the image from the camera also no longer works.  I have tried recreating the textures from scratch but this doesn't help. Thanks in advance.


I have two sentences:          John, Jane, and I went to the party.     He and I went to the party.    But I think there is a rule that says a pronoun at the end of a list should be in a special form (for "I", the special form is "me").  So, my sentence 1 and 2 should be rewritten like this:        John, Jane, and me went to the party.     He and me went to the party.    But in a lot of writing, sentences like sentence 1 and 2 are used instead of sentence 3 & 4.  Is there a special rule that allows not using "me" for sentences similar to 1 and 2 for casual writing?


How to prove that $\sum_{j=0}^k {n\choose j} \cdot{m\choose k -j} = {n+m\choose k}$

I am a high school student and I need help proving that $$\sum_{j=0}^k {n\choose j}  \cdot{m\choose k -j} = {n+m\choose k}.$$


Isn't Newton's Second "Law" merely a definition of force?

Is it just me, or is Newton's Second "Law" in fact no law at all, but a mere definition of force? The concept of force does not exist prior to the statement of N2, and thus it would seem that the law is entirely analytic and does not in itself improve our knowledge about nature. Things were different if the concept of force had been introduced separatedly, and if N2 then postulated a proportionality between $\mathbf F$ and $d\mathbf p/dt$. The fact that N2 is a statement of equality now has the consequence that no better unit can be given for force than the traditional Newton = metre kilograms per second squared.  As I see it, the only synthetic statements that could be considered part of N2 are: 1) all behaviours of and interactions between bodies may be described in terms of forces, which are applied to bodies from other bodies (note that this fact is not at all evident in itself); and 2) the values of the individual forces are independent of any other simultaneous forces acting from other objects. 1) now allows us to state real laws about concrete interactions, like gravitation. 2) gives rise to the superposition principle, while 1) and 2) together allow us to extend the concept of force from N2, which only defines the net force acting on a body. The force applied from a body on another body is then defined as what would be the net force on the body if all other objects did not exist.  In fact, it is not even evident that the concept of force is necessary for the physical science and its ability to describe the nature around us. The use of force is probably a consequence of its great practical applicability, which is in turn the result of a desire to describe nature in terms of linear differential equations. For entirely mathematical reasons, the study field of linear differential equations is rich, and thus its use in physics gives us invaluable tools that allow us to easily analyse physical systems. Work and energy are examples of concepts with properties that are again direct consequences of the mathematical framework (at least I think most of them are). However, were it not for those rich mathematical systems, it is not obvious that the mathematical framework for classical physics is even the most natural one. For example, a concept like velocity (central to the force-oriented mathematical framework) seems less natural in a relativistic context, where rapidity in some ways seems more in accordance with the physical system itself.  So any thoughts about whether Newton's Second Law actually contains synthetic information about the physical world?


Confidence interval around binomial estimate of 0 or 1

What is the best technique to calculate a confidence interval of a binomial experiment, if your estimate is that $p=0$ (or similarly $p=1$) and sample size is relatively small, for example $n=25$?


Book where girl can grow nails and might be a thief

I'll apologize for this being a vague description up front. I read a book about 8 years ago about a girl who could grow her nails into essentially razorblades or long enough that they could be used as razors. She travels to a city and either becomes an assassin or a thief (pretty sure it was a thief). I vaguely remember the book opening with her being chased by a mob. At some point during her thief training she realizes that the layout of the city is the key to some important plot device. I think she was given some scroll or cryptic image and then during her training she realizes that the layout of the city correlates to it.  Although I did read this 8 years ago I'm pretty sure the book was at least 5-10 years older than that, maybe even more because it was my mom who gave it to me and she said had read it when she was younger. The dust cover was missing when I read it so I have no description for the cover. I do remember that the author was male. It was a fantasy setting and there may have been vampires involved at some point but that part of my recollection of the book is even fuzzier than what I've already described. I've tried googling for this book but obviously my description is fairly vague. I will gladly answer any follow up questions that I can to try and help figure this out because it has been bothering me for years.


Connecting line features and determining the length of the longest line

I have a line feature (see image) representing a river that I created using the Stream_to_Feature tool. The attribute table contains several records representing different lines - the problem is the longest line (easily distinguishable visually) is not represented as a single line in the table, it is actually made up of many smaller lines. The lines appear to be touching, although they do not cross through each other.   How can I merge these lines and then determine the length of the longest line using ArcObjects or manual methods that I can convert to ArcObjects? An even better solution would involve getting rid of all of the tributaries and leaving me with just the river channel as a line.


Parametrization of pythagorean-like equation

Is there any known complete parametrization of the Diophantine equation $$ A^{2} + B^{2} = C^{2} + D^{2} $$ where $A, B, C, D$ are (positive) rational numbers, or equivalently, integers?


I try to save some data I get into a form in the database but I don't know how to do it.  Currently, here is what I have in the database (I try to add articles). As you can see I already have 2 of them but I set them using directly the CMS. Now I would like to be able to modify these data (for exemple the title of an article) and even add new full articles if possible.     To get the articles this is what I am doing (it works).      $query = \Drupal::entityQuery('node');     $query->condition('type', 'Article');     $items_ids = $query->execute();     $items = Node::loadMultiple($items_ids);   How do I set the title for the article 2 to title 2 changed?


I have changed my system to boot from UEFI instead of BIOS and have installed Windows 7 on my internal SSD which has GPT partition type.   I am trying to install Ubuntu 13.04 on my external HDD. My machine is a Lenovo . My HDD is a 1TB USB3 .  Here is some of what I have been trying:   My laptop is set to boot in UEFI mode. I have 64 bit version of Ubuntu, on my bootable flash disk    I took out my SSD before installing Ubuntu    Before installation my external HDD was also partitioned as GPT and it only had one 950GB partition   I tried two different methods:     First: When I let the Ubuntu to install itself automatically, without changing anything, the installation completed but Ubuntu did not boot. SSD was out and I am sure the systems boots in UEFI mode. Second: I tried to do the partitioning myself in the following order, but I still have the same problem, I am sure my HDD is partitioned as GPT:     /EFI Boot /(root)  /swap   /home     I chose to install the bootloader in /EFI boot.    Please let me know what I am doing wrong. Thanks  Update:  I was sure that Windows, on SSD, boots in UEFI mode. However, I disconnected my HDD and the windows did boot from SSD.I used the live USB to boot Ubuntu and let it do the partitioning and install Ubuntu on the external HDD. I still had the same problem and Ubuntu did not boot. Then I used the live USB and installed Boot-Repair. After running Boot-repair and a restart everything was good, and Ubuntu did boot from HDD. However, there is a line before booting into Ubuntu: ata_id[279]: HDIO_GET_IDENTITY failed for '/dev/sdb': Invalid argument But the system boots.  Boot Info Script: Here is a  I got after using Boot Repair.   I tried to change the partitioning and partition sizes. After reading , I changed the partitioning using Gparted. I also installed the bootloader in /dev/sda1 which is flagged as the /boot partition. As expected after installation and a reboot, Ubuntu did not boot. So by following  and  posts, I tried to register the bootloader to the EFI. But I was not successful. I even noticed that my machine might have  problem, and I changed the /EFI/Ubuntu/bootx64.efi name and location but no effect, Ubuntu did not want to boot.  Again, I used boot repair to solve the boot problem and it worked like the previous time and I am in Ubuntu. But I really like to know what is causing this problem. The interesting thing is that Boot Repair has created all possible folders and files. Is there a way that I know which folders are being used for boot? These are the different folders and files:   -/boot/efi/EFI/Boot/bootx64.efi   -/boot/efi/EFI/Microsoft/Boot/bootmgfw.efi and bootx64.efi   -/boot/efi/EFI/ubuntu/bootx64.efi and grubx64.efi


After MikTeX and TeXstudio upgrade I'm getting error at includegraphics

since my stuff were outdated I decided this afternoon to update everything to a newer version but now my .tex source do not compile anymore. Specifically I started getting errors on every \includegraphics I have in the source file and moreover it looks like the compiler can't find the images anymore since for each one of them it says "File /Images/[name of the image] not found". The folder structure is this one:    Tex [Name of the PDF] .tex source files Images   Image 1 Image 2    A typical (they're are all like this one) part of code giving me errors looks like this  \begin{figure}[h]     \centering     \includegraphics[scale=0.4]{Images/Ampere}     \caption{Definizione di Ampère}     \label{fig:Ampere} \end{figure}   I already included graphicx to my document so that is not the problem here.  How can I fix this?


Indentation of a broken line in beamer interacts with bib latex style

I've created the following MWE: \documentclass[aspectratio=169]{beamer}   \usepackage[citestyle=authoryear-comp,bibstyle=authortitle]{biblatex}  \begin{document}    \begin{frame} \begin{itemize} \item This is a bullet point \item Here, this is a very very very very very very very very very very extremely long bullet point that basically never ends, because it continues on the second line \end{itemize} \end{frame}      \end{document}  The second bullet point is so long that it gets continued on the next line, but with less indentation than usual (see picture below). If I remove any one of the options to the biblatex package, the indentation works as it's supposed to work. It doesn't matter if there are any actual citations in the document.  Any idea how to fix this? PS: I'm doing this with MacTeX 2020, and after having updated all packages to their current state, today. PS2:  indeed solves it.


Published paper not showing up on google scholar

I have a paper that I uploaded to arXiv and google scholar listed it as a publication.  Since then the paper has been published in a nature journal several months ago.  The nature publication still hasn't showed up on my scholar profile, which still lists the arXiv version.  Is there any way to resolve this conflict?


I would like to perform some action on sliced DataFrame with multiple slice indexes. The pattern is df.iloc[0:24] , df.iloc[24:48], df.iloc[48:72] and so on with step 24 as you get it. How I can iterate it without to set it manually every time. More like df.iloc[x:z] and each iteration x=0, z=24 and next iteration with 24 step, x will be 24 and z=48 and so on. Thanks in advance, Hristo.


Singleton template base class is giving an undefined reference

I wrote a template class for a Singleton singleton.cpp: template<typename T> class Singleton {    protected:     Singleton() = default;    public:     virtual ~Singleton() = default;     Singleton(const Singleton<T>&) = delete;    public:     Singleton& operator=(const Singleton&) = delete;    public:     static T& GetInstance() {       static T instance;        return instance;     }  }  And my logger class inherits this template class Logger : public Singleton<Logger> {    private:     Logger();    public:     ~Logger; }  but when i call Application::GetInstance() I get an undefined reference undefined reference to `Singleton<Application>::GetInstance()


How can you know that you are quite close to losing your account?

I just came to know about this new policy of Stack Overflow.     Sorry, we are no longer accepting questions from this account.   Initially it was funny that people are losing their accounts :-D. But I think it's a very good step to create a clean community.  Honestly saying I did same mistakes like if I got some downvotes for particular question, I deleted that one. And sometimes I asked a question and deleted that question after a while.  So my question is: how can you know that you are quite close to losing your account? Means there will be some kind of progress bar, some threshold value, etc. I hope you are getting what I am trying to say.  It's kind of funny, but seriously I want to know about this.


I would appreciate if someone could tell me difference between [t] and [ht] in the following example? I don't see a difference in the output pdf file.  \begin{figure}[ht] ... \end{figure}   and  \begin{figure}[t] ... \end{figure}


How do I turn off the sql server by default on startup?

As soon as I turn on my system and run the command :  service mysql status   It shows that the service has been activated since the PC was turned on, I want it to be off my default and when I want to, I should be able to activate it by :  service mysql start   Is this possible?


Is there a built-in function to print all the current properties and values of an object?

So what I'm looking for here is something like PHP's  function.  This is so I can debug my scripts by seeing what's the state of the object in question.


a problem in justifying ONLY IF truth table

EDITED:I saw the link above but it does't answer my question.I have a clear understanding of "P ONLY IF Q", I know that it equals "IF P THEN Q" .. but I see that there is a difference in the case where Q is True and P is False... in "IF P THEN Q" I know that it's true .. but in the "P only if Q" it seems like t violates the "if Q" part because it means when having Q is True then P is true - by understanding the "if" part in the "if Q"-.  I am  facing a problem in understanding one of the cases in the "P only if Q" truth table-which I didn't find anyone asking about it- that is: when Q is True and P is False ..I am trying to justify how this can be a true condition, I understand that the "only" part means P must be False When Q is False but the "if" part means -as we know from implication-  when the "if" part-Q- is True, the other proposition -P- should be true- but this is not the case-  the following is an example for more illustration: P is:"we'll go swimming" Q is:"weather is sunny"  then P ONLY IF Q: "we'll go swimming only if the weather is sunny" in the case when Q is True but P is False: "the weather is sunny but we'll not go swimming" here the violation of "IF" part is clearer


I'm trying to include an image, and keep it centered, and prevent from wrapping from the next page.  The following code works for that:  \begin{minipage}{\textwidth}     \begin{center}         Caption for image          \includegraphics[scale=0.5]{myimage.png}      \end{center} \end{minipage}   I'd like this image to be in a figure, with a caption.  The following doesn't compile:  \begin{minipage}{\textwidth}     \begin{figure}         \includegraphics[scale=0.5]{myimage.png}         \caption{Caption for image}         \label{fig:sample_figure}     \end{figure} \end{minipage}   I get the errors:  ! LaTeX Error: Not in outer par mode. ! Undefined control sequence.   How can I fix this?


SVCHOST uses a large amount of memory for short periods of time

Every now and again my laptop starts to be choppy (from lagging mouse response to complete freeze). If I manage to open the Task Manager I find SVCHOST using up all the memory it can get. After a minute or two it releases the memory and the computer returns to normal.  What is the cause and how can I prevent this from happening?  I'm running Windows 7 with 8 Gb RAM.


Delete key-value from object in array, Javascript

I have an array that looks like this:  $scope.quotes =     [         {             'quote': 'foo',             'author': 'bar',             'source': 'foobar',             'first': 'slideout',         },         {             ...         },     ]   I'm trying to remove the key-value first: slideout from the array. like this:  delete $scope.quotes[0][first];   I also tried:  delete $scope.quotes[0].first;


A word to describe something that exists because of historical reasons and isn't useful anymore but is still used nonetheless

Looking for a succinct word that describes something that has been measured simply because "that is the way things have been done". Something exists more for historical reasons than for practical ones.  Criteria for best word:   noun is preferred, ideally a noun that can act like an adjective (e.g. priority, necessity) should have a neutral connotation (or at the very least, not too negative) compound phrases considered but single words are preferred formal or informal   some words that almost fit:   vestigial  artefact  leftover  historic  remainder residual (best of the bunch)   Example sentence:  We have many measurements of elbow diameter not because it is particularly useful, but because the measurement is a "word"; all British ship logs from 1750 to 1899 were required to take such measurements.


Installing Ubuntu 13.04 after installing Windows 8

I have made a BOOTABLE USB installation of Ubuntu 13.04 using . I also have Windows 8 on separate partition. After I finished installing Ubuntu 13.04 from the USB, it went straight to Windows 8 without Grub showing to ask me to select an operating system, how can i fix this ? I don't have UEFI or secure boot.


How many words of length n with letters from {A,B,C} with atleast 1 occurence of AA?

I want to find a recursive formula to determine the amount of different words that you can build by taking n letters from the set {a,b,c}. Also, there needs to be atleast on occurence of two consecutive a's in the word. For example, baac is a valid word, but abac is not. How would you approach this?


What is the difference between ArrayList and LinkedList? I watched a video on it by TheNewBoston but i am still confused. Please answer in a short form and in plain English. Please do not use any advanced code.


How do I make a custom right click command for nautilus?

Possible Duplicate:          I'm trying to make a Mark as executable command for the right click in nautilus for a faster work flow. I came up with this script:  #! /bin/bash for file in $NAUTILUS_SCRIPT_SELECTED_FILE_PATHS; do gksudo "chmod +x $file" & done   How do I get this to work though. I currently have a .sh file and have no idea where to put it.


What factors cause or prevent "generational loss" when JPEGs are recompressed multiple times?

For years, I've believed that recompressing JPEG files multiple times would gradually degrade its quality until they are an unrecognizable mess, the way making photocopies of photocopies does. This intuitively makes sense because JPEG is a lossy format. There are also other Q&As that claim this is so:       However, I've also read that recompressing JPEGs at the same quality level will not degrade the image quality. This runs counter to the gradual degradation that is described elsewhere.  What technically happens when a JPEG is recompressed? What is being lost and how? Will the image really transform into the snowy mess that used to appear on television? What about those videos showing images that fall apart after being recompressed multiple times?  (Please don't merely handwave and appeal to the general concept of lossiness.)  (This question, and the answers it has attracted so far, focus on the technical factors (specific settings and image manipulations) that cause or prevent image degradation when a JPEG file is recompressed multiple times.)


Prove that if $H$ is a subgroup of group $G$, $H\circ x=H$ if and only if $x\in H$.   Not sure how to start this proof about the right coset.


PGFPlots with function definition and then use it by replacing a constant

I need to plot several functions in PGFPlots, and each function I plot is actually the same main function minus the function evaluated at some point x. Instead of hard-coding the value of the function for each x, I was wondering if there's a way to define a function, and then evaluate such function at x. So far the code I have is:  \documentclass{article} \usepackage[usenames,dvipsnames,svgnames,table]{xcolor} \usepackage{amsmath} \usepackage{mathptmx} % Use the Adobe Times Roman as the default text font together with math symbols from the Symbol, Chancery and Computer Modern fonts  \usepackage{tikz} % Required for drawing custom shapes \usepackage{pgfplots} \usetikzlibrary{plotmarks, calc, spy, pgfplots.polar, external} \usepgflibrary{shapes.geometric}  \begin{document}  % add and edit tikz figure here:  \begin{tikzpicture}[scale=1]     \begin{axis}  \addplot + [mark=none, domain=0:2, samples=70] { (x^0.65 + sin(1.5*pi*x)))/2}; \addplot + [mark=none, domain=0:4, samples=70] { (x^0.65 + sin(1.5*pi*x)) - (2^0.65 + sin(1.5*pi*2))))/2}; \addplot + [mark=none, domain=2:6, samples=70] { (x^0.65 + sin(1.5*pi*x)) - (4^0.65 + sin(1.5*pi*4))))/2}; \addplot + [mark=none, domain=4:8, samples=70] { (x^0.65 + sin(1.5*pi*x)) - (6^0.65 + sin(1.5*pi*6))))/2}; \addplot + [mark=none, domain=6:10, samples=70] { (x^0.65 + sin(1.5*pi*x)) - (8^0.65 + sin(1.5*pi*8))))/2}; \addplot + [mark=none, domain=8:12, samples=70] { (x^0.65 + sin(1.5*pi*x)) - (10^0.65 + sin(1.5*pi*10)))/2}; \addplot + [mark=none, domain=10:13, samples=70] { (x^0.65 + sin(1.5*pi*x)) - (12^0.65 + sin(1.5*pi*12))))/2};      \end{axis} \end{tikzpicture} \end{document}


Might be a dupplicate, but I don't think it is...  Looking here :   I've seen that the Canon 1200D has a mount type called "Canon EF-S".  I know that you cannot mount EF-S lens on a full frame, but I never quite realized that camera had their mount specification as well (which is logical but still...)  Anyway, does it mean that you cannot mount an EF lens on this kind of entry level DSLR ?


I have a large book (1052 pages) it's got a lot of pictures and even more endnotes (2037 to be exact). We've recently switched to a system where we have a database that all of the reference info is stored and a function that generates a .tex file with a \newcommand{} containing all of the reference info formatted properly. This has been working great for all of our other books, but when we switched to this method on the big book we keep getting this error when processing. So the question is, could my method of making a file with the \newcommands for all references be causing it to throw the memory error? This seems unlikely to me, but it's the only thing that's changed since it worked last. I'm running vtex, and the examples on how to up the memory limit for MikTex, TeXlive, etc. aren't working for me in vtex.


How are standard basis of polynomials linearly independent?

Consider the set $\{1,z,z^2,...z^m\}$. As this is the standard basis for a vector space of polynomials, the list should span the space and also be linearly independent.   One problem I'm having though is considering the equation   $0 = a_{0}1 + a_{1}z + ... + a_{m}z^m$  If I let z = 0, then all the polynomials with the exception of the first one are equal to 0, should I should be able to pick scalars, not all 0 that lead to a representation of the 0 vector in this basis that does not correspond to the trivial solution. So this would contradict the linear independence of the set.  I'm not exactly sure where I'm getting confused. Is it because you are not supposed to let z be any particular value? I can see how the list would be linearly independent if the value of z was not fixed.


I want to know how to copy a folder from a desktop to an external disk like pen-drive using terminal in Ubuntu 16.04.  The name of the disk is /dev/sdb1 in my system.  What is the exact command for copying a folder into the pen-drive?


How do I limit the node count of a content type to one per user?

I have a custom content type. I would like to limit that each user can only create one node of this content type. How can I achieve this?


Given that $a,b,c \in \mathbb{R}^{+}$ and $abc(a+b+c)=3$,   Prove that $(a+b)(b+c)(c+a)\ge8$.   My attempt: By AM-GM inequality, we have  $$\frac{a+b}{2}\ge\sqrt {ab} \tag{1}$$  and similarly  $$\frac{b+c}{2}\ge\sqrt {bc} \tag{2},$$ $$\frac{c+d}{2}\ge\sqrt {cd} \tag{3}.$$  Multiplying $(1)$, $(2)$ and $(3)$ together we reach  $$(a+b)(b+c)(c+a) \ge8abc.$$  Now, I need to show that $abc = 1$.  Again by AM-GM inequality we have  $$\frac{a+b+c}{3}\ge\sqrt[3]{abc} \implies \frac{\frac{3}{abc}}{3}\ge\sqrt[3]{abc} \implies abc\le1$$    Now if we show somehow that $abc\ge1$, we are done and that's where I am stuck. Can someone please explain how to show that?  Other solutions to the above question are also welcomed.


I'm trying to use svg graphics in my big latex document. I followed other posts and included the svg and the amsmath package. And used the following to test it:  \begin{figure}[htbp]     \centering     \includesvg{Images/Evaluation/Comparison/atlanta/SuccessRate}     \caption{svg image} \end{figure}   Unfortunately, I get three error messages for the line where I include the svg: 2x "LaTeX Error: File .../SuccessRate not found. [...]" 1x "LaTeX Error: File .../SuccessRate.pdf_tex not found. [...]" Especially the second one is weird becaus I don't even want to find a .pdf_tex file. The svg-file is in the specified directory and adding .svg to the path in includesvg doesn't help either.  I'm using Miktex and Texmaker on Windows 8.1. My document class is scrbook and not article as in the other posts I saw.


What is correct?   He was logging on to the Bitrack database. He was logging in to the Bitrack database. Please note a password is required to log on/in to the database.


Possible Duplicate:          How do I fix this error?   W:Failed to fetch http://ppa.launchpad.net/deluge-team/ppa/ubuntu/dists/quantal/main/source/Sources  404  Not Found,  W:Failed to fetch http://ppa.launchpad.net/deluge-team/ppa/ubuntu/dists/quantal/main/binary-amd64/Packages  404  Not Found,  W:Failed to fetch http://ppa.launchpad.net/deluge-team/ppa/ubuntu/dists/quantal/main/binary-i386/Packages  404  Not Found,  E:Some index files failed to download. They have been ignored, or old ones used instead.     The same error occur when I tried,   sudo apt-get update && sudo apt-get upgrade


Where should I ask this question which is possibly Programmers.SE/Webmasters.SE related?

I heard someone say that I should never open links in new windows or tabs, because this will confuse the end-user. I've seen my mother do this several times - she tries to click the back button (even though it's greyed out). In many cases this results in leaving the website. I am not sure if I should open pages in new windows or tabs or in the current page. They both have their own advantages. My website is for a hosting company, so probably, many developers will visit the website. So what should I do? Err on the side of caution?  Where should I ask this question? I was thinking about Programmers.SE or Webmasters.SE but I'm not sure.


Driving car with (almost) the speed of the light and switch the headlights on

I'm curious what will happen if we 'drive' a car with (almost) the speed of light, and all of sudden we switch the car headlights on? Will the car headlights ray have double speed (speed of 600.000km/h) or that ray will never be seen?


I cannot run apt update properly - apt update hangs

Version: Ubuntu 16.04  I have used it some weeks, but now it gives me this message when I'm trying to install software and update or upgrade:  Could not get lock /var/lib/apt/lists/lock - open (11: Resource temporarily unavailable) /var/lib/apt/lists/ locked   followed by this:    .  and another error:  ** (appstreamcli:4560): WARNING **: Exception: Unable to get write lock on /var/cache/app-info/xapian/default: already locked   What should I do?


How  can  i  prove  that :  $$\binom{n}{0}^2+\binom{n}{1}^2+\binom{n}{2}^2+\cdots+\binom{n}{n}^2=\binom{2n}{n}$$  i tried to prove it : by   $$\binom{2n}{n} = \frac{(2n)!}{n!n!} = \frac{2^n (1\cdot3\cdot5\cdots(2n-1))}{n!}$$  but i can’t  take advantage of it.


How to detect key press without using an input tag in Blazor

I want to be able to capture keyboard input without using an HTML INPUT tag in Blazor. Once the key is pressed i will display a graphic to represent the letter pressed.  Something like this  @page "/counter" @using Microsoft.AspNetCore.Components.Web  <div @onkeypress="e => KeyPress(e)">     Press any letter key </div>  @code {      private void KeyPress(KeyboardEventArgs e)     {         var letter = e.Key;     } }   The KeyPress method does not appear to be called when I set a breakpoint on it. Any help much appreciated.


Is it theoretically possible that electrons are made up of quarks just like protons and neutrons?

Before closing it as a dupe of . Please go through the question once . Is it theoretically possible that quarks make up an electron ( like you may get a particle with the same electronic charge $(-e)$  with three down quarks however the binding energy for that down quarks triplet should be a great number since Dr jh pointed out that the mass of even a single down quark is greater than that of an electron) ?   According to , the mass of a down quark is approximately $4.8\; MeV$ . So after converting it into $kg's$ and multiplying by $3$ (since I considered three down quarks) , I got roughly $(256 × 10^{-31})kg$ . So the difference in the mass of an electron and three down quarks can be calculated (which is roughly $28 \; Times\; of \;mass\; of\; electron)$ and this serves as our binding energy . So , $E = (247) (9 × 10^{16}) J$.   Have the particle accelerators reached this energy level (since I have heard that the maximum number they reached is $7 \; TeV$) ? I don't know. And  Can this huge energy requirement be the reasons why we can't break down an electron ? Or am I misinterpreting something here ?


Not able to assign any scripts to my game object

I am not able to assign a particular C# script to a game object. When I try to do so, I get this error as shown below Only the script I have is different.  In brief, just like the error above I am getting it as Can't Add Script Component 'AIWaypointNetwork' because the script class cannot be found. Make sure that there are no compile errors and that the file name and the class name match And when I try to create a script component, I get the warning Associated Script cannot be loaded. Please fix compile errors and assign a valid script. Here is a screenshot of the situation.  As far as I know, I don't see anything wrong with the script and it's pretty simple too. using System.Collections; using System.Collections.Generic; using UnityEngine;  public class AIWaypointNetwork : MonoBehaviour {     public List<Transform> Waypoints = new List<Transform>(); }  The unity version that I am using right now is Version 2020.1.11f1 Personal. And I have not faced these types of errors before. Based on my search, I see that I would probably have to reimport assets over again. How do we do that in this version of unity? Is there something else I am missing here?


windows 8.1 preview to pro version all programs deleted

After the update from Windows 8.1 to Windows 8.1 pro all programs were deleted.  At the update dialog they said that you have to reinstall all apps. I understood this to mean only the apps in the store.  Unfortunately windows have not created a recovery point.  Is it possible to go back to windows 8.1 preview by recovering the old partition table?


Why c++ program with logical and operator and increment operator gives different output than expected?

I am trying following C code. I my opinion output of this code should be 0 0 0 0. But after executing it output comes as 0 -1 -1 0. Can anybody explain how output comes.      #include<iostream>     using namespace std;     int main()     {         int x=-1, y=-1, z=-1;         int w= ++x && ++y && ++z;         cout<<x<<" "<<y<<" "<<z<<" "<<w<<endl;         return 0;     }


Having a retired professor write my letter of recommendation,

One of my math professors (in a U.S. university) retired this semester.  He was one person that I had planned on asking to write my letters of recommendation this coming fall semester, when I send out PhD applications in math / applied math.  He is very old and he seems anti-social and seems to not communicate with our math department very much.  I am just basing this on some stuff that he says, which scares me, e.g., "tell them (our math dept.) that I said this..."  So, I wonder whether anyone external to our own math department would even know who he is - or whether admissions committees even value his opinions about grad students, at this point in his career.  Would it be best to find someone else to replace him as one of my letter writers?  Someone who is younger and currently active in research?  I do have replacements in mind, but I am somewhat attached to this particular professor, since I feel that I got my start in rigorous mathematics with him.  Edit:  To add a bit more context, he is a full professor and has served on admissions / doctoral committees at our department numerous times.  So, he's very much qualified, of course.  My main concern is that perhaps he no longer communicates actively with people internal and external to our department, but that is only my best guess.  Thanks,


How do I find the technical name for a function so I can assign a hotkey to it?

I'd like to assign hotkeys to certain actions, like for example "Extrude Individual Faces"? Is there a list of all possible commands somewhere?  For example, in this picture "view3d.edit_mesh_extrude_move_normal" is the command or function. So where can I find a list of all possible commands so I can assign hotkeys to them?


How do I fix the left mouse opening the menu instead of breaking blocks?

I've already tried clicking and holding the left button of my mouse, and it just won't work! Whenever I press it, it opens the game menu instead.


iBooks Author on iMac 10.13. Preview on iPad not available

In iBooks Author, the preview on iPad option is not working. I have tried 2 different iPads on all ports and my iPhone, but it is still greyed out and not available. What could be wrong?


Should "building blocks" be hyphenated? I am using the two words (or perhaps one word) as a noun. E.g.,     These axioms serve as the building-blocks of the English language.   I understand that hyphens should be used to avoid ambiguities, but in this case, a hyphen makes the sentence easier to read, rather than lessen the ambiguity of it. The actual sentence I'm using the words (or word) in is quite long, and consists of many clauses, so one might accidentally read the sentence incorrectly the first time, but once the sentence is read entirely, the reader will understand what is meant. I know this is a stretch.


I am trying to find the average of hash rate (benchmark) for SHA-3(Shake128) for a normal and supercomputer in order to estimate the brute-force attack which I can get if from ( keyspace / hash rate )...then I found this website:     I could not understand these tables i.g. (Cycles/byte for 8 bytes) what do they mean by cycles/byte? Is it that hash rate for 8-bytes?


You have uncommitted work pending. Please commit or rollback before calling out error in test class

I have a requirement to create subscriber third party API. So here is a requirement before callout:  I need to do callout for getting the inventory name from thirdparty before creating subscriber. Then I need to get the value of subscriber then pass it to create a subscriber.  I'm getting a error in test class  System.CalloutException: You have uncommitted work pending. Please commit or rollback before calling out. Please help me because it's a production issue.Any help will be really appreciated. Thank you in advance Thanks Akshit Jain


$a^x\equiv a^{x\bmod(m-1)}\pmod m$ for m prime.

Prove that $a^x\equiv a^{x\bmod(m-1)}\pmod m$ for m prime: I attempted to prove the cyclicity using Fermat's little theorem, that $a^p\equiv a\pmod{p} $ but didn't succeed. Could you please explain to me how to prove it?


Find the positive integral values $n$ can take :${(x+y+z)}^2=nxyz$

Find the  positive integral values $n$  can take for which  :${(x+y+z)}^2=nxyz$ is solvable for positive integers.  My try: Due to symmetry WLOG let $x\ge y\ge z$. Now ,making it in a quadratic in $x+y$,we have $$nxyz={(x+y)}^2+2(x+y)z+z^2$$ or $z| {(x+y)}^2$. But I don't know what to do with this. Also I tried playing with inequalities to get $$nyz\le 9x$$ and the equality condition $x=y=z$, yields $$nx=9$$ or $n$ can take the values $(1,3,9)$ but I can't find more. I know this question has been asked before but I have not learned that much. I also tried using a little bit of calculus but nothing promising came  up.


Do web users understand the 'sandwich icon' for side bar when used on a desktop site?

I'm aware that the usage of the sandwich icon and side bar for mobile apps is wide-spread and well known by the users (so it seems, anyway), like this one from the Facebook app:    I'm developing an interface for an web online digital menu for restaurants and I believe this concept might come in handy for navigation purposes.  The only thing I'm afraid of is that this may not be clear enough for web users who aren't using a mobile / tablet.  My question is: is this a good choice or is this probably going to pass unnoticed? Maybe, given the lack of other navigation menus, the users will be curious/persistent enough to find it?


convert Python list to ordered unique values

I encounter many tasks in which I need to filter python (2.7) list to keep only ordered unique values. My usual approach is by using odereddict from collections:  from collections import OrderedDict  ls = [1,2,3,4,1,23,4,12,3,41]  ls = OrderedDict(zip(ls,['']*len(ls))).keys()  print ls   the output is:     [1, 2, 3, 4, 23, 12, 41]   is there any other state of the art method to do it in Python?   Note - the input and the output should be given as list   edit - a comparison of the methods can be found here:   the best solution meanwhile is:  def get_unique(seq):     seen = set()     seen_add = seen.add     return [x for x in seq if not (x in seen or seen_add(x))]


Validation set used for early-stopping. Do I retrain the model using the validation data as training data?

I've read posts mentioning that after selecting your model with the validation set you train with the full set (training + validation set) and test the model on the test set.  However, what if the validation set was used for early stopping during training?  The training part might early stop at 12 epochs but that doesn't mean that it is the optimal amount of epochs for any training set in order to achieve generalization in unseen data.  Even worse, in my case, I am training a neural network where the amount the learning rate decreases in each iteration depends on the maximum number of epochs.  So even if I find that the optimal amount of epochs during training was 12, setting the maximum amount of epochs at 12 in order to retrain will yield a different result than early stopping at 12 when the maximum amount of epochs is 30.  So my question is:   Do I have to somehow retrain the model and include the validation set in the training data? If yes, how?  Or do I just use the model trained with early stopping and test it on the test set without retraining the model using the validation set?


I have a 64-bit machine that has Windows 7 32-bit and Ubuntu 32-bit installed as a dual boot setup. Can I run 64-bit software on top of these 32-bit OSes, or are they a "bottleneck" limiting the true capability of the underlying hardware?


On my Ubuntu 16.04 laptop installation, Alt-Gr does not work. So I cannot type characters like {, }, ~, | etc. (doing this on my PC where everything works). I tried various suggestions from multiple Ubuntu wikis, forums, Ubuntu support site: Nothing works.  Most solutions are for older Ubuntu versions, a lot seems to be different on Ubuntu 16.04: There is no System Preferences (you can install the app manually, but there are no keyboard settings there), I don't find Keyboard Layout anywhere...  This is not a duplicate of , Ubuntu 16.04 is different!  Edit: Found the keyboard layout display, and it matches the keyboard (now). But Alt-Gr combinations don't work.


How to return one row but concatenate the reason column

I have an sql server 2012 database table which contains data just like below:  id    import_id    tenancyname    owner    reason ----- ----------   ------------   -----    ------ 1      1            test          null     Owner is missing 2      2            null          null     Tenancy Name is Missing 2      2            null          null     Owner is Missing   As you can see from the data above there are 2 reasons for row id 2, because there are 2 things wrong with that row.  Now what im trying to do is to only return the row once but concatenate the reasons into 1 cell so it will look like the following:  id    import_id    tenancyname    owner    reason ----- ----------   ------------   -----    ------ 1      1            test          null     Owner is missing 2      2            null          null     Tenancy Name is Missing \newline Owner is Missing   help please from the experts would be greatly appreciated


Is there a topological space whose fundamental group is the real numbers?

Most of the examples of fundamental groups have been "discrete" in nature. I'm wondering if there is an example which is not like that. A possible preliminary question could be if there is a space whose fundamental group is the rationals.  Edit: This has been marked as a duplicate; it is with respect to my subquestion about rationals however the linked answer does not say anything about topological spaces whose fundamental groups are the real numbers.


Is this possible with Nividia GeForce GT 520MX graphics card?  One monitor is connected to VGA port, another monitor to HDMI. But in the Display -> Screen resolution menu, one of the 3 monitors is always grayed out.  The laptop is Samsung NP 300E7A.


resize Ubuntu Partition to install windows alongside

I wanted to install ubuntu alongside windows but it formatted the disk completely, now I want to install windows alongside ubuntu, above is the link to present status of harddisk (gparted)  Please help me how to resize the partition and install windows, I am a complete newbie to linux/ubuntu as such.


So I play all my games with a pc, I do everything technology related on a pc. I don't use an xbox. I want to play games and stuff with my friends, who do use xbox, and thats mainly Minecraft. So I downloaded the xbox app, set everything up, but apparently to play minecraft I need a game pass, so my main question is, once I buy the gamepass, since I already have minecraft on my pc, do I have to buy it again on the xbox app, which is also on my pc?


Prove by induction: $2^{n+2} +3^{2n+1}$ is divisible by $7$ for all $n \in \mathbb{N}$

I want to prove that $2^{n+2} +3^{2n+1}$ is divisible by $7$ for all $n \in \mathbb{N}$ using proof by induction.  Attempt  Prove true for $n = 1$  $2^{1+2} + 3^{2(1) +1} = 35$  35 is divisible by 7 so true for $n =1$  Induction step: Assume true for $n = k$ and prove true for $n = k+1$  $n = k$  $2^{k+2} + 3^{2k +1} = 2^k \cdot 2^2 + 3^{2k} \cdot 3^1 = (4) 2^k + (3) 3^{2k}$  $n = k+1$  $2^{k+3} +3^{2k+3} = (8) 2^k + (27) 3^{2k}$  Thoughts:  I know I need to use the expression for $n = k$ to prove that it is true for $n = k+1$ but I am not sure where to start. I think that using modular arithmetic would be too complex.  Any ideas would be greatly appreciated!  Update  Thanks for all of the useful answers/suggestions. I understand the approach to take now!


How can I programmatically stop/start a windows service on a remote box?

I want to write a console or Click Once WinForms app that will programmatically stop and/or start a windows service on a remote box.  Both boxes are running .NET 3.5 - what .NET API's are available to accomplish this?


hi so I bought windows 10 and I’m using Ubuntu, and i want to just use windows now and get rid of Ubuntu. I have no clue how to do this or how I can even start, I have the .iso file and I’m ready to start, but like how? I cant just open it, it says I cant, please help asap. keep in mind I’m really bad at the whole Linux thing so please try and clearly go through step by step as if I’m completely new, because I really am, thank-you :) I've tried googling it and i dont understand it at all, i was hoping someone can walk me through it really easy and simple :) also my cd drive doesnt work...


Why did Kakashi's Sharingan fade after Obito died?

In Chapter 691, after Obito died, Kakashi’s Sharingan faded. Why is it that Kakashi's Sharingan faded, while the Sharingan Danzo had stolen from Shisui and the one Shisui had given Itachi, were still okay even after its original owner had died?


Does modifying the geodesic Lagrangian $L$ with a smooth function $f(L)$ give the same geodesic curves as solutions?

Mathematical side of the problem Given the metric $$ds^2 = dr^2+r^2d\theta^2+r^2\sin^2\theta d\varphi^2$$ we can easily construct the action of a free particle $$S=\alpha \int d\tau \underbrace{\sqrt{\dot{r}^2 + r^2 \dot{\theta}^2+r^2\sin^2\theta \dot{\varphi}^2}}_{:=L},\quad \text{where}\quad \dot{\vphantom{r}}:=\frac{d}{d\tau}.$$ Consider now the following action $$\bar{S} := \alpha \int f(L)d\tau, $$ where $f$ is an arbitrary smooth function. For the specific case $f(g)=g^2/2$ one can show that the resulting equations of motion will describe the same curve, see  and . My question is now if one can generalize this to an arbitrary smooth function $f$? For example, $f(g)=g^2$ seems to work just as well. Physic's problem Even if the above works out form the mathematical side, I'm still confused on why we are allowed to do this in a physics context. The Lagragian is a well defined property for a given physical system, as well as the action. Why can I just square the Lagragian and still get something physically meaningful? What about the parametrization of time? If I change the parametrization, form lets say the eigentime to some arbitrary frame, what happens then to the equations of motion when such a function $f$ is involved?


Like in nuclear physics we deal with binding energies, i heard someone saying Chemical binding energy. What is that and how a chemical reaction follows mass energy interconversion based on this concept like a nuclear reaction follows?


When are Opportunity Attacks provoked while holding a reach and a non-reach weapon?

Assume I wield a Whip in one hand and a dagger in the other.  If a creature moves from 5ft to 10ft it has technically moved out of my reach (dagger), but at the same time it is still inside my reach (whip). When does it provoke opportunity attacks from me?  I am fully aware that this would not enable me to make off-hand attacks since the whip is not a light weapon, just to cut that issue out of the question.


if statement help when reading attribute values from XML tree

Im trying to read the value of an attribute called "version" from a tree. The value of that is "2.0". I set an if statement asking if the attribute value is equal to 2.0 to run this code, instead it runs the else statement. I got confused to i made a boolean value and set it equal to the equation. I print it out and it reads false when it is indeed true. Here is my code:  out.print("Enter the URL of an RSS 2.0 news feed: ");         String url = in.nextLine();         XMLTree xml = new XMLTree1(url);         boolean t = xml.hasAttribute("version");         if (t) {          out.println(xml.attributeValue("version"));//this prints 2.0          boolean a = (xml.attributeValue("version") == "2.0"); //added this to debugg          out.println(a);  //this gets set to false. why?             if (xml.attributeValue("version") == "2.0") {                   out.println("Hello");              } else {                 out.println("URL entered is not of version 2.0");             }         } else {             out.println("No attribute Version");         }          /*          * TODO: fill in body          */          in.close();         out.close();     }  }   Im entering the URL: , which its tree has a root tag "rss" that has an attribute "version" who is equal to 2.0:


Adding a camera shows only yellow rectangle

I originally removed the default camera, but now when I wanted to add a new camera, it won't show up. There's only this weird yellow rectangle.  I suppose this rectangle somehow represents the camera, but it's difficult to move it, because if I grab or rotate it, it disappears completely. If I open a new Blender project, then it opens with the normal default cube and camera all working as they should. So, what's going on and how do I fix the camera in this current project? Thanks for assistance!


I am trying to derive  in GR as an exercise: a spherically symmetric gravitational field is static in the vacuum area. I managed to prove that $g_{00}$ is independent of $t$ in the vacuum, and that $g_{00}*g_{11}=f(t)$.  But the next question is: Show that you can get back to a Schwarzschild metric by a certain mathematical operation. I am thinking at a coordinate change (or variable change on $r$) to absorb the $t$ dependence of $g_{11}$, but I can't see the right one. Does someone has a tip to share?


I followed the following process to create the CA, certificate and key PEF files:      I run "openssl verify" and verified that they are OK.   I then followed the following process to enable SSL on MySQL community:      However, when I tried to connect to it:   mysql --user=root --password=mypassword --ssl-ca="C:\ProgramData\MySQL\MySQL Server 5.7\SSL\ca.pem" --ssl-cert="C:\ProgramData\MySQL\MySQL Server 5.7\SSL\client-cert.pem" --ssl-key="C:\ProgramData\MySQL\MySQL Server 5.7\SSL\client-key.pem"   I got the following error:   ERROR 2026 (HY000): SSL connection error: SSL is required but the server doesn't support it


How do I handle thumbnails of white-on-transparent pngs in Bridge?

When handling multiple white-on-transparent png images, I am hindered by the fact that the thumbnails of these images are all-white. Both Adobe Bridge CS6 and Windows Explorer suffer the same problem, I can't discern between two of these pngs.  Is there a way to make these thumbnails useful? Is there some setting I missed that allows changing the thumbnail background colour for a png -- now a deafult white?


What is the purpose of a t-distribution?

As far as I know, we use a t-distribution if the sample size is small and the population is normally distributed. But if the population is normally distributed, then the sample mean is also normally distributed, so why not just use the z-distribution instead?


I connect a 5v 5w solar panel a usb port and a 3.7v 2.5A lipo with pcb.  If I connect a phone to usb port it doesn't charge, but if I remove the battery from the circuit, it does. I suppose it's because battery pcb downgrade the voltage to 4.2v or there is not enough energy to serve both. There is a simple way to prioritize the usb or make them share? Thanks in advance for your help  PS Sorry to eventual mistakes but I'm still learning electronics. I did not blow anything yet, thanks also to t  ______________________________________  Summary of requirement:  Given:   5V 5 Watt PV panel    Cellphone with "USB" "5V" charger input.   Single cell LiPo 3.7V nominal 2500 mAh.   Requirement:       Use PV to charge phone if connected.    Otherwise charge battery.    If possible share PV energy between phone and battery if both present.    Problem:  Connecting the panel to the LiPo loads it to battery voltage which is too low a V to operate the phone charging circuit.


$l^p (1≤p<{\infty})$ and $L^p (1≤p<∞)$ are separable spaces.     What on earth has changed when the value of $p$ turns from a finite number to ${\infty}$?   Our teacher gave us some hints that there exists an uncountable subset such that the distance of any two elements in it is no less than some $\delta>0$.   Actually I don't understand the question very well, but I hope I have made the question clear enough.  Thank you in advance.


I have the following object  b.push({ data: d, width: 5, color: color });   then I have   b= [{data:10,width:5, color:"yellow"},{data:12,width:5, color:"red"},etc...];   I added color property and now I do not need and I want to remove it. I would like to know what is easiest way to do it?


Where is the persistent option for Startup Disk Creator in 16.04?

The Startup Disk Creator no longer shows the option to create a persistent drive. How do I get back this setting in the application?


On which Stack Exchange site should I post a question about releasing a PC App? (not a programming question)

I'm writing a Windows/Mac app, it is the same as a mobile app I have. I have no experience releasing PC apps, only mobile apps. On mobile I know how to monetize with ads and sales, but on PC I have no idea what the preferred methods are. So, which Stack Exchange site would be the right one to ask that type of question?


StringBuilder remove comma at the end of Last record

I am using StringBuilder to show comma between records, but also getting comma at the end of Last Record  How to control on this ? I don't like to see comma at the end of last record - because it's useless     for (int i = 0; i < arrayList.size(); i++) {          String name = arrayList.get(i).getName();         int price = arrayList.get(i).getPrice();          stringBuilder.append(strName);         stringBuilder.append(" - "+price+",");      }          stringFinal = stringBuilder.toString();


How to prove that $n- \sqrt{n+a} \sqrt{n+b}$ converges to $-\frac{a+b}{2}$?

Let $a>0$ and $b>0$. Prove that $n- \sqrt{n+a} \sqrt{n+b}$ converges to $-\frac{a+b}{2}$. I need some help!


I have to prove that the mapping $f(x,y) = {\displaystyle \sum_{i=1} ^ {n} }{ \displaystyle \sum_{j=1}^{n} }x_iy_j{f}(e_i,e_j)$  is a bilinear form, that is, inter alia, the condition: $f(x+y,z)=f(x,z)+f(y,z)$  I have: $f(x+y,z)=f\left({\displaystyle \sum_{i=1}^{n}}x_{i}e_{i}+{\displaystyle \sum_{k=1}^{n}}y_{k}e_{k},{\displaystyle \sum_{j=1}^{n}}z_{j}e_{j}\right)=f\left({\displaystyle \sum_{i=1}^{n}}{\displaystyle \sum_{k=1}^{n}}\left(x_{i}e_{i}+y_{k}e_{k}\right),{\displaystyle \sum_{j=1}^{n}}z_{j}e_{j}\right)=\ldots$  and what's next?  Help!


how to find out which software is using my webcam?

cyberlink youcam is not opening my webcam.it is showing that some other program is using my webcam and i have to close that program first and restart the youcam to get started.and the problem is that I dont know which program is using my webcam.


I've been wracking my brain trying to remember a word for a try-hard, pleb artist! It starts with a "d", if I remember correctly, and I'm sorry if the details aren't enough and such. You know, even the definition of this supposed "d" word I can't remember, I'm also quite hazy with. Though I think the general gist of it is mildly derogatory but in a "stating the facts" kinda way. An artist that can't be great or masquerading to be great or something... Starts with a "d" I think... Oof! Any suggestions? Answers?


If $A$ is matrix from $M_{n-1,n}$ such that sum of all elements in row is zero.  Prove  det$(AA^T)=nk^2$, for some $k\in\mathbb{Z}$.  I tried to solve it, but I’m really confused.   I know that $A[1, 1, \dots, 1]^t= 0 * [1, 1,\dots, 1]^t$  So zero is eigenvalue of $A$, so it's singular and $\det A=0$.   So $\det(AA^{T})=\det(A)\det(A^T)=\det(A)\det(A)=\det(A^2)=0$   Is this correct? Is there any other way to solve this?  Thank you in advance.


Distance of a 3D point from the parametric form of a line?

I have calculated the parametric form of my line as: $X = (2,2,0) + t(1,2,2)$ and have been given a point $Q = (1,-1,-1)$, how would I calculate the distance from $Q$ to the line?


Manually detect malware (such as a keylogger)?

Is there any way to manually detect if malware, specifically a keylogger is installed? Looking for answers on XP, 7 and 8.1.  For example, is there a combination of any of these options that can positively identify the malware:  * places to look in the registry * processes running in Windows Task Manager * writing an application myself (eg. in Visual Studio) to hook WM_XXX messages   I'm looking for technical details to investigate this manually ie. NOT using something like an AV that just reports it. 3rd party tools that technically help identify and track down the presence of the malware might be useful.  UPDATE: Have discovered  which more or less covers what I was looking for. Recommend readers who find this question re-direct to that one.


Top of answer covered by sticky top bar after clicking direct link

With the introduction of the network-wide sticky top bar , I noticed a bug that's happening on every site (except for Stack Overflow). When you click on an answer link (of the form https://site.stackexchange.com/a/####), the very top of the answer and the upvote button are covered by the top bar:    Stack Overflow shows the correct behavior:


So $\hat x$ and $\widehat x$ give upper hats of different length, however, unlike \overbrace{} had an \underbrace{}, one sometimes needs an \uhat and \uwidehat.     What is the best (cleanest, fewest conflicts with possible usage, e.g, as interval endpoints in a definite integral, ie, scale properly) to get a underhat and underwide hat (same hats, but flipped, and below the symbol in question).   I suppose one can use  \documentclass{article}\usepackage{amsmath,mathtools,amssymb} \newcommand*{\uhat}{\underset{\mathrel{\text{\raisebox{.25ex}{\rotatebox[origin=c]{180}{$\wedge$}}}}}} \newcommand*{\uwidehat}{\underset{\mathrel{\text{\raisebox{.25ex}{\rotatebox[origin=c]{180}{$\widehat{~}$}}}}}} \begin{document} $\uhat x ~ ~ \uwidehat X$ \end{document}   But there must be better ways.


Is there a way to find every combination to select an element from each list (in a list)?

I am trying to find all combinations to select exactly one element from each list inside a list. (I prefer the computationally fastest method.)  Example: If my list is [[1], [2,3], [4,5,6]] I would want to get the following result (in any order): [[1,2,4], [1,2,5], [1,2,6], [1,3,4], [1,3,5], [1,3,6]]  I tried finding functions in modules like itertools without any success and am not sure how to start this.   I was thinking about doing the following, but I have no idea how to finish this: Find the number of permutations to find (called m here):  m = 1 for letter in letters:     m *= len(letter)   Then set up a for loop:  for i in range(m):   Then find each combination by cycling through all lists in the list and taking one element. I was thinking of doing the selection somehow using the modulus (%) function, but I don't know how to make it work.


Deleting a UNIX directory with a hyphen in the name

Through a boneheaded maneuver on my part, I accidentally created a directory called (for instance) -A, and ended up filling it with files.  I want to delete said directory. I've tried:  rmdir -- -A   but it then tells me that the directory still has files in it. And I can't figure out how to cd into the directory to delete said files.  What should I do to get rid of this troublesome directory?


Today, I came across , in which the same user has answered twice for the same question.  As answers are editable, shouldn't this be disallowed?  If someone has multiple solutions to the same question, should they be provided in the same answer?  If multiple answers are allowed, what should be done if the some part of a user's multiple answers are identical?


Given the traditional ACM copyright license, is it legal to publish the paper on ResearchGate?

The ACM license states     (iii) Post the Accepted Version of the Work on (1) the Author's home   page, (2) the Owner's institutional repository, (3) any repository   legally mandated by an agency funding the research on which the Work   is based, and (4) any non-commercial repository or aggregation that   does not duplicate ACM tables of contents, i.e., whose patterns of   links do not substantially duplicate an ACM-copyrighted volume or   issue. Non-commercial repositories are here understood as repositories   owned by non-profit organizations that do not charge a fee for   accessing deposited articles and that do not sell advertising or   otherwise profit from serving articles.   Does this (somehow) include ResearchGate?


If a women from Ghana wants to visit the US and she is a first time traveler,will she have to have $5000.00 travelers check in her possession before she can come?


How to manually copy home files on hdd from live-usb

For reasons I won't go into on this thread, I would like to simply backup the home files on my machine using live cd.  I have downloaded a live usb, and am currently running on it now. I cannot boot into Ubuntu, and would like to rather backup my files on my hdd, and do a fresh install thereafter.  My issue is, once I log into live cd, and attempt to recover my files by using:  sudo ecryptfs-recover-private  I get the following error:     INFO: Searching for encrypted private directories (this might take a   while)... find: ‘/proc/1670/task/1670/net’: Invalid argument find:   ‘/proc/1670/net’: Invalid argument find: ‘/proc/2541/task/2541/net’:   Invalid argument find: ‘/proc/2541/net’: Invalid argument find:   ‘/run/user/999/gvfs’: Permission denied   I am able to use nautilus to browse the hdd, and the home user directory I want to copy, however, they are all encrypted.  I have been stuck on this for the whole day now and all I want to do is simply use live cd to browse my files on my hdd (decrypted), copy them to an external hdd, format my machine, and re-install ubuntu.  I am using Ubuntu 17.10, and if you must know, Kali or Katoolin took over the machine and grub. It must have overwritten major system files because it won't even boot. Not worried about that, Just want to be able to get my files from live cd (de-crypted)  Thank you in advanced.


I am trying to create a ubuntu bootable USB disk .  I have downloaded Ubuntu 64 bit Desktop version to my Windows 7 PC . It shows up as 'ubuntu-13.10-desktop-amd64' winRAR application.  The instructions say to 'Open the dash and search for StartupDiskCreator'. I have searched and thankfully I understood dash means the menu.  But where is this menu shown ?  Should  I use a utility to run the 'ubuntu-13.10-desktop-amd64' file instead of extracting using WinRAR?  Will I then be able to see the 'dash/menu'?


Is it Possible to Sacrifice a Sacrificed Creature?

The title is confusing, I know. Here's the scenario: I sacrifice two creatures with Whisper, Blood Liturgist, can I then, in response to the creatures becoming sacrifice targets, sacrifice one of those same creatures using Hell's Caretaker and have both abilities still resolve correctly? I would think I would be able to because Whisper's ability is already on the stack when I activate Hell's Caretaker, but I'm not positive.


I have been trying to work with random variables in Python and more denerally.  My model works with large numbers and lohnormal distributions, but it is very hard to get a clear answer anywhere on the intuition of the parameters as various software packages see it, which stems from the fact that the mathematical explanations are equally unclear about what the parameters mean, or are even called.   My code Python Scipy code looks like this:  rv = lognorm(s=1., scale=100000., loc=0) x = numpy.arange(1, 1000000, 1000) plt.plot(x, rv.pdf(x)) plt.show()   When s=1 you get a graph that looks like a textbook lognormal dostribution, with e believable shape that would have the right means, mode, etc.  What I find is that as I INCREASE s, the plot gets tighter to the left, and does not flatten  out as suggested by any text.  By the time s=3 or 4, the graph looks like a spike at zero, and zero everywhere else.  s is the standard deviation of the underlying random variable X which is a normal with mean equal to ln(100000) and standard deviation equal to whatit should be to achieve the desired result.  In my instance, a 10% random change (100,000 units) is what I want to model.  After hours of thinking, tinkering, and experimenting, I finally cut through the clutter and figured out the answer, which - having re-written the question - I will now give.  The tricky bit here is pulling back from the real world into the fictitious normally distributed RV, $X$, which is generating the lognormal $Y=e^x$.  That underlying RV is normally distributed with a mean of $ln(1,000,000)$ which is 12.816.  The trick is to go mentally back 'into the real world' and ask yourself "what would be the number if a one stnadrad deviation event occurred?"  In my  case that would be a 10% range, or 1,100,000 (or 900,000).    But the natural log of 1,100,000 is 12.919.  This is only about.10 difference, so the underlying RV has mean 12.816 and stdev .10.  Since stdev is what goes into the lognorm formula (often called 'shape'), it explains (1) how to get the thing to work and (2) why the 'shape' factor is usually so small (<2): when dealing with variations in the real world of reasonable sizes (plus or minus 50% standard deviations or less), the underlying RV $X$ has a very, very tight variance.  Hope this is helpful to others.  I sure spent a lot of time and never found a good resource or answer.


I used this command  echo $(dpkg --list | grep linux-image | awk '{ print $2 }' | sort -V | sed -n '/'`uname -r`'/q;p') $(dpkg --list | grep linux-headers | awk '{ print $2 }' | sort -V | sed -n '/'"$(uname -r | sed "s/\([0-9.-]*\)-\([^0-9]\+\)/\1/")"'/q;p') | xargs sudo apt-get -y purge   from  this  to remove old kernels to free up the disk space, but while executing that command I get the following message  ... 1 upgraded, 2 newly installed, 2 to remove and 288 not upgraded. Need to get 52.0 MB of archives. After this operation, 186 kB of additional disk space will be used. ...   Shouldn't this command free up the disk space instead of using additional disk space ?


In some cases two species can hybridize. For example, Tigers and lions can hybridize to produce "".   Would it also be possible for humans and chimpanzees (or any other species) to hybridize ? If not, what would be the likely cause of failure?  Why do some hybridization matings produce offspring, like the Liger, and some not? What mechanisms prevent hybridizations?


Efficient algorithm for finding primes and adding them?

For project euler Problem 10, we are supposed to add all primes but that is taking my computer years to do it. Need a more efficient algorithm! Heres my present C code:  #include <stdio.h>  int main(void)  { int i, j, flag, sum=0; for(i=3; i< 2000000; i = i + 2) {   flag=0;   for(j=3; j<=i/2; j = j + 2)   {     if(i%j==0)     {       flag=1;       break;     }   }   if(flag==0)     sum += i;  } printf ("%i", sum + 2); }


Find and execute multiple scripts in parallel

G'day,   I have tried to solve this problem all morning but have not had success. I would like to search for certain scripts in a particular folder and execute them all in parallel. The scripts have different names, but all end with "run.sh". Below what I have tried without success.   The first approach was to use find in combination with -execdir. This works, however, the scripts are executed in a sequantial fashion. I want all scripts to be executed simultaneously (parallel). There seems to be no option to achieve this with -execdir  find . -name "*run.sh" -type f -execdir 'nohup' {} '&' \;   Then, I tried using xargs because there is has a parallel option (-P). I have not tried the parallel option yet, because I am unable to get xargs to run the scripts in their respective subfolders. The commands below execute all scripts, but do that in the folder I am running the command in, therefore the scripts themselves do not work. The scripts have to be executed in their own subfolders. In the above example, -execdir is doing that as opposed to -exec. How do I achieve that with xargs?  nohup find . -name "*run.sh" -type f | xargs -0 -I{} bash -c f\ \{\}   or  nohup find . -name "*run.sh" -type f | xargs -0 -I{} bash -c "f {}"   or  nohup find . -name "*run.sh" -type f | xargs -0 -I{} bash -c "./{}"    I am really frustrated and am hoping that there is somebody out there that can help.  Thank you so much!


Why do physical bodies in the universe follow the law of physics ( or any rule/pattern ) ?

Why do physical bodies in universe are bound to follow a rule ( eg. laws of physics ) ? Is their any imaginary condition possible, where they stop following any rule. And everything becomes random ? ( For example, a flying butter fly moves randomly, diseases like cancer occur randomly, then why physical bodies too cannot be random ? Why universe is based on rules ?


My maths isn't as good as it should be, I need to pick up some reference books on Trig.  Could someone give me an idea of the maths if I wanted to revolve many sprites around a central point?  It's a 2D system in MonoGame.  I'm going to try to describe the scenario, I can't think of anything quite like it to reference.  Imagine a game screen, you are looking down on the world, with my character in the middle, my character sprite will never change, but if I turn left or right I want everything else to rotate around the central point.  Of course every sprite will have to be moved, and also rotate to account for the spin.  Can someone point me in the right direction? Thanks.


If a there's a new user with less than 50 reputation Stack Overflow must hide the "add comment" option instead of displaying a popup saying: "You need 50 reputation to comment". And then if the user reaches 50 reputation it must show a notification saying something like: "You have been enabled to comment".  So the "add comment" option will only show if the user has 50 reputation.


Is libertarian free will a necessary condition for moral responsibility?

Does it make sense to hold a rock morally responsible for falling downhill due to the law of gravity and crushing somebody's head? Likewise, does it make sense to hold humans morally responsible for anything in the absence of  free will?


I am looking for the author of a book - or perhaps a trilogy - about an invasion from Mars.   This invasion involves Martian symbiotic life forms propagating to Earth and slowly changing the ecology of Earth to match their needs.   The humans attempt to fight those aggressive Martian worms, and also attempting to use nuclear bombs to fight off the Martian invasion.  I originally read it in a foreign language, but I think it is a modern English science-fiction opera, with an American author.  I want to go back and read it again. Search on-line did not help.


I have a little console C# program like   Class Program  {      static void main(string args[])      {     } }   Now I want to do something after main() exit. I tried to write a deconstructor for Class Program, but it never get hit.  Does anybody know how to do it.  Thanks a lot


My freewheel stopped working. I can still pedal forward, but not backward. What's wrong with it?


Fourier transform of a radial function is radial

Let $f\in S(R^2)$ radial. Its Fourier transform is radial because the Lebeasgue measure is invariant under rotation?


Could someone guide me through logic for this combinatorial proof   Let $c_n$ denote the number of triangulations of a regular $(n + 2)$-gon by non-intersecting diagonals.


If $S$ is a nonempty subset of group $G$, then $S^{|G|}$ is a subgroup of $G$.

Let $G$ be a group with $|G| = n$ and let $ \emptyset \ne S \subseteq G$.   I want to show that $S^n$ is a subgroup of $G$ where by $S^n$ I mean the set $\lbrace s_1\cdots s_n \; | \; s_i \in S\rbrace$.


After going from 16.04 to 18.04 I noticed that there are a few things missing (apart from the obvious lack of the useful Alt+alt menu search)   I install Netbeans 9 and when I run it, there is no right click and lock in launch panel... How do I keep it handy in the leftmost launcher? It also has awful simple looking checkboxes and tabs within Netbeans (Java?) but that's another topic. Middle scroll doesn't seem to do anything on the leftmost launcher. You used to be able to jump through all the terminal windows or windows of a certain app with the scroll wheel which is very handy.


I have an object, in this object I have an InputStream which contains a file.  I want to write what is inside of InputStream to a file inside of a folder.   How would I go about doing this in Core Java?  I was able to print out each line of the InputStream using BufferedReader and .readLine(), however I want the entire file wrote to disk not just what is inside of it.  Hopefully this makes sense, thank you.


Highlight specific parts of the output in python

I have the following code: from sklearn.metrics import mean_absolute_error def score_model(model,xt=X_train,yt=y_train,xv=X_valid,yv=y_valid):  model.fit(xt,yt)  pred=model.predict(xv)  mae=mean_absolute_error(pred,yv)  return(round(mae,0))  li=[] for i in range(0,len(models)):  li.append(score_model(models[i]))  print("For model:",i+1,"MAE is:",score_model(models[i]))  the output is:  For model: 1 MAE is: 24015.0  For model: 2 MAE is: 23741.0  For model: 3 MAE is: 23529.0  For model: 4 MAE is: 23997.0  For model: 5 MAE is: 23707.0  Now I'd like to highlight specific parts of the output (the least error for example). How could i'd do that using termcolor or any other library? thanks,


I have a somewhat silly question about pressure and atmosphere

The very basic calculation of pressure is <<$\rho gh$>>. So now if I keep myself in a totally enclosed room, then the force exerted by all the air above me should be cut out by the structure of the room and not affect me, in other words the pressure that I feel in the chamber should be very low compared to when I am exposed in the atmosphere.  Perhaps pressure is also(or merely?) affected by the density of fluid(air) in the room, that's why I am feeling the same atmospheric pressure as outside because the moment I close the room, the pressures inside and outside are equal. But this doesn't sound so true when I look at <<$\rho gh$>>, the height is still in the equation. One might argue that the deeper you get in a container full of fluid (like in the ocean) the density increases, which is very true when huge depth is concerned, but clearly in the basic <<$\rho gh $>>, density is assumed to be constant.  My thought looks kinda messy, hopefully someone would be able to clear it up a bit, thank you. Btw when I asked this question to my physics teachers, somehow they managed to shut me up or what, I don't remember.


Group with proper subgroups infinite cyclic

Suppose $G$ is an infinite group such that any proper non-trivial subgroup of $G$ is infinite cyclic. Is $G$ itself then infinite cyclic?  If we would only require the proper subgroups to be cyclic, then the Tarski monster groups would yield some counter-examples. Are there analogous examples of Tarski monsters where proper subgroups are infinite cyclic?


$\mathbb{R}\to\mathbb{R}$ Diffeomorphism with special property

$\phi:\mathbb{R}\to\mathbb{R}$ be a diffeomorphism with the following property  $a\in\mathbb{R},|a|<\frac{1}{10}$  (i)$\phi(a)=0$  (ii) $\phi(x)=x$ when $|x|>1$  and how to generalize that in $\mathbb{R}^n$   please help.


Java RMI server - server error Class not found

Hi there i have been doing some coursework for a auction system. The server has been working fine until today where there is a error occuring:  Server Error: java.rmi.ServerException: RemoteException occurred in server thread; nested exception is:      java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is:     java.lang.ClassNotFoundException: auction   This si the code where the error is occuring  import java.rmi.Naming; public class auctionserver {     public auctionserver() {       try {         Auction a = new auctionimpl();         Naming.rebind("rmi://localhost/AuctionSevice", a);      }       catch (Exception e) {        System.out.println("Server Error: " + e);      }    }     public static void main(String args[]) {         new auctionserver();    } }   I do have the RMIregistry in the path where i am doing the work. Any help would be much appricated. Thanks


Assume $f : [0, 1] \rightarrow [0, 1]$ is continuous. Show that there must be a point $x \in [0, 1]$ such  that $f(x) = x$  I am not even sure how to begin with this problem,  I know that $f$ is continuous so for all $\epsilon > 0$ there is a $\delta > 0$ such that whenever $|x-c|< \delta$ it follows that $|f(x) - f(c)| < \epsilon$  Any advice?


Is $X^2-Y^2/ \sqrt{X^2+Y^2}$ normal where $X,Y\sim N(0,1)$

Can I say that  $(X^2-Y^2)/ \sqrt{X^2+Y^2}$ is normal since $X,Y\sim N(0,1)$ and $X,Y$ are normal and independent?  I am trying to do those problem using polar coordinates with $X=r \cos \theta$ and $Y=r \sin \theta$, but I got stuck when I was trying to simplify $(X^2-Y^2)/ \sqrt{X^2+Y^2}$. Can anybody please help me? Thanks!


Ever since update, disk added to computer

Ever since I recently updated Windows 10 (v1803), a new "Local Disk" appeared (F):   When I open it, it's empty. These are the properties:   Then, every few minutes it seems, even if I keep clearing the notification, this pops up:    Which is, needless to say, annoying.  What could be causing this? How do I stop it?  Edit: Hidden files is enabled


On podcasts, inclusivity and transcriptions

This originally started as a Discord discussion around the theme of the  on the blog. Whilst this podcast in particular only really dealt with the theme of color, there are many other ways in which accessibility being limited is a problem, and inclusion is inhibited. Would it be possible, even if the transcriptions are not perfect, to run the podcasts through an automated transcription service and provide those for the deaf/hard-of-hearing that also make up part of this community? It would also benefit more than just the deaf/hard-of-hearing. For instance, I tend to read a lot more than I listen, and would find it easier to both consume the podcasts, and refer to them, with a transcription, even a partial one. I've had the need to use  before, and even though the transcriptions are not always spot-on, it would be a lot better than no transcriptions, and even allow people to correct them down the line if need be. This could be a quick avenue to get this started.


Visiting Italy or Germany with a Schengen (Sweden) Type C single entry visa

I have a single entry Type C Schengen visa (Sweden). While in Sweden, can I visit Italy or Germany and return to Sweden before I return to the UK?


Dash in folder name prevents me from setting environment variables correctly?

I've tried several things below, but when there is a - in the path it seems to screw with the environment variable that I'm setting:  leeand00@somehost MINGW64 ~/OneDrive - Some Company Somewhere/mycsvdb (develop) $ export CSVFILE="/c/Users/leeand00/OneDrive\ -\ Some\ Company\ Somewhere/mycsvdb/.mycsv.sys.csv"  leeand00@somehost MINGW64 ~/OneDrive - Some Company Somewhere/mycsvdb (develop) $ cat $CSVFILE cat: unknown option -- \ Try 'cat --help' for more information.  leeand00@somehost MINGW64 ~/OneDrive - Some Company Somewhere/mycsvdb (develop) $ export CSVFILE="/c/Users/leeand00/OneDrive\ \-\ Some\ Company\ Somewhere/mycsvdb/.mycsv.sys.csv"  leeand00@somehost MINGW64 ~/OneDrive - Some Company Somewhere/mycsvdb (develop) $ cat $CSVFILE cat: '/c/Users/leeand00/OneDrive\': Is a directory cat: '\-\': No such file or directory cat: 'Some\': No such file or directory cat: 'Company\': No such file or directory cat: Somewhere/mycsvdb/.mycsv.sys.csv: No such file or directory  leeand00@somehost MINGW64 ~/OneDrive - Some Company Somewhere/mycsvdb (develop) $ export -- CSVFILE="/c/Users/leeand00/OneDrive\ -\ Some\ Company\ Somewhere/mycsvdb/.mycsv.sys.csv"  leeand00@somehost MINGW64 ~/OneDrive - Some Company Somewhere/mycsvdb (develop) $ cat $CSVFILE cat: unknown option -- \ Try 'cat --help' for more information.  leeand00@somehost MINGW64 ~/OneDrive - Some Company Somewhere/mycsvdb (develop) $ export CSVFILE="/c/Users/leeand00/OneDrive\ -\ Some\ Company\ Somewhere/mycsvdb/\.mycsv\.sys\.csv"  leeand00@somehost MINGW64 ~/OneDrive - Some Company Somewhere/mycsvdb (develop) $ cat $CSVFILE cat: unknown option -- \ Try 'cat --help' for more information.   Is there a way around this?


I want to highlight the code in comment box, How can do this. I want to highlight my syntax code highlight in comment field


'BLOB is not a valid UTF-8 string' error?

Im reading in a document that the user uploads from the visualFlow:  <apex:inputFile value="{!contentFile}" filename="{!nameFile}" id="file"/>   And its accessed in apex in this manner:  String nameFile = contentFile.toString();   And it works like a charm. I am able to parse through the document and extract all the information needed, but only for English users. But for Spanish users that's not the case.  Those files have some special characters, and cause a BLOB is not a valid UTF-8 string error.  I've tried to base64Encode the file contents, but the results come out illegible.   String nameFile= EncodingUtil.base64Encode(contentFile);


How to skip few iterations in a for loop based on a if condition?

I have a for loop and I'm looking for a way to skip few iterations whenever that condition is satisfied. How can I do it in python?  Here's an example when condition is satisfied for the first time,  for i in range(0, 200000):     # (when 0 % 300 it meets this criteria)      if (i % 300) == 0:                      # whenever this condition is met skip 4 iterations forward         # now skip 4 iterations --- > (0, 1, 2, 3)      # now continue from 4th iteration until the condition is met again          Similarly, this should happens whenever if condition is satisfied.


I have a C++ program as below  #include <iostram>  using namespace std;  class abc {     public:         abc()         {             cout << "in Constructor\n";         }; };  int main() {     abc a(); }   I compiled and I saw that "in Constructor" is not getting printed which means constructor is not getting called. I was wondering that both abc a and abc a() are same and both will create object a. But that seems to be wrong. Can any one please let me know what abc a() means because I didn't get the compilation error also.


OS : Ubuntu 20.04 LTS I was following a HPLIP guide from hp cause my printer wasnt being detected and it said to enter this command sudo apt-get install --assume-yes libcups2 cups libcups2-dev cups-bsd cups-client libcupsimage2-dev libdbus-1-dev build-essential ghostscript openssl libjpeg62-dev libsnmp-dev libtool libusb-1.0-0-dev wget python-imaging policykit-1 policykit-1-gnome python-qt4 python-qt4-dbus python-dbus python-gobject python-dev python-notify python python-reportlab libsane libsane-dev sane-utils xsane  But this gives out an error Note, selecting 'python-dev-is-python2' instead of 'python-dev' Note, selecting 'python-is-python2' instead of 'python' Package python-imaging 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:   python-pil  E: Package 'python-imaging' has no installation candidate E: Unable to locate package python-qt4 E: Unable to locate package python-qt4-dbus E: Unable to locate package python-notify E: Unable to locate package python-reportlab  I have tried various solutions but none worked.


A readOnly Equivalent for HTML Select Elements

Is there an attribute or technique for HTML select fields that's equivalent to  readOnly="true" for HTML inputs?   I have an form select field I'd like to disable, but still pass on when the form is posted.  If this were an HTML input, I'd do something like this  $('select_id').setAttribute('readOnly', 'true');   and the browser would render the field as un-editable, but it's value would still be passed to the backend.  I'd like something similar for an HTML select, but doing the following  $('#select_id').setAttribute('readOnly', 'true');   doesn't work.  The attribute is successfully added to the DOM, but the browser still renders it as selectable.   I realize I could do the following  $('#input_id').disabled();   but when a field is disabled its value isn't passed through to the backend.    I'd like a way to disable this select field but still pass in on to the backend.   (examples use Prototype JS, but I'm interested in any general solution)


Maximum norm and the triangle inequality

Suppose $(X,d_X)$ and $(Y,d_Y)$ are two metric spaces then  $d^{\infty}_{X\times Y}((x_1,y_1),(x_2,y_2))=\max(d_X(x_1,x_2),d_Y(y_1,y_2))$ is a metric for $X\times Y$  I have tried to prove the triangle inequaltiy   i.e.:   $\max(d_X(x,x''),d_Y(y,y''))\leq\max(d_X(x,x'),d_Y(y,y'))+\max(d_X(x',x''),d_Y(y',y''))\tag{*}$  But I don't know how. I have first assumed without loss of generality   $d_X(x,x'')\geq d_Y(y,y'')$. Then I have in $(*)$ on the LHS $d_X(x,x'')$ if I could somehow Show that the already made assumptions would implicate that $d_X(x,x')\geq d_Y(x,x')$ and $d_X(x',x'')\geq d_X(x',x'')$ I would be done. But I really don't know how I can make these conclusion.


How to show that the nth power of a $n \times n$ nilpotent matrix equals to zero $A^n=0$

$A$ is a $n\times n$ matrix such that $ A^m = 0 $ for some positive integer $m$.   Show that $A^n = 0$.   My attempt: For $n > m$, it's obvious since matrix multiplication is associative.  For $n < m$, $A^n\times A^{m-n} = 0$; not sure what to do next. Also I know that $\det A = 0$.


Schengen visa for non-EU spouse of EU citizen

Most of the already posted questions were about traveling between EU countries. In my case I would like to visit Austria with my South African wife. We got married over 20 years ago in Austria, lived there together for 6 years, but moved to SA 16 years ago. The permanent residence my wife had once expired and she needs a Schengen visa. The Austrian Embassy tells me that my wife has to apply in person, show proof of income, proof of accommodation, has a travel insurance and all fulfills all other requirements like every ordinary applicant.  Is the Directive 2004/38/EC only applicable for spouses when they are already within the EU or is it also valid in our case?   In particular the personal appearance is a problem as we are living in the Southern Cape and going to the embassy means a round trip of 2600 km, closer is the consulate in Cape Town but still requires a 1200 tour.


Is there any solution for drawing simple graphs in LaTeX like the following? I came across tikz but couldn't figure out how to do it. Are there also possibilities to extend such graphs without caring too much about node distances etc?


The C++ language has specific rules about how you must free the memory to which a pointer points.  These rules require you to know how the memory was allocated in order to correctly free it.  For example,  int *p = new int(); std::free(p);   results in undefined behavior. ()  In modern C++, we like to use smart pointers where possible, but sometimes we may want to use libraries or functions that allocate raw pointers.  Suppose I want to use a function of the form:  char* NotMyFunction();   How do I properly manage the memory allocated by this function?


When I try to render a wave, it keeps being rendered in extremely low quality. I'm not sure exactly which setting is causing this, but increasing the renderand viewport sampling don't seem to help.


When Canadian who is British has a British passport visiting England be covered by nhs

Can a Canadian with British passport get medical treatment when in country


World Mercator Projection with Chucotka region in right part?

How can I choose or modify World Mercator projection to display eastern part of Chucotka region in the right part of the map? I have already tried to change the parametr +lon_0, but the map looks like in the picture.  user projection parameters  +proj=merc +lon_0=+10 +k=1 +x_0=0 +y_0=0 +datum=WGS84 +units=m +no_defs


how to make complete os backup to create update.zip?

how exactly can i create a update.zip file from  an android device that runs on android kitkat? i tried to backup using titanium backup but it needs root access. is there any way to backup the complete rom without rooting?