apt-get update errors - 50unattended-upgrades.ucf-dist

I am getting a few errors when doing apt-get update. Some seem fatal, some are just ignored, but anyway I want to remove them to prevent further issues.  It was working until I added:  add-apt-repository ppa:scribus/ppa   The first error is:  N: Ignoring file '50unattended-upgrades.ucf-dist' in directory '/etc/apt/apt.conf.d/' as it has an invalid filename extension   This does not seem to cause issues, as saw it before.  But, it still appears each time.  The second error is:  W: chmod 0700 of directory /var/lib/apt/lists/partial failed - SetupAPTPartialDirectory (1: Operation not permitted)   One last error is:  E: Could not open lock file /var/lib/apt/lists/lock - open (13: Permission denied)   There are other errors, but I will list them once I correct these.


Can you please check my Cesaro means proof

I wanted to prove the following:  if $x_n \to x$ then $y_n \to x$ where $$ y_n = {x_1 + \dots + x_n \over n}$$  Please can you tell me if my proof is correct? My proof is this:  Let $\varepsilon > 0$. Fix $N$ such that $n > N$ implies $|x_n - x| < {\varepsilon \over 2}$.   Then $\left |{1 \over n} \sum_{k=N+1}^{N + n} x_k - x \right | < {\varepsilon \over 2}$. Now let $M$ be such that ${|x_1 + \dots + x_N | \over M} < {\varepsilon \over 2}$ and $M > N$. Then  $$ \left | \sum_{k=1}^M {x_k \over M} - x   \right | \le  \left | \sum_{k=1}^N {x_k \over M}   \right | +  \left | \sum_{k=N+1}^M {x_k \over |M-N|}  - x   \right | < \varepsilon $$ Here the proof is finished. But one can observe:  It is possible that $y_n$ converges even if $x_n$ doesn't: If $x_{2n} = 0$ and $x_{2n + 1} = 1$ then $x_n$ does not converge but $y_n \to {1 \over 2}$.


One of my process written in C# is forked by another process during application startup. This process needs administrator rights  as it is accessing drivers, but the parent application (forking process) was launched in user mode.   There were two ways which I could think of: 1. Change the manifest, but the UAC dialog box would be irritating for the users. 2. Like Linux rpm installation, install the application with super user and give full control to the process  Is there any other better way of doing this?  Please guide  Thanks


From time to time, my Magic Trackpad gestures will stop working. I can restart to bring them back, but this is pretty disruptive.  Is there a process I can kill to bring them back?  (I've tried turning off the Magic Trackpad; unfortunately, it doesn't fix the problem.)


Ubuntu 18.04 - get Ubuntu dock to only display the windows from the current screen (monitor)

I am using Ubuntu 18.04 (with Linux kernel 4.15.0-33-generic) on a setup with laptop and an external monitor. Is there a way to make the dock in Ubuntu 18.04 only display the windows from the current screen. There was a similar feature in Ubuntu 16.04.  In short if an app is only opened on one of the screens it was still displayed in the launcher but with a different indicator. When there are two windows of an app (e.g. I have two gedits or two chromes opened) one for each screen, clicking on the icon in the dock opened the window for the corresponding screen (instead of displaying a picker with the two windows).   Is there a way to have similar configuration for Ubuntu 18.04?


A question about how to express a fraction as ${1\over q_1}+{1\over q_2}+ \cdots+{1\over q_N}$

Let $x$ be a positive rational number, strictly between $0$ and $1$. Prove that there is a finite strictly increasing list of positive integers $2 \leq q_1<q_2<\cdots<q_N $ such that $$x={1\over q_1}+{1\over q_2}+ \cdots+{1\over q_N}.$$  I have tried many methods, such as mathematical induction. I know it is obvious that $\frac{1}{m}$ is right for assumption, but when I begin to prove $\frac{2}{m}$, I feel it is hard to find some patterns for $\frac{2}{m}$. Thus, maybe my thoughts are wrong.  Also, I still tried to change the fraction so that the numerator will be smaller and smaller. But I still cannot find a way to lower the numerator. Can someone help me solve the question? Or, can someone give me some hints. I will appreciate you very much!


"... the following subset of $X$ denoted by $[x]$ $(x\in X)$ is called the equivalence class generated by $x$:  $$[x]:= \{y \in X; x\sim y \}$$  Show that the equivalence classes give a partition of $X$.   According to my book "Given a nonempty set $X$ we say that the family of subsets $\{X_\alpha\}_{\alpha \in I}$ is a partition of $X$ iff   $$\bigcup_{\alpha \in I} X_\alpha = X$$  $$ X_\alpha \cap X_\beta = \emptyset \text{ if } \alpha \not = \beta$$  I missed my lecture on this topic and I dont have any clue where to start. As I understand it the equivalence classes is the set of all $x \in X$ s.t for $y \in X$ then $x\sim y$. But after here I am lost.  I guess I could denote the equivalence classes by  $$ [x_i] := \{y \in X; x_i \sim y\}$$ And now try to prove that   $$\bigcup_{\alpha \in I} [x_{i}] = X$$ and  $$[x_i] \cap [x_j] = \emptyset \text{ if } j \not = i \text{ ?}$$


Category of Riemann surface is balanced?

Let $A$ and $B$ are Riemann surfaces. $f:A→ B$ is morphism of Rieman surface, in other word, holomorhic function, and supposed that $f$ is bijective. Then, can we say that inverse of $f$ is also holomorphic? Thank you in advance.


Trapped by a Redstone Signal and command block around 50 blocks away

I got trapped in a position when I had an observer tping people to a position and it's stuck on repeat. Anybody who joins my LAN gets tpd. How do I remove the observer from almost 100 blocks away? I've tried /fill and don't know the coords and I don't want to abandon the world. It's really important. anybody know anything?


Removing Ubuntu from dual boot Windows 7 PC

How to remove the Ubuntu OS installed on a separate partition from a dual boot Windows 7 PC.  I would like to continue using Win 7.  the grub should also be sorted out.


How can I echo a newline in a batch file?

How can you you insert a newline from your batch file output?  I want to do something like:  echo hello\nworld   Which would output:  hello world


Pronoun question: referring to inanimate objects as 'he' or 'she'

I read the following claim concerning pronouns referring to inanimate objects:      Anything that is meant to contain you, protect you or provide you with something beneficial is [often referred to as] a she; anything that is a perceived threat is a he. That's why cars, boats and some countries are she.    Is this really the case, or is it just a subjective claim? (According to the  using he/she for inanimate objects is not recommended and it should be used instead.) Is there a 'rule' for determining whether to use he, she or it based on the impression one would like to express? (I only know the 'rule' for animals: In the case where you know their gender and they are important to you, you refer to them using he/she. E.g. A dog attacked me in the street. It bit me. versus This is my dog Roger. He is 7 years old.) Have these practices changed over time?   Note 1: There is already a similar question (), but that considers only the feminine case and none of the answers offers an objective discussion of the matter.  Note 2: My native language is Czech, where the gender of the pronoun is based only on the grammatical gender of the noun. E.g. a cat (kočka) is always she, a dog (pes) is always he, a boat (loď) is always she and a car (auto) is always it.


90's sci-fi book series, humanity is attacked by aliens, point of view switches between the humans' and the aliens' between books

I'm attempting to find the name of a book series that I read in the mid 90's that was (I believe) new at the time.   It is either a 2 or 3 part series in which humanity is attacked by an alien race (not very specific I know).    I distinctly remember the first book being told from the perspective of the humans and the second book was told from the perspective of the aliens that attacked.  I seem to recall that it was a trilogy, but I don't remember whose perspective it was for it.


This isn't a question about the theoretical underpinnings of mixed modeling, it is more about how dependant variable should be entered into a dataset to successfully run a model. I have recently finished running a linear mixed model in R and am now attempting to run a second model using a different outcome variable. Previously I examined the impact on participant reaction times through a series of factors. My data was in a long format where each row was a trial from a computerized task. Hence each trial had an associated reaction time where participants completed a task and each participant had many rows showing their reaction time by trial in the dataset. It was the trial reaction time column I used as my dependant variable. However, the dependant variable I am looking at now is somewhat different and I am not sure if the same principles carry over. Let's call the new dependant variable the number of accidental button presses. It is still numerically continuous, but in a trial, a participant can either accidentally press a button (scoring 1) or not (scoring 0). Therefore while a participant could have for example 10 accidental button presses in total from the computerized task, on a single trial they ether score a 1 or a 0. This means that when I look at a histogram of the accidental button press variable where each trial is a row it appears dichotomous and not like a normal distribution. This makes me wonder if the data should be entered into a different format to run a linear mixed model. I don't think totaling the accidental button press for each participant is quite correct because the mixed model is losing the variability between trials. Also by aggregating into a single number per participant I don't think the model would run as the number of observations would equal the number of participants. Yet it is the total number of button presses that I want to compare between participants. The only other option I have is that I do have a column for cumulative accidental button presses. By row for each participant, this increases in count as accidental button presses occur. For a single participant, it looks like 0, 0, 1, 2, 2, 2, 3 … etc. I am wondering if I should be trying to analyze this, however, it doesn't feel quite right. Thoughts for a stats dummy? Thanks.


Class doesn't get defined. Linking error

I encountered the following linker errors and I can't seem to find out why Observable<T> doesn't get defined:  CMakeFiles/Sapling.dir/Core/Window/SdlWindow.cpp.o: In function `se::SdlWindow::SdlWindow(se::Window::State const&)': /home/glados/ClionProjects/Sapling/Core/Window/SdlWindow.cpp:9: undefined reference to `se::Observable<se::WindowEvent>::addObserver(se::Observer<se::WindowEvent>*)' CMakeFiles/Sapling.dir/IO/SdlInput.cpp.o: In function `se::SdlInput::processEvent(SDL_Event const&)': /home/glados/ClionProjects/Sapling/IO/SdlInput.cpp:83: undefined reference to `se::Observable<se::WindowEvent>::notify(se::WindowEvent const&)' collect2: error: ld returned 1 exit status   The problem seems to be about these two classes:   Observer.h  #ifndef OBSERVER_H #define OBSERVER_H  #include "../Util/UID.h"  namespace se {      template <typename T>     class Observer {      public:          Observer();         virtual ~Observer() { }          virtual void onNotify(const T& subject) = 0;          const UID& getId() {             return m_id;         }      private:         UID m_id;         static UIDPool m_uidPool;     };  } // namespace se #endif   Observer.cpp  #include "Observer.h"  namespace se {      template <typename T>     UIDPool Observer<T>::m_uidPool = UIDPool();      template <typename T>     Observer<T>::Observer() : m_id(&m_uidPool) { }  } // namespace se   Observable.h  #ifndef OBSERVABLE_H #define OBSERVABLE_H  #include "Observer.h" #include <vector>  namespace se {      template <typename T>     class Observable {     public:          void addObserver(Observer<T>* observer);         void removeObserver(Observer<T>* observer);      protected:          void notify(const T& topic);      private:         std::vector<Observer<T>*> m_observers;     }; } // namespace se #endif // Include guard   Observable.cpp  #include <cstdlib> #include <cassert> #include "Observable.h"  namespace se {      template <typename T>     void Observable<T>::addObserver(Observer<T>* observer) {         m_observers.push_back(observer);     }      template <typename T>     void Observable<T>::removeObserver(Observer<T>* observer) {         assert(observer->getId().get() < m_observers.size());          for (size_t i = 0; i < m_observers.size(); ++i) {             if (observer->getId() == m_observers.at(i)->getId()) {                 m_observers.erase(m_observers.begin() + i);             }         }     }      template <typename T>     void Observable<T>::notify(const T& topic) {         for (size_t i = 0; i < m_observers.size(); ++i) {             m_observers.at(i)->onNotify(topic);         }     } } // namespace se   The problem isn't a circular dependency one as Obervable<T> is not circularly dependent (UID.h only includes STL headers). I'm using cmake to make and gcc to compile/link.  I hope you can help me out as I have spent over 7 hours trying to resolve this...


I am reading a book. A paragraph begins with this sentence:     They say we Scots are a pessimistic people. Maybe it has to do   with the weather - all those dreary, rainy days.   I am searching for pronouns "they" but I couldn't find what it refers to because I could not find anything for it.  Can anyone help me about it?  This is the whole passage:     But to do that, you need to be more than usually canny.   And that provides an important clue as to just where the history   of insurance had its origins. Where else but in bonny, canny   Scotland?      Taking Cover      They say we Scots are a pessimistic people. Maybe it has to do   with the weather - all those dreary, rainy days.


How are head shots and deep throat gashes filmed?

I was watching a movie the other night and the main character slits the throat of another person. The camera stayed on the victim the whole time this happened. I'm wondering how this is achieved.  Similar question is head shots (via gun fire) where someone gets shot in the head and you see an entry wound and the exit splatter all without cutting away then coming back.   I'd imagine some kind of exploding blood pack on the back of the head for the splatter, but what about the forehead wound/neck gash spurting blood all over? Some of the cuts go pretty deep too.   How do they film/setup these types of shots? How are these types of "live" shots achieved without cutting away to another shot, then coming back?


I'm currently using log4net in my ASP.NET MVC application to log exceptions.  The way I'm doing this is by having all my controllers inherit from a BaseController class.  In the BaseController's OnActionExecuting event, I log any exceptions that may have occurred:  protected override void OnActionExecuted(ActionExecutedContext filterContext) {     // Log any exceptions     ILog log = LogManager.GetLogger(filterContext.Controller.GetType());      if (filterContext.Exception != null)     {         log.Error("Unhandled exception: " + filterContext.Exception.Message +             ". Stack trace: " + filterContext.Exception.StackTrace,              filterContext.Exception);     } }   This works great if an unhandled exception occurred during a controller action.  As for 404 errors, I have a custom error set up in my web.config like so:  <customErrors mode="On">     <error statusCode="404" redirect="~/page-not-found"/> </customErrors>   And in the controller action that handles the "page-not-found" url, I log the original url being requested:  [AcceptVerbs(HttpVerbs.Get)] public ActionResult PageNotFound() {     log.Warn("404 page not found - " + Utils.SafeString(Request.QueryString["aspxerrorpath"]));      return View(); }   And this also works.  The problem that I'm having is how to log errors that are on the .aspx pages themselves.  Let's say I have a compilation error on one of the pages or some inline code that will throw an exception:  <% ThisIsNotAValidFunction(); %> <% throw new Exception("help!"); %>   It appears that the HandleError attribute is correctly rerouting this to my Error.aspx page in the Shared folder, but it is definitely not being caught by my BaseController's OnActionExecuted method.  I was thinking I could maybe put the logging code on the Error.aspx page itself, but I'm unsure of how to retrieve the error information at that level.


If my power supply is 700w, do I need a 700w UPS?

if my power supply is 700w, do I need a 700w UPS?  I am running dual 20" dell LCD's, a i7 quad core system with a radion 4870 1gb video card, 2 hard drives.


Data from two modems for faster browsing?

I'm stuck with DSL Lite (a slow Internet connection).   Is it possible to speed up my AT&T 'DSL Lite' connection by augmenting it with some bandwidth from my Cellphone's tethered 'hot-spot' connection?   I often use my cellphone's tethered hotspot because it is much faster than my DSL-Lite connection; however, I find it is too expensive to use regularly. It seems like I should be able to combine these two data streams and use them simultaneously.  My current thinking is that some software might exist that makes it possible to use the cheapest bandwidth first (ATT's DSL-Lite) and leave it on (always flowing) but when the connection pauses/waits/bottlenecks/etc., it would then get a boost of bandwidth from the cellphone hotspot.


Python list for each 4 in the list from right

I have a list in python, eg. [1,2,3,4,5,6,7,8,9,10,11,12]  I want to make a new list with only the 4. element from the right? .. how to do that, eg. with a one liner.  eq. to .. [4,8,12]


dpkg: unrecoverable fatal error, aborting: ('libpeas-common' is missing)

I know this is a commonly asked question in this forum but none of the solution worked for me. Whenever I try to update or, install any package I'm getting this error  dpkg: unrecoverable fatal error, aborting:  files list file for package **'libpeas-common'** is missing final newline  E: Sub-process **/usr/bin/dpkg** returned an error **code (2)**   Please, help me to get rid of this problem.


KDEConnect & Oppa A5 can't detect one another

Tried to use this KDEConnect on Linux Mint yesterday. No joy. This morning I installed Ubuntu thinking it may have more luck. But no connection. What I've tried:  Turned off 5ghz band on router cuz phone & linux box was on different bands. tried manually connecting to Ubuntu from phone by inputting ip address. tried GSConnect, still no connection used gufw to allow KDE Connect to pass through  I'm using a BT Home Hub 2. None of this has worked. I'm getting the feeling that KDEConnect is perhaps no longer functional, is this true? Or is there a step I'm missing. Much appreciate any help anyone can offer, I'm only using Linux a few months so any help should be dumbed down.


What happens if a target for removal becomes ineligible after a card has been cast?

When you have a card like  which reads "Exile Target Creature with power 3 or less", as I understand it, it becomes untargetable if the opponent's creature power increases thanks to a pump spell like .  But what if the Disregard is already on the stack and targeting; and they respond with Brute Strength? I'm pretty sure (and my opponent with Brute Strength was certain) that it won't exile the creature, but I don't know which rule states this, and there's no gatherer ruling on the spell.


Can this:     These same officials, however, would have been appalled had they known what was going on behind this façade of self-help.   be rephrased as     These same officials, however, would have been appalled if they had known what was going on behind this façade of self-help.   ?


Delete the phrase "I'm" from the sentence by native speaker

I hear many native speakers say, for example, "glad to connect" or "Not sure about that". Where they delete "I am" at the beginning of the sentence, Is that kind of "short the talk", I mean to speak a fewer words, or it has a conditions/rules to delete those words?


I have a Java Application running on Linux machine, it is generating a file  in which each record is separated by new line,  This file will be used by an application running on Unix SunOS system and  my code below does not generate proper file . I mean following code generates a file in which each line end with ^M charater when I open it with vi editor in Unix system  bw = new BufferedWriter(new FileWriter(file)); bw.write("\n");   Which character I have to write in order to see the file properly in Unix system.


How can I provide star rating metadata to search engines?

Some search engines (including Google and Bing) display a star rating for things like movies and downloads on sites such as IMDB and cnet.    How can I configure my site to provide this data?


How to add value to a field in a node through code?

I have a field that I need a value assigned to, I want this field to be populated with a particular value when the node is being saved. Where should the code be placed? And how would I go about accomplishing this?


Bind click function not working on ajax content refresh

The filter mechanism (item_filter) below returns fresh html-content (product_data) via an ajax function (load_resorts). In this freshly loaded html content is (also) a class which -when clicked- should trigger a function (via class myresort).  +add   The myresort click function works for the default loaded resorts (on page load), but not for the ones loaded via ajax.  I have used a bind function.    $('.item_filter').on('click', function(event) {   $('.product-data').html('

');   sure = multiple_values('sure');   country = multiple_values('country');   altitude = multiple_values('altitude');   level = multiple_values('level');   size = multiple_values('size');   price = multiple_values('price');   offpiste = multiple_values('offpiste');   family = multiple_values('family');   apresski = multiple_values('apresski');   load_resorts($("#snow1").val(), $("#snow2").val()); });  function load_resorts(ssnow, esnow) {   $.ajax({     url: "ajax.php",     type: 'post',     data:{sure:sure,country:country,altitude:altitude,level:level,offpiste:offpiste,family:family,apresski:apresski,size:size,price:price,ssnow:ssnow,esnow:esnow,filter_order:filter_order},     success: function(result) {       $('.product-data').fadeIn('slow').html(result);     }   }); }  $('span.myresort').on('click', function(event) {   var myres = $(this).attr('data-src');   $.ajax({     type: 'POST',     url: '/v4/ajax/myresorts.php',     data: {       myresort: myres     },     success: function(msg) {       $('#myresorts').fadeOut(800, function() {         if ($('*[data-src="' + myres + '"]').hasClass('loveit')) {           $('*[data-src="' + myres + '"]').removeClass('loveit');           $('*[data-src="' + myres + '"]').html('+add').fadeIn().delay(1000);         } else {           $('*[data-src="' + myres + '"]').addClass('loveit');           $('*[data-src="' + myres + '"]').html('-remove').fadeIn().delay(1000);         }         $('#myresorts').html(msg).fadeIn().delay(1500);        });     }   }); });


Should I cite the author of software tool or script that I use?

I'm writing a paper for my Ethical Hacking class. In 'hacking', you use a lot of tools written by other people, some of them are mainstream and/or made by big teams, others are less known and made by individuals or small teams.  If I'm using a relatively uncommon software tool for a particular task, a tool that my readers may not know of, would it be courteous/helpful to cite the individual or lead developer of said tool? Would it be acceptable that the reference is just the website, or should I find another article that talks about the tool?  (NB: We use Harvard referencing)


Winter 18  does not get values from a parent record

I am testing the new  <lightning:datatable>, it is really good, and is a good replacement for most of my use cases which today I use a custom list component that I have developed.  I am getting data from my server through apex method, to populate it into the <lightning:datatable> component. I can bind the returned list directly to the data attribute and if the column names are same as the field names, all data is bound correctly.  The problem occurs when I get data from a parent record. For example - I want the Account name of my contact.  This example can show the problem:  Component Markup    <aura:handler name="init" value="{!this}" action="{!c.doInit}"/>  <aura:attribute name="mydata" type="Object"/> <aura:attribute name="mycolumns" type="List"/> <aura:attribute name="sortedBy" type="String"/> <aura:attribute name="sortedDirection" type="String"/>  <lightning:datatable data="{! v.mydata }"                      columns="{! v.mycolumns }"                      keyField="Id"                      onrowselection="{! c.getSelectedName }"                      onsort="{!c.updateColumnSorting}"                      sortedBy="{!v.sortedBy}"                      sortedDirection="{!v.sortedDirection}"                      hideCheckboxColumn="{!false}" />        Component Controller  ({     doInit: function (component, event, helper) {         component.set('v.mycolumns', [                     {label: 'Id', fieldName: 'Id', type: 'id', sortable:"true"},                     {label: 'First Name', fieldName: 'FirstName', type: 'text', sortable:"true"},                     {label: 'Last Name', fieldName: 'LastName', type: 'text', sortable:"true"},                     {label: 'First Name Hebrew', fieldName: 'First_name_Hebrew__c', type: 'text', sortable:"true"},                     {label: 'Last Name Hebrew', fieldName: 'Last_name_Hebrew__c', type: 'text', sortable:"true"},                     {label: 'Account', fieldName: 'Account.Name', type: 'text', sortable:"true"},                     {label: 'Email', fieldName: 'Email', type: 'email', sortable:"true"},                     {label: 'Phone', fieldName: 'Phone', type: 'phone', sortable:"true"}                 ]);          var action = component.get("c.getRecordsFromDb");         action.setParams({             sObjectName: "Contact",             commaDelimitedFieldNames: "Id,FirstName,LastName,First_name_Hebrew__c,Last_name_Hebrew__c,Account.Name,Email,Phone",             filter: ""         });         action.setCallback(this, function(response){             var state = response.getState();             if (component.isValid() && state === "SUCCESS") {                 var data = response.getReturnValue();                  component.set("v.mydata", data);             }         });         $A.enqueueAction(action);     } })   APEX Aura Enabled Method  @AuraEnabled public static List<sObject> getRecordsFromDb(String sObjectName,         String commaDelimitedFieldNames,         String filter) {      system.debug('\n\n\n\ngetRecordsFromDb sObjectName: ' + sObjectName + ', commaDelimitedFieldNames: ' + commaDelimitedFieldNames + ', filter: ' + filter + '\n\n\n\n');      // create a dynamic soql to get the value of the field     String sql = 'SELECT ' + commaDelimitedFieldNames + ' FROM ' + sObjectName;      if (!String.isBlank(filter))         sql += ' WHERE ' + filter;      system.debug('\n\n\n\ngetRecordsFromDb sql: ' + sql + '\n\n\n\n');     List<sObject> records = Database.query(sql);     system.debug('\n\n\n\ngetRecordsFromDb: ' + records + '\n\n\n\n');      return records; }   The problem is with the Account.Name field - the <lightning:datatable> component does not display the column data.   I know that the data is returned ok, and I know that in the object that is returned, the Account is contained like an object (probably this is the problem):    Is there a good way to show parent record data with this component?


How to create third partition on a Mac with Mavericks and Bootcamp?

Right now I am running OS X 10.6.8 (Snow Leopard) on my MacBook Pro, with Windows 7 via Boot Camp, and I also have a third FAT32 partition where I share data between Mac/Windows.   I am going to upgrade to Mavericks. I Googled and it seems Mavericks is not going to be happy with letting me create the third FAT32 partition.  Did anyone create a third partition with Mavericks before? What are the steps?  (I have backed up all my data from both OS X and Windows, and I am going to format whole hard disk, and fresh install snow leopard, then update to Mavericks).


How prove that $q \geq b+d$ for $ad-bc = 1$ and $\frac{a}{b} > \frac{p}{q} > \frac{c}{d}$?

Let $a,b,c,d,p$, and $q$ be natural numbers such that $ad-bc = 1$ and $\frac{a}{b} > \frac{p}{q} > \frac{c}{d}$.  How prove that  $q \geq b+d$?


Consider the following function given by;  $f(x,y) = \begin{cases} \frac{xy}{x^2+y^2},&(x,y) \neq 0 \\\\ \ \ \ \ 0,&(x,y)=0 \end{cases}$  Is the function differentiable in the ordinate pair $(0,0)$???  Prove it    I calculated the following derivative.  $$ \frac{\lambda f}{\lambda y}(0,0)=\lim_{h\to 0}\frac{f(0+h,0)-f(0,0)}{h}=\lim_{h\to 0}\frac{\frac{(0+h)-0}{(0+h)^2+0^2}-0}{h}=\lim_{h\to 0}\frac{0}{h^3}=0$$  considering $(0,0)$  $$ \frac{\lambda f}{\lambda y}(0,0)=\lim_{h\to 0}\frac{f(0,0+h)-f(0,0)}{h}=\lim_{h\to 0}\frac{\frac{0(0+h)}{0^2+(0+h)^2}-0}{h}=\lim_{h\to 0}\frac{0}{h^3}=0$$    I could not differentiate the derivative  Replica of  I need another answer


I'm trying to prove the third Isomorphism theorem as stated below  Theorem. Let $G$ be a group, $K$ and $N$ are normal subgroups of $G$ with $K⊆N$. Then $$(G⁄K)⁄(N⁄K)≅G⁄N.$$  I look up for some answered on google, but I don't understand any of those. I wonder if any one can show me this proof step by step. I don't want to get it done, I want to understand why this theorem is true.


Why should I use lambda/proc ?Explain it's importance

I am new to ruby, and while learning it I didn't understand the concept of lambdas or procs. I know lambda and  proc are the blocks of code that have been bound to a set of local variables. But I don't understand their use.  So  what advantage does a programmer get from it?  I had asked this question in past and got marked as duplicate and was given a link that had totally unrelated answered so please before marking it as duplicate or scolding me please view the answers of other links by yourself first.


I am experiencing anissue when installing Windows 7 64-bit on a clean 240GB SSD. My motherboard is a GA-MA785GMT-UD2H, BIOS detects the SATA drive and Windows 7 does detect the drive when booting off my old HDD.  I know the drive is good.  Updated the Firmware on the SSD  Updated the motherboard BIOS firmware  I have enabled SATA and using AHCI  Connected my SSD to sata port 0 on the mortherboard  Disconnected all other HDD  Downloaded the Windows 7 64-bite Sata AHCI drivers from Gigabyte website and installed on thumb drive  I click on load drivers, browse to the thumb drive, select the drive and click OK.  Windows 7 still does not find the SSD drive.


JS .children Returns an Object, Want an Array (ES6)

According its  (everyone's favorite resource, I know), the .children property returns      A live HTMLCollection object, representing a collection of element   nodes   This object can be looped over as if it were an array like so:    var elements = document.getElementById('test').children;  for (var i=0; i < elements.length; i++) {   console.log(elements[i]); }

paragraph 1

paragraph 2

paragraph 3

     However attempting to use the .map function throws an error:    var elements = document.getElementById('test').children;  var x = elements.map((element, index) => {   console.log(element); });

paragraph 1

paragraph 2

paragraph 3

     Is there a better way to get an array of child DOM elements, or do I have to loop through the object and manually create an array in order to use array methods like .map()? Note, I do not want to use jQuery. Thanks in advance.


On the use of hypocorisms on publications and university personnel list

Suppose my legal name is Stephen and that everyone (family, friends, and also colleagues and professors) calls me Steve (being aware that my legal name is actually Stephen).   Suppose also that I prefer being called Steve and would like to publish my papers (starting from the first one) under "Steve Surname".   It seems to me that the academic world (in particular, the mathematical world, as it is pointed out in other questions asked on this website) is very liberal when it comes to these matters (i.e. pseudonyms).  However, I'd like to ask preemptively if -- to the best of your knowledge and experience -- there could be any nuissances of any kind (not necessarily in the form of legal troubles) in signing legal documents (which, of course, include my thesis) using Stephen while employing Steve instead of Stephen on papers or (if in the future it will be the case) monographs (let's assume published by the main publishers -- Springer, AMS, PUP, OUP, etc.) and in the personnel list on the university website.     To make an example of possible nuissance: do Research Gate, Academia.edu, and other similar websites allow you to register under a name that is a shorter form of your legal one?    To clarify: in order to pose this question, I choose    Stephen: because, like my own name, it is a nice name, that is to say, neither too long nor cumbersome; Steve: because, like my own "calling name", it is slightly shorter, but not very-informal-sounding per se: in fact many people in various countries use it as legal first name.     Further clarification: I've seen . Mine is quite different though. In fact, I realize that it is possible (and accepted) to publish under a pen-name, and I'm asking specifically if there are any "legal" (so to say) nuissances associated to this practice. To make just few examples, when being included in the personnel list on the university website, when being included in the list of participants to a conference, when signing up to a website like Research Gate, etc.


At PCA why we find the Eigenvalues of the covariance matrix and not the eigenvalues of the matrix $A\times A^T$, where $A$ is the data matrix and $A^T$ its transpose? I saw a professor at YouTube who explained PCA but he said that the solution is the eigenvalues of $A\times A^T$.


My proof for $|R|=1$ if and only if $1=0$ where $R$ is a ring with unity.

I'm reading Dummit's book. (Abstract Algebra, 3ed, p224) Now I want to prove the following. Suppose $R$ is a ring with 1. Then, $|R|=1$($R$ is a trivial ring, [or the zero ring in the book]) if and only if $1=0$. $(\Rightarrow)$ : Since $0\in R$, $1\in R$ and $|R|=1$, it is immediate that $1=0$. $(\Leftarrow)$ : Suppose that $a\in R$. Then $a=a\cdot1=a\cdot0\stackrel{(*)}=0$. Thus $R=\{0\}$. But how can I justify $(*)$? Does that follow immediately from the definition of a ring with unity? Or, is there another proof for $(\Leftarrow)$?


The uniform limit of holomorphic functions is also a holomorphic function

Let $f_{n}$ be a sequence of holomorphic functions on an open set $U \in \mathbb{C}$, which tends to f uniformly on $U$. Prove that f is holomorphic on U  I have proved a simple case which is if $U$ is a simply connected domain, then a continuous function $g$ on $U$ is holomorphic if and only if $\int_{\gamma}g=0$ for any closed curve $\gamma$ in $U$.  But I don't know how to apply to the general case $U$ is an open set.  Thanks.


What is the most elegant way to cite two things connected by a 'joining word' with biblatex?

This question is about author-year citations using biblatex where citations are set inline in parentheses.  Sometimes, it is necessary to cite two authors and to specify some connection between them using a 'joining word'. [Is there a technical term for this?]  For example:     Marvin 2009, citing Arthur 2007   or:     Marvin 1333, interpreting Dent 1245   More specifically, I want this typeset as an in-text citation in parentheses:     (Marvin 2009, citing Arthur 2007)   or:     (Marvin 1333, interpreting Dent 1245)   I cannot figure out how to do this at all, or at all elegantly, using biblatex. The closest I've come is    a version which uses a semicolon rather than a comma; a long-winded hack which fails if one of the entries has no author.     \documentclass{article} \usepackage[citestyle=authoryear-comp,bibstyle=authoryear,backend=biber]{biblatex} \addbibresource{biblatex-examples.bib}  \begin{document}    Desired output is (CTAN 2006, interpreting Gillies 1933).    The following are almost correct except that they use the default delimiter (of course) so I have a semicolon rather than a comma: \autocites{ctan}[interpreting][]{gillies} or \parencites{ctan}[interpreting][]{gillies}.    The following is a bit long-winded. Worse, it fails if an entry does not actually have an author: \parentext{\citeauthor{ctan} \citeyear{ctan}, interpreting \citeauthor{gillies} \citeyear{gillies}}.  \end{document}   Note that redefining the delimiter between citations from a semicolon to a comma is not a good solution as the semicolon is correct for almost all occurrences of multiple citations (all bar 2 in my paper). Only when there is a special 'joining word' do I want the comma instead.  I'm wondering if I need to define a new citation command. That's fine but I'd like to know that I'm not missing something before I reinvent the wheel and end up with a lop-sided parallelogram instead of the roundish circle I could more easily have used.  It seems surprising if there is no straightforward way to do this as it seems like a fairly common thing to want to do. Hence, I suspect I'm missing some obvious solution and just can't find it.  What is the most elegant way to arrange such citations?


infinite monkey problem - probability of an infinite sequence containing an infinite sequence

Note: This question is specifically about when the infinite monkey theorem is extended to reproducing an infinite sequence (as oppose to a finite one)  I was browsing wikipedia, and came across the infinite monkey problem. I understand that if Random keys are selected for an infinite period of time, eventually any finite combination of characters will eventually be produced. For example, a complete copy of Hamlet. However, I am confused about what happens when this is extended to infinity. According to wikipedia:     If the monkey's allotted length of text is infinite, the chance of typing only the digits of pi is $0$, which is just as possible as typing nothing but Gs (also probability $0$).     However, this suggests that the probability of typing any combination of characters (that are infinitely long) is also $0$. However, the probability that a combination is typed is 1. However the sum of all possible events appears to be $0$, not $1$ (as the probability of any combination of infinite length being typed such as pi is $0$ as $0+0+0+0+...+0=0$   I'm not sure if I have just misunderstood this problem or if I have made a false assumption. It might have something to do with concept of "Almost certainly", but I was a bit intimidated by the wikipedia article.


Text deselecting when using Logitech mouse scroll wheel in Sierra

I'm using a Logitech Performance MX mouse and since upgrading to Sierra I'm having difficulty when using my scroll wheel to select large amounts of text. Usually, I scroll while holding left mouse and this has always worked. Now when I scroll, it deselects the text that I have selected.  Could this be a driver issue?


Issues with creating class with image file path as argument

I am attempting to make a class which can take a string with an image path and set it as this objects image. I have done it manually before, i.e. creating a new class with an extends main class, but this will get out of hand quickly. Here is the code I have so far:  import java.awt.Image; import java.net.URL; import javax.swing.ImageIcon;  public class Sprite { private int x;     private int y;     private ImageIcon ia;     private URL loc;     private Image image;  public Sprite(int x, int y) {     this.x = x;     this.y = y; }  public Sprite(int x, int y, String imgLoc) {     this.x = x;     this.y = y;      URL loc = this.getClass().getResource(imgLoc); //problem area is here     ia = new ImageIcon(loc); //and here     image = ia.getImage();     this.setImage(image); }   When I had a child class, It worked in the child classI put in something like this:  public class Dude extends Sprite {    public Dude (intx, int y) {       super(x, y);        URL loc = this.getClass().getResource("images/dude.png");       ia = new ImageIcon(loc);       image = ia.getImage();       this.setImage(image);    } }   But when I try to use the second Sprite Constructor, it gave me an  Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException     at javax.swing.ImageIcon.<init>(ImageIcon.java:217)     at Sprite.<init>(Sprite.java:26)   Any suggestions on how to fix this?


\mathcal and \mathscr output the same thing in my template

In my template compiled by XeLaTeX, \mathcal and \mathscr output the same thing. \documentclass{article} \usepackage{latexsym} \usepackage{amsmath} \usepackage{amssymb} \usepackage{arydshln} \usepackage{pmat} \setmathfont{xits-math.otf} \begin{document}     $ \mathcal{ABCD}, \mathscr{ABCD} $ \end{document}  Then I get this  What should I do to get a normal output from \mathcal{ABCD} like


Impossible to use BindValue in the SELECT field names?

I have a MySQL database containing Countries   id  | de          | en          | fr    ---------------------------------------------   1  | Afghanistan | Afghanistan | Afghanistan  2  | Albanien    | Albania     | Albanie ...   I'd like to get a list of the countries, according to visitor's language.  Here's the method in my class :  public function getList($language){     $countries = array();     $req = ('SELECT id, :language FROM country ORDER BY :language ASC');             $q = $this->_db->prepare($req);     $q->bindValue(':language', $language, \PDO::PARAM_STR);     $q->execute();     while ($data = $q->fetch(\PDO::FETCH_ASSOC)) {         $countries[] = new Country($data);     }     return $countries;     $q->closeCursor(); }   It returns an array, but country names are replaced by the language.  It seems bindValue is adding quotes to my variable, which is fine in the ORDER BY, but creates problems in the fields i want to SELECT.  $countryManager->getList('fr');   returns something like this   Array ( [0] => Entities\Country Object     (         [id:Entities\Country:private] => 1         [de:Entities\Country:private] =>           [en:Entities\Country:private] =>          [fr:Entities\Country:private] => fr     )  [1] => Entities\Country Object     (         [id:Entities\Country:private] => 2         [de:Entities\Country:private] =>          [en:Entities\Country:private] =>          [fr:Entities\Country:private] => fr     )   If you have any idea on where the problem might be, i'd be very glad to know :)  Thank you in advance for your help.


Using the definiton of the t-distibution prove that t-statistic has t-distirbution

I am trying to prove that t-statistic has a t-distribution, but I am pretty much lost at the moment. I was not able to find any proofs in the internet as well. Can somebody help me to understand how to prove it?


Collection initializer and TypeInitializationException vs IEnumerable

I have used collection initializer for a Dictionary and received a TypeInitializationException:  public static Dictionary<Environment.SpecialFolder, string> specialFolders = new Dictionary<Environment.SpecialFolder, string> {     // ...     {Environment.SpecialFolder.MyDocuments, "abc"},     // ...     {Environment.SpecialFolder.Personal   , "def"},     // ... };   As there is no useful info like InnerException, call stack or whatever else it is confusing. So I investigated the problem a bit and realized that there are two keys having the same value.   Regarding the IL, this collection initializer syntax is converted to Dictionary.Add(...) calls and as such calling Add two times with the same key raises System.ArgumentException (which is the inner exception I would expect in the TypeInitializationException). So I effectivelly answered my original question, but another one has emerged:  Why the class has to implement IEnumerable (and thus provide IEnumerator) - which is intended to read the collection, not to write it - when finally the collection initializer is converted to Add call (which is not guaranteed to be present in the class via the IEnumerable)? Am I missing something important?


What is the origin of blackbody radiation?

Of course I know what  is, like everyone else who has taken a thermal or statistical physics course. But it was recently pointed out to me that one thing that is rarely taught (including to me) is what the mechanism for the radiation is.  At the particle level, how does black-body radiation arise (which radiative process is this)? In other words, where are the photons coming from?    To perhaps clarify a bit further, borrowing a comment from Kevin Driscoll on an answer:     The point of the question is that there are materials whose emission spectra are quite well described by a black-body spectrum. And yet we know that at the atomic level photon emission are caused by some quantum mechanical transitions. So, how is it that such an underlying quantum mechanical description gives rise to a black-body spectrum at everyday temperatures? What is the mechanics that causes light to be absorbed/emitted at all frequencies rather than at the discrete set we might expect from the electronic transitions in isolated atoms?   With a caveat from me:     That's a good re-statement, though I'd caution that the description need not a priori be quantum mechanical in nature - there is radiation in classical electrodynamics.


What is deadlock in programming Object Oriented ?  I had knew deadlock in transaction of Database Systems. But in programming I'm not clear.  I want to know when deadlock occur and how to resolve it.  Thanks!


What does a linear transformation do to a vector in $\mathbb{R}^2$ 1

As in the last question i had, I'm doing some linear algebra. This question has me stumped however. I can't seem to visualize it.   $$ T_{B}: R^2 \to R^2,\qquad B = 1/2 \left[\begin{array} {rr}1 & 1 \\   1 & 1 \\ \end{array}\right]. $$  What, geometrically, does the linear transformation $T_{B}$ do to a vector in $R^2$?  Thanks


It seems to me that "You are correct" means that the person in question is supposedly "correct" in their quiddity. "That is correct" or "You are right" seems a lot better.  I also would like to know if someone is using correct(ly) correctly, as to correct someone who is potentially using correctly incorrectly.


How do you improve smithing really well without using the 'iron dagger' technique?

I want Daedric armour really quick.   I am playing on the PS3.


Novel where frozen people from a lost civilisation are discovered in the arctic/antarctic

Years ago (70's or 80's) I read a sci-fi novel.  It started with the discovery in the arctic (or antarctic) of a pair of humans (male and female) frozen in a block of solid helium.  When thawed out, they revive and tell a story of an ancient high-technology civilization (back when Gondwanaland existed I seem to recall).  This civilization had access to incredible energy sources having developed a grand unified theory of everything.      In the end, they destroyed themselves in a conflict so huge that it shifted the earth on its axis.   Does anyone know what the novel was?


I can't use the "sudo" command on my server

After I edited the /etc/sudoers.d/my_sudoers file with nano I was unable to use sudo.  The following errors are giving when trying to use sudo:  sudo: parse error in /etc/sudoers.d/my_sudoers near line 4 sudo: no valid sudoers sources found, quitting sudo: unable to initialize policy plugin   I know exactly what is wrong but I have no way to edit the file since it is owned by root.  I can't use chown to change the ownership because that would involve using sudo.  pkexec has not been installed or configured on the server so I'm not sure if that is an option.  I have tried using the copy command to make a back up but I get the same errors.  Can someone please tell me how to solve this?  Please don't recommend reboot the server because that is not an option.


Obtaining "nClusters" value in Google Earth Engine

After training the kmeans model, how can i obtain the number of classes of the model? i've tried with get(), getInfo() and doesnt work.      Value that must to be extracted in "//var to_print_2 = clusterer.get('nClusters')"  // STEP 1: Import image we wish to classify var l8 = ee.ImageCollection('LANDSAT/LC08/C01/T1')  // Remove the clouds var cloud_free = ee.Algorithms.Landsat.simpleComposite({   collection: l8.filterDate('2018-01-01', '2018-12-31'),   asFloat: true })  // STEP 2: Draw your box which you will sample from!   // Make the training dataset. var training = cloud_free.sample({   region: geometry,   scale: 30,   numPixels: 5000 });  // Step 3: Create the clusterer and train it, play around with // number of classes var clusterer = ee.Clusterer.wekaKMeans(3).train(training);  print('clusterer',clusterer instanceof ee.ComputedObject);  var to_print = clusterer.getInfo();  print('clusterer_info',clusterer.toString());  print(typeof clusterer);  var clusterer_list = ee.List(clusterer);  print('clusterer_list',clusterer_list);  print(typeof clusterer_list);   //var to_print_2 = clusterer.get('nClusters');  //print(to_print_2);  //var to_print_3 = clusterer.Filter.filterMetadata('nClusters','equals',3);  //print(to_print_3);  // Step 4: Classify our image var classified = cloud_free.cluster(clusterer); print(classified); var cluster_1 = classified.eq(0); print('min',cluster_1);   // Display Map.setCenter(-122.31040963183364, 37.782065864682096, 11) Map.addLayer(classified.randomVisualizer(), {}, 'clusters');


Where do I need to change "Ubuntu" when naming my own custom distribution?

i am building my own distro (which i am almost done) but one thing left is the name of it. since i am not sure what to name it im leaving the "ubuntu" there  i know i will have to change the following files   /etc/lsb-release /etc/issue   to my own name and version and code name. am i missing other files?  (on my site it shows it's an ubuntu version - i read the tm etc... but i want the name of my distro to be there) thanks


how to display columns values in single line in sql server

How to display a single column values ofsql server in a single line or row.  and seperating each values by * symbol.  i tried this:  SELECT GROUP_CONCAT(ordernum SEPARATOR ' , ') AS File_viewer FROM Functional WHERE OrderNum Order by asc;   my column is:  **ORDERNUM** 00 NULL 00 NULL ZZ 2UN ZZ 263923720 NULL 1234 ^ 0001 000000901 0 o :


Why is 'Did anybody said something?' grammatically incorrect?

"Did anybody said something?" is an incorrect sentence grammatically, but I don't get why.  This might be an excessively silly question, but I am new to the English Language.


I have a matrix and want to reference several nodes of this matrix. How do I add a line for some of the cells?  I came up with this:  \documentclass[12pt]{scrbook} \usepackage{tikz} \usetikzlibrary{matrix}  \begin{document} \begin{tikzpicture}         \matrix (m) [matrix of nodes]         {1 & 2 & 3 & 4 & 5 \\};          \foreach \i in {0, 3}         {                 \pgfmathsetmacro\iplusone{1+\i}                 \pgfmathsetmacro\itimesfour{4*\i}                 \draw (m-1-\iplusone .south) -- node [at end] {\itimesfour} +(0, -1);         }; \end{tikzpicture} \end{document}   Which is a simplified version of what I want to do. However, this does not work and gives the error:  Package PGF Math Error: Unknown operator `s' or `so' (in '0.south').   I don't know where to start with this error at hand.


What's the quickest way to do a "clean" google search?

Currently I'm going into my account settings and switching Web History to off. I then have to go back each time and switch it on again. Is there a quicker way to be able to do a search in Google not tainted by personal results?


The galois group of polynomial ($x^5-3$) over $\mathbb{Q}$

Let the splitting field of $x^5-3$ over $\mathbb{Q}$ be $L$.  I solved the 3 statement,   $L = Q(\sqrt[5]{3}, w) (w=e^{2\pi i/5})$ $\operatorname{Gal}(L/\mathbb Q)$ has unique normal subgroup $H$ of which the order is $5$, corresponding to $\mathbb Q(w)$ by Galois theory. the fixed field of $H$ is $\mathbb Q(w)$   Then, I hit the following:   Distinguish $\operatorname{Gal}(L/\mathbb Q)$ is abelian or not The number of subgroups of $\operatorname{Gal}(L/\mathbb Q)$ of which order is $4$.   How can I solve this?


I need to analyze the output of some script  So, I know their header and their tail of some part of the output script, but not the content.  I found an approach [1] But I need something like:  $ myscript Line A Line B Line C Line D Line E Line F  $ myscript | tee /dev/stderr | <some option from C to E> > out.file  $ cat out.file Line C Line D Line E   [1] -


Currently, I read Paradise Lost of John Milton and I found a grammatical structure I have not met yet. The sentence is:     Pandemonium, the palace of Satan, rises, suddenly built out of the deep: the infernal peers there sit in council.    I have thought that "there" could be used such as:   At the beginning of a sentence following by  a verb: "There is ..." or "There lives a man who ..." A the beginning of a sentence by the subect-verb inversion in English : "There he is" At the end of a sentence: "He is in the house. He is there."    Is this form akin to middle (John Milton's) English or is it a grammatical structure I don't know?   If yes, could you say according to that grammatical structure of there "He there is"?


I don't understand why the value of foo is undefined in the following code:  var foo = 1;  function bar() {     if (false) {         var foo = 10;     }     alert("Foo is " + foo); }  bar();   Result : Foo is undefined.    Whereas these variations behave as expected.  var foo = 1;  function bar() {     if (true) {         var foo = 10;     }     alert("Foo is " + foo); }  bar();   Result :  Foo is 10  var foo = 1;  function bar() {     if (false) {        // var foo = 10;     }     alert("Foo is " + foo); }  bar();   Result: Foo is 1  Any help will be really appreciated.


Inaccurate aggregation return of double values in complex data structures

When I use the aggregation framework to get values from my database and I got complex data structures, such as arrays of struct with doubles, I get inaccurate values.   I use the ToList() on my IAsyncCursor to get my values. The double values should be such as 13.23 and in the return json string the values are like 13.2300000001 or something like that. This is just a behavior if I use this complex structures of data.  What can I do against this Inaccuracy? Am I using the false classes and methods of the csharp api?


When $(\mathbb{Q}(\zeta_n) : \mathbb{Q}) = 2$?

maybe this is a stupid question . Anyway, when $(\mathbb{Q}(\zeta_n) : \mathbb{Q}) = 2$, i.e., $\phi(n) = 2$ (where $\phi$ is the Euler's totient function)?    Thanks in advance.


A migrated question's "newness" should be based on when it was migrated

I noticed  was on the Programmers.SE for a day or so without any answers.  So, I answered it.  Not long after that, it was migrated to SO.  I was surprised to find that it was not located on the first several pages after being migrated.  It seems that it's .  A large reason for putting new questions at the top of the list is so that enthusiastic answerers can jump at the ones that interest them right out of the gate.  However, a question that's migrated is nearly hidden from these most eager answerers, because the question jumps immediately to a sad page that is normally full of questions that people have either answered or deliberately passed over.  Should newly-migrated questions get a chance at being displayed prominently along with their newly-posted counterparts?  EDIT: To be clear, I am not asking what the current behavior is (which has already been asked and answered in another question). I am asking if the current behavior best serves the SO community.


What is meant by "! Package tikz Error: Giving up on this path. Did you forget a semicolon?." when I use pgf-umlcd?

My code is   \documentclass{standalone} \usepackage{pgf-umlcd}  \renewcommand{\unidirectionalAssociation}[4] {   draw[umlcd style, ->] (#1) -- (#4)   node[near end, auto]{#2}   node[near end, auto,swap]{#3}; }  \begin{document} \begin{tikzpicture}    \begin{abstractclass}[text width = 6cm]{FileStore}{0,0}     \attribute{$\sim$ com.alhelal.textpad}     \operation{+ orderFile(file : File) : EditableFile}      \operation[0]{\# createFile(file : File) : EditableFile}   \end{abstractclass}    \begin{class}[text width = 6cm,anchor = west,xshift = 5cm]{ProgrammFileFactory}{FileStore.east}     \inherit{FileStore}     \attribute{$\sim$ com.alhelal.textpad}     \operation{+ orderFile(file : File) : EditableFile}    \end{class}    \begin{class}[text width = 11cm, yshift = -2cm]{EditableFile}{ProgrammFileFactory.south}     \attribute{$\sim$ com.alhelal.textpad}     \attribute{+ languageBehavior : LanguageBehavior}      \operation{+ options : Options}      \operation{+ getCodeAreaFromTab(tb : Tab) : CodeArea}      \operation{+ saveFile(fileTabArrayList : ArrayList$<$FileTab$>$, option : Options)}     \operation{+ printFile(node : Node)}     \operation{+ toggleLineNumber(cd : CodeArea)}     \operation{+ setLanguageBehavior(langBehavior : LanguageBehavior)}     \operation{+ performRunCode(file : File)}     \operation{+ performBuildCode(file : File)}     \operation{+ performSetHighlightableText()}     \operation{+ performSetAutocompletableText()}   \end{class}    \begin{class}[text width = 3.5cm,anchor=north east,yshift = -2cm, xshift=-6cm]{TextFile}{EditableFile.south west}     \inherit{EditableFile}     \attribute{$\sim$ com.alhelal.textpad}   \end{class}    \begin{class}[text width = 3.5cm,anchor=north east,yshift = -2cm, xshift = -1.5cm]{CFile}{EditableFile.south west}     \inherit{EditableFile}     \attribute{$\sim$ com.alhelal.textpad}     \attribute{-path : String}   \end{class}    \begin{class}[text width=3.5cm,anchor=north west,yshift = -2cm,xshift=-3cm]{CplusFile}{EditableFile.south}     \inherit{EditableFile}     \attribute{$\sim$ com.alhelal.textpad}   \end{class}    \begin{class}[text width  = 3.5cm, anchor = north west, yshift = -2cm, xshift = -4cm]{JavaFile}{EditableFile.south east}     \inherit{EditableFile}     \attribute{$\sim$ com.alhelal.textpad}   \end{class}    \begin{class}[text width = 3.5cm,yshift = -2cm,xshift = 1cm]{PythonFile}{EditableFile.south east}     \inherit{EditableFile}     \attribute{$\sim$ com.alhelal.textpad}   \end{class}    \begin{class}[text width = 3.5cm, anchor = north west, yshift =-2cm,xshift = 5cm]{LaTeXFile}{EditableFile.south east}     \inherit{EditableFile}     \attribute{$\sim$ com.alhelal.textpad}   \end{class}   \unidirectionalAssociation{ProgrammFileFactory}{}{$<<$instantiate$>>$}{EditableFile}   \node [above=3mm] at (current bounding box.north) {Factory Method Pattern} \end{tikzpicture} \end{document}   I run this using pdflatex in terminal that results in


How to setup proxy server on XP to test software?

I need to test some software using a proxy server. The software communicates over the network using http and I need to ensure that it works in enviornments that use proxy servers.  How can I setup a proxy server in XP?


Pull mysql rows with max value of specific column in group


When to post on Stack Exchange meta, when to post on [site] meta

After browsing some questions here some of them are site specific. Should they be posted here or on that site's meta?  If you post it here the question could get more attention from a wider audience but otherwise I’m not sure.


How prove this two symmetric matrices $AB=0$

Let $A,B$ be real symmetric matrices, and for any $n\in \Bbb N^{+}$, and for all $x,y\in \Bbb R$, we have $$tr(xA+yB)^n=x^ntr(A^n)+y^ntr(B^n).$$  Show that $AB=0$.  My try:since $$(xA+yB)^n=x^nA^n+\binom{n}{1}x^{n-1}A^{n-1}yB+\cdots+\binom{n}{n-1}xA(yB)^{n-1}+y^nB^n$$ so $$tr\left(x^nA^n+\binom{n}{1}x^{n-1}A^{n-1}yB+\cdots+\binom{n}{n-1}xA(yB)^{n-1}+y^nB^n\right)=x^ntr(A^n)+y^ntr(B^n)$$  then  $$tr\left(\binom{n}{1}x^{n-1}A^{n-1}yB+\cdots+\binom{n}{n-1}xA(yB)^{n-1}\right)=0$$ so $$\binom{n}{1}x^{n-1}ytr(A^{n-1}B)+\cdots+\binom{n}{n-1}xy^{n-1}tr(AB^{n-1})=0$$ then I can't  I found this is a nice result, maybe this is an odd problem, and I can't solve it. Thank you.


Value of float is different from what was scanned

So I have this program in which I need to compare values in 0.0X range and if I scan for example 50.21 with this little thing  scanf("%f",bill);   the value stored in var. bill is actually 50.2099990845... which messes up calculations later in program. Is there any way to turn this number into 50.210000? Thanks for your time.


Proving that $\int_0^1 f(x)e^{nx}\,{\rm d}x = 0$ for all $n\in\mathbb{N}_0$ implies $f(x) = 0$

I'm trying to show that if $f$ is a continuous function on $[0,1]$ and $\int_0^{1} f(x)e^{nx}\,{\rm d}x = 0$ for all $n = 0, 1, 2, \dots$, then $f(x) = 0$.  I'd like to use Weierstrass approximation theorem to find a sequence of polynomials $p_m$ that converge uniformly to $f(x)$. Then we could say $\lim\limits_{m\to \infty} \int p_m(x)e^{nx}\,{\rm d}x = \int f(x)e^{nx}\,{\rm d}x = 0$, but I'm struggling to deduce that then all the $p_m$ are zero which would give the result.


Scheduling a team based activity with 10 different teams and X different games. Every team must meet each other ONCE but never twice,

Hi there I am planning a ”Scavenger hunt”-like activity (I have no other words for this event), and I am having trouble creating the schedule.   The idea of this hunt/run/game/competition is that 10 teams will battle each other at X different mini games. The games on are team vs. team based, meaning that there will always be two teams on each post and one winner and one loser.  I require that every team fights every other team. Meaning that team 1 will have to meet team 2, 3, 4, 5, 6, 7, 8, 9, and 10, and team 2 will have to meet team 1, 3, 4, 5, 6, 7, 8, 9, 10 (and so forth). The amount of mini games must be so, that every team only meets the other teams ONCE each, but still they have to meet every team.  How many posts do I need to create, and how could I schedule the overall activity? (A table of rounds and teams would be much appreciated).


How to import a data with unknown coordinate system to a data with known coordinate system

I have recieved a Group of shape files with unknown coordinate System. The coordinates are like: 536605 , 5658923 and I can not find the corresponding projection/coordinate System. It looks like that the data has been from dxf to shp converted. I have tried to Change their coordinate to the one I need  (ETRS_1989_UTM_Zone_N32) in Arc Catalog. When I add them to the mxd for the data with coordinate System, still they would have shift and do not place correctly. I tried to change it now in a new mxd to UTM32N and it comes a bit closed but still is in another ocation. what other Options I have to correct this data?  I use ArcGIS 10.5 but the toolboxes of projection and Transformation are not available.


Blender crash while rendering image after building BVH

Once render is started, the building BVH value goes to 100% and then the whole Blender program gets closed ! What could be the reason ?


Can I configure Remote Desktop Connection for multiple users in the same time?

How  I  can have a multiple users Remote Desktop Connection to a Windows Server in the same time ?


I have the database filled with some data (added from command line), i setup encoding of the database to utf-8 as well as my website is.  But the output from the database where special chars like "š" etc. is outputted as "�", so what have I done wrong or what should I add? I am siply ECHOing as echo $row['title']; etc.


How to set up wireshark with correct permissions

Ubuntu 13.10, Saucy Salamander here. I am trying to install wireshark in order to monitor USB activity with a certain device. The problem is that wireshark does not have access to the USB bus (or any bus, for that matter, no interfaces show up).   they describe, that wireshark can be run either as root, or as an ordinary user. I tired executing dpkg-reconfigure wireshark-common but after the dialog, nothig happens, and I don't know why.   an alternative procedure for other Linux users (non-Debian) is outlined. I haven't tried it, as the dpkg method is the recommended one for Ubuntu and I would like to know what is going wrong.  Where should I look?


"Studying PhD at the university" or "studying PhD in the university"?

Which of these two sentences is correct:        I am studying PhD at the university.   I am studying PhD in the university.      Should I use "at" or "in"? Or is there no difference?


how to get multiple cell values in a single cell in sqlserver

i want to get all the employee names in one cell in sqlserver. values should come with comma separated in one cell.  output arvind chang deepak   desired output  Arvind, Chang, Deepak   query   select EmpName from Employee


if subsequence of even terms and odd terms both converge to L, prove the whole sequence converge to L

if ${S_n}$ is a sequence of real numbers and if  $$\lim_{2m \to \infty} S_{2m} = L$$  $$\lim_{2m-1 \to \infty} S_{2m-1} = L$$  then prove $$\lim_{n \to \infty} S_{n} = L$$   This is how I began: let $\epsilon>0$ There exists $N_1\in\mathbb{N}$ s.t $|S_{2m}-L|<\epsilon$ for all $m\ge N_1$ and  There exists $N_2\in \mathbb{N}$ s.t $|S_{2m-1}-L|<\epsilon$ for all $m\ge N_2$   Now let $n=\text{max} \{N_1 , N_2\} $ ( my curly brackets do not show. sorry about that ) Now I guess I have to prove that  $|S_n-L|<\epsilon$ for all $n \ge m$ But I am not sure how to do that. or even have I been correct in the beginning? I will appreciate your help with this question .


Inheritance or delegation? Which one to pick?

Sometimes there is no doubt, but sometimes it can be a very hard decision. Let me show you a couple of examples:  Inheritance:  public class Employee{     public void goToWork(){         //...     } } public class Lawyer extends Employee{     //private Employee body;     /*public void goToWork(){         body.goToWork(); // Does that make any sense?     }*/ }   Delegation:  public class Lights{     public void turnOn(){         //...     } } public class Car{ //public class Car extends Lights? Nice car then...     private Lights light;     public void turnOnLights(){         light.turnOn();     } }   Which one?  public class Field{ public void grow(Seeds s){         //...     } } public class Plantation{ //extends Field{ makes sense too     private Field field;     private Worker[] workers;     private Vehicle[] tractors;      public void grow(Seeds s){         //...         field.grow(s);     } }   So, are there any tips that can help to choose between inheritance and delegation when both are acceptable and each one has their own advantages and disadvantages? Is the choice random and totally based on programmer's mood?


I want to check email by using regular expression.I checked ([-\w.]+@[-\w.]+.[_-\w.]) for email regular expression.But "character class may not be used inside character range" error occurs.How can I do that?


Here is my program:  import datetime  b=input() a = datetime.date(b)-datetime.datetime.now().date()  print(a)   When I enter the date 2015,2,2, or some another, I have a problem  Traceback (most recent call last):   File "", line 4, in <module>     a = datetime.date(b)-datetime.datetime.now().date() TypeError: an integer is required   How to input the date right? I tried 2015-2-2 and 2015.2.2 and 2015-2-2 and other versions. But nothing works :(


Java Regex Matcher encountering NullPointerException, when handed null input

I am trying to use the java regex matcher-class and I'm encountering a NullPointerException in my code:  String input = null; System.out.println("\nEnter your username: "); Matcher matcher = VALID_USERNAME_REGEX.matcher(input); //EXCEPTION IS HERE if (matcher.find()) {     username = input; } else {     input = null;     System.out.println("\nInvalid input, please try again!"); }   Stack Trace: (line: 173 is in the above code where the comment "//EXCEPTION IS HERE" is located)  Exception in thread "main" java.lang.NullPointerException     at java.util.regex.Matcher.getTextLength(Unknown Source)     at java.util.regex.Matcher.reset(Unknown Source)     at java.util.regex.Matcher.<init>(Unknown Source)     at java.util.regex.Pattern.matcher(Unknown Source)     at org.console.Interface.createAccount(Interface.java:173)     at org.console.Interface.login(Interface.java:78)     at org.application.Application.run(Application.java:31)     at org.application.Application.main(Application.java:37)   The value of the input should be what the user enters in the console. The regex should match the input to validate that it meets the regex requirements.


On my Toshiba Encore 8 Tablet I noticed that the CPU usage is very high. In Taskmgr / ProcessExplorer, I can see that OneDriveSetup.exe is hogging 1 CPU cores heavily for hours.    How an I solve this hang and finish the OneDrive Update?


root@server # tar fcz bkup.tar.gz /home/foo/ tar: Removing leading `/' from member names   How can I solve this problem and keep the / on file names ?


The scale in Qgis is not setting to feet

I am working in QGIS 2.4. I have changed the CRS of all the layers and in the project properties to EPSG:102739 - NAD_1983_StatePlane_Texas_Central_FIPS_4203_Feet.   I am in print composer trying to create a scale bar and I can not figure out why the scale is so off. I am trying to go from feet to miles and it just creates a really long scale bar. Basically 1 mi = 5280 is what I am going for I have already checked each layer and they are all in state plane 4203. I am not sure what I am missing. I checked other threads about scale in QGIS and I am still at a loss. I have tried flipping the conversion around and its still not working.   Edit 2: Sounds crazy is there a difference between Qgis for Windows and for Linux. I loaded the exact same data(just copied and pasted the file with the map and data) to a windows computer. Opened it and everything works fine.   Edit: The answer given  does not address my issues. I have already done everything in that answer. All of my layers have been resaved with projection and the project projection has been changed.


error with LuaLaTeX, lstinputlisting and an extension-less file

I'm having troubles with LuaLaTeX and the listings package: the former doesn't seem to accept me performing \lstinputlisting on a filename that doesn't have an extension.  Minimal example:  Makefile:  hello: hello.c     cc -o hello hello.c   test.tex:  \documentclass[a4paper]{article} \usepackage{listings} \begin{document} \lstinputlisting{Makefile} \end{document}   pdfLaTeX is successful, LuaLaTeX displays the following error:  ! Package Listings Error: File `Makefile(.tex)' not found.  Type X to quit or <RETURN> to proceed, or enter new name. (Default extension: tex)  Enter file name:   I'm using the freshest versions from TeXLive 2012 (pdfTeX 3.1415926-2.4-1.40.13, LuaTeX beta-0.70.2-2012052410).  What's the trouble?


sufficient condition for a polynomial to have roots in $[0,1]$

Question is to check :  which of the following is sufficient condition for a polynomial   $f(x)=a_0 +a_1x+a_2x^2+\dots +a_nx^n\in \mathbb{R}[x] $ to have a root in $[0,1]$.   $a_0 <0$ and $a_0+a_1+a_2+\dots +a_n >0$ $a_0+\frac{a_1}{2}+\frac{a_2}{3}+\dots +\frac{a_n}{n+1}=0$ $\frac{a_0}{1.2}+\frac{a_1}{2.3}+\dots+\frac{a_n}{(n+1).(n+2)} =0$   First of all i tried by considering degree $1$ polynomial and then degree $2$ polynomial and then degree $3$ polnomial hoping to see some patern but could not make it out.  And then, I saw that $a_0= f(0)$ and $f(1)=a_0+a_1+a_2+\dots +a_n$.  So, if $f(0)<0$ and $f(1)>0$ it would be sufficient for $f$ to have root in $[0,1]$  In first case we have $a_0 <0$ i.e., $f(0)<0$ and $f(1)>1>0$.  So, first condition should be implying existence of a root in $[0,1]$  for second case, let $f(x)$ be a linear polynomial i.e., $f(x)=a_0+a_1x$  Now, $a_0+\frac{a_1}{2}=0$ implies $0\leq x=\frac{-a_0}{a_1}=\frac{1}{2}< 1$ So, this might be possibly give existence in case of linear polynomials.  Now, $\frac{a_0}{1.2}+\frac{a_1}{2.3}=0$implies $0\leq x=\frac{-a_0}{a_1}=\frac{1}{3}< 1$ So, this might be possibly give existence in case of linear polynomials.  So, for linear polynomials all the three conditions imply existence of a root in $[0,1]$.  But, i guess this can not be generalized for higher degree polynomial.  I think there should be some "neat idea" than checking for roots and all.  I am sure about first case but I have no idea how to consider the other two cases.   please provide some hints to proceed further.


It seems that when someone drops their saber it turns off, but Lukes hand still gripped his when his hand got chopped. Why did it extinguish?


Starting Tasks In foreach Loop Uses Value of Last Item

I am making a first attempt at playing with the new Tasks, but something is happening that I don't understand.    First, the code, which is pretty straight-forward.  I pass in a list of paths to some image files, and attempt to add a task to process each of them:  public Boolean AddPictures(IList<string> paths) {     Boolean result = (paths.Count > 0);     List<Task> tasks = new List<Task>(paths.Count);      foreach (string path in paths)     {         var task = Task.Factory.StartNew(() =>             {                 Boolean taskResult = ProcessPicture(path);                 return taskResult;             });         task.ContinueWith(t => result &= t.Result);         tasks.Add(task);     }      Task.WaitAll(tasks.ToArray());      return result; }   I've found that if I just let this run with, say, a list of 3 paths in a unit test, all three tasks use the last path in the provided list.  If I step through (and slow down the processing of the loop), each path from the loop is used.  Can somebody please explain what is happening, and why?  Possible workarounds?


I am trying to create a table in bash - I have collected all headings into a var - however when I print these strings enclosed in "'s are treated as new columns and not as one by the printf command When I pass the same values directly it works fine, but I get different behavior when I use $var instead. $ printf '%-20s' "some spaced words" other values; echo -e "\n" some spaced words   other               values  $ values='"some spaced words" other values' $ echo $values "some spaced words" other values $ printf '%-20s' $values; echo -e "\n" "some               spaced              words"              other               values   I'm clearly misunderstanding something about how my variable is different to < some string > and therefore results in the different behavior. How do I get the output that matches output 1 when using a variable? edit: I can see the var version has the quotes - is there a way I can pass quoted strings to printf as a variable?


Send authenticated mail without editing DNS records

How can a mail server send authenticated mail (using DKIM, SenderID, SPF etc) without adding records to the sending domain name's DNS server?  I've read  to sending mail so it doesn't end up in spam. I've also read many other articles on the topic, but they all need modification of sending domain name's DNS server.  I'd like to create these records on my mail service's domain name, but authenticate mail from other domain names. MailChimp does this, where you can send mail from any email address (after email verification), but don't need to edit DNS records.  There's  which refers to MailChimp setting the Reply-to: header and sending From: a MailChimp email address, but I've checked some campaigns sent to me, and the From: is not a MailChimp address, but the sender's address.  EDIT:  of the headers from a MailChimp campaign as seen in Gmail  Can anyone shed some light on how this is done?


Is the list of badges standard across all Stack Exchange sites? Or can one site have a different set of badges?  This question asked on behalf of


Principal components with and without centering

Suppose that I am given various samples of a vector random variable as the columns $v_1,v_2,\dots,v_n$ of a certain matrix $A$. Is there a relation between  the SVD $A = USV^T$ the SVD $\hat{A} = \hat{U}\hat{S}\hat{V}^T$, where $\hat{A}$ is the 'de-meaned' version of $A$, i.e. the matrix with columns $\hat{v}_j = v_j - \frac{1}{n}\sum_{k=1}^n v_k$.  If I understand correctly, when doing principal component analysis one typically uses the latter, because that is the matrix such that $\hat{A}\hat{A}^T$ is the covariance matrix of the $v_j$. Would it make a big difference to use the former instead? Is there an algebraic relation between the two sets of singular values and vectors obtained? Is one considered more meaningful than the other in practice?


They did not tell me anything about the matter.     a) Nothing was told me about that matter.      b) Nothing was told about this matter to me.   Which one is the correct answer? I prefer #b as ''about this matter '' is more important than ''to me''.


How to find a reputable open access journal?

I found few open access journals that show quite good quality articles. However, I have been advised that open access journals may be predatory. When I searched websites, I was surprised that all lists are "possibly" predatory journals. I tried to figure out why these lists are "possibly" predatory. One of the answers is that the websites claiming predatory publishers attempt to avoid judicial consequences. On the other hand, I also found that editors from the conventional publishers could have conflict of interests with competing open access publishers. I am completely puzzled and do not know if these lists of "possibly" predatory journals are due to conflict of interests or due to commercial interest of the open access journals. I want to publish my research paper timely and do not know if I should choose an open access journal. And, if yes, then how to find a reputable open access journal? Please advise.


Recent commitments means one of our group cannot attend our once monthly DnD game for a few weeks. We are in the middle of a campaign, a close knit group and we are usually always present at every meeting (there's only 4 of us). In the player's absence, we have done a few non-DnD evenings but we're all itching to get back into it, so it's been decided we'll do a little mini quest to scratch the DnD itch whilst one of our group is away. The players do not want to re-roll new chars. They want to play as their existing PCs.  I am unsure how best to proceed.    I could carry on from where we left off in the story and just somehow explain the absence of the PC for a while. This will take some story manipulating and will definitely feel contrived in some respects. Or... I could wind the clock back to an earlier time to do some quest that is assumed to have happened in the past but we just never actually looked at it before. Again, a little contrived but possible.   I would love to hear some of your experiences of handling this problem and any other ideas you may have for side quests that don't derail the main story but also don't require a whole lot of story wrangling.


I got the brand new Custodian badge today for reviewing posts. Inspired by that, I reviewed some more suggested edits. Now I ran into a limit:     You have no more suggested edit votes today; come back in x hours.   How is that limit calculated? I made 61 reviews today which seems to be some calculated limit.  I searched for an answer on meta but found nothing helpful.


How to escape text for regular expression in Java

Does Java have a built-in way to escape arbitrary text so that it can be included in a regular expression? For example, if my users enter "$5", I'd like to match that exactly rather than a "5" after the end of input.


Android Java null pointer exception even if object instantiated

I have this code in an Android activity;  public static TwoWeeksActivity context; public static DBHelper dbHelper;  @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.activity_two_weeks);      RadCartesianChartView chartView = new RadCartesianChartView(this);      ViewGroup rootView = (ViewGroup)findViewById(R.id.container);     rootView.addView(chartView);      ArrayList<DateCountChart> vvv=new ArrayList<DateCountChart>();      vvv=dbHelper.getCigCountTwoWeeks();   When I execute the app, when it arrives at tthis last line it returns java null pointer exception.  Why vvv is null? I have instantiated it:  ArrayList<DateCountChart> vvv=new ArrayList<DateCountChart>();   Please note that   dbHelper.getCigCountTwoWeeks();   function in in dbhelper returns       ArrayList of DateCountChart object  Any help appreciated.


I tried to install Netflix on Ubuntu 20.04 and now it gives me some errors

whenever I try sudo apt-get update it give me an error. Here is what it says. (including the download). Ign:1 http://ppa.launchpad.net/ehoover/compholio/ubuntu focal InRelease Hit:2 http://dl.google.com/linux/chrome/deb stable InRelease                    Hit:3 http://ppa.launchpad.net/maarten-fonville/android-studio/ubuntu focal InRelease Hit:4 http://ca.archive.ubuntu.com/ubuntu focal InRelease Hit:5 http://ca.archive.ubuntu.com/ubuntu focal-updates InRelease         Err:6 http://ppa.launchpad.net/ehoover/compholio/ubuntu focal Release   404  Not Found [IP: 91.189.95.85 80] Hit:7 http://ca.archive.ubuntu.com/ubuntu focal-backports InRelease Hit:8 http://ca.archive.ubuntu.com/ubuntu focal-security InRelease Reading package lists... Done E: The repository 'http://ppa.launchpad.net/ehoover/compholio/ubuntu focal Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.


Book set on an alien planet with a symbiotic plantlife

I'm trying to find the name of a science-fiction book I read at least 20 years ago (late 1990s), though it was most likely a second hand book so I can't say how much older than that it might be. I can only remember a few details though some are quite specific:   It was mostly (possibly completely) set on a recently colonized planet (not in our solar system) The planet had some kind of plant or fungus that covered most of the surface This plant formed some kind of symbiotic link with the human colonists, making them more empathetic and reduced conflict There was some kind of galaxy spanning religion that was specifically against forms of mind control (and so distrusted what this plant was doing) One very specific part of this religion I can remember, is that the members didn't cut their hair because someone long dead that they viewed as a prophet said something along the lines of "Don't let anyone mess with your head" which they took to mean condemn mind control plus don't cut your hair!   The only other thing I can remember is that this plant/fungus was completely benign and I think ended up with one of the religious types being "infected" and realizing this.


What methods can be used to micro-adjust autofocus of a camera body to a particular lens?

I have a Canon 7D with a 50mm f/1.4 lens, and I think the auto-focus of the lens is off.  How can I test and adjust this reliably?  Will this approach work with all of my lenses? If I had a different camera body, would I have other/different options?


Why don't electrons and protons collide?   Hydrogen atoms are often ionized. After ionization, it is divided into electrons and protons, which can merge into hydrogen atoms at any time.  Why don't electrons crash on protons?  According to Coulomb's law, when they are getting closer, they attract more and more. One of the most possible choices is to crash.   This is not a duplicated question. Because instead of talking about the structure of atoms (why electrons don't crash nuclei), we're talking about why they don't merge together because of the Coulomb attraction when electrons are close to protons.


Is there a way to automatically change my keyboard language when I switch between windows on macOS?

For example, when I use the Messages app in which I use one keyboard, and in Xcode, I use only English keyboard. Can macOS switch my keyboard to English when I make the Xcode window active?


I used locate <filename> in order to see where are all the files with <filename>. Is there a command to delete all the files with that <filename>? For example, I want to delete all the files with the name qownnotes as in image


Isomorphism map between $\frac{\mathbb{Z}_3[x]}{(x^2+x+2)}$ and $ \frac{\mathbb{Z}_3[x]}{(x^2 + 1)} $

$\frac{\mathbb{F}_3[x]}{(x^2+x+2)} \cong \frac{\mathbb{F}_3[x]}{(x^2 + 1)} $ I know $\frac{\mathbb{F}_3[x]}{(x^2+x+2)} $ and $ \frac{\mathbb{F}_3[x]}{(x^2 + 1)} $ is isomorphic because they are both 2-degree extension of $ \mathbb{F}_3 $ . But I cannot contract explicit isomorphism between them.  Could you show me isomorphism map between $\frac{\mathbb{F}_3[x]}{(x^2+x+2)}$  and $ \frac{\mathbb{F}_3[x]}{(x^2 + 1)} $?  Thank you for your help.


We all know that we have system users and service users. I am looking for a way to separate them as system users and service user list.  Is there any way ?


How to work with changing element id in the html code

I am working in a ERP where the elements id are changing/rotating randomly. so if I am writing a code to locate a id, next time I run the selenium code it gets me error as the id changes by that time  How to capture the ids everytime


Proving continuous image of compact sets are compact

How to prove: Continuous function maps compact set to compact set using real analysis?  i.e. if $f: [a,b] \rightarrow \mathbb{R}$ is continuous, then $f([a,b])$ is closed and bounded.   I have proved the bounded part. So now I need some insight on how to prove $f([a,b])$ is closed, i.e. $f([a,b])=[c,d]$. From Extreme Value Theorem, we know that $c$ and $d$ can be achieved, but how to prove that if $c < x < d$, then $x \in f([a,b])$ ?  Thanks!


I'm trying to continue the numbering of examples in enumerate environments in beamer. For example, I'd like one slide to feature   Foo Bar   and the next slide   Zip Yadda   My strategy so far has been to define a counter that saves the enumerate counter at the end of the first environment and can then be queried to set the enumerate counter at the start of the second enumerate environment. (This is essentially the proposal also found at )  That works wonderfully so long as I don't try to uncover elements of the slide sequentially. The problem, of course, is that as each of the pdf-pages that make up the slide is created, the counter is advanced. Here's a MWE.  \documentclass{beamer}  \setbeamercovered{highly dynamic}  \newcounter{saveenumi} \newcommand{\seti}{\setcounter{saveenumi}{\value{enumi}}} \newcommand{\conti}{\setcounter{enumi}{\value{saveenumi}}}   \begin{document}  \begin{frame}[<+->]   \begin{enumerate}   \item foo   \item bar%     \seti   \end{enumerate} \end{frame}  \begin{frame}[<+->]   \begin{enumerate}     \conti   \item zip   \item yadda%     \seti   \end{enumerate} \end{frame}  \end{document}   As the second slide is progressively uncovered (pages 3 and 4 of the resulting PDF), the counter at the beginning of the enumerate environment is advanced each time. So page 3 of the PDF has the right numbering, (3) and (4) respectively, while the fully revealed page has the wrong numbering. Pictures follow:   on one of the slides    on the following one


Updating / Indexing auto generated 1 million pages after around two years

I have auto generated 1 million page website. Pages are Something like  (Feel fee to remove the URL if it is against SE TOC)....... Now website is almost two years over. And I received around 5000 organic views per month. There is no increase of traffic last 6 month... I mean traffic is almost same in last 6 month. The questions I have.........  Even it has one million pages Google indexed only around 40,000 pages still. (Yes, I have submitted multiple site maps) Why Google not indexed other pages even after two years gone?  If I update (all pages will be updating), will Google notice that I have updated all pages? If not what can I do about it?  5000 organic views per month is not enough to just cover the hosting fee. So I need to increase traffic little bit. Is there anything can I do to increase traffic which is not in the  ? I asked this question because I can't apply most of the points in above question because this is a auto generated  content.


When deriving $d\sin\theta=n\lambda$ are the light rays approximately parallel or actually parallel?

In learning to derive the diffraction grating equation to form an interference pattern on a screen parallel to the diffraction grating, this kind of image is used extensively:    Then as normal, $AB = d$, $AC = n\lambda$ then $d\sin\theta = n\lambda$  This assumes the lines are parallel. However, in every derivation I've searched, it states this, but not if this is an approximation as my intuition states:  My possibly flawed understanding is that these 3 light rays shown in the picture would converge onto a single point and constructively interfere, creating a maxima, however this means that these light rays aren't parallel.  Is there something I'm missing? Are they parallel enough to ignore the small differences in angles, or are they actually parallel?


If $f,g$ are holomorphic in an open connected set $U$ and for some $z_0\in U$ we have $|f|+|g|\leq|f(z_0)|+|g(z_0)|$ then $f$ and $g$ are constant

I want to prove the statement of the question. I know we should apply some form of the maximum modulus principle, however, I don't know which function to pick, because the absolute values are quite distracting.  I think the first step to prove this is to see that $f+g$ is constant. For that, we could restrict our attention to a disc $D(z_0;R)\subset U$ for a suitable $R>0$ since the latter is an open subset. If we can prove that $f+g$ is constant in that disc, we can conclude from the identity theorem that it must be constant in the whole $U$. By the maximum modulus theorem we can obtain a $z_1\in\partial D(z_0;R)$ such that $$|f(z)+g(z)|\leq|f(z_1)+g(z_1)|$$ And from the triangle inequality $$|f(z_0)+g(z_0)|\leq|f(z_1)+g(z_1)|\leq |f(z_1)|+|g(z_1)|\leq |f(z_0)|+|g(z_0)|$$ However, I don't know how to conclude from this that we must get $|f(z_0)+g(z_0)|=|f(z_1)+g(z_1)|$, and hence that $f+g$ is constant on $D(z_0;R)$.  But once we prove that $f+g$ is constant, how should we proceed to prove that both $f$ and $g$ are constant? My idea is that if both are not constant functions, we should deduce from the hypothesis they must attain some local maxima in $U$, which cannot happen if those aren't constant functions.  Thanks in advance for your help.


How to store and receive variables in WP sessions?

I have a form with some checkboxes and inputboxes selectboxes and it shows what the user wants via an ajax call. The problem is that when the user click on the item and the detail page is shown and then decide to go back to the previous page he needs to click and select his previous choice again.  I would like to make WP to store all the options in the session when the button to the detail page is clicked and save actual info in the session and then when he visits the page again the  values will be chcecked in sessions and set if any are found.  Could that be done in WP?  If yes, how?  Let's oversimplify that and say that we have something like this in our form:  <input class="car_color" type="checkbox" name="car_color" value="1" /> <input class="car_color" type="checkbox" name="car_color" value="2" /> <input class="car_color" type="checkbox" name="car_color" value="8" /> <input class="car_color" type="checkbox" name="car_color" value="4" /> <input class="car_color" type="checkbox" name="car_color" value="6" />   I don't use submit button in my form, it's handled via AJAX on input change.  And in my results get via ajax I have a link to the detail page:  <a class="detail-info-link" href="<?php echo $url ?>">   Any idea how can I store my values in Session and call them when revisiting/reloading/back button in the browser?  I need to be able to read the session stored stuff and use it via ?Javascript? and trigger my search fuction via ajax which is already working well.  I just need to store (probably before going to $link in href of by detail button and read and send session variables (if they exist).


How do I replicate installed package selections from one Debian system to another? (Debian Wheezy)

I am trying to set up a staging environment in a VM, in order to test updates before applying them to my main system.  In order to do so, I have done a basic installation of Debian Wheezy (same as on the main system) in the VM, then ran as root from within the VM:  # dpkg --clear-selections # dpkg --add-architecture i386 # apt-get update # ssh me@main-system 'dpkg --get-selections | grep -v deinstall' | \   dpkg --set-selections   The i386 architecture is unfortunately needed in my case; the system is amd64 native.  The problem is with dpkg --set-selections run in the VM. I do have some packages that require special handling (those are actually the main reason why I want a staging environment in the first place) but when I run the last command above, I get about a gazillion lines of output like:  dpkg: warning: package not in database at line NNN: package-name   for packages that really should be available in the base system. Examples include xterm, yelp and zip.  Now for my question:  What is the specific process for transferring the package selection list from one Debian system to another (assuming same Debian release level, in Wheezy) and then subsequently applying those changes? The goal is that both have the same list of installed packages, ideally such that doing a diff between the outputs of dpkg --get-selections or dpkg --list on the two comes back showing no differences.  The grep -v deinstall part is borrowed from  over on Ask Ubuntu.  I have changed the source in the VM to be the same as on the main system, also installing apt-transport-https:  deb https://ftp-stud.hs-esslingen.de/debian/ wheezy main non-free deb-src https://ftp-stud.hs-esslingen.de/debian/ wheezy main non-free deb https://ftp-stud.hs-esslingen.de/debian/ wheezy-updates main non-free deb-src https://ftp-stud.hs-esslingen.de/debian/ wheezy-updates main non-free deb [arch=amd64] http://archive.zfsonlinux.org/debian wheezy main   Looking at the --set-selections output, I'm seeing:  dpkg: warning: package not in database at line 1: a2ps dpkg: warning: package not in database at line 1: abiword dpkg: warning: package not in database at line 1: abiword-common dpkg: warning: package not in database at line 1: abiword-plugin-grammar dpkg: warning: package not in database at line 1: abiword-plugin-mathview dpkg: warning: package not in database at line 1: accountsservice dpkg: warning: package not in database at line 1: acl dpkg: warning: package not in database at line 4: aglfn dpkg: warning: package not in database at line 4: aisleriot dpkg: warning: package not in database at line 4: alacarte dpkg: warning: package not in database at line 4: alien ...   The line numbers looked odd, and the corresponding portion of the output of --get-selections is:  a2ps install abiword install abiword-common install abiword-plugin-grammar install abiword-plugin-mathview install accountsservice install acl install acpi-support-base install acpid install adduser install aglfn install aisleriot install alacarte install alien install   Notice that in between acl and aglfn are acpi-support-base, acpid and adduser for which no errors are being reported. It seems that the packages for which errors are being reported are either un according to dpkg -l, or dpkg -l doesn't have any idea at all about them (dpkg-query: no packages found matching ...). I know there are some locally installed packages, but not many. i386 doesn't figure until gcc-4.7-base:i386 install much farther down the list (line 342 in the --get-selections output).


does anyone know good books and/or other sources of information regarding black hole mathematics/physics? Currently I'm reading the black hole wars by Leonard Susskind; it seems to be a collection of general explanations rather than a mathematical resource.


Let $A$ and $B$ be two sets. Prove the existence of an injection from $A$ to $B$ or an injection from $B$ to $A$.  I don't know how to proceed, since I don't have any information on $A$ or $B$ to begin with.  Does anybody have a hint ?


What is the best design for a table that contains many columns?

I designed a table to display a set of data, some take up a lot of space, and the table contains many columns .. Because of that I had no space to display the rest of the columns


Is most of the human genome functionless “junk DNA”?

In January 2012, David Icke published a book (ISBN: 9780955997334) entitled “Remember where you are and where you come from” in which he challenged what he claimed to be the view of mainstream science that 90–97% of the human genome was , serving no function. He implied, instead, that it must have a function, but that this was unknown.  Is it still true that we do not know what all this DNA does? I see that we consider this DNA to be non-coding, but does that mean it is “junk”? I find it hard to believe that it can serve no function, otherwise why would the DNA be there? Is it possible that it is used for things we don't yet understand?


I am simply attempting to install Neofetch in Ubuntu 20.04, but the above image shows that I am unable to. What should I do? Any help is appreciated.


How to get the number of elements of a C-array like this?

I have a C-array like this:  double arr[] = {     0.0,    0.1, 0.2, 0.5,     0.1,    0.2, 0.3, 0.4,     0.2,    0.0, 0.1, 0.3 };   Is it safe to get the number of elements like this?  int numElements = sizeof(arr)/sizeof(arr[0]);   Or is there a better way?


How to convert column to row in SQL Server

I would like to convert following data  CLAIMID CODENUMBER ------------------ 2          465.9 2          238.8 2          461.9 2          786.2   Would like to see as  CLAIMID ICD1    ICD2    ICD3    ICD4 2       465.9   238.8   461.9   786.2   Your help will be appreciated..