How do extension tubes affect focusing distance? More specifically, what I mean to ask is : why does the maximum focusing distance become shortened when an extension tube is attached? - Why does the maximum focusing distance become reduced (from infinity to XYZ)? I don't understand why moving the image plane further back would have any effect :( On a related topic, am I correct in stating that the reason the minimum focusing distance decreases (when a lens is used with extension tubes) is because the lens's focal length stays the same, but the light has to travel further to reach the sensor/film? Does that make any sense, it does (kinda) in my head - but I am a silly person aha ;)   I should make it apparent that I have tried to look for an answer, but I have yet to find an explanation. I have read from multiple sources e.g. (   ,  )  If you could provide a basic answer as well as a more technically savvy answer that would be greatly appreciated :) Also, I know it is a lot to ask, but you guys please provide a picture or a video in your answer? <3 :)  I would like to thank you all in advance for your answers and support! :)


Which thing/component does increase the current on same volt in the charger

What causes a mobile phone charger or any adapter to increase the current on same voltage. I saw that chargers are rated with different amp on same volt ( 5v.1A 5v,500ma 5v,250ma).  Ohm law says (V=IR) I am confused....!!!


City/Street Photography; is it morally okay and what laws govern it?

I love to take photos of people in urban areas; buildings, houses, cars, motion, expression... everything. However, taking photos of people and taking photos of indoors without having any permission, might not be morally correct?   Taking a photo of another human being without his or her permission - is this ok? Taking photos of interiors (like a pub, not a house) through the windows - is this ok? Taking photos of street performers without permission of the actors - is this ok? Taking a photo of a painting that an artist is selling on the street - is this ok? Taking photos of random kids - correct or not?   From my point of view, I am not doing any harm, just looking for beauty; probably 3/4 of my photos will be deleted anyway. But I do understand that people do not feel ok to be photographed by someone. I try to ask, but you can't do that all the time; many times it is just a spontaneous moment...  Is there any 'law' I should be aware of?  EDIT  I want to only publish photos on e.g. 500px, not to sell or anything, just to share them as something I find nice.  Unfortunately, I live in the country where these rules are old and everything is regulated by the statement that photo must not disturb the privacy of the subject. But than shooting two people sitting on the bench is not legal. Etc.


When I touch with my bare finger the oscilloscope probe I get a perfect sine ac wave 155V peak to peak!.  This is my first oscilloscope and I don't know if this is a normal glitch.  Do I have a faulty one?


I encounter the phrase "I will appreciate your help" from time to time and it doesn't sound too honest to me. To be more specific, I don't have a problem with this phrase coming from a friend, because he will appreciate my help by "owing me one". But a stranger from the Internet, that's different, methinks.  "How will you appreciate it?" pops in my mind every time I see it, because to me, appreciation equals reward and, well, you can't reward people over the internet much. It is quite possible that I am just wrong and this is a perfectly fine figure of speech.


Review sections to be always in the same place

I find it not comfortable to have the order of the review sections changing all the time.  Within few seconds it changed from        to        Wouldn't it be better to have all of them in the same position, no matter the number of posts in each queue?  It assumes that the most important part is to lower the queue, although it is said there is no problem in having Close Votes with thousands of items. IMOH, most of us prefer going to one or other section (for example I like "Suggested edits") rather than to the queue with the most items, so having them changing their position makes it not that intuitive.  What do you think?


client-side REST API call across domain (site collection)

I am trying to use my javascript to make a call to a list that lives in a separate site collection. It is not working and blocks me due to CORS. Is there any way around this?  My question is different. The other post's user is asking for a request from the "internet", so outside of SharePoint. I am using an intranet and simply want to do a get request internally, but to call a different site collection to the one I'm on. My main javascript function looks something like this:      function getJson(endpointUri, success, error) {     $.ajax({         url: endpointUri,         type: "GET",         processData: false,         contentType: "application/json;odata=verbose",         headers: {             "Accept": "application/json;odata=verbose"         },         success: success,         error: error     }); }  function logError(error) {     console.log(JSON.stringify(error)); }


I am currently using Putty virtual machine (UNIX) for my class, and we are doing a short C++ assignment. The assignment is to: "Create a C++ program that tests to see if the file accounts exists and prints a message to say whether the file exists"  This is what I have, but when I try to compile the code, I get this error: error: ‘::main’ must return ‘int’  #include<iostream> #include<fstream>  using namespace std; inline bool exists_test1 (const std::string& name) {  if (FILE *file = fopen(name.c_str(), "r")) { fclose(file); return true; } else { return false; } }  void main() { string s; cout<<"Enter filename"; cin>>s; bool ans =exists_test1(s); if(ans) { cout<<"File Exist"<<endl; } else { cout<<"File Does not Exist"; } }


What is the difference in building ISVForce apps vs Force.com embedded?

I understand the licensing model between these two partner programs and what to use based on the needs.  I wanted to understand how developing force.com embedded differs from ISVforce. Is the difference only during the packaging stage? How do we packages force.com embedded apps? How do we sell them? etc etc.  Can we create an app on ISVForce and also have it available as force.com embedded with minimal effort?  I am finding it difficult to find resources related to force.com embedded. Any pointers are highly appreciated.


Probabilistic method Kraft-McMillan inequality

I am trying to solve as many problems as I can but I am a little confused on this one. It is in chapter 1, problem 9 (Probabilistic method, Alon & Spencer). The problem says   Let $F$ be a finite collection of binary string of finite lengths and assume that no two distinct concatenations of two finite sequences of codewords result in the same binary sequence. Let $N_i$ denote the number of string of length $i$ in $F$. Prove   $$\sum_i \frac{N_i}{2^i}\leq 1$$  The problem that I have is that I understand the problem as if $w_1w_2=w_3w_4$ then we must have $w_1=w_3$ and $w_2=w_4$, but if this is what they mean then let $F=\{1,0,100\}$ then the possible contatinations are: $11,00,10,01,1001,1100,0100,1000,100100$, so no two are the same, but then we would have $N_1=2,N_3=1$, so $N_1/2+N_3/2^3=2/2+1/8>1$. I assume I must be understanding the condition incorrectly.


Let $S=\{a_1,a_2,\dots,a_n\}$ be a set of distinct integers. Let $k$ is the least common multiple  of the numbers $\{a_1+1,\dots,a_n+1\}$.  Prove that the sequence that is take all the elements of $S$  $k$ times each is a graphic sequence. Trying to use the Erdos-Gallai  theorem but cant prove the second statement  with the inequality i try to use induction but i cannot do the second inductive step.  Definition :Graphic sequence if obeys at


find limit of $\frac{1+\sqrt{2}+\sqrt[3]{3}+...+\sqrt[n]{n}}{n}$ with squeeze theorem

I'm trying to prove with squeeze theorem that the limit of the following series equals 1: $$\frac{1+\sqrt{2}+\sqrt[3]{3}+...+\sqrt[n]{n}}{n}$$ For the left side of the inequality I did: $$\frac{1+\sqrt{1}+\sqrt[3]{1}+...+\sqrt[n]{1}}{n} <  \frac{1+\sqrt{2}+\sqrt[3]{3}+...+\sqrt[n]{n}}{n}$$ For the right side, at first I did the following: $$\frac{1+\sqrt{2}+\sqrt[3]{3}+...+\sqrt[n]{n}}{n} <  \frac{n\sqrt[n]{n}}{n}$$ But then I realized it wasn't true and that the direction of this inequality is the opposite. Do you have any idea which series with limit 1 is bigger from the original series? Thanks!


why arcane legacy steps to boot from USB with GPT and UEFI?

To run the live AVG rescue "disk" on USB for Windows 10, how is it made to work with a GPT and UEFI system?  (Possible solution listed below.)  I enabled the boot menu so that pressing F12 will display a list to select from.  Also, I put everything USB at the top of the boot sequence and Windows and the HDD at the bottom.  However, I hadn't realized GPT and UEFI are so different from a BIOS.  Because the USB flash drive isn't compatible with GPT it's not being picked up?  This  was suggested:   Open the notebook and press quickly F2 to enter the BIOS. Under the MAIN menu, enable the F12 Boot Menu option. Under the BOOT menu, select Legacy boot and press F10 Save & Exit. While the notebook is rebooting, press F2 again to enter the BIOS. Under the BOOT menu, select as your first boot option the USB HDD stick (your USB stick). Press F10 Save & Exit.    Perhaps this will work, but what is the problem that prevents UEFI boot from registering the thumb drive?  Because it's using GPT and not an MBR?  I don't want to switch to legacy, but stay with UEFI.  The laptop:


minecraft summon item with custom name 1.14

I'm making something for my friends and I've been trying to find a summon item generator with a custom name and I have found one but the custom name does not work. /summon item -137 28 -204 {Item:{id:black_terracotta,Count:1,tag:{display:{Name:"Dark Matter"}}}}


Need help for proving: $f(f^{−1}(A)) ⊆ A$.

Informations: $f:X \longrightarrow X$ and $A \subseteq X$.  How can i prove this statement: $f(f^{-1}(A)) \subseteq A$  This is my thoughts until now:  $f^1(A)=\{x\in X |f(x)\in A\} \subseteq X$.  $f(A)=\{f(x)|x\in A\}$  $f(f^1(A))=\{y\in A:\exists \in f^1(A):y=f(x)\} \in A$


German language for Phd courses in Germany

Can PhD students study in universities in Germany, in engineering courses, without knowing the German language?  Can they research and live without any problems?    Does applying to these universities require knowledge of the German language?


Proving that a linear functional is matrix trace

Let $W=\operatorname{M}_{n\times n}(\mathbb{F})$ (square matrices $n\times n$ over $\mathbb{F}$), and $f\in W^*$.  If $f(AB)=f(BA)$ for every $A,B\in W$ and $f(I)=n$ prove that $f(A)=\operatorname{tr}A$ for every $A\in W$.  I can understand why it's true, the only part in $AB$ that is the same in $BA$ is the diagonal, and together with $f(I)=n$ it is pretty obvious. But how can I prove it? I tried writing the base for $W$ and then writing $I$ as a linear combination of that base, but I got stuck.  Thank you.


What's the word or name of someone who "gets sick" just by talking about it but they're not really sick?

I know a person that I can say: "The flu is going around again" and next day he has the flu, but two days later he out in the woods hunting. If he comes in contact with someone that has heartburn then the next day he has heartburn! I called him on the phone and told him I had a cold, the next day he had the cold... I can go on and on and on...   This has been a fact for many many  years. Is there a name for a person like this or is it some type of disease?


At work, I have two monitors.  Both of them are Dell E198WFPs, however, manufactured 8 months apart from one another, so they're not from the same lot.  I'm looking to calibrate them.  Currently, my secondary monitor (on the left) is the one I use for text reading, because it's easier to read.  Can someone suggest either a cheap calibration puck that works well, or a software solution that's relatively easy to work with?  I run Windows XP and have full admin access to my machine (I'm the domain administrator)  My graphics card in the machine is an nVidia Quadro NVS 285, if that makes much of a difference.


Numbers that are solutions to polynomials with coefficients that are rational numbers. Do $e$ and $\pi$ belong to this family?

We know $e$ and $\pi$ are transcendental. Meaning that they aren't the solutions to any polynomial equation with coefficients that are integers. The next obvious question to ask - what about polynomials with coefficients that are rational numbers? Is there a name for such numbers? And has anyone proven that $e$ and $\pi$ don't belong to this family?   The next obvious extension is polynomials with coefficients that are algebraic numbers.   I assume all of these sets will be countable, so it's almost certain $e$ and $\pi$ won't belong to them. Is this a fair assertion to make?


Good Morning,  I have an issue with SQL Insert command from php. I'm trying the following code:  $TeamMatchTable = "INSERT INTO Team Match Table                    (LineupForward) VALUES ('$HomeLineupForward')";`   However the contents of the $HomeLineupForward variable is: Alexandre D'Acol;   This is resulting in an error because of the '.  What can I do to solve this problem?


There are some very good questions in SE network. Some of the best questions do not have answers. I do not really have examples now. So can we bring out a feature say "Follow Question" button near the question, So clicking on the button will subscribe us to the question and when someone answers it the notification would go to those who have clicked the "Follow Question" the question.  Or is there already a feature like this ?


if we could abort a committed transaction what would happen with durability

If we could abort a committed transaction, what would happen with durability? Then durability would not be ensured, right? Note: I mean undoing a committed transaction by aborting


How to disable syntax highlighting in Markdown fenced code blocks

For indented code blocks, adding <!-- language: lang-none --> disables syntax highlighting. What about for fenced code blocks? Can I use lang-none or none in fenced code blocks too? Which of the below is correct? #1:  ```lang-none === some text here === ```  #2:  ```none === some text here === ```


Why all motherboards have the limit for how much memory can be installed?

This has never been clear for me. Modern CPUs have the addressable space of 64 bits. The most expensive part of adding more memory is obviously the memory hardware itself, chips on them, etc. But why do motherboards also always impose the limitation? Is there a downside in supporting all 64 bits to pass the signal between CPU/controller/physical memory?


Novel(s) based on humanity fleeing from Earth and regressing to a pre-industrial state on a Colony so as to escape detection

Shortly before his death, my father spoke to me about a series of novels that he had just finished reading which had a fascinating concept.  However I soon forgot the title(s) and author and I've been absolutely desperate to find out what they were.  The premise (as I understood) was that humanity had expanded out from the solar system into the local star systems before coming into contact with an incredibly aggressive species which was focused on wiping out the entire species.  Earth and her colonies were lost as remnants of the species fled.  Eventually it was decided by the military leadership to set up a colony in order to rebuild the human race.  However, in order for this colony to escape detection and to keep humanity from going back out into space and thus potentially running into this hostile alien race again, a series of satellites were set up around the planet chosen that would lock onto and destroy any form of technology (and usually the surrounding city) that went beyond pre-industrial standards.    One of the series protagonist is a long living android who possesses the consciousness of a human who was present at the original founding of the colony (and who seems shielded from detection) which observes as civilization is repeatedly regrown and torn down again and who attempts to try and reverse humanities self imposed lot in life.      From what I understood this was a series of novels, but I could be wrong. I've been trying to find this for years on my own with only a rough plot line as a guide and it's gotten me nowhere.


Lighting parameters to render interior architectural scene?

I'm rendering some indoor architecture, and I'm having trouble with the texture color, because it changes a lot depending on the HDRI I use. I would like to know what the setup of lights is recommended for the so that the textures do not change color as much.


looks like someone got happy with the CSS - you can now no longer tell what tab is active, e.g. answer tabs:        Even if you hover over an option - it wont show you what tab is currently selected - it only shows you what tab you are currently hovering over:


What is the most efficient way to split a list evenly in half

I need to split a list into halves such that if it has an odd length the middle element is ignored entirely, I have a function for this, but it's quite slow for what I'm trying to do.  My function (variables renamed because they make no sense out of context):  def splitList(array):     half = len(array)/2     if len(array)%2==0:         return array[:half], array[half:]     else:         return array[:half], array[half+1:]   This function has to be called about 17 million times if my estimations are correct, so it has to be rather faster. Since I'm new to this though, if you could explain why your answer works faster, that would be perfect :)  last-minute thingy: it's for a small part of a projectEuler challenge if you were wondering, you're supposed to be able to get an answer in under a minute is why it has to be so fast.


Product of a nondecreasing unbounded sequence and convergent series

I can not prove the following statement. Could you please help me? Thanks   Prove that for each $a_k>0$ with $\sum_{k=1}^{\infty}a_k< \infty $ there exists a nondecreasing unbounded sequence $(b_k)^\infty_{k=1}$ such that $\sum_{k=1}^{\infty}b_k a_k< \infty $


polymorphism: why would you assign a interface reference to a subclass of superclass that implements the interface

i'm trying to understand the basics of polymorphism.  I do understand why it could be useful to assign a superclass to a sub class or a sub to a super.  what i don't understand quite well is the logic of assigning or accessing a interface to the reference of a sub class, can someone explain why this can be usefull?


Why is 4.5GB of my 8GB of RAM not recognised?

I have recently purchased 8 GB of RAM to upgrade my system to go along with a new shiny i5!  When I run speed checks on my system online I get told I only have 3.5 GB of RAM, also in  I only see around that value of RAM yet that stupid Windows rating index tells me I have 8.0 GB.  Am I doing/reading/interpreting this incorrectly?  See below what I see:


While trying to understand polarization in quantum field theory, I wondered how a single photon could go through a linear polarizer. I found a  which asked "Is a single photon always circularly polarized?"   This paper proposes an experiment to determine if a single photon can be linearly polarized, or if only pairs of photons can be linearly polarized.  It suggests that there may be non-trivial consequences regarding all Bell experiments with a "linearly polarized single photon" (because such thing may not exist).  The paper is from 2014 and the experiment seems simple if you have the right equipment, so do we have the result of the experiment yet?


Unmet Dependencies when installing Wine, ubuntu 13.04

I'm running Ubuntu 13.04, 64 bit, and I can't install wine.  I've tried the solutions presented  and , but to no avail.    When I use the command sudo apt-get install wine, the terminal returns   Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming.` The following information may help to resolve the situation:  The following packages have unmet dependencies: wine : Depends: wine1.6 but it is not going to be installed E: Unable to correct problems, you have held broken packages.   How can I install wine if these solutions do not work?  EDIT:  It should be noted that I'm dual-booting Ubuntu 13.04 and Win7 EDIT:  By following theseI was able to successfully install wine.  Whether or not this is a result of all of the answers and these results, or just these results, I'm not sure.


After routine update on 14.04, cannot even SEE internet (no ethernet, no wifi)

I am posting this question from my Windows desktop, because as of this morning my laptop is no longer even an internet accessible device, and doesn't even seem to think it's supposed to be an internet accessible device.  My OS is Ubuntu 14.04, 64 bit. The laptop is an Asus X551CA, and I got it in 2013 April.  Last night, I installed a routine Ubuntu update. I then restarted my computer. This morning, I have no internet. Like, at all. When I open up Firefox, every single tab says it failed to load the requested page. At the top right corner of the screen, there isn't even an internet icon. I tried connecting my ethernet cable, but it didn't even react at all.  I tried restarting like three or four times. It doesn't help. The internet is still missing.  I tried the following terminal commands, as suggested by responders to .  sudo service networking restart  sudo service networking force-reload  sudo dhclient  sudo apt-get update   Each one returned errors.  The first one returned this.  stop: Job failed while stopping start: Job is already running: networking   The second one returned this.  reload: Job is not running: networking   The third one returned this.  avahi-daemon stop/waiting   And the fourth one, after spitting out a large wall of text, then returned this.  W: GPG error: http://deb.opera.com stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 63F7D4AFF6D61D45   I have no idea what to do. It's the very end of the semester, and I have a research project that I need to complete by the end of monday. So it is, to say the least, absolutely imperative that my internet be working soon. Please, please help.


I saw a post on  which links to a video where a person . Is he saying a large portion of the numbers wrong? Back in high school my algebra teacher was extremely picky.  If we were going to say the number 135, we would say one hundred thirty-five.  If a person said one hundred and thirty-five my teacher would interpret that to mean 100.35.  Was my algebra teacher wrong, or did Jon just waste over 80 hours counting to 100,000 incorrectly. I tried searching the web, but searching for ‘numbers and’  doesn’t work very well.  Can you point me to a reference or style guide that describes how to properly say large numbers?


Ubuntu LiveUSB boot with or without install results in black screen on i3 Core notebook w/ Intel HD3000 Graphics

I have a HP Pavilion g4-1363la Notebook PC with the i3 Core CPU and Intel HD3000 graphics.  I had Windows 8 on it, but i guess it got corrupted somehow or something, it wouldn't start up anymore.  My uncle, who somewhat knows a thing or 2 about computers, says that i need a new OS, because it was missing or something, so i checked out this Ubuntu & saw that u could install it to a laptop via USB flash drive, i have done everything i need (at least i think i have), every time i turn on my laptop, it shows me the Ubuntu install menu.   The options that i have are:   "Try Ubuntu without installing" "Install Ubuntu" "Check for disc for defects" "Test memory" "Boot from first hard disk"    The first 3 options takes me to a black screen, then the screen sorda turns off. "Test memory" takes me to a blue screen with a bunch of weird statistics that i have no idea what it is for, then i have options like "(ESC)Reboot" - "(c)configuration" - "(SP)scroll_lock" - "(CR)scroll_unlock". The "Boot from first hard disk" also takes me to the black screen till the screen turns off, unless i hit enter, it shows me the installing menu again.  I really need help installing Ubuntu, do i really need to repair my laptop?? am i missing something? or am i doing something wrong??


Why is a subwoofer bigger than a tweeter?

I came across this video -  - where it says in 14:00:  Subwoofer is larger because it needs to be bigger for those larger low frequency waves to propagate through and the tweeter is smaller because higher frequency are very small waves and they don't need as much space to propagate  Remembering from basic physics, neither the amplitude nor the wavelength (or frequency) has anything to do with how fast a sound wave propagates. The speed of a sound wave should only be a matter of the medium, and within the same medium all sound waves should travel at the same speed. Perhaps temperature has an effect on the medium but certainly not the volume of the medium from what I recall. So the above statement does not make much sense to me. Great if someone can help explain the physics or the concept of why a subwoofer needs to be bigger for the lower frequency waves to propagate, and vice versa for a tweeter.


So i took my senior pictures and it said it was at 72 dpi. My school said they needed pictures to at least 300 dpi. I researched and found out that 300 dpi is the best printing quality. I changed the dpi from 72 to 300 but i did not resample the image so the length and width of the picture remained the same. Is this something good or bad? I'm scared that I did something wrong and that my picture will be blurry in the yearbook.  Help please!


I have an ASUS X551M that I am trying to boot from the CD ROM. When I go to the boot menu the screen says:  Boot Option #1   Windows Boot Manager  Add New Boot Option Delete Boot Option  There is no option to boot from anywhere else! Please help!


Helmet glass part makes hair not show for character

I've been following a course on creating a character with Blender 2.8 and have got to a point where I should make the helmet glass part look like glass. After applying the filters to do that, the hair on my character disappears. Do you know why that might be?  Filters for helmet glass    Filters for hair


How can I tell Siri to restart dictation? How can I correct her?

I know that Siri has "code words" which are not directly transcribed but which insert punctuation.   I find it essential to be able to restart or to go back and clear out words which were dictated improperly.  Is there a way to do this? I have tried saying "Delete", "backspace" and "cancel" and a few more, but they are all (properly) just simply getting dictated.


Remote callback method raise a Java NullPointerException - Java RMI

topics and subs are two private ArrayList filled by remote Strings and ISubs (interface)  private synchronized void notify(MyMessage msg){     for(int i=0; i<topics.size(); i++){         if(topics.get(i).equalsIgnoreCase(msg.getTopic())){             try {                 subs.get(i).getListener().onMessage(msg);             } catch (RemoteException e) {                 // TODO Auto-generated catch block                 e.printStackTrace();             }         }     } }   notify() is called by publish(MyMessage msg) method and it gets a remote MyMessage object   public boolean publish(MyMessage msg) throws RemoteException {      if(!total.tryAcquire()){         System.out.println("Publish respinta");         return false;     }      try {         concurrent.acquire();          mutex.acquire();         FileWriter file = new FileWriter("messaggi.txt",true);         BufferedWriter bw = new BufferedWriter(file);         bw.write(msg.getTopic()+": "+msg.getContenuto());         bw.newLine();         bw.flush();         bw.close();         mutex.release();          notify(msg);      } catch (IOException e) {         // TODO Auto-generated catch block         e.printStackTrace();     } catch (InterruptedException e) {         // TODO Auto-generated catch block         e.printStackTrace();     } finally{         concurrent.release();         total.release();     }     return true; }   Everytime publish() is invoked I get the following exception:     java.lang.NullPointerException at   server.MessageServer.notify(MessageServer.java:87) at   server.MessageServer.publish(MessageServer.java:61) at   sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at   sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at   sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at   java.lang.reflect.Method.invoke(Unknown Source) at   sun.rmi.server.UnicastServerRef.dispatch(Unknown Source) at   sun.rmi.transport.Transport$1.run(Unknown Source) at   sun.rmi.transport.Transport$1.run(Unknown Source) at   java.security.AccessController.doPrivileged(Native Method) at   sun.rmi.transport.Transport.serviceCall(Unknown Source) at   sun.rmi.transport.tcp.TCPTransport.handleMessages(Unknown Source) at   sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(Unknown   Source) at   sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(Unknown   Source) at java.security.AccessController.doPrivileged(Native Method)   at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(Unknown   Source) at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown   Source) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown   Source) at java.lang.Thread.run(Unknown Source) at   sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(Unknown   Source) at sun.rmi.transport.StreamRemoteCall.executeCall(Unknown   Source) at sun.rmi.server.UnicastRef.invoke(Unknown Source) at   java.rmi.server.RemoteObjectInvocationHandler.invokeRemoteMethod(Unknown   Source) at   java.rmi.server.RemoteObjectInvocationHandler.invoke(Unknown Source)   at com.sun.proxy.$Proxy0.publish(Unknown Source) at   publisher.PublisherThread.run(PublisherThread.java:22)   Obviously topics and subs are filled before publish() is invoked.  EDIT: alright, I found the issue, please don't kill me, I forgot to initialize the MsgListener in the Subscriber constructor.


possible duplicate of , but I think this question is more specific, and I can not find specific help in the above link. So I posted it.  I've ask a question here. . Now I want to give a bounty to it. I find this link , which is right below the comment area question , a link titled "eligible for bounty in 2 days". but I could not think how it offered any help.


I'm the new to Ubuntu. Recently, I downloaded the ISO image (32-bit). I have a laptop in which Windows 7 is pre-installed and now I want to install Ubuntu alongside Windows 7. I have burned a DVD for it but I don't know how to install it.


My Pictures in a Beamer file do not stay on the screen and I'm unsure why?

I am trying to create a Beamer file with some images alongside lists. However, when I insert my image it either does not appear or it shifts it half off the slide to the rigth - see below. My question is how do I move it into the white space above? I did try seperating the page into columns but had the same issue. Any help would be appreciated.  My code:  \frame{     \frametitle{Coordinate Systems}     \begin{itemize}         \item Cartesian          \item Cylindrical          \item Spherical      \end{itemize}  \begin{figure}[h!]\centering     \includegraphics[scale=0.1]{C:/Users/john/Documents/Uni/MMath/Major Project/Major Report/Python/Co-ordiantes/sphere_no_numbers.png} \end{figure}  }


The prequel  I am a Stack Exchange user mainly interested in sciences. However, I sometimes notice something an interesting question on the Hot questions block and open it.  In some rare cases I feel that I can contribute to this question by providing a new perspective or additional information. For example, my only post on Workplace SE turned out to be number 3 answer on that question with 80 upvotes.  The problem is that in most of those cases even though I have something to add, I can not add it because the question is protected. Here is a recent (and still hot) .  I was going to address a point in question that no one else had touched and also provide some additional information/examples regarding other points. But I could not post an answer. Instead, I provided the information in comment form. But all of the comments on that question got removed by a moderator (I guess it's because the total amount was too large).  I am not going to become an active user of Workplace SE or UX SE. But is there no worth in single answers? How could adding information harm anyone? What is the point of questions being protected?  I know the answer (it's written by the "protected" stuff) - it protects the question from low-quality answers. Guess what - it also protects the question from medium quality and high quality answers. The Hot questions are the cases where an expert that is not an active user might come and contribute. Why are we protecting a question from such people?  A protection mechanism against low quality answers is already there - it is the downvote. Those low quality answers and questions should not be seen as strain by moderators. They should just get downvoted to hell (just as this post probably will).  The point  I beckon you to embrace the downvote and stop fearing it. Stop crying "please explain the downvote" and fearing to hurt someone by downvoting a post. If you think a post is crap - downvote it. Let the community moderate the content quality. There is no need for some elitist protections, content removals and other demonstrations of moderator power that hurts far more than downvotes would. Leave moderation for actual problems of illegal content and let the simple folk vote on quality. They are sometimes more competent than the moderators are.  Why this is not a duplicate of   The initial problem was that I (and others) can't answer where something useful might be provided. However the solution I ask for is different. Just check . Stop calling out explain your downvote? There is too much sympathy for the poor downvoted fellows here. Let the people downvote without punishment. This is a system that works great elsewhere ( is the best example I know). I am sure that bad answers would receive enough downvotes if downvoting wouldn't be seen as a bad thing.  So what is someone answers "thanks, I had the same problem"? Let him get five downvotes, a single toxic comment of "this is useless, you don't understand what an answer is" and fade out so no one else sees the "answer". Protection guaranteed.


Why a half-integer spin implies "antisymmetry" on the wave function?

I've read that the Pauli's exclusion principle can be explained because the wave function of fermions (half-interger spin) change sign when you permute two arguments and that this makes it impossible to have two equal states, which in bosons (integer spin) doesn't happen. But why is it the spin that makes this difference? Is the Spin-Statistics theorem another approach or the same?


Why does the moon drift away from earth?

I once saw on TV that the moon is slowly drifting away from the earth, something like an inch a year. In relation to that the day on earth what also increase in time. I wonder why is that?


How to determine which type of transposition cipher I have?

I have some ciphertext that I have determined using frequency analysis to be most likely encrypted using a transposition cipher, as the letter frequencies are similar to plain English language text. I believe the next step should be to determine which transposition cipher it is, but I don't know how to do that. Am I right to assume that what I have is definitely a transposition cipher? And if so, how do I determine which transposition cipher it is? For what it's worth, here is the ciphertext I have. But (as asking for decryption of a specific ciphertext would be off-topic here) I'm interested in general techniques that could be applied to any ciphertext. CTCRAL TYNIH ORFLN NLONH LTOWH SLINI IIEER NOENT AHRNE NWAAM CTEAK ERDHH DMIOD AEINA YTFEI IEINM FSTGI UOVED GLMEI YINEE EYNGS BSCRA TUVGU UEIEV OHIDA TISRO IEEEA TETMG RSFHD DHARA ICSEU EVHNS WIYII YIRND TFVCX GSMVL IUELH RETRG NNREC ONEYI OTLUN SBRSH AIIEE TTOOI ESCLS KWSLE ETGHN EOTNU STGIM EEACR TAEEN LAPEH RHNHE GWIEH EWRNN UETHT EPREN SDNFW YUFGI TUEAY ETLMR TBIPW UPANI OEFUS RSEAT NRTDP RENOA EETIL HNNAD HECWD TTILI UECDT DTLAM RQERS MVVTR HYTYO UFOAM ONCNS NFSST EEVHA YHERE OEONM RE- GAO HCVLO COIYT HSENZ FAHHL LYRII USBAS IEHEO IOSOT TILAI EOGOT ETEHL DEENP AEISP IDDMT RHNBI EEEMO NTIOE ISGZE SEAEE IDLNI TRTTD RIDUT PTNIY NIYNQ MMMIR BDAOI AYDOT DTELG HAIHO BDESA RSYLN HNWCN TRLRE NTAMN AESEI EHAEY NHGMO REFOT TFTUP AEREE HTONG OISHT TVEHO MSEFO OLINE TOLET SOATR AERTC TGEGT STTNA ONNTG OHAIA TYUOT IIARN TENCO TKGAU TSEHH EIBWO SDTUW INDTR UECHC RSEAT DEOEW ENWFA ELGKM


do I need to send my online access information if someone is depositing money into my account is this a scam?

I met someone online. She says she wants to help me with legal issues. She said her late father left her a business and she says she is selling the business and sending the money to my account. She says she needs: my full name my routing and account numbers  Online information such as screen name and password. is this a scam?


Is it possible to use switch to select ImageFormat?

I convert an image from one format to another and want to use the switch to process different formats. System.Drawing.Imaging.ImageFormat is public sealed class and switch doesn't work with it. The below code is working, but I want to use the switch here. Can you help me with some advice?  public static void ConvertImageFormat(Image image, string targetImageFilePath, int newWidth, int newHeight, ImageFormat imageFormatToConvert)     {         using (Bitmap bitmap = new Bitmap(image, newWidth, newHeight))         {             using (Graphics graphic = Graphics.FromImage(bitmap))             {                 graphic.InterpolationMode = InterpolationMode.HighQualityBicubic;                 graphic.SmoothingMode = SmoothingMode.HighQuality;                 graphic.CompositingQuality = CompositingQuality.HighQuality;                 graphic.PixelOffsetMode = PixelOffsetMode.HighQuality;                  graphic.DrawImage(image, 0, 0, newWidth, newHeight);                  if (Equals(ImageFormat.Png, imageFormatToConvert))                 {                     bitmap.Save(targetImageFilePath, ImageFormat.Png);                 }                 else if (Equals(ImageFormat.Gif, imageFormatToConvert))                 {                     bitmap.Save(targetImageFilePath, ImageFormat.Gif);                 }                 else if (Equals(ImageFormat.Jpeg, imageFormatToConvert))                 {                     ImageCodecInfo[] arrImageCodecInfo = ImageCodecInfo.GetImageEncoders();                     using (EncoderParameters encoderParameters = new EncoderParameters(1))                     {                         encoderParameters.Param[0] = new EncoderParameter(Encoder.Quality, 90L);                         bitmap.Save(targetImageFilePath, arrImageCodecInfo[1], encoderParameters);                     }                 }                 else                 {                     throw new Exception($"Convert to <{imageFormatToConvert.ToString()}> from " +                                         $"<{new ImageFormatConverter().ConvertToString(image.RawFormat)}>" +                                         $" image format is not supported now.");                 }             }         }     }


Voltage tester detecting voltage in non-hot wires when the light switch is off

I just switched the wiring of a single-pole light switch from back wiring to side wiring and noticed that my voltage tester (non-contact pen-style one, Klein Tools NCVT-3) detects voltage in both the other black wire going into light fixsture and the ground wire when the switch is off. The tester beeped with one or two yellow lights on, so the voltage seems lower side.   I did continuity testing with my multimeter and the reading looked fine (overload when the switch was off and 0 and beeping when the switch was on).  From my completely novice point of view, the switch should cut off any current when it is off and voltage should be detected in the hot wire only but not in others. Is it not true? Does what I see indicate something's wrong or is it actually normal (like picking up voltage from the nearby hot wire)?


How do I copy a file without pasting immediately from terminal?

When using the command "cp", I need to know where exactly I want to paste my file. Often, I have to copy a file but without having to paste immediately or sometimes I do not know where I have to paste it. I want to have the option of navigating to the directory where I want to paste the file and then do it. Is there any command that does this? Basically, I want something like this- cp file.txt cd .. cd RandomDirectory paste  This can be done in GUI easily- Ctrl+C the file, navigate to the required directory and then Ctrl+V


So, I'm finding that when I break Redstone blocks while mining I am getting nothing in return. I've read this happens on PE but I'm using the PC version(Windows 7), which I downloaded yesterday. I am in survival mode. Has anyone experienced this? I've mined about 10 of these and have gotten nothing. From what I've read every one of those blocks should have given me something, it doesn't appear to be a rare drop. Thanks!


What is causing the null pointer exception in solution to deleting an nth node in a doubly-linked list?

The task is to delete the nth node of a doubly-linked list. I drew it out, and I don't see the nullpointer error that's tripping me up.   I've created an if-statement to handle the edge case of an empty list. I created a while loop to traverse the linked list otherwise. I get there error when I'm attempting to set the node links. Details below.       public double delete (int k) {      int i = 0;     Node temp = first;     double retVal;      if (k < 0 || k >= N) throw new IllegalArgumentException ();      if (temp == null)         return 0;      while (temp != null) {              if (i == k - 1) {                 temp.next = temp.next.next;                 temp.next.next.prev = temp;                 temp.next.next = null;                 temp.next.prev = null;                 return temp.next.item;             } else {                 i++;                 temp = temp.next;             }         }      return 0;   I was expecting to delete and return the node to be deleted. Instead I got a nullpointerexception at the line commented with "//Issue".


I recently installed Ubuntu on my HP Probook 430 and quickly found out I had no way of wirelessly connecting to the internet. How do I fix this?


Is it possible to interpolate between two different meshes?

Lets say that mesh 1 is Suzanne And mesh 2 is also suzanne but the vertices are moved around alot  Can I tell blender to make Suzanne 1 to morph into suzanne 2?  Edit:  I heard I can do it with shapekeys if I "model it" in edit mode. But the thing is, its already modeled, its just a different mesh.  Seems like a waste of effort to remodel what is already modeled.  Is it possible to do it without manually re-modeling mesh number one?


change from five boxes to the same length rectangle using tikz

Hi All: I have a code snippet below which works beautifully and was provided by someone on this list to me a while back.  But now I want to change it so that I draw one long rectangle instead of the adjacent five boxes. The text inside the rectangle should just be at the far right of it and could say $Y^{*}_{whatever}$. I'm thinking that I need to define a rectnode instead of a squared node with different things in it.  But I don't understand how to make it the same length as the length of the boxes and in the same position. "minimum size" currently inside the definition of squarednode isn't making sense to me. EDIT: I have edited this question by including a handwritten drawing in order to express the fact that I need the rectangles to line up with the horizontal axis as shown. So, the first rectangle travels from 0 to 5. The second rectangle travels from 1 to 6, etc all the way to the 6th rectangle travelling from 5 to 10. Also, all the rectangles should be the same width and length even though it may not seem that way by the picture. I also don't need a y-axis. Thanks and I'm sorry for not being clearer the first time.  \begin{tikzpicture}[ squarednode/.style={draw=black, minimum size=9.9mm}, y=1.5cm ]    %boxes      \draw (0.5, 5.5) node[squarednode] {$X_{1}^{*}$};     \draw (1.5, 5.5) node[squarednode] {$X_{2}^{*}$};     \draw (2.5, 5.5) node[squarednode] {$X_{3}^{*}$};     \draw (3.5, 5.5) node[squarednode] {$X_{4}^{*}$};     \draw (4.5, 5.5) node[squarednode] {$X_{5}^{*}$};                  \draw (1.5, 4.5) node[squarednode] {$X_{2}^{*}$};     \draw (2.5, 4.5) node[squarednode] {$X_{3}^{*}$};     \draw (3.5, 4.5) node[squarednode] {$X_{4}^{*}$};     \draw (4.5, 4.5) node[squarednode] {$X_{5}^{*}$};     \draw (5.5, 4.5) node[squarednode,dashed] {0};      \draw (2.5, 3.5) node[squarednode] {$X_{3}^{*}$};     \draw (3.5, 3.5) node[squarednode] {$X_{4}^{*}$};     \draw (4.5, 3.5) node[squarednode] {$X_{5}^{*}$};     \draw (5.5, 3.5) node[squarednode,dashed] {0};     \draw (6.5, 3.5) node[squarednode,dashed] {0};          \draw (3.5, 2.5) node[squarednode] {$X_{4}^{*}$};     \draw (4.5, 2.5) node[squarednode] {$X_{5}^{*}$};     \draw (5.5, 2.5) node[squarednode,dashed] {0};     \draw (6.5, 2.5) node[squarednode,dashed] {0};     \draw (7.5, 2.5) node[squarednode,dashed] {0};          \draw (4.5, 1.5) node[squarednode] {$X_{5}^{*}$};     \draw (5.5, 1.5) node[squarednode,dashed] {0};     \draw (6.5, 1.5) node[squarednode,dashed] {0};     \draw (7.5, 1.5) node[squarednode,dashed] {0};     \draw (8.5, 1.5) node[squarednode,dashed] {0};          \draw (5.5, 0.5) node[squarednode,dashed] {0};     \draw (6.5, 0.5) node[squarednode,dashed] {0};     \draw (7.5, 0.5) node[squarednode,dashed] {0};     \draw (8.5, 0.5) node[squarednode,dashed] {0};     \draw (9.5, 0.5) node[squarednode,dashed] {0};                      \end{tikzpicture}


Create a PDF in illustrator with links to pages

Is it possible to create a multi-page PDF using Adobe Illustrator with various elements on a page linked to other pages in same PDF?  The purpose is, we want to output semi-interactive prototypes with Illustrator.  EDIT on receiving a possible duplicate: My question is about creating links that point to different pages in the same file, not an Internet address. (something like #page3)


Trying to run gparted in fresh installed Ubuntu. System not found this program. When I try to install I have report that it is already installed. How to solve this problem?  g@g-Lenovo:~$ gparted The program 'gparted' is currently not installed. You can install it by typing: sudo apt install gparted g@g-Lenovo:~$ sudo aptitude install gparted [sudo] password for g:  gparted is already installed at the requested version (0.25.0-1) gparted is already installed at the requested version (0.25.0-1) No packages will be installed, upgraded, or removed. 0 packages upgraded, 0 newly installed, 0 to remove and 130 not upgraded. Need to get 0 B of archives. After unpacking 0 B will be used.


Can `cat` show files using code markup in colors?

Sometimes I quickly want to view the contents of a file from the command line. For this I of course use , but it is often source files in ,  or simple . For these files it would be handy if cat could give some color markup to the files, so that it reads more easy.  Can cat do such a thing?


cfsdaacdfawd virus. usb flash file and folder keeps coming back after being delete?

I got a silicon power 16gb usb flash and it has a bad virus in it. I called "cfsdaacdfawd". I have Windows 10 with bitdefender total security 2015.  tried everything to format it, BUT NOTHING WORKS.   I have tried these:   CMD and diskpart. 3rd party programs. (USB fix - Rufus - USB Format tool & ...)      partition manager. (partition manager 12 in safemode) disabling write-protected in registry.   After plugging in the USB flash, antivirus detect the viruses and deleting them, but when I pull it out and put it in again, all my files and folders coming back again with the virus.  I even deleted the partition with "partition manager 12" in safe mode, but it automatically going to the same old format again and the files and folders are still remains.   More Information:  the virus folder name: cfsdaacdfawd  in the cfsdaacdfawd folder:  aiasfacoafiasksf.vbss  Bitdefender Knows the virus with this name: Trojan.Downloader.JQVE  The flash also has the .lnk virus and make as u see. And the hidden files wont show up if i remove the flash and plug it in again.  when i'm trying to format it, right after i hit the format button, it looks like my taskbar gets refresh, i repeat my taskbar gets refresh, not desktop or my computer. please help with some more Professional suggestion.


I am new to D&D and haven't even played the game. In fact, I haven't bought anything at all!  If I were to buy the newest D&D starter set (the one with the green dragon on the front, I think it's the 5th edition), is there anything else I would need to buy?  From the starter set I would already have...   5 ready to play characters   6 die   One Adventure book: Lost Mine of Phandelver   One rulebook   One character sheet


Number of connected components of the complement of a compact

Let $X$ be a connected, locally compact space and let $K$ be a compact subset of $X$. Is the number of connected components of the complement $X\setminus K$ finite? If it is not, are there some hypotheses over $X$ for finiteness of connected components?


Are there many more irrational numbers than rational?

Does it make sense to say that there are more irrational numbers than rational?


How do I send a cross-domain POST request via JavaScript?  Notes - it shouldn't refresh the page, and I need to grab and parse the response afterwards.


User is suspended network-wide, except not really

A user has been active on one of the sites recently, even though they're concurrent suspended network-wide on the rest of the network. How is this possible, and is it possible to evade a network suspension on only one site?


How do I execute terminal commands by clicking an icon?

I'm trying to set up my sister's laptop with Ubuntu 14.04 running the LDXE shell. The only issue is, on boot, the wifi is disabled by default and I can't seem to reactivate it except with these terminal commands:  sudo modprobe rt2800pci sudo ifconfig wlan0 up   I'm wondering if there's a way for me to put these two into an executable, and just have her click that to start the wifi instead of opening the terminal and possibly forgetting the command.


Lightning in space, would it be a perfectly straight line?

I have read this question:     I do understand that here on Earth lightning consists of electrons moving in space and some of these electrons are tracing path, and eventually lightning will move in the direction of least resistance.  Now the reason why some electrons need to trace the path is because there is atmosphere here and the electrons moving interact with air, and the actual lightning is where the electrons find the path of least resistance through the air molecules.  Now in space, there is no air, there is no resistance from air. I do understand that even vacuum is not empty and there is permettivity and permeability of space (meaning in some sense some resistance), but still, there is no air and electrons can practically move freely in vacuum.  Now if there is no resistance from the air molecules, and the electrons do not interact with anything (matter or other particles) in space, then they could just go in a perfectly straight path, because there is no need for tracing the path of least resistance.  Question:   Since there is no air, there is no resistance, and the path of least resistance should be a straight line?


zonal statistics / join with two vector layers

I have a shapefile containing three polygons of river basins with different values. I want to know the average values per country. The country thus contains three river basins. When I use join in Arcgis or join by location in QGIS the average value is just the average of the three values, not weighted by the amount of (area) overlap.   example: basin 1 value 1 overlap 1% ; basin 2 value 9 overlap 99% should result in an average value of 8.92 and not 5  the eventual analysis is a global one so speed is critical. I am aware of the option the rasterize and use zonal stats.


Two players alternate flipping a coin until the result is head. How to derive that the probability for the first player to win is $2/3$?

Two players, $A$ and $B$, alternately and independently flip a coin and   the first player to obtain a head wins. Player $A$ flips first. What is   the probability that $A$ wins?      Official answer: $2/3$, but I cannot arrive at it.   Thought process: Find the probability that a head comes on the $n$th trial. That's easy to do, it's just a Geometric random variable. Then find the probability that $n$th turn is player's A turn. Finally, multiply both probabilities.  When I came up with each probability, both of them depended on the amount of trials $n$, so my answer was a non-constant function of $n$.  However, what I find quite fantastic is that the answer is a constant, so the amount of tries until a head comes doesn't seem to matter.


Polynomial arithmetic uses coefficient ring arithmetic

How is it works ?  What is different between divide with remainders in a ring and without ?  e.g I have this question:  Calculate $\frac{6x^5+2x^4+5x^3+x+2}{5x^3+x^2+6}$ in the ring $\mathbb{F}_{7}[x]$.  So I how do I do this ?  Because the way I calculated, the result is:   $1.2x^2+0.16x+0.968$ with the reminder: $-9.128x^2 +x -3.808$  So what is the differences ?  I know I probably wrong but this is what I know


How do I find where my website ranks in Google for a keyword or group of keywords?

I'd just like to know, if for a keyword, or a sentence, my website is in the search pages, and if so, where? Is there a way to do this?


Comment upvote, undo, and then re-upvote: why not?

I recently tried to un-upvote a comment, and received a message that if I did so, I would not be able to upvote it again:     Are you sure you want to undo your upvote on this comment? You will not be able to upvote it again.   Unlike , I completely understand what the message is saying. However, why am I not allowed to upvote it again? What's the reasoning behind this decision?


Two coffee beans in a cup of water + vibrations = gravity?

If you float two coffee beans in a cup of water that is being vibrated by your subwoofer (go to a sin wave generator online), the two beans will either be attracted to the sides of the cup or if positioned right will be attracted to each other in an accelerating manner.  What phenomenon is this, and could it be related to gravity in space?


SQLite when comparing two passwords with if they do not match while sysout prints them correctly

I am setting up a database with users and their passwords. I have a gui made in jfx 8, intellij IDE used  I have successfully extracted my code from my db and only when comparing them with if x == x i get the wrong password message  try {             Connection conn = DriverManager.getConnection("jdbc:sqlite:C:\\Users\\user\\Desktop\\java\\Java\\Just Messing Around\\MessyDB.db");             System.out.println("DB Connected");             Statement statement = conn.createStatement();             ResultSet rs = statement.executeQuery("SELECT * FROM UserDB WHERE Tab = " + tabelis);             while (rs.next()){                 int id = rs.getInt("ID");                 String  name = rs.getString("Name");                 int tab  = rs.getInt("Tab");                 String  DBpassword = rs.getString("Password");                 float right = rs.getFloat("Right");                 System.out.println("********************");                 System.out.println("********************");                 System.out.println( "ID = " + id );                 System.out.println( "Name = " + name );                 System.out.println( "Tab = " + tab );                 System.out.println( "Password = " + DBpassword );                 System.out.println( "Right = " + right );                 System.out.println();                 String password1 = pfPassword.getText();                 String password2 = DBpassword;                  if (password1 == password2){                     System.out.println("**************");                     System.out.println("if statement ok");                     Parent mainMenuParent = FXMLLoader.load(getClass().getResource("MainMenu.fxml"));                     Scene mainMenuScene = new Scene(mainMenuParent);                     Stage appStage = (Stage) ((Node) event.getSource()).getScene().getWindow();                     appStage.setScene(mainMenuScene);                     appStage.show();                     statement.close();                     conn.close();                 }else{                     System.out.println(pfPassword.getText() + "  " + DBpassword);                     System.out.println("wrong password");                     statement.close();                     conn.close();                 }   In the sys out in else, after if statement it prints identical passwords     Else SysOut:    lel  lel wrong password


How do I convert pt/in/cm/mm to em/ex as they are defined at a given point in the document?

I am using various macros that I have fine-tuned with units like pt and cm. I use those macros normally in certain places (say, in main body text or in footnote text). To properly generalize those macros, I would like to replace the absolute units by relative ones.  Say I have a macro \newcommand*{\aalso}{\textsl{and also}\hspace{1.1pt}}. Say I normally use that macro in footnotes. But now I realize that I made a mistake and would like to change the length 1.1pt to something of the form ...em so that I can use the macro elsewhere. How do I get the right number? I assume that the right way is to define some macro like \emConverter{1.1pt} that, if issued in a footnote context, gives me the length of 1.1pt in a footnote context converted to a relative length in em. It doesn't need to be a LaTeX-parsable value; it's okay if this is just printed out directly into the document, for me to then manually write the new em-value into the source code.  Some relevant questions:


Print odd-numbered lines, print even-numbered lines

I want to print the odd-numbered and even-numbered lines from files.  I found this shell script which makes use of echo.  #!/bin/bash # Write a shell script that, given a file name as the argument will write # the even numbered line to a file with name evenfile and odd numbered lines # in a text file called oddfile. # ------------------------------------------------------------------------- # Copyright (c) 2001 nixCraft project <http://cyberciti.biz/fb/> # This script is licensed under GNU GPL version 2.0 or above # ------------------------------------------------------------------------- # This script is part of nixCraft shell script collection (NSSC) # Visit http://bash.cyberciti.biz/ for more information. # -------------------------------------------------------------------------  file=$1 counter=0  eout="evenfile.$$" # even file name oout="oddfile.$$" # odd file name  if [ $# -eq 0 ] then     echo "$(basename $0) file"     exit 1 fi  if [ ! -f $file ] then     echo "$file not a file"     exit 2 fi  while read line do     # find out odd or even line number     isEvenNo=$( expr $counter % 2 )      if [ $isEvenNo -ne 0 ]     then         # even match         echo $line >> $eout     else         # odd match         echo $line >> $oout     fi     # increase counter by 1     (( counter ++ )) done < $file echo "Even file - $eout" echo "Odd file - $oout"   But isn't there a way to do it in one line?  Yes, use awk, I read.  Even-numbered lines:  awk 'NR % 2' filename   odd-numbered lines:  awk 'NR % 2 == 1' filename   But it doesn't work for me. Both produce the same output, according to diff. When compared to the original file, they are both indeed half as long, and they both contain the odd-numbered lines. Am I doing something wrong?


I recently bought a new laptop with following configuration   CPU: Intel i5 2450 RAM: 8 GB DDR3 GPU: NVIDIA GeForce GTX 520 1GB   I've setup a virtual machine using VirtualBox with Windows 7 as guest. I want to use my (host's) graphics card in it but the virtual machine is only showing 128 MB of video memory.  I am using Bumblebee and start the virtual machine using   $ optirun VBoxManage startvm "Windows 7"   Please suggest me how should I use my graphics card for 3D acceleration in virtual machine.


How can I copy files by modified date using terminal?

I am attempting to copy files based on their modified date, as the file names do not include the date in them. Coincidentally, the files are the 22 newest files in the directory, so if I run the command ls -lt | head -22, the outputted files are exactly what I want to copy.   I had read , but the accepted answer didn't seem to work in Terminal, and it isn't exactly filtering by date, just by head.   I am running macOS Sierra 10.12.5.


The set of self-adjoint operators over a Hilbert space doesn't form a lattice

How can someone prove, that over a Hilbert space $\mathcal{H}$ with $dim \mathcal{H} \geq 2$, the set of all self-adjoint operators doesn't form a lattice?  I found a result from Kadison, that if two self adjoint operators $A, B$ are not comparable, then they don't have a least upper bound. In 2 dimensions, I got two upper bounds of the (standard) projections $P_1, P_2$, which are not comparable. I think its not enough, but I can't go any further.   Please help!


Why is $\frac{x}{\| x \|}$ a unit vector?

Let $x$ be a vector in $\mathbb{R}^n$. Why is $\frac{x}{\| x \|}$ a unit vector, for $x\neq 0$?  If I try to simplify it, I get the following: $\frac{x}{\sqrt{x \cdot x}}$, and I'm not sure how to proceed.  So I'm looking for a proof or explanation as to why it is a unit vector.


Request to be able to delete tag synonyms

I made a typo while proposing a synonym for the [gtk+] tag and ended up with [gtkgtk2]. Nobody has voted on it. This is a feature request for the proposer of a tag synonym to be able to retract that proposal if nobody has voted on it yet.


Is it possible to dynamically show different themes for different users?

I have a website that I need to show slightly different content and color scheme to different groups.  Is it possible to show different users a different theme simultaneously? So if I send a link to User A) and User B) with a separate _GET value of the theme in the URL, can they both see different themes in the same second?


How do remove all Unicode from string, BUT keep lanauges such as: Japanese, Greek, Hindi etc

How would I remove all Unicode from this string【Hello!】★ ああああ I need to remove all the "weird" symbols (【, ★, 】) and keep "Hello!" and "ああああ". This needs to work for all languages not just Japanese.


How full is too full for mechanical hard drives?

I have heard many claim that it doesn't matter how full a drive is until it starts cutting into temp and virtual memory space.  This doesn't make sense to me, given the nature of how the data is transacted on a hard drive. The inside of the platter presents less data per revolution than the outside of the drive does, by significant factors. The inside 40% of the radius of full size hard drive is used for the spindle, so only the outside 60% is used for data storage, but that still means that the inside track of a hard drive presents data 60% slower than the outside track.  By my calculation, a Hard drive that is only 10% full should perform about 2.25 times faster than a hard drive that is 90% full, assuming that the flow is constrained by other factors.  Am I wildly off base here? For all the drives I know, even the top speeds of the first 1% of the drive would be well within the bandwidth provided by a SATA 2 connection.


Text “figure” appearing after section number in Table of Figures

I am having the same issue as MarkSvalov in . Sadly it seems like it has been removed.    The same thing is happening to the List of tables, but not to the listings (source code).  So what I am using is classicthesis.  I can just download the zip and build it with my TeXstudio and I'll get the exact same behaviour.  As I tried to cope with this issue for an hour now I already tested all the ctf pre and after commands. What I believe is that the word "figure" or "table" gets somehow into the section numbering.  If I take a look at the *.lof or *.lot file the content supports my findings:  \contentsline {figure}{\numberline {1{figure}}{\ignorespaces SomeFigure}{9}{figure.caption.9}   As you can see {1{figure}} doesn't seem right.  I am really happy with TeXstudio, but I'll try another environment to see if it'll still occur.  Do you guys have any idea how I can disable this behaviour?  I read somewhere that people had problems with the automatic language detection of their latex Editor/IDE and some package called bable.  But I couldn't find any settings that would support this idea.  Maybe you guys can help me. Thanks a lot in advance!  Best regards.


What is comanswer.com and why is it copying stackoverflow.com content?

I just did a search for "find out how much memory a python program takes" on Google and came up with two hits that contain the same content:       Interestingly, the comanswer.com site was higher ranked. I guess they do a better job at search engine optimization (SEO).


In plugin development, what is the best practice to prevent jQuery component collision on the front end?  For instance, let's say I include the jQuery Apprise dialog in a plugin that loads this on the front-end for something, yet another plugin may do the same. Because this gets loaded and declared twice, or perhaps one is forked and customized while mine is not, we get Javascript errors on the frontend (I assume).  (Note that I'm doing the best practice of using the wp_register_script() and wp_enqueue_script() strategy via a wp_head() action event in order to load a jQuery component on the frontend.)


How to delete file with this name on linux: -]???????q

Somehow a file named -]???????q got created on my terminal. I tried  rm -f "-]???????q"  (in double quotes), but it did not get deleted. (Error::  rm: invalid option -- ]).  How do I delete it?


Keep sharp edges when using subdivision surface

How can I use the subdivision surface modifier to create more high poly meshes without ruining sharp edges? For example this mesh  The sphere should be subdivided but the rim of the cylinder should stay the same because it is a sharp edge. This is the result of the subdevision  How can I get sharp edges to not be affected by the sub surf mod?


What kind of lenses will work on an entry-level Nikon DSLR?

I am total noob at cameras/lenses so I don't know what I am buying. My cousin has asked me to bring 70-300mm or 18-300mm lens for his D3300. Now, I don't know what lens will be compatible with the D3300.   I tried visiting a camera store () and was blown away with lens options. Can someone guide me, what brand, mount, or whatever technical terms are are compatible with D3300?


Alternative proof that $(a^2+b^2)/(ab+1)$ is a square when it's an integer

Let $a,b$ be positive integers.  When $$k = \frac{a^2 + b^2}{ab+1}$$ is an integer, it is a square.    Proof 1: (Ngô Bảo Châu): Rearrange to get $a^2-akb+b^2-k=0$, as a quadratic in $a$ this has two values: $a$ and $kb - a = (b^2-k)/a$. (The second root is determined in two different ways from the expansion $(x-r_1)(x-r_2) = x^2 - (r_1 + r_2)x + r_1 r_2$.)  Now suppose we have $a,b$ such that $k$ is an integer but not a square, by the investigation about roots we have that the second root is a nonzero integer since $k,b,a$ are integers and $k \not = b^2$, futhermore it is positive which is easily seen from its defining equation.  WLOG assume $a \ge b$ so that the second root is strictly smaller than $a$. This leads to a decent, replacing $a$ with the second root.    Proof 2 (Don Zagier): Apply reduction theory (specifically, Sätze 1 and 2 of Section 13 of my book on quadratic fields) to the quadratic form $x^2 + kxy + y^2$, which is the unique reduced quadratic form in its equivalence class.    Note that Proof 2 is pretty much the same as Proof 1 when written out in explicit detail, but I could not read Zagier's book because I cannot read German.  I would like to know more approaches to this and other alternative proofs of this result if possible! Thanks in advance.  I would also be interested in related problems (especially easier ones of a similar nature) and texts which cover the reduction theory in English.


How can I solve this quantum mechanical "paradox"?

Let a (free) particle move in $[0,a]$ with cyclic boundary condition $\psi(0)=\psi(a)$. The solution of the Schrödinger-equation can be put in the form of a plane wave. In this state the standard deviation of momentum is $0$, but $\sigma_x$ must be finite. So we find that $\sigma_x\sigma_p=0$. Is something wrong with the uncertainty principle?


I have a tire -standard 25 mm.  Normally I get tubes  700x20/25c which is what I ordered, but received 700x18x25c   will they fit and be ok?


So I've created a path, and used a circle as the bevel object to create a pipe like structure (as seen in the picture below). I often use this to create arms and legs for characters. However, I can't figure out how to make the ends rounded (like a capsule)  Is that even possible? And if so, what's the best way of going about it. I know I could probably join a sphere to the end, but I feel like there must be an easier way to do it. Any help would be appreciated!


I'm building a child theme and it currently has a very simple <head> section in header.php:  <head>   <meta charset="<?php bloginfo( 'charset' ); ?>">   <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1">   <title><?php wp_title( '|', true, 'right' ); ?></title>   <link rel="profile" href="http://gmpg.org/xfn/11">   <link rel="pingback" href="<?php bloginfo( 'pingback_url' ); ?>">   <!--[if lt IE 9]>   <script type="text/javascript" src="<?php echo get_template_directory_uri(); ?>/js/html5shiv.min.js"></script>   <![endif]-->    <?php wp_head(); ?> </head>   I'm guessing wp_head() is responsible for the second <title> element (it appears just there in the final HTML), but other things I've read say this is impossible.  Should I be removing the <title> from my header.php, or should I be adding something to my functions to remove the title from wp_head() (eg. remove_action('wp_head', 'title') ?  Or should I be doing something else altogether?


I want to have subsections named all the same with a number behind it. The straight forward approach I came up with is this:   \section{User Stories} \subsection*{Userstory 1} This is story 1 \subsection*{Userstory 2} This is story 2   But I though isn't this possible as a list? So I have tried a few things but none worked. I have just learned the basics of LaTeX, and I want to try some more advanced tricks in LateX, but it won't work. I have tried this and some things very similar to this:   \section{User Stories} \begin{enumerate} [label=\subsection*{Userstory \arabic*}]     \item This is story 1     \item This is story 2 \end{enumerate}   Is this behaviour even possible to automatically? What is the best approach, for not typing the number and the title every time. Thanks in advance!


Can a wizard partially switch out and replace prepared spells during a short rest?

In the section Preparing and Casting Spells (PHB 114) it is said (emphasis mine):     You can change your list of prepared spells when you finish a long rest.  Preparing a new list of wizard spells requires time spent studying your spell book and memorizing the incantations and gestures you must make to cast the spell: at least 1 minute per spell level for each spell on your list.   The first highlighted segment makes it so that a wizard is essentially preparing their spells for the day (or a very large portion of the day with a good nap).  However, the second highlighted segment indicates that the preparation for each individual spell is not that onerous (6 first level spells would take less than 10 minutes).  The wizard in my group has realized that he would like to have two sets of spells, one when combat was unlikely (5 non-combat spells and 1 combat spell) and one when combat was likely (5 combat spells and 1 non-combat spell).  Sometimes, the nature of role playing makes this impossible.  However, when the party walks up to the mouth of the cave or the entrance to the cobwebbed dungeon, it seems reasonable that he asks the party for a short rest so that he can memorize new spells (not a rest for him, as he would be spending the hour memorizing).  Assumptions I make about the wording:   It is designed to limit the Wizard class's flexibility, and thereby its power The game mechanic of a long rest is intended to represent the erasure of a wizard's spell specific memory - and thus it is free to receive new spells   Can a wizard partially switch out his spell list?  In other words, can he trade rest duration to replace a smaller number of spells during a short rest?  Note: I have asked several questions here that are at the limits of printed rules.  I understand that I can modify the rules as I see fit as the DM.  The point here is that I am working with several young people, and I don't want them walking into a AL or other 5e game and not understanding the nuances of the game based on learning house rules the first time.


How can one predict whether an individual infected with the SARS-CoV-2 virus will be asymptomatic?

According to  , half of the   virus carriers show no symptoms.   What are the biological factors that determine whether an infected individual will be asymptomatic or not?


To show the client what the finished design will look like on the actual product (brochure, business card, envelope etc.)  How do you create branding/packaging images like the ones below.  Until recently I always thought these images were photographed but looking at it closer I've realized the designs and logo are all computerized.  how do I get it to look like this and where can I get the original packaging from? further more how would I get something with typography to look 3 dimensional on piece of paper?  Would it just be easier to spend money and get it photographed?


How to implement basic arrow-key movement in the console window with java?

I'm struggling with trying to find a way to implement basic arrow-key movement in a console window. I have come across a C# script which simply uses a switch statement and some variable's, but my teacher insists on using Java.   From some other threads the answers all seemed to say that it's not possible in Java unless you install certain (correct me if im wrong) "frameworks" like JNA and/or Jline, but as a beginner i have no idea what those things even mean.  Now before you say my teacher is an idiot for thinking we could do that, he never said it had to be arrow-key movement, i just thought it'd be cool :)


What force creates the reflected wave in a string attached to a rod?

I am a student of class 11 and I have a doubt about reflection of waves on a string tied to a massless ring which can slide on a frictionless rod. When the wave reaches its end, the ring overshoots its amplitude because there is a lack of restoring force on it, as is written in the book Concepts of Physics. And in some places, it is written that this is due to superposition of the incident and reflected waves. But I am not able to understand what causes reflection of the wave in physical terms - like, which force creates the reflected wave of the same amplitude?


If the future is already priced in, how does the average/non-professional person make profit at the stock market?

It seems a common canon, that when you get to know information about the future of something at the stock market, that the price at the stock market already has this information calculated in. For example if it is expected that the next quarter a company will sell less and therefore be worth less, the price has already gone down, and if good sales for the next quarter are expected the price has already gone up because professional traders react faster (because of having more time to follow the news of the companies and better news sources, better analyzing tools, ...). Also for example for bonds the price per coupon seems to be original price + remaining dividends - likelihood/risk of non-payment for example because of bankruptcy. Simplified there is 50% chance expected that the value after the quarter announcement is $90 and a 50% chance the value after the announcement is $110, so the value before is $100. So you buy it at $100 and hope you are lucky and it will be worth $110. If you are unlucky you lost $10 per share. On average it will be $100. So to me it seems that for a non-professional it is just a gamble with an average 0 payout (before fees). Still many people seem to use it, for example for increasing money or in the USA for pension because of the missing pension system in the USA. Are those just speculators or what am I missing in my conclusions/where am I wrong/how does the non-professional person beat the predictions of the professionals? (I hope I didn't hurt anyone by the use of some terms because English is not my native language and I am not that familiar in this area) To clarify: I am asking for investing/holding a position for longer terms like at least multiple months/years, not day-trading. Even if a non-professional doesn't compete with professionals/doesn't want beat them they influence it so they can only buy it at a price that already includes expected future gains if I understand it correctly. But still people seem to make money with it. This is what I don't get. Please keep in mind that I am a beginner and have a beginner flaw in my thinking or not familiar with all effects/consequences in the market.


GE brand new front load washer trips breaker every single time within 5 mins (model GFW850SSNWW). Connected to a GFCI protected outlet (does not have TEST/ RESET buttons on it) and GFCI breaker (SWD brand) since it's in the utility room. Washer works when plugged to a standard  Can you please suggest what could we do?


By working together can a party of X size perform 2X skill checks on the same task?

For example, my entire party is versed in Arcana and they attempted to recall lore on a spell.   Party member A made the skill check while being helped by B and failed with advantage. B tried while being helped by A and failed with advantage. C tried while being helped by D and failed with advantage. D tried while being helped by C and failed with advantage. E tried while being helped by A and succeeded because of advantage.   By working together in this way can a party of X size perform 2X skill checks on the same task?


How do we know the age of Cosmic microwave background?

How do scientists know the age of the CMB? And how does it correlate to the age of universe?


Avoid automatically connecting to wireless network on windows 7

I have a internet connection with a Wi-Fi router. I use my Dell laptop to connect to it and it automatically connects to this network whenever it is available. This is just fine for me, However, sometimes one more wireless network becomes visible in my range and it seems my laptop tries to automatically connect to that network also. This causes a momentatry loss of network which is very irritating. Is there any where to configure windows not to try to connect to other networks than the one I use?


Automatically, and freely, download PDFs for a set of references

In EndNote, I know there's an option to automatically download PDF files for the references you have in your library. Is there any way to do the same thing in some kind of non-commercial software, like for example Mendeley or BibDesk?


What is wrong with parsing the ls command ?

I have been told that it is unwise to parse the output of LS due to security precautions.   The adage used was "parse sparsely and dont eat parsley"   I was attempting to count the amount of files within a directory by using   ls -la | wc -l     I was told to never, never do this but I cant grasp why.   I was told one reason is because a file name could be shuffled into another command by accident. For example, if a file was within the directory named '-l'.   I was also told about using '--', for example ls -la --. If I understand correctly this is supposed to tell bash where to signal the end of commands but even if you used this you still shouldn't parse the output of ls.   Why ?


Construct a continuous function such that $\int_{-\infty}^\infty|f(x)|\,dx<\infty$ but $\lim_{x\to \infty}|f(x)|$ does not exists.

I have to construct a continuous function such that  $$\int_{-\infty}^\infty |f(x)| \, dx<\infty$$  but  $$\lim_{x\to \infty}|f(x)|$$  does not exists.  I have already known one messy example that deals with lines and minimum distance. I just want to see different examples. I know we can construct a triangle with fixed height and decreasing base such that the area get's smaller and the integral is like the geometric series. However, the fixed height makes the limit inexistent. I just dont know how to describe that properly.  Thanks.


calling methods dynamically with reflection

I'm trying to call a method in an aspx.cs but getting an InvalidOperationException with message      Late bound operations cannot be performed on types or methods for   which ContainsGenericParameters is true.   My code is:  protected void BuildSurface(int newValue) {     IEnumerable<dynamic> models = InitializeConfigurationForWorkflow(newValue);     List<Panel> panelList = new List<Panel>();      foreach (dynamic workflowConfiguration in models)     {         Type dynamicType = workflowConfiguration.GetType();          if (dynamicType.IsGenericType)         {             Type genericDynamicType = dynamicType.GetGenericTypeDefinition();              string methodName = null;             if (genericDynamicType.In(typeof(List<>), typeof(IEnumerable<>), typeof(IList<>)))                 methodName = "GenerateListPanel";             else if (genericDynamicType == typeof(Dictionary<,>))                 methodName = "GenerateDictionaryPanel";              if (methodName.IsNullOrEmpty()) continue;              Type[] listType = genericDynamicType.GetGenericArguments();             MethodInfo method = typeof(_admin_WorkflowConfiguration)                 .GetMethods()                 .Where(w => w.Name.Equals(methodName))                 .First();              MethodInfo generic = method.MakeGenericMethod(listType);             panelList.Add(generic.Invoke(this, workflowConfiguration})); // here the error appears         }     } }   my methods that will be called look like this one:  public Panel GenerateListPanel<T>(IEnumerable<T> workflowConfiguration) {     Panel panel = new Panel();     return panel; }   The dynamic-value is a json that gets deserialized to either Dictionary or List.  Any idea what I'm doing wrong?


Can anyone explain to me how the power meter can differentiate between the reactive power and real power? If power is current times voltage, can we assume that since reactive elements give back the current to the generators the average power for using them is zero? If this true, how come indusrtries pay for reactive current?


Defining interface as variable type in JAVA

How is it possible to define a variable type as an interface :  List<BigDecimal> filter = new ArrayList<BigDecimal>();   Shouldn't we define a variable by class or primitive data types and not an interface as follows :  ArrayList<BigDecimal> filter = new ArrayList<BigDecimal>();   How is it accepting interface variable definition?


I have to include a technical document in my citations. The document doesn't have a specific author, but is rather published by an Institute. The sample bibtex entry is given below:  @manual{river2009, author = {Alternate Hydo Energy Centre}, institution = {Some Institute},  month = {August},  organization = {Some Organization},  publisher = {Some Directorate Ministry, Some Government},  title = {{Status Paper On Environment}}, year = {2009} }   When I compile the document the author entry is automatically changed to following:  @manual{river2009, author = {Energy, Centre Alternate Hydro}, institution = {Some Insitute}, month = {August}, organization = {Some Organization}, publisher = {Some Directorate Ministry, Some Government}, title = {{Status Paper On Environment}}, year = {2009}  }   And in the final citation the entry comes under the name of Energy, C. A. H instead of Alternate Hydo Energy Centre. Is there anyway in which I can preserve the author name as it is, without the entry being juxtaposed and abbreviated?   I am using  \bibliographystyle{kluwer} .


I am sorry for this elementary question, but i could not figure out a rigorous proof for why the Lebesgue integral of any function over a null set is zero.  Thanks for helping!


For periodic $f,g$ (and continuous), does $\lim (f-g) = 0 $ imply $f=g$?

Take $f, g: \mathbb{R} \to \mathbb{R} $ continuous and periodic and assume $\lim_{x \to  \infty} (f(x)-g(x)) = 0$. Does it follow $f=g$? Prove or give counter   example.   I cant find any counterexample, so maybe we should prove it:  we given that for any $\epsilon > 0$ we can find some $\delta > 0$ such that $x> \delta$ imply $|f(x)-g(x)| < \epsilon $  Let $H(x) = f(x) - g(x)$. and so $H$ better also be periodic and continous.  Now, certainly for any $\delta > 0$ we have $|H|< \epsilon $ which implies $H=0$ or that $f(x) =g(x)$.   But, we still need to prove for $x \leq \delta$  Now, this seems intuitively obvious as because periodicity and continuity:  if after some $\delta > 0$, we have that $f(x) = g(x)$ then we can find some interval after $\delta> 0$, say $[a,b]$ for which $H(x)$ is identical in $[0,\delta]$ and thus $H(x) = 0$ for every $x \in \mathbb{R}$. Now, this argument seems fishy.   Am I on the right track or I am completely off tracks?


Concurrent read and write from different programs in Java

I'm writing two programs that communicate through a text file. The first program writes to the file and the second one reads from it. However, there is a problem when the reader program tries to read from the file while the writer is still writing and reads inconsistent data. Is there a way to synchronize the read/write from two different JVMs?


Can anyone explain why commuting matrices share common eigenvector?

If two matrices $A$ and $B$ commute with each other, why would they share some eigenvector?  Does that mean that an eigenvector for $A$ is also an eigenvector for $B$ and vice-versa?


Is there a dividend effect on stock prices?

If a stock costs $100  and the quarterly dividend is $3, can I expect the stock to drop $3 in value when:   the dividend is announced? the dividend is granted?  the dividend is paid?


problem when writing an equation with latex: missing delimiter (. inserted) \end{equation}

I tried this and that, but could not solve this problem. Here is the code that produces this error:  \begin{equation} o=g(h)=\left\{\begin{array}{rcl}     1 & if & h <   0 \\     0 & if & h \le 0  \end{array}\right \end{equation}   The error is given on the line \end{equation} resides. Thanks.


how to recover data from drive which has data but not showing

im using laptop with windows xp OS..my D: drive is infected with virus..its not displaying the data but properties show a data of 9gb present in the drive.i tried show hidden files and folders also...i also tried . by typing it in search box but it didn't work..it worked well with windows8.but my OS is Windows XP.. please tell me a way to recover the data.


Why are ships in Star Wars so ridiculously easy to steal?

Throughout both continuities, we see many times that stealing ships is exceptionally easy, as they appear to only rarely be locked, and to not require keys, passcodes, etc. to fly them.  A few examples:   In the Knights of the Old Republic series, the Ebon Hawk is infiltrated or broken into by a stowaway, the Handmaiden and a gang of criminals, respectively. In The Phantom Menace, Anakin and R2-D2 are able to jump in a starfigher that apparently features a security system so weak that they accidentally fly it away.  In the Star Wars: The Clone Wars pilot movie, Anakin and Ashoka are easily able to take over The Twilight, granted the door was already open. In the episode Twilight if the Apprentice, of Star Wars: Rebels, Chopper is able to enter and pilot the Eighth Brother's ship and      Maul is able to steal a TIE Advanced.  In The Return of the Jedi, Luke is able to take an Imperial Shuttle and fly it away.     (Anakin was dead at this point, so he wouldn't have been able to help.)  In The Force Awakens, Finn and Poe were able to steal an Elite TIE-Fighter (though this one was at least connected by a cable, it still apparently had no security systems more advanced than that of a pen at a bank). We also learn that the Millennium Falcon has been stolen four separate times since Return of the Jedi.    Why aren't ships in Star Wars locked? And why can just about anyone fly them? Wouldn't people like Han, who obviously cares immensely about his ship, add some advanced security systems, or at least make the ship require keys or something?


Is there any single command or method do determine if a W7 machine is a laptop or a desktop?

I'm looking for a command, probably in 'wmic', that will help determine whether a computer is actually a Laptop or Desktop.   Normally I check in the active directory organizational unit, but this is not reliable as there are always errors made by the person assigning the OU.  Another way that I check is, Start > Run > mblctr. If it is desktop it will say that mobility centre is not available for desktops In My computer properties, under System , Model it is Notebook PC . The word notebook gives some idea of laptop.   Is There any other way, without using 3rd party software.


I am just using the regular library ( not pytest) and trying to confirm a ValueError.   test:  data = get_time_zone("sun/10-21 tz:US/Eas2tern")    Result:  if zone not in pytz.all_timezones:     raise ValueError("Invalid Time Zone Used: " + time_zone)  >>> ValueError: Invalid Time Zone Used: US/Eas2tern   I would like to test it with a similar structure;  Assert "valueError"  etc...


When I execute my code I get this error:      Error: Compile Error: Method does not exist or incorrect signature: [Id].contains(String) at line 29 column 12   Here is my code:  List<Case> cas = Trigger.new;  List<Integration__c> listAll = [SELECT id,name,username__c,password__c,URL__c,account__c,integrationwith__c FROM Integration__c ];  for(Case c : cas  ) {     for(Integration__c intObj:listAll)     {         //this line causing for compiletime error         if(intObj.IntegrationAccount__c.contains(c.Account.Name)){   Why do I get this error? How can I fix it?


How can I print elements from same list in one line in 2 colors?

I am tring to program Game in Life in python. My output looks like this. I don't really want to use any modules (those where installations and download is needed) because my old teacher said that if he won't be able to start program he will fail you. That is why I need basic python. I would love to change colors of my "1" to green to make it easy to spot changes while program is working. I heard about colorama, but I am not sure how to make it possible to choose every "1" from my list and paint it without changes in output besides colors. Screenshot:


I have written the following code  \newpage \begin{figure}   \centering   \includegraphics[height=\textheight]{my_fig}   \caption{My caption}   \label{fig:my_fig} \end{figure}  \newpage \bibliographystyle{splncs03} \bibliography{my_bib}   The image covers an entire page. When I compile my document, the image comes after the bibliography and I receive the following warning   LaTeX Warning: Float too large for page by 22.75pt on input line 221   I want the image to be put right before the bibliography. How can I do it? I already tried with the options [h] and [!h]. Consider also that I am using the llncs style.


Error: Cannot convert the value of '{!pitem.Stock}' to the expected type

<apex:page controller="StoreFrontController" tabStyle="Product__c" > <apex:form>      <apex:pageBlock title="Our Products">         <apex:pageBlockSection columns="1">             <apex:pageBlockTable value="{!products}" var="pitem">                 <apex:column headerValue="Product">                 <apex:outputText value="{!pitem.Name}"/>                 </apex:column>                 <apex:column headerValue="Condition">                 <apex:outputText value="{!pitem.condition}"/>                 </apex:column>                <apex:column headerValue="Price">                 <apex:outputText value="{0,number,currency}" style="text-align: right;">                 <apex:param value="{!pitem.Price}"/>                 </apex:outputText>                    </apex:column>                 <apex:column headerValue="Stock">                 <apex:outputText value="{!pitem.stock}"/>                 </apex:column>                 <apex:column headerValue="Qty to Buy">                 <apex:inputText value="{!pitem.quantity}" rendered="{! pitem.Stock}"/>                 <apex:outputText value="Out of Stock" rendered="{! NOT(pitem.Stock)}"/>                 </apex:column>             </apex:pageBlockTable>         </apex:pageBlockSection>         <apex:pageBlockSection>             <apex:commandButton title="Add to Cart" value="{!addToCart}"/>         </apex:pageBlockSection>     </apex:pageBlock>     <apex:pageBlock title="Cart Contents" id="shopping_cart">         <apex:outputText value="{!cartContents}" escape="false" />     </apex:pageBlock>     </apex:form> </apex:page>


I see there are many questions with this title, but this one is different, so please give it due thought:  Is time travel possible? If so, Can we go both forwards and backwards in time?  Paradox:  I am studying for a very competitive exam, wherein I must put in a LOT of effort to hope for any success. Now, I am lazy. And assume that time travel is possible, and I have access to it.  I decide to check my future, and (god-permitting) I see that I have passed with flying colors. Now, I "come back in time" and enjoy life, and don't study. So, it is just Impossible that I succeed. So, where is the flaw??  Does this prove that time travel must not exist, and will not exist?


Macbook Pro 13" 2015 with OS X Yosemite on board. I've been trying to install OS X El Capitan, but always get the following message:  "This copy of the Install OS X El Capitan application can't be verified. It may have been corrupted or tampered with during downloading."  By the way this is not a date time issue, date is correct on my computer.    How can I fix this? Who knows the solution, please help.


Let $f$ be an entire function on $\Bbb{C}$ such that $|f(z)|\le 100 \ln |z|$ for $|z|\ge 2$ and if $f(i)=2i$, then what is $f(1)$?   I think $f$ will be constant i.e. $f(1)=2i$, but I'm unable to use liouville's theorem or any theorem which proves $f$ is constant.


Heisenberg's principle in classical world

I have a ball with me and I have been observing it's position which remains constant at a place only, hence it must be largely localised, further as it remains on the same place from so long, it's velocity must be largely localised to 0 only. Now with both momentum and position know to any degree, Where is the uncertainty?? With the understanding of quantum mechanics, we must expect the "fixed" ball to have any arbitrary momentum, but that is not the case. Where am I going wrong??


Box and title of the box containing code

As the attached picture describe, this is what I am trying to replicate. Now the text does not need to be the same, since I am going to write different content inside but I really like the way this Figure is presented, with a title in between two lines.    Are they using a package I am missing or a strategy I am not aware of ?


What is the connection between the standard basis and some other basis in $\mathbb{R}^n$?

For example if i have a linear operator $\ T:\mathbb{R}^n\to \mathbb{R}^n$ and some basis $\ B=\{v_1,v_2,..v_n\}$.  Let $\ [T]_B$ be the representation matrix of $\ T $ with respect to the basis $\ B$. for example if I do $\ [T]_B*v_2 $ do I get the coordinates of $\ v_2$ in the standard basis?