Let's assume I'm using this character.  (source: ) How would you implement collision detection for it? Using a bounding box doesn't seem to be a good approximation, because the bird's shape is nowhere near a square. I was thinking of having a sort of quad tree data structure inside the object that represents portions of the image. Each leaf could be either false (in case it covers the white/transparent space outside the bird) or true (in case it represents an area of the bird i.e. beak, eye etc). Then somehow test the only obstacle in the scene for collision with the bird. But my problems in my approach are:  I don't know how to initialize the quad tree. Once the quad tree is initialized, I'm not sure how to traverse & use it once the obstacle is within the coordinates of the image.  How would you do collision detection with non-squarish characters? LE: The other approach I've seen was to use multiple bounding boxes. For example I'd have one or a few bounding boxes for the beak, then a few of them for the hair or the tail. But it can get tedious. If this is a valid approach in my case, how would I generate those bounding boxes? I doubt I'd have to have them hardcoded in my program. LE2: I care about fairly precise collisions. I can't imagine how a single bounding box or circle can at least approximate decently that shape, so this approach won't work.


Fix overlap issue to show drop-down arrow for Sort by: option list on the new Blog search results page

The newly re-designed  search results page displays the results by sorting them in its "Relevance" (by default). These results can also be sorted/filtered by using the "Date" option. But, due to the current overlap issue there is no way one can tell if there is any option at all. Let me illustrate this by sharing some screenshots.  Try searching for "Joel Spolsky" (or whatever you prefer) in the  (located on the right side panel). Pay attention to the top right side of the search results page where you will see the "Sort by: " label. Here is the screenshot of the same:        In the above screenshot, the "Relevance" option is slightly overflowed (marked in Red circle) outside the gray color outlined option box. But, if you look very carefully, you can see the drop-down arrow overlapped on the letter "n" (marked in Blue circle). Just out of curiosity, I clicked on it to see what other option is available to choose from, and here is what I get:        The "Sort by:" drop-down select box does offers a "Date" option to choose besides the "Relevance". Upon selecting the "Date" option, the page was refreshed with new results sorted by date as expected. But, notice how the drop-down option box looks now:        You can see the drop-down arrow right next to the "Date" option which clearly gives an indication to the user that a options list is available for the selection and/or the current filter applied to the search results shown on the page. Whereas, in case of "Relevance" option due to the width of it, the drop-down arrow got overlapped.  Upon doing inspect element I found out the CSS code and the property that was causing this issue. Here is the relevant code:  .gsc-selected-option-container { . . /* width: 50px!important; */ . . }   All I had to do is uncheck (comment out) the width property, and here's what it looks like now:        See the difference. The "Relevance" option now perfectly fits into the select box along with the drop-down arrow on the right side. The drop-down arrows are definitely universal and IMO displaying arrow would make it more intuitive for users. Please fix this overlap issue at the earliest. Also, though commenting out width property solved the issue but it might have other drawing implications somewhere else. I didn't experiment much. I would leave this to SE's UI/UX team for further experiment.  Please share your thoughts, ideas or any suggestions.  P.S.  I can reproduce this on the three browsers i.e. Chrome (Version 43.0.2357.134 (64-bit)), Firefox (Version 39.0) and Safari (Version 8.0.7 (10600.7.12)) -- MacBook Pro (Retina, Late 2013; OS X Yosemite Version 10.10.2)


Why automatic mode is worse than manual?

I have bought a micro 4/3 camera recently and only getting into the basics of photography. What I heard on photo forums is that a rule of thumb is to try not to use an automatic shooting mode and prefer a manual mode. In the manual mode I can control shutter speed, aperture and ISO as well as many other settings. However, it takes quite some time to balance the aperture, shutter speed and ISO, and I am not talking about the other settings. So, I wonder why can't the automatic mode adjust these settings better? What makes it so difficult? Why should I always try to use the manual mode?


"The reason is that" vs. "the reason is because"

The reason we cannot go is [because/that] our car needs new tires.   Which word to choose?


Connecting a map to live data from Yahoo Finance

I have a vector world map and am trying to connect it to Yahoo Finance, Live, in such a way that:  a) If a particular country's currency goes down, the map of that country will go RED and if it goes up then it's map would turn Green. b) Mouse over will display the 'Price' and 'Change'  May I kindly request everyone to please help me with an appropriate solution.


Suppose we have a simple discharge tube with two electrodes connected externally through ammeter and battery and evacuated internally.Now we shine radiation of suitable frequency on emmitter so that electrons are emmitted and photocurrent flows.Now my doubt, is the current flowing in external circuit measured by ammeter the same as that flows in the vacuum between the two electrodes due to photoelectric effect?Suppose 100 electrons are emitted per second from emitter plate.Will 100 electrons pass through any cross-sectional area in between the two electrodes and is the expression I=neAv valid for photocurrent?


Installed Free Windows 10 Upgrade - Months Later Had To Restore System....How Do I Get Windows 10 Again?

I upgraded an old laptop running Windows 7 to Windows 10 back when Microsoft was giving them away.    Since then, the entire OS just....well....died on me.  I tried doing the automatic recovery by booting into safemode.  That froze up half way and after that I couldn't even get to safemode anymore and a regular boot would just power down my laptop.    Without any media for Windows 10, I used the recovery partition.  Now I'm back to factory specs (Windows 7).  Is there any way to get the Windows 10 that I had before installed again?  IE - without paying for it.


The way to use `/usr/bin/env sed -f ` in shebang?

Typing /usr/bin/env sed -f in terminal works.  But if use it as a shebang,   #!/usr/bin/env sed -f  s/a/b/   The script will be fail to execute:  /usr/bin/env: sed -f: No such file or directory   I kind of believe that it's related with the -f. But how to resolve this?


User managed to post a question twice within the same second of each other

Somehow a user managed to accidentally post a  twice:    I may be missing something, but this shouldn't be able to happen, should it? They should be subjected to a 45 minute cooldown between questions shouldn't they?


Submitted to a non Scopus-indexed journal, later found that University only accept Scopus journals. How can I submit to another journal?

I submitted a paper to Thomson Reuters ESCI Journal, and they are asking me to complete a registration and pay a fee of around $400 to publish the paper.   But later I found that my University gives preference to Scopus-Indexed journals. How can I cancel the previous submission (the paper has not been published), and how can I submit to another Scopus-Indexed journal?


How to add pattern to bash completion (for unzip)?

When I type   unzip <tab>   I get a list of all files ending in .zip, which is the standard behavior of tab completion for the unzip command.   However, I also want bash completion for unzip list files which end in .udp, in addition to .zip files. How can I achieve this behavior in my local .bashrc?


I am new in shell.  I'am writing a very basic script:  #!/bin/bash example() {      echo "Code that don't need sudo."     sudo -s      echo "Code that need sudo"  }  example   After running this script i expect :   prompt Code that don't need sudo. shell ask me password  if the password is OK prompt Code that need sudo.   But after typing the good password the prompt Code that need sudo. does not appear why and how to fix it ?


What is the logic of priority of operations?

For example $2+2\times2$ is $6$ not $8$.   Actually $+$ and $\times$ are binary operations on $\mathbb Z$. but here there is an triple $(2,2,2)$ which we sent to $2+2\times 2$. So we have to put and order for applying operations as binary such that $$a+b\times c \: : \: (a,b,c) \to a+(b\times c)$$ with assuming that $(\cdots)$ has priority more.  My question is why multiplication has priority more than addition? We could also define $$a+b\times c \: : \: (a,b,c) \to (a+b) \times c.$$


How to encrypt a shared NTFS partition that is used by Windows and Linux on a dual boot system?

I use an NTFS partition for data that I want to access with applications both on Windows 10 and Ubuntu (Text files, Emails, Source code, ...).  Is there a way to encrypt this data partition such that it stays accessible for both OS that I have installed? Also it should be possible to make a backup, the backup however doesn't need to be encrypted (even preferably not encrypted).


Is $\frac{1}x\cos\left(\frac{1}x\right)$ Lebesgue integrable on $[0,1]$?

I have to decice if the following function is Lebesgue-integrable on $[0,1]$:  $$g(x)=\frac{1}x\cos\left(\frac{1}x\right) $$ where $x\in[0,1]$.


How can I solve this?  /usr/bin/ld: cannot find -lssl /usr/bin/ld: cannot find -lcrypto collect2: error: ld returned 1 exit status error: command 'x86_64-linux-gnu-gcc' failed with exit status 1   I tried installing the following commands  sudo apt-get install -y libxml2-dev libxslt1-dev zlib1g-dev python3-pip sudo pip install lxml


Peaches, apricots and medlars: combination exercise

We have to create a fruit composition with peaches, apricots and medlars. How many ways is it possible to create a basket of 20 pieces, under the condition that there are at least 6 peaches, at least 4 apricots and at least 2 medlars?  My solution: I named with $a =$ number of apricots; $n =$ number of medlars, and $p =$ number of peaches. The condition want that into a basket I must to have $12$ fruits: $6+4+2=12$. I have thinked that there are class 8 repetition combinations of the 3 '$abc$' objects i.e.. I know that for the combinations (without repetitions) there is a formula: $$C_{n,k} = \frac{D_{n,k}}{P_k} = \frac{n!}{k!(n-k)!} = {n \choose k}$$ and with repetitions $$C'_{n,k}=\binom {n+k-1}{n-1}=\binom {8+3-1}{8-1}=C'_{8,3}=\binom {10}{7}$$ The result is $45$ but $\binom {10}{7}=120$.  My level of combination theory is low. I have never made combinations with repetition. I ask you if my reasoning is right, if there is another solution and what I did wrong.


Well we know that Force Lightning is generally considered a Dark Side ability in both Canon and Legends, we also know that there was a Light Side variant of the power known as Electric Judgement/Emerald Lightning, and I also know the Baran Do Sages had their own version called 'white lightning technique' so is Force Lightning just manipulating/generating electricity or is it something else entirely?  Force lightning was a well known Force ability used most often by practitioners of the dark side of the Force, especially the Sith. The ability was commonly referred to as Sith lightning due to the affiliations of its typical users and manipulation of lightning. Electric Judgment, also known as Emerald Lightning, was a Force technique used by the Jedi to spray electric bolts of variable intensity from the hands and fingers.   They were also proficient in a white lightning technique, possibly a variation of Electric Judgment.


I accidentally formatted my C: drive while I was using Ubuntu

My C drive had Windows installed and all of my important files. I know there is a way to try to recover it using testdisk. But I wanted to know if there are anythings that change since the dive I want to recover had Windows installed on it. Please help!!!


Automate keyboard layout change in Ubuntu 20.04

I couldn't find the Belgian keyboard layout during Ubuntu 20.04 install, the option seems to be missing (some "belgien" layouts are listed, they're not what I need). The workaround is to execute the command sudo setxkbmap be at startup. Of course I'd like to automate this hassle. I've tried putting the command (both directly and as a (tested) script) in crontab, preceded by @reboot through sudo crontab -e. The cron log lists this script so I suppose it has been executed, however, on startup the correct keyboard layout had not been loaded. I thought that perhaps it got overruled afterwards by system settings, but adding a minute of sleep did not work either. Neither does evoking crontab -e as regular user. Nor doing something like @reboot root /path/to/script.sh. I've looked at anacron, but that one doesn't seem to be promising more control at startup either. I've also tried putting the script in /etc/profile.d/. This breaks the system. Using ~/.profile appears not straightforward either for that matter, with reportedly inconsistent behavior. Listing bash /path/to/script.sh in startup application preferences, too, is ineffective. So do I really need to create a systemd service just for this? It seems like such a complicated ordeal for just changing the bloody keyboard layout..


I need help Proving this: "For Every $n\in \mathbb{N-{0}}$ Prove the following: $$\sin(1)+\sin(2)+...+\sin(n)=\frac{\sin(\frac{n+1}{2})\sin(\frac{n}{2})}{\sin(\frac{1}{2})}"$$ I assume we have to use Induction On this but I failed to do so If anyone can provide a simple and clear proof I would be grateful!


How to find out whether there is leap year between a date range?

Could anyone please advise how to find out between a date range if there is leap year or not.  e.g Start Date = 1 Jan 2019 and End Date is 31 Dec 2022  now using formula field or Apex , how to check if there is a leap year is present or not between a date range.


Why is a flight going west longer than the same flight going west to east?

I noticed that my flight going east to west took almost an hour longer than when coming back from west to east in continental US. What is the reason for this?


I have a little trouble understanding how to write a mathematically notation for r = x%n. How should I write this in math notation if I want to get the remainder value, after dividing by $n$? $r$ is also not just an integer in this case, just the rest of $x$ (double) divided by $n$ (integer), "$r = \operatorname{mod}(5.4, 3) = 2.4$" in this case. I think $x \equiv r \mod n$ means something different. Edit: After thinking a while, I am still confused by the notation. Why is the notation $x \equiv r \mod n$ used at all? If $\operatorname{mod}$ is a mathematical operator like $\sin$ or $\cos$, why is the notation $r = \operatorname{mod}(x,n)$ not used always?


Can I ready an action to roll away from an attack or special attack?

In the video game Dark Souls, a key strategy is to watch for an enemy to start making an attack, such as a melee attack or breath weapon, whereupon you tumble out of the way to avoid the attack. The attack strikes your previous location, and you are unharmed.  Is it possible, within the standard rules of D&D 5th edition, to ready an action to avoid an attack or special attack (e.g. breath weapon) in this manner?


Generators of a finitely generated free module over a commutative ring

Let $L$ be a finitely generated free module over a commutative ring $A$. Set $n=\operatorname{rank} L$. Let $x_1,\dots,x_m$ be generators of $L$. Then $m \ge n$? If $m = n$, then is $x_1,\dots,x_m$ a basis of $L$?


Do I need a visa for Zurich, if my connecting flight stops for 24 hours in Zurich?

Do I need visa for Switzerland, if my connecting flight stops at Zurich for 22hrs and I want to visit Zurich during those 22 hrs? I have US H1-B visa. I'll be travelling from Minneapolis to Mumbai (India) via Zurich. I hold an Indian passport. Also while returning back, I have a halt in Vienna for 16 hours.  What type of Schengen VISA would I need and what is the procedure for that visa?


Confusion about sampling rate of a scope and its bandwidth

In sampling theory the BW is determined by the half of the sampling rate. But in a scope things seems to be different if I'm not mistaken.  But for example if you look at the front panel of the oscilloscope model TDS1002B, among other things two things are written. It is written 1GS/s and it is also written 60MHz.  So the BW is explicitly given here as 60MHz. On the other hand if we apply Nyquist law we could have also conclude the BW is half the sampling freq. so 1GHz/2 = 500MHz. So where am I thinking wrong here?


I have downloaded a bin installation file named "LianjaAppBuilder-1.2.2-linux-x86_64-installer1.bin". I want to run it in terminal but when i type "./LianjaAppBuilder-1.2.2-linux-x86_64-installer1.bin" it says not such file or directory is found. How can I run this file?


What are the dangers of accepting gifts from unknown accounts on Steam?

A user named 'steamfairy1' gifted me a game on Steam. I don't know this user, their profile shows no games, no friends and zero hours played. The profile of 'steamfairy1' was created the day I received the gift.  It very much looks like a scam, but I can't figure out how the scam is supposed to work. What's the worst thing that could happen if I accept the gift? Any idea what the trick here is? It could be just a random act of kindness and I'm just paranoid…  I contacted the Steam support, but they were unhelpful as usual: responding in the wrong language and with a canned one-liner that didn't make a whole lot of sense or had much to do with my question.  Keywords (not really tags, but I want this to be searchable): steamfairy, steam fairy


Can I get individual man pages for the bash builtin commands?

Is there anywhere you can download a manpage for every builtin commands?  I know you can just use help or man bash and search to find info about it, but I want them separated, so I can just do man read and get the read manpage.


In The Hobbit, what were the origins of the Dwarves?

After watching the movies, I was left wondering: where do the Dwarves come from? Do they all originate from the same place, or do they have different "countries"? Also, are the dwarves we meet all related to each other?


I want to upgrade from Ubuntu 16.04.5 LTS to 18.04, so ran sudo do-release-upgrade. After downloading and extracting bionic.tar.gz I get:  Can not upgrade   Your python3 install is corrupted. Please fix the '/usr/bin/python3' symlink.   I saw  and so I did sudo ln -sf /usr/bin/python3.6 /usr/bin/python3 thinking that it would be a similar problem. But that didn't work (still same error message).  I have a few python versions:  $ ls /usr/lib | grep python python2.7 python3 python3.5 python3.6  $ update-alternatives --display python3 python3 - auto mode   link best version is /usr/bin/python3.6   link currently points to /usr/bin/python3.6   link python3 is /usr/bin/python3 /usr/bin/python3.5 - priority 1 /usr/bin/python3.6 - priority 2   How do I fix python3?


I have the following classes  Entity  class Entity {   public:     virtual std::ostream& write(std::ostream& os) const {         os << "Can't output Entity";         return os;     } };   And StringEntity  class StringEntity : public Entity {   public:     std::string data;      StringEntity(std::string str) {         data = str;     }      std::ostream& write(std::ostream& os) const {         os << data;         return os;     } };   Using these classes like so  int main(int argc, char** argv) {     StringEntity entity = StringEntity("MY STRING ENTITY");     Entity gen_ent      = (Entity) entity;      entity.write(std::cout)  << std::endl;     gen_ent.write(std::cout) << std::endl;     return 0; }   Because the base Entity class' write function is virtual and write is overriden in the derived StringEntity class, I would expect both write statements to print out MY STRING ENTITY. Instead, the first one correctly prints MY STRING ENTITY, but the second prints Can't output Entity.  How do I override a function such that it is completely overriden (ie. not dependent upon how a variable is declared)?


Mouse pointer and keyboard Freeze when pluggin in external hard drive

so as I say in the title I have this very big, annoying problem. On my new PC (HP Omen 2020, i7-10750h, Nvidia RTX 2070, 16GB RAM) when I connect an external hard drive (precisely an WD My Passport Ultra, 3TB) I get occasionally mouse and keyboard freezes. Practically, the system becomes unusable. The mouse and keyboards works, they even show in device manager, but from time to time (too often) they "freezes": mouse pointer freeze, and it won't respond to my input, and keyboard too, if I type something it will not respond. First I thought this was a behaviour due to bad drivers, or something related to my new PC, the fact that it has USB 3.1 ports. But then I've noticed that this fact happens only when I connect my WD Hard Disk (which is USB 3.0) to my pc. I've tried some stuff online, suggesting to update drivers, change some windows settings, but with no success. My guess is that the hard disk and the mouse-keyboard does interfere with each other in some ways. I guess that it's a software problem, at driver levels maybe, not a physical one. When the mouse doesn't respond, I've tried to use the touchpad on the notebook, and it does work. So it's not a windows freeze, it's just the device (mouse-keyboard-receiver) that doesn't respond. The mouse and keyboard are from Logitech, bot connected with the Unifiying receiver (a wireless receiver they provide for the mouse and the keyboard). Model: MX Anywhere 2S for the mouse, K360 for the keyboard. Please, help me solve this problem, monday I start taking my engineering class lessons from MS Teams, and I need my pc up and running and well responsive (I need to access data from the hard disk while I take classes). PS: I've seen that there are some other questions like this in the forum, but none of them seems to provide a solution to the problem. I would also change the external hard drive in the future, but I need to know that the problem with this one won't show with another hard drive, or other devices. I've already sent this very same post to Microsoft community, I really need help with this thing otherwise it will be a problem following my online classes. Thank you if you will try to help me EDIT: On the notebook in question I have 4 USB 3.1 Ports, with two ports on each side, and a single Type-C Thunderbolt port (I'm not counting that one cause both the hard disk and the logitech receiver are USB 3.0 type A connectors). I've already tried switching USB port, connecting the WD Hard Disk to another port, doing the same on the logitech receiver, and I've even tried putting them one on the left side and the other to the right side, to minimize "interference" as someone suggested. But nothing, I still got this problem, which seems driver-related. Hope this will give more info


If Kerckhoffs's principle is correct why does the NSA not publish their Suite A ciphers?

The  offers little insight. To quote the page:     the decision to keep them secret is in keeping with a layered security   posture   How should we (the cryptographic community) interpret the NSA's decision to keep their best ciphers private? It seems that if obfuscation works, then Kerckhoffs's principle represents an extreme viewpoint and should not be applied generally.


MacBook Pro stuck in gray screen when booting

I've got a Late-2011 15" MacBook Pro stuck in the gray screen when booting AFTER login. I've tried removing the drive (it's non-retina) and booting from a working bootable Yosemite installer, no luck. (it sees the startup USB drive, the progress bar progresses, but stuck at the gray screen again even without a drive.  Tried NVRAM reset (cmd option P R), it has reset (the login sound's volume changed) but nothing changed.  Tried holding D on startup, AHT doesn't start, instead, it tries to boot into the OS.  Tried Cmd V, it sometimes works and displays the verbose output, sometimes, it acts like I haven't even pressed. Again, stuck after login.  Tried booting again from USB, I select USB (after seeing both drives correctly), but no luck, it's also stuck.  I've stumbled upon this:    I've tried booting into single user mode with Cmd S, it worked ONCE, I've disabled the graphics extensions just as shown at that post, restarted, but again, nothing changed.  More weirdly, now the Cmd S doesn't work either. It just takes me to login screen without showing the terminal, just as I haven't pressed anything.  Why would this happen? Why would a Mac refuse to enter hardware test mode, single user mode, or refuse to boot from a working bootable Yosemite drive both with or without the main drive installed?  UPDATE: I've run the AHT and got an error:  4MEM/66/40000000: 0x84e0ec98  It looks like a memory issue, but I'm not sure.   UPDATE 2: I've tried reinserting the RAMs and the the problem is not reported anymore. However, the Mac still won't boot.


I would like to paraphrase a sentence:     "This is how the costs of each course should be."   So my idea was:     "This is how the price/prices per course should be."    What are the differences between singular + per vs. plural + per?  Or  If you have better paraphrases, you're very welcome to share them.  Thank you very much :)


Is Jon Snow still bound by his oath to the Night's Watch?

The Night's Watch begins:     Night gathers, and now my watch begins. It shall not end until my death.   Since      Jon Snow has died and been resurrected   is he still bound by his oath?


How to create an computationally efficient fan or sheet of light in Cycles?

I want a light source to put out a sheet or fan of light. It would illuminate only along a line if it were shining on a flat surface. But I want to shine this on complex shapes.    One way I've tried is to put a point light or emitting object between two closely spaced parallel planes. It can cast a line of light if I crank up the sample count to several thousand, but it's noisy, not well collimated, and of course slow. This is for an animation.


Why the software center doesn't allow multiple downloads?

I was wondering why the software center doesn't download all the requested apps and install one by one as they finish to download. Or instead why the software center doesn't download an app while the other is installing


Question past perfect, action/state finished

Does the sentence "I have been married for five years" mean that I am still married?


This question was asked in my complex analysis quiz and I was unable to solve it . So, I am asking for help here.  If f(z) is analytic and non-zero in the disk |z|<1 , prove that 0< r< 1  exp($\frac{1}{2\pi} \int_{0}^{2\pi} log|f( re^{i\theta})| d\theta)$ = |f(0)|.  The term $\frac{1}{2\pi} \int_{0}^{2\pi} log|f( re^{i\theta})| $ in exp looks mean value of $log|f(r e^{i \theta})|$ over 0 to 2$\pi$ but I am unable to use it to simplify the term asI am unable to find what will be the value of mean in this case. So, can you please help me in simplifying it?


I want to have a primed product symbol, i.e. something like  $\prod^\prime$   but it puts the prime on top of the product symbol instead of next to it (as a superscript, as it usually works). Does anyone know how to do this?


Is the trace of the product of two positive semidefinite matrices always nonnegative?

Is $\mbox{tr}(XY) \geq 0$ for all $X, Y \in \Bbb S_+$?


I am using C++11 and have a general question. I have a counter to count number of messages received so it's just a simple "count = count + 1" but my co-worker said I should put a mutex around it. I would think this simple operation only takes a few assembly instructions and it's impossible to be preempted by another thread. I'd like to hear input from experts. Thanks.


Is there any difference between the free homotopy classes and homology classes of oriented loops in a closed oriented surface $S$?  I know that the conjugacy classes of the fundamental group $\pi_1(S)$ are in one to one correspondence with the free homotopy classes of oriented loops in $S$. But the conjugacy classes of the fundamental group $\pi_1(S)$ are identified with the homology classes of loops in $S$. Therefore, free homotopy classes and homology classes of loops in $S$ are in one to one correspondence. So there is no difference if we say homology class or free homotopy class. Am I right?


Notice that the wp_enqueue_style is not being called correctly!

I get this error due to one of the plugins which I rely on.   Notice:  wp_enqueue_style was called incorrectly. Scripts and styles should not be registered or enqueued until the wp_enqueue_scripts, admin_enqueue_scripts, or init hooks.   What does this error mean and how do you fix it?  Mind due that this is not a critical error. It only appears when I put WP into debug mode.   The full plugin-code is below.   It's one heck of a plug in that makes it a breeze to deal with the highly complicated and hierarchical cats. I'm posting it not just for the sake of debugging where the bloddy error is but also to hope that it helps someone.   <?php /*  **************************************************************************  Plugin Name:  Category Collapse Description:  Makes children categories hidden on the Write screens until an icon is clicked. Version:      2009.02.12 Author:       Viper007Bond Author URI:   http://www.viper007bond.com/  **************************************************************************/  class CategoryCollapse {      // Plugin initialization     function CategoryCollapse() {         if ( !is_admin() ) return;          wp_enqueue_style( 'category-collapse', plugins_url('/category-collapse/category-collapse.css'), array(), '2009.02.12', 'screen' );         add_action( 'admin_head', array(&$this, 'edit_form_advanced') );     }       // Output the Javascript (it's not in an external file due to the dynamic image URLs)     function edit_form_advanced() { ?>  <?php     } }  // Start this plugin once all other plugins are fully loaded add_action( 'plugins_loaded', create_function( '', 'global $CategoryCollapse; $CategoryCollapse = new CategoryCollapse();' ) );  ?>


Probability of drawing certain hand, incorrect answer, but why?

So I am drawing $5$ cards from a standard deck of $52%$  I want to find the probability that I draw $5$ consecutive cards of same suit with no card looping, and the ace is card $1$.  So the consecutive cards can start on any of $A,2,3,4,5,6,7,8,9$ but can't start on $10$ since that would not complete, e.g $10,J,Q,K$, and then it can't loop so doesn't work.  So we should have $\frac{9*4}{52}$ starting cards, being the four suits and the $9$ possible numbers. Then we should have four appropriate options, being any of the four cards that needs to be grabbed, out of $51$ remained, and then three cards out of $50$  Giving me: $$\frac{9*4}{52}\cdot\frac{4}{51}\cdot\frac{3}{50}\cdot\frac{2}{49}\cdot\frac{1}{48}=2.77*10^{-6}$$


VWP travelling for 80 days then going to Canada, can I reenter the US and for how long?

I am travelling in California at the moment under the Visa Waiver Program. I am going to be here until the 9th of December then heading to Michigan for Christmas. I was planning to spend some time in Canada to reset the 90 days but have just heard this isn't possible.  I already have the ticket etc booked, will I have an issue driving back into the US even if I am clearly leaving in a few weeks?


in our company we developed an android app installed on nexus 7 tablets and on tablet we release to several customers. This app stays in foreground active 24/7 but we have problems in monitoring  the devices due to the restrictive access policies of unrooted Android devices.   We can't for example reboot the device remotely.  We are evaluating the possibility of installing Ubuntu touch to replace android on this tablets. Does Ubuntu touch offer more freedom for the remote access of the device? May I do remotely everything I could do normally with the tablet?   Moreover, are the apps developed with ubuntu sdk stable enough to run 24/7?  Thanks


Can an airline offload you for not having a visa when the destination country offers visa on arrival for your country's passport holders?

My son was travelling using multiple carriers from Dar-Quito via Nairobi, Amsterdam and Panama City. He had through tickets for both onward and return journeys.  Ecuador issues visas on arrival for Indian citizens.  A letter from the Ecuador embassy in India, downloaded from their website, was also shown to them along with all valid documentation.  The airline, KLM, which was flying him from Nairobi to Panama City, did not allow him to board at Nairobi.  Are they right in doing this and why? If not what needs to be done?


I always stuck on this.     Withania somnifera has proven itself in treating depression and anxiety. OVER   Withania somnifera has proved itself in ...   Whether to use past participle is confusing in such cases. Both seem okay. Another such case is light-weight software that opens fast and light-weighted software that opens fast.


Interesting Proofs using degree theory technique

Many times I faced proofs using degree theory technique and I am interested in such proofs and I want to know more about powerfulness of  this technique and see more proofs using this technique. I would be appreciate if you show me your experience about this.


Can concentration spells be "adjusted" while silenced?

For an example, the party is fighting Strahd, a vampire spellcaster.  The party cleric casts Dawn, off center on Strahd to only affect him. Then the party wizard casts silence directly on top of Strahd, which will also affect the cleric.  On Strahd's turn, he moves out of the effected area of Dawn.  When the cleric's turn comes back around, they will attempt to move Dawn to return Strahd into the spells effected area. The Relevant parts of Silence (from PHB p.276):  For the duration, no sound can be created within or pass through a 20-foot radius sphere centered on a point you choose within range. ... Casting a spell that includes a verbal component is impossible there.  This does make it clear that as long as the cleric remains inside the effected area of silence, they cannot cast any spells with verbal components, which shouldn't be a problem as they have already cast the spell, and are just concentrating on it. The relevant parts of Dawn (from XGtE p. 153-154):  Components: V, S, M (a sunburst pendant worth at least 100gp) If you're within 60 feet of the cylinder, you can move it up to 60 feet as a bonus action on your turn.  Moving the cylinder is not "casting a spell," however it is not specified whether or not this bonus action would require the same components as the initial casting of the spell.  If doing so does not require any verbal component, then that also would mean that the cleric does not need the other components. This means if an ally of Strahd took the sunburst pendant from the cleric this would not stop them from concentrating on the spell, or from being able to move the cylinder on their turn. Given this situation, is it possible for the cleric to move the Dawn cylinder while remaining inside the silence area?


prove $\sqrt{a_n b_n}$ and $\frac{1}{2}(a_n+b_n)$ have same limit

I am given this problem: let $a\ge0$,$b\ge0$, and the sequences $a_n$ and $b_n$ are defined in this way: $a_0:=a$, $b_0:=b$ and $a_{n+1}:= \sqrt{a_nb_n}$ and $b_{n+1}:=\frac{1}{2}(a_n+b_n)$ for all $n\in\Bbb{N}$    To prove is that both sequences converge and that they have the same limit. I don't know how to show this. I have spent 2 hours on this, no sign of success


Evaluating $L=\lim\limits_{x\to \infty}\left[\left(\left(\frac{x+1}{x-1}\right)^x-e^2\right)\ x^2 \right]$

$$L=\lim\limits_{x\to \infty}\left[\left(\left(\frac{x+1}{x-1}\right)^x-e^2\right)\  x^2 \right]$$ $\displaystyle{\lim_ {x\to \infty}}\left(\frac{x+1}{x-1}\right)^x$ is $1^{\infty}$ form and limit is $e^2$ so $L$ becomes$0\over0$ form. let $t=1/x$ $$L=\displaystyle{\lim_ {t\to 0^{+}}}\frac{\left[\left(\frac{1+t}{1-t}\right)^{1/t}-e^2\right]}{t^2}$$ How I do proceed now?


Is the brass brazier required for the Find Familiar spell, or can it be replaced by a spellcasting focus/component pouch?

When spell components are consumed or have a cost, they need to be provided and cannot be substituted by a spellcasting focus. The  spell has such components:  10 gp worth of charcoal, incense, and herbs that must be consumed by fire in a brass brazier  Now obviously, the charcoal, incense, and herbs have to be provided as they have a specified cost and are consumed. However, what about the brass brazier? Does the caster have to provide that as well, as there are components that have to be provided and they directly interact with the brazier? It doesn't logically seem like something a component pouch could replace, mostly those things are some small items. On the other hand it seems unreasonable to carry a brass brazier around, sounds heavy.  A related question about the brass brazier:


how do I long expose in harsh light for a lake view?

I have this problem of long exposure in harsh light. This in a lake side where I wanted to get that silky movement of water with a stone in foreground. However, since the daylight was harsh my images were over exposed and much of the details were lost. How should I get that silky look of water with long exposure in a harsh daylight?


Windows Linux Subsystem - Accessing Files outside of Ubuntu

Why, when I create a file from within Windows for example, can I not see it under the Linux sub system in Windows 10 (bash.exe)   The screenshot should explain.  Folder: OMG was created from within Windows Explorer.  Folder OMGBash was created from with Linux sub system bash.exe  When a folder OR file is created outside of bash.exe I can never see it, regardless of permissions and ownership.  To show the information I have had to use Cygwin to show file permissions, I have also altered the permissions to see if the folder would appear. (The two command windows at the bottom)   Screenshot showing folder, bash.exe and Cygwin permissions:    I am trying to move all my Cygwin scripts over to the Linux subsystem, but I don't fancy recreating every file, then having to copy and past using bash, then reformatting then using Dos2unix (very long winded).  Found this on GitHub for the Linux subsystem:      copying directly into the Linux subsystem from Windows is not   supported, according to discussion on other tickets. There is a   directory under AppData somewhere (I forget where) that appears to   contain the files for the WSL filesystem. But if you put new files   there, or modify existing files there, your changes are not reflected   correctly inside WSL.      My best guess is that Linux needs to store different metadata (and   more caching information, etc, since its disk-buffering model is also   different) about its files than Windows does, and that this is   currently implemented by storing the master copy of the structure of   the Linux filesystem in a database of some sort, and just using the   Windows filesystem as a convenient BLOB-store for that database.      If you really need to do this, a workaround would be to write a   drag'n'drop .bat script or somesuch that does bash.exe -c "mv %1   /home/$USER/". (You'll have to do some clever work with sed and tr,   probably, to translate %1 to a valid WSL path.)      Alternatively -- could you put your files in a Windows directory and,   within WSL, do "cd ~; ln -s /mnt/c/path/to/my/files" to make them   appear to be in your WSL homedir?


I am building a PCB with some ICs. To sum up, I have a global 3.6V supply and I need to have an 1.8V reference for some IOs.  I know the right way to do it is to use a voltage translator circuit (generally an IC), but I was wondering why not to do it with two similar resistors ?  Thanks


Fetch Files Related to opportunity in salesforce

I want to run a SOQL query that fetches files associated with opportunities(in a particular stage). If I am not wrong content version is the actual object I need to be querying on to fetch content? Here is the query I am running  SELECT IsAssetEnabled, Checksum, ContentBodyId, ContentLocation, ContentModifiedDate, Origin, ContentUrl, ContentDocumentId, Id, CreatedById, CreatedDate, Description, ExternalDataSourceId, ExternalDocumentInfo1, ExternalDocumentInfo2, FeaturedContentBoost, FeaturedContentDate, FileExtension, SharingPrivacy, FileType, IsDeleted, FirstPublishLocationId, LastModifiedById, IsLatest, LastModifiedDate, IsMajorVersion, OwnerId, NegativeRatingCount, PathOnClient, PositiveRatingCount, SharingOption, PublishStatus, RatingCount, ContentSize, ReasonForChange, SystemModstamp, TagCsv, TextPreview, Title, ContentModifiedById, VersionData, VersionNumber   FROM ContentVersion   Questions:   How do I add the column in the query that tells me what opportunity is this file associated with, plus how do I fetch files associated with the opportunity in XYZ stage only? I am running this query in G-connector for salesforce, when the above query runs I get the data in spreadsheet, how do I convert this data to the actual file png, JP, Pdf whatever it is, to make it usable for other application?   Thanks


Profile picture on the Stack Exchange profile is gray but not on Stack Overflow profile

Why is my profile picture rendered like this?    But this is the picture I've uploaded:    This issue will render for Chrome, Edge and Firefox on Window 10.


Union of the conjugates of a proper subgroup

Let G be a finite group and H be a proper subgroup. Prove that the union of the conjugates of H is not the whole of G.  Thanks for any help


Sort the list values based on Created Date

List<Account> Acc// this list contains Account records. Acc.Sort() is not working  How to sort the records based on Created Date? Basically i need the recently record from the Acc list


For a better detection of the modulated signal with the diode detector below, one requirement is that the time constant of the RC filter conforms to:  $$ \frac{1}{\omega_{c}} \leq RC \leq \frac{ \sqrt{1-\mu^{2}}}{\omega_{m}\mu}  $$  where:   \$\omega_c\$ is the angular frequency of the carrier \$\omega_m\$ is the angular frequency of the information, and \$\mu\$ is the modulation index.   How exactly can we prove that?


Media Library page super slow, loading up full quality images

On my WP site (which sells retail products), I have large images (up to 4000x4000 px) so people can zoom in. Unfortunately, when adding images to a page and using the Media Library, the images all load up at full quality (though resized down). This makes the Media Library page load up really slowly, and make my browser slow to a crawl. Why is it doing this? Why isn't the ML page using thumbnails? If I click on "Media" on the left admin menu, that list of images are proper thumbnails, but when adding media to a page, the list that comes up is using full quality images.  Is this a bug in WP?


Is there a way to downgrade from iOS 8 to iOS 7?

My iPhone 4S is very slow. Is there anyway to downgrade to iOS 7 (legal or jailbreak)?


I need to start a custom activity by clicking on a browser-link (e.g. market://details?id= opens the app  in Play Store).  How can I do that?  (I hope, you understand what I want to do - sorry for my bad english)


I have a quiz in SharePoint.   It works perfectly but what I want is:   After a student have taken the quiz, I would like a list named quizlist to store information for the users who has taken the quiz to show what the score he/she got and to show the user name.  How can I do this?


Statements used as questions in casual speech

I see people say statement as question while speaking by raising their voice at the of it to mean it's a question.   For example consider followings.         You want to stay here? ==> Is used to mean "Do you want to stay here?"   You guys spoke to anyone? ==> Is used to mean "Did you guys speak to anyone?"      Are these really used by native speaker in casual speech? And can I write them in the same way while writing them as dialogue by putting them between quotes? Are there any special grammar rules for these kind of questions?


Windows page file on multiple hard drives

I cant find any documentation or articles online online for this...  how does Windows handle page files on multiple hard drives?  Does windows treat them as a concatenation, writing to one till its full then moving to the next?  Or does it treat them like a stripe, writing to each one incrementally?  Does it write to the first one free?  Or perhaps some other method?


How to permanently disable the "save session" feature in Xubuntu?

I'm running Xubuntu 13.10 with xfce4-panel 4.10.1 and my sessions keeps getting saved involuntarily. I'm well aware that this is a bug so I'd like to ask if anyone knows a workaround to permanently disable/delete this feature (by removing/editing some files maybe)?   I've spent hours searching and tried a lot of the methods already but none of them worked, or at least were not permanent. Some of the stuff I've tried:   (This basically just removed the tick-box in the logout prompt)   (Deleting the cached sessions was not a permanent solution)  I would greatly appreciate your help!     My temorarily solution: I created a simple bash script and placed an   application launcher (which runs the script when pressed) on my task   panel. The script will delete the "~/.cache/sessions" directory and   promt log out.      The script can be found here:        Basically this will be the button which you use to logout/reboot/shutdown.    Update: This only occurs if you added "restart" to the listing, in your "Action Button" (the button with your username written on). If you restart using log out -> restart it should reboot normally and not save your session. Thus, the temporarily solution above is not necessary, I will leave it there as a reference.


Is there a specific reason why we can't upcast Sets?

As most stories here begin, I was writing some code for a project that I was working on, and stumbled across an oddity when writing some unit tests. I was testing a method that has a Set<sObject> parameter, and I was attempting to pass this method a Set<Account>.  As Account inherits from sObject, I thought this would work fine. However, when running my test, I got the error     Method does not exist or incorrect signature: [TestClass].someMethod(Set<Account>)   Yes, the method that I was testing expects an argument of Set<sObject>, but an Account can be up-cast to an sObject, and Salesforce handles that implicitly, right?  Since Salesforce was throwing a fit when I tried to rely on implicit casting, the next thing I tried was explicitly up-casting. When I tried to explicitly up-cast my set, I was greeted with a different error     Line: someNumber, Column: otherNumber   Incompatible types since an instance of Set<Account> is never an instance of Set<SObject>   This can be reproduced with the following snippet  Set<sObject> testSet1; Set<Account> testSet2 = new Set<Account>();  testSet1 = (Set<sObject>)testSet2;   I haven't found anything in the documentation to suggest that up-casts for sets aren't allowed. Given that we can up-cast Lists and Maps, I feel this is rather unexpected.  Furthermore, knowing that an Apex set is really a Java HashSet in the back-end (look at the bottom of ), I tried to look for documentation to see if this is somehow dictated by Java, but I came up empty there as well.  I've been able to move on with my project, but this leaves me wondering...  Is there some documentation (Salesforce or Java) that explains this behavior? Failing that, can someone cobble together a feasible explanation for why Sets can't be up-cast?


Travel without an Italian residence permit in the Schengen area

I'm a non-EU citizen, and I'm studying in Italy.  I traveled to Hungary last week with Ryanair from Italy. I showed them my passport, residence permit and Italian identity card. Everything was OK. But after a week when I wanted to come back to Italy I found that I lost my residence permit. But still I have the passport and identity card (paper).  Now I'm afraid they don't let me get back to Italy at the Hungarian airport. What should I do now?  I have a picture from my residence permit (Permesso di soggiorno).     UPDATE: Fortunately, I found my card in the house, YaaaaY.


I've been seeing a lot of comments, on a lot of questions and answers, and most of them, seem to be related, some are asking new questions themselves, some are talking to the poster, looking for more information, but most of them seem to be more of discussion rather than comment.   But all these comments, are scattered, some are on the question itself, some are throughout all the different answers.  Would we benefit from having a separate Talk/Discussion page/tab/section that we could flesh out the details of the question, and ask more on, in one unified spot?  Also, it might be nice for questions that go unanswered, or the poster accepts a half-baked answer; so that people had a way of asking something like "hey did you ever figure this out" kind of deal and the poster still getting notifications on both sides.  I know it'd probably be difficult to get right, but maybe others have similar ideas on how to refine it, or something they'd like to see, or how to implement it?


Finding the series of of sequence $n(n-1)$

Given the formula of sequence $$B_{n}=n(n-1)$$ Find the series $S_{n}$ of the sequence, such that $n \geq 0$.  What I did.  $$S_{n} = B_{0} + B_{1} + B_{2} + ... B_{n}$$ $$S_{n} = (0)(0-1) + (1)(1 - 1) + (2)(2 - 1) + ... + n(n-1)$$  Next thing is, I'm stuck. I have no idea how to progress from here. I spend quite some time to reduce this to a closed formula to no avail.


Cannot launch Lollypop music player after installing from a deb package on Ubuntu 16.04

I am trying to install Lollypop on a new Linux install 16.04 LTS.  When I run   sudo apt-get install lollypop   I get the error 'file not found'. (Yes, I added the repo)  I found a deb package online and installed that but Lollypop would run for a second then close.  Can't find any info on this problem after looking for a couple of hours.  Any ideas?  The original info I used to install Lollypop I found . I found the Xenial package  and installed using GDebi.


How do the different types of energy apply to voltage in a circuit

I was just wondering what happens in a circuit in terms of different types of energy transformations. If you apply a voltage to a circuit then electrons start moving (very slowly). Since the electrons want to flow to the positive terminal they will have electrical potential. But the electrons are also now moving once the voltage is applied as there is a current so would they have kinetic energy as well?   Some information I have found online says that electrons collide with atoms in a bulb and this is why the filament heats up. But this would imply that kinetic energy is being transformed into heat and this can't be correct because surely any change in kinetic energy would alter the current flowing? Also, in a series circuit, if you measure the potential difference between any 2 points after all of the loads then you always get zero. I was just wondering why it is zero because don't the electrons keep moving even after passing through all the load in order to get back to the power source so surely they cannot do this without some form of energy?


I want to know if there is any way to install Kali tools like sqlmap, nikto, john, aircrack-ng, ... on Ubuntu 12.04?  If yes, then how should I proceed?


I have a 2012 15" MacBook Pro and the Bluetooth is "unavailable". It has been like this for a while actually, probably about a year and a half. Sometimes it randomly becomes available and turns on only to become unavailable again only minutes later. Also a Bluetooth setup wizard app opens sometimes, usually after I turn the computer on after it had shut off from low battery, but when I click on it nothing happens. I haven't cared about this issue too much because I didn't have anything connected using Bluetooth, but now I actually do have something that I want to connect. I have tried resetting the SMC, deleting the .plist file and restarting, but neither of these worked. Does anyone know what might solve this issue?


If $\int_0^1 f x^n dx=0, \forall n \in \mathbb{N} $, then $f\equiv 0.$

Let $f:[0,1]\to \mathbb{R}$ continuous, such that  $\forall n \in \mathbb{N},\int_0^1 f x^n dx=0$, show that $f\equiv 0$.  I think I should use Stone-Weierstrass Theorem and the Bernstein Polynomials, but I failed in my attempt of using, because the coefficients change at each power you choose. Is there any other way to do it, or someone that could help me with this method?


Does anybody have an idea how to get this kind of unsmooth grainy gradient effect in illustrator ?     I tried with sketch torn edges, i tried with a grunged up photo, edited the levels and saved that as a bitmap, then applied it to a mask, but i does not look good    So does anybody know a better way to get this effect in Adobe Illustrator ?


Why are the group axioms called "axioms"?

My book says:  A group is an ordered pair $(G, \cdot)$ where $G$ is a set and $\cdot$ is a binary operation satisfying the following axioms [emphasis mine]: $\vdots$  Why doesn't it say  A group is an ordered pair $(G, \cdot)$ where $G$ is a set and $\cdot$ is a binary operation satisfying the following propreties: $\vdots$  As far as I know, axioms are statements which we take for granted; I don't understand why the group axioms are something we have to take for granted; we already know that there exist objects (such as the set of permutations of $3$ objects) which satisfy those propreties. Even if we knew of no objects which satisfy those propreties, then perhaps the axiom should be "There exists an object which satisfies those propreties" rather the axioms being the propreties themselves.


Can different gauges of wire be used on the same circuit?

My father-in-law is a builder. He has put in 20 amp and 15 amp breakers, and ran 12-2 as the home runs to the switch's and the first plug to make them hot. He then ran 14-2 to feed the rest of the plugs, lights, and ceiling fans.   Is it okay that he used different gauge wires on the same circuit?


Can forces from outside the observable universe be observed through a distant object?

I recently saw a video on dark flow from PBS space time on youtube, and it said that the flow had to be a constant motion, and not accelerating, because the object likely that caused the flow using gravity was now outside our sphere of influence due to the expansion of the universe faster than the speed of light.  However, is it not possible to observe something accelerate due to gravity from outside the observable universe, if we observe a distant object that is still inside the observable universe of the thing causing the pull, and also inside ours? In other words, in the following picture, is it possible for A to observe the gravitational acceleration of B, even if A is outside the sphere of influence of C?


preventDefault when clicking bounty "cancel" link

When you click "start a bounty" then "cancel," href="#" exiles you to the top of the page and you lose your spot near the end of the question's comments. Clicking anywhere else on the page simply closes the bounty popup; clicking "cancel" ought to do the same.  In case that wasn't clear:    Dramatization aside, it's a nuisance. Can the click event on that anchor be preventDefaulted?


Where can I find the Ivory Claw to open a door in Reachwater Rock?

I'm at Reachwater Rock and I've encountered a series of doors, the first I had to open using the Emerald Claw I found near a body, but now the door's telling me to use an Ivory Claw. Where can I find it, because I don't have it in my inventory yet.


Why does reputation start at 1, and have a lower bound of 1?

If a user is the type of person to consecutively get downvoted to potential negative reputation, so be it. What's the reasoning to maintain a minimum of one?  One reason that may justify this is of trying to not deter new users from the site who haven't read the FAQ and unknowingly and wrongly ask or answer a question. But most of us acknowledge this and not downvote in such a scenario.  So what's the reasoning behind this lower bound of 1?


What could cause a toilet to leave the flapper up and keep running?

I have an American Standard toilet I installed last year. I don't know much about plumbing, but I was able to install this toilet. It seems to function okay, except for what I think is a mechanical problem.  Sometimes when the toilet is flushed, the flapper doesn't close and water keeps running.  The handle feels like it's slightly stuck in the up position.  I looked inside the tank once when it was doing this, and the chain attached to the handle was slack. I don't understand why the flapper isn't closing.  I've tried putting more slack in the chain and loosening the plastic nut that holds the handle on the toilet, but it doesn't seem to be helping.    How can I fix this?


Exporting 2D vector graphic from ArcScene to Illustrator

How can I export 2d vector graphic from ArcScene so I can edit it with Adobe Illustrator? I've tried changing the options when I export 2D scene as AI file or PDF file, but they always remain as a unique image that does not allow me to edit the lines and polygons.


I am trying to take advantage of workspaces in Ubuntu 18.04. I was used to the Windows 10 equivalent (don't blame me) and I am trying to replicate a feature that it's pretty useful to me.  On the application bar (Ubuntu dock) I see all the open applications for all the workspaces. Is there a way to see the open applications only for the current workspace? I can do this for the applications I cycle through using super+tab with an option in dconf-editor, but it doesn't affect the applications I see in the bar


If $\alpha<\beta$, there exists a ordinal $\gamma$ such that $\alpha + \gamma = \beta$. Why?

I want to prove the following proposition. proposition: Let $\alpha,\beta$ be ordinals. If $\alpha<\beta$, there exists a ordinal $\gamma$ such that $\alpha + \gamma = \beta$. I am trying to prove this by  transfinite induction. However, I have some trouble with the case $\beta$ is a limit ordinal.(I know the definition of the sum of a ordinal and a limit ordinal) please give me some ideas.


how to remove IPV4 address port number using javascript

I have a javascript array of IP addresses,but some of IP address contains prot number like this: 198.228.200.169:46835 how can I use a javascript function to remove port number like this:  198.228.200.169   Thank you so much!


Half of my house does not have any electricity even thou nothing has been plugged it to the outlets on that side of the house. What can I do to fix it. Thank You Terro


How to recover folders from formatted drive

I had 500GB portable hard drive. it fell from the table and when i joined it was not showing any data and asked me to format it. i did format. Then again it was not functioning properly so i had to quick format it again.  Now i had lots of data in it. Is there any software which can recover my files and folders with same structure as original


Mann-Whitney U and KS tests in R are not producing significant results

I wish to compare two test data sets using the Mann-Whitney U and KS tests in R.    As a start, I thought to compare two similar sets (an A/A test) expecting to see a highly significant indication of similarity.  The two lists are these shown below:     The results for the Mann-Whitney U test (wilcox.test) were:  W = 22073, p-value = 0.1948 alternative hypothesis: true location shift is not equal to 0   The results for the KS test (ks.test) were:  D = 0.1021, p-value = 0.2058 alternative hypothesis: two-sided   Why are neither of these statistically significant (p-value being below 0.05)?  Here's a display of the values for the two sets:


Sudo is also user login password - why? how to change?

When installing Ubuntu I can create a user with an encrypted folder, what I always do. Now after the installation the login password for this user is also the sudo password. Is that how it should be? I actually would like to have a different user login and sudo password, does is make sense? Should I do that, how?


Should list my advisor as an author on a paper I wrote alone?

As a part of my PhD project, I wrote a paper. When my supervisor read it, she said “it is perfect and complete, go ahead and publish it yourself because I cannot contribute more to it”. She really meant it and tried to do me a favor.  However, I still think it can be more beneficial for my future to have her name on my paper. Should I insist to have her as a coauthor or it might be useful in the future to have all the credits of a good paper?


Ideas to create a Best Move in a match 3 game

I'm trying to make a match 3 game in C++ and I want to make a best move method to show the player the ideal position to move to get the most amount of points.   The rules of the game are as follows:   Pairs of objects adjacent vertically and horizontally can be swapped. You can only swap objects when this will result in a match being created. A match happens when there are 3 or more objects of the same kind adjacent vertically or horizontally. objects that match are removed from the board. objects above a gap will keep fall down until all gaps are filled. New matches made by objects falling into place will be removed with the process repeating until there are no matches left. Points are awarded based on the number of objects removed. The best move for a given board is the one that removes the most objects .   However, I'm stumped for ideas on how to implement such a method. Can anyone give me some ideas on how I can do it?   If you've made a match 3 game, and have implemented a similar method; how did you do it?


$ sudo add-apt-repository ppa:bitcoin/bitcoin  error: NOT MAINTAINED. The OS-library linking packages here had a series of issues.  PLEASE DOWNLOAD DIRECTLY FROM bitcoincore.org (and verify the signatures of said files).  IF YOU WANT AUTO-UPDATES, please see the officially-maintained snap package - https://github.com/bitcoin-core/packaging/tree/master/snap  More info: https://launchpad.net/~bitcoin/+archive/ubuntu/bitcoin Press [ENTER] to continue or Ctrl-c to cancel adding it.  Hit:1 http://in.archive.ubuntu.com/ubuntu focal InRelease Get:2 http://in.archive.ubuntu.com/ubuntu focal-updates InRelease [111 kB]     Get:3 http://in.archive.ubuntu.com/ubuntu focal-backports InRelease [98.3 kB]  Ign:4 http://ppa.launchpad.net/bitcoin/bitcoin/ubuntu focal InRelease          Get:5 http://security.ubuntu.com/ubuntu focal-security InRelease [107 kB]      Err:6 http://ppa.launchpad.net/bitcoin/bitcoin/ubuntu focal Release              404  Not Found [IP: 91.189.95.83 80] Reading package lists... Done E: The repository 'http://ppa.launchpad.net/bitcoin/bitcoin/ubuntu focal Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.


I'm quite sure someone already has asked this question before. However, I can't find an answer to my question so I thought I'd ask you guys.   As the title says, I'd like to have two signature lines next to each other with 2 names below them. So far I've written this code:     \begin{center}     \hbox{         \vbox{------------------------------------------------  \\ Name 1} \hspace*{2cm}          \vbox{------------------------------------------------  \\ Name 2}          } \end{center}   However it seems like the first \vbox is swallowing the other one and it visually looks like this (I know, nothing special to see here I guess):   Any idea how I could solve this problem (two \vboxes in one \hbox, or maybe another solution with two \vboxes)?


if(value=="") why this block returning as false

Please, consider the following code:  public static void main(String[] args) {     String value="abc";     value="";     if(value==""){         System.out.println("blank "+value);     } }   I do not understand why if(value=="") is returning as false.


I run om-my-zsh and my prompt usually says      gregg@Gumby $    where Gumby is the name of my Mac.  Today it said       gregg@Michaels-iPhone $    I was not connected to any iPhone. All sharing features in system preferences sharing are off.  what is going on?


Childrens sci-fi story about space travelling family, racist rabbits, and a utilitarian computer?

I am trying to remember a story I read many years ago - early 90s I think - featuring a small family travelling on a spaceship, which I remember being called "dragonball", but I suspect that might be wrong as googling for it only finds "dragonball z", so I've probably just totally forgotten the name.  The story featured them landing on a planet occupied by anthropomorphic rabbits, racially segregated by fur color (black and white). Their society was governed by a computer designed to favour the greatest good for the greatest number, which caused it to to attempt to exterminate the slower breeding (less-populous) variant. The visitors solved this by convincing the gray-furred rabbits, who lived outside the computers control, to register themselves. As the number of gray rabbits was greater than either of the others, this somehow something something something and so the computer stopped trying to kill anyone, cue happily ever after.  Any idea what the book was?


Converting 12-hour time to 24-hour time using Field Calculator

Does anyone know how to convert string time formats in ArcMap v10.2 from 12-hour to 24-hour using a simple query in the Field Calculator? i.e. NO Python, NO editing in Excel, NO changing my Windows PC settings, etc...  This is a successful calculation I used (which I found on a discontinued forum) to convert my dates from MM/DD/YYYY to YYYY/MM/DD:  year([DateFld]) & "/" & Month([DateFld]) & "/" & Day([DateFld])  Perhaps there is some sort of modification that I could make to the above calculation that would change my times to 24-hour?  I've searched for an answer everywhere and played around with it without any luck, but I would like for the times to be in h:mm:ss format.  Forgot to mention that this is a regular shapefile, not part of a GDB.


What are the different ways to copy and back up devices?

The dd command is one method to copy files from one device to other device. Other method is using Clonezilla. What are other ways to do it. What are the differences? In what conditions it's preferable to use this and not that?


Centralizer of a given element in $S_n$?

It is known that any two disjoint cycles in $S_n$ commutes. Therefore, any $\pi\in S_n$ which is disjoint with $\sigma$ is in the centralizer of $\sigma$: $C_{S_n}(\sigma)$. Also  $$ \sigma^i\pi\in C_{S_n}(\sigma), 0\leq i\leq|\sigma|. \tag{*} $$ Here are my questions:  Are these all the elements in $C_{S_n}(\sigma)$? If the answer is no, is there an method to find all the elements in $C_{S_n}(\sigma)$ other than check the elements one by one?    A quick search returns several relevant questions:        The method ($*$) is what I learned so far from these questions and their answers. An immediate example in which ($*$) does not work that I can come up with is $\sigma=(12)(34)(56)$ in $S_6$. No disjoint $\pi$ can be found in this case and  $$\langle(12),(34),(56)\rangle\subset C_{S_6}(\sigma).$$


Prove that if $a$  is odd, then $a^2\equiv 1\pmod 8$I got this question in my discrete mathematics class, can anyone help me?Thanks.


Is it safe to connect two MCU pins directly to each other?

I am working on an MSP430 project that requires me to route the output of one peripheral into the input of another peripheral. Thus, I have two MCU pins connected directly to each other. This looks suspicious to me since there is the possibility of a programming error causing both to be (possibly conflicting) outputs. Also, there is the issue of startup and programming states.  In the worst case, if one pin is driving HI, the other is driving LO, the GPIO pins generally have way more sink capability than source capability... so it'll be somewhat like taking a HI output and shorting it to near-ground. Which is bad... but how bad is it? Is it likely to cause damage to the MCU?  I often see examples on the web of people using Arduinos to light an LED between two pins without a resistor, and I haven't heard of any stories of anyone frying anything but the LED. Clearly you wouldn't want to do this in a product, but do manufacturers generally try to protect the MCU from GPIO pins being overloaded anyway?  Thinking about it in retrospect, putting a current-limiting resistor between the two pins would have prevented any worries, but even a minor hardware change is a very difficult thing to do at this point.  For future reference and the benefit of posterity, does anyone have any other ideas about the proper way of minimizing the risks of connecting two MCU pins together, and more generally, minimizing the risks that come from the possibility of overloading a GPIO pin?


How to recursively delete a dir after find

find .   -name "DIR-NAME" -type d -delete   because i want to delete specific dir name recursively  well it returns  find: cannot delete `./DIR-NAME': Directory not empty   which is expeted but I have no idea how to make -delete to delete non-empty dirs here as i can with rm -rf


My PC has Ubuntu 14.04 (32 bit). During the installation of skype it's showing this error:  W: There is no public key available for the following key IDs:                  1397BC53640DB551 W: Failed to fetch http://dl.google.com/linux/chrome/deb/dists/stable/Release  Unable to find expected entry 'main/binary-i386/Packages' in Release file (Wrong sources.list entry or malformed file)  E: Some index files failed to download. They have been ignored, or old ones used instead.   How can I solve this?


Story about spacemen encountering city of the dead

When I was a child I remember reading a story in a comic book about two spacemen who encounter a city in space that, legend has it, only the dead can see. The story ends with one of the spacemen questioning whether they were dead or not and how it was possible for them to see the mythical city. The comic book was in colour. I don't know if it was a Marvel comics publication or some other publisher. One of the spacemen's names was (I think) "Jake Radic" If I try Googling this name, it comes up (not surprisingly) with lots of people from Serbia!


Why does my computer beep when I turn it on? What are these beep codes?

Due to the amount of beep codes a PC can give, there are many questions on Super User about beep codes! I'm hoping this post will help to provide a community answer about all (dare I say all?) beep codes, with my fictional question.  When I try to turn my PC on, I hear some beeps. This is not beeping from the HDD or fan, but from the motherboard. Regardless of the number of beeps, what do the beeps mean?


Why do I need to escape the '/' character in JavaScript?

What exactly needs to be escaped in javascript strings.  Or, more specifically, why does   var snaphtml = '<script src="http://seadragon.com/embed/lxe.js?width=auto&height=400px"></script>';   give a syntax error?  Escaping the final <\/script> seems to fix the syntax error, but this doesn't make sense to me as a javascript beginner.


Styling lines depending on several attributes

I have a line shape file which I made from DWG file. I have several fields which I want to use for styling. I have colour, width and type. I need to specify colour, width and type independantly. For example colour=1, width=2 and type="dashed line" or colour=3, width=1 and type="continious line". Colours are not range or random colours, they should be specified manually 1 is red, 2 - is yellow etc. The same with line types. Width can be either range, or specified manually as well as colour and width.


Trying to make aliases that open the last modified file

One thing that I frequently do is edit the most recently modified files, so instead of typing "ls -lr" and then "vim lastfile", I thought I would make some shortcuts in my ~/.bash_profile file:  alias via="vim `ls -rt | tail -1`" alias vib="vim `ls -rt | tail -2 | head -1`" alias vic="vim `ls -rt | tail -3 | head -1`" alias vid="vim `ls -rt | tail -4 | head -1`" alias vie="vim `ls -rt | tail -5 | head -1`"   The problem is that, weirdly enough, these commands don't work.  They open some file that isn't one of the last, or even a file was deleted from the current directory (I wonder if there's some kind of file cache updating issue in the directory.  This occurs on both my local machine and the cluster I work on).  However, if I type vim `ls -rt | tail -1` directly, without using the alias, it works every time.


My java HW is to play around with some Stock Market data, read/write to files. I'm trying to throw this option (below) into the code and for some reason when I enter Y, it doesn't enter the for-loop. I can't figure out why. When I enter my Y it just goes straight to the next chunk of the code and starts printing data to the screen (as it is supposed to do), without any of the below outputs/inputs.  System.out.println("Would you like to add items to the StockMarket data? (Y or N)"); Scanner input_check = new Scanner(System.in); if(input_check.next() =="Y"){     //Scanner inp = new Scanner(System.in);     System.out.println("Enter name of stock (all caps): ");     //String input = inp.next();     names.add(input_check.next());     System.out.println("Enter date (MM/DD/YEAR) of stock data: ");     dates.add(input_check.next());     System.out.println("Enter the opening price: ");     opening.add(input_check.next());     System.out.println("Enter the closing price: ");     closing.add(input_check.next());     System.out.println("Enter the highest price: ");     highest.add(input_check.next());     System.out.println("Enter the lowest price: ");     lowest.add(input_check.next()); }


How much is ${\aleph_0}^{\aleph _ 0}$?   On the left I can find ${2}^{\aleph_0}\le {\aleph_0}^{\aleph _ 0}$ but on the right I can not found someone that is $\le$.  In general, how do I use Cantor-Bernstein to find equalities of cardinalities.


How to show that $\lim_{n\to \infty}n\sin(2\pi en!)=2\pi$?

Please give me some hint to proceed. I'm clueless:     Show that, $\lim\limits_{n\to \infty}n\sin(2\pi en!)=2\pi$


In cricket, in UDRS screen, if the ball hits the wicket, then why is not out still given?  I saw this situation so many times happened; bowler appealed for UDRS for LBW, in UDRS it shows ball hits the wicket, but still not out is given sometimes.


I'd love to be able to hide meta boxes using screen options, instead of removing them or restricting them to user roles, the goal is to just "uncheck" the meta box for the user.  I see how this would be tricky since any code that would make a DB change for a user wouldn't be allowed to run every time they hit the page because it would just reset. But smarter people than I code the core, so maybe there's a way. And if there is, I'm dying to know.  Any ideas?


Windows 8.1 VPN connection to customer's network blocks access to local domain's shares, SQL Server

With Windows 7, I could access my company's Windows Server file shares and SQL Servers (with Windows authentication) from that same LAN while connected to my customer's VPN.  With Windows 8.1, I lose the ability to connect to my domain's own shares and (with Windows authentication) SQL Servers while connected directly to my company's LAN and connected to my customer's VPN.  I can connect to the VPN and then connect using SQL authentication to local SQL Servers, but Windows Authentication fails.  Example:  C:\>NET VIEW \\servername System error 5 has occurred.  Access is denied.   As soon I disconnect from the VPN, I'm able to access these domain resources.  I'm using the VPN client included with Windows 8.1 to connect to PPTP VPN.  I've not selected the option to "Automatically use my Windows logon name and password."  Perhaps once the VPN connection is made, further authentication requests are made using the credentials provided for the VPN connection rather than the domain credentials with which I logged into my own PC.  This seems like a useful feature that didn't get its control function surfaced in the VPN connection properties UI.  There's got to be a way to switch this off.  Thanks for your input.  EDIT:  Contrary to suggestions, this does not duplicate "".  That question described loss of access to the Internet, while this describes loss of access to the intranet.


How to use both my dual internet connections in the same exact moment on Mac OS X

I am running Mac OS X and I have two different Internet connections on two different local networks: One is wireless and the other is wired. I want to use both on the same time to get higher download bandwidth. I saw Nvidia has something like that called “”  So can I download using my two networks in the same time if the download server allows it.


How can I get more feedback from my Ph.D supervisor in our meetings?

I am currently a math Ph.D. student, and I meet my advisor every two weeks for an hour.  I have been here for over a year.  I spent the first six months studying the basics of the topic, though I still have no clear vision of what my advisor wants me to do.  During our meetings, I always try to discuss my research ideas, propose topics and show my results.  However, he seems to agree with everything I say, and at the end, I don't think I am really having any feedback from him. I don't know what topic he wants me to do research in.  Questions:   Is it normal for math Ph.D. students to not receive feedback when interacting with their advisor? What can I do to get more feedback?


A capitular letter in a font different than the text

How can I make a capitular letter in a different font of that one used in the main text? I mean, I'd like to do something like this (image made in paint):      Thank you very much, guys!


Easiest way to display a range of lines in a huge text file? Don’t need to edit

IN order to display from line 1 million, for 20 lines, I ended up with   head -1000020 myfile | tail - 20    That works and I’ve wrapped in a function that does arithmetic for it.  But I was wondering if there’s an existing bash or unix command for it.   Am on macOs, but happy knowing Linux for it too.


So the bevel appears to only be applying to the x-axis, when I also need it on the y axis. Any solutions and thoughts would be much appreciated. I have tried with the modelling bevel and the modifier, it may be a settings issue or preferences I am not sure.


Let $T$ : $\mathbb{R}^n \rightarrow \mathbb{R}^m$ be a matrix transformation given by   $T(x) = Ax$ ,   where $A$ is an $m \times n$ real matrix. Assuming $\mathbb{R}^n $ and $\mathbb{R}^m$ are given their standard Euclidean norms, prove that $T$ is continuous.  Not really too sure how to go about proving this, in this situation could you use the fact that if a linear map $T:V \rightarrow W$, with $V$ and $W$ normed vector spaces, is continous at $0$ then $T$ is continous?


How to measure correlation between multi-item likert scales?

I recently conducted a online survey and are now having trouble deciding for the right analysis method. For example: I wanted to see if there is a correlation between Factor A and Factor B. However in my survey I did not ask the participants to directly rate Factor A and Factor B, but rather asked multiple subquestions for these two factors which were rated from 5(Strongly Agree) to 1 (Strongly Disagree). I created a sum score for item A and a sum score for item B by summing up the values of each subquestion and calculated the mean of the sumscores to measure them. So my question ist: Which method would be best to use here? I want to test if e.g. people with a higher score in Factor A would be more likely to decide for Factor B. I actually planned using Spearman or ANOVA depending on the number of independent variables, but I am not sure if that would really be the correct way to measure the correlation.


Rasterio + QGIS - rasterio.drivers() -> TypeError: 'module' object is not callable

I have been trying to get rasterio working with my QGIS setup so that I can take advantage of the fast raster manipulations.  After a day of installing / uninstalling and then piece by piece searching and getting components installed one by one where needed (From upgrading GDAL, numpy, and a whole slew of other modules which were fighting each other) I manged to get to the point where I could import rasterio without any errors.  However now when I run, the first call in the example causes a Traceback:  with rasterio.drivers(CPL_DEBUG=True):     creates error =>  TypeError: 'module' object is not callable   I have noticed that other rasterio objects seem fine, but all functions that are in .pyc files have this same issue.  Any help?  - I will continue in the morning, but I was hoping some elves would appear and help solve this one tonight! :-)


OS X El Capitan Installer.app has crippled my Mac Mini

Mac Mini (Mid-2011), 16GB SSD, 16GB RAM, El Capitan (v10.11.6)  The Mac ran fine until I upgraded to Sierra. The latest Mac OS conflicted with most of the specialized apps I use every day, So I immediately returned to El Capitan.  Activity monitor shows that two "Installer/Installer.app" items are always running and are they major users of all of my available memory. Consequently, all my others apps become unresponsive.  I run Disk Utility, and the Installer.app show up there as .dmg files; but I cannot erase, delete, or unmount them. None of my 3rd party app can remove the installers.  My Mac Mini, which should be running super-fast (as it used to), now runs dreadfully and disgustingly slow. I a truly upset with Apple for this kind of garbage. To get their help: $$$.


How do we move forward in space without air or atmosphere?

This might be a stupid question, but I am trying to understand the fundamentals. The closest I've come to is Newton's Third law of Motion which states for every action (force) in nature there is an equal and opposite reaction. So if we are expending energy by firing rockets in one direction there must be a reaction that push us forward. This seems easy to understand on earth (ie. pushing back the ground or atmosphere) but in vacuum of space what are we pushing backwards. I don't want to accept, with all due respect, Just because Newton said so. While this seems so obvious that this is the expected behaviour but is there some underlying physics that can help me understand this better? One surprising theory might be dark matter but that rises many more questions like does it still qualify as vacuum if there is dark matter and also an obvious one, have we ever calculated that? Edit: ground pushing us forward might seem a bit abstract so here is what I remember from my high school physics, If Object A pushes Object B, then Object B pushes Object A at exactly the same time, with exactly the same amount of force, but in the opposite direction. The reason the Earth pushes up on you with the same force has to do with the nature of solids. When you stand on the ground, you are actually compressing the dirt beneath you. This compression also applies to the billions of interparticle and intermolecular electrochemical bonds in the solid matter of the Earth, which act a bit like little springs holding things together down at the atomic level. Cars, boats, airplanes, and humans move forwards by pushing back on the ground, the water, or the air. Above text is copied from here ->  ps. Not related, but will the airplanes stop working is we take away the atmosphere from Earth.


How to automatically color a tabular's cell using its values?

I have a table of values and I want the cells to range from green to red depending on their values. I tried the following function:  \newcommand{\cellc}[1]{     \pgfmathparse{#1 <= 256 ? #1 / 256 : 1}     \pgfmathsetmacro{\r}{\pgfmathresult}     \pgfmathsetmacro{\g}{1 - \pgfmathresult}     \cellcolor[rgb]{\r ,\g ,0}\r, \g,  #1 }   but it just turns every cell green (or red if i flip \r and \g) even when \r is close to one and \g close to 0.   Here's a list of my packages in case it's due to a conflict:  \usepackage{ragged2e} \usepackage[french]{babel} \usepackage[T1]{fontenc} \usepackage{amsmath} \usepackage{amssymb} \usepackage{mathrsfs} \usepackage{graphicx} \usepackage{enumitem} \usepackage{float} \usepackage[table]{xcolor} \usepackage{slashbox} \usepackage{diagbox} \usepackage{fontspec} \usepackage{tikz}   EDIT: The link with the triangular matrix was actually what I was looking for. Thanks I didn't find it while looking up my problem.


How can I convert DC 1. 5V (R20 cell) to DC 2.6V with as much as possible amps?  I would like to charge 500F supercapacitor with it. (I can use only 1 R20 1.5V cell).


What if I use a boy with its hidden ability and a genderless Pokemon

OK my krabby is a boy with sheer force and a staryu who hold a everstone and is timid do you think I will get a staryu with its hidden ability?


is redirecting to the old 2012 site:   Shouldn't it redirect to ?


Troubleshoot High CPU usage by the "System" process

I have noticed that from some time my system is freezing and its probably caused by the high CPU usage which is caused by the system process.  All applications I'm running is the Skype, TeamSpeak and Chrome so it definitely shouldnt eat that amount of CPU.  You can see the problem itself and running processes in the screenshot below:    Sometimes CPU usage is reaching 90%, but the average usage is like 40-65%.  My PC parameters:   Windows 8 (customer preview) Intel Core i3 - 2350M 8 GB RAM   I'd appreciate any help attempt! Regards.  --UPDATE--  As the user below posted a great answer, I have noticed that the process that is eating the most CPU in the system is called Arthurx.sys, simple google tells that it's a TPLink driver (an wifi adapter, I have bought like 2 weeks ago!) drivers has been installed from the Windows MSDN, but also tried to install the drivers from the attached CD, but it doesn't help. From the system start, it is using like 5% of the CPU only, but after 2-4 hours of working it is growing up and reaching 40-60% of the CPU usage.  Device name: TPLink WN722N


Does Illusory Gains allow someone to block their own creatures?

strikes me as a rather strange card with the potential for some rather unique interactions, one of which I'm hoping someone might be able to explain to me. Take this situation: My opponent has a Bear Cub and an Baulduvian Bear, I cast Illusory Gains on the Bear Cub and the cub comes under my control. I end my turn. On my Opponents turn he attacks with the Baulduvian Bear. I declare the Bear Cub as a blocker. After blockers have been declared but before damage my opponent flashes in a , so I must attach Illusory Gains to it and lose control of the Bear cub. What happens?  Is the cub removed from combat and nothing takes damage? The only thing that is changed is who controls the creature, so it is still the same card (unlike if it had been exiled and returned).  Do both Bear Cub and Baulduvian Bear take 2 damage from each other?  Or does something else happen?


Obtaining a Cuban visa as an Australian travelling through the USA

I will be travelling to the USA from Australia (flights booked) in February 2017 and am planning to visit Cuba (flights not yet booked). I would like to know what the easiest and cheapest method of getting into Cuba with a tourist visa is.  I have so far received conflicting information suggesting the following:  Suggested method 1. Once in the USA, travel to Mexico or Canada where I can purchase a Cuban tourist visa, then fly to Cuba (as the USA will apparently not issue a tourist visa)  Suggested method 2. Contact the local Cuban consulate (in Canberra here in Australia) who will issue a tourist visa (we have contacted the consulate and were told they do not do this, but I know others who have obtained Cuban visas this way)  Has anyone had any recent experience travelling to Cuba and obtaining a tourist visa? If so, what method was successful for you?


English is not my native language. I read much more than I speak or hear. In fact, the only time I hear English being spoken is when I'm at my lectures in college or watching a movie.   However, I read a lot, and I know how to words are spelt but don't know how they are enunciated.  For example, I have long know  the word "lingerie", having come across it in my reading, but only recently knew that it was pronounced "lawngzere" and not "lingerie".  So how do I know how a word in pronounced just by looking at it's letters on a page?


Do red blood cells have no MHC? (I have often heard that they do not.)  If so why are they not destroyed by immune cells?


I can understand the physical existence of centripetal acceleration, the orthogonality of that with the linear (tangential) velocity - but how to physically understand jerk and snap in case of uniform circular motion?


Almost no free space left on D drive, but files/folders only take up little space

I'm using Windows 7.  All of a sudden from nowhere, my D: Drive is showing a red bar for space, and it says there are only 620 MB free out of 28.9 GB. Yet when I browse into D:, select all files and folders, right click, and choose "Properties", the total space taken by the contents of D is a mere 2 GB. I've already enabled viewing hidden files, but the hidden files are really small. What on earth is taking up the rest of the space? Or is the My Computer's browser falsely saying I'm almost out of space?   Edit  I tried the solution here:   But I got this error:  Error: The shadow copy provider had an unexpected error while trying to process the specified command.


Possible Duplicate:          I just tried to edit the tags of  to add the  tag to it (since the feature is already present), but every time I submit the edit I get dumped back to the edit page again.  Is this a moderator only tag (i.e. only moderators can apply it? Does the same apply to the other  tags?


Spreading out text vertically inside a parbox or minipage automatically

How can TeX (whether it is in its own terms or in those of LaTeX2e) be told to typeset the text spread out vertically and evenly inside a parbox or a minipage that has been defined with a given vertical size through the optional arguments of the parbox command or the minipage environment?   Please, consider that I'm talking about running text that is to be divided into vertical boxes (lines) automatically by TeX, as opposed to being broken into different lines manually by the author (in the latter case, I already know I could issue \vfill commands).   Pointing to a package that does this would be acceptable as an answer.  I  believe this question does not require an MWE, but if so required I'd provide one.


Deleted my only Launcher and APK - Black Screen. Please help!

I have a Lenovo A806. The device was rooted and I downloaded a root uninstaller from the PlayStore to uninstall some apps that I couldn't otherwise.   In the process, among other apps, I deleted the only launcher I had on the phone (Lenovo Launcher) and I might have deleted the APK (not sure about the APK). The result was a black screen without any apps.   When turn on the phone I can see the home screen (same one you see before you unlock keyboard) and I also have some of the functionalities (eg messages, can make calls etc). However, if I open one of these functionalities and I click on the "back" button, the screen goes completely black and the phone goes unresponsive.  I tried to,   reset factory settings by holding the Volume Up + Down + On/Off button which opened the "Lenovo Recovery" screen and I choosing the "wipe user data (both fuse format and fuse wipe data).  install update package option and I rebooted the phone. Nothing of those worked.    Could anyone direct me towards the right way?


How can I find the residue of the following function at the point $z=0$     $$f(z)=\frac{\cot(z)\coth(z)}{z^3}$$


Should 'is' or 'are' be used before a list of possible types of one thing?

I'm considering editing a Stack Overflow question titled:     What is functional, declarative and imperative programming?   It seems like "are" should be used instead of "is" since it comes before a list of things, and if you weren't familiar with the topic it might sound like it was asking about one type of programming that was all three of those at the same time. But does it make a difference when the list of things is a list of adjectives describing a single thing? I mean, does the "is" or "are" apply to the "functional, declarative and imperative" or to "programming"?  I know that the sentence actually means     functional programming, declarative programming, and imperative programming   and if I write it like that it seems clear that "are" should be used, but for some reason when I look at the original sentence, both "is" and "are" look wrong.  I'm not sure of the terminology I should use to refer to a sentence with this structure, so I'd also appreciate it if someone could tell me if there is a name for this type of "distributive" list.


Deriving Lagrangian density for electromagnetic field

In considering the (special) relativistic EM field, I understand that assuming a Lagrangian density of the form  $$\mathcal{L} =-\frac{1}{4}F_{\mu\nu}F^{\mu\nu}  + \frac{1}{c}j_\mu A^\mu$$  and following the Euler-Lagrange equations recovers Maxwell's equations.   Does there exist a first-principles derivation of this Lagrangian? A reference or explanation would be greatly appreciated!


Is there a way to mv,cp, or any file operation such that I could specify all the files I don't want affected?  For example, say I have a folder with the files file1, file2, and file3, and I want to move file1 and file2 somewhere. Rather than explicitly naming the files to move (mv file1 file2 /path/to/destination), I want to name the files not to move and have all the others in the folder get moved (mv --some-switch file3 /path/to/destination)


Where can I find a repository for older unsupported releases?

I remember I saw a apt mirror somewhere containing older distributions but I cannot find it anymore. Does anybody know where to find it?


Which is correct in this sentence: "me and my" or "my and my"?

Which of the following sentences contains the grammatically correct bolded section:  "He affected me and my friend's day." or "He affected my and my friend's day."  It seems clear to me that the first sentence clearly sounds the best, but I was always told that you should be able to isolate the sentence to just one of the objects, i.e. remove my friend from the sentence, and when I do that, only the second sentence makes sense.  What is the correct grammar to use here?


$\mathbf{Question}$: Can we construct an outer measure that is determined by the non-measurable set of Vitali? Although I can construct an non-measurable set, I cannot calculate its outer measure. Now I want to construct two disjoint sets: A and B which satisfy the following : $$ m^*(A \cup B) <m^*(A) +m^*(B)$$ $m^*(\cdot)$ stands for outer measure


[Ljava.lang.String; error when trying to split Array List in Java

I'm fairly new to java and I believe the problem comes from my lack of understanding. I am trying to read an Array List of CSV values.  Below is my code:     public static void readFile(){         String line = "";         try{             BufferedReader br = new BufferedReader(new FileReader(Main.filepath));              while((line = br.readLine()) != null){  //reads whilst the next line is not null                 fileData.add(line);                 //adds current line to array list         }         catch (Exception ex){             System.out.println("File Not Found");   //if file not found, print         }     }  public class Film{     public static void duration(){         readFile();         for (int i = 0; i < (fileData.size()); i++) {             //System.out.println(fileData);             String[] temp = fileData.get(1).split(",");             System.out.println(temp);         }     }  readFile() reads the CSV file and saves each line as an element in an ArrayList filedata is the ArrayList filepath is the path to the file The CSV file is in format "filmName,releaseDate,filmRating,filmGenre,filmDuration,filmScore" I'm trying to get Film() to print out the release dates of every element in the ArrayList, however my output is: [Ljava.lang.String;@6bf2d08e [Ljava.lang.String;@5eb5c224 [Ljava.lang.String;@53e25b76 [Ljava.lang.String;@73a8dfcc  When I'm expecting something more like 1999 2007 1956 1987  Any help is appreciated.


Does anyone know why AC coupling caps should be implemented in USB3 interface while it's not required in USB1/2?  Anything to do with transmition speed, encode method?


Distribution function terminology (PDF, CDF, PMF, etc.)

I am confused about the following terminologies:   Distribution Function Cumulative Distribution Function (CDF) Probability Distribution Function Probability Density Function Probability Mass Function (PMF)  (1) Distribution Function == CDF. I.e. they are the same. Am I right?  (2) Which is called PDF: Probability Distribution Function or Probability Density Function?  (3) What is the difference between Probability Distribution Function and Probability Density Function?  (4) Which one is the continuous equivalent of PMF, Probability Distribution Function or Probability Density Function?    Die roll examples could be used for the discrete case and picking a number between 1.5 and 2.5 as an example for the continuous case.