I have noticed that both Firefox/Outlook don't have auto spellcheck for the subject text box of emails. For Firefox, I am referring to Yahoo web mail.  The subject is supposed to contain texts; then why isn't any spellcheck enabled for these fields?

As you know, we can enable the spell checker on single line text boxes in the following way:    We have to enable it every time for checking words.  How can we enable it forever, so it doesn't need to be enabled each time?


A similar but easier question is   “What is the probability that when a dice is rolled $3$ times, the sum of score is $13$ ?”  For which you can easily solved by listing down all the possible combination of three numbers $(\leq 6)$ to get $13$.  But if the dice is rolled a lot of times, it becomes very tedious to list down all the combinations. Is there easier method to solve this type of question?  Any help is much appreciated.

A function $\textbf{face}_{\mathrm{sum}}$ that takes a vector  $f$ that represents the number of faces of each die, and a positive integer  $s$ , and returns the probability that the sum of the top faces observed is  $s$ .  For example, if $f=[3,4,5]$  and  $s≤2$  or $s≥13$ , $\textbf{face}_{\mathrm{sum}}$ returns $0$, and if  $s=3$  or  $s=12$ , it returns  $\frac13*\frac14*\frac15=\frac1{60}$  $\textbf{face}_{\mathrm{sum}}([2,4,4,6], 10)$  I tried to solve this but I can't find the formula to calculate the number of combination of die faces that add to $10$, as the number of faces are different for each die.  Since max no of possible combination is $6*4*4*2=192$, all I need to find is the number of combination of die faces that add to $10$.  Thanks in advance.


What permissions is it advised to set my website at?  I know 777 is a bad idea, but what should it actually be?

I was trying to open a file and write to it with PHP at /var/wwwfolder but it wasn't working so I did  sudo chmod 777 /var/www   now I want to set the permissions for /var/www to the default. what are the default permissions for /var/www?


Two years ago, when I was a super beginner to logic, my logic teacher, who is famous in our Country, told me that $1+1=2$ is not a tautology, but a logical truth. However, after reading some truly rigorous logic books(not mathematical logic books yet), I think that $1+1=2$ is neither a tautology, nor a logical truth; my teacher was wrong.  What I think is that $1+1=2$ is followed by the axioms of natural numbers or real numbers. It may be transfered to a predicate logic sentence like $f(a,a)=b$, so it is not automatically true under every model. Instead, $1+1=2$ is a logical consequence of the axioms of numbers, only the models that satifies the axioms of numbers will satisfy $1+1=2$. Am I right? Or is there somewhere I should revise?

Possible Duplicate:          I once read that some mathematicians provided a very length proof of $1+1=2$.  Can you think of some way to extend mathematical rigor to present a long proof of that equation? I'm not asking for a proof, but rather for some outline what one would consider to make the derivation as long as possible.  EDIT: It seems the proof I heard about is a standard reference given here multiple times :) I stated that the proof itself is less useful than an outline for me as I know only "physics level maths". Can someone provide a short outline what's going on in the proof? Some outline I can look up section by section in Wikipedia to at least get a feel of what could be needed to make such a proof?


I observed when a helicopter rotor or fan is spinning the blades blur making it impossible to count the blades, but after a certain speed the blades seem to become visible making it possible to count the blades. Cameras can also do this better.   Do human eyes have a frame rate? What is that called and the most a person can see?  This video in the link shows how these blades seem not to move by timing with the cameras frames rate.

I often read that people believe that human vision has an inherent frames-per-second rate (FPS) that causes stroboscopic effects - such as seeing the spokes of a rotating wheel apparently rotating at a different speed or appearing stationary when moving. For example: in a Physics.SE answer to   The human eye-brain visual refresh rate has an "effective frame rate" of around 30fps. Have you never watched the rims of the wheel in a car next to yours? I can clearly recall many times watching as the wheels sped up how it appears to stand still then move backwards.  This surprises me as I would expect there is no synchronisation of neuron firing in the retina, that neuron firing rates would vary widely depending on light levels and that the brain has no need to process the continuous signals in fixed cycles or in cycles whose length is invariant. I believe this question, or a good answer to it, would differ from  Is human vision in any way subject to a fixed frame rate of 30 FPS?


I have six solar panels but each are different from one another. The first is 4.5V. The second is 6V. And the last four are all equal up to 6V. It all adds up to 16.5V in series or on a good sunny day, 18V max. That's what my multimeter says.  I have a 1N1914 diode connecting to the positive lead connecting to my double pull switch. Now for my batteries, I have one 9V rechargeable battery and 4 AA (1.2V each) rechargeable batteries. The batteries total to 13.8V.  When I try to charge my batteries, it doesn't charge any of it. The switch actually works fine. But when I try to charge the batteries, the meter shows my battery voltage rather than my solar panel. What am I doing wrong?

I've got two solar panels set up in series as shown on the below schema. I connect positive on panel A to positive on battery, and negative on panel B to negative on battery. The two panels produce 9V each, and 18V in series on a good sunny day. That's what my multimeter says.    If I disconnect cabling between panels and battery, my multimeter shows that the panels produce about 15V (a bit cloudy today). However, when I connect the cables between panels and battery, my multimeter shows about 12.2V. I believe this is the battery voltage.  Why is it that when I connect my multimeter at point A and B it shows 12.2V (when solar panels are connected to the battery). As you can see on the schema, there's a diode in front of point B. Shouldn't that diode make sure that current from the battery not flows back to the panels?   If this is how it is supposed to work, how do I check the voltage my panels produce when the panels are connected to the battery.


I'd like to know how to prove algebraic numbers form a field, i.e.,  if $a,b$ are algebraic numbers, prove that $ab$ and $a+b$ are also algebraic numbers by finding specific polynomials that satisfy $ab$ and $a+b$.  I know there is a way to do this using Kronecker Symbol, but not sure exactly how to do it. Edit: This question is different from the suggested duplicated one in that this question asks for answer to prove that algebraic numbers form a field in unconventional ways such as using Kronecker Symbol. As the result, answers are  very different from the one suggested duplicated. So this question deserves remaining open.

The proof I'm familiar with that the algebraic numbers $\mathbb A$ form a field uses the fact that the resultant of two polynomials $p,q\in\mathbb Q[x]$ satisfies the following properties:   It is $0$ iff $p$ and $q$ have a common factor. It is a polynomial in the coefficients of $p$ and $q$.   We then introduce a new variable and cleverly manipulate $p$ and $q$ to get polynomials which vanish at the sums and products of their roots. This is in some ways a nice proof, e.g. it is constructive and so can be converted into an algorithm to find such polynomials (which I in fact just finished doing in C). But I don't find it very enlightening; it seems like the fact that $\mathbb A$ is a field is simply an accident. Is there a more enlightening proof of this fact?


I've seen this in a lot of scripts. When is it better to do  var foo = function() { console.log("Foo!"); };   than  function foo() { console.log("Foo!"); }   when it's obvious that function name(){} is more compact and seems to do the same things? At first, I thought it was so you could use foo as a variable, but you can still do that with both methods. They can even both be redeclared by either method.  I know that var foo = function(){}; creates the function at runtime, but I don't see the advantage of this, because it can lead to crashes, which I assume are unwanted.

I've recently started maintaining someone else's JavaScript code. I'm fixing bugs, adding features and also trying to tidy up the code and make it more consistent.  The previous developer used two ways of declaring functions and I can't work out if there is a reason behind it or not.  The two ways are:  var functionOne = function() {     // Some code };     function functionTwo() {     // Some code }   What are the reasons for using these two different methods and what are the pros and cons of each? Is there anything that can be done with one method that can't be done with the other?


I was given a computer with Ubuntu 14.04 LTS on it. I am not familiar with this system and it will not support a device that i would like to connect to the computer and use. I want to remove the Ubuntu so that i can install windows. When I put in the windows disc nothing happens so i have read that i need to remove Ubuntu first.  I have no idea at all how to do this. Can someone please give me the step by step to remove it. I greatly appreciate anyones help. I have never removed software but was so thankful to be given the computer that i have so i need to get windows on it so that I can use it. Thanks!

I have absolutely no experience with Linux, and I desperately need to get my computer back up and running again with Windows.  How do I remove Ubuntu and reinstall Windows?    Editor's note: many of the answers are about removing Ubuntu from dual-boot but keeping Windows (which is a bit complicated), while other answers are about removing Ubuntu from single-boot (which is easy: basically just format the disk while installing Windows). The question as written is ambiguous between dual-boot or single-boot.


How do I resize my virtual disk space? I'm running Ubuntu 10.04 LTS with only 8GB (which is the default allocated size) but it's running low on disk space. Thanks.    Here's the screenshot. Thanks to @Suhaib for the +points in reputation.

I have run out of space on my WinXP virtual machine, which I only gave 10 GB space for when I created it.  Is there an easy way to increase it to, say, 20 GB?  I can't see any obvious option in VirtualBox settings.    The suggestion below gives this error  wim@wim-ubuntu:/media/data/winxp_vm$ VBoxManage modifyhd wim.vdi --resize 20000 VBoxManage: error: Cannot register the hard disk '/media/data/winxp_vm/wim.vdi' {46284957-2c09-4e70-8a49-bfbe0f7f681d} because a hard disk '/home/wim/VirtualBox VMs/winxp_vm/wim.vdi' with UUID {46284957-2c09-4e70-8a49-bfbe0f7f681d} already exists VBoxManage: error: Details: code NS_ERROR_INVALID_ARG (0x80070057), component VirtualBox, interface IVirtualBox, callee nsISupports Context: "OpenMedium(Bstr(pszFilenameOrUuid).raw(), enmDevType, AccessMode_ReadWrite, fForceNewUuidOnOpen, pMedium.asOutParam())" at line 210 of file VBoxManageDisk.cpp     Removing the .vdi from VirtualBox before calling VBoxManage command, then adding it back in, was successful.  But now I can't boot the virtual machine, I get this worrying screen:    By the way, it says FATAL: Could not read from the boot medium!  System halted.    The vdi must be reattached to the VM after VBoxManage command.  Further, the partition will need to be resized from WITHIN windows, because you will have this empty space:    I was able to resize the partition easily using a bit of freeware called .


Suppose that: $E_1 \begin{bmatrix}12\\35\end{bmatrix} = \begin{bmatrix}48\\35\end{bmatrix}$ Find $E_1$ and $E_1^{-1}$   I know how to find the inverse of a matrix, that's easy. It's just $E_1^{-1} = E_1 * I$  What I don't understand is how I can find $E_1$?  I know the equation in my book says $A\vec{x} = b$  Am I essentially finding $A$? If that is so, would I need to find the inverse of $x$?  So would I need to manipulate $Ax = b$ to $x^{-1}[Ax = b] = AI = x^{-1}b \implies A = x^{-1}b$?

Suppose that $E_1 \begin{bmatrix}12\\35\end{bmatrix} = \begin{bmatrix}48\\35\end{bmatrix}$ Find $E_1$ and $E_1^{-1}$   I set up the equation and saw that $E_1 * A = B$ so I know that:  $E_1 = A^{-1} * B$   where $I_m =$ Identity Matrix   So I attempted to find $A^{-1} = A*I_m = \begin{bmatrix}12&1\\35&0\end{bmatrix}$  After RREF I got: $A^{-1} =\begin{bmatrix}1&1/12\\0&35\end{bmatrix}$  So then I tried $E_1 = \begin{bmatrix}1&1/12\\0&35\end{bmatrix} * \begin{bmatrix}48\\35\end{bmatrix}$ but It is saying that I am incorrect? What am I doing wrong?


How many years does it take to get a PhD in the USA?  What is the typical time to degree?  I heard a rumor it was five years.

I am trying to find out what the average duration of PhD studies are in the USA. Here in Spain it used to be 4 years, but it seems that Europe is moving towards a 3-year scheme since students are expected to do their MSc before they start. What is it like in the USA? Is some kind of shortening also occurring?


If I have a query like   select sum(number) as points, user from point where expiryDate < NOW() group by user limit 1;   will the DB need to process the entire point table even though it will only need to return 1 row (or afew rows).     Some background:   Users have points that can expire, when points expire, I want to process it. Here I am querying for expired points for each user. Since there are possibly many such points, I am trying to do this process in batches, thus the LIMIT. But my guess is this does not actually optimize anything if the DB searches the entire DB anyways. Is there a better way?

When I add LIMIT 1 to a MySQL query, does it stop the search after it finds 1 result (thus making it faster) or does it still fetch all of the results and truncate at the end?


i basically want find /dir -print0 | wc -0  , unfortunately wc doesn't have a 0/look-for-nulls argument; this works: find /dir -print0 | php -r '$ret=0;while(!feof(STDIN)){$ret+=substr_count(stream_get_contents(STDIN),chr(0));}echo $ret,PHP_EOL;'  but it looks like ass and requires php, is there some way to do this using just standard-ish linux utilities?

I have a shell script which uses find -print0 to save a list of files to be processed into a temporary file.  As part of the logging I'd like to output the number of files found, and so I need a way to get that count.  If the -print0 option weren't being used for safety I could use wc -l to get the count.


I would like a detailed explanation and justification if possible regarding the topic. I would like to know what happens at an atomic level. Most of the answers I have found were very basic and did not explain it thoroughly enough. What I have deduced (which does not feel right) is, a denser object has more particles/atoms, therefore, when the object becomes submerged in water it sinks because it exerts more force per area or pressure (because it has more particles to exert the force), that pressure exerted by the object, is stronger than water's (because water is less dense, therefore less pressure) and it sinks, it will only stop sinking at lower depths when the water's pressure increases. Is this similar with why a bullet is able to pierce (not push) through less dense cotton and not denser concrete.  I am a gr.9 student who is enthusiastic about physics and would like to thank in advance for your responses!

I realised, reading another Phys.SE question about  that I don't really understand how  works. Particularly concerning, for a SCUBA diver.  The top answers to that question seem to claim that balloons get their "sense of down" from a pressure differential. They continue: when a car accelerates, the air at the back of the car becomes more dense, and at the front less dense, changing the plane of the pressure differential and so also, the balloon's sense of up. I find that extremely hard to credit. However, I realised that I don't really know why less dense things float in more dense things.  I'm fairly sure it's something to do with displacement of heavier things by lighter things, and I think pressure acting on the lighter thing's surface has something to do with it, but that's about it.


How can one find out on a 7/24 machine which SSD type (connector) is used? I know that I'll run out of disk space in a certain time and I'd like to order a replacement SSD.   If it's not absolutely necessary I'd prefer not to shutdown and open the computer just to examine which SSD with which connector is used.  How can I find out:   either exact type of used SSD  or which connector is used for the SSD   Thank you for your suggestions!

I want to know which hard disk drive corresponds to which device path. It's trivial to match the hard disk stats (brand, size) with the dev path, but I want more. I want to know which drive is which inside my case. What's a good way to go about getting this info?  Constraints   I am lazy. I don't want to tear apart my server to remove all the drives, then add back one by one. Reboots are acceptable. The drives are inconveniently scrunched together in the case. The label information is hidden. The case can be opened. Most disks are SATA, so theoretically hot swappable. Unplugging cables is fair game.   Bonus  I'll award answer to the best/easiest gui or cli answer, and give a bounty to the next-best answer of the other kind. I prefer a cli answer, but understand that a lot of other folks will appreciate a good point-and-click method.


In some cases, questions and answers that have been deleted are still showing up on /review pages. They do not have "Improve" buttons, but they can still be approved or rejected. I'm not sure what causes a post to end up in this limbo state instead of being removed from the queue entirely, which I think is what's supposed to happen.  The suggested edit I noticed this on was , but it just leads to a "Page Not Found" message now.  Tim Stone provided the following screenshot of another instance :

This expands off of  about orphaned tag wiki edits still existing in the suggested edit queue. Today, I also noticed this edit:    This edit was made on a  which was subsequently voluntarily removed by its author. Hence, the Improve button has been removed. Additionally, the  links to a "Page Not Found" which also isn't very useful (does it do that for 10k users too?).  When the post that a suggested edit belongs too gets deleted, so should the suggested edit. The edit gets deleted in all other aspects, since the permalink doesn't even work, but why does it still display in the suggested edit queue?  To tie into the previous issue (linked at the beginning), this should also apply to suggested edits which are made on a tag wiki which is subsequently deleted.


I have a question about compact and complete metric space.  These two concepts how related to each other.   Is  compact metric space complete?  If the question is elementary I apologize you.    Thank you.

I need to prove that every compact metric space is complete. I think I need to use the following two facts:    A set $K$ is compact if and only if every collection $\mathcal{F}$ of closed subsets with finite intersection property has $\bigcap\{F:F\in\mathcal{F}\}\neq\emptyset$. A metric space $(X,d)$ is complete if and only if for any sequence $\{F_n\}$ of non-empty closed sets with $F_1\supset F_2\supset\cdots$ and $\text{diam}~F_n\rightarrow0$, $\bigcap_{n=1}^{\infty}F_n$ contains a single point.   I do not know how to arrive at my result that every compact metric space is complete. Any help?   Thanks in advance.


I wasn't sure how to write the title because I don't really understand this topic. Here's my question: When we are constructing hadrons we put quarks together to form higher representations of the flavour symmetry $SU(3)$ (which I know is not exact, but let's deal only with three quarks for now). Mesons are built with a quark and an antiquark   \begin{equation} 3\otimes \bar{3}=8\oplus1 \end{equation}  This equation can actually be written in a tensorial way like this  \begin{equation} q_i\bar{q}_j=\big(q_i\bar{q}_j-\frac{1}{3}q_k\bar{q}_k\delta_{ij}\big)+\frac{1}{3}q_k\bar{q}_k\delta_{ij}   \end{equation}  Since the last term is a singlet, the first term must be the octet. This is super useful because now we know how to write the octet and the singlet representations in terms of the foundamental quarks. I was wondering how to do this with the baryons. They are built with three quarks  \begin{equation} 3\otimes 3\otimes3=10\oplus8\oplus8\oplus1 \end{equation}  but I don't know how to write this in a tensorial way like with the mesons. I looked all over the literature but I only found the meson formula. How is the decomposition of three quarks writen in a tensorial way?

I am dealing with the tensor product representation of $SU(3)$ and I have some problems in understanding some decomposition.  1) Let's find the irreducible representation of $3\otimes\bar{3}$  we have that this representation trasforms like   $${T^\prime}^i_j=U^i_k {U^{\dagger}}^l_j T^k_l $$  hence I observe that  $$Tr(T)=\delta^j_iT^i_j$$ is an invariant and so  $$T^i_j=\left(T^i_j-\frac{1}{3}\delta^j_iT^i_j\right)+\frac{1}{3}\delta^j_iT^i_j$$  allows me to write $$3\otimes\bar{3}=8\oplus1$$ Here comes my questions: I have heard that this $8$ representation is an "$8_{MA}$" where MA is for "mixed-antisymmetric". The meaning of "mixed-antisymmetric" shold be: "the tensor $\left(T^i_j-\frac{1}{3}\delta^j_iT^i_j\right)$ should be antisymmetric for an exchange of 2 particular indexes but not for a general exchange of 3 indexes". What does this mean? I see only 2 index in that tensor.  2) Consider this representation: $$3\otimes3\otimes3=3\otimes(6\oplus\bar{3})=3\otimes6_S\oplus3\otimes\bar{3}=3\otimes 6_S\oplus8_{MA}\oplus1$$  and now on my notes I have $$3\otimes6_S=10_S\oplus8_{MS}$$  Where "MS" is for "mixed symmetric": symmetric for an exchange of 2 particular indexes but not for a general exchange of 3 indexes.  I could not demonstrate this last decomposition using tensor method. I started noticeing that: $$3\otimes6_S=q^iS^{k,l}$$ where $S^{k,l}$ is a symmetric tensor But then I am not able to proceed in demonstrating the above decomposition (note: I would like to demonstrate this decomposition using only tensor properties, not Young tableaux). I tried to look on Georgi, Hamermesh, Zee and somewhere online but I have not found any good reference which explains well this representatin decomposition...  EDIT: the demonstration should not include the use of Young diagrams...my professor started the demonstration by writing $\epsilon_{\rho,i,k}q^i S^{k,l}=T'^l_\rho=8_{MS}$ and then stopped the demonstration.


As the title of the question suggests, if $\langle A\,,\,<\rangle$ is an infinite linearly ordered set such that for each $a\in A$, the initial section $\text{sec}(a,A,<)$ is a finite set, ¿is it true that it must be isomorphic to  $\langle\mathbb{N}\,,\,\text{<}_{\mathbb{N}}\rangle$?  Obviously, every well-ordered set that verifies this property is isomorphic to $\langle\mathbb{N}\,,\,\text{<}_{\mathbb{N}}\rangle$, for if $\langle A\,,\,<\rangle$ is a well-ordered set, there exists a unique ordinal $\alpha$ such that $\langle A\,,\,<\rangle$ is isomorphic to $\langle\alpha\,,\,\in_{\alpha}\rangle$. In that case, every initial section of the first turns into an ordinal less than $\alpha$, and if every initial section of the first is finite, then every ordinal less than (or in other words, contained in) $\alpha$ is finite, so $\alpha$ is equal to $\omega$, the set of all natural numbers.  However, since a set that is not well-ordered cannot be isomorphic to one that is well-ordered, like $\langle\mathbb{N}\,,\,\text{<}_{\mathbb{N}}\rangle$, we must prove that if every initial section of $\langle A\,,\,<\rangle$ is finite, then the set is well ordered. How shall we proceed?  Thanks in advance.

It's true that a set with a linear order where every initial segment is finite is necessarily countable? I don't think so but I can't find a counterexample (or make a proof)


I have an edit partial view to load in a dialog, which works the first time it's called, the edit then saves the data, great.   However if you don't refresh the page, which I don't want to have to do, and click 'edit' again, you are redirected to the partial page I am trying to load.  It looks like the AJAX is being ignored and the Action method in the controller is being called instead.  I have unobtrusive added through the bundles in my layout page, which the main view uses, the partial doesn't, but I don't believe it needs to.  I have also tried using preventDefault and different approached of return false; with no success, like the below:  editBtn.click(function (e) {             editDialogPlaceholder.load(this.href, function () {                 e.preventDefault(); //tried                 $(this).dialog('open');                 return false; //tried             })         return false;     });   How can I stop this?  AJAX/JS  $(function () {         var editBtn = $('.editLink');         var editDialogPlaceholder = $('#editDialogUI');          editBtn.button();         // build the dialog form         editDialogPlaceholder.dialog({             autoOpen: false,             modal: true,             resizable: false,             open: function (event, ui) {                 $(this).load('@Url.Action("Edit","Announcements")');             },             buttons: {                 "Save": function () {                     saveAnnouncement();                     fetchList();                     $(this).dialog("close");                 },                 "Close": function () {                     $(this).dialog("close");                 }             }         });         // on click load the dialog form, return false to stop redirect         editBtn.click(function () {             editDialogPlaceholder.load(this.href, function () {                 $(this).dialog('open');             })             return false;         });     });     //post data back to the controller to save to the db     function saveAnnouncement() {         $.ajax({             url: '@Url.Action("Edit","Announcements")',                 type: 'POST',                 data: $('form').serialize()             })         }          function fetchList() {             var aList = $('#announcementList');             aList.load('@Url.Action("Fetch")');         }   Edit action method  [HttpGet]         public ActionResult Edit(int id)         {                 var announcementModel = (from a in db.DbAnnouncement                            where a.Id == id                            select a).SingleOrDefault();                 return PartialView("Edit", announcementModel);         }   Html.ActionLinks being used to open the dialog - second time of clicking it redirects to the partial specified in the controller.  <div class="announcementTableCell">                     @Html.ActionLink("Edit", "Edit", new { id = Model[i].Id }, new { @class = "editLink" })                      @Html.ActionLink("Delete", "Delete", new { Model[i].Id }, new { @class = "dltLink" })                 </div>

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


We thought of upgrading MySQL to new version 5.5.16. While testing the scripts with the new version, I had found one column Maxvalue is a Keyword in latest version.  For this one, we need to change all the application where it is used. Instead is there any way to make the keyword Maxvalue interpret as a Normal column, so that we will not have to change our application.  Maxvalue is just column name, it is not the maximum value.  And I am looking for some other option apart from backticks: `Maxvalue`.

In MySQL we can create queries with or without the backtick (`) symbol. Example:   SELECT * FROM TEST; SELECT * FROM `TEST`;   Both works fine in mysql-console.  Is there any technical difference between them?  Is there any benefit using (`) over over simple queries?


I am able to run the adduser command with a script automaticly, but I have no idea how I can get the script to automaticly enter the password hello without needing to type it. Do you have any ideas? The idea of my script is being able to create a new user without interaction with the standard password "hello".

I'd like to use the adduser command to add a user (with disabled password) via a shell script.  By default, adduser prompts you for various values (e.g., Full Name). Is there any way to submit these values via command line? Or will I need to useradd instead?


When I first installed Ubuntu 13.04 from a USB stick I was asked to fill in for user username and password so I set one on my own. When I run Ubuntu I click log in but it automatically logs me in as user so I can't type my username. As a result, in order to run certain apps or set up my network I'm asked to type the root password for authentication. I don't wanna log in as a superuser. Please note that I'm a newbie to Ubuntu.

I installed  (Precise Pangolin), 64 bit. Nowhere was I asked to set password for root.  I just installed  software. It was installed under the /root folder by default. Now I try do something on that folder. I tried with su to switch to root, but I don't know its password.   Should I always use sudo or get the default root password, if any?  How do I create a  for software installed inside the /root directory?


When I run sudo apt-get update, I receive this error message:    W: The repository 'http://ppa.launchpad.net/ubuntu-wine/ppa/ubuntu yakkety Release' does not have a Release file.   N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.   N: See apt-secure(8) manpage for repository creation and user configuration details.   E: Failed to fetch http://ppa.launchpad.net/ubuntu-wine/ppa/ubuntu/dists/yakkety/main/binary-amd64/Packages  404  Not Found   E: Some index files failed to download. They have been ignored, or old ones used instead.     Due to this error I can not install any application, please help me in detail, I am very new to Linux.

PPA seems to be constantly offline. Whenever I use sudo apt-get update, this error is shown:  W: Failed to fetch http://ppa.launchpad.net/ 404  Not Found   How do I fix these errors?


I have a table like this:  Product_ID | Size_ID          3 |      S          3 |      M          4 |      L          5 |      S   And I would like the result to be like:  Product_ID | Size_ID          3 |   M, S          4 |      L          5 |      S   Is it possible to do that? My query is this:  Select Product_ID, Size_ID FROM product Group by Product_ID Order by Product_ID Desc

Consider a database table holding names, with three rows:  Peter Paul Mary   Is there an easy way to turn this into a single string of Peter, Paul, Mary?


So, I am trying to implement taking of photos in my app.  I am following the official "Taking Photos Simply" tutorial, but it just gives me errors.  The only thing I am doing differently, it that I am using a popup dialog fragment.  Below is the error I get:  java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=131073, result=-1, data=null} to activity {com.myapp.demo/com.myapp.demo.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'android.os.Bundle android.content.Intent.getExtras()' on a null object reference         at android.app.ActivityThread.deliverResults(ActivityThread.java:3605)         at android.app.ActivityThread.handleSendResult(ActivityThread.java:3648)         at android.app.ActivityThread.access$1400(ActivityThread.java:154)         at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1370)         at android.os.Handler.dispatchMessage(Handler.java:102)         at android.os.Looper.loop(Looper.java:135)         at android.app.ActivityThread.main(ActivityThread.java:5289)         at java.lang.reflect.Method.invoke(Native Method)         at java.lang.reflect.Method.invoke(Method.java:372)         at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:904)         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:699)  Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.os.Bundle android.content.Intent.getExtras()' on a null object reference         at com.paulcanning.mote.NoteDialogFragment.onActivityResult(NoteDialogFragment.java:179)         at android.support.v4.app.FragmentActivity.onActivityResult(FragmentActivity.java:153)         at android.app.Activity.dispatchActivityResult(Activity.java:6192)         at android.app.ActivityThread.deliverResults(ActivityThread.java:3601)             at android.app.ActivityThread.handleSendResult(ActivityThread.java:3648)             at android.app.ActivityThread.access$1400(ActivityThread.java:154)             at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1370)             at android.os.Handler.dispatchMessage(Handler.java:102)             at android.os.Looper.loop(Looper.java:135)             at android.app.ActivityThread.main(ActivityThread.java:5289)             at java.lang.reflect.Method.invoke(Native Method)             at java.lang.reflect.Method.invoke(Method.java:372)             at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:904)             at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:699)   Button click listener  takePhoto.setOnClickListener(new View.OnClickListener() {          @Override         public void onClick(View v) {             Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);             if (takePictureIntent.resolveActivity(getContext().getPackageManager()) != null) {                 //startActivityForResult(takePictureIntent, 1);                  File photoFile = null;                 try {                     photoFile = createImageFile();                 } catch (IOException ex) {                     // Error occurred while creating the File                 }                 // Continue only if the File was successfully created                 if (photoFile != null) {                     takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT,                             Uri.fromFile(photoFile));                     startActivityForResult(takePictureIntent, 1);                 }             }         }      });   onActivityResult (note, it wouldn't let me use protected)  @Override public void onActivityResult(int requestCode, int resultCode, Intent data) {     if (requestCode == 1 && resultCode == getActivity().RESULT_OK) {         Bundle extras = data.getExtras();         Bitmap imageBitmap = (Bitmap) extras.get("data");         imageView.setImageBitmap(imageBitmap);     } }

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


This is the first time it has happened to me where I am using the su command and it actually displays the password on the terminal and doesn't stay hidden. Here is my code snippet:   sshpass -p "password" ssh -q username@74.11.11.11 "su -lc 'mkdir temp/'"   Code explanation:  I am accessing a remote server and trying be root on that server to create a folder. In doing so I have to use the su command and it prompts me for the password. When I enter the password, it gets displayed and doesn't stay hidden. How do I fix that?


I have a lot of volumes (folders) mounted from remote machines, about 10 of them, which I set to be mounted automatically when I'm logging in by adding them to the Login Items list in Users & Groups. Of course, I made sure to tick the Hide check box of each of the volumes, yet OS X opens each of the folders whenever I log in so I have to close them one by one manually.  When an application starts, the hide button makes sure no windows are drawn visibly. Can Finder be configured to respect the "hide" flag similarly?

I have some shares that are mounted during login. I used Users & Groups' "Login Items" panel to do this. When I login, all of the shares pop up in their own Finder windows.  How can I keep the Finder windows from popping up at login? I've already tried checking the Hide checkbox.


I don't really like the animation with which the icons load up after I click on show applications button is there any way to change it and make it cleaner probably the animation used in windows 8 for start button.

I just installed Ubuntu 18.04 and one of my first negative impressions is the long animation of flying-in icons when opening the app menu.  Can I speed this up or disable it?


Let $a$, $b$, $m$ be integers. Prove that if $2a + 3b \ge 12m + 1$, then $a \ge 3m + 1$ or $b \ge 2m + 1$.   I need help proving this. I am not sure what to do.   Thank you for all of the edits.   I am still unsure on how to word the problem.    Right now.  Proof - By contrapositive.  Assume that a < 3m + 1 and b < 2m + 1 for the integers a, b, and m. Then,  2a + 3b < 12m + 1 = 2(3m + 1) + 3(2m+1) < 12 m + 1  = 6m + 2 + 6m + 3 < 12m + 1 = 12m + 5 < 12m + 1  Which is false because 5 < 1  So next, I would say...  Assume that a < 3m + 1 and b < 2m + 1 for the integers a, b, and m. Then a < 3m < 3m + 1 and b < 2m < 2m + 1.  Then plug in again to show 12m < 12m + 1  Then what?

Let $a, b, \& \, m$ be integers. Prove that if $2a + 3b \geq 12m + 1$, then $a \geq 3m + 1$ or $b \geq 2m + 1$.   My Attempt: I don't conceive apace how to contrive, from the one inequality in the antecedent, the two inequalities in the consequent. So a proof by contraposition may be more facile. The contrapositive is: $\text{If }  \color{Green}{a < 3m + 1} \; \& \; \color{#0073CF}{b < 2m + 1}, \text{ then } 2a + 3b < 12m + 1 \tag{*}.$  From $(*)$, $\color{Green}{2a} + \color{#0073CF}{3b} < \color{Green}{6m + 2} \; + \;\color{#0073CF}{6m + 3} = 12m +5$. But this doesn't prove $(*)$.     Given Solution:  Assume that $a < 3m+1$ and $b < 2m+1.$ Since a and b are integers, $a ≤ 3m$ and $b ≤ 2m.$ Therefore, $2a + 3b ≤ 2(3m) + 3(2m) = 12m < 12m+ 1,$ as desired. $\blacksquare$   What went wrong in my attempt? I understand the given solution but I persisted with the more natural and direct green and blue, instead of deviating to weak inequalities. Shouldn't both solutions work?  Source: Problem 4.19 on P102 (related to P90, Result 4.8) of Mathematical Proofs, 2nd ed by Chartrand et al.    $\large{\text{Supplement to Cameron Buie and pritam's Answers :}}$  What overriding, catholic lessons can be extrapolated from this example to generalise about inequalities?   Moreover, in order to circumvent the problem here (ie the loss of information from the weaker inequalities), should I always start with the strictest inequality? If so, should I always rework any weak inequality into the equivalent strict inequality?   For example, define $r \in \mathbb{R} $ and $n \in \mathbb{Z}$ and $g(...) \neq h(...)$. Then $ f(r) < h(r) \require{enclose}      \enclose{updiagonalstrike}{\iff} f(r) \leq g(r).$ But $ f(n) < h(n) \text{ MAY OR MAY NOT }\iff f(n) \leq g(n).$


I have a fresh install (well, with package updates) of Linux Mint 16 (Maté) on a 3TB hard drive. I installed with the following partition table:  /dev/sda1: bios_grub   1MB /dev/sda2: /           8GB   ext4 /dev/sda3: linux-swap  2GB   swap   with the rest of the drive unpartitioned and unused.  Now that I have things working like I want them, I open up GParted and create a partition for the remaining space. However, after doing so, it lists the partition as having used 43.90GiB: (transcribed from GParted's GUI, with superfluous columns/rows removed).  Partition  File System  Size      Used        Unused /dev/sda4: ext4         2.72GiB   43.90 GiB   2.68TiB   I mount the drive and run df -h:  Filesystem      Size  Used Avail Use% Mounted on /dev/sda2       7.3G  4.2G  2.7G  61% / none            4.0K     0  4.0K   0% /sys/fs/cgroup udev            1.8G   12K  1.8G   1% /dev tmpfs           362M  1.2M  360M   1% /run none            5.0M     0  5.0M   0% /run/lock none            1.8G   76K  1.8G   1% /run/shm none            100M   44K  100M   1% /run/user /dev/sda4       2.7T   73M  2.6T   1% /media/storage   So that is correct. I know it's an empty partition - this is a brand new drive. Refreshing GParted: (again, transcribed from GParted with extra rows/columns removed)  Partition  File System  Mount Point     Size      Used        Unused /dev/sda2  ext4         /               7.45 GiB  4.40  GiB   3.05 GiB /dev/sda4  ext4         /media/storage  2.72 GiB  43.90 GiB   2.68 TiB   So, does anyone have any ideas as to why GParted is showing incorrect information for that partition? You can see that it's correct for /dev/sda2.  Thanks,

I used du to list all folders and sort by size, the results simply doesn't add up to how much disk space is used(using df). There's about 20G in discrepency, why?   [root@xxx lib]# du --max-depth=1 -h /| sort -n -r 310M    /lib 123M    /root 96K /dev 88M /etc 75G / 73G /var 30M /sbin 20M /boot 20K /tmp 18M /lib64 16K /mnt 16K /lost+found 12K /home 8.0K    /srv 8.0K    /selinux 8.0K    /opt 8.0K    /misc 8.0K    /media 7.0M    /bin 1.2G    /usr 0   /sys 0   /proc [root@xxx lib]# df -h Filesystem            Size  Used Avail Use% Mounted on /dev/mapper/VolGroup00-LogVol00                       298G   94G  189G  34% / /dev/sda1              99M   26M   69M  28% /boot tmpfs                 2.0G     0  2.0G   0% /dev/shm


$I=1/2\pi i\int_C |1+z+z^2|^2dz$ where C denotes the unit circle centered at zero and integral is taken anticlockwise.  I saw that as application of Cauchy Goursat theorem as it seems analytic to me everywhere. So the integral should be zero?

Let $C$ denote the unit circle  centered at the origin in Complex Plane  What is the value of   $$ \frac{1}{2\pi i}\int_C |1+z+z^2 |dz,$$ where the integral is taken anti-clockwise along $C$?   0 1 2 3   What I have answered is 0 because it seems like $f(z)$ is analytic at 0 hence by Cauchy's Theorem.


What is the value for  $$\lim_{n\to\infty}\left(\frac{n+1}{n}\right)^{n}\ ?$$  According the answers given in the book, it should be $e$, but I can't solve it.  Can someone help me please?

Assuming the definition $e = \lim (1+\frac{1}{n})^n$, I want to show that one also has $e = \lim (1+\frac{1}{n+1})^n.$ My idea was to try and squeeze $(1+\frac{1}{n+1})^n$ between two sequences which we know converge to $e$, i.e., something like  $$ \left(1+\frac{1}{n-1}\right)^{n-1} \leq \left(1+\frac{1}{n+1}\right)^n \leq \left(1+\frac{1}{n}\right)^n,$$  but the equality on the left sadly isn't true. Is there a way to adapt this idea into a working proof?  Thanks!


I have a little bit of programming experience in web development languages such as HTML, CSS, JQuery, JavaScript, PHP, Python etc., but I am no taking an AP Computer Science class at school to learn Java. To see how similar it is to other languages in both syntax and how to go about different problems I decided to make a simple blackjack game that i have made in other languages before.   I have run into and error where I want to check to see what the user has input, and if it is a certain character, output different things such as a help sentence, welcome message, or just simply start or stop the game. For some reason it reads the input and I can log it to the console but it will not run the methods that I have created and called in the if statement inside the while loop. I am going to post the whole script since I have only been programming in Java for 2 weeks or so now and have no idea where my error could be.  import java.util.Scanner;  public class testClass {  public static void main(String[] args) {      Scanner kbd = new Scanner(System.in);     // Creates a scanner to get input from the keyboard      boolean gameStart = false;     // starts false, turns true when 'B' is input      welcome();     //displays the welcome message      while (true) {         // loop to play the game          String input = kbd.nextLine().toUpperCase();         // gets the next input from the user          if (input == "B") {             // checks the users input              gameStart = true;             // 'turns on' the game              double[] hand = drawCards();             // makes an array of 2 cards             System.out.print(input); //REMOVE          } else if (input == "?") {             // checks the users input              help(gameStart);             // displays the help message depending on if the game has started or not             System.out.print(input); //REMOVE          } else if (input == "Q") {             // checks the users input              System.out.print(input); // REMOVE             break;             // ends the game loop          } // ends if      } // ends while   } // end main  public static void welcome() {     // displays the welcome message      System.out.printf("Welcome to blackjack! %nEnter 'B' to begin. %nEnter '?' at any time to see help %nEnter 'Q' at any time to quit %n => ");     // the welcome message  }  public static void help(boolean gameStart) {     //displays the help message      if (gameStart) {          System.out.printf("Enter '?' at any time to see help %nEnter 'Q' at any time to quit %nEnter 'H' to hit %nEnter 'S' to stay %n => ");         // the help message when the game has already started      } else {          System.out.printf("Welcome to blackjack! %nEnter 'B' to begin. %nEnter '?' at any time to see help %nEnter 'Q' at any time to quit %nEnter 'H' to hit %nEnter 'S' to stay %n => ");         // the help message when the game hasn't started      }  } //  end help  public static double randCard() {     // creates a random card      double card = Math.round(Math.random() * 10);     // number 1-10      if (card == 10 || card == 0) {         // no cards at 10 or 0          double x = Math.round(Math.random() * 10);         // variable used to choose J Q K or A when card is 0 or 10          if (x < 3) {             // Jack             card = 11;         } else if (x < 5) {             // Queen             card = 12;         } else if (x < 7) {             // King             card = 13;         } else {             // Ace             card = 10;         }       }      return card;     // returns a single card  } // end randCard  public static double[] drawCards() {     //creates 2 random cards and returns an array      double card1 = randCard();     double card2 = randCard();     // stores the 2 random cards in variables      double[] cards = {card1, card2};     // places the 2 random cards in an array      return cards;     // returns the array of cards  } // end drawCards  } // end class

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


I need this information to make my own English language site, but I do not want to use copy-paste from other sites or books. I need to find the source of information to make a correct content.  If there are no such organizations can you give me a most competent source of such information?

Some languages have a "regulatory body" issuing recommendations and guidelines regarding the use of that language.  For example in the case of Spanish it's the  whose status is recognised in all Spanish-speaking countries. The Academy, among other things, publishes a dictionary (""), in print and , which is usually given a lot of prestige (but is not without , of course).  Are there any such authorative—or at least influential—institution(s) or publication(s) for the English language?


Is this a right way to check for characters (both English and non English characters like umlauts in German and others)?  var alphabet = /[A-Za-z \u00C0-\u1FFF\u2C00-\uD7FF]/g;

How can I use Unicode-aware regular expressions in JavaScript?  For example, there should be something akin to \w that can match any code-point in Letters or Marks category (not just the ASCII ones), and hopefully have filters like [[P*]] for punctuation, etc.


My Lubuntu v12.04 (I'm not using the newest one because my Laptop doesn't support PAE) doesn't boot when the USB I used to install it isn't plugged in. I've overwritten my Windows XP with Lubuntu and the hard drive is the top priority in the boot options. I can even remove the USB while Lubuntu is running, it just needs it for booting, which is really annoying. What am I doing wrong?

First of all: this is not a duplicate of the all the " questions.  Problem:  When booting, the system will not boot unless the installer USB flash drive is present. If I boot without the USB drive, the screen goes black AFTER GRUB lists the different configurations available - so GRUB is on the correct disk, its what it does next that seems to be the problem.  With the USB drive inserted, its access light starts flashing while the system boots in a normal manner.  And yes: I have tried booting from the USB drive directly and then I get the "live" version, so I have not installed the OS on the flash drive by mistake :)   I have tried sudo grub-install /dev/sda and sudo update-grub just for fun, but nothing changed.  System in short:  Ubuntu 12.04 64-bit. i3 processor. UEFI bios. 128Gb SSD drive. The SSD has a 47 Mb EFI partition and the rest mounted as '/' (XFS).


Is it possible to configure Mac, so I will be able to switch to English keyboard with Alt+Shift?

How do I change (switch) the input language in Mac OSX  (English->Russian->Hebrew). In Windows it is done by pressing alt-shift.  What is the equivalent in OSX ?


I have a list of arbitrary length, and I need to split it up into equal size chunks and operate on it. There are some obvious ways to do this, like keeping a counter and two lists, and when the second list fills up, add it to the first list and empty the second list for the next round of data, but this is potentially extremely expensive.  I was wondering if anyone had a good solution to this for lists of any length, e.g. using generators.  I was looking for something useful in itertools but I couldn't find anything obviously useful. Might've missed it, though.  Related question:


consider $S^1 =\{(x,y)\in \mathbb{R}^2 : x^2 + y^2 =1\}$ ,   $D=\{(x,y)\in \mathbb{R}^2: x^2 + y^2  \leq 1\}$  and $E = \{(x,y)\in \mathbb{R}^2: 2x^2 + 3y^2 \leq 1\}$  Which of the following statements are true?  a. If $f : D \to S^1$  is a continuous mapping, then there exists $x \in S^1$ such that $f(x)=x$.  b. If $f: S^1 \to S^1$ is a continuous mapping, then there exists $x \in S^1$ such that $f(x)=x$.  c. If $f : E \to E$ is a continuous mapping, then there exists $x \in E$ such that $f(x) = x$.  i was using the intermediate theorem, that  from my point of view , all option a b and c are correct by intermediate theorem.  But im doubting about my answer.  If anbody help me i would be very thankful to him.

Let $S^1 = \{(x, y) \in \Bbb R^2 : x^2 + y^2 = 1 \}.$ Let $D = \{(x, y) \in\Bbb R^2 : x^2 + y^2 \le 1 \}$ and $E = \{(x, y) \in\Bbb R^2 : 2x^2 + 3y^2 \le 1\}$ be also considered as subspaces of $\Bbb R^2.$ Which of the following statements are true?  a. If $f : D \to S^1$ is a continuous mapping, then there exists $x \in S^1$ such that $f(x) = x$.  b. If $f : S^1 \to S^1$ is a continuous mapping, then there exists $x \in S^1$ such that $f(x) = x$.  c. If $f : E \to E$ is a continuous mapping, then there exists $x \in E$ such that $f(x) = x$.


How do I take a picture with a blurred background with my canon eos 70D using the 18-55 mm lens

I'm currently using an entry-level DSLR with 18-55mm lens and having great trouble trying to creating a blurred background effect in my photos. Now matter what aperture or shutter speed I choose, I'm not able to get it.  There's a general question about , but what specific things can I do to get this effect with an entry-level lens?


I am working on an app and I want to format a number such as 1,000,000 as a short string.  Some examples would be:  1000 => "1k" 50000 => "50k" 83952 => "84k" 1000000 => "1m" 1000000000 => "1b"   I was thinking the best way to do this would be using a  or just rounding it then counting the number of "0"'s.  Anyone have an example of using a NSNumberFormatter in this manner or any resources to get started.

Is there a simple way to do something like..  [NSMagicDataConverter humanStringWithBytes:20000000]   ..which would return "19.1MB"?


Trying to remember this scifi short story I stumble on from time to time. The only thing I can recall is that the universe or solar system was ending, and some scientists went into a vault to gather a few seconds more of data before everything ended.

I've read a story online in the past couple of years, possibly on Tor.com, involving the end of the world, which I would like to reread.  A female scientist has calculated the exact moment some wave of destruction, most likely the Big Rip, will hit earth. She's awaiting that moment together with her mother. A probe has been constructed that might survive, but humanity will not, so there will be no-one to read out the data. Her partner has committed suicide, since he (like many other people) doesn't want to witness the destruction.  I went through the stories on Tor.com but I haven't found it yet.


I think I've heard it some time ago but I can't remember. Is there an English word or idiomatic expression for "A person who doesn’t drink much to control others"?

Is there a word that describes a person who is usually not too drunk and takes care of the rest of the folks at a party?  Typically, they're the ones who drag the sloshed ones back to beds, clean up the house and generally maintain a bit of sanity.


I had this as a statement in my book, but I am unable to prove it using the four basic properties of a group:   Closure Associativity Existence of identity Existence of inverses.

Let $N$ be a normal subgroup of $G$. Let $G/N = \{gN : g \in G \}$. Show that the $(G/N, \circ, 1_{G/N})$ is a group, where:  $\circ : G/N \times G/N \rightarrow G/N$ is defined by $(gN \circ hN) = ghN$ and $1_{G/N} = 1*N$.  Thanks for your help.


I am looking to replace my old battery operated thermostat with a new wifi model. There is no "C" common wire connected to my old thermostat. There is a blue wire that is at the thermostat but cut short with no copper exposed. I went up to the attic and took a look at the A/C unit. There was also a wiring diagram that was available. There is no "C" terminal on the unit but there is a "B" terminal which I assume is the right one I should use. I tested the voltage from "R" to "B" and it was about 26.5 Volts (The new thermostat requires 24 volts). There is a wire connected to the the "B" and "Y1" terminal it seems like its the wiring that goes to the outside Unit. Its the other Red wire and white wire. (See photo below.)  I have attached pictures of the wire terminal on the A/C unit in the attic as well as the Wiring diagrams. In the wire terminal picture you will see the extra blue wire wrapped around the main wire and is not used. I would like to use that wire as my "C" common wire. Is it safe to connect the Blue wire to the "B" terminal? Im worried because another cable is already connected to it and its reading 26.5 volts...       Click for full size  Update 1  First off, big thank you for the help and responses! I really appreciate it!  I went back up and opened the unit. This is what I saw inside. The two wires coming out of the transform have a voltage of about 26.5 volts. I could not find 24 volts anywhere. The transformer says its a 24VAC transformer. Looking at this picture, where do I connect the C wire to? Which wire coming out of the transformer?

How do I identify the C terminal on an HVAC, furnace, or boiler? If the terminals don't have a screw labeled C what should I look for on the wiring diagram? What steps should I take if a wiring diagram cannot be found or if it indicates that a C terminal doesn't exist?  Note: This is an extension to  which asks about running the wires through the wall. This question is about where to connect the wire at the HVAC.


Yesterday, after some problems, finally I could install Ubuntu Server 14.04.2 and gnome GUI. Then I close the server. This morning, when I open it again it stops in this line: AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1 set the 'ServerName' directive globally to suppress this message.  I've been looking for in Google, there are a lot of solutions, but no one works for me. Sure, because I'm new and there are a lot of things I don't know, but can somebody tell me how can I fix this problem? Please, step by step, I've tried to restart using recovery mode - root, but all commands fails.

When I restart my Apache server using the command  sudo /etc/init.d/apache2 restart   I get the following error:  Restarting web server apache2 apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1 for ServerName ... waiting apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1 for ServerName   Is the server using 127.0.1.1 instead of 127.0.0.1? What causes this error?


I am very very new to all of this.   I get it that sudo is some kind of authorisation. When it asks for the password, I can't type anything.   EDIT: OMG GUYS THANKS. I just realized that I might have a solution for my wireless network now!! Well since I had no idea what Sudo was and when I tried to boot up 12.10 I couldn't since I thought I couldn't access to it! YES, I'm gonna try this out!

When I'm about to install a program in the terminal it wants the password:  [sudo] password for xxx:   But when I start to type my password nothing happens. What should I do?


As far as I know, PBKDF2 uses an underlying pseudorandom function in order to generate a hash (like SHA256) so as far I understood PBKDF2 is basically a hash function that uses an underlying function in order to generate a hash but what I don't understand is that what's the point of hmac here?  I expected to use something like PBKDF2WithSHA512 instead of PBKDF2WithHmacSHA512 and I really can't understand what's the point of HMAC.

I've been reading a little bit about hashing lately and , they use "SHA512 within PBKDF2" in their new vault file.  I've looked in Wikipedia for both names and I know PBKDF2 is a key derivation function and SHA is a cryptographic hash function but I can't really understand the difference and why they are both used together with one inside the other.  Can anyone explain this for a person without experience in cryptography?  (You can assume I only know about math, if necessary).


In Guardians of the Galaxy, Vol 2,        Space travel is accelerated by passing through jump points.  The jump points are illustrated as hexagon-shaped opening in walls that are comprised of hexagon-shaped pieces.     What is the back story of the walls?

In Guardians of the Galaxy vol. 2, we see long-distance space travel. It involves piloting your ship into some sort of "jump point" that opens up in space, taking the shape of a honeycomb-like structure with a single hex missing.  The way it's describe, these points are fixed in space: early in the movie, the Guardians have to out-run an enemy fleet to reach the one they need; later on, we see them fly through a very long series of them in sequence. It's also made clear that doing too many of these "jumps" in a row has consequences for the passengers.  The process seems to be similar to, say, the Mass Effect relay setup, mixed with a bit of Star Wars hyperspace travel.  Is this the first time we have seen long-distance space travel in the MCU? Is there anything from the source material that explains how this works from a logistical standpoint? If there's any information on the "science" behind it, that would also be helpful.


I want to figure out whether the number 2014411 is prime or not.  What kind of mathematical searching tools/strategy I have?  Do I have to start from 1 and proceed to 2014410 while I found one as a divisor or any other efficient way to find it?

How do I determine if a number is prime?  I'm writing a program where a user inputs any integer and from that the program determines whether the number is prime, but how do I go about that?


If I have a string a = I,II,III,IV,V,VI,VII,VIII  How can I use pattern to check if my input string matches any of these roman numbers?  Or is there any easier way to do so?

Thinking about , i decided I can't even create a regular expression that will match roman numerals (let alone a context-free grammar that will generate them)  The problem is matching only valid roman numerals.  Eg, 990 is NOT "XM", it's "CMXC"  My problem in making the regex for this is that in order to allow or not allow certain characters, I need to look back. Let's take thousands and hundreds, for example.  I can allow M{0,2}C?M (to allow for 900, 1000, 1900, 2000, 2900 and 3000). However, If the match is on CM, I can't allow following characters to be C or D (because I'm already at 900).  How can I express this in a regex? If it's simply not expressible in a regex, is it expressible in a context-free grammar?


Here is the picture I am talking about. I found it on Facebook. I have seen cards in my childhood which used to show different images when tilted at different angles but this image seems strange.   Can anyone explain me which phenomenon is working here?  Edit: one more thing I found is that the smiling girl appear while looking at the image from some distance too!

Can someone explain this? Or maybe it's not physical, but cognitive phenomenon?


Edit: Solved - soltion by @moewe - Run Biber instead of BibTeX  MacOS,TeXstudio 2.12.18  This has been asked but I can't seem to find a solution that works for me, some suggest the same thing however copying the answer doesn't yeild the same output (e.g. )  I'm writing a thesis which has individual chapters in their own .tex files.  I would like to have a bibliography at the end of each chapter, where the .bib file is the same file used in each instance.  I have tried running the code listed in the example thread above and I can't even get it to work, let alone when I am looking at using separate .tex files.  Code from the example, amended for my own .bib file  \documentclass{article} \usepackage[T1]{fontenc} \usepackage[utf8]{inputenc} \usepackage[refsegment=section,style=authoryear]{biblatex} \addbibresource{lib.bib} \begin{document}  \section{first} \cite{bibid}  \printbibliography[segment=\therefsegment,title=first bib]  \section{second} \cite{Albonetti2005,An2012}  \printbibliography[segment=\therefsegment,title=second bib] \end{document}   With the above code it yields no bibliographies in the output at all. The log states:  Process started: bibtex "test2".aux  This is BibTeX, Version 0.99d (TeX Live 2019) The top-level auxiliary file: test2.aux I found no \citation commands---while reading file test2.aux I found no \bibdata command---while reading file test2.aux I found no \bibstyle command---while reading file test2.aux (There were 3 error messages)  Process exited with error(s)    Process started: pdflatex -synctex=1 -interaction=nonstopmode "test2".tex  Process exited normally   So, I must be missing something, but I am unsure what at this point. Thanks!

Running the minimal example  \documentclass{article} \usepackage{filecontents} \begin{filecontents*}{\jobname.bib} @ARTICLE{example,   author  = {Other, Anthony Norman},   title   = {Some things I did},   year    = {2014},   journal = {J.~Irrep. Res.},   volume  = {1},   number  = {1},   pages   = {1-10} } \end{filecontents*} \usepackage[backend=biber]{biblatex} \addbibresource{\jobname.bib} \begin{document} Hello\cite{example}. \printbibliography \end{document}   I get the warning There were undefined references.  I have read  and know that I need to run:   LaTeX Biber LaTeX   However, my editor is only set up to run BibTeX. How do I go about setting up my editor/IDE to be able to run Biber, and how do I run the LaTeX/Biber/LaTeX cycle?  Answers (sorted alphabetically by editor name)                    Answer guidelines   Each answer should be for one editor. If the editor is cross-platform, if possible give a single answer with notes covering the minor platform variations. Please edit the question to include new answers in the 'link list' Each answer should be 'stand alone', i.e. don't say 'It's almost the same as editor Y but ...' for the editor part Instructions for 'build tools' such as arara or latexmk are welcome but should explain how to set up the editor in question as not all editors allow simple addition of arbitrary tools


Much in the same vein as  question, I am trying to convert 5e so players roll all the dice. I'm using  as a starting framework that seems to work well with 5e so far, without changing monster vs. player statistics.   My stumbling block is spell saves. Take a humble goblin and his +2 dex vs. a high level save of 19 (8+6+5). He has a 4/20 chance of passing that save. If I stick to the same-ish formula of 14+2 vs. (caster mod)+proficiency on the players’ side, I end up with the goblin having 4/20 of saving.  I am looking to convert spell save DCs from 8+proficiency+caster mod vs d20+ stat mod+proficiency fairly. I think 14+saving throw does so correctly, and fairly. If not I want someone to tell me why that’s wrong.

In D&D 5, the saving throws for spells has the following formula:  The DC is set to 8 + prof bonus + magical stat bonus.  The target then makes a saving throw, adding their stat bonus and hoping to get above that DC.  Instead of having the defender roll the saving throw, we would like the attacker to roll the attack against the "defense" of the monster. (Mainly to make play by post run smoother)  Would this mean that the attacker just rolls d20+prof + magic stat bonus, and they try to get a number which is higher than 8+ monster def stat bonus, or is there a different formula which better maintains the math? (This math sounds wrong to me, so I assume there is a better formula)


Prove that if $a$ and $b$ are relatively prime, then $\gcd(a+b, a-b) = 1$ or $2$.  I started off by putting $\gcd(a+b, a-b) = d$. This implies that there are two relatively prime integers $x_1, x_2$, such that   $dx_1 = a+b$   $dx_2 = a -b$  Adding the first equation to the second gives us: $d(x_1 + x_2) = 2a$, and subtracting the second from the first gives us $d(x_1 - x_2) = 2b$. This implies that $d\mid2a, d\mid2b \implies \gcd(2a, 2b) = d \implies d = 2\cdot \gcd(a,b) \implies d = 2$.   This is based on the fact that $\gcd(x_1 + x_2, x_1 - x_2) = 1$, which is in fact the statement of the problem. How do I prove this? Can I somehow use the Euclidean Algorithm for this.

I want to show that for $\gcd(a,b) = 1$ $a,b \in Z$   $\gcd(a+b, a-b) = 1$ or $\gcd(a+b, a-b) = 2$ holds.      I think the first step should look something like this:      $d = \gcd(a+b, a-b) = \gcd(2a, a-b)$   From here I tried to proceed with two cases. 1: $a-b$ is even, which leads to $\gcd(a+b, a-b) = 2$ 2: $a-b$ is odd, which leads to $\gcd(a+b, a-b) = 1$  My main problem I think is, that I do not know how I should include $\gcd(a,b) = 1$ in the proof.  Any help is appreciated. Thx in advance. Cherio Woltan


Found something different with my  today, seems something goes wrong.    After inspect the element, found the class of it is choose-tracker-settings. As i used to click label location to choose tracker, the added icon is not useful to me. Anyway, the location is not proper.    More details:    OS: macOS Sierra 10.12.1 Browser: Chrome Version 58.0.3029.110 (64-bit)


I have working development project of Drupal 7 using PHP 5.x. I changed the PHP version to PHP 7 using nginx webserver. It does not work and I have got the following error message:   Fatal error: Uncaught Error: Undefined class constant  'MYSQL_ATTR_USE_BUFFERED_QUERY' in  C:\xampp-2\htdocs\d738\includes\database\mysql\database.inc:46 Stack  trace: #0 C:\xampp-2\htdocs\d738\includes\database\database.inc(1689):  DatabaseConnection_mysql->__construct(Array) #1  C:\xampp-2\htdocs\d738\includes\database\database.inc(1479):  Database::openConnection('default', 'default') #2  C:\xampp-2\htdocs\d738\includes\database\database.inc(2570):  Database::getConnection() #3  C:\xampp-2\htdocs\d738\includes\cache.inc(348):  db_escape_table('cache_bootstrap') #4  C:\xampp-2\htdocs\d738\includes\cache.inc(329):  DrupalDatabaseCache->getMultiple(Array) #5  C:\xampp-2\htdocs\d738\includes\cache.inc(56):  DrupalDatabaseCache->get('module_implemen...') #6  C:\xampp-2\htdocs\d738\includes\module.inc(723):  cache_get('module_implemen...', 'cache_bootstrap') #7  C:\xampp-2\htdocs\d738\includes\module.inc(892):  module_implements('system_theme_in...') #8  C:\xampp-2\htdocs\d738\modules\system\system.module(2502):  module_invoke_all('system_theme in  C:\xampp-2\htdocs\d738\includes\database\mysql\database.inc on line 46   This error means that Drupal 7 is using obsoleted MySQL functions and it is not support with PHP any more!  However, I don't think Drupal still uses this obsoleted PHP extension. So I have a strange error as I think!

For the last couple of days I've been getting the following error:     Fatal error: Undefined class constant 'MYSQL_ATTR_USE_BUFFERED_QUERY' in /home/mydomain/public_html/drupal/includes/database/mysql/database.inc on line 46   This comes after my Hosting did an upgrade and PHP is now version 5.2.17.  From what they have told me, I think I have to enable a PDO MySQL extension in php.ini.  The problem is I'm on a shared hosting and I don't have access to the file; also, my Hosting said they can't change it either.  My info.php shows:     PDO      PDO support enabled      PDO drivers sqlite, sqlite2        pdo_sqlite      PDO Driver for SQLite 3.x enabled      PECL Module version (bundled) 1.0.1 $Id: pdo_sqlite.c 293036 2010-01-03 09:23:27Z   sebastian $      SQLite Library 3.3.7     I tried modifying the .htaccess file and/or adding my own php.ini file to the root directory per some suggestions I found, but nothing I've tried has worked yet.  Can anyone please suggest what else I could do?  EDIT:  Once again I asked the Hosting to enable PDO_MySQL extension and their answer was that they could not, that cPanel (to which they migrated from Plesk, causing this whole problem) had this extension disabled by default and changing it would affect their servers.  Their solution?  That I would change my programming to adjust to these new features, which I wouldn't even know how to go about.  Are they right requesting that I do this? Is there any other way?


Let R be a ring.  The center of R is defined to be the set of all elements x ∈ R such that xr=rx for all r ∈ R. Prove that the center of R is always a commutative subring of R.  I understand how to prove tha the center of R is always a subring, but how do I show the commutative subring?

The center of a ring $R$ is $\{c\in R : cr=rc $ for every $ r \in R\}$. Prove that the center of a ring is a subring. What is the center of a commutative ring?  Is my solution right?  solution  You just need to prove that the centre is a ring within itself.    Associativity of both addition and multiplication is inherited from R, and distributivity of multiplication over addition is inherited from R.  Show that it is a group under addition:  Take a and b in the centre and r in R.  Then  $(a + b)r = ar + br = ra + rb = r(a + b)$   hence it is closed under addition.  Show that $0$ (additive identity) is in the centre.  $0 = 0.r = r.0$  so $0$ is in the centre.   For a in the centre, there exists $-a$ in R such that $a + (-a) = 1 = (-a) + a$  Show that $-a$ is in the centre.  Let r in R  $0 = 0.r = (a + (-a))r = ar + (-a)r $ and  $0 = r.0 = r(a + (-a)) = ra + r(-a) $  as $ ra = ar$, it follows that $(-a)r = r(-a) $ Hence inverses exist in the centre.  So the centre is a group under +.    Show that the centre is closed under multiplication:  For a,b in the centre and r in R,#  $(ab)r = a(br) = a(rb) = (ar)b = (ra)b = r(ab) $   thus multiplication is closed.  And show that 1 (the multiplicative identity) is in the centre.  $1.r = r = r.1$ hence 1 is in the centre.   So the center is a subring of R.   The center of a commutative ring is the ring itself. (By definition the centre is the ring of all commutative elements.)


I am creating a shortcode to display data based on some options.  function dot_irt_top_posts ( $atts, $content = null ) {      // get our variable from $atts     extract(shortcode_atts(array(         'before' => '
',         'after' => '
',         'number' => '10',         'post_type' => 'post',         'year' => '',         'monthnum' => '',         'show_count' => '1',     ), $atts));      global $wpdb;      $request = "SELECT * FROM $wpdb->posts, $wpdb->postmeta";     $request .= " WHERE $wpdb->posts.ID = $wpdb->postmeta.post_id";      if ($year != '') {         $request .= " AND year=$year";     }      if ($year != '' && $monthnum != '') {         $request .= " AND &monthnum='$monthnum'";     } elseif ($monthnum != '') {         $request .= " AND monthnum='$monthnum'";     }      $request .= " AND post_status='publish' AND post_type='$post_type' AND meta_key='_recommended'";     $request .= " ORDER BY $wpdb->postmeta.meta_value+0 DESC LIMIT $number";     $posts = $wpdb->get_results($request);      $return = '';       foreach ($posts as $item) {         $post_title = stripslashes($item->post_title);         $permalink = get_permalink($item->ID);         $post_count = $item->meta_value;         $return .= $before.'' . $post_title . ' ';          if ( $show_count == '1') {             $return .= '' . $post_count . ' ';         }          //$return .= get_the_post_thumbnail($item->ID, 'showcase-thumbnail');         $return .= $after;      }     return $return;  } add_shortcode('irt_top_posts','dot_irt_top_posts');   And then the shortcode would be like:  <?php echo do_shortcode("[irt_top_posts post_type='showcase' number='10' monthnum='9']"); ?>   UPDATED QUESTION's   There seems to be some issue with my query. The Codex  has an example for using the date to retrive results when using WP_Query. I want to know what changes I need to make to my code to have YEAR or MONTH in the query when getting results I noticed most shortcodes when communicating with database use wpdb class and not wp_query. Is there a reason behind this?

I am using the following code to output a list of items in my 'documents' Custom Post type by Year and Month.
 <?php $post_type = 'documents'; global $wpdb; /**/ $years = $wpdb->get_col("SELECT DISTINCT YEAR(post_date) FROM $wpdb->posts WHERE post_status = 'publish' AND post_type = '".$post_type."' ORDER BY post_date DESC"); foreach($years as $year) : $years_count = $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM $wpdb->posts WHERE post_status = 'publish' AND post_type = '".$post_type."' AND YEAR(post_date) = ".$year.";" ) ); ?>
<?php echo $year; ?> (<?php echo $years_count; ?> Posts)
     <? $months = $wpdb->get_col("SELECT DISTINCT MONTH(post_date) FROM $wpdb->posts WHERE post_status = 'publish' AND post_type = '".$post_type."' AND YEAR(post_date) = '".$year."' ORDER BY post_date DESC");     foreach($months as $month) :     $months_count = $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM $wpdb->posts WHERE post_status = 'publish' AND post_type = '".$post_type."' AND YEAR(post_date) = ".$year." and MONTH(post_date) = ".$month.";" ) );     ?>
>         <a href="<?php echo get_month_link($year, $month)."?post_type=".$post_type; ?>"><?php echo date( 'F', mktime(0, 0, 0, $month) );?> (<?php echo $months_count; ?> Posts)          <?php  $theids = $wpdb->get_results("SELECT ID, post_title, post_date FROM $wpdb->posts WHERE post_type = '".$post_type."' AND post_status = 'publish' AND YEAR(post_date) = ".$year." and MONTH(post_date) = ".$month.";");                 foreach ($theids as $theid):                          ?>

<?php echo $theid->post_title; ?>

                                                  <?php                     endforeach; ?>
     <?php endforeach;?>

 <?php endforeach; ?>
   Currently this is working as expected but I am having problems trying to do the same thing for a specific category within my documents post type. How would I refine this code for my category 'cascade-campus-docs' within my 'documents' post type.


Is there a name for such multivariate polynomial where each varaible appears alone. For example:  $P(x,y,z)=x+x^2+3x^3+y+5y^2+z +2$  So as it can be seen there is no terms in the polynomial  where the variables are multiplied by each other like  $xy$ or  $xz^2$ for instance.

Is there a standard name for multivariate polynomials wherein each term consists of only one coordinate? That is, polynomials of this form: $$p(x_1, \ldots, x_n)= \sum_{i=1}^n \sum_{j=1}^n a_{i,j}x_i^{j}$$ where all of the $a_{i,j}$ are constants.


Let $T : \mathbb R^n \rightarrow \mathbb R^m$ is a Linear Transformation. Prove that $im(T)$ is a subspace of $R^m$  I am very bad at problems like this, I know what defines a subspace, I'm just uncertain on how to apply it.

$V$ and $ W $are two real vector spaces.  $T: V \rightarrow W$ is a linear transformation.  What is the image of $T$ and how can I prove that it is a subspace of W?


I was following Bracky's fps tutorial but he didn't add crouching as an option. I took a stab at it but came up empty handed. Here is my script for player movement. public class PlayerMovment : MonoBehaviour { public CharacterController controller; public float speed = 12f; public float gravity = -9.81f; public float jumpHeight = 3f;  public Transform groundCheck; public float groundDistance = 0.4f; public LayerMask groundMask;  Vector3 velocity; bool isGrounded;  // Update is called once per frame void Update() {     isGrounded = Physics.CheckSphere(groundCheck.position, groundDistance, groundMask);      if(isGrounded && velocity.y < 0)     {         velocity.y = -2f;     }      float x = Input.GetAxis("Horizontal");     float z = Input.GetAxis("Vertical");      Vector3 move = transform.right * x + transform.forward * z;      controller.Move(move * speed * Time.deltaTime);      if(Input.GetButtonDown("Jump") && isGrounded)     {         velocity.y = Mathf.Sqrt(jumpHeight * -2f * gravity);     }      velocity.y += gravity * Time.deltaTime;      controller.Move(velocity * Time.deltaTime); }  And also have a separate script for mouselook, here that is aswell. public class Mouselook : MonoBehaviour { public float mouseSensitivity = 100f;  public Transform playerBody;  float xRotation = 0f;  // Start is called before the first frame update void Start() {     Cursor.lockState = CursorLockMode.Locked; }  // Update is called once per frame void Update() {     float mouseX = Input.GetAxis("Mouse X") * mouseSensitivity * Time.deltaTime;     float mouseY = Input.GetAxis("Mouse Y") * mouseSensitivity * Time.deltaTime;      xRotation -= mouseY;     xRotation = Mathf.Clamp(xRotation, -90f, 90f);      transform.localRotation = Quaternion.Euler(xRotation, 0f, 0f);     playerBody.Rotate(Vector3.up * mouseX); }  } How would I go about adding one without adding a rigidbody or changing my script fully to follow other tutorials? Thank you!

I tried to make a crouch system. In my script I changed .height and .center properties of collider in CharacterController component. But there are some problems. First, once I press "crouch button" collider is changing its height and center position but when I release the key the collider isn't returning to its previous state. Secondly, if I change its height and position by hand when collider is under a block, it's just stuck. How can I fix this problem?   Here's my script:  using System.Collections; using System.Collections.Generic; using UnityEngine;  [RequireComponent(typeof(CharacterController))] public class PlayerController : MonoBehaviour {      public float moveSpeed;     public float jumpForce;     public CharacterController controller;     public GameObject myCamera;      private Vector3 moveDirection = Vector3.zero;     public float gravityScale;      public Animator anim;      // Use this for initialization     void Start () {         transform.tag = "Player";         controller = GetComponent<CharacterController>();            }      // Update is called once per frame     void Update () {         Vector3 forwardDirection = new Vector3 (myCamera.transform.forward.x, 0, myCamera.transform.forward.z);         Vector3 sideDirection = new Vector3(myCamera.transform.right.x, 0, myCamera.transform.right.z);         forwardDirection.Normalize ();         sideDirection.Normalize ();         forwardDirection = forwardDirection * Input.GetAxis("Vertical");         sideDirection = sideDirection * Input.GetAxis("Horizontal");         Vector3 directFinal = forwardDirection + sideDirection;          if (directFinal.sqrMagnitude > 1)         {             directFinal.Normalize ();         }          if (controller.isGrounded)         {             moveDirection = new Vector3(directFinal.x, 0, directFinal.z);             moveDirection *= moveSpeed;             if (Input.GetButtonDown("Jump"))             {                 moveDirection.y = jumpForce;             }              if(Input.GetButtonDown("Crouch"))             {                 controller.height = 1f;                 controller.center = new Vector3(0f, -0.5f, 0f);                 moveSpeed = 3f;             }         }         moveDirection.y = moveDirection.y + (Physics.gravity.y * gravityScale * Time.deltaTime);         controller.Move(moveDirection * Time.deltaTime);          anim.SetBool("isGrounded", controller.isGrounded);         anim.SetFloat("Speed", (Mathf.Abs(Input.GetAxis("Vertical")) + Mathf.Abs(Input.GetAxis("Horizontal"))));     } }   Thanks for any help!


I am currently a prospective computer science Ph.D. applicant with a 3.75/4.00 GPA at an R1 CS school ranked in the top 30. I am considering applying to 15 schools roughly in the top 50. I have an extremely strong research background with one first author ML pub in a reputable IEEE conference and a second author applied ML/psychology journal article under review. My letters of rec will all likely be very strong and from well-known professors that I have worked under or with for at least 6 months. That said, I have a few questions about the application process:  I am not the best standardized test taker, and I currently am looking at quantitative GRE scores of around 75th-80th percentile with verbal scores in the same range. Will my subpar GRE scores likely prevent the comparatively stronger portion of my application from being reviewed at many schools? With this in mind, should I retake the GRE until I'm closer to the averages of the schools? I am going to complete my undergraduate in 2.5 years and am hoping to enter a Ph.D. program directly after graduation. Will the reduced length of my undergraduate career reduce my chances of acceptance, or is this viewed somewhat favorably?  Any insight would be greatly appreciated. Thank you.

I have a good GPA (over 3.5) from a top 5 CS school. I also have lots of research experience and a few publications. I also expect to have very good recommendations. The only problem is that I did badly on the GRE general exam (just under below average). The exam seems like a big scam, so studying for it felt like a waste of time.  One of JeffE's  mentions that schools filter applicants into three piles based on GPA and GRE: MAYBE, PROBABLY NOT, and NO. Will my GRE scores land me in the PROBABLY NOT pile, even though I have an otherwise excellent record?  Will my GRE hurt my chances of getting into CMU and Stanford? Should I try to retake them, even though it's getting late? Application deadlines are around December 13.  Edit: should I say something about my bad GRE scores in the statement of purpose, or do something else if I don't end up retaking them?


Today i deleted my home directory (in wrong action) with:  sudo rm -rf *   And when i use extundelete i get this message:  root@ubuntu:~# sudo extundelete --restore-directory /home/hamed/ /dev/sda2WARNING: Extended attributes are not restored. Loading filesystem metadata ... 746 groups loaded. Loading journal descriptors ... 29931 descriptors loaded. Searching for recoverable inodes in directory /home/hamed/ ...  498 recoverable inodes found. Looking through the directory structure for deleted files ...  498 recoverable inodes still lost. No files were undeleted.   why it can't recover?  Anyone can help me to return my Desktop, Documents and etc? I have ubuntu 14.04.

Are there any tools, methods, incantations to recover recently deleted files on Ubuntu?  If it makes any difference, I want to recover a  2.x database file. But would be better to have a method/tool that works on any kind of file.


Prove that the set of continuous functions $f: (0,1) \to (0,1)$ has the same cardinality as the open interval $(0,1)$.  I am not sure exactly how to get started. I have access to Schröder-Bernstein, but don't think there is a good way to use it. I can prove that $(0,1)$ has the same cardinality as $\mathbb{R}$, so it would suffice to show that the set of continuous functions has the same cardinality as $\mathbb{R}$, but I don't know how to " exclude" non-continuous functions. Any help would be appreciated.

I believe that the set of all $\mathbb{R\to R}$ continuous functions is $\mathfrak c$, the . However, I read in the book "Metric spaces" by Ó Searcóid that set of all $[0, 1]\to\mathbb{R}$ continuous functions is greater than $\mathfrak c$:  "It is demonstrated in many textbooks that $\mathbb{Q}$ is countable, that $\mathbb{R}$ is uncountable, that every non-degenerate interval is uncountable, that the collection of continuous functions deﬁned on  $[0,1]$ is of a greater cardinality than $\mathbb{R}$, and that there are sets of greater and greater cardinality."  I understand that (via composition with the continuous function $\tan$ or $\arctan$) these sets of continuous functions have the same cardinality. Therefore, which claim is correct, and how do I prove this?


Is there a way to clone with the relative coordinates of a player and the command block? I am trying to make a "one-command-creation" with those two things. I am in 1.12. Like  /clone {Relative coords of command block} {Relative coords of player}

I'm making a randomizer that randomly clones 1 of the 9 units to all armorstands called "chunk". Inside every unit is an armor_stand called "Unit" and this is the command I used:  execute @e[type=armor_stand,name=chunk] ~ ~ ~ execute @r[type=armor_stand,name=Unit] ~ ~ ~ clone ~-3 ~-1 ~-3 ~3 ~5 ~3 ~ ~15 ~  What this does is, it clones a unit 15 blocks above itself but I want it to clone ~-3 ~15 ~-3 above every armor_stand called "chunk"  You can see a random unit is clone ~ ~15 ~ above the armor_stand calling unit. The armor_stand you can see is called "chunk".


There's a situation I don't quite understand. I have this directory, where the group 'webadmin' has rwx rights :  $ ls -la total 8 drwxrwxr-x 2 root webadmin 4096 Aug 27 12:17 .      ⋮                                       ⋮   I am in the group webadmin :  $ groups eino eino : eino sudo webadmin   however, I can't create any file in the directory :  $ touch test.txt touch: cannot touch 'test.txt': Permission denied   How come? Shouldn't the rwx permissions give me right to do it?

I changed permissions of a file (chmod g+w testfile) and running ls -l testfile gives:  -rwxrwxr-x 1 user1 user1 0 2011-01-24 20:36 testfile   I then added a user to that group ("/etc/group" has user1:x:1000:user2 line), but am failing to edit that file as user2. Why is this so?


I have seen a number of recipes that call for using "kosher salt". This is ridiculous to me, as I very well know that all salt is kosher, and so I am wondering what I am missing here. What is the advantage (and uses) of kosher salt as opposed to ordinary table salt?


I have not seen an answer to this in other questions.  So, if I visit my own page over and over with an interval of, let's say, 60 min. will my profile views counter grow?  Is the counter for unique views only?

This is related to the 'number of times your profile is visited by others'.  How exactly does it work? For example, in my profile page, profile view count is 171.


I'm currently studying ring theory in my algebra course and I must admit I'm kind of lost. I was given the following problem:     Let S be a multiplicative system of R, a ring. Prove that the set $f=\{ I\triangleleft R\mid I\cap S=\emptyset\}$ has a maximal element and that $f$ is a prime ideal.   Since a multiplicative system is defined as a subset of R with no zero divisors, with the identity element included and such that for every $x,y\in S\implies xy\in S$, I can assure R has an identity. Furthermore, I can assume it is conmutative, since that is the kind of rings we are studying.  For the first part of the excercise I know I have to use Zorn's Lemma, but honestly I don't truly understand how to do that. How can I prove it is partially ordered? And how can I find an upper bound for every chain?  Thanks in advance, and please make me notice any mistake in my formulation. I'm new in the forum and I'm not quite sure how to do it.

Let $R$ be a commutative ring with identity. I've been trying to prove the following:     If $S \subset R$ is a maximal multiplicative set, then $R \setminus S$ is a prime ideal of $R$.   I have spent some time in it, but nothing is coming to my mind. Any idea/solution will be appreciated.


This is known as the factor formula. It is used for the addition of sin functions. I don't understand how the two are equal though. How would you get to the right side of the equation using the left?  $$\sin(s) + \sin(t) = 2 \sin\left(\frac{s+t}{2}\right) \cos \left(\frac{s-t}{2}\right)$$

In my math text book the proof for the Sum to Product rule starts with a substitution:  let A = (u+v)/2, let B = (u-v)/2  ...and then uses this substitution to prove that A+B = u  and  A-B = v  ...then substitutes (u+v)/2 and (u-v)/2 in the Product-to-Sum equation to demonstrate that the Sum-to-Product rule is true.  As it appears to me from what is presented in the text book, the substitutions  (u+v)/2 and (u-v)/2 were pulled out of thin air.  How was this determined to work? I doubt it was just a lot of guess and check until something worked.   Is there a point in math where one just needs to accept an equation for what it is and not worry about why or how it is?  I'm getting the feeling that understanding some of the how's and why's right now requires an understanding of math concepts that I haven't learned yet.  Any insight would be appreciated. Thanks!


Is it correct to say:     even if only James Bond will benefit from...   or      even if only James Bond benefits from...

Given the following sentences that use will in the if clause (which is seldom with if-clauses and therefore, I'm not sure they all are even grammatical or not).        If you will/would kindly lend me your book, I will be thankful to you.   If you will not/would not mind lending me your book, I will be thankful to you.     If you will/would wait for a while, I will check it for you.              If you will use it, you can have it   If you will not arrive before six o'clock, I cannot meet you.      What if the last sentence is modified as follows?     If you will not be arriving before six o'clock, I cannot meet you.   Once upon a time, it was found in a grammar book.       If the play will not be finished until ten o'clock, I will have to spend the night at your place.   Can the following version of this sentence have a different meaning (or no meaning at all — a wrong sense)?     If the play is not going to be finished until ten o'clock, I will have to spend the night at your place.   After all, the question is when is will used in if-clauses as the title implies?    Moreover, both the following sentences appear to indicate a probable condition.        If he came, I should help him.   If he came, I would help him.      Using should and would interchangeably in such contexts implies a significant difference in meaning?


How do you choose the size and the parameters related to via stitching and shielding when you need to create a shielding on pcb around a RF micro strip?  OPTION A    OPTION B

I'm working on a 4-layer PCB that has a wifi module and a chip antenna, the antenna is placed at the corner of the PCB and the copper beneath it is removed, I see that via fences are used on the breakout board of the same module, but the reference design doesn't say much about it, so I was wondering how they work ? how many via do I need ? their placement, sizes and the spaces between them ?   This is the breakout board   This is my current design   Edit: This is the reference design for the module   Edit:  In addition to the references in the answer, I've also found a paper that mentions via fences in RF design, and has some evaluation of different layouts,  section 4.3. Ground Via Shielding Evaluation  Also, I've calculated the spacing between the vias for 2.4GHz to be around 100mils.


I have a few questions.    Do the following structures sound natural to native speakers?  Is there any difference in meaning between them?         Try to open the car.   Try opening the car.      You may notice that the two structures are in the imperative form. Have you ever used "Try to open.../ Try opening... that way? Or, do you just say "Open the car"?

I try to ride a bike. I try riding a bike. I try ride a bike.   What is the difference between above three sentences? Please, tell me about it.


I have a heat only system with two wires leading to the thermostat - red and white - and am wanting to add a wireless thermostat.  The new thermostat however requires a "C" wire.  Can I add a C wire?

So, the spiffy new wi-fi thermostats want power on the C wire from thermostat, but the old thermostat doesn't have a C wire at it.  What's the easiest way to add the C wire/24 volt to the thermostat location?


I am running the following two queries but both of them are giving the same output.  Query 1  SELECT * FROM EMP LEFT JOIN DEPT ON EMP.EMP_ID = DEPT.EMP_ID   Query 2  SELECT * FROM EMP INNER JOIN DEPT ON EMP.EMP_ID = DEPT.EMP_ID   THESE both queries give the same output i.e. all rows from both the tables. As far as I know left join should give only rows from the first table i.e. "EMP" and not from other table (DEPT).  thanks.

Also how do LEFT JOIN, RIGHT JOIN and FULL JOIN fit in?


I am trying to delete a vector list from another vector list but the program stops responding as soon as I reach the specific part of the program.Here is the program:  #include<iostream> #include<vector> #include<iterator> int main(){     using namespace std;     vector<int> a(5);     int ints[3] = {2,3,5};     vector<int> b(ints,ints+3);     for(int i=0; i<5; i++){         a[i] = i+1;     }     vector<int> :: iterator pra;     vector<int> :: iterator prb;     cout << "initial list:";     for(pra = a.begin(); pra!=a.end(); pra++){         cout << *pra << " ";     }     cout << endl;     for(pra = a.begin(); pra!=a.end(); pra++){         for(prb = b.begin(); prb!=b.end(); prb++){             if(*pra == *prb){                 cout << *pra << " ";                 a.erase(pra);                 b.erase(prb);                 break;             }         }     }      cout << " Final List:";      for(pra = a.begin(); pra!=a.end(); pra++ ){         cout << *pra << " ";     }  }

I want to clear a element from a vector using the erase method. But the problem here is that the element is not guaranteed to occur only once in the vector. It may be present multiple times and I need to clear all of them. My code is something like this:  void erase(std::vector<int>& myNumbers_in, int number_in) {     std::vector<int>::iterator iter = myNumbers_in.begin();     std::vector<int>::iterator endIter = myNumbers_in.end();     for(; iter != endIter; ++iter)     {         if(*iter == number_in)         {             myNumbers_in.erase(iter);         }     } }  int main(int argc, char* argv[]) {     std::vector<int> myNmbers;     for(int i = 0; i < 2; ++i)     {         myNmbers.push_back(i);         myNmbers.push_back(i);     }      erase(myNmbers, 1);      return 0; }   This code obviously crashes because I am changing the end of the vector while iterating through it. What is the best way to achieve this? I.e. is there any way to do this without iterating through the vector multiple times or creating one more copy of the vector?