Assuming the string has at least one character in it. If the string length is odd, then you may assume it returns (𝑛−1)/2 characters where n represents how many characters are in the original string. For example: 'small' => 'sm'  I would also like to write another function that returns the 2nd half of a string.

I need a good explanation (references are a plus) on Python's slice notation.   To me, this notation needs a bit of picking up.   It looks extremely powerful, but I haven't quite got my head around it.


When I'm writing a comment on skeptics.se, it takes a lot of time to create it and fix it and I use all the characters allowed that it looks like a small paragraph.  Usually you have to link studies, and academic articles, etc...  Many times, my browser went back automatically when pressing backspace (to delete something), and (on my macbook if you slide two fingers on the left of the pad, it will go back), it is really annoying and it happened with me many times.  The comment will be ereased and I would have to re-write it again.  Please add:     You haven't posted your comment yet, are you sure you want to navigate away from this page?   when trying to navigate away from a page with an unposted comment.

If I add a comment but navigate (by mistake) to another page, I lose my unfinished comment (ok, depends on browser etc). On the other hand, when formulating a question, and I click on a link by mistake, I'm asked if I really want to leave.  It would be nice to have this warning for comments as well.


Okay, even if the wire has zero resistance, then charges are being transferred in the direction of electric field, which means there must be a potential drop according to the distance travelled by the charges in the direction of electric field. But, in my book, as it is explained, it seems like the potential remains constant throughout the journey of the charge and that it abruptly changes when the charge reaches the other end of the battery. Well, that's just like saying that a body dropped from a height has an abrupt potential drop when it reaches the ground and has no potential drop along its journey if there is no air friction.  I think the potential drop still happens. The difference is only that in case of an ideal wire, the potential drop corresponds to the increase in kinetic energy of the electrons, because the electrons can accelerate forever in this case when there are no positive ions to collide to, while in case of a real wire, the potential drop mostly corresponds to the heat developed.

I'm having trouble conceptualizing why the voltage drop between two points of an ideal wire (i.e. no resistance) is $0~V$. Using Ohm's Law, the equation is such:  $$ V = IR \\ V = I(0~\Omega) \\ V = 0$$  However, conceptually I can't see how there is no change in energy between these two points.  It is my understanding that the electrical field of this circuit produces a force running counterclockwise and parallel to the wire which acts continuously on the electrons as they move through the wire. As such, I expect there to be a change in energy equal to the work.  Voltage drop is the difference in electric potential energy per coulomb, so it should be greater than $0~V$:  $$ \Delta V = \frac{\Delta J}C \\ \Delta J > 0 \\ \therefore \Delta V > 0 $$  For example, suppose I have a simple circuit consisting of a $9~V$ battery in series with a $3~k\Omega$ resistor:    If the length from point 4 to point 3 is $5~m$, I would expect the following:  $$ W = F \cdot d \\ W = \Delta E \\ F > 0 \\ d = 5 > 0 \\ \therefore W > 0 \\ \therefore \Delta E > 0$$  Since work is positive for any given charge, the change in energy for any given charge is positive -- therefore the voltage drop must be positive. Yet, according to Ohm's Law it is $0~V$ since the wire has negligible resistance.  Where is the fault in my logic?


In the Apostol's Calculus (at first) integrals are treated without limits but derivatives are postponed to come after limits, their conceptual foundation.  I want to know that could the author have defined derivatives similar to the he defined integrals? If yes can you write how? If not, what is the conceptual difference between derivatives and integral that makes this happen?  edit: (My question is different from the general question of defining derivatives in terms of other things as it demands a similar way the author defines integrals.)  EDIT2:The author uses the darboux integral,Which is equivalent to the riemann integral;Now it now remains to be seen if there is a way to define a darboux-esque  derivative too?

These days, the standard way to present differential calculus is by introducing the Cauchy-Weierstrass definition of the limit. One then defines the derivative as a limit, proves results like the Leibniz and chain rules, and uses this machinery to differentiate some simple functions such as polynomials. The purpose of my question is to see what creative alternatives people can describe to this approach. The nature of the question is that there is not going to be a single best answer. I have several methods that I've collected which I'll put in as answers to my own question.  It's not reasonable to expect answers to include an entire introductory textbook treatment of differentiation, nor would anyone want to read answers that were that lengthy. A sketch is fine. Lack of rigor is fine. Well known notation and terminology can be assumed. It would be nice to develop things to the point where one can differentiate a polynomial, since that would help to illustrate how your method works and demonstrate that it's usable. For this purpose, it suffices to prove that if $n>0$ is an integer, the derivative of $x^n$ equals $0$ at $0$ and equals $n$ at $1$; the result at other nonzero values of $x$ follows by scaling. Doing this for $n=2$ is fine if the generalization to $n>2$ is obvious.


In order to help the system make a better guess of the corner locations,...   In this sentence, why is "make" not succeeded by "s"? It seems it is needed!

What is the correct way to use infinitive after the verb "help": with or without "to"?  For example:     Please, help me to understand this.   or:     Please, help me understand this.


I'm trying to parse lines of input that look like  8=FIX.4.2^A9=0126^A35=0^A34=000742599^A49=L3Q206N^A50=2J6L^A52=20130620-11:16:27.344^A369=000733325^A56=CME^A57=G^A142=US,IL^A1603=OMS2^A1604=0.1^A   where you have different fields of data separated by ^A. I'm trying to get at the individual data fields (like 8=FIX.4.2, 9=0126, 35=0, etc). The problem is that python sometimes interprets ^A as a single character (in vim this is ctrl-v, ctrl-a) and sometimes as the string '^A' with two characters. So I have tried doing   entries = re.split('^A|^A', str(line))   but later when i do   for entry in entries:     print entries   I just end up with the original string, with nothing split. Is this a problem with re.split?

I am tired of always trying to guess, if I should escape special characters like '()[]{}|' etc. when using many implementations of regexps.  It is different with, for example, Python, sed, grep, awk, Perl, rename, Apache, find and so on. Is there any rule set which tells when I should, and when I should not, escape special characters? Does it depend on the regexp type, like PCRE, POSIX or extended regexps?


I'm having some troubles recently understand why every set can be well ordered. I mean suppose it's true, then $\mathbb{R}$ can be well orderd, suppose $a\in \mathbb{R}$ is the first, then we will define a function $f:\mathbb{R} \rightarrow \mathbb{N}$ and say $f(a)=1$. Then we will look at $\mathbb{R}\backslash \{a\}$ (it's a subset of $\mathbb{R}$) then there is $b\in \mathbb{R}$ such that he is the first, and we will define $f(b)=2$ and then we can continue like that in contradiction that $\mathbb{R}$ is uncountable. Can you please tell me where is my mistake? And maybe give me a "feeling" about why we can suppose this axiom is true? Thank you very much.

How is well-ordering in real line possible?  I know that the axiom of choice provides possible well-ordering, but intuitively, this does not seem to make sense.  How can you compare 1.111111.... and 1.111111... when we can never know the full digits of each number?


What is the PDF of $Z=\sqrt{(X-x_0)^2+(Y-y_0)^2}$ when $X$ and $Y$ are i.i.d. normal random variables with zero mean, i.e., $X \sim N(0,\sigma^2)$ and $Y\sim N(0,\sigma^2)$?

We have a bivariate normal process where $X, Y \sim N(0, \sigma)$, with no covariance.  (For convenience we can assert that $\sigma = 1$, or that we have a good estimate for its value.)  What is the distribution of the random variable $R(n) =  \sqrt{\overline{x_i}^2 + \overline{y_i}^2}$ — i.e., the Euclidean distance between the sample center of a n points and the true center (at the origin)?  Note that as defined:   $R(n) \ge 0$ $E[R(n)] \to 0$ monotonically as $n \to \infty$ The Rayleigh distribution gives us $R(1) = \sigma \sqrt{\pi/2} \approx \sigma 1.25$   Furthermore, based on a Monte Carlo simulation for $n \in [2, 25]$ with $\sigma = 1$:   Variance decreases monotonically as n increases Skewness appears constant across n at 0.63 Kurtosis appears constant across n at about 0.24   (This question is a simplified version of  that seems to have gotten derailed in complications.)


Is the comma usage in the second sentence correct?      An alaunt with short grey fur emerged from the darkness baring its teeth. Shortly after, its master followed.   I understand that a comma should follow a dependent clause. I'm unsure if, "shortly after" is a dependent clause.   I would like the sentence to communicate that the dog's owner appeared after the dog. (Is the comma necessary?)

I am no native speaker and always confused about the comma in introductory phrases, in particular in prepositional phrases. Is there any hard rule when a comma must be set? If I make a google search for certain phrases, I often find both variants. Typical examples where I am not sure whether a comma must be set are:        First[ly][,] I must phone mother   In this case[,] we must...   For simple problems[,] the algorithm...   From Lemma 1.2[,] we obtain...   For a typical user[,] the algorithm...   In our theory[,] we...   A dark line on the horizon[,] the mountain range we were headed for seemed somehow not as threatening as when we had started out on the trip.   Avidly reading her novel[,] Jane did not notice that her stop was approaching.   To be sure[,] it is not easy to see a solution.   When you get to Rome[,] give me a ring.


I have read this sentence recently: "Formal exams are used to assess students at the end of each semester in many countries."  What i can't understand is : "are used to assess" does it indicate what it used to be used for in the past? or he is talking in general (present) that it is used for assessing?. I am grammatically confused.

I am curious about using "used to" which is used for expressing some habitual actions in the past. But how to use it for passive voices?  Example 1:  I used to eat chocolate too much when I was a baby  This example is OK. What about the second one?  Example 2:  a) This computer is used to calculate statistics.  b) This computer is used for calculating statistics.  Which one is more suitable? In other words, are both of them give the same meaning? I am avoiding making contextual mistakes.  My problem is that I have read a sentence and I thought it should be corrected:  Actual sentence:  Bivariate linear regression is used to measure the degree of linear relationship between two variables.   After correction (not sure if it is really required):  Bivariate linear regression is used for measuring the degree of linear relationship between two variables.   I think (b) should be.


=query(importrange("12HAbnTv4g_6m1UeCOs9ZO0gAYvy8tlaXr-cc2ecPEic","Master!A:ba"),  "select col1,col2,col3,col4,col5,col6,col7,col8,col9,col10,col11,col12,col13,col14,col15,col53    where col53<> 'Deal Cancelled'",0)   is resulting in error message:     Unable to parse query string for Function Query parameter 2:NO_COLUMN:col1

This is the problem I'm seeing:      Error - Unable to parse query string for function QUERY parameter 2: NO_COLUMND     The formula is of the form:  =query(importange("...", "Sheet!A:V"), "select D where V = 1", 1)   I imported data from another sheet, I want this current sheet to display column D when Column V is 1.  Is there a different way rather than my current formula?


I want to send a string variable to a mysql database so that database uses a query with my variable and finds something in the database.Also the database/query needs to send me back another variable which i can use it in my c++.  I probably need to find how to connect the c++ with the mysql also and how exactly i can send this variable to the query.  How do you advice me to do this?  LE: I've found this and covers preety much exactly what i need to do:  #include <mysql.h> #include <cstdio>  int main() {     MYSQL *conn;     MYSQL_RES *res;     MYSQL_ROW row;     char *server = "server";     char *user = "user";     char *password = "password";  // got tot keep my data secret     char *database = "cpp_test";     conn = mysql_init(NULL);  // connect to database if(!mysql_real_connect(conn, server, user, password, database, 0, NULL, 0)) {     fprintf(stderr, "%s\n", mysql_error(conn));     return -1; }  // send SQL query if(mysql_query(conn, "select * from cpp_testTAB")) {     fprintf(stderr, "%s\n", mysql_error(conn));     return -1; }  res = mysql_use_result(conn);  // output table name printf("MySQL Tables in mysql database:\n"); while ((row = mysql_fetch_row(res)) != NULL) {     printf("%s %s %s %s\n", row[0], row[1], row[2], row[3]); }  // close connection mysql_free_result(res); mysql_close(conn);  return 0; }

Does anyone know of a simple way for a C++ program to communicate directly with a MySQL database?  I have looked at MySQL++ and found it to be very confusing.  If anyone knows of a very simple way of doing this, please let me know.  Thanks  P.S. I am developing on a Windows machine.  PHP and MySQL web web application setup.  C++ setup to talk to the serial port.  Thus why I need a way for C++ to talk to the MySQL database directly.


I have installed and configured the Ubuntu 20.04 and Visual Studio Code. It is connected to the my org. But a simple deploying in the production I gets "An internal server error". Sometimes it stucks, other times it gets an error, it worked only once. The command that I proceed to interface it just by clicking on "SFDX: Deploy Source to Org" sfdx force:source:deploy --sourcepath /home/myUser/myProject/force-app/main/default/classes/collections/UsingListCollection.cls --json --loglevel fatal  How to fix that? How to troubleshooting the Error ID? The output is an HTML like this:  <title>An internal server error has occurred</title>
An internal server error has occurred

An error has occurred while processing your request. The salesforce.com support team has been notified of the problem. If you believe you have additional information that may be of help in reproducing or correcting the error, please contact Salesforce Support. Please indicate the URL of the page you were requesting, any error id shown on this page as well as any other related information. We apologize for the inconvenience.

Thank you again for your patience and assistance. And thanks for using salesforce.com!

An internal server error has occurred

 An error has occurred while processing your request. The salesforce.com support team has been notified of the problem. If you believe you have additional information that may be of help in reproducing or correcting the error, please contact Salesforce Support. Please indicate the URL of the page you were requesting, any error id shown on this page as well as any other related information. We apologize for the inconvenience.

Thank you again for your patience and assistance. And thanks for using salesforce.com!

 Error ID: 7538977-70447 (1534884652)

    There's another question similar to this. The error message is the same but the cause I don't think is related to the scenario that I have provided here. It is this one:  The original apex code. It was only a test. There was nothing wrong. public with sharing class UsingListCollection { public UsingListCollection() {  }  public void showAccounts() {          List<Account> listAccount = getAccounts();     for(Account account : listAccount){         System.debug(account);         }  }  public List<Account> getAccounts() {       List<Account> listAccount = [         SELECT              AccountNumber,             AnnualRevenue,             Name          FROM Account     ];      return listAccount; }  }

I got this error message:  An internal server error has occurred An error has occurred while processing your request. The salesforce.com support team has been notified of the problem. If you believe you have additional information that may be of help in reproducing or correcting the error, please contact Salesforce Support. Please indicate the URL of the page you were requesting, any error id shown on this page as well as any other related information. We apologize for the inconvenience. Thank you again for your patience and assistance. And thanks for using salesforce.com! Error ID: 1137932444-43272 (-1640688306)  What does it mean? What can I do about it?


I would like to ask about the grammaticality of a 'that' relative clause modifying a noun phrase that begins with a possessive pronoun. Please consider these examples:        Please send in your technician that I can talk to.   They scrapped our project that had taken us so much effort.      From a somewhat prescriptive standpoint (I'm trying to quit...), I would like to ask whether this construction might require the 'that' pronoun to be replaced with the stronger alternatives, 'which' or 'who', also preceded by a comma.        Please send in your technician, who I can talk to.   They scrapped our project, which had taken us so much effort.      Alternatively, beginning the noun phrases with an indefinite article would then allow the 'that' relative clause.        Please send in a technician that I can talk to.   They scrapped a project that had taken us so much effort.      I would really appreciate knowing your views on this--particularly on the ungrammaticality I see in the first examples.  Thank you very much.

Which of the following is correct?        There were 10 people that went to the store.   There were 10 people who went to the store.      Edit:  Which of the following is correct?        There were 10 people that had brown hair.   There were 10 people who had brown hair.


When I type who in my console terminal, I get the following output:  hubert   :0           2014-05-16 21:40 (:0) hubert   pts/0        2014-05-16 21:46 (:0)   From info who I know that both :0 and pts/0 should name instances of the terminal. It is clear to me what pts/0 means but I have no idea how to interpret the first line of the output.  What is even more confusing, when I type who hubert :0, I get:  hubert   pts/0        2014-05-16 21:46 (:0)

The return value of command who will always include root :0 in X Window pts. I guess it actually means the GNOME login. Am I right?  Another question is where to get this knowledge, as I don't see it in the man who, neither in info who.  Example  [root@localhost root]# who root     :0           Sep 11 06:33  root     pts/0        Sep 11 06:36     (:0.0)


I'm new to feature selection and I was wondering how you would use PCA to perform feature selection. Does PCA compute a relative score for each input variable that you can use to filter out noninformative input variables? Basically, I want to be able to order the original features in the data by variance or amount of information contained.


I have been playing CSGO on my Lenovo Ideapad 300-15isk for more than two years. Few days back when I was playing CSGO multiple keypresses stopped working. It still detects two keys pressed at once. But, it is not detecting more than two keys. Now I can't move diagonally while shooting or I can't shoot while crouch moving. This is really annoying and the game is almost unplayable. What could be the reason behind it and how to fix it?

Whenever I play a PC game with the directional keys, I can only press two buttons at a time.  For instance if I am playing a shooter like R-Type, I cannot hold down the fire button while moving diagonally at the same time.  The computer simply ignores the extra button press.  How do I remove this limit so I can shoot while moving diagonally?  This limitation seems to apply for every game.  I am running Windows 7 if it makes any difference.  I noticed the same problem back when I used Windows XP.


It's a tricky question. I have this ghost mosquito mesh, and my goal is to only render the verticies which are currently visible from the camera view. It's an animation so cutting the invisible parts off is not an optiton. Is there a node or some masking trick what you can suggest? Thanks a lot! :)

I would like to have my object transparent, with a color only on the edges, would someone know how to do this? I am starting with the nodes, if anyone can help with some guidelines I would really appreciate ;-)  EDIT:  I was looking for something like the hand in Kinectimals :    Thanks


I have completed my BS and MS in physics and I want to apply at different US universities for graduate program. What I have heard from my seniors that, I should mail the program coordinator to confirm if my profile is good enough to get admitted. For that I need to write a cover letter.    Am I in the right direction?    Who should I contact, my potential adviser or the graduate coordinator, to know if my profile is strong enough for getting admitted?

I am applying for a PhD programme in Europe. For that I need to write a cover letter. It will be more like a SOP (technical but shorter version, as it's one page) or it can be more general stuff, as in why I want to do a PhD, what I like about this particular field, what background I have. Any suggestions welcome.


I have a table:

               AuthDB User	               Unset

               AuthDB Password	               Unset

               Web Session Timeout 	               12

               Runtime Session Timeout	               14400

   that I am updating values for by clicking in the spans, changing the HTML and saving the new value with a button click from the changed markup:      $(document).ready(function() {       $('span[class^=config]').on( 'click', function (){         var thisSpan = $(this);         var cellText = $(this).text();          var cellID = $(this).attr('id');         $(this).html('
<input type="text" value="' + cellText +'" class="config_input">&nbsp;&nbsp;<button id="config_long_edit_save_8" class="detailsbutton_nomarg save_config" role="button">Save</button>&nbsp;<button id="config_item_edit_cancel_8" class="detailsbutton_nomarg cancel_config" role="button">Cancel</button>&nbsp;<button id="config_item_reset_8" title="" class="detailsbutton_nomarg reset_config" role="button" disabled="disabled">Reset</button>
').insertAfter(this);          $('.save_config').on( 'click', function (e){             e.preventDefault();             var inputText = $(this).prev('input').val();             $(this).closest('td').html(''+ inputText +'');         });           }); });   Clicking the "Save" button definitely updates the span (BTW, I would definitely prefer to not clear out the  every time, but it was the only dependable way to get this functionality working). But it only works one time per session. I don't want to refresh the page every time I click this "Save" button and I thought the using .on() was asynchronous and that any function invoking that would work with whatever HTML that was dynamically generated during a single session.  This may be an elementary programming principle I've missed somewhere along the line. I welcome your help in finding out how to get this working more than once. Thanks for your attention.

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.


I'll be short. When i use some Blender tools which should make a sub-menu appear in the left window, it doesn't always happen. For example, according to a tutorial I was following, I should have gotten the sub-menu you see in the picture after using "spin", but it doesn't appear. Maybe it's something related to the fact that I'm using Blender 2.75 while the tutorial uses some 2.5x? How can I get that sub-menu to appear?  Thank you in advance.

When you add a new object into the blender scene, normally on the tool shelf a window will become available where you can put in the objects size or number of vertices etc.  These options:   For what-ever reason, when I now add an object I am no longer seeing that area where I can alter the measurements. Currently I want to use the Spin function but I need to alter it but I have no way of effecting how the spin operates. Does anyone know what I have done or how to fix it?


I'm a bit concerned that I am forgetting some details, but here is what I know: I THINK it was part of a collection called something like "World's best Sci Fi", probably 1974, 1975, 1976, or 1977.  I remember that there was at least one character, possibly two, who were on a planet and trying to understand why people were entering a cave (or swimming in a pool or something like that) and never returning.  Eventually, the main characters enter the cave/thing and realize that they will just experience euphoric happiness while there.  The story ends with them staying in the thing.

In the early '80s, I read a story about a Terran man on another planet, where the natives develop skin lesions and eventually die, but are happy, as they become part of the planet they live on. I remember that the protagonist is not developing the lesions, because he hates the planet. Once he starts loving the planet, he starts having the lesions as well. In this story, the planet is "alive".  I have read about "" and "". They do not match my memory. Thank you.


I'm trying to install ROS Kinetic Kame in my Ubuntu 16.04 VirtualBox VM but when I run sudo apt-get install ros-kinetic-desktop-full, I'm getting the following error :  anant@Ubuntu-ROS-DK:~$ sudo apt-get install ros-kinetic-desktop-full [sudo] password for anant:  Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  ros-kinetic-desktop-full : Depends: ros-kinetic-desktop but it is not going to be installed                             Depends: ros-kinetic-perception but it is not going to be installed                             Depends: ros-kinetic-simulators but it is not going to be installed                             Depends: ros-kinetic-urdf-tutorial but it is not going to be installed E: Unable to correct problems, you have held broken packages.   I googled a lot and found many answers on StackOverflow and AskUbuntu but non of them seemed to help.So I tried installing ROS Indigo Igloo in Ubuntu 14.04 but again when I ran the sudo apt-get install ros-indigo-desktop-full command I got the same error but with different packages.Here is the full error message:  anant@Anant-ROS-DK:~$ sudo apt-get install ros-indigo-desktop [sudo] password for anant:  Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  ros-indigo-desktop : Depends: ros-indigo-common-tutorials but it is not going to be installed                       Depends: ros-indigo-geometry-tutorials but it is not going to be installed                       Depends: ros-indigo-robot but it is not going to be installed                       Depends: ros-indigo-ros-tutorials but it is not going to be installed                       Depends: ros-indigo-visualization-tutorials but it is not going to be installed                       Depends: ros-indigo-viz but it is not going to be installed E: Unable to correct problems, you have held broken packages.   Thanks.

I added some extra repositories with the Software Sources program. But when I reload the package database, I get an error like the following:     W: GPG error:  trusty InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 8BAF9A6F   I know I can fix it using apt-key in a terminal, according to the official Ubuntu documentation. But I would have liked to do it graphically. Is there a way to do this without using a terminal?


I am new to the field of embedded systems. Recently I was learning about the differences between different bit size (8, 16, 32) microcontrollers. What I found was that the size of bit indicates the memory addressing capacity, data bus and address bus size etc. Every other website has almost the same explanation. But still I could not find answer to some of the questions. To list them:   Is it really necessary for the address and data bus to be the same size as the bit size of the micro.  What is it that will become fixed for sure for a given bit sized microcontroller?  Do a microcontroller have have same address bus for all the memories (RAM, flash, EEPROM) and if so, is it the choice of manufacturer to allot any size to any type of memory out of the available addresses?  Say there's an 8 bit microcontroller. So it can adress 2^8 memory locations (that's what I figured out, I am not sure). If each register is 8 bit it means a total of (2^8)*8 =2048 bits of memory. That's not even close to the 32kb of flash inside most of them. What blunder am I making?

I started learning about pointers in C++ and I figured I should educate myself a bit on how memory works and is accessed. I read that when we say a processor is 64-bit, it has a 64-bit register and can access 2^64 address locations. I also read that it can fetch 64/8, so 8 bytes of data at a time, but the data bus is not the same thing as the register right? Do they need to be the same size or does that just happen to be the case usually? And is it the size of the register or the data bus size that determines what we refer to it as, such as 32/64-bit? Also is there a difference between register size and address size?


I remember a scene where they fly over a wall and land in a forest.  They find a huge home and realise that when the world was dying due to overpopulation, the poor were moved to the walled area while rich elites got to enjoy a green world.  There was also a scene with an animal who didn't attack them due to something in the DNA, which I think meant that the walled humans also were genetically spliced with animals.

Sci-fi book in the future about a city that had 2 levels.    The top level was for the rich people. A game center with a space flight game is added. The main character (male) plays with friends and wins a competition. He ends up in huge competition and does well. He finds his sister (twin I believe) and joins the military as the competition was just a recruitment game. He flies into "destroyed land" and finds out that rich barons are living on private islands.  The destroyed lands were caused by some plague.  I read this book in 2010.


For instance: "That was an insane amount of money" The word "insane" is used to indicate that the person describing the money thought it was a very large amount.  "That was a pro move catching the glass before it hit the ground"  Here "pro" is used to acknowledge a combination of skill/speed/luck but in reality no one is professionally catching glasses before they hit the ground.  What is the term for using words incorrectly to add additional "spice" to a sentence?

There's a verse in Bob Seger's song Mainstreet that has this wonderful little seemingly-nonsensical word pairing:     There was this long, lovely dancer in a little club downtown;    I loved to watch her do her stuff.    Through the long, lonely nights she filled my sleep,    her body softly swaying to that smoky beat.   On face-value, the word "smoky" to describe a "beat" just doesn't make sense; smoky isn't really a quality that a [musical] beat can have. And yet, the the words do make sense together and evoke a clearer (err, smokier) image of the nightclub.  Is there a term for this literary device? Are there other examples that come to mind?


The problem is simple:  float f1 = Float.parseFloat("41.975779")  //Value for f1 is 41.97578  -> An error of 1ppm   And even worse!!  float f2 = Float.parseFloat("41.975645")  //Value for f2 is 41.975643  -> An error of 2ppm   It doesn't matter if I use Float.parseFloat or Float.valueOf, they both give the same result.  Note: This problem occurs me when programing in android, I didn't try it in pure-java but I assume will be the same result.

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


In this , suddenly I can't notify Ben Bitdiddle, typing "@B" won't show the autocomplete box. I have tried write "@Ben Bitdiddle" manual but after I enter, this notify words disappear (you can see yourself in this . Notify other people in other comment boxes on that same question still function. Refresh the page won't solve the problem. I use the latest Firefox version in Windoes 8.1.

How do the comment replies (aka "pinging users") work?  Who can I send an @reply to? How do I respond to a specific user when entering my comment? Will they be notified? What do people mean when they talk about "pinging" another user?  Related:


i have to find all functions $f: \mathbb{Q} \rightarrow \mathbb{R}$, such that $f(x+y)=f(x)+f(y)$.  So functions of the form $f(x) := ax, a \in \mathbb{R}$ satisfy the above condition: $$ f(x+y)=a(x+y)=ax+ay=f(x)+f(y) $$  But how do i proove that all functions that satisfy the above condition have the form $f(x) := ax, a \in \mathbb{R}$?  Thanks in advance!

My lecturer was talking today (in the context of probability, more specifically Kolmogorov's axioms) about the additive property of functions, namely that:  $$f(x+y) = f(x) + f(y)$$  I've been trying to find what functions satisfy this. Intuition says that, for functions over $\mathbb{R}$, the only functions should be of the form $f(x) = ax$ for some real a. Unfortunately I've only shown this is true when the domain of the function is the rational multiples of a given real number.   My question is if it is possible to extend this result (that $f(x) = ax$ given additivity) to the real numbers, possibly without assuming the continuity of f. It seems to me that additivity introduces so many constrains on a function that nothing but the trivial case would be able to sneak through. The following is a summary of my thoughts to date, though they're obviously long and not 'compulsory reading'. :)  When x is rational - Preliminary Investigation  It is not hard to see that:  $$f(x + x + x) = 3f(x)$$  and more generally, for $a\in \mathbb{N}$,  $$f(ax) = af(x)$$ It is not too hard to prove (well, it took half a bus trip ... ) that this also applies first for $a\in \mathbb{Z}$ and then for $a\in \mathbb{Q}$, (for the latter you just need to consider $a=m/n$ and then note that:  $$f\Big(\frac{m}{n}x\Big)=mf\Big(\frac{x}{n}\Big)=\frac{m}{n}\cdot nf\Big(\frac{x}{n}\Big)=\frac{m}{n}\cdot f\Big(n\frac{x}{n}\Big)=\frac{m}{n}\cdot f(x)$$   The reason this little equation is cool is that we can set $x = 1$ and get:  $$f(a)=a\cdot f(1)$$  which is equivalent to what was expected intuitively, namely (after changing $a$ to $y$ and $f(1)$ to $a$)  $$f(y) = a\cdot y$$  as long as y is rational   $y$ is a rational multiple of a real number  But we can do a bit better than that. If we substitute in $x = \sqrt{2}$ or any other real number in $f(ax) = af(x)$ (which we know for rational $a$), you can conduct the exact same argument above and show that, for instance   $$f(y) =  \Big(\frac{f(\sqrt{2})}{\sqrt{2}}\Big)\cdot y=a\cdot y$$  Whenever $y = \frac{m}{n}\sqrt{2}$ i.e. whenever $y$ is a rational multiple of $\sqrt{2}$. Note however, that the value of the coefficient $a$ (i.e. the slope of the line) is apparently completely unrelated to the value taken in the case where $y$ is purely rational.   What I'm actually asking  We still haven't shown that $$f(x) = ax$$ for all $x \in \mathbb{R}$, as the slope of the line may change depending on what real number we are taking rational multiples of. As far as I've shown now, we might have $f(x) = x$ when $x$ is rational, $f(x) = 3x$ when $x$ is a rational multiple of $\sqrt{2}$, etc.  I still feel that $f(x) = ax$ for all $x \in \mathbb{R}$. One reason for thinking this comes from noting that $$f(2) = f(2-\sqrt{2})+f(\sqrt{2})$$  $2$, $2-\sqrt{2}$ and $\sqrt{2}$ are not rational multiples of each other, however the equation above gives a restraint on the slopes of the lines formed by their rational multiples (which we'll call $a_1, a_2$ and $a_3$ for the slopes on the rational multiples of $2, 2-\sqrt{2}$ and $\sqrt{2}$ respectively). We have $2a_1 = (2-\sqrt{2}) a_2 + \sqrt{2} a_3$  There's so many constraints here - all the rational multipes have the same coefficient, whenever 2 (or more) numbers which aren't rational multiples of each other are added together we get another constraint on their coefficients. The trivial solution is just that$$f(x) = ax$$  over $x \in \mathbb{R}$ and I really struggle to see how any other solution could possible squeeze through all these constraints.   Is there an additive function on $\mathbb{R}$ not of the form $f(x) = ax$?


I am having a slight problem, I need to be able to create image file from two other images, and I have to able to place other image over the other one. Example:  Blue_box.png:    Yellow_box.png:    And I have to let javascript create a new image file that would look something like this:  Final_box.png:    And I have to be able to place the yellow box using cords

I am wondering if there is a way to combine multiple images into a single image using only JavaScript.  Is this something that Canvas will be able to do.  The effect can be done with positing, but can you combine them into a single image for download?  Update Oct 1, 2008:  Thanks for the advice, I was helping someone work on a js/css only site, with jQuery and they were looking to have some MacOS dock-like image effects with multiple images that overlay each other.  The solution we came up with was just absolute positioning, and using the effect on a parent <div> relatively positioned. It would have been much easier to combine the images and create the effect on that single image.  It then got me thinking about online image editors like  and wondering if there could be a browser based image editor with photoshop capabilities written only in javascript.  I guess that is not a possibility, maybe in the future?


I am looking for a MP3/Ogg player that has the ability to playback a file at a higher speed, preferably without affecting the pitch. What players allow that? The only one I know right now is alsaplayer, but it can't do it without affecting the pitch and also has currently a bug that causes it to use 100% of the CPU at all times, so that renders it kind of unusable. What alternatives are out there?

Is there an application for Ubuntu that can play audio faster but maintain its pitch?  This is possible in Windows using an application like PowerDVD.


In the spaces station moving around the world, we can see that people are floating inside the station. There are two forces acting on the station.    Gravitational force Centrifugal force   Now these forces can't cancel themselves. If that would happen then the station won't move in the orbit. But we see people floating. How can they float? There should be a net force acting on them which should cause them to move in a direction? But it doesn't happen.  So where am I wrong?

Well, this question has been puzzling me for kinda long time, many people believe that orbiting astronauts feel weightless because they are "beyond the pull of Earth's gravity"...How far from the Earth would a spacecraft have to travel to be truly beyond the Earth's gravitational influence? If a spacecraft were really unaffected by Earth's gravity would it remain n orbit? If so, what is the real reason for weightlessness in orbit?


My end portal (in Minecraft) is no where to be found. The current version is 1.94 and the seed is 1990018518. When I try to use an eye of ender to locate the portal the strong hold is empty and I can't get the eyes of ender to locate a different portal. Is there something I'm missing?

I'm working towards beating the Ender Dragon on hardcore vanilla Minecraft. I've gotten myself all the way up to locating the stronghold, however the End Portal is nowhere to be seen. I had 10 Eyes of Ender, and used up all but one of them to find the exact coordinates of where the eye ends up:    This is where the eye floats to when you're near the portal, meaning it triangulates on the Y axis as well. Thinking that it has to be nearby, I exploded a small stack of TNT to open the place up a bit:    It floats in the exact same spot, but there's still no portal nearby. It does not matter if I'm above or below that spot, it always floats to that exact location. Looking at the wiki, it says the PC version of Minecraft Eyes of Ender go to the exact coordinates of the End Portal, however I've dug all the way down to bedrock without any luck.  I seem to have exhausted all methods to locate the End Portal here. Is there a way I can still salvage this game without having to resort to cheating?  Edit: Here's my coordinates and seed as requested.


I killed Grelod and bought a house but I never got the letter from Constance? Why?

I bought two pieces of land. One from Morthal, and one from Falkreath. Morthal was the first plot of land I purchased. I only finished half of it. I bought the plot of land in falkreath because I liked the nature better. I finished the house completely in Falkreath. Every time I try to adopt a child off the streets it keeps saying "I have a place but no room for you" Even though I have the bedrooms in my Falkreath house. Why can I not adopt a child and have him/her live at my house in Falkreath?


This is just one more idea for a way to rejuvenate people's interest in the SO CV queue - which, at the time of this writing, is at 84.7k reviews needed.  Some people are working hard to try to drum up more interest in the queue - Robert has a great idea with the . Still, it seems that the big number scares many people off.    What can we do about this? From what I can see, the problem stems primarily from the big number. So let's get rid of the big number! But we can't lie. Lying is bad.  So, I propose that we stop showing the total number of reviews needed all big and bold like that - let's just show the total number of reviews added today minus the number of reviews performed today:    Much better!  When the community is making progress on the queue, let's show that:    Basically what I'm getting at is some kind of a delta-reviews (delta-R) system - thereby making the big number seem a little less huge.  I'd even be in favor of showing both numbers simultaneously, though this would probably be bordering on too complicated:    Thoughts?

This is just depressing:    And I don't mean it's depressing that there are that many questions that might need to be closed. There are nearly 6 million open questions on Stack Overflow - if under 2% of those are crap, we're doing great. Realistically, that number is probably going to get a lot bigger before we're done... But I'm working on another post about that, so enough said for now.  No, that number is depressing because I can't do anything about it. Ok, realistically I could - since I'm immune to the normal voting limits, if I spent the rest of my evening reviewing stuff I might be able to bring it down by... .1 or .2K. That's assuming my wife doesn't kill me first. But for most other folks reviewing stuff, there's literally nothing they can do that will affect that number. They can burn through their entire review limit, and it'll still be exactly the same.   That's depressing. And it's a lie. Those folks are helping, they are accomplishing something useful... The system just doesn't tell them this. And that's wrong.   So here's what I'm proposing: every time the background task that populates the queue adds another bunch of items to it, figure up how many pending review tasks are in there from the past 24 hours... And display that number. Yeah, it'll still be a pretty big number - but now we're talking 2-3 digits at worst rather than a progress-hiding abbreviation. And more importantly, with sufficient effort it'll be possible to watch it go down.   For informational purposes, I would keep the full backlog displayed on .  This might eventually be useful for other queues (broken links...) but for now it's only really needed for close and only on Stack Overflow.


Is it allowed to stay in Canada beyond the date on which an eTA (and the passport it is linked to) expires? I haven't yet entered, so it's hypothetical, but if I wasn't limited by CBSA on entry I would be allowed to stay for 6 months. If my passport and eTA expired in a month from my date of entry, could I still stay for 6 months?

The Canadian  states that starting March 2016 some tourists that fly into Canada will need an .  As an Italian citizen  and I think I may stay . Is this period subject to change with the introduction of eTA? Just for clarity, I will be entering Canada by flight.


In more detail, let's say I get a PhD degree at a university which is ranked 51-100, according to QS ranking system. Is it possible for me to get a job at higher ranked university, like 1-50 ? Let's say without extraordinary publication record, which I believe the answer would be possible..

What I'm trying to understand is, to what degree does the status/rank of the University (where one completes his/her Ph.D) matter while shaping his/her career after graduation? I would like to know the weight given to one's school in both the following cases:   While applying for post-docs/faculty positions in academia While applying to industrial research labs   For instance, I've read on some forums (I can't locate the link now) that while considering prospective applications for tenure-track faculty positions, very few Universities accept a candidate who has completed his/her Ph.D from a lower ranked school having a lesser "brand" value, irrespective of the fact whether he/she has published equally original work as his/her counterpart from an Ivy league college. How much truth is in this statement? It would be really great if someone already in academia, either as a newly-accepted faculty or someone on the Faculty Hiring committee could share their experiences/statistics on this regard. I'm simply interested to know the answer, without commenting at all on whether such a practice is justifiable.  Similarly, what about recruitment to internationally acclaimed research labs (like  or ) - what importance do they place on the pedigree of a candidate's college, before taking into consideration what they published ?  I'm personally interested in answers related to the field of Computer Science (theory), but the question is applicable to any prospective grad student in any discipline in my opinion. Feel free to share your personal experiences post-Ph.D in detail, as that would give me (and future viewers of this question) about what its like to carve a career once you are out of school!


I am using the following code to loop through an arraylist and then the method setAllDancersRest() will edit the arraylist that I am looping through. I tried to fix this issue by using an iterator but I still get the exception.      for (Iterator<Dance> iterator = allDances.iterator(); iterator.hasNext();) {         Dance dance = iterator.next();         if(generated.size()<= 0) {             generated.add(dance);         }         else if(allDancersReady(dance, gap)) {             generated.add(dance);             for(Dancer dancer: dance.getPerformers()) {                 dancer.setPerformed();             }             setAllDancersRest(dance);         }     }   my error:      Exception in thread "main" java.util.ConcurrentModificationException at java.util.ArrayList$Itr.checkForComodification(Unknown Source) at java.util.ArrayList$Itr.next(Unknown Source) at EliminationGenerator.generateOrder(EliminationGenerator.java:23) at EliminationGenerator.generateOrder(EliminationGenerator.java:1) at Model.generateRunningOrder(Model.java:98) at TUI.getAndProcessUserOption(TUI.java:70) at TUI.<init>(TUI.java:27) at testMain.main(testMain.java:11)   Body of allDancersReady():  private boolean allDancersReady(Dance dance, int givenGap) {     for(Dancer dancer: dance.getPerformers()) {         dancer.setGap(givenGap);         if(!dancer.isReady()) {             return false;         }     }     return true; }   body of setAllDancersRest():  private void setAllDancersRest(Dance dance) {     allDances.remove(dance);     Set<Dancer> dancers = new HashSet<Dancer>();     for(Dance tempo: allDances) {         dancers.addAll(tempo.getPerformers());     }     dancers.removeAll(dance.getPerformers());     for(Dancer dancertemp: dancers) {         dancertemp.notPerformed();     }  }

We all know you can't do the following because of ConcurrentModificationException:  for (Object i : l) {     if (condition(i)) {         l.remove(i);     } }   But this apparently works sometimes, but not always. Here's some specific code:  public static void main(String[] args) {     Collection<Integer> l = new ArrayList<>();      for (int i = 0; i < 10; ++i) {         l.add(4);         l.add(5);         l.add(6);     }      for (int i : l) {         if (i == 5) {             l.remove(i);         }     }      System.out.println(l); }   This, of course, results in:  Exception in thread "main" java.util.ConcurrentModificationException   Even though multiple threads aren't doing it. Anyway.  What's the best solution to this problem? How can I remove an item from the collection in a loop without throwing this exception?  I'm also using an arbitrary Collection here, not necessarily an ArrayList, so you can't rely on get.


I've been playing with the Stack Exchange API and developed a UserScript that adds icon next to users that are employees.  It appears as though the  of API is still reporting that  is an employee, yet his bio indicates that  for the company.     However, I no longer work at Stack Exchange, Inc.    Calling the Users method returns the following result. (filtered unnecessary fields)  {   "items": [     {       "account_id": 1,       "is_employee": true,       "reputation": 260720,       "user_type": "moderator",       "user_id": 1,       "display_name": "Jeff Atwood"     }   ] }   Should this be updated to reflect his currently employment status?

As far as I know, the diamond symbol is given to the folks who  are the community elected moderators, for example,  are employees of the Stack Exchange, Inc., for example,   In those regards,  is neither a , nor is he a part of the  since March 1st, 2012. So my question is, other than the fact that he is the , is there any other reason why he still has the diamond symbol next to his name and whether he can still exercise his moderation abilities? :) Note: I do not have any problems with him having the Diamond Symbol. I just wanted to know the reason and whether he still has those privileges or not. In fact, I'd be very happy to know that he still has those privileges because, you know, he knows the site, the Best. :) Note: as of October 2017, .


This is in regards to  with $M$ images of size $N \times N$.  In short: My question lies in the following statement (bottom of page 4 in above link): "If the number of data points in the image space is less than the dimension of the space $(M<N^2)$, there will be only $M-1$, rather than $N^2$, meaningful eigenvectors". Essentially, if there are 30 images, we can simply use the $M \times M$ COV matrix, rather than the $N^2 \times N^2$ COV matrix to find the meaningful eigevectors. I am assuming this is a simple linear algebra result, which I have long forgotten.  Let's suppose we have a matrix A of size 256 x 256 x 30 (i.e. 30 images). As a Casorati matrix the size is now 65536 x 30.  The covariance matrix can be calculated as $C = A A^T$, which results in a matrix of 65536 x 65536, yielding 65536 eigenvectors.  As outlined in the paper linked above (bottom of page 4), we can instead use the following form to find $M = 30 - 1$ meaningful eigenvectors:  $$A \, A^{T} \, A \,\, \vec{v} = \lambda \, A \, \vec{v}$$  such that $A \vec{v}$ are the eigenvectors of $A \, A^T$.  My question lies in the following statement: "If the number of data points in the image space is less than the dimension of the space $(M<N^2)$, there will be only $M-1$, rather than $N^2$, meaningful eigenvectors.  I am having difficulty understanding why the above statement is true. It makes sense, when I think about having $M$ images, but how does this relate to the 65536 eigenvectors that would be calculated using the traditional COV formalism?  I hope my question is clearly stated.

I am following  on face recognition. In "calculating eigenfaces" section, the authors present a solution for the problem of calculating a very big matrix:   Let $A_{N^2\times M}$ be an $M$ sized dataset, where each column in an $N\times N$ image. Instead of calculating the $M$ large eigenvectors of the $N^2\times N^2$ co-variance matrix they calculate the $M$ eigenvectors of $L=A^TA$ matrix which is of size $M\times M$.    Why is this a valid\good enough solution? What are the criteria for a largest vector? larger in which seance?


I am a Ph.D. student in pure mathematics and I am in my final year of graduate studies. I found that academia is not suited for me: unstable job, low salary, and a self-sacrifice culture that it is based on the motto "Publish or Perish". I want to ask you what are the odds to get a good job with a Ph.D. in pure mathematics? I am truly lost. I consider myself a big failure. I have expended three years of my life in pursuing a thing that it is useless and purely theoretical. Currently, I only want to make some good money in the industry. I want to ask you: what can a pure mathematician do in the real world? Is there any kind of investment banking or hedge funds interested in hiring mathematicians holding a Ph.D. in pure mathematics and a master´s degree in big data and business analytics? Thank you very much for any response.

I have scoured the internet and everyone seems to be saying different things. These range from    "You will have no problem getting a job in quant/finance etc", to  "You are in a hopeless situation and are completely unemployable"   Consider the following situation:   I am at a PhD student at a mid-20s US institution studying pure math I have very limited programming skills I am an Australian national and want to live in Australia long term.   I am not overly optimistic about my future career prospects. Since I am near the beginning I thought I better think about this now rather than 5-6 years down the track.  Question: Is it likely that I'll be able to find a reasonably well-paid, stable job after graduation (even outside of academia)? Are there things I can do now to improve my chances (beyond "trying hard")? Would I be better off doing another masters in computer science or machine learning back in Australia instead of this PhD in pure math?


I never covered infinite products in my real analysis class, so I have no idea. I was wondering about the convergence of the above product. Thanks in advance.

I have to show that if $|z| < 1$, $z \in \mathbb{C}$, $$(1+z)\prod_{n=1}^{+\infty}(1+z^{2^{n}})= \frac{1}{1-z}$$  I want to understand how to do this kind of exercises, any hint ?


I want to style the input button type="file" of the PrimeFaces component <p:fileUpload value="#{dms.fileToUpload}" mode="simple" skinSimple="true" styleClass="chooseFile"/>.     As you can see the whole background of the ` changes and not the input button itself. Is it possible to change the style of the button?  I'm using PrimeFaces 5.1

How do you style an input type="file" button?


While going through some of my notes, I came across a formula for evaluating an integral of the form: $$\int_0^\infty {\frac{dx}{x^n+1}} = \frac{\pi}{n\sin(\frac{\pi}{n})}$$  I was wondering if any other formulas exist for solving more complicated integrals where an antiderivative can't easily be found. If you could also include a proof of said formula, that would also be greatly appreciated.  Thanks in Advance!

I am currently studying for the GRE math subject test, which heavily tests calculus. I've reviewed most of the basic calculus techniques (integration by parts, trig substitutions, etc.) I am now looking for a list or reference for some lesser-known tricks or clever substitutions that are useful in integration. For example, I learned of this trick   $$\int_a^b f(x) \, dx = \int_a^b f(a + b -x) \, dx$$  in the question    I am especially interested in tricks that can be used without an excessive amount of computation, as I believe (or hope?) that these will be what  is useful for the GRE.


I need to have a uniq map object to store key-vlaue globally. So I created a class with a static unordered_map as the member, my code as following please: class PopMap {     public:         static unordered_map<string, string> dataMap;         PopMap(){};         ~PopMap(){}; }; int main(){     PopMap::dataMap["name"]="Tom";     return 0; }   But I got the following exception: undefined reference to PopMap::dataMap

Can anyone explain why following code won't compile? At least on g++ 4.2.4.  And more interesting, why it will compile when I cast MEMBER to int?  #include <vector>  class Foo {   public:       static const int MEMBER = 1;   };  int main(){       vector<int> v;       v.push_back( Foo::MEMBER );       // undefined reference to `Foo::MEMBER'     v.push_back( (int) Foo::MEMBER ); // OK       return 0; }


I tried to add user to sudoers with adduser username sudo, as well as in /etc/sudoers, but it cannot be change because is read only.   Can someone help me please?

After I add a user using adduser, I can't see it via System > Administration > Users and Groups unless I log out and then log in again. Is that normal?  Also, can I set a newly added user as a sudoer or do I have to change that only after adding it? How can I do that via the shell?  Finally, can I delete the original user that was created upon initial installation of Ubuntu, or is this user somehow 'special'?


Hi I have exactly same problem as    I am new and I dont have 50 reputaion to comment on the question.  When I run   sudo add-apt-repository ppa:canonical-kernel-team/ppa   it shows  ERROR: '~canonical-kernel-team' user or team does not exist. Error: 'ppa:canonical-kernel-team/ppa' invalid   I am connected to the internet already. Is there another way to get kernel 4.8?

I'm trying to follow the  (on my Ubuntu 10.04 VM).  The first step is:  sudo add-apt-repository ppa:linaro-maintainers/toolchain   But when I run that I get:  Error reading https://launchpad.net/api/1.0/~linaro-maintainers/+archive/toolchain: <urlopen error [Errno 110] Connection timed out>   I'm guessing the problem is with my configuration for my employer's proxy server, particularly for HTTPS.  When I opened  in Firefox, I got "The connection has timed out".  I then went into Firefox Preferences -> Advanced -> Network -> Settings... and set HTTP Proxy to "gateway" and Port to 8080, and checked "Use this proxy server for all protocols".  Then the page loaded.  This supports my theory.  I've tried setting the http_proxy and https_proxy environment variables (both lower and upper case):  $ set | grep -i proxy HTTPS_PROXY=https://gateway:8080 HTTP_PROXY=http://gateway:8080 http_proxy=http://gateway:8080 https_proxy=https://gateway:8080   I also tried changing them to:  $ set | grep -i proxy HTTPS_PROXY=gateway:8080 HTTP_PROXY=gateway:8080 http_proxy=gateway:8080 https_proxy=gateway:8080   And I tried adding this second line to /etc/apt/apt.conf:  Acquire::http::proxy "http://gateway:8080/"; Acquire::https::proxy "https://gateway:8080/";   But I continue to get the same error.  How do I troubleshoot this?  Update: I followed the instructions in the  to  and got further:  $ sudo add-apt-repository ppa:linaro-maintainers/toolchain Executing: gpg --ignore-time-conflict --no-options --no-default-keyring --secret-keyring /etc/apt/secring.gpg --trustdb-name /etc/apt/trustdb.gpg --keyring /etc/apt/trusted.gpg --primary-keyring /etc/apt/trusted.gpg --keyserver keyserver.ubuntu.com --recv 1DD749B890A6F66D050D985CF1FCBACA7BE1F97B gpg: requesting key 7BE1F97B from hkp server keyserver.ubuntu.com gpgkeys: HTTP fetch error 7: couldn't connect to host gpg: no valid OpenPGP data found. gpg: Total number processed: 0   I wonder if the "HTTP fetch error" means I also need to add "Defaults env_keep = http_proxy" to /etc/sudoers...  Update #2: I added:  Defaults env_keep="http_proxy" Defaults env_keep="https_proxy"   ...as in , but I still get the same "gpgkeys: HTTP fetch error 7: couldn't connect to host" error.  And this is curious:  $ sudo env | grep proxy https_proxy=https://gateway:8080   ...because http_proxy isn't there.  Any advice is appreciated.  Update #3: Since the host of my VM is a laptop, I took it home and tried there (with no proxies):  $ sudo add-apt-repository ppa:linaro-maintainers/toolchain Executing: gpg --ignore-time-conflict --no-options --no-default-keyring --secret-keyring /etc/apt/secring.gpg --trustdb-name /etc/apt/trustdb.gpg --keyring /etc/apt/trusted.gpg --primary-keyring /etc/apt/trusted.gpg --keyserver keyserver.ubuntu.com --recv 1DD749B890A6F66D050D985CF1FCBACA7BE1F97B gpg: requesting key 7BE1F97B from hkp server keyserver.ubuntu.com gpg: key 7BE1F97B: public key "Launchpad Linaro Overlay PPA" imported gpg: Total number processed: 1 gpg:               imported: 1  (RSA: 1)   It worked.  So problem is related to proxy configuration.  But I suppose I have a workaround.


In the United States most banks are insured by the FDIC, for individuals up to $250,000.  If I have $200,000 in bank A and bank A fails the FDIC will make sure I get my money back.  If I have $400,000 and bank A fails then I will get $250,000 covered by the FDIC, and the remaining $150,000 may or may not come back to me if bank A fails, depending on how the failed bank's money is allocated.  Suppose I take my $400,000 and split it between bank A and bank B, $200,000 in each bank.  If both bank A and band B fail (unlikely but suppose it did happen) would both deposits be insured by the FDIC, or is the limit per person?

I was reading that FDIC insurance covers accounts up to $250,000. Does this mean each account you have at a bank is insured up to $250,000 or is $250,000 the maximum for all accounts at a bank?   Also, if you reached the maximum at one bank, could you open an account at another bank and be insured for up to $250,000 at each bank?  Thanks


I try to get a title page done and have filled the respective fields. I have used addtokomafont to adapt the size of the text lines. Title and Author both have the size Huge but the title line font is smaller than the author line (by about 50%). What is wrong? Would there be a simple way to use just for the title (not for the other title matter) a formated text? (I have KOMA script v. 3.21)  \documentclass{scrbook} \KOMAoptions{paper=156mm:234mm, BCOR=8mm,twoside,     headinclude=false, footinclude=false,  %   footsepline=true,   mach strich, nicht abstand     headsepline=true,     headings=normal,     }  % % titel \addtokomafont{subject}{\raggedright\LARGE\normalfont} \addtokomafont{title}{\Huge\raggedright\normalfont} \addtokomafont{subtitle}{\raggedright\LARGE\normalfont} \addtokomafont{author}{\Huge\raggedright\setlength{\tabcolsep}{0pt}} \addtokomafont{publishers}{\LARGE\raggedright}  %\titlehead{{\Large TitleHead \\} %   moretitlehead} \subject{Contesting Ontology \\} \title{The forms   Buildings and Real Estate or Buildings and Real Estate\\ \vspace{1cm}} \subtitle{Writings on something or other\\ \vspace{5mm}1999 - 2999} \author{\vspace{2cm}Andrew U. Frank} \date{} \publishers{\vfill topdown Editions\\Vol. xz}   \begin{document}  \maketitle   \end{document}

I'd like to use a smaller title. I'm using the scrartcl documentclass from the . I can change it's color font but not it's size.  \setkomafont{title}{\normalfont\bfseries\small}   Everything works exept the size.


I have recently installed ubuntu 20.04.  in top bar power and Log out buttons are joined. to power off I have to click 2 buttons. but in ubuntu 18.04 I powered machine off with 1 button. How can I get back to ubuntu 18.04 top bar

I recently installed Ubuntu 20.04 LTS on my laptop and I noticed that I no longer have the Power Off button but rather a menu that I need to click on and then I need to click on Power Off... and then Power Off. Is there a way to get the button back?


I'm trying to put a rounded div in the centre of any size page and make it responsive both vertically and horizontally when resizing the browser.  So far, I've managed to put the div in the middle of a page but it is only horizontally responsive. I need to make it also vertically responsive if possible.  Could you please suggest something?  Here is the code and fiddle

           Login
         <form class="login-box__form-usr-details" action="/somesearchaction" name="search" method="get">           Enter your email            <input title="Enter user email" placeholder="Enter your email" name="email" id="user-email" type="text"></input>            Enter your password            <input title="Enter user password" placeholder="Enter your password" name="password" id="user-password" type="text"></input>            Forgot password?           Login         </form>

    #login{     background: red;      .login-box{         background: green;         width: 60%;         height: 60%;         overflow: auto;         margin: auto;         position: fixed;         top: 0;         left: 0;         bottom: 0;         right: 0;         z-index: 9999;         border-radius: 50%;          &__header{                 font-size: 20px         }          &__form-usr-details{                 font-size:25px;         }     } }

Best way to center a <div> element on a page both vertically and horizontally?  I know that margin-left: auto; margin-right: auto; will center on the horizontal, but what is the best way to do it vertically, too?


I currently have a table called People. Within this table there are thousands of rows of data which follow the below layout:  gkey |    Name |  Date       | Person_Id 1    |    Fred |  12/05/2012 | ABC123456 2    |    John |  12/05/2012 | DEF123456 3    |    Dave |  12/05/2012 | GHI123456 4    |    Fred |  12/05/2012 | JKL123456 5    |    Leno |  12/05/2012 | ABC123456   If I execute the following:  SELECT [PERSON_ID], COUNT(*) TotalCount FROM [Database].[dbo].[People] GROUP BY [PERSON_ID] HAVING COUNT(*) > 1 ORDER BY COUNT(*) DESC   I get a return of:  Person_Id     | TotalCount ABC123456     | 2   Now I would like to remove just one row of the duplicate values so when I execute the above query I return no results. Is this possible?

What is the best way to remove duplicate rows from a fairly large SQL Server table (i.e. 300,000+ rows)?  The rows, of course, will not be perfect duplicates because of the existence of the RowID identity field.  MyTable  RowID int not null identity(1,1) primary key, Col1 varchar(20) not null, Col2 varchar(2048) not null, Col3 tinyint not null


I have Samsung galaxy s plus i9001. i have format factory my phone recently but i had some important notes in memo and mobisle Note and i didn't backup them before formatting, is there a way to restore them? i think they were stored in system storage.  i have a full copy of my usb storage, but i don't have copy of system storage, and i just need memo and mobisle note data, is there any copy of them in usb storage?

Without remembering application data, I reset my Galaxy S3 to factory state. Now, I lost data for one expense manager app. Is there any way to recover the data?


Show that if $G$ is Hamiltonian, then $L(G)$ is Hamiltonian. Attempt: For any graph, we can relabel the vertices.  For a graph $G$, then we must have a Hamiltonian cycle $(1, 2, \ldots , n)$. Now, I think it is just a matter of guaranteeing that in $L(G)$ there is a cycle $((1,2), (2,3), \ldots )$.

I have a graph G = (V, E). I know that the line graph L(G) of G is defined as follows: each vertex in L(G) corresponds to an edge in G, and two vertices are connected by an edge in L(G) if and only if the corresponding edges in G are adjacent.  Now I am trying to (a) prove that if G has a Hamiltonian circuit, then L(G) also has a Hamiltonian circuit, and (b) give an example of a graph G such that G does not have a Hamiltonian circuit but L(G) does.  However, I'm extremely stuck on how to do this, and any help would be greatly appreciated. Thanks so much!


I changed my display name.  Now all comments still refer to my old @name.  Can this be fixed?

The fact that a user can change their name at will can lead to some confusion in the comments.  For instance, suppose a user named "foo" changes his name to "bar", all those comments signed by "foo" are now signed by "bar", but responses to "bar"'s comments still start with "@foo".  Could those "@foo" references in comments be changed to "@bar"?    A brief discussion on this has set me straight.  I didn't think it through.  Request withdrawn.


First of all let me begin with saying that I have seen there is a question quite similar to this one, but I thought I'd ask again so I could get more specific about my situation since I am guessing it's different for every major. I am currently doing a master in mathematics, thinking about possibly pursuing a phd after that. During my undergraduate studies in mathematics, I mainly took pure math classes with an extra emphasis on algebra related courses(group theory, field theory, applied algebra). So far I thought that if I were to do a phd it would be in algebra. During my masters I also continued with pure math classes, such as real analysis, algebra etc. But I am currently taking a class in theory of computation and it has really caught my attention. That along with the fact that during the last year of my undergraduate studies I took a class in design & analysis of algorithms which I really enjoyed, has made me thinking that maybe if I were to do a phd, it wouldn't necessarily be in algebra after all but maybe in something in the interface of mathematics and theoretical computer science or in foundations of mathematics,or maybe even something that combines algebra with theoretical computer science if there's even something like that. Not really sure yet. My questions are:  1. Can my master thesis area be different than my phd area? If yes, how different?Say if I were to do a master thesis in pure or applied algebra, would it be possible to then pursue a phd in something that maybe combines math and theoretical computer science?  2. What kind of background is needed for a phd in a topic somewhere between pure math and theoretical computer science? Would maybe a second masters in computer science be needed? (Also I guess a good 3rd question would be if maybe having taken only 2 classes in theoretical computer science that I enjoyed is not enough for me to be able to tell if I would actually like something like that?)

I am doing masters in physics. I recently did internship in high energy physics for 2 months. But my institute allows me to do 6 months project only in condensed matter physics. I want to pursue PhD in high energy physics only. So, is it possible to pursue PhD in different area than master's thesis?


I have the following code: <div> <script> // get the width of the parent element </script> </div>  it is possibile to get the width (and the height) of the parent element where the script tag is placed?

How can I reference the script element that loaded the javascript that is currently running?  Here's the situation. I have a "master" script being loaded high in the page, first thing under the HEAD tag.  <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"  "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <script type="text/javascript" src="scripts.js"></script>   There is a script in "scripts.js" which needs to be able to do on-demand loading of other scripts. The normal method doesn't quite work for me because I need to add new scripts without referencing the HEAD tag, because the HEAD element hasn't finished rendering:  document.getElementsByTagName('head')[0].appendChild(v);   What I want to do is reference the script element that loaded the current script so that I can then append my new dynamically loaded script tags into the DOM after it.  <script type="text/javascript" src="scripts.js"></script> loaded by scripts.js--><script type="text/javascript" src="new_script1.js"></script> loaded by scripts.js --><script type="text/javascript" src="new_script2.js"></script>


I want to add an image to Photoshop and make it look as if it is lying down/isometric as in the attached image. I can achieve the effect using the Transform tool but without being able to add precise numbers it feels very random to me and I get slightly different results every time I do it.  Anyone know the best/simplest way to achieve this.

How do I create this type of effect with an image? I'm wondering how to get the thick edges and the tilted look. Is there an online tool that will convert a flat image to look like this?


I have the following appender in my logback configuration file:  <configuration> <appender name="SIFT" class="ch.qos.logback.classic.sift.SiftingAppender">     <discriminator>         <key>classname</key>         <defaultValue>unknown</defaultValue>     </discriminator>     <sift>         <appender name="FILE-${classname}" class="ch.qos.logback.core.FileAppender">             <file>target/logs/${classname}.log</file>             <append>false</append>             <layout class="ch.qos.logback.classic.PatternLayout">                 <pattern>[%thread] %level %logger{35} - %msg%n</pattern>             </layout>         </appender>     </sift> </appender> <root level="DEBUG">     <appender-ref ref="SIFT" /> </root> </configuration>   How can I configure logback to do the following:   On startup always generate a new files and delete existing Clear the file when it is over than 50 mb   Thank you

I want the log to roll over as long as the application is running, but I want the log to start fresh when the application is restarted.  Updated: Based on  feedback, my appender looks like this:     <appender name="myRFA" class="org.apache.log4j.RollingFileAppender">       <param name="File" value="my-server.log"/>       <param name="Append" value="false" />       <param name="MaxFileSize" value="10MB"/>       <param name="MaxBackupIndex" value="10"/>       <layout class="org.apache.log4j.PatternLayout">          <param name="ConversionPattern"             value="%d{ISO8601} %p - %t - %c - %m%n"/>       </layout>    </appender>   I simply added the following line:  <param name="Append" value="false" />   It now truncates the base log file at startup, but it leaves the rolled files alone.


I'm trying to reverse url for django admin "view on site button".  My route  (r'^product/(?P<num>.*)/(?P<url>.*)/$', set),   Models get_absolute_url method looks fine:  def get_absolute_url(self):         from django.core.urlresolvers import reverse         return reverse('core.views.set', kwargs={'num': self.url_num, 'url': self.url})   SO, it should be like this: http://127.0.0.1:8000/product/97/n3/ But when it rendered in django admin form, it is http://example.com/product/97/n3/  How can I fix it?

I added a get_absolute_url function to one of my models.  def get_absolute_url(self):     return '/foo/bar'    The admin site picks it up and adds a "view on site" link to the detail page for that object (when I put a real URL there instead of "/foo/bar").  The problem is instead of going to http://localhost:8000/foo/bar, it goes to http://example.com/foo/bar.  What am I doing wrong?


Many materials, such as glass, are transparent over some wavelength interval. In the photon picture, as far as I understand it, this is because there are no allowed transitions corresponding to the energy of the light for which the material is transparent. If this is so, and if these photons don't interact with the material in question, then how can light at the same time be "slowed down", i.e. propagate with a lower speed than c ?

I know that if we solve the Maxwell equation, we will end up with the phase velocity of light being related to the permeability and the permittivity of the material. But this is not what I'm interested in - I want to go deeper than that. We know that the real speed of light is actually not changing, the decrease in speed is just apparent. Material is mostly empty, the light will still travel with $c$ in the spacing. The rare atoms will disturb the light in some way. So I am interested in how the atoms affect the light. Photon absorption-emission theory Some textbooks that I read explain it in a way kind of like this: In a material the photons are absorbed by atom and then re-emitted a short time later, then they travel a short distance to the next atom and get absorbed&emitted again and so on. How quickly the atoms in a material can absorb and re-emit the photon and how dense the atoms decides the apparent speed of light in that material. So the light appears slower because it has a smaller “drift speed”. Interference theory But recently I realize an alternative explanation: Atoms respond to the light by radiating electromagnetic wave. This “new light” interferes with the “old light” in some way that results in delayed light (advanced in phase), this can easily be shown by using simple phasor diagram. Consequently effectively the light covers a smaller phase each second, which gives the impression of a lower phase velocity. However the group velocity is changing in a complicated way. I think that the first explanation does not explain the change in phase velocity of light. if we consider light travelling into a slab of negative refractive index non-dispersive material, let’s say the light is directed perpendicular to the slab. The phase velocity’s direction will be flipped, but group velocity’s direction in the material will not change. Only the second explanation can explain the flipped phase velocity direction. I guess that the velocity that we get in the first explanation is actually belongs to the group velocity. It makes sense to me that the front most of the photon stream determines the first information that the light delivers. So the question is What really cause the phase velocity of light to be decreased?  "drift velocity" of photons (they aren't the same photons, they are re-emitted all the time) phase difference between absorbed and emitted light something else  And also, I still don't really understand detailed explanation of the absorption-emission process for small light's wavelength (for large lambda compare to the atoms spacing, the photons will be absorbed by the phonons). The dispersion relation that we know is continuous and also some material is non-dispersive, therefore the absorption process must occur in all frequency for a certain range. So definitely it doesn't involve the atomic transition, otherwise it will be quantized. My guess is that the relevant absorption process gets smooth out by the dipole moment. What makes the spectrum continuous? EDIT: link for dispersion relation:


Can someone give an example of a commutative ring where there are elements $a$ and $b$ such that $a\mid b$ and $b\mid a$ but $a$ and $b$ are not associates (i.e. there is no unit $u$ such that $a = ub$)?

Please help me to find elements $a,b$ in a ring $R$ such that $a\mid b$ and $b\mid a$, but there does not exist any unit $u$ in $R$ such that $a=ub$.


I would like to link three of these resources, present my understanding of what I read, and pose the question if my understanding is approximately correct        Reading the linked resources and assuming that the answers and comments are correct, I gather that (I quote myself, including bad spelling: this post is heavely edited, the initial content is in the history)     From a certain, very abstract viewpoint, a supervised machine learning problem is an optimization problem. You try to maximize some "measure of good-ness" or minize some measure of "bad-ness". The way you formulate the problem defines, in a way, the "machine learning model". There might be different ways how you solve the optimization problem ("train the model").   is not wrong. [A]  Question 1: is [A] correct?  If [A] is correct, than in that sense, f.ex. a CNN (or ANNs in generall) is not different from a SVM or a Random Forest. [B]  Question 2: Is [B] a reasonalbe conclusion?  However, there exists proof that  1) FFN are universal approximators  2) RNNs are Turing complete  I've read (unfortunately, I can't find the resource anymore) that it is possible to approximate Random Forest (and I would assume SVMs, ...) with certain kind of ANNs, but not the other way round.  So in that sense the concept of ANN is more generall than SVMs or Random Forests (I'm struggling with the language a lot here...) [C]  Question 3: Is [C] correct?

As we delve into  literature, we get to identify other methods with neuromorphic topologies ("Neural-Network"-like architectures). And I'm not talking about the . Examples are given below.  Then, it makes me wonder: what is the definition of an artificial Neural Network? Its topology appears to cover everything.    Examples:  One of the first identifications we make is between PCA and a linear Autoencoder with tied-weights in the encoder and decoder and thresholded activations in the bottleneck layer.  Also, a common identification is done between linear models (logistic regression in special) and a Neural Network with no hidden layer and a single output layer. This identification opens several doors.  . ? ANN. Gaussian Process? ANN (with single hidden layer with infinite hidden units).  And so, just as easily, we can incorporate arbitrary regularized versions with specialized loss functions of these algorithms into a Neural Network framework.  But the more we dig, the more similarities appear. I just stumbled into , which makes the identification of a specific ANN architecture with decision trees, allowing these to be learned by ANN methods (such as Gradient Descent backpropagation). From this we can construct Random Forests and Gradient Boosted Decision Trees from solely Neural Network topologies.  If everything can be expressed as an Artificial Neural Network, what defines an Artificial Neural Network?


Show that if a transitive subgroup $G\subset S_n$ of the symmetric group $S_n$ contains a n-1 cycle and transposition,then $G=S_n$.   Firstly, without loss of the genralization, we can assume the n-1 cycle is $(2,   3,4,....,n-1)$, and the transposition is (1,2), but how can we prove that (1,2) and (2,3,...,n-1) generates $S_n$

Suppose $G$ is a transitive subgroup of $S_n$ such that it there exist $\sigma, \tau \in G$ such that $\sigma$ is an $(n-1)$-cycle and $\tau$ is a transposition. Prove that $G = S_n$.   I just don't understand how to mathematically use the transitive nature of the subgroup.


I have seen 127.0.0.1 is local host address. But what is it and what is the differences between this and my local adapter like LAN  IP address or WLAN IP address. Is there any connection between this l27.0.0.1 and my LAN or WLAN Network card?

I found some articles related to this, but they were not sufficient for me. I want to know how the localhost works and why is it the same on many different machines?   How does the localhost block the access to the website when we use it in the host file to block the website?


I seen in many texts for set theory that ZFC forms a foundation for most of math, e.g. analysis, topology, algebra, etc.  Are they any fields of mathematics that cannot be built on ZFC?

I often read that ZFC can formalize "most" of everyday mathematics, but I could never find an example which it cannot. The closest I got is differential geometry (DF), where some article mentions that the translation from concepts of DF into set theory would render it almost "meaningless", in the sense that any intuitions one could have would be lost in the translation. So, if I didn't misunderstand, at least in theory, the translation could be done, so that a future AI machine could prove theorems of differential geometry using set theory. On the other hand, the Stanford Encyclopedia of  Philosophy states that "all of mathematics can be reduced to a formal system of set theory"().   So, the questions are:    Is there any current area of mathematics that could be not formalized within set theory? If so, which ones? and  Is there any reason to think that every math of the future will be always formalizable in set theory? any references to read on the subject are welcomed!   Clarification: by set theory I am not restricting to ZFC, but to any flavor of it, including all additional axioms you want (about large cardinals or any kind)


I understand the simple version answer to this question what does not make sense is if most of the matter around us is normal matter then for the blackhole to losemass from the virtual particle pairs. Doesnt more antimatter or antiparticles need to fall in then positive?   I understand the temperature or radiation one should see is one of the particles escaping the virtual pair. But unless the virtual pairs are always created with a slightly above 50% chance that the anti particle always is crossed the event horizon and the regular one on the other side how is any mass actually being lost?  Ive looked and am really surprised nobody's asking this.  Conservation of energy isnt a valid answer. Because if a particle escapes why wouldn't it just vanish instead of the one in the blackhole?  My understanding is that hawking radiation has more to do with the fields in bent space time and the reference frame point then actual virtual particle pairs. Thats just the simple answer.  Also if mass is just energy and a particle and antiparticle collide they release energy How would this released energy escape the blackhole if it happened inside the event horizon.  Wouldnt this just stay trapped in yhe gravity well. And if gravity separates the virtual pair and they dont annihilate then new energy has been created hasn't it?  I know im miss some things here.  I just haven't found a satisfactory explanation for how the virtual pair reduces any mass inside the blackhole.  Unless the two particles are quantum correlated and when one interacts with one inside the blackhole it basically teleports to the one outside the blackhole and the pair ceases to exist because it cant exist for more then a fraction of time anyways.

Could someone please provide an explanation for the origin of ? (Ideally someone who I have been speaking with on the h-bar)  Any advanced maths beyond basic calculus will most probably leave me at a loss, though I do not mind a challenge! Please assume little prior knowledge, as over the past few days I have discovered that much of my understanding surrounding the process as virtual particle pairs is completely wrong.


After spilling a tea into the macbook 11 i have disassembled it. Cleaned everyhing with IPA and brush. Put together. Macbook is working but charger does not charge. LED does not light. System says it does not charge, source of power adapter. There is small icon of battery with flash saying 2%. I have changed I/O Board, battery, performed NVRAM/SMC reset. Still behave the same. No change.   Any other suggestions?

Sadly, yesterday I've spilled some water on my MacBook Pro (El Capitan). Before you yell at me - it was closed, turned off and it wasn't a lot of water, the laptop was wet only on the top and under - not inside.  Today I've turned him on. At first battery wasn't recharging for some reason, but SMC reset fixed the problem.  At the first booting speaker was like talking to me, hard to explain but it was weird. Also only right speaker was "talking", despite the fact that only left side of the laptop was watered. Then there was no sound at all, not from the speakers, nor from the headphones. Also microphone's not working. USB ports are okay. The water was spilled from the left side of the laptop. I know this is hardware issue, and something's broken, but I want to be 100% sure. No it's not muted. I've also tried NVRAM reset a few times, but it doesn't fix the problem :(  There might be one factor, before spilling, my laptop "died" for the first time (battery energy ran off), but I doubt it's the case. (but hey, every info matters, right?)  It wouldn't be weird for me, if only left speaker wouldn't work, but built-in microphone not working is kinda weird in this case, isn't it?  I just want to ask you guys, what else can I check, before I'll be 100% sure it's dead inside?  I've plugged in external microphone - it's not working too.


Can someone please help me order things up? There are 4 houses, and it is said that each dorm has 5 beds, which means 10  students (5 boys and 5 girls) per house, times 4 is 40.  I realize it does not mean that there are 40 students each year no matter what, and they are all divided equally as 10 students for each house, so give or take.  Who are the students of each house who started school together with Harry? At least the ones we know about?

I'm currently making a mind map of the Harry Potter universe, but when I got to filling in the houses of Hogwarts, I realised that I barely know any names.  What are the names of everyone from Harry's year?


I'm a novice R user with only a little stats experience.  I'm using the coxph function to determine the effect of a continuous variable on survival using the following code: fit <- coxph(Surv(Survival, Dead) ~ LymphRatio, data = Survivalbylymphratio)  from which I get the following output:    coef exp(coef) se(coef)     z      p LymphRatio -1.2028    0.3004   0.6168 -1.95 0.0512  Likelihood ratio test=4.15  on 1 df, p=0.04159 n= 133, number of events= 45   I'm trying to understand the purpose of the likelihood ratio that's shown at the end of the output.  I've read up a bit but all I've found are complex statistical formulae but without a basic explanation for what it is actually saying about my data. e.g.In this output, the HR is non-significant (p=0.0512) but the likelihood ratio is p=0.04159.  Which do I report for this variable? What would different results for the likelihood ratio mean for my dataset? For example:  Likelihood ratio very high vs very low Likelihood ratio p-value > 0.05 vs <0.05  I know these are basic nuts and bolts questions.  Thanks for any help

I have built a logistic regression where the outcome variable is being cured after receiving treatment (Cure vs. No Cure). All patients in this study received treatment. I am interested in seeing if having diabetes is associated with this outcome.   In R my logistic regression output looks as follows:   Call: glm(formula = Cure ~ Diabetes, family = binomial(link = "logit"), data = All_patients) ... Coefficients:             Estimate Std. Error z value Pr(>|z|)     (Intercept)   1.2735     0.1306   9.749   <2e-16 *** Diabetes     -0.5597     0.2813  -1.990   0.0466 *   ...     Null deviance: 456.55  on 415  degrees of freedom Residual deviance: 452.75  on 414  degrees of freedom   (2 observations deleted due to missingness) AIC: 456.75   However, the confidence interval for the odds ratio includes 1:                     OR     2.5 %   97.5 % (Intercept) 3.5733333 2.7822031 4.646366 Diabetes    0.5713619 0.3316513 1.003167   When I do a chi-squared test on these data I get the following:  data:  check X-squared = 3.4397, df = 1, p-value = 0.06365   If you'd like to calculate it on your own the distribution of diabetes in the cured and uncured groups are as follows:  Diabetic cure rate:      49 /  73 (67%) Non-diabetic cure rate: 268 / 343 (78%)   My question is: Why don't the p-values and the confidence interval including 1 agree?


Let $a_n$, $n \geq 1$ be a sequence of real numbers satisfying $|a_n| \leq 1$ for all $n$. Define $$ A_n = \frac{1}{n}(a_1+a_2+\cdots+a_n)$$  for $n\geq 1$. Then $\lim_{n\to \infty} \sqrt n(A_{n+1}-A_n) $ is  A. $0$  B. $-1$  C. $1$  D. None of them  ATTEMPT  I tok sequence $a_n=1$ and answer came out to be 0. But how do i choose between A and D.  Thanks

Let $\{a_n\}, {n\geq 1}$, be a sequence of real numbers satisfying $|a_n|\leq 1$ for all $n$. Define  $$A_n = \frac{1}{n}(a_1 + a_2 + \cdots + a_n),$$ for $n\geq 1$. Then find $\displaystyle\lim_{n \rightarrow \infty}\sqrt{n}(A_{n+1} − A_n)$ .    I proceed in this way  $$\lim_{n \rightarrow \infty}\sqrt{n}(A_{n+1} − A_n)=\lim_{n \rightarrow \infty}\sqrt{n}\left[\frac{1}{n+1}(a_1 + a_2 + \cdots + a_n+a_{n+1})-\frac{1}{n}(a_1 + a_2 + \cdots + a_{n})\right]=\lim_{n \rightarrow \infty}\left[{(na_{n+1}-a_1 - a_2 - \cdots - a_n})\frac{1}{\sqrt{n}(n+1)}\right]$$  Please help me to complete from here


Referring the slide 16 from this :  I want to ask why is MAC encrypted along with the data to be transmitted. Why isn't MAC just appended at the end of encrypted data ?

Encrypt-then-Authenticate (EtA) seems to generally be considered the better option, compared to Authenticate-then-Encrypt (AtE) (see this  question, for example). The people writing the RFC for TLS 1.2 , but have chosen to use AtE anyway.  Is there a reason why this is the case? Is this a case of "Someone standardized something at some point and now we're stuck with it for backwards compatibility, even though we know it's bad", or is there a good reason why AtE is better for TLS?  Clarification, because this wasn't very well-written originally: I am referring to the actual encrypted channel after the handshake has finished. It's clear that you have to authenticate the server and perform a key exchange before you can perform any useful form of encryption.


$f(x)=\begin{cases} 1, & \text {if x is rational}\\ 0, & \text {if x is irrational} \end{cases}$   How to use $\varepsilon$-$\delta$ method to prove that the function $f(x)$ is an everywhere discontinuous function?  I approached the problem using 'Proof by Contradiction'...but i couldn't work it out.If anyone could please help me  approach these type of problems correctly it would be very helpful indeed!  Thanking you in advance!

The Dirichlet function is defined by $f(x)=\begin{cases} 1 &\text{ if } x\in \mathbb{Q}\\0 &\text{ if } x\notin \mathbb{Q}.\end{cases}$ Let $g(x)=\begin{cases}0 &\text{ if } x\in \mathbb{Q}\\ 1 &\text{ if } x\notin \mathbb{Q} \end{cases}$ be its evil twin.  (1) Prove that $f$ is discontinuous at every $x\in \mathbb{R}$.  (2) Prove that $g$ is continuous at exactly one point $x_1\in \mathbb{R}$.  (3) Prove that $f+ g$ is continuous at every $x\in \mathbb{R}$.  Definition (Continuous at a point): A function $f: D \longrightarrow \mathbb{R}$ is continuous at $X_0\in D$ if for every $\epsilon > 0$ there exists some $\delta > 0$ such that $|f(x) - f(x_0)| < \epsilon$ whenever $|x-x_0|< \delta$.  Response: I don't have any work yet, hints and answers would be extremely helpful.


I'm looking for a very simple architecture design program. If it were open source, that would be awesome! I just want to create a kind of map of rooms, and add only borders of furniture items.

I'm planning to have a house built. I want to draw up some sketches on the computer, so I am looking for a program that can help me do this. It doesn't have to be a professional architecture tool; in fact that would be too complicated just yet (but maybe later on, for the detailed work...?). A simpler tool would be better.   Features should include such things as ability to draw and move walls (not just using simple boxes), calculate room/floor area, add windows and doors, and the like. That's why Inkscape or OOo Presentation won't do. On Windows, a friend would just download a cracked professional architecture tool but that is not what I want to do.  Suggestions?


Are there any rules for centring lower case letters like a 'd' in a circle? To me it doesn't look right unless it's moved more to the left but then it's not in the middle.

I'm currently working on a logo for a client. Here is the work in progress.   It seems obvious to me that the S should align with the line above. I feel that the best way of aligning it however is to align the bottom part of the S rather than the top curve, even thought the top curve does protrude more. See the following example   Also at the other end of the logo, the A I feel can do something similar, minimising the white space triangle at the end of the logo    The end result I think is more pleasing in its alignment   I feel that this is correct, but my client is questioning it. This alignment is a habit I have picked up during my career, so I haven't been formally taught this, in fact I can't remember where I picked this up.   Tell me, have I picked up a bad habit here? Is my client correct? If this is correct does this type of alignment have a name? Or is there an article somewhere I can refer my client to?


I need to open a Debian deb package file in MacOS High Sierra to compare a binary with one that I have installed in Linux.  Actually the package is mssql-server_14.0.3008.27-1_amd64.deb  The file command says Debian binary package (format 2.0).   tar x and unzip do not work.  What to do?

I am running Debian jessie stable in order to understand how the .deb package interacts with the system. What is the correct way to extract and install a packge_name.deb without the command dpkg?