How to find and replace using sed on records starting with Specific number


A classmate and I were practicing speaking where he used a saying "the early bird catches the worm", I did hear this idiom though I didn't know where it originated, so I asked  Do you know what country it originates from?  Is this sentence clear and natural? Should have I said it like this?  Do you know which country it originates from?


When setting   sql_mode=""  in  /etc/mysql/my.cnf  server leaves this variable in it default value:    mysql> show variables like 'sql_mode';  +-------------------+------------------------------------------------------------------------+  | Variable_name | Value                                                                                | +-------------------+------------------------------------------------------------------------+  | sql_mode         | STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION  | +-------------------+------------------------------------------------------------------------+   However, if i set it manually in mysql shell:   set global sql_mode="";   server sets it as desired - to empty value. Till next server restart, when server sets this variable to default value again.  Tried in single and double quotes - no matter. No errors in error log. No other default configuration files of mysql loaded What's wrong?  Why?


In Matlab I can create a matrix by typing A = [1 2 3; 4 5 6; 7 8 9], for this the space is a delimiter between the entries of the matrix.  I am wondering if there is a package which makes it possible to input a numerical array in a similar way directly into LaTeX?    For example, I would want to use the syntax:  $\SpaceDelimMat[c]{1 2 3; 4 5 6; 7 8 9}$,   instead of typing & (ampersand) 6 times like this:  $\left[\begin{array}[c]{rrr} 1 & 2 & 3\\ 4 & 5 & 6\\ 7 & 8 & 9\end{array}\right]$;   as to do the latter is very time consuming and makes LaTeX document less readable, especially when presenting a course about Matrices.


An idiom meaning someone's doing something useless and has no result at the end

In my native language, we use an idiom to warn someone that they're doing something which has no result at the end:     Trying to convince him is like squashing water ...   Is there any idiom in English with the same meaning?


What is the most efficient way to level up my blacksmithing while conserving as much of my resources as possible?

Ok so on skyrim I decided to start a new game and play as a argonian blacksmith. Now as I am only level 3 at the moment what is the quickest way to level up my smithing while using the smallest amount of resources possible?


Points on a scheme with given norm (or finding the maximal ideals of $\mathbb F_p[T_1, \dots, T_n]$)

Motivation: Say you have a noetherian scheme of finite type $X$ over $\mathbb Z$. Then to every closed point $x$ corresponds a norm, which is the number of elements in the residue field (which we know to be finite) $$ N(x) = |k(x)|. $$ So, this number will be $p^n$ for some prime $p$ and integer $n$. We want to prove that the number $$ a(p,k) = \{x \text{ closed point }\mid N(x) = p^k \} $$ is finite. Given this, we reduced the problem to the following: Let $X = \textrm{spec }\mathbb{F}_p[T_1, \dots, T_n] = \textrm{spec }R$ defined over $\mathbb F_p$. The closed points now correspond to maximal ideals of $R$, and therefore, we want to prove that for each $k$ there are finitely many ideals $\mathfrak m$ such that $R/\mathfrak{m} = p^k$. If $n=1$ this is easy to determine (since $R$ will be a PID, we can count irreducible polymonials of given degree). For a generic $n$ we have no clue how to proceed. One strategy may be to use the Nullstellensatz on $\overline{\mathbb{F}_p}$ and hope we can get something back by using the Frobenius morphism.


Can we handle the wave function as if it was a real valued function?

I am trying to analyze in general simple one dimensional QM problems. To be more specific let's consider this kind of Hamiltonian: $$H=\frac{\hat{p}^2}{2m}+V(\hat{x})$$ From this one we can derive the following: $$\frac{\partial^2\psi(x)}{\partial x^2}=\frac{2m}{\hbar ^2}(V(x)-E)\psi(x) \ \ \ \ \ \ (1)$$ Where of course $\psi(x):\mathbb{R}\to\mathbb{C}$ is the wave function. Now for example let's consider the case of a symmetric potential well, and also let's consider the case in which $V(x)>E$. In this case my lecture notes state that we can see from (1) that $\psi ''$ has the same sign as $\psi$. Now here I have a problem: this statement would of course be true for a real value function $\psi(x):\mathbb{R}\to \mathbb{R}$, but the wave function assumes complex values, why are we authorized to treat the wave function as a real value function? This is not the only example of this way of handling the wave function, often in my lecture notes the wave function is depicted in a $2D$ graph as if it was a real value function and not a complex one. Why can we do this? If we want to talk about real functions in this context shouldn't we consider the probability density $|\psi(x)|^2$ instead of the probability amplitude $\psi(x)$?


Is it possible to source ~/.profile in the current shell from a script?

Take the following ~/test.sh script as an example:  #!/bin/bash  sudo -u ${SUDO_USER} cp ~/.profile ~/.profile.bak  cat <<EOF >>/home/${SUDO_USER}/.profile export HELLO="Hello StackExchange" EOF  sudo -u ${SUDO_USER} source ~/.profile  sudo -u ${SUDO_USER} cp ~/.profile.bak ~/.profile sudo -u ${SUDO_USER} rm ~/.profile.bak   I then run it like this:  User@MACHINE:~$ sudo bash test.sh User@MACHINE:~$ echo $HELLO   I was expecting Hello StackExchange to be printed on the terminal, but a blank line was printed instead.  If I understand what's happening correctly, the source ~/.profile command is not being applied to my current shell. So how I can source changes done to files like .profile to the current running shell from a script without having to logout and log back in? Is this even possible?  P.S: Assume test.sh is always ran with sudo and never without it. The script above is just an example, but I use sudo -u ${SUDO_USER} command when I need certain commands to run as the user who invoked the script and not as root.


Let $D$ be an integral domain $a,b \in D$. $m,n$ are relatively prime   and $a^n=b^n$ and $a^m=b^m \implies a=b$.   I quickly realized that since $m,n$ are relatively prime then $\exists p,q \in \mathbb{Z}$ s.t. $pm+qn=1$.  So we have $a^m=b^m \implies a^{pm}=b^{pm}$ and similarly $a^{qn}=b^{qn}$.  Then $a^{pm} a^{qn}=b^{pm} a^{qn} = b^{pm}b^{qn} \implies$ $a^{pm+qn}=b^{pm+qn} \implies a=b$.  Now my concern is I didn’t use any properties of integral domain. Am I jumping the gun here? What mistake did I make?


I know that many kind of groups can be represented by matrices; for example: rotation groups can be represented by matrices.  Especially all elements of rotation groups can be represented by orthogonal matrices with determinant positive one. Also Permutation group can be represented by matrices.  But I need to know:    are there any kind of group which can not be represented by matrices?           Or is there any kind of group which does not have a representation?                 Can you show me sample?


need help with deforming a mesh over another mesh

say you have sphere and plane meshes and you want to take the plane and slide it to the sphere without it clipping through but you also need it to deform around the sphere. is there a way to do this?  im asking because im trying to put windows on a boeing 777 and i need the windows to take the shape of the plane's body and i dont want to go editing them to fit each area one by one. i tried the snap function but i need something that can deform it too


determine shell in script during runtime

As per my knowledge, to determine the current shell we use echo $0 in the shell. Rather I want my script to check in which shell it is running. So, I tried to print $0 in the script and it returns the name of the script as it should. So, my question is how can I find which shell is my script running in during runtime?


Is there a way to set the actual size of an external display for extending the desktop?

I have a Surface Pro 4 with a screen size of ~12 inches diagonal and a resolution of 2736x1824, and I'm using it with an external monitor that's about 18 inches but has a much lower resolution (1680x1050). I have the scaling at 200% on the Surface Pro screen and 100% on the monitor, which is good for the size of text and stuff.  But for extending the desktop, Windows thinks the monitor is much smaller than the Pro screen since its resolution is lower. This means that moving the mouse between screens is totally thrown off, and it's impossible to line the monitors up in the display settings to reflect how they are in reality.  ;   Does anyone know of a way to fix this issue? I know it can't be fixed through Windows settings, but I was hoping there's some utility out there that can, or some other creative solutions.


During a collision, why is momentum not conserved in a participant's frame of reference?

[This question is inspired by an astute observation from a student of mine.]  When we discuss conservation of momentum, students often ask, "When is momentum conserved?" And the lazy, mechanical response is often, "Momentum is always conserved."  A thoughtful student might then reply, "But what about falling objects? If I drop my pen, it accelerates towards the ground and gains momentum. Clearly, momentum is not always conserved."   This is a fair criticism. But one with an easy answer: "You aren't taking into account the momentum of the earth," we say, "As the earth pulls down on the pen, the pen (by Newton's Third Law) pulls up on the earth, accelerating it. Therefore, the downward momentum of the pen is cancelled out by the upward momentum of the earth.  "The more correct statement," we conclude, "is that momentum is always conserved in a closed system - namely, in a system containing all of the equal-and-opposite force pairs. None of the forces are allowed to cross the boundary of the system (like the weight of the pen does when you watch it fall without considering the earth)."  "Alright," the student concedes, "I'll buy that. But even when we neglect gravity, why doesn't momentum always appear to be conserved?"  "How do you mean?"  "I mean this: imagine floating in empty space - just you and a baseball. You look around and notice that you have zero momentum. And why shouldn't you? After all, you are in your own center of mass reference frame (where momentum is always zero).  "But then you throw the baseball," the student continues, "and it begins to move away from you with some momentum. However, from your point of view, you still are not moving. The system of you and the baseball is closed (there are no external forces), so momentum should be conserved. Yet before you threw the ball, momentum was zero, and afterwards, it is non-zero.  "What happened? Why was the momentum of this closed system not conserved?"


I've seen the homoskedasticity assumption stated as the constant conditional variance of the error (i.e., Var(u|x)=constant).   I was wondering if I can also state the homoeskedasticity assumption as constant variance across values of a same dependent variable, conditional on the independent variable (i.e., Var(y|x)=constant)?   I remember a professor one time told me that they were essentially the same thing and you could state one or the other and they meant the same. However, I have been looking around the internet and cannot find info on the matter.


How to get a list of the installed app on my Mac?

How I can parse the list of all Mac applications? I am executing:  ls /Library/Preferences/ > apps.txt   But still there are some apps that are missing from the list. I think it parse only user apps and do not parse common apps


How can I check the details of my Ubuntu installation?

Recently, I installed Ubuntu 16.04 LTS. How do I check if it has installed 16.04 LTS? What is its name? Release Date? Expiry Date?


Auto-jump on today's date upon upening the spreadsheet

I use a spreadsheet with a date in a row per column. I would like to have the sheet open on the current date when opening. How can I make this?


I have selected 'Nursery' data set from UCI machine learning repository and run 2 different clustering algorithm on, K Means and Hierarchical clustering. How should I compare these to algorithm to see which one did a better job on the data set? I have calculated the parameters:   adjust_rand_score adjust_mutual_info_score silhouette_score     for each 2 clustering model. Is that true to compare the calculated parameters to see which one did better? For example: K Means model:    adjust_mutual_info_score = 0.044 silhouette_score = 0.56   For Hierarchical Clustering model:     adjust_mutual_info_score = 0.16    silhouette_score = 0.59   So can I say the Hierarchical model has did a better job? Or there is another parameter to compare these 2 clustering algorithms?


I just bought a new laptop with Windows 7 installed and I'm planning on installing Ubuntu 11.10 for a dual-boot.  Here's my rather basic problem :  I have a 750go hard drive, pretty much partitioned like this :   Recovery : 25go C: (Windows 7) : 295go D: (Data) : 380go   That is the factory configuration, the hard drive is still fairly empty (I removed all the bloatware and didn't install anything yet).  This is what I'd like to obtain :   Keep my recovery partition A partition for Windows 7 A partition for Ubuntu A "big" common partition for Windows and Ubuntu data, all the files I'm going to create.   How can I do that? Do I have to resize/create the partitions in Windows 7 before installing Ubuntu? Do I have to do it while installing Ubuntu using Gparted?  I'm quite confused and I'd like to make it right so I guess I need your help.  Thanks a lot everyone.


How to create ArcGIS tool with list and "sublist" using arcpy?

I have been tasked with making a tool, that when you open it you can choose from a list in a dropdown box, which then populates the second dropdown box with a sublist, like so:    However I only have a basic understanding of Python and I barely understand GIS, so this is a giant learning experience for me. I have tried using ESRI's site and this community, but alas I am still horribly stuck.  Where it goes wrong is at "self.params.filter.list =" I can make it work with if I give it a list like ["Option 1", "Option 2"], however i already have the list "mergedList" where I have the values I want, but I cannot for the life of me make it work.   I have tried with: self.params.filter.list = mergedList  and  self.params.filter.list = sorted(mergedList.keys()) and one other which eludes my brain right now.  Current code, it only has one of the params, since I can't get that to work I haven't done the other one.  import arcpy  class ToolValidator(object):   """Class for validating a tool's parameter values and controlling   the behavior of the tool's dialog."""    def __init__(self):     """Setup arcpy and the list of tool parameters."""     self.params = arcpy.GetParameterInfo()    def initializeParameters(self):     """Refine the properties of a tool's parameters.  This method is     called when the tool is opened."""      # Variables for Cursor     featureClassName = r'ArcGIS_Drift_Grundkort_DB.GISGRUNDKORT.Jordstykke'     cursorNavn = "ELAVSNAVN"     cursorNr = "MATRNR"      #Generate empty Lists     listNavn = []     listNr = []      #Populate lists     with arcpy.da.SearchCursor(featureClassName, (cursorNavn,)) as cursor:         for row in cursor:             listNavn.append(row)      with arcpy.da.SearchCursor(featureClassName, (cursorNr,)) as cursor:         for row in cursor:             listNr.append(row)      #Merge lists into a single list with keys     mergedList = {}     for i, v in enumerate(listNavn):         mergedList[v] = mergedList.get(v, []) + [listNr[i]]      #toolbox stuff     self.params[1].filter.list = mergedList      return    def updateParameters(self):     """Modify the values and properties of parameters before internal     validation is performed.  This method is called whenever a parameter     has been changed."""     return    def updateMessages(self):     """Modify the messages created by internal validation for each tool     parameter.  This method is called after internal validation."""     return   It is very likely there is a better way of doing this, I just need the unique data from column A (ELAVSNAVN) which is like companies and then a sublist with the numbers (MATRNR) that goes with that.  The tool itself is incomplete since i am stuck on just the list part, just need some pointers / tips for that.


Convert value/type string pair to enumeration value in C#

This is my declaration.  public enum Egypt {     Cairo = (long)1521894,     Alexandria = (long)1522006,     Giza = (long)1521643 }   From aspx page I get the value Egypt as a query-string. With this value I want to parse the names and values of this enumeration Egypt.  var values = Enum.GetValues(typeof(Egypt)).Cast<Egypt>(); foreach (Egypt in values) {     long woeid = ((long)(Egypt)(s)); }   I have the code to get the values like this but my point is the value enum - Egypt is itself determined at runtime. How will I achieve it?


Are those stars moving past the window when the ship is at warp?

When the enterprise (ENT) is moving at warp we see numerous stars flying past in the windows:    However, according to , at warp 5 (the maximum speed of the 1st enterprise) it would take 7.4 days to get from the Sun to Alpha Centari, our nearest star(s) approximately 4 light years away. So to have stars whizzing past every few seconds would imply that the stars are very close together.  Is this an inaccurate depiction of star movement at warp, or is there some explanation like the warp bubble creates a lensing effect?  Now I realise the classic answer is "suspend your disbelief, it's a tv show", but the animators have at least thought about the star movement as they have added in a bit of red shift and blue shift which you can see in the image.


Can I charge my laptop with this charger

I forgot my charger at home but really need to get my pc running. I have a charger from a friend of my my pc has an output of 19V / 7.1 A and the friends has 19V/ 4.3 A. I know that the charger might overheat but what if I only charge when my pc is turned of will it still draw as many electricity when it is turned off? And I have a bit of a problem finding the polarity of my pc I found the one on the charger though  Edit: Found another one 19,5 V and 6,7 A should that one work


I don't understand dynamic_cast or what?

I'm a bit newbie in c++ but why this code prints that the queue item is not a child while I created him as a child:  class Parent { public: virtual const char* getName() { return "Who is your daddy?"; } };  class Child : public Parent { public: virtual const char* getName() { return "La gente esta muy loca?"; } };  int _tmain(int argc, _TCHAR* argv[]) {     std::deque<Parent> queue;        queue.push_back(Child());     Parent* p = &queue.back();     if (dynamic_cast<Child*>(p) == 0) { std::cout << "I am not child"; }     else { std::cout << "Welcome, son"; }     std::cin >> c;     return 0; }


What are the consequences if Axiom of Infinity is negated?

What mathematics can be built with standard ZFC with Axiom of Infinity replaced with its negation?  Can the analysis be built?  Is there special name for "ZFC without Infinity" set theory?  I also assume that using symbols like $+\infty$, $-\infty$ when dealing with properties of functions and their limits would still be possible even with Axim of Infinity negated (correct me if I am wrong).  UPDATE  In light of the answer by Andres Caicedo which suggested Peano arithmetic, I want to point out that Wikipedia says about Peano arithmetic "Axioms 1, 6, 7 and 8 imply that the set of natural numbers is infinite, because it contains at least the infinite subset". I do not know how this can be interpreted as having axiom of infinity but I am interested what if Peano arithmetic modified the following way:   Added an axiom 5a:   There is a natural number $\infty$ which has no successor, for any natural number n $S(\infty)=n$ is false.   Axiom 6 modified:   For every natural number n except $\infty$, S(n) is a natural number


Locked message should reference Help Center

I noticed that the locked message still references the FAQ. See :  locked by  yesterday This question exists because it has historical significance, but it is not considered a good, on-topic question for this site, so please do not use it as evidence that you can ask similar questions here. This question and its answers are frozen and cannot be changed. More info: .  Since the FAQ has been replaced by the , this message should provide a link there instead. Currently, the link actually takes you to the ; even if it doesn't link to the help center, the text should probably be something like "More info: ".


$ \sum a_n \sin (nx)$ converges uniformly iff $na_n\to 0$ as $n \to \infty$

Let $\{a_n\}$ be decreasing sequence of positive terms then prove that $\displaystyle \sum a_n \sin (nx)$ converges uniformly on $\Bbb{R}$ iff $na_n \to 0$ as $n\to \infty$.   I proved that convergence of $ \sum a_n \sin (nx)$ implies $na_n \to 0$ as $n\to \infty$ . I got stuck while prove the converse,  I tried ussing Dirichlet's test but the problem here is that partial sums of  $\displaystyle \sum^{n}_{k=1} \sin (kx)$ are bounded by $\displaystyle \frac{1}{|\sin (\frac{t}{2})|}$ , so as per Dirichlet's test requirement I'm not getting uniform bound.


Planck length implies lattice structure of space?

There is known to be a lower limit on space, which can be derived from the Planck units. It can describe the minimum distance resolvable between two points; but what then would the structure of space look like?  Would it be a lattice, where each point of space, planck length apart on each axis, forms the 3 dimensional space, and space is absolute? Or is it literally just the limiting distance between two arbitrary points? Thoughts?


How can I remove the write-protection from a USB?

I'm looking to remove the write-protection from a USB drive and have done everything I found on the internet. Some examples of what I have done are:  Tried to format it by right-clicking the icon through file explorer and clicking format then ok and by using diskmgmt.msc  Used diskpart, attempted to change it via properties  edit the registry (the key wasn't there)   None of these methods worked. My USB drive is one of the "2 TB" USB (I know, it was probably one of those fake ones from China considering the price I paid was under $20). This has been going on ever since the middle of an h2testw scan to check the real amount of storage. I am currently running on windows 10.0.18363.1016


$request = '/test.php?action=save&key=e7s2uHhKKtcM32cHKUKM&login=test'; $param = preg_match("#^test.php?action=save&key=(\w+)&login=(\w+)($)#", $request, $match); print_r($param);   It's not working. How to fix?


Programmatically align a toolbar on top of the iPhone keyboard

In several cases I want to add a toolbar to the top of the iPhone keyboard (as in iPhone Safari when you're navigating form elements, for example).    Currently I am specifying the toolbar's rectangle with constants but because other elements of the interface are in flux - toolbars and nav bars at the top of the screen - every time we make a minor interface change, the toolbar goes out of alignment.  Is there a way to programmatically determine the position of the keyboard in relation to the current view?


Where do you place words such as certainly, surely in a sentence?

I struggle constantly or is it I constantly struggle with the usage of such words. I don't even what they are called in English grammar.   My question: how do I know whether I'm grammatically correct when using such words?  Examples: Is it      I certainly will complete the report   or      I will certainly complete the report   Is it     I struggle constantly with English   or     I constantly struggle with English   Is it     Am I grammatically correct?   or     Am I correct grammatically?   I hope you get the idea.


Why import by filename is not supported?

I want to import all python modules in a directory in python, and came across this snippet:  for name in os.listdir("modules"):     if name.endswith(".py"):         module = name[:-3]   # remove extension name for convenience.         globals()[module] = __import__(os.path.join("modules", name))   program outputs:  ImportError: Import by filename is not supported.  How to I import file by filename?


Changing data type in ArcGIS attribute table?

How can I change the data type in an attribute table in ArcGIS for multiple fields?    For example, if the fields have been exported as a string from Excel, and I would like to use them as numerical values?


Sum of Harmonic series: $ 1+\frac {1}{2}+\frac {1}{3} + \frac {1}{4} + \cdots + \frac {1}{50}$

How to find the sum of this series : $ 1+\frac {1}{2}+\frac {1}{3} + \frac {1}{4} + \cdots + \frac {1}{50}$


Gravitational field intensity inside a hollow sphere

It is quite easy to derive the gravitational field intensity at a point within a hollow sphere. However, the result is quite surprising. The field intensity at any point within a hollow sphere is zero.   What exactly is the reason behind this? Except for, of course, the mathematics behind it. Is there any logic why the field intensity should be zero within a sphere? For example, it is logical to say that the field intensity would be zero at the center, as all the intensities cancel out. However, this cannot be the case for any point within the sphere.


So, Im working in a UNIX environment and I noticed that inside my working directory, which is miles miles away from my UNIX home, there is a ~.  Now, once in the past, I did rm -rf ~ from my working directory and ended up erasing my home directory completely and had to involve IT.  I do not want to do it again. At the same time, I want to know   Why is ~ created in my working directory? Is it a faulty finger slip while saving (:w! but what happens is :w~ ?!!) Before checking in, there is a script that looks for extra files or folders that p4 is not aware so def this ~ might cause an issue. So how can I remove the ~ from my working directory and at the same time not erase my home?   I do have a backup command called del that I use instead of rm -rf. It just places stuff in a temporary location. I could use that and get rid of the ~. But I'm more interested in knowing why this happens, and how I can remove it?


How is it that each probability in a normal distribution occurs with the same frequency?

I recently noticed that if you generate 10000 normally distributed numbers and then find the probability associated with each number (pnorm), each probability from 0 to 1 occurs with approximately the same frequency. Here's how I did it in R: var2 <- numeric(10000) normnos <- rnorm(10000) for (i in 1:10000) {   var2[i] <- pnorm(normnos[i]) } hist(var2)   How is this possible? If all probabilities have equal likelihood of occurring, then wouldn't the resulting distribution be uniform instead of normal? I'm really confused and would appreciate an explanation.


Creating Event Listeners for individual DIVS that have not been made yet, and how to trigger the individual command?

I am trying to create clickable divs that will set a variable once they are clicked.  For example,  If my program had to do with playing with balls.  When a user inputs a name, and what kind of ball they want (lets say name= Johnny and Ball=BasketBall) and then clicks "Create a Ball", My program will create a div called "Ball0". The "Ball0" div will display Johnny's name. When a user Clicks on his name it will say "Johnny has a BasketBall.  Here is how I am trying to do this code  var ballRefrence = -1;  function createBall() {     ballRefrence +=1;     var myElement = document.createElement('div');     myElement.id = 'individualBall'+ballRefrence;     ballArea.appendChild(myElement);//ball area is where I want to list the divs     myElement.style.width = "550px";     myElement.innerHTML= userName+" has bought a ball!";      createEventListner(); }   function createEventListner() {     var iBall = document.getElementById("individualBall"+ballRefrence);     iball.addEventListener("click",showBall,false); }   function playCaption() {     //I am not sure how to pull the individual up here.      //Since I am using the "BallRefrence"variable     //it will always be the last person clicked..     //(Basically I cannot say      //alert.(ballRefrence); }   I guess what I am trying to say is this,  I have my "BallRefrence" that goes up by 1 each time. I store all the items in an array. (so first person will go to index 0, second will go to index 1...ect) I am having problems refrencing the element, because I am not sure how to pull the corrisponding numbe from the div.  Example: After 3 clicks of "create ball" my html will look something like this.

   Since each individual div will match up to the element in the array I want, How will tell my program  "When you click individualBall0, I want ball[0].." or "when you click indivdualBall2, I want ball[2]"  I hope this makes more sense.


I want to use Danish chars on my database (MySqli)  Normally this is not an issue, and i have been running my code with no problem at all. When i recently changed to Unoeuro there was nothing that worked - Same code, same DB, nothing has changed but the hosting service.   Here is how i connect to the database      <? $conn=mysqli_connect("MyHost","MyUser","MyPass","MyDB"); // Check connection if (mysqli_connect_errno())   {   echo "Failed to connect to MySQL: " . mysqli_connect_error();   }   mysqli_set_charset($conn,"utf8");  ?>   The connection to the databse works perfect, but when i send a Danish charto the DB, it changes to another unknown char.   Here is an example of my page that sends data to the mysqli:      <html> <head>   <meta charset="UTF-8"> </head> <body> <? include "config.php"; //The Database connection  /* Here are a lot of variables, not important in this question */  mysqli_query($con,"INSERT INTO WaterWithdrawalLog (XUserID, Location, antalLiter,chipId,note) VALUES('$xuid','$location','$MinusAntalLiter','$usrid','".$_GET["note"]."')"); ?>   The Database is set to UTF8_danish_ci  How to i get the Danish chars to show propperly in my database ??


Running more than one Firefox Profile at once?

Firefox can run in different profiles, that can be setup using different plugins, for different purposes such as basic web browsing, web development, trading on ebay etc...  Is it possible to run more than one of these at a time, or does Firefox always run as a singleton?


I just installed a Ubuntu 11.10 box and I'm trying to figure out how to set the timezone to UTC. I have it set to London at the moment, but UTC doesn't appear to be an option.  Help?


At HTML form tag why should I use GET method instead of POST?

I was studying HTML and I saw that when someone is making a form the safest method is POST. So why someone should choose GET method? And when we choose GET or POST method?


What if client doesn't like any logo design concept?

I'm in a process of creating Graphic Design contract. I've decided to provide each client with 3 logo concepts and 3 rounds of revision. Ideally, I would create 3 concepts and client will chose one, but it happend to me before that client didn't like and concept and I end up with doing 10+ more (yes, I've worked without contract).  How can I prevent this situation? Should I charge hourly for each new concept separately? How can I express my thoughts clearly in a contract (without sounding like 'if you don't like any, you'd have to pay more)? I don't want to scare client and put thoughts into their minds saying that there is a possibility that they won't like me ideas.


I had recently installed ubuntu 14.04.2 LTS using the option replace windows xp using ubuntu. So all my partitions lost. But i had the very important contents and backups please help me how to retrieve the deleted partition. Pls help me.  its in my Office so pls help me guys.


I am new to Ubuntu. I can find my error log here in var/log/apache2/error.log. but i couldn't clear it. i tried to change the permission to edit the content. But couldn't achieve it.   Please help me to remove it. I have read some question previously asked. but it does-not help me .  this one I read .   Here is my terminal screen-shot:


Center absolute div inside relative parent with dynamic width

I need to center(left to right) absolute elements(green) inside a relative container(blue). The child elements(green) need to have a dynamic/unset width. I would rather not use JavaScript(CSS and html only).  Code:   .relativeParent {   width: 100px;   height: 100px;   background: blue;   position: relative;   overflow: visible;   display: block;   margin-left: 100px;   margin-bottom: 20px; }  .absoluteChild {   display: block;   background: green;   position: absolute; }

test

asd asdf asdf asdf asdfa sdf


Removed operating system blank screen with flashing underscore

I recently used DBAN boot and nuke to completely wipe a PC I was planning on giving away. I now want to install Ubuntu on it before I hand it over. I've wrote the iso to a usb however when I set the correct BIOS settings I just get a flashing underscore.   If I don't put in the USB I simply get the message 'no operating system found'. Can anyone help?


I want to examine the convergence of $(1-\frac{1}{kn})^n$ for $k\in\mathbb{N}$. My intuition is that for $k=1$, the sequence converges towards $1/e$ and for all other value for $k$, it should converge towards $0$. I'm just unsure about how to prove this.


Does the phrase 'little too' mean same as 'very', or is it mild form of very ? For instance, I am little too comfortable talking to you. Does it mean same as 'I am very comfortable talking to you' ?


Let $E$ be a measurable set of finite measure and $1\leq a<b<\infty$. Consider the $L^b(E)$ space normed by $L^a$ norm. Is this space a Banach space?  I think this is wrong, so I tried to find a counterexample but it is hard to find one...


Do all planets have an electric charge?   If yes, is positive or negative?  And how much each magnitude?   I have read some articles which really confused me. Some of these articles said that all planets have a negative charge and the sun has a positive charge. Some other articles said the the exact opposite.


I am repairing an iMac 27" , late 2009 model (EMC 2374), 2.8 gHZ.  It has a bad video card causing stripes on the screen and problems booting.  The video card is an AMD ATI Radeon HD 4850 Video Card.   This model is very hard to find and very expensive.  Does anyone know of any other compatible video cards for this model apple machine?  thanks


Was Gandalf's fight against Balrog a violation of "Inspire but don't fight instead of Men" rule?

As was , it is known that Istari were meant to inspire and guide the mortals of Middle Earth in the fight against Sauron.  Does the fight against Balrog in Moria violate that "rule"/"guideline"?  If so, why did Eru restore Gandalf back to life after?  If not, is there a canon confirmation that it was NOT against the rules (aside from circumstantial evidence I noted, namely that Gandalf was restored, promoted and given seemingly greater powers; instead of being punished/demoted)?  I'm guessing it was within the rules since Balrog was a servant of Melkor, not Sauron; and Istari's limitations were on fighting Sauron directly, but at the moment it's a guess not backed up by canon sources.


Why do we build the final model on the full data instead of just the training set?

I am going through the ISLR book (by Hastie, et al.). In the chapter on model validation, the author suggests that we build the final model on the full data instead of the training data only. The way I always understood the process is that we build the model on training set, validate it with test set and finalize the model. If we use the full data to build the model then what is the point of anything that we did before that step? Thank you!


While trying to update (by editing) my answer, I accidentally edited another answer and submitted the edit. A message told me that the edit wouldn't be visible until it was peer reviewed.  How  can I revoke the edit I made?


Prove $a \equiv b \pmod{c} \implies a^n \equiv b^n \pmod{c}$.   Here is my proof, which I'm slightly doubtful I've done correctly:  Suppose  $a \equiv b \pmod{c}$ and $d \equiv e \pmod{c}$  We have:  $a-b=ck$ and $d-e=cs$  $a=ck+b$ and $d=cs+e$  And hence:  $$ad=(cs+e)(ck+b)=c^2sk+cab+eck+eb$$  $$=c(csk+ab+eck)+eb$$  Therefore,   $$ad-eb=cn$$  $$ad \equiv eb \pmod{c}$$  The special case $d=a^{n-1}$ and $e=b^{n-1}$ through induction is reduced to:  $$a^n \equiv b^n \pmod{c}$$  For $n \geq 1$  Induction:  If $n=1$, then by the proof above  $a=b \pmod{c}$  implies $a^2=b^2 \pmod{c}$. Assume that $a^{n-1}=b^{n-1} \pmod {c}$ is true, then we have  by the proof above: $a^{n}=b^{n} \pmod{c}$. Hence because we proved $a^{2}=b^{2} \pmod{c}$,  $a^{3}=b^{3} \pmod{c}$. And because of this $a^{4}=b^{4} \pmod{c}$. And because of this $a^{5}=b^{5} \pmod{c}$. Etc..  Is my proof valid? Because this question is more of a yes or no one, a different proof would also a nice supplement to the answer (or just  a nice answer) if you wish to provide one.


Pairwise independence of three events does not imply their mutual independence.How?

I am acquinted with the independent event derived from the the conditional probability.But In my book I read that mutual independence always imply pairwise independence but the converse is not always true.But I find difficulty when I was trying to find out an example to understand the matter well.Please give a suitable example which will meet my purpose.Thank you in advance.


Correct location for piping and redirecting output in find -exec?

I'm using find with the -exec option in console, on FreeBSD (for example, find . -exec sha1 {} \;).   How do I correctly place (and if needed, escape) redirect and other execution control symbols that could syntactically apply to either of the exec command or the find command, such as > >> | and &, where I might want the symbol to apply to the find or the exec commands on different occasions?  On the same theme, what is the syntax if I want to use tee to view the output of the -exec commands on the console (to watch progress) and also appended to a file (for later use)?   (I know shells vary but hopefully the most used shells such as sh/csh are quite similar?)  Update:  In part, I want to learn if nested find -exec can be done without scripting, as a simple command. Here is the use-case that prompted the questio :   outer find: find all subdirs matching DIR_MATCH_TEXT in DIR1  inner find: for each matching subdir found in the outer loop (call it DIR2), execute the commandfind DIR2 -name "FILE_MATCH_TEXT" -exec sha1 {} \; >> DIR1/DIR2_hashes.txt   The aim being to create a set of files, one for each matching subdir, containing the output of some find -exec action on that subdir.  By this I mean that, if /backups contains /jan2017 and /feb2017, the result will be two files at /backups/jan2017_hashes.txt and /backups/feb2017_hashes.txt, with jan2017_hashes.txt containing the output from sha1 for (say) all .pdf files in /backups/jan2017, and feb2017_hashes.txt containing the output from sha1 for all .pdf files in /backups/feb2017.  From replies so far I gather the outer find would have to use a shell call as the argument to -exec?


Proof: If no prime less than or equal to $\sqrt{n}$ divides $n$, then $n$ is a prime

I have the following theorem:  If no prime less than or equal to $\sqrt{n}$ divides $n$, then $n$ is a prime.  And the following proof (proof by contradiction) for said theorem:  Suppose that no prime less than or equal to $\sqrt{n}$ divides $n$ but $n = ab$, with neither $a$ nor $b$ equal to $1$. Now $a$ and $b$ cannot both be strictly larger than $\sqrt{n}$ or their product would be larger than $n$. So one of $a$ or $b$ is not larger than $\sqrt{n}$: assume (without loss of generality) that $a \le \sqrt{n}$. Now $a$ cannot be prime (as we have assumed $n$ has no prime factor this small), and so is composite. Therefore $a$ has a prime factor $p$, which must be less than $a$. But then $p < a \le \sqrt{n}$ is a prime factor of $n$, and this contradicts our hypothesis. Hence $n$ is prime.  We deduce that $a$ is composite. But why does this then mean that $a$ has a prime factor $p$? So this is saying that all composite numbers have a prime factor? Why? I would greatly appreciate it if people could please take the time to clarify this. PostScript: I am assuming that  is the definition of composite number being used here.


I am not sure if it is the same as  and  but I am trying to set up the following mydomain.com is managed by a provider like IONOS or Dyn.com which does not provide an API for creating and managing records with Terraform.  Since we have several records there already, I don't want to switch everything to Route53 all at once. What I want to do is set up such that tenants.mydomain.com and *.tenants.mydomain.com is managed by Route53 but I only want to manually configure tenants.mydomain.com on the existing provider once. The instructions  does it for each subdomain.  However, it does not say whether it can handle the sub-subdomains. (Just trying it out right now, but learning on how to set up Route 53 right now so I am not sure if it would work). UPDATE: doing the steps for   allows me to set up the sub-subdomain records and works well with Terraform


Enumerate alignment problem in theorem environment

I'm using amsart. When I create an enumeration inside a theorem environment, the numbering is not aligned properly:  Theorem 14. (1) (2) (3) (4)   How do I shift the (2),(3),... to be aligned with (1)?  MWE:  \documentclass{amsart} \newtheorem{thm}{Theorem}[section]  \begin{document} \begin{thm} \begin{enumerate} \item Item 1 \item Item 2 \item Item 3 \end{enumerate} \end{thm} \end{document}


Where would I ask a question about phone service technology?

I had a question about why phone companies are  with unlimited data (whether there is actually a physical limit on how much data they send over their network), but I can't figure out where on Stack Exchange I would ask it.  Is there even a site for it right now? If so, which one? If not, what should I call the area51 proposal that I would start?


Which of the following sentences are correct?  Calves require less medication and gain weight quicker than that those raised in consignment.  Calves require less medication and gain weight more quickly than that those raised in consignment.


This is my first time using this site, so sorry if I do anything incorrect. I am asking this here because I couldn't find any relevant answers to my question here or elsewhere on the web. If anyone knows a webpage that has a detailed overview of this process, I would appreciate it if you could link me to it. Anyways, on to the question.  I am trying to find a general equation to determine how many permutations p exist for a set of marbles M if you select m at a time. For instance, for a set M comprising of 1 blue marble, 1 green marble, and 2 red marbles, each of which is indistinguishable aside from color, there are 12 distinct permutations p if you take the marbles $m = 3$ at a time. I am wondering if there is an equation that gives you p for any set M and any selection m. I know that the number of permutations of M with length\size L is $\frac{L!}{1!1!2!}$ if $m = L$, but what if $m \lt L$?  I have found some equations on my own that work, but only for certain sets M. One equation I have found is: $$p = \sum_{i=0}^k C_i^m \cdot P_{m-i}^{n-1}$$ $$\text{or}$$ $$p = \sum_{i=0}^k \binom{m}{i} \cdot \binom{n-1}{m-i} \cdot (m-i)$$ with n being the number of colors that exist in set M and k being the largest amount of marbles per color in M. However, this only works if all the marbles are different colors except for one color.  I was also able to develop another equation for M of type {0,1,2,2,3,3} (with the different numbers representing colors), where there are 2 colors with 2 marbles a-piece and all the other colors have only one marble: $$p = P_m^n + 2 \cdot C_2^m \cdot P_{m-2}^{n-1} + C_2^m \cdot C_2^{m-2} \cdot P_{m-4}^{n-2}$$ $$\text{or}$$ $$p = m \cdot \binom{n}{m} + 2 \cdot \binom{m}{2} \cdot \binom{n-1}{m-2} \cdot (m-2) + \binom{m}{2} \cdot \binom{m-2}{2} \cdot \binom{n-2}{m-4} \cdot (m-4)$$  Unfortunately that's about as far as I was able to get. I couldn't find any solid unifying equation much past that. If anyone has any ideas or knows the full equation, please share. I would be very grateful to be enlightened about this. Thanks!


The question is as follows:  Let $G$ be a finite and abelian group that satisfies $$\#\{g\in G\,\vert\, g^p=e\}\leq p$$ for all $p\in\mathbb{N}$, where $e$ is the identity element in $G$. Prove that $G$ is a cyclic group.  It doesn't seem difficult, but I have hit a wall and I don't know where to start. Any help or hit would be highly appreciated!


Mahalanobis distance to detect multivariate outliers

I have to detect outliers on 3 variables. On the internet I found the mahalanobis distance but I understood I can use it only on multivariate normally distributed data, and my data isn't. So, do you have any suggestions? And, for you is a correct way detect univariate outliers first, then bivariate and then trivariate outliers? Thanks in advance for any suggestions :)


What is this line on water? What causes this difference in appearance? I often see it on lakes. Not sure if it appears in the sea too.


How to save a random string from a list of strings?

How do I save a random string from a list so I can recall the exact thing later in the code? For example:  name = ['Hans', 'Peter', 'Eliza'] print('Your name is ' + random(name) + '!') print(name)   What can I use here in place of random(name), and how can I save it?


IEEE Transaction on Circuits and Systems Review Process

I submitted a journal paper to IEEE Transaction on Circuits and Systems for Video Technology on June 12th. Today, after 40 days, I checked its status and it went from "In Peer Review" to "Awaiting Recommendation". What does "Awaiting Recommendation" mean? Also, Considering that it usually takes the review process about 100 days to finish, should I expect the manuscript to be rejected?  Thanks


Independent coloring of contour and 3D plot in pgfplots

I have a problem with pgfplots where the addition of a contour plot at the bottom of a 3D plot changes the coloring of the surface plot. This is a simple example:  \documentclass[preview=true]{standalone} \usepackage{pgfplots} \usepackage{tikz} \begin{document}  \def\zmin{-6} \def\zmax{8}  \begin{tikzpicture}       \begin{axis}              [                  zmin=\zmin,                  zmax=\zmax,              ]              \addplot3[                  contour gnuplot={                      output point meta=rawz,                      number=20,                      labels=false,                  },                  domain=-5:5,                  y domain=-5:5,                  samples=20,                  z filter/.code=\def\pgfmathresult{\zmin}              ]              {%                  min(x+y, \zmax)              };              \addplot3[                  surf,                  samples=20,                  domain=-5:5,                  y domain=-5:5              ]              {%                  max(min(x+y, \zmax), 0)              };         \end{axis}     \end{tikzpicture} \end{document}   This example turns out like this:   Without the contour, the resulting image is:   What I would like to have is an image with the contourplot, but using the coloring of the surfplot as it is shown in the image without the contourplot. Any help is greatly appreciated.


What are the fastest vehicles, and where or how can I get them?

For the different vehicle categories, what are the fastest? And where or how can I get them?   Since fully upgrading a vehicle costs a lot of money, it would be nice to know which vehicles are the fastest, so I could focus all upgrades on that particular vehicle.


Just curious but are there any two words (possibly three in a tri-relationship) in the English language that define themselves with the other, therefore being subjected to a definition paradox? (They have to have no other meanings besides the other word.)  e.g.  (Not really a legit example, but what I am looking for) Compassion: The act of having pity. Pity: The act of having compassion.


How do I remove a large file from an unsynced commit when that commit is 5+ commits ago?

As with all Git questions, I'm sure this has been answered a dozen times before, but I haven't been able to find my special snowflake twin, so thanks for the patience.  Here's the rub: 5 commits ago, I accidentally added a large file, around 500 megs, and didn't realize it. Now when I go to push to GitHub, I get an error about the 100meg limit and the push fails.   Most fixes to this concern the most recent commit- How do I tell git to just forget about that 500 meg file from 5 commits ago?


Regex and Javascript : find word with accents

I try to find and stock in HTML paragraphe all the word.  Actually, I have a function like this  p.html(function(index, oldHtml) { return oldHtml.replace(/\b(\w+?)\b/g, '<span>$1</span>'); });   But it's only return word without accent. I test on regex101.com   Any idea ?


Are there any risks to manually flashing a stock or custom ROM?   Does it have the potential to brick the device? Will it void my warranty? Will I stop getting updates? Anything else I should be aware of?   (See also: )


How to show that $\bigcup_{n \in \mathbb{N}} \{ \frac{k}{2^n} : 1 \leq k \leq 2^n \}$ is dense in $\mathbb{Q} \cap [0,1]$?

I want to show that some subsets of the rationals are dense in $[0,1]$. Right now I have the set $$P =\bigcup_{n \in \mathbb{N}} \{ \frac{k}{2^n} : 1 \leq k \leq 2^n \}$$ If I can show that this is dense in $\mathbb{Q} \cap [0,1]$ then I'm done since $\mathbb{Q} \cap [0,1]$ is dense in $[0,1]$. I want to find a sequence $(x_n)_n \subset P$ which converges to an element $\frac{p}{q} \in \mathbb{Q} \cap [0,1]$.


Removing video streaming audio device from my Mac

Recently I installed ScreenFlow app and then I found this thing called "video streaming audio device " in my audio selection and it screws everything up. Sometimes I can't hear people and sometimes they can't hear me. I am trying to get rid of it but nothing has worked.  So far I have tired:   removing the ScreenFlow app. removing "video streaming audio device " from Audio MIDI Setup app but (but the - sign is disabled.    Any help?


I recently switched my CentOS 7 machine from Apache to nginx, and I am running into some issues getting my machine properly functioning. I recently installed a new server block into the system with the following configuration:  server {     listen       80;     server_name  example.com;     root         /usr/share/nginx/example.com/public_html;      access_log   example.com/logs/example.com_access.log;     error_log    example.com/logs/example.com_error.log crit;      location / {         index  index.html index.htm;     } }   However, whenever I go to the homepage (e.g. example.com), I am given a 403 error on the page. Additionally, I've noted that I get the same result whenever I add anything to one of my already existing server blocks that I imported from Apache virtual hosts. The files I imported originally work as expected, but whenever I write new content, I also get a 403 error on those pages.  The owner and group of the public web directory is myuser:nginx (I want to edit files as part of the group nginx, but that's already in ). The public web root has had chmod -R 755 run on it as well.  I am confused about where to proceed or how to debug this further. What could be causing the issue?


Is Middle-Earth a time, or is it a place?

I was looking at the map of Middle-Earth and it made me wonder. Does Middle-Earth refer to the time frame in which the LOTR stories took place, or does it refer to the area in which the LOTR tales unfold? To help clarify what I'm asking: Is the rest of Tolkiens' unmapped world Middle-Earth too, or is Middle-Earth the era?


How to tell cleveref to use the correct label type

I'm trying to use cleveref to reference some figures, but it is incorrectly labelling them as sections. (i.e. It will say something like Section 5.12 instead of Figure 5.1 in the text)  I'm also using hyperref to make the links, which might be confusing cleveref?  My code looks something like this:  \usepackage[pdftex,letterpaper=true,pagebackref=false]{hyperref} \usepackage{cleveref} % A bunch of hopefully unrelated stuff in between  Some text here \Cref{fig:first,fig:second,fig:third}.  \begin{figure}\label{fig:first} \centering \includegraphics[width=0.45\textwidth]{./figures/first.png} \caption{First Caption} \end{figure}  \begin{figure}\label{fig:second} \centering \includegraphics[width=0.45\textwidth]{./figures/second.png} \caption{Second Caption} \end{figure}  \begin{figure}\label{fig:third} \centering \includegraphics[width=0.45\textwidth]{./figures/third.png} \caption{Third Caption} \end{figure}   Any idea what could be causing the problem? Alternatively, is there to use just hyperref to reference multiple figures at once? What I want to be able to do is have a reference that looks like: Figures 5.1-5.4 but I couldn't find a way to do that with just hyperref, so I tried using cleveref, and instead it is giving me Sections 5.12 to 5.12 for the same set of labels.


Show that if any continuous real-valued function on a metric space $X$ attains its maximum value, then $X$ is totally bounded.  So, want to show that for every $\epsilon > 0$ there exists a finite subset $\{x_1,...,x_n\}$ of $X$ s.t. $X\subset\cup_{k=1}^nB(x_k,\epsilon)$. I'm thinking to prove it using contrapositive, that if $X$ is not totally bounded then there exists a continuous real valued function on $X$ that is unbounded above, but I'm stuck!! Any help would be appreciated.


"Neither of us are" -vs- "Neither one of us is"

This cartoon was recently posted on Facebook. My sister (who is a retired HS English teacher) says the grammar is wrong and that the correct wording should be: "Neither one of us is." but I disagree.   I am not an English teacher but I believe that "US" relates to "WE" and the correct wording for that pronoun is "WE ARE". On the other hand "ONE OF US" relates to "I" and "YOU" but the correct wording for those pronouns would be "I AM" or "YOU ARE" ... There absolutely is no place in English where we correctly use "I IS", "YOU IS", or "WE IS" so why would "US IS" be correct?


How to stop the terminal from wrapping lines

Is there a way to tell the terminal not to wrap long lines. I wish to see a line in the same space without wrapping to the next one. I do not care if I can not see the end of the line just as long as the line stays in one. A horizontal scroll would be good for this also but for the moment the removal of the wrapping is what I need.


When using the metropolis theme for beamer, I get text and math in Fira Sans, except for math operators. I compile the following MWE using LuaTeX.  \documentclass{beamer}  \usetheme{metropolis}  \begin{document}    \begin{frame}     Ordinary text.     \[ a^2 + b^2 = \sin^2(x) - \mathsf{y} + \mathrm{z}  \]   \end{frame}  \end{document}   The outcome for me is that a, b, 2 and x are set in Fira Sans Light Italic, and y is set in Fira Sans Light, but sin is set in the sans font of (I guess) Latin Modern. (The z is also in Latin Modern, but this is expected behaviour from beamer.)  Unsurprisingly, I get the same result if I replace \usetheme{metropolis} with  \usepackage[no-math]{fontspec} \setsansfont[ItalicFont={Fira Sans Light Italic},   BoldFont={Fira Sans},   BoldItalicFont={Fira Sans Italic}]%   {Fira Sans Light}   I guess that this is to do with beamer's patching parts of the math fonts to match the text font (see ). However, I don't understand the font system well enough to modify this.  There was , but I've no idea how to apply that answer when using fontspec, or if this is even possible.  Is there a way to change the operator font to match the upright/sans math font (i.e., Fira Sans Light)?


How to set up htaccess to transfer from http to https?

This is my .htaccess - site does redirect to HTTPS but still gives: Your connection to the site is encrypted, but Google Chrome has detected mixed content on the page.  How to avoid this? Thank you.  # BEGIN WordPress <IfModule mod_rewrite.c> RewriteEngine On RewriteBase / RewriteRule ^index\.php$ - [L] RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule . /index.php [L] RewriteEngine On  RewriteCond %{SERVER_PORT} 80  RewriteRule ^(.*)$ https://www.example.com/$1 [R=301,L] </IfModule>


Show that $\frac{xy}{z} + \frac{xz}{y} + \frac{yz}{x} \geq x+y+z $ by considering homogeneity

Well, I'm preparing for an undergrad competition that is held in April and because of that I've been trying to solve the inequalities I find on the internet. I found this problem: $$\displaystyle  \frac{xy}{z} + \frac{xz}{y} + \frac{yz}{x} \geq x+y+z \text{ for all }  x,y,z \in \mathbb{R^+}$$  It's easy to show that this inequality holds by applying the AM-GM inequality three times like the following:  $$ \frac{xy}{z} + \frac{xz}{y} \geq 2 \sqrt{\frac{xy}{z} \cdot\frac{xz}{y}} = 2x$$ $$ \frac{xy}{z} + \frac{yz}{x} \geq 2 \sqrt{\frac{xy}{z} \cdot\frac{yz}{x}} = 2y$$ $$ \frac{zy}{x} + \frac{xz}{y} \geq 2 \sqrt{\frac{zy}{x} \cdot\frac{xz}{y}} = 2z$$  Then summing these inequalities and canceling a factor of $2$ at the end will give us the desired inequality.  But if you look at the problem from another point of view, if we substitute $x'=\lambda x$, $y'=\lambda y$ and $z' = \lambda z$ the inequality stays the same. So, I was wondering if there could be another way of solving this inequality and the inequalities that are homogenous like this one in a more systematic way that could be applied to a broader range of problems.  I decided to add a constraint $x^2+y^2+z^2=1$ to the problem because the inequality in the problem could be thought of as a function in the three variables $x,y,z$ in $\mathbb{R}^3$. So, it's sufficient to study this function on the unit sphere because homogeneity allows us to define it for other points of $\mathbb{R}^3$, but I have no idea how this could lead me anywhere.


Why is the sum of outer products equal to the matrix product of a matrix and its transpose , so $A^TA = \sum_{i=1}^n a_i a_i^T$?

Why is the sum of outer products equal to the matrix product of a matrix and its transpose? So $A^TA = \sum_{i=1}^n a_i a_i^T$, where $A = [ a_0, a_1 , ... , a_n ] $, $a_i \in \mathbb{R}^k$. An answer or a link to the answer would be greatly appriciated. It seems so simple but I just cannot figure it out.  It is essentially this question of which I do not understand the answer:


Looking for old book, SF, artificial world, different zones for different species that visitors "inhabit"

I read this book at least ten years ago.  Any help identifying it would be appreciated.  Characters are teleported to an artificial world where each take over the mind of a different species.  I remember a moving sentient plant, a faun-like character, and a wasp-like character.  The planet is subdivided into different zones designed for each species.  One of the characters had long sharp fingernails with poison in them.  Thanks for any help, steve


How to find $\left|\operatorname{Aut}(\mathbb Z_2\times\mathbb Z_2)\right|$

How to find $\left|\operatorname{Aut}(\mathbb Z_2\times\mathbb Z_2)\right|=?$  Since $\mathbb Z_2\times\mathbb Z_2$ has 4 elements, $1 \leq \left|\operatorname{Aut}(\mathbb Z_2\times\mathbb Z_2)\right|\leq \left|S_4\right|$.  How to proceed further?  Thanks in advance...


Exceeding the speed of light using gravity?

From what I have learned, objects must accelerate as they approach a heavy mass. But I also know that they cannot travel faster than the speed of light.   What if you had a proton travelling at .99999c towards a heavy object? Would it have to keep accelerating or would the acceleration of the proton slow down to zero and only it's mass would increase?   Edit: If the latter is true, then why do we describe a gravitational field by its effect on velocity? (i.e. Earth's gravitational field is always described as 9.8m/s^2). Shouldn't it be described by its effect on momentum?


How can there be instantaneous rate of change?

To find rate of change you need two instants.  how is the rate of change calculated at a particular instant when at least two instants are needed to find it?


After I press ctrl + alt + f4 the virtual terminal appears but I can't exit anymore because it is always back to "input username" and "password". Any idea how to go back to my desktop?


Can $\pi$ or $e$ be a root of a polynomial with algebraic coefficients?

Since $\pi$ and $e$ are transcendental, neither can be the root of a polynomial with rational coefficients. However, it is easy to construct a polynomial transcendental coefficients (with $\pi$ or $e$ as one of it's roots), namely $(x-\pi)$ and $(x-e)$. However, is it possible to construct a finite polynomial (one of whose roots is $\pi$ or $e$) with only algebraic coefficients? (i.e. something such as $y=x^5-(\sqrt 2 -1)x^2+x$ .) A polynomial with only radical coefficients would be the best.  P.S. The polynomial doesn't necessarily need to have BOTH $\pi$ and $e$ as it's roots, just one is interesting enough.


How to directly run the examples of "man" for a particular function

man function are best way for learning new information in Ubuntu. They are the most extensive source possible. Every man has a section of **Example (in majority of cases),my query is on ways to use it without opening man and then copy-pasting the lines. Let me elaborate further below.   Suppose I am wishing to learn about the find function. I type  man find   My query is  I wish to directly run the example section of the man so that I can get a practical understanding on seeing outputs. How to directly run the examples of the man in terminal quickly?  In the above example of man find, the example codes were  EXAMPLES        find /tmp -name core -type f -print | xargs /bin/rm -f         Find files named core in or below the directory /tmp and delete them.  Note that this will work incorrectly if there are any filenames containing newlines, single or double quotes, or spaces.         find /tmp -name core -type f -print0 | xargs -0 /bin/rm -f         Find files named core in or below the directory /tmp and delete them, processing filenames in such a way that file or directory names containing single or double quotes,  spaces  or  newlines        are correctly handled.  The -name test comes before the -type test in order to avoid having to call stat(2) on every file.         find . -type f -exec file '{}' \;         Runs  `file'  on every file in or below the current directory.  Notice that the braces are enclosed in single quote marks to protect them from interpretation as shell script punctuation.  The        semicolon is similarly protected by the use of a backslash, though single quotes could have been used in that case also.    One of the solution on way to just view the example directly in terminal (which I could think off) is   man find | grep -i "example" -C 2    Ofcourse, this did not take me to the example section and in turn help me in running it


Splitting strings on an nth character in Python

I would like to know how to slice my Python string every nth character/letter (in my case the 5th character/letter).   So I have this string "ilikestackoverflow" and I would like for the output to be "ilike stack overf low".


What are Non-Community Wikis in Stack Exchange and why is it named so?

I am really curious to know about the differences in the names of Community Wiki and Non-Community Wiki prevailing in Stack Exchange.  As I have known about what a Community Wiki is pretty much, I just specifically want to know the existence of Non-community wiki.   What is the reason behind its existence? What is the advantage that I get from it?   I have seen the term Non-Community wiki in the Badges area.  Bronze Badge -  You must have a total score of 100 in at least 20 non-community wiki answers to achieve this badge.   Silver Badge - You must have a total score of 400 in at least 80 non-community wiki answers to achieve this badge.   Gold Badge -  You must have a total score of 1000 in at least 200 non-community wiki answers to achieve this badge.  Hence so curious.


Flying to, but not entering, Turkey without passport

I am a Swedish citizen and will fly to Saudi Arabia (with approproate visa) shortly. My route is as follows; Gothenburg-Istanbul and Istanbul-Riyadh (GOT-IST-RUH). On the flight IST-RUH, I will be travelling with my mother flying from Stockholm (ARN-IST-RUH). We both fly with, and have booked our tickets at Turkish Airlines.  My question now is, can I travel to IST without my passport, meet with my mother in the international area of the terminal (provided that we end up in the same arrival terminal), receive my passport who my mother (who may pick it up from the visa application center) and give it to me for the continued travel.  In short; can I enter the terminal without passport, or do I need a passport already before entering the airport in Turkey?


I stupidly disrupted the process of installing MPEG-4 AAC decoder and the H.264 decoder. Now whenever I try to use sudo apt upgrade  I get this. Waiting for cache lock: Could not get lock /var/lib/dpkg/lock-frontend. It is held by process 18442  How do I continue process 18442?


Is there a command to create multiple ZIP files based on file size? So that in a folder of 600 files, totalling 1 GB, the command will create 4 zips roughly equal to 250mb.  There's a similar command . But it ZIPs files according to a file number limit.  I also don't want the resulting zip files to be connected with each other, so that I can open them individually and won't need to open all of them at the same time.


I'm having an issue trying to disable SSLv3 on my nginx installation.  HTTPS works fine, but I just can't seem to disable SSLv3 and it makes my site vulnerable to the POODLE attack. Also, for some reason the connection is encrypted over 128-bit instead of 256-bit even though I got a 256-bit certificate.  Nginx version: 1.6.2  Here's what I entered into my server block on the site I wanted to use:  ssl_protocols TLSv1 TLSv1.1 TLSv1.2; ssl_prefer_server_ciphers On; ssl_ciphers ECDH+AESGCM:DH+AESGCM:ECDH+AES256:DH+AES256:ECDH+AES128:DH+AES:ECDH+3DES:DH+3DES:RSA+AES:RSA+3DES:!aNULL:!MD5:!DSS;   Thanks!


How to draw this in TeXstudio? help me please.


Send email failed, No body supplied for file attachment in a batch apex

I wrote a batch apex to send reports. PFB the main class and test class but not able get the code coverage. Please assist me.  public class BatchReportsAutoSend implements database.Batchable<sobject>,Database.AllowsCallouts {     public transient list<Messaging.EmailFileAttachment> emailAttach;     String reportName1;     Set<String> processingList;      List<String> reportsList;      /*     public BatchReportsAutoSend(set<string> objs ){        processingList = objs;           reportsList = new List<String>(objs);         reportName1 = reportsList[0];     } */     public Database.QueryLocator start(Database.BatchableContext bc) {         list<string> reportListName = new list<string>();         reportListName.add('Testing_Reports1');         reportListName.add('Testing_Reports2');        //String query = 'SELECT Id,name FROM Report where DeveloperName in :reportsList';        //return Database.getQueryLocator(query);         return Database.getQueryLocator('SELECT Id,name FROM Report where DeveloperName IN :reportListName');      }     public void execute(Database.BatchableContext bc, List<Report> scope){         emailAttach = new list<Messaging.EmailFileAttachment>();         for(Report rp : scope){                      system.debug('OBJPAGE ##'+rp.Id);                        ApexPages.PageReference objPage = new ApexPages.PageReference('/'+rp.Id+'?csv=1');             system.debug('OBJPAGE ##'+objPage);             Messaging.EmailFileAttachment objMsgEmailAttach = new Messaging.EmailFileAttachment();             objMsgEmailAttach.setFileName(rp.name+'.csv');             objMsgEmailAttach.setInline(false);             Blob pageContent;             if(!test.isRunningTest()){              pageContent = objPage.getContent();             objMsgEmailAttach.setBody(pageContent);             objMsgEmailAttach.setContentType('text/csv');             }else{             pageContent = blob.valueof('TEST');              }             emailAttach.add(objMsgEmailAttach);         }             system.debug('Attachments'+emailAttach);             Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();             String[] toAddresses = new String[] {'smuti98@gmail.com'};             mail.setUseSignature(false);             mail.setToAddresses(toAddresses);             mail.setSubject('Email from Salesforce');             mail.setPlainTextBody('Hi Team, Please find the reports as you requested');              mail.setFileAttachments(emailAttach);             Messaging.SendEmailResult [] sendMsgResult = Messaging.sendEmail(new Messaging.SingleEmailMessage[] {mail});       }         public void finish(Database.BatchableContext bc){       }   }   Test Class:   @isTest(seealldata=true) public class Test_BatchReportsAutoSend { @isTest static void runReport() {  List<Messaging.SingleEmailMessage> emailList = new List<Messaging.SingleEmailMessage>(); PageReference pdf = Page.Report; //pdf.getParameters().put('id', String.valueOf(testAccount.Id)); Test.setCurrentPage(pdf);  Blob b = blob.valueof('Unit.test'); try {b = pdf.getContentasPdf();  }catch(Exception e) {}  system.debug('The document page  is'+b); Messaging.EmailFileAttachment efa = new Messaging.EmailFileAttachment(); efa.setFileName('FileName'); efa.setBody(b);  Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage(); String[] toAddresses = new String[] {'smuti98@gmail.com'}; mail.setToAddresses(toAddresses); mail.setSubject('Email from Salesforce'); mail.setPlainTextBody('Hi Team, Please find the reports as you requested');  mail.setFileAttachments(new Messaging.EmailFileAttachment[] { efa }); emailList.add(mail); List<Messaging.SendEmailResult> result = Messaging.sendEmail(emailList); System.assert(result[0].isSuccess(), 'Email not sent');   Test.StartTest();  BatchReportsAutoSend bp = new  BatchReportsAutoSend(); Id jobId = Database.executeBatch(bp); Test.stopTest(); } }


Is it "Forty centuries was a long time" or "Forty centuries were a long time"?

I need to know if the verb form should be singular or plural in such sentences.


In sh (not Bash), how would we abort execution of command when the prompt is in > mode?  For example, when entering a string with quotes only at the beginning, it makes the prompt look like >, without the ability to quit it normally, unless hitting Ctrl + D. Example:  root@MyPC:~# echo "hello > I am > (How do I exit of this mode?)   In case that I don't know which character delimits the string (" or ' or simply escaping a newline/spaces with backslash), is there a way to let Bash know that I want to abort the execution of the current command?


How do I reset my key chain on Mac High Sierra?

I'm using Mac High Sierra.  How do I reset my key chain?  I went in to the "Keychain Access" application, clicked on the "Reset My Default Key Chains" button and then entered my login password, but get the message  Unable to obtain authorization for this operation.   What do I need to do to reset my keychain?  I know I'm entering the right password because when I enter the same one in a termiainl using "sudo" it accepts it.


Haalp! Really long question titles are a bit borked! You can (no longer) see the bug in action right here

I just noticed that when a question's title is long enough that it would normally wrap around, it does so a tad late. If the title has a word in the right place, it gets cut off by the background(?!?) of the page.


Can I use my Windows 7 license key when doing a clean Windows 10 USB installation?

I've now clicked the "Get windows 10" button on the taskbar of my Windows 7 Home Premium installation, and gotten the email confirming I'm eligible for a free Windows 10 upgrade.  says I'll need the License Key if I'm doing a "first time installation":      If you will be installing the operating system for the first time, you will need your Windows product key (xxxxx-xxxxx-xxxxx-xxxxx-xxxxx). For more information about product keys and when they are required, visit the FAQ page.   Even though I proceeded to read the FAQ, it's not perfectly clear to me if the product key on a sticker of my old Windows 7 box can be used on a clean Windows 10 installation, or if I'll receive a new license key some time during the installation. Anyone know this?


Grep of many keywords over many files: speeding it up

I am currently facing a "performance problem" while using grep. I am trying to locate the occurrences of many (10,000+) keywords in many (think Linux kernel repository size) files. The objective is to generate a kind of index for each keyword:   keyword: my_keyword filepath 1 filepath 2 ------ keyword: my_keyword2 ...   Being fairly new to shell scripting, I have tried a few naive approaches:  while read LINE; do     echo "keyword: "$LINE >> $OUTPUT_FILE     grep -E -r --include='Makefile*' "($LINE)" . >> "$OUTPUT_FILE"     echo "-----" done < $KEYWORD_FILE   This takes about 45 minutes to complete, with the expected results.  Note: all they keywords I search for are located in a file ("KEYWORD_FILE", so fixed before anything starts), and the files in which to search can be determined before the search starts. I tried to stored the list of files to search in before the search like that:  file_set=( $(find . -name "Kbuild*" -o -name "Makefile*") )   and then replace the grep call by  echo {$file_set[*]} | parallel -k -j+0 -n 1000 -m grep -H -l -w "\($LINE\)" >> "$OUTPUT_FILE"   It takes about an hour to complete…  Question: considering I can use whatever technique I want, provided it's sh compliant, how can this be done "faster" and/or more efficiently ?  Perhaps grep is not the tool to use, and my use of parallel is wrong… any ideas are welcome!


Given the system function, how can i tell if it is a lowpass or a highpass filter?

If i am given the system function of a FIR digital filter obtained by recursive  frequency sampling design procedure., how can i tell if it is a lowpass, highpass, or bandpass filter?


Proving "A graph $G$ with chromatic number $𝑘$ has a proper coloring with a walk with $k$ vertices in $k$ different colors" by induction

I'm trying to prove "A graph $G$ with the chromatic number $𝑘$ has a proper coloring with a walk with $k$ vertices in $k$ different colors". I tried using induction to prove this statement such as color the graph, remove edges to change it into a $(k-1)$-colorable graph, and then connect the $(k-1)$-walk with one deleted edge. From here on I'm not sure how to proceed to connect the walk, especially about how to ensure I can find such a vertex to connect. Thanks in advance!


Let $f$ be a real-valued Lebesgue measurable function on $\mathbb{R}$. Prove that there exist Borel measurable functions $g$ and $h$ such that $g(x)=h(x)$ almost everywhere and $g(x)\le f(x) \le h(x)$ for every $x \in \mathbb R$. I know that $f$ is measurable since there exists a sequence of simple function that converges to $f$. I have no further idea how to tackle this problem.


Attaching a list in based on Indice Python

If I have a text such as:  There was no possibility of taking a walk that day We had been wandering indeed in the leafless shrubbery an hour in the morning but since dinner (Mrs Reed when there was no company dined early) the cold winter wind had brought with it clouds so sombre and a rain so penetrating that further out door exercise was now out of the question I was glad of it I never liked long walks especially on chilly afternoons dreadful to me was the coming home in the raw twilight with nipped fingers and toes and a heart saddened by the chidings of Bessie the nurse and humbled by the consciousness of my physical inferiority to Eliza John and Georgiana Reed The said Eliza John and Georgiana were now clustered round their mama in the drawing room she lay reclined on a sofa by the fireside and with her darlings about her (for the time neither quarrelling nor crying) looked perfectly happy   and I wanted to create a list such as: (I want to attach like a listing in front of the sentences, but depending on the position of the sentence)  0: There was no possibility of taking a walk that day 1: We had been wandering indeed in the leafless shrubbery an hour in the morning but since dinner (Mrs Reed when there was no company dined early) the cold winter wind had brought with it clouds so sombre and a rain so penetrating that further out door exercise was now out of the question 2: I was glad of it I never liked long walks especially on chilly afternoons dreadful to me was the coming home in the raw twilight with nipped fingers and toes and a heart saddened by the chidings of Bessie the nurse and humbled by the consciousness of my physical inferiority to Eliza John and Georgiana Reed 3: The said Eliza John and Georgiana were now clustered round their mama in the drawing room she lay reclined on a sofa by the fireside and with her darlings about her (for the time neither quarrelling nor crying) looked perfectly happy   How would i go about it?   Obviously, the first sentence would be 0, because the first sentence in this paragraph will be regarded as a 0, when we consider counting in indice rule. What i tried was  for line in open("MYEXAMPLETEXT"):   line_strip = line.rstrip()   words = line_strip.split()    print(line_strip[0],":", words)   Except obviously line_strip[0] is wrong because it prints out the first letter in each word so it will look like:  T: There was no possibility of taking a walk that day W: We had been wandering indeed in the leafless shrubbery an hour in the morning but since dinner (Mrs Reed when there was no company dined early) the cold winter wind had brought with it clouds so sombre and a rain so penetrating that further out door exercise was now out of the question I: I was glad of it I never liked long walks especially on chilly afternoons dreadful to me was the coming home in the raw twilight with nipped fingers and toes and a heart saddened by the chidings of Bessie the nurse and humbled by the consciousness of my physical inferiority to Eliza John and Georgiana Reed T: The said Eliza John and Georgiana were now clustered round their mama in the drawing room she lay reclined on a sofa by the fireside and with her darlings about her (for the time neither quarrelling nor crying) looked perfectly happy   I just need to consider the position of the sentence in terms of the overall paragraph of text???


CS type explanation needed on how heap and the stack work interms of reference variables and primitive variables in java for a non-CS guy

I need a CS kind of explanation on how the following 2 methods work differently from each other. I do not have a CS background (studied accounting .. blaahh) so please elaborate where you think is necessary. So java is a pass by value language from what I've read.  Consider the below primitive method. What exactly is it going to do in the background? The bit equivalence of lets say int myvar =7; will be made a copy of and passed into the method? How, please elaborate?  public void changePrim(int var){     var = 100;     System.out.println("in change prim:"+ var); }   Next, the below method is going to have a variable passed into it that will be of type Person.  public void changePersonObject(Person p) {     p.setAge(100);     p.setFirstName("Lost");     p.setLastName("Boy");     //   p = new Person("Lost", "Boy", 24, 100);  // this creates new. why? }   So the first primitive argument method didn't change the int variable that was passed in to it from the client. Why does the second butcher the Person object's first and last name? Please elaborate with some emphasis in Computer Science. I'm learning that in parallel along with how java works. So bits and bytes would be deliciously devoured.  Thank you.


Legendre symbols and primitive roots modulo $p$

Suppose that $\omega$ is a primitive root modulo $p$. What is $(\frac{\omega}{p})$?  $p$ is prime.


I've looked at multiple sources on this and some claim that static friction can do no work in any situation while others say that it can do work as an external force. A couple of scenarios are: static friction allows a human to walk forward (the system is the human), static friction allows a car to move forward (the system is the car), a crate on a truck moves forward as the truck moves forward (the system is the crate). In which of these cases is static friction doing work and why?


Exporting data with different data types in Google Earth Engine. How to make data consistent to download?

I am working with Sentinel-2 data in GEE and I added NDVI and a specific SAVI as new bands to an Image. I had an error downloading 6 bands (RGBI, and VIs) because the data type is not the same:  Error: Exported bands must have compatible data types; found inconsistent types: UInt16 and Float32.  Then I selected only the VIs (because I have already downloaded the other bands) and the error is still there but with a new data type:  Error: Exported bands must have compatible data types; found inconsistent types: Float32 and Float64.  I used the normal difference function for NDVI and a edited operation for SAVI. After that I used a operator for NDVI as well (to have 'same' result type) but the error is the same. Do you know how to manage it to obtain the same data format to export? Code sample: // Parameters for Vegetation Index (NDVI-SAVI). var nir = scene.select('B8'); var red = scene.select('B4'); var L = 0.38 var L1 = 1.38  var ndviParams = {min: -1, max: 1, palette: ['red', 'yellow', 'green']};  //Calculating VIs var ndvi = scene.normalizedDifference(['B8', 'B4']).rename('NDVI'); var savi = nir.subtract(red).divide(nir.add(red).add(L)).multiply(L1).rename('SAVI');  //Selecting to download var download = ee.Image(sorted.first()).addBands(savi).addBands(ndvi).select(['B4', 'B3', 'B2','B8','NDVI','SAVI']);


date ranges, up to, through a specific date

"My patient has been under my care from January 1st to Jan. 19th."  "My patient has been under my care from Jany 1st through Jan. 19th."  Do both of these windows of time include the 19th as part of the span of time that the patient was under the doctor's care?  thanks!


As the question says, when should I upgrade my camera body? In particular, if I have a low- to mid-range body (A DSLR such as a Nikon D3200 or Nikon D5100, or Canon SL1 or T5, or a mirrorless camera such as a Panasonic GH3 or an Olympus E-PL6). How do I know when I need to upgrade?  I have a complement of "kit" lenses, such as an 18-55mm f3.5-5.6 and a 55-200mm f4-5.6. Maybe I've even added a 50mm 1.8 to the kit. Flash is only for indoors (right?) and I usually shoot outside, so that means I don't need an external flash.  I shoot photos of my family and friends whether out at the park or having a picnic, my kids sports practices and games, vacation photos, as well as some landscapes, flowers, and whatever else catches my eye. Pretty familiar territory. I'm not a professional and don't intend to become one.


I'd like to prove the following:  If $f_j$ are continuous functions on a compact set $K$, and $f_{1}(x) \leq f_{2}(x) \leq \dots$ for all $x \in K$, and the $f_j$ converge pointwise to a continuous function $f$ on $K$ then in fact the $f_j$ converge uniformly to $f$ on $K$.  Attempt:  Let $g_{j}(x) = f(x) - f_{j}(x)$ for all $j$. Then, since $f_j \rightarrow f$ pointwise, we see $g_j \rightarrow 0$ pointwise.  Now, let $\varepsilon > 0$ . And examine { $x \in K : g_{j}(x) < \varepsilon$ }.  I've been told that the next step should be to  show that { $x \in K : g_{j}(x) < \varepsilon$ } is equal to the intersection of $K$ with some open set $U_j$. But I'm not certain why this is true?   Advice? Insight?


Difference between virtual and abstract methods

Here is some code from :  // compile with: /target:library  public class D {     public virtual void DoWork(int i)     {         // Original implementation.     } }  public abstract class E : D {     public abstract override void DoWork(int i); }  public class F : E {     public override void DoWork(int i)     {         // New implementation.     } }   Can anyone explain the above code with respect to the differences between abstract and virtual methods?


I'm not a parent but this is a question for parents.  I've been Agnostic for a while now, but my Mother is a Christian, and a very big one at that.  I'm kind of scared to tell her, but that may be my inferiority complex kicking in, so I would like some advice.  Edit: I'm still a young kid, and my Mother is the type of person who thinks she's always right, so I don't know how to go about this without major problems.


Stuck on crucial step while computing $\int_{- \infty}^{\infty} e^{-t^2}dt$

This is a not mandatory exercise I am struggling with from my Analysis II Class, at the very end of it I am supposed to compute $$\int_{-\infty}^\infty e^{-t^2}dt \tag{*}$$ The most famous way to do that is switch to polar coordinates but I am not supposed to do it that way, one of my tutors even called it a 'dirty trick'.  Instead the exercise gives us the following two Integrals to work with:      $$F(x)= \int_0^1 \frac{e^{-x^2(1+t^2)}}{1+t^2}dt \text{ and } G(x)= \left( \int_0^x e^{-t^2}dt\right)^2, \ \forall x \in \mathbb{R} $$   I yet fail to see how these two integrals relate to (*) but I can naively follow the instructions given by exercise sheet and hope that the result will follow:     Problem: Show that $F,G$ are of Class $C^1(\mathbb{R})$, compute $F',G'$ for all $x \in \mathbb{R}$ and show that $F+G$ is constant   My approach: There isn't much to do really rather than to quote some Lemmas, clearly the parametric integral $F$ is of class $C^1$ because $f(x,t): \mathbb{R} \times [0,1] \to \mathbb{R}$ given by $f(x,t)=e^{-x^2(1+t^2)}/(1+t^2)$ is of class $C^1$, I can therefore switch the partial derivative with the integral and obtain that  $$F'(x) =-2 x \int_0^1e^{-x^2(1+t^2)}dt$$ I doubt that I can further simplify this integral.  With a little help of the fundamental theorem of Calculus one obtains that $$G'(x)= 2 \left( \int_0^x e^{-t^2}dt\right)e^{-x^2} $$    At this point I hope that the exercise (or my computation) is flawed, at least the limit points of the integrals because I wouldn't know how to show that $F'+G'=0$ for all $x\in \mathbb{R}$ to conclude that $F+G$ is constant.   The only sense I could make out of $F'$ would be if I integrated it with respect to $x$ rather to $t$. Are there any further simplifications I can do?


I've search on internet but I need some help how to work with lampp ,like I know the folder to save our work is hotdocs but when i do it it give an error message....some as a turtorial or somethink to help me??


Counterxample: A continuous closed surjective map doesn't preserve Hausdorff property

I'm looking for counterexamples such that      $f: X \rightarrow Y$ is a continuous closed surjective map with $X$ Hausdorff and $Y$ non-Hausdorff   I know perfect maps preserve Hausdorff property. The only extra assumption that is crucial in the proof is $f^{-1}\{y\}$ is compact for all $y\in Y$. That's why I try to drop this assumption. The closest question I can find is , which almost excites me except for the open. I looked at the answers in it and tried them one by one. Unfortunately, none of them work or can be mimicked. I also tried the quotient map with $Y$ being the "line with infinitely many origins". Also failed. Any hint would be appreciated.


Software Center lists no apps under the categories

Just installed 20.04.1 LTS, it worked before. ran, sudo apt install --reinstall gnome-software, but it did not fix it.


No specific word allowed before a specific pattern at the end of the string

in one of some configs files i have the next RegEx: /\.story\.jsx?$/ It's select all files with 'story.jsx' in name, but i also want ignore file if his name has 'template' word. How can i do this with single RegEx: if (.story.jsx && !template) ?


How to extract and manipulate text from docx file using python?

I have a docx file which I converted into text using the docx2txt library.After that, I have to extract text in between.I used a regular expression for the task but it's just showing "[]"  as output.  import  docx2txt import  re te=docx2txt.process("y.docx")  n=re.findall(r'Reg(.*?)Reg',te) print(n)


I have found this in the cover of seminar(one tool to make slide) document.  The final result I have captured below:    The complete document can download .  I wonder how to make this. Is there any easy way?


I wanted to prove this by mathematical induction. I have proved that it is less than two and that the sum is greater than 0 but I am stuck on how to prove it to be greater than 1. Please help!!!  I would like a conclusive proof for this. Thank you so much!  I do believe there was an answer to a question similar to this, but the answers provided there did not use mathematical induction to provide the answer.


How long will it take to show the signs of pregnancy after intercourse

How long will it take to show the signs of pregnancy after having intercourse without using any birth control method? Please assume the couple as fertile.   Ex:- Nausea with or without vomiting, Increased urination, Food aversions or cravings, Fatigue  Thanks


Return is always true, even when it's false

I'm trying to make a dutch zipcode validator. On the first step i need to check if the first char of the zipcode (which is always a number), is between 1-9. But when i just tried to make a simple if statement to check if the first char is false, it comes back as true. In this example I took a premade string "2097AR" as input for the method "checkPostcode".  public static boolean checkPostcode(String postcode){         String postcodeEen = postcode.substring(0,1);          boolean resultCheck = true;          System.out.println(postcodeEen);          if (postcodeEen == "1"){             resultCheck = false;         }           return resultCheck;      }


Installing Ubuntu, I need a walkthrough for me and my Hp windows 8.1 laptop

Okay, so I followed some tutorials, but I could not get it to work still...... I just need a walkthrough or something for me and my Hp windows 8.1 laptop.


I am writing a paper, need some review. I want to send it to IEEE, without the name of my co-authors. I might get acceptance. I need to know, in that case, will I be allowed to add my co-authors or not?


How do I spell the possessive form of children?

In the sentence below, are the usages of apostrophes correct?     In research about parent stereotypes, the correlation between parents’ beliefs about their early elementary age children’s’ mathematics abilities and the children’s actual abilities increased as children aged.


Problem with linux kernel configuration during update operation

During the update operation I got the following error:  (Reading database ... 713992 files and directories currently installed.) Removing linux-image-extra-4.10.0-35-generic (4.10.0-35.39~16.04.1) ... depmod: FATAL: could not load /boot/System.map-4.10.0-35-generic: No such file or directory run-parts: executing /etc/kernel/postinst.d/apt-auto-removal 4.10.0-35-generic /boot/vmlinuz-4.10.0-35-generic run-parts: executing /etc/kernel/postinst.d/dkms 4.10.0-35-generic /boot/vmlinuz-4.10.0-35-generic run-parts: executing /etc/kernel/postinst.d/initramfs-tools 4.10.0-35-generic /boot/vmlinuz-4.10.0-35-generic update-initramfs: Generating /boot/initrd.img-4.10.0-35-generic Warning: No support for locale: en_IN depmod: WARNING: could not open /var/tmp/mkinitramfs_XGKldO/lib/modules/4.10.0-35-generic/modules.order: No such file or directory depmod: WARNING: could not open /var/tmp/mkinitramfs_XGKldO/lib/modules/4.10.0-35-generic/modules.builtin: No such file or directory  gzip: stdout: No space left on device E: mkinitramfs failure cpio 141 gzip 1 update-initramfs: failed for /boot/initrd.img-4.10.0-35-generic with 1. run-parts: /etc/kernel/postinst.d/initramfs-tools exited with return code 1 dpkg: error processing package linux-image-extra-4.10.0-35-generic (--remove):  subprocess installed post-removal script returned error exit status 1 Errors were encountered while processing:  linux-image-extra-4.10.0-35-generic E: Sub-process /usr/bin/dpkg returned an error code (1)   I tried to purge the kernel that causes the problem with no success. How can I solve this problem.


How to confirm the file attributes of a document

Is there a way of confirming that the file attributes of a document are correct/genuine.  For example, the date created, modified etc.


My visa was refused for insufficient funds. There is no time to go through the whole visa application and it is expensive.   Would I be allowed to enter, or do I need to consult an attorney?   My airfare and accommodation have been paid, and I have $3000 as spending money. The airfare and accommodation are $2000 and $3000 is just spending money. This combined is $5000AU, or 3000 pounds; that is 200 pounds a day. Is this acceptable for travelling for 15 days in the UK from Australia?


Currently I deleted one table from the database. But now I want some of the information from that table.   Please suggest how to restore or get back the table.  I am using SQL Server 2008 R2.


How to write negative numbers in text properly

I have problems with hyphenation of negative numbers in an article document. It sometimes happens that the minus is on one line, whereas the number begins on the next line. A possible fix is to write numbers in math mode, that is with $ before and after the number. But then the minus becomes very long, which looks odd to me. Compare $-$ with a simple -. I am using amsmath and amsfonts and amssymb, which might be related to that problem. Is there any way to make the minus before numbers shorter?


Why does the shower get cold when I flush, and how can I prevent it?

When the shower is running and someone flushes a toilet, why does the shower get cold (or sometimes hot) in some houses, but not others?  More importantly, would fixing that require replacing the water heater, or re-doing the piping in the entire house?  Or is there some cheap/easy way to fix it?


(Probability) How many integer solutions are there to the inequality $x_1 + x_2 + x_3 \le 17$

How many integer solutions are there to the inequality  $$ x_1 + x_2 + x_3 \leqslant 17 $$  if we require that  $$ x_1 \geqslant 1,\; x_2\geqslant2,\; x_3\geqslant 3 $$  My first approach to this problem was to see 3 boxes: $x_1, x_2,x_3 .$ After putting the minimum amount into each box (1 for $ x_1$, 2 for $x_2$ and 3 for $x_3$) we have 11 choices left. Using the star and bars method I got 11 spaces for the variables and 2 for the bars, giving me a final answer of:   $$ \dbinom{13}{2} $$  However, the second way to solve this problem would be to find the total amount of combinations without the restrictions, then to subract for when $ x_1 <1, x_2 <2$ or $x_3 < 3 $.  $$ \dbinom{19}{2} $$ for the first part where 17 is for the places of the integers and 2 are for the separators, but how do we find the restrictions? I am wondering if this has anything to do with a slack variable, our professor hinted at it and I do not know how to apply it to this problem.  Thank you.


My favorite animal are dogs.  Is this acceptable?  I believe this is ok because I see "animal" as one species and "dogs" as the variety of breeds.  Of course, the best answer would be "my favorite animal is the dog" but that's not the point.   Could someone give me a clear, technical answer as to whether or not this is acceptable (grammar)?  Thanks


\listfiles \documentclass[12pt]{standalone}      \usepackage{fontspec}  \begin{document}  test  \end{document}   creates  MiKTeX 2.9/tex/luatex/luaotfload/fontloader-2016-04-21.lua:353: attempt to call global 'getsubtype' (a nil value)  \endsa@boxit ... dvarwidth \color@endgroup \egroup  1.9 \end{document}  ?   Any ideas what this could be? I cannot imagein that I am wrong typsetting this example?


When to use "use" and when to use "utilize" in a sentence?

Sometimes I go through articles and find the expression utilize, I've always been wondering if there are special cases in which it should be used instead of used.  Also because  clearly shows that used is used (sorry for that ;D) much more.  Thanks for your help and happy new year!


Whoever vs. whomever where the phrase seems to serve as both indirect object of main clause and subject of subordinate clause

"Would you give my extra points to whoever needs them the most?"  Should   whoever  be whomever?  My "opponent" in this discussion is using grammatical terms that I find unique.


What is the grammatical role of *your* in "... by your being ..." phrases?

While writing a sentence the other day, it struck me that the following phrase has an odd feel to it that I cannot explain:    Everyone will benefit by your being well cared for.   I kept wanting to use you're but I knew that wasn't right yet somehow the word your in this context feels sort-of possessive (as it should) and at the same time sort of verb-like. I can't explain it any better than that and maybe someone with better grammar chops than I have can help me understand how it fits grammatically in this context.     Another way looking at this might be: "Why does this usage of your seem to create a grammatical dissonance?"


Should one ask generic or specific question?

Let's assume that one has some problems with coding or designing specific project. Should one ask general question about techniques, algorithms, generic problem (anonymising the project references), or should one ask about specific problem in specific problem? Or perhaps something in between?  Example:   generic: Cross-browser implementation of “HTTP Streaming” (push) AJAX pattern specific: How to implement AJAX-y 'incremental blame' view in gitweb (git web interface in Perl)?   If one should ask generic questions, how to anonymise problem? If one should ask specific question, how avoid 'homework' syndrome?