Heated and cooled air effects on combustion

In a turbocharged engine, an intercooler is installed to cool down the compressed air (apparently for better combustion). In contrast, in the power plant they use air preheater to heat up the air before it mixes with the fuel to fire up. What is the difference?


Probability of at least some number of heads

Let's say you flip a fair coin 50 times. What is the probability that you get at least 15 heads?   Any hints?


How to recall the window with the original creation settings of an object

After I place, for example a new mesh, and do any actions after that it is impossible to recall again the settings in the picture.  I know there is a way but I was not able to find an answer to that. Any ideas? Thank you!


I have game situation as shown in picture:     Red dot: player Brown dot: obstacle ( rock, tree, etc) Grey: non visible area ( under fog of war)   My question is: how can I draw that kind of shape, changed dynamically, with XNA 4.0. I can calculate each point of this shadow polygon. I would avoid drawing it pixel by pixel due to performance reasons, maybe particles? But i won't have sharp edges with this technique. Any tips?


Complete list of UK postcodes plus their city, county, uk country

Is there a free data set of all current UK postcodes (about 1.7 million-ish) plus their city name, county and UK country (e.g. Liverpool, Merseyside, England) and ideally lat, long, east, northings?


How to repair a corrupted word 2013 document?

Yesterday I was working on a very important Microsoft Word (2013) document, when it suddenly crashed. Upon trying to reopen the file Word said: “The file is corrupted and cannot be opened”. I have tried all of the other methods of restoring it, such as opening it in a different program, or opening it and choosing "open and repair" in MS Word.


I try to use sushi (which offer similar feature like Quick Look on MacOS ) on Ubuntu 19.04. Got this error:  (sushi-start:8478): Gjs-WARNING **: 15:07:50.705: JS ERROR: Error: Requiring Sushi, version none: Requiring namespace 'GtkSource' version '3.0', but '4' is already loaded @/usr/share/sushi/js/viewers/text.js:33:7


Is this a good example of "Rule of Thirds"?

I've been doing extensive research into photography, and I want to ensure that I understand the "Rule of Thirds" correctly.  So my question, to all the experts out there, is, is this photo a good example of rule-of-thirds? Can you tell what the intended subject is?  (Note: This was taken with a smartphone camera purely as a quick demonstration. So ignore the over-exposed sky :-P )


I want to build my own PIC programmer, can any one point me into right direction. Links, tutorials, books etc would be very helpful ? The programmer should use USB for communicating with the computer but even Serial port communication will also work?


Why does work equal force times distance?

My book says:     Energy is the capacity to do work and work is the product of net force and the 1-dimensional distance it made a body travel while constantly affecting it.   This seems quite unmotivated to me.  Why does  equal $F \cdot d$ ?  Where does the distance part come from?  I always thought of time as the one thing we can only measure (not affect) so it justifies why we may measure other things in relation to time. But we have a much greater control over distance (since it's just a term for a physical dimension we can more or less influence as opposed to time).  Edit: That^ doesn't make much sense, but it's been graciously addressed in some of the answers.  Level: High-school Physics.


Now the time has come for me to quit. I am not able to manage with Ubuntu, I should not blame the developers rather I should blame myself for not understanding. I would humbly request the experts to help me in the following   I have a windows ISO package downloaded and stored on the desktop.  Please help me to create a boot-able USB of the Windows OS.  Please help me in finding the right application to create a boot-able USB from Ubuntu (I don't have any alternative system, not alternative OS installed or nothing.  I am really stuck with this.. please help me to survive by installing Windows.


What is the meaning of "-y" in this command

I don't understand the meaning of -y.  command:   apt-get install -y clickhouse-client & sudo apt-get install -y passenger   There are many commands have -y.


While loop exit condition not working properly

So I'm trying to run a while loop, which should ideally stop when winner is either True or False. The table.isWinner() method returns either one of these values. But the loop for some reason is not getting stopped, until outerCount is bigger than tableColNum*tableRowNum (the other condition).             tableRowNum = table.getNumRows()             tableColNum = table.getNumColumns()             stackNum = table.getNumStacks()             winner = None             outerCount = 0             while winner == None and outerCount < tableColNum*tableRowNum:                 for i in range(tableRowNum):                     for j in range(tableColNum):                         domino = table.select(i, j)                         played = None                         count = 0                         while count < stackNum and not played:                             played = table.playDomino(domino, count)                             count += 1                         print(table)                         winner = table.isWinner()                         print(winner)                         outerCount += 1


Looking for free / open source Lidar web viewer?

I have lidar data which I want deploy my users using web viewer.  I will probably hold the data in PostGIS (not sure yet).  Is there good open source/free lidar viewer that I can integrate with OpenLayers site?


If $G$ is a graph with at least one cut-vertex, then at least $2$ of the blocks of $G$ contain exactly $1$ cut-vertex. To illustrate, I have this example:  A simpler example would be to consider two cycles with a common vertex, we can see that it is a cutting vertex and has only two blocks, since each pair of vertices is in a common cycle.


I am a begginner at C so please bear with me; I am aware that i can make an array statement as *c or c[];  My question is about memset:     char str[] = "hello!";   memset (str,'-',2);   puts (str);   Works fine. But:  char *str = "hello!";   memset (str,'-',2);   puts (str);   Dont work, I know that char *str = ... is a normal array statement.  If anyone can help me with this one i Thank you!


I have noticed that when I move apps to the SD card, it doesn't move everything. Is this a bug or a known behaviour or something weird going on with my phone?  Here's an example:   Start point: Phone free space: 18MB Install Skype app: Phone free space: 3MB, Skype is apparently using 15MB for the App Move Skype to SD Card: Phone free space: 8MB, Skype is now apparently using just 5MB for the App.   What appears to have happened is it's only moved some of the App, not the whole thing. It's a real pain for me as I have an HTC Desire, which doesn't have much internal memory (I live on the balance of the low memory warning). It's running the official HTC Gingerbread install...


How to design a database with product-dependent columns?

I am very new to database design. I have a task to create an inventory program with  asp.net core and entity framework core.  The inventory program will be used to manage various kind of products. Products have some common fields (aka columns) such as:   ProductId Contidion (new, 2nd hand) Price  etc   But each product also has some specific fields. For example, a mother board has   MemorySlots (either 2, 4, etc) MemoryType (DDR2, DDR3, etc) CpuType (Amd, Intel) etc   Another product, for example, is a book. It has:   ISBN Authors  Title etc   Question  How can I manage the product-specific fields in a database?


Extracting IP addresses from a log file and list them in another file

I have a honeypot set up and would like to analyse the sources of the many brute force attacks. I would like to extract all the IP addresses and add them in a list formation to another file. The script would then be part of a cron job with additional unique IP's appended to the bottom of the list file.  How do I extract IP addresses from a log file and list them in another file?


Splitting/Resizing a partition in GParted - got a key symbol next to the partition

I was trying to free up some space on my ubuntu ext4 partition using GParted to install Windows 7. However, when I right-click the partition, most options to edit it are greyed out. There is a symbol of a key next to the partition name. There's about 29 GB free space on the partition. I am using ubuntu 13.04 and GParted 0.12.1.


For a person who doesn't work but got the necessary money. How the bank statement should be when applying for uk tourist visa?

I am a student and I want to apply for a UK tourist visa. A month ago my parents sent me the money for my trip (as a gift). So if I apply for a UK tourist visa, is it okay that my only source of revenue is that money? And what should be on the bank statement?


Cauchy Schwarz inequality for $\langle f,g\rangle = \int_0^1f(x)g(x)\mathrm{d}x$

For the vector space of continuous functions on $[0,1]$ Define the inner product as  $$\langle f,g\rangle = \int_0^1f(x)g(x)\mathrm{d}x$$ Please help me to prove the Cauchy Schwarz inequality for this given inner product.  Cauchy Schwarz Inequality: $|\langle v,u\rangle|\leq \lVert v\rVert\lVert u\rVert$ for the elements $v,u$ in the inner product space.


I want to overlay one image with another using CSS. An example of this is the first image (the background if you like) will be a thumbnail link of a product, with the link opening a lightbox / popup showing a larger version of the image.   On top of this linked image I would like an image of a magnifying glass, to show people that the image can be clicked to enlarge it (apparently this isn't obvious without the magnifying glass).


A Norman window has the shape of a rectangle surmounted by a semicircle. Find the dimensions of a Norman window of perimeter 24 ft that will admit the greatest possible amount of light.  I know that I need to find two different equation to make the main equation have one variable. I would assume in this case we would use the radius of the semicircle to find something in this equation. P=24. I also know that we can split this into two different equation which would be the area of a rectangle and the area of a semicircle. The area of the rectangle is L*w and I have no idea what the area of the semicircle is. I also think that in this case we are trying to maximize the area of the overall shape. Ive been working on this for a while but I keep getting it wrong. I need help!


Evaluate:: $ 2 \sum_{n=1}^\infty \frac{(-1)^{n+1}}{n+1}\left( 1 + \frac12 +\cdots + \frac 1n\right) $

How to evaluate the series: $$  2 \sum_{n=1}^\infty \frac{(-1)^{n+1}}{n+1}\left( 1 + \frac12 + \cdots + \frac 1n\right) $$  According to Mathematica, this converges to $ (\log 2)^2 $.


Show $\inf_f\int_0^1|f'(x)-f(x)|dx=1/e$ for continuously differentiable functions with $f(0)=0$, $f(1)=1$.

Let $C$ be the class of all real-valued continuously differentiable functions $f$ on the interval $[0,1]$ with $f(0)=0$ and $f(1)=1$. How to show that $$\inf_{f\in C}\int_0^1|f'(x)-f(x)|dx=\frac{1}{e}?$$  I have been able to show that $1/e$ is a lower bound. Indeed, $$\begin{align*} \int_0^1|f'(x)-f(x)|dx &= \int_0^1|f'(x)e^{-x}-f(x)e^{-x}|e^xdx \\ &\geq \int_0^1\left(f'(x)e^{-x}-f(x)e^{-x}\right) dx \\ &= \int_0^1 \frac{d\left(f(x)e^{-x}\right)}{dx}dx  \\ &= f(1)e^{-1}-f(0)e^{0}\\ &=\frac{1}{e}. \end{align*}$$ But how to show this is the infimum? Is there a function $f\in C$ such that we get $\int_0^1|f'(x)-f(x)|dx=1/e$?


Can I safely reinstall the OS on an infected virtual machine and still keep my data?

My Windows 10 guest OS running in VirtualBox on Mac OS X seems to have . Is there a way to reinstall the OS and wipe any hidden malware, but keep my data files (program customizations, documents not yet backed up to the host, etc.)?


Let $\rho(x,y)= \frac{d(x,y)}{1+d(x,y)}$, show that $\rho$ is a metric equivalent to $d$

Let $(E,d)$ be a metric space and $\rho(x,y)= \frac{d(x,y)}{1+d(x,y)}$. Show that $(E,\rho)$ is a metric and $\rho$ and $d$ are equivalent.   I have proved the part about the metric space. However, I cant remember how to prove the equivalence. Also I'm stuck with a follow up which says:     Show that there are no constants $c,C >0$ such that for all $x,y \in E:$ $$cd(x,y) \leq \rho(x,y) \leq Cd(x,y)$$


Package inputenc Error: Unicode char - {U+2010)

I am encountering the following error and have no idea where to find the solution;   Package inputenc Error: Unicode char ‐ (U+2010) (inputenc)                not set up for use with LaTeX.  See the inputenc package documentation for explanation. Type  H <return>  for immediate help.  ...                                                l.129   boundedness and actor‐                                 network theory. Your command was ignored. Type  I <command> <return>  to replace it with another command, or  <return>  to continue without it.  [32] [33]) [34] \openout2 = `chapters/abbreviations.aux'.   Can anybody aid me in finding the solution? I am using ShareLatex if that is necessary information.


I was trying out a command yesterday that put my computer into hibernation mode. The first line in the command sequence was sudo -s which made my command line go from   userName@computerName:~$    to   root@computerName:~#    I looked at the manual page for sudo and it did not give any explanation as to why this happen or what mode it had entered.   What does the root and # mean in the second command line tag? what does this mode allow you to do and how do I get out of it? Thank you in advance for any help!


Why would Anakin Skywalker trust Chancellor Palpatine?

Why would Anakin Skywalker trust Chancellor Palpatine once he knew Palpatine was a Sith Lord?  In one scene of Revenge of the Sith, Palpatine invites Anakin to chat with him and reveals a legend about a Sith Lord that could save the people he cared about from death. (That alone should have been a big honking clue that Palpatine was a Sith Lord or in cahoots with one). Later when Anakin finally figures out that Palpatine is a Sith Lord, why would he trust anything Palpatine ever said to him? The safest assumption is that Palpatine was lying and manipulative. So when Palpatine, almost beaten by Mace Windu, says "only I can save the one you love", Anakin should have replied with "What!? You expect me to believe that? You're a sociopath!"  Edit: This is different from asking why Anakin believed turning to the Dark Side of the Force would save Padmé? For Anakin to believe Palpatine could help him save Padmé, he would first have to trust Palpatine. Once you know somebody is a murderous, lying, manipulative dictator, there is no reason to believe any word he ever said.


Add "log out globally" button on user popup

I propose adding a "log out globally" button on user pop-up to fast log out from all Stack Exchange pages. Why enter a  page and then logout if we can have one button ?


so this:    so I need:  any suggestions?


Do I need schengen visa if I have 3 hour layover at Zurich and then connecting flight to Toronto?

I am flying next month from Mumbai-Zurich-Toronto. The layover at Zurich airport is 3 hrs and then I have a connecting flight to Toronto. Do I need a Schengen Visa?  There is also another flight from Mumbai - London-Toronto, so if there is a layover of 3 hours in London do I need any transit visa?


Best way to find a point on a circle closest to a given point

Given a point (pX, pY) and a circle with a known center (cX,cY) and radius (r), what is the shortest amount of code you can come up with to find the point on the circle closest to (pX, pY) ?  I've got some code kind of working but it involves converting the circle to an equation of the form (x - cX)^2 + (y - cY)^2 = r^2 (where r is radius) and using the equation of the line from point (pX, pY) to (cX, cY) to create a quadratic equation to be solved.  Once I iron out the bugs it'll do, but it seems such an inelegant solution.


why cant you use both parts of the register in 32/64 bit x86 assembly

in 16 bit assembly you can use a 16 bit register like or use one of the 2 8 bit registers that comprise it why can you only use the high memory addresses in 32 and 64 bit assembly ?


Ordering of "My Communities" in the Stack Exchange drop-down menu appears to be broken

I would have thought that someone must have asked this already but .  The ordering of the Stack Exchange drop-down menu is at times [in parts] logical, and then there are random positionings. Take a look at this:         to the question , does not explain the ordering that I see:     Sites where you have > 200 reputation will be sorted by reputation,   highest reputation accounts at the top.      Sites where you have < 200 reputation will then be listed in random   order. e at the top.   It is not because I need to wait 24 hours either, as it has been like this for nearly a week. In fact, it has always been badly ordered - only now am I analysing the order, or trying to.  3D Printing messes up the ordering at the top of the list - is this because I have always been on that site, in the past few weeks, and so it has been positioned as a favourite?  Surely Ask Ubuntu should be just below Stack Overflow, and Arqade at the bottom?   If I scroll down that menu, it gets even more random, and not all of them are < 200, so the explanation in the answer above, doesn't appear to apply:


winrmsrv Virus, Windows Security all gone

I have been hit with a Virus that disables Windows Security by removing all its components (Windows 10). Startup Repair fails to run and I don't have a system restore that dates back before this (or even the virus somehow survives system restores not sure). The virus also disguises as the winrmsrv service and tries to get firewall access (I denied that).  I've downloaded MalwareBytes and scanned for malwares, the threats were detected and removed but the security components are still missing. Previously, I've resorted to resetting the PC which fixed the issue but now it's back again (after around 6 months) and I can't find the source of it. My initial thought is that the malware could be up within a removable flash drive (I got an infection previously within a drive but it was scanned and removed before opening anything within the drive). But upon further inspection, all other laptops within my home are not affected and we use the flash medias interchangeably so it must be still stuck somewhere within my PC. The Defender Firewall appears to be running but can only be accessed from the start menu, and I get this message as well (screenshot below). In control panel, the firewall appears to be working.   My question is: How it is coming back after a PC reset? Is there something that I'm missing or misunderstanding? In addition, can I fix missing components in Windows without resorting to a factory reset?


Is $R^2 = R$, if the relation R is transitive?

I am new to relations and while learning about their properties, I thought about this. I tried to prove it, but I don't know how. Also I can't think of a counter example.  Let R be a transitive relation, then $R^2 = R$  Or  $R^2 = R$ if and only if R is a transitive relation.  I also looked on the internet, but didn't find anything useful.  P.S. This is my first question and maybe I made some mistakes or broke some rules about it, so be gentle.  EDIT: This is not the same question as , because I asked how to prove or disprove $R^2 = R$ if R is a transitive relation. The other question is about transitivity of a square of a relation and mine is about the connection between square of a relation and transitivity of a relation.


What is the correct pronunciation of 'Ubuntu'?

I have never been good at deciphering the pronunciation guides:     ubuntu |oǒ'boǒntoō|   What is the best way to describe the pronunciation with like sounding words for each syllable?  "oǒ": ?  "boǒn": like Boone as in Daniel or like bun as in hamburger?  "toō": like too as in also?


Short Solution for SQL Injection Attacks with MySQLI

I've gotten into the habit of writing the following sort of code:  $q = mysqli_query($mysqli,"SELECT * FROM table WHERE a='$a', b=$b;"); while ($row = mysqli_fetch_array($q)) {     // do something     }   Where $a is a string entered by the user (gotten through $_GET) and $b is a user-entered integer.  Obviously the code I have above is vulnerable to SQL injection attacks, so my habit is to rewrite it like this:  $q = mysqli_query($mysqli,"SELECT * FROM table WHERE a='".str_replace("'","",$a)."', b=".($b+0).";");   But this of course has problems if $a needs to have apostrophes (or quotation marks when quotation marks are used to mark the string).  Recently I learned about prepared statements in mysqli and started playing around with them. I wrote the following function to make it easier to make calls without having to change much of my code:  function safequery($a,$b,$c) {     global $mysqli;     $q = mysqli_prepare($mysqli,$a);     $e = "mysqli_stmt_bind_param(\$q,\$b";     $i = 0;     while ($i < count($c)) {         $e.=",";         $e.="\$c[$i]";         $i++;         }     $e.=");";     eval($e);     mysqli_stmt_execute($q);     return $q;     }  safequery("SELECT * FROM table WHERE a=? AND b=?;","si",array("unsafestring",37));   But what is returned from this function turns out not to be a mysqli_result and thus doesn't work with the first bit of code above. After some more research, I found an alternative, but it would require a complete rethink of how I write my code. Is this necessary or is it possible to protect against MySQL injection attacks with only small changes to the first bit of code (no new lines, same output style, etc.)?  I have looked around on StackOverflow and the rest of the web but I can't find a good simple solution; all of them require the edition of at least three more lines for every call and a different way of reading each row. I'd prefer to do this procedural-y...


Im stuck at this problem  Find an invertible Real Matrix $P$ such that $P^{-1}AP$ and $P^{-1}BP$ are both diagonal where $A$ and $B$ are real matrices.  a)   $A=\begin{bmatrix}   1&2\\ 0&2\\ \end{bmatrix}$ and  $B=\begin{bmatrix} 3&-8\\ 0&-1\\ \end{bmatrix}$  b) $A=\begin{bmatrix}   1&1\\ 1&1\\ \end{bmatrix}$   and $B=\begin{bmatrix} 1&a\\ a&1\\ \end{bmatrix}$  I know that diagonalisable commuting matrices can be simultaneously diagonalised but I'm not able to proceed.Kindly help.


Is $$\frac{a+b}{c+d}<\frac{a}{c}+\frac{b}{d}$$ for $a,b,c,d>0$  If it is true, then can we generalize?  EDIT:typing mistake corrected.  EDIT, WILL JAGY. Apparently the real question is  Is $$\color{magenta}{\frac{a+b}{c+d}<\frac{a}{c}+\frac{b}{d}}$$ for $a,b,c,d>0,$ where letters on the left hand side and in the numerator stay in the numerator on the right-hand side, and letters on the left hand side and in the denominator stay in the denominator on the right-hand side.


How to compile libimobiledevice 1.2 on Ubuntu 15.04?

How can compile libimobiledevice 1.2 on Ubuntu ?, also with usbmuxd, libimobilerestore,libiplist.


how do I have alternating background colors for a table?

I have the following table:  \documentclass{article}  \begin{document}  \begin{tabular}{ll} this row should be blue & \\ this row should be red & \\ %% these rows alternate between green and yellow a & b \\ c & d \\ e & f \\ f & g \end{tabular}  \end{document}   and I would like to have different background colors for the cells, as mentioned in the table. Any ideas?


I wanted to make sweet potato fries but it was very disappointing and not crunchy at all. I put the first batch in a medium-heat oil and left them for a while, they got out all soggy. I turned up the heat for the second batch, it got a bit better but still way below my crunch expectations. I even tried to put the first batch back in the hot oil, remembering that good Belgian potato fries should go in the oil twice, but I just managed to burn them. Do you know what I did wrong? Is it because of an excess of humidity? They were pretty dry already when I put them in the oil. I've read that they should be coated in flour before, does that work? I don't see how it would stick well to the sweet potatoes, aren't them too dry for that?


Does True Seeing automatically detect the illusions from Weird?

The  spell creates illusions in the minds of those it is cast upon (unless they make their save).  The  spell gives truesight, which grants the automatic detection of visual illusions and saves against them automatically succeed.  Do the illusions created by weird qualify for this though?  The illusions the spell creates are visible to the targets, but only to them. They aren't visible in the classic sense like those produced by certain other illusion spells like minor illusion.


Does resistance matter when charging devices

I've been searching all over the web and couldn't find a simple answer to my question. Partially because I'm no electrical engineer, so I really need a simple and direct answer.  My question is if you have a portable battery with the same output voltage as the input voltage on your device, does the amp matter?  A little more background. I'm trying to power a PAM8403. I was wondering if this battery can be used   Would any portable batteries used to charge android phones work, for example?  Thanks a lot


Let $ f $ be a function that is differentiable on a deleted neighborhood of $x_0 ∈ R$ and continuous at $x_0$. Show that if $\lim \limits_{x \to x_0} f'(x) = L$ then $f'(x_0) = L $


Why is $\{\emptyset\}\not\subseteq\{\{\emptyset\}\}$ true?

My book "Introduction to SetTheory" says      $\{\emptyset\}\in\{\{\emptyset\}\}$ but $\{\emptyset\}\not\subseteq\{\{\emptyset\}\}$   When we say $\{\emptyset\}\not\subseteq\{\{\emptyset\}\}$, we mean that $\emptyset$ is not listed amongst the elements of $\{\{\emptyset\}\}$.  I was under the impression that every set contains the empty set. Hence, the elements of $\{\{\emptyset\}\}$ would be $\emptyset,\{\emptyset\}$. If that were true, wouldn't the assertion that $\{\emptyset\}\not\subseteq\{\{\emptyset\}\}$ be false?


How do you make an element "flash" in jQuery

I'm brand new to jQuery and have some experience using Prototype. In Prototype, there is a method to "flash" an element — ie. briefly highlight it in another color and have it fade back to normal so that the user's eye is drawn to it. Is there such a method in jQuery? I see fadeIn, fadeOut, and animate, but I don't see anything like "flash". Perhaps one of these three can be used with appropriate inputs?


I need to reinstall Blender but I want to backup my startup file first. Where is this data stored?


How to store "large" amounts of data in a desktop app?

Update  On a completely unrelated search, I have found this:  which lists a few possible options with about the same goals.  Original post  We have a desktop .Net/WPF app, with large (for a desktop app) amounts of data stored: it's has layouts, templates, products list and technical specs, and many more stuff.  Today it's stored in an Access DB, but we have hit the Access limitations pretty hard: it's not very fast, the DB weights 44Mb (which results in a large setup package), and more importantly, it's a pain to use with version control, because we can't merge the data from a branch to another. For instance, we might create a branch to add a few products, but then we have to add them manually in the trunk when we merge. We could use SQL scripts, but writing advanced SQL scripts for Access is a pain.  Basically, I want to replace the MS Access DB with another storage format, because Access is not well adapted.  I had tought of using JSON files that would be unzipped during or after install, but I'm a bit afraid of performance problems. I'm also thinking of splitting the data into multiple files with multiple formats, depending on its usage, but using different formats might get complicated or annoying to develop.  Performance  Some parts of the DB are accessed pretty often and should be performance-optimized, whereas others are accessed maybe 1 or 2 times per work session, and using a poor-performance but high-compression format could be OK.  Size  We want the installer to be the smallest possible, so the library should be small, and the format should use small files. Using a library that adds 5 Mb to the installer file is out of the question.  Compatibility  The software must be able to run on .Net 4 (not 4.5), and it would be great if it ran on Windows XP (even though we're thinking more and more of just abandoning it going forward, it's still more than 7% of our market share).  Moreover, it should not need to install a server (like MS Access or SQLite) because it will be installed on end-user's computers, and we don't want to bloat them.  Versionning  It should be easy to version the data and the DB structure. The file should either be a text file (like JSON), or scripts should be easy to run in the continuous integration platform (like SQL server).    So, which technology would you use that answers all these contraints ?  Thanks !


I want to return true when consignmenttypeName is to instock or consignment.Otherwise false. This is my code.  public boolean checkPurchaseMethod(String skuID) throws RepositoryException{      String consignmenttypeName = "";      RepositoryItem skuRepItem=getProductRepository().getItem(skuID.trim(), "sku");     if (skuRepItem != null) {       RepositoryItem consignmentType = (RepositoryItem) skuRepItem.getPropertyValue("consignmentType");         if(consignmentType!=null){              consignmenttypeName = (String)consignmentType.getPropertyValue("id");              if(consignmenttypeName !="instock" && consignmenttypeName != "consignment"){                 return true;             }         }        }     return false; }   Is there is any error with this code. Is this code return false when consignmenttypeName not equal to instock or consignment.


Transfer all messages of thunderbird with windows 7 to thunderbird ubuntu 14.04?

How can I transfer all messages and contacts of thunderbird with windows 7 to thunderbird ubuntu 14.04?   I know that have a free app called . But it don't works with linux.   There a way that can I make this moving?   Thanks!


Will default gcc version change in 20.04

I'm writing a book that discusses the assembly language generated by gcc. I'm using Ubuntu 20.04. The default version of gcc is 9.3.0. The latest version of gcc in the repositories is 10.2.0. It's an introductory book, so I want everything to be as "standard" as possible for the reader. They've got enough to deal with in the book's material without having to deal with bleeding edge OS and compiler issues. Will gcc 9.3.0 remain the default during the remaining 4 years of 20.04's lifetime?


Why do I get a notification for an edit I did?

I edited  to change the tag used (I reverted the change I previously made), and I got a notification about a new edit; when I clicked on it, I discovered .    As I was the author of the edit, should not a page refresh be done, in this case? I should see the notification only when somebody else edited the question while I was viewing it, or answering to it.


For all infinite cardinals $\kappa, \ (\kappa \times \kappa, <_{cw}) \cong (\kappa, \in).$

I don't understand the proof to the a/m claim. How we know that $\eta < \kappa$ and $(\alpha,\beta)<_{cw} (0, \eta) $ and hence $h: \mu \to \eta \times \eta$ is injective? Appreciate if anyone could advise.  Here is an excerpt of the proof:  For an infinite ordinal $\kappa,$ the canonical well-ordering of $\kappa \times \kappa,$ denoted by $<_{cw}$ is defined as follows: $(\alpha_1, \beta_1)<_{cw} < (\alpha_2, \beta_2)$ iff either one of the following holds.  $(1): \max\{\alpha_1,\beta_1\} < \max\{\alpha_2,\beta_2\}$  $(2): \max\{\alpha_1,\beta_1\} =\max\{\alpha_2,\beta_2\}$ and $\alpha_1<\alpha_2$   $(3): \max\{\alpha_1,\beta_1\} =\max\{\alpha_2,\beta_2\}$ and $\alpha_1 = \alpha_2$ and $\beta_1 < \beta_2.$  Claim: For all infinite cardinals $\kappa, (\kappa \times \kappa, <_{cw}) \cong (\kappa, \in).$  Proof: (It has been show that it is true for $\kappa = \omega$) Assume there is a counterexample  $\kappa.$ Let $A= \{\lambda \in \kappa + 1| \lambda\geq \omega \ is \ a \ cardinal \ and \ (\lambda \times \lambda, <_{cw}) \not\cong (\lambda, \in)\}.$ Then, $\kappa \in A.$ Let $\mu$ be least element of $A.$ Thus, $\mu > \omega$ and for all $\lambda,$ if $\omega \leq \lambda < \mu$ and $\lambda$ is a cardinal, then $(\lambda \times \lambda, <_{cw}) \cong (\lambda, \in).$  By Comparability theorem, $(\mu, \in)$ is isomorphic to initial segment of $(\mu \times \mu, <_{cw})$ since $|\mu \times \mu| \geq \mu$ and $\mu$ is cardinal. Let $(\alpha, \beta) \in \mu \times \mu$ such that $(\mu, \in)$ is isomorphic to initial segment of $(\mu \times \mu, <_{cw})$ given by $(\alpha, \beta).$ Let $h$ be the isomorphism. Let $\eta= \max\{\alpha, \beta\}+ \omega.$ Then $\eta < \kappa$ and $(\alpha,\beta)<_{cw} (0, \eta).$ HENCE, $h: \mu \to \eta \times \eta$ is injective.


How to dim the screen on an Android phone without locking?

Given a phone with a password, the screen turns off and the phone locks by single pressing the power button, or if the sleep time-out is reached.  The user then must enter the password to get access.  In order to conserve battery power, is is possible to have the screen dim but NOT lock the phone?  The user could increase the sleep setting so the screen would take longer to auto-dim, but that would not preserve the battery.  There are references to a "screen mode widget" that would dim the screen without locking, it does not appear to be available any longer.  Is there a trustworthy app that does this? By trustworthy I mean one that has an Internet presence other than their own page.


Using the command-line, I want to create a log file with today's date in the name (for example, today is 05/17/2011, so the filename would have to be log051711).  I know how to create the file (touch filename), but I don't know how to get today's date. I have looked at the manual for date, but it seems that I can't really format its output?  Any help would be appreciated.


Can i change a 26×1.95 tire to 26×1.75 tire on the same wheel? If possible,am i need to change the innertube also?


Where did Magister Illyrio Mopatis get the dragon eggs from?

... you know, the ones that he famously ?  Disregarding whether he knew what they actually were or not, I think knowing where the eggs originated from might be fairly important, too.


Can users delete questions after getting an answer

That just disappeared and the OP had a good question, he clearly has the capacity just not the knowledge, it suddenly disappeared and the OP has no questions showing on his page.  Is that bad? It doesn't feel good? (I'm not sure what to make of it)


I'm on the Diplomatic Immunity quest and I'm playing on an Xbox. I never received my weapons out of the chest and I've tried loading from old saves which still did not take me out of the Thalmor Embassy.


Probability of deck of cards such that each person receives one ace

Suppose that a deck of 52 cards containing four aces is shuffled thoroughly and the cards are then distributed among four players so that each player receives 13 cards. Determine the probability that each player will receive one ace.   The answer to this is given as$$\frac{13^4}{\binom {52}4}$$  My doubt is the following:   The book justifies ${\binom {52}{4}}$ as number of possible different combinations of the four positions in the deck occupied by 4 aces. That sounds like a case of arrangements to me, so shouldn't we think about permutations and not combinations if we are concerned about how the aces are to be arranged in the deck ?. Shouldn't the denominator be ${\binom {52}{13}}$ since you are choosing 13 cards for 4 people.


Since one or two months ago, my laptop with ubuntu 12.10x64 hangs during shutdown. There's just a black screen, no harddisk activity, it justs sits there. I feel it happens near the end of a normal shutdown cycle, judging from time elapsed.  Only resolution is hard power-off (holding power key for several seconds) - neither Ctrl-Alt-Backspace (which normally works, I have it switched on in Settings) nor Ctrl-Alt-Del help, nor can I get into a text console with Ctrl-Alt-F1.   How do I diagnose that? It does not happen on every shutdown, but often enough to be annoying (as it forces a diskcheck on reboot, of course).   Which log files can tell me what's going wrong? More or less blindly searching in the sys log viewer reminds me of needles in a haystack.  I imagine I could pinpoint the time it happens via log timestamps, but how do I read timestamps like e.g. in kern.log: [36169.146130]? How do I get this human-readable?  Lastly, a bit of a btw, I've never managed to execute an Alt-Sysrq-REISUB to force a cleaner shutdown, but that's probably because I'm on a laptop, PrintScr is only accessible via an Fn key, and I'm not sure of the exact key sequence I need. Is there a "harmless" but user-visible magic command I could practice this with (during normal operation), so I can find out how to do a REISUB next time?  Thanks all! Comment if you need additional data...


First Port of entry for German National visa holders

I will be travelling to MUC from India on a German national visa type D via Paris. My visa says that it is valid for Deutschland (not Schengen states, unlike for Schengen Visa). Will I be allowed to travel through Paris as my first port of entry?   I am concerned since I will have to do immigration at Paris.


Excel - how to stop automatic destructive re-formatting of fields on document load

I am trying to edit a csv file in excel, but am running into issues with its supposedly-helpful automatic format detection, and I don't know how to turn it off.  I have a field with an original value "28:55". Excel converts this immediately on loading the file into "28:55:00", thinking it needs to be in hh:mm:ss format. When I try to manually convert the format back to a string, it inexplicably transforms into "1.204861111".  How do I turn off this automatic data conversion when loading a file? I haven't been able to find anything helpful in the excel settings.  [edit]: This is Excel 2010. All online resources I have looked at just tell you how to stop automatic conversion once a file is loaded, not how to stop the conversion that happens during Excel's initial reading of the data.


How does trample interact with damage prevention effects and indestructible blockers?

Say I have a 4/4 creature with trample. I attack, and my opponent blocks with a...   : Does my 4/4 trampler's extra 3 damage carry over even though the blocking creature wasn't dealt lethal damage? Does the situation change if my 4/4 trampler also has infect?  Can I even deal lethal damage to it? 0/1 Creature with protection from my creature's color: Can I deal damage to it at all?   When does the damage carry over to my opponent? I made all of these hypothetical creatures 0/1 for simplicity's sake. I know the creatures actually linked to are slightly different, but I believe this will simplify the answers.


Url Hack not showing prefilled value on custom Visualforce page with custom object

I Have a simple visualforce page on which ik want to prefill a lookup field with a contactid to create a new record. I used the Id of the customfield Contactpersoon__c and used CF before the lookup ID as I found in the documetation of URL Hacking. I added a contactid as value ending with _lkid as it is a lookup according to URL hacking.  My page loads without the field beiing prefilled why is this not working?  Visualforce:  <apex:page standardcontroller="Relatie_Contact__c"  showHeader="false"   applyBodyTag="false" lightningStylesheets="true">     <apex:slds />     <div class="slds-scope">         <apex:sectionHeader title="" subtitle="Relatie contact"/>         <apex:form >             <apex:pageBlock >                 <apex:pageBlockButtons location="bottom" >                     <apex:commandButton action="{!save}" value="Save"/>                        </apex:pageBlockButtons>                 <apex:pageBlockSection >                     <apex:pageBlockTable value="{!Relatie_Contact__c}" var="r"  >                         <apex:column style="width:250px">                             <apex:facet name="header">Contactpersoon</apex:facet>                              <apex:inputField value="{!r.Contactpersoon__c}"/>                         </apex:column>                         <apex:column style="width:250px">                             <apex:facet name="header">Relatiesoort</apex:facet>                              <apex:inputField value="{!r.Relatiesoort__c}"/>                         </apex:column>                         <apex:column style="width:250px">                             <apex:facet name="header">Organisatie</apex:facet>                              <apex:inputField value="{!r.Organisatie__c}"/>                          </apex:column>                     </apex:pageBlockTable>                 </apex:pageBlockSection>             </apex:pageBlock>         </apex:form>     </div> </apex:page>   URL:  var url = '/apex/NieuweRelatie?CF00N5800000BNqkB=0039E00000LifHz_lkid';


I have a Whyte Portabello hybrid, I wanted to swap to an adventure bike with drops. I thought as an alternative it might be easy to convert my existing bike instead, and save a bit of money.  It has hydraulic disk brakes but most brakes on drop bars seem to be cable operated?   The rear derailleur is a Shimano, so would I just have to get some Shimano road brake/ shifters and fit some cable operated calipers instead? Or is it a bit more complicated than that?     thanks


What's the difference between sudo -s , sudo su and su root

They all do the same, logging into root but it doesn't make sense to me because while su root requires root password, sudo -s and sudo su requires only user password. I know the difference between sudo and su but it's strange to me that I can access root with primary user password...


Is placing one or two keywords in the URLs still good for SEO?

My urls do not seem to have my main keywords in them. Is this bad for SEO? Should I include them?   Of course I do not mean actually writing one keyword after each other, but have an organically / naturally readably URL which makes sense to the user and to SEO, if at all, hence my question.


How to keep the structure of the Tablix and Field names when there is no data to show

When the data set returns no data, the tablix column headers display, but I also need the detail rows to display with a blank or zero for all fields.  Adding an additional row to the tablix is not an option, as the textbox names on the additional row must be different within SSRS.  I am using this SSRS report as a data source to a PowerPivot model.  I do not want the PowerPivot model to break when it refreshes and no data exists yet.   I would like to avoid adding an empty row to the data set.  I would prefer a solution that can be implemented with in the SSRS report.


Drawing different tikz shapes parameterized by data from a file

I have a file with three columns of data, x, y, r.  # x y r 1 1 0.1 2 2 0.5 3 3 1.2   and so on. I'd like to loop over the rows, and draw a circle at x,y with radius r for each row.  I first thought I'd use pgfplots with customized marks, but I couldn't figure out how to pass the radius parameter into the pgfplot mark handler. Then I thought I'd use tikz and pgf directly, but I couldn't figure out how to reference the values for r inside a draw command sequence.   Any thoughts ? I'd be very grateful for some help.


Additive identity in a semiring need not be multiplicative annihilator.

We know that an additive identity in a ring is always a multiplicative annihilator. But this doesn't need always be true in case of a semiring. Consider that $e$ is the additive identity of a semiring $S$, then for any $a\in S$, we see that $a.e=a.(e+e)=a.e+a.e \implies a.e=e \iff -a.e \in S.$ Looking for a better suggestion.  Thanks


Save site as template using client object model

I would like to reproduce the "Save site as template" action with the client object model. Can someone give me a hint how to do this?


Trying to run 32bit application on 64bit Ubuntu 16.04 LTS

Just to clarify: I've look up to each existing question with accepted answers, but these questions were asked before Ubuntu 16.04 LTS came out and these answers are no longer working. Tried everything from said commands, but I still can't run 32bit applications.  I'm using Ubuntu 16.04 LTS 64bit. All said libraries are installed, but I still can't get the 32bit applicaton work. This is terminal dump:  error while loading shared libraries: libX11.so.6: cannot open shared object file: No such file or directory   Google doesn't help much and as I said, each question that already have an accepted answer just has outdated informations that are no longer supported or I don't know why it doesn't work, it just doesn't. I've got a little bit upset and will accept ANY working answer.


Can I use the metadata API to check if an instance is being terminated?

Using Windows server 2016 instances.  I want the instance to run a local command before it terminates.  I can have a script run when windows is shutting down.  I would like the script to check if the instance itself is in the terminating state and if so run some clean up stuff.  Not sure from the docs, is there a way to check if the local instance is being terminated from the instance itself?   This returns InstanceStatuses:  aws ec2 describe-instance-status --include-all-instances --instance-ids i-123123123   Which looks like:  {     "InstanceStatuses": [         {             "AvailabilityZone": "us-west-2a",             "InstanceId": "i-123123123",             "InstanceState": {                 "Code": 16,                 "Name": "running"             },             "InstanceStatus": {                 "Details": [                     {                         "Name": "reachability",                         "Status": "passed"                     }                 ],                 "Status": "ok"             },             "SystemStatus": {                 "Details": [                     {                         "Name": "reachability",                         "Status": "passed"                     }                 ],                 "Status": "ok"             }         }     ] }   What does the state looks like when the instance is "terminating"? Not already terminated but pending termination? How can I check if an instance is in the pending termination state?


I have just installed the latest Ubuntu 14.04 and I would like to install KDE along side my Gnome/Unity that I have now. How can I do this?  Thanks!


Can I travel 100% safely with only my Identity Card from Romania to Svalbard?

This is my first trip outside the country, never been on a plane before.. and at the same time I’m going alone. So I’m scared and worried and trying to do as much research as possible. Many sources say that I should be able to go with my identity card, but our ministry’s site still recommends a passport and that stresses me. A passport isn’t free and I don’t want to throw money around.  So is there any 0,0001% chance that I could be stopped because I don’t have a passport?  Yes, I’ve read the Dutch Identity Card post before I came here, but it’s not the same thing, at least that’s how I see it. And I want to make sure it works for my country too.


Prove the following statement about Cauchy sequences...

...without using the fact that a Cauchy sequence of real numbers converges:  If a subsequence of a Cauchy sequence converges, then the Cauchy sequence converges.


How to get the system HTTP proxy configuration in Java

Is it possible to get the system proxy configuration in Java?  In the Java Control Panel, you can set a proxy configuration. How can I access to that proxy configuration in order to open URL connections behind a proxy?


Different behaviors for HashMap and Hashtable when Equals overridden to always return False

I am little confused as I thought HashMap and Hashtable should behaves same way when it comes to hashCode and equals method. in this example below my key class has overridden equals method to always return false.  does any one have any idea that can explain in this difference in behavior because it seem like output is different for both  value null  value null  value Value 1  value Value 2  import java.util.Hashtable; import java.util.HashMap;  public class HashTest {      public static void main(String[] args) {          Hashtable ht = new Hashtable();         HashMap hm = new HashMap();         KeyClass k1 = new KeyClass("k1");         KeyClass k2 = new KeyClass("k2");          ht.put(k1, "Value 1");         ht.put(k2, "Value 2");         hm.put(k1, "Value 1");         hm.put(k2, "Value 2");          System.out.println("value " + ht.get(k1));         System.out.println("value " + ht.get(k2));          System.out.println("value " + hm.get(k1));         System.out.println("value " + hm.get(k2));     } }  class KeyClass {     String key;      public KeyClass(String str) {         key = str;     }      @Override     public int hashCode() {         return 2;     }      @Override     public boolean equals(Object obj) {         return false;     } }


Is the Stack Overflow source code available?

Do the SO admins have any plans to release the underlying code for SO at all? I appreciate that the code may be part of their competitive advantage, but it strikes me that the underlying system would work for any topic, not just programming.  I am not advocating this, just curious really, but figured it might be under consideration as most of the value in SO is in the questions and answers, which have been released under a relatively open CC license.


How do you make tnt spawn on you every 10 seconds in Minecraft?

How do you make TNT spawn on you every 10 seconds in Minecraft with command blocks? I've looked at multiple reddit posts, but they didn't seem to work. The other solutions did not work, as after the timer scoreboard reached the point nothing happened


I have the following simple 2D lists program:  rowMatrix = [0]*4 matrix = [rowMatrix]*4  for a in range(4):     for b in range(4):         matrix[a][b] = random.randrange(0,2) print(matrix)`   It seems like it would put random numbers (0, 1) in all 16 cells of the 4x4 array. But all 4 rows are identical every time. What's wrong?


Transform multiple non-primitive recursive calls to iterative solution

I am writing a handwritten recursive descent parser as a self exercise. I'd like to see if an iterative approach is possible. Generally speaking, I'd like to know what mindset I should have in order to transform interdependent recursive functions into an iterative solution.  In my current minimal example, I have a list of Tokens (which is simply a type with a lexeme) and they are consumed via recursive descent to build an abstract syntax tree represented by a unique_ptr to an expression:  #include <string> #include <memory> #include <vector>  enum Type { Num, Add, Mul, LParen, RParen };  struct Token {   Type type;   std::string lexeme; };  struct Expr {   Token token; };  using AST = std::unique_ptr<Expr>;  struct Literal : public Expr {   double value; };  struct Grouping : public Expr {   AST inner; };  struct Binary : public Expr {   AST lhs, rhs; };  using CIT = std::vector<Token>::const_iterator;  auto expression(CIT& it, CIT end) -> AST;  auto literal(CIT &it, CIT end) -> AST {   if (it != end and it->type == Type::Num) {     auto value = std::stod(it->lexeme);     auto token = *it++;     return std::make_unique<Literal>(Literal{ token, value });   }   else if (it != end and it->type == Type::LParen) {     auto token = *it++;     auto ast = std::make_unique<Grouping>(Grouping{ token, expression(it, end) });;     if (it != end and it->type == Type::RParen)       return ast;     else       throw "Mismatched parenthesis";   }    throw "Unable to parse literal"; }  auto multiplication(CIT &it, CIT end) -> AST {   auto ast = literal(it, end);    while (it != end and it->type == Type::Mul) {     auto token = *it++;     ast = std::make_unique<Binary>(Binary{ token, std::move(ast), literal(it, end) });   }    return ast; }  auto addition(CIT &it, CIT end) -> AST {   auto ast = multiplication(it, end);    while (it != end and it->type == Type::Add) {     auto token = *it++;     ast = std::make_unique<Binary>(Binary{ token, std::move(ast), multiplication(it, end) });   }    return ast; }  auto expression(CIT &it, CIT end) -> AST {   return addition(it, end); }  int main() {   std::vector<Token> tokens = {     { Type::Num, "5"},     { Type::Add, "+"},     { Type::LParen, "("},     { Type::Num, "4"},     { Type::Mul, "*"},     { Type::Num, "3"},     { Type::RParen, ")"},   };    auto it = tokens.begin();   auto ast = expression(it, tokens.end()); }   Here there is a circular dependency of recursive calls: addition depends on multiplication, multiplication depends on literal, and literal 'depends on' addition.  I'd like to see if there is a way to flatten these calls into a singular iterative call. My first thoughts were to loop through the tokens and do a switch case between the precedence of operators; however, I am unsure where to go come there.  Non-complete attempt:   auto parse(const std::vector<Token>& tokens) -> AST {   AST current;    enum class Precedent {     Addition, Multiplication, Literal   };    for (const auto& token : tokens) {     switch (precedent) {       case Precedent::Addition: {         ???       } break;       case Precedent::Multiplication: {         ???       } break;       case Precedent::Literal: {         ???       } break;     }   }    return current; }   I feel that I am missing some kind of stack as a lot of iterative solutions from recursive solutions appear to maintain a manual call-like stack.  Any hints would be appreciated.  Edit: I've reviewed the post referring to the duplicate, though I believe my question is different that the one linked. I am not trying to make a single recursive function into an iterative one, I am trying to make multiple recursive functions into a single iterative function. I hope that explains why I asked this question.


The axiom of Replacement Scheme implies separate axiom. I can not show this lemma. Does someone have any idea about it?


Suppose that the conclusion of a particular argument is ‘Grass is green and it is not the case that grass is green.’ Without knowing anything more about this argument – in particular, without knowing what its premises are – is it possible to tell whether it is valid or invalid? Explain your answer.


I will report to you "in" or "at" Blacktown Hospital?

I am confused about this sentence.  Which statement is correct?  I will report to you in Blacktown Hospital, at 8:00 AM.  I will report to you at Blacktown Hospital, at 8:00 AM.


Zero divisors of $\mathbb{Z}×\mathbb{Z}×\mathbb{Z}$

Find elements $a,b,$ and $c$ in the ring $\mathbb{Z}×\mathbb{Z}×\mathbb{Z}$ such that $ab, ac,$ and $bc$ are zero divisors but $abc$ is not a zero divisor.  Work:   $a=(1,1,0)$ $b=(1,0,1)$ $c=(0,1,1)$   Why this works: because $ab=(1,0,0)\neq(0,0,0)$.     Definition of zero divisor. A zero divisor is a non-zero element $a$ of a commutative ring $R$ such that there is a non-zero $b \in R$ with $ab=0$.   Amy hint or suggestion will be appreciated.


The definition of a metric and the triangle inequality

Let $f:X\times X \to [0,\infty)$ and   1) $f(x,y)=f(y,x)$   2) $f(x,y)=0 \Leftrightarrow x=y$  (Note that we remove the triangle inequality from the definition of a metric.) My question is why the triangle inequality is necessary in the definition of a metric? Why it is useful?


Interpreting glmnet Lasso coefficients on dummy variables (multiple levels)

I am trying to apply glmnet's lasso to a set of features in which there are multiple categorical variables with multiple levels. My intention is to let lasso reduce some of the coefficients of the features down to 0, so that they can be thrown out. Some of my categorical predictors have as many as 50 levels.  The result is that the glmnet is throwing out only some of the levels of the categorical predictors, but keeping some others. My understanding is that this is incorrect - the dummified levels are all a part of the same predictor - so one needs to throw out the entire predictor (with all it's levels) or keep all of them. The data set is large, maybe 600,000 rows. I am trying to predict a binary outcome between two classes.  Here is an example of my code:  library(glmnet) x <- model.matrix(project.status~., data = data_train) y <- data_train$project.status  lasso.net <- cv.glmnet(x, y, alpha = 1, family = "binomial", nfolds = 5,  type.measure = "auc")   and the output:  >coef(lasso.net)   86 x 1 sparse Matrix of class "dgCMatrix"                                                        1 (Intercept)                                    -9.099069e-02 (Intercept)                                     .            project.gradeGrades 6-8                         .            project.gradeGrades 9-12                        6.891742e-02 project.gradeGrades PreK-2                      3.107257e-03 project.resourceBooks                           .            project.resourceClassroom Basics                8.106422e-01 project.resourceComputers & Tablets             5.849269e-01 project.resourceEducational Kits & Games        8.442034e-01 project.resourceFlexible Seating                5.031112e-01 project.resourceTrips                           .            project.resourceVisitors                        .            project.cost                                   -5.286631e-04 school.metro.typesuburban                       1.991501e-02 school.metro.typetown                          -8.060338e-02 school.metro.typeurban                          2.380249e-01 school.percent.lunch                            4.178175e-04 school.stateAlaska                              .            school.stateArizona                            -2.095588e-01 school.stateArkansas                           -1.652419e-01 school.stateCalifornia                          1.209260e-03 school.stateColorado                            6.299693e-02 school.stateConnecticut                         1.186827e-01 school.stateDelaware                            1.829217e-01 school.stateDistrict of Columbia                4.099672e-01 school.stateFlorida                             . school.stateGeorgia                            -2.292140e-01   I've not included the entire output (it's long) but hopefully this presents my issue. The school.state predictor is a categorical predictor with the 50 states. I essentially want to see if I can throw this predictor out, but instead of zeroing the entire predictor, it is only zeroing out some of the states, and keeping the others. Likewise with the project resource and project grade (it's essentially a charity project, I am trying to predict whether they met their funding goal or not).


New QGIS user, 2.6 Brighton.  My project CRS is default to Nad83ft / N.Carolina (US).  I loaded various polygon and line (provided to me) that have various CRS's but they still show correctly in place over USGS / ortho-imagery.  Oddly, setting each file's CRS to NAD83ft / N. Carolina moves them out of view. Clearly I'm missing something about CRS basics.


I'm using the plugin File Upload Types, trying to allow .rfa uploads.  I've tried the three MIME types below to no avail.  Do you have any suggestions? application/octet-stream application/rfa application/CDFV2-unknown


What does left clicking in the 3D view do?

I don't understand what the white circle with the cross is for. I can change its position by left mouse click in the 3D view. Why does it change its position and what it is for?


Universal covering spaces of homotopy equivalent spaces are homotopy equivalent

I'm working on an exercise from Hatcher's Algebraic Topology (exercise 1.3.8):     Let $\tilde X$ and $\tilde Y$ be simply-connected covering spaces of the path-connected, locally path-connected spaces $X$ and $Y$. Show that if $X \simeq Y$ then $\tilde X \simeq \tilde Y$.   The exercise recommends using the following result from earlier in the textbook:      A map $f: X \to Y$ is a homotopy equivalence if there exist maps $g, h: Y \to X$ such that $fg \simeq \mathbb{1}$ and $hf \simeq \mathbb{1}$.    This problem has been solved  and , but both proofs include a step that seems to be a bit of a jump. It's possible I'm missing a very simple argument, but this is the one piece I'm having trouble with.   Here's what I have so far: Let $p : \tilde X \to X$ and $q: \tilde Y \to Y$ be the respective covering maps, and let $f : X \to Y$ and $g : Y \to X$ be homotopy inverses (so $gf \simeq \mathbb{1}_X$ and $fg \simeq \mathbb{1}_Y$). Consider the map $fp : \tilde X \to Y$, and the induced homomorphism $(fp)_*: \pi_1(\tilde X) \to \pi_1(Y)$. Since $\tilde X$ and $\tilde Y$ are simply-connected, $(fp)_*(\pi_1(\tilde X)) = 0 = q_*(\pi_1(\tilde Y))$, so by the lifting criterion (prop. 1.33 in Hatcher), we have a lift $\tilde f : \tilde X \to \tilde Y$ of $fp : \tilde X \to Y$. We similarly have a lift $\tilde g : \tilde Y \to \tilde X$ of $gq: \tilde Y \to X$.   This gives us that $p\tilde g \tilde f = gq\tilde f = gfp \simeq p$. Call this homotopy $h_t : \tilde X \to X$, so that $h_0 = p\tilde g \tilde f$ and $h_1 = p$. By the homotopy lifting property, since $\tilde g \tilde f : \tilde X \to \tilde X$ lifts $p \tilde g \tilde f$, there is a homotopy $\tilde h_t$ between $\tilde g \tilde f$ and a lift $\tilde p$ of the covering map $p : \tilde X \to X$. In particular, $p\tilde p = p$.   Here's my problem: In the first of the links I shared, they claim that $\tilde p$ is a deck transformation of $\tilde X$ (ie a homeomorphism with the property that $p \tilde p = p$). In the second of the links, they claim something stronger: that by uniqueness of lifts, in fact $\tilde p = \mathbb{1}_{\tilde X}$. The trouble with the first of these answers is that it's not clear to me that $\tilde p : \tilde X \to \tilde X$ is a homeomorphism. The trouble with the second is that uniqueness of lifts only applies if we can prove that $\tilde p$ fixes a point of $\tilde X$, which is also not clear. (Plus $\tilde p = \mathbb{1}_\tilde X$ seems like too much to ask for because then one could similarly show that $\tilde q = \mathbb{1}_{\tilde Y}$, which gives that $\tilde g \tilde f \simeq \mathbb{1}_\tilde{X}$ and $\tilde f \tilde g \simeq \mathbb{1}_\tilde{Y}$, and we are done without using the recommended hint.)   The proof can easily be completed after this is taken care of, but I'm having trouble justifying this. Is there a good reason $\tilde p : \tilde X \to \tilde X$ is a homeomorphism, or better, the identity map of $\tilde X$? Thanks!


is it possible for someone to run a computer search for me to turn up integers $a,b,c,d$ such that $$1+\sqrt{2}+\sqrt{3}+\sqrt{6}=\sqrt{a+\sqrt{b+\sqrt{c+\sqrt{d}}}}$$? Note: I know they exist, I just can't find them.


If early exercise is a bad idea, why American option is more expensive than European

American options are more expensive than European options because they give the buyer the right to early exercise.   But in a low interest environment, early exercise is   So it seems like the extra premium paid for American option is not worth it. Is it true?


minted environment not working in overleaf

The code it's not working on Overleaf when it comes to minted environment (or mint command) used in a file placed in a subdirectory. Note that the very same code works if placed in main directory. Tested on Chrome with LaTex,PdfLaTex,XeLaTex and LuaLaTex  You can test the example on  but for your convenience I can add a MWE:  \documentclass{article} \usepackage{minted}  \begin{document} test \begin{minted}{python} import numpy as np  def incmatrix(genl1,genl2):     m = len(genl1)  \end{minted}  \mint{html}|
Something here
|  \end{document}   This will produce only the line "test".  Please note that \inputminted works as a charm; I adopted this as a workaround but there are cases in which it is really a nuisance.  Obviously with non trivial projects it is almost impossible for me to keep every file in the same (overleaf) folder.  The log says:(twice, another almost identical is for \mint)  Package minted Error: Missing Pygments output; \inputminted was  probably given a file that does not exist--otherwise, you may need  the outputdir package option, or may be using an incompatible build tool, or may be using frozencache with a missing file.  See the minted package documentation for explanation. Type  H <return>  for immediate help.  ...                                                l.12 \end{minted}  This could be caused by using -output-directory or -aux-directory  without setting minted's outputdir, or by using a build tool that  changes paths in ways minted cannot detect,  or using frozencache with a missing file.


I went to sign up for Ubuntu One and during the sign up process, I had to wait for the authentication code before I could proceed. I thought this was an instant process and it took a while for the email to come. So I exited the program and now I cant find where to enter in the authentication code at or how to bring it back up. Any help would be appreciated, Thank you.


Why is java telling me the string are not matching?

I'm reading in from a text file. every time the frame number changes I need to check if the ipv6 address is changed. every time I compare the strings it tells me they don't match even after setting the value to the source address.


Page numbers in roman numerals instead of cardinal numbers

I don't understand why in the first chapter of this book, the page number is made of roman numerals, like in preface pages  \documentclass[italian,a4paper,11pt,twoside]{book} \usepackage[T1]{fontenc} \usepackage[latin9]{inputenc} \usepackage{geometry} \usepackage{graphicx} \usepackage{forest} \setcounter{secnumdepth}{3} \setcounter{tocdepth}{1} \usepackage{float} \usepackage{babel} \usepackage{microtype} \usepackage{indentfirst}    \geometry{textheight=24.2cm,textwidth=16cm} \pagestyle{headings} \frenchspacing  \title{ \huge Guida semplificata a Herbertlandia}  \author{Salvo Errori}  \makeindex  \begin{document} \frontmatter  \maketitle \tableofcontents  \chapter{Introduzione}  Il gatto è sul tavolo. Il gatto mangia il cibo. Il gatto è sul tavolo. Il gatto mangia il cibo. Il gatto è sul tavolo. Il gatto mangia il cibo.   \end{document}   The preamble has been written having in mind the example


What Stack Exchange sites and features are not available in the Android app?

I just installed the app, and noticed that not all sites are present there, and are not directly accessible in the app.  My question is, what are the sites which not available on the app directly?  As This would be informative to the other users.


Why are both Blade Runner films largely shot in darkness?

I watched both the Blade Runner movies today. A few significant things I come across were that 90% of both of the movies' scenes are night scenes.  Why did both the directors choose to direct so many dark and night scenes? And some part of Blade Runner 2049 is shot in orange forecolor, for displaying radiation. Why orange? Radiation has nothing directly to do with orange color, so why this choice?


How to Moq Mock a LoggerFactory in C# AspNet Core

I am trying to write some unit tests for controller actions.  To do that, I am using XUnit and Moq.  The controllers have an ILoggerFactory injected in the constructor.  How does one Moq this up for testing?    I have tried mocking a Logger for the controller class, and then mocking up CreateLogger to return the mock Logger, but I keep getting various test runtime NullReferenceExceptions when the LogInformation() function is called.          //   Logger that yields only disappointment...                   var mockLogger = new Mock<ILogger<JwtController>>();         mockLogger.Setup(ml => ml.Log(It.IsAny<LogLevel>(), It.IsAny<EventId>(), It.IsAny<object>(), It.IsAny<Exception>(), It.IsAny<Func<object, Exception, string>>()));         var mockLoggerFactory = new Mock<ILoggerFactory>();         mockLoggerFactory.Setup(mlf => mlf.CreateLogger("JwtController")).Returns(mockLogger.Object);   I assume the problem is that LogInformation is being called, and this is an extension method, so how to moq that?


$$\begin{bmatrix} 1235 &2344 &1234 &1990\\ 2124 & 4123& 1990& 3026 \\ 1230 &1234 &9095 &1230\\ 1262 &2312& 2324 &3907  \end{bmatrix}$$  Clearly, its determinant is not zero and, hence, the matrix is invertible.   Is there a more elegant way to do this?  Is there a pattern among these entries?


Why don't Jedi (or Sith) use the Force to snap their foes' necks?

I understand that the Jedi use the Force for self defence, but still, couldn't they just use the Force to snap their foes' necks and be done with it? Like when Jaina Solo was hunting down Darth Caedus. Or even when Caedus was duelling Grand Master Skywalker. If he just used the Force to snap Skywalker's neck (like he did to poor Lieutenant Tebut), it will all be over very fast.  Is there a canon reason why Jedi and Sith don't use their powers to directly harm their opponents?


Find all positive integers n such that 20n+2 can divide 2003n+2002

Could someone give me a hint to this problem please? Here is what I do: $2003n+2002=100(20n+2)+3n+1802$ then I'm stuck at $20n+2|3n+1802$ Please help


I am trying to write a new enviroment to add text into a \fbox, when I use \fbox on its own, it works quite nicely  \fbox{\begin{minipage}{0.9\textwidth} does this work, I would love if it did \end{minipage}}   If I then add this into a new comand called notes Latex dosen't seem to like it  \newenvironment{notes} {\fbox{\begin{minipage}{0.9\textwidth}}} {\end{minipage}}   When I then enter something into this environment in my document it comes up with errors  \begin{notes} Does this work, I would love if it did \end{notes}   The error I recieve is:  ! Extra }, or forgotten \endgroup. \fbox ...xsep {#1}\kern \fboxsep \color@endgroup } \@frameb@x \relax  l.80 \begin{notes}  ?


So, in season 5/The Winds of Winter,      Myrcella dies/will likely die.   If not, let's just say for the sake of argument that that's the case.  Now assuming for some reason that      Tommen and Margaery did not conceive   at a time when      Joffrey, Tommen and Myrcella   are dead, who      becomes king/queen   ?  Let's not get into speculative stuff like the      kingdoms rebel or secede or someone invades Westeros   Let's assume some ideal situation like the relevant lords believe (at least in practice) that      Tommen, Myrcella and Joffrey are legitimate heirs of Robert Baratheon   and      Daenerys/Aegon/fAegon   doesn't/don't invade anytime soon.  In general, what does the small council/High Septon et al do in situations like these?  What about the wardens or other lords and ladies of Westeros? What might they do? Would this affect them?


I am having trouble explaining what I really want...here is another try... On sheet The digits in range a5:a is multiply by 12,13,37,101,111 using the formula arrayformula(if(a5:a="",,a5*{12,13,37,101,111})).. the results are distributed across b5:f which is then conditionally formatted to highlight duplicates when compared to the list of digits in i5:I and k5:k.. This is working great.... But I to advance this setup.... I actually want the following... Once a duplicate is detected..... state's name and duplicate number (h5:I or j5:k)..is generated in the range B5:f or even A5:f .. thus displaying the state and exact number drawn in that specific state... And in the case where there are no duplicates....results from the arrayformula(if(a5:a="",,a5*{12,13,37,101,111})) Remains the same....until a duplicate is generated ....it is important to note that foundation of these data is scrapped from a webpage...I have got several help from persons online with the creation of formula as I develop the sheet


Possible to overload null-coalescing operator?

Is it possible to overload the null-coalescing operator for a class in C#?    Say for example I want to return a default value if an instance is null and return the instance if it's not. The code would look like something like this:     return instance ?? new MyClass("Default");     But what if I would like to use the null-coalescing operator to also check if the MyClass.MyValue is set?


How can I make pokestops and gyms around me? This game isn't just for adults it's also for kids not all mothers let their kids go where they want. There is a pokestop pretty close to me but I can't walk all the way over there crazy things happen and the gyms are even further the only time I get around them is when we are driving but of course when your driving it's only for a few seconds I can't have my mom park in the middle of the street to be in a gym or for a pokestop... How can I add them around me?


How to secure or protect files and derectory with password using software

I am now use Ubuntu 14.04 desktop and I want to secure directory or files using password then please suggest me to best software or else if any other methods than also suggest me...


What is the recommended exposure time for presentisized positive photoresist board?

What is the recommended exposure time for presentisized positive photoresist board using UV light, fluorescent light, CFL bulb and (will it also work with LED light)?   How do we also determine if the resulting exposed board that failed is overexposed or underexposed like this?


Translate postgis data to a coordinate system

I have a PostGIS database where the data is in an unknown or incorrect coordinate system.  Is there a way given some known points in the data to translate all the data to a specific coordinate system.


How to read "service --status-all" results

I need to identify the currently running services but I can't figure out the results of running service --status-all, I mean what does ?, - and + mean ?  $ service --status-all  [ + ]  acpid  [ + ]  anacron  [ + ]  apparmor  [ ? ]  apport  [ ? ]  atieventsd  [ + ]  avahi-daemon  [ ? ]  binfmt-support  [ + ]  bluetooth  [ - ]  brltty  [ + ]  console-font  [ + ]  console-setup  [ + ]  cron  [ + ]  cups  [ + ]  cups-browsed  [ - ]  dbus  [ ? ]  dns-clean  [ + ]  friendly-recovery  [ - ]  grub-common  [ ? ]  irqbalance  [ - ]  kerneloops  [ ? ]  killprocs  [ + ]  kmod  [ ? ]  lightdm  [ - ]  lm-sensors  [ ? ]  mysql  [ ? ]  networking  [ ? ]  ondemand  [ ? ]  pppd-dns  [ - ]  procps  [ - ]  pulseaudio  [ ? ]  rc.local  [ + ]  resolvconf  [ + ]  rfkill-restore  [ + ]  rfkill-store  [ - ]  rsync  [ + ]  rsyslog  [ + ]  saned  [ ? ]  sendsigs  [ + ]  setvtrgb  [ ? ]  speech-dispatcher  [ - ]  sudo  [ + ]  timidity  [ + ]  udev  [ ? ]  umountfs  [ ? ]  umountnfs.sh  [ ? ]  umountroot  [ - ]  unattended-upgrades  [ - ]  urandom  [ + ]  virtualbox  [ - ]  x11-common   And would running this command with sudo make any difference ? I tried it and in my case it didn't make any difference, but may it differ in other setups ?


I really wonder which sentence below is correct with using "more".      We have 2 hours more.   Or     We have 2 more hours.   What I was thinking about "more" is that the second sentence sounds correct. but I am still not sure..


What is a word for "a person who studies all subjects"?

I think it should be "philosopher", but I am not sure.  Does philosophy encompass all subject matter?  Is there a word that describes someone who studies all subjects?  So, if a scientist studies science, and a theologian studies religion, is there a word for someone who studies both?  A sample sentence might be:     The '_____' is constantly learning, because the universe is infinite.   Here is an analogy:     Science is to Scientist as Everything is to '_____'.   Edit:  The word is likely to end with -ist or -er. The word should describe a person who specifically studies everything. My made up word would be: "everythingologist".


Why did the slaver in Astapor think Daenerys wouldn't do exactly what she did?

Spoilers! (do I have to even say that here?)  I recently rewatched the episode of Game of Thrones where Daenerys is in Astapor. She makes the deal with the master slaver guy, where she trades him one of her dragons for 8,000 of his very tough slaves. I immediately thought this was stupid for two reasons:   Why would he think the dragon would immediately obey him rather than her? Maybe he doesn't quite believe the 'Mother of Dragons' lore, but it's still basically a pet at the very least. This one isn't as bad though, as... Why would he possibly think she wouldn't betray him and use her freshly bought slaves to take back her dragon? He just traded her literally all his slaves and he has not been kind to her so far. He has motivation to not go back on the deal -- he's running a business, basically... but she has no reason not to.   I guess you could argue that he was blinded by greed, but I think that would be poor writing -- he's in a vicious trade, I can't imagine he would've survived long thinking so naively.  Does anyone have a good explanation?


What is a term for sentences that are grammatically correct but carry no meaning of their own?

An example of a sentence like this would be "The bus will come when it comes." and others along the same line. Do these types of sentences have a special name?


What nouns of German origin should be given capital letters?

On another post an interesting fact has just been discovered about the OED's treatment of nouns adopted into English from German (loan-words).  A lot of them e.g. Nazi are spelled with a capital letter. Similar words, which are not of German origin, such as communist or socialist are not spelled with a capital.  Equally Zeitgeist, and Blitzkrieg are also given capitals, but interestingly not kindergarten or bratwurst.  Of course, in German all nouns are given capital letters, not just proper nouns as in English.   What is it that determines whether a noun adopted into English from German should have a capital letter?


We know that the protons in a nucleus are positively charged. So why does the nucleus stay intact?

We know that the protons in a nucleus are positively charged, whereas the neutrons do not possess a charge; we also know that unlike charges attract. So why does the nucleus stay intact, even though there isn't supposed to be any electrostatic force of attraction within it? Instead, why isn't there any repulsion between the protons which are like-charged?


Minecraft - how can you teleport someone in an area to another area?

I'm asking if there is a 3x3 area and if a player hits a specific part of that area can he be teleported to a similar 3x3 area I set up?


Hi are there any tips or procedures in order to get a neural network which generalizes over whole data and difference between training loss error and test error does not increase dramatically over time? what can we do at all except just training and watching if training loss error and test error diverge or not?


User Search results not sorted by reputation

The  used to sort users by reputation in the given timeframe both when listing all users and when searching specific user names. This allowed us to find the user with the highest reputation and a specific name, or search for specific high reputation users when we knew their name but not their user ID.  Now, it only appears to sort users by reputation when a search term is not entered, otherwise it is sorted by user ID.  Results without search term:   Results with search term:   We can see from the results in  that it used to work as intended (although the image is old I remember it functioning far more recently):    This appears to affect all sites.


Please help, had been trying but I always get 0% code coverage, I need a test class for the Invocable method below (Please note that the class is called being called from a flow which is triggered by a button), thanks in advance:  public class CMZoomUpdater{ @InvocableMethod(label='CMZoomUpdater')        public static void cmzuM(List<String> campL){          System.debug('g ' + campL[0]);                List<CampaignMember> deleteL = new List<CampaignMember>();          List<CampaignMember> idLMember = new List<CampaignMember>();          List<CampaignMember> memberL = [SELECT Id, Status, CampaignId, ContactId, Zoom_Reg_Link__c FROM CampaignMember WHERE CampaignId = :campL[0] AND Zoom_Reg_Link__c = NULL];          for(CampaignMember memberF : memberL){              idLMember.add(new CampaignMember (ContactId = memberF.ContactId, Status = memberF.Status, CampaignId = memberF.CampaignId));              deleteL.add(new CampaignMember(Id = memberF.Id));           }             System.debug('deleteL count is ' + deleteL.size());             delete deleteL;          System.debug('idLMember count is ' + idLMember.size());         insert idLMember; //        System.debug('idLMember count is ' + idLMember.size());      }  }


Crazy automatic float rounding in MySQL 5.7

My exact MySQL version is 5.7.29-0ubuntu0.18.04.1. And I'm beginning to think that I'm getting crazy...  Just try these queries:  CREATE TABLE `float_bug` (   `v` FLOAT NOT NULL ) ENGINE=INNODB DEFAULT CHARSET=utf8;   INSERT INTO float_bug VALUES(92160596);   SELECT * FROM float_bug;   Returns 92160600.  Then I tried these:  SELECT * FROM float_bug WHERE v = 92160596; SELECT * FROM float_bug WHERE v BETWEEN 92160596 AND 92160600;   Both return nothing!  However this  SELECT * FROM float_bug WHERE v = 92160592;   Returns 92160600.  I'm ready to throw my computer into the wall, but unfortunately that won't help because I have exactly the same behaviour on my remote server and I can't throw it into the wall physically.  Any ideas what is going on here?


Can this phrase be used this way?: to mock at someone who said some kind of nonsense or the way what he did or the way how he looks. Or is it possible?  For example: I can't with/from your stupid laugh.     I can't with/from you     Urbandictionary's Definition:  Meaning, you're a weirdo. You need help  Example: I can't with you right now Joe


I created an account on StackOverflow when I had no idea of how to ask questions or what exactly needs to be asked on StackOverflow. I had just started with Python at that time. Currently I have been banned to ask questions but now I have better idea(not good yet) on which questions are for StackOverflow and which are for a forum or chat.I recently got to know about Meta, and Code Review too and here I got my first question >=0greater than or equal to 0 votes whereas on StackOverFlow I have all questions with <=0less than or equal to 0 votes. So how do I start afresh? Well, it's written to improve previous questions but those questions are too bad to be improved or some I 'm tired of improving. I can't but just delete them. What should I do? I know deleting an account or creating multiple accounts won't help but what is the option for people who are learning to code by themselves? StackOverflow doesn't have any prerequisites but I 'm learning slowly and like I said I tried on all three sites Meta, Code Review and StackoverFlow. I got my first answer +5 on Meta , +3 on CodeReview and <=0 for all StackOverFlow. Should I take it that I 'm unfit to ask on StackOverflow ?


Programatically create new CSS rules in a stylesheet

For creating new CSS rules in a stylesheet, as of now, I only know .insertRule() (excluding the non-standard ways).  Are there any other ways of creating more CSS rules? Something, for example: Warning: this is not standard, it is just an example to display the intent  var rule = new CSSStyleRule(); rule.selectorText = '.selector'; rule.style.display = 'block'; rule.style.color = 'red'; ruleSet.append(rule);   Anything like or somewhat like the above works as an answer. Instead of new, it may be document.createCssRule() or stylesheet.createCssRule()... I just this it would be useful for a piece of software I'm developing which left me if there's a programatically way of modifying values in such interface where to add new stuff is not restricted to a parsed string.  Do not worry about IE9 and below when answering, please.  Note: (to unclose) This is not about how to find and modify current CSS rules, this is about making new ones without using the text parser which is what .insertRule() is without building a complete CSS string like .insertRule() requires.


Why does the fundamental theorem of calculus work?

I've known for some time that one of the fundamental theorems of calculus states:  $$ \int_{a}^{b}\ f'(x){\mathrm{d} x} = f(b)-f(a) $$  Despite using this formula, I've yet to see a proof or even a satisfactory explanation for why this relationship holds. Any ideas?


Proof of $\lim_{n\to \infty}\frac 1 {n^{k+1}}\sum_{i=1}^n i^{k}=\frac 1 {k+1}$

Prove the relation $\lim_{n\to \infty}\frac 1 {n^{k+1}}\sum_{i=1}^n i^{k}=\frac 1 {k+1}$ for any non negative integer k.


Evaluating $ \sum_{i=0}^{\infty}ir^i$ for $|r|\lt 1$

I'm doing my mathematics homework and there's question which I'm pretty much unable to solve. I've literally tried every method but no results. It'd be great, if anybody could help me. Thanks (in advance).  $$ \sum_{i=0}^{\infty}ir^i$$  $$|r|\lt 1$$I need the step-wise procedure.  I tried solving it on wolfram alpha and the answer which it gives it, $$\frac{r}{(1-r)^2}$$


I run Ubuntu 14.04 64 bit and I have a Canon PIXMA MG5450 printer connected to the PC with cable. I turn it on and it is not recognized automatically, I can't find any drivers official drivers for it.  Is there any unofficial driver that make it work?


Find a formula for $1 + 3 + 5 + ... +(2n - 1)$, for $n \ge 1$, and prove that your formula is correct.

I think the formula is $n^2$.  Define $p(n): 1 + 3 + 5 + \ldots +(2n − 1) = n^2$  Then $p(n + 1): 1 + 3 + 5 + \ldots +(2n − 1) + 2n = (n + 1)^2$  So  $p(n + 1): n^2 + 2n = (n + 1)^2$  The equality above is incorrect, so either my formula is wrong or my proof of the implication is wrong or both.  Can you elaborate?  Thanks.


Why is my camera showing a lot of stuck red and white pixels?

After shooting for one hour with my Rebelt2i + Tamron 17-55 f2.8, I went back home and checked pictures on my computer.  For every single picture, there are a lot of 'dead' pixels at the same location. I searched on Google and it could be dust, dead pixels, hot pixels...  Do you have any suggestions on what the problem really is, and how to solve it?  Look between two buildings on the right, a few in the sky too:  (Click for large version.)    Question  by :  Every picture that I took today have a red dot on the same place in every photo.  It looks like a monitor "pixel error".  Is just the lens dirty or did something bad happen to my cam?   Best mode to detect the dot is download the picture in original size (click the (i) then download)


I have not seen any Star Wars movies till date. I don't have any idea about the timeline of Star Wars but recently after the release of Solo: A Star Wars Story, a curiosity has been awakened in me. So I would highly appreciate if anybody can tell me the order in which I should watch these movies to get a better understanding of the Star Wars universe.


Actually i am a new developer .these errors come: Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException

The eclipse compiler shows Null pointer exception and large number of statements.Actually i am coding for a basic calulator in desktop application and i dont know what went wrong     `       import java.awt.*;       import java.awt.event.ActionEvent;       import java.awt.event.ActionListener;    import javax.swing.*;   class Calcc extends JFrame implements ActionListener   {   Calcc n;   String l="b";   int z=0;   JFrame f;   JTextField t1=new JTextField(30);      JTextField t2=new JTextField(10);     JButton b1=new JButton("1");   JButton b2=new JButton("2");   JButton b3=new JButton("3");   JButton b4=new JButton("4");   JButton b5=new JButton("5");   JButton b6=new JButton("6");   JButton b7=new JButton("7");   JButton b8=new JButton("8");   JButton b9=new JButton("9");   JButton b10=new JButton("0");   JButton b11=new JButton("+");   JButton b12=new JButton("-");   JButton b13=new JButton("*");   JButton b14=new JButton("/");   JButton b15=new JButton("=");   Calcc()   {     f=new JFrame();     f.add(t1);     f.add(t2);     f.add(b1);     f.add(b2);     f.add(b3);     f.add(b4);     f.add(b5);     f.add(b6);     f.add(b7);     f.add(b8);     f.add(b9);     f.add(b10);     f.add(b11);     f.add(b12);     f.add(b13);     f.add(b14);     f.add(b15);     b1.addActionListener(this);     b2.addActionListener(this);     b3.addActionListener(this);     b4.addActionListener(this);     b5.addActionListener(this);     b6.addActionListener(this);     b7.addActionListener(this);     b8.addActionListener(this);     b9.addActionListener(this);     b10.addActionListener(this);     b11.addActionListener(this);     b12.addActionListener(this);     b13.addActionListener(this);     b14.addActionListener(this);     b15.addActionListener(this);     f.setVisible(true);     f.setSize(350,350);     f.setLayout(new FlowLayout());     f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);   }   public void actionPerformed( ActionEvent e)   {      String d;     d=t1.getText();     if(e.getSource()==b1)     {         t1.setText(d+"1");     }     if(e.getSource()==b2)     {         t1.setText(d+"2");     }     if(e.getSource()==b3)     {         t1.setText(d+"3");     }     if(e.getSource()==b4)     {         t1.setText(d+"4");     }     if(e.getSource()==b5)     {         t1.setText(d+"5");     }     if(e.getSource()==b6)     {         t1.setText(d+"6");     }     if(e.getSource()==b7)     {         t1.setText(d+"7");     }     if(e.getSource()==b8)     {         t1.setText(d+"8");     }     if(e.getSource()==b9)     {         t1.setText(d+"9");     }     if(e.getSource()==b10)     {         t1.setText(d+"0");     }     if(e.getSource()==b11)     {         t1.setText(d+"+");     }     if(e.getSource()==b12)     {         t1.setText(d+"-");     }     if(e.getSource()==b13)     {         t1.setText(d+"*");     }     if(e.getSource()==b14)     {         t1.setText(d+"/");     }     if(e.getSource()==b15)     {         while(l!="a")         {             int b=n.CalcA(d);             if(l=="+")                 z=z+b;             else if(l=="-")                 z=z-b;             else if(l=="*")                 z=z*b;             else if(l=="*")                 z=z*b;         }         t2.setText(String.valueOf(z));     }    }    int CalcA(String d1)   {      l="a";     int k = 0;     while((d1!="+")&&(d1!="-")&&(d1!="*")&&(d1!="/"))     {     if(d1!="\n")     break;     k=k*10+Integer.valueOf(d1);     }     l=d1;     return k;     }  }   public class CalcD  {    public static void main(String[] args)  {    new Calcc();  }  }   `


"~19 suggested edits pending approval" -> "There are no items for you to review."

Why there are no items for you to review while the counter fluctuates around 20 (never seen it that big)? I remember that the counter is not precise, but now it's way off.  After some page refreshes, it showed me a some reviews, but fewer than usual (the counter is still high).


How to save a command you entered without executing it?

Every Linux user has experienced this annoying thing: you begin typing a long and boring command, then realise you should have executed another one before. How to save the first one to execute it later?  Example  You begin typing   mycommand -a -F --conf /very/long/path --and /another/one /input/file.txt   But before pressing "Enter", you realise you should've done cp f.txt /input/file.txt at first.  So, you're stuck with your command, and if you don't press Enter you won't be able to have it back using your bash history.  What's the best way to handle this?


I’d like to implement a function in Bash which increases (and returns) a count with every call. Unfortunately this seems non-trivial since I’m invoking the function inside a subshell and it consequently cannot modify its parent shell’s variables.  Here’s my attempt:  PS_COUNT=0  ps_count_inc() {     let PS_COUNT=PS_COUNT+1     echo $PS_COUNT }  ps_count_reset() {     let PS_COUNT=0 }   This would be used as follows (and hence my need to invoke the functions from a subshell):  PS1='$(ps_count_reset)> ' PS2='$(ps_count_inc)   '   That way, I’d have a numbered multi-line prompt:  > echo 'this 1   is 2   a 3   test'   Cute. But due to the above mentioned limitation doesn’t work.  A non-working solution would be to write the count to a file instead of a variable. However, this would create a conflict between multiple, simultaneously running sessions. I could append the process ID of the shell to the file name, of course. But I’m hoping there’s a better solution which won’t clutter my system with lots of files.


What do you call someone when they don't believe in something then they believe in it when they see it themselves?

Jesse didn't believe that there are notebooks, Then when he saw it for himself he believed the was.


I had always assumed that it was a struggle to capture Mad-Eye Moody, one of the most powerful and paranoid ex-Aurors in the history of the Ministry.  Following on from this  it seems like Mad-Eye was overwhelmed quickly and quietly:     Wormtail and I did it. We had prepared the Polyjuice Potion beforehand. We journeyed to his house. Moody put up a struggle. There was a commotion.... I was ready to face Arthur Weasley when he arrived to sort out the Muggles who had heard a disturbance. I made the dustbins move around the yard.   To my knowledge, the dustbins moving were the only thing that alerted Arthur, or anyone else, to the commotion. Unless I'm misunderstanding, Wormtail and Crouch Jr incapacitated Moody without any noise, and then set off the bins... But this doesn't make sense.  What am I missing?


How to play an original dvd (.vob file) in VLC?

When I play an original DVD in VLC, it does not play properly. i.e. it sticks too much, while on the other hand it plays smoothly in Windows Media Player (though it doesn't allow seeking).  The video files in the dvd are in .vob format. The other movies and clip in my pc that are also in .vob format are played perfectly by VLC. Why isn't it the case for this this DVD? Moreover I copied the entire DVD on my computer but the problem persists.  I'm using VLC 2.1.3 (Rincewind). How can I make it work well on VLC? Do I have to use another video player?


can't install both packages duplicity and python-gi

Both packages duplicity and python-gi are no longer available in the repositories. I'm using Ubuntu 16.04 LTS. Can anyone suggest a solution? Thank you in advance.  ~$ sudo apt-get install duplicity python-gi Reading package lists... Done Building dependency tree        Reading state information... Done Package python-gi is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source  Package duplicity is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source  E: Package 'duplicity' has no installation candidate E: Package 'python-gi' has no installation candidate


this method keeps returning Null for some reason  it should create and return either a .jpg or a .mp4 file  private static File getOutputMediaFile(int type) {     // External sdcard location     File mediaStorageDir = new File(             Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),             Config.IMAGE_DIRECTORY_NAME);     // Create the storage directory if it does not exist     if (!mediaStorageDir.exists()) {         if (!mediaStorageDir.mkdirs()) {             Log.d(TAG, "Oops! Failed create "                     + Config.IMAGE_DIRECTORY_NAME + " directory");             return null;         }     }     // Create a media file name     String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss",             Locale.getDefault()).format(new Date());     File mediaFile;     if (type == MEDIA_TYPE_IMAGE) {         mediaFile = new File(mediaStorageDir.getPath() + File.separator                 + "IMG_" + timeStamp + ".jpg");     } else if (type == MEDIA_TYPE_VIDEO) {         mediaFile = new File(mediaStorageDir.getPath() + File.separator                 + "VID_" + timeStamp + ".mp4");     } else {         return null;     }     return mediaFile; }   i can't figure out why? i call for it here in order to obtain a file Uri ontop of the specified action above  private void captureImage() {     Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);     fileUri = FileProvider.getUriForFile(Camera.this,             "com.company.example.provider",             Objects.requireNonNull(getOutputMediaFile(MEDIA_TYPE_IMAGE)));     intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);     startActivityForResult(intent, CAMERA_CAPTURE_IMAGE_REQUEST_CODE); }   but as soon as captureImage() gets to FileProvider.getUriForFile() it crashes due to Null Pointer Exception  2020-01-16 14:39:52.766 13603-13603/com.company.example E/AndroidRuntime: FATAL EXCEPTION: main     Process: com.company.example, PID: 13603     java.lang.NullPointerException         at java.util.Objects.requireNonNull(Objects.java:203)         at com.company.example.Camera.captureImage(Camera.java:76)         at com.company.example.Camera.lambda$onCreate$0$Camera(Camera.java:44)         at com.company.example.-$$Lambda$Camera$TibLnS7dWo_dEUw9GC45GOADOCo.onClick(Unknown Source:2)         at android.view.View.performClick(View.java:6274)         at android.view.View$PerformClick.run(View.java:24859)         at android.os.Handler.handleCallback(Handler.java:789)         at android.os.Handler.dispatchMessage(Handler.java:98)         at android.os.Looper.loop(Looper.java:164)         at android.app.ActivityThread.main(ActivityThread.java:6710)         at java.lang.reflect.Method.invoke(Native Method)         at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:770)