I have the following code and I am getting these errors:  "/tmp/ccymmVdG.o: In function `main': 1main.cpp:(.text+0x30): undefined reference to `unique_int_ptr::unique_int_ptr(int*)"   unique_int.hpp  #ifndef UNIQUE_PTR_HPP_INCLUDED #define UNIQUE_PTR_HPP_INCLUDED #include <typeinfo>  template<class Template> class unique_ptr {      public:            unique_ptr(Template* ptr);           ~ unique_ptr();           Template* get();           Template* operator->();           Template& operator*();      private:           Template* m_ptr;          /* unique_ptr(unique_ptr<Template> const&);           unique_ptr& operator=(const unique_ptr&);*/ };  #endif /* UNIQUE_PTR_HPP_INCLUDED */   unique_int_ptr.hpp  #ifndef UNIQUE_PTR_INT_HPP_INCLUDED #define UNIQUE_PTR_INT_HPP_INCLUDED   class unique_int_ptr {     public:         int* get();         unique_int_ptr (int* data);         ~unique_int_ptr ();     private:         int* m_ptr; }; #endif //UNIQUE_PTR_INT_HPP_INCLUDED   unique_ptr.cpp  #include <stdio.h> #include "unique_ptr.hpp"  template<typename Template>  unique_ptr<Template>::unique_ptr(Template* ptr) {     m_ptr = ptr; }  template<typename Template>  unique_ptr<Template>::~unique_ptr() {     delete m_ptr; }  template<typename Template>  Template* unique_ptr<Template>::get() {     return m_ptr; }  template<typename Template> Template* unique_ptr<Template>:: operator ->() {     return m_ptr; }  template<typename Template> Template& unique_ptr<Template>::operator *() {     return *m_ptr; }   unique_int_ptr.cpp      #include "unique_int_ptr.hpp" #include <stdio.h>  unique_int_ptr::unique_int_ptr (int* data) {     m_ptr = new int;     m_ptr = data; }  unique_int_ptr::~unique_int_ptr() {     delete m_ptr; }  int* unique_int_ptr::get () {      return m_ptr; }   1main.cpp  #include "unique_ptr.hpp" #include "unique_int_ptr.hpp" #include <stdio.h> #include <iostream>  #define TEST_TRUE(x)  printf("Test '%s' %s\n", #x, (x) ? "passed" : "failed!") struct SimpleData {     int first;     char second; }; this is my main function  int main() {     {         int* data = new int(55);    // allocate raw pointer          // create a managed pointer and let it manage data         unique_int_ptr data_ptr(data);          // Make sure that both pointers show the same value         TEST_TRUE(*data == *data_ptr.get());          // Both ways         *(data_ptr.get()) = 99;        TEST_TRUE(*data == *data_ptr.get());     };     {         int* data = new int(55);    // allocate raw pointer          // create a managed pointer and let it manage data         unique_ptr<int> data_ptr(data);          // Make sure that both pointers show the same value         TEST_TRUE(*data == *data_ptr.get());          // Both ways         *(data_ptr.get()) = 99;         TEST_TRUE(*data == *data_ptr.get());     };     {         SimpleData* data = new SimpleData;    // allocate raw pointer         data->first = 55;         data->second = 'C';          // create a managed pointer and let it manage data         unique_ptr<SimpleData> data_ptr(data);          // Make sure that both pointers show the same value         TEST_TRUE(data->first == data_ptr->first);         TEST_TRUE(data->second == data_ptr->second);          // Both ways         data_ptr->first = 99;         data_ptr->second = 'D';         TEST_TRUE(data->first == data_ptr->first);         TEST_TRUE(data->second == data_ptr->second);          unique_ptr<int> int_ptr(new int);         *int_ptr = 199;       // both allocations are released here     }     return 0; }   Do you have any idea why I am getting that error? This error appears several times. I looked at other examples about templates but it does not work.

Quote from :     The only portable way of using templates at the moment is to implement them in header files by using inline functions.   Why is this?  (Clarification: header files are not the only portable solution. But they are the most convenient portable solution.)


I am new to Linux and Ubuntu.  I need to run multiple instances of desktop Telegram. I saw the answers in   I do not understand how can I use the answer.   I extracted tsetup.1.1.23.tar.xz. and then opened the terminal and cd to that directory.   Also I created another administrator user named atk2 with no password.  I tried running telegram as another user like this:  sudo -u user2 ./Telegram   but it does not work. I get  No protocol specified QXcbConnection: Could not connect to display :0 ./Telegram(_ZN14SignalHandlers8internal7HandlerEiP7siginfoPv+0x175)[0xe52725] ./Telegram(_ZN14SignalHandlers8internal12DumpCallbackERKN15google_breakpad18MinidumpDescriptorEPvb+0x2e)[0xe52f7e] ./Telegram(_ZN15google_breakpad16ExceptionHandler12GenerateDumpEPNS0_12CrashContextE+0x3d4)[0x10b83e4] ./Telegram(_ZN15google_breakpad16ExceptionHandler13SignalHandlerEiP7siginfoPv+0x97)[0x10b86f7] /lib/x86_64-linux-gnu/libpthread.so.0(+0x13150)[0x7f6673f36150] /lib/x86_64-linux-gnu/libc.so.6(gsignal+0xcb)[0x7f667360d0bb] /lib/x86_64-linux-gnu/libc.so.6(abort+0x16d)[0x7f667360ef5d] ./Telegram[0x1d6007e] ./Telegram(_ZN14QXcbConnectionC2EP19QXcbNativeInterfacebjPKc+0x97c)[0x1495bfc] ./Telegram(_ZN15QXcbIntegrationC1ERK11QStringListRiPPc+0x31e)[0x146971e] ./Telegram[0x14683bd] ./Telegram[0x1c3cb5d] ./Telegram[0x19810e5] ./Telegram[0x1981eb5] ./Telegram[0x1f1b63c] ./Telegram[0x198358c] ./Telegram[0x1657ad9] ./Telegram(_ZN11ApplicationC2ERiPPc+0x1e)[0xe5f13e] ./Telegram(main+0x8a)[0x8c94ea] /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf1)[0x7f66735f71c1] ./Telegram[0x8e6b1d] Aborted   I also tried  mkdir ~/.telegram2ndprofile Telegram -many -workdir ~/.telegram2ndprofile   but I get this error in using telegram command.   # telegram -many -workdir ~/.telegram2ndprofile usage: telegram [-ynsr] user [ttyname] [message...]   What should I do to run multiple telegram instances?

Is there a way to have two copies of  app in Ubuntu each with a different account?  It seems copying the app in another folder does not work.


ianjoh@ausjenkins0:~$ date Mon Mar  6 03:34:57 PST 2017 ianjoh@ausjenkins0:~$ timedatectl       Local time: Mon 2017-03-06 03:35:05 PST   Universal time: Mon 2017-03-06 11:35:05 UTC         RTC time: Mon 2017-03-06 11:35:06        Time zone: America/Los_Angeles (PST, -0800)  Network time on: yes NTP synchronized: yes  RTC in local TZ: no ianjoh@ausjenkins0:~$   I want the system time to be the Universal/RTC time but can't figure it out. How can I set this up?

Currently when I execute the date command from bash I get the following displayed  Thu May 17 12:21:00 IST 2012  Below is my timezone config based on executing dpkg-reconfigure tzdata     Current default time zone: 'Europe/Dublin'   Local time is now: Thu May 17 12:32:52 IST 2012.   Universal Time is now: Thu May 17 11:32:52 UTC 2012.     Any idea how I change from IST to UTC/GMT?


Chatting about laundry facilities and meal times, Pam led us through an entryway jumble of backpacks and umbrellas. In the kitchen, she poured apple ( From an ACT test)  Please help me understand why nouns " jumble of backpacks and umbrellas" can directly post-modifies another noun " entryway". I think at least a preposition like "with" or others are needed here between "entryway" and " jumble of backpacks and umbrellas".

What exactly are "noun compounds"?       Is it possible to use any words to construct a noun compound?   How we can distinguish between a noun compound and an adjective compound?


I am building a portfolio and for some reason cannot adjust the margins of my bio container. Adjusting the width won't work and if I try adjusting the left-right margin to 0vh, it just pushes my container to the left like this:   Here is my CSS (with left-right margins set at auto instead of 0vh) and HTML:   .wrapper {   background-color: rgb(232, 234, 246);   padding: 6vh 0vh 4vh; }  .container {   margin: 4vh auto 4vh;   padding: 2vh 5vh 2vh;   border: 1px solid gray;   border-radius: 2rem; }

         <Image className='bio-pic' src={profile} alt='casey' />
About Me

           I am a full-stack web developer, passionate about turning ideas into           reality. Experienced with front-end and back-end development, I enjoy           the logical puzzles that come with software engineering and take pride           in writting elegant, dry code. I am excited to apply the skills I've           built as a developer in a challenging environment where I can grow as           a professional and be a positive impact as a team member.

 Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed           do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim           ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut           aliquip ex ea commodo consequat. Duis aute irure dolor in           reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla           pariatur. Excepteur sint occaecat cupidatat non proident, sunt in           culpa qui officia deserunt mollit anim id est laborum.

     I'd like for the container to have a width of 80vh and be centered. Can any CSS wizards help me out?

How can I horizontally center a
 within another
 using CSS?

Foo foo


In reinforcement learning, there is a known example of a robot/agent that is placed in a random room whose task is to find the exit of a house. (Illustration here ) The house has multiple rooms, with some rooms connected to the others.   The link above provides a simple solved example of how Q-learning works. It is very intuitive and fairly easy to follow.   It repetitively updates the $Q(s,a)$ matrix until it converges. So for every row $s$, I will select the element with the highest value and the find the corresponding column $a$. This means that the $\max {a_i}$ will be the optimum action I should take while in state $s$. This is good for the case of discrete states.   In the case of continuous states, there is a something called the features-based representation. Hence, $Q(s,a) = w_1f_1(s,a) + w_2f_2(s,a) +\cdots +w_nf_n(s,a)$. $f_n$ are the features and $w_n$ are the weights.   My questions are:   What will happen to this $Q(s,a)$ function in the continuous case? Will it also update itself repetitively like the one in the discrete case?  If it does update and 'converge', how should we interpret the result?    Your insights will be very helpful.

In reinforcement learning, linear function approximation is often used when large state spaces are present. (When look up tables become unfeasible.)   The form of the $Q-$value with linear function approximation is given by   $$Q(s,a) = w_1 f_1(s,a) + w_2 f_2(s,a) + \cdots, $$  where $w_i$ are the weights, and $f_i$ are the features.   The features are predefined by the user. My question is, how are the weights assigned?   I have read/downloaded some lecture slides on $Q-$learning with function approximation. Most of them have slides on linear regression that follow. Since they are just slides, they tend to be incomplete. I wonder what the connection/relation is between the two topics.


My Swap space is currently set to 2 GB.  How do I increase it?  Also I'm running with an SSD and have 16GB of RAM.  What is the Max Memory I can set the swap file to?

I'm going to install 64 bit 14.04 on a new machine with something like 1 to maybe 128GB RAM and even more RAM later. How much space should I allocate to the swap partition?   And especially: WHY those recommendations for these numbers?    (None of the existing answers  and  explain any of the why and are a bit dated if we look at 1GB or RAM and up)


I am using longtabu package to span a large table to multiple pages but my problem is that I get the name of this table for all pages that it span in the list of tables. I need to eliminate this and get only the first page of the longtabu referenced in the list of tables. Since I use a template, I can not be sure about the structure of the list of tables and wanted to ask if I can do anything with longtabu package. Thanks in advance.

I'm using longtable to spread my table over three pages. Unfortunately the caption is also added three times to the list of tables. Is is possible to have it displayed only once?


So, SNES Donkey Kong Country 3 keeps deleting my saves. First we noticed that the game has erased one of the earlier saves (game is my cousins, I'm just borrowing it) and one night when we were about to try again the second to last stage the game had erased our save. Well, we started again and got as far as before with no problems in saving. My friend finally got through it and I was so happy that I accidentally ripped my controller off SNES. Of course SNES didn't response and we had no option but to restart. And again the save had been deleted. This has happened few times before, when the controller comes off, the save erases itself also.. The weird thing is that there is one of my cousins saves that have survived through all this so I think it can't be about the batteries... I have a PAL version. I don't know if it matters.  Does anyone have the same problem and/or know how to fix it? Or at least where's the problem? My SNES doesn't do this with any other game, just this one.

I have a very old SNES and a Donkey Kong Country 3 game. The last few times I played it, it seemed to randomly lose save games. People told me it was battery. Fine, I study electronics, I can fix that.  So I put in a battery holder and a new battery; all secured nice and tight.  I played it for a few nights with no problems.  This morning, I took my SNES downstairs with the game in it. I plugged it in, and woop, the save game was gone.  Does anyone have any clue why this game keeps losing its save game?   I am not able to replicate this on purpose by doing the following:   Wiggle the console while the game is in it. (like I would walk with it.)  Shake the cartridge heavily in all directions (to make sure it is not the battery being faulty or disconnecting.) Plug in the power after no power for at least a few minutes.   Any advice is appreciated.


Consider a naive Bayes classier with a binary class $Y ∈ {0, 1}$ and three binary features $X_1, X_2, X_3$ ∈ {0, 1}. You are given a set $D$ of $n$ training examples, i.e.  D={$(x^{(1)}_1, x^{(1)}_2, x^{(1)}_3, y^{(1)}), . . . ,(x^{(n)}_1, x^{(n)}_2, x^{(n)}_3, y^{(n)})$}.  Suppose for some example the posterior is $P(Y = 1 | X_1 = x_1, X_2 = x_2, X_3 = x_3) = p$ and assume that there is a cost $c_m$ for misclassication (that is, classifying a sample with label 1 as having label 0 or vice versa). For each prediction you have the choice between trusting the naive Bayes classier or asking a human expert with cost $c_h < c_m$, who is 100% accurate.   Which of these two choices minimizes the expected cost as a function of p?  My solution:   $ \begin{equation}    \text{Conditional distribution $P(Y=y|X)$}  =      \begin{cases}       p, & \text{if}\ y=1 \\       1-p, & \text{if y= -1}     \end{cases}   \end{equation}$ Action set A = $\{-1,1,H\}$ $ \begin{equation}    \text{Cost-function $C(y,a)$} =      \begin{cases}       c_m . \mathbf{1}_{y \neq a}, & \text{if a $\in$ {1,-1}}\  \\      c_h  & \text{if a = H}     \end{cases}   \end{equation}$   In the Bayesian optimal decision framework we want to pick the action which minimizes the expected loss:  $a^* = argmin_{a \in A}   \mathbb{E}[C(y,a)|x]= argmin_{a \in A} \sum_y (c_m.\mathbb{1}[y \neq a]\mathbb{1}[a \neq H]+c_h.\mathbb{1}[H=a])P(y|x)$  By analyzing each cost separately:  $\begin{equation}    \text{ $\mathbb{E}[C(y,a)|x]$}  =      \begin{cases}       (1-p).c_m, & \text{if a=1} \\       p.c_m, & \text{if a= -1}  \\ c_h, & \text{if a= H}  \\     \end{cases}   \end{equation}$  But I dont know how to conclude from here which make me doubt about my solution. Can somebody help?  Thanks a lot

This is from an exercise about the cost of missclassifications using a Naive Bayes classifier. We know that for some example which has three binary features $x_1,x_2,x_3$ the posterior is $P(Y = 1 | X_1 = x_1, X_2 = x_2, X_3 = x_3) = p$. There are two classes, y $\in$ {0,1}.The cost for misclassication is $c_m$. For each prediction we can either trust our naive bayes classifier, or ask a human expert with cost $c_h $ < $c_m$, who is 100% accurate.   The question is which of the two procedures would  minimize the expected cost?  Edit: I think part of the confusion we are having is this: We have two possible outcomes. So normally, if y = 1 is true, but we decide on state y = 0, i.e. a = 0, the cost should be $p*c_m$. If in contrast  y = 0 is true, but we decide on state y = 1, i.e. a = 1, the cost should be $(p-1)*c_m$. Would choosing the optimal action a* not imply by itself then that we are deciding based on the higher posterior?  BUT, the the answer below suggests that we already should take into account that the classifier goes with the maximal posterior before searching for optimal action a*: In this scenario, the cost would always be $c_m*min(1-p,p)$. For instance, if p = 0.45, the Naive Bayes decides on y = 0 (because of the higher posterior for y=0), so the cost is $0.45*c_m$, but even if p = 0.55, the cost would be $0.45*c_m$ since now Naive Bayes is choosing y =1.


I'm a relative high rep user (177k) on Stack Overflow. I am accustomed to being able to unilaterally close a question as a duplicate. But, today when I voted to close as a duplicate , the question did not close. It just registered one close vote.  Did a policy change? Or is there something different about  that keeps it from being subject to the immediate closure as a duplicate?

In order to increase the efficiency with which poor quality questions are closed, it could make sense to have weighted close votes for a small subset of qualified users.   A very good way to measure the qualified users would be to leverage the tag badges. However, it needs to be rationally limited to a set of users that are knowledgeable with the subject. A very good way to measure the top users in a tag would be to look at those who have a gold badge in the tag.  If two users who have a gold tag badge pertinent to a question issue a close vote, the question should probably be closed (or probably will be very soon under the current system). I think it would make sense to allow users with a gold tag badge to have a 3x weight for close votes in those tags.  Please keep in mind, this isn't suggesting full moderator one click closure. It only adds weight to the vote. A single user could not do it on their own. These singular users cast close votes all the time, so that aspect would not change. Some will vote to close, some wont, but the ones who do should have a stronger weight to their vote. Even with 3x it will require 2 of said votes to accomplish, or still 2 other users (meaning 3 agreed it should be closed - which is the same amount of high rep users it takes to delete a question and that has a much greater impact than closure).  tldr;  Allow gold tag badge users to have a weighted close vote in their tag


Scenario is my party's rogue has a ring of spell storing, I tend to give him Green Flame Blade and Booming Blade to use in conjunction with his sneak attack.   Can I also fill the ring with Quickened GFB and BB so he can use his bonus action to get another swing in?  Or would the quicken effect wear off inside?

The Ring of Spell Storing is a unique item in that it allows one spell to be cast two times. The first time is when the spell is cast into the ring:     Ring of Spell Storing, DMG 192      This ring stores spells cast into it, holding them until the attuned wearer uses them. [...] Any creature can cast a spell of 1st through 5th level into the ring by touching the ring as the spell is cast.   The second time, when the spell is cast from the ring:     Ring of Spell Storing, DMG 192      [...] While wearing this ring, you can cast any spell stored in it. [...]   Metamagic works on a per-cast basis:     Metamagic, PHB 101      You can use only one Metamagic option on a spell when you cast it, unless otherwise noted.   Furthermore, it's possible for two Sorcerers to share one RoSS. The first one can cast, for example, one Heightened and Empowered fireball into the ring, and then give it to the second. The second would then be able to cast the previously-Metamagicked fireball from the ring, but also apply Careful Spell on top of another Empowered Spell.  This seems to make it possible, albeit with some difficulty/resources/planning, to cast one spell with four applications of Metamagic. Is this possible, or am I missing a rule that forbids this?


I installed Arma Combined Operations off the anniversary disc. Now I want a new CD key to play DayZ as that one is my brothers so I purchased Arma 2 and Arma 2 Operation Arrowhead on steam.   Can I transfer the Arma files that I already have to the Steam folder so I don't have to download it? I have limited bandwidth.   I've tried to put it in steamapps under common and in the the folders that Steam makes for it when downloading. But it doesn't work it just tries to download it.

Let's say I have a game bought on retail/other digital download and installed on my hard drive. I buy the same game (or a minor variant of it, say the GOTY edition) on Steam. It should be possible to use the existing installation to avoid the generally big downloads. This is very useful as it saves both bandwidth and time.   Previously, as far as I understood, Steam downloaded the game files directly to steam\steamapps\common\<game_name>. Since this folder would be created on starting the download, pausing and closing steam, copying the game files to this folder and then validating game files would make Steam absorb as much as possible and just download the missing files.  Currently, Steam downloads the files to steam\steamapps\downloading\<game_id> and then moves them over to the aforementioned folder once the download finishes. So first of all, what the final folder would be is not clear. So what would be the correct way of doing the same thing, that is, make steam use as much of the existing files as possible? Should the files be copied to downloading\*\, or should I figure out the actual folder (say via googling) and copy the files to steamapps\common\*\?  More specifically, I had a retail copy of Arkham City installed and I just bought the GOTY version on Steam. Now I tried both of the above things, in either case, the validating does not seem to do anything. Assuming I have the correct folder name steamapps\common\Batman Arkham City GOTY, according to , if I copy the files there, Steam seems to just continue with its 17GB download. If I copy it to steamapps\downloading\200260 then the download keeps stopping every few seconds with "Disk Write Error" after modifying 1 or 2 files, and I have to keep hitting resume.


How do I answer a question when only one number is given and the other we need to find and the lcm and gcd are given. $X$ is a integer. The lcm of $x$ and $12$ is $120$. The $\gcd$ of $x$ and $12$ is $4$. Work the value of $x$.

These two exercises I encountered recently seem to develop some type of connection between GCD and LCM I can't quite figure out. Exercise 1:  Find all the numbers $x$ and $y$ such that: $a) \ GCD(x,y)=15, \ LCM(x,y)=150$ $b) \ GCD(x,y)=120 \ LCM(x,y)=1320$ $c) \ GCD(x,y)=100 \ LCM(x,y)=990$  Exercise 2:   Find all the numbers $m,n$ such that $GCD(m,n)=pq , \ LCM(m,n)=p^2qs$  where $p,q,s$ are prime  The first thing that is known to me is that $GCD(x,y) \cdot LCM(x,y)= x \cdot y$ Also $LCM(x,y)$ is at most $x \cdot y$ while $GCD(x,y)$ is at most $\max \{x,y\}$. Last thing is that $GCD(x,y)|LCM(x,y)$. Using all this I tried to solve the first exercise: $a)$ First two obvious pairs are $x=15, y=150$ and $y=15, x=150$. Now neither of the numbers can be bigger than $150$ or smaller than $15$. So we are looking for numbers in the range $15-150$ that satisfy $x \cdot y = 15 \cdot 150$ Another such pair is $(x,y)=(30,75), \ (x,y)=(75,30)$. Similarly for $b)$ we find that the only possible values are permutations of the set {$120,1320$} and in $c)$ since $100$ does not divide $990$ no such numbers exist. Now exercise 2 is what made me think there is actually another connection I'm not quite aware of since now it's about arbitrary prime numbers and the previous method doesn't work anymore. My intuition is that it has something to do with $GCD$ or $LCM$ of the $GCD(x,y), \ LCM(x,y)$


I am writing a shell script that will create a user that I will use for deployments. I want to add that user to be able to use sudo without a password. How can I create this user from a shell script or from the command line?  This is what I have so far (this script is run as the root user):  # create user useradd deploy -m -s /bin/bash  # copy authorized keys mkdir -p /home/deploy/.ssh cat ~/.ssh/authorized_keys > /home/deploy/.ssh/authorized_keys chown -R deploy:deploy /home/deploy/.ssh

I have run the following commands:   sudo groupadd -r testgroup sudo useradd -g testgroup -M -r testuser   Notice the -r option, which according to the man page:     -r       Create a system account.   Assuming I have a user account with root privileges, I then run:  sudo -u testuser cat /dev/input/mouse0   However, I get:     cat: /dev/input/mouse0: Permission denied   Running the same command as root provides the expected output (garbled output from the mouse driver).  How can I create a user with root privileges?


And, technically, would the color of the light change at different car speeds?

The title says it all.  If I was on a bus at 60 km/h, and I started walking on the bus at a steady pace of 5 km/h, then I'd technically be moving at 65 km/h, right?  So my son posed me an interesting question today: since light travels as fast as anything can go, what if I shined light when moving in a car?  How should I answer his question?


I'm using:  apt-get dist-uprade   and it's about to drive me insane.  To make a long story short, I grew up in the country-side. We have electric fences to keep the bovine off the roads. 56k was actually 2k for us because of the static on the line. DSL speeds are anywhere from 1kb to 70kb/s. Apt-get is connecting to multiple servers concurrently on these swinging conditions. I feel it would be better to just limit apt-get to a single connection at a time instead of downloading two or three package files at once.

I need the update manager to only download a single package at a time and not try to download multiple packages at once.  My slow internet cannot handle multiple connections; slows the download to a crawl and some packages will reset themselves halfway through when they time-out.  EDIT  When using apt-get update multiple repositories get checked:   When using apt-get upgrade multiple packages are downloaded:


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

I know Newton's third law of motion might be the answer for this but still I am wondering how the rockets could thrust in the empty space and move in the opposite direction. I guess an astronaut wouldn't be able to push in the empty space with his hands or legs to move himself, but with a rocket engine it's possible. How? What might be the explanation for this in General Relativity?


Someone has asked me about developing a site for a new division that this company is expanding to include in their services.  They have purchased a domain for this new service, but I was wondering:  Since they already have an established domain with a Pagerank (3), would they be better suited with a subdomain (specialty.domain.com), redirected to from their new domain?  Any SEO benefit here?

We are currently planning on registering multiple domains for different parts of the website we own. For example consider that we have example.com as the main domain and have assigned all the sub-departments their own subdomain.    There will be tutorials.example.com, videos.example.com, articles.example.com, etc.  Now for marketing reasons we plan to register examplevids.com, exampletuts.com, etc.    The catch here is all these domains should somehow point to their respective subdomains. We can either use a permanent redirect or have and iframe to display the content directly from the subdomains.   Which approach is better considering SEO?  Will using iframes be considered replicating content by search engines? Or is it at all wise to have different domains?


Edited:  I would like to work out the above relationship, more precisely:     Let $(Y_{1}, ..., Y_{m})$ be a zero-mean vector with covariance matrix   $\Sigma$, and let $S \subset \{1, ..., m\}.$ The best linear predictor   of $Y_{S}$ upon $Y_{\setminus{S}}$, defined as $\tilde{\beta}_{S} =  \Sigma^{-1}_{\setminus{S}, \setminus{S}} \Sigma_{\setminus{S}, S}$, is   a matrix multiple of $\Sigma^{-1}_{\setminus{S}, S}$.   It is assumed that$(Y_{1}, ..., Y_{m})$ is jointly normally distributed.  The above statement seems to imply that there is a number of steps from  $\tilde{\beta} = [X^{T}X]_{\setminus{S}, \setminus{S}}^{-1} [X^{T}Y]_{\setminus{S}, S}$  to   $[X^{T}X]_{\setminus{S}, S}^{-1}  c$, where c is some scalar.  I would be interested in those steps.  Thanks!

I'm struggling with a proof of the normal equation, so I posted a  which hopefully will get resolved soon. However, I mentioned there that I'm uncomfortable with the proofs dealing with , particularly when it comes to derivatives of product of vectors or product of matrices and vectors.  Furthermore, there are a couple of "layout conventions" which are not even used consistently. Because of this, I thought I could get rid of all that insanity by using tensor notation instead.   In relation to the normal equation question, I would be very interested in looking at a proof of this equation (here you can see the ):  $$\beta = (X^{T}X)^{-1}X^{T}{\bf{y}}$$  using tensor notation.  And as a more general request, I'd like to get an advice on the issue of dealing with matrix calculus and derivatives. Particularly, I want to hear about your approach when you have to calculate something of this kind given the inconsistencies in notations and non-intuitive nature of some identities. Do you consult Wikipedia or some handbook every time you want to calculate a derivative of some product of vectors or matrices? Do you memorize some recurrent identities? Do you know an alternative procedure?


Prove that: $$\lim_{n \to \infty} n^{-1/(p+1)} (1^{1^p}2^{2^p} \cdots n^{n^p})^{1 /n^{p+1}} = e^{\frac{-1}{(p+1)^2}}$$  I really have no clue how to go about this. I try converting it into summation form by taking logarthims and then trying to approximate each term but to no avail. Can anyone please help me?

Prove that for real number $p\geq  0$ we have   $$\lim_{n\to\infty}\frac{(1^{1^p} \cdot2^{2^p}\cdots n^{n^p})^\frac{1}{n^{p+1}}}{n^\frac{1}{(p+1)}} = \exp\left(\dfrac{-1}{(p+1)^2}\right).$$


I have a sequence of integers between 0 to 100. Is there any free software like Sage, where I can test randomness of this sequence? I have Linux machine.     I have huge data set. Actually I have my own generator. I want to test its randomness.

In the past I have used the Chi-squared test to check the statistical randomness of my generator. Is this a good test to use? Are there other tests?


I am creating a bash script which read the Txt file and with While Loop and then do some tricks with SED to get the string out it and the Value of string needs to be hold into another Varibale.  Here is my Script.  while read p; do PATH="$p | sed -r 's|.*media/([^/]+).*|\1|'" #FILE = "$p | awk -F"/" '{print $4}'" echo $PATH #echo $FILE #echo $p done < /tmp/list.txt   List.txt  cap/media/101/101.mp4 cap/media/102/102.mp4 cap/media/103/103.mp4 cap/media/104/104.mp4 cap/media/105/105.mp4 cap/media/106/106.mp4    thank you

I want to test if there is any output from the diff (test if files are same), if none echo "Passed $x" else echo "Failed $x". I came up with some intermidiate step (save the output from diff to a file then read from file)  diff "./helloworld$x.out" "./output/helloworld$x.out" > tmp.txt; output="`cat tmp.txt`";  if [ "$output" = "" ];   then     echo "Passed $x";   else     echo "Failed $x";   fi;   I'm sure the code can be improved? Main question is: is it possible to save the output from diff directly into a variable?


After a fresh install of Ubuntu 20.04  The WiFi option is not available in the desktop environment Settings -> Network panel. I only see Ethernet.  This driver was working on Ubuntu 19.04, but not on 20.04    After installing the driver and re-starting there is still no WiFi options nor icons.  Also, tried a few various other flavors of the drivers like    Currently installed via:  sudo apt install rtl8812au-dkms  Then did a reboot. Still no WiFi.  ~$ dkms status rtl8812au, 4.3.8.12175.20140902+dfsg, 5.4.0-26-generic, x86_64: installed   ~$ lsmod | grep realtek snd_hda_codec_realtek   118784  1 snd_hda_codec_generic    81920  1 snd_hda_codec_realtek ledtrig_audio          16384  2 snd_hda_codec_generic,snd_hda_codec_realtek snd_hda_codec         131072  4 snd_hda_codec_generic,snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec_realtek snd_hda_core           90112  5 snd_hda_codec_generic,snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec,snd_hda_codec_realtek snd                    90112  37 snd_hda_codec_generic,snd_seq,snd_seq_device,snd_hda_codec_hdmi,snd_hwdep,snd_hda_intel,snd_usb_audio,snd_usbmidi_lib,snd_hda_codec,snd_hda_codec_realtek,snd_timer,snd_compress,snd_soc_core,snd_pcm,snd_rawmidi   This shows the USB WiFi device.  ~$ lsusb | grep Realtek Bus 007 Device 002: ID 0bda:b812 Realtek Semiconductor Corp. 802.11ac NIC   Shows the Ethernet adapter:  ~$ ip link show 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 2: enp4s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000     link/ether d0:50:99:7a:52:94 brd ff:ff:ff:ff:ff:ff   ~$ nmcli device status DEVICE  TYPE      STATE      CONNECTION          enp4s0  ethernet  connected  Wired connection 1  lo      loopback  unmanaged  --      Is there anything specific that one should try to get this to work?  Thanks

My ethernet connection is quite unreliable (It uses powerline adapters) so I bought an external wifi adapter. I have plugged it in and run the command sudo ip address add 192.168.0.39/24 brd + dev enp7s0, and KDE has detected it. Unfortunately, it doesn't seem to realise it is a wireless network and therefore needs credentials. Where I could normally find a place to enter credentials (the network widget, system settings) there are none. KDE reports that the device is connected in the UI. How do I make it work out that it is wireless and therefore needs credentials? Edit: With ethernet plugged out, (USB) adapter plugged in: $ ip address show 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00     inet 127.0.0.1/8 scope host lo        valid_lft forever preferred_lft forever     inet6 ::1/128 scope host         valid_lft forever preferred_lft forever 2: enp7s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc fq_codel state DOWN group default qlen 1000     link/ether 04:d9:f5:8a:f5:e0 brd ff:ff:ff:ff:ff:ff  With ethernet plugged in, adapter plugged in: 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00     inet 127.0.0.1/8 scope host lo        valid_lft forever preferred_lft forever     inet6 ::1/128 scope host         valid_lft forever preferred_lft forever 2: enp7s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000     link/ether 04:d9:f5:8a:f5:e0 brd ff:ff:ff:ff:ff:ff     inet 192.168.0.51/24 brd 192.168.0.255 scope global dynamic noprefixroute enp7s0        valid_lft 863988sec preferred_lft 863988sec     inet6 fe80::7eb1:eca2:96a0:fe5c/64 scope link noprefixroute         valid_lft forever preferred_lft forever  With just ethernet: 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00     inet 127.0.0.1/8 scope host lo        valid_lft forever preferred_lft forever     inet6 ::1/128 scope host         valid_lft forever preferred_lft forever 2: enp7s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000     link/ether 04:d9:f5:8a:f5:e0 brd ff:ff:ff:ff:ff:ff     inet 192.168.0.51/24 brd 192.168.0.255 scope global dynamic noprefixroute enp7s0        valid_lft 863960sec preferred_lft 863960sec     inet6 fe80::7eb1:eca2:96a0:fe5c/64 scope link noprefixroute         valid_lft forever preferred_lft forever  With nothing: 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00     inet 127.0.0.1/8 scope host lo        valid_lft forever preferred_lft forever     inet6 ::1/128 scope host         valid_lft forever preferred_lft forever 2: enp7s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc fq_codel state DOWN group default qlen 1000     link/ether 04:d9:f5:8a:f5:e0 brd ff:ff:ff:ff:ff:ff  lsusb, adapter plugged in: Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 003 Device 002: ID 046d:c31c Logitech, Inc. Keyboard K120 Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 001 Device 003: ID 1d57:32da Xenta 2.4GHz Receiver (Keyboard and Mouse) Bus 001 Device 004: ID 0bda:b812 Realtek Semiconductor Corp. 802.11ac NIC Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub  I'm not adding it with it plugged out because it's obviously the Bus 001 Device 004: ID 0bda:b812 Realtek Semiconductor Corp. 802.11ac NIC. There were no restarts between any of these changes.


I am a novice programmer. I want to learn basic math on number theory and         combinatorics. At first, i want to read basic level books then mid level and high level books on number theory and combinatorics.  Can anyone suggest me best books on number theory and combinatorics ? ( step by step basic,mid and high level).

I know the basics of logic, sets, relations and the like, so studying intros to abstract algebra and real analysis is not that hard. That said, I have a deficiency when it comes to elementary number theory and combinatorics topics. Things like divisibility, modular arithmetic, congruences, prime numbers and such like regularly pop up as examples to illustrate certain topics in analysis.  What are some very concise books or, maybe, online resources for learning these topics from number theory and combinatorics? Since I need to know them to understand what's going on in other subjects I probably need the bare minimum.


SimpleDateFormat dateFormat = new      SimpleDateFormat("yyyyMMdd");//20180603     dateFormat.setTimeZone(TimeZone.getTimeZone("GMT"));     Date dateResult = dateFormat.parse(inputString);       Calendar cal = Calendar.getInstance();     cal.setTime(dateResult);     cal.setTimeZone( TimeZone.getTimeZone("GMT"));     System.out.println(cal.get(Calendar.YEAR)); // 2018     System.out.println(cal.get(Calendar.MONTH)); //05 ?? (instead of 96)     System.out.println(cal.get(Calendar.DAY_OF_MONTH)); // 03    Strangely, when I'm converting a string to date using the above method, the output is 20180503 instead of 2018063. Couldn't find out why this month mismatch occurs. Any suggestions would be appreciated.

In java.util.Calendar, January is defined as month 0, not month 1. Is there any specific reason to that ?  I have seen many people getting confused about that...


The faeces contain nitrogen and it is that which fertilises the desert soil.     What does "it" stand for?  I'm considering two possibilities:  1, "it" refers to nitrogen. And "that which" can be replaced by "what".  2, "it is....which..." work together to make the cleft sentence construction.

Are these Dummy subjects?  It was nice to see him   It's obvious that in this sentence "It" is a dummy subject and the sentence can be reconstructed as "To see him was nice".  But what about this: It is time to watch   Is the case same here as in the first one? Can it be reconstructed to "To watch is time"?  Also wanna ask something additional: We were happy to see each other  Now what happens in this sentence? "to see" is something lie a complement to the adjective "happy"?   Some other examples like this one: He is ready to play, She is prepared to play the piano


I am looking for python memory debugging techniques? Basically I am looking at tools available for python and see what data we can look at when a python process is taking lot of memory? I am aiming to isolate such memory eating process and dump statistics.

I've recently become interested in algorithms and have begun exploring them by writing a naive implementation and then optimizing it in various ways.  I'm already familiar with the standard Python module for profiling runtime (for most things I've found the timeit magic function in IPython to be sufficient), but I'm also interested in memory usage so I can explore those tradeoffs as well (e.g. the cost of caching a table of previously computed values versus recomputing them as needed). Is there a module that will profile the memory usage of a given function for me?


This is the regular expression I use, but it doesn't match string "%test\n###Hello". Could anyone help what's wrong in my regular expression ? Thanks  private static Pattern REPL_PATTERN = Pattern.compile("%([\\w\\.]+).*");

For example, this regex  (.*)<FooBar>   will match:  abcde<FooBar>   But how do I get it to match across multiple lines?  abcde fghij<FooBar>


This simple program crash when I compile and run it on Windows with Visual C++:  #include <stdio.h>  void foo() {     printf("function begin\n");     int n[1000000];     for(long int i = 0; i < 1000000; i++)     {         n[i] = 2;     }     printf("function end\n"); } int main() {     printf("hello\n");     foo();     printf("end of the program\n"); }   I compile with cl bug.c.  In this case, the console only displays:  C:\Users\senss\Desktop>bug hello   However, when I change the 1 000 000 value to 100 000, there is no problem :  C:\Users\senss\Desktop>bug hello function begin function end end of the program   Thank you!

The following code is generating a stack overflow error for me  int main(int argc, char* argv[]) {     int sieve[2000000];     return 0; }   How do I get around this? I am using Turbo C++ but would like to keep my code in C  EDIT:  Thanks for the advice.  The code above was only for example, I actually declare the array in a function and not in sub main.  Also, I needed the array to be initialized to zeros, so when I googled malloc, I discovered that calloc was perfect for my purposes.  Malloc/calloc also has the advantage over allocating on the stack of allowing me to declare the size using a variable.


I am using Google Cloud Platform with the Bitnami Stack, and my website is: .  This morning I got this error:     This site can’t be reached www.hienthaoshop.com refused to connect.   Try:   Checking the connection   Checking the proxy and the firewall   ERR_CONNECTION_REFUSED     And now I cannot connect to my website and admin as well.    What can I do now? Has anyone experienced this like me? I think this is the hosting problem, but I cannot contact Google support because my support package is Bronze only.

This is a  about Connection Refused    We see a lot of questions to the effect      When I try to connect to a system I get a message      Connection refused      Why is this ?


Is there a command line or a  tool in Ubuntu to "Find & Replace" a word in a 80mb file that accours about 150000 times?   I want to replace http://www.old-domain.com/subfolderA with http://www.new-domain.com/subfolderB  I tried it with gEdit and Atom but both crashed.

Is there any text editor, which can edit such file?  I've  tried:   gedit kate nano vim mcedit   without success.


At least in KiCad, the footprints of through-hole pin headers have one squared annular “ring”, the other ones are round:    What does the square indicate?  (Also I’m wondering if there is perhaps a convention of connecting GND to it.)

I'm curious why PCBs have one square pad in row for 0.1" headers. What is purpose of putting one square pad? What it indicates? Can you push more amps through square pad than round?


<img src=\"https://s1.yimg.com/bt/api/res/1.2/1aLfwfzLVx7.osxsV87uog--/YXBwaWQ9eW5ld3NfbGVnbztmaT1maWxsO2g9ODY7cT03NTt3PTEzMA--/http://media.zenfs.com/en_us/News/Reuters/2016-06-20T125326Z_1_LYNXNPEC5J0TN_RTROPTP_2_FLORIDA-SHOOTING.JPG\" width=\"130\" height=\"86\" alt=\"***A woman mourns as she sits on the ground and takes part in a vigil for the Pulse night club victims following last week&#039;s shooting in Orlando\" align=\"left\" title=\"**A woman mourns as she sits on the ground and takes part in a vigil for the Pulse night club victims following last week&#039;s shooting in Orlando***\"** border=\"0\" />The Florida nightclub killer called himself an &quot;Islamic soldier&quot; and threatened to strap hostages into explosive vests in calls with police during the three-hour siege, according to transcripts released by the FBI on Monday. In a first call he made to a 911 emergency operator, Mateen said &quot;I pledge allegiance to Abu Bakr al-Baghdadi, may God protect him, on behalf of the Islamic State,&quot; referring to the head of Islamic State. The FBI and U.S. State Department released partial transcripts of the four calls with the emergency operator and crisis negotiators earlier on Monday, omitting the shooter&#039;s references to the leader of Islamic State, saying they did not want to provide a platform for propaganda.

   For the above HTML tag by using regex I am eliminating HTML tags and getting only description about news. In that descripton i.e., "A woman mourns as she sits on the ground and takes part in a vigil for the Pulse night club victims following last week's shooting in Orlando " this quoted part is missing. How to get that data also ?  This is the regex i am using to get description  String news_description = item_obj.getString("description");  String news_description_noHTMLString = news_description.replaceAll("\\<.*?>","");   Can anyone suggest me how to get that ?

Is there a good way to remove HTML from a Java string? A simple regex like replaceAll("\\<.*?>", "")   will work, but things like &amp; wont be converted correctly and non-HTML between the two angle brackets will be removed (i.e. the .*? in the regex will disappear).


I wanted to created a simple login form for a system I am tasked to do, however when I click the button (even without any data in the textfields) it would say "Java.lang.NullPointerException". I already tried checking my code but I am still clueless as to which is causing the problem. Here is my JFrame Login Form:  package login; import java.sql.*; import javax.swing.*;  public class LOGINN extends javax.swing.JFrame {     PreparedStatement pst = null;     ResultSet rs = null;     MySqlConnect m2 = new MySqlConnect();      /** Creates new form LOGINN */     public LOGINN() {         initComponents();     }       @SuppressWarnings("unchecked")      private void btnloginActionPerformed(java.awt.event.ActionEvent evt) {              Connection con = m2.getConnectDB();              String SQL="Select * from login where username=? and password=?";       try{            rs=pst.executeQuery(SQL);           pst.setString(1,txtusername.getText());           pst.setString(2, txtpassword.getText());           rs=pst.executeQuery();             if(rs.next()){                 JOptionPane.showMessageDialog(null, "Welcome!");                 ADMIN a=new ADMIN();                 a.setVisible(true);           }            else{                JOptionPane.showMessageDialog(null, "Invalid Username or Password", "Access Denied",JOptionPane.ERROR_MESSAGE);            }             }       catch(Exception e){       JOptionPane.showMessageDialog(null, e);        }     }       public static void main(String args[]) {         java.awt.EventQueue.invokeLater(new Runnable() {             public void run() {                 new LOGINN().setVisible(true);             }         });     }      // Variables declaration - do not modify     private javax.swing.JButton btnlogin;     private javax.swing.JLabel jLabel1;     private javax.swing.JLabel jLabel2;     private javax.swing.JPanel jPanel1;     private javax.swing.JPasswordField txtpassword;     private javax.swing.JTextField txtusername;     // End of variables declaration  }   Here is MySqlConnect class:   package login; import com.mysql.jdbc.Connection; import java.sql.DriverManager;   public class MySqlConnect {     public Connection getConnectDB()         {         Connection con ;         try{                 Class.forName("com.mysql.jdbc.Driver");                     con = (Connection) DriverManager.getConnection("jdbc:mysql:///login", "root","");                     return con;             }          catch (Exception e){                 e.printStackTrace();                 return null;                 }       } }   PS. I also have a Jframe form named ADMIN and I have data in my PhpMyAdmin SQL Database.

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


I'm trying to make it so certain text and images on an HTML page cannot be highlighted with the cursor, so it appears as if they're a part of the background.

I'm building an HTML UI with some text elements, such as tab names, which look bad when selected. Unfortunately, it's very easy for a user to double-click a tab name, which selects it by default in many browsers.  I might be able to solve this with a JavaScript trick (I'd like to see those answers, too) -- but I'm really hoping there's something in CSS/HTML directly that works across all browsers.


A lot of strange loop devices appear in my Kubuntu OS.      [translation:     Hard disk 107.4GB     Hard disk 487.0GB     Loop Device     Hard Disk 4.0GB     Loop Device     Loop Device     Loop Device     Loop Device     Victor Disk]   Can anybody tell me what it is? .

I just realized using gnome-disk-utility (3.18.3.1) that my 16.04 installation is featuring several small loop devices.  In detail:   78 MB Loop Device (/var/lib/snapd/sn_ntu-core_352.snap -> /dev/loop0) 76 MB Loop Device (/var/lib/snapd/sn_ntu-core_216.snap -> /dev/loop1) 79 MB Loop Device (/var/lib/snapd/sn_ntu-core_423.snap -> /dev/loop2) 705 KB Loop Device (/var/lib/snapd/snaps/tpad_12.snap -> /dev/loop3) 684 KB Loop Device (/var/lib/snapd/snaps/tpad_11.snap -> /dev/loop5) 705 KB Loop Device (/var/lib/snapd/snaps/tpad_13.snap -> /dev/loop6)   Image showing gnome-disk-utility    My questions are as follows:   What are those loop devices used for? Is that an expected behaviour in 16.04? Can  I remove them? And if so - how (just by unmounting)? Is there any risk in removing the 2 installed snaps mentioned below (tpad and ubuntu-core)   UPDATE  Installed snaps  According to snap list I do have   tpad (1.8.1) ubuntu-core (16.04.1)   installed. I remember I did tinker with snaps for a short time when  I realized this option - but am pretty unsure if  I  installed those 2 snaps - or if they are pre-/auto-installed.  tpad is a Terminal text editor with GUI-like user interface  I  did install manually, as  I don't use it  I removed it now via sudo snap remove tpad. As a result the 2 loop devices pointing to tpad are gone in gnome-disk-utility.  So - at the current point  I am still having 1 snap installed called ubuntu-core and I don't know what it is used for. The summary of this particular snap is   The ubuntu-core OS snap


Can I re enter into the United Kingdom on my Australian Passport (with a photocopy of my british passport) ??   I am travelling to the USA and need to leave my UK passport here to get a visa sorted out to Russia, can I get back in with out my UK Passport with out any problems?

I'm a British National (Overseas), which basically means that while I don't have the right of abode in the UK, I am permitted to visit the UK without a visa. However, my passport has expired, and while it's being renewed, the schedule is a bit tight.  At the same time, I'm an US Citizen, and since I'm only planning to visit the UK, I don't need a visa if I enter on my US passport.  I'm not familiar with UK immigration law, and given that this probably isn't too common a situation, the UK Border Agency website doesn't have an answer that I can can find, nor do they seem to have a contact form that fits my situation, so here's hoping someone knows—given that I'm a British National (Overseas), am I required to enter the UK on my UK passport, or can I just use my (valid) US passport?


Problem: Show for two positive definite matrices $A$ and $B$, if $A \succeq B$ then $B^{-1} \succeq A^{-1}$ Definition: $A \succeq B$ if $A-B$ is positive semidefinite. I've been trying to use the adjunct matrices since $A^{-1}=\frac{1}{det(A)}adj(A)$ so from the $\frac{1}{det(A)}$ it seems sort of obvious that if $A \succeq B$ then $B^{-1} \succeq A^{-1}$. However, I have no idea beyond this how to use the positive definite nature of $A$ and $B$ or definition of $A \succeq B$ to prove the statement. All I know is that if a matrix $A$ is positive definite then so is $A^{-1}$. Any help would be appreciated!

Let $A$ and $B$ be two $n \times n$ symmetric and positive definite matrices.   If $A \prec B$, then is it true that $B^{-1} \prec A^{-1}$?  Here, $A \prec B$ means that $B-A$ is positive definite.


This is a very general question: How exactly does Google determine the desirability of the content of a website to users (and therefore rank websites), given some search keywords? I kept seeing people saying that you should make you website great as the long-term strategy for SEO. But how exactly does Google know how great the content of a website is? If the important factor is the website being mentioned in many other quality websites, would the best strategy be to post the link of the website on as many quality websites as possible? If the number of visits by users given searching certain keywords is a factor, then wouldn't it further polarize the already popular and not-so-popular websites? Other than these two, I cannot come up with other ways that explain how Google's algorithm may work right now. I am really stuck on this issue. My website is for people to live stream their working and find work buddies, and there is little textual content on the website that is explicitly related to things like "study buddies." There are just user profiles on the website, and I do not want to add explicit content on the website. I cannot find my website page after page even my search keywords perfectly matched the content of the html meta description tag. I used to post the link on many subreddits but it was super inefficient in attracting the traffic to the site compared to having a high ranking on Google. Looking forward to any help!

What are the best ways to improve a site's position in the Google search results?


I just entered Stackoverflow and saw "-10" on the top, I checked it and it said "User was Removed". I was like "What?".  So: I answered X's question. Y upvoted it. Y's account got deleted. Y's vote got deleted. I lost points.  No problem until here.  I got notification saying "User was Removed".  This is a problem.  It scared me.  I ask you to change it to: "The account of upvoter was removed" or sth.

The message that appears in the reputation tab of a user's profile when they gain or lose reputation due votes disappearing when another user is deleted is simply:     user was removed   This message is confusing and unhelpful. Below are comments that demonstrate this confusion, . I don't have any quotes from the users who could not find it and remained confused.  There is , and . However, the message has not been changed.  I know that in the past the developers have been reluctant to direct users to meta in some situations, such as question bans, because it may cause users to post here appropriately. That does not seem to apply to this case. This is not typically a case of ""; most of us have probably seen the message at some point.  Why is this message vague and unlinked? What negative behaviour does this confusion mitigate?       My first interpretation was that I was the user who was removed!        I just simply wished the explanation on the reputation page was better. Seems like I shouldn't have had to come to the meta section to figure this out.        It must be better to show "User  was removed". For a moment I just thought that I was removed :-(        the information should be better. I lost 10 points yesterday by "user removed" and assumed that I was the one being removed, leaving me wondering why and feeling somewhat embarrassed.         The recalc policy is fine. But the red mark and "user was removed" looks cryptic and unnecessarily negative--especially since the only user name mentioned on a profile is one's own. So the natural impulse is to bind "user" to the account you're looking at. (It was jarring to me and I could tell what it meant, but still this could be clearer.) I agree that orange is better than red and ideally all of these things would have hyperlinks to a help page (or at least a meta post) explaining what the deal is.        +1 (to HostileFork) for the idea of linking to an explanation of 'User was removed'. It just took me 10+ minutes to find this particular thread and read through, when I could have simply clicked through! I would also like a little more info on why user was removed (abuse, friend upvotes, rules, etc) , as that could help educate the community as a whole on what behaviors to report.        I could care less about the rep gain or loss, but when you have a loss it is a scary message without context. I honestly thought for a moment that my account had been inhibited in some way. No, it didn't say "Your account was removed." Still, there is that moment of "what did I do wrong?" which seems silly to cause simply by not posting a few extra words. A clearer "A user who voted on your posts was removed along with reputation changes they caused" would have gone a long way to not cause me to question my participation in the review queues as of late.         My problem is that the message "user has been removed" is not a clickable link like the other messages - so I had to search meta to discover this question to find out what it meant.


Device loaded  with Ubuntu Gnome works perfectly with one exception: bluetooth. I cannot get any response from Broadcom 4352. Tried to replace driver () -no success. Any advice would be appreciated.

Bluetooth is on but can't find or be found by any other devices.  Output of sudo service bluetooth status:  ● bluetooth.service - Bluetooth service    Loaded: loaded (/lib/systemd/system/bluetooth.service; enabled; vendor preset: enabled)    Active: active (running) since ხუთ 2015-06-04 22:33:18 GET; 13min ago  Main PID: 26678 (bluetoothd)    CGroup: /system.slice/bluetooth.service            └─26678 /usr/sbin/bluetoothd -n  ივნ 04 22:39:14 Rangoo bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/HFPAG ივნ 04 22:39:14 Rangoo bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/HFPHS ივნ 04 22:39:14 Rangoo bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/A2DPSource ივნ 04 22:39:14 Rangoo bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/A2DPSink ივნ 04 22:39:14 Rangoo bluetoothd[26678]: bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/HFPAG ივნ 04 22:39:14 Rangoo bluetoothd[26678]: bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/HFPHS ივნ 04 22:39:14 Rangoo bluetoothd[26678]: bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/A2DPSource ივნ 04 22:39:14 Rangoo bluetoothd[26678]: bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/A2DPSink ივნ 04 22:39:14 Rangoo bluetoothd[26678]: Adapter /org/bluez/26678/hci0 has been enabled ივნ 04 22:39:14 Rangoo bluetoothd[26678]: bluetoothd[26678]: Adapter /org/bluez/26678/hci0 has been enabled   Output of lsusb:  Bus 003 Device 005: ID 0a5c:21d7 Broadcom Corp. BCM43142 Bluetooth 4.0   How can I fix it?


I'm a doctor doing my internship now and it will finish by the end of February. I will be jobless till applying for residency in May and I'm planning to sit for PLAB 2 examination and travel to the UK in April.  Can I apply for visa (Standard Visitor) during my internship in February, or will my application have a high probability of being refused, as I won't be employed by the time I will be in the UK?  What documents can support me?

I am a medical doctor in Pakistan. I have been on a career break to allow myself to study full time for the IELTS exam (from which I recently got the required band score) and PLAB 1. I have now registered and paid for the PLAB 1 exam in UK for June 2016, as the next sitting in Pakistan is in November 2016 and I feel like I am ready to do the exam sooner.  Due to having no current employment, my savings are limited (around 25,000 Pakistani Rupees) but I live with my parents and do not have any financial commitments at home.  My savings have depleted in the past ten months whilst I have taken a career break and the money has been used for my own personal expenses. My trip to the UK is being funded by my grandfather who is a British citizen. He is a retired doctor with a good NHS pension. He has provided me with:   6 months bank statements which clearly show his pension deposits   Letter from NHS Pensions stating his pension   Sponsorship letter stating that he will pay for my PLAB exam fee, travel, accommodation and subsistinence costs whilst in the UK   Copy of British passport  Document confirming that he owns the house he lives in mortgage-free Confirmation email from GMC stating he has paid the PLAB exam fee.   Without large personal savings and no current job (but I have job offers now) would my application be rejected or is the strong sponsorship going to be good enough?  Are there any other documents I should consider submitting that may help me get a visa?


I'd like to improve my duplicator script. bpy.ops.object.duplicate() seems to require me to select the object first. I'd like to just feed the object straight to it instead.  Is there a smarter way to handle it than I did so far?  def duplicator(name):     # select the object     obj = bpy.data.objects.get(name)     obj.select_set(True)      # Loop 3 times, duplicate it, name it     for i in range(1,4):         # duplicate selected object         bpy.ops.object.duplicate()          # name new object with a string and number         newObj = bpy.context.selected_objects[0]         newName = 'Plane_' + str ( i )         newObj.name = newName   duplicator('Plane_0')

I would like to duplicate a mesh object, but on a particular object. Right now this is working:  import bpy   for i in range (0,5):     bpy.ops.object.duplicate(linked=0,mode='TRANSLATION')      bpy.data.objects['cube.001'].animation_data_clear()   The way I want it to do it though is that the script should only duplicate a particular object in the scene that I enter through as a string name. ATM its just duplicating the 1st object and duplicating the duplicates of the duplicates.


I have a stacked bar chart and surprisingly not all the percentage of the bars are shown. I only allowed values more than 3% to be shown, however some are clearly more than 3% and at the same time not shown (circled in red). I hope someone can rectify where's the problem. Thanks.      \documentclass[10pt,twoside,a4paper,fleqn]{report} \usepackage{xcolor,pgfplots} \pgfplotsset{compat=1.14} \begin{document} \definecolor{BIPV facade}{HTML}{83BA2B} \definecolor{conventional facade}{HTML}{3b5998} \definecolor{Column}{HTML}{fa8072} \definecolor{Core}{HTML}{666666} \definecolor{Drywall}{HTML}{794044} \definecolor{Foundation}{HTML}{66cccc} \definecolor{Roof Construction}{HTML}{daa520} \definecolor{Slab}{HTML}{ffc3a0} \definecolor{Window}{HTML}{ff00ff}   \begin{figure}[ht!] \centering \begin{tikzpicture} \begin{axis}[     xbar stacked,     legend style={     legend columns=8,         at={(xticklabel cs:0.5)},yshift=-5mm,         anchor=north,         draw=none     },     every node near coord/.style={     color=black,       check for zero/.code={         \pgfkeys{/pgf/fpu=true}         \pgfmathparse{\pgfplotspointmeta-3}         \pgfmathfloatifflags{\pgfmathresult}{-}{            \pgfkeys{/tikz/coordinate}         }{}         \pgfkeys{/pgf/fpu=false}       }, check for zero, xshift=3, font=\scriptsize},     nodes near coords={\pgfmathprintnumber[fixed zerofill,precision=0]{\pgfplotspointmeta}$\%$},     nodes near coords align=center,     ytick=data,     xtick=data,     xlabel= Percentage(\%),     ylabel= Environmental indicators,     axis y line*=none,     axis x line*=bottom,     tick label style={font=\footnotesize},     legend style={font=\footnotesize},     label style={font=\footnotesize},     xtick={0,10,20,30,40,50,60,70,80,90,100},     width=.9\textwidth,     bar width=6mm,     yticklabels={GWP, ODP, POCP, AP, EP(T), EP(FW), EP(M), ADP, CED},     xmin=0,     xmax=100,     area legend,     y=8mm,     enlarge y limits={abs=0.625}, ] \addplot [conventional facade,fill=conventional facade]  coordinates {(9.3,0) (6.7,1) (9.2,2) (13.7,3) (9.5,4) (7.5,5) (10.1,6) (6.9,7) (4.8,8)}; \addplot [Column,fill=Column]  coordinates {(7.6,0) (6.4,1) (7.9,2) (6.3,3) (6.8,4) (8.3,5) (7.1,6) (7.7,7)(4,8)}; \addplot [Core,fill=Core]  coordinates {(21.6,0) (18.3,1) (20.7,2) (16.8,3) (18.8,4) (20,5)(19.2,6)(30.4,7) (11.2,8)}; \addplot [Drywall,fill=Drywall]  coordinates {(10.4,0) (23.3,1) (12.1,2) (17.1,3) (18.8,4) (14.9,5)(15.4,6)(21.3,7) (52.8,8)}; \addplot [Foundation,fill=Foundation]  coordinates {(3.1,0) (1.9,1) (1.9,2) (1.6,3) (2.3,4) (1.0,5)(2.2,6)(1.4,7) (1.4,8)}; \addplot [Roof Construction,fill=Roof Construction]  coordinates {(0.2,0) (0.2,1) (0.2,2) (0.2,3) (0.2,4) (0.1,5)(0.2,6)(0.2,7) (0.2,8)}; \addplot [Slab,fill=Slab] coordinates {(38.58,0) (34.48,1) (39.00,2) (31.05,3) (33.96,4) (40.43,5)(35.30,6)(24.43,7) (20.71,8)}; \addplot [Window,fill=Window]  coordinates {(9.15,0) (8.63,1) (9.03,2) (13.30,3) (9.56,4) (7.72,5) (10.49,6)(7.68,7)(4.93,8)};  \legend{Conventional facade, Column, Core, Drywall, Foundation, Roof construction, Slab, Window} \end{axis}   \end{tikzpicture} \end{figure} \end{document}

I had a problem with disappearing marker as the data sum up to more than 100 while xmax was set to 100. See .  As written in the answer to the cited question I tried to avoid the problem by normalizing the value to 100. But this lead to (much smaller) rounding errors in previously correct rows and now the marker disappear there. See the following example. Before the normalisation the column F ist affected, after the column B.   How can I in a reliable way avoid this rounding problem? Or at least get a clear error message. I have quite a number of this plots and I don't want to have to check them all the time for missing markers.    \documentclass{scrreprt} \usepackage{pgfplots} \pgfplotsset{compat=1.13} \usepackage{pgfplotstable} \pgfplotsset{  my stackbar plot/.style={              xbar stacked,              xmin=0,xmax=100,              symbolic y coords={A,B,C,D,E,F,G},              ytick=data,              nodes near coords={xxx},}}  \begin{document}  \pgfplotstableread[col sep=space]{  text   --  -    +       ++  A      0.0 1.7 13.8    84.5  B      0.0 0.6 20.1    79.3  C      0.0 1.9 13.2    84.9  D      0.0 1.6 27.9    70.5  E      1.3 3.9 19.5    75.3  F      0.0 1.4 15.0    83.7  G      0.3 1.7 24.8    73.2  }\data   \pgfplotstablecreatecol[create col/expr={\thisrow{--}+\thisrow{-}+\thisrow{+}+\thisrow{++}}]{sum}\data %  \pgfplotstablecreatecol[create col/copy=--]{--o}\data  \pgfplotstablecreatecol[create col/copy=-]{-o}\data  \pgfplotstablecreatecol[create col/copy=+]{+o}\data  \pgfplotstablecreatecol[create col/copy=++]{++o}\data  \pgfplotstablecreatecol[create col/expr={100/\thisrow{sum}*\thisrow{--o}}]{--}\data  \pgfplotstablecreatecol[create col/expr={100/\thisrow{sum}*\thisrow{-o}}]{-}\data  \pgfplotstablecreatecol[create col/expr={100/\thisrow{sum}*\thisrow{+o}}]{+}\data  \pgfplotstablecreatecol[create col/expr={100/\thisrow{sum}*\thisrow{++o}}]{++}\data  \pgfplotstablecreatecol[create col/expr={\thisrow{--}+\thisrow{-}+\thisrow{+}+\thisrow{++}}]{sumnew}\data  \pgfplotstabletypeset[columns={text,sum}   ,precision=10,columns/text/.style={string type}]\data \quad \pgfplotstabletypeset[columns={text,sumnew},precision=10,columns/text/.style={string type}]\data   %\pgfplotstablesave{\data}{pgfplotstempout.dat} \begin{tikzpicture} \begin{axis}[my stackbar plot]  \addplot table [x expr = \thisrow{--o},y=text] {\data};  \addplot table [x expr = \thisrow{-o}, y=text] {\data};  \addplot table [x expr = \thisrow{+o}, y=text] {\data};  \addplot table [x expr = \thisrow{++o}, y=text] {\data}; \end{axis} \end{tikzpicture} \quad \begin{tikzpicture} \begin{axis}[my stackbar plot]  \addplot table [x expr = \thisrow{--},y=text] {\data};  \addplot table [x expr = \thisrow{-}, y=text] {\data};  \addplot table [x expr = \thisrow{+}, y=text] {\data};  \addplot table [x expr = \thisrow{++}, y=text] {\data}; \end{axis} \end{tikzpicture}  \end{document}


I´m searching for a good blog editor like Windows Live Writer something similar.

I want a software for blogging like Live Writer in Linux and GNOME.  Do you have any idea?


While   empirical means deriving from experiment and observation rather than theory.  What is would be the word for deriving from experience or past performance.

I'm trying to figure out a word that describes subconsciously knowing something from experience. My initial attempt was "instinct", but that has more gifted and primal connotations.  The use case I had in mind was as follows:     "If we assume that the model is applicable, it tells us what we've ________ known for a while [...]"     Update:  The word that fits best for my use case seems to be intuitively.  Another good one was empirically, but it tends to imply there were some experiments carried out to glean the knowledge, which wasn't the case.


I have start point (latitude) I know direction, lets say strictly north, and I want to calculate latitude which is 100 meters above the start point.  The same for longitude.  I believe there should be a simple way to do that, but I couldn't find any relevant to this, only how to calculate distance knowing start and end points.

I am wanting to find a latitude and longitude point given a bearing, a distance, and a starting latitude and longitude.  This appears to be the opposite of this question ().  I have already looked into the haversine formula and think it's approximation of the world is probably close enough.  I am assuming that I need to solve the haversine formula for my unknown lat/long, is this correct? Are there any good websites that talk about this sort of thing? It seems like it would be common, but my googling has only turned up questions similar to the one above.  What I am really looking for is just a formula for this. I'd like to give it a starting lat/lng, a bearing, and a distance (miles or kilometers) and I would like to get out of it a lat/lng pair that represent where one would have ended up had they traveled along that route.


How do I find out which (apt-get-installed) package a particular file came from?

Simple enough question: is there some shell command (or GUI method) I can use that, given the path to a file on my system, tells me what package put it there? Assuming the file did in fact come from a package, that is.  Bonus question: what if it's a file that isn't installed on my system? Is there, say, a website that will let me look up a file and see what packages, if any, provide it?


Say I have the following code:  int main() {     enum colors { red = 0, green = 1, blue = 2 };     int myvar = instructions::red;     cout << myvar; }   This will (of course) output '0'.  However, is it in any way possible to obtain the color name via user input and store the corresponding number in 'myvar'?

Suppose we have some named enums:  enum MyEnum {       FOO,       BAR = 0x50 };   What I googled for is a script (any language) that scans all the headers in my project and generates a header with one function per enum.  char* enum_to_string(MyEnum t);   And a implementation with something like this:  char* enum_to_string(MyEnum t){       switch(t){          case FOO:             return "FOO";          case BAR:             return "BAR";          default:             return "INVALID ENUM";       }  }   The gotcha is really with typedefed enums, and unnamed C style enums. Does anybody know something for this?  EDIT: The solution should not modify my source, except for the generated functions. The enums are in an API, so using the solutions proposed until now is just not an option.


I am an android developer. Using my moto g first gen for testing my applications. I connect the device to laptop for 12 hrs per day. Now i am planning to buy s4. Will it reduce my device's life?

I usually disconnect my cellphone from the charger some time after it's fully charged because I'm afraid the battery could lose capacity over time if I don't. However, I believe modern electronics should be able to handle this kind of scenario and automatically stop charging the battery once it's full. Does this apply to modern Android phones? Or do I need to continue disconnecting it all the time?


When you are editing a post on the Android app, the text doesn't really fit in the box. It simply overflows like the box is just a background image and also there's a small empty space at the bottom of the screen for some reason.  Take a look at this screenshot:

When writing posts in the Android app, some of text is getting outside the lines. This is only in the main body, not in the title or tags fields    As you can see, it happens when posting answers, too.    Motorola Moto X (1st gen) with Android 4.4.4.  (This may be related to )


I have this line of code:  assert 0 <= j <= self.n, "First edge needs to be between 0 and {}".format(self.n)   I want pep8 to be happy, but I don't understand how to break this line. I tried breaking after the comma and got invalid syntax. I've tried breaking the string with additional ""'s as in . PEP8 was happy but the assert only produced the first half of the message.  What is the proper way to break long assert strings?

I have a long line of code that I want to break up among multiple lines. What do I use and what is the syntax?  For example, adding a bunch of strings,  e = 'a' + 'b' + 'c' + 'd'   and have it in two lines like this:  e = 'a' + 'b' +     'c' + 'd'


So I'm making character hair and I have plane beveled on to a curve like this    Now I'm able to see the texture I apply on it, but I want to edit the UVs for it. I usually select the faces in edit mode in order to see them in the UV editor, but I'll have to convert the curve to a mesh for that.  Is there a way to do it without converting it into a mesh? I'll be duplicating this curve a lot and editing each one.  I'm using Cycles, if that makes a difference

I really want to be able to apply mapping to a curve object. For instance a rope or pipe that has a repeated pattern along its length that follows it's twists and turns.  There must be a simple way to generate UV coordinates for such an object without converting it to a mesh and unwrapping it. Can anyone help?


I'm using Ubuntu 14.04 on a VirtualBox and I've done updates to the Ubuntu install today. After a reboot I get a black screen after login. I have another VBox of 14.04 without any updates and it works fine. I'm assuming the updates have caused the issue.   I've done some of the attempts at fixing with GRUB remove splash quiet, remove .Xauthority, use boot-repair (I get Gtk-warning cannot open display).   I can't create a new install because I'll lose all of my data and programs.   Help!

I am trying to boot Ubuntu on my computer.  When I boot Ubuntu, it boots to a black screen.  How can I fix this? Table of Contents:


I have two columns in Microsoft Excel, A and B. The input is displayed below  A      B ABC    1 ABC    1 ABC    2 ABC    2 ABC    2 DEF    1 DEF    3 DEF    3 CDE    1 CDE    2 CDE    3 CDE    4   I need an output like below whose meaning is also explained  ABC   2.....which means (two unique values with ABC, which is 1 & 2) DEF   2......(1 & 3) CDE   4.......(1,2,3,4)

Suppose I have an Excel sheet with below data    CODE (COL A) | VALUE (COL B) ==============================   A01         | 10   A01         | 20   A01         | 30   A01         | 10   B01         | 30   B01         | 30   Is there an Excel function working like ..    SELECT CODE, count (Distinct *) FROM TABLE GROUP BY CODE    CODE    | Distinct Count of Value ===================================   A01    | 3   B01    | 1   or, better yet, can I have an Excel formula pasted in column C to get something like this:     CODE (COL A) | VALUE (COL B) | DISTINCT VALUE COUNT WITH MATCHING CODE (COL C) ===============================================================================   A01         | 10            | 3   A01         | 20            | 3   A01         | 30            | 3   A01         | 10            | 3   B01         | 30            | 1   B01         | 30            | 1   I know I can use pivot table to get this result easily. However due to reporting requirements I have to append the "distinct count" column to the Excel sheet, hence pivot table is not an option.  My last resort is to use Excel macros (which are fine), but before that I would like to learn whether Excel functions can accomplish this kind of task.


Does the management or the Welcome Wagon care to know about activity that makes existing users want to leave their platform or is the goal only to welcome new users?  I would like to post some simple suggestions and cases but in the past I've been attacked for it.

In the last couple of months Stack Exchange has undertaken significant effort to make the network more welcoming. From a regular user's perspective, we can only see the internal consequences and ripple effects this has had.   I was re-reading  about the science behind what led to determining the necessity of the welcoming push.   In this post it is mentioned that Stack Exchange now employs highly skilled data scientists that seem to have a finger on the pulse of whether or not the efforts are paying off.  I'd be interested if the trend and numbers on this have seen a significant change with the welcoming push and in which direction. Has the initiative worked so far? How is Stack Exchange measuring this? Are there any particular areas that yet need more work?  Edit 15.10.2019:  It's been a full year now, it doesn't look like a response is forthcoming


Malaysian returning home after holiday in Australia, is there any restriction in bringing back health supplements & vitamins that we bought.

I was just packing for an international flight, and realized that my little plastic bags of protein powder and creatine look an awful lot like the bags of cocain I see on tv. Does the airport have some way to identify drugs, or should I leave it at home?  I make my own mix of BCAAs creatine CLA etc. so I can't just bring it in the original packaging, it's all in carefully measured individual bags which look a lot like what I imagine a drug dealer might be carrying to sell, along with a bunch of vitamin pills.


I really have no idea about what's going on here: "They are proud of the country whose independence they helped to establish". why "whose"? what does it mean here?

When I was a student of English as a foreign language, more years ago than I care to count, I was taught that the relative pronoun “whose” could only be used for human beings, i.e., when someone possesses something.   My teachers were native speakers from England, then.   Since that time, I’ve seen “whose”, as a relative pronoun, used in several contexts where no human beings are mentioned, e.g. with animals, objects, countries, abstract nouns, etc, in American newspapers and magazines. Unfortunately, I can’t remember any of the sentences and cannot give examples.  What is acceptable in written and spoken English, and what isn’t, concerning the use of “whose” ?


Wouldn't it be nice to have cross-site bounties?  After all, if I am a developer I am likely to have points on SO, and not many on SF, and vice-versa.  I think probably everyone would benefit from such a feature.  Update: I agree that cross-site reputation, privileges or many other things would be bad. Bounties however, are a completely different topic. You "pay" some earned rep to the person that will answer a question that isn't get an answer otherwise. You are skilled in a field, and you need help in another field: that's the founding principle of the entire economic system in general.  Cross-site privileges would mean awarding powers in a field to people who do not have earned it in that filed, and that is bad.  Cross-site bounties means allowing you to sell your milk to buy some meat.

Here's one to get shot down: How about letting bounties to be set using the reputation gained through the use of another site? So, for instance, I'm a programmer with a high Stack Overflow rep who hates using computers. Wouldn't it be useful for me to be able to exchange some of my excess Stack Overflow credit to incentivise a question on Super User?   Or perhaps I'd like to highlight a question on Meta Stack Overflow, but I don't spend my time there.


My approach was as follows, select 3 people from 23 and then assign any one of the 365 days, then assign the remaining 20 people any of the 364 days and divide it by the total possibilities, which comes out to be the following :-  $\frac{{23\choose3}*365*^{364}P_{20}}{365^{23}}$  I would like to know what is wrong in my approach, because if you consider the number of people who have their birthday on the same day as a variable and sum the above formula from 2 to 23 it should lead to an answer close to 0.5, which is not happening.

"How large must a class be to make the probability of finding two people with the same birthday at least 50%?"  I have 360 friends on facebook, and, as expected, the distribution of their birthdays is not uniform at all.  I have one day with that has 9 friends with the same birthday. (9 months after big holidays and valentines day seem to be big ones, lol..)  So, given that some days are more likely for a birthday, I'm assuming the number of 23 is an upperbound.  Has there been a better estimate to this problem?


When I try to run Maya I get:  gravit@Gravit-PC:~$ sudo /usr/autodesk/maya2017/bin/maya.bin  Initialized VP2.0 renderer {  Version : 2016.3.18.11. Feature Level 5.  Adapter : GeForce GT 1030/PCIe/SSE2  Vendor ID: 4318. Device ID :   Driver : 4.6.0 NVIDIA 390.87.  API : OpenGL V.4.6.  Max texture size : 16384 * 16384.  Max tex coords : 32  Shader versions supported (Vertex: 5, Geometry: 5, Pixel 5).  Shader compiler profile : (Best card profile)  Active stereo support available : 0  GPU Memory Limit : 2048 MB.  CPU Memory Limit: 7524.27 MB. /usr/autodesk/maya2017/bin/maya.bin: symbol lookup error:  /usr/autodesk/maya2017/bin/../lib/libOGSDeviceOGL4-16.so: undefined symbol:  EVP_CIPHER_CTX_init   I used this instruction   When I try solution from here:   I get this:   gravit@Gravit-PC:~$ sudo ln -s /usr/lib/x86_64-linux-gnu/libssl.so.1.0.0 /usr/autodesk/maya2017/lib/libssl.so.10 ln: failed to create symbolic link '/usr/autodesk/maya2017/lib/libssl.so.10': File exists

I've installed Maya 2018 on Ubuntu 18.04 and tested it with the amdgpu driver (open source) and it launched without problems, but some components were not working with the open source driver so I tried amd gpu pro 18.20 (amd closed-source driver). I ran  ./amdgpu-pro-install   but since then Maya won't work and gives this warning message:  ./maya.bin: symbol lookup error: /usr/autodesk/maya2018/bin/.. /lib/libOGSDeviceOGL4-16.so: undefined symbol: EVP_CIPHER_CTX_init   My card is hd7770 and it's supported by the amd closed driver, so what am I doing wrong?


The units of $\mathbb Z_4[x]$ should be $$\{f(x)=a_0+a_1x+a_2x^2+\dots+a_nx^n\mid a_0\in\{1,3\},a_i\in\{0,2\}, 1\le i\le n\}.$$ But I don't know how to prove. Any suggestion?

I am trying to prove a result, for which I have got one part, but I am not able to get the converse part.  Theorem. Let $R$ be a commutative ring with $1$. Then $f(X)=a_{0}+a_{1}X+a_{2}X^{2} + \cdots + a_{n}X^{n}$ is a unit in $R[X]$ if and only if $a_{0}$ is a unit in $R$ and $a_{1},a_{2},\dots,a_{n}$ are all nilpotent in $R$.  Proof. Suppose $f(X)=a_{0}+a_{1}X+\cdots +a_{n}X^{n}$ is such that $a_{0}$ is a unit in $R$ and $a_{1},a_{2}, \dots,a_{r}$ are all nilpotent in $R$. Since $R$ is commutative, we get that $a_{1}X,a_{2}X^{2},\cdots,a_{n}X^{n}$ are all nilpotent and hence also their sum is nilpotent. Let $z = \sum a_{i}X^{i}$ then $a_{0}^{-1}z$ is nilpotent and so $1+a_{0}^{-1}z$ is a unit. Thus $f(X)=a_{0}+z=a_{0} \cdot (1+a_{0}^{-1}z)$ is a unit since product of two units in $R[X]$ is a unit.   I have not been able to get the converse part and would like to see the proof for the converse part.


In Ubuntu 16.04, if I double-click on an ISO file, Ubuntu gets the volume ID, then mounts that ISO at a directory at /media/$USER/ with the volume ID as the name of the directory. It does this without any request for root permissions.  I want to replicate this behavior in the terminal. I don't want to go first parsing the output of isoinfo -d -i data.iso, then granting root permissions to the user so that they then run mkdir in /media/ followed by running the mount command etc. I want to replicate what Ubuntu is actually doing and I want to replicate it without asking the user for root permissions.  How might this be done?

I have a file with an ext4 file system in it and want to mount it without using sudo every time (the script should run with user rights). The file I want to mount and the folder which I want to mount it too both are in my home directory which is encrypted, so I can't put the file location into /etc/fstab.  I tried fusermount but I always get error messages like "fusermount: extra arguments after the mountpoint".


I ran a dist-upgrade on my Ubuntu 20 machine and ran into some error with the packages. I tried to apt —-fix-broken but I was still unable to get past the errors.  I decided to do a reboot and I now have Kali in my startup instead of Ubuntu. However while trying to boot Kali is stuck in Failed to start mailman master queue. I’ve done some research and believe this was caused by katoolin. I’ve had katoolin with only a few select tool on my pc for a long time and done several dist-upgrades and never run into this problem. Any ideas how I can reverse this process and boot back into my Ubuntu directly without a fresh install?

Updated Ubuntu 16.04 today using the software updater. Now my PC is running Kali? There were something like 2Gb of updates, which I thought at first was because I haven't updated in a while. Now I'm thinking that it was downloading Kali. Here's a  of the new boot-up process.  The screen will continue to flicker for another 30 seconds or so, then stop flickering leaving the text on the screen. I tried switching the display manager from gdm to lightdm, which will boot me straight to the console and without flickering, but still no desktop.  I'm not altogether sure how I managed to accomplish this. It must have been when I was trying to get Katoolin running.  Any tips as to how I can either get the desktop or revert the updates?  Contents of cat /etc/lsb-rolling:  DISTRIB_ID=Kali DISTRIB_RELEASE=kali-rolling DISTRIB_CODENAME=kali-rolling DISTRIB_DESCRIPTION="Kali GNU/Linux Rolling"


how to add the cross vertical line in two column table. There should be cross vertical line in below.  My code is starting like this:  \begin{table*}[t] \centering \caption{cap} \scalebox{0.67}{ \begin{tabular}{c|ccc|ccc|ccc} \toprule kk & 1  & 2 & 3 & 1 & 2 & 3 & 1  & 2 & 3 \\ \midrule name & \multicolumn{3}{c}{aa} & \multicolumn{3}{c}{bb} & \multicolumn{3}{c}{cc} \\


I wanted to know if a given binary tree is a binary search tree or not.  I don't know How to do that?  The only thing I know is that the inorder traversal of BST will gives you ascending order output.  So, is this the only condition we need to verify or is there anything else we are suppose to check.  In case if there are some other necessary conditions to be checked, What are they? and why those conditions are necessary to be checked?  Because, I think, INORDER traversal itself can tell you easily if the given tree is BST or not.

I read on here of an exercise in interviews known as validating a binary search tree.  How exactly does this work? What would one be looking for in validating a binary search tree? I have written a basic search tree, but never heard of this concept.


The following "red" styles are prohibited, but are sometimes applied by LibreOffice Writer automatically. The following "red" styles are prohibited, but sometimes they are applied by LibreOffice Writer automatically.   Could somebody say which version is correct and sounds better? I tend to think that only the second one is grammatically correct in English, but I'm not really sure, and in my native language it would definitely sound cumbersome.

Should I mention the pronoun again in this case?     "All of these things are not beneficial and (they?) do not   help her"   I know that there is already answer about the question "if it's needed to repeat on the pronoun in case that they are in the same position of grammar tense". But in this case it's different because the question deals with case of two different  tenses (in bold).


In Window, I installed python3.6 and, installed matplotlib by commandline:  pip install matplotlib   After installation, I was running matplotlib in python console,  import matplotlib.pyplot as plt --> not error import matplotlib.pylab as plb --> not error   In python36\lib\site-packages    I want in blender to use the matplotlib library in python, Can I copy the matplotlib in python36\lib\site-packages of Python into the Blender\2.78 \python\lib\site-packages?  I tried copying but only importing matplotlib, but when `import matplotlib.pylot as plt the error is as follows    I do not know how to fix it, please help me  Thank you so much!

I'm currently developing a script for Blender to handle Mesh Frequency Decomposition.  The script is nearly complete, but i need one more thing: The SciPy library to compute eigenvalues and eigenvectors.  Following the installation instructions on , I'm able to install it as well as Numpy. Numpy works fine, but I can't even import SciPy:  Traceback (most recent call last): File "/CAF_FD.py", line 4, in <module> ImportError: No module named 'scipy' Error: Python script fail, look in the console for now...   By the way, I'm working on Linux 64 bit and I've installed SciPy and Numpy with my package manager.  Edit: When I try to use SciPy with a terminal prompt, it works.


For a universe with a constant expansion rate, i.e. the Hubble constant $H_0$ is a constant, the  Hubble law is $$v=H_0d$$ where $v$ is relative velocity between two galaxies and $d$ is the separation between them. I read that the age of the universe is given by $$\frac{d}{v}={1\over H_0}$$ which is the Hubble time $t_H$. This calculation implies that at all times, the relative velocity between two galaxies is constant. But Hubble's law say that galaxies that are nearer to each other have a smaller relative velocity. So an earlier instant of time, when the two galaxies are nearer to each other, the relative velocity should be smaller. How then can we use a constant relative velocity between two galaxies to calculate the age of the universe?

Hubble's law states that $v=Hx$  Age of the universe is calculated by $T= \frac{x}{v} = \frac{1}{H}$  but the velocity is not constant; it changes with distance, so I think that this equation cannot be applied because simply the velocity is NOT uniform  $v$ should have been replaced with $\frac{\mathrm{d}x}{\mathrm{d}t}$, so it gives this differential equation $\frac{\mathrm{d}x}{\mathrm{d}t}=Hx$.  Nevertheless, when this differential equation is solved, and we substitute for initial condition ($x=0$ when $t=0$), it appears that there are no solutions, because it will be an exponential function, which can't take the value $0$ ever.   What is wrong with my understanding?


Question: Suppose today is Wednesday. What day of the week will it be $10^{{10}^{10}}$ days from now? Answer: This is what I have tried so far. I know that you need to find $10^{{10}^{10}}\text{mod} 7$ to solve this problem. If $10^{{10}^{10}} \text{mod}7=0$, then it will be Wednesday, if $10^{{10}^{10}}\text{mod}7=1$, it will be Thursday, and so on. I tried breaking up the large exponent as follows: $10^{{10}^{10}}\text{mod}7=(10^{{10}^5} \text{mod}7\cdot 10^{{10}^5}\text{mod7})\text{mod}7$. However, I do not know how to find $10^{{10}^5} \text{mod}7$. The answer to this problem is Sunday, so that means that $10^{{10}^{10}}\text{mod}7=4$.

I've read about Fermat's little theorem and generally how congruence works. But I can't figure out how to work out these two:   $13^{100} \bmod 7$ $7^{100} \bmod 13$   I've also heard of this formula:  $$a \equiv b\pmod n \Rightarrow a^k \equiv b^k \pmod n $$  But I don't see how exactly to use that here, because from $13^1 \bmod 7$ I get 6, and $13^2 \bmod 7$ is 1. I'm unclear as to which one to raise to the kth power here (I'm assuming k = 100?)  Any hints or pointers in the right direction would be great.