Why do groups in the periodic table have missing periods?

What is the reason for skipping groups in the periodic table?  To word this another way: why isn't the electron configuration of Vanadium defined as 1s2 2s2 2p6 3s2 3p6 3d5 instead of 1s2 2s2 2p6 3s2 3p6 3d3 4s2?  What causes the jump to the fourth group instead of filling out the third group first?  Along a similar line of reasoning I have a few more questions:  Is Nitrogen the most potentially spin-polarizable element (that is, having the most valence elections in the same orbital) with its 1s2 2s2 2p3 configuration?  Do the outermost s1 and s2 electrons block an outside observer from measuring the larger inner group orbitals for elements heavier than Nitrogen (for instance, would Chromium's 4s1 electron or Manganese's 4s2 electrons prevent you from detecting the spin of the 3d5 electrons in either case?)  Is there any relation in discernible properties between an s, p, d, f, g orbital electron with the same spin (in other words, say every partially-filled shell is spin polarized, would you be able to detect an all-up or all-down configuration of 3d5 4s1 in an atom of Manganese vs an atom of Manganese with either an up spin on 3d5 and down spin on 4s1 or a down spin on 3d5 and an up spin on 4s1?)


What is the solution to the equation $9^x - 6^x - 2\cdot 4^x = 0 $?

I want to solve: $$9^x - 6^x - 2\cdot 4^x = 0 $$  I was able to get to the equation below by substituting $a$ for $3^x$ and $b$ for $2^x$:  $$ a^2 - ab - 2b^2 = 0 $$  And then I tried   \begin{align}x &= \log_3{a} \\ x &= \log_2{b} \\ \log_3{a} &=\log_2{b}\end{align} But I don't know what to do after this point. Any help is appreciated.


How did the use of "could of" and "should of" originate, and is it considered correct?

Possible Duplicate:          It bothers me that so many people use could of, would of, should of instead of could've or could have, etc.  For instance, I have seen people write I could of been hurt or I should of seen that truck.  Does anyone know how this originated? Is this a mistake only American English speakers make, or is it common with British English speakers too?  Also, is that actually legal English?


method invocation 'toString' may produce 'java.lang.NullPointxception'

package com.tp468.dell.automatedfishpondmonitoringsystem;  import android.os.Bundle;  import android.support.annotation.NonNull;  import android.support.v7.app.AppCompatActivity;  import android.widget.TextView;  import com.google.firebase.database.DataSnapshot;  import com.google.firebase.database.DatabaseError;  import com.google.firebase.database.DatabaseReference;  import com.google.firebase.database.FirebaseDatabase;  import com.google.firebase.database.ValueEventListener;  public class MainActivity extends AppCompatActivity {      TextView Temperature;      DatabaseReference dRef;      String status;      @Override     protected void onCreate(Bundle savedInstanceState) {          super.onCreate(savedInstanceState);          setContentView(R.layout.activity_main);          Temperature = (TextView)findViewById(R.id.textView);          dRef= FirebaseDatabase.getInstance().getReference();          dRef.addValueEventListener(new ValueEventListener() {              @Override             public void onDataChange(@NonNull DataSnapshot dataSnapshot) {                 status=dataSnapshot.child("Temperature").getValue().toString();                  Temperature.setText(status);              }             @Override             public void onCancelled(@NonNull DatabaseError databaseError) {              }         });     } }


I want to grep the output of my ls -l command:  -rw-r--r--   1 root root       1866 Feb 14 07:47 rahmu.file -rw-r--r--   1 rahmu user     95653 Feb 14 07:47 foo.file -rw-r--r--   1 rahmu user   1073822 Feb 14 21:01 bar.file   I want to run grep rahmu on column $3 only, so the output of my grep command should look like this:  -rw-r--r--   1 rahmu user     95653 Feb 14 07:47 foo.file -rw-r--r--   1 rahmu user   1073822 Feb 14 21:01 bar.file   What's the simplest way to do it? The answer must be portable across many Unices, preferably focusing on Linux and Solaris.  NB: I'm not looking for a way to find all the files belonging to a given user. This example was only given to make my question clearer.


We're using SharePoint online, I've created a custom list, item is save and close per item. Is there such a thing as saving and adding another item (redirecting you to the add item again). Without clicking the add item again.


Problem:     Let $f$ be a real valued continuous function on $\mathbb{R}$ . Suppose that    $$f(x+y) + f(x-y) = 2[f(x)+f(y)]$$   for any $x,y\in \mathbb{R}$. Show that there exists $\alpha$ such that $f(x) = \alpha x^2$ for all $x\in \mathbb{R}$.    My attempt: Frankly, I'm not really sure where to begin. I can rewrite the problem as  $$\frac{f(x+y) + f(x-y)}{f(x)+f(y)} = 2$$  which looks a little bit like the Lipschitz condition. Also, it seems like a clever substitution is going to happend with $f(x-y)$ and $f(x+y)$. Beyond that I can't really get a hold on the problem. Any hints or suggestions?


Prove limit of $\frac1{n+1}+\frac1{n+2}+\ldots+\frac1{n+n}$ exists and lies between $0$ and $1$.

Prove limit of $\displaystyle \frac{1}{n+1}+\frac{1}{n+2}+\ldots+\frac{1}{n+n}$ exists and lies between $0$ and $1$.  So far I have $\displaystyle \lim_{n\rightarrow\infty}\sum_{k=1}^n\frac{1}{k+n}=L$ for some $L>0$.  Then given any $\epsilon >0,\exists N>0$ such that if $n>N$, then $\displaystyle\left|\sum_{k=1}^n\frac{1}{k+n}-L\right|<\epsilon$  A hint would be appreciated!


How often is a Powered Rail required to keep going uphill?

When going up a slope, how often must you insert a powered rail to keep your cart going? What is the minimum to keep going at all, and what is a good recommendation for maintaining a reasonable speed?


Can QGIS Measure Line tool compute correct geodetic distance?

As I understood, this tool normally shows distance in the project CRS units, not the geodetic meters (despite it actually says the distance is in meters).  However,  (Section III, 4 - Measure some distances) that in the Measure Tool Options you can change the "Ellipsoid for distance calculation":     Does it mean it can actually finally compute correct geodetic distance?  However, I don't see this option in the QGIS ver 1.9.0-Master.


Can't delete folder due to incorrect syntax / name

Somehow I have a folder called "http:" on my computer, I can't delete or access or rename it. When I try to delete I get the message "The file name you specified is not valid or too long, specify a different file name".  I can't seem to do anything with that directory.  I have win 7 64 bit, I'm just trying to delete it normally.  Also, I checked properties > security, and it says the info is either unavailable or can't be displayed.


Can I travel to Italy on UK-issued refugee document?

I want to visit Italy at the end of September as a tourist. I have a refugee travel document, issued by the UK. In older refugee passports there was an additional page mentioning countries where we could go without having a separate visa in consequence of the European Agreement on the Abolition of Visas for Refugees (1959) but on my passport it's not there. Someone told me people are facing problems with it so I would like confirmation:  Do I need to get a Schengen visa? If yes, where can I go in Europe without getting a visa?


Is it acceptable to say "fed up OF" - surely it should be "fed up WITH" or "bored WITH something" rather than "bored OF something"?

I hear people using of when I have always thought it was with in the circumstances explained above.  It seems to be getting more common.


How to align three images on the same row with subcaption package

\usepackage{graphicx}  \usepackage{subcaption}    \begin{figure}[h!]  \centering    \begin{subfigure}[b]{.3\textwidth}             \includegraphics[width=\textwidth]{nano1_Images/eclipsed_iron.png}         \caption{Eclipsed Cobalt}         \label{img1}         \end{subfigure}       \begin{subfigure}[b]{.3\textwidth}           \includegraphics[width=\textwidth]{nano1_Images/staggered_iron.png}         \caption{Eclipsed Cobalt}         \label{img2}         \end{subfigure}      \begin{subfigure}[b]{.3\textwidth}           \includegraphics[width=\textwidth]{nano1_Images/eclipsed_cobalt.png}         \caption{Eclipsed Cobalt}         \label{img3}     \end{subfigure}        \caption{DMol3, atom colors} \end{figure}


Generating data with a given sample covariance matrix

Given a covariance matrix $\boldsymbol \Sigma_s$, how to generate data such that it would have the sample covariance matrix $\hat{\boldsymbol \Sigma} = \boldsymbol \Sigma_s$?    More generally: we are often interested in generating data from a density $ f(x \vert \boldsymbol\theta) $, with data $x$ given some parameter vector $\boldsymbol\theta$. This results in a sample, from which we may then again estimate a value $\boldsymbol{\hat\theta}$. What I am interested in is the reverse problem: What if we are given a set of parameters $\boldsymbol\theta_{s}$, and we would like to generate a sample $x$ such, that $ \boldsymbol{\hat\theta} = \boldsymbol\theta_{s}$.   Is this a known problem? Is such a method useful? Are algorithms available?


What does "certain" mean in this passage?

I am a ESL learner, has been recently started doing some practice test of IESLTS. Here is a question I am confused about within a reading passage.      There had, of course, been dictionaries in the past, the first of these being a little book of some 120 pages, compiled by a certain Robert Cawdray, published in 1604 under the title A Table Alphabeticall 'of hard usuall English wordes'.   I am struggling with the words "certain" that author used here, I will be really grateful if someone help me figure out the question, or any of the ideas would give a lot of help.


If Rey's staff (and others like it, such as the scavenger that tries to kidnap BB8) is just an ordinary staff, then why is it all techy looking?  What exactly is this staff, just techy looking sections or something more?


What is a good way to remember the essential angles from the unit circle? For instance $$\cos\left(\frac{\pi}{4}\right)=\frac{\sqrt{2}}{2} \text{ and } \sin\left(\frac{\pi}{4}\right)=\frac{\sqrt{2}}{2}$$


Latex tag for making a comment appear or disappear in pdf?

Is it possible to tag sections of your .tex file so that you can make text appear or not?  I have a long document and would like to be able to comment a certain section in each chapter, and produce two different pdfs, one with the comments, and one without.  I read . Is it possible to make this appear if I redefined the comment tag? How is this done?  (On suggestion, migrated this question from StackOverflow: )


ubuntu python 3.4 no site-packages library

I've been trying to import the blender python library into python so I can use it in another python IDE. I followed some steps on the blender wiki page and achieved the correct files. My only problem left is to copy and past the correct files in the 'site-packages' folder under python 3.4 but I don't have such directory... I did not install this python version manually, It came with Ubuntu by default.  -Bert  The blender wiki page:


Setting the hostname: FQDN or short name?

I've noticed that the "preferred" method of setting the system hostname is fundamentally different between Red Hat/CentOS and Debian/Ubuntu systems.   and the  say the hostname should be the FQDN:     HOSTNAME=<value>, where <value> should be the Fully Qualified Domain   Name (FQDN), such as hostname.example.com, but can be whatever   hostname is necessary.   The  is slightly more ambiguous:     Setup prompts you to supply a host name for this computer, either as a   fully-qualified domain name (FQDN) in the format hostname.domainname   or as a short host name in the format hostname.    says the hostname should not use the FQDN:     3.5.5. The hostname      The kernel maintains the system hostname. The init script in runlevel   S which is symlinked to "/etc/init.d/hostname.sh" sets the system   hostname at boot time (using the hostname command) to the name stored   in "/etc/hostname". This file should contain only the system hostname,   not a fully qualified domain name.   I haven't seen any specific recommendations from IBM about which to use, but  seems to have a preference.  My questions:   In a heterogeneous environment, is it better to use the vendor recommendation, or choose one and be consistent across all hosts? What software have you encountered which is sensitive to whether the hostname is set to the FQDN or short name?


Clipping custom UITableViewCells to group rounded corners

I'm trying to make a UITableViewCell that has a group color panel on the left.  The gradient color part I think I can handle, but I can't work out how to get it to clip correctly at the round corners.  I'm after something like this:    I've tried a custom draw UIView added as a subview of the cell's contentView, but it didn't clip.  I've also noticed that UILabels added as sub-views don't clip to the cell boundaries.    Is there's some magic to get these clipped correctly, or do I need to manually do the clipping - and if so is there an easy way for UITableViewCell to know if it's first/last in a section.  Any help appreciated.


Can I leave the Schengen area from another country other than the one I issued the visa from?

I have a Spanish visa type D for 115 days. I will spend the last week of my visa with a friend in Finland. Is it ok to return to my country from Finland directly or do I have to return to Spain first then travel from Spain to my country?  And I know I have the ability to visit the Schengen area with my student visa for 90 days within 180 days. Are the days I spent in Spain are calculated within the 90 days (as Spain is the country where I study and I already spent more than 90 days in it)?


During the prequel trilogy, we learn that the predecessor to the Imperial stormtroopers are all clones. Are the stormtroopers of the original trilogy still clones? If not, where do they come from?


How to re-setup grub2 booting over UEFI from scratch

After cleaning up old unnecessary disk partitions, my UEFI/hardware will not find my single and only remaining Ubuntu installation, a perfectly working newly upgraded Ubuntu 20.04 on a disk partition /dev/sda5 on disk /dev/sda; my system will not boot that installed Ubuntu system but only enter that pre-boot BIOS/UEFI settings user interface where it does not seem to recognize any boot option at all. As I understand it, the more modern way of booting over a UEFI enabled motherboard is to allocate a partition where grub2 will sit alongside proper configuration directing grub2 at my /dev/sda5 installed Ubuntu system. Which is arguably now missing after my cleanup of old partitions. Space for a new partition for grub2 is not an issue: I have a ~200MB empty and contiguous unallocated disk space in my disk's partition table for that disk. I can also shrink my Ubuntu partition to get more space for a new partition if more is needed. I have found various conflicting posts and posts answering to a very specific scenario, or to a Microsoft Windows compatibility scenario, on various stackoverflow websites (askubuntu and others) but would like to have a clean, up-to-date, UEFI oriented procedure ― for making a system boot into an existing Ubuntu system via UEFI by recreating a grub2 partition for UEFI from scratch. In Summary Looking for a clean scratch approach ― one based purely on a live USB Ubuntu disk and on commands/tools available on the later releases of the Ubuntu distribution, which will accomplish a UEFI compliant partition that will direct the UEFI hardware to successfully load the pre-installed Ubuntu OS partition upon boot! What should be the cleanest series of steps, from creating a new partition for grub2 for the UEFI hardware to use, to configuring it to point to my /dev/sda5 fully operational Ubuntu? Disk Information as much as it matters, according to gparted the disk's partition table type is gpt. Further Clarification Edit: I have had no functioning UEFI partition on the same disk at the time of asking. My question assumes that one removes it and builds it from scratch: that you only have an Ubuntu OS partition on the disk and your goal is to "connect it" such that UEFI hardware will become able to boot it.


I studied propositional logic, and everyday I see applications of what I learned on the internet, in mathematical books and miscelaneous resources.        One particular case is sentences in the form $a \rightarrow b$ , that is, material implications. While I fully understand the mathematical logic approach to the study of those kinds of formulas, sometimes I get confused about what someone ( using implication sentences in the ordinary language ) is trying to say.        In ordinary language, I often see affirmations in the form of an implication.  One example would be someone affirming that "the moon is made of cheese" $\rightarrow 2+2=4$. [ Kleene, Mathematical Logic ].      I perfectly understand that if we choose the interpretation that gives the antecedent as false ( and the consequent as true ) we get that the whole implication is also true, but I would like to understand EXACTLY what he is trying to say when he AFFIRMS a sentence in the form of an implication. Is he saying that under the commonly agreed interpretation of that sentence ( antecedent = false, consequent = true ), that implication becomes true?      Another example, totally different, would be someone affirming that $x \in \mathbb{N} \rightarrow x \in \mathbb{N}$ or $x \in \mathbb{Z}_{<0}$. Is he now affirming the same kind of sentence or saying something totally different?      When he affirms that sentence, is he saying that he finds the sentence to be a tautology?   Why didn't he say that?          Then, with these two examples we have an affirmation of the same kind of sentence (implication) meaning completely different things, in one case he affirms to say that under the commonly agreed interpretation of the sentence, it is true. In another case, he affirms to say that there's no interpretation that makes the sentence false.       Am I missing something? There is really that ambiguity in ordinary language, when people are affirming sentences?  Can't I just take some general instance of the affirmation of a sentence in the form $a \rightarrow b$ in ordinary language and know exactly what he's trying to say, regardless of the propositions he chooses the substitute $a$ and $b$ for?       Thanks a bunch.


JDK 8 made Interface to have non-abstract methods then why to use abstract class?

Why we have both Interface and abstract class, even we can achieve interface by making all methods of abstract class abstract. Please explain the usage difference between both.    List list = new ArrayList(); ArrayList arraylist = new ArrayList();   what difference the above two lines make, except dynamic method dispatch. Rather if we define with ArrayList reference we can have more methods to use.  Thanks in Advance. :)


I was on my creative server and fell out of the world. I was in one of the little towns that are already spawned and I sort of built off of one of them, creating a larger "town". When I fell, I lost the place I was and I absolutely cannot find it. Is there a way to teleport back to your bed?


Surface area of a sphere with integration of disks

Why it is not correct to say that the surface area of a sphere is:  $$ 2 \int_{0}^{R} 2\pi r \text{ } dr $$  In my mind we are summing up the perimeters of disks from $r=0$ to $r=R$, so by 1 integration, we would have $\frac{1}{2}$ of the surface area of the sphere.  I know that it's not correct because that will give us $2\pi R^2$ that it's different from $4\pi R^2$, but why???  Thanks!


Should I force my 4 year boy to play sports or activities?

He refused to join any activity (Karate/Gymnastics/Tennis). He doesn't even want to join church lessons for kids (Sunday school).   Shall I force him or wait until he is 6?


How to open Leafpad as root in gnome-terminal in kali linux?

I am following  in which there is some commands:  deb [arch=i386,amd64,armel,armhf] http://http.kali.org/kali kali-dev main contrib non-free deb [arch=i386,amd64,armel,armhf] http://http.kali.org/kali kali-dev main/debian-installer deb-src http://http.kali.org/kali kali-dev main contrib non-free deb [arch=i386,amd64,armel,armhf] http://http.kali.org/kali kali main contrib non-free deb [arch=i386,amd64,armel,armhf] http://http.kali.org/kali kali main/debian-installer deb-src http://http.kali.org/kali kali main contrib non-free deb http://repo.kali.org/kali kali-bleeding-edge main ## Security updates deb http://security.kali.org/kali-security kali/updates main contrib non-free   to be written in leafpad to install clamav and other softwares.  but I want to know how to open leafpad as root in terminal writing above commands and saving it.  Any Help? Sory for the bad English.  I am trying to install clamAV using commands still there is problem.


It's a well-known problem that new/unregistered users tend to neglect accepting answers. This is usually because they just don't pick up on the concept. If new users wind up sticking around and continuing to participate, they will eventually get clued in and then hopefully go back and accept answers to previous questions. The real problem occurs with "one-shot" users. We all know the scenario:  a 1-rep member-for-today user asks a question on SO, let's call him "timmy."  Stack Overflow members help timmy with his question. Comments are exchanged, suggestions thrown out.  Eventually somebody nails it on the head, let's call him "Jon Skeet."  Up-votes indicate general consensus. timmy emphatically thanks Jon in comments using various emoticons.  Then timmy is never to be seen again.  Stack Overflow members linger on the question page, and an awkward silence falls. Maybe this time it'll be different they whisper to themselves. Nope - timmy's half across the internet by now.   Now, I'm not pretending this problem hasn't already been discussed (in great detail): , but that suggestion is centered on auto-forcing accepted answers based on some algorithms, which would be heavy-handed. What I'd like to propose is more tempered: the ability to flag an answer for forced acceptance. I realize this would be a pretty radical change, but I think there's merit to it given the issue. The criteria for such a flag would be very strict:  Question is some X amount of time old (or OP has not been seen for X amount of time). OP is a user that has never accepted an answer. Flagged answer has at least X upvotes.  And essentially:  OP has given some indication of the answer's correctness in the comments. These criteria would limit the global effect of this flag. It would not be a site-wide sweep like the auto-force suggestion. Mainly it would be a procedural solution going forward, reserved for situations were there should very obviously be a check mark.   As with the previous suggestion, feel free to add/remove rules to make this viable. EDIT: I'm getting a mostly negative reaction on this suggestion; fair enough. Before I give up, I thought I'd post some examples of the posts this would be targeting specifically:       Here is the query I used to locate these (modified from the query in the linked discussion): SELECT q.Id as [Post Link] ,  q.Score, users.Id, users.DisplayName, a.Score, q.AcceptedAnswerId FROM posts q  INNER JOIN posts a ON (q.Id=a.ParentId) LEFT JOIN users ON (q.OwnerUserId=users.Id) INNER JOIN comments c on (a.Id=c.PostId) WHERE a.Score >= 2  AND a.Score = ( SELECT MAX(p3.Score) FROM posts p3 WHERE p3.ParentId=q.Id ) AND users.Reputation < 15 AND q.PostTypeId = 1 AND q.AcceptedAnswerId is null AND datediff(day, users.LastAccessDate, q.LastActivityDate) < 8 AND c.UserId = users.id AND (c.Text LIKE '%hank%' OR c.Text LIKE '%preciate%' OR c.Text LIKE '%:)%') GROUP BY q.Id, q.Score, users.Id, users.DisplayName, a.Score, q.AcceptedAnswerId  The query returns several thousand posts, after which some manual filtering is needed to find the ones I'm targeting. The examples were just pulled from the top of the list after looking them over. Anyway thanks for hearing me out at least.


How can I choose the correct laptop Wifi driver for my HP 630 notebook laptop?  I go to the relevant HP site and choose my operating system. It gives me the list of drivers but how would I know what is the correct vendor of my wireless network adapter.


How do I figure out the value of a number raised to a fractional power?

For example, if I had something like $9^{1\over 2}$, how should I determine how many times I should use the base (the number being raised to the power of the exponent) as a factor?  I just need something specific and readable.  Should I use a root symbol or something?  I'm asking this because I'm thinking it might be the opposite of a normal power.


I am trying to copy variables of the same class type  FUNCTION[] funcs; FUNCTION[] orphelines;   as follows   orphelines[nb_orphelines]=funcs[numero];   Is = right for this task? I get a NullPointer error....


I got research paper accepted in international conference to be held at Zurich, Switzerland. I got my visa rejected with following reason: Justification for the purpose and conditions of the intended stay was not provided. As i found that i did not mention the reason to stay for more three days after the conference. Basically my purpose was site seeing. As a justification of purpose, i already attached the invitation and acceptance letter from the conference committee. Should i need to apply for visa again with justification of purpose and stay. If yes, then should i need to mention in the cover letter about the refusal. Please suggest.


Cayley theorem to prove that a group of order $2^mk$, $k$ odd, can't be simple

I have to solve this exercise WITHOUT Sylow theorems and Cauchy Lemma. In fact this exercise is given in the Cayley's theorem section.     let $G$  be a group of order $2^mk$, where $k$ is odd. Prove that if $G$ contains an element of order $2^m$, then the set of all elements of odd order in $G$ is a normal subgroup of $G$.   The author gives this hint     Consider $G$ as the permutations via Cayley's theorem, and show that it contains an odd permutation   now by Cayley I have an imbedding of $G$ in $S_{|G|}$ (call $\varphi$ the injective homomorphism) using the left regular representation. Now, let $g \in G$ be the element of order $2^m$. Considering that $\alpha := g \mapsto L_g \in \text{Im}\varphi$, then $\alpha$ is a regular permutation composed by $r$ disjoint $2^m$-cycles, and so $\alpha$ is odd (an odd number of odd cycles)  but then? I don't know how to use the hint that I hope I've proved:(  I checked for similar question and I didn't found any, if someone think this is a duplicate,link the question and I'll delete this immediately:)


From :           To demonstrate the concept of Naïve Bayes Classification, consider the   example displayed in the illustration above. As indicated, the objects   can be classified as either GREEN or RED. My task is to classify new   cases as they arrive, i.e., decide to which class label they belong,   based on the currently exiting objects.      Since there are twice as many GREEN objects as RED, it is reasonable   to believe that a new case (which hasn't been observed yet) is twice   as likely to have membership GREEN rather than RED. In the Bayesian   analysis, this belief is known as the prior probability. Prior   probabilities are based on previous experience, in this case the   percentage of GREEN and RED objects, and often used to predict   outcomes before they actually happen.      Thus, we can write:            Since there is a total of 60 objects, 40 of which are GREEN and 20   RED, our prior probabilities for class membership are:             Having formulated our prior probability, we are now ready to classify   a new object (WHITE circle). Since the objects are well clustered, it   is reasonable to assume that the more GREEN (or RED) objects in the   vicinity of X, the more likely that the new cases belong to that   particular color. To measure this likelihood, we draw a circle around   X which encompasses a number (to be chosen a priori) of points   irrespective of their class labels. Then we calculate the number of   points in the circle belonging to each class label. From this we   calculate the likelihood:            From the illustration above, it is clear that Likelihood of X given   GREEN is smaller than Likelihood of X given RED, since the circle   encompasses 1 GREEN object and 3 RED ones. Thus:                  Although the prior probabilities indicate that X may belong to GREEN   (given that there are twice as many GREEN compared to RED) the   likelihood indicates otherwise; that the class membership of X is RED   (given that there are more RED objects in the vicinity of X than   GREEN). In the Bayesian analysis, the final classification is produced   by combining both sources of information, i.e., the prior and the   likelihood, to form a posterior probability using the so-called Bayes'   rule (named after Rev. Thomas Bayes 1702-1761).            Finally, we classify X as RED since its class membership achieves the   largest posterior probability.   This is where the difficulty of my maths understanding comes in.     p(Cj | x1,x2,x...,xd) is the posterior probability of class membership, i.e., the probability that X belongs to Cj but why write it like this?   Calculating the likelihood?    Posterior Probability?    I never took math, but my understanding of naive bayes is fine I think just when it comes to these decomposed methods confuses me. Could some one help with visualizing these methods and how to write the math out in an understandable way?


beamercolorbox with transparency creates a darker horizontal line

I try to make a transparent beamercolorbox (or any transparent box) but always get a horizontal line that is a bit darker than the rest of the box. Is there a way to get it to go away? I took the example from  and adapted to     \documentclass[dvipsnames]{beamer}     \usetheme{Copenhagen}     \setbeamercolor{mycolor}{fg=RoyalBlue,bg=red}     \begin{document}        \begin{frame}        \pgfsetfillopacity{0.5}        \begin{beamercolorbox}[wd=0.5\paperwidth,ht=2.5ex,dp=1.125ex,rounded=true]{mycolor}%         colored text         \end{beamercolorbox}%         \end{frame}       \end{document}  But I get a box that looks like this How do I get rid of the red horizontal line at the top of the box?


What do i need to have or do to install ubuntu on a windows 8 PC?

I'm tempted to download and install ubuntu. Can anyone run me through the basic things I need to do or have to succesfully install and run this operating system on my PC?


If click on an earned badge in my achievements using the Android app, some of them will open up the browser, but just showing the "index" page of the  linked exchange site. I'll receive the message:  ** "Could not load question; loading in browser instead"**  With" some badges" I mean those not linked to a question e.g. Autobiographer or linked to removed questions, comments etc.   That's annoying, why can't the app just show me that page in the app without opening the browser? Because the app specifically asks me how to open that link and choosing the Stack Exchange App to do so won't change the result.   Is this really intended?   I am using Android version 5.1.1 and Stack exchange app version: 1.0.89


Is there a file explorer/manager for the command line?

I would like to know if there is something like DOS interface for Ubuntu. I mean a "GUI" that can run from the console (for example if you are using Ubuntu Server). Some file explorer like Nautilus but in console.


Why cp and mv behave differently in bash script than command prompt?

I have cp and mv commands withaliases preset in my system.  [root@IMSSA ~]# which cp mv alias cp='cp -i'         /bin/cp alias mv='mv -i'         /bin/mv [root@IMSSA ~]#   If I try to replace a file, it will ask for prompt when try in command line.  But when I use a same within a script, they won't ask for prompt and just replaces the file.  [root@IMSSA ~]# echo "t giv" > /tmp/givin.txt; echo "r giv" > /root/givin.txt [root@IMSSA ~]# cat /tmp/givin.txt /root/givin.txt t giv r giv [root@IMSSA ~]# cat /tmp/givi.sh mv /root/givin.txt /tmp/givin.txt [root@IMSSA ~]#   [root@IMSSA ~]# mv /root/givin.txt /tmp/givin.txt mv: overwrite '/tmp/givin.txt'? ^C               ### Used ^C to cancel the Operation. [root@IMSSA ~]#    [root@IMSSA ~]# sh -x /tmp/givi.sh + mv /root/givin.txt /tmp/givin.txt [root@IMSSA ~]# cat /tmp/givin.txt /root/givin.txt r giv cat: /root/givin.txt: No such file or directory [root@IMSSA ~]#   So the aliases are not used inside the script, but why bash script and command prompt have different env? How does alias work here?  EDIT: This answers the question.


Is this lens too heavy for my micro four thirds body?

This is the setup I'm planning to use: Camera is an Olympus OMD E-M10 II, the lens is a Bower 500 mm f/6.3 using a Bower T mount to micro four thirds adapter.  The cause for my concern is that I plan to mount this on a tripod, which requires putting the camera on the tripod, since the lens does not have a tripod mount on it.  This in turn means the camera has to support the entire weight of the lens: about 1 lb 6 oz.  If it's necessary for getting an answer, I'd estimate the center of gravity of the lens is between 3 and 4 inches from the mount.  Am I safe mounting this lens on the camera body, and then placing the camera on a tripod?


Close vote review queue ! Currently it has 101.7k questions pending. My idea, based on a simple research from  is to introduce another queue that will partially balance the close vote queue. It should work as follows:   Questions from users with less than, let's say, 10 rep won't be shown immediately on the site. Instead they would go to a buffer, namely: Novice questions approval queue. This queue would be presented along with other queues on the , and would be available for users with, let's say, at least 2000 rep. For each presented question, in most simple version, there would be two options: Approve and Reject (possibly also Edit & Approve). The new queue could of course offer some gamification infrastructure: small rep rewards for reviewing for users, lets say, under 3000 rep, and analogously to other queues: badges. If in the meantime OP would manage to earn enough rep, their question would get published automatically.   Roughly relating to  if we assume that all users that were to ask "good questions" (score 3 or more) would be completely discouraged by this policy and give up asking at all, we would lost 2% of "good questions", while the Close votes queue length would be reduced by 23%. What's more important, it seems that the queue would at least grow slower then now.  Differences from First posts queue:   First posts queue handles both questions and answers. The latter do not seem a big problem on SO. This queue would somehow shield the page and close vote queue from very low quality questions. First post queue is based on the post being ... a first post :) This queue would work with regard to rep.   EDIT: In response to some points made in the comments&answers:   This would not prevent people from posting completely. Earning 10 rep isn't much work, and would give them right to post without review.  Any arguments in regard to gamification encouraging bad behaviour are not specific to this proposal - they describe valid problems, but in regard to the gamification idea in general. I think that this would introduce better behaviour of the queues (instead of one Close votes queue): for example it's very easy not to approve a question by a lazy programmer, who didn't even bother to spell correctly. Such easy to review questions are currently hidden in thousands of other, more complicated cases in the Close votes queue. two smaller problems are easier to handle than one big problem :)


Take command line arguments on java execution

I'm trying to make a program that can run with a gui or in a terminal only mode with no gui. How could I make it so that when the program is called in the terminal, the user adds an argument to determine whether to run with a gui or not?  By entering something like this when they start my program: java myprogram -Nogui


I have version 11.10 and am having trouble login in can only access guest account and cannot get into adminastrator account. I have gone to root menu and tried to enter password change it posts authentication token manipulation error  password unchanged. What can i do to get back adminastration account?


'contribute to achieve' or 'contribute to achieving'?

I have the following sentence and I need your help:  "Renewable energy sources can contribute to achieving the climate goals" Is this correct or do I have to write: "Renewable energy sources can contribute to achieve the climate goals"  I'd appreciate every comment.


How to get tag info for tags with special characters using SE API?

Let's say we have the tag . How can I get its info with the Stack Exchange API? I tried doing api.stackexchange.com/2.2/tags/c#/info. However, it returns:  {"error_id":404,"error_message":"no method found with this name","error_name":"no_method"}   So do I encode the #? Or I can't access it?


How do I connect to a WPA wifi network using the command line?

So basically, I'd like to use iwconfig to connect to my wifi network when I'm not inside X. But I just don't see a way to do it in the man page. Any idea?


How to read /proc/PID/maps without sudo?

I want to read the memory map (/proc/PID/maps) of some process without being sudo. And that is trivial, unless, the process has capabilities. See what I mean: If I run: $ bash $ cat /proc/$$/maps  This works and I get the output! But if I run: sudo setcap "cap_net_raw+p" /bin/bash  And try the test case again: $ bash $ cat /proc/$$/maps  I get: cat: /proc/1151842/maps: Permission denied  I hope this is understandable. Thanks for your help


How to display enumeration's StringValue (Title) in a combo box C# WPF

I'm working with small wpf app and I need to load enumation into my combo box as possiblities that user might choose when he's adding new product and it looks like this:  my enumeration:  public enum ProductTypeEnum : int {     Unknown = 0,      [StringValue("Final product for sale")]     FinalProduct = 1,      [StringValue("Ingredient for product")]     Material = 2  }   Here is how it looks in my C# WPF App when I'm fetching values to display it in my combobox:  var myEnums = ProductTypeEnum.GetValues(typeof(ProductTypeEnum));   if(myEnums.Length > 0) {     cmbArticleType.ItemsSource = myEnums;   //cmbArticleType.DisplayMemberPath = "SOMETHING.. WHATEVER IT AINT WORKED";  }     And this displays as you can see my real values "FinalProduct" and not the "Final product for sale"   [StringValue("Final product for sale")]   and I would like to display Final product for sale because it looks more natural in combobox (with spaces and so) =)  Thanks guys for any kind of help Cheers  EDIT AFTER MM8 HELPS:  How could I get real value out of this, cast it in integer as enums holds value of 0,1,2,3 etc :      But articleType does not provide Value so I could cast it in integer and store to db?


I simply want to create a date that is 3 days from now for use in a typescript angular component.  I have looked at  but this seems only to relate to pipes. Although I did see  about using pipes in code, looks a bit hacky...  Maybe I'm missing something as this should be really simple?!  Thanks


How to send multiple value with sql parameter for in()

I guess it is simple but I couldn't figure it out. I want it for asp.net project.   Normally I use Int for sql parameter for one int value but I need it for in() statement.  alter procedure abc   @id int  select * from tbl where id = @id   It works for one value,  alter procedure abc   @id int -- how should I change it  select * from tbl where id in (@id)   that one which I want. And how can I send the values in asp.net c#. Normally I send int value, but I do not know either?


10-faces dice "emulation" from N 6-faces dices

I want to play a game which uses one 10-faces dice, but I only have 6-faces "classic" dices at my disposal. Is it possible to approximately recover, to an arbitrary precision, a 10-faces dice probability distribution using N classic 6-faces dices and clever algorithm ? I have no clue how or even if this is remotely possible. Thanks you in advance for your kind help.


How to calculate the number of palindromes of a given number of characters?

A palindrome is a set of characters which equal the same thing forwards and backwards, for example; abccba. For a set of a given amount of  characters (we can use 9 as an example) how would you calculate the amount of palindromes of characters mathematically? This doesn't mean the words that can be formed but rather characters which are the same at start characters and end characters. What formula can be used to calculate this for simple lengths like 9 with lowercase letters?


My problem is that after I export my meshes to Ue4 it shows me that the normals are flipped. I tried both way, flipped and not flipped normals. This is what I get every time. Any tips what I might be missing?


LaTeX command inline in the caption of a figure

I want the caption of a figure to contain a LaTeX command without it being executed:    Using verbatim environment doesn't work in this case and throws errors. Please suggest a solution to this.


Bash is automatically reloading (injecting) updates into a running script upon saving it: Why? Any practical use?

I was writing a bash script, and happened to updated the code (saved the script file to disk) while the script was waiting for some input in a while loop. After I returned to the terminal and continued with the previous invocation of the script, bash gave an error about the file syntax:  /home/aularon/bin/script: line 58: unexpected EOF while looking for matching `"' /home/aularon/bin/script: line 67: syntax error: unexpected end of file   So I tried doing the following:  1st: create a script, self-update.sh let's call it:  #!/bin/bash fname=$(mktemp) cat $0 | sed 's/BEFORE\./AFTER!./' > $fname cp $fname $0 rm -f $fname echo 'String: BEFORE.';   What the script does is reading its code, changing the word 'BEFORE' into 'AFTER', then re-write itself with the new code.  2nd Run it:  chmod +x self-update.sh ./self-update.sh   3rd wonder...  aularon@aularon-laptop:~$ ./self-update.sh  String: AFTER!.   Now, I wouldn't have guessed that on the same invocation it would output AFTER!, on the second run for sure, but not on the first one.  So my question is: is it intentional (by design)? or it is because of the way bash runs the script? Line by line or command by command. Is there any good use of such behaviour? Any example of it?    Edit: I tried reformatting the file to put all command in one line, it does not work now:  #!/bin/bash fname=$(mktemp);cat $0 | sed 's/BEFORE\./AFTER!./' > $fname;cp $fname $0;rm -f $fname;echo 'String: BEFORE.';   Output:   aularon@aularon-laptop:~$ ./self-update.sh #First invocation String: BEFORE. aularon@aularon-laptop:~$ ./self-update.sh #Second invocation String: AFTER!.   While when moving the echo string to the next line, separating it from the rewriting (cp) call:  #!/bin/bash fname=$(mktemp);cat $0 | sed 's/BEFORE\./AFTER!./' > $fname;cp $fname $0;rm -f $fname; echo 'String: BEFORE.';   And now it works again:  aularon@aularon-laptop:~$ ./self-update.sh  String: AFTER!.


What changes can improve my visa application?

I am an Indian oil and petrol bunk dealer. I am travelling to UK and Europe in a tour package with my wife. I have started my business in Jan 2018. So I’m unable to refelect my proof of income in my ITR. Kindly suggest what else I can show to prove my income( i have stated my income has 1,60,000 INR per month).  Documents provided:   6 months statement of credit, over draft and saving account bank statement.    1lakh FD statement of my wife. Invoice of purchase of fuel for 6 months indian oil dealership agreement. land documents   Travel itinerary  Flight tickets Hotel booking voucher  Kindly answer my question its not answerd before. Its not duplicate My question: If I giving CA documents along with my previous documents and fill application correctly next time. Will they find any new mistakes and reject the visa again? Pls answer me.


What resolution should large formatted photography be for print?

I have been given a request to re-size and up the resolution on a handful of images to be printed 40 in. x 30 in. to be hung on the walls in a new facility conference room where clients will see them. A lot of the images I've been given are pretty lo-res (10 in x 8 in, 96 dpi), so obviously when I try to re-size them to 40 in x 30 in, the quality decreases significantly.  So my question really is, do you think I need to get a photographer to go out and shoot new images (these are the only images they have on file), or do you think just upping the resolution in Photoshop on the images I've been given will do the trick?  If we need to re-shoot, what file size/format should as ask to receive from the photographer? And if I can just re-size what resolution do you think it should be in order fpr the images to look clear for viewing?


Prove the identity:   $$\sum_{k=0}^{\frac{n}{2}}(-1)^k\binom{n-k}{k}2^{n-2k}=n+1$$   To prove this by induction is useless. I guess the best one solution would be to prove this by generating functions. Does anybody know how can I prove this equation?


Problem   Let $n = p_1.p_2.p_3 \cdots p_k.m^2$, where $p_1, p_2, p_3 \cdots p_k$ are distinct primes. Prove that n is sum of two squares if and only if $p_i$ is either 2 or $p_i \equiv 1 \pmod{4}$   For $p_i = 2$ , this is trivial case since $2m^2 = m^2 + m^2$. For $p_i \equiv 1 \pmod{4}$, I tried to use the fact that the product of a number of the form $4k + 1$ is also in this form. So I come up with: $$n = (4k + 1) \cdot m^2 = 4km^2 + m^2$$ Apparently, $m^2$ is a square, but I could not figure out how to prove $4km^2$ is a square, since k is in unknown form. Any idea?    Thanks,


Traveling with expired passport and Visa in same country

My passport is expired and US Visa also expired can I travel to different state of USA with expired passport of my home country and expired Visa of USA?


If I'm not mistaken, tens of means 10 to 99 and hundreds of means 100 to 999. Is this correct? I found in some dictionaries that tens of is actually not correct.  I also found that hundreds of could also mean any arbitrary large number. So how would people usually interpret hundreds of? Based on context?  In my case, I want to describe numbers of some items that are usually 50-90 but sometimes could be around 100-200, but definitely not as many as 300 or so. I want to really emphasize that there are a lot of these items. In this case, can I say "... have tens or even hundreds of ..."? Would people misinterpret what I actually want to say?


SDFX / Developer Console Delay in Deploying Lightning Component Changes

I am using the sfdx force:source:push plugin, and editing my components in a <aura:component>, that is displayed inside a Lightning Component Tab. When I make markup changes to the component in my local file-system and push via the above command OR in the developer console to my scratch org,   I am not seeing the changes reflected until I log out of the org and reload the app?   I am not seeing any errors in the developer console "Problems" tab? Is there some sort of delay in updating lightning components?   I have disabled the cache in chrome developer tools, to no greater effect.  Sometimes they show immediately, otherwise I am not sure if they have unless I change a text string?


How do I solve this? $$\int_0^\infty\frac{\ln(1+{x^2})}{1+{x^2}}$$ I know the answer is $\pi\ln2$.


We say that a sequence of random scalars $\{z_{n}\}$   converge in probability to a constant $\alpha$   , if for any $\epsilon>0$  ,$$\lim_{n\rightarrow\infty}\mathbb{P}\left(|z_{n}-\alpha|>\epsilon\right)=0$$  I understand the application of this notion to the Weak Law of Large Numbers, where I understand that when the sample size grows, the sampling distribution of the sample mean approaches the population value. However, the sample mean is a statistic. How can I think of a *sequence *of random scalars when it is not a statistic? What does $n$ mean in that case? Does it still mean sample size? What would convergence in probability mean in that setting? What 'distribution' or hypothetical distribution do we have in mind to compare to $\alpha$?


TypeError: unsupported operand type(s) for &: 'str' and 'int' in Python

I keep getting the error in the title when I try to run this code. I thought that the problem was to do with the variables not being integers, but that didn't fix the problem. Here is the code: shoeSize=int(input("Please enter your shoe size.")) ageOne=int(input("Please enter your age."))  if ageOne >= 18:     print("Your membership fee is £" & shoeSize*10) elif ageOne <= 65:         print("Your membership fee is £" & shoeSize*5) else:         print ("You cannot join!")


How does XP bonus from Ruby socketed on helms interact with XP bonus from Torment level?

With the new difficulty system I was wondering for Torment 6 if it was worth putting a Ruby in my helm instead of increasing my survivability with an Amethyst. How does the bonus from the ruby interact with the new XP bonus from Torment level ? Is it :    Additive : Put the total of XP bonus in T6 up to 1633% (1600% from T6 + 33% from Ruby) so a monster worth 100 XP now brings 1633 XP Multiplicative : A monster worth 100 XP will bring me 1600XP (T6) * 1.33 (Bonus from Ruby) = 2128 XP   Thanks


How do I embed an image from the web into a Trello card comment or description?

So far I have been successful embedding Youtube videos into Trello card comments; simply by including the URL in the comment Trello picks it up and renders an embedded Youtube thumbnail.   What I would like to do is the same thing, but with a simple PNG image. I don't want to upload the image as it is a Balsamiq mockup permalink which will get updated periodically, and I want the latest version to be displayed on the Trello card.   However, pasting the image URL into the Trello card has no effect.  Am I missing somthing?


Groups of order $pq$ without using Sylow theorems

If $|G| = pq$,  $p,q$ primes, $p \gt q, q \nmid p-1 $, then how do I prove $G$ is cyclic without using Sylow's theorems?


removing common words from php/mysql search program

Ok so I'm pretty new to PHP and building a question/answer site.  I want a page where the user can search my questions table to find a question and after some research and work I've come up with this but my problem is common words.  If a user types "is" in the search every question with "is" in it turns up.  My question is either 1) Is my approach to this search function completely wrong?  or 2) is there a way I can inject an array of common words to be omitted from the query?    search_reslut.php:  <?php   $servername = "127.0.0.1"; $username = "dylan326"; $password = ""; $dbname = "questions87"; $port = 3306;  // Create connection $conn = new mysqli($servername, $username, $password, $dbname, $port); // Check connection if ($conn->connect_error) {     die("Connection failed: " . $conn->connect_error); }   echo "Your search results:
"; echo "
"; $query = $_POST['query'];  $query  = "$query $query $query"; $pieces = explode(" ", $query); $qindex0 = $pieces[0]; // piece1 $qindex1 = $pieces[1]; // piece2 $qindex2 = $pieces[2]; // piece3 $qindex3 = $pieces[3]; $qindex4 = $pieces[4]; $qindex5 = $pieces[5]; $qindex6 = $pieces[6];    echo $query;  $sql = "select q_id, question, username, q_date from questions where (question like '%$qindex0%' or question like '%$qindex1%' or question like '%$qindex2%' or question like '%$qindex3%' or question like '%$qindex4%' or question like '%$qindex5%' or question like '%$qindex6%')";    $result = $conn->query($sql);  if (mysqli_num_rows($result) > 0) {     // output data of each row     while($row = mysqli_fetch_array($result)){          $question = $row['question'];  echo ('' . $question .'Asked by:'.' '.$row['username'].' '.$row['q_date'] .' '  . '
');   }}  else {echo "No resluts found";}     ?>


variable name contains a variable inside it


I don't want to render from the Video Sequence Editor

As soon as I have a strip in the Video Sequence Editor it renders from that. How can I choose between rendering from the Video Sequence Editor and rendering the actual Scene?


What does "all the more" mean and how is it used?

Here is a sample context:     As you might expect, the framework also provides some convenience   classes to make the task of writing custom validators all the more agreeable.   (Emphasis added.)


Is there a way to get html footer on bottom of any page?

I'm building my own website for a project. I have an event page where I show all upcoming events. Every time you add an event, the page will get bigger. ATM, the footer is in the middle of the page because there are not enough events.  The problem is, I want the footer to be on the bottom of the screen, unless the page is bigger than the screen. If the page is bigger than the screen, the footer should be on the bottom of the page.  I tried to use height: 100% or height: 100vh but they put the height on "fit to screen", so if there are for example 20 events (bigger than the screen), the footer will be stuck on the bottom of the screen and the events will go through the footer.  The page now looks like this:     and the table is build up like this:

       Date/Time	       Event

                      #_EVENTDATES                 #_EVENTTIMES         	                      #_EVENTLINK             {has_location}
#_LOCATIONNAME, #_LOCATIONTOWN #_LOCATIONSTATE{/has_location}


how to add callback function to elements which are added by JQuery

The callbacks functions are not working on the elements which are added by JQuery. Here in my example there is a parent div with class=parent. After clicking on it a Child is being added. But when I am click on the the child it does not alert the message. Please see the example below
             Parent


Understanding the meaning of @ in package management

I discovered tmux is installed on my system. In order to find out if it was preinstalled with fedora I ran the command dnf info tmux which prints out:  Installed Packages Name         : tmux Version      : 2.7 Release      : 1.fc28 Arch         : x86_64 Size         : 765 k Source       : tmux-2.7-1.fc28.src.rpm Repo         : @System From repo    : updates Summary      : A terminal multiplexer URL          : https://tmux.github.io/ License      : ISC and BSD Description  : tmux is a "terminal multiplexer."  It enables a number of terminals (or              : windows) to be accessed and controlled                     from a single terminal.  tmux is              : intended to be a simple, modern, BSD-licensed alternative to programs such              : as GNU Screen.   Based on the above output it seems that @ means "at" so Repo: @System means "at system" (i.e. the package is not in a repository instead the package is installed at the system) or in other words (package tmux is) installed at the system.  However tracking down the transaction when tmux was installed with dnf history list tmux (which showed something like transaction ID 55), and dnf history list 55 the following line is part of the resulting output:  Install    tmux-2.7-1.fc28.x86_64               @updates   Based on the above findings which of the following understanding of @ in package management is correct?   The line above makes it clear that tmux was installed from the updates repository but assuming that @ means "at" shouldn't that mean installed at the updates repository? In other words, why does @ in the output of dnf info <packagename> mean "at" e.g. @System means "at System", but in the output of dnf history list 55, @ seems to mean "from"? Alternatively does @ mean "install the package tmux-2.7-1.fc28.x86_64 at the repository @updates", or in other words, "install the package tmux-2.7-1.fc28.x86_64 that is at the repository updates"? Which makes sense given that the line below from the same output should read as: upgraded subversion at the repository fedora/27.   Upgraded   subversion-1.9.7-1.fc27.x86_64       @fedora/27   Edit: My question is not a duplicate. Where as the other question is asking what @ means, this question is different in that I researched/investigated the meaning of @ in the package manager after which I posted a question to confirm which of my understanding of the results of the research/investigation is correct. Besides the answers to the  question are low quality. For example the first answer makes the following statement:     All "Installed Packages" are preceded by @ sign, while "Available Packages" are not. So I believe @ signs show the packages are installed.   This is not correct because for example with that flawed answer   Install    tmux-2.7-1.fc28.x86_64         @updates   would mean that tmux is already installed which it is not. So that rules out @ meaning that a package is already installed  and the second answer states:     DNF uses @ to denote the repo an installed package was installed from. As you noted   That's wrong because then @System would mean that the package was installed from your system.  My understanding of @ in the main question shows why this quote from the second answer to the other question is wrong.


What is the difference between   a three-week holiday   a three-weeks' holiday     I am so tired so I want to take a three-week / a three-weeks holiday.    Which one is more suitable to use or which is the correct one?


How can a REIT fund grow when it has to distribute 90% of their taxable income?

You can't grow that much if you invest only 10% of what's left after dividends


Proving the Limit of a Sequence of without the Dominated Convergence Theorem

Show:       $$ \lim_{n\to \infty} \int_{0}^{\frac{\pi }{2}} \sin^n(x) = 0. $$   I showed this using the . I want other methods to prove it. Thank you.


This is the error that stops the compile  {/var/lib/texmf/fonts/map/pdftex/updmap/pdftex.map}] ! Argument of \UTF@three@octets@noexpand has an extra }. <inserted text>                 \par l.48 \end          {document} ?   When I searched for UTF@three@octets@noexpand I couldn't find anything. When I looked at my bib file I couldn't find anything that could be causing this and the .tex document I'm trying to compile doesn't seem to have any major errors in it. I can't post the actual document but this is the code with the citations  \documentclass{article} \usepackage[backend=biber,style=apa]{biblatex} \addbibresource{uni.bib} \usepackage[a4paper,left=25mm,top=15mm,]{geometry} \usepackage{setspace} \doublespacing  \author{my name} \title{document title}  \begin{document} \maketitle  \textcite{mcgray09} \textcite{agyeiwaah18} \textcite{mcgray09} \parencite{MFAJ17}  \printbibliography \end{document}   EDIT: I wasn't looking at my bib file well enough, ` and ' both have to be put in {}


Prove the following identity combinatorially  $$\left(\begin{array}{c} \left(\begin{array}{c} n \\ 2 \end{array}\right)  \\ 2 \end{array}\right) = 3 \left(\begin{array}{c} n \\ 4 \end{array}\right) + 3 \left(\begin{array}{c} n \\ 3 \end{array}\right) $$


How to install vte-ng from the source: make command fails

Trying to install  from source. I did try the usual methods like using make. There is nothing related to installing in the readme file and could not find a configure folder.  So how do I install this?


UnMounted external HDD and lost everything

So I accidentally unmounted my external HDD in gparted and now it shows empty But in testdisk and getDataBack I can see the files and eventually copy them but they make around 900Go and even my two computers together aren't up to that size I wish to know if there's any other way to fix it Thanks in advance


I have been searching on the web and I can't find this. What is the meaning of the color of the node sockets in the node editor?


Please help me to write test class for event object. I am getting only 25% code coverage.  // Method to validate start and End Time on events     public static void ValidateStartEndTime(List<Event> evts) {         for(Event ev: evts)         {             if(ev.StartDateTime.time() < Time.newInstance(7, 30, 0, 0))             {                 ev.StartDateTime.addError('Start time should be greater than or equals to 7:30 AM');             }             if(ev.EndDateTime.time() > Time.newInstance(18, 00, 0, 0))             {                 ev.EndDateTime.addError('End time should be less than or equals to 6 PM');             }         }     }   Test class:  @isTest public class EventTrigger_Test {      static testMethod void myUnitTest1(){          Event e = new Event();         e.StartDateTime=system.today();         e.EndDateTime=system.today()+5;          Test.startTest();               insert e;         Test.stopTest();     } }


Does meat/poultry keep in the fridge for just a couple of days after purchase, or a couple of days after the sell-by/use-by date?

I usually freeze all of my meat unless I plan to use it within one day, but I was just wondering whether I could keep some raw chicken in the fridge until Thursday (three days from now). I wanted to make sure it wouldn't go bad, so I did some searching and it seems that most sites recommend discarding raw poultry .  But the sell-by date on the package is August 6th, which is six days from today. The implication is that if I had boughten this chicken six days later, then it would somehow last in my fridge all the way until August 8th (6+2 days).   Why does the usual food safety advice seem to be suggesting that raw poultry/meat will degrade much more slowly while on grocery store shelves? Are they kept colder there than in conventional refrigerators? Or will my chicken actually be safe to eat for another week?


On Windows I can use  to quickly and easily find any file or folder on my PC. What are equivalent programs/commands for Ubuntu?


I'm learning to code java and at the moment I'm trying to make a basic game of "21".   There are two "do while" loops in the code:    where I want the player to choose whether he wants to draw a new card and  where I want the player to choose if he wants to play a new game when the last one finished.   However, it doesn't matter if I answer both questions with "Yes" or "No", the loop always breaks and "ends".  Is there something wrong in my logic?   Thanks a lot for the help.  import java.util.Scanner;  public class twentyOneGame {   public static void main(String[] args) {     int computerCard;     int playerCard;     int playerSumCards = 0;     int computerSumCards = 0;     int cardAmount = 0;     String keepPlaying = "Yes";     String keepGoing;       System.out.printf("Enter your name %n");     Scanner input = new Scanner(System.in);     String playerName = input.nextLine();      do {         do {              playerDraw playerdraw = new playerDraw();             playerCard = playerdraw.getPlayerCard();             playerSumCards += playerCard;              computerDraw computerdraw = new computerDraw();             computerCard = computerdraw.getComputerCard();             computerSumCards += computerCard;             cardAmount += 1;              System.out.printf("Your have %s card(s). Your total is %s. %n", cardAmount, playerSumCards);              input = new Scanner(System.in);             System.out.printf("Do you want to draw another card? Yes or No %n");             keepGoing = input.nextLine();          } while (keepGoing == "Yes" && cardAmount < 3);           if (cardAmount == 1) {             System.out.printf("Your total is %s %n", playerSumCards);             System.out.printf("The computers total is %s %n", computerSumCards);              if (playerSumCards > computerSumCards) {                 System.out.printf("Good job %s, you won! %n", playerName);             } else {                 if (playerSumCards == computerSumCards) {                     System.out.printf("It's a draw! %n");                 } else {                     System.out.printf("Oh no, the computer won! %n");                 }             }         } else {             if (cardAmount == 2) {                  System.out.printf("Your total is %s %n", playerSumCards);                 System.out.printf("The computers total is %s %n", computerSumCards);                  if (playerSumCards > computerSumCards) {                     System.out.printf("Good job %s, you won! %n", playerName);                 } else {                     if (playerSumCards == computerSumCards) {                         System.out.printf("It's a draw! %n");                     } else {                         System.out.printf("Oh no, the computer won! %n");                     }                 }             } else {                 if (cardAmount == 3) {                      System.out.printf("Your total is %s %n", playerSumCards);                     System.out.printf("The computers total is %s %n", computerSumCards);                      if (playerSumCards > computerSumCards) {                         System.out.printf("Good job %s, you won! %n", playerName);                     } else {                         if (playerSumCards == computerSumCards) {                             System.out.printf("It's a draw! %n");                         } else {                             System.out.printf("Oh no, the computer won! %n");                         }                     }                 } else {                  }             }         }         input = new Scanner(System.in);         System.out.printf("Do you want to keep playing? Yes or No %n");         keepPlaying = input.nextLine();          if (keepPlaying == "Yes") {             playerSumCards = 0;             computerSumCards = 0;         } else {             System.out.printf("Thanks for playing, %s %n", playerName);             break;         }      } while (keepPlaying =="Yes"); } }


category of linear maps between fixed vector spaces

Let $V,W$ be fixed $k$-vector spaces. Let $C$ be the category whose objects are linear map $f:V\to W$ and morphisms from $f$ to $g$ are pair of linear maps $(\alpha,\beta)$ where $\alpha:V\to V,\beta :W\to W$ such that $g \circ\alpha = \beta \circ f$.  I want to find the product in this category. Note that $C$ is the full subcategory of $D$, whose objects are linear maps between any $k$-vector spaces, with morphisms $(\alpha,\beta)$ such that $g \circ\alpha = \beta \circ f$. I proved that in $D$, the product of linear maps $f_i:V_i \to W_i$, $ i \in I$ is given by $f: \prod_{i\in I} V_i \to \prod_{i\in I} W_i$ where $f((v_i))=(f_i(v_i))$.  So given $f_i:V \to W$ in $C$, if there exists isomorphisms $\prod V\simeq V$ and $\prod W\simeq W$, we can also find the product in $C$.  But is it the necessary condition? In other words, if there exists product of $f_i:V\to W$ in $C$, then is it true that $\prod V\simeq V$ and $\prod W\simeq W$?


I'm fitting a linear model to a dataset. I've reduced the model from 7 variables to 3 and as part of that I've transformed one of my variables (wt) in order to get a better fit.  For my final model, the summary is:  summary(lm22) Call: lm(formula = mpg ~ poly(wt, 2) + year + origin, data = redautoi)  Residuals:     Min      1Q  Median      3Q     Max  -6.4126 -1.5029 -0.0003  1.5994  7.6032   Coefficients:                Estimate Std. Error t value Pr(>|t|)     (Intercept)   -33.94088    2.84630 -11.925  < 2e-16 *** poly(wt, 2)1 -100.09492    3.14080 -31.869  < 2e-16 *** poly(wt, 2)2   27.18431    2.61085  10.412  < 2e-16 *** year            0.74125    0.03736  19.839  < 2e-16 *** origin          0.55447    0.20314   2.729  0.00665 **  --- Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1  Residual standard error: 2.477 on 367 degrees of freedom Multiple R-squared:  0.8842,    Adjusted R-squared:  0.883  F-statistic: 700.7 on 4 and 367 DF,  p-value: < 2.2e-16   My question is how do I interpret these estimates? Especially  poly(wt,2)1 and poly(wt,2)2  Substituting values from the original dataset using the above estimates gives a wild fitted value. (but using fitted(lm22) appears to give reasonable estimates)


Html value attribute having multiple values

I am new to angular js. Now I have an input where I have implemented a token field. Now, the value attribute of the input box has values in an array. Now I don't know how we can use that array in the html. Like  value="abc,pqr"   This works , But I have an array and that array I need to use in the html.
     Should
         <input name="should"              id="should"              type="text"             value=""              placeholder="should requirement"              class="form-control setmargin">

  $scope.somevalues = ['abc','pqr','hhhh'];   This values are coming from the ajax call. Now I have bootstrap tokenfield so I need to have all this values in that input box . How can I use this array values in the html value atttibute ?


Though there are several posts discussing the reference books for topology, for example . But as far as I looked up to, all of them are for the purpose of learning topology or rather on introductory level.  I am wondering if there is a book or a set of books on topology like Rudin's analysis books, S.Lang's algebra, Halmos' measure (or to be more updated, Bogachev's measure theory), etc, serving as standard references.  Probably, such a book should hold characteristics such as being self-contained, covering the most of classical results, and other good properties you can name.  In the end, I only have the interest on general-topology (topological space, metrization, compactification...), and optionally differential topology (manifolds). So please don't divert into algebraic context.  Cheers.  ---------------------update-----------------------  Thanks for all the delightful replies. I will try to quickly check the books mentioned beneath. And I may accept the answer which is most closed to my personal flavor.  Sorry for others. It's a pity no multiple acceptance can be made for such a ref-request question.  Greetings.


Incorrect certificate on hatdash.com / blog.gaming.stackexchange.com

It looks like  was used during the . Both of these links use certificates that are invalid for their domains, making the site show as insecure.


Where can I find people for hire with LaTeX skills and designer skills?

I have now written my first e-book in LaTeX but, before I publish it, I wish to hire someone with superior LaTeX skills to fix the design and formatting of the book. At the moment I have tons of issues with the e-book and it doesn't look too great. Where could I find people for hourly hire with good book design skills and good LaTeX skills who could help me? It's easy to find people with good book design skills, but all of them work in Illustrator or CorelDRAW and not LaTeX.


Is there any way to hook, parent, or constraint something to a vertex of a particle hair strand? Such as a hair accessory dangling from a braid that needs to move with the hair?  Converting the hair to mesh isn't viable, as I then lose hair dynamics and have to rig some other way.  Scripting solutions are fine too. There must be some way to get the location of a particle hair vertex or vertices from the API. Then you could have an empty copy it or something?


Getting this exception while running following program    Exception in thread "main" java.lang.NullPointerException     at pojo.Bill.main(Bill.java:20) Java Result: 1   Bill.java  public class Bill {     public static void main(String s[]){         Bill b=new Bill();         b.getBillDetails().setBillNo(444);// line 20         System.out.println("bill no "+ b.getBillDetails().getBillNo());     }      private BillAction billDetails;      public BillAction getBillDetails() {         return billDetails;     }      public void setBillDetails(BillAction billDetails) {         this.billDetails = billDetails;     }   In BillAction there is  getter and setter of billNo How to resolve this.


I currently hold a US F1 visa on my Iranian passport, and I've booked a flight from NYC to Tehran. The problem is that the trip is from JFK (US) to ZRH (Switzerland), from ZRH to FRA (Germany), and then from FRA to IKA (Iran). I'm wondering if I can stay in the international area of the airport for the domestic flight (ZRH to FRA) because I don't have a Schengen visa. If not, do I need a transit Schengen or another kind? I'm not sure if getting the visa would be easier/cheaper than canceling/rebooking the flight.  edit: turns out that even a transit visa wouldn't work for 2 layovers, so I contacted the booking website and canceled the flight, fortunately with a full refund.


I need an advice.. I need to recreate the following formula:   The only difference is that color of the brackets needs to be red. Is it neccessary to do this in math mode, or can be achieved in some other way ?


How to transfer files between Ubuntu machines?

I understand that this is a totally novice question but...  What is the best way for me to transfer files between two PC's? I have a laptop with Ubuntu Desktop (12.04) and a local server I'm setting up using Ubuntu Server. I'm used to windows environment where I might typically browse the network via Windows explorer and move files around. This might work for Ubuntu desktop, but what's the best way for Ubuntu server?  Do I need to create a user on the server, then SSH into the server from the laptop? Can I then use a move command to move my files back and forth? What do I need to look into?  Thanks.


Nowadays, I see a lot of users live streaming on YouTube and wanted to try it for myself. However, when I go to my channel I don't see an option for live streaming.  I tried researching how to do this on YouTube and Google, but without luck.  So I was wondering, how can I live stream on YouTube?  I don't have any pro account or any of that, but I've watched livestreams from users who I don't think have pro accounts either.  So livestreaming is open for everyone, right?


Does SQL Server really require fully qualified object references to match a statement to a cached execution plan

From SQL Server Docs, section :  The algorithms to match new SQL statements to existing, unused execution plans in the cache require that all object references be fully qualified. For example, the first of these SELECT statements is not matched with an existing plan, and the second is matched: SELECT * FROM Contact SELECT * FROM Person.Contact  Is the above statement also true for object references that use the default dbo? The reason I ask is because I personally never fully qualify object references (and I assume most people don't) even when using a driver like JDBC. Does this mean that all of my SQL statements are being re-compiled every time they're executed?


why I get this error while using templates in c++

I am new to Templates and trying to get name and item but I run into weird error. I thought the problem was the string so I changed to int but it didn't work. can you help me please. Thank you! when i delete the templates form cpp class i get many different errors even tho i am defining them in hpp file   Template.hpp  #ifndef Template_hpp #define Template_hpp  #include <stdio.h> #include <iostream> #include <string> using namespace std;  template <typename T1 ,typename  T2> class Temp { private:     T1 item;     T2 name;  public:     Temp();     Temp(T1 item, T2 name);     T1 getItem();     T2 getName();  }; #endif /* Template_hpp */   Template.cpp  #include "Template.hpp" #include <stdio.h> #include <iostream> #include <string> using namespace std; template <typename T1 ,typename  T2> Temp<T1,T2>:: Temp() {  } template <typename T1 ,typename  T2>  Temp<T1, T2>::  Temp( T1 item, T2 name) {     this->item=item;     this->name=name; } template <typename T1 ,typename  T2> T1 Temp<T1,T2>:: getItem() {     return this->item; }  template <typename T1 ,typename  T2>   T2 Temp<T1,T2>::getName() {     return this->name; }   main.cpp  #include <iostream> #include<string> #include "Template.hpp" using namespace std;  int main(int argc, const char * argv[]) {      //Error here      Temp<int,string>t1(10,"zaid");     t1.getName();     return 0; }   Error  Showing All Issues Undefined symbol: Temp<int, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >::Temp(int, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >)


Which Force-sensitive species in the Star Wars Galaxy have never produced a Jedi?

I was reading  regarding whether any species can produce Force-sensitive beings, and it lead me to wonder a related and (hopefully) separate question: Are there any species in the Star Wars Galaxy that, even though they produce Force-sensitive beings, have never produced a Jedi, particularly "well-known" species?   The Wookieepedia article mentions one, the , and another example I'd imagine would be , they are a well-known species in Legends, producing lots of dark side users, but did they ever produce a Jedi?   Which other well-known, or not, Force-sensitive species have never produced a Jedi?  Answers can be from Legends or Canon.


Can an Medium Enlarged PC pick up and wield a Large Weapon?

Scenario:  A PC has become Large through means of Enlarge Person. All of the gear he carries has been Enlarged with him as per  spell.  A Large Greatsword lies on the ground nearby and he goes and picks it up. Does the greatsword:  A: Remain Large allowing the PC to wield it just as the equipment enlarged with him?  Follow up:  What happens when the PC returns to their original size?  Can a Medium PC then carry around a Large weapon on their back, drop it before Enlarge Person is cast, then pick it up and wield it?  B: Enlarge by one size into a Huge Greatsword as soon as it is picked up by the Enlarged PC  C: do something I haven't thought of....?


Handler Class Crashing after removing object

That was probably a very confusing title, but I'm pretty confused. I am making a game, and there are explosions. I just ran into this one stupid problem. Here's my code for the explosions (without the package and imports):  public class LBExplosion extends GameObject{ private int tick; private int startSize,endSize,size; Handler handler; public LBExplosion(float x, float y, ID id, int startSize, int endSize, Handler handler) {     super(x, y, id);     // TODO Auto-generated constructor stub     this.startSize = startSize;     this.endSize = endSize;     size = startSize; }  @Override public void tick() {     // TODO Auto-generated method stub     tick++;     size++;     if (size >= endSize) {         this.handler.removeObject(this); //here     } }  @Override public void render(Graphics g) {     // TODO Auto-generated method stub     if (tick % 2 == 0) {         g.setColor(Color.white);     } else if (tick % 2 == 1) {         g.setColor(Color.red);     }     g.fillRect((int) x - size/2, (int) y - size/2, size, size); }  @Override public Rectangle getBounds() {     // TODO Auto-generated method stub     return null; }   }  And it errors when I try to remove it (at line 25).  Here's the code for the handler class (without the package and imports):  public class Handler { LinkedList <GameObject> objList = new LinkedList <GameObject>();  public void tick() {     for (int i = 0; i < objList.size(); i++) {         GameObject tempObject = objList.get(i);         tempObject.tick();     } } public void render(Graphics g) {     for (int i = 0; i < objList.size(); i++) {         GameObject tempObject = objList.get(i);         tempObject.render(g);     } }  public void addObject(GameObject object) {     objList.add(object); } public void removeObject(GameObject object) {     objList.remove(object); } public void removeAllEnemies() {     for (int i = 0; i < objList.size(); i++) {      } }   } And here's the constructor for the game class (where it's spawned):  public Game() {     handler = new Handler();     hud = new HUD();     spawner = new Spawner(handler);      this.addKeyListener(new KeyInput(handler));     new Window(WIDTH,HEIGHT,"Game", this);      handler.addObject(new Player (16, 16, ID.Player,hud,handler));     handler.addObject(new LBExplosion (300, 316, ID.LBExplosion,0,64,handler));  }   It gives me this error:  Exception in thread "Thread-2" java.lang.NullPointerException at com.wave.noah.two.p.a.c.k.a.g.e.something.main.LBExplosion.tick(LBExplosion.java:26) at com.wave.noah.two.p.a.c.k.a.g.e.something.main.Handler.tick(Handler.java:12) at com.wave.noah.two.p.a.c.k.a.g.e.something.main.Game.tick(Game.java:80) at com.wave.noah.two.p.a.c.k.a.g.e.something.main.Game.run(Game.java:62) at java.lang.Thread.run(Unknown Source)   Don't mind the long package name.  How do I fix this unexpected error?


Can anyone help me or at least give me some hints   how to prove following inequality  :  $ \lvert z-a\rvert \le \lvert \lvert a\rvert-\lvert z\rvert\rvert + \lvert z\rvert*\lvert arg (z/a)\rvert $  for any $ z, a \in \Bbb C, a \neq 0$


As you know, Earth rotates around it's axis in an angle of 23.5 degrees. How do I make a sphere in Blender rotate like this?


Prove that every number of the sequence $49,4489,444889,\ldots$ is a perfect square.    We can observe that $49=7^2, 4489=67^2, 444889=667^2, \ldots$  I have tried expanding terms of the sequence, and to express it as a whole square. But it was too tough for me.   Any help will be appreciated.


prove that if $k|m$, $\mathbb{Z}_m$ has a subgroup of order $k$

prove that if $k|m$, then $\mathbb{Z}_m$ has a subgroup of order $k$.  im not sure where to start with this.  any help is appreciated.  thanks!


How can I get bash to exit on backtick failure in a similar way to pipefail?

So I like to harden my bash scripts wherever I can (and when not able to delegate to a language like Python/Ruby) to ensure errors do not go uncaught.  In that vein I have a strict.sh, which contains things like:  set -e set -u set -o pipefail   And source it in other scripts. However, while pipefail would pick up:  false | echo it kept going | true  It will not pick up:  echo The output is '`false; echo something else`'    The output would be   The output is ''  False returns non-zero status, and no-stdout. In a pipe it would have failed, but here the error isn't caught. When this is actually a calculation stored in a variable for later, and the value is set to blank, this may then cause later problems.  So - is there a way to get bash to treat a non-zero returncode inside a backtick as reason enough to exit?


Sheduling a shell script using crontabs for a rolling 5 hour interval across days

I need to schedule a shell script execution with crontabs to execute it every 5 hours starting from 01:00 and daily.  sample execution times:  2020-05-29 01:00  2020-05-29 06:00  2020-05-29 11:00   2020-05-29 16:00   2020-05-29 21:00   2020-05-30 02:00   2020-05-30 07:00 .....  please note that the interval is rolled forward per the day.  I have tried the following expression but crontab is giving an error saying "bad hour".  0 1/5 * * * path_to_shell_script   Can anyone suggest a way accomplish this if it is possible with crontabs?


kernel add swap partition without it be list in /etc/fstab

I created a swap partition during installation, but I commented it out latter, and my computer has been reboot many times. # swap was on /dev/sda3 during installation #UUID=71b04cbb-8779-4b0d-8664-9f2c402f5328 none  swap    sw              0       0  but I found the swap partition was still being used despite this: $ swapon --show NAME      TYPE      SIZE USED PRIO /dev/sda3 partition 7.5G   0B   -2  I found the following entry in /var/log/messages: debian kernel: [    5.665876] Adding 7812092k swap on /dev/sda3.  Priority:-2 extents:1 across:7812092k SSFS  I'm not sure what's going on and how to fix this. Can anyone help?  update $ lsblk -o +PARTUUID NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT PARTUUID sda      8:0    0 447.1G  0 disk             ├─sda1   8:1    0   190M  0 part /boot/efi  3838849b-e3fd-4b5f-81c0-422b61fa5b5e ├─sda2   8:2    0   286M  0 part /boot      2406c09a-459e-422b-86b9-24b993df1826 ├─sda3   8:3    0   7.5G  0 part [SWAP]     4d1a1f8f-a4ae-4fad-b9ab-40c2e2f0c106 ├─sda4   8:4    0  46.6G  0 part /          7552267d-9ca8-4b3a-bf42-e688cdc9ada1 ├─sda5   8:5    0 111.8G  0 part            eb053a9b-bd97-44ab-b864-45655589f2c2 └─sda6   8:6    0 280.9G  0 part /home      6179cce6-66d5-42db-a288-5675910be9cb  $ systemctl list-units --type=swap UNIT          LOAD   ACTIVE SUB    DESCRIPTION                                                                                dev-sda3.swap loaded active active Swap Partition  LOAD   = Reflects whether the unit definition was properly loaded. ACTIVE = The high-level unit activation state, i.e. generalization of SUB. SUB    = The low-level unit activation state, values depend on unit type.    systemctl status dev-sda3.swap ● dev-sda3.swap - Swap Partition    Loaded: loaded (/run/systemd/generator.late/dev-sda3.swap; generated)    Active: active since Thu 2021-04-01 16:56:20 CST; 16h ago      What: /dev/sda3      Docs: man:systemd-gpt-auto-generator(8)     Tasks: 0 (limit: 4915)    Memory: 536.0K    CGroup: /system.slice/dev-sda3.swap  Apr 01 16:56:20 debian systemd[1]: Activating swap Swap Partition... Apr 01 16:56:20 debian systemd[1]: Activated swap Swap Partition.   to prevent the swap (/dev/sda3) from automount by systemd, use sgdisk -A 3:set:63 /dev/sda


What is the difference between a 'Type' and an 'Object' in Python

I came upon this reading the python  on the super keyword:  If the second argument is omitted, the super object returned is unbound. If the second argument is an object, isinstance(obj, type) must be true. If the second argument is a type, issubclass(type2, type) must be true (this is useful for classmethods).  Can someone please give me an example of a distinction between passing a Type as a second argument versus passing an Object?   Is the documentation talking about an instance of an object?  Thank you.


How to show that if $\sum_na_n=\infty$ and $a_n\downarrow 0$ then $\sum\limits_n\min(a_{n},\frac{1}{n})=\infty$?

Suppose $a_n\downarrow 0, \sum\limits_{n=1}^{\infty}a_n=+\infty,   b_n=\min\{a_n,1/n\}$. Prove that $\sum b_n $ diverges.  In fact, I have known that two positive divergent series $\sum a_n ~\sum b_n$,  $c_n=\min\{a_n,b_n\}, \sum c_n$ is not always divergent. But I do not know why this above series is surely divergent. Sincerely thanks.


I'm try install and configure Mod_Security on Amazon EC2 Linux 64 bits, but one error happens  Syntax error on line 23 of /etc/httpd/conf.d/modsecurity.conf: ModSecurity: Found another rule with the same id  Need help to solve this, I tried to find in many search engines, but found nothing.  Can someone help me?


How do I get the browser to reask me to integrate with a website?

I'm using  and I accidentally clicked "No" when asked if I want to integrate with the website.  How can I have Firefox or Chrome reask me to integrate the site with Ubuntu?


Where does the expected value definition come from?

The definition of the expected value on the domain $[a,b]$ is given by $$E[X] := \int_a^b x f(x) \, \mathrm dx $$ I understand what the mean is, but I don't fully understand how this specific equation gives you the mean. How can I understand this without just taking it at face value?


Partition of vertex set of a graph containing less than a third of all edges each

I am asked to prove that for a graph $G$ with vertex set $V$:    $\exists \text{ a partition } V_1 \cup V_2 \text { of } V \text{ such that }       e(G[V_1]) + e(G[V_2]) \leq \frac{1}{2}e(G)$ We may also require that $e(G[V_1]), \;e(G[V_2]) \leq \frac{1}{3}e(G)$   Using an inductive argument I have proven the first part, but am unsure of how to continue to prove the second. I want to use an inductive argument on the number of vertices by first removing a vertex, finding a partition of the remaining subgraph, and then appropriately adding the original vertex and its edges back in.   However, my problem is that I don't know how I could justify that no matter how many edges the removed vertex has, there is a way to place it in either $V_1$ or $V_2$ such that the conditions are still met. In fact I suspect it might not actually be always possible, however I am unsure how else I may approach this question.


Number of distinct total orders on a set

This is from a class question, not looking for someone to do homework for me, just seeking clarification.  Let the set X=(a,b,c)  How many distinct total orders can be defined on this set? Why?  I did search around a bit and from , someone said that for a set of N elements the number of total orders is N!  My question is: is this correct, and why? My class notes define a "total order" as a partial order which is comparable, with a partial order being a relation that is Reflexive, Transititve and Antisymmetric. I get all that, but I'm confused as to how this relates to the question given.


Solving equation with complex numbers: $\bar z = z^n$

Let $z \in \mathbb{C}$ and $\bar z$ be its conjugate, $n \in \mathbb{N}$. Solve following equation:  $$\bar z = z^n\qquad (1).$$  My (uncomplete) solution to this:  let $z := a+bi$, where $i$ is imaginary number, and $a,b\in \mathbb{R}$. Then $\bar z = a- bi$.    Using $Moivre's$ formula we get     $$z^n = r^n(\cos n\phi + i\sin n\phi),$$ where $r = |z| = \sqrt{a^2 + b^2}$.  Now we can rewrite $(1)$:  $$a-bi = (a^2+b^2)^{\frac{n}{2}}\cdot(\cos n\phi + i\sin n\phi)$$  Is such approach useful ? I am not if I am steering into right direction, for I'm not sure how solution should look.


"Visit Meta" sidebar element on beta sites

It seems that launched SE sites have a "Visit Meta" sidebar element on the front page with a list of top meta questions, but beta SE sites only have it on question pages. It seems to me that beta sites need people to participate in meta and help define the site.  Could SE add the Visit Meta element on the front page of beta sites as well?


Hello ladies and gentlefolks,  I am trying to create a live USB running Ubuntu server. I have everything loading fine and dandy (after a lot of trial and error with the network) and everything is installing fine now. My question is where do I install grub? I am using my computer that runs Windows 10 by default on a 1TB hard drive, and I have been unplugging that so that I can guarantee that I don't screw that up. I have 1 USB as my installer, ande another USB as my drive to install everything on. Where should I install grub if I eventually want to plug my hard drive back in and use Windows 10?  Also: is there a way to clear out all partitions and completely reset a USB drive? Just formatting doesn't seem to be working for me.  Cheers!


Let me set inbox message status to unread without having to click on the message

In the android app I sometimes receive inbox messages that I have already seen on the web interface. However, the only way that I seem to be able to set their status to be unread is to click on them.  Better: menu option to "Mark all as read"  Best: way to mark individual message as read (swipe to the right?)


"if" in method on the BroadcastReceiver service will not work

I have a problem with checking variables in the "if". I get a userPhoneNumber variable from SharedPreferences and phoneNumber of SmsMessage.  I will displaying Toast with both variables and they are the same, but the if didn't work. Where is the problem?  My BroadcastReceiver class:  public class IncomingSms extends BroadcastReceiver { String userPhoneNumber = ""; String senderNum= ""; String message= ""; final String TAG="LocationService"; GPSTracker gps; double latitude = 0.0; double longitude = 0.0;   // Get the object of SmsManager final SmsManager sms = SmsManager.getDefault();   public void onReceive(Context context, Intent intent) {     SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(context);     userPhoneNumber = settings.getString("userPhoneNumber", "");      Log.e(TAG, "userPhoneNumber:"+userPhoneNumber);     int duration = Toast.LENGTH_LONG;      // Retrieves a map of extended data from the intent.     final Bundle bundle = intent.getExtras();      try {         if (bundle != null) {             final Object[] pdusObj = (Object[]) bundle.get("pdus");              for (int i = 0; i < pdusObj.length; i++) {                 SmsMessage currentMessage = SmsMessage.createFromPdu((byte[]) pdusObj[i]);                 String phoneNumber = currentMessage.getDisplayOriginatingAddress().toString();                  senderNum = phoneNumber;                 message = currentMessage.getDisplayMessageBody();                  turnOn(context);             } // end for loop         } // bundle is null      } catch (Exception e) {         Log.e("SmsReceiver", "Exception smsReceiver" +e);     }     Log.i("SmsReceiver", "senderNum: " + senderNum + "userPhoneNumber: "+ userPhoneNumber + "; message: " + message);   }  public void turnOn (Context context){     Intent i  = new Intent(context, MyService.class);     gps = new GPSTracker(context);      Toast.makeText(context,"Method turnOn!\nsenderNum: "+senderNum + "\n userPhoneNumber: " + userPhoneNumber, Toast.LENGTH_LONG).show();      if (senderNum == userPhoneNumber) {         Toast.makeText(context,"works in IF", Toast.LENGTH_LONG).show();         if(gps.canGetLocation()){             latitude =  gps.getLatitude();             longitude = gps.getLongitude();             i.putExtra("Latitude", latitude);             i.putExtra("Longitude", longitude);              context.startService(i);         }else         {             gps.showSettingsAlert();         }     }     gps.stopUsingGPS(); }


Is it fine to flag one line answers or link-only answers?

Recently I noticed one person who gave two answers in one hour. In the first answer he/she just added one link and another answer he just added few words in the answer. Stack Overflow provides a comment feature so I think they should use this instead of giving very short answers without description or more info about answer.   So my confusion is if it's okay to flag these particular types of answers, who just give answers for getting reputation only.


Ways to set umask on Ubuntu for daemon processes

I have an http daemon server process (yaws) that I would like to have server write any new files with a umask of 002, so that another user in the same group can modify, move, or delete files created by the daemon process.  This is on Ubuntu 10.04.  Unlike Apache, yaws does not have a configuration option for umask, so what methods are there for setting the umask of any daemon process?  I found  about changing the init script to add umask 002.  This did work, but I'm not sure editing the init script is the best way of making this easy to document and configure on multiple machines.  I also found reference to the pam_umask module .  It looks like this allows per user settings of the umask to be configured in the GECOS field of /etc/passwd.  Are there any other ways to set the umask for daemon processes?  And what would be the recommended way?


Proof of this simple inequality: $\frac{a}{b} + \frac{b}{c} + \frac{c}{d} + \frac{d}{a} \geq 4$

Let $a, b, c, d \in \mathbb{R}_{>0}$, then prove that  $\frac{a}{b} + \frac{b}{c} + \frac{c}{d} + \frac{d}{a} \geq 4$  Can this be done without using AM-GM inequality, or without using any identity/theorem of inequality? I don't want it to be concise or elegant, I just want rigorous steps that show explicitly how we achieve that result.   Thanks in advance


Is there any web browser with NPAPI plugins support?

As per  article, Mozilla has dropped the support of NPAPI plugins from Mozilla Firefox version 52. Is there any web browser with NPAPI plugin support? I have to use a website frequently, which uses Oracle Java plugin. I'm using Ubuntu 16.04 64 bit with Java JDK 8u121. Helps are much appreciated. Thanks. Edit1: After 3 years of asking this question, Java plugin still works fine in Palemoon v28.9.2-1 64 bit on Ubuntu 20.04 LTS. Java version is JRE 8u251 64 bit Edit2: As of 20th October 2020, Oracle completely removed Java Plugin from 8u271 JRE and JDK packages mentioned in  article. But 8u261 or prior versions works just fine.


ST_Length (GEOM, true) for calculating distances in Geographic Reference System

I use (1) ST_Length (ST_Transform (geom, 3395)) to get distances in meters from points in Geographic Reference Systems EPSG: 4326. The thing is I found that  with  (2) ST_Length (geom, true)  you can get also the distance in meters but using the spheroid. If I am right, is the option (2) more accurate if the GIS project use a Geographic Reference System for Global data, especially near to the poles? ST_Length reference:  EPSG:3395 reference:


Min and max of exponentialy distributed random variables

If $X$ and $Y$ are i.i.d. exponential as $f_X(x)=\lambda e^{-\lambda x}$ and $f_Y(y)=\lambda e^{-\lambda y}$, and $Z=\min(X,Y)$, then we may say that probability of event $Z=X$ or $Z=Y$ is $\frac 1 2$. This may be valid for any kind of distribution.   If $X$ and $Y$ are independent but not identical exponential as $f_X(x)=\lambda_x e^{-\lambda_x x}$ and $f_Y(y)=\lambda_y e^{-\lambda_y y}$, and $Z=\min(X,Y)$, then how I can find the probability of event $Z=X$ or $Z=Y$ ?.  Most importantly, I need how to find this probability when $X$ and $Y$ have any kind of continuous distributions which are independent.


Linux: How can I get a different exit code from the find command if no files matching the pattern I used are found?

I have a script which runs the next command:  find /storage2/hpfiles_staging/ -name \*.gz -mmin +600   And then rsync's the files to a remote location.  Sometimes the find command returns no output (as there are no files named *.gz with age of 10 minutes or more in that location). When it happens, I want to write a message to the log saying there are no files there.  But when I run the find command, whether it finds files to transfer or not the exit code of the find command is always "0" (unless there's a syntax error of course) and thus cannot give me indication about files being found in that location or not.  Is there any switch or a trick to get a different exit code than 0 if no files have been found by the find command?  Thanks in advance