I installed 32 bit Ubuntu 14.04 OS for my computer. But I can't play music / videos.  When I do a double click a song / video  an error message will appear on the screen asking me to install the plugins.

I would like to install the restricted extras package, which I didn't select during the install. How can I do that?        is a meta-package that installs:         Support for MP3 and unencrypted DVD playback   Microsoft TrueType core fonts   Flash plugin   codecs for common audio and video files


dic={} l=[] for i in range(0,2):     c=input("Enter your name").strip()      for i in range(0,3):         d=int(input("Enter Your marks: "))         l.append(d)     dic[c]=l    print(dic) print(l)   Output:  {'alex': [36, 54, 78, 57, 78, 94], 'harry': [36, 54, 78, 57, 78, 94]}   Expected Output:  {'alex': [36, 54, 78], 'harry': [57, 78, 94]}   Where I am doing wrong?

I needed to create a list of lists in Python, so I typed the following: my_list = [[1] * 4] * 3  The list looked like this: [[1, 1, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1]]    Then I changed one of the innermost values: my_list[0][0] = 5  Now my list looks like this: [[5, 1, 1, 1], [5, 1, 1, 1], [5, 1, 1, 1]]    which is not what I wanted or expected. Can someone please explain what's going on, and how to get around it?


As far as I understand,  stacks when multiple people pull enemies (it stacks additively in that if 2 people each add 30%, you get 60% damage instead of 1.3*1.3 = 69% damage). In ,  has been redesigned so to "Enemies take 25% increased damage from all sources for 6 seconds".  Does this stack with multiple party members, like Strongarm does? Does it stack additively in the same pool as Strongarm and other 'enemies take more damage' effects?

Do Barbarian shouts, such as , stack? If two barbarians cast War Cry, does the armor bonus stack or does it remain constant at increasing armor 20% for 60 seconds? What if each Barbarian has a different rune equipped?


I'm reading Richard J. Trudeau's book "", in page 54 it listed out the number of non-isomorphic graphs, given vertices $v$:  V: number of graphs 1: 1 2: 2 3: 4 4: 11 5: 34 6: 156 7: 1,044 8: 12,346 9: 308, 708  Then in exercise 27 it asks:  In the table on page 54, the numbers in the second column are mostly even. If we ignore the first row on the ground that v = 1 is such a trivial situation that its uniqueness is unremarkable, that leaves v = 4 as the only number of vertices listed for which there are an odd number of graphs. Do you think this is due to chance, or can you think of some reason why v = 4 should be unique? If the table were continued, do you think more odd numbers would turn up in the second column?  I'm a bit lost here. There number of $v$ vertices graphs (in the sense of non-isomorphic) is quite huge and I don't see a way to determine if it's even or odd. The key, i guess, is the self-complementary graphs. However, given vertices number $v$, there might be multiple self-complementary graphs, e.g. $v=5$ has 2. Pls enlighten me.

I am working through Trudeau's Introduction to Graph Theory, which contains the following problem:     In the following table, the numbers in the second column are mostly even. If we ignore the first row on the ground that $v=1$ is such a trivial situation that its uniqueness is unremarkable, that leaves $v=4$ as the only number of vertices listed for which there are an odd number of graphs. Do you think this is due to chance, or can you think of some reason why $v=4$ should be unique?     v    number of non-isomorphic graphs  1            1  2            2  3            4  4           11  5           34  6          156  7        1,044  8       12,346  9      308,708   Note, this problem concerns the number of non-isomorphic graphs.  Here's what I have so far:  The maximum number of edges in a graph with $v=4$ is $\max(e)=\frac{1}{2}(v)(v-1)=\frac{1}{2}(4)(3)=6$. The graphs with $e=0,1,2,4,5,6$ come in pairs because each graph has a complement. So, there are an odd number of graphs with $v=4$ iff there are an odd number of graphs with $v=4$ and $e= \frac{\max(e)}{2}$.  There are 3 graphs with $v=4$ and $e= \frac{\max(e)}{2}=3$, so therefore there is an odd number of graphs with $v=4$.  However, I don't understand why $v=4$ should be special in this regard, even though it feels special.


I'm looking for an idiom or expression that means someone just makes frustrating or disappointing remarks. Maybe some of you have watched the TV cartoon  in which there was as a character named "Glum". He was all the time pessimistic about everything and used statements like:  "We'll never make it"; "We'll never get out of here alive"; and "We're doomed."  I want to use that idiom or expression in examples like this:  Husband: After getting my promotion, I will take you to a fantastic trip. Wife: Oh, stop talking nonsense! I know It won't never happen, it's impossible you get a promotion. Husband: You remind me of 'Glum'! All the time _____ (i.e. acting like Glum, just having a gloomy outlook on everything). Please stop using such remarks and be a little optimistic!  I have found  for describing such people. PS: We Iranians use an expression that literally says "to read a frustrating or disappointing verse". So in above example, the husband might reply like this:  Hey Glum, the only thing you know is reading a frustrating/ disappointing verse!  (Sometimes we call these people 'Glum'.)

Any situation, any time; this person has always something negative to say about it.  It should be a noun or an adjective to describe a person who is a damp cloud walking over every sunshine situations at the cubicle, hoping to drench other people with his miserable comments.    I considered "sourpuss" but would prefer something more important sounding, like "misogynist."


I want to be able to right click on a folder called (C:\myFolder) and have a command prompt open  like this...  Microsoft Windows [Version 6.1.7601] Copyright (c) 2009 Microsoft Corporation.  All rights reserved.  C:\myFolder>   Is this possible?

When browsing in Windows Explorer, sometimes I want to start a command prompt "here", e.g. with the current browsed folder as the current directory.  For example, when I am browsing "D:\Foo\Bar\Bar1", I want to open the command prompt with current dir pointing to this directory. Normally what I do is   Copy the current folder path from Windows explorer's address bar Open cmd via Start Menu > Run  Type D: (because I have to change drive, the default is C:)  Type "cd " and then paste the folder path that I copied earlier   I do it quite often in my daily work, and I think by adding a context menu I will improve my efficiency (and also having to do the above repeatedly can be kind of annoying). I imagine I can just Right-Click > Start cmd here and then I will have a command prompt already in D:\Foo\Bar\Bar1  Is this possible?


Prove that for all integers $n\geq 0$:  $$\gcd(F_{n+1},F_n)=1$$  I am extremely lost. Please can some provide some hint or direction? Thank you so very much

Prove that any two consecutive terms of the Fibonacci sequence are relatively prime.   My attempt:    We have $f_1 = 1, f_2 = 1, f_3 = 2, \dots$, so obviously $\gcd(f_1, f_2) = 1$. Suppose that $\gcd(f_n, f_{n+1}) = 1$; we will show that $\gcd(f_{n+1}, f_{n+2}) = 1$. Consider $\gcd(f_{n+1}, f_{n+2}) = \gcd(f_{n+1}, f_{n+1} + f_n)$ because $f_{n+2} = f_{n+1} + f_n.$ Then $\gcd(f_{n+1}, f_{n+1} + f_n) = \gcd(f_{n+1}, f_{n}) = 1$ (gcd property).  Hence, $\gcd(f_n, f_{n+1}) = 1$ for all $n > 0$.  Am I on the right track? Any feedback would be greatly appreciated.  Thanks,


A beggar is a person who beg for getting money or something from a person but what do we call that person who gives the beggar the money ? Like Hop-ons are people who jump onto the back of the stair car for a free ride. In the question, I mean people who gives money not always or gives money in an irregular form, like not giving donation at a particular time/date or day.

Is there an antonym for beneficiary that is not simply "giver" or "payer"? I'm looking for a word that roughly mean someone who loses financially in the case of an event.


We're studying electrostatics in class, and the teacher introduced us to Gauss' Law a few days ago as $$\int \vec{E} \cdot \mathrm{d}\vec{A} = \frac{Q}{\epsilon_0}$$  Now suppose that the entire universe had a charge density $\rho$ and there was no other charge. By symmetry, the field everywhere must be $0$. Then by taking any Gaussian surface, my teacher claims, we can see that $Q_\text{enclosed}$ must be zero so $\rho$ must be zero. This means that charge has a fixed true zero point, similar to acceleration but unlike position and velocity (under classical non-relativistic mechanics). This is surprising to me.   Is this idea correct? Is this proof correct?

Consider that space is uniformly charged everywhere, i.e., filled with a uniform charge distribution, $\rho$, everywhere.  By symmetry, the electric field is zero everywhere. (If I take any point in space and try to find the electric field at this point, there will always be equal contributions from volume charge elements around that point that will vectorially add up to zero).  Consequently, from Gauss' law in the differential form  $$\nabla\cdot E = \frac{\rho}{\epsilon_0}$$  if $E$ is zero, the divergence is zero hence the charge density is zero.  What is going on here? is a nonzero uniform charge distribution that exists everywhere has no effect and is equivalent to no charge at all?


My goal is to create a framed minipage environment that will contain text and math environments in varying combinations. I noticed that the top (and bottom) margin of the minipage is quite a bit larger if the first (and last) entry is a math environment (than it is if the first thing is normal text).  I tried to extract the relevant parts into a MWE:    \documentclass{article} \usepackage[fleqn]{amsmath}  \begin{document} \setlength{\mathindent}{-.15em} \setlength{\abovedisplayskip}{0pt} \setlength{\belowdisplayskip}{0pt} \setlength{\abovedisplayshortskip}{0pt} \setlength{\belowdisplayshortskip}{0pt}   \fbox{     \begin{minipage}{.1\linewidth}       XXX \\       XXX     \end{minipage}   }   \fbox{     \begin{minipage}{.1\linewidth}       \begin{align*}         \textnormal{XXX}       \end{align*}       \begin{align*}         \textnormal{XXX}       \end{align*}     \end{minipage}   } \end{document}   Which results in:     So why are there larger top/bottom margins for math environments and how do I get rid of them?

It seems that the align environment adds additional vertical space if it starts at the top of a page or minipage.  Below are two pages, and two minipages (on Page 1), where the first page/minipage has text followed by an align* environment, and the second page/minipage starts with an align* environment, and note that the equations are still aligned.  Attempted Solution: The closest related question I found was:    I attempted to use the  at the above by adding \setlength\abovedisplayskip{0pt} (after the preamble as per ).  Although, this did move the equations up vertically, they were still vertically aligned:  And since the problem occurs at top of a page as well, I don't think this is related to  Question:  How can I adjust the align environment to automagically not have additional space at the top of a page or minipage? Is there a reason for this behavior, and perhaps should not be changed?  Code: \documentclass{article} \usepackage[showframe,paperwidth=3.5in,paperheight=2.2in,margin=0.5in]{geometry} \usepackage{amsmath}  \begin{document}%\setlength\abovedisplayskip{0pt} Top of Page 1 \begin{align*}% Text above at top of page  e &= m c^2 \end{align*}  \hrule \begin{minipage}[t]{0.45\linewidth}     Top of minipage 1     \begin{align*}% Text above this minipage      e &= m c^2     \end{align*} \end{minipage} \begin{minipage}[t]{0.45\linewidth}     \begin{align*}% No text above in this minipage      e &= m c^2     \end{align*} \end{minipage}  \newpage \begin{align*}% No text above at top of page  e &= m c^2 \end{align*} \end{document}


Below is a print screen of a summary(lm(..)).  I called the response variable response explained by a continuous variable X and a factor Y.    I'm trying to understand (not to the point of understanding the algorithms used to compute these results) the meaning of this output. My questions might be duplicates, but I haven't found the answer anywhere or if I did, I couldn't understand it!   The model is response = -4.461010 + blabla... What does the p.value for this intercept mean? Does it mean that the predicted line of my data significantly does not pass by the Origin? factor(Y)2 is significant. Does it mean that for the subset of data2 where Y equals 2, the values of response are significantly different than in the subset where Yequals 1 (which is taken as a reference)? Imagine a graph where the lines for subset(data2,Y==1) and subset(data2,Y==2) look alike but the line for subset(data2,Y==3) is totally different. If factor(Y)3 is taken as a reference, we'll get the two others to be significant and if factor(Y)1 is taken as a reference, factor(Y)3 will be significant but not factor(Y)2. Is it correct? For the interactions X:Y2 and X:Y3. Does the low p.values mean that for both the subset  Y==2 and Y==3, the variable X acts differently than it does for the subset Y==1?   Thanks a lot for your help!

The help pages in R assume I know what those numbers mean, but I don't. I'm trying to really intuitively understand every number here. I will just post the output and comment on what I found out. There might (will) be mistakes, as I'll just write what I assume. Mainly I'd like to know what the t-value in the coefficients mean, and why they print the residual standard error.   Call: lm(formula = iris$Sepal.Width ~ iris$Petal.Width)  Residuals:      Min       1Q   Median       3Q      Max  -1.09907 -0.23626 -0.01064  0.23345  1.17532    This is a 5-point-summary of the residuals (their mean is always 0, right?). The numbers can be used (I'm guessing here) to quickly see if there are any big outliers. Also you can already see it here if the residuals are far from normally distributed (they should be normally distributed).  Coefficients:                  Estimate Std. Error t value Pr(>|t|)     (Intercept)       3.30843    0.06210  53.278  < 2e-16 *** iris$Petal.Width -0.20936    0.04374  -4.786 4.07e-06 *** --- Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1    Estimates $\hat{\beta_i}$, computed by least squares regression. Also, the standard error is $\sigma_{\beta_i}$. I'd like to know how this is calculated.  I have no idea where the t-value and the corresponding p-value come from. I know $\hat{\beta}$ should be normal distributed, but how is the t-value calculated?  Residual standard error: 0.407 on 148 degrees of freedom   $\sqrt{ \frac{1}{n-p} \epsilon^T\epsilon }$, I guess. But why do we calculate that, and what does it tell us?  Multiple R-squared: 0.134,  Adjusted R-squared: 0.1282    $ R^2 = \frac{s_\hat{y}^2}{s_y^2} $, which is $ \frac{\sum_{i=1}^n (\hat{y_i}-\bar{y})^2}{\sum_{i=1}^n (y_i-\bar{y})^2} $. The ratio is close to 1 if the points lie on a straight line, and 0 if they are random.  What is the adjusted R-squared?  F-statistic: 22.91 on 1 and 148 DF,  p-value: 4.073e-06    F and p for the whole model, not only for single $\beta_i$s as previous. The F value is $ \frac{s^2_{\hat{y}}}{\sum\epsilon_i} $. The bigger it grows, the more unlikely it is that the $\beta$'s do not have any effect at all.


I recall hearing about this quite some time ago and thought it was very strange.  I recently had it pop in my head again and was curious if anyone knew what was going on with this.    Why would activity on/in the sun cause changes in radioactive decay rates?   Presumably the only known thing that might induce a change are neutrinos but as far as im aware there is no mechanism for this?  Does anyone have an answer or an inkling as to the physics behind this phenomenon?

Recently I found out this  about nuclear decay rates somehow showing seasonal variations with a high correlation with sun activity.   Has this been experimentally confirmed/disproved? An experiment using neutrinos from a fission reactor would be awesome, although probably a couple orders of magnitude below the required luminosity (at least to be comparable with solar sources) Could the standard model possibly allow neutrinos to modulate decay rates in this way? Or do we need new physics?   Link to the .  Another paper about this, but now the SuperKamiokande data is compared with data from Brookhaven:  They also propose a model of the effect called neutrino "resonant spin-flavor precession".


I'm trying to find outliers in this mixed model:  m1 <- lmer(y ~ service + lectage + studage + (1|d) + (1|s), data=InstEval)   So I used the merTools REsim function  reEx <- REsim(m1)   and plotted reEx  p1 <- plotREsim(reEx)   but how can I find which observations are the actual outliers?

I  need to identify outliers and high leverage points, and perform model diagnostics, in an lme4 model. For outliers and high leverage points, simply making a plot to visually inspect would be nice, but is insufficient.  I have 10,800 data points, and need to mark each point via some analytic or computational test as either outlier/high-leverage or not outlier/high-leverage.   After identification of outliers/high-leverage points, I will go through a separate process to decide whether or not to exclude the points from the data set.    Exclusion of points will take into consideration prior detailed analysis of each observation's raw data source (an audio recording), in addition to the automated identification mentioned above. Here, I refer to this process as "selective deletion".   I also need to understand if my outliers should be based on "marginal" or "conditional" residuals, and if my leverage should be based on fixed or fixed plus random effects. For defintions of "marginal" and "conditional", as well as potential defintions of leverage, I am following .  I.e., with a mixed model of the form... $$ y= X\beta + Zb + e $$ $$ e \thicksim N(0,\sigma^2I) $$ $$ b \thicksim N(0,G) $$ Where $G$ is a symmetric, positive definite matrix.  By marginal, I mean residuals of the form: $$ \zeta = y-E[y]=y - X\beta $$ By conditional, I means residuals of the form: $$  e = y - X\beta - Zb $$ My questions are:      How to identify outliers via an automated procedure based on an lme4 model.   Whether marginal or conditional residuals should be used to identify candidates for selective deletion. What kind of residuals should be used for assessment of normality, linearity, homoscedasticity, etc.   How to identify high leverage points for the purposes of selective deletion, and whether to use leverage from fixed or all effects (see Singer et al, above). How to test that $b$ is distributed as $N(0,G)$, i.e., general multi-variate normal? Is this done simply by looking at QQ plots of the random effects?  What if $G$ has covariances, i.e., non-zero off-diagonal terms?  Is looking at 1-dimensional QQ plots for each random effect still adequate to evaluate this type of normality?  Or is some sort of transformation required?


In the most recent movie Fantastic Beasts, Crimes of Grindelwald the minister said to Dumbledore somthing like "Only you can take on Grindlewald, because he's so powerful". That made me somehow wonder. I know there are many types of magical abilities (Foreseeing, Beast transformations, Mind reading, ...) but what makes a wizard more powerful than others? The most powerful wizards mentioned are: Dumbledore, Grindelwald and Voldemort (Maybe the fathers of Hogwarts). I don't recall hearing people discribe Harry as powerful. What makes a wizard more powerful than others? And why can we say that Dumbledore and Grindlewald at their peak were the most powerful?

It is obvious that different wizards can cast spells with different power and/or effect (same for potions). But why?   Just some observations from my side - perhaps I'm wrong for some of them:  Spell casting seems to be like playing music or painting. More or less everyone can do it and the quality depends on some factors like:   knowledge - gained by studying experience - gained by practicing intelligence - innate and cannot be gained easily concentration at the moment (or ability to concentrate in general)   and last but not least   innate ability (talent) - you either have it or not   To me it looks like that the last one is determining everything. Some wizards like Dumbledore or Voldemort just "have it" and others will never be able to reach their power no matter how hard they try. Another example - Hermione is very intelligent and has read all the books but Harry beats her in defense against the dark arts nevertheless (and no - it's not Quidditch that helps him :) ).


Recently I created a package named  for linux and any system that has a CLI. This package solves a boring problem for terminal geeks, it can help you surf the paths and do some actions on them just in terminal and no writing stuff. I need help to introduce this package and collect people to use it.

As a developer of free software, I want to get my application into Ubuntu.  Should I provide a source tarball and ask for packaging? Or should I create a package myself? Should I target Ubuntu directly, or should I try to get into Debian and then into Ubuntu automatically?


So I came across an , screenshot shown below, for this .    I felt that this answer really wasn't an answer, so I raised a "it is not an answer" flag, but that flag was disputed, but it's apparent that there are others that feel the same way as I do.  So my question is why was my flag disputed?  I just want to get some perspective on this so I can better understand what really constitutes an answer and what doesn't.  And if this shouldn't have been disputed, well then obviously my flag should be corrected and the answer removed.  Don't know if it's worth mentioning, I have nothing against Jeff Yates, just doing my part to help keep the boards following the established guidelines.  Cheers.

In my flagging summary under the statistics, there is 1 flag listed as "disputed".  This is the first time I've ever seen a disputed flag in my summary, so I'm just curious, what is a disputed flag? How would you even dispute a flag? Is this the same as voting a flag as invalid?


The 's Elemental Affinity feature description (PHB, page 102) says:  ...when you cast a spell that deals damage of the type associated with your draconic ancestry, you can add your Charisma modifier to one damage roll of that spell.  The  spell description (PHB, page 273) says:  You create three rays of fire and can hurl them at targets within range. You can hurl them at one target or several. Make a ranged spell attack for each ray. On a hit, the target takes 2d6 fire damage.  Because I make an individual ranged spell attack for each ray of fire, and I have fire elemental affinity, can I add my Charisma modifier to each of the rays? Would it just impact one of the rays, because it's through one spell cast?

This may be quite obvious, but I want to be certain.  As a  with Elemental Affinity to fire, do I get to add my Charisma modifier to each ray of , or just one of the three?


It seems that Magic Lantern has several features that is very handy for a photographer, i.e. Focus Peaking and Zebra (which Canon sadly left out in its latest mid-range DSLR) but after searching for compatibility online, I couldn't find any result.

I recently bought a Canon Rebel T6i (750D) and have a short film project coming up soon. I want Magic Lantern on my camera (SD Card) for its fantastic enhanced features, but I am unable to find it from the Magic Lantern website or any other sources.  It would be a great help if someone could post a source where I can download this.


Let $a$ and $b$ be positive integers such that $b^n + n$ is a multiple of $a^n + n$ for all natural numbers $n$. Prove that $a = b$. Here is my start: $a^n + n | b^n + n$, $a^n + n | b^n - a^n$ $a^n + n|(b - a)(b^{n-1} + ab^{n-2}... + a^{n-2} b + a^{n-1})$ Now we attempt to prove $b - a = 0$ by proving $a^n +n$ does not divide $(b^{n-1} + ab^{n-2}... + a^{n-2} b + a^{n-1})$. If we prove this successfully then we have $a^n + n | b-a$ for all $n$ and clearly $a=b$. I do not know if this method is valid, though I have had a hard time proving $a^n +n$ does not divide $(b^{n-1} + ab^{n-2}... + a^{n-2} b + a^{n-1})$ which leads me to suspect I am missing a more clever approach.

I need help with this question.     Let $a$ and $b$ be positive integers such that $a^{n}+n$ divides $b^{n}+n$ for every natural number $n$. Show that $a=b$.   Any help would be appreciated! Thanks!


What is the noun of "Receive"? I need to frame this sentence :      This is the date of your (Receival/Receiving/receipt).   What is the right answer?

Receipt?  Receiving?  I'm trying to come up with a name for "the acceptance of a delivery."  I'd like to be able to say      Ten deliveries were made but there are only five [fill_in_the_blank_here] on record.   Any suggestions?


I receive this error:  Incorrect parameter type for subscript. Expected Number, received Text  when I try to access the size of a List like this:  <apex:outputText value="{!accountsMap[key].size}" />   with a Map declared in the controller like this:  public Map<Id, Account[]> accountsMap {get; set;}   Does this just not work or am I missing something?

Can anyone please help me to understand the below code. I am not able to understand how we are  extracting value from map on visualforce page.  Actually i am trying to get the size of value list which is associated with respective key in map.              <apex:outputPanel >                 <apex:repeat value="{!attributeWrapper.mapAllAttributesLabel}" var="M">                     <div>                         <div>{!attributeWrapper.mapLabels[M].Name} </div>                         <div>                             <ul>                                 <apex:repeat value="{!attributeWrapper.mapAllAttributesLabel[M]}" var="attribute">                                     <li>                                     <p>                                         <apex:outputLink onclick="selectAttribute('{!attribute.attributeLabel.Label__c}','{!attribute.attributeLabel.Attribute__c}');return false;">                                            <apex:outputLabel value="{!attribute.attributeLabel.Attribute__r.Name}"/>                                         </apex:outputLink>                                     </p>                                     </li>                                 </apex:repeat>                             </ul>                         </div>                     </div>                 </apex:repeat>             </apex:outputPanel>    public with sharing class AttributeWrapper {      public Map<String, List<AttributesLabelWrapper>> mapAllAttributesLabel{       // some code to populate this map     } }   If i do:  {!attributeWrapper.mapAllAttributesLabel[M].size}   I get an error so how do i get the size of value list on VF page?


Hey guys so when I hit this particular button it is supposed to take me to the another layout. However everytime i hit it, the entire app crashes. Here is the onCreate method for that page im trying to get to:  protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_bench_data_entry);         //opens the database         openDB();         //Initializes and declares the sensors, and accelerometer         mInitialized = false;         mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);         mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);         mSensorManager.registerListener(this, mAccelerometer, SensorManager.SENSOR_DELAY_NORMAL);       //  tv.setText("Aasfdaf");    }   Here is the onClick for the button I am pressing:   public void onClick_Bench(View v){         //Intent to create a new activity         Intent intent = new Intent(MainMenuActivity.this, BenchDataEntry.class);         //Goes to the Data Entry Screen         startActivity(intent);     }   and here is the error log I am getting when I press the button:  08-08 17:30:30.785  31113-31113/com.example.jacob.repcapture E/AndroidRuntime﹕ FATAL EXCEPTION: main     Process: com.example.jacob.repcapture, PID: 31113     java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.jacob.repcapture/com.example.jacob.repcapture.BenchDataEntry}: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.view.Window.findViewById(int)' on a null object reference             at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2327)             at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)             at android.app.ActivityThread.-wrap11(ActivityThread.java)             at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)             at android.os.Handler.dispatchMessage(Handler.java:102)             at android.os.Looper.loop(Looper.java:148)             at android.app.ActivityThread.main(ActivityThread.java:5422)             at java.lang.reflect.Method.invoke(Native Method)             at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)             at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)      Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.view.Window.findViewById(int)' on a null object reference             at android.app.Activity.findViewById(Activity.java:2096)             at com.example.jacob.repcapture.BenchDataEntry.<init>(BenchDataEntry.java:49)             at java.lang.Class.newInstance(Native Method)             at android.app.Instrumentation.newActivity(Instrumentation.java:1067)             at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2317)             at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)             at android.app.ActivityThread.-wrap11(ActivityThread.java)             at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)             at android.os.Handler.dispatchMessage(Handler.java:102)             at android.os.Looper.loop(Looper.java:148)             at android.app.ActivityThread.main(ActivityThread.java:5422)             at java.lang.reflect.Method.invoke(Native Method)             at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)             at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

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


I'm trying to do some calculations based on team results in Excel. The format is:  Team | Player | Yards  A   |   x    |  100  B   |   y    |  142  A   |   z    |   93   I'd like to be able to sum all the yards for a particular team, so for example if there are several players from team A then it sums their yardage. How would I go about doing this?   The dataset is long enough that it is impractical to do it all manually.  Thanks in advance!

I'm trying to figure out how to "group by" values in an Excel spreadsheet.  Given the following example (this is an inventory sheet I use at my restaurant:)    At the far right of the spreadsheet there is a column named Cost of Goods Sold.  I would like to be able to come up with a total COGS figure for each Category.  Is this possible in excel? Moreover, I'd like to do it in a separate worksheet so that the first worksheet (what is pictured) isn't affected.  Any ideas?  Thanks!


A person I know is trying to find a story about a teacher who travels from Earth to Mars and starts working there. It's old, maybe from Bradbury or Asimov. That's the only information she gave to me.

It is about school in the future. In this system, all classes are taught through television and students all learn at home. Students get to decide what classes they wish to attend and teachers get paid by how many students sign up for their courses. As a result, teachers resort to tricks to get attention. One dresses up as a clown, another wears a bikini, etc. There is an older teacher who decides to teach the old-fashioned way. That's all I remember.


I am new to generator in python. I have a simple enough code which I am playing with but I can not understand the output I am getting out of it. Here is my code :  def do_gen():     for i in range(3):         yield i  def incr_gen(y):     return y + 1  def print_gen(x):     for i in x:         print i  x = do_gen() y = (incr_gen(i) for i in x) print_gen(x) print_gen(y)   I expected my output to be like this :  0  1  2  1  2  3   But I am seeing only :     0  1  2  I do not understand this output. Can anyone please help me sort out my lack of understanding? Thanks in advance.

What is the use of the yield keyword in Python? What does it do? For example, I'm trying to understand this code1: def _get_child_candidates(self, distance, min_dist, max_dist):     if self._leftchild and distance - max_dist < self._median:         yield self._leftchild     if self._rightchild and distance + max_dist >= self._median:         yield self._rightchild    And this is the caller: result, candidates = [], [self] while candidates:     node = candidates.pop()     distance = node._get_dist(obj)     if distance <= max_dist and distance >= min_dist:         result.extend(node._values)     candidates.extend(node._get_child_candidates(distance, min_dist, max_dist)) return result  What happens when the method _get_child_candidates is called? Is a list returned? A single element? Is it called again? When will subsequent calls stop?   1. This piece of code was written by Jochen Schulz (jrschulz), who made a great Python library for metric spaces. This is the link to the complete source: [Module mspace][1].


Photos on my iPhone iOS 11.3.1 revert automatically into original even after editing and re editing .. pls resolve this

I edited about 20 photos on my phone yesterday -- cropped, altered saturation and contrast etc. This morning, on my phone, those edits have all reverted to the original photos.   I use iCloud library. The photos had not completed uploading to iCloud library before I edited them. My phone uses ios 11.3  Can these edits be recovered now that iCloud sync up is complete and those edits are reverted to the original photos?  EDIT: given that there is no solution, and that others report the same problem (and that it happened again), I have filed a bug report at Apple:


"A Math Club has 12 members. They have to choose euclid contest team   of 3 members and a National Math Competition team with 4 members. Students can be on both teams, but James agrees to   only be on at most one team. In how many ways can both teams be chosen?"   Here's what I thought should be the answer but doesn't make much sense:  Case 1: James is in Euclid team:   $\therefore $  $11\choose2$ for Euclid Team  This would be because James is in team Euclid assumed so we only have to get 2 other players and we have 11 students left.  Also : $11\choose4$ for Math team  so total ways would be  $11\choose2$ . $11\choose4$ (Product Rule)  Case 2: James is in Math team:   $\therefore $  $11\choose3$ for Math team  This would be because james is in team Math assumed so we only have to get 3 other players and we have 11 students left.  Also : $11\choose3$ for Euclid team , as the 11 students can form a team of 3 for Euclid competition here.  so total ways would be  $11\choose3$ . $11\choose3$ (Product Rule)  Case 3: James in no team  $\therefore $  $11\choose3$ . $11\choose4$ (Product Rule)  as James is in no team so we are left with 11 people for both teams  Now the question is did I do it correctly? Because I have never seen cases being used in a permutation questions?  Therfore, The total number of ways would be to add all the cases meaning  Case 1 + Case 2 + Case 3 :  ($11\choose2$ . $11\choose4$) + ($11\choose3$ . $11\choose3$) +($11\choose3$ . $11\choose4$)  Is that correct?

A club has $12$ members. They need to choose a programming team of $3$ members and a hacking team of $4$ members. Members can be on both teams, but Jack only wants to be on at most one team. How many ways can both teams be chosen?  I did two different ways. I solved if Jack chooses programming, $C(12,3)=220$ $C(11,4)=330$. In total there are $550$ different ways both teams can be picked.  But, if Jack chooses hacking, I solved $C(11,3)=165$ and $C(12,4)=495$. In total there are $650$ ways both teams can be chosen.  I was wondering if this is the correct method.


Firefox on my Ubuntu installation requires me to update the  plugin and following the link, I get to the page which ask me to download the latest Firefox package.  I download the tar.gz and unzip it. It is the new version, but it is in an independent folder and if I want to use it, I need to open the folder and click on the Firefox executable.  How can I replace the old version of Firefox on my Ubuntu installation with the newly-downloaded?  I checked the old version:  nanger@mypad:/usr/lib/firefox$ which firefox /usr/bin/firefox nanger@mypad:/usr/bin$ whereis firefox firefox: /usr/bin/firefox /etc/firefox /usr/lib/firefox /usr/bin/X11/firefox /usr/share/man/man1/firefox.1.gz   I'm not very familiar with the linux system. But what is /usr/bin/firefox? Is it a symbolic link which link to the Firefox executable in /usr/lib/firefox? How can I replace it with the new version?

Even though I have the latest Adobe Flash player 11.2 for Linux in Firefox -   - a particular online flash game still requests that I update to the latest flash player.  I've tried this online game on my laptop (Windows 8 with Flash Player 11.8) and it has no problems.  Is there a way to trick Ubuntu or this game into thinking Flash Player 11.8 is "installed"?


The bug has been patched in the Linux kernel 5.0.8 version, according to the news. What about the kernel version 4.15.0-50-generic? How to check a given kernel to find out whether CVE-2019-11815 has been patched? How to patch the CVE-2019-11815 bug in Ubuntu 18.04.2 LTS with the kernel version 4.15.0-50-generic?

Today a couple of buffer overflows in NTP were announced , . It looks like updating my system to fix these issues is in order.   How can I find out if they have been fixed in the Ubuntu repositories, such that if I were to run:   sudo apt-get update sudo apt-get upgrade   then the fix would get installed and the vulnerability closed?   Edit: The selected answer specifically addresses the question of how to identify if a given CVE has been fixed or not, "Does Ubuntu generally post timely security updates?"  is certainly related but not identical


My code below is currently cloning a row from a table to another table on click of table row. Once that happens I'm appending an increment and decrement button and a input text value to the end of the row (The input value changes upon click of increment and decrement button). This works perfectly if there is only one row, but once there are more than one my buttons will increment or decrement based on how many rows are attached to table. Why is this happening?  "initComplete": function() {   $("#itemsAvaliableList tr").on("click", function() {     var items = [];     $("#item-table tbody tr[id='no-item-row']").hide();     $("#backToList").hide();     $("#acceptButton").show();     var newTr = $(this).closest("tr").clone();     // Increment button that goes next to added items in Screen Entry     var newIncrementButton = "<input class='qty' size='5' type='text' value='1' name='Quantity' onkeypress='return isNumberKey(event)'/><button class='ml-3 btn btn-danger qtyminus' display= 'inline-block;' id='valueChange'>-</button> <button id='valueChange' class='qtyplus btn btn-success'>+</button>	"     items.push(newTr);     newTr.appendTo($("#item-table tbody"));     $(newTr).append(newIncrementButton);      $('.qtyplus').on('click', function(e) {       e.preventDefault();       var num = Number($(this).siblings('.qty').val());       $(this).siblings('.qty').val(++num);     });      $('.qtyminus').on('click', function(e) {       e.preventDefault();       var num = Number($(this).siblings('.qty').val());       $(this).siblings('.qty').val(--num);     });    }); }

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


How do I create a tag in Stack Overflow?

Can someone please create the tag  on our site? We need to have it because        Foo is a recent/upcoming release / edition / model / episode of a popular, established OS / board game / bike brand / TV show   Foo is a hot new language / ingredient / game   we're currently using some other tag for questions about Foo, but it's causing ambiguity with a separate thing that's also named Foo      This is not a joke post. We get a lot of feature requests that ask for this or that tag to be created, and every time, a discussion ensues wherein people explain that there is no "tag creation department" and that community members create tags just by using them. I'm posting this "question" so that future requests of that type can be closed as a duplicate of this, saving time and eliminating redundant conversations for everyone involved.     See also:


I'm using a software that use PDO to do request. The database requests are like this :   $query = "SELECT * FROM res_attachments WHERE res_id = ? AND status = ?"; $data = array('152', 'DEL');   The question I have is, how can I get the whole request with the "?" replace by $data elements ? I get this infos ($query and $data) after the query, I just have to "merge" it. I have to make a dynamic things, to works with a request with 2 arg or 10 args.  The result I want have to looks like :   "SELECT * FROM res_attachments WHERE res_id = '152' AND status = 'DEL'"   Solution  For those who have a similar issue, here is the solution I make :   $query = "SELECT * FROM res_attachments WHERE res_id = ? AND status = ?"; $data = array('152', 'DEL'); $tab = explode("?",$query); for($i =0; $i < count($tab); $i++){     $Request .= $tab[$i] . "'" . $data[$i] . "'";     $finalRequest = str_replace('\'\'', '', $Request); // delete the double quote at the end } var_dump($finalRequest);

Is there a way to get the raw SQL string executed when calling PDOStatement::execute() on a prepared statement? For debugging purposes this would be extremely useful.


I have a need to use a prepared statement to use an array of integer in my SQL statement.   When I try to create the array, and when I read the  It only shows the creation of an array of strings. I have to search for a lot of table key ids in one call (previously iterating through them one at time resulted in 22k queries) So I need all of the results at one time.   A piece of my query string looks like this   AND A.KEY in (?) order by KEYID DESC   Here is where I build my query (via using java.sql.Array with my list of IDs)  StringBuilder query = new StringBuilder(Query);               PreparedStatement stmt = connection.prepareStatement(query.toString());  java.sql.Array array = connection.createArrayOf("varchar", Ids.toArray()); stmt.setArray( 1, array);  ResultSet results = stmt.executeQuery();   I tried to run them through as strings, as the sql.Array uses strings, but I NEED to send them as ints.   My ids come through as an ArrayList<Integer>, this is the key to why this is not a duplicate question I need to send the sql statement a list of integers - my way works for strings.  edit when i run through my program sending one int at a time, it works fine.  How can I solve this to send the SQL statement with integers in place of my? In the sql query?

What are the best workarounds for using a SQL IN clause with instances of java.sql.PreparedStatement, which is not supported for multiple values due to SQL injection attack security issues: One ? placeholder represents one value, rather than a list of values.  Consider the following SQL statement:  SELECT my_column FROM my_table where search_column IN (?)   Using preparedStatement.setString( 1, "'A', 'B', 'C'" ); is essentially a non-working attempt at a workaround of the reasons for using ? in the first place.    What workarounds are available?


A(x) is a predicate logic formula. A is a property (predicate), x is a variable. ∃!A(x) would mean that exactly one x exists which has the property A.  First thing that comes up is: ∃x( A(x) ∧ ∀y( A(y) → (x=y) ),  where y is a variable, but my assignment forbids the use of functional symbols such as =.  How do I rewrite this without using any functional symbols? Only the use of →, ⇔, ¬, ∨, ∧, ∃, ∀, variables, formula A(x) and brackets are allowed.  My idea was to simply write this: ∃x( A(x) ∧ ∀y( A(y) → (A(x)⇔A(y)) )  not sure if it's correct, though.  Thank you in advance.  By the way, the question is not a duplicate, as I'm trying to rewrite this without the use of =.

During a lecture today the prof. posed the question of how we could write "There is exactly one person whom everybody loves." without using the uniqueness quantifier.  The first part we wrote as a logical expression was "There is one person whom everybody loves.", ignoring the 'exactly one' part of the question initially. From this he wrote  $L(x,y): x$ loves $y$; domain for $x$ and $y$: $\{\text{people}\}$  $\exists x\forall y: L(y,x)$  Which I understand to mean 'There is a person $x$ such that for all $y$, $x$ is loved by $y$' AKA 'There is a person who is loved by everyone'. I get that part.  The part I don't get is how the expression of 'exactly one'.  $\forall z(\forall y(L(y,z))\to x =z)$  which then creates the joint expression  $\exists x\forall y(L(y,x))\land \forall z(\forall y(L(y,z))\to x=z)$  I just can't seem to understand how $\forall z(\forall y(L(y,z))\to x =z)$ means exactly one here.  I suppose you can take $\forall z$ here to mean 'for any given person', which means the $\forall z$ is considering every person in the world.  This would translate the second expression block to something like, "For any given person $z$, if everybody loves $z$ then $z$ is the same person as $x$".  To me though $\forall z$ generally means for every element in the domain which I see as meaning every person in the world simultaneously, as it seems to for $y$.  Is that just plain wrong?  How can I tell when $\forall$ means 'all' and when it means 'for any (one)'?  In the previous English translation the only reason I was able to translate it (if it's even right) is because I already knew what the statement was suppose to mean.  Is it just that $\forall z$ means that this statement could be true for any element, and if so what's the difference between $\forall z$ and $\exists z$?  Someone told me that $\exists z$ would be redundant because the expression says $x=z$ but how do I know that $x$ and $z$ are automatically the same person if $\exists$ is used for both?  Sorry if this is a bit long with too many questions.  I just wanted to try to make the cause of my confusion as clear as possible so you can help me figure this out.


I have table like this - how can I select value of product bought lastly?  From this table I need select as shown below:

Table:   UserId, Value, Date.   I want to get the UserId, Value for the max(Date) for each UserId. That is, the Value for each UserId that has the latest date. Is there a way to do this simply in SQL? (Preferably Oracle)  Update: Apologies for any ambiguity: I need to get ALL the UserIds. But for each UserId, only that row where that user has the latest date.


I'm looking for a simple and cheap way of creating a variable delay of up to about 2 minutes.          – Schematic created using   I want to know if there's an alternative to using an RC circuit that is simple and cheap. Other concerns are secondary, within reason.  The problem with this circuit is it just seems a bit 20th century.   Firstly, the capacitor needs to be large physically because of leakage current and the small current required to turn Q3 on. This means the cost possibly leaves room for improvement. The size, weight and lifespan can probably be improved. The delay consistency can certainly be improved.  (Since the capacitor's internal leakage and other leaks will vary significantly with temperature, humidity etc). Plus there's the surge when the cap gets charged.  Are there any tricks I could use? I'm wondering if there are any off-the-shelf ICs which are dirt cheap that perhaps combine a small RC circuit and some way of configuring the delay that is perhaps implemented by a binary counter.  I'm still playing around with ideas so I'm not sure what there will be in the way of power rails; if necessary I could make a 5v rail available, but it would be useful to know if there's a solution that could work on as little as 1 volt. So this question is less about solving my specific problem, but checking that I'm not oblivious to some general purpose alternatives.  [Re: duplicate: This is not a duplicate question. The answers given for the question identified as a possible duplicate offer no improvement as requested by my question. A 555 timer still uses an RC circuit without a solution for a large capacitor!]

What I would like to do is have an LED turn off 1 minute after the power is turned off. The LED would be on all the time when power is on. Thus:  Turn power on: LED comes on immediately. Turn power off: LED stays on for 1 minute and then turns off.  This is to signal when someones eyes have adequately adjusted to the dark in a darkroom.  Thanks in advance.


Actually I already read the answer given but that is not satisfactory. The real image is always inverted and virtual image is always erect. But we see a virtual inverted image. How is this possible? Please answer my question as early as possible.

We see a virtual inverted image whereas in case of concave mirror we can see a virtual image which is erect.


I have problems with this equation: $$U_G ~=~ G\frac{m_1m_2}{r}.$$  It's for potential energy of say something placed on Earth.  But it intrigues me. $r$ is the distance from the very center of the Earth to its surface. But anything placed on the surface of Earth will never fall any deeper into the earth. So I think there will not be any potential energy for anything placed at the very lowest point possible on Earth. Though it's no where close to the core of the Earth.

I usually think of gravitational potential energy as representing just what it sounds like:  the energy that we could potentially gain, using gravity.  However, the equation for it (derived by integrating Newton's law of gravitational force)...  $$PE_1 = -\frac{GMm}{r}$$  ..has me thrown for a loop, especially after .   If potential energy really meant what I thought it did, then it would always have to be non-negative... but this equation is always negative.  So what does "negative potential energy" mean!? If $KE + PE$ is always a constant, but PE is not only negative but becomes more negative as the particles attract, doesn't that mean the kinetic energy will become arbitrarily large?  Shouldn't this mean all particles increase to infinite KE before a collision? If we are near the surface of the earth, we can estimate PE as $$PE_2 = mgh$$ by treating Earth as a flat gravitational plane.  However, $h$ in this equation plays exactly the same role as $r$ in the first equation, doesn't it?   So why is $PE_1$ negative while $PE_2$ is positive?  Why does one increase with $h$ while the other increases inversely with $r$? Do they both represent the same "form" of energy?  Since $PE_2$ is just an approximation of $PE_1$, we should get nearly the same answer using either equation, if we were near Earth's surface and knew our distance to its center-of-mass.  However, the two equations give completely different answers!  What gives!?    Can anyone help clear up my confusion?


I am a Canadian citizen living in Mexico with a status of a permanent resident FM2 card with a house a Mexican drivers license and my truck which is originally from Canada has been imported to Mexico and is legally registered and has Mexican plates with vehicle insurance. My question is can I drive my vehicle to Canada from Mexico and enter Canada for a 1 or 2 month vacation. I believe that I may have to up my Liability coverage to at least $200,000 Canadian or more.

I am a dual Canadian and EU citizen living in central america. I bought a new car in Mexico, have mexican tags and insurance that has coverage for Mexico, Usa and Canada up to 100k USD (is this enough?). I am planning to drive up to Canada for a short visit, one month or maybe two. The confusion starts here.   I have a EU drivers license, haven´t been to Canada for 20 years. I know that my EU drivers license is valid in Canada (at least Ontario province) for a maximum of 2 months. Is this correct? Then the next question is if I can legally drive the mexican car as a canadian citizen with canadian passport but without a canadian drivers license a mexican plated car for a short period of time in Canada without facing any problems at the border or then inland? In the US it is quite clear with a valid insurance for the US. I appreciate any information also for the same questions regarding USA, but specifically Canada. Thanks.


I want my character to flex his Bicep, when he does, veins should show up, but only when activated. The problem I have is the normal map is already used for all the other details of my character.  If I put the veins in, they'll be static. Is there a way I can clip the veins on ONLY when he flexes?  How would I approach this? Thanks for your help!

I use this node setup to combine my two normal maps.   I adapted this method from here.    It works perfectly to just combine the maps. But now i need individual contol over the strength each of them.   Is there a way to do this ?


I am trying to use the java regex matcher-class and I'm encountering a NullPointerException in my code:  String input = null; System.out.println("\nEnter your username: "); Matcher matcher = VALID_USERNAME_REGEX.matcher(input); //EXCEPTION IS HERE if (matcher.find()) {     username = input; } else {     input = null;     System.out.println("\nInvalid input, please try again!"); }   Stack Trace: (line: 173 is in the above code where the comment "//EXCEPTION IS HERE" is located)  Exception in thread "main" java.lang.NullPointerException     at java.util.regex.Matcher.getTextLength(Unknown Source)     at java.util.regex.Matcher.reset(Unknown Source)     at java.util.regex.Matcher.<init>(Unknown Source)     at java.util.regex.Pattern.matcher(Unknown Source)     at org.console.Interface.createAccount(Interface.java:173)     at org.console.Interface.login(Interface.java:78)     at org.application.Application.run(Application.java:31)     at org.application.Application.main(Application.java:37)   The value of the input should be what the user enters in the console. The regex should match the input to validate that it meets the regex requirements.

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


I was about to put together an MWE for testing pgfplotstable when pdflatex gave me the error: ! LaTeX Error: Environment table undefined.  See the LaTeX manual or LaTeX Companion for explanation. Type  H <return>  for immediate help.  ...                                                                                l.6 \begin{table}  I've already loaded all the packages I used in my main document, which displayed a table. I was not able to find the answer to this simple issue, which is probably due to some silly mistake I can not find. The MWE: \documentclass{minimal} \usepackage{booktabs,pgfplotstable} \begin{document} \begin{table}   \centering   \begingroup\makeatletter\@makeother\_     \pgfplotstabletypeset[       % columns={index[0],index[1]}        col sep=comma,       columns/Name/.style={string type},       columns/misc/.style={string type},       every head row/.style={         before row={\toprule},         after row={           \midrule         }       },       every last row/.style={after row=\bottomrule},     ]{cermaic_chip_capacitors.csv}   \endgroup \end{table} \end{document}

In a comment to my , Peter Grill said that he read that the minimal class should not be used for a Minimal Working Example. I wonder why, and which class should I use instead?  BTW: Is it preferable to use article or scrartcl, i.e. the standard classes or the ones form the KOMA-Script bundle?


When I use the text tool, my letters always appear as boxes on the side menus and do not appear in the render area. In fact, whenever I type in blender I just get a string of boxes.  How can I fix this?

How can I add text with non Latin characters? I'd like to get text in other languages like Arabic, Russin (Cyrilic), Japanese, Chinese, Malayalam among others, but I get rectangles instead of Arabic letters.


I have a user who is trying to open an .xlsx file and modify its contents. However, the user is constantly faced with the message saying that someone else is in it. I have checked the Open Files on the server and no is in the file, also the person who is apparently locking it has left the company and the account has been deleted.  When looking at the permissions of the file the user has read-write access as well as the file not having a locked status on the Get Info window.  The version of Mac Excel that is being used is 12.3.6, and has not have any other issues opening other Excel sheets.

I'm opening an Excel file and I'm getting the File in use pop-up that says it's locked for editing by me. However, I've not got it open on this computer (I think I had it open and my machine blue-screened). How do I go about fixing this?  Should specify, this is a file on a file share.  edit I'm not talking about if this is being used by another user on another machine, this is only accessible by me on this file share.


This must have been known. Let $L/K$ be a finite number field extension. Then is $O_L$ a free $O_K$ module? How to prove it if so? So far, I know how to prove the following:  Let $\alpha_1,\dotsc,\alpha_n\in O_L$ be a $K$-basis of $L$ and let $d=d_{L/K}(\alpha_1,\dotsc,\alpha_n)$. Then $dO_L\subset O_K\alpha_1\oplus\dotsm\oplus O_K\alpha_n$.

Let $K\subseteq F$ be number fields with ring of integers $\mathcal{O}_K\le \mathcal{O}_F$.   Question: Is $\mathcal{O}_F$ a free $\mathcal{O}_K$-module ?   By the integral basis theorem this is true when $K=\mathbb{Q}$ but I don't know about the general case.


I am struggling to see how to use the following two pieces of information (which I have proven):  $\frac{1}{n}< \ln{n}$ for $n=2,3,4,\dots$  and  $\ln{(1+n)}<n$ for $n=1,2,3,\dots$  to show that  $\frac{n}{1+n}<\ln{\left(1+\frac{1}{n}\right)^n}<1$ for $n=1,2,3,\dots$  I know it's more than likely something very straight forward.

I'm learning calculus, specifically derivatives and applications of MVT, and need help with the following exercice:      Show that, for all $n > 1$ $$\frac{1}{n + 1} < \log(1 + \frac1n) < \frac1n.$$    I tried to follow the below steps in order to prove the RHS inequality:   Proving that $f < g$ on $I$ from $a$ to $b$:  Step $1$. Prove that $f' < g'$ on $\operatorname{Int}(I)$.  Step $2$. Show that $f(a) \leq g(a)$ or that $f(a^+) \leq g(a^+)$  Following the above steps, let $f(x) = \log(1 + \frac1x)$ and $g(x) = \frac1x$, for all $x > 1$. One has  $$f'(x) =  -\frac{1}{x^2 + x} \quad \text{and} \quad g'(x) = -\frac{1}{x^2}.$$  We note that, for every $x > 1$, $f'(x) > g'(x)$. Moreover, $f(1^+) = \log(2) < 1 = g(1^+).$   My problem is that I got the wrong inequality sign in Step $1$.    Looking at the solution in my textbook, the author suggests using the MVT but I don't know how to apply it in this case.


One day I asked me: "How do game designers work?". I knew what the "main mission" of their work, but I didn't know: "How to do it?" and "What do they need to write?"  I want to know full "list" of terms with examples that they need to write.  For example:  Genre - Action  Setting - Retrofuturism etc...  Please answer me :)

I know someone who is thinking about getting into game design, and I wondered, what does the job game designer entail? what tools do you have to learn how to use? what unique skills do you need? what exactly is it you'd do from day to day. I may be wording this a bit wrong because I'm not sure if the college program is become a game designer or learn game design. but I think the same questions apply either way.


I have this problem when I use apt-get update:  Err:1 http://security.ubuntu.com/ubuntu bionic-security InRelease                                                                       503  Service Unavailable [IP: 91.189.88.161 80] Err:2 http://ppa.launchpad.net/compiz/ppa/ubuntu bionic InRelease                                                       503  Service Unavailable [IP: 91.189.95.83 80] Err:3 http://archive.canonical.com bionic InRelease                                           503  Service Unavailable [IP: 91.189.92.150 80] Leyendo lista de paquetes... Hecho W: Fallo al obtener http://co.archive.ubuntu.com/ubuntu/dists/bionic/InRelease  503  Service Unavailable [IP: 200.35.32.3 80] W: Fallo al obtener http://co.archive.ubuntu.com/ubuntu/dists/bionic-updates/InRelease  503  Service Unavailable [IP: 200.35.32.3 80] W: Fallo al obtener http://co.archive.ubuntu.com/ubuntu/dists/bionic-backports/InRelease  503  Service Unavailable [IP: 200.35.32.3 80] W: No se han podido descargar algunos archivos de índice, se han omitido, o se han utilizado unos antiguos en su lugar.   Somebody can help me. thanks!

I am using a transparent proxy (other box). When I try to do an 'apt-get update' I get these warnings (in german):  ...  W: Fehlschlag beim Holen von http://security.ubuntu.com/ubuntu/dists/maverick-security/restricted/source/Sources.gz  503  Service Unavailable  W: Fehlschlag beim Holen von http://security.ubuntu.com/ubuntu/dists/maverick-security/universe/source/Sources.gz  503  Service Unavailable  W: Fehlschlag beim Holen von http://security.ubuntu.com/ubuntu/dists/maverick-security/multiverse/source/Sources.gz  503  Service Unavailable  W: Fehlschlag beim Holen von http://security.ubuntu.com/ubuntu/dists/maverick-security/main/binary-i386/Packages.gz  503  Service Unavailable  W: Fehlschlag beim Holen von http://security.ubuntu.com/ubuntu/dists/maverick-security/restricted/binary-i386/Packages.gz  503  Service Unavailable  W: Fehlschlag beim Holen von http://security.ubuntu.com/ubuntu/dists/maverick-security/universe/binary-i386/Packages.gz  503  Service Unavailable  E: Einige Indexdateien konnten nicht heruntergeladen werden, sie wurden ignoriert oder alte an ihrer Stelle benutzt.   I changed ~.bashrc:  http_proxy=http://192.168.120.199:8080 https_proxy=https://192.168.120:8080 export http_proxy export https_proxy   I wrote on commandline:  export http_proxy=http://proxyusername:proxypassword@proxyaddress:proxyport sudo apt-get update   And I edited /etc/apt/apt.conf:  Acquire::http::proxy "http://192.168.120.199:8080/"; Acquire::ftp::proxy "http://192.168.120.199:8080/";   Nothing has worked.  Does anyone knows how to make apt-get working through a transparent proxy?  Regards,  ubuntu2man


When I open Pokémon Go, after the login, appears the loading screen with a pokeball spinning...And the pokeball doesnt stop, I mean the game doesn't open.  I've tried downloading again, cleaning dads, turn the Wi-Fi off and on... What else can I do?

I noticed, that when I freshly connected into the game (or sometimes during playing) a pokeball appears which probably symbolizes loading (see screenshot).  But what does it indicate ...   ... Server issues? ... Client connection issues? ... Location service issues? ... Other problems?     In this example the server seems to be one problem as the bar in the right bottom, which displays near pokemon, is empty. Is this assumption correct?  Another hint for this is the empty shop page:    I couldn't find a site where I can check the server status as well.


The previous solution , no longer is accurate for the Java version of Minecraft. I am running the command on a server and trying to use my .  Unfortunately when I try the solution that was posted in that 2014 question:  /scoreboard objectives add mine dummy /scoreboard players set @e[type=Wolf] mine 1 {Sitting:1} /tp @e[score_mine_min=1] @p   And switch {Sitting:1} with OwnerUUID="UUID", I get the error "Invalid or unkown entity type 'minecraft'.  Is there a way to teleport all the wolves I own?

I told my wolves to sit down and I accidentally forgot to tell them to stand up and I left them. Now I cannot find them, how do you get back to your wolves if they are lost?


I am trying to show that:  $$A \subset B \implies A \cap B = A$$  So far I got:  $$A \subset B$$ $$A \cap B \subset A$$ $$A \cap B \subset B$$ $$A \cap B \subset A \subset B$$

Showing   $A \subset B \iff A\cap B=A$  How would I show this?  My proof  Assume  i. $A \cap B \subset A$  ii.$A \subset A \cap B$  Let $x$ be any element.  Assume $x \in A \cap B$. Then $x \in A$ and $ x \in B$. By hypthesis $x \in A \rightarrow x \in B$ Thus $x \in A$  ii.  Let $ x \in A$ By hypthesis $x \in A \rightarrow x \in B$   thus $x \in A \cap B$.  Part 2  $ A\cap B=A \rightarrow A \subset B$  But I find myself stuck here.


I have an account on Seasoned Advice, but it has been question banned. I would like to create an additional account so I can continue to ask questions. How can I do this?

If you are reading this, you may have been affected by one of our post quality bans. If so, it is important that you  to understand what has happened and how to regain the permissions that you lost. While trying to ask a question, one could see:  We are no longer accepting questions from this account. See  to learn more.  Likewise, for answers:  We are no longer accepting answers from this account. See  to learn more.   Why am I getting this message? Are deleted posts taken into account too? Is a question/answer ban the same as a suspension? How do I avoid getting a question ban? How long do I have to wait before I can post again? What can I do to release the ban? How can I reactivate my account? Can I simply create a new account? I'll just ask somewhere else on the SE network, and they'll migrate my question to the correct site! Will a ban on one Stack Exchange site affect my standing on other sites in the network? Does this apply to meta sites too? My account is in good standing. Why am I still blocked?


Im trying to write a Comparator which compares two objects of the class Coordinate. The Coordinate class is Pretty simple:   public class Coordinate {      private int x, y;      public Coordinate(int x, int y) {         this.x = x;         this.y = y;     }      public int getX() {         return x;     }      public void setX(int x) {         this.x = x;     }      public int getY() {         return y;     }      public void setY(int y) {         this.y = y;     }  }   Now I want the Comparator to compare the x and the y value for two instances of the class Coordinate. Here is an example: I have a Coordinate c1 which has x = 42 and y = 23. My second Coordinate c2 has x = 23 and y = 54. Now i put them both in an ArrayList an want to sort the List. I wanted to be sorted like the following: The Coordinate with the lowest y value goes Always first, when you have two Coordinates having the same y value the Coordinate goes first which has a lower x value. Example:    c1 (y = 4, x = 5 ) < c2 (y = 4, x = 6) < c3 (y = 5, x = 2)     So how can I write a Comparator for this Purpose? Thank you very much!

Assume you have some objects which have several fields they can be compared by:  public class Person {      private String firstName;     private String lastName;     private String age;      /* Constructors */      /* Methods */  }   So in this example, when you ask if:  a.compareTo(b) > 0   you might be asking if a's last name comes before b's, or if a is older than b, etc...  What is the cleanest way to enable multiple comparison between these kinds of objects without adding unnecessary clutter or overhead?   java.lang.Comparable interface allows comparison by one field only Adding numerous compare methods (i.e. compareByFirstName(), compareByAge(), etc...) is cluttered in my opinion.   So what is the best way to go about this?


I just install Ubuntu. One of the things I miss about windows is the lack of executable.   When I right click the .sh file, go to permissions, and check "Allow executing as a program", it never does execute as a program when I double click it.   Another solution I found is doing it in the terminal. This doesn't work either.    What am I doing wrong? Is this really too stupid of a question or am I too stupid? Thanks for any help!

Whenever I open a .sh file, it opens it in gedit instead of the terminal. I can't find any option similar to Right Click → Open With → Other Application... → Terminal.  How do I open this file in the terminal?


I want to save a user's email and username when a button is clicked. I assume I have to do this via PHP but I can find the user column at localhost/phpmyadmin. Where is the users' information being stored and which is the MySQL query to achieve that?

I'm programmatically creating a user with the following code.  $newUser = array(   'name' => $mail,    'pass' => 'password',  // note: do not md5 the password   'mail' => $mail,    'status' => 1,    'init' => $mail,   'roles' => array(5) ); $user = user_save(null, $newUser);   I have got a role with the role ID equal to 5; when I create the user, in the table "users_roles" there is only a row with the value 0 for the role ID, but if I print the user object with var_dump(), it looks like the roles are created.  What am I doing wrong?


I have been asked by my college to design a banner for print, this is going to help promote the course we are on etc.   The print size is 500cm x 250cm.  I was going to do this in Photoshop with the following sizes: 50cm x 25cm @ 300DPI  Do you think that these sizes in Photoshop is correct? and would look great printed, not pixelated? I've never designed for something so big before, and when i've entered the full size its over 1gb file size!  Thanks

For wall-sized graphics and large banners (e.g. 3m × 5m), what is an acceptable PPI for print? As I understand it 300 ppi is the typical for 'small' artworks (esp. for clean text resolution). However, for small artworks, the audience usually engages at a much closer distance. Therefore, in the interests of keeping a bitmap file down to a reasonable size, can you get away with a much-reduced PPI for a large format/banner print?


I recently installed Ubuntu 14.04 for the first time. Although I have set brightness a million times, every time I start the computer, it goes to maximum again. If I restart the computer it remembers my brightness definitions, but I completely turn off, it forgets.   How can I get it to remember my preferences?  Thank you, cheers.

The brightness of my laptop is reset to max on every restart. I tried the solution provided at  but had no luck.   This command   cat /sys/class/backlight/acpi_video0/max_brightness   Returns   cat: /sys/class/backlight/acpi_video0/max_brightness: No such file or directory   Then I found that I don't have a folder named acpi_video0, but a folder called intel_backlight:    Every time I increase or decrease the brightness using the brightness control keys, the values in brightness and actual_brightness get updated.  Is there any method I could follow to set the brightness to a fixed value on every boot and vary it as and when I need it using the brightness control keys?


My clipboard ceased to work (it did not copy anything), so I look into the service to restart it. But I found 2 Clipboards User Service:  What is it? Is it legit? Opening the key of this service I fund this duplication and number "63366" in several keys:  (I did fix my clipboard issue following )

there are a couple of services from UnistackSvcGroup, BcastDVRUserService and others running on my Windows 10 machine with a weird name. I did some research on the web about services from these groups and they seemed fine (simply part of the services that come with Windows), but what I found odd was that they were duplicated with a strange rename with them: _a1bddec, like:   BcastDVRUserService and the duplicate, BcastDVRUserService_a1bddec BluetoothUserService and the duplicate, BluetoothUserService_a1bddec etc.   I googled for this "name" and I couldn't find anything, nor could I find anything about duplicated services from such groups. More then that, I discovered this services when I was trying to understand why suddenly my computer started to suffer performance issues while I was watching a movie with nothing working behind that would justify gradual performance changes. After closing some apps plus stoping these services, my computer went back to normal, what leads me to think if it's not a virus of some sort.  So what do you know of these "double services" with different end names? Here are some prints with all of them:          EDIT  Following the comments below asking me to clarify my question, here is what I want to know: What are these duplicated services with different end names on my PC?. Knowing if they are viruses and why they are here would be part of the answer.  Since I'm already editing this post, it is worth to know that today, after restarting my PC, I found the previously shut down services had vanished from my PC and in their place I found a complete list of duplicated services with different end names, some of which were already stoped:    while some were running:


I don't know really how to ask this as a question because I'm not sure what is going on: in my Google Chrome browser the search bar's text is upside down when I try to type in it or click on it, everything else on the page is the proper way and when I click off the search bar the text goes back to normal. Is there something that I may have done to have this happen? It just started today and it is really really annoying. The only inference I have seen about this happening to someone else was on here:  and although several people claimed to have a similar problem that started occuring this week no one has been able to solve it

Google Chrome is my favorite browser, and I can't imagine going on without it. Suddenly (without closing and re-opening) the browser; chrome has been reading characters upside down, very weird:    Chrome version:    I tried restarting my browser and my MAC (running OS X Yosemite 10.10), but the error keeps on coming.


I got a new PC and I'm installing Ubuntu again as a dual boot alongside Win10, but this time Ubuntu won't even boot, instead I get some errors.   I think that there is something wrong with GRUB give that when I turn on my PC Windows boots automatically; the GRUB menu never appears.  Here's what i get when I try to force boot into Ubuntu from BIOS    System information: Dell latitude, Legacy BIOS, secure boot OFF.

I have a Lenovo Thinkpad e540 laptop with dual graphics, Intel integrated and Nvidia GT 740m Discrete. After changing from nouveau drivers to Nvidia binary driver 346.82 proprietary before login screen I've got a message:  [0.646495]Error parsing PCC subspaces from PCCT [0.646521]ACPI PCC probe failed.   Kernel version:  3.19.0-26-generic #28~14.04.1-Ubuntu SMP Wed Aug 12 14:09:17 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux   I've read somewhere that if I put in grub file quiet splash nomodeset that will fix this, but that doesn't work for me, then I get into login loop.  How can I fix this?


Consider two particles (having same mass) moving with constant velocity very close to speed of light, say $0.99c$ in opposite directions. Will the magnitude of their relative velocities exceed the speed of light?

I understand that nothing can move faster than light due to time dilation. I want to build upon my understanding of Einstein's theory of Special Relativity, so I came up with this hypothetical problem for myself:  If both particles are moving at 0.9c towards each other (according to an observer on Earth), what speed does each particle have relative to the other?  I'm stumped since I am only familiar with Newtonian classical mechanics to solve this (which would be wrong). I am aware of Lorentz' factor $\gamma =\frac{1}{\sqrt{1 - \frac{v^2}{c^2}}}$ and the time dilation equation $t_m = \frac{t_o}{\sqrt{1 - \frac{v^2}{c^2}}}$, but I'm not sure how to apply it in this instance. I'm just looking for a gentle push in the right direction. Edit: My prior research:  This article, ,  talks about the effect of a baseball thrown at 0.9c would have as it traveled towards a batter. This is not what I'm looking for since it doesn't explain the math behind finding the collision speed between two high velocity entities.  This question on Yahoo, , asks a similar question to mine, but no math is involved to demonstrate the calculations behind the reasoning.  This question on Physics.SE, , does not answer my question either. I have not been able to find a similar Physics.SE question which can provide me to clues to my own hypothetical question.  I have also Googled the following phrases:    i. "collision faster than the speed of light" ii. "collision of high speed particles" iii. "lorentz transformation in a collision" iv. "collision analysis at light speed"


I just got confused by seeing votes for comments. While hovering over the vote button it shows "number of useful comment votes received". So where can I give an upvote to a comment?

Comments can now be upvoted and flagged. How do those features work? Do users get rep for their upvoted comments? Do upvoted comments have any effect on comment sorting? And can users see their own comment upvote number somewhere?  Related:  The  about comments


i have been thinking, why only base class with virtual method needs virtual desctructor? look at this piece of code (read the comment):  class Base{ private:     int x; public:     Base():x(0){}     ~Base(){         cout<<"Base dtor"<<endl;     } };   class Derived : public Base{     int y; public:     Derived():y(0){}     ~Derived(){         cout<<"Derived dtor"<<endl;     } };  int main(){     Derived *pd = new Derived;     Base *pb = pd;     delete pb; // this destroys only the base part, doesn't it?                // so why doesnt the derived part leak?     return 0; }   I ran it with Valgrind and saw that the output was "Base dtor", and no memory leaks occurred. So, if only the base class dtor was called, why doesn't the derived class part leak?

I have a solid understanding of most OOP theory but the one thing that confuses me a lot is virtual destructors. I thought that the destructor always gets called no matter what and for every object in the chain. When are you meant to make them virtual and why?


I was recently looking through J. J. Rotman's book: An Introduction to Algebraic Topology, where on page 23 he has the following result:  Theorem 1.11. For every space $X$, the cone $CX$ is contractible.  Proof. Define $F:CX\times I\to CX$ by $F([x,t],s)=[x,(1-s)t+s]$. $\square$  Now it is clear to me that if $F$ is continuous, then it is a homotopy from $1_{CX}$ to the constant map which sends each point of $CX$ to to the "top" point of the cone; hence, $1_{CX}$ is null-homotopic and so $CX$ is contractible as claimed.  This is all well and good, but it is not immediately apparent to me which result Rotman is relying on to ensure the continuity of $F$. Does anyone have any ideas about how to guarantee the continuity of $F$?  Thanks in advance.

Let $X$ be a topological space. I want to show that the cone $CX$ is contractible. Here we construct a deformation retraction from $CX$ to  the tip point of the cone  $$H_t: CX\to CX;\; (x,t')\mapsto (x,t'(1-t))$$ is this correct?


I am learning java programming from   This guy, till now have been using the void keyword before declaring any method but once he reached to the passing parameters in methods part, he starting using the public keyword instead of the void keyword. Why did he start using public instead of void?  I have a vague understanding of both the keyword but it would be better if you could explain these keywords to me too.

In Java, are there clear rules on when to use each of access modifiers, namely the default (package private), public, protected and private, while making class and interface and dealing with inheritance?


I've done a fair share of googling and I've found some rather complex solutions. I feel as though there must be something simpler.  Let's say I have   ./1.txt ./2.txt ./more/3.txt ./more/4.txt ./more/even-more/5.txt   I'd like to rename anything .txt to .info  so   find . -type f -name "*.txt"   .........then what?  EDIT: Pure bash would be preferred

I have a directories with .MP3 files which I'd like to change the extensions to .mp3. What's the easiest way to do this? I'm think something along the lines of:  find /RootPath -type f -iname "*.mp3" -exec mv {} sed s/.*MP3/\1.mp3/ \;    ...though I know that isn't quite right. :) The substitution isn't correct and I'm not sure how to use both a mv and a sed command with -exec in find.  Would I need a bash script for this?


I would like to capture the bandwidth usage to and from one specific remote machine across time on my system. iftop command is definitely one option, which gives the network usage, and has filtering , but I need to parse the text output to get the incoming bandwidth usage and outgoing bandwidth usage.  sudo iftop -t -s 2 -f "src host <remote_machine_ip>"   My current plan is to run the above command in a loop, parse the text output each time and append to a csv file (current_time, transmitted, received).  Is there a better alternative ?

I have a freebsd box, which serves as a router from LAN to the outside world. It has several Internet providers, OpenVPN servers and clients, NAT and so on.  I would like to have complete statistics on when, who, to whom, via which provider, via which protocol, and how many bytes have been sent.   I agree that the minimal time scale will be an hour, i.e. no need for millisecond precision.  I tried vnstat2, ntopng and some other programs, but they don't seemed to have what I need or it is not obvious.   I don't understand, why this feature is not easily available. But I am not good in freebsd, so please, give me some clues.


I am currently spending the week in a place with very faulty Internet service whilst simultaneously trying to scrape online data for a project. In particular, I am visiting each URL from a list of URLs and scraping a specific piece of data from each website to put into a CSV. The list of URLs is fairly large (33,000+ URLs), and I am finding it difficult to pick up where I left off when the internet goes down. Is there a way to do this quickly? Here is what I have:  def makeCSV(csv_src): #END_TOKEN = " __END__ENTRY__" with open(new_src, 'r') as f, open(csv_src, 'a') as fcsv:     count = 40     for i, url in enumerate(f):         while i >= count and count < len(f.readlines()):             count += 1             wr = csv.writer(fcsv, quoting=csv.QUOTE_ALL)             speaking, studying, entry, incorrect, correct = mineLearnerData(url)             data = [speaking, studying, incorrect, correct]             wr.writerow(data)             #f2.write(str(entry + END_TOKEN) + '\n')             print(count) f.close(); fcsv.close()   'f' represents the file of URLs I am using. I am sending specific information from the URLs in that file to a specified CSV file path. 'Count' represents the next URL to be looked at. Ideally I'd also like to be able to use something line len(fcsv.readlines()) but I keep getting ascii errors.  Also, I'm open to suggestions regarding efficient ways to do this, as I am completely new to the data collection & cleaning process.

I'm writing a log file viewer for a web application and for that I want to paginate through the lines of the log file.  The items in the file are line based with the newest item at the bottom. So I need a tail() method that can read n lines from the bottom and support an offset.  This is hat I came up with: def tail(f, n, offset=0):     """Reads a n lines from f with an offset of offset lines."""     avg_line_length = 74     to_read = n + offset     while 1:         try:             f.seek(-(avg_line_length * to_read), 2)         except IOError:             # woops.  apparently file is smaller than what we want             # to step back, go to the beginning instead             f.seek(0)         pos = f.tell()         lines = f.read().splitlines()         if len(lines) >= to_read or pos == 0:             return lines[-to_read:offset and -offset or None]         avg_line_length *= 1.3  Is this a reasonable approach?  What is the recommended way to tail log files with offsets?


Most plants require carbon dioxide for their photosynthesis, which Mars has in overabundance.   Would atmosphere composition (let's ignore temperatures for the purpose of this question) of Mars allow vegetation to grow?

Do we know of any living forms on Earth that could continue to live on Mars?


Is it possible to calculate the pearson correlation, r or r^2 value from a linear regression using pgfplots? I already have the curve and would like to display the r value in the legend. I couldn't find any information in the manual nor google search. Please advise, thanks in advance.

I have the following code   \documentclass{article} \usepackage[utf8]{inputenc} \usepackage{pgfplotstable} \usepackage{pgfplots} \pgfplotsset{compat=1.11}  \pgfplotstableread{ x1 y1 y2 0   1   1 1   2   4 2   3   9 3   4   16 4   5   25 5   6   36 6   7   49 7   8   64 8   9   81 9   10  100 10  10  100 }\tableLabel  \begin{document}  \begin{tikzpicture} \begin{axis}[ legend pos = north west, title = Cool Graph, xlabel ={Cool X}, ylabel ={Cool Y}, grid = major, legend entries = {best fit, y1, y2}, ]  \addlegendentry{%     $\pgfmathprintnumber{\pgfplotstableregressiona} \cdot x     \pgfmathprintnumber[print sign]{\pgfplotstableregressionb}$ lin.     Regression} % \addlegendentry{y1}  \addplot table [x index=0, y = {create col/linear regression={y=y2}}]     {\tableLabel}; \addplot table [x index=0, y = y1]{\tableLabel};        %The data entries in column y1 \addplot table [x index=0, y index=2]{\tableLabel};     %The data entries in column y2 %\addplot table[row sep=\\, y={create col/linear regression={y=Y}}]  \end{axis} \end{tikzpicture} \end{document}   I wish to also show the R^2 value (least squares regression value) on my graph, is this possible?


I'm trying to make a for loop that loops through an array, comparing the user input to each object using a method called getID() that returns the stored user IDs for various employees. The data is not saved between runs, so on the first loop, all objects (I believe) should be null. With that being said, I get a nullPointerException on the line that's supposed to compare the strings retrieved by getID() and the userInput string. The array is initialized as follows:  Salesperson[] staffList; staffList = new Salesperson[20];   Here is the loop in question, the if statement is the line that throws the NPE:  for(i = 0; i < staffList.length; i++)   {      if(staffList[i].getID().equals(idNum))      {           duplicateID = true;      }  }   Here is the class for the Salesperson array:  public class Salesperson { private String name; private String idNum; private double annSales;  //Various getter and setter methods here }   If I missed anything please let me know. I've used Stack Overflow in the past but have never asked a question myself. I've tried searching around here but have yet to find anything that helped me. Thanks in advance!

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


I have recently upgraded from Ubuntu 16.04 LTS to 17.04 LTS via the upgrade notification I received.  The computer boots up and I am shown the login screen with my existing account.  If I log in with the account in GUI mode, I get a black screen with desktop items (blinking those items when I click on the desktop screen). I can switch to a terminal and log in with the admin account, so the credentials are ok.  Any ideas as to why this is happening and how I can get the GUI mode back for my account?  I am aware of all the commands and direct command line with ALT + CTRL + F1 but there is no upgrade required. All packages are fully updated.

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


I read that everything is an object in Python. So what is 2:4 in L[2:4]? Is it a slicing object? When I just type 2:4 in the interpreter, an SyntaxError is raised.

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


I'd like to draw vertical border lines in merged cells, but now merged cells do not have any vertical border line.  How can I add lines?  \begin{table}[htbp] \centering \caption{policy} \label{tab:mutationoperators} \begin{center} \begin{tabularx}{\textwidth}{|c|L|} \hline ope                 & Description               \\ \hline \multicolumn{2}{l}{Category1 }               \\\hline   d                       &       d                    \\\hline \multicolumn{2}{l}{Category2}                \\\hline                      f    &         f                  \\\hline                        f  &         f                  \\\hline \multicolumn{2}{l}{Category3}                \\\hline                      f    &       f                    \\\hline                       f   &        f                   \\\hline \multicolumn{2}{l}{Category4}              \\\hline                    f      &        f                   \\\hline                    f      &        f                   \\\hline                     f     &        f                   \\\hline \multicolumn{2}{l}{Category5} \\\hline                      f    &       f                    \\\hline                      f    &        f                  \\ \hline \end{tabularx} \end{center} \end{table}

I tried to use this for the last part of my table, but I can't get a vertical line at the end. Does anyone know?   \begin{tabular}{|CC|C|C|C|C|C|C|C|C|C|C|}\hline \Tab{Method Based on \\\hline       Radiography\\Magnetic Particle (A.C.)\\ \\Eddy Current\\Dye Penetrants\\ Ultrasonics} & \Tab{ \\\hline \\ Wet \\ Dry \\ \\ \\ \\} & \Tab{\rotatebox{90}{~\parbox{5cm}{Minute Surface Cracks }~}  \\\hline       N\\ G\\F\\F\\F\\P}  & \Tab{\rotatebox{90}{~\parbox{5cm}{Deeper Surface Cracks      }~}  \\\hline            F\\G\\G\\G\\G\\G} & \Tab{\rotatebox{90}{~\parbox{5cm}{Internal Cracks      }~}  \\\hline            F\\N\\N\\N\\N\\G} & \Tab{\rotatebox{90}{~\parbox{5cm}{Fatigue Cracks      }~}  \\\hline            P\\G\\G\\N\\G\\G} & \Tab{\rotatebox{90}{~\parbox{5cm}{Internal Voids      }~}  \\\hline            G\\N\\N\\N\\N\\G}           & \Tab{\rotatebox{90}{~\parbox{5cm}{Porosity and Slag in Welds      }~}  \\\hline            G\\N\\N\\P\\N\\F}           & \Tab{\rotatebox{90}{~\parbox{5cm}{Thickness      }~}  \\\hline            F\\N\\N\\P\\N\\G} & \Tab{\rotatebox{90}{~\parbox{5cm}{Stress Corrosion      }~}  \\\hline            F\\G\\F\\N\\G\\F} & \Tab{\rotatebox{90}{~\parbox{5cm}{Blistering      }~}  \\\hline            P\\N\\N\\N\\N\\F} & \Tab{\rotatebox{90}{~\parbox{5cm}{Corrosion Pits      }~}  \\\hline            G\\N\\P\\N\\F\\P} \\\hline & \multicolumn{11}{l}{G=Good;F=Fair;P=Poor;N=Not suitable.} \\ \hline \end{tabular} \label{tab:NDETechniques} \end{table}   It comes out like this:


Similar to this question, but specifically for the Swedish version  () I would like to know which letters each of the 16 dice have. Also any extra information on how the game works with the Swedish vowels å, ä, ö. I know with the German version you use extra letters to make up for the missing umlauts e.g. ä --> ae, is it similar to this?

This is the dice configuration for the English Boggle:  Other variants and discussions concerning letter distributions for English can be found here:  , , ,  (Wikipedia).  I am interested in the 16 dice configurations for also other languages (Spanish in particular) and I am unable to find it anywhere online.  Versions I have managed to find so far:  ,  English 25 dice version:   Spanish 25 dice version:   Italian 25 dice version:


How to add column to an existing SQL Server table along with data simultaneously. The below syntax with DEFAULT clause appears to load data in the new column for INSERTs only.  ALTER TABLE LanguagePacks ADD LgDt DATETIME DEFAULT GETDATE()   EDIT: Thanks for all your answers. It worked. I tried all your suggestions and is an excellent learning. Since this question is marked as dup, appears to have affected my option to post this edit as answer.  ALTER TABLE ##LangPak  ADD  LtDt3  DATETIME DEFAULT GETDATE(), --LtDt1  DATETIME NOT NULL, --ERROR: Msg 4901 LtDt DATETIME NOT NULL DEFAULT GETDATE(), LtDt2 DATETIME DEFAULT GETDATE() WITH VALUES, LtDt4 DATETIME NULL DEFAULT GETDATE()  WITH VALUES

How can I add a column with a default value to an existing table in  / ?


When i remove a comment of mine and after that directly try to upvote another one i receive the message, that a upvote for a comment is only possible every 5 seconds.  Is this a wanted behaviour?  This is reproducable. Try it yourself.

I had an old question that I revisited in order to link it in a new answer. I noticed that in the comments Steven A Lowe had a funny comment that I -- at the time -- had responded to with "why can't I upvote comments?"  Well, of course, now I can.  So, I voted Steven's comment up then went to delete mine. I got the warning box that I can only submit comment votes once every 5 seconds. This seems like a bug to me. Deleting is not the same as voting.


I went into system preferences and completely unchecked the swipe between pages button for my magic mouse, but it still does it.  Why won't this feature turn off?  If you're going to tell me my question is a duplicate, please tell me where I can find the answer to this duplicated question because I still have no answer!!!  thank you

I recently picked up the new Magic Mouse 2.  Since then, the 'Swipe Between Pages' has started working on it's own.  With the old mouse, I turned it off, as I was constantly flipping through web pages accidentally.  Even though the prefs say it is deactivated... it won't stop!  I tried turning it on and back off... no luck.


I want to display data in UITableView in reverse order. I manage to do it with little effort but can any one provide a better way to do it. Thanks in advance.

I need to reverse my NSArray.  As an example:  [1,2,3,4,5] must become: [5,4,3,2,1]  What is the best way to achieve this?


Prove that:  $a^3\cos(B-C) + b^3\cos(C-A) + c^3\cos(A-B) = 3abc$  Here a,b,c are the sides of the triangle ABC opposite to angles A, B, C respectively.  My attempt: I tried putting $a = 2R \sin(A)$ and replacing $\sin(B+C) = \sin(A)$ but that didn't help out. I tried applying AM $\ge$ GM but that too did not work out for this question.   Please help me out!!!

How to Prove $a^3 \cos (B-C) + b^3 \cos (C-A)+ c^3 \cos (A-B)=3abc$?  If $A,$ $B,$ and $C$ are the vertices of the Triangle ABC, and $a,$ $b$ and $c$ is the side opposite to the sides of the triangle.  You may use -  Projection Formula:  $$a=b \cos C + c \cos B$$  and Sine and Cosine Relation too.    My try  $$a^3 \cos (B - C)+ b^3 \cos (C-A) + c^3 \cos (A-B)=3abc$$ LHS = $$ 3(b \cos C + c \cos B)(a \cos C + c \cos A)(a \cos B + b \cos A)$$ $$ 3[ ab \cos B \cos ^2 C + abc \cos A \cos B \cos C +a^2c \cos ^2 B \cos C +ac^2 \cos A \cos ^2B ]+[b^2 \cos A \cos^2 C + b^2c \cos^2 A \cos A+abc \cos A \cos B \cos C + ac^2 \cos A \cos^2 B] $$  Now I can't solve it further because there seems no way to reduce that further.  Thanks :)


OK, so I haven't find any answer, only one that claims the "nvidia-updates" is newer versions, yet the driver instalator says this:  4 options:  nvidia 331.113, nvidia-updates 331.113, legacy nvidia 304.125, legacy nvidia-updates 304.125  Which one to install? What's the difference between nvidia and nvidia-updates? Since both report as the same version.  Which should I choose? Legacy or non-legacy? Both 331.113 and legacy 304.125 were released at the same day, bot are supported by my card.. Which is GT520M   AND   They have some common changelogs.. so I'm confused. And new non-legacy drivers are still being developed for this GPU.  And last question. Why the driver is so outdated? It's from 2014.

What's the difference between the , and  packages?  The former has a higher version number, and the description of the packages are the same.    Which do I use? Which is the most recent one What's the purpose of this split packaging?