I've got data on mail volume sent by household for seven age groups, with 12 years of data for each age group. I originally ran a simple regression on each age group individually and realized I needed to dig deeper. My aim now is to pool the data (giving me 84 observations) and try to identify some period effects (or year effects, whichever you prefer). My pooled data are currently organized like this (PPHPY stands for Pieces per Household Per Year):  Age Group    Year   PPHPY 1            2001   127.62 1            2002   144.47 1            2003   111.70 1            2004   95.96 1            2005   96.46 1            2006   139.91 1            2007   85.52 1            2008   75.43 1            2009   109.34 1            2010   53.16 1            2011   64.09 1            2012   50.94         2            2001   176.48 2            2002   172.86 2            2003   137.79 .              .      . .              .      . .              .      . 7            2012   163.39   I first regressed PPHPY on year and year dummies (leaving the intercept as 0 to avoid perfect multicollinearity). This gave me period effects for the aggregated data (ie something like a period effect across all age groups, I think). This looked like the following:  > ## Generate YearDummy using factor() > > YearDummy <- factor(YearVar) > > ## Check to see that YearDummy is indeed a factor variable > > is.factor(YearDummy) [1] TRUE > > ## (...+0) ensures intercept is left out and thus YearDummy1 remains in.     ## One or the other must be subtracted out to avoid perfect mutlicollinearity > > LSDVYear <- lm(PPHPY ~ YearVar + YearDummy + 0, data=maildatapooled) > summary(LSDVYear) Call: lm(formula = PPHPY ~ YearVar + YearDummy + 0, data = maildatapooled) Residuals: Min 1Q Median 3Q Max -99.658 -39.038 8.814 43.670 82.300 Coefficients: (1 not defined because of singularities) Estimate Std. Error t value Pr(>|t|) YearVar 5.743e-02 9.851e-03 5.830 1.45e-07 *** YearDummy2001 1.099e+02 2.795e+01 3.930 0.000193 *** YearDummy2002 1.209e+02 2.796e+01 4.324 4.85e-05 *** YearDummy2003 7.791e+01 2.797e+01 2.786 0.006819 ** YearDummy2004 8.053e+01 2.797e+01 2.879 0.005251 ** YearDummy2005 6.887e+01 2.798e+01 2.461 0.016236 * YearDummy2006 6.572e+01 2.799e+01 2.348 0.021618 * YearDummy2007 5.975e+01 2.799e+01 2.134 0.036210 * YearDummy2008 5.836e+01 2.800e+01 2.084 0.040696 * YearDummy2009 4.119e+01 2.801e+01 1.471 0.145745 YearDummy2010 3.056e+01 2.801e+01 1.091 0.278990 YearDummy2011 1.472e+01 2.802e+01 0.525 0.600951 YearDummy2012 NA NA NA NA --- Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 Residual standard error: 52.44 on 72 degrees of freedom Multiple R-squared: 0.9316, Adjusted R-squared: 0.9202 F-statistic: 81.71 on 12 and 72 DF, p-value: < 2.2e-16   What I want, however, is to tease out period effects for each age group individually. This is what I'm not sure how to set up. I was hoping someone might help me devise some code in R that would kick out those period effects for each of the seven age groups using the pooled data, as well as help me understand the problem conceptually.   EDIT: I forgot to mention that I see I must include an interaction term involving the time dummies to allow the coefficients to vary across age groups. I'm just having difficulty constructing the proper interaction term and resulting regression equation.  EDIT 2: I came up with two models and ran them. I felt like the question had evolved at this point and might merit a new post, which is can be found .


Usage of imagined content in direct speech

I've seen and used quotations that I'm not sure is correct. If it is correct, I'd like to know what it is called. If it is incorrect, I'd like to know how to punctuate it correctly. Here is an example of this usage in a hypothetical text conversation.     Mary: I cleaned him out.      Joe: Wait, do you mean, "I won all of his money, so now he has none"?   To add some clarity, I believe the second example below also illustrates the same usage of quotes.     Bob: I think I heard him say, "I like you".     Bob hearing "I like you" is purely hypothetical. It's possible that Bob misheard "I despise you" for "I like you".  Is it correct to use the hypothetical content within quotes? If not, how should it be punctuated?   Update  Every definition of quotation or quote, and every rule I've read regarding their usage mentions an origin or source of text or speech. To me, this implies that there must be an original source in order for something to be considered a quote. However, in the cases above there is no original source as the whole quotation¹ is made up.  Is there an authoritative definition of quotation that includes a hypothetical or entirely paraphrased quote¹? Or if no such definition can be found, is there an example of this type of quote¹ in an authoritative work?  ¹The usage of quote or quotation here may be incorrect in accordance with the outcome of this question.


Prove that if f is holomorphic on all of $\mathbb{C}$ then $f(z)=\lambda z+c$

Let $f:\mathbb{C} \rightarrow \mathbb{C}$ be holomorphic on the form $f(x+iy)=u(x)+iv(y)$ where $u,v$ are real functions. Prove that $$f(z)=\lambda z+c$$   for  $\lambda \in \mathbb{R}$ and $c \in \mathbb{C}$.    How do I prove this? I think I have to use the Cauchy-Riemann equations somehow but I can't quite figure it out. Thank you!


Which site to ask a technology's theory?

Which site to ask a software technology's theory? Such as , there have the source code, but I don't know the deep theory. there is also no detail description of it. is there any site I can ask this type question? the StackOverflow only accept the code questions, not appropriate.  EDIT-01 My first example(ngrok) is not good. if there is a practical technology, such as VPN, such as PPTP, GRE and so on, I want to know its theory, still no site in SE suitable? if you say , but it only accept questions under layer 3. the VPN technology is belong to application layer.


Accepted answer appearing below top voted

On , sorted by votes, the accepted answer is #3 in order of votes.  It appears as number 3 in the list as well. Is this new behavior intended?


A newspaper of the ruling Communist Party ( said Saturday ) that no religion is above the law in China, urging officials to stay firm while dealing with a rare protest over the planned demolition of a massive mosque in the northwest. is it said on Saturday ?


Do I need a Zoom, Macro, or Telephoto lens for birds and sports?

What lens should I purchase to take pictures of fast moving subjects at a distance, magnify them with crisp detail so to speak freeze them in action, and bring them close (as subjects for my drawings and paintings)?  I have an EOS Rebel T7i, Canon EF-S 18-55mm, and EF-S 55-250mm lenses.  I am an amateur photographer, I have great interest in motion subjects, from  flying birds to a kite surfer, to civil war re-enactments. I found myself wanting to capture expressions and out of the ordinary movements, cannonball fire, the facial expression of a Kite surfer that is 50 feet in the air, and actions.  I went on the Canon website and read many reviews on macro and telephoto and it shows sample pictures like a dragonfly's head or pictures of still subjects, which are all great but I want the same effect on an eagle sitting on a branch 300 feet from me and if he takes off I want to be able to shoot pictures in flight. I actually captured a bald eagle sitting on a branch with my zoom lens, but it just did not bring it close enough for me.  I am also more concentrated on being able to hike and be on the go and snap a picture instead of setting up a tripod unless it is an event. I do not want to spend a ton of money to start out with, but around of $1000 I am game.


Let $\phi : R\to  S $ be a ring homomorphism.  Definition: $Im\left ( \phi \right )=\left ( R \right )\phi=\left \{ \left ( a \right )\phi \mid a \in R \right \}$  Prove that $Im\left ( \phi  \right )$is a subring of S By the subring test, we need to show that the $Im\left ( \phi  \right )$ is closed under multiplication and subtraction. Suppose $\left ( a_{1} \right )\phi,\left ( a_{2} \right )\phi \in Im\left ( \phi \right )$. Thus, $s_{1}=\left ( a_{1} \right )\phi$ and $s_{2}=\left ( a_{2} \right )\phi \in Im\left ( \phi \right )$ $\left ( a_{1} \right )\phi$ + (-$\left ( a_{2} \right ))\phi=  s_{1}-s_{2}$ but S is a ring so $s_{1}-s_{2} \in$ S Is this correct?


How to skip to a particular option in man pages?

I have a simple request: Is there a way to quickly find out what a particular option for a command means using man? I know you can just Google for it, but I want to use the man pages if possible.  Something like man ls -l which seems identical to be identical to man ls, but I would like to find out what the -l option does, without having to scroll down to it.


Can't report a bug on for a project on Launchpad--What to do (e.g. Skype Wrapper)

I want to report a bug in Skype Wrapper  but am not able to do it. Do I need to be a member to report a bug? I have a Launchpad account and I tried reporting it while logged in but I see no option to do so.


I need to prove $A⊆B$ where A and B are defined as: ${A =\{x | x = 2n + 1}\}$ ${B =\{x | x = 2m - 21}\}$ where $n,m∈\mathbb{Z}$    I know that I need take an arbitrary element from A and show that it works in B, but I'm stuck on how to do it in this example.


Essentially, this code should take input from user for:trip description, miles of trip, and gallons of gas used.  That info should be placed into an array for each, then have the MPG for each trip calculated. In the end I want it to display a listing that includes: name, miles traveled and the MPG for each trip.  The problem I am having is that the code compiles, but when executed I receive:     Exception in thread "main" java.lang.NullPointerException       at week6challenge.Week6Challenge.main(Week6Challenge.java:25)   Java Result: 1"   I am still VERY new to programming and I have searched for solutions all over, but I cannot find how to fix it. I learned what the problem is, but an clueless as to how to fix it. Any help would be GREATLY appreciated. Thanks!  Code:  import java.util.Scanner; public class Week6Challenge {      public static void main(String[] args) {         Scanner scan = new Scanner (System.in);         int count = 0;         String[] tripName = null;         double[] tripMiles = null;         double[] tripMPG = null;         double miles = 0, gallons = 0;          while (count <= 10){             System.out.println("Enter a description of this trip");             tripName[count] = scan.next();             count++;              System.out.println("How many miles did you drive?");             tripMiles[count] = scan.nextDouble();              System.out.println("How many gallons of gas did you use on this trip");             tripMPG[count] = answer(miles, gallons);         }         int k = 0;         System.out.println("Trip Name \t Miles Traveled \t MPG");          while(k < 10){             System.out.println(tripName[k]+ "\t" + tripMiles[k] + "\t" + tripMPG[k]);             k = k++;         }     }      public static double answer(double num1, double num2){         return (num1 / num2);     }     }


How to make the header of a table from 2 line to 4 line?

I had tried to increase the number from 2 to 4 where I need 4 lines  \multirow{4}{*}{\thead{Pair number \\ (Class 11 sample sample \& \\ Class 22 sample sample \\ Reference X sample sample)}} &      \documentclass[12pt,oneside]{book}  \usepackage[showframe]{geometry} \usepackage{amsmath} \usepackage{ragged2e} \usepackage{makecell, multirow, tabularx} \renewcommand\theadfont{\small\bfseries} % for bold in table using \small \renewcommand\theadgape{} \usepackage[svgnames, table]{xcolor} \usepackage{hhline, boldline} \usepackage{seqsplit, caption} %for table spacing to second row \usepackage{booktabs, ragged2e} % Use booktabs rules and get rid of vertical rules, ragged2e to ragged text \usepackage{siunitx} %for table spacing to second row \usepackage{threeparttable} %to add footnote below table \usepackage{tabulary} \usepackage{graphicx}  \usepackage[font=small,labelfont={bf,sf}, textfont={sf}, justification=centering]{caption}  \begin{document}   \begin{table}[h!] \centering \sisetup{table-format=3.0, table-number-alignment=center, table-column-width=2.0cm}  \begin{tabular}{lrr}     \toprule      \multirow{4}{*}{\thead{Pair number \\ (Class 11 sample sample \& \\ Class 22 sample sample \\ Reference X sample sample)}} &  \multicolumn{2}{c}{\thead{\makebox[0pt]{Accuracy Accu Accuracy (\%)}}}\\ \cmidrule{2-3}     &{\textbf{Accuracy}}      & {\textbf{Inaccuracy}} \\      \midrule     Pair 11 (A8 \& B35) & 0  &   0 \\     Pair 12 (A10 \& B42) & 0   &  0 \\     Pair 13 (A8 \& B32) & 0   &  0 \\         \bottomrule     \end{tabular} \end{table}   \end{document}


Is there a way to play minecraft with the same accounts without a server?

So I had gotten Minecraft about a  year ago and I paid for an account. We have another computer so my brother plays on it with my account. Now we both can play on it at the same time. Is there a way for us both to play together without an actual server you have to pay for?


SEO - URLS submitted in sitemap is excluded( 'Discovered not indexed ') in coverage report

I submitted a new sitemap for the items that should be listed in google. But it is seen that out of 300 only 21 is indexed. Rest went to 'Discovered not indexed'. The urls in sitemap are not duplicate URLS. Contents in the URLs are dynamically generated. Can anyone explain why it is happening.


When I was browsing the internet, a new site opened and it said that I have a virus in my battery and that it will then also infect my sim card and everything else, infected by a recent adoult side that opened while I was watching anime. It was android site so I clicked continue and then it asked for my number so I closed it. I don't know if it's real, and if it is, what should I do?


So, my professor me gave this exercise as a challenge:  -First, prove that:  $$1+{1\over 1+{1\over 1+{1\over 1+{1\over 1+...}}}}={1+\sqrt{5}\over 2}.$$  -Then, prove that:  $$1+{1\over 1+{1\over 1+{1\over 1+{1\over 1+...}}}}=\sqrt{1+\sqrt{1+\sqrt{1+\sqrt{1+...}}}}$$  He said you need no advanced maths to solve it: you just need high-school math with no calculus...  The thing is that it's been 2 weeks now and I'm as lost as when I first saw the problem.  Can someone help me!


Ubuntu 16.04 ssh connection permission denied error

We are unable to solve the below error in Ubuntu16.04:   Permission denied (publickey,password).   We have tried .  What else can we try?


Is it possible to rasterize a text layer in Photoshop CC where each letter gets its own layer?


I'm trying to create alertdialogs through a custom dialogframent class  public class Dialogs extends DialogFragment {     @Override     public Dialog onCreateDialog(Bundle saveInstanceState) {         AlertDialog.Builder alert=new AlertDialog.Builder(getActivity());          //additional custom layout here(skipped)          alertDialog=alert.create();         return alert.create();     }      public static Dialogs newInstance(String title, String fields, String buttons) {         Dialogs d = new Dialogs();         Bundle args = new Bundle();         args.putString(TITLE,title);         args.putString(FIELDS, fields);         args.putString(BUTTONS,buttons);         d.setArguments(args);         return d;     }      public List<Button> getButtons() {         return this.buttons;     }      public AlertDialog getDialog(){         return alertDialog;     }   I am calling it in my main activity via  public void AddNewTask() {     Dialogs my_dialog = Dialogs.newInstance("Add New Task",NEW_TASK,NEW_TASK_BUTTON);     my_dialog.getDiag().show(); }   getting  java.lang.NullPointerException: Attempt to invoke virtual method 'void android.app.AlertDialog.show()' on a null object reference   I have a hunch it's that the arguments were put after the d was created. So the argumnets didn't pass through? Any help is appreciated  Edit: This is not a question of what is a nullpointer exception. I understand very well what it is. I have solve the problem  for those that possibly have similar issues in the future. I changed the way the dialog was launched inside main activity. It seems like I was missing a fragmenttransaction.   final Dialogs my_dialog=Dialogs.newInstance("Add New Task", NEW_TASK, NEW_TASK_BUTTON);         FragmentTransaction  ft = getFragmentManager().beginTransaction();         my_dialog.show(ft, "dialog");


I've been playing SW:TOR for about a week now, and the game has been completing the download in the background.   It stopped at 99.18% downloaded three days ago. Now, I'm level ten and finished on my planet, but I can't get off the planet because the game "is not fully downloaded". How do I get my computer to finish that last percent of download?


Is it East Coast, East coast, or east coast when used in a sentence such as, "The airline flies to both the East Coast and the West Coast?" I've seen it all ways. I can't find a definitive answer as to if or where capital letters are needed in this phrase. Thanks for your help.


How to close on screen keyboard from menu bar option "A" near the spotlight search

I have been trying to close onscreen keyboard (Assistive control) via Terminal and AppleScript, but it restarts after getting closed for 1-2 seconds. Is there anyway to close it? I have used scripts like these: tell application "Assistive Control"      quit  end tell  Please let me know how will I close it via applescript or any terminal command


What are these spots on the PCB that are by the mounting holes?

When you look at the board, there is a weird part of the PCB right of the top left mounting hole. There is also another one above the top right mounting hole.    ****                            ↓ Here's one                                            **   This image is directly copied from .    What are these? Is this just created when this is manufactured (to grip to to move the board or to grip during solder mask creation), or does it serve a purpose (something to hook a multimeter to)?


Print two or more outputs from functions side by side in python

I'm a little new to Python and I was wondering how you would present more than one output side by side if it was part of different functions. So for a simple example:  def function1():     print("This is")  def function2():     print("a line")  def main():     function1()     function2()  main()   If I do this it would print:  This is  a line   But how would I adjust it to print out like this:  This is a line   EDIT: I noticed .end function would help here but what if I had a long list of item? It doesn't appear to work in that scenario. So for example what if my two outputs were:  252 245 246 234   and   Bob Dylan Nick Ryan   and I wanted to join the two so it would be like:  252 Bob 245 Dylan 246 Nick 234 Ryan


Apologies for the simpleton question, but how exactly can we see objects around us if our atmosphere is made up of a vast amount of nitrogen, oxygen, carbon dioxide and myriad other such atoms and molecules? Surely such atoms should be "blocking" out view, like trillions of tiny billiard balls? Or can we see "through" atoms, due to their being made up of mostly empty space or due to something stranger and more complex such as their wave-particle duality?


A changing magnetic field passes through a wire loop but the loop itself is not in the field. Is an EMF induced in the loop?

$$\nabla \times \vec{E} =-\frac{\partial{\vec{B}}}{\partial{t}}$$  Applying Stokes' theorem:  $$\oint_{loop} \vec{E} \cdot d\vec{l}=\int_S -\frac{\partial{\vec{B}}}{\partial{t}} \cdot d\vec{S}$$  Where $S$ is any open surface with the loop as its perimeter. Considering the simplicity of the derivation I struggle to see why this shouldn't hold in all cases. However, consider the setup described below:     A uniform magnetic field parallel to the $z$ axis crosses the $x$-$y$ plane in a circular region radius $r$ centred at the origin. A wire loop of radius $R>r$ is also centred at the origin in the $x$-$y$ plane. The field changes with time (but remains parallel to the $z$ axis). Is an EMF induced in the loop?   According to Faraday's law as expressed above, the answer surely should be yes. The integral on the right hand side will not return 0, so therefore the left hand side cannot be 0 and an EMF should be induced in the coil.  Physically, however, the answer surely should be no. An EMF is induced in the wire ultimately because of the magnetic force that acts on the charges in the loop itself, moving them along the loop and producing a potential difference. If the loop itself is not in the magnetic field, then how can the field exert a force on the charges in it?  There is an error in reasoning somewhere here. Where am I going wrong?


Prove that $a/(p-a) + b/(p-b) + c/(p-c) \ge 6$ , where $a,b,c$ are the sides of a triangle and $p$ is the semi-perimeter .


Random generate 1 character a random amount of times

Hi im trying to make it so I can generate a random number 1-35 so for example if the number is 25 it will write out in a string 25 equal signs. How can I do that?  Random r = new Random(); r.next(1, 35); R's result = 25 string result = 25 equal signs


Writing empty set as union of basis elements for a topology.

In Munkres’ topology, there are two instances where we would have to represent the empty set as a union of sets.  First, we have a lemma that says if $X$ is a set; and $\mathcal{B}$ is a basis for a topology $\tau$ on $X$, then $\tau$ is equal to the collection of all unions of elements of $\mathcal{B}$.  Later on, we define a subbasis $S$ of a topology on a set $X$ to be a collection of subsets of $X$ whose union equals $X$, and the topology generated is the collection of all unions of finite intersections of elements of $S$.  So there are a few questions I wanted to ask about these just to make sure that I'm understanding them correctly. First in the case of the subbasis, when Munkres says finite intersections, he's allowing for a set to be intersected with itself right? There's nothing that says the sets have to be different? This is important because we will need the elements of S to be in the collection of finite intersections so that we can get the full set X.  Secondly, and more importantly, when dealing with the empty set, how do we say that this set is a union of anything? If I have a collection of sets D and I take the empty collection $\mathcal{A}$, then can I say the union of the empty collection is the empty set? I think this is ok to do, and Munkres mentions this earlier in the book, so is he allowing this to occur when he says all unions of elements from a collection of sets? I suppose its not that hard to understand but I guess I'm not used to thinking this way.  Lastly, in the proof of the lemma I mentioned first, Munkre's proves that every open set is a union of basis elements in the following way. Let $U \in \tau$, choose for each $x \in U$ an element $B_x$ of the basis such that $x \in B_x \in U$. Then $U = \bigcup_{x \in U} B_x$, so $U$ equals a union of elements of the basis.  I'm having trouble interpreting this statement if we start with $U=\emptyset \in \tau$. Then there is no $x \in U$, so how do we interpret the rest of the statement?  Thank you


I've read several sources so far. Here are the three options I have encountered:  /etc/systemd/system  /usr/lib/systemd/system  /lib/systemd/system   I was originally putting my service in /lib/systemd/system, and it seems a bunch of other services are in that directory as well. However, it's supposed to be in /etc/systemd/system?? This source never talks about the third option:   Also, this tutorial seems to put it in that directory.   Please help clarify for me. Enabling my unit is leading to an error message: "Failed to enable unit: Invalid argument" I hypothesize because the directory is wrong. (I am using Arch Linux)


Do I have an SSD and a hard drive on my MacBook Pro?

I looked at the details provided in  my system report/storage and I noticed that it appears I have a hard drive of 499.05GB and an additional SSD drive of 499.42GB. Does this mean I have 1TB of data? I only have 139GB available so do I have 500GB 'hiding' somewhere? (If so where??)  I am unsure how to interpret this information- why does it list both storage types? Is it duplicating the information?     Macintosh HD:      Available:    139.8 GB (139,800,666,112 bytes)   Capacity: 499.05 GB (499,046,809,600 bytes)   Mount Point:  /   File System:  Journaled HFS+   Writable: Yes   Ignore Ownership: No   BSD Name: disk1   Volume UUID:  EF0908C8-XXXX-XXXX-XXXX-XXXX80333709         Logical Volume:  Revertible:  Yes (unlock and decryption required)   Encrypted:    Yes   Encryption Type:  AES-XTS   Locked:   No   LV UUID:  8CC9C88D-XXXX-XXXX-XXXX-XXXX2002329B        Logical Volume Group:   Name:    Macintosh HD   Size:    499.42 GB (499,418,034,176 bytes)   Free Space:  18.9 MB (18,903,040 bytes)    LVG  UUID: EE040070-XXXX-XXXX-XXXX-XXXXA83B309         Physical Volumes:      disk0s2:     #is this a second disk?      Device Name:  APPLE SSD SM0512G   Media Name: APPLE SSD  SM0512G   Media   Size:   499.42 GB (499,418,034,176 bytes)   Medium Type:  SSD    Protocol:  PCI    Internal:  Yes   Partition Map Type: GPT(GUID Partition Table)  #does this mean its partitioned?   Status: Online   S.M.A.R.T. Status:  Verified   PV UUID:    A1391405-XXXX-XXXX-XXXX-XXX2E8FCDF3


How does the quadratic formula work for complex variables?

Suppose for $z, a, b, c \in \mathbb{C}$ that we have $az^2+bz+c=0,$ how do you define solutions in the complex plane? Can you even use the quadratic formula at all for the non-real case?


Bash Linux random CLI Password generator and `<`

I recently discovered this method for generating a 9 character password from the linux prompt in bash:  < /dev/urandom tr -dc A-Za-z0-9_ | head -c9   What is < doing?


The drawer has M different colored socks. What is the least amount of socks I that I need to draw to guarntee N pairs

So in my discrete math class, we all know that if the drawer has 2 different colored socks, you need to pull out 3 socks to ensure a pair.   However, I am puzzled after there are more different colored socks and more pairs of socks.  For example, if there are 3 different colored socks in the drawer and I need to draw out 50 pairs, at least how many socks do I need to draw out to ensure that I have 50 pairs of sock?  How about if there are M different colored socks in the drawer and I need to draw out N pairs, at least how many socks do I need to draw out to ensure that I have N pairs of sock?  Are there any general formulas for these types of problem? Or are there any rules for this type of question?


Why are there fewer female users on Stack Overflow?

I've been here for a little while, but I've never seen a single female user. I know maybe there are some, but I've honestly never seen any.  I know that out there in the world the female to male programmers ratio is way better than here.  Is my appraisal of the situation correct and can anyone explain why representation seems skewed towards predominantly male participants on Stack Overflow specifically?


Is that a bug between `xymatrix`, the `input` command and .sty file?

I have a problem compiling the following document.  First, I have a file macros.sty that consists of :  \newcommand{\test}{ \xymatrix@R=0mm{x} }   Then, I have an auxiliary file out.aux that consists of :  \test   Finally, the main file is :  \documentclass{article} \usepackage[all]{xy} \usepackage{macros} \begin{document} \input{out.aux} \end{document}   The error message is :  ./out.aux:1: Undefined control sequence. \xymatrix@R ->\Addop@@                     \xymatrixrowsep@ \dimen@ii    Note that if you remove the R=0mm, the problem no longer holds.  Is that a bug ?  It is very strange because I remember to have already used a command similar to \test in an input file without any problem.  Does it come from my distribution ?  Thank you :)


Converting Lat Lon in WGS84 format to UK NGR in QGIS

I have csv file that has WGS Lat/Lon, what I need to do is convert these to UK NGR i.e Easting/Northing. In QGIS there under Field Calculator I think there are some defined operator like $X and $Y that does this but I can't make it work.


My app crashes when first opened and when I sign out using android firebase

I have created an android chat app using firebase - the app works fine but when first opened, the app crashes in login page but after this the app restarts and works fine. Please help me with a solution because I am a beginner in this field tell me what I should change to make it work   My logcat: beginning of crash     Caused by: java.lang.NullPointerException: Attempt to invoke virtual   method 'java.lang.String   com.google.firebase.auth.FirebaseUser.getUid()' on a null object   reference at   com.dndna.chat_rooms.views.base.BasePresenter.getCurrentUserId(BasePresenter.java:78)           at com.dndna.chat_rooms.views.main.MainPresenter.checkPendingNotification(MainPresenter.java:198)           at com.dndna.chat_rooms.views.main.MainActivity.onResume(MainActivity.java:262)   at   android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1456)           at android.app.Activity.performResume(Activity.java:7614)           at android.app.ActivityThread.performResumeActivity(ActivityThread.java:4412)   The problem seems to be in these locations  public void checkPendingNotification() {     if (getCurrentUserId() != null)         notifyManager.checkPendingNotification(this::showBadgeAt); }   and  if (presenter != null) {     presenter.checkPendingNotification(); }   and  protected String getCurrentUserId() {     FirebaseAuth.getInstance();     return FirebaseAuth.getInstance().getCurrentUser().getUid(); }


The remote package repository is not online. You have to choose another repository

After updating MikTex last night I am getting the error message in subject when trying to install or update the packages.  By default I was using  but to try and recover from this error I switched the updater to use the "nearest" repository which happened to be  and that also threw the same error.  Then I changed the updater to "allow me to choose the package repository" but the list that comes next is empty.  Did the last night's update to MikTex break the repository listing/querying in general, or something is wrong with my installation?


Dynamic component creation in Lightning Web Components

Is there any way to create and add lightning web components dynamically in the component tree ? I mean the equivalent one in Aura is $A.createComponent().  The usual Web Components can be dynamically created through standard DOM APIs like document.createElement('c-my-cmp') or element.appendChild(element), but as far as I tried in pre-release org it would not work at all.


Identify a story about a teen boy who learns to use magic with his lizard companion

Can you help me identify a book I read?  It was intended for teenagers.  I believe I read it in the late 1980s or early 1990s.  The main character is a teenage human boy from earth, who is learning to use magic with the help of a humanoid lizard companion, who knows all about magic, but can't use magic himself.  They travel to numerous worlds.  I remember one of the lessons was to draw in magic from the ground with every step he takes.  And there are different lines or streams of magic flowing through the world.  Different areas have different concentrations of magic to draw from.  At one point they travel to another world where there is a bazaar or marketplace selling lots of different things.  I believe at one point they travel to yet another world where they are hanged.  The main character survives by lifting himself up by using magic, and the lizard companion uses his strong neck muscles to avoid being killed.  I believe there's also a house where the front door is in one world, but the rest of the house is in a different world.


On meta sites, require at least one non-required tag

A question with just a required tag isn't really a tagged question.  doesn't really explain what topics the discussion is about... it's basically a meta tag. A useful meta tag, but quite not enough tagging.  Whenever I see  on Meta Gaming, , but it would be nicer if it was the asker who did this.


Where is the link to my privileges page?

Am I so myopic as to not see the obvious link somewhere? I came looking for it immediately after seeing King Atwood's post but couldn't find it.  It seems appropriate to just put the list on the "reputation" tab of user profile, or at least a prominent link.


Installing libpci-dev library in Ubuntu 18.04.5 LTS (Bionic Beaver)

I am trying to install libpci-dev library in Ubuntu 18.04.5 LTS since I am working on Linux driver stuff that communicates with a board over PCIe. However, using apt-get command I get the following error: $ sudo apt-get install libpci-dev Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  libpci-dev : Depends: libpci3 (= 1:3.5.2-1ubuntu1) but 1:3.5.2-1ubuntu1.1 is to be installed               Depends: libudev-dev (>= 196) but it is not going to be installed E: Unable to correct problems, you have held broken packages.  I tried to run the following set of commands hoping it will fix the dependency issue, but no success: sudo apt-get autoremove sudo apt-get clean sudo apt-get update sudo apt-get upgrade sudo apt-get install -f  I checked the output of this command and there is no error: sudo dpkg --configure -a  I installed synaptic and tried to install the development library from there, however, this is what I get as an error:  So how can I solve this issue? What am I missing? Some additional output to the problem from the commands: apt-cache policy libpci-dev libpci3 libudev-dev zlib1g-dev  libpci-dev:   Installed: (none)   Candidate: 1:3.5.2-1ubuntu1   Version table:      1:3.5.2-1ubuntu1 500         500 http://us.archive.ubuntu.com/ubuntu bionic/main amd64 Packages         500 http://archive.ubuntu.com/ubuntu bionic/main amd64 Packages libpci3:   Installed: 1:3.5.2-1ubuntu1.1   Candidate: 1:3.5.2-1ubuntu1.1   Version table:  *** 1:3.5.2-1ubuntu1.1 100         100 /var/lib/dpkg/status      1:3.5.2-1ubuntu1 500         500 http://us.archive.ubuntu.com/ubuntu bionic/main amd64 Packages         500 http://archive.ubuntu.com/ubuntu bionic/main amd64 Packages libudev-dev:   Installed: (none)   Candidate: 237-3ubuntu10   Version table:      237-3ubuntu10 500         500 http://us.archive.ubuntu.com/ubuntu bionic/main amd64 Packages         500 http://archive.ubuntu.com/ubuntu bionic/main amd64 Packages zlib1g-dev:   Installed: (none)   Candidate: 1:1.2.11.dfsg-0ubuntu2   Version table:      1:1.2.11.dfsg-0ubuntu2 500         500 http://us.archive.ubuntu.com/ubuntu bionic/main amd64 Packages         500 http://archive.ubuntu.com/ubuntu bionic/main amd64 Packages  And for the following command: grep ^deb -r /etc/apt/ --include=*.lis  /etc/apt/sources.list:deb http://us.archive.ubuntu.com/ubuntu/ bionic main restricted /etc/apt/sources.list:deb http://us.archive.ubuntu.com/ubuntu/ bionic universe /etc/apt/sources.list:deb http://us.archive.ubuntu.com/ubuntu/ bionic multiverse /etc/apt/sources.list:deb http://archive.ubuntu.com/ubuntu bionic main


Let $p$ be a prime number and $n, m$ positive integers. I want to find    $\gcd(p^n+1, p^m+1)$  $\gcd(p^n-1, p^m+1)$   I know that  $$\gcd(p^n-1, p^m-1)=p^{\gcd(n,m)}-1,$$ and it seems that if I can solve the first one, then the second one can be solved too, since (assume that $n>m$) $$\gcd(p^n+1, p^m+1)=\gcd(p^n-p^m, p^m+1)=\gcd(p^m(p^{n-m}-1), p^m+1).$$  At last I have  $$\gcd(p^n+1, p^m+1)=\gcd(p^{n-m}-1, p^m+1).$$  So, my problem is     Find $\gcd(p^n-1, p^m+1)$.   It seems to me that it should have some formula which appears in some where, but I can't remember it.


Just installed ubuntu 13.04 and cannot login

I just installed Ubuntu 13.04. I used Wubi so I could have a windows dual boot setup because I am new to Linux and wanted to be able to switch back to Windows (7) if need be.  Everything seemed to install properly.   I entered the initial information: installation size, drive, language, desktop envi, username, and password  I rebooted my computer and selected Ubuntu instead of windows, but when I enter my username and password (the same exact credentials I had typed in for the initial information window a few min. ago) it keeps giving me a wrong password error message.  I can log in via a guest account, but cant do much from that. I cannot connect to the internet except with Ethernet cord. From the guest account I cannot edit user accounts.  [one thing I did notice that I thought was odd is that on the initial information window I mentioned above I remember it saying Ubuntu 12.04 but when I went into thew guest account and clicked system information it said I had Ubuntu 13.04....]  I am new to Linux, but I'm not a computer idiot and do not know what the problem could be??


How to show that the given equation has at least one complex root ,a s.t |a|>12

How do I show that the equation $x^3+10x^2-100x+1729$$=0$ has at least one complex root $a$ such that $|a|$$>$$12$.


Where is the menu to modify newly created objects?

So I've installed the Add Mesh: Extra Objects add-on because I want to make a mesh from a mathematical function.  However, the tutorial I'm following seems to use an old menu that I cannot find in the latest version. It looks like this :    How can I find this menu in the latest version of Blender. I'm new to Blender so any help would be appreciated.


How to check whether a particular directory is mounted?

How to check a particular directory is mounted on the Linux machine. For instance there is a folder named test, I want to check if it is mounted or not.


simple wordpress ajax plugin not working when not logged in

anyone encountered this bug that it will work when you are logged in but once you log out it won't work anymore.  this is a very simple plugin that will fetch zip code and display the corresponding rate.  here's the code.   TIA!


What is the proper way to add or correct a word in another person's quote?

I am trying to add a missing word in another person's quote.  What is the proper way to do this?


Do Tutorials or Practice Tools count as a matchmade game?

I am trying to get out of low priority and they said I needed to play 5 matchmade games without leaving and I would like to know if Tutorial or Practice tool counts as a matchmade game and I would like to know what does count in a matchmade game.


Microsoft Launches Visual Studio for Linux

Today, I read here that Microsoft Launches Visual Studio now support Linux.    but after downloading it here   I have a zip file but I dont know how to install it.  I need help on command to use.


I have a Category entity which has a Nullable ParentId field. When the method below is executing and the categoryId is null, the result seems null however there are categories which has null ParentId value.  What is the problem in here, what am I missing?  public IEnumerable<ICategory> GetSubCategories(long? categoryId) {     var subCategories = this.Repository.Categories.Where(c => c.ParentId == categoryId)         .ToList().Cast<ICategory>();      return subCategories; }   By the way, when I change the condition to (c.ParentId == null),  result seems normal.


can I put 3 new light fixtures and switches on the same breaker

I have a person that wants to wire in four actually  light boxes for ceiling fans with switches and I need to know if I can run all four of them safely from one breaker and if so what kind of breaker? This question may be absurd but I just don't know the answer to it. I do home improvement work for a living at least I have the good sense ask a question before I even attempt something I don't know about.  needless to say I have not done a lot of expensive wiring I have put up plenty of ceiling fans and even ran one circuit very short distance in a garage from a breaker panel and I knew to have the proper testing equipment and to take my time and to ask questions if necessary and also most importantly to have the proper tools and some basic knowledge of how to use them.


E: Malformed entry 1 in list file /etc/apt/sources.list.d/ros-latest.list (Component) E: The list of sources could not be read. Go to the repository dialog to correct the problem. E: _cache->open() failed, please report. W: Ignoring file 'ros-' in directory '/etc/apt/sources.list.d/' as it has no filename extension


Why am I being asked to pay for iPhoto when I already have it?

I just upgraded from Snow Leopard to Mavericks and when I run 'check for updates' in iPhoto it says there is an upgrade available but that I need to pay for it (this was not the case with the GarageBand update)  Why is this happening and how do I get round it?


Is the interval $[0,1]$ equinumerous with $\mathbb{R}$

I recall reading a proof that showed these two sets were equinumerous, but I'm having trouble finding it. Is there any intuitive method to show that they are in fact equinumerous? It seems like since $[0,1]$ is a subset of $\mathbb{R}$ that $\mathbb{R}$ should be larger.


Creating checkbox parameter in Python script tool for ArcGIS Desktop?

I am working on creating an ArcGIS tool from a Python script I am writing.  I am wondering if it is possible to have a checkbox parameter.    I want to have a parameter where the user selects a feature class, then from the feature class the user will choose the field for the upper most layer in their model, then I want the user to be able to choose what layers they want the script to run on with a checkbox structure derived from the upper most layer field.    Is this possible with python, and ArcGIS Desktop?


When answering a question today on SO, I was asked for a . I know it is good practice to have a question with an SSCCE, but how about answers?  As far as I know, an answer doesn't have to provide a complete implementation for a given problem, but at least it should tell how to solve it.  Any thoughts?


Stretch one item to the available height

I've found multiple stack overflow solutions that suggest to use align stretch in order to make one child occupy the rest of the available container height, but can't make it work for now.   P.S: I would like to keep the position absolution on the parent container.        .parent {   position: absolute;   top: 0;   left: 0;   bottom: 0;   right: 0;   height: 100%;   width: 100%;   display: flex;   flex-direction: column;   align-items: stretch;   justify-content: stretch;   background-color: lightgrey; }  .child-1 {   background-color: green;   width: 100%; }  .child-2 {   background-color: yellow;   width: 100%;   align-self: stretch; }

no need to stretch

would be nice to stretch to rest of available height


Trisect a quadrilateral into a $9$-grid; the middle has $1/9$ the area

Trisect sides of a quadrilateral and connect the points to have nine quadrilaterals, as can be seen in the figure. Prove that the middle quadrilateral area is one ninth of the whole area.


Do charges attractions cause time dilation?

I was pondering whether charges will cause time dilatation? Let me explain more, well we know that gravity causes time-dilatation because of gravitational acceleration which is equal to: $$a = \frac{G* m_1}{r^2}$$   That said we can say if we say since the $a$ does not get stronger with time we can say substitute $a$ in Special Relativistic effects so we can get the relativistic results although small it can still show some scientific significance anyhow similarly we can use 2 opposite charges and simply gain the acceleration and we will get $$a = \frac{q_1* q_2* k}{r^2*m_2}$$   This shows that since charges will also have an "charge acceleration" we can also say since the acceleration is constant and does not increase with time we could also substitute into special relativistic environment. to get results, so would this thought process me correct or am I incorrect in saying this?   If so can somebody explain to me what is incorrect assumptions or thought processes?


Do the real numbers and the complex numbers have the same cardinality?

So it's easy to show that the rationals and the integers have the same size, using everyone's favorite spiral-around-the-grid.  Can the approach be extended to say that the set of complex numbers has the same cardinality as the reals?


How to set world wide IP in Ubuntu server?

How can I set an IP that I can have access to my server around the world with the Internet I mean something like global IP (maybe!)?  I just want to know how to do that in Ubuntu server.


Can I reuse part of a paper for my thesis?

I am finishing writing my master's thesis (~100 pages) and I also just submitted a paper (8 pages) to a conference. Since both are on the same subject and I am an author on both, is it ok if I reuse one page from the paper and put it in my thesis without many changes? The paper will not be published until 2013 (if at all). Is it necessary to cite it in any way?


trying to overwrite ... which is also in package

I'm trying to do apt-get install -f -o APT::Immediate-Configure=0 (just apt-get install -f doesn't work currently for me...) which fails with  Unpacking libboost1.46-dev (from .../libboost1.46-dev_1.46.1-7ubuntu3_i386.deb) ... dpkg: error processing /var/cache/apt/archives/libboost1.46-dev_1.46.1-7ubuntu3_i386.deb (--unpack):  trying to overwrite '/usr/include/boost/aligned_storage.hpp', which is also in package libboost1.40-dev 1.40.0-4ubuntu4 dpkg-deb: error: subprocess paste was killed by signal (Broken pipe)   and many similar errors.  There are similar questions (, ) already but the suggested solution is for dpkg and I don't know how to apply that to apt-get.  How can I resolve this?


Which groups have precisely two automorphisms

Which groups $G$ have precisely two automorphisms, i.e., precisely one non-trivial automorphism?  Examples: $G= C_3, \mathbf{Z},\ldots$.  I think $G$ has to be abelian. In fact, we have $ \vert G\vert \geq 3$. Therefore, if $G$ is not abelian, we have at least two non-trivial inner automorphisms.  If we can show that $G$ is cyclic the above examples are all of them.


So on the , I see:   Yet, I was unable to find the normal review button, so I clicked on , it says that:     Note: These two queues do not exist on per-site Metas.   So, my question is why is this even listed as an achievement?


There should be a section for less or inexperienced programmers

I think that it would be highly beneficial for users like myself who are less or indeed inexperienced with programming, to have a section where said user could talk to a professional without fear of being insulted or disregarded when there questions aren't clear. I have had first hand experience of not having the correct terminology or indeed not hitting the topic at all because quite frankly I don't know where to start I don't know how to explain my problems. If there was a section for users to be brought up to a certain level of understanding it wouldn't seem so much like this forum is for seasoned professionals :/


I am using C# to add extended properties to the tables in my database. When I use a SQL editor, this code works, as each statement is on a new line. However, when creating the command as a string in C#, I get 'Incorrect syntax near GO' twice in the same error message. How can I write this out so that c# executes it on seperate lines or in the correct syntax?  USE UserList;  GO EXEC sys.sp_addextendedproperty  @name = N'Description',  @value=N'some text',  @level0type=N'SCHEMA', @level0name=N'dbo',  @level1type=N'TABLE',  @level1name=N'table_name' GO


Maximizing $\int_0^y \sqrt{x^4+(y-y^2)^2} dx$

Q: If $M$ be the maximum value of $$72\int_0^y \sqrt{x^4+(y-y^2)^2}dx$$ for $y\in [0,1]$, then find $\frac{M}{6}$ $$$$ A: $4$  My first thoughts involved differentiating it and equating it to zero, but since the integrand is dependent on the upper bound, I'm unable to do so. Then I thought of actually integrating it, and the trying to find its maximum value, but the $x^4$ is throwing me off track; had it been $x^2$ I'd be able to carry out my thoughts. But since it isn't I'm stuck. Thanks in advance.  Edit: My question is a teeny bit different from ; the solutions there use multivariable calculus, while I'm looking for a solution involving single variable calculus, as I encountered this one while studying for an exam whose syllabus doesn't involve multivariable calculus. Edit 2: Since a user pointed out that this is a possibile duplicate, I edited the question body to show how my question is different from that one, yet the question was marked duplicate.


Stack Overflow webpages are not displayed properly any more

My Opera browser has been unable to display Stack Overflow webpages properly since the other day. See the image. I don't know why. But there is no problem when it opens other webpages like Super User, Stack Exchange. Has anyone ever encountered such a problem?


What does actually occur- ATP is hydrolysed and esterification between glucose and HPO4^2- (formed as a result of hydrolysis) take place to form Glucose-6-phosphate or nucleophilic attack of O- of glucose on ATP leads to formation of ADP and Glucose-6-phosphate?


My code throw NullPointerException in if (encryptedPinBlockKeySerialNumber.length() == 0 && encryptedPinBlock.length() != 0) {             encryptedPinBlockKeySerialNumber = cksn;         }  public void getDebitParameters (String realAmount, String amountPurchase, String pan, String cardName, String expiryDate, String ctrack1,                                     String ctrack2, String ctrack3, String cksn, String devID, String emvICCData, Enums.WSAction intAction,                                     Enums.WSMobileAppTransType transactionType, Enums.WSAccountType accTypeId, String encryptedPinBlock, String encryptedPinBlockKeySerialNumber, boolean fallback ) {           if (encryptedPinBlockKeySerialNumber.length() == 0 && encryptedPinBlock.length() != 0) {             encryptedPinBlockKeySerialNumber = cksn;         }          try {             // with (EPB)EncryptedPinBlock             /* card_action = 1-Swipe, 2-Insert realamount = Double.parseDouble(realAmount);*/             realamount = realAmount;             displayamount = amountPurchase;             cardnum = pan;             track1 = ctrack1;             track2 = ctrack2;             track3 = ctrack3;             cardHolderName = cardName;             date = expiryDate;             ksn = cksn;             strDevID = devID;             emvData = emvICCData;             card_action = intAction;             mobile_app_trans_type = transactionType;             account_type = accTypeId;             epb = encryptedPinBlock;             epbKsn = encryptedPinBlockKeySerialNumber;             isfallback = fallback;         } catch (Exception ex) {             errorOccured();         }     }


Count Frequency of particular words in tex file, e.g. "Hence", "Now"

I would like to find number of occurrence of specific words in a tex file. For example, I need to find out number of "the" used. It is foolish to just "ctrl+F" to find word by word because I am working with a book.  So, I would like to ask if there are any solutions that any commands or extensions can help like: "The total number of "the" is 2345 in the text." (just like the searching function of web browser, Chrome.)  I have been finding old posts but I have found nothing related to my specific problem. I know "texcount" can help the total number of words but it seems it does not suit my current problem.  Thank you in advance.  Here is my example:  \documentclass[12pt,a4paper]{article} \usepackage[utf8]{inputenc} \usepackage{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \begin{document} While psychological knowledge is often applied to the assessment and treatment of mental health problems, it is also directed towards understanding and solving problems in many different spheres of human activity. The majority of psychologists are involved in some kind of therapeutic role, practicing in clinical, counseling, or school settings. Many do scientific research on a wide range of topics related to mental processes and behavior, and typically work in university psychology departments or teach in other academic settings (e.g., medical schools, hospitals). Some are employed in industrial and organizational settings, or in other areas[9] such as human development and aging, sports, health, and the media, as well as in forensic investigation and other aspects of law. \end{document}   So, is there a simple way to sort out number of "the" used in this short paragraph?


DNS Resolution fails, and /etc/resolv.conf isn't persistent, how can I force the use of certain DNS servers?

I have this persistent and annoying issue. When I first boot up, my desktop can't resolve any DNS names unless I edit the /etc/resolv.conf file and remove the entry for name-server 127.0.0.1 and change it to 8.8.8.8  This is only a temporary fix because this file is reset after each reboot.  I googled this for hours and tried multiple solutions but can't find a solution. I think there also might be a bug associated with this issue? Not sure though.  Can someone help?


Why do electrons/photons create an interference pattern in the double slit experiment?

So...if electrons and photons are both particles and they pass the two slits, why do they create an interference pattern as if they were waves? Now from what I've read, it's because of the superposition of an electron and since an electron is in every possible state until observed, it is going through both slits and interferes with itself and that's why, if not observed, the double slit experiment will show that interference pattern.  Now my question is: how can that electron propagate as a wave if it interferes with itself? Shouldn't the outcome of the experiment be the same with or without an observer? I mean...that's just so very extremely counter-intuitive that I can't grasp it...an observation changing the outcome. Why does the observation of the slits change the outcome and not the observation of the screen? Why do we get wave interference even with one slit?  Please correct me if I'm mistaken about how this double slit experiment works cause I've also seen interpretations about the wave nature of electrons and photons and it just made things more complicated for me.


Best methods to solve class imbalance problem and why?

I have a data set where I need to detect fraud. 99% are not fraud and 1% are.  What methods can be used to solve problems where classes are imbalanced?


I lost my Android, am I able to recover my contacts onto the new one?

I lost my galaxy s5 active a day ago and have a next generation phone being shipped. Is there anyway through android or through at&t that I can recover my contacts from my old phone even though it's since been lost and shut off?


Forms display label elements as placeholder

Do you have any solution for this?  I know I can hide labels via template.php but how to add placeholders to some inputs?


What do you call the crunching sound from bone joints?

When I wake up and do stretching I hear some sounds from my joints. What do you call this crunching sound from bone joints?


best way to delete unused apex classes and triggers in production

We currently have around 20 apex classes and 5 triggers which are not used in our production org. We want to delete them in our production instance. We dont have ant scripts ready yet to be used for our deployments and so we cannot use destructivechanges file. Currently our production deployments are done by our support team and they need documentation from us to do these deletes. Changesets do not allow to delete apex classes and triggers. So what is the best way to delete these apex classes and triggers from production?


I'm compiling with XeLaTeX and in my document, when I put \Chi, or \Alpha, or any normal symbol it raises the error Undefined control sequence This is my preamble:  \usepackage[utf8]{inputenc} \usepackage{fontspec} \usepackage[spanish]{babel} \usepackage[left=3cm, right=2cm, top=3cm, bottom=3cm]{geometry} \setmainfont{Arial} \setmonofont{Inconsolata}   Update: I added \usepackage{unicode-math}, now there is no error but in the PDF there is a white space (Because Arial doesnt have greek letters). How can I set a different font for unicode-math?


I want to make a slowly waving(?) flag, but it must be a loop, and i don't know how to do it :( Help me please  P.S. Also interested in making more realistic material with cycles, but that's not necessary


How can add non English characters in Mysql Using php

I can insert some non English languages (indian languages) such as hindi malayalam etc.It display properly in PHPMYADMIN page. But when I open my webpage it appear as question mark. How can I fix this error .. I tried the old answer which marked as duplicate but which is not working properly


Share long proofs in beamer to many frames

Hi everyone please I am writing a proof in beamer with \begin{proof} \end{proof} but the proof is too long so I can't have it in one frame, I wanted to share the proof to many frames but it didn't work. Thanks for helping.


Future.get() method results in null pointer exception

I have rest call, it will returns the values based on the start and end parameters. For ex: if total records are 1000, so there would be 10 rest calls each call returns 100 records.  I already seen this link, but no luck :(    For this I am calleble interface for restcalls:     ExecutorService executor = Executors.newFixedThreadPool(iterationCount);     List<Callable<Response>> callables = new ArrayList<Callable<Response>>();       MyTask e = new MyTask(//necessary params);              callables.add(e);     try {         List<Future<Response>> futures = executor.invokeAll(callables);         for (Future<Response> future : futures) {             if(!future.isDone()) continue;             if (future.get().getAccessoryModelSpecs() !=null) {                 returnValue.addAll(future.get().getObjects());             }         }     } catch (InterruptedException | NullPointerException e) {         // TODO Auto-generated catch block         e.printStackTrace();     } catch (ExecutionException e) {         // TODO Auto-generated catch block         e.printStackTrace();     }   My callable class     public class MyTask implements Callable<Response>{   public GetAccessoryTask(params) {  }  @Override public Response call() throws Exception {     return connectSvc.getRessponse(params); }  }   So here I am getting 10 callable objects and 10 future objects. even I checked that callable objects are not null. but,      future.get()   call results in Nullpointer exception.  if I call the service method one by one 10 calls I am getting correct results that is 100 objects each time, but it's taking some long time. So reduce that time I have used this logic.  How to resolve this error? Thanks in advance!!!


Admission to graduate school for physics

I am a dual major (Math+Physics) student from one of the reputed Indian University. I want to peruse PhD in physics (mainly theoretical/High Energy Physics). I have CGPA 9.6/10 in Physics but overall (Math+Physics) CGPA is 8/10. How do I improve my CV to get into good grad school in US/Germany etc? Any helpful comments/answer are welcome and thanks for that.


How many connected components does $\mathrm{GL}_n(\mathbb R)$ have?

I've noticed that $\mathrm{GL}_n(\mathbb R)$ is not a connected space, because if it were $\det(\mathrm{GL}_n(\mathbb R))$ (where $\det$ is the function ascribing to each $n\times n$ matrix its determinant) would be a connected space too, since $\det$ is a continuous function. But $\det(\mathrm{GL}_n(\mathbb R))=\mathbb R\setminus\{0\},$ so not connected.  I started thinking if I could prove that $\det^{-1}((-\infty,0))$ and $\det^{-1}((0,\infty))$ are connected. But I don't know how to prove that. I'm reading my notes from the topology course I took last year and I see nothing about proving connectedness...


Texlive 2014 on Ubuntu 14.04: Font WebOMintsGD not found

I upgraded to Texlive 2014 on Unbutu 14.04 and after this I'm getting this error (for some files):     !pdfTeX error: pdflatex (file WebOMintsGD): Font WebOMintsGD not   found   I would highly appreciate if someone help me to figure out this problem. Thanks  Edited  I asked the question which is liked as duplicated. At Texlive 2014 on Unbutu 14.04, I'm not able to fix the problem      !pdfTeX error: pdflatex (file WebOMintsGD): Font WebOMintsGD not   found   even after install the required fonts. Any help will be highly appreciated. Thanks  I found this  but still struggling.  I used getnonfreefonts-l to check the installed fonts and this command shows Webomints font in this list. Even then I'm getting the same error (Might be in different directory, looked  for the same problem where fonts were in different directory). I'm not very expert and struggling with it. Any help will be highly appreciated. Thanks


Harmonic numbers, proof that h2^k >= 1+(k/2) with induction

I'm just starting with the concept of proving mathematical statements with induction.  The complete exercise with solution can be found under:    I'm struggeling with the translation from step 4 to step 5.  According to the notes its because we have 2^k elements (I got that part) which are >=1/2^(k+1) since its the smalles number.  However the part I don't understand is why we are using 1/2^(k+1) and not 1/2^k+1. shouldn't we calculate with the bigger number since we want to prove that H2^(k+1) is bigger than that?   Our tutor explained, that you are allowed to do the following:  H2^k+2>= 1 + k/2 + 1/2^k+1+...+1/2^(k+1) >= 1+(k+1)/2 and because of that you have to use the smaller term. However that education is not prooven as far as I get the concept, or am I wrong?  Any help is much appriciated!


What's the name of this "barcode-like" graph (used for visualizing spread in data)?

Is there any specific name for the barcode-like graph shown above?  The vertical axis does not correspond to any number and (as far as I can tell) the graph only serves to illustrate spread in the data.    The graph appears in the  in nonlinear time series analysis.  The numerous short impulses represent the test statistic computed under the null hypothesis.  The single long impulse near the center shows the observed value.  (Obviously, one cannot reject the null hypothesis here.)  The mean (cross $\times$) and the standard deviation (of the null distribution) is represented by the horizontal line.


I have been seeing this a lot at work and at home. At home, a single device will not obtain an IP from the DHCP so it self assigns an IP in the 169.xxx.xxx.xxx range. If I put in a static IP it works most of the time. I only have that issue with that specific laptop at home. ANYWHERE else it works fine.  I have also seen this a work with Windows 8 surface tablets. I can connect a students surface to our open network but not any of the 4 secure networks we have set up.   In both situations I have tried 'ipconfig /release' and 'ipconfig /renew' Release tells me that it can be performed because no media is connected and renew just sits there and doesn't renew the IP at all.


Removed msftdata partition from a live Lubuntu USB. Is it safe?

I have an 8gb USB stick with Lubuntu 18.04 installed on it. It was created with mkusb and has persistent storage filling up maximum possible area. At some point I needed more persistent storage capacity, so I'm trying to clone the entire installation to a larger stick, using .  While the "dus" part of that answer completes nicely, resulting in a bootable 1-to-1 copy on the new stick, the "gparted" part later on gives me some trouble.  The  contains a small partition /dev/sdb1 situated at the end, flagged "msftdata". In order to resize the casper-rw one, I guess I need to move this one to the end of the new stick also, so that casper has the room to grow. The problem is, gparted seems to have some issues with this little partition and refuses to move it on the new stick. Deleting it seems to be the only way gparted is able to touch it.  My question is, what is this small partition all about, what does it do, why is it there, what can I break by deleting it?  In fact I did some experimentation with deleting it on the new stick, then growing casper to a suitable size. The clone still boots, all seems normal, but I'm wondering if I'm facing any risks later on after removing this little guy.  Here's  from gparted concerning the partition in question.


How to have an auto incrementing version number (Visual Studio)?

I want to store a set of integers that get auto incremented at build time:  int MajorVersion = 0; int MinorVersion = 1; int Revision = 92;   When I compile, it would auto-increment Revision. When I build the setup project, it would increment MinorVersion (I'm OK with doing this manually). MajorVersion would only be incremented manually.  Then I could display a version number in menu Help/About to the user as:     Version: 0.1.92   How can this be achieved?  This question asks not only how to have an auto-incrementing version number, but also how to use that in code which is a more complete answer than others.


Can't render fire effect on transparent background

I am trying to render a fire effect on a transparent background for a PNG sequence (Cycles). I'd like to add it to a video in After Effects.  2 problems I'm experiencing:   renders always on black background (Although I checked box 'Transparent' in 'Film' in Render Settings, and set to RGBA I got the fire effect to render (I had to switch to CPU for it to work), but it appears almost not visible, with dots around it. Do you know why it appears so dull and where the dots are coming from? (screenshots attached) I added a light in the scene to make the fire more visible although I don't even know if that's necessary for rendering fire..   Any advice and feedback would be appreciated. I'm kinda stuck here :)  PS: i'm a total Blender newbie  cheers :)


Derived functor not called when passed as template parameter

I am using a pattern in my program that calls for the calling of different kinds of functors depending on what the object type is. In the code below, the b1 object is explicitly instantiated with derived functor type FunctorX. But when I make the call in the code, the base functor gets called instead of the derived functor. Why is that?  struct Functor {   Functor() {}   ~Functor() {}    virtual int operator()() { return 33; } };  struct FunctorX : public Functor {   FunctorX() : Functor() {}   ~FunctorX() {}    int operator()() { return 44; } };  template< typename FunctorT > struct B {   B( FunctorT FunctorArg ) : Functor { FunctorArg } {}   ~B() {}    FunctorT Functor; };  int main() {   B< Functor > b1 { FunctorX() }; // initialize with derived functor. Derived functor gets instantiated.   int num = b1.Functor(); // error: calls base functor, not derived functor    return 0; }


How do I manually adjust the space between a symbol and the plus sign in amsart?

I found that  seems to deliberately create space between a symbol and the plus sign. But sometimes I do not need the space, say   \documentclass[12pt]{amsart} \begin{document} \[ f(x) \to l \text{ as } x \to a+. \]  \end{document}   How do I resolve this problem?


Territory lost through Vassal Inheritance - what should I have done?

I'm confused.  As the King of Aquitaine, I had a vassal Countess of Foix. Her heir was Count of a single county in France (both nations are Elective Gavelkind). I had a Vassal Inheritance Warning, which makes sense; when the countess dies, her title would pass to her heir, who would add it to his French title, that being older.  So I created the Duchy of Toulouse and granted it to my Countess of Foix. I figured that this way, when she died, both titles would pass to her heir, and he'd bring his French county to over to join his higher Aquitainian Dukedom.  But when Comtesse du Foix / Duchesse du Toulouse kicked the bucket, I lost Foix to France, and another vassal held Toulouse. Is this an effect of the succession laws? Did one title pass to one heir, and the other to another heir? Could I have seen that, and prevented it somehow?


Comparing String with It's Reference by "=="

Recently I have seen a code like this -   class Test{         public static void main(String[] args){                  String s1 = "String1"; //1                 String s2 = new String("String2"); //2                  System.out.println(s1.equals("String1"));                 System.out.println(s1=="String1"); //3                  System.out.println(s2.equals("String2"));                  System.out.println(s2=="String2"); //4         } }   and the out put is -   true true true false   So far I know, at point 1 "String1" is placed in String pool and assigned with String type reference variable s1. Isn't there any String object created?  We know a new String object is created at point 2 and at point 4 the expression (s2=="String2") evaluated to false. If a new String object is created at point 1 then how the expression at point 3 (s1=="String1") evaluated to true. And if a new object is not created at point 1 how the expression at point 3 (s1=="String1") evaluated to true?  Thanks in Advance


Advice for installation on Probook 450 G

I would like to install Ubuntu 14 on my new HP Probook 450 G2 with windows 7. At the step "Installation Type", I don't have the choice "Install Ubuntu alongside Windows 7". I looked at the choice "something else" but I don't understand well what to do.  When I try Ubuntu on my USB live it works well. And the hard drive is divided like this: sda1 : system sda2 : HP recovery sda3 : HP tools.  Do you know why I don't have the choice "Install Ubuntu alongside Windows 7" and how to do a not too comlicated installation? Moreover do you know any problem with this model of computer or this brand?  Thanks  Marcel


There is no X button and i tried to open the "Preferences" menu and when I tried to close it I somehow opened 12 of them. I somehow managed to close 1 of the menus but I did it by accident and I couldn't do it again.


hdd issue in my ubuntu as well as in windows 8 too

i have a 1TB external hdd but its showing some error in ubuntu   Error mounting /dev/sdc1 at /media/ubuntu/NAPSTER: Command-line `mount -t "ntfs" -o "uhelper=udisks2,nodev,nosuid,uid=999,gid=999,dmask=0077,fmask=0177" "/dev/sdc1" "/media/ubuntu/NAPSTER"' exited with non-zero exit status 14: Metadata kept in Windows cache, refused to mount.  Failed to mount '/dev/sdc1': Operation not permitted  The NTFS partition is in an unsafe state. Please resume and shutdown Windows fully (no hibernation or fast restarting), or mount the volume read-only with the 'ro' mount option.


As of  we can crop images by using something like \documentclass{article}  \usepackage{graphicx}  \begin{document} % trim from left edge \includegraphics[trim={5cm 0 0 0},clip]{myImage.pdf} \end{document}  in order to crop away the left 5cm of our example image. In my example it would be really neat if I could use relative crop directions instead of absolute ones (e.g. crop a way 10% from the left, 25% from the top, etc.). Is this possible? And if so: how? Unfortunately the documentation of the graphicx package is not very verbose when it comes to the trim option (at least as far as I have found). In case it's relevant: I am looking for an option that works with PDF files included as images.  Note that I found  that explains how the effect can be achieved by using a savebox to query the image's dimension first. I am hoping for a solution where this is automated in the background so I don't have to do this every time...


What's the difference between the apt packages: 'cinnamon' and 'cinnamon-desktop-environment'?

I have a fresh Ubuntu install and want to install Cinnamon as the desktop environment. When I do apt search cinnamon, I get multiple results, but two seems like they are the correct one.   The first is just   cinnamon/xenial 2.8.6-1ubuntu1 amd64 all     Innovative and comfortable desktop (Common data files)   while the other is   cinnamon-desktop-environment/xenial,xenial 2.8.0 all     Cinnamon desktop environment - full desktop with extra components   What's the difference between the two? What does the cinnamon-desktop-environment package contain that the cinnamon doesn't?


I have this assembly file bits 32 global _start extern kmain  section .text _start:     cli     call kmain     hlt  And this .cpp file void kmain(void) {     }  And when running these commands: nasm -f elf32 asmfoo.asm -o asmfoo.o gcc -m32 -c cppfoo.cpp -o cppfoo.o ld -m elf_i386 -T ./linker.ld -o foo-output asmfoo.o cppfoo.o   I get this error: ld: asmfoo.o: in function `_start': asmfoo.asm:(.text+0xe): undefined reference to `kmain'  But when I change the name of the cpp file from cppfoo.cpp to cppfoo.c and run the same compile commands it works without any errors. So how would I call a c++ function from assembly as this doesent work with c++ for some reason.


Why is there a different opacity in my xray?

so I'm making a car in blender when I noticed a weird opacity on my mesh while in X-ray mode, why is it there? can I get rid of it? and how can I prevent it from happening?


How to Pass an Argument into ElapsedEventHandler

I am trying to pass an integer value into a ElapsedEventHandler so I can do logic based on the integer passed in. However, when the Event is raised, the value coming in is not the value I initialized it to. I may not be understanding completely how the delegate works.  class Example {     Dictionary<int, Timer> timer;      public Example()     {         timer = new Dictionary<int, timer>();         for(int i = 0; i < 12; ++i)         {             timer.Add(i, new Timer(5000));             timer[i].Elapsed += delegate { TimerTickCustom(i); };         }     }     public void Process() // called each cycle     {         for(int i = 0; i < 12; ++i)         {             timer[i].Start();         }     }     private void TimerTickCustom(int i)     {         // The value of i coming in does not match the dictionary key.     } }


Don't display pending edit counter if you've exhausted your suggested edit votes

Once a user has exhausted their (currently) 30 edit suggestion approval/rejections, the pending edit box in the top bar can still show up:    You click through and see some edits suggested to vote yay or nay on.   But when trying to approve/reject you get the warning:      Out of votes - you may only vote 30 times a day.   Don't tease me, bro!


What is the "Bootable flag" option when installing a distro?

Is the "bootable flag" needed in today's distributions? If not, then why is it still in the installers? What is it exactly?


Why is it true that $\mathrm{adj}(A)A = \det(A) \cdot I$?

This is a statement in linear algebra that I can't seem to understand the proof behind.  For a square matrix $A$, why is: $$\mathrm{adj}(A)A = \det(A) \cdot I$$  Any explanation would be greatly appreciated.


Missing score in Top Users section of a tag

I was looking at the Top Users page on  and I saw that it showed that in the past 30 days I had answered two questions for a total score of 3:  This seemed odd, as I had recently answered a question in this tag that has a score of +7 (i.e. more than the total of all my answers in the past 30 days according to the listing). At first I thought that it might not be counting my most recent answer (i.e. the system might only update every so often and it had not updated since my last answer), and indeed in  it is claimed that it gets updated at midnight UTC. However, if you don't count my most recent answer then I have only one answer within the last 30 days. As you can see in my profile, my previous answer in this tag (prior to the one that is definitely being counted) was back in August, which is well more than 30 days ago:  The Top Users listing must necessarily then be counting my most recent answer, and it is counting it as having a score of +1. I then thought that perhaps if it updated at midnight then it might have only had +1 at midnight with the other upvotes coming on the next day. However, the timeline of the answer shows that all the upvotes came on the same (Stack Exchange) day:  In fact, if you look at the timestamp of the answer you can see that it was posted less than two hours after midnight. I am almost 100% certain that more than one of the upvotes came within the first 22 hours. It is also worth noting that it seems to be only the "Last 30 Days" column that has this issue; the "All Time" column lists my score as 292, which seems to be up to date as that is what it shows in the tag page of my profile:  So, is there a bug in the calculation of score for Top Users? Or is there some other calculation of the updates that explains how it would have been updated when there was only one upvote on the answer?


how to update mactex from 2016 to 2017 the correct in macos sierra?

system:   macos sierra 10.12.5 mactex 2016 default installation   Thank you.


How to disable select and activate and return to just select tool

How to disable the select and move tool  and return to just select tool in the blender interface  I'm using Blender 2.8 on Ubuntu 18.04 with default settings.


Most JS buttons on SE and SO stopped working this weekend

I use Stack Overflow and the related sites on a semi-daily basis. Today I found that the following no longer works (the buttons do nothing):   "Log in using Google" on at least rpg.se (I can work around this by clicking "More login options" and filling in the OpenID in the text box) The StackExchange drop-down and the two icons to the right of it on the top toolbar on rpg.se and workplace.se   The icon to the left of the URL showed a warning sign for workplace.se and tex.se in Firefox. When clicking it I got a "This website does not supply ownership information." message. After reloading using Ctrl-Shift-r the icon changed to the familiar lock on workplace.se, but not on tex.se. The voting buttons now work on both sites, so maybe this is unrelated?  I'm currently using HTTPS Everywhere. Is there a known issue with this?


If we consider two implementations below, what's the actual use of the first one?  List<String> a= new ArrayList<String>(); ArrayList<String> b= new ArrayList<String>();   From what I have read in the posts, the first implementation helps in avoiding breaking change like we can change the implementation again as   a=new TreeList<String>();   But I don't understand whats the actual use of changing the implementation with treelist as we can use only the List interface methods?


If $\frac{a}{b}<\frac{a'}{b'}<\frac{a''}{b''}$, with all values positive, then $\frac{a}{b}<\frac{ab+a’b’+a’’b’’}{b^2+b’^2+b’’^2}<\frac{a’’}{b’’}$

Bonjour. I need help for this.     Let $a$, $b$, $a^\prime$, $b^\prime$, $a^{\prime\prime}$, and $b^{\prime\prime}$ be six non-zero positive numbers such that    $$\frac{a}{b}<\frac{a^\prime}{b^\prime}<\frac{a^{\prime\prime}}{b^{\prime\prime}}$$    We want to prove that this stuff holds:    $$\frac{a}{b}<\frac{ab+a^\prime b^\prime+a^{\prime\prime}b^{\prime\prime}}{b^2+{b^{\prime}}^2+{b^{\prime\prime}}^2}<\frac{a^{\prime\prime}}{b^{\prime\prime}}$$   Thanks.


Is it possible to fit a chain guard to a bike with derailleur gears?

I've been slowly going through the process of converting my old hardtail mountain bike into a commuting bike. One of the things that I'd like to do is to fit a chain guard so that I can ride the bike while wearing long trousers and not have to worry about chewing up the trouser cuffs.  A complication is that the bike (like most mountain bikes) is fitted with both front and rear derailleur gears. I'm not keen to replace these with an internally geared hub system as I have been trying to keep the changes relatively modest in their cost.  Are there chain guards that you can add to bikes with derailleur gears?


Proof that the nth root of a rational s/t is irrational unless s and t are perfect nth powers

I'm trying to prove that $\sqrt[n]{\frac{s}{t}}$ is irrational unless both s and t are perfect nth powers. I have found plenty of proofs for nth root of an integer but cannot find anything for rationals. Also trying to work up from the proofs I have found is rather difficult.  My lecturer wants me to prove this using uniqueness of prime factorisation but I also have no idea where to start with that.   Any help is greatly appreciated.


How can subtract 2 floats which have been extracted from 2 other files with BASH

I'm trying to get the difference between two numbers which I have taken from two files. I think my code will make sense:  I've tried to make it work by two different methods, didn't work. What I get as an output is zero (0).  #method 1 difference_btwn_eng_hrs_MX3_122=$(($(sed -n '1p' engine_hours_new_MX3_122.txt)-$(sed -n '1p' engine_hours_old_MX3_122.txt))) echo "$difference_btwn_eng_hrs_MX3_122"  #method 2 new=$(sed -n '1p' engine_hours_new_MX3_122.txt) old=$(sed -n '1p' engine_hours_old_MX3_122.txt) echo "$new $old" | awk '{print $new - $old}'   Eventually I will use the difference to set intervals for email updates.  The values inside the files are 511.786 (new) and 509.768 (old), and the error I get from the terminal is as follows:  line 40: 511.786-509.765: syntax error: invalid arithmetic operator (error token is ".786-509.765")


I get confused about how to use "a" and "an" correctly. The question of "a" vs "an" should be decided by the pronunciation of the word that follows the article, right?  But I've seen the following sentences on the internet.   {Alternatives to the TOEFL (ACT, SAT, IELTS)—Minimum Score Requirements An ACT English subscore of 21 An SAT Critical Reading score of 540 An IELTS (International English Language Testing System) total score of 6.5, with no subscore lower than 6.0}  I wonder why "an" is used in the sentence "An SAT Critical Reading score of 540". Shouldn't we say "A SAT Critical Reading score"?  Another example, in the following sentence: {The minimum English language requirement of this position is an TOEFL ibt score of 90.}  Shouldn't we say "a TOEFL ibt score" rather than "an TOEFL ibt score"?


Worldwide Dissertation Database? or French, German, Italian ones?

Is there a global/worldwide database of dissertations? If not, how can I access French, German, Italian, etc. dissertations online?


Django - ordering multiple models by date created

So far, this is my models.py page:  from django.db import models from datetime import date from django.conf import settings  class Star(models.Model):      thumbnail = models.TextField()     title = models.CharField(max_length = 200)     description = models.TextField()     star_power = models.TextField()      def __str__(self):         return self.title  class recent_update(models.Model):      title = models.CharField(max_length = 200)     description = models.TextField()     video = models.TextField()     date = models.DateField(("Date"), default=date.today)     ordered_videos = recent_update.objects.order_by('-created_date')      def __str__(self):         return self.title   yet my terminal says that recent_updates is undefined. I need to organize the model content so that the most recent model created comes at the top of the page; the oldest model goes at the bottom of the page.


How to use force:createRecord for a stand alone app or lightning out?

I'm trying to use force:createRecord and it works okay in Lightning Experience, and S1 but but I get the following error message when I am using a stand alone app. If I preview the "sampleCreateRecordApp.app" I get the below error message:     "This page has an error. You might just need to refresh it. Action   failed: c:sampleCreateRecord$controller$createRecord [Cannot read   property 'setParams' of undefined] Failing descriptor:   {c:sampleCreateRecord$controller$createRecord}"   Below is the simple compoment I'm trying to get to work in a stand alone app (or lightning out). The   alludes that they can be used outside of LEX or S1   If I try to extend the application with extends="ltng:outApp" the application does not render at all. Any advice would be great. Thanks!  sampleLightningOutPage.page  <apex:page >       <script src="/lightning/lightning.out.js" />     <div id="sampleComponentDiv" />          <script>          $Lightning.use("c:sampleCreateRecordApp",function() {             $Lightning.createComponent(                 "c:sampleCreateRecord",                 {},                 "sampleComponentDiv"             );          });     </script> </apex:page>   sampleCreateRecordApp.app  <aura:application >     <c:sampleCreateRecord/>  </aura:application>   sampleCreateRecord.cmp   <aura:component implements="flexipage:availableForAllPageTypes">     <lightning:button variant="brand" label="Submit" onclick="{! c.createRecord }" />   </aura:component>   sampleCreateRecord.js  ({     createRecord : function (component, event, helper) {         var createRecordEvent = $A.get("e.force:createRecord");         createRecordEvent.setParams({             "entityApiName": "Contact"         });         createRecordEvent.fire();     } })


I've made a big mistake of rebasing a branch into master instead of the master into branch. So now instead of having changes of master in a branch, I have master that's out of sync with remote repo.  How can I take changes back?


RegEx to match only {n} digits and not much or less surrounded by whatever

I'm trying to match only {n} digits not more or less and may be surrounded by characters or special symbols  example: suppose the {n} = {14}   *12345678901234*300 OK  12345678901234x21 OK  *123456789012345*300 NOT OK  12345678901234 OK  123456789012345 NOT OK


I have a 250G disk on my Mac with around 100G in use. But the system reports only around 20G of free space. I'm using macOS 10.13.2. I have the problem at least since the upgrade to High Sierra, but probably also before.  "About This Mac" --> "Storage" reports that "System" is using around 180G. But if I check the complete disk, it looks like that:  $ sudo du -cxhd 1 /   0B    /.HFS+ Private Directory Data 1.0K    /home 4.3G    /usr 4.2G    /.Spotlight-V100 1.0K    /net  34G    /nix   0B    /.PKInstallSandboxManager   0B    /.PKInstallSandboxManager-SystemSoftware 2.6M    /bin   0B    /Network 1.1M    /sbin 3.8G    /Library   0B    /.Trashes 6.5G    /System 476K    /.fseventsd du: /private/var/db/ConfigurationProfiles/Store: Operation not permitted du: /private/var/folders/z7/[...]/0/SafariFamily: Operation not permitted du: /private/var/folders/z7/[...]/0/com.apple.LaunchServices.dv: Operation not permitted du: /private/var/folders/z7/[...]/0/com.apple.nsurlsessiond: Operation not permitted du: /private/var/folders/z7/[...]/0/com.apple.routined: Operation not permitted du: /private/var/folders/zz/[...]/0/com.apple.nsurlsessiond: Operation not permitted 8.0G    /private 8.6M    /.DocumentRevisions-V100   0B    /.vol  32G    /Users  11G    /Applications 207M    /opt 5.0K    /dev 4.0K    /Volumes   0B    /cores 104G    / 104G    total   df also says that only 20G are available:  $ df -h / Filesystem     Size   Used  Avail Capacity iused               ifree %iused  Mounted on /dev/disk1s1  234Gi  211Gi   20Gi    92% 4019132 9223372036850756675    0%   /   Any tool I was using (Finder, Disk Inventory X, etc.) shows more or less the same numbers like df and du.  Output of mount:  $ mount /dev/disk1s1 on / (apfs, local, journaled) devfs on /dev (devfs, local, nobrowse) /dev/disk1s4 on /private/var/vm (apfs, local, noexec, journaled, noatime, nobrowse) map -hosts on /net (autofs, nosuid, automounted, nobrowse) map auto_home on /home (autofs, automounted, nobrowse)   I read and tested many, many things like:         ... but with no success. So what could consume more than 100G of disk space without showing up in any tool?  Update  Running „First Aid“ in recovery mode:   What does this error message mean?  error: btn:1: invalid key order (1) oid 440198 / oxid 114577 fsroot tree is invalid.   Update 2018-01-25  Another report of the same error:  (but no answers, yet)  I'm pretty sure this file system error is the root cause for the missing disk space. But I have no idea how to fix that. I was hoping that 10.13.3 would maybe solve it, but it didn't change anything. I guess I need to reinstall...


Extract dateTime from Google Calendar with different Format

My problem is the OutPut that Google Calendar's code gives me. If I tell my program to output the next 10 events in a label he shows me only the last (ins't the problem itself though) like :  Event YYYY-MM-DDTHH:MM:SS.Z which would be okay, but I need it to look something like:  Event DD MM (preferably formatted as ('%a %d') 'cause the year is obvious).  WHAT I KNOW  In google's code is this:  for event in events:     start = event['start'].get('dateTime', event['start'].get('date'))   the problem occurs (I think) in the  .get('dateTime' I did a print (events) and besides a bunch of useless code I got this: 'start': {'dateTime': '2018-04-03T15:30:00+02:00'}, 'end': {'dateTime': '2018-04-03T16:30:00+02:00'}. Supposedly when I print the events I print that section of 'dateTime' as it's written there.  Now, how do I tell python to print ONLY the ninth, tenth, sixth and seventh character from the dateTime he extracts?  If any clarification is needed please tell me.


Set Theory - Elementary Question on Empty Sets

Ok so we are going to begin looking at Set theory next week in class so I thought I would try to learn a bit about it before we start. I am curious and perplexed by $(A \cap \emptyset)′$ in regard to what it can be simplified to as when using the rules of set theory.   For example if I have $U$ and $A$, $B$ are both subsets does that mean that $(A \cap \emptyset)′ = U$ or does  $(A \cap \emptyset)′ = (A)'$?  If anyone can please provide some insight that would be much appreciated.


In D&D 5e after the errata it was clarified that monks unarmed attacks are not weapons. But in saying that, they are melee weapon attacks which is a form of a weapon attack.  My question is for spells like Divine Favor or Ensnaring strike that specifically state "your weapon attacks" or "hit a creature with a weapon attack" do they work and buff your unarmed attack?  I know a buff spell such as Magic Weapon won't work as you specifically improve the stats of a "non-magical weapon".  There's just no clarification for whether or not these spells definitively work that I could find.


Intermediate code generated in visual studio

As why Intermediate code is needed is described in ,my question is that,  Is the intermediate code saved in the solution ?  How can I view the whole IL generated ?    Reflector and the File Disassembler add-in from Denis Bauer. It actually produces source projects from assemblies, where Reflector on its own only displays the disassembled source and not Intermediate Code.


If you are talking "on behalf of" you and someone else, what is the correct usage?

If you are talking on behalf of you and someone else what is the correct usage?  On behalf of my wife and me On behalf of my wife and I On behalf of me and my wife On behalf of myself and my wife On behalf of my wife and myself ...  My understanding is that after that phrase you would carry on talking in first person.


What means "CDF of one group does not cross the CDF of the other" from the dunn.test description?

From the dunn.test manual: "CDF of one group does not cross the CDF of the other". What this means? I am not a statistician, but I want to understand. What I found using a Google search not helped me very much :(.


Recommendation of a good real analysis book on several variables

I have put myself in the task of looking for a book of real analysis in several variables that has a solid theory in critical points and theory of maximums and minimums (convex functions, Hessian, etc.) but I have not found a good text that has the proofs of the theorems on critical points, I would like you to recommend a good bibliography at the undergraduate level


Changing the default parameters of new meshes

In 2.79 it was easy to change the default parameters of new meshes added to a scene, e.g. number of edges on a UV sphere. In 2.82 I have been tearing my hair out trying to find similar options. Have they disappeared?


I am trying to explicitly compute the Galois group of $x^4-2$ over $\mathbb{Q}$. I found that the resolvent polynomial is reducible and the order of the Galois group is $8$ using the splitting field $K=\mathbb{Q}(2^{1/4}, i)$. Hence I need to find 8 automorphisms. Thus do I just map elements of the same order to each other that fix the base field $\mathbb{Q}$ $2^{1/4}$ to $i2^{1/4}$


What is the difference between fglrx* and fglrx?

Is there a difference between fglrx* and fglrx?  What is the meaning of * if added??  I did use the following steps because I was not sure whether I've had a graphic driver or not. So I wanted to activate a driver...    Then many problems occured - like changes of the quality of the desktop environment - and I wanted to know if they happened because of the difference of *?  I am a new Ubuntu 12.04 user. Was it wrong to have purged fglrx*? I also get this error each time I boot Ubuntu since then:     The disk drive for /dev/mapper/cryptswap1 is not ready yet or not present   I would be really glad if someone could help me out!


For $x\in\mathbb{R}$ find minimum of $P$.  $P=\dfrac{\sqrt{3(2x^2+2x+1)}}{3}+\dfrac{1}{\sqrt{2x^2+(3-\sqrt{3})x +3}}+\dfrac{1}{\sqrt{2x^2+(3+\sqrt{3})x +3}}$  Source : Viet Nam national test for high school student.   I can't slove this problem.


What's the difference between `type a[]` and `type[] a` in JAVA

I tied the following, it seems that there's no difference  import java.math.BigInteger; import java.util.Random; import java.util.Scanner;   public class Main {      /**      * @param args      */      final static int MAXN = 100005;        public static void main(String[] args) {         // TODO Auto-generated method stub         int n = 100;         BigInteger[] a = new BigInteger[n];         BigInteger b[] = new BigInteger[n];         for (int i = 0;i < n;i++){             a[i] = BigInteger.valueOf(i);         }         b = a;         for (int i = 0;i < n;i++){             b[i] = BigInteger.ZERO;         }         if (a == b){             for (int i = 0;i < n;i++){                 System.out.println(a[i]);             }         }     }  }


How to set Unity directly delete files on sda without possibility of recycling

I need to delete two Oracle VirtualBox snapshots from /dev/sda because it is running out of space.  Unfortunately there is even not enough space to remove them by VirtualBox Manager. It seems to me it is because VirtualBox Manager uses the trash function of Unity and this function does not enough space to move the file for recycling purpose.  How to   change my Trash folder from /dev/sda to /dev/sdb or somewhere else where there is enough space to save the recyclable files or how to disable this feature for /dev/sda where the OS and VirtualBox are located.   After fixing this issue, hopefully with some good answers here, I am going to move the default snapshot directory for this machine on /dev/sda where there is more space available.


What is the correct output (meaning correct by the ECMA standard) of the following program?  function nl(x) { document.write(x + "<br>"); } nl(Function.prototype); nl(Function.prototype.prototype); nl(Function.prototype.prototype == Object.prototype); nl(Function.prototype.prototype.prototype);   Chrome and IE6 agree in saying:   function Empty() {} null for Chrome / undefined for IE6 false   and then crashing.  Mozilla outputs:  function () { } [object Object] false undefined   Are either of these correct? It seems that the Mozilla one does better, but that the best output is  function () { } [object Object] true undefined


wish sentence with past perfect ... before going

Seonaid! I often use your  It is very helpful. Now I need your personal help. Please can you help me? I am an English teacher and I have a question about something, which I don't know/ understand. This is a sentence from a test: Complete the sentence with the correct form of the verb. Don't you wish you ....................... a year off before going to university? (take) The correct answer is had taken, according to the test key. My question: How do we know, that here we speak about past situation? Otherwise we could use also  took. This is form English in Mind, book 4, entry test, Cambridge, by Sarah Ackroyd. I live and work in Bulgaria, in a small town. If my students ask me this question I do not know what to say. Please, write me soon. Krasimira Kuzeva facebook: Krasimira Kuzeva Kripadhara


Why there are so many upvotes for a simple answer?

I am a regular user of stack-overflow, i have seen members up voting small answers which takes minimum amount of time to identify the problem and solved, whereas the answers which took lot of effort and time receives only one or two up votes, sometimes there won't be up votes too.Why users are not willing to up vote answers which deserves upvotes?


Did Sauron's Men vassals worship Morgoth?

Silmarillion tells how Sauron made Numenoreans worship Morgoth and offer him human sacrifices.  However,  states that Sauron first created this cult before his Numenorean captivity, for Men tribes of Middle-earth he dominated. There's no citation though. Is it true? Did Sauron's Men vassals in Second Age Middle-earth have Morgoth cult as their religion, and did they perform human sacrifices? Or did they worship Sauron himself as a god?  Also, are there any indications that this practice had survived until War of the Ring?


How to make a skewed orthographic perspective camera?

is it possible to have a skewed orthogonal perspective camera? I want to make a perspective like in the old ultima games where the x and y axis are aligned with the screen and the z axis is at a 45 degree angle. Essentially the same question has been asked before here:  However sadly I can't use the proposed solutions there. I cannot shear the image after rendering because I need the image to be pixel perfect. Also I cannot transform the rendered model because that will mess with the lighting. Ideally, I'd like to be able to enter the view transform matrix of the camera directly myself. Can this be done somehow, maybe via scripting?