Where to ask questions, that are related to 2 Different sub-Sites?

I have a question about how to mount best a DSLR camera to an aeroplane. But now I'm wondering, where I would have to ask it? The camera does also have to be controlled from inside the plane.   In the aviation section, because they have the knowledge about aeroplanes, structure and aerodynamics.  In the photography, because they have experience with mounting cameras to all sort of things (GoPro)  Arduino/Raspery Pi - For how you would control the camera.  somewhere else?  I believe posting it to all sites is not a good answer, but how could I reach all the people? I believe duplicate questions wouldn't be a good Idea.  I know there has been a similar question before (where they said, ask similar questions on different networks and point to each other, but I doubt that this would be helpful in this case.  What should I do?  Are there some tags, where you could tag another Stack Exchange community, to include them as well?


Riccati differential equation $y'=x^2+y^2$

$$y'=x^2+y^2$$ I know, that this is a kind of Riccati equation, but is it possible to solve it with only simple methods? Thank you


Identify a book - young adult, unable to interact with physical objects, Mars poster

I encountered this book about thirty years ago at school. It was probably a young adult novel rather than anything more serious and I think it was not part of any series.   The details are:    A boy finds himself progressively unable to interact with physical objects, slowly moving away from his physical reality into an alternate reality. There was a mosaic poster of Mars made from images returned by Viking featured as well.   What is the name of this book?


Call of Duty: Black Ops 2 controller issues

On Call of Duty: Black Ops 2 the controller goes down when I want to go up and up when I want to go down. How do I fix this?


Are "random sample" and "iid random variable" synonyms?

I have been facing hard time understanding meaning of "random sample" as well as "iid random variable". I tried to find out the meaning from several sources, but just got more and more confused. I am posting here what I tried and got to know:  Degroot's Probability & Statistics says:     Random Samples / i.i.d. / Sample Size : Consider a given probability distribution on the real line that can be represented by either a p.f. or a p.d.f. $f$. It is said that $n$ random variables $X_1 , . . . , X_n$ form a random sample from this distribution if these random variables are independent and the marginal p.f. or p.d.f. of each of them is $f$. Such random variables are also said to be independent and identically distributed, abbreviated i.i.d. We refer to the number n of random variables as the sample size.   But one of the other statistics book I have says:       In a Random Sampling, we guarantee that every individual unit in the population gets an equal chance(probability) of being selected.   So, I have a feeling that i.i.d.s are elements that construct random sample, and the procedure to have random sample is random sampling. Am I right?   P.S.: I am very confused about this topic, so I will appreciate elaborate reply. Thanks.


Why does computing product derivations eliminate degrees of freedom?

I'm trying to get an intuition as to why degrees of freedom is n - 1 when calculating sample covariance. This is what I found:  1) Start with 2n degrees of freedom from the bivariate data 2) Lose 2 degrees of freedom from calculating the means 3) Lose n-1 degrees of freedom from computing product derivations  In step 3, are the degrees of freedom being halved, or is n-1 being subtracted? What is the intuition of step 3?


I don't know why we need the concept of Filters and Ultrafilters.  they just seem nothing, and I don't know where to use them  can you tell me where do we use those concepts.


I am having some issues with trying to detect collision of two isometric tile.  I have tried plotting the lines between each point on the tile and then checking for line intercepts however that didn't work (probably due to incorrect formula)  After looking into this for awhile today I believe I am thinking to much into it and there must be a easier way.  I am not looking for code just some advise on the best way to achieve detection of overlap


Using passport of country of nationality after being granted refugee status

I hold refugee status in the EU and I have a refugee travel document under the 1951 convention. I want to visit a specific country but this country doesn't accept refugee travel documents.  If I used the passport of my country of nationality, I wouldn't need a visa to travel to this country, but my passport is expired.  If I renew my passport at the embassy and use it for traveling, would it affect my refugee status in EU?


Single word describing something "outside of oneself"

ie.:  The idea was "(blank)".  It didn't come from myself, it was divine inspiration, dumb luck, etc.  or maybe: My essence/spirit was outside my body.  It was "(blank)".


Let A be a commutative entire ring. Why does an automorphism of A[x] act as identity on A?

In Chapter 4 of Lang's Algebra, Exercise 8 states: "Let $A$ be a commutative entire ring and $x$ a variable over $A$. Let $a,b \in A$ and assume that $a$ is a unit in $A$. Show that the map $x \mapsto ax+b$ extends to a unique automorphism of $A[x]$ inducing the identity on $A$. What is the inverse automorphism?" I showed that the inverse is $a^{-1}(x-b)$. Then Exercise 9 states: "Show that every automorphism of $A[x]$ is of the type described in Exercise 8."  It is clear to me that we must have $x \mapsto ax+b$ for some $a,b$, but why must an automorphism of $A[x]$ induce the identity on $A$?  (I explained why this is not a duplicate of the problem referenced in the comments.)


I've got an enum like this:  public enum MyLovelyEnum {     FirstSelection,     TheOtherSelection,     YetAnotherOne };   I got a property in my DataContext:  public MyLovelyEnum VeryLovelyEnum { get; set; }   And I got three RadioButtons in my WPF client.  <RadioButton Margin="3">First Selection</RadioButton> <RadioButton Margin="3">The Other Selection</RadioButton> <RadioButton Margin="3">Yet Another one</RadioButton>   Now how do I bind the RadioButtons to the property for a proper two-way binding?


How to create connectors that cross other connectors properly?

Using Draw.io can you create a connector that will "jump" over another connector without simply crossing it or going around it?


I have a file that contains phone numbers of the following formats:   (xxx) xxx.xxxx (xxx).xxx.xxxx (xxx) xxx-xxxx (xxx)-xxx-xxxx xxx.xxx.xxxx xxx-xxx-xxxx xxx xxx-xxxx xxx xxx.xxxx   I must parse the file for phone numbers of those and ONLY those formats, and output them to a separate file. I'm using perl, and so far I have what I think is a valid regex for two of these numbers   my $phone_regex = qr/^(\d{3}\-)?(\(\d{3}\))?\d{3}\-\d{4}$/;   But I'm not sure if this is correct, or how to do the rest all in one regex. Thank you!


Single lens for both portrait and landscape

Is there any budget lens for Nikon d5600 which is best for both portrait and landscape? I'm looking for one lens which does both portrait and landscape.


How can Neo use his powers outside of the matrix?

I just finished The Matrix Reloaded. Not for the first time, though this run through of the trilogy is very enlightening. Every piece of it makes sense to me so far except at the end. When The Neb is destroyed by the bomb sent by the machines, the machines attack Morpheous, Trinity and Neo. Neo then destroys them with some kind of EMP like attack. How is this possible? How do his powers exist outside of the Matrix?


How can I install make in ubuntu without internet?

I have Ubuntu Server 16.04. I need to install the pacakge make because I need to install drivers for my Ethernet device with the command "make install".  I don't have internet on this computer.  Is there any way to install this package without an internet connection?


Get id of last added feature in qgis python action

I created a python qgis action that open the dialog form so the user can add a new feature.  maintenance_lyr = QgsMapLayerRegistry.instance().mapLayer('od_maintenance_event20180212171049766')  maintenance_lyr.startEditing() qgis.utils.iface.setActiveLayer(maintenance_lyr) qgis.utils.iface.actionAddFeature().trigger()   My question: How can I get the id of the newly created feature?


Why does my Review Button show 4 reviews but there are none?

From time to time, my Review Button will show a number of reviews to consider, yet when I click on the button fewer (always fewer, never more) reviews are shown?  Sometimes the number resets to 0, sometimes the number increases, but the reviews in the queue are less and are different to reviews done just previously.   Looking at the related questions, the examples were either there were no edits or there is a persistence in the number of edits in the queue. Neither seem to be the same as my case where the number changes, but there is nothing in the queue, or the number remains the same, but there are different reviews in the queue. Coincidence in the latter seems possible but highly unlikely.  This also seems to happen in the middle of the night EST.  Is this an update problem or am I missing something else I should be doing?  Thanks.


I want to know how to create a multi boot DVD with all the Ubuntu flavors (Kubuntu, lubuntu, Xubuntu and Ubuntu)

I am a computer teacher. I am introducing my students to Linux, and I wish to create a multi boot live-DVD (single layer, 4.5GB)  with all the Ubuntu flavors (Kubuntu, Lubuntu, Xubuntu and Ubuntu 14.04) to use it in class. I have tried the following Windows utilities (because I am used to Windows, but I also have installed Ubuntu 12.04 LTS on my computer): - X-boot: the ISO image is too big to fit in a single DVD (it duplicates the ISOs). - SARDU: only support certain flavors of Ubuntu (Ubuntu y Kubuntu) - Magic ISO: created the ISO image successfuly, but it failed to recognize the blank DVD in the DVD unit. Tried to burn the ISO with Nero, but the DVD does not boot, an error message appears.  I got tired to search over the internet, so I hope someone could help me  Regards  Jorge Arce Ortiz


Is it possible to reach outer space with this method?

Could we use a hot air balloon to carry a rocket and send it into orbit at a higher altitude? That is, do I need to reach a specific speed to be completely free of Earth's gravity, or can I just ascend to some height?


Debugging a DNSmasq server using it's logs, I find a LOT of:  dnsmasq: query[ANY] . from RANDOM-IP dnsmasq: query[ANY] . from RANDOM-IP dnsmasq: query[ANY] . from RANDOM-IP dnsmasq: query[ANY] . from RANDOM-IP   All legitimate queries seem to be more specific, like:  dnsmasq: query[A] specificdomain.com from KNOWN-IP   EDIT: This is NOT intended as a public DNS service  We want to create a white-list DNS filter, it should ONLY answer to a list of specified domains. Typical amplification attacks would only affect our server, nobody else. We just want a cleaner log to be able to operate better.  The intended operation is:   Client uses this DNS for their internet connection. Client requests domain resolution If the domain is in the white-list, we resolve, if not, we don't reply.   How can we achieve this? Only process request that match our white-list, discard anything else.


Can I use one Apple ID for Apple Music and another for iTunes & App Store?

Let us suppose I want to use a shared Apple ID for logging into iTunes & App Store, in order to share music and app purchases with a friend.  But let us also suppose that, despite this, my friend and I have very different tastes in music, so I don't want to share Apple Music playlists and "like" assertions with my friend. In other words, I don't want Apple Music to think I like the music my friend likes, and vice versa.  Is there a way that my friend and I can share an Apple ID for logging into iTunes & App Store, but use different Apple IDs for Apple Music?  I suspect the answer is no, but I just wanted to ask.


sda1 -> Windows XP  sda2 -> Windows 7 sda3 -> Data Partition   I have created 4 primary partitions, I have 7xx GB left, how can I create one more partition?


Comb space has no simply connected cover

I'm having trouble solving the following exercise in Hatcher's Algebraic Topology(1.3 #5):  "Let $X$ be the subspace of $R^2$ consisting of the four sides of the square $[0,1] \times [0,1]$ together with the segments of the vertical lines $x=\frac{1}{2},\frac{1}{3},\frac{1}{4},\ldots$ inside the square. Show that for every covering space $\tilde{X}\to X$ there is some neighbourhood of the left edge of $X$ that lifts homeomorphically to $\tilde{X}$. Deduce that $X$ has no simply-connected cover."  I tried piecing together open sets in $\tilde{X}$ which were homeomorphic to open square shaped $\epsilon$-neighbourhoods of points in the left edge of $X$, but I couldn't glue them together coherently.  My second idea was to use the path lifting property to lift the left edge, but I couldn't extend it to a lift of an open neighbourhood of the left edge.  Edit: Some more detail on my first attempt:  Suppose I have two open squares $U_1$ and $U_2$ in $X$ (containing the left edge) with nonempty intersection, and that have preimages $\coprod_i U_{1,i}$ and $\coprod_j U_{2,j}$ with each piece of that mapping homeomorphically onto $U_1$ and $U_2$ respectively.  Suppose I've chosen a specific $U_{1,i}$, and I want to choose a specific $U_{2,j}$ so that their union maps homeomorphically to $U_1$ union $U_2$. Such a choice can be specified by a point in the chosen $U_{1,i}$ that maps into $U_2$, but for each such point, there could be a different choice of $j$.  My intution tells me that to make this choice, one needs to appeal to the bad local nature of the left edge of $X$, (so that you're certain to get some of the vertical lines inside of the desired open set) but I'm not sure how to proceed with that.


Latex Column Ending Too Soon - Too Much White Space

So I'm trying to make a standard a1 poster using the a0 document class.  This is my code so far:  \documentclass[poster, a1]{a0poster} %%%Load packages \usepackage{multicol}            \usepackage[left=2cm,right=2cm,bottom=0cm,top=0cm]{geometry} \usepackage{mathpazo}            \usepackage{color}                \definecolor{headingcol}{rgb}{1,1,1}         \definecolor{boxcol}{rgb}{0.408,0.157,0.376} \fboxsep=1cm                             \setlength{\columnsep}{2cm}               \makeatletter                            \renewcommand\@maketitle{% \null                                    {     \color{headingcol}\sffamily\veryHuge        %Set title font and colour     \@title \par}% \vskip 0.6em% {     \color{white}\sffamily\large                %Set author font and colour     \lineskip .5em%     \begin{tabular}[t]{l}%         \@author     \end{tabular}\par}% \vskip 1cm \par } \makeatother  \title{TEXT HERE}  \author{NAME \\ Supervisor: NAME}  \begin{document}  \hspace{-3cm}                               %Align with edge of page, not margin \colorbox{boxcol}{                          %Coloured banner across top     \begin{minipage}{1189mm}                    %Minipage for title contents         \maketitle     \end{minipage}} \vspace{1cm}  \begin{multicols}{4}         \section*{Hello}     jkboub\\kglhvkjb\\liugiub;ub\\lylyvjhb\\ktftuyvuyvyuvluf\\lubaub     \columnbreak     \section*{Hello}     \columnbreak     hello     \columnbreak     hello \end{multicols}  \end{document}   and yet the outcome is this:    Why is there some text in the second column, which should be continuing in the first?


Do lure modules and incense cause new pokemon to spawn near you, or existing pokemon to be drawn to you?

When a Lure Module is used on a PokéStop, do existing pokémon in the area get drawn to the PokéStop? Or rather do new pokémon spawn within the PokéStop area of effect? Or both?  When I head to a PokéStop with a lure module, it seems Pokémon appear from nowhere, and the Pokémon listed Nearby don't get any closer. So I am guessing it only causes random spawns.  Has anyone found the lure module to actually draw existing Pokémon to your location, or only spawn new pokémon? And does an individual's incense act the same way?  For an individual's incense, this could be an important question. If I see a rare pokémon 3 'steps' away, I would want incense to actually help draw that pokémon closer to me as I search for it. Whereas if the incense only spawns new pokémon, I'd rather use incense at other times.


I took with my first skill points "Self" and "Regenerate" and "Projectile". Now I can make only 2 spells - "Self Regenerate" & "Projectile Regenerate" - which I both can't cast. The first uses 270 Mana, the second uses 540 mana - but I have only 100.  How can I progress further? I don't have any points to unlock other spells and I can't cast my current ones because I don't have the mana - thus I can't progress.   How do I level up so I can unlock more points?


What is the relationship between orthogonal, correlation and independence?

I've read an article saying that when using planned contrasts to find means that are different in an one way ANOVA, constrasts should be orthogonal so that they are uncorrelated and prevent the type I error from being inflated.  I don't understand why orthogonal would mean uncorrelated under any circumstances. I can't find a visual/intuitive explanation of that, so I tried to understand these articles/answers        but to me, they contradict each other. The first says that if two variables are uncorrelated and/or orthogonal then they are linearly independent, but that the fact that they are linearly independant does not imply that they are uncorrelated and/or orthogonal.  Now on the second link there are answers that state things like "orthogonal means uncorrelated" and "If X and Y are independent then they are Orthogonal. But the converse is not true".  Another interesting comment in the second link state that the correlation coefficient between two variables is equal to the cosine of the angle between the two vectors corresponding to these variables, which implies that two orthogonal vectors are completely uncorrelated (which isn't what the first article claims).  So what's the true relationship between independence, orthogonal and correlation ? Maybe I missed something but I can't find out what it is.


Finite $G$ with involutory automorphism $\alpha$ with no nontrivial fixed points. Proving properties of $\alpha$.

The question at hand is:     Let G be a finite group and $\alpha$ an involutory automorphism of G, which doesn't fixate any element aside from the trivial one.    1) Prove that $ g \mapsto g^{-1}g^{\alpha} $ is an injection    2) Prove that $\alpha$ maps every element to its inverse    3) Prove that G is abelian    I think I've found 1).  I assume $ g_1^{-1}g_1^{\alpha} = g_2^{-1}g_2^{\alpha} $ and from this I get $ (g_2g_1^{-1})^\alpha = g_2g_1^{-1} $, so $g_2 = g_1$ (is this correct?)   For 2) I'm sort of stumped though, not sure how to start proving that, so any help please?


Given the scrutiny that parents find themselves under from social workers, teachers, councils and any other busybody who stick their noses in, How is it possible that Muggle Borns such as Hermione can just "Disapear" from the system? Given that it is a legal requirement to stay at school till 16 the ministry would have to go full time to obliterate all documentation, and obliviate all personages with knowledge of such a child.  Therefore why was Hermione allowed to dissapear from the system?


How to calculate the following determinant: $\begin{vmatrix}  a & b & b & ... & b \\   b & a & b &  ... & b \\   . & . & . & . ... & .\\  b & b & b & ... & a\\  \end{vmatrix}$ I don't have idea from where to start. Any help is welcome. Thanks in advance.


Catch-all rewrite rule for apache that doesn't cause duplicate urls from .htaccess

You can make a catch-all rewrite rule for apache that acts somewhat like an alias, but can be implemented in a .htaccess file while an alias can't.  As an example, assuming your document root is a hierarchy like this:  /.htaccess /test/ /test/.htaccess /test/file   You can "Alias" all requests to the test folder by making the root .htaccess contain:  RewriteEngine On RewriteRule ^(.*)$ /test/$1 [L]   And the second .htaccess contain:  RewriteEngine On   This works great, and usually is all you need. It just has one problem - it creates multiple valid urls. Now you can access the file with both /file and /test/file.  Ordinarily this isn't a problem, but if you add a file called /test/test you'll see the problem, as the fake alias stops working entirely. If the subfolder has a complex .htaccess of its own it can cause major headaches.  Is there any way to fake an alias from a .htaccess without the original urls still working? (Any RewriteCond for the subfolder that would check if we've already been rewritten or not?)


Win7 command-line: How to copy a file and create the missing subtree

I have a number of files I need copied to different networked locations.  However, it is a regular occurrence that the sub-directories need to be created.  I considered building an app to do this, but I'd rather not "re-invent the wheel" if I don't need to.  An example would be as follows:  Copying:   C:\ProjectFolder\Project\WCB\2010\CA\ON\EmployeeReport.aspx.cs   To:  \\Server1\Downloads\Patches\Web\Project\   would end up copying the file to:  \\Server1\Downloads\Patches\Web\Project\WCB\2010\CA\ON\EmployeeReport.aspx.cs   (because "Project" is common in both paths, that's the starting point where we'd need to create the new path.)  Any suggestions?  -- Post Update: Sorry, it seems this is a duplicate of   The answer, although there isn't an automated way of doing this (maybe I'll write that utility after all) is using XCOPY:  XCOPY C:\ProjectFolder\Project\WCB\2010\CA\ON\EmployeeReport.aspx.cs \\Server1\Downloads\Patches\Web\Project\WCB\2010\CA\ON\EmployeeReport.aspx.cs


Ubuntu 12.04.3 LTS installation failed. says: "GRUB installation failed"

The error message is :the grub-efi-amd64-signed package failed to install into /target/. Without the GRUB bootloader the system will not boot  I'm trying to install on HP pavilion g6-2303 TX using USB.  How do I fix this problem?


How to get a reference to an instance of a class where there is no known object relationship

I have a C# application running under a vendor provided application framework that has a bug in it. I can work around the bug by using reflection to redirect an event handler, but I need to get the instance of the class. I can see the bug from the logging.  I don't have source for the application framework and the application framework is no longer supported by the vendor.  I know that memory profilers like redgate can inventory everything in memory so there must be an approach that can get me started.  So how do I grab an instance of an object where I do not have a direct reference?


MacBook 13" Mid 2012 shuts down with 20% with new battery

I have this problem with my MacBook: when I turn it on, the battery reports 0%. After replacing the battery, I've the same problem.  New battery  has 4 cycles and 100% of charge capacity.  I have already tried SMC reset.  Is it a possible High Sierra problem? Has anyone solved it?


Prove that $H$ is a normal subgroup in the finite group $G=\langle S\rangle $ iff $sHs^{-1}$ $\subseteq H$ for all $s\in S$.

Let H be a subgroup in a group $G$. If $G$ is generated by a set $S$, so $G=\langle S\rangle $, prove that $H$ is a normal subgroup in $G$ iff $sHs^{-1}$ $\subseteq H$ for all $s\in S$.    Note with the question: Results of this sort are useful because it is easier to check an algebraic property for a small set of generators than to prove it holds for all elements of G.  Hi, the forward direction is quite straightforward but I will be really grateful if somebody can help me with the reverse direction. Thanks!


Stimulated emission and No cloning theorem

I have a little trouble with the . I know of the  which states that it is not possible to duplicate any state. One the other hand, I know about the stimulated emission which out of a photon produce exactly the same (wavelength, polarisation, etc...). Maybe the fact is that the excited atom do a measure. (Let's say it can stimulate emission with only one direction of polarisation.) But now if I have a statistical number of atoms with random "polarisation" direction, I should be able to copy any incident photon. I've made a cloning machine. This cannot be true because of the no-cloning theorem. But I can't figure why.


My heart is bleeding internally after having to go so deep to subtract two dates to calculate the span in number of days:      GregorianCalendar c1 = new GregorianCalendar();     GregorianCalendar c2 = new GregorianCalendar();     c1.set(2000, 1, 1);     c2.set(2010,1, 1);     long span = c2.getTimeInMillis() - c1.getTimeInMillis();     GregorianCalendar c3 = new GregorianCalendar();     c3.setTimeInMillis(span);     long numberOfMSInADay = 1000*60*60*24;     System.out.println(c3.getTimeInMillis() / numberOfMSInADay); //3653   where it's only 2 lines of code in .NET, or any modern language you name.   Is this atrocious of java? Or is there a hidden method I should know?  Instead of using GregorianCalendar, is it okay to use Date class in util? If so, should I watch out for subtle things like the year 1970?  Thanks


How to write to a memory buffer with a FILE*?

Is there any way to create a memory buffer as a FILE*. In TiXml it can print the xml to a FILE* but i cant seem to make it print to a memory buffer.


After SQL Server 2016 (SP1-CU3) patching we are not able to open the user database properties. Whenever its opened am getting below error:     Method not found: System.collections.specialized.stringCollection   Microsoft.sqlserver.management.smo.server.getpropertynames(System.type)'.   (SqlManagerUI)


Unable to install Steam because of broken packages

I can't install Steam no matter what I try. Dependencieo over dependencies ... you got it. I tried anything I could, and ended up damaging my system. Now it's like new. Here is the link of tutorial I followed:  Here is what happens when I execute sudo apt-get install steam: techguy@techbook:~/steam$ sudo apt-get install steam 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: steam:i386 : Depends: libgl1-mesa-dri:i386 (>= 17.3) but it is not going to be installed or libtxc-dxtn0:i386 but it is not installable Depends: libgl1-mesa-glx:i386 but it is not going to be installed Depends: libudev1:i386 but it is not going to be installed E: Unable to correct problems, you have held broken packages.  I tried reconfiguring and adding repositories and anything I could, but that libgl1-mesa problem is still there. I have managed to install steam installer (via .deb) but the problem comes when I launch Steam installer. Here is what happens: Steam needs to install these additional packages: libgl1-mesa-dri:i386, libgl1:i386, libc6:i386 [sudo] password for techguy: ...... 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: libgl1:i386 : Depends: libglx0:i386 (= 1.3.1-1) but it is not going to be installed libgl1-mesa-dri:i386 : Depends: libglapi-mesa:i386 (= 20.0.4-2ubuntu1) but it is not going to be installed E: Unable to correct problems, you have held broken packages. Press return to continue:  Any ideas?


Travelling outside of UK on a tourist visa

I am a Canadian citizen and currently visiting the UK to be with my girlfriend. I have the 6 month tourist visa stamp and have a return flight booked back to Canada on February 2nd.     My question is can I travel to Barcelona with my girlfriend for a few days before I fly back to Canada. Will they allow me back into the UK to get on my flight back to Canada?


How do I create a tag on Stack Overflow without having required reputations to create one?

I want to create a tag called "pyez" on Stack Overflow, but I do not have required reputations to create one. Can someone please help me?


In an old house, do I need a ground wire to install newer outlets, lights, and appliances?

If I have an old house, as in 80 years old (the wiring is newer than that), and it only has two wires, hot and neutral, no ground, can I connect newer things like ceiling fans or hanging lights? The house wiring isn't 80, but it is old enough to have Wadsworth breakers.  The outlets are not grounded, and someone said if I get GFCI outlets this will ground the outlet (put on in each room they said.)  One person said if I don't, my computer and electronics will get surges or fry.  The house is grounded, but not the receptacles. I really did not want to rewire the whole house.  The wiring itself is good, not paper sheathing the electrician said.  This particular electrician said it would be "ok" and he wouldn't worry about plugging in things like computers or get a UPS.  The electrician also said even though a couple of the GFCI outlets in a bathroom were ten years old that they still trip and are ok. Does the house have to be rewired to use modern electrical devices (lights, tv, refrigerators, computers, etc.)?


A way of defining particle colours by where they emit form and have them stay that colour instead of just mirroring the emission object?

Does anyone know a way of defining particle colours by where they emit form on an object and have them stay that colour instead of just mirroring the emission object? I've got particles emitting from an object with a colourful Voronoi pattern on it to another object with a force field and turbulence so the particles mix and move around once stuck to it. At the moment I have the colour pattern mapped on to the particles using a texture coordinate, mapping and color ramp but the pattern is just projected onto the particles. What I want is for the particles to have their colour defined by where they emit from and then keep that colour so that they mix in the turbulence. Is there a way of doing that? Many thanks in advance.


Chinese Remainder Theorem $\ x\equiv m_k-2\pmod{m_k}$

I am trying to find all integers that give remainders 1,2,3 when divided by 3,4,5 respectively.  So I start defining  $$a_1=1, a_2=2, a_3=3,$$$$ m_1=3, m_2=4, m_3=5,$$$$ m_1m_2=12, m_1m_3=15, m_2m_3=20,$$$$ m=60$$ All the moduli are pairwise coprime, so by the Euclidean Algorithm $$12x+5y=1\Rightarrow x=-2, y=5.$$ $$15x+4y=1\Rightarrow x=-1, y=4.$$ $$20x+3y=1\Rightarrow x=-1, y=7.$$ Therefor a solution should be  $$20\cdot(-2)\cdot1 +15\cdot (-1)\cdot 2+12\cdot (-1)\cdot 3=-40-30-36=-106$$ But under mod 60, this implies a solutions should be of the form, $60t+14$.  But it is not.  THis is not right.  Why did this technique not work?


Answering a Question which might be a little OFF TOPIC

Today I answered  which you can consider to be a little off topic but there was some major misunderstanding that how that person was approaching an issue so I gave him a little advice to put him in the right direction.  Soon after my answer I got down voted and was  that I shouldn't answer off topic questions:     Please don't answer off-topic questions; by actively answering them, you give the question that questions like this are appropriate for SO, which only encourages more off-topic questions.   My argument is IF someone has a problem and they dont even realise that  what is the problem and where is it? and they ask a question on SO not about the actual problem but about the symptoms of that problem, Would it be not better to explain them how they end up having these problems and they can be avoided.  Since the person doesn't even realise where the actual problem is their questions will appear to be off topic. Would it be not better if we can help them to address the actual issues rather than down voting these questions or putting them on hold?  I might be wrong in saying all this but its just a thought, Help someone in need when it doesn't cost you a penny, why not then pal?


Force figures and figures* to appear in order of appearance

I am using the  to typeset a preprint. The MNRAS template is divided into two columns and I am using the figure and figure* environment to place graphs either into one column or over the two columns.   However, the figures are put into the document in the order of appearance and figures* are independently put into the document in the order of appearance of figures*. As a result a "Figure 5" (a non* figure) appears in the document before "Figure 1" (a figure*).   How can I force the correct order of appearance of both figures and figures*?    Renumbering the figures is not an option as the journal requires the figures to appear in order of reference in text. I have tried using the afterpage package as a workaround so that Figures 1-4 are typesetted before Figure 5 but unfortunately \afterpage{\clearpage} triggers already after the left-column ending and the whole right column is left blank.


Train crash: are these situations alike?

I was just wondering... I believe that if a car travelling 50 miles per hour crashes into a wall, the result should be the same as crashing to another car also travelling 50 miles per hour (but in the other direction of course)  Is this true? Why is that?


Let $s_n = 1$ and for $n \geq 1$, let $s_{n+1} = \sqrt{s_n+1}$. Given this sequence and assume that it converges. I have to prove that the limit is $\frac{1+\sqrt{5}}{2}$  By using the definition of limit, I tried to set $n > N\ implies\ |\sqrt{s_n+1}-\frac{1+\sqrt{5}}{2}| < \epsilon$. But I have no idea how to simplify the expression in the absolute value and get rid of absolute value!!! Can anyone give some hints??


I was reading over some notes of mine from the Linear Algebra class I took a while ago in order to prepare myself for Computer Graphics course I'll be taking this Fall and I ran across a sentence that I can't quite grasp. It states that     Since we have a non-zero vector $x$ in the nullspace of $A - \lambda I$, then $\det(A - \lambda I) = 0$.   From reading Wikipedia page on determinants I got that     ... the system has a unique solution exactly when the determinant is nonzero; when the determinant is zero there are either no solutions or many solutions.   So if we have vector $x$ in the nullspace of $A-\lambda I$, then we have either 0 solutions or many solutions. But I still don't understand why $\det(A - \lambda I)$ has to be equal zero?


Finding function $f(x)$ which satisfy given functional equation

Find all function $f:\mathbb{R}-\{0,1\}$ in $$f(x)+2f\left(\frac{1}{x}\right)+3f\left(\frac{x}{x-1}\right)=x$$   Attempt: put $\displaystyle x = \frac{1}{x}$, then $$f\left(\frac{1}{x}\right)+2f(x)+3f\left(\frac{1}{1-x}\right) = \frac{1}{x}$$  could some help me how to solve it , thanks


How to prevent a view layer from rendering?  I'm rendering bunch of objects and some needs to be rendered in 2 passes, but most of them don't and I'd like only render the first view layer for those. How do I keep my extra view layer but prevent Cycles from rendering it?


Delete all but the most recent X files in bash

Is there a simple way, in a pretty standard UNIX environment with bash, to run a command to delete all but the most recent X files from a directory?  To give a bit more of a concrete example, imagine some cron job writing out a file (say, a log file or a tar-ed up backup) to a directory every hour. I'd like a way to have another cron job running which would remove the oldest files in that directory until there are less than, say, 5.  And just to be clear, there's only one file present, it should never be deleted.


Using  has no difference. I don't mind if it indents, but the image should be center-aligned.  \documentclass{article} \usepackage{graphicx} \graphicspath{{C:/Users/Ooker/Desktop/Images/}} \title{Quả cầu}  \begin{document} \maketitle text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text   \includegraphics[width=1\textwidth]{Octahedron}  test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test   I use XeLaTeX.


Why did Tarkin say that Vader was the last of the religion of the Force?

In Episode IV, Tarkin says to Vader:     The Jedi are extinct, their fire has gone out of the universe.  You, my friend, are all that's left of their religion   This struck me quite a bit, because the question arises that if Vader is part of 'their religion', then surely the Emperor is also.  My question is then, why did Tarkin say that Vader was all that was left of the 'religion' of the Force, when Emperor Palpantine would equally be part of that religion?


When asking about , people sometimes refer to the strict aliasing rule. What are they talking about?


Can I install Windows after Ubuntu 14.04?

I'm thinking about if Windows can be installed after Ubuntu like a Dual Boot thing...  Please tell me if its possible.. without losing any Ubuntu files  Anyway I'm a new to Ubuntu


Can I use my first name instead of last name?

I am a Korean with my first (given) name comes last and my last (family) name comes first, just like many other east asians. So, I write my name as "Aaa Bbb Ccc", where "Aaa" is my family name and "Bbb Ccc" is my given name. There are literally several millions of other Koreans who also have "Aaa" as their family name, and many of them spell it in English in the same way. Imagine citing a paper written by a Korean with family name Aaa. How can people possibly distinguish hundreds of Korean researchers with the same name working in same field? For this reason, I want to use my given name (which is still quite common, but far less common than my family name) instead of my family name. For example, I want to be cited as [Bbb Ccc, 2020] instead of [Aaa, 2020]. Is this possible to do? I don't mind to be called as "Dr Bbb Ccc", and actually I prefer that way; imagine being called as "Dr Aaa", where there are 8 other "Dr Aaa"s in the same department! Of course I have to deal with other problems, like being called as "Bbb" or "Ccc" which is just like "von" and "Neumann" instead of "von Neumann"; but I think that is less annoying than being one of those "Aaa"s. Is it possible?


Can you explain "Did you mess with /etc/fstab before rebooting"

I have struggle with AWS EC2 ubuntu server ssh connection refuse. After I wrote mount path on /etc/fstab and reboot, I can`t access the instance.  I found your comment at   Can you help me about this.  Thank you


Improving a tag wiki entry not an option

I am on a new private beta, and looking at tag wiki entries. I see some that are good fundamentally, but perhaps have a small error, like a spelling error. I can't figure out a way to improve the edit, either by accepting it, or trying to manually edit it. Is there a way to do this, and if not, can we make there be a way to do it?


Gparted - Can't resize win 10 partition?

I can't to be able to re-size windows 10 file system partition using Gparted.  The partition is un-mounted and this is not about swap-partitioning    Do help me?


In the early days of the Stack Overflow trilogy (including SO, Server Fault, and Super User), I noticed that many of the most active members were good contributors on all three trilogy sites. These days, with 150+ sites in the network, it's more true than ever that many people are active on several different sites.  This has led me to wonder about the possibility of cross-site badges, which would be awarded for a certain level of participation in multiple Stack Exchange sites. For example, there could be a hypothetical badge awarded for visiting each of a particular set of 3 different SE sites every day for a 15 day period. Or one for achieving 200 reputation on 5 or more sites. Or one for having an answer with +10 upvotes on each of 3 or more sites. (I'm not saying that these would be good badge criteria, just trying to provide illustrative examples.) Basically, these badges would reward people who don't limit their activity to just one site, and hopefully would encourage existing contributors who specialize in one site to branch out and look for new Stack Exchange sites to get involved in, thus strengthening the network.  Of course, the obvious problem is, which site(s) would these badges display on? Would they be associated with all the sites they were earned for, or would they display on every site at which that user has a linked account? And I have no idea what sort of problems could arise on the development side - there isn't really any other feature (that I know of) that really integrates different trilogy sites like this, so I can imagine it might be a lot of work to implement such a feature on the backend.  Is the cross-site badge idea something that people would be interested in? If the implementation details can be worked out, can we get this implemented?  Also, for the purpose of giving people on meta something to answer, what would be more good badge criteria? It's easy enough to come up with cross-site badge ideas of the form "[criteria for single-site badge] on [number] sites". What makes this feature really interesting, I think, is the possibility for badges that don't fit that pattern.


Are topics suggested on the homepage based on user history?

During the last semester, I had some Prolog courses and I look topics on StackOverflow to help me during my praticals work. I have noticed that SO shows on the homepage more and more questions about . The same behaviour occurred with  (I had a project with this too), but it's less dramatic.  My question is simple: does StackOverflow (and SE sites in general) show questions on the home page according to a user's visit history, in addition to favorite tags?  I never answered any questions about prolog or wpf, so I don't think it came from my answers and I never saw a prolog question on my homepage before.


Is there a notion of causality in physical laws?

I was reading  by Pedro Domingos and towards the end of the paper he makes this statement:  "Many researchers believe that causality is only a convenient fiction. For example, there is no notion of causality in physical laws. Whether or not causality really exists is a deep philosophical question with no definitive answer in sight..."  I was surprised by this statement because apart from Heisenberg's uncertainty principle, everything else (that I know of) in physics seems to operate under the assumption of . If you have an equation that describes a definitive outcome as the result of some input factors, then it is describing a causal relationship, is it not?


What is the easiest way to obtain the capital version of tipa's letter \textyogh (which is apparently LATIN CAPITAL LETTER EZH U+01B7, Ʒ)?


Why did the TIE fighter in The Force Awakens have life support?

In The Force Awakens, Finn and Poe steal and escape in a TIE wearing no personal life support apparatus. TIEs have been upgraded with shields, hyperdrives (for "/sf"), weapons etc, but as far as I know they weren't upgraded with built in life support.   Finn and Poe should have frozen and/or suffocated after hitting space in the TIE. In the Rebels series, Sabine did the same thing. I've looked at what Wookieepedia states about the TIE as well as the old video game Star Wars "TIE Fighter".  Does the movie or any other work explain how Poe and Finn survived?


Accidentally deleted Win 8 while installing Ubuntu 14

My problem is that I accidentally deleted Win 8. But actually I don't need it and I don't want to buy Recovery disk. I need to install Ubuntu. So when I installing Ubuntu I just Erase my disk and install Ubuntu. The is happening at the end of installation. It's coping files, but at the end it's showing me a message   "We are sorry;the installer crashed. After you close the window, we'll allow you to file a bug using..."   I don't know what to do. Help please :(


I want to upgrade to Bionic Beaver from 17.10, but the Software Updater says everything is up to date.  I followed  but at the step the upgrade button should pop in Software Updater it still says everything is up to date. I did change the settings to notify me for "Any new version".  What else could be wrong?


what to do when the acceptance deadline has passed with no notification from the reviewers?

I submitted a paper for an Elsevier journal in which the acceptance deadline appears as the 5 of may. The problem is that when I enter into the author´s menu it appears that my paper is with the status Required Reviews Completed and it has been like that for more that one month. Does it mean my paper has already got rejected? what should I do in this case?


how can i select div?
Test
   this code does not work  #languageForm:j_id427:0:j_id432 { color:#00aa00; }   . . . . . . . . . . . . . . . . . . .


Does the model $E[Y]=\beta_0 + \beta_1 X_1 + \beta_2 X_1^2 + \beta_3 X_1^3$ meet the assumption of linearity for multiple linear regression?

I was trying to help a student with stats homework, but an example given in class has me a bit confused.  Background, to my understanding: A linear model is given to be one where $E[Y] = \beta_0 + \beta_1 X$. So for example, the model $E[Y] = \beta_0 + \beta_1 X^2$ can be framed as a linear model with the change of variable $X' = X^2$. Or $E[Y] = \exp{\beta_0 + \beta_1 X_1}$ with the change of variable $Y' = \ln{Y}$.  So then we get to the model $E[Y]=\beta_0 + \beta_1 X_1 + \beta_2 X_1^2 + \beta_3 X_1^3$. The professor says that, no problem, we can just substitute $R = X^2$ and $S = X^3$, and get $E[Y] = \beta_0 + \beta_1 X + \beta_2 R + \beta_3 S$, and we have a multiple linear regression with three variables.  It seems ridiculous to me to just hide non-linear terms this way and call them new variables. So ridiculous I'm having a hard time even finding the right foothold to criticize it. Could someone either explain why I'm wrong or help articulate my objection a bit more clearly?


Order archive custom posts by taxonomy term

I cant change the way things are, so I cant use custom meta...   I have terms that are years and I have to display the archive in order (newest to oldest-in terms, not published date) For example the terms are 2007,2008,2009. I need the posts to display first the 2009 ones then the 2008, then the 2007.  I prefer to use a function than the query call. Why? I am using a generic archive.php page, not using one for post types. I'd like to keep it that way.  I try to add a function to the theme to change the way some posts are displayed with no success. Please help me out! :D   add_action('pre_get_posts', 'my_change_sort_order');  function my_change_sort_order($query) { if (is_post_type_archive($post_types = 'zee_publications')):     $query->set('order', 'desc');      $query->set(get_terms(array(         'taxonomy' => 'cat_publications',         'orderby',         'slug'     ))); endif; };


So i have downloaded an object, when i open it on blender, it shows gray object (no texture). There is a file called "character texture.psd", how do i apply the .psd file on my object? I'm new on blender, glad you'll help.


Does the Force travel through space-time?

If I were a Force user and were to cast a Force push targeted at another person standing so far away, would they have the ability to dodge it or would the person, no matter how fast they reacted, still be affected and hit by it?  To put in a crude manner: does the Force behave the same way that a projectile does or does its effect manifest at the point of the target?  I hope this makes sense. If not, please voice your concern(s) and I'll do my best to clarify.


"spent a lot of time to shop" vs. "spent a lot of time shopping"

She spends a lot of time to shop. She spends a lot of time shopping.   Are both of these sentences grammatically correct and do they have the same meaning?


Show that if a $C^*$-algebra $A$ is reflexive as a Banach space, then $A$ must be finite dimentional.  I tried to solve it; but, I could not. please help me for this exercise.  Thanks a lot!


VECM Cointegration Relationship Coefficient(s) Interpretation

Theory dictates that when there is one cointegration relationship, it's coefficient in a VECM must be statistically significant and negative to maintain the long-run equilibrium.   Nonetheless, when there are two cointegrating relationships (Coint 1 and 2), should both their coefficients, C(1) and C(2), be negative and statistically significant or only the first coefficient, C(1)? Thanks  a, b, c, d, e, and f are real numbers.                Coint 1        Coint 2  Var 1           1.00           0.00 Var 2           0.00           1.00 Var 3           a              d Var 4           b              e Constant        c              f   VECM:                 ∆Var1(t)  Coint 1       C(1)  Coint 2       C(2)  ∆Var1(t-1)    C(3)               ... etc


I was watching a Mythbusters episode (the Superhero Special) and one of them mentioned kryptonite as a metal.  And I was wondering what exactly it was—a metal, a gas, as is shown in Batman vs. Superman, a rock or mineral?  I am not asking what kryptonite is made of; rather, I am aksing what form (metal, rock, gas, liquid) it takes.


Changing thickness line using pst-solides3d:  I'm trying to draw a thinness line in space using pst-solides3d:  \begin{center} \psset{unit=0.4cm} \psset[pst-solides3d]{viewpoint=40 30 25 rtp2xyz,Decran=60,fontsize=0} \begin{pspicture}(-2,-3)(3,10) \defFunction[algebraic]{paraboloid1}(r,t){r*cos(t)}{2*r*sin(t)}{r^2} \psSolid[algebraic,object=surfaceparametree,base=0 2 pi 2 div 3 pi mul 2 div,linewidth=0.5pt,function=paraboloid1,ngrid=20 25,linecolor=blue,incolor=Turquoise]% \psSolid[object=line,args=0 4 0 0 4 4,linewidth=0.1pt] \end{pspicture} \end{center}   but command linewidth seems have no effect. Thanks.


"don't forget to vote both the question and the answers up" even when they're all locked

When I visit a site I haven't visited (while logged in) for a while, I see:  Welcome back! If you found this question useful, don't forget to vote both the question and the answers up.  That's often intended behavior. But today I visited  and was shown that banner even though the question and all its answers are locked. Voting arrows aren't even shown on any of the posts on that page. I believe that banner should be disabled on pages where there is no post that can be voted on by anyone.


I want to login using ssh and password store in a text file or may be in a varible  I am trying below method but i am getting an error please suggest me correct way.  echo "123456" | ssh root@127.0.0.1  error: Pseudo-terminal will not be allocated because stdin is not a terminal.


Installing a package with Ansible and not starting the service

I have the following play snippet:   27   - name: ensure necessary packages are installed  28     apt:  29       state: present  30       name:  31         - apache2  32         - libapache2-mod-rpaf  33         - nginx   I don't run IPv6 (LAN) so I have ipv6.disable=1 in my boot args.   When Ansible installs Nginx, it defaults to listening on listen [::]:80 default_server; and returns an error in the play.  How can I tell Ansible/apt not to start Nginx (or any service for that matter.. probably the same story with Apache) when installing the package?


How to find the canonical equations of the RLC circuit

First, I consider the LC circuit with an ion in the capacitor, which is like this:  The current $I$ can be derived easily by using Shockly-Ramo theorem \begin{equation}  I = -\frac{qp}{dM} + C\dot{U} \ \ \ (1)  \end{equation} where $q$ is the charge and $M$ is the mass of the particle, $p = M\dot{z}$ is the momentum of the particle, $d$ is the separation of the two plates, $C$ is the capacitance and $U$ is the voltage across the capacitor. By taking the circuit-charge $Q$ on the capacitor as the generalized coordinate and the magnetic flux through the inductor $\Phi = L\dot{Q}$($L$ is the inductance of the inductor) as the momentum, it is easy to derive the canonical equations of the circuit with Kirchhoff's law $U = -\dot{\Phi}$. \begin{equation}  \dot{Q} = \frac{\Phi}{L}\ \ \ (2)  \end{equation} \begin{equation}  \dot{\Phi} = -\frac{Q}{C} - \frac{qz}{Cd}\ \ \ (3)  \end{equation} Now we consider the series RLC circuit case. My question is that how to find the canonical equations of the series RLC circuit with the same canonical coordinates(which is $Q$ and $\Phi$)? , it says that there will be two more terms added in equation(3), $-\Gamma\Phi$ and $\sqrt{2\Gamma L k_BT}\xi(t)$, where $\Gamma = \frac{R}{L}$. So the first term is the damping term and the other term, according to that paper, should be the thermal noise of the resister. I just can not find the correct canonical equations that satisfies the result in the paper.


Reference for creative set criterion theorem

I was recently reading a Ph.D. thesis in which the following result was cited:  (Jockusch-Mohrherr) Let $A$ be any r.e. set except for $\mathbb{N}$. $A$ is creative iff for every r.e. set $B$ disjoint from $A$, it follows that $A \equiv_{1} A \cup B$.   I found this interesting and was trying to track down the source of the theorem, but nothing was given in the bibliography. Does anyone know where I could find this result? Or, I guess, alternatively provide a sense of how to prove this? Thanks.


A filter within my profile to show questions with no accepted answer

Please can we get a filter or additional tab within the profile screen to show questions I have asked with no accepted answer.  Perhaps render the acceptance %age as a link to said questions.  In this way we could quickly see the sorts of questions that someone has been unable to accept answers to.


One of the roots of the equation $2000x^6+100x^5+10x^3+x-2=0$ is of the form $\frac{m+\sqrt{n}}r$, where $m$ is a non-zero integer and $n$ and $r$ are relatively prime integers.Then the value of $m+n+r$ is?     Tried to use the fact that another root will be $\frac{m-\sqrt{n}}r$ as coefficients are rational but there are six roots and using sum and product formulas would allow many variables in the equations.


My Samsung netbook NP300E5A screen is continually dimming. The screen is forty percent dim on battery, but if I plug in the charger, the screen will be normal. I have tried all I know and I could not fix it. What should I do? what am trying to explain is that the system is dimming like flooricent light the screen resolution systems are all ok. When I pluging my charge the dimming we stop but when is on battery it look like flashing someone light when driving


What is the filter attachment size of nikon AF-S 50 mm f/1.4G lens?


Call function from element inserted from Javascript/Jquery

I am trying to invoke a javascript function from some HTML code inserted by some other javascript code (see below).  $(".leave-a-note").click(function() {             var id = $(this).closest('li').attr('id');             $('#' + id).children('.write-comment-space').html("Save Cancel");});   When I try to call a function from the ".save-comment" url nothing happens.  $(".save-comment").click(function() {             console.log("test");         });   However, if I leave the ".save-comment" URL directly in my HTML the function works. What am I doing wrong?


Is there a database for non time series data sets?

I am searching for some data sets that would be suitable for regression analysis that my teacher wants for Statistical Learning lesson's homework. But as I search I only encounter with time series data.  Q: Does anybody familiar with such websites that I can download Non-time series data with enough dimensions to do regression analysis?  Any help with be appreciated.


Can autoshrink permanently damage a database?

I've been given the task of finding out why our server is slow. I ran a stored procedure I downloaded called sp_Blitz. It let me know that our database had auto-shrink enabled, and to disable it. So, I did that. I don't know how long it's been enabled, but I'd guess at least 3-4 years. When I checked the fragmentation percent of the indexes, a lot of them were 60% - 99%. I then ran a script to rebuild the indexes and update the statistics, but the fragmentation percent didn't really change for these indexes.  Is there something else I need to do to repair what auto-shrink has done?  Any advice for me?


I am trying to call my methods within main but after entering my dollars and cents, the values don't change when I print them  import java.text.DecimalFormat; import java.util.Scanner;  public class ChangeMachine {   public static void main(String[] args) {  System.out.println("Change is good");  int dollars = 0; int cents = 0; int toonie = dollars/2; int loonie  = dollars%2; int quarter = cents/25; int dime = (cents%25)/10; int nickel = ((cents%25)%10)/5;      ChangeMachine.getAmountFromUser(dollars, cents);     ChangeMachine.calculateCoins(dollars, cents);     ChangeMachine.displayInvoice(dollars, cents, toonie, loonie, quarter, dime, nickel);  }   Method to input the dollars and cents Here I'm able to enter the amount but it won't appear when I try to display it  public static void getAmountFromUser(int dollars, int cents) {  Scanner input = new Scanner(System.in);      System.out.print("How many dollars? ");     dollars = input.nextInt();      System.out.print("How many cents? ");     cents = input.nextInt();     System.out.println();      input.close();  }   Method to calculate coins  public static void calculateCoins (int dollars, int cents){ DecimalFormat df = new DecimalFormat("#0.00"); double amount = dollars + cents/100.0; System.out.println("$"+df.format(amount)+" requires:");  //-----Bonus----- dollars=dollars+(cents+2)/100; cents=(cents+2)%100; //---------------  }   Method to display coins needed  public static void displayInvoice (int dollars, int cents, int toonie, int    loonie, int quarter, int dime, int nickel){   System.out.println(toonie+" Toonies"); System.out.println(loonie+" Loonies"); System.out.println(quarter+" Quarters"); System.out.println(dime+" Dimes"); System.out.println(nickel+" Nickels");  }  }


Submodules finitely generated if sum and intersection are finitely generated?

Let $M,N$ be submodules of an R-module $L$, where $R$ is a commutative ring with unity. I would like to prove that if $M+N$ and $M \cap N$ are finitely generated so are $M$ and $N$. Trying to combine the generating sets of the sum and intersection did not bring me any results. Any idea how to approach this problem?


Some trouble with a wordpress directory I've added to an old site

I have fixed many 404 pages on the site, and added a few blogs with deep links, and some good authoritative backlinks, but it is still not ranking. Tried submitting to webmaster, added some fundamental SEO apps, but worried this is going to take a year to come back to life because of the 404s that I had. Any ideas on what could be the problem. I have tried literally everything, the URLs are canonical, etc.. still issue... I use to have  really high ranking bog, but I hosted it on a different site, and forwarded my blog links to this other site, then I thought traffic would be higher if I matched everything over to the same site, but appears this was more of an issue,


sudo, problems with terminal emulator excepting my pass word

i am trying to get my bluetooth working and looked on the forum for answers,what i found, that i thought might work was a command,  sudo apt-get install bluetooth. i typed this into  the terminal emulator, followed by a prompt to enter my pass word, it would not let me put my pass word in,what can i do know ? i am running Bionic Beaver 18.04 on a dell studio inspiron 1557 i have tried several times but keeps asking for pass word,which it will not let me enter,I am using my ubuntu log in pass word,but still the terminal emulator will not allow it!


Why do wave functions need to be normalized? Why aren't the normalized to begin with?

Before I started studying quantum mechanics, I thought I knew what normalization was. Just pulling off Google, here's a definition that matches what I've understood normalization to mean:      Normalization -- to multiply (a series, function, or item of data) by a factor that makes the norm or some associated quantity such as an integral equal to a desired value (usually 1).   Most often I have seen normalization that normalizes to 1 or 100% or something like that.  For instance, isn't putting things in percentages a kind of normalization? If I take a quiz and get 24 / 25 points, then I "normalize" this by saying I got 96%. That's what I understood normalization to be.   Why I am Confused Now   Ever since I started studying quantum mechanics, I have felt confused by the term normalization. Let me quote this portion from Griffiths to illustrate an example of how he uses the term:      We return now to the statistical interpretation of the wave function, which says taht $|\Psi(x,t)|^2$ is the probability density for finding the particle at point $x$, at time $t$. It follows that the integral of $|\Psi|^2$ must be 1 (the particle's got to be somewhere.    \begin{equation} \int^{+\infty}_{-\infty} |\Psi(x,t)|^2 dx = 1  \end{equation}    Without this, the statistical interpretation would be nonsense.       However, this requirement should disturb you: After all, the wave function is supposed to be determined by the Schrödinger equation --- we can't go imposing an extraneous condition on $\Psi$ without checking that the two are consistent. Well, a glance at [the time-dependent Schrödinger equation] reveals that if $\Psi(x,t)$ is a solution, so too is $A\Psi(x,t)$, where $A$ is any (complex) constant. What we must do, then, is pick this undetermined multiplicative factor so as to ensure $\int^{+\infty}_{-\infty} |\Psi(x,t)|^2 dx = 1 $ is satisfied. This process is called normalizing the wave function.    I get the idea we need the probability distribution $\rho$ to be 1 over the whole position space. That makes sense and is obvious. So the integral makes sense. But I don't understand a couple things:    What was the wave function like prior to normalization? Why did it need to be normalized in the first place? To use my quiz analogy, why wasn't the test out of 100 points to begin which in which case no normalization would be needed. 96% would be 96 points.   Why if $\Psi(x,t)$ is a solution, so too is $A\Psi(x,t)$?   Perhaps an answer could comment on how my initial definition of normalization relates to normalizing the wave function. Also, if you like to write, adding a comment or two about Dirac normalization would be awesome.


How to prevent CDN content URLs being indexed by Google

Well, robots.txt prevent crawling and meta robots tag in HTML (or) X-Robots-Tag HTTP header prevents indexing (and other functionalities available too).  So, even when a URL is disallowed in robots.txt, it can be indexed in Google if it is referenced somewhere using an anchor tag.  So, my question is, how can I prevent public CDN URL being indexed by Google?  For example, I upload an image on Facebook which is private. But, the CDN URL holding the data is actually public, so anyone with the complete link can access the content. How does Facebook prevent these URLs being indexed?  Example textual URL:   Now, I posted the above URL here. Will google index this URL? Update:  How about this anchor URL: .  Will this be indexed if this is referenced this way?  Update:  When I say "link indexing", I'm not talking about  but .   Example:  in the site's  but you can see that it is actually indexed.  My question is, how does Facebook prevent the FBCDN URL above being indexed while you search like this in Google: site:fbcdn.net inurl:21616414_867163746798211_8462429064810946636_n.jpg  This didn't work, and my question is how does Facebook do this.  Reference 1:   Reference 2:   Reference 3:  (Check the table at bottom)


Importing Python file from PostgreSQL stored procedure

It is possible to have Python code in a PostgreSQL stored procedure. For example:  CREATE FUNCTION someProc() RETURNS void AS $$     # Some Python3 code... $$ LANGUAGE plpython3u;   But how can I include a python file from this code?  The current directory of Python running in PostgreSQL is this:  >>> os.getcwd() ... /var/lib/postgresql/9.3/main   I tryied the following, which worked:  CREATE FUNCTION someProc() RETURNS void AS $$     import sys     sys.path.append("/dir/to/file")     from python_file import pythonFunction     # More Python code $$ LANGUAGE plpython3u;   This doesn't seem very good for many obvious reasons. Is there a better way to import a python file, or just calling a python function from a python file?  Edit: There isn't any specific PostgreSQL method to import a file. But  the best way is in the correct answer bellow, which resembles my original solution but it is better.


How does killing Barron affect the timeline in Miss Peregrine's Home for Peculiar Children?

In the movie "Miss Peregrine's Home for Peculiar Children", Mr. Barron kidnaps Miss Peregrine in order to use her in his immortality experiment.  With Miss Peregrine gone, the time loop she created in September 1943 collapses, stranding Jake and the other kids in 1943.  So to rescue Miss Peregrine, they take a ship to Blackpool, where Miss Avicet's loop in January 2016 is located.  While aboard the ship, Emma says this to Jake:     Jake, you know what this means don't you? ... We have to get to our own time but you don't.  You can continue to live in 2016... If we kill Barron, he'll be gone but time will carry on.  He won't go to Florida, Abe won't die, and you can go home."   My question is, how would killing Barron save the life of Jake's grandfather Abe?  Abe died in July 2016, so theoretically killing a version of Barron from before then would prevent Abe's death.  But that's not what happens; in Blackpool Barron speaks about Abe's death:     I tracked Abe Portman for months.  All I needed was a few minutes to get the location of Miss Peregrine's loop from him.  But no, Mathus couldn't wait.  And instead, I had to masquerade as a psychiatrist for three weeks in Florida.   So if Barron has already participated in the Florida events, how will killing Bareon mean that "he won't go to Florida [and] Abe won't die"?  Is it supposed to be that if you die within a time loop you get erased from the timeline or something?  This is mighty peculiar, no pun intended.


What constitutes Date Usage on an iPhone 5?

I have an iPhone 5 and I just received notice that my data usage for free is almost up.  I presently have 1GB. I am total unaware of what data usage is and should I change to a plan with 2GB.  Do I have to do something to make sure I use Wi-Fi in all places that I am.  Exactly what takes up my data usage when using my phone? Is it from receiving a message, text, taking photos. Please be specific if possible.


How do I catalog files on several external hard drives that I want to store off-line?

I have quite a few external hard drives that I want to store off-line, and possibly off-site.  The contents is not saved in a structured manner, however; basically  there's lots of project data for lots of projects.  Is there any software for Windows XP that will catalog all the hard drives, so I can search the catalog, find the files, and get the ID of the disk that has the content?


Ubuntu system update from 16.04 to 18.04 issue

I have upgraded my Ubuntu 16.04 to 18.04. System upgraded successfully but graphics is not coming properly. After that run some commands for resolved graphics issue. But not corrected. Now the system is running but showing a blank screen with cursor blinking. Created users show and type the password for login but not getting login. Please help me. How to take backup my data?


SQL Server 2016 - Availability Groups - How To Copy Permissions To Secondary Node

SQL Server 2016 SSMS v18.4  I want to create the same logins and give the same privileges on both node. In primary node I have no problem about this operation. But when I create the same login on secondary node and want to user mapping, it gives below error:  Create failed for login 'loginname'. Additional information: An exception occured while executing a Transact-SQL statement or batch. (Microsoft.SqlServer.ConnectionInfo) Failed to update database "dbname" because the database is read-only. (Microsoft SQL Server, Error:3906)  But my database is not read-only. I'm trying the give permission like this: Node 2 (Secondary) -> Security -> Logins -> Right click on MyLogin-> Properties -> User Mapping -> Select database and choose dbo for default schema -> Select public and db_owner -> OK.  It gives this error all of the databases for secondary node. How can I solve this problem without doing failover (failover can solve this because it does primary node to Node-2 but I don't want to failover)? If it possible with using PowerShell, how can I do it on this operation on PowerShell for Node-2? Thank you. Best regards,


Is there a limit to $\frac{d^nx}{dt^n}$?

There is already a question on the limit of acceleration($\frac{d^2x}{dt^2}$) and we all know the limit of velocity($\frac{dx}{dt}$) which is $c$ or the speed of light. My question is a generalized version of the previous questions. Is there a limit to $\frac{d^n x}{dt^n}$? And if there is a limit then what is the general formula based on the physical constants to calculate the limit of $\frac{d^n x}{dt^n}$?


I got a div with a default class of 'unlock' and text named 'UNLOCK'. when i click it, it says 'UNLOCK' and at the same time remove the class 'unlock' and add a class of 'lock'.  html
UNLOCKED
   this worked  $('.unlock').click(function(){     $(this).removeClass('unlock').addClass('lock').text('LOCKED'); });   but this did not worked  $('.lock').click(function(){    $(this).removeClass('lock'); });   And I'm not sure why it didn't work coz the class was already replaced so it should work right?  Basically, all I want is like a toggle functionality that when you first click it should say LOCKED. then when you click it again, it should say UNLOCKED.   I tried the toggle() but it didn't work also or I just don't know how to implement it. So any ideas how I can make this functionality work?  here's the


Apparent Earth-Centricity of the Federation

AFAIK, the United Federation of Planets and Starfleet both have their headquarters on Earth and it is somewhat implied to be where it all started. I'm not sure about that second point -- there's probably some canon about the creation of the Federation that I'm not familiar with -- but the "lay impression" given is that it is very much human/Earth-centric.  It seems hard to believe that a bunch of other races would unite with the upstart humans, once they discovered warp technology. It's even harder to believe that said races didn't have the collective wherewithal to have formed a political union already, letting Earth join once it had reached a certain "maturity".  Is there an in-universe reason for the Earth-centricity (presuming that's the case, of course)?


Mac Finder: Getting the path of a directory or file as as string

In Windows it is possible to right-click on a file. Then select "properties". In "properties" the file-system path is shown. Can then be copied by marking and storing (into the clipboard).  I couldn't figure out a way to do that in Mac.   Therefore my question:  Can I retrieve the file-system path of a directory or file via the GUI of the Mac Finder?


How to Backup and Restore Android OS without Rooting

I want to find a way to restore my phone in case the process of rooting my phone or dual booting a custom rom breaks it. However, most of the ones I've looked at require the phone to be rooted before installing. I know I can create a nandroid backup through system settings, but I don't know how to recover that without rooting my device, or if there are better options. I'm not terribly concerned for any personal data on my phone (I can backup my pictures pretty easily), but I mostly just want to be able reinstall Android OS or reset to factory default in case my device breaks. Thanks! Edit: I am going to ask a new question (one different enough to justify not simply modifying this one) with the new info I learned from the possible duplicate.


A plan to defeat a betting game where the odds of winning are 50/50. Help me understand why it's flawed.

My friend has this plan where he implies that it's impossible to lose, as long as the odds of winning are 50/50 on each bet. His idea is that basically you keep doubling your bet until you win and then start over again.  So for example, you bet 1 dollar and you lose, your net profit is now -1 dollar. Now you double your bet to 2 dollars and you lose again so your net profit is -3 dollars. Now you double your bet to 4 dollars and you win. This means you gain 4 dollars and now your net profit is 1 dollar. So you've made a profit. Now you start again. The reasoning here being that it is highly unlikely for you to lose a 50/50 toss x number of times in a row.  My counter-argument here is that basically if you go in with 50 dollars with the aim of doubling up to 100 dollars, you have the same odds of winning if you do one bet of 50 dollars or the technique outlined above. I cannot wrap my head around explaining this issue in a clear manner though, so maybe you wonderful folk at Mathematics can help!  Oh and I've pointed out that he uses gamblers fallacy in very obscure way, as he insists you need to go back to betting 1 dollar once you've won. This appears to be an obscure case of gamblers fallacy to me as it implies there is some hidden force which are changing the odds on each individual coin toss.


Can anyone suggest me some good reference books where different properties and characteristics of matrices are explained in details and in lucid language?


Copying files over from Ubuntu to Windows via Ethernet?

Why?  I need to share some files (copy over) from my Laptop (running Ubuntu 17.04) to my Desktop (running windows 10). As the summed amount of files come to over 800GB and not wanting to do multiple trips with a 16GB flash drive I thought the next best course of action would be to connect the two devices together somehow. I chose to do it via ethernet cable as transfer should be reliable and the throughput should be decent.   The problem  After connecting the 2 devices together and sharing all the relevant folders on BOTH systems they still don't seem to recognise each other nor do I seem to be able to find any simple solution to what I assumed might be a common occurence.  Extra (but not necessary)  Tips on speeding up the transfer. I was thinking of potentially adding all the folders to a 7z archive (only because I've had good results with it in the past) and save that archive on windows so that you transfer the archive (which would surely be smaller).


I'm running Windows 7 and I need to test a web application in IE8. I can't seem to find a version of IE8 anywhere for windows 7.  Can IE8 even be installed in windows 7?


Durrett Exercise 2.5.5 Convergence of Random Series

Let $X_n \geq 0$ be independent for $n \geq 1$. Then the following are equivalent:   (i) $\sum_{n=1}^\infty X_n$ converges a.s.  (ii)$\sum_{n=1}^\infty  {[P(X_n >1) + E[ X_n I_{X_n \leq 1} ] }]  < \infty $  (iii)$\sum_{n=1}^\infty E [ X_n / (1+ X_n)] < \infty $  How could we show the above? I tried using Kolmogorov's Three-Series Theorem but I was unable to show it.


How do I execute PHP that is stored in a MySQL database?

I'm trying to write a page that calls PHP that's stored in a MySQL database. The page that is stored in the MySQL database contains PHP (and HTML) code which I want to run on page load.  How could I go about doing this?


Can every string of numbers be found in the number pi (cfr. infinite monkey theorem)?

The infinite monkey theorem states that a monkey hitting keys at random on a typewriter keyboard for an infinite amount of time will almost surely type a given text, such as the complete works of William Shakespeare.   Source:   My question is actually if pi is a "random" sequence of numbers. (I've read in other posts that it's likely to be such a sequence, and that e.g. irrationality isn't a sufficient condition, as can be seen in 0.01001000100001...) But is there an elegant mathematical way to proof if a number is such a random sequence? Or can it be proven with statistics/numerical methods with a kind of certainty that it's such a number?  EDIT: people stated that the exact mathematical term for "random" that I was searching for, should've been "normal". So my questions boils down to:  Pi is likely to be a normal number; if it is, it contains every sequence of numbers. But if it isn't, does it then contain every sequence of numbers (although in this case not with the same likelihood)? Or is this not sure (or even a contradiction)?


How can I prove this by induction? $\sum _{k=1}^n\left(\frac{1}{\sqrt{k}}\right)\ge 2\left(\sqrt{n+1}-1\right)$

I am given this expression and I have to prove it using mathematical induction  ${\displaystyle \forall }n\ge 1 $ , $$ \sum _{k=1}^n\left(\frac{1}{\sqrt{k}}\right)\ge 2\left(\sqrt{n+1}-1\right)$$  I have proved it is true for $n=1$, then suposed it was true until $n$ and wanted to prove it was also true until $n+1$.   I have operated a bit and arrived to this expression I want to prove: $${\frac{1}{2\sqrt{n+1}}}\ge (\sqrt{n+2}-\sqrt{n+1})$$ , and I don't know how to continue to clear that inequality to prove it. Can you help me please?? (I have just started studying this method so I'm a bit lost :/ )


I have some Jasper reports which are displayed in HTML format. I would like the width of the columns in the HTML tables to automatically resize to fit the content of the widest cell (in that column), such that all the data is displayed.  Currently this does not happen because the HTML generated by Jasper specifies fixed widths for the
 and some  elements, e.g.     foo-bar-baz@examp 	   I can't simply remove all these width properties (using JavaScript), because (as shown in the HTML above) any data that would be hidden when using these widths is not even returned to the client-side  Cheers, Don


Find the number of ways to select ten distinct letters from the alphabet {􏰘A, B, C, . . . , Z}􏰙 if no two consecutive letters can be selected.

I have no idea how to answer this problem. Right now even my professor is a little stumped.


Why Java data structure (like array) doesn't seem to support vectorized operation?

Given an array T of integers, if we want to multiply each item by 2, in Java we will do it via a for-loop (Known as scalar operation). With python 's numpy array, we can just multiply array by 2 (Known as vectorized operation).  My question is: Is there a way in Java that allows us to perform that multiply operation in a vectorized way?  And if Java doesn't support that, is there a reason why?   Update: I'm not asking for sugar syntax. It is about CPU instruction vectorization like SIMD     Thank you.


Python: TypeError: can't multiply sequence by non-int of type str

So, I was making a text-based "shopping" program, and I came across an error that didn't quite make sense to me. The error message was this:  TypeError: can't multiply sequence by non-int of type str   Here is a code snippet of where I think the error is located (Comment above line where I believe error to be located):  def buy():     print "\nType in a store item to buy."     find_item = raw_input(prompt)     if find_item in store_items:         print "Amount?"         amount = raw_input(prompt)         if amount:                         #Error in next line?             store_rec.append(store_items[find_item] * amount)             get_buy()   If you're wondering, store_items is a dictionary containing the store items like this:  store_items = {     "carrot": "carrot",     "apple": "apple",     "pear": "pear",     "taco": "taco",     "banana": "banana",     "tomato": "tomato",     "cranberry": "cranberry",     "orange": "orange", }   Then store_rec is an empty list, like this:  store_rec = []   It contains recommendations for telling the user what to buy next time, but that's not where I think the error is located. What I was trying to do in the line where the error appears to be, is append the amount of items specified by the user to the empty store_rec list. Unfortunatly, then I get the error. It seems like it should work, but it doesn't. So, with that in mind, any help on my problem is appreciated!


Holding Two Mutually-incompatible Beliefs at One Time

Encountered this word for the first and only time at an Anglican church, from a rector.  I suspect that it is a word from Christian liturgy.  I had pointed out that two of the beliefs he had been promoting were completely contradictory - i.e. if one held one of them it was not possible to hold the other at the same time.  He took this in stride, smiled easily, and used the word I am looking for.  In reply to the replies below:  Thanks all for the input.  "Antinomy", from philosophy, might be close, and "koan" might be another word for what the rector was describing!  Uh oh ... I'll admit that I am now wondering whether memory serves me well enough to recognize the word when I see it!  Could antinomy be it?  Koan is too short.  I'm guessing that the best bet for a definitive answer will come from a student of this level and form of Christianity.  (Anyone care to call up their well-schooled rector?  Orthodox Anglican as mentioned below.)  To answer questions posed to me here:  Unfortunately I do not recall the beliefs promoted.  It was in Canada and, when pressed, the rector - who did have a high-level affiliation with the Church of England - said that this flavour of Anglican would be "orthodox".  More as of April 13 2017:  I don't understand how this board works.  Seems 5 users have claimed that my question is a duplicate.  I am asked to explain why this is not the case.  But I don't see where those 5 users have provided the "duplicate" question and answers ...  Also, there is a 2nd claim that this question has already been asked and answered - which includes a question which is clearly not the same as mine ...  Anyway, I've seen evidence neither of my question having been asked before nor its answer (though koan and antinomy are closest and on the right track).  Thanks.


How do you protect your software from illegal distribution?

I am curious about how do you protect your software against cracking, hacking etc.  Do you employ some kind of serial number check? Hardware keys?   Do you use any third-party solutions?  How do you go about solving licensing issues? (e.g. managing floating licenses)  EDIT: I'm not talking any open source, but strictly commercial software distribution...


i am writing thesis and need to have separate font (Calibri-like) for title page. How to change font family (for example, to "Allerta") for one page only?


Prove that $\forall n \in N: \ln(n!) \geq n\ln(n)-n+1$

I thought about Stirling equation for the solution but I couldn't get the answer.  How i need to approach in order to solve that?


I just accidentally uninstalled a lot of programs, is there way to get all of them back at once?

Okay, so, this question may have been asked before, but I really need help.  I ran sudo aptitudeto find a specific package that I wanted to delete. I pressed "Install/Remove Pkgs" and there was a section of packages that were to be removed because they were "no longer used". So, I did a noobish move and pressed "g" to remove these seemingly unused packages.  The menu closed and the terminal processes began, I watched. I started seeing programs that were obviously being used by me. So, I hurried up and exited terminal to stop the process.   A few moments later, two programs "Puddle tag" and the Software Center on my dock became grayed (they were open at the time) and disappeared. A handful of used/needed programs seemed to be uninstalled. And I am now at a lost of what to do. But I have a little hope.  I went to the history log and it has everything that was uninstalled [which was a crap load of things] thankfully. Is there a way to batch download/install all of these back onto my computer with this information? I'm assuming it's impossible, but is it possible? There is no way I can see myself doing all of this one at a time, it's way too much. Oh, and at the end of the log, there was an error   Error: Sub-process /usr/bin/dpkg returned an error code (1)


When will Lightning components be available for Android phones?

Lightning components works well with iOs whereas does not work with Android. When will this feature be available for Android?


Why do anime use parody brand names in their series, and what benefit do anime like Code Geass and Darker than Black get when they use original brand names like Pizza Hut? Do they get paid for promoting the brand? If not, so they have to pay the company for copyrights? What benefit do the anime/manga artists get in the end?


How to calculate take home salary in Sacramento, California?

How can I calculate my take home pay in Sacramento area in California?  I have an offer of USD 95,000 per year in Sacramento. After searching multiple sites for tax calculations, I understood that it depends on the number of dependents as well.  I have a spouse not working, and one child of 4 years.  Can someone please suggest, how much take home pay I can expect?


Create groups according to spatial contiguity?

I have a large set of points for school sites and I want to divide these schools into 6 groups, for example, and I want each group to consist of 200 schools, provided they are spatially close to each other. How can I do that in ArcGIS Pro?


File Select that Only Accepts Generic Files

How would I use the accept attribute to only accept generic files (no extension) on selects?  I tried this:    <input type="file" accept="application/octet-stream">     However no files were showing in the file selector.  Thanks.


I just got off a very long and very frustrating phone call with Apple support.  I purchased a used Apple computer which came installed with Mountain Lion. Meaning that the computer was shipped by Apple with Mountain Lion installed, and received by me with that same installation.  As a precaution, I tried to reinstall Mountain Lion via Recovery mode. This failed because my Apple ID hasn't purchased Mountain Lion.  Apple insisted that because I didn't purchase the computer new, I don't have a license for OS X. I don't believe this is correct, or even legal. This means that anyone using a used computer is doing so illegally, unless they've purchased a separate OS license.  Am I way off-base here? I'm pretty sure I now "own" a copy of Mountain Lion, and Apple is in the wrong. If this is correct, what are my options?


How do I find out what filling up the space in dev/sda2 using ssh command

My apologies if the question is vague and too naive. I am totally new with the Linux commands.  We have a dedicated server with  and have several sites hosted there. Our server is running out of space.  This is what I got by running df -h in the command prompt after connecting with the server via ssh    I have little to no experience with Linux shell command. How do I figure out what is filling up the space and where the folder is located. How do I go to Home directory?   My assumption is the server is running cache . But I an't figure out where these cache is getting stored. I am not an expert with server and system administration. Please treat me as total novice in this sector.  appreciate your help


What are to differences pros/cons for Latex, Luatex, Context, etc?

I have used Latex several times for small papers and thesis' for University. So I know a bit about how to create formulars, tables and stuff. However, I still consider myself a newbie, who barely scratched the surface (for example, most of the problems I come across, in order to save time, I just google the answer and apply it without really understanding the reason behind an error).   A friend of mine suggested Luatex to me, since it lets you automate more things via the Lua scripting language and therefore according to him, with that you can really  decouple the semantics from the presentation (which isn't really possible for standard Latex).   I did a bit of google-ing around and I am a bit at a loss, as more and more questions are appearing. Here are some of them:   Is LuaTex still developed and supported What is Context? Is this still developed/supported. Is it recommended over Luatex, a complete different thing, or a competitor? There is a lot of knowledge for standard Latex our there (here). How is that for LuaTex and Context in case I have a problem.  How about other versions: XeTex, Koma-Tex,... How do you install those versions? Does it run along with your standard Latex version (In my case I use MikTex and work in TexnicCenter) What is recommended to use...let's say for a Master or PhD Thesis (a technical, math-heavy one) in 2019?   I know these are partly a bit oppinion-based questions, what I'm looking for in general is a Site, that summarizes these things and gives a good overview (and is up to date).


Do we re-estimate all the ARIMA model when we add GARCH effect?

I wonder because the rugarch library on R allows to generate an ARMA-GARCH, but the coefficients of the ARMA are totally different from those generated by Arima from the forecast package.  I thought that the addition of the GARCH was only done by adding the GARCH, and not by re-estimating the model, am I right or am I wrong?


Determine the size of an object from an aeriel photo

Given:  I shoot from 1,000 feet ASL I used Canon 1000D with 500mm telephoto lens  Question:  How can I measure or find the size of an object that i shoot using the following data? Can you show me the formula?


Confirmation that someone is listening to another person's speech

When someone is telling you a very long and detailed story he usually wants to hear some "confirmations" (or response) that you are listening to his story. In Russian we often use something like "tak" (which has a meaning of "ok" and "well, proceed further"), "a-ha" or "uh-huh".  What word serves the same purpose in English and American English?


How would I make this material in cycles?  Thanks


Can I fit a Minolta 35mm lens to a Micro 4third mount?

I have old 35mm lenses for my old Minolta camera. I'm going back to photography and getting an Olympus PEN E-PL1 (micro four thirds mount).  Can I use my old lenses on such a box or do they become completely useless? They were pretty expensive lenses, so why throw them away?


Finding the "square root" of a permutation

Suppose $r$ is odd, and ${\rm ord}(\alpha)=r$. ($\alpha,\beta$ are cycles.)  Now, $\alpha=(a_1\cdots a_n)$.  I need to find $\beta$ that will make $$\alpha = \beta^2$$   How can I show it?    What I tried?  ${\rm ord}(\alpha)=r$ so $a^{r+1}=\alpha$.  Let say that $\beta=\alpha^{\frac{r+1}{2}}$, $\frac{r+1}{2}$ is an integer, how do I prove that $\alpha^\frac{r+1}{2}$ is a cycle?  Because then $\alpha=\beta^2$...  Thank you!


Union of disjoint sets : Equivalence relations

I'm not exactly sure how to go about doing this question. I've attempted it but I'm not exactly sure if it's correct.  Question: Let $S$ be the union of disjoint sets $A_1, \cdots, A_k$. Let $R$ be the relation consisting of pairs $(x, y) \in S \times S$ such that $x, y$ belong to the same member of $\{A1, \cdots, A_k\}$. Prove that $R$ is an equivalence relation on $S$.  The three axioms are: reflexivity, symmetry, transitivity,  I have a brief idea of how to do the first 2, however, for transitivity, I don't have any ideas. Could anyone help out on this please?


Our iPad is locked and we're not sure of the Apple ID / iCloud password

My Granddaughter has lost/forgotten her ID and passwords for her iPad. When the iPad powers on, it goes straight to an iCloud password request and I cannot get past it.  I have installed iTunes on my laptop but it fails to connect to the server (error 310).  I installed iCloud control panel and tried a restore but that failed because of "Find my iPad" was active, which I cannot turn off because of the original password problem!  This is driving me crazy. I just want to reset everything now so that I can hand it back to her. Can anyone help?


Immediately rebanned after flag ban was lifted; should I wait to flag again?

I recently got automatically flag-banned on my Worldbuilding account. When I regained the ability to flag, I flagged another post that I had intended to flag but been unable to because of the ban. That flag was within 24 hours of the ban being lifted, probably within the hour because I was on the site at the time and happened to notice. The flag was accepted as helpful, but the system promptly banned me once again. Now that the ban has once again ended, I am hesitant to flag anything. Will I get banned once again? If so, how long do I have to wait?  I don't have anything specific in mind to flag, but it would help to know whether to leave anything I see as needing flagging to someone else so that I don't get banned again. Getting banned would be a lot less helpful than skipping one post and being able to flag more than one post later on.  The majority of my flags have been helpful, with almost all of the declined ones for off-topic or moderator attention. I do not try to spam the review queues and my flags are well intentioned and usually helpful. I am fairly sure that both bans were because of the system because I flagged more posts than normal in a short amount of time.  Here is a screenshot of my recent flag history. This is not a complete list. To the right, you will see my flag count: 13 post flags, 8 helpful, 5 declined; 3 comment flags, all 3 helpful.    Recently declined flags:


Let $K[x_1, x_2,\dots, x_n] $ be a polynomial ring. If it is a graded ring, then under certain conditions, its subalgebras may be finitely generated.    Isn't a subalgebra of a finitely generated k-algebra always finitely generated?


Consider the Laplacian on the $n$ dimensional torus $T$, given by $-\Delta : L^2 \rightarrow L^2$. Let the domain of $-\Delta$ be all $C^\infty$ functions initially. Now consider the Friedrichs extension of $-\Delta$, still called $-\Delta$. I want to find explicitly what the domain of $(-\Delta)^{1/2}$ is. Intuitively it seems to me that it should be all $L^2$ functions $u$ such that $\frac{\partial}{\partial x_k} u \in L^2, k = 1, 2,...,n$, but cannot prove it. Any help would be appreciated. Thanks!  Edit after Neal's comment: Instead of $-\Delta$, let's say, we consider the following operator $-A = \sum^n_{i = 1} X_i^2$, where $X_i$ are vector fields generating the tangent space at each point, and $A \geq 0$, symmetric and densely defined on $L^2$, so that we can use the Friedrich's extension on $A$. Can we still say that the domain of $A^{1/2}$ consists exactly of all $L^2$ functions $u$ such that $X_i u \in L^2$ for all $i$? Thanks for your time.


I now know the error of my ways and the stack overflow community has shunned my ability to ask a question but I am on my way to recovery. How do you suggest I bounce back? I have a question that I really need answered but I can't post and I can truly say that I regret having asked a few of my questions which were unclear.


Intuition behind the definition of linear transformation

I have studied that given vector spaces $V_1$ and $V_2$, a function $T:V_1 \rightarrow V_2$ is called a linear transformation of $V_1$ into $V_2$, if following two properties are true for all $u, v \in V_1$ and scalar $c$:  $(1)$:  $T(u+v) = T(u) + T(v)$ and $(2):  T(cu) = c T(u) $.  My questions are   $1$: What is the geometrical interpretation of properties $1$ and $2$ which says that $T$ preserves additivity and scalar multiplication. I am not able to see this geometrically. What is the meaning of preserving additivity and scalar multiplication.  $2$: At some place I have studied that a linear transformation will be linear if it sends each line to line and planes to planes and so on. How can we interpret this based on these two properties.  I need help to understand this.   Thank you very much for your time..


I've occasionally seen a negative (when a number is simply negative, not a subtraction), typeset as negative sign that's slightly skinnier and above the centre line of text. Is this proper notation for mathematics and how would one go about typesetting this in LaTeX?   Edit  I believe that calculators were what happened to give me this idea, couldn't find it in any of my math books. Thank you all for the help, it's much appreciated.     Thank you 'Antal S-Z' for the photo link.  However, the question remains, how exactly would I typeset this?


How do you apply colormanagement settings to EXR files?  When i do some color adjustment by using colormanagement and try to save exr file and open it in photoshop it looks like colormanagement settings was not applied to it.


I have created a logo similar to an existing one. Is it plagiarism?

I have designed a logo for my friends company and just now have found a similar one existing in real. I feel very bad about that, what should I do? Redesign or not?   I have made all needed research in order to make violet logo according to companies values.


Find high powers of a matrix with the Cayley Hamilton theorem

Let A =  \begin{bmatrix} 0 & 1 & 0\\ 0 & 0 & 1\\ -1 & -1 &-1\\ \end{bmatrix}  Compute $A^{10000} + A^{9998}$  I know this should be done by the Cayley-Hamilton theorem. I get as characteristic polynomial $-A^3 - A^2 - A - I = 0$ but I don't see how to calculate $A^{10000} + A^{9998}$ from there. I hope someone can help me out!