Hello I wan't to do model collsion in JBullet but that don't won't to work. Models look like have some invisble holes.  Here the code for creating collsion shape:  int triangles_count = (int) ((mesh.getVertices().length) / 3);     int vertices_count = (int) (mesh.getVertices().length);      ByteBuffer index = BufferUtils.createByteBuffer(vertices_count * 3 * 4).order(ByteOrder.nativeOrder());     index.clear();     for(int i=0; i < triangles_count; i++) {         index.putInt(i);     }      ByteBuffer shape = BufferUtils.createByteBuffer(triangles_count * 3 * 4).order(ByteOrder.nativeOrder());     shape.clear();     for(int i=0; i < triangles_count; i++) {         shape.putFloat(mesh.getVertices()[i].getPos().x());         shape.putFloat(mesh.getVertices()[i].getPos().y());         shape.putFloat(mesh.getVertices()[i].getPos().z());     }      shape.rewind();     index.rewind();      TriangleIndexVertexArray triangle_mesh = new TriangleIndexVertexArray(triangles_count, index, 3 * 4, triangles_count, shape, 3 * 4);     BvhTriangleMeshShape out_shape = new BvhTriangleMeshShape(triangle_mesh, true);      return out_shape;   When I change first for loop to this:  for(int i = 0; i < vertices_count; i++)   I have exception  java.lang.IndexOutOfBoundsException produced in this line of code:  BvhTriangleMeshShape shape = new BvhTriangleMeshShape(trimesh, true);

I have a problem with JBullet mesh collsion. Everything works fine when I create a mesh from my object without scaling, but the problem starts when I want to scale the object. I also tried scaling in Blender, but it has the same problem. Here is my code for creating a mesh from an object:      int numtriangles = mesh.vertices.length / 3;     int numverts = mesh.vertices.length;      ByteBuffer indexBuffer = BufferUtils.createByteBuffer(numverts * 3 * 4).order(ByteOrder.nativeOrder());     indexBuffer.clear();     for(int i=0;i<numtriangles;i++) {        indexBuffer.putInt(i);        indexBuffer.putInt(i);        indexBuffer.putInt(i);     }      ByteBuffer geometry = BufferUtils.createByteBuffer(numtriangles * 3 * 4).order(ByteOrder.nativeOrder());     geometry.clear();     for(int i=0;i<numtriangles;i++) {        geometry.putFloat(mesh.vertices[i].getPos().x);        geometry.putFloat(mesh.vertices[i].getPos().y);        geometry.putFloat(mesh.vertices[i].getPos().z);     }      geometry.rewind();     indexBuffer.rewind();      TriangleIndexVertexArray trimesh = new TriangleIndexVertexArray(numtriangles, indexBuffer, 3 * 4, numtriangles, geometry, 3 * 4);     BvhTriangleMeshShape shape = new BvhTriangleMeshShape(trimesh,true);     return shape;   My scaling was something like this:       for(int i = 0; i < vertices.length; i++) {         Vertex acc = vertices[i];          Vector3 pos = acc.getPos();         pos.x *= scale.x;         pos.y *= scale.y;         pos.z *= scale.z;         acc.setPos(pos);          Vector2 tex_coord = acc.getTexCords();         tex_coord.x *= scale.x;         tex_coord.y *= scale.z;         acc.setTexCords(tex_coord);          vertices[i] = acc;     }   The problem is when I scale the object, it no longer collides with other objects.


I am trying to draw a sign line like the one in the image in LaTeX. How can I do this?

As you have probably guessed from the title my mother tounge is not English.  Therefore I have no idea if "Functional lines" is the correct term for what I am looking for.   Basically I am looking to make a command similar to the one below  \functionalines{3x}{x-4}{F_x = (3x)(x-4)}   Then the output should be similar to the tikz code below.   \documentclass{article} \usepackage{tikz} \usetikzlibrary{positioning}  \begin{document} \begin{tikzpicture}[% negativ/.style={blue,dashed}, positiv/.style={red}, vertlinje/.style={dotted,opacity=.7}, node distance=1.5ex, nullpunkt/.style={fill=white,inner sep= 1pt}]   \draw [->,>=stealth] (-5,0) node (linestart) {} -- (5,0) node (lineend) {};   \node (null1) at (-2,0) [label=above:-2] {};   \node (null2) at (1,0) [label=above:1] {};   \node [matrix] (produktledd) [below left=of linestart]{     \node [left] (f1) {$x+2$}; \\     \node [left] (f2) {$x-1$}; \\     \node [left] (f)  {$f(x)= x^2+ x - 2$}; \\    };   \draw [vertlinje] (null1)       -- (null1 |- f);   \draw [vertlinje] (null2)       -- (null2 |- f);   \draw [positiv]   (null1 |- f1) -- (lineend |- f1);   \draw [negativ]   (f1)          -- (null1 |- f1) node[nullpunkt] {$0$};   \draw [negativ]   (null1 |- f)  -- (null2 |- f);   \draw [positiv]   (null2 |- f2) -- (lineend |- f2);   \draw [negativ]   (f2)          -- (null2 |- f2) node[nullpunkt] {$0$};   \draw [positiv]   (f)           -- (null1 |- f)  node[nullpunkt] {$0$}                 (null2 |- f) node[nullpunkt] {$0$} -- (lineend |- f); \end{tikzpicture} \end{document}   A very good friend showed me this code =) Although there are a few small edits that would have been nice.  The top vectorline should be lowered a tad, and go over the equations. Above the equations and the vector there should be an x, indicating we are looking at the x-axis.  Preferably there should be a line below the equations, same length as the line above. Images below.  Is this possible to accomplish?  How the code looks    If I could get the output any way I want, I would want it to be like the one below.     So yeah, any idea, how to make a command which gives the desired output?


Suppose $a_0$ and $B$ are positive numbers , define a sequence $a_{n+1} = \frac{1}{2}(a_n +B/a_n)$. Show that $a_{n+1} \geq\sqrt B$.

Suppose that $S_0$ and A are positive numbers, let $$S_{n+1} = \frac{1}{2}\left(S_n +\frac{A}{S_n}\right)$$ with $n \geq 0 $.      (a)Show that $S_{n+1} \geq \sqrt{A} $ if $n \geq 0$       (b)Show that $S_{n+1} \leq S_n $ , if $n \geq 1$      (c) Show that $s= \lim\limits_{n \rightarrow \infty} S_n$ exists      (d) find s   (a) Show that $S_{n+1} \geq \sqrt{A} $ if $n \geq 0$  Given $$P_n:  S_{n+1} = \frac{1}{2}\left(S_n +\frac{A}{S_n}\right) \geq \sqrt{A}$$  $$P_0: S_{1} = \frac{1}{2}\left(S_0 +\frac{A}{S_0}\right) \geq \sqrt{A}  $$  We assume that $P_n$ is true  $$P_{n+1}: S_{n+2}= \frac{1}{2}\left(S_{n+1} +\frac{A}{S_{n+1}}\right)$$ by assumption $$S_{n+2}= \frac{1}{2}\left(S_{n+1}\left(1 +\frac{A}{(S_{n+1})^2}\right)\right) \geq \frac{1}{2}\left(\sqrt{A}\left(1 +\frac{A}{(\sqrt{A})^2}\right)\right)$$ $$ S_{n+2}= \frac{1}{2}\left(S_{n+1} +\frac{A}{S_{n+1}}\right) \geq \sqrt{A}  $$  It follows that $S_{n+1} \geq \sqrt{A} $    (b) Show that $S_{n+1} \leq S_n $ , if $n \geq 1$  $$S_{n+1} \leq S_n$$ $$\frac{1}{2}\left(S_n +\frac{A}{S_n}\right) \leq S_n $$ Dividing by $S_n$ $$\frac{1}{2}\left(1 +\frac{A}{S_n^2}\right) \leq 1 $$ $$\frac{A}{2S_n^2} \leq \frac{1}{2}$$ $$A \leq S_n^2$$ $$S_n \geq \sqrt{A}$$ As  $S_{n+1} \leq S_n$ yields a true statement, it follows $S_{n+1} \leq S_n$ is true.    (c) Show that $s= \lim\limits_{n \rightarrow \infty} S_n$ exists  Since $S_{n+1} \leq S_n$, the sequence is non-increasing,   using the non-increasing theorem stating that      if $\{S_n\}$ is non-increasing then $$\lim\limits_{n \rightarrow > \infty} S_n = \inf\{S_n\} $$     (d) find s    Is the argumentation in (a) and (b) appropriate? Also, I have to admit I m getting less confident in my argumentation (c) and (d). How to proceed in (c) and (d)?  Much appreciated for your input or help.


I have following text:   response={\n  &quot;status&quot; : &quot;ERROR&quot;,\n &quot;message&quot; : &quot;<ERROR Mes$@ge can be anything>&quot;,\n &quot;responseMessage&quot; : &quot;Response&quot;,\n &quot;reason&quot; : &quot;REASON&quot;,\n  }   I want to extract this part from the above text -   &quot;message&quot; : &quot;<ERROR Mes$@ge can be anything>&quot;   Please note - error message can have any chars including special chars.  I have written following regex -   \&quot;message\&quot; \: \&quot;.+\&quot;,\\n   However, it extracts till the last occurrence of &quot;,\n.  I think somehow I should count the occurrences of &quot; in the regex.  Need help with the Regex.

I have this gigantic ugly string: J0000000: Transaction A0001401 started on 8/22/2008 9:49:29 AM J0000010: Project name: E:\foo.pf J0000011: Job name: MBiek Direct Mail Test J0000020: Document 1 - Completed successfully  I'm trying to extract pieces from it using regex. In this case, I want to grab everything after Project Name up to the part where it says J0000011: (the 11 is going to be a different number every time). Here's the regex I've been playing with: Project name:\s+(.*)\s+J[0-9]{7}:  The problem is that it doesn't stop until it hits the J0000020: at the end. How do I make the regex stop at the first occurrence of J[0-9]{7}?


My left crank arm keeps coming loose on the square taper BB -I can't tell for sure but whats most likely at fault the arm or the bottom bracket wearing?When I bang it back on and tighten it's fine for a while.I've tried not to ride far when its loose to avoid more damage.

Any idea what kind of tool should I but to fix the loose left crank on my bike? I found this  but not sure if it's gonna suit. Or is it enough to buy only nut driver?


I am totally new to electronics and don't know much but am trying to create a project that uses a 29rpm 6v DC motor. I was wondering if I were to use a higher voltage battery ( a 9v battery) would it be able to power the lower voltage motor?

I am thinking about buying a 12V DC motor but want to keep everything, including the motor, battery, and power switch somewhat compact. I am not very knowledgeable about these kind of things and am curious whether or not my 12V DC motor would run at all on a 9V battery.


I want to change the QGIS logo(like in the image) when QGIS starts. Can me help someone for this?

Where can I find the splash image which is shown while starting QGIS, and how to customise it?  I am developing a GIS software for myself based on QGIS, but I don't want to just start anew with QGIS's include and lib as it cost much time and energy. Instead, with the QGIS interface, I can pay more attention to create my own algorithms and add them to QGIS as plugins like sextante. Yet,I got my favoured bgimage before and still want to use it in this software I am developing.


I want to specify the default behavior of floats to be htbp and I want to do this in a class definition for the whole document. I already found floatpos in the documentation, but this does not affect the default of existing documents does it?

I have a document with many floats (figures, specifically).  I want to be able to change the global floats positioning policy from htbp to just h (or even H with the floats package).  For my-own reasons, I don't want to do this by appending the [h] argument to each float env.  One option that I can think of is using a macro:  \newcommand{\mypos}{h} % or htbp \begin{figure}[\mypos]...   I also prefer not to do that - It is cumbersome.  Is there a way to set the global float positioning argument globally?


According to  Stack Overflow Careers should be on topic here. However I had a  about a possible bug closed with the reason "This question pertains only to a specific site in the Stack Exchange Network". I tried asking about this in the comments but got no responses. So if this is the wrong place for this type of question, where is the correct place to ask for support? Or is careers.stackoverflow.com a website with no support?

From  it appears that the Meta site for Jobs (formerly Careers) is now  but I do not recall that being written here on Meta Stack Exchange in other than a comment or two.  Are questions on Jobs (formerly Careers) now off-topic here at Meta Stack Exchange?  I think they must be because some recent questions on that topic have been migrated from here to :       Looking for guidance I found  but it seems concerned with arrangements for Careers rather than Jobs, and thus to be outdated.


In Goldstein's Classical Mechanics, he suggests the use of Lagrange Multipliers to introduce certain types of non-holonomic and holonomic contraints into our action. The method he suggests is to define a modified Lagrangian $$L^{'}(\dot{q},q;t) = L(\dot{q},q;t) + \sum^{m}_{i = 1}\lambda_{i} f_{i}(\dot{q},q;t),$$ where $f_{i}(\dot{q},q;t)$ are $m$ equations of constraint, and $L$ the original Lagrangian. He then proceeds to define the action $S^{'} = \int_{t_{1}}^{t_{2}}L^{'}\,dt$ and takes the variation of $S^{'}$ to be zero, thus applying Hamilton's principle. My confusion in this approach arises from the way in which the Lagrange Multipliers are introduced. I don't see why $\sum^{m}_{i = 1}\lambda_{i} f_{i}(\dot{q},q;t)$ should be introduced inside the integral. In multivariable calculus, the Lagrange multiplier system stems from the idea that if we want to extremize a function subject to certain constraints, then the gradient of the function will be proportional to a linear combination of the gradient of the constraint equations. Here, the function in question is the action, not the Lagrangian. So, I feel like the resolution should be that $$\delta S + \delta \sum^{m}_{i = 1}\lambda_{i} f_{i}(\dot{q},q;t) = 0;\, S = \int_{t_{1}}^{t_{2}}L\,dt$$ and not $$\delta S^{'} = 0; \, S = \int_{t_{1}}^{t_{2}}L^{'}\,dt.$$ To me, it isn't clear if this makes sense or if the two methods are equivalent.

I am studying from Goldstein's Classical Mechanics, 3rd edition. In section 2.4, he discussed Hamiltion's principle with semiholonomic constraints. The constraints can be written in the form $f_\alpha(q_1,...,q_n;\dot{q_1},...,\dot{q_n};t)=0$ where $\alpha=1,...,m$. Using variational priciple, we get  $$\delta\int_{t_1}^{t_2}\left(L+\sum_{\alpha=1}^m \mu_\alpha f_\alpha\right)\mathrm dt=0 \tag{2.26}$$  where $\mu_\alpha=\mu_\alpha(t)$.  But how can he get the formula   $$\frac{d}{dt}\frac{\partial L}{\partial\dot{q_k}}-\frac{\partial L}{\partial q_k}=-\sum_{\alpha=1}^m \mu_\alpha \frac{\partial f_\alpha}{\partial\dot{q_k}} \tag{2.27}$$   for $k=1,...,n$ from the previous formula?  When I go through the steps as in section 2.3, I get $$\frac{dI}{d\beta}=\int_{t_1}^{t_2}\sum_{k=1}^n\left(\frac{\partial L}{\partial q_k}-\frac{d}{dt}\frac{\partial L}{\partial\dot{q_k}}+\sum_{\alpha=1}^m \mu_\alpha\left(\frac{\partial f_\alpha}{\partial q_k}-\frac{d}{dt}\frac{\partial f_\alpha}{\partial\dot{q_k}}\right)\right)\frac{\partial q_k}{\partial\beta}\mathrm dt$$ where $\beta$ denotes the parameter of small change of path: \begin{align} q_1(t,\beta)&=q_1(t,0)+\beta\eta_1(t)\\ q_2(t,\beta)&=q_2(t,0)+\beta\eta_2(t)\\ &\ \,\,\vdots \end{align} Using the same argument as in the part of holonomic constraint in section 2.4, I get $$\frac{\partial L}{\partial q_k}-\frac{d}{dt}\frac{\partial L}{\partial\dot{q_k}}+\sum_{\alpha=1}^m \mu_\alpha \left(\frac{\partial f_\alpha}{\partial q_k}-\frac{d}{dt}\frac{\partial f_\alpha}{\partial\dot{q_k}}\right)=0$$ for $k=1,...,n$.  What am I missing?


I would like to receive a dataset of N elements and group it every 59 elements, considering that the first element would have the index 0. The problem in this script is that in the sample.append(data [i]) part, it groups all the data again in a single list, I would like to divide it as follows. [[60 elements], [60 elementps], ...]. Any suggestions for correction?  Script:  @staticmethod         def sampleDivision(data):     parts = int(len(data) / 60)     collections = []     i = 1     while i <= parts:         i * 60         collections.append(i * 59)         i += 1     print(collections)     i = 1     sample = []     for position in collections:         while i <= int(position):             sample.append(data[i])             i += 1      return sample   Output:  [68, 69, 68, 69, 70, 71, 75, 72, 73, 72, 72, 73, 72, 72, 73, 70, 71, 73, 72, 72, 71, 69, 68, 69, 68, 69, 68, 69, 68, 68, 68, 68, 69, 68, 69, 70, 71, 75, 72, 69, 68, 68, 68, 69, 68, 69, 70, 71, 75, 72, 69, 68, 69, 68, 69, 68, 69, 68, 68, 60, 60, 61, 60, 61, 65, 69, 69, 72, 73, 72, 72, 73, 72, 72, 73, 70, 71, 73, 75, 78, 80, 82, 84, 87, 84, 84, 83, 82, 79, 78, 76, 74, 73, 72, 72, 72, 71, 75, 72, 69, 68, 68, 68, 69, 68, 69, 70, 71, 75, 72, 69, 68, 69, 68, 69, 68, 69, 68]

I have a list of arbitrary length, and I need to split it up into equal size chunks and operate on it. There are some obvious ways to do this, like keeping a counter and two lists, and when the second list fills up, add it to the first list and empty the second list for the next round of data, but this is potentially extremely expensive.  I was wondering if anyone had a good solution to this for lists of any length, e.g. using generators.  I was looking for something useful in itertools but I couldn't find anything obviously useful. Might've missed it, though.  Related question:


I have a roughly 4'x 3' hole in plaster wall.  I've seen few youtube videos about how to repair it, but none of them say what product/mix they use.  I've read about using DAP Plaster Wall Patch, but it's not carried by most stores anymore.  Neither is structalite.  Any other product I can use instead of actual plaster?

I have a 100+ year old house and while it's quite structurally sound there's been some settling over the years, leading to small cracks in the old plaster around the house.  I hired a professional to take care of some big cracks in the dinning and living room. But now I want to tackle the upstairs bedrooms myself. What is the best method for repairing these cracks in plaster (not drywall)? What products do you recommend for using in this project?


I have programs from snap - Telegram, Skype and some others.  And I have secondary ntfs hdd drive shared with Windows.  All programs from snap can not read files from ntfs - Telegram, Skype.  I know that my Kubuntu using ntfs-3g driver.  ntfs drive mounts with dolfin (or I can mount on startup with KDE settings GUI with the same result).  The same programs from other repositories works fine.  Can it be solved, and how?  PS: I tried the way . It fixes problem with Telegram using   sudo snap connect telegram-desktop:removable-media   but the same does not work with skype.   sudo snap connect skype:removable-media      error: snap "skype" has no plug named "removable-media"

I have installed KeePassXC snap package on Ubuntu 17.10. I have multiple linux systems installed on the same drive, so I have made most of my home folders like ~/Documents created as links to a separate ext4 partition (users have same uid so permissions are correct). I tried to open my passwords' database which I have inside Documents, but keepassxc cannot see any files inside Documents. If I put the file in my home folder then it sees it.  Are snap packages able to find files outside from my home folder? Any way to make KeePassXC (and the rest snap packages) access the files at my separate ext4 partition (maybe some configuration somewhere)?


There is this annoying thing going on when I render my image in blender. Here is what it looks like without rendering  And here is what it looks like when I render it.

I made a character, and its one of my first times texturing, and I saved my character into a new folder, and when I came back to the model ALL the textures were pink, I used to know what to do, but I stopped texturing, how do I bring my textures back?


On Ubuntu 14.04, MATE desktop. I have just installed Tilda terminal, and so I added it to Startup Applications, just as /usr/bin/tilda. Rebooted, saw Tilda startup, and then noticed this:    "Your 131072x1 screen size is bogus. expect trouble"  Then I tried killall tilda, started tilda again, same message.  Anyone know how can I fix this bogus screen size issue?

I opened terminal windows and I got a message   your screen size %d%d is bogus. Expect trouble   I closed the terminal and the next time I opened terminal, the message didn't show up.   What is this message and why did I receive it?


I love using the 'User Agent Switcher' Firefox addon on most sites on my desktop PC, in order to trick websites into using the mobile versions by masquerading as an iPhone/Android user agent. I like how on mobile sites I can enlarge text as much as I want and it will move text to the next line instead of making me scroll left and right to read it all.  However, of course, video sites such as YouTube ask me to install the Safari plugins, which I cannot do. I would love to be able to use the 'User Agent Switcher' addon in separate tabs, or only for certain websites.  How can I do this?

I have to use a particular web site for work, but this web site checks to see whether I'm using Internet Explorer and, if not, won't allow me to log in.  I can switch my User-Agent header using the  Firefox plugin and the web site works fine, but I really don't want to switch the header every time I go to the site and also don't want my User-Agent header to perpetually say I'm using IE.  I'm on Linux, so actually switching to IE unfortunately isn't an option.  Is there any way to define a particular User-Agent for a particular web site in either Firefox or Chrome?


I'm curious if "May you" + verb is grammatically correct - any comments?  Thank you.

At a family dinner, my 18-year-old niece asked my sister, "May you please pass the salt?" My sister said that she was impressed with her daughter's politeness, but that that particular wording was not correct.  My niece said that she had been taught to say that (by whom she could not say, but probably by her father—the parents divorced years ago.)   Despite our best attempts, we were unable to convince her of the illogical nature of the "May you please" construction.  How would you explain it to her?


You say 'I like to do something' or 'I like doing something' to refer to something in general, as in "I like to watch movies." or "I like watching movies." Can you use like in more specific situations showing some kind of intention as in "I like to watch the/this movie."    Does the sentence "She doesn't like to admit she's wrong." refer to a general or a specific situation? Is it that she generally doesn't like to admit she's wrong, or that in a specific time and place she is refuring to accept she's wrong?

This is what I read in an answer to a :     Verbs Followed by Either Gerund or Infinitive      Sometimes the meaning changes according to the verb used.         <…>   (dis)like   <…>      I’d like to ask a more specific question: What is that change in the case of (dis)like, exactly? What is the difference between, say, I like being married and (?) I like to be married, I like to eat paper and I like eating paper?


I'm trying to write a regular expression for parsing address.   My address strings have next format: AddressLine (City) SomeFixedText  The only problem that (City) part is optional. For example:  Abingdon Road (Oxford) Water Network Pumping Adderbury Water Network Pumping   Without capturing optional group I've come up with following expression:  (?<Line>.*) \((?<City>.*)\) Water Network Pumping   But of course it doesn't not handle the second case. I tried to use an optional group:  (?<Line>.*)( \((?<City>.*)\))? Water Network Pumping   But in this case Line and City are captured incorrectly for the first case.  Here is the fiddle:   How can I handle this situation?

I have this gigantic ugly string: J0000000: Transaction A0001401 started on 8/22/2008 9:49:29 AM J0000010: Project name: E:\foo.pf J0000011: Job name: MBiek Direct Mail Test J0000020: Document 1 - Completed successfully  I'm trying to extract pieces from it using regex. In this case, I want to grab everything after Project Name up to the part where it says J0000011: (the 11 is going to be a different number every time). Here's the regex I've been playing with: Project name:\s+(.*)\s+J[0-9]{7}:  The problem is that it doesn't stop until it hits the J0000020: at the end. How do I make the regex stop at the first occurrence of J[0-9]{7}?


Apart from automatically setting the size for brackets, the commands \left and \right also adds spacing around the corresponding brackets. The spacing in which one uses both \left( and \right) and parentheses without these commands  the spacing might therefor be inconsistent. Is the intention behind this that the commands \left and right should always be used when parentheses are inserted into equations?  If not, what is good practice for when to use these?

For mathematics, is it ever disadvantageous to use \left(  and \right)  in equations?  I can't see any way that doing this would hinder the typesetting, so why isn't () just converted into \left( \right) automatically? This would save a lot of typing.  Cheers!


Would u please help me with understanding the end of this proof? I want to know that why J=R at the end of the proof. How we could get that? Do we use of “J contains ker(f)” for proving that? How? Question : Let f:R—>S be a homomorphism of commutative unital rings. Suppose that f is surjective. Prove that if P is a maximal ideal of S then f^(-1)(P) is maximal in R. Proof: If J is an ideal of R which contains f^(−1)(P) then J contains ker f and f(J) is an ideal of S containing P. Since P is maximal, we have either f(J) = P or f(J) = S. Since J contains the kernel of f, we have J = f^(−1) (P) or J = f^(−1)(S) = R. This proves that f^(−1)(P) is maximal.

Let $f :R \to S$ be a surjective ring homomorphism , $M$ be a maximal ideal of $S$ , I am writing a proof showing $f^{-1}(M)$ is a maximal ideal of $R$ , Please verify whether it is correct or not .   Proof :- Let $J$ be an ideal such that $f^{-1}(M) \subset J \subseteq R$ , we want to show $J=R$ i.e. $R \subseteq J$. Now as  $f$ is surjective , $M=f(f^{-1}(M)) \subseteq f(J) \subseteq S$ . As $f$ is surjective , $f(J)$ is an ideal of $S$ . Now if it were possible that $M=f(J)$ , then $x \in J \implies f(x) \in f(J)=M \implies x \in f^{-1}(M)$ , so $J \subseteq f^{-1} (M)$  ,contarry to our assumption $f^{-1}(M) \subset J$ . Thus $M \ne f(J)$ , $f(J)$ is an ideal of $S$ containing $M$ ; since $M$ is maximal ideal in $S$ , so $f(J)=S$ . Then $x \in R \implies f(x) \in S=f(J) \implies \exists j \in J : f(x)=f(j) \implies f(x-j)=0_S \in M $  $\implies x-j \in f^{-1} (M) \subset J \implies x=x-j+j \in J$ , so $R \subseteq J$   Is the proof correct . Please comment .


I would like to know if there is a method for reading characters from a file and saving them into an array without a specified array length.   In normal situation I read all the characters and count them. (step 1) Then I create the array with malloc and read the characters from the file, so I am forced to read the whole file twice. Can it be done with only one reading?

How can I figure out the size of a file, in bytes?  #include <stdio.h>  unsigned int fsize(char* file){   //what goes here? }


If you have never logged in to Google, for example when you install a new browser (specifically, if no Google cookies are set), and you try to log in to a Stack Exchange site using your Google account, when you click the red "Google" button, you get this message:  Suspicious request Sorry, your request could not be completed because it looked suspicious. If you meant to perform an action on Stack Overflow, please return to the previous page and try again.  Here's a screen shot:  "Trying again" yields the same result. The problem is the attempt is not "suspicious", so the message is incorrect/inappropriate. It's a reasonably expected scenario that should be catered for, probably by redirecting to the Google log in page as it does when Google cookies are set, but you're just not logged in to Google.  To repeat:  Clear browser cookies Browse to a stack exchange site Click "log in" Click the red Google button The above message immediately appears  Then, to make the problem go away, change step 1. either to:  Log in to Google Log off from Google  or, of course:  Log in to Google   I have verified that this problem occurs on:  Ubuntu/Firefox Ubuntu/Chrome Windows 7/Firefox Windows 7/Chrome Windows 7/Internet Explorer Windows 10/Chrome Windows 10/Internet Explorer Windows 10/Firefox   For completeness, other related scenarios work OK:  If you have a Google account cookie set, but you're not logged in, clicking the red Google button works - you get redirected to the Google account log in page, where you can log in to Google, and then you're logged in to Stack Exchange too If you're not logged into google already, clicking the red Google button logs you in to Stack Exchange immediately

I am getting this error repeatedly when I try to login to the  site for the first time using a Google id.  Sorry, your request could not be completed because it looked suspicious. If you meant to perform an action on Physics, please return to the previous page and try again.  I am using few other Stack Exchange and Stack Overflow sites,


I want to generate a table from a list. However for some reason it fails to work. I searched:      and tried different solutions but none of them work for some reason :(  \documentclass{minimal}                                                          \usepackage{tikz}                                                                \begin{document}                                                                   \begin{tabular}{ll}                                                                  \foreach \x/\y in {-2/a,-1/b,1/c,2/d} {%                                               \edef\temp{\noexpand \x & \y \\ }%                                                   \temp                                                                              }%                                                                                \end{tabular}                                                                    \end{document}      Edit...  Also tried   \documentclass{minimal} \usepackage{tikz,etoolbox} \makeatletter \newtoks\@tabtoks \newcommand\addtabtoks[1]{\global\@tabtoks\expandafter{\the\@tabtoks#1}} \newcommand\eaddtabtoks[1]{\edef\mytmp{#1}\expandafter\addtabtoks\expandafter{\mytmp}} \newcommand*\resettabtoks{\global\@tabtoks{}} \newcommand*\printtabtoks{\the\@tabtoks} \makeatother \begin{document} \resettabtoks \foreach \x/\y in {-2/a,-1/b,1/c,2/d}{%   \eaddtabtoks{\x & \y \\ }% }%  \begin{tabular}{ll} \printtabtoks \end{tabular} \end{document}   Does not seem to work.     (/usr/local/texlive/2013/texmf-dist/tex/generic/oberdiek/etexcmds.sty)))   (/usr/local/texlive/2013/texmf-dist/tex/latex/latexconfig/epstopdf-sys.cfg))   ! Undefined control sequence. \  ->\let \reserved@e                           \relax \let \reserved@f \relax \@ifstar {\let \reserv... l.17 }         % ?

I am trying to build a table, and inside the tabularx environment I would like to have a loop, something like (here is a MWE):  \documentclass[10pt,a4paper]{article} \usepackage{tabularx} \usepackage{tikz} \newcommand{\nRows}{5} \begin{document}   \begin{tabularx}{\textwidth}{@{}>{\raggedright}p{2.2cm}@{}>{\raggedright}X@{}>{\raggedright}X@{}>{\raggedright}X@{}>{\raggedright}X@{}}     \foreach \r in {1,...,\nRows}{  % https://stackoverflow.com/questions/2561791/iteration-in-latex         \textbf{column1} & two & three & four & five      } \end{tabularx}  \end{document}   This doesn't work, because the ampersands (&) are causing problems. If I escape the &s, then the entire line gets printed in the first column, along with the literal ampersands, kind of like:  \documentclass[10pt,a4paper]{article} \usepackage{tabularx} \usepackage{tikz} \newcommand{\nRows}{5} \begin{document}   \begin{tabularx}{\textwidth}{@{}>{\raggedright}p{2.2cm}@{}>{\raggedright}X@{}>{\raggedright}X@{}>{\raggedright}X@{}>{\raggedright}X@{}}     \foreach \r in {1,...,\nRows}{  % https://stackoverflow.com/questions/2561791/iteration-in-latex         \textbf{column1} \& two \& three \& four \& five      } \end{tabularx}  \end{document}   This yields:  |column1 &      | | | | | two & three & | | | | | four & five   | | | |   Whereas what I want is:  |column 1 | two | three | four | five | |column 1 | two | three | four | five | |column 1 | two | three | four | five |   ....  Any ideas on how I can achieve this? I'm actually NOT looking to make identical rows - the rows will be different. This is just a MWE. Thanks!  Edit: I have tried implementing Herbert's answer as recommended in the comments section. It results in no output - just a blank PDF. Here is how I implemented it:  \documentclass[10pt,a4paper]{article} \usepackage{tabularx} \usepackage{tikz} \newcommand{\nRows}{5}  \makeatletter \newtoks\@tabtoks \newcommand\addtabtoks[1]{\@tabtoks\expandafter{\the\@tabtoks#1}} \newcommand*\resettabtoks{\@tabtoks{}} \newcommand*\printtabtoks{\the\@tabtoks} \makeatother  \begin{document}      \resettabtoks     \foreach \r in {1,...,\nRows}{  % https://stackoverflow.com/questions/2561791/iteration-in-latex         % \textbf{column1} \& two \& three \& four \& five          \addtabtoks{\textbf{column1} & two & three & four & five \\\hline}%     }  \begin{tabularx}{\textwidth}{@{}>{\raggedright}p{2.2cm}@{}>{\raggedright}X@{}>{\raggedright}X@{}>{\raggedright}X@{}>{\raggedright}X@{}} \printtabtoks \end{tabularx}  \end{document}   Any ideas on what I am doing wrong? Thanks!


I am wondering if ASP.Net MVC 2 is a good choice for my current project. I want to build a social site that will allow for plugins or modular apps to be added on to it. An example of what I am talking about would be socialengine.net or even Joomla.  I was thinking that mvc areas would make good modular apps to plug into a core app but wondering if some sort of installer could be created that would wire things up automatically.  Anyone know of any examples of this somewhere on the net?

I've been spending some time looking at Phil Haack's article on  very interesting stuff.  At the moment I'm trying to figure out if it would be possible to use the same ideas to create a plug-in/modular architecture for a project I'm working on.  So my question is: Is it possible to have the Areas in Phil's article split across multiple projects?  I can see that the name spaces will work themselves out, but I'm concerned about the views ending up in the right place. Is it something that can be sorted out with build rules?  Assuming that the above is possible with multiple projects in a single solution, does anyone have any ideas about the best way to make it possible with a separate solution and coding to a predefined set of interfaces? Moving from an Area to a plug-in.  I have some experiences with plug-in architecture but not masses so any guidance in this area would be useful.


I want all traffic to the non-https example.com and www.example.com to be redirected to the https www.example.com with the exception of a certain path, i.e.   , /import/XXX, /import/YYY should stay http.  At the moment, I'm using the following to redirect all non-https traffic to https.  <VirtualHost *:80>         ServerName www.example.com          Redirect permanent / https://www.example.com/ </VirtualHost>   Which I think is where most of my problems are coming from when I try and do rewrites as I end up in a loop.  Update  I've enabled mod_rewrite logging and got the result:  ... (2) init rewrite engine with requested uri /import/batch_name ... (3) applying pattern '^(.*)$' to uri '/import/batch_name' ... (1) pass through /import/batch_name ... (3) [perdir /var/www/] add path info postfix: /var/www/import -> /var/www/import/batch_name ... (3) [perdir /var/www/] strip per-dir prefix: /var/www/import/batch_name -> import/batch_name ... (3) [perdir /var/www/] applying pattern '^' to uri 'import/batch_name' ... (3) [perdir /var/www/] add path info postfix: /var/www/import -> /var/www/import/batch_name ... (3) [perdir /var/www/] strip per-dir prefix: /var/www/import/batch_name -> import/batch_name ... (3) [perdir /var/www/] applying pattern '^' to uri 'import/batch_name' ... (3) [perdir /var/www/] add path info postfix: /var/www/import -> /var/www/import/batch_name ... (3) [perdir /var/www/] strip per-dir prefix: /var/www/import/batch_name -> import/batch_name ... (3) [perdir /var/www/] applying pattern '^' to uri 'import/batch_name' ... (3) [perdir /var/www/] add path info postfix: /var/www/import -> /var/www/import/batch_name ... (3) [perdir /var/www/] strip per-dir prefix: /var/www/import/batch_name -> import/batch_name ... (3) [perdir /var/www/] applying pattern '(^|/)\.' to uri 'import/batch_name' ... (3) [perdir /var/www/] add path info postfix: /var/www/import -> /var/www/import/batch_name ... (3) [perdir /var/www/] strip per-dir prefix: /var/www/import/batch_name -> import/batch_name ... (3) [perdir /var/www/] applying pattern '^' to uri 'import/batch_name' ... (2) [perdir /var/www/] rewrite 'import/batch_name' -> 'index.php' ... (3) [perdir /var/www/] add per-dir prefix: index.php -> /var/www/index.php ... (2) [perdir /var/www/] strip document_root prefix: /var/www/index.php -> /index.php ... (1) [perdir /var/www/] internal redirect with /index.php [INTERNAL REDIRECT] ... (2) init rewrite engine with requested uri /index.php ... (3) applying pattern '^(.*)$' to uri '/index.php' ... (2) rewrite '/index.php' -> 'https://www.example.com/index.php' ... (2) explicitly forcing redirect with https://www.example.com/index.php ... (1) escaping https://www.example.com/index.php for redirect ... (1) redirect to https://www.example.com/index.php [REDIRECT/301]

This is a  about Apache's mod_rewrite.   Changing a request URL or redirecting users to a different URL than the one they originally requested is done using mod_rewrite. This includes such things as:   Changing HTTP to HTTPS (or the other way around) Changing a request to a page which no longer exist to a new replacement. Modifying a URL format (such as ?id=3433 to /id/3433 ) Presenting a different page based on the browser, based on the referrer, based on anything possible under the moon and sun. Anything you want to mess around with URL   Everything You Ever Wanted to Know about Mod_Rewrite Rules but Were Afraid to Ask!  How can I become an expert at writing mod_rewrite rules?   What is the fundamental format and structure of mod_rewrite rules? What form/flavor of regular expressions do I need to have a solid grasp of? What are the most common mistakes/pitfalls when writing rewrite rules? What is a good method for testing and verifying mod_rewrite rules? Are there SEO or performance implications of mod_rewrite rules I should be aware of? Are there common situations where mod_rewrite might seem like the right tool for the job but isn't? What are some common examples?   A place to test your rules  The  web site is a great place to play around with your rules and test them. It even shows the debug output so you can see what matched and what did not.


What are the advantages of:  1) namespaces  2) including headers in a namespace  3) reverse of " using " namespace

I come from a Java background, where packages are used, not namespaces. I'm used to putting classes that work together to form a complete object into packages, and then reusing them later from that package. But now I'm working in C++.  How do you use namespaces in C++? Do you create a single namespace for the entire application, or do you create namespaces for the major components? If so, how do you create objects from classes in other namespaces?


For example I want to print long dash  I read that it's possible to do with numpad and code of Unicode of character, so I tried doing Alt+Shift+u + code, but without success.

The title pretty much says it all: how can I type Unicode characters - specifically the em-dash —?


I have already beat Uncharted 3 on Normal and I am trying to do it on Hard. I have gotten to the final boss fight with Talbot and nothing I do seems to work. I can only attack him at the very beginning of the fight. After about 30 seconds of fighting, every time I press square to attack him he puts me in the hold where he holds my arm behind my back and tries to stab me. I press circle as fast and as many times as possible but Nate never bites his arm. Talbot always just throws me out of the hold. This just happens over and over again for sometimes longer than 10 minutes or until I get frustrated and start over. I must be doing something wrong or there is a glitch in the game. Please help me out?

This may seem like a bit of a weird question, especially considering I beat the game on Crushing last night, but here goes...  What is the trick to winning the final boss fight against Talbot on the Crushing difficulty? While I did finally defeat him last night, it seemed due more to luck than skill. But there must be some pattern to it, or some sequence of events that must happen. However, it took me many, many attempts to finally overcome him, and during all these attempts I seemed to be getting a lot of successful hits, and fending attacks successfully. Some attempts I was fighting him for well over 3 minutes, but when I finally defeated him, it took just over 2.   In summary; I beat him, but I have no idea what the magic formula was that allowed me to do so.


so the code that tests my exercises is giving me the fail test of:   "nullpointerexception, in call addPlayer(Player: Atro, 0). Code that caused the failure Team j = new Team("HIFK"); Player p = new Player("Atro"); j.addPlayer(p);  I've ran this code in my main and it works just fine so I dont understand why the testcode has a problem.  public class Main { public static void main(String[] args) {     Team barcelona = new Team("FC Barcelona");     barcelona.setMaxSize(16);     Player brian = new Player("Brian");     Player pekka = new Player("Pekka", 39);     barcelona.addPlayer(brian);     barcelona.addPlayer(pekka);     barcelona.addPlayer(new Player("Mikael", 1));      System.out.println("Total goals: " + barcelona.goals()); }   }  import java.util.ArrayList;  public class Team { private String name; private ArrayList<Player> playersOnTeam = new ArrayList<>(); private int maxSize;   public Team(String teamName) {     name = teamName; }  public String getName() {     return name; }  public void addPlayer(Player playerToAdd) {     if (playersOnTeam.size() == maxSize) {         return;     }     playersOnTeam.add(playerToAdd); }  public void printPlayers() {     String playerList = "";     for (Player i : this.playersOnTeam) {         System.out.println(i.getName() + ", " + "goals " + i.goals());     } }  public void setMaxSize(int setSize) {     maxSize = setSize; }  public int size() {     return playersOnTeam.size(); }  public int goals() {     int allGoals = 0;     for (Player i : playersOnTeam) {         allGoals = allGoals + i.goals();     }     return allGoals; }   }  public class Player { private String playerName; private int goals;  public Player(String name) {     this(name,0); }  public Player(String name, int score) {     playerName = name;     goals = score; }  public String getName() {     return this.playerName; }  public int goals() {     return goals; }  public String toString() {     return "Player: " + playerName + ", " + "Goals " + goals; }   }

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


I'd like to know if is possible exit from a while loop pressing a key,  for example do a program that load number until you press 'q'. I work on linux and I'd like do something like this:  do{    cin >> num;    numbers.push_back(num); }while(key(q));   not gui

I can never remember how I do this because it comes up so infrequently for me. But in C or C++, what is the best way to read a character from standard input without waiting for a newline (press enter).  Also ideally it wouldn't echo the input character to the screen. I just want to capture keystrokes with out effecting the console screen.


I'm trying to use a .dmg file. I have it downloaded and everything but whenever I try to open it, it doesn't do anything. Am I doing something wrong?

Not entirely sure if this is where to ask this, but I can't find another place to...  I've recently switched from Windows to Mac and I am trying to understand more in depth what I'm working with.  My question is: are .dmg files the equivalent of .zip files in Windows? I came to this theory when downloading a .dmg and when I opened it, it contained a .app and and text file read me. To me, this seems like a compressed file.   Is this correct?


I have been getting a null pointer exception at the split statement. I have initialised all_data1 variable, which when using a split must be an array. Please suggest what am I doing wrong... This is the code for your reference...      test_cases = t_inp.nextInt();      //input test cases     for(i=0;i<test_cases;i++)     {          String all_data = "";          all_data = d_inp.readLine();          all_data1 = all_data.split("\\s+");          up_bnd[i] = Integer.parseInt(all_data1[i]);          lw_bnd[i] = Integer.parseInt(all_data1[i+1]);          Arrays.fill(all_data1, "");          System.out.println(up_bnd);          System.out.println(lw_bnd);      }


I am contacting you guys concerning one of the problems that I believe I will have them during my trip through Barcelona Airport.   I am traveling from Morocco (CMN Airport, Casablanca) to Indianapolis, USA. I have the USA visa and I found out that I may have problems ( I am sure that as Moroccan I don't need a Transit visa thought Spain), but in my electronic flight ticket I have to stay in Barcelona Airport for 6h and 35min and at the same time I have to get my checked luggage and I have to register them again in the same airport (Same Terminal 1 (Arrival/Departure).  My question is: do I am going to apply for a transit visa if I am going to stay 7hours in the airport waiting for my second flight (Even if I am asked to search for my checked luggage and I am asked to register them again which means that I have to pass through the security check I believe).   I hope I am being clear enough with my question and the situation description.  I would like to thank you in advance for your time and comprehension.

I found many related questions on this site but I am still not sure about the rules. How can I decide if I need a visa to transit? Schengen members as of May 2021 are as follows:  Austria Belgium Czech Republic Denmark (excluding Greenland and the Faroe Islands - but an open border with the Schengen Area is maintained) Estonia Finland France (excluding overseas departments and collectivities) Germany Greece Hungary Iceland Italy Latvia Liechtenstein Lithuania Luxembourg Malta Netherlands (excluding Aruba, Curaçao, Sint Maarten and the Caribbean Netherlands) Norway (excluding Svalbard) Poland Portugal Slovakia Slovenia Spain (except Ceuta and Melilla) Sweden Switzerland


I am a undergraduate majoring in CS. In preparation for a discrete mathematics exam coming up next week, I am looking through problems I got wrong on the homework. A concept I don't understand are surjections, injections, and bijection. From lecture, for a function to be a bijection, it has to be both an injection and a surjection. So say I proved a function is not a surjection, why couldn't I say that it has to be injection since we know it can't be a bijection by definition?   So my homework problem is in the link below.        Problem 4.26. Let $A$, $B$, and $C$ be sets and let $f\colon B\to C$ and $g\colon A\to B$ be functions. Let $h\colon A\to C$ be the composition, $f\circ g$, that is, $h(x)::=f(g(x))$ for $x\in A$. Prove or disprove the following claims.         (a) If $h$ is surjective, then $f$ must be surjective.   (b) If $h$ is surjective, then $g$ must be surjective.   (c) If $h$ is injective, then $f$ must be injective.   (d) If $h$ is injective and $f$ is total, then $g$ must be surjective      I got  a) True b) False c) True d) False  When the answer is supposed to be  a) True b) false c) false d) true  I think the reason why I got them wrong is because I assumed that if a function is not surjective, then it has to be injective and vice versa. Could someone help me understand this concept? That would be much appreciated!

Suppose $f: A \to B$ and $g: C \to D$ are functions, and that $B ⊆ C$.  I need to come up with an example where $g \circ f$ is surjective but $f$ is not. I'm confused on how exactly to do that, but I understand that to show something is surjective you have to have the range of the function equal to the codomain of the function. Here's my attempt:  So if $g(x) = x^2$ with a codomain of $ℝ$, and $f(x) = \sqrt{x}$ with a codomain of $ℝ$, then $g(f(x)) = (\sqrt{x})^2 = x$. Since the range of this function and codomain are the same, this is surjective.  But, since $f(x) = \sqrt{x}$, its range is only $[0, ∞)$, which is smaller than its codomain of $ℝ$, meaning $f$ is not surjective.


I want to write person information from input to text file. My problem is that I always get NullPointerException. What could be wrong with this code? I have this method:       public void skriveObjekt()throws IOException{      try {          RandomAccessFile randomAccessFile = new RandomAccessFile("bruker.txt", "rw");         //randomAccessFile.defaultWriteObject();         randomAccessFile.writeUTF(getFornavn());         randomAccessFile.writeUTF(getEtternavn());         randomAccessFile.writeUTF(getBrukernavn());         randomAccessFile.writeUTF(getPassord());         randomAccessFile.writeUTF(getAdresse());         randomAccessFile.writeUTF(getEmail());         randomAccessFile.writeChar(getFødselsdato().hashCode());          FileHandler fileHandler = new FileHandler();         fileHandler.lageFil();          randomAccessFile.seek(200);      } catch (IOException e) {     e.printStackTrace(); } }   Controller class      @FXML     private void LoggInn() throws IOException {     FileHandler fileHandler = new FileHandler();     fileHandler.lageFil();     fileHandler.leseFil();     Bruker bruker = null;      bruker.skriveObjekt();     }   I have this too but am unsure if it is right  void lageFil(){     if(!file.exists()){         file.mkdirs();     }  }  File leseFil() throws IOException {      try {         FileReader fr = new FileReader( "brukere.txt");          System.err.println("Filen finnes");     }catch (FileNotFoundException fnfe){         FileWriter fileWriter = new FileWriter( "brukere.txt");         System.out.println("Filen er laget");     }      return null; }


How can we find the Laurent series of the function $$f(z)=\frac{1}{\tan z }$$ around 0.  Thank you very much.

Find the Laurent Series for $f(z) = \cot(\pi z)$ at $z= 0$.  I just need hints; I am not sure how to do this at all. I am very new to this.


What I want to ask is monochromatic light necessary for interference?  Doesn't interference occur on just the superposition of two waves(any waves)? And Why don't waves of different wavelengths don't interfere in a diffraction grating with  other waves but only with waves of the same wavelength(again as interference is just superposition of two waves)?  Why do we say that the waves interfere seperately?

As the title says, from books and results from internet, I find that examples of wave interference always have the same frequency, only different in phase constant.  So, I'd like to know if wave interference happens only to same frequency waves


I have some 	 elements as shown below. Hello	 World	  I need to add style to this  by calling the class. I have tried as below, but no changes are taking place.   I don't want to use id attribute. I know that something is missing here, but can't quite figure it out!

What characters/symbols are allowed within the CSS class selectors? I know that the following characters are invalid, but what characters are valid?  ~ ! @ $ % ^ & * ( ) + = , . / ' ; : " ? > < [ ] \ { } | ` #


Hello graphic design exchange.  I have a question about creative commons and its mix usage for printed materials.  As you know there are lots of websites offering free vectors for commercial uses. In my case, it is freepik.com. It says it allows commercial usage if we attribute them.  My question is how can we attribute on printed materials like business cards?  For example I design some business cards for my freelance customers and want to use some brush or shape from one element. Maybe I use lots of background elements seperately.  How can I attribute on business card for example? For example a web banner, how can we attribute? or a smaller project a logo and I like a shape vector and want to use by mixing other elements, how can I attribute these types of designs?  edit: this question marked as a duplicate, but I have different situation. On a magazine, there can be a copyright, on a poster, there can be a little statement, but on a business card design? For example floral vector backgrounds from a cc licensed file?

Edit:   To be extremely succinct: How to credit imagery used on a business card or ballpoint pen?      Inspired by  I started to think:  How do you attribute and give credit, when you use images and resources that are Creative Commons, copyleft; are in the public domain or have variation of "free" licensing?   (Some of the answers to the above questions grazes that question but it is not really the main issue in that question).  How do you attribute - say -:    a background tiled image for web? a background tiled image for print?   (the point here being tiny-weeny images)   an icon set web? an icon set print? To make it more fiddly: tiny images you might use for t-shirts, printed objects such as ballpoint pens, t-shirts, keyrings, letterheads?   For web; there seems to be divided between those who think that in the source code is fine and those who do not. For web you could make a link somewhere discreet that says "credits". This does not really work for print. If you enthusiastically stand on the shoulders of giants, and use what is legally yours to use, your printed leaflet would be bogged down in 6point text attributions.   (Yes, there are differences between countries; I am asking on a general note.)   Edit: I could add GNU licenses, but that is usually pretty straightforward, as it is mainly concerned with software, code, programming snippets, digital programmable objects etc.


I'm interested in getting a gaming computer by buying an HP Z210 for $210 which is actually pretty decent with 4 gigs of 1333 ram and a quad core i5 running at 3.2 or something like that and slapping a $200 graphics card in it, but there has to be a place that cut corners.  My question is, since I know that it's using a sandy bridge (2nd generation processor), is there that significant of a difference between the different generations, such as the difference between AMD and Intel (sorta like how 2 ghz on an i3 matches a 3 ghz quad core amd processor? Will it render worse?) (btw I'm not just using it for gaming, but am planning on using photoshop, illustrator, word processing all for school and blender to create modded weapons for CoD WaW Zombie maps, so will it also render that program worse than a newer gen?)

What are the main differences between each processor generation of Intel processors/chipsets? Is there a performance difference?  I've already seen processors from first to sixth generation, however I don't know/understand the exact differences.


I played clash of clans in my laptop using blue stacks.   After some weeks blue stacks is unable to open it shows some error. Now I cannot play the game. I already connected the game to my Google+ account. Can I able to recover my village again after re installing blue stacks or is there any other way to get into my village.

I unintentionally and stupidly wiped my Clash of Clans game data. I went to Application Manager on my Android and clicked 'Clear data'. (I used this for fixes before and it never started a new game.)   Now, my level 60 or so base has been wiped as if was to start a new game. Have I doomed myself to starting again or is there a way in which I can retrieve my old game save? Maybe by contacting Supercell? I have a snapshot of my base.


I want to find all html files and only show the file names, not the full file path, what I tried:  find /home/irakli/Desktop/irakli_linux -print | grep -i '.*[.]html'   Results:  /home/irakli/Desktop/irakli_linux/htmll/10.html /home/irakli/Desktop/irakli_linux/htmll/11.html /home/irakli/Desktop/irakli_linux/htmll/12.html /home/irakli/Desktop/irakli_linux/htmll/13.html /home/irakli/Desktop/irakli_linux/htmll/14.html /home/irakli/Desktop/irakli_linux/htmll/15.html   I only want  1.html 2.html ...

I am trying to look for all XML files in a particular directory and all sub-directories (recursively) inside it.  ls -R *.xml is only listing files in the current directory. I am quite sure, the sub-folders themselves have several .xml files, but none are showing up.  Is this a configuration issue?


I am trying to install a package python-pygments under Ubuntu. After launching sudo apt-get install python-pygments, it is blocked:  Reading package lists... Done Building dependency tree        Reading state information... Done Suggested packages:   ttf-bitstream-vera The following NEW packages will be installed:   python-pygments 0 upgraded, 1 newly installed, 0 to remove and 43 not upgraded. Need to get 347 kB of archives. After this operation, 2,527 kB of additional disk space will be used. 0% [Connecting to cache.polytechnique.fr (129.104.38.6)]   cache.polytechnique.fr in the line line is the proxy of my school. A download in the campus should work, but the problem is that I am physically not in the campus. I try to remove proxy setting via Chromium (the method of network proxy: NONE), it still drives to cache.polytechnique.fr, does anyone know how to let sudo avoid this proxy?

For the command   sudo apt-get update   I get following error:  W: Failed to fetch http://ch.archive.ubuntu.com/ubuntu/dists/maverick-updates/multiverse/binary-i386/Packages.gz   407  Proxy Authentication Required (The ISA Server requires authorization to fulfill the request. Access to the Web Proxy filter is denied. )   I am running Ubuntu 10.10 installed on Windows XP using VirtualBox. For Internet connections I am using proxy server with an authentication. I tried to use gnome-network-proxy tool to set proxy settings system-wide.   After that /etc/environment has been updated by http_proxy variable with the format http://my_proxy:port/, there were no authentication data.  I checked this with Firefox. Browser asked my for login and password and everything was working fine. It was unfortunately not the case for apt-get. I have also tried to do as described . Unfortunately it does not work.  May it be somehow related to the fact that a proxy is in a Windows domain, any ideas?  My proxy name is http-proxy. Is '-' a special character here?


I am struggling with this proof where $X$ is $m \times n$ matrix, $a$ is $m$ vector, $b$ is $n$ vector.  $$\frac {\partial a^{T}X^{-1}b}{\partial X} = -\left( X^{-1}\right) ^{T}ab^{T}\left( X^{-1}\right) ^{T}$$  I know $$\frac {\partial }{\partial X}f\left( X\right) ^{-1}=-f\left( X\right) ^{-1}\dfrac {\partial f\left( X\right) }{\partial x}f\left( X\right) ^{-1}$$  and am guessing to use this fact, I also know $\dfrac {\partial a^{T}Xb}{\partial X} = ab^{T}$.  When I use the chain rule I don't seem to get the form with the transposes.  I believe the result should be $\in \mathbb{R} ^{1\times \left( m\times n\right) }$

Prove that $$\nabla_{\mathrm X} \mbox{tr} (\mathrm A \mathrm X^{-1} \mathrm B) = - \mathrm X^{-\top} \mathrm A^\top \mathrm B^\top \mathrm X^{-\top}$$   My proof is below. I am interested in other proofs.    My proof  Let   $$f (\mathrm X) := \mbox{tr} (\mathrm A \mathrm X^{-1} \mathrm B)$$  Hence,  $$\begin{array}{rl} f (\mathrm X + h \mathrm V) &= \mbox{tr} (\mathrm A (\mathrm X + h \mathrm V)^{-1} \mathrm B)\\ &= \mbox{tr} (\mathrm A (\mathrm X ( \mathrm I + h \mathrm X^{-1} \mathrm V))^{-1} \mathrm B)\\ &= \mbox{tr} (\mathrm A ( \mathrm I + h \mathrm X^{-1} \mathrm V)^{-1} \mathrm X^{-1} \mathrm B)\\ &= \mbox{tr} (\mathrm A ( \mathrm I - h \mathrm X^{-1} \mathrm V + O (h^2)) \mathrm X^{-1} \mathrm B)\\ &= \mbox{tr} (\mathrm A \mathrm X^{-1} \mathrm B) - h \, \mbox{tr} ( \mathrm A \mathrm X^{-1} \mathrm V \mathrm X^{-1} \mathrm B) + O (h^2)\\ &= f (\mathrm X) - h \, \mbox{tr} ( \mathrm X^{-1} \mathrm B \mathrm A \mathrm X^{-1} \mathrm V ) + O (h^2)\end{array}$$  Thus, the directional derivative of $f$ in the direction of $\mathrm V$ at $\mathrm X$ is  $$D_{\mathrm V} f (\mathrm X) = - \mbox{tr} ( \mathrm X^{-1} \mathrm B \mathrm A \mathrm X^{-1} \mathrm V ) = - \mbox{tr} ( (\mathrm X^{-\top} \mathrm A^\top \mathrm B^\top \mathrm X^{-\top})^\top \mathrm V ) = - \langle \mathrm X^{-\top} \mathrm A^\top \mathrm B^\top \mathrm X^{-\top}, \mathrm V \rangle$$  and, lastly,  $$\nabla_{\mathrm X} \mbox{tr} (\mathrm A \mathrm X^{-1} \mathrm B) = - \mathrm X^{-\top} \mathrm A^\top \mathrm B^\top \mathrm X^{-\top}$$


I am new to linux Ubuntu 12.04. Every time I open a file with the gvim editor it gives me following warning:  ** (gvim:4620): WARNING **: Unable to create Ubuntu Menu Proxy: Timeout was reached   What should I do to solve this problem?

Gvim does not have a global menu (appmenu / application menu) in 12.04, and when starting gvim from a terminal, the following warning appears in the terminal after 25 seconds:  ** (gvim:20320): WARNING **: Unable to create Ubuntu Menu Proxy: Timeout was reached   How to fix this?


I've just started using Texmaker and am using it on a fairly large screen, large enough that it would be useful for me to be able to type my document and have the output PDF file next to it. I know it's possible as the setups at my university do exactly that. However, when I click the arrow next to "build pdf" it opens the PDF in a separate window. I've found a similar question on here to what I'm asking, but it refers to a preferences window that I simple cannot find anywhere.  Any help would be appreciated.

How do I get Texmaker to display the source and ouput in the same window, as advertised. This seems to be the default behavior on some systems, but not on others.


, for example, has 1x , 1x , and 1x . Since it's a 60 card deck the odds of drawing any one of them is 1/60. ie. quite slim. So why do they include cards they likely won't be drawing? Why not run 4x of each card? Gives you less versatility, I suppose, but what good is versatility if you don't draw the cards you need?

In this instance, I'm looking at Matt Sperling's , and there's one thing I don't get--what's the single  doing here?     Creatures:         4    1    4          Spells:         4    3    4    4    4    4    4          Lands:         4    3    9    4    4


Please reopen. This is not a duplicate, because here I am asking why it doesn't work, not just for workaround.    Bash manual says that     tilde expansion, parameter and variable expansion, arithmetic expansion, and command substitution (done in a left-to-right fashion)   If I understand  correctly,  "left-to-right" means that "brace expansion; tilde expansion, parameter and variable expansion, arithmetic expansion, and command substitution" have the same priority.  So is it possible to use arithmetic expansion inside parameter expansion? (i.e. one level recursion)  If no, why can't arithmetic expansion work inside parameter expansion, given that "tilde expansion, parameter and variable expansion, arithmetic expansion, and command substitution (done in a left-to-right fashion)"?  If yes, how?  For example,  $ set hello world $ echo $2 world $ echo ${$((1+1))} bash: ${$((1+1))}: bad substitution   I hope to    first expand $((1+1)) in ${$((1+1))} to 2. and then ${2} to world.   Thanks.

Follow-up to the background part in .  In bash I can use ${!FOO} for double substitution, in zsh ${(P)FOO}. In both, the old-school (hack-y) eval \$$FOO works.  So, the smartest and most logical thing for me would be ${${FOO}}, ${${${FOO}}}… for double/triple/n substitution. Why doesn’t this work as expected?  Second: What does the \ do in the eval statement? I reckon it’s an escape, making something like eval \$$$FOO impossible. How to do a triple/n substitution with that that works in every shell?


I am having the same problem I reported in April 2019.  I am getting a message "Ubuntu has detected a system problem" when I boot up.  The pop-up window asks me to report the problem.  I have clicked the button to report the problem, but nothing has happened for over a week.    I don't even know If I really have a problem.  Can someone on your end help resolve this issue ?

I found a problem with an application on Ubuntu.   Questions :   How do I best report the issue?  What sort of information should I provide?


Super newbie question. I accidentally pressed something on my keyboard and now every time I go to edit mode, there's this yellow circle thing that won't disappear. How do I remove it?

I think I have entered a sequence of commands as a mistake and now a yellow line appears in top of my selection. I don't know what it is for or how to enable/disable it.  I have tried closing the editor but it keeps appearing.


I'm trying to write an extension method on numeric types to be used in a fluent testing framework I'm building. Basically, I want to do this:  public static ShouldBeGreaterThan<T>(this T actual, T expected, string message)     where T : int || T: double || etc...   Just where T : struct doesn't do, since that will also match string and bool, and possibly something else I'm forgetting. is there something I can do to match only numeric types? (Specifically types that implement the > and < operators, so I can compare them... If this means I'm matching dates as well, it doesn't really matter - the extension will still do what I expect.)

Can anyone tell me if there is a way with generics to limit a generic type argument T to only:   Int16 Int32 Int64 UInt16 UInt32 UInt64   I'm aware of the where keyword, but can't find an interface for only these types,  Something like:  static bool IntegerFunction<T>(T value) where T : INumeric


I changed my email on Stack Overflow. And after that, I received back a lot of badges but not all.  For example, I lost Quorum and Constituent.  And I had one more silver badge and one other bronze badge but I don't remember which one.  So my question is: is it a bug, or are the answers to  (last one in 2012) deprecated?  And if it's normal, can we add a warning when we want to change our e-mail?  (I don't want to have my badges back, I just want clarify this thing).

I updated my email on SO, and for some reason now, I've lost 4 silver badges and 10 bronze badges. Not sure what is going on here, does anyone have an idea?


I am looking at the following question: "Let $H$ be a normal subgroup of prime order $p$ in a finite group $G$. Suppose that $p$ is the smallest prime that divides the order of $G$. Prove that $H$ is in the center $Z(G)$."   Thoughts: We know that $H$ is a normal subgroup of $G$ and that $H$ has prime order. So, $H$ is cyclic and generated by some element $x \in G$. So, $H=\langle x\rangle$. Since $H$ is normal $gH = Hg$ for all $g \in G$. Thus, $x$ is in the center $Z(G)$. Since $H = \langle x\rangle$, then $H \in Z(G)$.   Is this the correct logic? Thanks!

$G$ is a finite group such that $|G|=n$. Let $p$ be the smallest prime such that $p|n$. If $H\triangleleft G$ such that $|H|=p$, then prove that $H\subset Z(G)$.  My Work:  Since $|H|$ is a prime $H\cong \mathbb{Z}/(p)$. Hence $H$ is cyclic and abelian. I was stuck afterwards. Can anyone please give me a hint?


My two databases(.mdb) are placed at a network shared folder.  Now at the same time few users are connected to database from the network place and doing their job.  In the middle get the error like :  error 1 : "The database has been placed in a state by a user "Admin" on machine "machine no." that prevents it from being opened or locked."   error 2: “Cannot Open Database”. It may not be a database that your application recognizes, or that file may be corrupt.  can anyone please suggest me how i can open this database in programatically, so that different users can run their own application simultaneously without any error.

I would like to ask if MS Access database supports working in networks & multi-user access?


I know that we don't have automatic login for the Data Explorer, but what's with the automatic timeout/logout?  There have been times that I am logged into the site, maybe I walk away for a little bit, and I come back to being logged out.    Is there a reason for logging us out of Data Explorer?  If so, is it possible to either remove the timeout or extend the period of time before timeout?

I'm pretty sure that since a month or so,  seems much more eager to get rid of my session and log me out in that process. I don't mind logging in a couple of times per day, if that helps to reduce resource consumption, but the user experience isn't all that great when it happens. Here is why: I'm most often in the middle of writing a query for an MSE question, for example . So I have the edit window open and am creating a new revision of my query. When I click "run," I do notice the button gets grayed-out, as it normally does, but I never get any result back. There is also no error message. To recover from this I have to copy the SQL text I have typed, open a new tab and load SEDE, log in, switch back to the stalled tab, refresh, paste the SQL text, run query. Repeat the process after 10 minutes. If the intended behavior is to log users out of their session on such short notice (I recall sessions lived for 24 hours), can there then be a slightly better handling in the browser of that state, so it is clear you're logged out once you click the run button? I prefer, however, to have the longer allowed sessions back. I'm experiencing this behavior mostly in Chrome on Win 10.


When we push the wall, no work is being done. But we feel tired after some time. Since energy cannot be destroyed , the question is where does all the energy get transferred in this scenario. Note : It cannot be all heat as we feel more tired than standing still and if it is being transferred in heat then why it is faster than standing still if no work is being done?

I read the definition of  as  $$W ~=~ \vec{F} \cdot \vec{d}$$  $$\text{ Work  =  (Force) $\cdot$ (Distance)}.$$ If a book is there on the table, no work is done as no distance is covered. If I hold up a book in my hand and my arm is stretched, if no work is being done, where is my energy going?


When Obi-Wan and Yoda return to the Jedi Temple, they discover that many Jedi knights, padawans and younglings were killed. Obi-Wan records a warning message for all Jedi to stay away from the temple. He then goes through the security recordings to discover why some padawans and younglings were killed with a lightsaber blade.                                Here is the script for that scene: 185 INT. CORUSCANT-JEDI TEMPLE-CONTROL CENTER-NIGHT  OBI-WAN enters the Main Control Center with YODA and heads for the hologram area. OBI-WAN: Wait, Master. There is something I must know . . . YODA: If into the security recordings you go, only pain will you find. OBI-WAN: I must know the truth, Master. OBI-WAN moves to a panel and flips some switches. He sees a HOLOGRAM of ANAKIN slaughtering JEDI, including the YOUNG ONES. OBI-WAN and YODA react. OBI-WAN: (continuing) It can't be . . . It can't be . . . As ANAKIN surveys the carnage, a DARK-ROBED SITH LORD enters. ANAKIN turns to DARTH SIDIOUS and kneels before him. ANAKIN: The traitors have been taken care of, Lord Sidious. DARTH SlDIOUS: Good . . . good . . . You have done well, my new apprentice. Do you feel your power growing? ANAKIN: Yes, My Master. DARTH SlDIOUS: Now, Lord Vader, now go and bring peace to the Empire. OBI-WAN watches in horror. Tears well up in his eyes.  As shown in this clip from Rebels, the message did not mention that Anakin had become Darth Vader. This knowledge would have been very important to the exiled Jedi so as not to trust Anakin, yet he does not share it.                                You could say that Obi-Wan learned shortly after he made the warning message that Anakin betrayed the Jedi, and not before. Even so, he could have altered the message. Why did he not warn the surviving Jedi about Darth Vader?

If you've seen the premiere episode of Rebels, you will have seen Obi-Wan's warning message that he broadcast to Jedi throughout the galaxy in RotS. In this message he speaks cryptically & warns of a "dark shadow" falling & to avoid the temple & await a "new hope".   Wouldn't it have been useful to inform the Jedi that their mortal enemy the Sith had returned? And specifically that Palpatine himself was a Sith? You'd assume that the majority of the Jedi who were not in the loop of the Council would be unaware of the existence of the Sith. Yoda mentions a few times that they should keep it under wraps. I think now would've been the time to reveal the truth. The more info the surviving Jedi have the better. Who knows if the likes of Kanan knows anything about the Sith's return! I find Obi-Wan's omission of this information bizarre.


I get a "Maybe:" in front of most iMessage contacts and only the phone number for SMS'es - even for persons from my contact list. What can be the cause and how can I solve it?

I got a call from a phone number that is not stored in my address book, and in the call log, under the number, a name was suggested: "Maybe: X" (where X is the guessed name).  Where is this guess coming from?


I use Office 365 (2016), but do not have Exchange. I use POP3 emails exclusively via my business account with 1 and 1. Outlook doesn't have the typical option to setup OoO Reminders underneath the "File" menu. Help?

How can you make a rule to auto reply when you are out of the office. Outlook doesn't have this kind of rule.


Oxford Dictionaries Online writes in their U.S. section that the phase  is  an informal phrase meaning:     Foresee and avoid the possibility of attack or criticism.         ‘I like to cover my ass when I make big generalizations’      And if you , you’ll notice that they mention how cover one’s ass is specifically a North American expression.  The Wikipedia page for  says:     The phrase cover your ass is generally viewed as a vulgar term, often   replaced by the less-vulgar sounding initials CYA. Safire identified CYA as   a synecdoche, in the same sense that the word “ass” had come to reference   the whole person.   The  states begins:        (Canada, US, idiomatic) To make preparations or take precautions to    ensure that a person is not blamed or punished for his or her conduct.      Collins English Dictionary says in  that:     slang, mainly US and Canadian   to take such action as one considers necessary to avoid censure, ridicule,    etc at a later time   While dictionary-dot-com’s page for  mentions (but only in their example citations, not their definition section): that some call it risk management     To provide or arrange for exculpation; devise excuses and alibis:           Some call it “risk management,” others “covering your ass.”   The FBI may have to let you be destroyed to cover its own ass.   CYA, you know, that old French expression that means making sure    that when historians write about it all it won’t be seen as happening on   your shift.              credited to The Dictionary of American Slang, Fourth Edition      by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D.;      Copyright (C) 2007 by HarperCollins Publishers.      Risk management is a nice little phrase, but  what other non-vulgar expressions are there that means the same thing as covering one’s ass means, but without being considered vulgar?

I'm looking for a couple of good coined phrases that I can use in front of business people, apologies if the one I had in mind offends anyone.   I'd use "can sleep at night" but I want the phrase to imply legal liability if we don't do something.


Followup to:   So this is a particularly ridiculous idea, but it might work.  A simulacrum normally cannot regain spell slots, but a spellcasting monster can. An archmage is in the table of monsters (with a CR of 12!) so it is definitely a valid true polymorph target. Spellcasting monsters recover spell slots by long rest, just like players.  The accepted answer on the other question has the text "The simulacrum's statistics are replaced."  Can a simulacrum true polymorphed into an archmage regain spell slots?

If a simulacrum is polymorphed through True Polymorph into a creature that can regain hit points normally, can the simulacrum regain hit points while polymorphed in that way?


Is the automorphism group of an abelian group abelian? If not is it true if either is finite? I cannot come up with a proof or an example.

Could you give me a simple example of $G$ abelian with ${\rm Aut}(G)$ non-abelian? Otherwise how could I prove that $G$ abelian implies ${\rm Aut}(G)$ abelian. (I don't really think that's true)


With operator methods we can set the Hamiltonian of the harmonic oscillator in the following form:  $$\hat{H}=\hbar \omega(A^{\dagger}A+1/2).$$  My question is that how can we know that the lowest eigenvalue for the  operator $A^{\dagger}A$ is zero and not a positive number?

My apologies if this question has already been answered. Using the notation of Sakurai, we have an energy eigenket N and an eigenvalue n.  $$N | n \rangle = n | n \rangle$$  For the number operator $N = a^\dagger a $. My question is precisely why does n have to be an integer. I do understand that it must be positive definite due to the norm condition on $ a | n \rangle $:  $$\langle n | a^\dagger a | n \rangle \geq 0$$  I can see that we can show:  $$ a | n \rangle = \sqrt{n-1} | n-1 \rangle $$ and similarly for $a^\dagger | n \rangle$  Sakurai argues that the sequential operation of $a$ operators leads to the form which he does not write, but I will write here for clarity:  $$ a^k | n \rangle = \left(\sqrt{n}\sqrt{n-1}...\sqrt{n-k+1}\right) | n - k + 1 \rangle $$   Since  $$ a|0 \rangle = 0 $$  the sequence must terminate, but can only terminate if n is an integer. How can we make that jump? Is there a formal mathematical proof that the sequence $\left(\sqrt{n}\sqrt{n-1}...\sqrt{n-k+1}\right)$ will terminate if and only if n is an integer?


Fairly new to SFDC and primarily using it as a source for our data warehouse.  We're ingesting data using the Bulk API and are manually checking rowcounts through workbench.  Running into an odd issue on Workbench where SELECT COUNT() FROM recordtype returns a count of 31 but SELECT id FROM recordtype returns 20 rows. Surprisingly SELECT id FROM recordtype GROUP BY id returned 31 rows.  Our admin is saying that 11 rows are marked as Reserved/Not usable.  If that's the case, shouldn't COUNT() also exclude them and return 20 as the count? Flummoxed by why the group by id returned 31 rows. Feels like this is a bug. How does Workbench query SFDC? Does it use the standard SOAP APIs or some other mechanism? Is the issue with the API?

SELECT count() FROM recordtype   This returns 41  SELECT count(id) FROM recordtype   This returns 41  SELECT id FROM recordtype   This returns 33 rows  I'm running these statements in SqlXplorer. Why the different results?


Here has two definitions:     In, at, or to this place or position:   'they have lived here most of their lives'   Used when indicating a time, point, or situation that has arrived or is happening:   'here we encounter the main problem'   So in the idiom "here you go" which definition is used? Is the present tense in this sentence used to signify future action like "my train leaves at seven" or something else?

As a non-native speaker, I cannot grasp any difference between the expressions "here we go" and "there we go": both expressions seem to underline an event that is going to happen immediately.  Is there any subtle usage detail that I am missing?


I'm not sure if the title is the best, but what I want to do can be illustrated in this example  class TestClass {     public String foo = "foo"      public void makeFooBar() {         String bar = foo;         bar = "bar";          System.out.println(foo); //should print "bar"     }  }   This is obviously a contrived example, but it illustrates the point. I want to change the value of foo by changing the value of bar that references foo. is that posible?

I always thought Java uses pass-by-reference. However, I've seen a couple of blog posts (for example, ) that claim that it isn't (the blog post says that Java uses pass-by-value). I don't think I understand the distinction they're making. What is the explanation?


When I go to install Ubuntu so I can dual boot Ubuntu with windows 8.1 on my Toshiba Satellite C55 the Ubuntu installer does not sense My pre-installed windows 8.   I referred to these guides:  and , but the first link suggests, to use the install Ubuntu along sideoption or make an EFI partition however it also says to only have one EFI partition on the hard drive and windows is in an EFI Partition.   So I need to know how to Get Ubuntu to sense windows 8.1 or how to manually partition the hard drive so I can dual boot. Just so you know I have a Kubuntu 13.10 on a disk, Ubuntu 13.10 on a disk, and Ubuntu 12.04 on a disk.    If you need any more tech specifications I can give them to you.

I'm absolutely new to Linux. I would like to know how to install Ubuntu alongside the pre-installed Windows 8+ OS.  Should I do it with Wubi, or through the Live USB/DVD?  What steps do I need to take to correctly install Ubuntu?


I have this    MS SQL Server 2008 Schema Setup:  CREATE TABLE AccessUser (     AccessUserID int,      AccessUserName varchar(255),      AccessUserType int,      AccessUserGroups varchar(255) );  INSERT INTO AccessUser (   AccessUserID,      AccessUserName,      AccessUserType,      AccessUserGroups ) VALUES     (1, 'Group 1', 2, ''),     (2, 'Group 2', 2, ''),     (3, 'John', 5, '@1@'),     (4, 'Nick', 5, '@1@@2@');   Query 1:  SELECT DISTINCT Empl.AccessUserName AS Name, Firm.AccessUserName AS FirmName FROM AccessUser AS Firm, AccessUser AS Empl WHERE Empl.AccessUserType = 5 AND Empl.AccessUserGroups LIKE ('%@' + CAST(Firm.AccessUserID AS VARCHAR(10)) + '@%') ORDER BY Empl.AccessUserName ASC   :  | NAME | FIRMNAME | |------|----------| | John |  Group 1 | | Nick |  Group 1 | | Nick |  Group 2 |   QUESTION: How can i modify the Query, to output this:  | NAME |      FIRMNAME      | |------|--------------------| | John |  Group 1           | | Nick |  Group 1, Group 2  |   What I want to do is to commaseparate the Firmname, if the user has more than one AccessUserGroups.  Is it even possible to do so in one query?

I'm trying to migrate a MySQL-based app over to Microsoft SQL Server 2005 (not by choice, but that's life).  In the original app, we used almost entirely ANSI-SQL compliant statements, with one significant exception -- we used MySQL's group_concat function fairly frequently.  group_concat, by the way, does this: given a table of, say, employee names and projects...  SELECT empName, projID FROM project_members;   returns:  ANDY   |  A100 ANDY   |  B391 ANDY   |  X010 TOM    |  A100 TOM    |  A510   ... and here's what you get with group_concat:  SELECT      empName, group_concat(projID SEPARATOR ' / ')  FROM      project_members  GROUP BY      empName;   returns:  ANDY   |  A100 / B391 / X010 TOM    |  A100 / A510   So what I'd like to know is: Is it possible to write, say, a user-defined function in SQL Server which emulates the functionality of group_concat?   I have almost no experience using UDFs, stored procedures, or anything like that, just straight-up SQL, so please err on the side of too much explanation :)


My setup:   Ubuntu 16.04 SSD with 256 GB of space HDD with 2 TB of space   My SSD is filling up with saved numpy arrays from all my Python code. I am hoping to move those data files onto my HDD to clear up space. Unfortunately I don't know how to do that since it doesn't look like a straightforward mv command will work.  Here is some information: after typing in gksu baobab, I get a pop-up where I can see memory usage. Here, you can see that my home drive (name is blacked out for privacy reasons) is almost filling up to 177.9 GB (say, why is it not 256GB? I thought this was my SSD?):  My disk usage:   Here is df -h:  $ df -h Filesystem      Size  Used Avail Use% Mounted on udev             32G     0   32G   0% /dev tmpfs           6.3G  706M  5.6G  11% /run /dev/sda2       166G  128G   30G  82% / tmpfs            32G   60M   32G   1% /dev/shm tmpfs           5.0M  4.0K  5.0M   1% /run/lock tmpfs            32G     0   32G   0% /sys/fs/cgroup /dev/sda1       511M  3.6M  508M   1% /boot/efi tmpfs           6.3G  156K  6.3G   1% /run/user/1000 none             32G  2.8M   32G   1% /tmp/guest-3qjkgk tmpfs           6.3G  108K  6.3G   1% /run/user/999   I think dev/sda2 corresponds to my default usage on my computer, so if I move stuff and make new files, it will be here. I tested this by creating and removing temporary files,and the dev/sda2 memory usage changed. Unfortunately it seems like my 2 TB hard disk is not visible here.  Here is fdisk -l:  Disk /dev/ram0: 64 MiB, 67108864 bytes, 131072 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes  // // ram1 through ram14 omitted for clarity on askubuntu.com ... //  Disk /dev/ram15: 64 MiB, 67108864 bytes, 131072 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes  Disk /dev/sda: 232.9 GiB, 250059350016 bytes, 488397168 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: gpt Disk identifier: 23607B86-A307-4986-9B20-6E4403223EF3  Device         Start       End   Sectors   Size Type /dev/sda1       2048   1050623   1048576   512M EFI System /dev/sda2    1050624 354359295 353308672 168.5G Linux filesystem /dev/sda3  354359296 488396799 134037504  63.9G Linux swap   Disk /dev/sdb: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes   Now, here I can see my hard disk, which is in dev/sdb. However, again I can't figure out how to simply move a bunch of numpy arrays over to this drive.  From looking online, the typical procedure seems to be related to mounting the dev/sdb. But from looking at descriptions (e.g. ) it seems like mounting the hard disk would give me access to the files within the hard disk, but I wouldn't be able to access the previous files in the SSD that I'm trying to dump over to the HDD. My logic is probably wrong somewhere... and also, that tutorial mentions some things about moving file systems around, but it then says:     no data is copied or removed, it is merely displayed in a different place   and the main reason why I need to move the files is indeed to free memory on the SSD.  I am a beginner with Ubuntu 16.04 so I am happy to provide more information that would be useful about my computer.  Note: the most closely related question here seems to be , since I too share that poster's concern:     I thought that the best way to solve this is simply to move everything from the SSD to the HDD? But I am not entirely sure how to accomplish that correctly!   But there is only one answer there which doesn't seem like it answered the question (and I'm not moving everything, I just want to dump some numpy arrays over).

Using Ubuntu 11.10, how do I format an external or USB drive? I don't find an option to 'format' when I right click. In the new version, the drives don't come up on the desktop, but instead come on the Launcher.


I am learning to program in Android and I have a question.  I have an application with a TextView, a Button and a EditText and I want my application to: I open it, I type something in the edittext and when I press the button, I want to check the text in the edittext if it's a valid email (using regular expressions) and display a message accordingly in the textview.

Over the years I have slowly developed a  that validates MOST email addresses correctly, assuming they don't use an IP address as the server part.  I use it in several PHP programs, and it works most of the time.  However, from time to time I get contacted by someone that is having trouble with a site that uses it, and I end up having to make some adjustment (most recently I realized that I wasn't allowing 4-character TLDs).  What is the best regular expression you have or have seen for validating emails?  I've seen several solutions that use functions that use several shorter expressions, but I'd rather have one long complex expression in a simple function instead of several short expression in a more complex function.


So I'm just wondering what JSON files are, as I lack some knowledge of python files. Please could you also tell me why these are very useful in python, as nearly every python book has them. Thanks. Edit: I have realized that this are other answers for this problem on stackoverflow which I didn't realize about when I made this quote. Sorry. I cannot delete this post anymore, since answers are already flowing in.

I've looked on Wikipedia and Googled it and read the official documentation, but I still haven't got to the point where I really understand what JSON is, and why I'd use it. I have been building applications using PHP, MySQL and JavaScript / HTML for a while, and if JSON can do something to make my life easier or my code better or my user interface better, then I'd like to know about it. Can someone give me a succinct explanation?


What rules apply to punctuation for an abbreviation, such as "etc," where another punctuation character follows?  My question is a perfect illustration of itself! That is, should I say  << such as "etc," where >> or << such as "etc.," where >>  Another example is "etc" followed by a right parenthesis:  << (lions, tigers, bears, etc) were >> or << (lions, tigers, bears, etc.) were >>  The period looks even worse at the end of a sentence.  << lions, tigers, bears, etc! >> or << lions, tigers, bears, etc.! >>  I omit the period because it just looks right. But most spelling checkers mark "etc," as wrong as "etc.," as right.  The primary authority at my workplace is the Microsoft Manual of Style for Technical Publications, 3rd edition. I looked there but found no guidance.

I always stumble when using abbreviations in a sentence, as they inherently contain a period in them. How do I use a comma or a semicolon after an abbreviation? How about a period?  E.g. (This is an example of my quandary)


I'm trying to cut a bunch of holes (created using two Array Modifiers and an empty) into a cylinder using a boolean modifier. It looks legit in the wireframe. However, when I turn on the shading mode, I get this instead:    Some of the holes are clearly missing. I'm not sure what's going on.

I am trying to create an truck exhaust mesh with blender.     Currently I am using a smaller size cylinder to cut inside and then using some other cylinders to cut every hole with boolean modifier.     Problem  As you see, the original mesh has many holes and cutting every single one of them with this method will take forever and if suddenly I decide to change the amount of holes in perimeter or exhaust diameter , I have to restart.  Question  Is there  any easier way to do this?


I'm just wondering why is __construct() called so. Why isn't it say just construct()? I mean maybe there's an interesting reason for that that only a few know because others didn't wonder. I'm sure that someone knows php good enough to explain that.

I have been noticing __construct a lot with classes. I did a little reading and surfing the web, but I couldn't find an explanation I could understand. I am just beginning with OOP.  I was wondering if someone could give me a general idea of what it is, and then a simple example of how it is used with PHP?


In given code I have written lambda expression but it shows an error that -- Can't convert lambda expression to type 'string' because it is not a delegate type.          EmployeeDataOperation emp = new EmployeeDataOperation(); //Class to perform CRUD operation.          List<EmployeeProp> data = new List<EmployeeProp>();          dt = emp.getEmployeeData();//return datatable with records.          //I want to use lambda expression to use Datatable data as a list         data = (from a in dt                 select new EmployeeProp { Name = a.Name, Email = a.Email }).ToList();         //error near select          return View(data);

Currently, I'm using:  DataTable dt = CreateDataTableInSomeWay();  List<DataRow> list = new List<DataRow>();  foreach (DataRow dr in dt.Rows) {     list.Add(dr); }   Is there a better/magic way?


I don't know why in the following example it is not possible to define null to the object, however it is possible to add properties to it    function callByReference(myFunc) {   myFunc.b = 2;   myFunc = null; // this not set null to Object arg    // myFunc.b = 2; //If I set it after, throws error }   let customObj = {   a: 1 };  console.log("Before call by reference method"); console.log(customObj);  callByReference(customObj);  console.log("After call by reference method"); console.log(customObj);     Even if I set it null first and then adding a property throws an error;  I don't understand this behavior well. Is there any reason? maybe I'm not understanding how javascript works when passing by reference a argument

The primitive types (number, string, etc.) are passed by value, but objects are unknown, because they can be both passed-by-value (in case we consider that a variable holding an object is in fact a reference to the object) and passed-by-reference (when we consider that the variable to the object holds the object itself).  Although it doesn't really matter at the end, I want to know what is the correct way to present the arguments passing conventions. Is there an excerpt from JavaScript specification, which defines what should be the semantics regarding this?


I'm trying to call a method in an aspx.cs but getting an InvalidOperationException with message      Late bound operations cannot be performed on types or methods for   which ContainsGenericParameters is true.   My code is:  protected void BuildSurface(int newValue) {     IEnumerable<dynamic> models = InitializeConfigurationForWorkflow(newValue);     List<Panel> panelList = new List<Panel>();      foreach (dynamic workflowConfiguration in models)     {         Type dynamicType = workflowConfiguration.GetType();          if (dynamicType.IsGenericType)         {             Type genericDynamicType = dynamicType.GetGenericTypeDefinition();              string methodName = null;             if (genericDynamicType.In(typeof(List<>), typeof(IEnumerable<>), typeof(IList<>)))                 methodName = "GenerateListPanel";             else if (genericDynamicType == typeof(Dictionary<,>))                 methodName = "GenerateDictionaryPanel";              if (methodName.IsNullOrEmpty()) continue;              Type[] listType = genericDynamicType.GetGenericArguments();             MethodInfo method = typeof(_admin_WorkflowConfiguration)                 .GetMethods()                 .Where(w => w.Name.Equals(methodName))                 .First();              MethodInfo generic = method.MakeGenericMethod(listType);             panelList.Add(generic.Invoke(this, workflowConfiguration})); // here the error appears         }     } }   my methods that will be called look like this one:  public Panel GenerateListPanel<T>(IEnumerable<T> workflowConfiguration) {     Panel panel = new Panel();     return panel; }   The dynamic-value is a json that gets deserialized to either Dictionary or List.  Any idea what I'm doing wrong?

What's the best way to call a generic method when the type parameter isn't known at compile time, but instead is obtained dynamically at runtime?  Consider the following sample code - inside the Example() method, what's the most concise way to invoke GenericMethod<T>() using the Type stored in the myType variable?  public class Sample {     public void Example(string typeName)     {         Type myType = FindType(typeName);          // What goes here to call GenericMethod<T>()?         GenericMethod<myType>(); // This doesn't work          // What changes to call StaticMethod<T>()?         Sample.StaticMethod<myType>(); // This also doesn't work     }      public void GenericMethod<T>()     {         // ...     }      public static void StaticMethod<T>()     {         //...     } }


I would like to classify individuals of a database by a single quantitative variable. Is hierachical clustering suitable to do this? If it is possible, how the algorithm work? If use hierachical clustering is not right, which other procedures or techniques could I use? My purpose is not classify the variable, but individuals. So decision trees are not suitable.

The following describes what I'm trying to accomplish, but it's possible an alternative problem statement can describe my goal:  I want to    divide the following numbers into groups where the variances of the numbers within each group are not too large, and the differences between the averages of groups are not too small  compare the distribution obtained in the end with the "perfect" ones and see how "different" it is from being perfect.     Layman's explanation of goal  , and determine the "income brackets" each population is in.  The income bracket is supposed to be self-adjusting based on the input data.  My goal is to ultimately measure or calculate the difference between the income brackets.  I assume there will be many brackets, and want to see how far "apart" each tier is.  Here is a sample of hourly income for a sample set of a population of 20, and a total income of 3587:  Population= 10                   pop=2   population=5              population =3 10, 11,13,14,14,14,14,14,15,20,  40,50  ,90,91,92,93,94      999,999,900    How can I use mathematical concepts to group, sort and analyze data that acts like income distribution over a given population?  At the end of the calculation, I want to determine tiered income distribution, where a perfect distribution would look (something) like this   (each person makes $10 more per hour than the previous; total is 3587) 89, 99, 109, 119, 129, 139, 149, 159, 169, 179, 189, 199, 209, 219, 229, 239, 249, 259, 269, 279   or this:   (evenly distributed groups of people make the same per hour)  (gaps between income groups is consistent and not "too far") (income total is 3587) 99 99 99   129 129 129   159 159 159   199 199 199  229 229 229  269 269 269    Question  How should I analyze the population groups, and measure the gap in a way that will tell me how much is needed to make it more like the last two model sets listed above?