Most of the times it happens to me that I have a question that is partly related to one domain and partly to the other domain(s). Asking a question on one domain has the side of effect of losing the answers that could be provided by the active users of other domains and asking it multiple times on different times will be wasting of resources. As a result I would like to know if there is going to be any external part in the question submission form, regarding on which domains one wants his question to appear?

I've been a Stack Exchange contributor for a couple of years now, currently most active on . One thing that keeps coming up is questions that would appeal to audiences on two different Stack Exchange sites but there are almost no features taking advantage of these questions. On travel.SE we have crossover questions most often with  and possibly next most often with  - but it can happen with almost any SE site. Today alone we had  with  and  had . I am absolutely sure that this must happen all the time between arbitrary pairs of Stack Exchange sites but the only feature that takes advantage of it is the possibility of migrating off-topic questions which leaves the original question acting as a redirect across the two sites. I think there is a missed opportunity to build the network between sites where users of one site don't realize they could make valuable contributions to a sister site they have had so far little to do with. At the very least there could be a way to "advertise" a question on a second site that could be interested in it. Probably by listing it in the sidebar where there are also links to meta questions, linked questions, related questions, new blog posts, and But there could also be some kind of features that make some sort of acceptable crossposting. There could be gamification/badges added around building cross-site questions or whatever else you can think up. I think this is a great way for people to spread their expertise from their main site onto other sites, to make the network stronger and more cohesive, to bring more attention to questions that would have a divided audience between two sites. I can think only of positives and no negatives. Does anyone else have some ideas to add or think this is a bad idea for any reason?  Example crossover questions: Here are some links to some crossover questions I've been finding in the Stack Exchange network here. (This was previously posted as an answer, but more people wanted it to be part of the question.)   ▶  :   ▶  :   ▶  :   ▶  :   ▶  :   ▶  :   ▶  :   ▶  :   ▶  :   ▶  :   ▶  :   ▶  :   ▶  :


My intuition tells me that the only connected 1-dimensional topological manifolds are the real line $\mathbb{R}$ and the circle $S^1$.   Is this true?   If yes, is it possible to prove it from first principles, or is it something that needs some highly technical theorems?  If no, do we have an example of connected 1-dimensional manifold not homeomorphic to $\mathbb{R}$ or $S^1$?

I recall having heard somewhere that the only 1-manifolds (second countable, Hausdorff, connected spaces locally homeomorphic to $\mathbb R$) are $\mathbb R$ and $S^1$. Is this true? If so, is there a reasonably elementary proof?


I am dealing with a binary response (good/ bad) type data set of size 2153, which reflects a dependent variable. Out of these, only 67 are in favor of "bad" and the remaining are of "good". Also, i have 3 independent variables.  How can i model my data set statistically? I tried the logistic regression, but the results are not satisfactory. Does SPSS have any solution for handling such types of imbalanced data?

Okay, so I think I have a decent enough sample, taking into account the 20:1 rule of thumb: a fairly large sample (N=374) for a total of 7 candidate predictor variables.   My problem is the following: whatever set of predictor variables I use, the classifications never get better than a specificity of 100% and a sensitivity of 0%. However unsatisfactory, this could actually be the best possible result, given the set of candidate predictor variables (from which I can't deviate).   But, I couldn't help but think I could do better, so I noticed that the categories of the dependent variable were quite unevenly balanced, almost 4:1. Could a more balanced subsample improve classifications?


I was using constructors. I notice that in TabWidget class. They used super sometimes. Again, sometimes this. public TabWidget(Context context) {     this(context, null); }  public TabWidget(Context context, AttributeSet attrs) {     this(context, attrs, com.android.internal.R.attr.tabWidgetStyle); }  public TabWidget(Context context, AttributeSet attrs, int defStyleAttr) {     this(context, attrs, defStyleAttr, 0); }  public TabWidget(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {     super(context, attrs, defStyleAttr, defStyleRes);      final TypedArray a = context.obtainStyledAttributes(             attrs, R.styleable.TabWidget, defStyleAttr, defStyleRes);     saveAttributeDataForStyleable(context, R.styleable.TabWidget,             attrs, a, defStyleAttr, defStyleRes);      mDrawBottomStrips = a.getBoolean(R.styleable.TabWidget_tabStripEnabled, mDrawBottomStrips);      // Tests the target SDK version, as set in the Manifest. Could not be     // set using styles.xml in a values-v? directory which targets the     // current platform SDK version instead.     final boolean isTargetSdkDonutOrLower =             context.getApplicationInfo().targetSdkVersion <= Build.VERSION_CODES.DONUT;      final boolean hasExplicitLeft = a.hasValueOrEmpty(R.styleable.TabWidget_tabStripLeft);     if (hasExplicitLeft) {         mLeftStrip = a.getDrawable(R.styleable.TabWidget_tabStripLeft);     } else if (isTargetSdkDonutOrLower) {         mLeftStrip = context.getDrawable(R.drawable.tab_bottom_left_v4);     } else {         mLeftStrip = context.getDrawable(R.drawable.tab_bottom_left);     }      final boolean hasExplicitRight = a.hasValueOrEmpty(R.styleable.TabWidget_tabStripRight);     if (hasExplicitRight) {         mRightStrip = a.getDrawable(R.styleable.TabWidget_tabStripRight);     } else if (isTargetSdkDonutOrLower) {         mRightStrip = context.getDrawable(R.drawable.tab_bottom_right_v4);     } else {         mRightStrip = context.getDrawable(R.drawable.tab_bottom_right);     }      a.recycle();      setChildrenDrawingOrderEnabled(true); }  Why they used this inside constructor? I haven't get any documentation or class or youtube video who worked with "this" inside constructor. We usually use super. So, this used for what?

Is it possible to call a constructor from another (within the same class, not from a subclass)? If yes how? And what could be the best way to call another constructor (if there are several ways to do it)?


There are a lot of questions very similar to mine, but I couldn't find one that accurately described what I want to do.  I am working in QGIS.  I have one vector layer which, among other attributes, has a production volume for oil wells.   I have a second layer which represents townships.  Some townships have five wells, some have none etc., all with different levels of production.  I want to create a new layer which displays all the townships with a summation of the total production volume within the township.  Can anyone think of an efficient way to do this? EDIT: I would also like to be able to the sum of the production volumes to the township layer.  Thanks!

I have a database of almost 10k crimes, which are divided in to 10 categories and plotted on a map  I also have a database of 12k addresses, which are also plotted on the map.   I aim to perform a multiple regression to determine whether there are correlations between types of crime and house price.  I have created a buffer of 250 meters around each of the addresses, and would like to list a count of each of the crimes which are located within this buffered zone for each of the addresses, however, I can only get QGIS to give me a count of all types of crime, rather than the specifics.   Does anyone know how to do a point to polygon analysis of this type? I am in the middle of breaking the crime databases to analyse each one separately, which is a bit difficult!


I got a little stuck with this proof. It is given that $AB=BA$.  Proof: $(AB)^2 = A^2 \cdot B^2$  I have been thinking of several ways to solve it. I got to this point:  $(AB)^2 = AB\cdot AB = BA\cdot AB = B\cdot A^2\cdot B$  But I don't know how to proceed. I think I am missing some general rule.  Can somebody help me?

From Dr. Pinter's "A Book of Abstract Algebra":     Given $a$ and $b$ are in $G$ and $ab=ba$, we say that $a$ and $b$ commute.         Prove $a^2$ commutes with $b^2$      I tried:  $$ ab=ba $$ $$ a^{2}b^{2}=b^{2}a^{2} \text{ // to prove that $a^2$ commutes with $b^2$} $$ $$ aabb=bbaa $$  Then, knowing that $$a=b^{-1}ab,$$ I substituted that '$a$' into '$aabb=bbaa$'.  But that simplified to '$aabb=bbaa$', i.e. I got nowhere with it.  How can I prove that $$aabb=bbaa$$ per this problem?


I am trying to round a number to 7 decimal places by converting my input number to a string and then back to a double. The value of the string is how I would like it, but when converting it back to a double more decimal places are revealed. Any remedy for this situation?  let inputNumber: Double = 99.99990338164251  let roundedString = String(format: "%.7f", inputNumber) //"99.9999034"  let outputNumber = Double(roundedString) //99.99990339999999

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


Suddenly, my Ubuntu reports an error and no longer does updates because of this error. The error seems to be the following:  Reading package lists... Error! E: Encountered a section with no Package: header E: Problem with MergeList /var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_trusty-updates_universe_i18n_Translation-en E: The package lists or status file could not be parsed or opened.              It seems that this prevents me from doing everything. Apt-get stops with an error, synaptics manager also, and so on and so forth. Any solutions out there?  Thanks,  Jim

The computer gave me this output in a window:  E: Encountered a section with no Package: header E: Problem with MergeList /var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_natty_main_binary-i386_Packages E: The package lists or status file could not be parsed or opened.   How can I fix this?


I recently read an article which said the the universe is expanding with a very high velocity, which is even a lot faster than the speed of light. So, doesn't this prove Einstein's theory wrong which says that nothing can go at the speed of light, whereas the expanding universe is even faster than that.

just after the Big Bang and before inflation the currently observable universe was the size of a coin. One millionth of a second later the universe was the size of the Solar System, which is an expansion much much faster than speed of light. Can space expand with unlimited speed?


Hello im new in this Community, i liked Ubuntu OS but i don't know if Ubuntu support My Hardware is a HP Pavilion dv4-4075la entertainment PC and this is his Hardware.    i want to play games like Team fortress 2, Sims 3 (i know i need to use virtual box or Playonlinux) my computer actually have Windows 7 Home basic and runs those games at medium high, i dont want to have lag on those games. Another thing, i want to install Ubuntu 12.04 LTS on my PC:D   And sorry for my bad english i'm a noob in the english.Greeting!

I'm thinking about installing Ubuntu Desktop, but I don't know what flavor is the best for my system. What are the minimum and recommended hardware requirements? What kind of CPU? How much memory? Should I have Hardware Acceleration? What flavor should I use?  This is an attempt of a canonical answer. My answers have the "official  requirements", the recommended are a mix of official sources and opinion based (along with the answer it's told the source). You can comment or edit if you feel that the information is obsolete or incomplete. It is a good rule of thumb that any system capable of running Windows Vista, 7, 8, x86 (Intel) OS X will almost always be a lot faster with any Ubuntu flavor even if they are lower-spec than described below.


I have a friend who is frequently depressed and about a week ago he left the clan. He doesn’t have any other form of contact, and yeah it’s weird, but I’ve already tried everything in my power. I’m really worried and he has seemingly gone inactive with no warning. Please help me and if I can send him an email somehow that would help me so greatly. Please, he needs help and so do I. Thank you!

I accidentally rejected someone entry from the clan. I felt really bad about it because I recognized his name, and he explained that he comes on leaves the clan frequently for trophy reasons. Is there anyway I can send an invite now that he's in another clan?  In clash of the clans can you communicate with anyone outside of your clan? I know there's the global chat, but it's not a good chance someone will see a message addressed to them?  Aside from your own clan, can you ever message another clan, for example in war?


If I have 1 independent variable (continues) and 1 dependent variable (binary), I can conduct logistic regression and ROC analysis, and I can get a cut-off point of independent variable using ROC analysis.  But, If I have 2 independent variable, how can I get two cut-off point in multivariate ROC analysis.   In STATA, I can get just maximal AUC score but I can't get the cut-off points each independent variables.

I'm trying to understand how to compute the optimal cut-point for a ROC curve (the value at which the sensitivity and specificity are maximized). I'm using the dataset aSAH from the package pROC.  The outcome variable could be explained by two independent variables: s100b and ndka. Using the syntax of the Epi package, I've created two models:  library(pROC) library(Epi) ROC(form=outcome~s100b, data=aSAH) ROC(form=outcome~ndka, data=aSAH)   The output is illustrated in the following two graphs:     In the first graph (s100b), the function says that the optimal cut-point is localized at the value corresponding to lr.eta=0.304. In the second graph (ndka) the optimal cut-point is localized at the corresponding value to lr.eta=0.335 (what is the meaning of lr.eta). My first question is:   what is the corresponding s100b and ndka values for the lr.eta values indicated (what is the optimal cut-point in terms of s100b and ndka)?   SECOND QUESTION:  Now suppose I create a model taking into account both variable:  ROC(form=outcome~ndka+s100b, data=aSAH)   The graph obtained is:    I want to know what are the values of ndka AND s100b at which sensibility and specificity are maximized by the function. In other terms: what are the values of ndka and s100b at which we have Se=68.3% and Sp=76.4% (values derived from the graph)?  I suppose this second question is related to multiROC analysis, but the documentation of the Epi package does not explain how to calculate the optimal cutpoint for both variables used in the model.  My question appears very similar to this question from , which says in short:     The determination of cut-off score that represents a better trade-off   between sensitivity and specificity of a measure is straightforward.   However, for multivariate ROC curve analysis, I have noted that most   of the researchers have focused on algorithms to determine the overall   accuracy of a linear combination of several indicators (variables) in   terms of AUC. [...]      However, these methods do not mention how to decide a combination of   cut-off scores associated with the multiple indicators that gives the   best diagnostic accuracy.   A possible solution is that proposed by Shultz in his , but from this article I'm not able to understand how to compute optimal cutpoint for a multivariate ROC curve.  Maybe the solution from the Epi package is not ideal, so any other helpful links will be appreciated.


I have a list of dictionaries like this but with many more dictionaries:  x = [{"duration":datetime.time(5,30),"date":datetime.date(2016,02,13)},{"duration":datetime.time(3,30),"date":datetime.date(2016,02,11)},{"duration":datetime.time(2,0),"date":datetime.date(2016,02,16)}]   Is there a way to sort this list in ascending order of date using Python keywords such as sorted and lambda without making a custom sorting function? I have been looking at the sorted  and the use of lambda in the optional key argument.

I have a list of dictionaries and want each item to be sorted by a specific value. Take into consideration the list: [{'name':'Homer', 'age':39}, {'name':'Bart', 'age':10}]  When sorted by name, it should become: [{'name':'Bart', 'age':10}, {'name':'Homer', 'age':39}]


I understand that for the parametric equations  $$\begin{align*}x&=f(t)\\   y&=g(t)\end{align*}$$  If $F(x)$ is the function with parameter removed then $\displaystyle F'(x) = \frac{\text{d}y}{\text{d}t}\big/\frac{\text{d}x}{\text{d}t}$  But the procedure for taking the second derivative is just described as " replace $y$ with dy/dx " to get   $$\frac{\text{d}^2y}{\text{d}x^2}=\frac{\text{d}}{\text{d}x}\left(\frac{\text{d}y}{\text{d}x}\right)=\frac{\left[\frac{\text{d}}{\text{d}t}\left(\frac{\text{d}y}{\text{d}t}\right)\right]}{\left(\frac{\text{d}x}{\text{d}t}\right)}$$  I don't understand the justification for this step. Not at all.   But that's all my book says on the matter then it launches in to plugging things in to this formula, and it seems to work well enough, but I don't know why.  I often find answers about question on differentials are beyond my level, I'd really like to get this, it'd mean a lot to me if someone could break it down.

I am looking to find out how the second derivative formula works.  I can blindly apply it but I don't have a grasp of what is going on or why. The first derivitive has the formula $\frac{dy}{dx} = \frac{\frac{dy}{dt}}{\frac{dx}{dt}}$. I told this was because if you divide them you cancel out the dts and get dy/dx. The second derivative has the formula $\frac{d^2y}{dx^2} = \frac{d}{dx} \left(\frac{dy}{dx}\right) = \frac{ \frac{d}{dt}\left(\frac{dy}{dx}\right) }{\frac{dx}{dt}}$. Is this something that can be explained with only a knowledge of calculus or is this something I would have to take on faith until I learn more. Any help would be greatly appreciated.


I have been searching for ages now, for this.  All I want is exactly as I mentioned in my question, I have many editors like Sublime Text, VS Code etc.  But they all seem useless when it comes to edit Windows Hosts file, directly without closing them, in my Windows 7 64bit system.  So I want a single batch script to provide the same administrator access to the editor(whose executable's path I give in the batch script) as when editor is "Run As Administrator" from the context menu.  So that I can open the editor in elevated mode and also pass hosts file's path as an argument to open that as well. I have tried below code but in vain:  OpenWinHosts1.cmd:  @echo off runas /profile /user:USERNAME "CMD /K \"C:\Path\to\OpenWinHosts2.cmd"" exit /b   OpenWinHosts2.cmd:  @echo off start "C:\Program Files\Sublime Text 3\sublime_text.exe" "C:\Windows\System32\drivers\etc\hosts" exit /b   Can anyone assist in this ?

I want to start Notepad with elevated privileges to edit C:\Windows\System32\drivers\etc\host. Notmally I would type notepad in the search box, and with the program highlighted hot Ctrl + Shift + Enter, click Yes on the UAC prompt and then open the file. I do this often, so I want a batch file to do it.  I tried the following command:  runas /user:Administrator /savecred notepad.exe path\to\file   But this is not exactly what I want, as it prompts for the password of the Administrator account. I really want a command to start a program with elevated privileges for the current user account.  I run Windows 7 RC.


I would like to understand what the transpose of a vector represents different from the vector itself.  I am not looking for a proof, just an explanation with some examples. I understand how the transpose can be used to follow the rules needed for matrix multiplication in linear algebra. But do the individual meanings of each element of a column vector have a different meaning when transposed to a row vector. For example, I have a good "feel" of what a vector in 2D Real coordinate space means, for example, when I see v =(2,5) I can think of this as a vector with a size of 2 units in the X direction and a size of 5 units in the Y direction. Do I change how I think of those values (2 and 5) when I take the transpose of v ?

I have seen a definition of orthogonality between two vectors something like this:  $$<\vec{u}, \vec{v}> = u^T \cdot v = 0$$  I am wondering what is the purpose of using a transpose of a vector (in this case and in general). I have also seen this in the formula to find the projection of a vector over another, but I have used just the normal vector instead of its transpose and everything seems to work.


I have a python script that is reading in an xml file using lxml.  However lxml is getting thrown off by the namespace.    Ie if delete xmlns="http://theurl.com" from my xml file before running the script it works fine and finds all the elements.  I am really struggling on how to modify the script to make it so I dont need to delete the name space reference from the xml file before parsing.   Sample Code  from lxml import etree root = etree.parse(r'myfile.xml')  Elements=[] for elements in root.xpath('//element'):       print(list(elements.keys()))   Sample File.    <ServiceDefinition xmlns="http://theurl.com" " version="1.0.1.0">       <schema>          <seqtype="xyz">             <element name="element 1"/>             <element name="element 2"/>          </seqtype>        </schema> </ServiceDefinition>

I am testing against the following test document:  <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"                        "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml">    <head>         <title>hi there</title>     </head>     <body>         <img class="foo" src="bar.png"/>     </body> </html>   If I parse the document using lxml.html, I can get the IMG with an xpath just fine:  >>> root = lxml.html.fromstring(doc) >>> root.xpath("//img") [<Element img at 1879e30>]   However, if I parse the document as XML and try to get the IMG tag, I get an empty result:  >>> tree = etree.parse(StringIO(doc)) >>> tree.getroot().xpath("//img") []   I can navigate to the element directly:  >>> tree.getroot().getchildren()[1].getchildren()[0] <Element {http://www.w3.org/1999/xhtml}img at f56810>   But of course that doesn't help me process arbitrary documents.  I would also expect to be able to query etree to get an xpath expression that will directly identify this element, which, technically I can do:  >>> tree.getpath(tree.getroot().getchildren()[1].getchildren()[0]) '/*/*[2]/*' >>> tree.getroot().xpath('/*/*[2]/*') [<Element {http://www.w3.org/1999/xhtml}img at fa1750>]   But that xpath is, again, obviously not useful for parsing arbitrary documents.  Obviously I am missing some key issue here, but I don't know what it is.  My best guess is that it has something to do with namespaces but the only namespace defined is the default and I don't know what else I might need to consider in regards to namespaces.  So, what am I missing?


i have a windows application that connects with a SQL Server 2012 database. This database is huge and yesterday, all the query's of the application give time out and we found that the log file was in the max size that was configured. So we change the size (it was in 8gb) to 16gb but we think that this was a temporary solution.   What solution should i take with this?  Edit: Because the "marked as duplicate question" appear i wanna edit this post to remark that i don't want to ask how to clear the transaction log. My question points to what is the best option to take in this scenario, maybe is to clear the transaction log but maybe there are another options too. Sorry if the users misunderstood the question.

I'm not a SQL expert, and I'm reminded of the fact every time I need to do something beyond the basics. I have a test database that is not large in size, but the transaction log definitely is. How do I clear out the transaction log?


This is a GIS question as well as a Remote Sensing question. I have downloaded CDF files from the ESA from MyEarth online and want to use them in ArcMap. In ArcMap you can Make NetCDF a Raster Layer. Is there some way I can convert CDF to NetCDF? Or do I need to? Should a CDF file work here?

I received some geospatial data (on rainfall) in a "cdf" format.   I have worked with "nc" files and uses the 'Make NetCDF Raster Layer' tool in ArcMap to read NetCDF files.   However, I wasn't able to use it to read the file with .cdf extension.   Is there an alternative way to read such files?   I have access to ArcMap, QGIS and Python so if there's a solution using any of these tools please let me know.


Lots of people have asked if Java is "pass-by-reference" or "pass-by-value", yet I feel I haven't gotten a good explanation of how Java actually stores references and how it dereferences them when called.  Would anyone be able to explain what happens when you have something like, say,  public class Foo {     public static void main(String a[]){         Object a = new Object();         Object b = a;         Object c = b;         bar(c);     }     public static void bar(Object obj) {         obj = new Object();         System.out.println(obj);     } }   in terms of pointers?   How is the JVM actually referencing and dereferencing objects and references?  I'm guessing it's semantically equivalent to the semi-pseudo C++ code:  int main() {     Object *a = new Object;     Object *b = a;     Object *c = b;     bar(c);     return 0; } void bar(Object *tempObj) {     tempObj = new Object;      //changes address of a copy of the ptr arg     cout << std::to_string(*tempObj) << endl; }   (I know there is no Object class in C++ and that to_string isn't defined for every class like it is in Java, but for the sake of example I think it helps illustrate the concept.)  Am I correct? Bottom line: what's going on under the hood? I'd like a more explicit answer.

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?


I’m going to Spain in 3 months, and it will be my first flight in 8 years.  I have always had problems with my ears when I was younger. I have had lots of grommets in because of hearing loss and ear infections and had my last ones removed 2 years ago.   I still get a bit of pain in my ears even now when we drive up a hill, and my ears pop or if we go on a train through a tunnel. Even if my mum has her window open in the car and I don’t, it sends my ears wild.   However, the last time coming home on a plane from America when I was 9 or 10, I had severe pain in my ears when landing. It has always put me off flying and now I have a flight coming up. I’m very nervous.   Can someone give me some tricks and tips to calm my nerves and ease my worries? I really don’t want to not go on a plane ever again. I want to travel and I don’t want this stupid reason to hold me back from life!   I have tried the ear pressure plugs, swallowing, bowing your nose and nothing works!   I will try and get some pain meds from doctors but what if it hurts?

I always feel a pain in my ears when flying. Specially when descending. The last time I had extreme pain, feeling it inclusive around my eye balls. It felt like someone was touching the eye and pulling it from the inside. I really had to focus, close my eyes and hold to avoid screaming. I am not sure but I think both things might be related. Such a severe situation only happened once.  I just heard that with a cold the ear pain gets worse. I am bit worried that I might go through that situation again. I have a cold and I am going to fly soon.  What can I do to improve this?  I see that some consider this a duplicate of the question "best way to make my ears pop" but after reading the answers I think my question goes a bit beyond that since my pain is more extreme and I think it goes beyond just popping the ears. I also want to know if other methods, like using earplugs, might be effective.


How temperature can be less than nothing or less than absolute zero?And how atoms interact in this level?

Just to get the thoughts rolling...  Consider a two state system with discrete energy levels $E_1$ and $E_2$ where $E_2 > E_1$ which contains $N$ particles.  We can easily deduce that the state of maximum entropy is when energy level $E_1$ and $E_2$ each contain $\frac{N}2$ particles.  Based on the (flipped-upside-down) thermodynamic definition of temperature, $$(\frac{\partial E}{\partial S})=T$$ we see that when energy as a function of entropy increases, temperature also increases.  This means, for our two state system, every time a particle populates level $E_2$, there is a corresponding increase in temperature because that population increases entropy.  What about when we go beyond the point of maximum entropy where there are $\frac N2$ particles in $E_1$ and $E_2$?  Well, then we are adding energy to the system, but the entropy is decreasing.  Based on the Boltzmann factor, this can't be possible unless the temperature of the system is negative. That is, $$\frac{P_1}{P_2}=e^{-\frac{(E_1-E_2)}{kT}}$$ which approaches infinity unless one says the system has a negative absolute temperature.  Now we're getting to the point: this increase in energy which is connected to a decrease in entropy is what has been called a . This is most often connected to .  Forgive me for saying things you already know.  All of this raises a lot of questions though, the most striking to me is that there does not seem to me to be a good physical explanation for how this can be possible. For instance, when people say that the negative temperature system is "hotter" I get what that means as far as saying that heat will flow from a negative temp. system to a pos. temp system.  I'm fine with that except that it invokes the idea of a fairly macroscopic quantity--hotness--for a purely quantum phenomenon. So, is there any macroscopic physical meaning to this statement that the negative temperature is "hotter"?  Concerning population inversion in lasers: doesn't this mean that the negative temperature required for that laser to exist ought to be so "hot" no mere mortal can handle such a device.  After all, negative absolute temperatures are often explained as being "hotter than infinite temperature." (I've heard this other places, but also see the neg. temp. Wikipedia article for quote.) I understand that again from a mathematical perspective, but what is the physical connection? A statement like that must surely manifest itself in some way that is noticeable beyond the quantum level.  I guess I really want to understand how it could be this "hotter than infinite temperature" system isn't perceptible in the macroscopic realm? I mean, lasers are cool, but they aren't just melting through everything as if they have infinite temperature.    My bad for the obvious misuse of the word "physical" when I probably meant something more like "macroscopic". I hope the point is clear anyways.  Thoughts?


I'm understanding this topology through doing an exercise.  We say that a subset $U \subseteq \mathbb{R}^{2}$ is radially open if if for every $x \in U$ and every $u \in \Bbb R^2$ with $||u||=1$, there is an $\epsilon>0$ such $x+su \in U$ for every $s \in (- \epsilon, \epsilon)$. I already proved these sets are a topology for $\mathbb{R}^{2}$.  First question (this was not asked for the exercise) is how can I visualize this strange topology. I got a picture for my book but still don't catch it up.  Second question, if $T_{e}$ is the usual topology for $\mathbb{R}^{2}$ and $T_{r}$ is the radially topology, how do I prove that $T_{e} \subseteq T_{r}$ and $T_{r} \not \subset T_{e}$. As I dont understand the image of this topology I cannnot figure out the first contention also for the second I have only find here confusing examples.  Last question, I want to prove that for every circumference in radially plane has discrete topology as topological subspace. I think this was asked once and they always explain that this intersection gives the center of the circumference but dont really understand the steps to conclude this.  Any help will be aprecciated. Thanks!

A subset $U\in\mathbb{R}^2$ is called radially open if for every point $x\in U$, $U$ contains an open segment through $x$ in every direction, that is for every $v\in\mathbb{R}^2$, $|v|=1$, there exists $\epsilon>0$ such that $x+sv\in U$ for every $s\in (-\epsilon,\epsilon)$. I proved that the familly of radially open sets is a topology on $\mathbb{R}^2$.   What are the induced topologies of this topology on a straight line of $\mathbb{R}^2$ and on a circle ?


If  $f : [-1,1]\rightarrow R$ be a continuous function satisfying $f(2x^2-1)=(x^3+x)f(x)$, then find the value of  $\lim\limits_{x \to 0}\dfrac{f(\cos x)}{\sin x}$  My approach is as follow, as the domain is $[-1,1]$, we check the value at $x=-1$, then $f(1)=-2f(-1)$, at $x=1$, then $f(1)=2f(1)$, then $f(1)=0$, hence $f(-1)=0$, putting $x=0$ we get $f(0)=0$.  Now  on differentiating we get $4xf'(2x^2-1)=(3x^2+1)f(x)+(x^3+x)f'(x)$ after this I am not able to solve as it is getting complicated

$f:[-1,1]\to \mathbb{R}$ is a continuous function such that  $f(2x^2-1)=(x^3+x)f(x).$ Find $\lim_{x\to 0}\frac {f(\cos x)}{\sin x}$  My approach : Using the functional equation I got f is an odd function. $\implies f(0)=0$  let $g(x)=\frac{f(\cos x)}{\sin x},x\ne 0\implies |g(2x)|= \frac{1+\cos^2x}{2}|g(x)|\le |g(x)|$ $\implies |g(x)|\le |g\left(\frac {x}{2^n}\right)|...(1)$   Also By replacing $x$ by $\sin x$ in the given functional equation we get $g(2x)=-\frac{1+\sin^2x}{2}\frac{f(\sin x)}{cos x}...(2)$ From (1) and (2) we get, $|g(x)|\le \left|\frac {1+\sin^2 \frac{x}{2^{n+1}}}{2\cos \frac{x}{2^{n+1}}}f\left(\sin\frac {x}{2^{n+1}}\right)\right|$  lets $n\to\infty\implies |g(x)|\le 0\implies g(x)=0\,\,\forall x\in[-1,1]-\{0\}.$  $\implies \lim_{x\to 0}\frac {f(\cos x)}{\sin x}=0$


I'm preparing for a presentation. I have four figures (fig 1, fig 2, fig 3 and fig 4). I want to show the fig 1 in the whole slide and then zooming it out to the top left corner of the slide. Then to show the fig 2 in the whole slide and zooming it out to the top right corner of the slide. Similarly, fig 3 to the left bottom corner and fig 4 to the right bottom corner of the slide after showing them in the whole slide. I do not have any idea on this. Any help will be highly appreciated. Thanks.

I want to:   Show an image full width On click, make a small sized image placed at a particular location starting from top left and show another image full width Repeat the process till all four images are shown End with a grid of four images vertically and horizontally centered   The problems I am facing is:   The location of the grid images changes as the third image (bottom-left) in the grid is displayed   Possible improvements I am looking at are:   When I go from full width image to the 'overview' slide, the transition should be like zooming the image to that location Better code than the one I have used?   Below is the MWE.  \documentclass[xcolor=dvipsnames,english,professionalfonts,smaller]{beamer}  \usetheme{Madrid}  \usepackage{graphicx} \usepackage{parskip} \usepackage{mwe} \graphicspath{{.}{./image}}  \begin{document}  \setlength{\parskip}{\bigskipamount}  \begin{frame}{Title Text}      \only <+ | handout:0> {\hfil \fbox{\includegraphics[width={\textwidth}]{example-image-16x9}}}     \only <+ | handout:0> {\fbox{\includegraphics[width={.470\textwidth}]{example-image-16x9}} \hfill}     \only <. | handout:0> {\phantom{\fbox{\includegraphics[width={.470\textwidth}]{example-image-16x9}}} \\ \vspace{.09in}}     \only <. | handout:0> {\phantom{\fbox{\includegraphics[width={.470\textwidth}]{example-image-16x9}}} \hfill}     \only <. | handout:0> {\phantom{\fbox{\includegraphics[width={.470\textwidth}]{example-image-16x9}}}}     \transduration<.>{.01}     \only <+ | handout:0> {\fbox{\includegraphics[width={\textwidth}]{example-image-16x9}}}     \only <+ | handout:0> {\fbox{\includegraphics[width={.470\textwidth}]{example-image-16x9}} \hfill}     \only <. | handout:0> {\fbox{\includegraphics[width={.470\textwidth}]{example-image-16x9}} \\ \vspace{.09in}}     \only <. | handout:0> {\phantom{\fbox{\includegraphics[width={.470\textwidth}]{example-image-16x9}}} \hfill}     \only <. | handout:0> {\phantom{\fbox{\includegraphics[width={.470\textwidth}]{example-image-16x9}}}}     \transduration<.>{.01}     \only <+ | handout:0> {\fbox{\includegraphics[width={\textwidth}]{example-image-16x9}}}     \only <+ | handout:0> {\fbox{\includegraphics[width={.470\textwidth}]{example-image-16x9}} \hfill}     \only <. | handout:0> {\fbox{\includegraphics[width={.470\textwidth}]{example-image-16x9}} \\ \vspace{.09in}}     \only <. | handout:0> {\fbox{\includegraphics[width={.470\textwidth}]{example-image-16x9}} \hfill}     \only <. | handout:0> {\phantom{\fbox{\includegraphics[width={.470\textwidth}]{example-image-16x9}}}}     \transduration<.>{.01}     \only <+ | handout:0> {\fbox{\includegraphics[width={\textwidth}]{example-image-16x9}}}     \only <+ | handout:0> {\fbox{\includegraphics[width={.470\textwidth}]{example-image-16x9}} \hfill}     \only <. | handout:0> {\fbox{\includegraphics[width={.470\textwidth}]{example-image-16x9}} \\ \vspace{.09in}}     \only <. | handout:0> {\fbox{\includegraphics[width={.470\textwidth}]{example-image-16x9}} \hfill}     \only <. | handout:0> {\fbox{\includegraphics[width={.470\textwidth}]{example-image-16x9}}}  \end{frame}  \end{document}


In particular, I need to display the following: P(success) = size of successful region/size of possible region But with a nice divisor line for the fraction. If I just enter this in typical fashion LaTeX makes each letter look like a variable:  $P(success) = \frac{size of successful region}{size of possible region}$

Lets say I have something like:   \[ Let x = number of cats \]   (This is a contrived example, but pretend we are actually inside a long align environment block...) "Let" and "number of cats" need to be written like normal text, while x= needs to be math type text.  I've seen this:  \[ \mbox{Let } x = \mbox{ number of cats} \]   and this:  \[ \textrm{Let } x = \textrm{ number of cats} \]   They seem to produce equivalent output, but I'm not sure which is the "correct" one. Also, they are not ideal in that the extra space needs to be placed inside the text mode block, otherwise it is ignored as math mode and butts the text right up against the math.  Ideally there would be some command which allowed embedding text into an equation, which correctly inserted leading and trailing space around the block as required without adding space inside the text block.  How does one do that "correctly"?


Are the following sentences emphatic sentence or relative clause? Why? What's the difference?     It is the factory that you visited last week.      It is Tom who/that I saw yesterday.   Thanks for your englightenment.

"Before the war, you always think that it's not you that dies."   - Ernest Hemmingway    I'm having trouble diagramming this sentence. My question is about the subordinate clause in bold.  Is the extraposed that-clause("that dies") at the end the subject or an adjective of the subject?  When you un-extrapose it, would it be : "that it that dies is not you" or " that that(who) dies is not you."?


I want to use the command "\angle". I have the "amsmath" package included im my document, and I can use any other math commands, but not this. What I need to do? It requires a different package?  Thank you!

I know what my symbol or character looks like, but I don't know what the command is or which math alphabet it came from. How do I go about finding this out?


Before I start, I want to say that this is not a duplicate of  "Is it possible for information to be transmitted faster than light by using a rigid pole?", Since point A is not a real object, it is possible for A to exceed the speed of light. Notice that I have already taken the bending effect into account and decided that if the widths of the bars are small enough, then it's safe to treat the scissor as if it weren't bending. In other words, when they are thin, then the motion will obey the equation in a small region around point O. Please read to the end and have a look on my analysis in the last part before you explain.  Suppose we have a "scissor", which is composed by two bars with a same width of length "l". Bring them closer to each other, during this process, we have the equation(#):$$v=-\frac l4\frac{cos\frac{\theta}2}{sin^2\frac{\theta}2}\omega$$, where v is the velocity of A, \theta is the angle between BC and BA as shown in the picture.It's also an arbitrary function of time t, or $\theta=\theta(t)$. $\omega$ is the angular velocity of $\theta$, thus $\omega=\frac d{dt}\theta(t)$.Here is the derivation: 1. Draw a line vertical to L from A, intersecting with L at C.    Since $sin\theta=\frac{AC}{AB}$,  $$AB=\frac{AC}{sin{\theta}}$$. Since $cos\frac{\theta}2=\frac{AO}{AB}$, $$AO=AB*cos\frac{{{\theta}}}2$$ from 2 and 3 we have: $$AO=\frac{cos\frac{\theta}2}{sin{\theta}}*AC$$ Since $AC=l$, the equation in 4 becomes: $$AO=\frac{cos\frac{\theta}2}{sin\theta}*l$$or$$AO=\frac l{2sin\frac {\theta}2}$$ Differentiate each side with respect to t, and denote $\frac d{dt}AO$ as "v", getting the equation(#): $$v=-\frac l4\frac{cos\frac{\theta}2}{sin^2\frac{\theta}2}\omega$$ Again, we just look at a small area around point O where our equation is obeyed. Now, at any time $t_0$, $\theta$ and $\omega$ are independent of each other, thus $\omega$ is a free variable. At t= 0, let's set the value of $\omega$ really large and constant, so that the instantaneous speed of A is larger than even the speed of light. Later, since the factor $\frac{cos \frac{\theta}2}{sin^2 \frac {\theta}2}$ in equation(#) is quite large when $\theta$ is close to 0, and since large $\omega$ leads to small $\theta$ during a short period of time, the velocity of A will be increased by this factor. Thus overall, $\omega$ is set to be a large constant, l is a constant, the only changing factor is increasing. Therefore, the velocity of A will increase. Meanwhile, we emit a beam of light. A is in a superluminal motion. And A will arrive at a detector first, causing the bars to touch the detector, and sending the command to the machine. Then the light beam comes later, thus being detected later. Notice that here again, we place the detector close enough to point O, so that our equation is valid.   Remark: Someone may argue that we are not sure if A could attain a speed higher to that of light. So suppose at t=0, the force has already affected the area around point O, and is now traveling further.Meanwhile, ${\theta}_0=\frac{\pi}3$ A is speeded up to 0.999c, then since our formula is valid at t=0 and later period of time, let's apply it and set $l=0.001m, c=3*10^8m/s,{\theta}_0=\frac{\pi}3$. Then plug them in, we get $$\omega=-3.461*10^{11}rad/s $$. Now we want to know its velocity at $t=1*10^{-12}s$, and we get $v=6.89062*10^8m/s$, faster than light.  According to relativity, this shall violate casualty, and therefore could never happen. With which kind of mechanism is this paradox solved? I have taken the bending effect into account, and decided that as long as the widths of the bars are small enough, then it's safe to treat the scissor as if it weren't bending.

Is it possible for information (like 1 and 0s) to be transmitted faster than light?   For instance, take a rigid pole of several AU in length. Now say you have a person on each end, and one of them starts pulling and pushing on his/her end.   The person on the opposite end should receive the pushes and pulls instantaneously as no particle is making the full journey.  Would this actually work?


I am confused why the below works but the following does not? Input: grid = [[0,1,0],[0,0,1],[1,1,1],[0,0,0]]  Working: def foo(grid):     m = len(grid)     n = len(grid[0])     gridCopy = [[grid[row][col] for col in range(n)] for row in range(m)]     return gridCopy == grid  Does not work: def bar(grid):     m = len(grid)     n = len(grid[0])     gridCopy = [[None] * n] * m     for i in range(m):         for j in range(n):             gridCopy[i][j] = grid[i][j]     return gridCopy == grid  I get the following grid returned from bar(): gridCopy = [[0, 0, 0], [0, 0, 0], [0, 0, 0], [0, 0, 0]]

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


I am using qgis2web with QGIS3.0 to make web map. The problems I encountered were:  Label styles not exported correctly. (e.g. color changed, background disappeared after export etc.) Zoom level - I set the Label Rendering based on scale-dependent-visibility. It displayed well in QGIS edit panel. However, it just did not want to work correctly after I exported the map into web map.  Just wondering if there is any bug in QGIS/ qgis2web.js or it was because I did not adjust some settings correctly? This is an example: picture(1) what I desire to see (in QGIS edit panel)  picture(2) faulty exported webmap: (result)  Scales, color, text of label background style are all wrong!

I am making a webmap using QGIS3. However, I set the text-label to be invisible from a certain zoom-level onward, and visible from another zoom-level. It displays correctly locally in QGIS edit screen but it does not work after I export it to web. (using qgis2web plugin) Goal: to make text disappear at 1:1800 scale(zoom) level and above. (text appear below 1:1800 when zooming out) This is what I mean:  Result after exporting is that "Lot number and land area" will not even show up at all. I try both OpenLayers and Leaflet. (this is the example with no label display setting based on zoom level) --> export outcome:  --> Ideally, I want to hide the appearance of text label totally when I zoom out to a certain level. Bad impression:  I wonder is there anyway I can modify the output code to modify and realize what I want to achieve or am I getting some settings wrong?


I have this tag
some text
   How can I change the attribute so that it is
some text

I would like to change all the names of the attributes where class="testingCase" throughout all my whole html document.  e.g. Change:  Blabla Bloo   To this:   Blabla` <a class="testingCase" href="#" newTitleName="name of another testing case">Bloo</a>`   I was thinking of a find and replace but that seems a lot of code for something so easy. Is there a jQuery function for this or a simple method?


Is there a way to turn off the controller without turning off the Steam Link?  I use the controller to turn on the Steam Link, but I don't actually like it and would like to play with a PS4 controller.  However, the Steam Controller just stays on, wasting its batteries...

I have a steam controller connected to my computer.   How do I turn the controller off without launching big picture mode?  Currently to turn the controller off, I do the following:   hit the steam button in center of controller (launches big picture mode) hold down the steam button until the option to turn off the controller appears.


Is this a sufficient way of proving that for for all real numbers $x$ and $y$, if $xy=0$ then $x=0$ or $y=0$?   My attempt:   $$xy=0$$  $$y=\frac{0}{x}$$  $$x=\frac{0}{y}$$  Is this a correct approach using axioms of real numbers?

I need to prove the following statement: if $xy=0$   then  $x=0$ $or$ $y=0$.  My first idea was to prove the negation of the original problem if $x\neq0$ and $y\neq0$ then $xy\neq0$ but I still don't know how to prove it rigorously.


I have two lists, for example: A = [1, 2, 3, 4 ,5]  and B = [23, 34, 44, 43, 32]  I have initialized an empty dictionary D = {}  I want to pick an element from A as key and pick the corresponding element from B as value. For example the dictionary should look like: D = {1: 23, 2: 34, 3: 44, 4:43, 5:32}  So far, I have done the following: D = {} for k in A:    for j in B:        D[k] = j print("D is", D)  This only gives me an output as follows: D = {1: 32, 2: 32, 3: 32, 4:32, 5:32}  For some reason, it only pulls the last value from B which is not desirable. Please help.

Imagine that you have the following list. keys = ['name', 'age', 'food'] values = ['Monty', 42, 'spam']  What is the simplest way to produce the following dictionary? a_dict = {'name': 'Monty', 'age': 42, 'food': 'spam'}


Is it possible to apply careful spell on a magic surge for a example a cast 3rd level fireball centred on yourself, can you utilize careful spell in this case to save yourself and your allies?

If a sorcerer wild mage rolls on the wild magic table and ends up casting a  centered on themself, can the mage use Careful Spell when they cast that fireball, allowing the mage and some of their party members to succeed on their saving throws against the spell and take half damage?


I have a .gpkg.tar.gz data file whose size is 3.8 GiB. Uncompressed to .gpkg, its size is 8.5 GiB.   It is spanning a large geographical area. I want to extract data from this for a small area, given by lat-long bounds.  It is fine if there are features in/crossing this area but extending beyond it - I don't want to bother with chopping/clipping features. But I want to exclude features that are entirely outside of the given bounds.  With .pbf (Openstreetmap) data I have a way of doing this, example:  osmconvert india-latest.osm.pbf -b=78.55834,12.54397,80.3558,13.71654 --complete-ways -o=small.pbf   Is there a similar command / process we can do with .gpkg?  I understand it is originally SQLite; and I've read that one doesn't need to load the entire file into memory to work with that. So some specific queries - table names, column names might be there? This file is too big for me to load up in QGIS etc at the moment to be able to investigate its contents.  Ref:

I am looking to use ogr2ogr to clip a specific layer (Towns) from an sqlite/gpkg data source to a bounding box. R is not necessary for running the code below it just makes it reproducible by providing an example dataset. Here is what I've tried:  library(sf) input_gpkg <- system.file("sqlite/test3.sqlite", package = "sf") st_layers(input_gpkg)      Driver: SQLite       Available layers:      layer_name geometry_type features fields      1      Towns         Point     8101      5      2   HighWays   Line String       10      2      3    Regions Multi Polygon       10      2   system(paste("ogr2ogr -f 'GPKG' -clipsrc 1077228.72991008 4218298.82092178 1211486.08907174 4469736.19302021 output.gpkg", input_gpkg)) st_layers("output.gpkg")      Driver: GPKG       Available layers:      layer_name geometry_type features fields      1      Towns         Point      433      5      2    Regions Multi Polygon        1      2      3   HighWays   Line String        0      2   I tried setting the clipsrclayer flag but I get the same result.  system(paste("ogr2ogr -f 'GPKG' -clipsrc 1077228.72991008 4218298.82092178 1211486.08907174 4469736.19302021 -clipsrclayer 'Towns' output.gpkg", input_gpkg)) st_layers("output.gpkg")      Driver: GPKG       Available layers:      layer_name geometry_type features fields      1      Towns         Point      433      5      2    Regions Multi Polygon        1      2      3   HighWays   Line String        0      2   How can I have the output contain only the Towns layer? I do not want a solution that involves loading the entire Towns layer into memory because of the possibility that it will involve a huge number of points and kill performance.  See also:


At this moment, Ubuntu 14.04 only offers  (released at 2016-11-16), while Chrome version 56 was just released. More recent versions of Ubuntu, e.g. 16.04, are already offering Chromium version 55 (and I guess 56 will follow soon). Looking at the upstream project, , I see that they don't offer a newer version than 53 for Ubuntu 14.04 either.  Is there a reason why a more recent version is not available? Has chromium-browser stopped supporting Ubuntu 14.04?

Why are packages in the official Ubuntu repositories older than the latest (upstream) versions from Debian Sid, PPAs, the authors, etc.?


I sligthly confused about Dirac notation. As of now I always thought that  $$ |ψ,t⟩ = |ψ(x),t⟩ = |ψ(x,t)⟩ . $$  However, now I found out that  $$⟨x|ψ,t⟩=ψ(x,t).$$  What does this notation actually mean?

Let's say I have eigenstates $|x\rangle$ associated with measurement of position. I know that the eigenstates corresponding to their respective eigenvalues form a basis, let's call it $A$. Now let's say I want to expand a generic state vector $|ϕ\rangle$ in that basis formed by eigenstates. Now, what does it mean when physicists say that:     "$ϕ(x)$ is the coordinate of the state $|ϕ\rangle$ in the basis $A$?"    Any explanation or reference to similar kind of questions would be helpful.


I'm using the Java default logger, and right now it's printing a lot of useless trash to the output, here is a example, this line of code:  log.info("Logging pointless information...")   Will output all of this:  Oct 26, 2011 9:37:57 PM java.util.logging.LogManager$RootLogger log INFO: Logging pointless information...   I don't need to know anything except that second line. How can I remove this trash? All I want is simple text logging.

At the moment a default entry looks something like this:  Oct 12, 2008 9:45:18 AM myClassInfoHere INFO: MyLogMessageHere   How do I get it to do this?  Oct 12, 2008 9:45:18 AM myClassInfoHere - INFO: MyLogMessageHere   Clarification I'm using java.util.logging


I purchased a ticket to fly from NYC to Santiago, Chile with a return from Bogota to NYC. Buying a round trip ticket from Santiago to Bogota is cheaper then one way so I wanted to lose the second leg of the ticket. Does anyone foresee any issues with this? It won't interfere with my Bogota to NYC flight will it?

Say I want to book a flight from Fort Lauderdale to Chicago.  Say the airline also flies to St. Louis from Fort Launderdale but has a connecting flight through Chicago.  If I book that flights from FLL->ORD->STL and just get off in Chicago, what possible problems can I run into, assuming I didn't check any bags and only have carry on?  This scenario exist for Southwest, but I wanted this be more of a general question that would apply to all airlines.


I have just dug out an old 8GB SDHC card which was used in my Cowon D2 MP3 player and my old car radio - it's filled to the top with various music files. When I tried copying all of this data to my computer, nothing happened. So I checked the size of all the files on the SD card, and it said 70GB ! I can vouch for the fact the SD says it is 8GB capacity. So I located which files were the heaviest with treesize, and it showed a bunch of garbage within one of the folders (the last one, but it may be a coincidence) which took the remaining 62GB. I can't delete this folder, I'm presently copying everything else and planning a full format.  What happened, what is this, how is this possible ?

I have a 2 GB Kingston  card which is about three years old. I put it in a reader today in my Windows Vista computer, wrote a 32 MB file onto it, safely removed it, and then tried to read it elsewhere. Nothing. Putting it back in the Windows Vista computer it now says:     You need to format the disk in drive F: before you can use it.   What should I do? I have access to many computers and OSes if your recommendations need that. I would be very sad if I lost all the contents of the card. Most of the data is backed up, but there are a few things that aren't. :(  Doing a   # dd if=/dev/sdg of=~/tmp/sd.bin   gives me a 2 GB file, and  the file it seems like lots of my data is still there. How can I put it back together?


My question came up after I had a disagreement over what it means when a card states “sacrifice a creature” as it’s ability. The disagreement is in whether or not this text allows a player to sacrifice ANOTHER players creature. The rules for sacrifice didn’t clear up the issue for me, the ruling is still vague enough that I could conceivably sacrifice my opponents creature in a game and think it’s perfectly legitimate. Anyway I wanted to get some feedback on this.

I have a  and I was a little curious about the description of it. It specifically says "At the beginning of your upkeep, if there are fewer than six creature cards in your graveyard, sacrifice a creature."   So what I was wondering is, do I have to sacrifice my own creature? Or can I try and keep less than six creatures in my graveyard and sacrifice an opponent's creature every upkeep? Since it does specifically says "a creature" — it does not say "your creature" or "a creature you control." Most cards that have a sacrifice involved are extremely specific about that and will say "your creature" or "a creature you control" if it wants you to sacrifice your own creatures.


How should I say the date written 'on 27 July' correctly? I was taught that such date can be read only as 'on the 27-th of July'. So my question is whether it's omitted only in written form and we have to say 'the implicit information' (or how to put it...) or it can really be said as it's written adding only -th-: 'on 27-th July'.  EDIT: I often come across this form of date in Wikipedia: 'on + number + year'. And I want to know if this written form is correct for British English. Then, if it is correct, then does it mean that one should add the words the and of when he's reading this date from that text?

Investigations continue into the break-in at Gringotts on 31 July   . . . (Harry Potter and the Philosopher's Stone; Harry Potter and the   Sorcerer's Stone)      The first reader (Stephen Fry) says ‘the thirty first of July,’ and the second one (Jim Dale) ‘thirty one July.’ I’m confused whether the latter can be used or not. Would you tell me?


Sounds crazy i know, but hear me out there are place's all over the universe with ice glaciers much bigger then what we can even imagine on earth.  So what if he build a Tower in the middle of Antartica where temperatures would never raise higher then 28 degrees (freezing point of salt water) we could make it any thickness and the most of materials would be much cheaper then anythings.  if anything happened it would be in the middle of no where and wouldn't be able to hurt anyone.  also since no one owns Antartica it would be a mutual interest for ever country to invest into.  with all of that it may also help with countries that have raising sea level problems and would lower the sea around the globe.

Let us say that we have unlimited manpower to construct a huge wall of water ice e.g. 200 m tall (700 feet). -and that the wall is placed in a climate, where the temperature never (for your purpose) goes above freezing point. The wall is to have fairly steep sides, so let us assume a perfect rectangular cross section. A very narrow wall would obviously shatter at the bottom. A very wide wall would approach a natural ice cliff side and thereby be possible.   How wide does the wall need to be? What properties of ice is relevant to calculate that?


Assuming I have a creature, with four natural arms (or a person with extra vestigial arms — RAI I know this is unintended, but RAW it's seemingly legit) and they decided to, instead of quad-wielding one handed weapons, dual wield two handed swords. According to the rules, the offhand weapon gets 1/2 Str bonus. However two handed weapons use 1+1/2 Str bonus.  How would this strength bonus/penalty work, assuming said creature or player could not access the Double Slice feat?  The similar question  does not explain how the bonus damage to strength is handled.

I was considering playing a Summoner in my next Pathfinder campaign, and I decided that I wanted my Eidolon to be a a four-armed giant (the character being a Gnome with a height complex).  Well, I thought to myself: If it has four arms, then shouldn't it be able to wield two two-handed weapons?  As far as I can tell, it should work. That said, how would that work, exactly? I would assume that it would work like usual two-weapon wielding as far as feats and the like, and it would gain all the bonuses from two-weapon wielding as well. However, as this isn't exactly something that happens often, and thus there are no rules for it (that I can find) I can't be sure of any of this. Does anyone know of anything that could help me with this?


Let $A \in L(V)$ where $V$ is finite-dimensional inner-product space such that $\langle x,y \rangle = 0 $ implies $\langle Ax,Ay \rangle = 0 $. Show that there exist $U$ and $\lambda$ such that  $A=\lambda U$ where $U$ is unitary operator on $V$ and $\lambda$ scalar.  I am given a Hint: If normed vectors $x$ and $y$ are orthogonal,$\langle x,y \rangle = 0 $ then $\langle x+y,x-y \rangle = 0 $.

If $A$ is such that if $u$ and $v$ are orthogonal than $A(u)$ and $A(v)$ are also orthogonal (that is, their scalar multiple is $0$) for any $(u,v)$ pair and $A \in Hom (V,V)$ where V is a complex vector space   then prove that A is a scalar (real,non-negative) multiple of a unitary transformation(so $A=\lambda D$ where $D^*D=I$ and $\lambda \ge0$ and $\lambda \in \mathbb R$).


Take two i.i.d. Gaussian R.V.s $X$ are $Y$ both of which are $~N(0,a\sigma)$.  Define a new R.V. $D = \sqrt{X^2 + Y^2}$.  What's the expected value $E(D)$?  In researching this I'm seeing references to chi-squared distributions and chi distributions (of different degrees of freedom?), but I haven't learned about those yet. Do they apply here? What are their means and how does the original mean/variance carry through?

Let $X$ and $Y$ be independent $N(0; 1)$ random variables. Let $Z = \sqrt{X^2+Y^2}$.  (a) Derive the marginal pdf of $Z$ and then using the marginal pdf to compute ${\rm E}[Z^2]$  (b) Can you propose a different way other than that in (a) to compute ${\rm E}[Z^2]$  (c) Compute ${\rm E}[Z]$.  This is the whole question that I was asked. I can do (c) but I don't know how to find the marginal pdf of $Z$ with the given information and can't seem to find any formulas. Any help would be appreciated.


I am trying to check if I am in a spesific area and I use command blocks for that: This is the code I use:     testfor @p[r=4,name=<\miner11crafter>]   It should be right acording to this syntax I found on the :     testfor @p[r=5,name=<\owner>]    \ is neccesary for the formatting in SO otherwhise you can't see my name and stuff. What am I doing wrong ?

I am trying to make a command block that when powered, it will looks for a specific player in a 5 block radius of the command block. I tried   /testfor @p[r=5][name=<name of player>]   but it doesn't work.


I'm not sure how floating point are represented in C, and how much of a precision someone could get. In a c source file, I have the macro:  #define NUMBER 123.367   In the main function there are these 2 instructions:  float x = NUMBER; printf("x is %f\n", x);   When I run it, I get:      x is 123.366997   Which is quite close to 123.367, but it kinda messes the purpose of the program. Is there any way to round up x to the desired value? Or is this a flaw of floating point arithmetic-representation that can't be fixed?

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


Recently I have upgraded to Ubuntu 18. One thing is not working which was really helpful as a developer, to avoid using mouse which is ALT + Spaceand then press C to close the window.    Please help.

On Ubuntu 16.04 LTS I have used simple keyboard shortcut to set property Always on Top (Nautilus window as example):   Alt+Space,    t After next Alt+Space or right mouse click I see that window was set to Always on Top.     In standard Ubuntu 18.04 LTS with GNOME Shell I can press Alt+Space:    but it does not react to t.  Seems to be a real .    How to enable such menu accelerators/mnemonics in standard Ubuntu 18.04 LTS?


I have a text(.txt) file as shown in below.  0   1   1       1   30  2014-08-30 14:38:40 1   1   1       1   30  2014-08-30 14:41:55 2   1   1       1   30  2014-08-30 14:47:54 3   1   1       1   30  2014-08-30 14:53:04 4   1   5       1   30  2014-10-02 14:29:42   I want to insert some of the data from that file into database. And here is the structure of staff_detail table:  id(int32) primary key no(int32) staff_id(int32) date_time(datetime)   So, I read the data from the .txt file and try to insert into database as shown in below:  <?php     include('dbconfig.php');     $handle = fopen($_FILES['record']['tmp_name'], "r");     while(!feof($handle)){         $row = fgets($handle);         if( strlen(trim($row)) > 0 ) {             $data = explode("\t",$row);             $no = $data[0];             $staff_id = $data[2];             $date = $data[6];             echo "No: $no | ID: $staff_id | Date: $date <br/>";             $query = "INSERT INTO staff_detail(`no`,`staff_id`,`date_time`)VALUES($no,$staff_id,$date)";             $rsl = mysql_query($query) or die(mysql_error());         }     } ?>   When I run this file, I get error like this:  You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '' at line 1  But, I can see all data in echo and just only can't insert into database.   When I check the text file data in Firebug. I see the data as shown below:  �0� �1� �1� �   �1� �3�0�   �2�0�1�4�-�0�8�-�3�0� �1�4�:�3�8�:�4�0� � �1� �1� �1� �   �1� �3�0�   �2�0�1�4�-�0�8�-�3�0� �1�4�:�4�1�:�5�5� � �2� �1� �1� �   �1� �3�0�   �2�0�1�4�-�0�8�-�3�0� �1�4�:�4�7�:�5�4� � �3� �1� �1� �   �1� �3�0�   �2�0�1�4�-�0�8�-�3�0� �1�4�:�5�3�:�0�4� � �4� �1� �5� �   �1� �3�0�   �2�0�1�4�-�1�0�-�0�2� �1�4�:�2�9�:�4�2� � �5� �1� �5� �   �1� �3�0�   �2�0�1�4�-�1�0�-�0�2� �1�4�:�3�7�:�4�4� � �6� �1� �7� �   �1� �3�0�   �2�0�1�4�-�1�0�-�0�2� �1�4�:�4�6�:�2�2� � �7� �1� �8� �   �1� �3�0�   �2�0�1�4�-�1�0�-�0�2� �1�4�:�4�7�:�5�6�   So, I try to check $no with var_dump($no) when $no value is 0.(I mean is test with the first line of txt file).   And I get the result like this: string(3) "0". I think it was wrong because it has just only one string as "0". But it shows string(3).  So, I guess it may be white space and so I try with str_replace and change $no and $staff_id type to int and try to insert into table again.  But it shows the same error and I have stuck with this problem. And now, I have no idea to solve it. I'm very appreciate for any answer and suggestion.

I'm setting up a new server and want to support UTF-8 fully in my web application. I have tried this in the past on existing servers and always seem to end up having to fall back to ISO-8859-1.  Where exactly do I need to set the encoding/charsets? I'm aware that I need to configure Apache, MySQL, and PHP to do this — is there some standard checklist I can follow, or perhaps troubleshoot where the mismatches occur?  This is for a new Linux server, running MySQL 5, PHP, 5 and Apache 2.


Installation (windows installer - Ubuntu 12.04 LTS)  I downloaded the (Ubuntu 12.04 LTS) ISO file then the (Install Ubuntu with the Windows installer) it fully installed and restarted.  Then I chose the Ubuntu OS and black screen... so I ESC and started in SAFE MODE and got "_" symbol flashing (to type something in) but turns off few seconds and black screen... have to force shutdown.  Please help thanks. Michael

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


e.g. - I hope you be/are fine during your travel   - I hope you be/are fine living in your new apartment

Why is the phrase "I hope this computer work" unacceptable? The word "hope" makes the phrase subjunctive, so why isn't it correct to use the infinitive verb form?


I use a square curve to be the bevel. With default settings. The result is like this.  More description: My purpose is to make a bunch of foot line all around room. I want to use poly spline type curve to achieve this. Without bevel object the curve geometry looks like this. The cross section is twisted at the corner which causes a shrink in the middle. Any way to prevent this?  samplefile:

I can't create a Pipe 3D without annoying shrinkage in the corner of my bezier curve using bevel object. Those are my step.  I create a bezier curve (on 3 axes) transforming two corner in Vector corner (to have a perfect angle)  I generate a circle and using bevel object I sweep the circle along the bezier (3d).  Easy...BUT I can't undestand how to solve the shrinkage in the corners. Other artifacts (such as compenetration) comes when instead using a Vector corner I use a normal (automatic) corner and model it in 90 degree shape.     Thanks


I just came to know that AlertDialog.Builder is a class in Android.BUt according to naming conventions java class cannot have "." operator.So, I was just confused ....can anyone help me out?

What is the main difference between an inner class and a static nested class in Java? Does design / implementation play a role in choosing one of these?


ok so I'm coding my own version of a GUI based addition calculator. and I've come upon an error . but when I run it , it gives a null pointer exception at the line where I marked in the code and i know null pointer means there is no value for a certain string or integer but this one here does have a value , if someone knows why pls tell me , thanks in advance! `public class Main implements ActionListener { private static JFrame frame; private static JPanel panel; private static JLabel label; private static JButton button; private static JTextField fnumField; private static JTextField snumField; private static JLabel answer; private static  JLabel fnum; private static JLabel snum; private static String c;  public static void main(String[] args) {               frame = new JFrame();     panel = new JPanel();     frame.setSize(350, 200);     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);     frame.add(panel);          panel.setLayout(null);           JLabel fnum  = new JLabel("1st number:");     fnum.setBounds(10, 20, 80, 25);     panel.add(fnum);          JTextField fnumField = new JTextField();     fnumField.setBounds(100, 20, 165, 25);     panel.add(fnumField);          JLabel snum = new JLabel("2nd number:");     snum.setBounds(10, 50, 80, 25);     panel.add(snum);          JTextField snumField = new JTextField();     snumField.setBounds(100, 50, 165, 25);     panel.add(snumField);          button = new JButton("ADD");     button.setBounds(10, 80, 80, 25);     button.addActionListener(new Main ());     panel.add(button);          JLabel answer = new JLabel("");     answer.setBounds(10, 100, 300, 25);     panel.add(answer);                                     answer.setText(c);         frame.setVisible(true);      }        public void actionPerformed(ActionEvent e) {     String a = fnumField.getText();             <---------- NULL POINTER      String b = snumField.getText();          String c = (a+b);      }     }  `

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 need to find whether a vector<unsigned> searchvec; is present in a vector<vector<unsigned> > containerVec;. One way to do the same is to iterate over vector<vector<unsigned> > containerVec; and see whether searchVec is present in containerVec. Is there any build in c++ function which can help me do the same.  Also my searchVec is of size 1 million vector  For example if my searchVec is (9,28,4,2) and my containerVec is ((1,3,678,27),(9,28,4,2), (595,85,52)). Then searchVec (9,28,4,2) is present in ((1,3,678,27),(9,28,4,2), (595,85,52)). However if my searchVec is (23,84,25,11) then it is not present in containerVec.  EDIT: I tried std::find but perf tool shows it takes the most time. Is there any other data structure which I can use.  This is not a duplicate. As I am mentioned in my question std::find is giving poor performance. Also the duplicate which u have marked nowhere talks about performance issue

All I want to do is to check whether an element exists in the vector or not, so I can deal with each case.  if ( item_present )    do_this(); else    do_that();


I'm trying to draw lines that predict the movement after collision between two balls, in a game of pool. How do I do that?  I heard it can be done via raycasts, but how do I draw a line?

I'm using Unity C#. How would I create the effect in my pool game, a line showing the direction of the second (not white) ball after collision.  Example:   I need to make the line coming from the ball (second/leftmost)  P.S. I made the other line by using Raycast to find the hit point and set that point last position of line renderer (white ball is a start position for line renderer and it casts the ray)


I have an AWS Ubuntu machine.  I want to find out which desktop GUI environment is installed and running on my Ubuntu machine.  Every time I'm logging into Ubuntu I'm getting the GNOME environment. I want to uninstall it and install mate-desktop instead.  How can I do this?

I have seen several youtube videos that are showing MATE (The Gnome 2.x fork) installed in 11.10. How can I install it to test it out in 11.10 and above.  If it helps the only sources I know of are:  , , and


An Argentine or Mexican tourist in Madrid, or A Brazilian tourist in Lisbon, will certainly hear phrases he has never heard before and may find some of them offensive. I myself have a list of Portuguese colloquialisms which may embarrass an uninformed Brazilian during his first trip to Lisbon. Likewise, there are slang words and phrases that may embarass or sound offensive to a native speaker of the English language visiting another country, if he has never heard them in such contexts. e.g.        A California girl to an English lady: "Oh, shut up!"   A Londoner to a young man in Kansas: "Will you have a fag?"      I don't expect swearwords or an exhaustive list, and I don't mean the knowleadgeable and well-informed tourist either. This type of person certainly knows most foreign colloquialisms.

This is similar to , but not quite the same.  There are quite a few words which have totally different meanings in American and British English and which are likely to cause confusion when heard by non-local speakers.  What are they?  We are looking for the same word with different meanings (for example jumper), and not words which are different between the two dialects (for example truck and lorry).


Has anyone in this community been through this book in its entirety? I started it about 18 years ago when I was just beginning undergraduate mathematics study and couldn't make any headway past the first three chapters. Now before you all start asserting that this is a much more advanced text than the undergraduate level, let me just say that even now, with the benefit and maturity of graduate studies I still have trouble getting past chapter 5 in this text. I realize that this is a concise, condensed presentation of results (hence the scarcity of examples) but my problem with this text is the complete lack of motivation for its results. Take for instance the Consistency Theorem and Herbrand's Theorem in chapter 4. I've tried hunting down the original works where these results first appeared,  for more background and examples, but these works either not available or, when they are, they're too obscure to read. Reverting to other, more elementary texts, is of no use either. They're either too elementary and deal almost exclusively with the basic predicate calculus (as if everyone needs a new text daily for THAT), or are equally inaccessible and by the time you master the author's favorite notation you're already lost in the abstraction. Is there any hope for material that introduces the advanced results more gradually, through background and examples, and more importantly through motivating questions? Motivation would be especially helpful with the advanced results of model theory presented in Chapter 5.

I was originally intending on reading Mathematical Logic by Joseph R. Shoenfield (1967) though after reading  I get the impression that despite being influential for the time it was written, there now exist many new books written from our current perspective that tend to be easier on non-experts by offering more thorough explanations for each new topic being introduced.   As of now I have a basic knowledge of abstract algebra (basics on vector spaces, rings, groups etc.) from doing elementary number theory and taking a course on linear algebra, also I have completed  a year long course on real analysis which used a lot of elementary set theory and some order theory.   With all that said, I was hoping based on my current basic knowledge of math that someone could recommend me an introductory book on mathematical logic which I could use as an alternative to Shoenfield's and which addresses Peter Smith's criticisms - any help would be greatly appreciated.


i have upgraded Ubuntu desktop from 12.10 to 13.04. Since then I can't see the Panel or Launcher, but I'm able to open the terminal using the keyboard shortcut Ctrl+Alt+T.  When I use the Guest login there is no such problem. I am facing the problem only with administrator account.  I have tried this , but I couldn't find the result.

When I login, nothing happens.   I am presented with my desktop wallpaper.    No Dash, no Launcher, nothing.


Given that  $$ \int_{0}^{\pi}\frac{dx}{2-\cos{x}}=\frac{\pi}{\sqrt{a^2-1}} $$  How to calculate the integral $$ \int_{0}^{\pi}\frac{dx}{(2-\cos{x})^2} $$

While solving another problem I have come across this integral which I am unable to evaluate. Can someone please evaluate the following integral? Thank you.      $$\int_0^{2\pi}\frac{1}{(2+\cos\theta)^2}\,d\theta.$$


I need to be able to search for SQL objects (logins, etc). With a smaller number of servers, I would connect to them all via a registration group in SSMS and do the search.  Does anyone have a better way with a large number of instances?  Thanks

SQL Server - What is the best method to run the same query over multiple databases on multiple instances? for example we have many application databases, with the same schema that need to have information aggregated.  I currently use a script that relies on linked servers already being setup and a table that identifies which instance and database to loop through.          /* declare some cursor variables and the dynamic sql string variable */     DECLARE @currentDB          nvarchar(64)     DECLARE @connectionstring   nvarchar(256)     DECLARE @sqlstring          nvarchar(max)  CREATE TABLE #TEMP1                 (                      currentDB      varchar(32)                     ,field1         varchar(128)                     ,field2         smallint                     ,field3         datetime                 )  /* Build and open the cursor */ DECLARE connectioncursor CURSOR FAST_FORWARD FOR     SELECT  currentDB, connectionstring     FROM    [admin].dbo.DatabaseList     WHERE   dbtype = 'PROD' OPEN    connectioncursor FETCH NEXT FROM connectioncursor INTO @currentDB, @connectionstring  /* Start the loop through db list */ WHILE @@FETCH_STATUS = 0     BEGIN         /* Build and set the sql string */         SET @sqlstring =             '                 select                          ''' + @currentDB + '''                         ,field1, field2, field3                         from ' + @connectionstring + '.dbo.table1             '          /* Insert the results from the iteration and fetch the next db */         INSERT INTO #TEMP1 exec sp_executesql @sqlstring         FETCH NEXT FROM connectioncursor INTO @currentDB, @connectionstring     END  /* Kill the cursor */ CLOSE connectioncursor DEALLOCATE connectioncursor   select * from #TEMP1  -- some output   Be gentle I'm a TSQL newbie!


I'm completely new and lost in Ubuntu 12.04, I'm having trouble navigating to my Sublime folder which I know is in my /opt folder. Yet I've tried to no avail to navigate into it via Terminal window. The directory is colored in blue, no idea what this means...but I am able to access the folder using the GUI explorer...?  k@k-Ubuntu:~$ cd /opt k@k-Ubuntu:/opt$ ls Sublime Text 2 k@k-Ubuntu:/opt$ cd Sublime Text 2 bash: cd: Sublime: No such file or directory k@k-Ubuntu:/opt$ cd /Sublime Text 2 bash: cd: /Sublime: No such file or directory

I want to enter the following folder in the terminal:  Milano, Torino (Jan)-Compressed   How should I write the command cd to enter this directory?  Spaces and several other special characters like \, *, ), ( and ? cause problems when I try to use them in the command line or scripts, e.g.:    $ cd space dir bash: cd: space: No such file or directory  $ cat space file cat: space: No such file or directory cat: file: No such file or directory  $ cat ( bash: syntax error near unexpected token `newline'  $ echo content >\ > ^C  $ ls ? (  )  *  ?  \   How do I enter file or directory names that contain special characters in the terminal in general?


Basically I want to pass a image file with ajax on submitting a form and retrieve the image and send it by email as an attachment file:  Here's the form :  <form role="form" action="" name="devis" id="devis" method="post" enctype="multipart/form-data" class="form-horizontal">     <fieldset>
             Company
                 <input type="text" class="form-control input-md col-md-8" name="societe" value="" maxlength="" id="societe">

             * Message
                 <textarea rows="5" name="message" class="form-control input-md col-md-8" maxlength="" required="" style="resize:none;" id="message"></textarea>

             Logo

                                                               Parcourir <input type="file" id="image_input_field" name="file">                                                       <input type="text" class="form-control" readonly="">

         <input type="submit" value="Envoyer" name="" class="btn btn-primary" id="submit">         <input type="reset" value="Annuler" name="" class="btn btn-default" id="reset">

     </fieldset> </form>   I can't seem to find what's the error in my code ! Here's the AJAX call :  jQuery(document).on("click", "#submit", function(e) {       e.preventDefault();       var fileInput = document.getElementById('image_input_field');       var file = fileInput.files[0];       var formData = new FormData();       formData.append('file', file);       // console.log(file);        var societe = $("input#societe").val();       var message = $("textarea#message").val();       jQuery.ajax({         url: "ajax.php",         type: "post",         data: {            'file': file,            'module' : 'ajax_data_form',            'societe': societe,            'message': message         },         cache: false,          success: function(reponse) {           if(reponse) {             alert(reponse);             // console.log(reponse);             // jQuery('#devis').trigger("reset");           } else {             alert('Erreur');           }         }       });      });   And here's the ajax.php:  <?php if( isset($_POST['module']) && $_POST['module'] == "ajax_data_form" ) {      var_dump($_FILES); }

I would like to upload a file asynchronously with jQuery.     $(document).ready(function () {     $("#uploadbutton").click(function () {         var filename = $("#file").val();          $.ajax({             type: "POST",             url: "addFile.do",             enctype: 'multipart/form-data',             data: {                 file: filename             },             success: function () {                 alert("Data Uploaded: ");             }         });     }); });  File <input type="file" id="file" name="file" size="10"/> <input id="uploadbutton" type="button" value="Upload"/>     Instead of the file being uploaded, I am only getting the filename. What can I do to fix this problem?


I'm new to python, I should convert the following operation in php:  if len (s) == 88:     return s[48] + s[81:67: -1] + s[82] + s[66:62: -1] + s[85] + s[61:48 : -1] + s[67] + s[47:12: -1] + s[3] + s[11:3: -1] + s[2] + s[12]   I do not understand exactly what you mean this formatting s[a:b: -c].

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


I am seeking a help regarding the following issues:   How to turn off the X server  when I have already logged into Ubuntu (I know about startx to start the X server but don't know how to shut it down). When I start my machine, Ubuntu directly boots automatically X. What I need to do if I want to boot to plane terminal instead of X? (after that I can use startx to start the X if I feel so).

Is it possible to disable X at boot time? I'm setting up a server so it would be nice if it wouldn't load the graphical interface every time I boot.


I need to generate a random integer with Java but random in a one sided bounded specific range. For example, a range from 15+ means that the only constraint is that the lowest value the integer can take is 15.

How do I generate a random int value in a specific range? I have tried the following, but those do not work: Attempt 1: randomNum = minimum + (int)(Math.random() * maximum);  Bug: randomNum can be bigger than maximum. Attempt 2: Random rn = new Random(); int n = maximum - minimum + 1; int i = rn.nextInt() % n; randomNum =  minimum + i;  Bug: randomNum can be smaller than minimum.


I have a problem with the application Quiz to college. Even after I pass the right answer application crashes: Incorrect on the main activity screen. Please help me. I think the issue lies in the transmission of a variable between the activities or in the if instruction.  My MainActivity code:  package com.example.mariusz.qiuz;  import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.Toolbar; import android.view.Gravity; import android.view.View;  import android.widget.Button; import android.widget.LinearLayout; import android.widget.TextView;   public class MainActivity extends AppCompatActivity {       Button b3;     private static final String answer_1= "Mariusz";     @Override     protected void onCreate(Bundle savedInstanceState) {           super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);         b3 = (Button) findViewById(R.id.answer1);           b3.setOnClickListener(new View.OnClickListener() {             @Override             public void onClick(View v) {                  startActivity(new Intent(MainActivity.this, Answer1Activity.class));              }         });         Intent intent = getIntent();         String message = intent.getStringExtra(Answer1Activity.EXTRA_MESSAGE);         if (message != null ) {              if (message == answer_1) {                 TextView textView_1 = new TextView(MainActivity.this);                 textView_1.setGravity(Gravity.CENTER);                 textView_1.setTextSize(40);                 textView_1.setText(R.string.correct);                 LinearLayout activity_main = (LinearLayout)findViewById(R.id.layout);                 activity_main.addView(textView_1);             } else {                 TextView textView_1 = new TextView(MainActivity.this);                 textView_1.setGravity(Gravity.CENTER);                 textView_1.setTextSize(40);                 textView_1.setText(R.string.incorrect);                 LinearLayout activity_main = (LinearLayout)findViewById(R.id.layout);                 activity_main.addView(textView_1);             }         }         else {          }             }      }   And my second activity code:  package com.example.mariusz.qiuz;  import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.EditText;  /**  * Created by Mariusz on 2016-03-04.  */ public class Answer1Activity extends Activity {      public final static String EXTRA_MESSAGE = "com.example.mariusz.quiz.MESSAGE";      Button a1;     EditText e1;      @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.answer1);         a1 = (Button) findViewById(R.id.buttona1);         e1 = (EditText) findViewById(R.id.text1);         a1.setOnClickListener(new View.OnClickListener() {             @Override             public void onClick(View v) {                   Intent intent = new Intent(Answer1Activity.this, MainActivity.class);                  String message = e1.getText().toString();                 intent.putExtra(EXTRA_MESSAGE, message);                 startActivity(intent);               }         });       } }

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


The plural of 'passerby' is 'passersby' with an 's' acting like an infix (W-B says that this is the only plural form of the  word). This seems like a very interesting exception, so I thought I would ask a question.  Are there any other English words that are made plural by an 's' put inside the noun?  One criterion has to be met: the singular noun is composed of one (unhyphenated) word only.

This is purely a curiosity, but I'm fascinated by mid-word pluralization, even if the word in question is a compound word.  For example, passersby or standersby.  No others have occurred to me. Can you provide other examples, or a link to a resource that enumerates them?  I'm particularly interested in compounds that do not include spaces or hyphens.


I’d like to have Bluetooth disabled automatically when I login to my user account. Is there any way to achieve this? I’m running macOS Sierra, and have blueutil installed.

Every time I turn on my laptop (from a completely off state) the Bluetooth is on by default. How can I prevent it from turning on at startup and then only turn it on (manually) when I want to connect any Bluetooth devices like mouse and keyboard?


I've been into photography for almost 7 years now and have been using the Canon 550D all along. I love it and have recently purchased a 1.4 lens which makes my photos even better. However, with my camera being really old and wanting my work to look better and more professional, I'm thinking of selling my Canon 550D upgrading to either a Canon5D mark II, or going mirrorless. I'm torn between wanting something lighter and easier to use and carry around, and crazy image quality.  Also, if I were to sell my used Canon 550D which works perfectly fine but looks used (a few scratches here and there), how much should I sell it for?  I appreciate all feedback and advice, thanks! :)

As the question says, when should I upgrade my camera body? In particular, if I have a low- to mid-range body (A DSLR such as a Nikon D3200 or Nikon D5100, or Canon SL1 or T5, or a mirrorless camera such as a Panasonic GH3 or an Olympus E-PL6). How do I know when I need to upgrade?  I have a complement of "kit" lenses, such as an 18-55mm f3.5-5.6 and a 55-200mm f4-5.6. Maybe I've even added a 50mm 1.8 to the kit. Flash is only for indoors (right?) and I usually shoot outside, so that means I don't need an external flash.  I shoot photos of my family and friends whether out at the park or having a picnic, my kids sports practices and games, vacation photos, as well as some landscapes, flowers, and whatever else catches my eye. Pretty familiar territory. I'm not a professional and don't intend to become one.


Help the mesh is moving at the wrong part when I move the bone!

I have an armature set up, but the bones aren't moving the mesh properly  The mesh and armature:    The vertex group of the bone I am going to move:    As you can see, the circled region doesn't belong to the vertex group. But, when I move the bone look what happens:    That part of the mesh has moved with the bone.. Why?


I have a file on master branch, I have then created a new branch new and wrote a few print statements. I then checkout onto master, and the same changes are on master aswell. I have not pushed the changes from new. How is that possible?

I am working on a git repository with a master branch and another topic branch. I have switched to topic branch and modified a file. Now, if I switched to master branch that same file is shown as modified.   For example:  git status in git-build branch:  # On branch git-build # Changes to be committed: #   (use "git reset HEAD <file>..." to unstage) # #       modified:   cvsup_current #   Switch to master branch  [root@redbull builder_scripts (git-build)]# git co master M       builder_scripts/cvsup_current Switched to branch "master"   git status in master branch  [root@redbull builder_scripts (master)]# git status # On branch master # Changes to be committed: #   (use "git reset HEAD <file>..." to unstage) # #       modified:   cvsup_current #   Why is that the file is shown as modified in master branch even though it was modified in git-build branch?   My understanding was that the branches are independent of each other and when I change from one branch to another the changes do not "spill over" from one branch to another. So I am obviously missing some thing here.   Anyone got a clue stick?


I’ve always assumed the warp factor recalibration was a result of someone not liking the warp numbers going bigger and bigger and thus limiting the max to 10, therefore the recalibration being an out of universe event. I have never stopped to think whether this was ALSO an in universe event in which the way the Federation itself measures warp changes and therefore this is something more akin to the US moving to SI units for example.  Is the warp factor recalibration in Star Trek an in universe event or is it an entirely out of universe event?

From  onward,  has a basically cubic scale from warps 1 - 9. But then, close to warp 10, it suddenly develops its own puzzling scale, as can be seen in .  In this scale, , occupying all points in the universe simultaneously and therefore effectively teleporting instantaneously.  My question is why have this confusing scale? Why not have a uniform cubic scale? Was there ever any "official" explanation for this?  Clarification: I'm looking for why the writers decided on this, not the "in-universe" explanation.


what is the difference between      how do I ask    and     how to ask   I am an Indian. Basically asking question we have to use "do, does and did". Please explain does How to ask make a question?

On the other hand  that fix mistype in "How to" got though community approval.  What is the rule about "How to" and "How do I"? Why are some tutorials called "How to"s?


I have been told that the acceleration of free fall is lower at the equator than at the poles, and that this has to do with the fact that at the equator, you are moving with circular motion so centripetal and centrifugal forces are at play, whereas at the pole this is not the case. I've considered two frames of reference: one at the pole (O) and one at the equator (O'). If a ball is dropped at the equator, then in the reference frame O', there is centripetal force $F$ acting on the ball so the force on the ball is $mg{_{1}}+F = mg{_{2}}$ where $mg{_{1}}$ is the ball's "true" weight while mg${_{2}}$ is the apparent weight, so it makes sense that acceleration of free fall, $g{_{2}}$ is smaller. However, from the reference frame O, the falling ball appears to undergo centrifugal force, $-F$, so $mg{_{1}}-F = mg{_{2}}$ meaning acceleration of free fall would appear greater ($g{_{2}}>g{_{1}}$). This is obviously a contradiction. Where is the flaw in my understanding?

Many sources state that the Earth's gravity is stronger at the poles than the equator for two reasons:   The centrifugal "force" cancels out the gravitational force minimally, more so at the equator than at the poles. The poles are closer to the center due to the equatorial bulge, and thus have a stronger gravitational field.   I understood the first point, but not the second one. Shouldn't the gravitational force at the equator be greater as there is more mass pulling the body perpendicular to the tangent (since there is more mass aligned along this axis)?


I am trying to figure out the following.  Suppose $G$ is a group and is finite; let $H$ be a proper subgroup. Show that the conjugates of $H$ do not cover $G$ (that is, there is some $g \in G$ which is not conjugate to an element of $H$).  As I understand it, we say that given $a,b \in G$, $a$ is conjugate with $b$ if $\exists g' \in G (a = g'bg'^{-1})$. Since $H$ is a proper subgroup of $G$, then there $\exists g \in G$ such that $g \notin H$. Since $g \notin H$, then $\forall h \in H (g \neq h)$. Suppose then that $\exists q \in G, \exists r \in H (g = qrq^{-1})$ $-$ i.e., that $g$ is conjugate with with some element of $H$. Then $q^{-1}gq = r$. However, I'm not sure where to go from here. I'm guessing that I have to somehow use the assumption that $G$ is finite however I'm not sure how to.

Let G be a finite group and H be a proper subgroup. Prove that the union of the conjugates of H is not the whole of G.  Thanks for any help


I tried history -c  but it doesn't work It will only clear the history for the current terminal session and when I open a new terminal history appears again Is there any option that I can try

I want to clear all previous commands from the history of my server. I used history -c and it seems all things are cleared but when I ssh to the server, all the commands are still there.  How can I clear them permanently?