Is it legal to work remotely in the UK for a non-UK based company?

Assuming a non-EU citizen is visiting the UK on a Standard Visitor Visa (or entered the UK without a visa, if their nationality doesn't require one), can they work remotely for a foreign company? If so, what are the rules for it?  We already have a great answer by , but it contains a lot of information which has recently been updated, so it's best to have a separate question.


I used LaTeX to write a document, and I was writing complex conjugates, so I had to make line a line on top of each number like this          \overline X\cdot\overline y   But there's an alignment issue with the line on top of them. How to fix that?


I routinely perform numerical computations in my laptop, using programs that I write myself in Python, Julia, C++, etc. I am not a perfect programmer (far from it), and I make coding errors frequently. Sometimes, I end up with a program that drains memory. Usually when this happens, my system becomes completely unresponsive, and I am forced to do a hard reboot (Ctrl + Alt + F1 does not work, sometimes not even the OOM killer, which I don't like because I can't be sure about what it will kill). See for example these relevant discussion:  ,   Given these risks, I would like to run my program in a shielded way, constraining the memory it will use. Is there a tool in Linux to execute a command with bounded memory?


I'm trying to extrude a new face and shrink it by a fixed number of units, rather than a percentage.  Starting from something like this:   I want to end up with this:   Note the distance between the original face and the new one is equal all round. I did this one by extruding the face, moving it a fixed numeric distance, then moving the 2 incorrect edges back double that distance. Obviously this only works for 90 degree edges, so less than ideal.  Using the normal scale method (E, S) I get a percentage based result, like this:   I've seen two possible method of doing this, mianly from :   Shrink / Fatten: I've tried (E, Esc, Alt+S) for this, but the face just travels straight up and down - I assume the vertex normals are not correct for this approach. Push / Pull: This is just apply percentage scaling for me at the moment.   If I actually extrude the face out a bit, then use Shrink / Fatten it works as expected, but I don't want to have to keep manually resetting heights.  Is there a quick way of scaling a face within it's normal, but by fixed units instead of axis percents?    Edit: @zeffii has pointed me in the direction of the  (W, I).


A question about a proof of Noetherian modules and exact sequences

I proved part (i) of the following:  Proposition 6.3. Let $0 \to M' \xrightarrow{\alpha} M \xrightarrow{\beta} M'' \to 0$ be an exact sequence of $A$-modules. Then  i) $M$ is Noetherian $\iff$ $M'$ and $M'"$ are Noetherian;  ii) $M$ is Artinian $\iff$ $M'$ and $M''$ are Artinian  Proof. We shall prove i); the proof of ii) is similar.  $\implies$: An ascending chain of submodules of $M'$ (or $M''$) gives rise to a chain in $M$, hence is stationary.   Can you tell me if my proof of $(i)\Longleftarrow$ is correct? Here goes:  Let $M^\prime$ and $M^{\prime \prime}$ be Noetherian. Let $L_n$ be an ascending chain of submodules in $M$. Then $\alpha^{-1}(L_n)$ is an ascending chain of submodules in $M^\prime$. Hence $\alpha^{-1}(L_n)$ is stationary, that is, $\alpha^{-1}(L_n) = \alpha^{-1}(L_{n+1})$ for $n$ large enough. Hence $L_n = L_{n+1}$ for $n$ large enough since $\alpha$ is injective hence $L_n$ is stationary.   The proof given in Atiyah-Macdonald is the following but I don't understand why they need both maps, $\alpha$ and $\beta$:  $\Longleftarrow$: Let $(L_n)_{n \ge 1}$ be an ascending chain of submodules of $M$; then $(\alpha^{-1}(L_n))$ is a chain in $M'$, and $(\beta(L_n))$ is a chain in $M''$. For large enough $n$ both these chains are stationary, and it follows that the chain $(L_n)$ is stationary. $\Box$


I'm new to blender. I have a version 2.90 and I  wanna apply the texture to my building model. But I can't do it is there anyone how to create a texture or import it from anywhere and then apply? I know it's a dumb question but don't mind. Everyone should help each other!


How do I remap keys in Mac OS high sierra

So I would want to swap the keys y and z with each other, is there anyway to remap the keys with something like a terminal command


I am having issues with a data layer that is not lining up with my other data layers!  What do I do?    I have all the parcel polygons, parcel pts. Jurisdiction polygons from Ashtabula county that all line up (I received these data layers all from the same source...from Ashtabula county).  Then I bring in a data layer for street centerlines from OGRIP (where I have obtained all my other street centerline data from that works great!)    How do I get these to work?  The extents on the street centerline data are completely different from the other data layers.    The projected coordinate systems are the same in all the layers?


Are there any theorems that can only be proved by induction? Induction seems to be proof by technicality.


Movies that I cannot find are taking up 200 GB on Mac

Movies that I cannot find are taking up 200 GB on my Mac. I tried looking for these movies but I cannot find them. I believe that this is being cause by a video editing software I use called "VideoBlend". I think that it creates backups of the videos onto my mac, but I cannot find any them. Not sure what I should do.   Note: I've searched countless of questions on this site and I was unable to find a solution.   Update: I also used to manually insert movies into my devices on Itunes. Could there be backup files of these movies?  Update 2: I completely missed out on the fact that my mac has storage space of only 128GB'S. So could this just be an error. If so, is there a way for me to fix it?


Attempt to invoke virtual method '...' on a null object reference

I getting the "Attempt to invoke virtual method 'java.lang.String[] android.os.Bundle.getStringArray(java.lang.String)' on a null " error in some devices:  Stack Trace:  Exception java.lang.RuntimeException: Unable to start activity     ComponentInfo{com.facebook.misstest/com.facebook.misstest.LoveMeterResultActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String[] android.os.Bundle.getStringArray(java.lang.String)' on a null object reference android.app.ActivityThread.performLaunchActivity (ActivityThread.java:3254) android.app.ActivityThread.handleLaunchActivity (ActivityThread.java:3350) android.app.ActivityThread.access$1100 (ActivityThread.java:222) android.app.ActivityThread$H.handleMessage (ActivityThread.java:1795) android.os.Handler.dispatchMessage (Handler.java:102) android.os.Looper.loop (Looper.java:158) android.app.ActivityThread.main (ActivityThread.java:7229) java.lang.reflect.Method.invoke (Method.java) com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run        (ZygoteInit.java:1230) com.android.internal.os.ZygoteInit.main (ZygoteInit.java:1120) Caused by java.lang.NullPointerException: Attempt to invoke virtual method    'java.lang.String[] android.os.Bundle.getStringArray(java.lang.String)' on a null object reference com.facebook.misstest.LoveMeterResultActivity.onCreate       (LoveMeterResultActivity.java:133) android.app.Activity.performCreate (Activity.java:6876) android.app.Instrumentation.callActivityOnCreate (Instrumentation.java:1135) android.app.ActivityThread.performLaunchActivity (ActivityThread.java:3207) android.app.ActivityThread.handleLaunchActivity (ActivityThread.java:3350)   Here is the code which is send data to the next activity:              //send this result to LoveMeterResultActivity             final Bundle basket = new Bundle();             basket.putStringArray("key", loveData);                     Intent intent = new Intent(LoveMeterActivity.this, LoveMeterResultActivity.class);                     intent.putExtras(basket);                     startActivity(intent);


Installing Ubuntu gets stuck during installation

Image where installation stops:    so I have been trying to install ubuntu on my pc, it has a amd fx 6300 processor, 8 gb RAM, and gtx 970 GPU. It keeps getting stuck here.


I'd like to upload or link to an animated GIF to Facebook in such a way that ideally it would display animated in the profile page.  If that's not possible, it should at least animate when clicked.  As it is, when I upload an animated GIF it gets flattened to a static image, in the profile as well as in the detail view.    I have found tips that say that it needs to be at most 120x120 pixels in size, which doesn't work for me.  Other tips say that the GIF needs to have a ".jpg" extension, which also doesn't work.


Ubuntu Installation In PC After Removing Windows 7 Without Loss Of Other Data

I want to install Ubuntu in a PC (having Gigabyte GA-J1800M-D2P-IN (Intel Celeron J1800 2.4Ghz processor) with maximum 4GB DDR3 RAM & 80GB Seagate Barracuda HDD) after removing Windows 7. Please tell how can I install Ubuntu OS in this PC without losing any data except Windows 7? Urgently waiting for your valuable reply.  Thankfully yours  Arpan Purakait


Grammar - Is this type of sentence structure correct

The higher is the ratio of the current debt to total debt, the lower is your utilization rate, and consequently the fewer are the financial options available to you and vice-versa.  Is there any rule for such constructions? If this is correct, why is there 'the' before adjectives, higher, lower, fewer.


How long would it take for a sha256 digest loop to reach the original hash or start cycling?

If I started with a sha256 hash such as  3f46fdad8e5d6e04e0612d262b3c03649f4224e04d209295ef7de7dc3ffd78a7   and rehashed it continuously (without salting):  i) What is the shortest time it would take before it started cycling in a loop or back onto the same value if at all?  ii) If it did cycle back on itself, could we assume that it had been cracked?  iii) How long would this take using modern GPU cracking techniques?  iv) If all the intermediary hashes were recorded in some kind of rainbow tables - presumably all the hashes within that cycle would be compromised?  v) What is to stop someone computing these cycles and offering cracks to sha256 hashes - likewise for other hashing protocols...  For Extra marks - What is the probability this question would be asked in this forum 60 billion years ago?


I am running a 64-bit version of Windows 7 Home Basic. I am trying to update the Windows but the update fails with an error code 80072EE2. I am connected to the internet through proxy.  Here are some things listed in my WindowsUpdate.log:  Access type: No proxy WSUS server: <NULL> WSUS status server: <NULL>   Then the download manager is restoring some persisted download calls. Then,  Initializing Automatic Updates WARNING: SendRequest failed with hr = 80072ee7. Proxy List used: <(null)> Bypass List used : <(null)> Auth Schemes used : <> UpdateDownloadProperties: download priority has changed from 1 to 2. WARNING: Failed to change download properties of call, error = 0x80070057 WARNING: WinHttp: SendRequestToServerForFileInformation MakeRequest failed. error 0x8024402c WARNING: WinHttp: SendRequestToServerForFileInformation failed with 0x8024402c WARNING: WinHttp: ShouldFileBeDownloaded failed with 0x8024402c Error 0x8024402c occurred while downloading update; notifying dependent calls.   There are very many errors/warnings and some other things listed in the log file. I have copied above the ones I thought are relevant to my problem.  Note that I have tried the solution provided on the Microsoft website but that was unable to solve my problem.  Can someone help me resolve this error?


Given weight = mass * gravity do I weight less during high tide and more when tide recedes?  My guess is weight = mass * gravity * gravitational pull of moon factor


Can I block a certain website from Google results?

Whenever I need to know a simple fact, Google often finds it in answers.com.  I loathe answers.com's user interface, and inability to deliver the information I need after I click through Google, requiring additional work to actually get the answer.    I'm signed into Google; is there a way to tell Google I don't want results that include answers.com without adding -answers.com in the search phrase?


Windows 10 - cannot change the user name folder

I wanted to rename folder C:\Users\Myname in Windows 10.   I renamed Users folder in Registry Editor Used netplwiz - and changed name there as well.   After that restarted Pc, now i'm login to temp account, where i should rename it manually and when i try rename it gives me:     The action cannot be completed because the file is open in other   program   What can i do in this situation?


Prove that a group G is not soluble if it has a non-trivial perfect subgroup.

My attempt:  Proceed by contradiction, assume that G is soluble. Then every subgroup and quotient group of G is soluble, so in particular, the non-trivial perfect subgroup, which we call H, is soluble.  But since H is perfect, the smallest normal subgroup (the derived subgroup H') of H where the quotient group H/H' is abelian, is H, so the subnormal series of H with abelian factors won't terminate, since we will have that H contains normal subgroup H' contains normal subgroup H'..... where none of the H'=H is = {e} since H is non-trivial.   Is this argument ok? I'm unsure if using the fact that the subnormal series doesn't terminate is strong enough for a contradiction.


Possible to cast Mind Spike without breaking concentration?

Mind Spike is cast with one action but has concentration up to an hour. Unless I'm mistaken, the actual casting process of the spell does not take concentration, due to it not being longer than a single action. Ending concentration is a non-action that can be taken at any time. Would it be possible for a player to cast it but choose to not concentrate on it after the initial damage, thus not breaking concentration on another spell?  The main reason I'm wondering this is because Mind Spike is the only weaponized Divination spell, and actually scales with higher slot levels. I could see this being used to get the most out of a Divination Wizard's Expert Divination class ability.  It makes sense that this would be possible to me, but I'd like to know a more concrete ruling.


Hello and sorry for my english skills =)  I'm coding a little calculation programm in Android Studio and have a problem.  I've made dynamically creating TableRow's in TableLayout like this:      TableLayout table2 = (TableLayout) findViewById(R.id.table2);     TableRow.LayoutParams rowParams = new TableRow.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ActionBar.LayoutParams.WRAP_CONTENT, Gravity.CENTER_HORIZONTAL);      TableRow row = new TableRow(this);     row.setLayoutParams(rowParams);      row.addView(floor2);     row.addView(ps2table);     row.addView(gsatable);     row.addView(vitable);     table2.addView(row);   Where floor2, ps2table, gsatable and vitable - are TextView's which calculating after a button is pressed.  After the Table has created i try to use one of the numbers (the last row of the TableLayout and the child at 2 position):      int gsn_count = table2.getChildCount();     TableRow gsnRow = (TableRow) table2.getChildAt(gsn_count);     TextView tGsn = (TextView) gsnRow.getChildAt(2);   My problem is, when i try to take a value of one or another number (double) from any TableRow from this TableLayout, i got this error:  java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.widget.TableRow.getChildAt(int)' on a null object reference  It is look for me as i have not a number in place which i refer to, but it is there. I'll add a picture with comments and all my code in links below.  Picture:   Code for a method in which i've got an error:   Thank you!


Assigning Object() containing reflected class MyItem objects to reflected class property MyItems()

I've run into an issue where I need to load a class into my code using reflection, create an array of that class, and then assign the array to another reflected object's property.  My minimum example would be:  My DLL:  Public Class MyItem     Public Property Id As Int32 End Class  Public Class MyMainItem     Public Property MyItems As MyItem() End Class   My Test App:  Sub Main()     Dim myAssembly As Assembly = Assembly.LoadFile("c:\temp\MyDll.dll")     Dim myMainObject As Object = Activator.CreateInstance(myAssembly.GetType("MyDll.MyMainItem"))     Dim myItemArray(1) As Object      myItemArray(0) = Activator.CreateInstance(myAssembly.GetType("MyDll.MyItem"))     myItemArray(1) = Activator.CreateInstance(myAssembly.GetType("MyDll.MyItem"))      myMainObject.MyItems = myItemArray End Sub   The error I receive is InvalidCastException when assigning myItemArray to MyItems:  Conversion from type 'Object()' to type 'MyItem()' is not valid.   Is there a way to make myItemArray be understood as an array of MyItem rather than Object?


What do we mean, concretely, by the unit $\rm N\:m$ (newton $\cdot$ meter)?  For example, $1 \:\rm m/s$ mean that each second, we make one meter. Also, $1\:\rm  m/s^2$ mean that each second the speed is $1 \:\rm m/s$ faster. Also, $1\:\rm  N/m$ mean that each meter, the force is $1\:\rm N$ more powerful.   Now, I don't understand when instead of division we have a multiplication. For example, what mean $1 \:\rm N\:m$? How can I interpret this? (instead the fact that $\:\rm N\:m=J$). What is the phenomena behind?


No way to unfavourite a question in the Android app

When I press the "favourite" button beneath a question in the Android app, there is no way to unfavourite it (from the app). I receive a success message, but when I click the button again, it just says I have already favourited the question. If this was never intended to be a feature, I will make a feature request.


I do a bunch of real estate reporting and the median price is often reported, particularly by the NAR (National Association Of Realtors). As best I can tell, they only get the medians of real estate prices from each area.  My question is, how should the national median be calculated, given the data restrictions? As a median of medians, as a simple average of medians, or weighted average of medians or something entirely different? Second, how valid would these estimates be? I know that the NAR is not getting the total transaction table, so can a reasonably accurate representation of the median still be estimated at the national level? I ask, in particular, because regional density and prices and market variances are so large.


What is the book series where people become "Forged"?

It's been a really long time since I've read this series.  It's a fantasy series (don't remember author or title).  If I recall correctly, it's a world where there are several plot lines set.  In any case, the part I remember is that there are some invaders that rape and pillage and "Forge" the locals and afterwords they cannot remember who they are, no higher intellectual behavior, just pure instinct and savagery.  Can anyone name the series and/or author?


How to be properly cited with a two-word last name

I have a two-word last name which gives as full name something like "Mike Adam Pince" (just an example) with "Mike" the first name and "Adam Pince" the last name (no middle name).   I have published few conference papers and I noted that Google scholar is referencing me (author's name in the results) as "MA Pince" which I'm sure other people would do too.  Now that I'm writing a journal paper I'm thinking of adding a hyphen to my last name "Adam-Pince" to avoid any confusion with others authors.   I wonder what's the common practice in such a situation.


How do I allow `multicols` environment to break across multiple frames? (beamer)

It does not seem that multicols environment can cross across pages. Is there an alternative to create multiple columns that are filled automatically (i.e., we just insert the items and the environment fills columns using its own algorithms) with the contents but can break frames if necessary?    \documentclass[aspectratio=169]{beamer}  \usepackage{blindtext} \usepackage{multicol}  \begin{document}  \begin{frame}[allowframebreaks=0.7]{Long Lists}      \begin{multicols}{2}          \blindlistlist[3]{enumerate}          \blindlistlist[3]{enumerate}          \blindlistlist[3]{enumerate}      \end{multicols}  \end{frame}   \end{document}


New with 10.9 is the ability to easily create a bootable drive from the installer that is downloaded from the App Store, with a single command createinstallmedia in the Terminal.   has details.  I encountered a problem with this, with an Error -9999 when trying to erase the USB drive I had inserted.  The error occurred while booted into 10.6.8; but since that particular computer also has a 10.8 partition, I booted from it and tried the same command with the same USB drive.  It was able to erase and create the boot drive successfully.  Don't know how widespread this problem is; but, if this occurs to someone else who does not have the newer OS available to boot into, I'm wondering if there is any other way to fix the error; or if the Disk Utility methods of creating the boot drive will need to be used.


To Find value of this infinite product $P=\frac{7}{9} \frac{26}{28} \frac{63}{65}...\frac{n^3-1}{n^3+1}...$

Given   $$P=\frac{7}{9} \frac{26}{28} \frac{63}{65}...\frac{n^3-1}{n^3+1}...$$  I have no idea how to do this  Thanks


How do I set environment variables from Java?  I see that I can do this for subprocesses using . I have several subprocesses to start, though, so I'd rather modify the current process's environment and let the subprocesses inherit it.  There's a System.getenv(String) for getting a single environment variable. I can also get a Map of the complete set of environment variables with System.getenv(). But, calling put() on that Map throws an UnsupportedOperationException -- apparently they mean for the environment to be read only. And, there's no System.setenv().  So, is there any way to set environment variables in the currently running process?  If so, how?  If not, what's the rationale?  (Is it because this is Java and therefore I shouldn't be doing evil nonportable obsolete things like touching my environment?)  And if not, any good suggestions for managing the environment variable changes that I'm going to need to be feeding to several subprocesses?


Using Mosfet with seperate Logic Converter and Arduino

I am trying to use an IRLB3034 with an Arduino even though it is not a logic level MOSFET. I am planning on using an LM2937 12v regulator like the schematic below:    The connection going off the page goes to an Arduino digital pin pulled down with a 10k resistor. I assumed this would work but wanted to check. As a side note, if anyone could recommend a similar MOSFET that could handle 200a and 40v (in TH) that would be great. (Only if such thing excists or is readily available)  EDIT: I have not made it clear what I am planning on using this for so I will now. It is to drive an airsoft motor and I want to use the LM2937 because I didn't think I could turn the mosfet on and off with the arduinos 5v - because the IRLB3034 isn't a logic level mosfet - so that is the reason I added the 12v regulator.  EDIT (Sorry for the previous incorrect name)  EDIT: Unfortunately, I have made a mistake, the current is not 200 amps, it is infact 30-40 amps. I don't know how I made this mistake but I think it will be helpful for people trying to follow along. I am currently trying to use busbars/6awg copper wire to carry the high-ish current around. (Only 40 amps now though)  EDIT: This question is different because it is asking how to convert 5v to 12v to run a mosfet rather then how to use a mosfet with an arduino in the best way like the other post. The accepted answer on this post also answers the other question though.


Two cyclists, 120 miles apart, approach each other, each pedaling at 10 miles per hour. A fly starts at one cyclist and flies back and forth between the cyclists at 15 miles per hour. When the cyclists come together (and squash the fly between them), how far has the fly flown?  I know that I am supposed to find some sort of series here, but I don't really know how to approach this. How do I find the terms?


the relationship between localization and inverse elements

We know that localized rings contains inverse of  elements at which we localized our ring. I want to know why do we need to invert elements to study local behavior? I would be grateful if someone help me understand this. I know this may be very basic thing, but I am really confused.


I am building an app in JavaScript. I am trying to get my head around how to use this in a JavaScript closure. Currently, I have the following code:  var ExternalResource = require('ExternalResource'); function MyObject() { }  MyObject.prototype.state = "Closed"; MyObject.prototype.execute = function(options, callback) {   if (!options) {     if (callback) {       callback(-1);     }     return;   }    try {     this.state = 'Connecting';     var client = new ExternalResource.Client();     client.connect(function(err) {       if (err) {         this.state = 'Failed';         if (callback) {           callback(-1, err);         }       } else {         this.state = 'Good';         if (callback) {           callback(1);         }       }     });   } catch (ex) {     if (callback) {       callback(-1, ex);     }   } };   I am currently executing execute by a Jasmine test.   it(' - Connect to a local instance', function(done) {   var myObject = new MyObject();   myObject.execute({}, function() {     expect(myObject.state).toBe('Good');   }); });   When this test gets executed, I see the following error:  Expected 'Connecting' to be 'Good'.   I am sure it has something to do with using this.state in the connect callback. Yet, I'm not certain.  Thank you!


Focus on a textarea to the last + 1 character cursor, javascript

I have this portion of code in my javascript file  function insertRespuesta(id, attach) {     document.getElementById(attach).value += " #" + id + " ";     document.getElementById(attach).focus(); }   My html file:  <textarea name="textoConversacion" id="textoConversacion" class="mensaje-mensajeria"></textarea> <a href='#' class='decoracion-link' onClick="insertRespuesta('<?php echo $cada['contador']; ?>','textoConversacion');">#<?php echo $cada['contador']; ?>   So if I click the link it will be focused on the textarea but the textarea cursor will be in the last position I had, and I need to put in the last cursor character + 1.  I preffer not using jquery.


Event listener (click) for new element.JQuery

i just started using JQuery and i have a problem, regarding adding a click event listener for a dinamically created button.  So when the user click on button number one, my first function simply add a second button into a div. The problem is that using the same method, my listener for the second button is not working. Here is a simple exemple of what I'm trying to do.   <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <script src="http://code.jquery.com/jquery-1.9.1.js"></script> <script type="text/javascript"> $(document).ready(function(){     //listener for first button     $("#button1").click(function(event){         event.preventDefault();         $("#newElement").append("<input type='button' id='button2' value='Need listener for this new button'>");     });      //listener for the seccond button (problematic one)     $("#button2").click(function(event){         event.preventDefault();         alert("Second button clicked!");     }); }); </script> <title>Exemple JQuery</title> </head> <body>     <input type="button" id="button1" value="Add a new button dynamically">     <div id="newElement">      </div> </body> </html>   Any ideas are very welcome. Thank you


Explain same encryption time for two files of different sizes

I am encrypting files in a two layered fashion as follows:   Inner layer is 128 bit AES-CTR encryption Outer/Second layer is a simple one time padding with a particular key.   While testing the running times I noticed that it takes same time to encrypt a 100kB file as it takes to encrypt a 10kB file. Logically it seems wrong to me, is it something that I am missing ?


potentially color-blind person: how to choose colors for a graph

I have a chart with 5 curves (curves 1-5). A person told me that colors 1 vs. 2 as well as colors 3 vs. 5 are difficult to distinguish. While I can understand that 3 and 5 are somewhat similar, the 1 and 2 are completely different in my view. I do not know, maybe this person color-blind. But I need to make the graph so that he will be able to distinguish the colors. My problem is that I have only 7 colors in total (additional two colors are 6 and 7). I did not use the yellow (6) originally because it is too faint in my view. The cyan (7) also is similar to blue.  How you would suggest me to choose the colors? The proximate curves should clearly have the most distinguishable colors.  Thanks!


How to integrate $\int\frac{x}{1+x^3}dx$?

How to integrate $\displaystyle \int\frac{x}{1+x^3}dx$? I tried using partial fractions and substitution but it didn't work, thanks.


I need to prove the  continuity of $f(x)=\log x$ using a $\epsilon-\delta$ proof  These is what I have so far but am not sure how to continue  $|\log x-\log a| < \epsilon$   $\log a- \epsilon < \log x < \log a+ \epsilon$  $\frac{a}{e^\epsilon} < x < {a}e^\epsilon$  Any help is appreciated


Where are these certificates coming from?

On an Ubuntu 12.04 server I have a bunch of certificates listed in my /etc/ssl directory...where could these have come from? I don't remember adding them myself, do they get generated when aptitude updates its repos or is it from something else?


What velocity has a mass when launched tangently on one side of moon, to let it arrive at a position diametrically opposite on the moon?

If we launch an object on one side of the moon (the velocity being tangent to the surface of the moon), how big must the velocity be to let the object arrive at a position on the moon diametrically opposite to the launching site (in some device to catch the mass)? The mass is very, very small compared to the moon's mass.  The acceleration due to the moon's gravitation is, of course, dependent on the distance to the moon (inverse square law).  Because of this dependence on the distance of the acceleration, it's more difficult to compute a trajectory, especially this particular one that also involves the curvature of the moon. I guess integration is involved, but I don't see how. For sure the velocity has to be higher than the velocity (which is easy to calculate) to let the mass make a circle around the moon. If we didn't catch the mass on the other side, the trajectory would resemble something that looks like an ellipse. This trajectory doesn't consist of two (opposite) parabola's because the trajectory in the question isn't a parabola, again because the acceleration depends on the distance of the mass to the moon.  Is there someone who knows how to do the calculation?


Why is general relativity considered to be a gauge theory?

I have studied the first five chapters of Carroll's book (up to the Schwarzschild solution). I see similarities to the Yang-Mill theories such as the covariant derivative to account for curvature in GR which is similar to the covariant derivative to account for local gauge transformations in Yang-Mill theories. I have heard that some consider GR to be a gauge theory, but I do not understand what the redundant degrees of freedom are required to make it gauge theory.


An empty usb drive -- "no permissions for creating a folder or file"

I have a usb drive with ext4 file system. It is empty. I can't create any files or folders because of the error displayed: "you have no permissions".


Client/Server-Socket Java sending string

I am having a problem with my client server program using sockets in java. So I want the client to send the string "chef", and in the server I want it to  send something back if the client sent "chef", otherwise do something else. The problem is the string sent from the client to the server does not match for some odd reason.  This is the snip of code I have on the client class, to send the string:   PrintStream PS=new PrintStream(sock.getOutputStream()); PS.println("chef");   In the server I have this snippet:  Socket sock=socket.accept(); InputStreamReader IR=new InputStreamReader(sock.getInputStream()); BufferedReader BR=new BufferedReader(IR);  String message="";    message=BR.readLine(); if (message=="chef") {     PrintStream ps=new PrintStream(sock.getOutputStream());     ps.println("Chef Connected"); } else {      System.out.println(message); }   So the problem is the server keeps going to the else statement even thought I am sending the correct string "chef". I used System.out.println(message) in the else and it prints the string "chef". So I am very lost at why this is happening. Hopefully I was clear, and any help or clarification would be greatly appreciated.


This is my code:   var FinalPath = Path.Combine(DestPath, FinalFile);  File.Copy(TempFile, FinalPath);   Destpath is "c:\Somepath\" and FinalFIle is "somefile.pdf" So FinalPath is: "c:\Somepath\somefile.pdf"  When Copy method is called i receive error (file already exists and throws an unwanted exception wich is not good).   How can i tell something like if(FinalPath.Exists = true)... ignore o continue ?


Creating Projection/Datum TransvMerc/OrdSurvGrtBrit in QGIS?

I have Memory Map files QCT exported to ECW.  The Projection/Datum is Transverse Mercator / Ordnance Survey Great Britain which is not mentioned in the list of Projections/Datums available.  How can I create it from the scratch or by modifying any available?


Please, can you explain why isn't the $$\int\frac{du}{\sqrt{a^2-u^2}} = \int\frac{du}{a\sqrt{1-(u/a)^2}}=\frac1a\sin^{-1}\bigg(\frac{u}{a}\bigg)+c$$ if $a > 0$ is a positive constant.


Why did I just lose some reputation without any explanation in my profile?

Possible Duplicate:          My reputation score has gone down, but the reputation tab in my profile does not indicate why. Is this a bug? What else could have caused it?


I don't really know if I'm right here, if so please say something.  But, I currently work on my bachelor-thesis and want to enable spell check in my VIM. But currently I have to do this every time when I open up a new document. Is there a way to enable spell checking and choose a default language in my .vimrc for all .tex files???  Thanks in advance!


Interpreting the output of linear regression

I used scipy.stats.linregress function for my dataset. It returns 5 output variables.  Slope = 0.0453 Intercept = 14.905 r-value = 0.91 p-value = 0 standard error of estimate = 0.00015  This is the documentation link if anybody would like to see  Can somebody help in understanding the output? Questions I would like to ask are the two variables highly correlated. The r-value is something that I think points to the correlation, but since it is not 1.0, what would be ways to find out which ones do not satisfy this constraint, can I use any of the parameters here? In general when you see such values how to grasp them?


Under which condition is $f : x \mapsto x^e \mod n$ invertible?  I mean, for each distinct $x \in \{0, 1, 2, \ldots, n-1\}$ the result is distinct?   Is that $e$ must be coprime with the totient of $n$ ($\varphi(n)$)?  I read several articles on RSA, but this point is still not clear to me.


Let $(x_n)$ be a sequence of reals. Show that if every subsequence $(x_{n_k})$ of $(x_n)$ has a further subsequence $(x_{n_{k_r}})$ that converge to $l$, then $(x_n)$ converge to $l$.   I know the fact that subsequence of $(x_n)$ converge to the limit same as $(x_n)$ does, but I'm not sure if I can apply this.  Thank you.


I've failed  audit on  question.  The problem is I've seen in my audit window something else as there actually is. The question in audit had  tag, while actually it has no such tag, and I should have never seen that question because of the tag filter in close queue.   I've chosen to close as unclear what you are asking because I couldn't see what that has to do with JavaScript.   Please don't add random tags to audit questions and expect us to take no action.


Dark futuristic sci fi shorts shown on UK TV in the 90s

I distinctly remember as a kid in probably the mid-90s watching a series of one-off sci fi shorts. Quite dark / hard sci fi. Kind of a manga vibe but not necessarily Japanese. I seem to recall they (or at least this one) had little / no dialogue? Almost certainly Channel 4 / BBC2.  I remember one in particular about someone (maybe an assassin?) who had to keep shooting a crane so it wouldn't dock with her escape pod while she was trying to finish something against the clock. I'm pretty sure she died in the end.


I have create a formula field "Lead Age" on Lead object which return # of days (Integer) as per below formula     ROUND( Now() - CreatedDate, 0)   Now I want to write a test class to test this formula. In my test class, How can I set CreatedDate to some date in past? I tried below code but it is not working  @isTest private class LeadAgeTest {      private static testMethod void testLeadAge() {         String leadJSON = '{"attributes":{"type":"Lead","url":"/services/data/v25.0/sobjects/Lead/00Qe0000003yEbR"},"Id":"00Qe0000003yEbR","Company":"Appirio","LastName":"Sharma","CreatedDate":"2014-09-01T11:54:26.000+0000"}';           Lead lead1 = (Lead) JSON.deserialize(leadJSON, Lead.class);            Lead lead2 = new Lead(Id = lead1.Id);         update lead2;          lead2 = [SELECT Lead_Age__c,CreatedDate FROM Lead WHERE Id=:lead2.Id];          System.debug('####-'+lead2.CreatedDate);     }  }   Any help would be highly appreciated.


Adding Regressors to Convolutional Neural Network

I have an idea for working with geospatial rasters to predict housing prices.  I have done this before using mulitivariate linear regression.  I would like to try using a convolutional neural network.  I have a series of rasters that represent a surface of interpolated housing prices over time.  The convolutional neural network will learn from the price rasters, but I need to add in other explanatory variables. The most important is time.  I might add additional scalar values such as interest rate or stock market.  I might also want to add additional rasters as regressors, such as crime maps, or distance to transit.  I know that in a typical neural network regression there is one neuron per explanatory variable, and in a typical CNN there is a neuron per pixel on the input layer.  So I would like some regressors to be rasters, and some to be scalers.  My question is how do I add additional explanatory variables, both rasters and scalars, to a convolutional neural network?  I am using Keras and TensorFlow.


could anyone help me how to write in latex suc kind of matrix? I tried for the first one but didnt get exact form..thanks for helping


Does the Shadow Magic sorcerer's Hound of Ill Omen stack disadvantage if I summon more than one?

I just became a level 6  (Xanathar's Guide to Everything, p. 50-51). At 6th level, shadow sorcerers gain the Hound of Ill Omen feature:  At 6th level, you gain the ability to call forth a howling creature of darkness to harass your foes. As a bonus action, you can spend 3 sorcery points to magically summon a hound of ill omen to target one creature you can see within 120 feet of you. The hound uses the  statistics, with the following changes:  The hound is size Medium, not Large, and it counts as a monstrosity, not a beast. It appears with a number of temporary hit points equal to half your sorcerer level. It can move through other creatures and objects as if they were difficult terrain. The hound takes 5 force damage if it ends its turn inside an object. At the start of its turn, the hound automatically knows its target’s location. If the target was hidden, it is no longer hidden from the hound.  The hound appears in an unoccupied space of your choice within 30 feet of the target. Roll initiative for the hound. On its turn, it can move only toward its target by the most direct route, and it can use its action only to attack its target. The hound can make opportunity attacks, but only against its target. Additionally, while the hound is within 5 feet of the target, the target has disadvantage on saving throws against any spell you cast. The hound disappears if it is reduced to 0 hit points, if its target is reduced to 0 hit points, or after 5 minutes.  It doesn't say a limit to how many I can summon. Does this mean I can stack disadvantage on a target?


Rewrite the sentence, using the noun form of its verb:

"Oscar Wilde wrote the novel, "The Picture of Dorian Gray."  (Rewrite this sentence, using the noun from of the verb "wrote".)     [1] Oscar Wilde was the writer of the novel, "The Picture of Dorian Gray".      [2] Oscar Wilde is the writer of the novel, "The Picture of Dorian Gray".   If [2] is right, please explain whether it's ok to change the tense of the original sentence.  If [1] is right, please explain why [2] isn't correct.


How can I find out which Mac apps are 32-bit?

On June 28, 2017, Apple  that     macOS High Sierra will be the last macOS release to support 32-bit apps without compromise.   How can I find out which apps on my Mac are 32-bit so that I can see if I need to upgrade them?


Where does the inconsistency between QM and general relativity stem from?

I understand special relativity works with QM (as seen by QFT) and I know that there is some discrepancy between GR and QM. Could someone elaborate on that? Where does the inconsistency stem from? Different formulations of the 2 theories, conceptual incompatibilities, or something else?


How to stop a remote desktop session from ending

We have Windows 2008 r2 servers running at the moment.  If I log into the server using remote desktop connection, and then someone else tries to log into the same server while I am working on it, I get thrown off the server and am displayed the following message:     Your Remote Desktop session has ended.      Another user connected to the remote computer, so your connection was   lost.  Try connecting again, or contact your network administrator or   technical support group.   My question is, is it possible to configure the server to stop this from happening.  So instead of kicking off the user who is already working on the server, stop the second user from connecting or allow both to connect at the same time?


What, according to the functionalist, is the difference between things which merely have functional roles and things whose functional roles amount to their having a mind? Different people may interpret identical events or stimuli differently due to their having a mind that differs from your own.  Which part of English grammar stipulates using their in these sentences? For me it should be either "to them having a mind" or "to their having of a mind."


I'm on windows 7 using Cygwin.  My script and text file are located in the same directory.  #!/bin/bash while read name; do echo "Name read from file - $name" done < /home/Matt/servers.txt   I get this error and I don't know why because this is correct while loop syntax..?  u0146121@U0146121-TPD-A ~/Matt $ ./script.sh ./script.sh: line 4: syntax error near unexpected token `done' ./script.sh: line 4: `done < /home/Matt/servers.txt'   Can anybody tell me what I'm doing wrong? I think its because I'm on windows and using Cygwin.


Do I use has had or had had for indirect speech

'We have had no rain since January' ,said Ramu.   How do I write this in direct speech versus indirect speech.   Should it be had or had had.  I want to know how to write this in in indirect speech.


Extra character before string comparison

In some bash codes, I see an extra character is added before the string comparison. Can somebody explain the reason? if [ "x$VAR" = "xString" ]; then ... fi


Python CSV Reader: No Get Line Function?

I have been reading the Python docs on the CSV module here:   And I noticed that it does not mention any way for a reader object to return the number of the line it is currently reading, or which iteration it is currently at. This seems like it would be a widely needed functionality. So, I am wondering how one can do this:  reader = csv.DictReader(readFile)     for row in reader:         # do something          # now want to find the line number that row corresponds to   Or if that is not possible, why that is the case.


Using only the standard analytic properties of the sine function, but no particular definition of it,  what's a neat little proof that the sequence $\sin(n)$ diverges?


I am a citizen of three countries. I am going to travel to not two but all three countries. How do I book the tickets, on which passports?

Australia to South Africa to Morocco. All travels are 4-5 days apart. So which ticket do I book with which passport? Which passport do I use to enter and exit to the next country?


I saw the binomial theorem in some 11th grade book in my library. It was proved by induction. But there was no derivation of it. I do not like to memorize it. So I'm hoping someone can show me a derivation for it and give hint for another way to derive it. It would be great if you try to use high school mathematical tools if possible, so I can understand it.  $$ (x+y)^{n}=\sum _{k=0}^{n}{n \choose k}x^{n-k}y^{k}=\sum _{k=0}^{n}{n \choose k}x^{k}y^{n-k}. $$


How can I get the content of the file specified as the 'src' of a  tag?

If I have a script tag like this:  <script     id = "myscript"     src = "http://www.example.com/script.js"     type = "text/javascript"> </script>   I would like to get the content of the "script.js" file. I'm thinking about something like document.getElementById("myscript").text but it doesn't work in this case.


How should I address a woman who serves food and drinks to passengers on a plane?

When I want to speak of a woman who serves food and drinks to passengers on a plane, should I use 'air hostess' or 'stewardess'? What's the difference? And when I take a plane, how should I address her?


Are there benefits of passing by pointer over passing by reference in C++?

What are the benefits of passing by pointer over passing by reference in C++?  Lately, I have seen a number of examples that chose passing function arguments by pointers instead of passing by reference.  Are there benefits to doing this?  Example:  func(SPRITE *x);   with a call of  func(&mySprite);   vs.  func(SPRITE &x);   with a call of  func(mySprite);


Sequence proof (by induction, presumably) giving me trouble.

Let $a_1,...,a_n$ be a sequence of positive numbers.  Show that  $$(a_1+a_2+\cdots+a_n)\left(\frac{1}{a_1}+\frac{1}{a_2}+\cdots+\frac{1}{a_n}\right)\geq n^2$$  Hint:  Use the fact that for $x>0$ we have $x+(1/x)\geq 2$.  My idea is to use induction.  But I can't seem to make it work.  On the other hand, I don't see how the hint is going to take me where I need to go.


No such file or directory error at log in after I downgraded from Ubuntu 18.10 to 18.04

I downgraded from 18.10 to 18.04 - and I got the same error as in this question     When I login it says:   Error found when loading /etc/profile: etc/profile.d/01-locale-fix.sh: line 2:/usr/bin/locale-check: no such file or directory  As a result the session will not be configured correctly.  You should fix the problem as soon as feasible.    The file is indeed not there. I can't apply the same solution because I do not have another Ubuntu laptop.   How/where can I find the missing file?   Thank you


Let $A \in M_n(\bf C)$ and let   $S=\{ A \in M_n(\bf C) : A=A ^*$ and  $\rho (A) \leq 1 \}$, $\rho(A)$ denotes spectral radius of $A$.     Show that $S$ is compact subset of $M_n(\bf C) \cong \bf C^{n^2} $ with usual topology.    $S$ is subset of $\bf O_n(C)$ which is compact so I think its enough to show that $S$ is closed.Please help.


Are there any clones/alternatives for running a Stack Exchange style Q&A site?

Since the source code for this site isn't available for purchase or external use, I'm looking for software that can run a Q&A environment similar to Stack Exchange. Are there any such pieces of software available?


What is the correct way to report a questionable audit?

I failed a triage queue audit today, and received a two-day review ban.  This was my first failed audit in (I think) weeks.    But this is not a protest if audit ban injustice.  Rather, I would like to know how to properly report a bad audit.  I checked meta and found a question talking about this at length and proposing such methods (), but cannot find any confirmation on how it works today.    The audit I failed was a question about an application automatically operating in the background.  I flagged it as Off-topic: General Hardware/Software:


define a static array in class templates

I have a static array inside a class template. The linker complains about a undefined symbol and even after applying the tips I saw on the web, I can't figure out what goes wrong.   Header  template<unsigned int N1, unsigned int N2> class Foo  { private:     static const int Size = N1 * N2;  public: // stuff  private:     static float mArray[Size];  }   CPP  template <unsigned int N1, unsigned int N2> float Foo<N1, N2>::mArray[size] = {0};   The linker complains about Foo<...>::mArray not being defined. I got it to compile (and link) when I move the definition to the header but I know that this is bad practice for statics. What is the best approach here?  Cheers


How do I copy existing properties in the UI so I can include them in my custom panel?

This has surely been asked before but I think I don't know the correct terms to search for. What I want is in my custom panel, sliders for changing the active camera's location and rotation. Basically, I get this easily with:  def draw(self, context):     layout = self.layout     scene = context.scene      cam = context.scene.camera      layout.label(text="Location:")     layout.prop(cam, "location", slider=True, index=0, text="X")     layout.prop(cam, "location", slider=True, index=1, text="Y")     layout.prop(cam, "location", slider=True, index=2, text="Z")     layout.label(text="Rotation:")     layout.prop(cam, "rotation_euler", slider=True, index=0, text="X")     layout.prop(cam, "rotation_euler", slider=True, index=1, text="Y")     layout.prop(cam, "rotation_euler", slider=True, index=2, text="Z")   However, this ends up in a slider with no limits (limits are number ranges of computer, I think), so a slight change in the slider will result in massive change in position/rotation of camera.   Actually, what I really want to achieve is a copy of the sliders like they appear in the "Item" tab when I select the camera. Anyone able to help me there with links to other threads or questions or a direct solution?


Is $\frac{\vert x+y\vert}{1+\vert x+y\vert}\leq\frac{\vert x\vert}{1+\vert x\vert}+\frac{\vert y\vert}{1+\vert y\vert}$ true?

Is $\frac{\vert x+y\vert}{1+\vert x+y\vert}\leq\frac{\vert x\vert}{1+\vert x\vert}+\frac{\vert y\vert}{1+\vert y\vert}$ true for all $x,y\in\mathbb{R}$?  If not, how can I prove that $\int\frac{\vert f-h\vert}{1+\vert f-h\vert}\leq\int\frac{\vert f-g\vert}{1+\vert f-g\vert}+\int\frac{\vert g-h\vert}{1+\vert g-h\vert}$? I tried C-S: $$\sum_{cyc}\frac{|x|}{1+|x|}=\sum_{cyc}\frac{x^2}{|x|+x^2}\geq\frac{(x+y)^2}{x^2+y^2+|x|+|y|}.$$ Thus, it's enough to prove that $$\frac{(x+y)^2}{x^2+y^2+|x|+|y|}\geq\frac{(x+y)^2}{|x+y|+(x+y)^2}$$ or $$|x+y|+(x+y)^2\geq x^2+y^2+|x|+|y|,$$ which is wrong for $(x,y)=(1,-1).$


Why is a REIT (Real estate investment trust) able to grow and appreciate, given that it is not able to retain its earnings?

REITs have to distribute out most of their earnings to shareholders. This deprives REITs the needed cash to reinvest into their business to grow organically. Wouldn't this stunt REITs' business growth and price appreciation? If REITs need capital, they ask money from shareholders. This is bad for shareholders and hold back the share price.   How do REITs' price appreciate, given that they do not retain earnings to reinvest back into their business like ordinary companies?


What does it really mean that telephoto lenses "flatten" scenes?

This is another perspective distortion question. I understand that perspective distortion is primarily a function of capture and viewing distance, but I am still working on fully understanding the causes of the "flattening" of scenes that is credited to telephoto lenses.  This seems to refer to our ability to discern the differences in size attributable to differences in distance from the lens for subjects beyond a certain distance from the lens. If this is correct, then is it just that with the longer distance from the subject when using a telephoto lens, this compression happens closer to the foreground, rather than in the mid- or background with a wide lens?  Is it fair to say that the compression effect occurs at a certain distance from the photographer regardless of lens, but the field of view influences how close to the foreground this effect takes place? Can you share any information to help people like me understand this?


What happened to my reputation (dropped about 1500 points)?

About an hour or so ago, my stack overflow reputation dropped from well over 1000 to just 41. What's going on?  At the same time, my username got reset to one of those numeric ones (user123456 or similar), though I've changed that back to "tobyink" now.  My account is  - you can see the history is fine, so it's not like I accidentally signed in with a different Open ID and ended up creating a new user with lower reputation.


Why didn't the ministry of magic call for help from foreign counterparts?

Why didn't the British ministry of magic call upon their foreign counterparts for aid in the war against Voldemort, I mean if they had the help from one other country they could gain the upper hand way quicker just through sheer numbers.


Is there any way to boot Windows 7/8 using BIOS on GPT?

I'd like to know if there's a method to get Windows 7 or Windows 8 Developer Preview to install to a GPT disk on my traditional IBM PC BIOS setup. Windows 7, of course, rejects my GPT partition, because I don't have UEFI. Well, Debian and Grub 2 seem to work fine... So I want to know if there's a way to force Windows to work as well.  I'd seriously prefer avoiding hybrid MBR/GPT, because it's quite fragile and feels hackish, but it does work. I would assume the main blocker is that Microsoft is simply not adding support in their BIOS bootloader for GPT, which is understandable, I suppose. Is there any recourse?  The way I see it, there are a few potential solutions:   Having an alternate bootloader for the Windows kernel. NOT a chainloader. As far as I know, none exist. That's a shame. Storing as little as possible on an alternate MBR-based disk. Not liking this idea, but it's doable. I'm not sure I'd call this a solution to the problem as much as a workaround. Emulating EFI enough to get the EFI bootloader to work... I remember hearing a bit about a UEFI-on-BIOS emulator, but I can't find anything about it now. I assume this is doable, but there's probably not much demand for it yet, and it's probably no fun at all to setup. GRUB 2 seems to be able to boot a hackintosh with necessary EFI emulation, but I guess there's no interest/UEFI 2 is harder to approach (and I would assume other EFI emulators used for hackintosh are on the same boat.) Coreboot with TainoCore. Coreboot does not work on my motherboard (as far as I know,) and I'm quite sure the last effort to do this during GSoC was a failure. I'd absolutely love this solution, if it did work, though.   Am I missing anything?


Potential malicious intent in code or am I imagining things?

There are number of issue with this post .    Why would you want to hide hidden bytes to a text file? He's asked virtually the same question 3 times The other question he's  is wondering how to upload an entire folder via FTP.   I think this has malicious intent.  So based on this answer  I have a number of options. I've confronted the user but no answer. I've flagged the duplicates.   Does this warrant a moderator flag?


I am trying to chain the commands in linux, I am using ubuntu 14.04 distribution. The aim to create a directory and go into that directory. Generally we do this  mkdir foldername cd foldername   Perfect, when tried this   mkdir gates cd gates    works as expected. But things are not working as expected when using &  mkdir gates & cd gates, does not work, the error is no such file or directory. When pressed enter, it would create the directory gates in the next step. Why this is happening?. But ls & mkdir gates seems to be working fine


I'm having trouble getting the bibliography to show up in the following example:  main.tex:  \documentclass[12pt]{report} \usepackage[utf8]{inputenc} \usepackage{biblatex} \addbibresource{references.bib}  \begin{document}  Hi \cite{bib:markramEqns}.  \printbibliography  \end{document}   references.bib:  @article{bib:markramEqns,     author        = {M Tsodyks, K Pawelzik, and H Markram},     title         = {Neural networks with dynamic synapses},     journaltitle  = {Neural computation},     year          = {1998},     volume        = {10},     number        = {4},     pages         = {821-835} }   Compiler complaints:   No file main.bbl.  LaTeX Warning: Citation 'bib:markramEqns' on page 1 undefined on input line 8.   LaTeX Warning: Empty bibliography on input line 10.  [1{/var/lib/texmf/fonts/map/pdftex/updmap/pdftex.map}] (./main.aux)  LaTeX Warning: There were undefined references.   Package biblatex Warning: Please (re)run Biber on the file: (biblatex)                main (biblatex)                and rerun LaTeX afterwards.   What is going on?


Confidence regions on bivariate normal distributions using $\hat{\Sigma}_{MLE}$ or $\mathbf{S}$

Given a $5 \times 2$ dataset $\mathbf{X} =\left( \begin{array}{rr}-0.9&0.2\\2.4&0.7\\-1.4&1.0\\2.9&-0.5\\2.0&-1.0 \end{array} \right)$. Assume that $X\sim N_2(\mu, \Sigma)$.   Using $\hat{\mu}_{MLE}$ and $\hat{\Sigma}_{MLE}$, I need to calculate the eigenvalues and eigenvectors and draw an 80% probability ellipse. In the statistical books I've seen, it is usually stated that to draw such an ellipse, you use $\mathbf{S} = \frac{1}{n-1}\sum(\mathbf{x_j} - \mathbf{\bar{x}})(\mathbf{x_j} - \mathbf{\bar{x}})'$ and calculate the eigenvalues and eigenvectors for this matrix. Then you can draw the ellipse, using these eigenvectors and the calculated $\mathbf{\bar{x}}$.  My Question  Now I now that $\hat{\Sigma}_{MLE} = \frac{n-1}{n}\mathbf{S}$. So what do I need to do here? Is it correct to use  $\hat{\Sigma}_{MLE}$ to calculate the eigenvalues and -vectors and use them to find the 80% confidence interval, or do you always need to use $\mathbf{S}$?


If someone is about to finish his or her lunch, and we want to know, can we ask him or her:      Are you done?


Does special relativity make magnetic fields irrelevant?

I've heard that special relativity makes the concept of magnetic fields irrelevant, replacing them with relativistic effects between charges moving in different velocity frames. Is this true? If so, how does this work?


Can I configure MySQL's typecasting to consider 0 != 'foo'?

points out the following security problem with MySQL:  USERS id | email            | password_reset_token 1  | one@example.com  | QTlXww)uV!Hdg3U6aGwKV2FPvAqzVgPx 2  | two@example.com  | CZor5t7WbX#LTeqiG3v@6f3@z#)BfK*n   Here we have nice, random tokens that a user must prove they have in order to reset their account. But the user manages to submit a reset token of 0, so we run this query:  SELECT * FROM `users` WHERE `email` = 'one@example.com' AND `password_reset_token` = 0   MySQL converts the token VARCHAR to an INT in order to make the comparison. It considers a VARCHAR that does not start with a number to equal 0. Therefore, an attacker can match any non-numeric string and take over the account.  Even if the reset token starts some numbers, the situation is not much better. MySQL ignores all characters but the initial numbers when making this comparison, so it considers 12blahblah3blah4 to be equal to 12, which makes guessing exponentially easier.  Can I configure MySQL not to do this kind of typecasting? If, for example, it cast INT to VARCHAR instead of vice versa, this attack would not work.  Note  If the query is run with '0' instead of 0, this doesn't work. The article discusses this vulnerability in terms of Ruby on Rails' acceptance of XML, where a type=integer property convinced Rails to send an actual integer in the query.  That bug has been patched in Rails; it now converts all request parameters to strings, so it would never build a query with an integer. But I still think MySQL should be configurable to prevent this.


Find the $n^{th}$ derivative of $$f(x) = e^x\cdot x^n$$  If i am not wrong i have following  $1^{st}$ Derivative: $e^x\cdot n\cdot x^{n-1} + x^n\cdot e^x$  $2^\text{nd}$ Derivative: $e^x\cdot n\cdot (n-1)\cdot x^{n-2} + 2 \cdot e^x\cdot n\cdot x^{n-1} + x^n\cdot e^x$  $3^\text{rd}$ Derivative: $e^x\cdot n\cdot (n-1)\cdot (n-2)\cdot x^{n-3} + 3 \cdot e^x\cdot n \cdot (n-1)\cdot x^{n-2} + 4 \cdot e^x \cdot n \cdot x^{n-1} + 2 \cdot x^n\cdot e^x$  From here how do I calculate the $n^{th}$ derivative?  Thanks. :)


How do I combine two lists into a dictionary in Python?

I have two lists of the same length:  [1,2,3,4] and [a,b,c,d]  I want to create a dictionary where I have {1:a, 2:b, 3:c, 4:d}  What's the best way to do this?


I am trying to let Latex shorten the authorlist in my bibliography automatically, but it seems to ignore my settings.  This is my MWE:  \documentclass{scrreprt} \usepackage[backend=bibtex, maxnames=2,style=numeric-comp]{biblatex} \addbibresource{Literatur.bib} \begin{document}  This is testing text... \cite{Huebler2011} \cite{Pierre2015}  \printbibliography \end{document}   This gives me following result:    As you can see, the selected style is applied, but all authors appear in the bibliography list. I am using TeXnicCenter with MikTex 2.9.  I get one warning message after compilation, which reads Package Biblatex Warning: Using fall-back BibTeX(8) backend. I did some online search on that too, as it seems related to the problem, but haven't found anything helpful. Not specifieing a backend does not generate a bibliography at all.  I hope this doesn't turn out to be a stupid newbie mistake, but could very well be. Any help is greatly appreciated.


The plus operator is not center aligned. Please help.


&& and ; chaining commands: does C get executed in A && B ; C if B returns a non-zero exit status?

A && B ; C    A returns an exit status of zero. B returns a non-zero exit status. C, if performed, returns an exit status of zero.   Then, which of the following two will happen (A is taken for granted to be performed in either case):   Bash will perform B and C Bash will perform B but not C   As an extension to this question, how would we modify the chain to allow for the behaviour of the alternative (1 or 2)?  Edit:    I'm not asking about the meaning of && versus ; .  I know A and B gets executed regardless. The remaining scenario is either C are ignored, because B returned non-zero exit status, or B is skipped over and C is re-evaluated on its own merit.


Read all files in a folder and also the filenames in python?

How to read all files and also the filenames? I am using MAC so is there any there a different way to give path on MAC in Python?


Is there an Oracle equivalent to MS SQL's full text search service?  If so, has anyone implemented it and had good / bad experiences?


Renaming mutliple files in one shot - what's wrong with that command?

I have multiple files in a directory:  $ ls -1 04PD.001 04PD.002 04PD.003 04PD.004 04PD.005   Now I'd like to change the name of each file to something like 04PD.7z.0*  Can someone tell me what's wrong with that command:  $ find 04PD* -type f -print -exec mv \{\} `echo \{\} | sed "s/04PD\.0/04PD\.7z\.0/"` \;   The result is utmost strange:  $ find 04PD* -type f -print -exec mv \{\} `echo \{\} | sed "s/04PD\.0/04PD\.7z\.0/"` \; 04PD.001 mv: '04PD.001' and '04PD.001' are the same file 04PD.002 mv: '04PD.002' and '04PD.002' are the same file 04PD.003 mv: '04PD.003' and '04PD.003' are the same file 04PD.004 mv: '04PD.004' and '04PD.004' are the same file 04PD.005 mv: '04PD.005' and '04PD.005' are the same file    To test the command I changed the command to simple echo:  $ find Pop*04PD* -type f -print -exec echo mv \{\} `echo \{\} | sed "s/04PD\.0/04PD\.7z\.0/"` \; 04PD.001 mv 04PD.001 04PD.001 04PD.002 mv 04PD.002 04PD.002 04PD.003 mv 04PD.003 04PD.003 04PD.004 mv 04PD.004 04PD.004 04PD.005 mv 04PD.005 04PD.005   Note: I've already found a very nice & simple solution with a loop, so please focus on what's wrong with this command, rather that proposing another solution.  I am pretty curious where the error is.


I am running a barbarian and fighter multiclass. When raging, I have resistance to all bludgeoning, piercing, and slashing damage. And the fighter Battle Master Maneuver Parry allows me to expend a superiority die to reduce damage. It is unclear in which order these would trigger. Rage halve it then Battle Master die lower it? Or Battle Master die then rage halve it? (I don't think this is stacking resistance since the Parry isn't resistance.)


Interesting behavior : LINQ query with integer

If I use any integer variable in a LINQ where clause, and after query execution if I modify / initialize the integer variable, then the result set of the LINQ query changes. For example:  static void Main(string[] args) {          int startPos = 0;                List<string> intList = new List<string>();      for (int i = 0; i < 10; i++)      {         intList.Add(i.ToString());      }       var qResult = from c in intList                    where Convert.ToInt32(c) >= startPos                    select c;       // prints count as 10      Console.WriteLine("List count is :"+qResult.Count());       startPos = 5;       // prints count as 5      Console.WriteLine("List count is :" + qResult.Count()); }   Output:  List count is :10 List count is :5   In above example you can see that after startPos = 5;, the qResult has changed. I don't understand how this has happened; as far as I know, int is value type.  Is the Linq query again executed at line startPos = 5;? If yes, then will it be a performance impact? And most importantly, am I missing anything here?


Summary for the impatient: I'm searching for good references on generating code for common language constructs but not parsing.  I am interested in programming languages and try to read the literature as much as possible. But most of them covers the topic in a functional and theoretical perspective that, I find them hard to understand let alone implement the ideas.  So the question is; Which resources do you suggest about programming language implementations that covers the topic in a more imperative and practical fashion?  For example, I find "The Implementation of Lua 5.0" paper very instructive.  Note that, I am not seeking articles about parsing or tokenizing.


How to update Mountain Lion 10.8 to Catalina OS?

I had Catalina OS on my Macbook, but I was needed to reinstall OS. So I make a restart hold Command + R (Mac utility was opened), so I erase all data and reinstall OS. But when I reinstall OS, there is was not choice which OS I would like to install and Mountain Lion 10.8 was installed.  Now, I would like to upgrade this OS version to Catalina like it was before...  But I can't, I get message from AppStore that I need to have 10.9 OS version or  later.   So, as far as I understand I need to install any intermediate OS version like El Captain or Mavericks and just than get update to Catalina, right?  But issue is, that Mavericks no longer supported by AppStore , but I found link to El Captain, but I also got a message that this version can't be installed...  What to do? How can I get update?  Feel free to ask


How to override the function's output .ToString() in c#

I have a function which return type is Object, when function return NULL, I am getting a object reference not set error. If I Use .ToString(). So how do I override the .ToString() to return empty when it returns null??


Does the engine provide the lift of the aircraft?

In the absence of the effect of natural wind, a stationary aircraft will not move without the thrust of the engine, there will be no velocity without movement, and there will be no lift without velocity. So, in this case, the engine provides the lift of the aircraft. Am I correct?    The wing has an angle of attack, so although the engine pushes the aircraft horizontally, it still produces upward force. It's like pushing an object horizontally on an inclined plane.  Gliders are powered by gravity, so in this case, gravity is the engine. So basically, the engine provides the lift of the aircraft.  A glider needs initial velocity to fly. How does this initial velocity come from? How can there be lift without this initial velocity? How can there be lift without initial velocity?


How to avoid tripping over UTF-8 BOM when reading files

I'm consuming a data feed that has recently added a Unicode BOM header (U+FEFF), and my rake task is now messed up by it.  I can skip the first 3 bytes with file.gets[3..-1] but is there a more elegant way to read files in Ruby which can handle this correctly, whether a BOM is present or not?


Is there a term for adjectives / modifiers that don't, at face value, seem to apply to the noun modified?

There's a verse in Bob Seger's song Mainstreet that has this wonderful little seemingly-nonsensical word pairing:     There was this long, lovely dancer in a little club downtown;    I loved to watch her do her stuff.    Through the long, lonely nights she filled my sleep,    her body softly swaying to that smoky beat.   On face-value, the word "smoky" to describe a "beat" just doesn't make sense; smoky isn't really a quality that a [musical] beat can have. And yet, the the words do make sense together and evoke a clearer (err, smokier) image of the nightclub.  Is there a term for this literary device? Are there other examples that come to mind?


"For security reasons, framing is not allowed; click OK to remove the frames." on Imgur upload

Ok first, there's that lugubrious use of the semicolon; not necessary.  Second, I didn't open a frame!  You did!  Alls I tried to do is upload a 5MB animated .gif file via Imgur.    Looking further into this, Imgur actually posts an error when you upload an animated .gif larger than 2MB.    Go figure!


How do you refer to a hyponym that is the same word as the hypernym?

What word (or how do you phrase things) do you use when the ostensible word for the class is the same as the word for a subset of the class?  For example, in the United States, there are many brands of sugared, carbonated soft drink that one can buy: Coca-Cola (or Coke), Pepsi, RC Cola, Sprite, 7-Up, A&W or Mug Root Beer, etc). The first two are kinds of 'coke' or 'cola' (but no one says 'cola').  , one asks for any type of such drink as 'coke'. How does one then ask for the particular kind of 'coke' that is 'Coke' (pronounced the same)? Does one reduplicate and say a 'Coke coke', does one repeat with emphasis (or without), does one use a different word like 'coca-cola' (co-cola), or what?  The (perceived) difficulty (surely those in the South are able to get the drink they want somehow) isn't limited to there. Where the drink is called 'soda', if you ask for a 'coke', you'll still sometimes have the choice among Coca-Cola, Pepsi, etc. "Can I have a Coke?" the response might be "Is Pepsi OK?". "Sure, Pepsi, Coke, whatever." You don't use 'cola', you just ask for the particular kind and hope the listener will help differentiate.   Given these multiple strategies for disambiguating, what do you do say to get a 'Coke' in the southern US? are there any other examples of a hypernym being the same as the hyponym, and so creating a disambiguation problem?


If two internal products are isomorphic and one of each are isomorphic then the others are isomorphic

I want to show that for abelian finite group $A$, $A = G \oplus H \simeq G' \oplus H'$ and $G \simeq G'$ then $H \simeq H'$. I found the proof : I defined $K=G\cap H'$ and $K' = G' \cap H$, and I showed that if $K$ or $K' $ is zero group then it is proved hence assumed $K$ and $K'$ nonzero. Now I want to use induction on $|G|$, so I need to prove $H \oplus G/K \oplus G'/K'$ is isomorphic to $H' \oplus G/K \oplus G'/K'$. Now by some calculation I found that I need to prove only $H'/K \oplus G' \oplus G'/K' \simeq H/K' \oplus G \oplus G/K$. And I stuck. Since $G$ is isomorphic to $G'$ the only left one is other two terms aand i'm guessing it's simple too, but I'm not sure how to prove it. What am I missing?


Let's say we have the expression $a^b \mkern-10mu\mod\! c$ and $b$ is really large, e.g. $37^{165}\mkern-10mu\mod 65$.  How to work this out by hand?  There's a way to avoid the large exponent.


From the book : English Grammar and Exercises by L. R. H. Chapman, book 4:  "must is a defective verb, with only this one part, which is used to speak about the present time or a near future, as in these sentences: I must answer this letter at once; I must get up early tomorrow."  But then it is used in the both following examples with the past tense.  I really don't understand. Could you explain, please?  "After dinner Mr. Drew told the girls that he must leave  the hotel for a few hours." (The Haunted Bridge by Carolyn Keene)  "The chimes of a clock warned Nancy that she must return  to the car to meet her father. "  (The Message in the Hollow Oak by Carolyn Keene)


Is there any go-to method for getting good exposure of both sky and land in landscape photography in broad daylight landscape photography?  I've noticed that in my dlsr and smart phone, I'm typically able to expose one or the other, but not both.  However, I feel like I've seen a number of images that have nice clouds, gradations of blue, along with pretty trees, nice fields, etc.  Are these done with multiple exposures? Or filters that reduce the brightness of the sky? Is there a go to method it is it catch as catch can?


How did Einstein generalise the Einstein elevator thought experiment to conclude with the equivalence principle?

Suppose a reference frame S1 is accelerated in the x direction with a constant acceleration g. A second frame S2 is at rest in a homogeneous gravitational field which imparts to all objects an acceleration −g in the x direction. Observationally there is no distinction in any respect between S1 and S2. All bodies are, to wit, equally accelerated in the gravitational field. By GENERALISING this mechanical equality, Einstein postulated the complete physical equivalence of a gravitational field and the corresponding acceleration of the reference frame. This is the so-called ‘equivalence principle’.  The first realisation of equality is from the Einstein Elevator thought experiment. Could someone please explain what grounds Einstein had to generalise his local observation to conclude with the equivalence principle.  Thank you.


I'm not looking for java-web-start, I'm looking for a thick-client application installation toolkit.  I've got a stand-alone application that consists of several files (jar files, data files, etc) and would need to do some pretty standard installation tasks, like asking the user for target directories, have them locate some parts of their system - choose some of the per-machine or per-user configuration options and possibly try to detect some of the machine settings for them.  I'm looking for something which is like the MSI or other wizard driven installation applications.  What's a good installer for Java?  It would be ideal if it were cross-platform capable (Linux, Mac OSX and Windows).


Height and minimal number of generators of an ideal

How can I determine the height and the least number of generators of the ideal $ I=(xz-y^2,x^3-yz,z^2-x^2y) \subset K[x,y,z] $?      I tried to calculate the dimension of the vector space $I/I\mathfrak m$ with $\mathfrak m=(x,y,z)$, but I'm not able to find it.  I think the height is $2$, because the affine variety should be a curve, and also I know that the ideal is prime, so I need a chain $0\subset \mathfrak p \subset I$. Maybe $(xz-y^2)?$ Is it prime?


Check all domains served by a DNS server

Is there any way to query a dns server to find out all the domains it is the authoritative server? [all domains it has configured?]  (I can use dig or any other tool)


I have 2 continuous variables as my predictors and the interaction between them, so 3 effects all together (when I center my predictors only the interaction is significant). I am using a binary logit model except where I have fixed the value of the number of trials at 20, for my dependent variable. My problem has to do with further understanding the nature of the interaction. I know that in generalized linear models the interaction is more complex compared to the linear model because of the link function. I have read that interpreting the sign of the parameter estimates is very limited, so I am trying to find a way to further understand the interaction, and graphing it would be nice as well. Unfortunately, I only have SPSS at my disposal. Jeff Gill () wrote about a method called first differences which seems very similar to the inteff command in stata. If anybody could tell me how to how to further understand and test the interaction in a generalized linear model using spss or hand calculations I would be eternally grateful.


What gear do I need for Portrait and Landscape photography, Canon 700D?

From several years ago I bought Canon 700D, due to some acts in my country I lost the interest in photography. Now I am having the comfortable environment to start all over. My question is: What simple gear do I need to practice Portrait and Landscape photography?  I am not planning to make money out of it, so please keep the recommendations simple.


sudo freshclam not working: ERROR: Can't open /var/log/clamav/freshclam.log in append mode (check permissions!)

If I comment out the UpdateLogFile line from /etc/clamav/freshclam.conf like so... \#UpdateLogFile /var/log/clamav/freshclam.log  ...then I am able to run sudo freshclam no problem: /etc/clamav$ sudo freshclam ClamAV update process started at Mon Feb  6 00:17:07 2017 main.cvd is up to date (version: 57, sigs: 4218790, f-level: 60, builder: amishhammer) daily.cld is up to date (version: 23009, sigs: 1509149, f-level: 63, builder: neo) bytecode.cld is up to date (version: 290, sigs: 55, f-level: 63, builder: neo)  However, if I uncomment the UpdateLogFile line in freshclam.conf and run sudo freshclam, I get this: /etc/clamav$ sudo freshclam  ERROR: Can't open /var/log/clamav/freshclam.log in append mode (check permissions!). ERROR: Problem with internal logger (UpdateLogFile = /var/log/clamav/freshclam.log).  Here are the permissions on /var/log: drwxrwxrwx  1 root root     9 Feb  3  2016 log  Here are the permissions on /var/log/clamav: drwxr-xr-x  2 clamav    clamav    4096 Feb  5 22:18 clamav  And here are the permissions on /var/log/clamav/freshclam.log: -rw-r-----  1 clamav adm       0 Feb  5 22:18 freshclam.log  I spent all day trying solutions mentioned in various forums with no luck. Here is the version of Ubuntu server I am running: Description:    Ubuntu 14.04.5 LTS  And the engine version of clamav: Engine version: 0.99.2  Could someone help me? Stopping the clamav-daemon does not help: /var/log$ sudo /etc/init.d/clamav-daemon stop   * Stopping ClamAV daemon clamd         [ OK ]  /var/log$ sudo freshclam ERROR: Can't open /var/log/clamav/freshclam.log in append mode (check permissions!). ERROR: Problem with internal logger (UpdateLogFile = /var/log/clamav/freshclam.log).  The output of sudo lsof | grep clam is nothing: /var/log$ sudo lsof | grep clam /var/log$  It appears that nothing has a lock on /var/log/clamav/freshclam.log Here is the output of sudo service --status-all | grep clamav, not including the lines that had question marks and were unrelated to clamav: $ sudo service --status-all | grep clamav  [ - ] clamav-daemon [ - ] clamav-freshclam $  Same Can't open /var/log/clamav/freshclam.log in append mode (check permissions!) error when I try to run clamav-daemon: $ sudo service clamav-daemon start  * Starting ClamAV daemon clamd ERROR: Can't open /var/log/clamav/clamav.log in append mode (check permissions!). ERROR: Can't initialize the internal logger $  UPDATE: purging and reinstalling clamav, clamav-freshclam and clamav-daemon did not resolve the issue. I still get the same error: $ sudo freshclam ERROR: Can't open /var/log/clamav/freshclam.log in append mode (check permissions!). ERROR: Problem with internal logger (UpdateLogFile = /var/log/clamav/freshclam.log). $  UPDATE 2: I did a sudo reboot, stopped clamav-freshclam, made sure sudo lsof | grep clam returned nothing and that the output of sudo service --status-all | grep clamav still only had minus symbols next to clamav and clamav-daemon. Ran sudo freshclam again, and same error as above (again).


Prove $\frac{\ln x}{x-1} \leq \frac{1}{\sqrt{x}}$ using derivatives

$$\frac{\ln x}{x-1} \leq \frac{1}{\sqrt{x}} \qquad x > 0,\ x \neq 1$$  From here we have that   $$0 \leq x-1-\sqrt{x}\ln x$$  So I was trying to prove that $f(x) = x-1-\sqrt{x}\ln x\ \geq\ 0,\ \forall \ x > 0,\ x \neq 1$.  By finding the first derivative we have  $$f'(x) = 1 - \frac{\ln \sqrt{x}}{\sqrt{x}} - \frac{1}{\sqrt{x}}$$  and the second  $$f''(x) = \frac{\ln x}{4x^{3/2}}$$  By analyzing both derivatives we see that in the interval $(0,1),\ f' > 0$. It reaches its minimum at $x = 1$ (not in the domain of the function) and, since $f'' > 0$ for $x > 1$, we have that $f' > 0$ for any value of $x$ in the domain, which in turn means that f is an strictly increasing function.  But, how can I show that $f \geq 0$ in the first place?  I haven't been able to do that. I graphed $f(x)$ and get that $f$ is indeed negative for values of $x$ near zero, so I don't know what to do.


Ubuntu 14.04 installation doesn't recognize Windows 8.1 partition

I have tried installing Ubuntu 14.04 64-bit alongside Windows 8.1 64-bit for several hours, but i can't seem to find the solution to actually installing it without removing my Windows 8.1 from the hard drive. The problem is that Ubuntu doesn't seem to recognize my Windows 8.1 on the hard drive and it show the whole hard drive as it is empty.  I have both tried installing it with CD and USB-drive. The outcome is still the same.  Some pictures:       GParted error message :     Some notations: 1) My Windows 8.1 seems to be operating on Legacy BIOS mode, because when i last checked 'Disk Management' it showed no sign of EFI System Partition.  2) With both CD boot (with WUBI the same) and USB-drive boot i get a black screen with an error saying 'could not open "\EFI\BOOT\fallback.efi": 14' before getting the menu options choosing if i want to try or install ubuntu. But i can still continue the procedure.  3) I have tried making partitions inside Windows with 'Disk Management' tool, partitions still don't show up.


Autodesk Maya symbol lookup error on start after installing AMD proprietary driver on Ubuntu 18.04

I've installed Maya 2018 on Ubuntu 18.04 and tested it with the amdgpu driver (open source) and it launched without problems, but some components were not working with the open source driver so I tried amd gpu pro 18.20 (amd closed-source driver). I ran  ./amdgpu-pro-install   but since then Maya won't work and gives this warning message:  ./maya.bin: symbol lookup error: /usr/autodesk/maya2018/bin/.. /lib/libOGSDeviceOGL4-16.so: undefined symbol: EVP_CIPHER_CTX_init   My card is hd7770 and it's supported by the amd closed driver, so what am I doing wrong?


Normalization of the overlap $\langle x'|p'\rangle$

Let $$\langle x'|p'\rangle = N \exp(\frac{ip'x'}{\hbar})$$ be the overlap between position and momentum space, where $N$ is a normalization constant to be determined.  We can then compute $N$ by  $$ \langle x'|x''\rangle = \int \mathrm{d}p'\langle x'|p'\rangle \langle p'|x''\rangle\\ \rightarrow \delta(x'-x'')=|N|^2 \int \mathrm{d}p'\exp(\frac{ip'(x'-x'')}{\hbar}) \\ =2\pi\hbar |N|^2 \delta(x'-x'') $$  see Sakurai - "Modern Quantum Mechanics" 2nd, Pearson, p. 54.  How was the factor $2\pi\hbar$ obtained? The intermediate step should look something like this: $$ \rightarrow  \delta(x'-x'')=|N|^2 \int \mathrm{d}p'\exp(\frac{ip'(x'-x'')}{\hbar}) \\ =|N|^2 \int \mathrm{d}p'\delta(x'-x'') $$  But all I can think of is that one can say $\int \mathrm{d}p'=\hbar k$ where $k$ is the wavenumber.   What am I missing?


How to dock a window to an inside edge of a dual-monitor setup without a Windows key?

I have read  about how to use the Windows key and the left/right arrow to dock a window against the right or left side of your screen.   My question is how does one perform that command with a keyboard that does not have a Windows key?


how I can fix "AppStream cache update completed, but some metadata was ignored due to errors."?"

I executed apt update as root, but I received this error message: AppStream cache update completed, but some metadata was ignored due to errors. I have found this link that offer a solution editing this config file: /usr/share/app-info/xmls/org.freedesktop.fwupd.xml. But I have opened this and I found that I have the same code as solution.  Can I update my packages with this issue? EDIT: Full log from shell:  Des:1 http://security.ubuntu.com/ubuntu xenial-security InRelease [102 kB] Obj:2 http://es.archive.ubuntu.com/ubuntu xenial InRelease   Des:3 http://es.archive.ubuntu.com/ubuntu xenial-updates InRelease [102 kB]     Des:4 http://security.ubuntu.com/ubuntu xenial-security/main amd64 DEP-11 Metadata [67,0 kB] Des:5 http://es.archive.ubuntu.com/ubuntu xenial-backports InRelease [102 kB]   Des:6 http://security.ubuntu.com/ubuntu xenial-security/main DEP-11 64x64 Icons [38,3 kB] Des:7 http://security.ubuntu.com/ubuntu xenial-security/universe amd64 DEP-11 Metadata [19,4 kB] Des:8 http://security.ubuntu.com/ubuntu xenial-security/universe DEP-11 64x64 Icons [25,6 kB] Des:9 http://security.ubuntu.com/ubuntu xenial-security/multiverse amd64 DEP-11 Metadata [212 B] Des:10 http://es.archive.ubuntu.com/ubuntu xenial-updates/main amd64 DEP-11 Metadata [293 kB] Des:11 http://es.archive.ubuntu.com/ubuntu xenial-updates/main DEP-11 64x64 Icons [182 kB] Des:12 http://es.archive.ubuntu.com/ubuntu xenial-updates/universe amd64 DEP-11 Metadata [119 kB] Des:13 http://es.archive.ubuntu.com/ubuntu xenial-updates/universe DEP-11 64x64 Icons [132 kB] Des:14 http://es.archive.ubuntu.com/ubuntu xenial-updates/multiverse amd64 DEP-11 Metadata [2.520 B] Des:15 http://es.archive.ubuntu.com/ubuntu xenial-backports/main amd64 DEP-11 Metadata [208 B] Des:16 http://es.archive.ubuntu.com/ubuntu xenial-backports/universe amd64 DEP-11 Metadata [212 B] Des:17 http://es.archive.ubuntu.com/ubuntu xenial-backports/multiverse amd64 DEP-11 Metadata [212 B] Descargados 1.186 kB en 1s (851 kB/s)                         AppStream cache update completed, but some metadata was ignored due to errors. Leyendo lista de paquetes... Hecho Creando árbol de dependencias        Leyendo la información de estado... Hecho Todos los paquetes están actualizados.


How to remove the tiny invisible TikZ picture frame?

Consider this example:  \documentclass{article} \usepackage{tikz} \usepackage[showframe]{geometry} \usepackage{lipsum} \begin{document} \lipsum[1]  \noindent\begin{tikzpicture} \draw (0,0)--(\linewidth,0); \end{tikzpicture} \end{document}   It gets a warning   Overfull \hbox (0.4pt too wide) in paragraph at lines 8--11    On my viewer, I can't even see the "too wide" part    Of course, it is very difficult to see it, because it is only 0.4pt! However, I don't like having such warnings pop-up, so how to make sure that the line perfectly fits the margin, i.e. set the "inner sep" of the "node" TikZ picture to exactly 0pt?  I know I can use \rule, etc. for this, but I have to draw something more in TikZ, so I use TikZ in the whole picture.  Thank you in advance!  Bonus question: You can see that I am using \noindent. Without modifications to \parindent, are there any better ways to do that?


I'm taking my first crack at  with jQuery. I'm getting my data onto my page, but I'm having some trouble with the JSON data that is returned for Date data types. Basically, I'm getting a string back that looks like this:  /Date(1224043200000)/   From someone totally new to JSON - How do I format this to a short date format? Should this be handled somewhere in the jQuery code? I've tried the jQuery.UI.datepicker plugin using $.datepicker.formatDate() without any success.  FYI: Here's the solution I came up with using a combination of the answers here:  function getMismatch(id) {   $.getJSON("Main.aspx?Callback=GetMismatch",     { MismatchId: id },      function (result) {       $("#AuthMerchId").text(result.AuthorizationMerchantId);       $("#SttlMerchId").text(result.SettlementMerchantId);       $("#CreateDate").text(formatJSONDate(Date(result.AppendDts)));       $("#ExpireDate").text(formatJSONDate(Date(result.ExpiresDts)));       $("#LastUpdate").text(formatJSONDate(Date(result.LastUpdateDts)));       $("#LastUpdatedBy").text(result.LastUpdateNt);       $("#ProcessIn").text(result.ProcessIn);     }   );    return false; }  function formatJSONDate(jsonDate) {   var newDate = dateFormat(jsonDate, "mm/dd/yyyy");   return newDate; }   This solution got my object from the callback method and displayed the dates on the page properly using the date format library.


Why doesn't my keyboard work when the computer is booting? I can enter BIOS and change the settings, but when the system is booting it doesn't work at all! This is not a new problem, but I now want to install Ubuntu alongside Windows, but what if GRUB doesn't work and will always boot into Ubuntu? I have tried to put the USB keyboard in the other slots including those on the front.


How to restrict access to applications in Big Sur?

How do I put FaceTime in a folder and assign a password to the folder? The aim is not to have access to the apps without password. I actually want to restrict access to minimize distraction ( tv app, FaceTime, App Store) and I was able to do that without any problem in Catalina, but with Big Sur it's another story. I have already tried using screen time but I don't think parental control is the solution to my problem as I want to use the Mac for academic use.  I wanted to prevent myself from being distract by them, but still use safari without any problem. I actually did try activating screen time, but it's not effective (as I explained in screen time, we aren't able to to activate "Downtime limitations" and "limits apps" but still use Safari) so I'm looking for solutions.


Upgrading to Ubuntu 13.04 with live USB on dual boot system

I have dual boot Win7/Ubuntu 12.10. I have a 13.04 live USB. How can I upgrade the 12.10 install from the live USB?  I read previous questions here that answer this question - they all say that the upgrade option comes up when you hit install. In my case, the options that come up are "Install Ubuntu alongside other OSes", fresh install, and "something else". I tried the first and last of those options, and neither of them showed any option for upgrades.


Computing the square root function with Newton's method

Show that Newton's method can be used to compute the square root function $\sqrt a$ using the formula   $$x_{n+1} = \frac{1}{2}\left(x_{n} + \frac{a}{x_{n}}\right)$$  show that the error is  $$\sqrt a - x_{n+1} = -\frac{1}{2x_{n}}\left(\sqrt a - x_{n}\right)^2$$  edit: As pointed out below $x^2-a$ has $\sqrt a$ as a root.  I have done as suggested below and plugged in $\sqrt a + \epsilon$ for $x_n$ giving me  $$x_{n+1} = \frac{2\epsilon\sqrt a + \epsilon^2}{2(\sqrt a + \epsilon)}$$ and once again not sure where to proceed.


I was learning about the relationship between the prime factors of a number and I came across this way to find the number of factors of a number. It goes like this if the prime factorization of a number $x= P_1^{L_1}  P_2^{L_2}  P_3^{L_3} \ldots$ then its number of factors is $(L_1 + 1)(L_2 + 1)(L_3 +1) \ldots$. My question is can someone find a proof of this?


Let $A$ be a commutative ring and $S$ a multiplicative closed subset of $A$. If $A$ is a PID, show that $S^{-1}A$ is a PID.   I've taken an ideal $I$ of $S^{-1}A$ and I've tried to see that is generated by one element; the ideal $I$ has the form $S^{-1}J$ with $J$ an ideal of $A$. $J$ is generated by one element but I can't see why $I$ has to be generated by one element, maybe I'm wrong.


After installing the app , when I open app and give email and password as input, app closes in android

I am trying to login the user through networking by using OkHttp library to send request and getting response. After running these when I open app and enter email and password as input and press the login button, my app crashes.  LoginFragment:   public void onClick(View view) {             String a=ed1.getText().toString();             String b=ed2.getText().toString();             Log.e("sas", "onClick: "+a );                 NetworkRequestAndResponse asyncTask = new NetworkRequestAndResponse(getActivity());                 asyncTask.execute(a,b);         }     });     return view;   AsyncTask:      public class NetworkRequestAndResponse extends AsyncTask<String,String,String> {     Context context;      public NetworkRequestAndResponse(Context context){         this.context = context.getApplicationContext();     }      @Override     protected String doInBackground(String... params) {         OkHttpClient okHttpClient = new OkHttpClient();         RequestBody requestBody= new FormBody.Builder().add("email",params[0])                         .add("password",params[1]).build();         Request request = new Request.Builder().url("http://192.168.1.8:8011/api/check")                         .post(requestBody).build();         Log.e("asd", "doInBackground: "+request );         Response response=null;         try {             response = okHttpClient.newCall(request).execute();           return response.body().string();         } catch (RuntimeException|IOException e){             Log.e("455", "doInBackground: ",e );         }         finally {             response.close();         }         return null;      }      @Override     protected void onPostExecute(String obj){          if (obj.equals("true")){             Intent intent = new Intent(context, WelcomeActivity.class);             context.startActivity(intent);         }else{             Toast.makeText(context,"Invalid Email or Password",Toast.LENGTH_SHORT).show();         }     } }   MainActivity:      protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.activity_main);     android.support.v4.app.FragmentManager fragmentManager = getSupportFragmentManager();     LoginFragment obj = new LoginFragment();     fragmentManager.beginTransaction().add(R.id.content,obj).commit();     MessagesFragment messagesFragment = new MessagesFragment(); } }   Error:


Difference between (function(){})(); and function(){}();

Possible Duplicate:          This is something I haven't quite figured out yet, but I have been using function(){}() just because my VIM syntax highlight screws up if I add the parenthesis, although I've seen (function(){})() around many times, maybe its an IE thing?  edit:  var singleton = function() {     // code }();  var singleton = (function() {     // code })();


Hi i have been having trouble figuring out what is wrong with this code. I am attempting to make a Tic-Tac-Toe game where you can choose the size of the square but each time i try it the game puts an x down the column i chose. Some parts of the code have been cut out because I've checked if they are the problem already, so there may be some useless variables at the beginning of the code.  edit: The variables aren't actually useless in the full code but they are in the chunk that has the problem  x=int(input('How big would you like the square to be (eg if you put 4 the board will be 4X4)? '))-1 fboard=[] for counter in range(x+1):     fboard.append('-') board=[] for counter in range(x+1):     board.append(fboard) print('Welcome to Gay Als SUPER noughts and crosses adventure!') gameOver=False Player=1 gameOverValidation=0 while gameOver==False:     Row=False     Column=False     valid=False     if Player%2!=0:         currentPlayer='x'     else:         currentPlayer='o'     print('Player',currentPlayer,'Is up next')     for row in range(x+1):         for column in range(x+1):             print(board[row][column],end=' ')         print()     while valid==False:         Row=False         while Row==False:             newRow=int(input('Which row would YOU like to put your piece in ,darling? '))             if newRow>(x+1) or newRow<1:                 print ("Invalid value. mmmmaybe come to GAY AL's cove of WONDERS!")             else:                 Row=True         Column=False         while Column==False:             newColumn=int(input('Mmmkay, interesting. The column por favor? '))             if newColumn>(x+1) or newColumn<1:                 print('GOD DAMN STUPID **** **** ***** **** **** THAT IS NOT VALID!')             else:                 Column=True         if board[newRow-1][newColumn-1]!='-':             print('Umm, that space is taken already, babe.')         else:             valid=True     board[newRow-1][newColumn-1]=currentPlayer   (then there are loops to figure out if the game has been won yet)  Player+=1


i'm a linux noob and just installed ubuntu.  I'm really enjoying it, so far. But the ram usage is quite high i think? The system is using 3,1gb ram while i'm just browsing the internet. is this normal? What can i do to lower it?


Let $(E,\leq)$ a partially ordered set. Zorn lemma says that if all chain of $E$ has a supremum, then $E$ has a maximal element.   So if I consider, $\Big((0,1),\leq \Big)$, it has no maximal element but all chain is upper bounded by $1$, so it doesn't work here, no ?


I am loading a listBox full of strings from a string array with a foreach statement. The strings say "Level 1" through "Level 20" and eventually further. It orders them as Level 1, Level 11, Level 12, Level 13, etc, skipping level 2, 3, 4 etc.   How can I order this correctly?  I am about to remove "Level " so it is just the numbers in the array then add them to the listBox with "Level " added. But performance is an issue with this WPF page and this may not be the best performance way.   Thanks.