i have htc wildfire 3  i can not scan qr code for whatsApp web  i see the "OK, got it" button , no problem with that  but it seems camera keep scanning but not getting anything any idea how to fix that ? every thing is updated already


How do I copy same files with a particular extension to another directory in terminal

I want to copy all my .png file to particular directory by using:  cp ...../*.png $pwd      but it seemed not working.


Are the red ports below eSATAp that can power a 3.5'' HDD?    I saw  about 12V eSATAp and I would guess that they are. However I have a cable like this:    which claims to support 3.5'' drives on 12V, but the disk does not even start spinning. I'm trying to understand if the cable is faulty or the port is not the one I think it is (the disk works fine, by the way).


How do I make the following subscript centred below the text?  $$\text{argmin}_{x,y,z,b}$$   As this one does automatically?  $$\Pr_{x,y,z,b}$$


Euler gave the most concise (I think so) connection between $e,\,i$ and $\pi$ (called Euler's identity), which states: $$e^{\pi i}+1=0$$ I would like to see some proofs of this. You can mention (I mean, give link to the webpage or article) as many as proof as you can. What I want to ask is, give alternatives to Euler's proof (which used Taylor series).


What happens if a Sha 256 input is too long?

Doesn't SHA-256 only take up to 512 bits for the input block? What happens if the input is really long?


The CellValueFactory throws a NullPointetrException (NPE) everytime the method is called from the GUI.   I read Data from an embedded Derby DB and turn it into a TableView - at least that's the goal. I already caught the NPE and the console gives the following output:  Cause: null  Message: null   StackTrace: [Ljava.lang.StackTraceElement;@79daf03c  I also checked the StringPropertys and they're not zero. Here's one, but I checked them for every row:  StringProperty [value: 170]StringProperty [value: Höhlenkrieger]StringProperty [value: null]      @FXML     // liegt auf test2, muss auf Optionen!      private void ladeTabelle() {      try {         SQLConnection.createDatabaseConnection("test35");          //Zeile 63 ist das Problem!         subfactionCol.setCellValueFactory(cellData                 -> cellData.getValue().subfactionProperty());         nameCol.setCellValueFactory(cellData                 -> cellData.getValue().nameProperty());         pointValCol.setCellValueFactory(cellData                 -> cellData.getValue().pointvalueProperty());     }// end initialize()      catch (NullPointerException npe) {         System.out.println("Cause: " + npe.getCause()     + "\t Message:   "+npe.getMessage()         + "\t StackTrace: " + npe.getStackTrace()         );     } }   And the code that produces the StringProperties          StatCard sC = new StatCard(name, faction, subfaction, unit_type, number_of_elements,                     pointvalue, units_in_collection, movementPoints, movemntOrderH, movemntOrderS,                     movemntOrderA, movemntOrderH, maneuvers, initiative, skillMelee, skillRange,                     attack1Name, attack1, attack2Name, attack2, attackMissileName, attackMissileRangeShort,                     attackMissileRangeLong, attack_bonus, overrun, size, armor_melee, armorRange, hitpoints,                     fear, moraleBreak, moraleRage, banner, musician, artilleryType, ballistic_range_short,                     ballistic_range_medium, ballistic_range_long, magic_points, commandPoints, controlArea,                     commandstars, special_rules);               SQLdataList.add(sC);         }     } catch (ClassNotFoundException | SQLException e) {         System.out.println("Fehler! exception. Cause: " + e.getCause() + "\n" + "\n"                 + "Message ist: " + e.getMessage());     }      SQLdataList_observable = FXCollections.observableArrayList(SQLdataList);      for (StatCard sC : SQLdataList_observable)      {          System.out.println(sC.pointvalueProperty().toString()                  + sC.nameProperty().toString()                  + sC.subfactionProperty().toString());     }   The StringPorperties are in the class StatCard:  public SimpleStringProperty subfactionProperty()  {     return new SimpleStringProperty(subfaction); }          public SimpleStringProperty nameProperty()  {     return new SimpleStringProperty(name); }  public SimpleStringProperty pointvalueProperty()  {     return new  SimpleStringProperty(Integer.toString(pointvalue)); }   I already googled the problem extensively, but so far I could not find a solution. I cannot figure out why the cellFactory gives zero, eben so the StringProperties are not.  Any ideas what I could try?


C# - Multi Values of an input string using Regex

I Have an input  text  :   string DefaultInput = "Name : John | FamilyName : Doe |";   I Want to be able to Extract the "John" & "Doe" and maybe other values from 1 input using Regex  My Code :   Match m = Regex.Match(DefaultInput,"Name : (.*?) | FamilyName : (.*?) |"); this.textBox1.Text = "ProfileName : " + m.Groups[1].Value + "\r\nProfileFamilyName : " + m.Groups[2].Value;


Prove that $390\mid n^{13}-n$ for all $n\in\mathbb Z$   Attempt:  $$390=2\times3\times5\times13$$  Fermat theorem: $a^p\equiv a\pmod p$, here:  $$n^{13}\equiv n \pmod{13}$$  So $\color{red}{13}\mid n^{13}-n$ but what can I say about $\color{red}{390}$?


I have a mobi file, and want to convert it to a pdf file. I tried several online conversion websites, but couldn't convert it. Can you help me? Thanks! Here is  to the mobi file.


Im attempting to create a function that when called it will create as many files as the value of a parameter given. For instance, if I call it :  ejercicio_VI file 4   It will create file1 and file2 and file3 and so on...  This obviously works manually but it seems it does not work correctly within a function.  Why is my function not expanding the filenames correctly?  ejercicio_VI() {     if [[ $# -ne 2 ]]     then         echo "Esta funcion solo acepta dos parametros"         return 255;     fi      if [[ ! $1 =~ ^[a-zA-Z]+$ ]]     then         echo "El primer parametro debe ser una string que matchee con esta expresion regular : ^[a-zA-Z]+$"         echo "Asi no creamos archivos basura :P "         return 255;     fi     if [[ ! $2 =~ ^[1-9]([1-9])?+$ ]]     then         echo "El segundo parametro debe ser un numero"         return 255;     fi      touch "$1"{1.."$2"}   }


Should accusations of plagiarism be allowed as baseless and easy way to put veto?

- this wiki was totally empty. Neither the excerpt nor the body had a letter. So I devised both.       And was accused of plagiarism "just because". There obviously is no "prior art" that i supposedly just copypasted, as I typed it from my head.  I am not speaking of the overall quality of the edit and whether it is worse than nothing - that is for another question, this one is strictly about plagiarism  That is bad because:   That is an insult. It is not good when people may insult others just because they felt like it. Person being accused should have a way to ask accuser to at least substantiate his claim or revoke it.  "Plagiarism" here works as a cheap way to put veto without thinking of reasons and at the same time prohibiting other reviewers from doing more thoughtful evaluation. If the baseless insult is a community-approved way, then that would discourage any attempt to compose an genuine text or make edits at all. It just feels as being suddenly raided by trolls that can not be argued with (and there really is no way at Stack Exchange to argue). So next time why risk it?   I think that piracy and plagiarism are rather strong insults and must not go without the substantiation, just because it was a lazy way to press buttons.  If a person wants to reject some contribution for reasons like plagiarism or license violation, I think it should be mandatory that Stack Exchange site requests him to back his claim and explicitly name what the pirated/plagiarized source was.   It is not matter of taste or habit - it is a public accusation of crime or dishonesty on their part. Just because it felt easy lazy way to press "no" is not enough to commit insults.    If a person is sure about his claim that that act had taken place - it would be easy to him to show the original source and/or original license and key in few words.  If he does not bother to spend few seconds in Google, then he does not has standing to make accusations like plagiarism/piracy.   PS. There is an answer suggesting that the reason of rejections just does not matter and it is normal when it is selected at random. If so - then there should not be insulting reasons. Accusations of piracy/plagiarism should be just removed from the list of canned responses then, if it is okay to throw a dice when rejecting.


Create a file that's treated like a btrfs file system

I want to do a few experiments on the btrfs file system, but I don't want to make any changes to my existing partitions, and I want full control over things like device size.  Is it possible to create a file that looks like a block device that I can mount and unmount, and that will act like a block device such as running out of space?


Get which Fields are selected in the SOQL Query as query is executed using Database.query method

I need to fetch data on basis of some conditions, each condition have different set of fields to be fetched from the same object. and those fields are to be displayed on  in vf page.   Insted of writing if-elseif-else tree for various selections, i stored all related queries in a map and i will use Database.query() for executing the queries.  Now when one of those queries will be executed, i want to figure out which fields are selected in the query executed.


I know that the minus sign of -r, where r is real, can never be moved under a radical sign. But there are no minus signs present when the sqrt of $i^4$ is taken in the following manner  $1 = i^4$  $\sqrt{1} = \sqrt{i^4}$  $+/-1  =  +/-i^2$  $+/-1  =  -/+1$  I realize it might be argued that i also can never be moved under the radical sign.  But $\sqrt{i}$ does have an open form solution which is $+/-[(1+i)/\sqrt2]$.  Repeating the above calculation with this open form I find that the associative law of multiplication no longer holds and all sorts of contradictions ensue. It might also be argued that $i^4$ factors into -1 x -1 and therefore cannot be placed under the radical sign. But that is also true of any positive real number. Any ideas for a consistent solution to the above derivation?  Thanks.


I am working on a LaTeX file with many plots containing a lot of data points. I have a main.tex file that is including chapter files and inside these chapter files I include the files that contain the \begin{figure}\begin{tikzpicture}...\end{tikzpicture}\end{figure} and I am running into this error ! TeX capacity exceeded, sorry [main memory size=5000000]  I have read many posts about externalizing etc. but I don't know how to apply this method or to put it into other words it is too complicated for me. I simply want to increase my main memory such that I do not run into such problems.  I would be glad if someone could explain to me how I can increase my main memory. I am not looking for a solution with externalization because it is too complicated for me. I am running Texmaker 4.5 as Editor, Miktex 2.9 and Windows 7.  EDIT: What I have tried  Finding: texmf.cnf (could not find it using the hint by Alan Munn) Typing: "initexmf --edit-config-file=pdflatex" into the cmd. The pdflatex.ini file opend and I added the following to the file and saved and recompiled without success.   main_memory=9000000 extra_mem_bot=9000000 font_mem_size=9000000


The Apple Watch Activity app purports to measure what it calls "Active Calories" which it counts towards its "Move" goal. But Apple's definition of such calories is clearly its own, not counting (at least apparently), for example, calories from , Pilates, or yoga or 7-minute workouts?  What is the (Apple) definition of "Active Calories"? What does one have to do to generate them?


Lost on which book / guides to progress in c++

I'm trying to get into c++ but I'm struggling to find good learn material. Currenlty I'm using this free tutorial  but I want to know what books I can buy to go from here. They should be new and help me get the necessary knowledge to understand new features from c11, c14 and c17. Can anyone point me into a direction? Thanks in advance !   (I have sufficient knowledge in other languages and the basics of cpp)


If two groups $G,G^{'} $ of order $n$ are isomorphic?

If we have two groups $G,G^{'} $ of order $n$ and both have the same number of elements of a given order then are the two groups isomorphic?  I meant that if $o(G)=o(G^{'})=n$ and if $G$ has $p$  elements of order $m$ then $G^{'}$ has also $p$ elements of order $m$ and this holds for each $m\in \Bbb N$ , then are $G,G^{'} $ isomorphic?


How to get list of installed packages with installation date?

How can I output a list of all installed packages with installation date and additional information?


how to remove oil from mtb disk brake at home

My cycle has got an front disc brake I not know how but unfortunately few drops of oil got on my disc brake now it was making a very bad sound like a violen and and could even not able to stop my cycle at all now I have only one way to fix it,s you please help me


I know that there is a similar questions, but I think mine is a bit different. I wonder if with the expansion of the universe the speed of light changes. It seems that the speed of light is very connected to the space-time continuum, e.g. it follows all it's deformations etc. So if the space-time continuum expands, does the speed of light change?


How can the MSE of predictions be greater than the variance of the response variable?

I saw an example on a blog where a k nearest neighbors algorithm was run to predict responses on a test data set.The MSE(mean squared error) of the predictions was larger than the variance of the response variable in the test set. Shouldn't the MSE always be less than the variance of the response variable as SSTO(total sum of squares) = RSS(model sum of squares) + SSE(error sum of squares).


Do I need loans for a good credit score?

I've never required legal loans from banks/businesses (eg: home loan, car loan)   Will this affect my credit score if i've never been in debt but later on in life decide to get a loan?  Edit:  Also, Is it worth getting a loan for no reason to improve credit score?


Writing in the first column first when using multicol package

I'm using the multicol package to enable writing with 3 columns or more, however I realise that the default behaviour is to balance out the content of the page with the columns.   But this is not what I want, since what I want is to fill out the first column first, then the second, and so on.   Does anyone know how to enable this in multicol package? Or does anyone know any other packages that can enable this?


I need lock screen and autolocking, but want to never see awful gnome3 lock screen with arrows and clocks. I need just to see gdm login window with password prompt in all cases. How can I completely disable slider with clocks on it?


When I make a new .tex document, three other files are created as well, .pdf, .aux and .synctex. I want the .pdf file, but are the other two necessary, can I delete them? Can I tell latex to not create .aux and .synctex files?


The squirrel's riddle - how many marks on the tree trunk?

"How many marks can you find on its trunk?" - I assume one does not have to calculate, as the riddle might be about the tree the squirrel sit's on. I counted the visible "marks" several ways, none of them was correct. Which is?


'Alert whomever may read' - should it be 'whoever'?

I read this morning :     ... words which leap from the second verse and alert whomever may read the epistle ... to the fact that ...   I am not clear with what exactly is going on with 'alert whomever may read'. Is 'whomever' the grammatical object of 'alert' or is it the grammatical subject of 'may read' ? Or is it both ?  So should it be 'whoever' ?


Where can I find saved WiFi AP passwords?

I have a WiFi modem and somehow misplaced the password, but my phone is able to connect to it since the password is already save, but clicking on show password dosen't work. How can I find the password from my phone?


What algorithm does a package manager use to decide if a package is unused?

My question is NOT "how do I remove unused packages." The answers from other questions do not address my question explicitly  It's convenient that apt-get can find packages that are not in use and remove them to keep your system clean using sudo apt-get autoremove.   But what is its definition of "unused"?   Not accessed for a long time Newer version also installed (but what if I need both Java 7 and Java 8?)   I'd like to use it to clean up my Ubuntu installation but if it's speculative in some way or risks breaking shared libraries I'd rather live in the filth of my server as is.


The scrolling in chat in Chrome latest (v36) doesn't work, but works for other people using the same version of Chrome. It simply: never scrolls.  Fix it fix it fix it fix it fix it fix it!


Can I use previously rendered frames as texture in Cycles?

A good example would be a giant screen in a football stadium. The last rendered frame would be used as texture on the screen for the current frame.  This texture would be emitting light (as it is a screen), so I really need it as a texture input for an emission shader in cycles.  It differs a bit from that question:  as the given solution gives me a pink screen on the ~20 first frames.  Is it possible in Blender and if yes, how?


I am relatively new to the linux world. I use OSX at home and Windows at work. In those worlds, there is a default folder for applications (C:\Program Files, /Applications). Is there any such directory in Ubuntu?   I understand that this is not very important and any location in the file system should be ok, but was just wondering whether there are such standard locations (I think there would be one). For instance where is Firefox or Libre Office (that are installed by default)?  Got this question when I was trying to install eclipse. Downloaded the zip, and was wondering...


JavaScript RegEx for Phone Number that allows for # sign, but not alpha characters

I am trying to build a javascript regex for phone number. I currently have this...but it is failing. ^\(?([0-9]{3})\)?[-. ]?([0-9]{3})[-. ]?([0-9]{4})?[#. ]?([0-9]{10})$  Examples: (555) 555-1212 - Acceptable  (555) 555-1212 #12525 - Acceptable (Up to 10 digits after the # sign) 5555551212 - Acceptable 555-555-1212 - Acceptable 555-555-1212 #12525 - Acceptable (Up to 10 digits after the # sign)  Any alpha characters should be Unacceptable (555) 555-1212 ext 12525 - Unacceptable (555) 555-1212 x12525 - Unacceptable  Regex has been a weak area of mine and I am not sure how to make it work.


Are there organized groups of Force users other than the Jedi and Sith?

In The Force Awakens Maz Kanata says     I am no Jedi, but I know the Force.   Are there any other groups who have learned to use the Force, or is every non Jedi/Sith force sensitive completely untrained?


I have two systems installed previously Windows 7 and Ubuntu. I was trying to reinstall Ubuntu and format the Ubuntu OS partition using a tool in Windows 7.   When I have Ubuntu ready on a USB stick and restart my laptop, it prompts me with the GRUB rescue screen. If I boot from USB to install Ubuntu, it just hangs.   Anyway, I messed up everything. So my question is how can I boot Windows 7 now?


I want to write chemical formulae in a predominant german Text with a small number of russian words. For that I use babel and chemformula, but they produce a heavy conflict. My MWE:  \documentclass{report} \usepackage[T2A,T1]{fontenc} \usepackage[russian,ngerman]{babel} \usepackage[utf8]{inputenc} \usepackage{chemformula} \begin{document} Deutscher Text \selectlanguage{russian}{русский текст} \ch{H2O} \end{document}   I get the following error message:       [path]/chemformula.sty.1168:"xparse/command-already-defined"! See the   LaTeX3 documentation for further information. { \chemformula_ch:nn {   #1 } { #2 } }   Lines 1167-8 of chemformula.sty contain the following:  \NewDocumentCommand \ch { O{}m }   { \chemformula_ch:nn { #1 } { #2 } }   Is there any way to combine these packages?


I have seen quite a few "sandboxes" on meta SE's and it seems like a brilliant idea. The problem I have, and I think other people may have too, is that the questions can sometimes be vague/confusing, too broad, badly put, etc. and a lot of the time, those questions get downvoted a lot and closed and eventually deleted (as they should).  The "sandbox" would be a place where questions which may be bad can exist without threat of the question getting downvoted into oblivion and the person getting punished for a bad question and said questions would be instead criticised for how to improve them (rather than get answered), and this way bad questions can be made into good questions, which can then get asked on the main site. Yes, this may induce spam and misbehaviour but they can get removed. Note that the reasons for closing and ultimately deleting a question in the sandbox would not be because of the question's quality, but rather the asker's lack of responding to the community suggesting ways to improve it and also the previously mentioned reasons of spamming and deliberate misbehaviour.  The low-quality questions can potentially be turned into high-quality ones and it means less low-quality questions on the main site.


Unable to create test-answer in Sandbox Question

This question  states that you require 10 reputation to be able to post an answer.  According to the site header bar, I currently have 101 reputation on the site (1 + 100 for association bonus).  Does the 10 reputation required not include the association bonus?  edit: My attempt to ask the question was via the API to test that posting answers would work.  I have not tested doing so directly from the website.


Accidently made wrong partition in Ubuntu and now windows not opening

So few days ago I dual booted my system with Ubuntu 18.04 and during the partition process it seems that I made some wrong partitions such that now by default windows open in automatic repair mode and gives error C:\recovery\windowsre\winre.wim\system32\logfiles\srt\srttrail.txt Partition is as follows:  Someone out there please help as major amount of data is on risk. Thank you.


What do empty (missing) values in the output of PCA or factor analysis mean in R?

I am doing factor analysis with factanal in R and observe empty spaces in the loadings table:  factanal(x = ~V1 + V2 + V3 + V4 + V5, factors = 2, data = airfoil_self_noise)  Uniquenesses:    V1    V2    V3    V4    V5  0.898 0.005 0.005 0.995 0.394   Loadings:    Factor1 Factor2 V1 -0.319          V2  0.877  -0.474  V3          0.997  V4                 V5  0.754  -0.194    Here, I have no idea what empty space means in Factor1-V3, Factor1-V4, Factor2-V1, and Factor2-V4. Weren't they supposed to be filled with some numbers, like with 0?  The same sometimes happens in PCA using principal function.


Inequality of arithmetic and geometric means

Prove that if $x_1,x_2,...,x_n$ are positive numbers, then $$\frac{n}{\frac{1}{x_1}+\frac{1}{x_2}+...\frac{1}{x_n}}\leq \sqrt[n]{x_1\cdot x_2\cdot ... \cdot x_n}\leq\frac{x_1+x_2+...+x_n}{n}$$


Has my textbook given the incorrect equation for calculating uncertainty in multiplication?

I am 99% sure that the calculation to obtain the uncertainty of two multiplied values given by my textbook and  is incorrect. They both say this: $$(A \pm a)(B \pm b) = AB \pm (\varepsilon_A + \varepsilon_B)$$ Which should be equivalent to (correct me if I'm wrong): $$(A \pm a)(B \pm b) = AB \pm \left(AB \left(\frac{a}{A} + \frac{b}{B}\right)\right) = AB \pm (Ba + Ab))$$ Lets consider: $(4 \pm 1)(2 \pm 1)$ This should equal ($8 \pm 6$) right? meaning the smallest value possible is 2 while the largest is 14. However we can see that the largest possible value is actually $15$ ($5 \cdot 3$) and the smallest is $3$ ($3\cdot1$). If this is plot on a 3D graph you will see there is no way to obtain lower or larger values than 3 and 15. Therefore there must be a problem with the formula. After some math I came up with the following equation which I believe is the correct equation: $$(A \pm a)(B \pm b) = (AB + ab) ± (Ab + Ba))$$ As long as $A \ge a$ and $B \ge b$ and $a, b \ge 0$. Is the equation in the textbook (and given by this university) incorrect or have I just missed something?


What is the standard interpretation of order of operations for the basic arithmetic operations?

What is the standard interpretation of the order of operations for an expression involving some combination of grouping symbols, exponentiation, radicals, multiplication, division, addition, and subtraction?


How do I get Ubuntu out of the way of Windows 10?

I installed Ubuntu on my desktop and put it on a completely separate hard drive from Windows 10, but it still seems to have hijacked the boot process. No matter which device I try to boot from, this screen always appears (see below picture) and I need to select Windows 10 otherwise it will default to Ubuntu. When it did this is messed up my Windows 10 and I used a recovery point I happened to make earlier that day and it started running again.     Sorry for what is likely a duplicate post, I don't even really know how to Google it and try to find the answer. Please link me to a relevant post and delete this one if necessary.


Is there an easy way to programmatically add a comment field to a content type?

I currently have the following code in a D8 module:  $sql = 'CREATE TABLE `comment__field_follow_up_date` (' .   "`bundle` varchar(128) CHARACTER SET ascii NOT NULL DEFAULT '' COMMENT 'The field instance bundle to which this row belongs, used when deleting a field instance.'," .   "`deleted` tinyint(4) NOT NULL DEFAULT '0' COMMENT 'A boolean indicating whether this data item has been deleted.'," .   "`entity_id` int(10) unsigned NOT NULL COMMENT 'The entity id this data is attached to.'," .   "`revision_id` int(10) unsigned NOT NULL COMMENT 'The entity revision id this data is attached to, which for an unversioned entity type is the same as the entity id.'," .   "`langcode` varchar(32) CHARACTER SET ascii NOT NULL DEFAULT '' COMMENT 'The language code for this data item.'," .   "`delta` int(10) unsigned NOT NULL COMMENT 'The sequence number for this data item, used for multi-value fields.'," .   "`field_follow_up_date_value` longtext NOT NULL COMMENT 'The actual value that is stored in the field.'" .   ") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='Data storage for comment field field_follow_up_date.'";  if ($dbConn->query($sql)) {   echo "'comment__field_follow_up_date' " .     "table (re)created successfully.\n"; } else {   echo "Error (re)creating 'comment__field_follow_" .     "up_date' table: " . $dbConn->error . "\n";   exit(); }  $sql = 'ALTER TABLE `comment__field_follow_up_date` ' .   'ADD PRIMARY KEY (`entity_id`,`deleted`,`delta`,`langcode`), ' .   'ADD KEY `bundle` (`bundle`), ' .   'ADD KEY `revision_id` (`revision_id`)'; if ($dbConn->query($sql)) {   echo "Keys successfully added to 'comment__" .     "field_follow_up_date' table.\n"; } else {   echo "Error adding keys to 'comment__field_follow_" .     "up_date' table: " . $dbConn->error . "\n";   exit(); }   It seems to work, but upon inspecting the DB changes made when doing this through the UI, I have noticed another seven tables that are modified in some way, just by adding a single comment field!  So I am worried that I am not doing this the "proper" way, and that things will fall apart when we eventually upgrade to D9 (currently in the middle of a D6 - D8 upgrade and data migration).  Is there an official way to do this in code? I am not interested in doing it through the UI for each and every field I have to add (23 in total!) and all of my Googling attempts have only come up with articles related to that. MTIA! :D


Is it possible for physical constant to change in time?

There are many physical constants, like Boltzmann constant, light speed, dielectric constant of vacuum and so on. But is it possible to have physical constant that changes in time, for example it oscillates? Is it possible to prove that is is impossible?


Connection betwen definition of mapping cone of a topological space and of a Complex

Definition 1: Given a Map $f: X \to Y$ between two topological spaces define the mapping cone $C_f$ as $(X \times I) \sqcup Y / \tilde{} $ with $(x,0) \tilde{} (x\prime{}, 0)$ and $(x, 1) \tilde{} f(x)$  Definition 2:  Given two Complexes $A: \dots  \to A^{n+1} \to A^n \to A^{n - 1} \to \dots $ and $B: \dots \to B^{n+1} \to B^n \to B^{n-1} \to \dots$ and a map $F: A \to B$ Note the degree shift by $n$ as $A[n]$ and the differentials of each complex by $d_A$ (or $d_B$)  Define the mapping cone of a complex as $C_f = A[1] \oplus B $ with differential $ \begin{pmatrix}  d_{A[1]} & 0 \\ f[1] & d_B\end{pmatrix} $.  I understand both definitions and have some geometric intuition for them. But I dont understand the connection between them. How is the second definition motivated by the first one?  bg, Johannes


I've been playing magic on and off for a long time. The most recent time, however I've been taking a closer look at rules and action orders.  The main thing that I've been doing now is cloudshifting allies in and out of play. I need explanation on returning to exile at the end step. Blessed vs. Cused spotlighted a card that exiles all creatures I want that I control and sends them back at the end step. I didn't know it was any different from returning during the rest of the turn, until a buddy said something about it being different. He basically said that instead of returning one by one and triggering separately each time, they all hit at once and only trigger once.  Is this true? If it is can someone explain the ruling and process?


Why there are real numbers with infinite digits, but no such natural numbers (or another reason why real numbers are uncountable)

This question is me trying to understand (again) why there can be no one-to-one correspondence between the sets of natural and real numbers.  The source of confusion is this: if we abstract completely from the properties and operations on numbers and just think of them as strings of digits, it appears to be possible to list all the real numbers between $0$ and $1$ and all positive integers having the same digits in the same (or reverse) order, for example:  $$0.1 \to 1$$  $$0.01 \to 10$$  $$0.0101 \to 1010$$  $$0.110101 \to 101011$$  I use binary expansion for simplicity.  Since irrational numbers have infinite expansions, we would have to consider some kind of 'infinite natural numbers', like:  $$101110001\dots$$  or  $$\dots101110001$$  I think the main (and only) reason why such numbers don't exist is this requirement:   We need the sets of real and natural numbers to be ordered. We need to be able to do arithmetics on real and natural numbers.   Obviously, if we consider any of two types of 'infinite natural numbers' and the usual absolute value, we find that it's impossible to order them, or do arithmetics with them.  The only way is to change the norm (to $p-$adic norm for example).  While with the real numbers it's still possible to order them, and do arithmetics with them when they have infinite amount of digits in their expansion (or at least in principle).     Is my reasoning correct? Are the two requirements (ordering and arithmetics) enough to explain why natural numbers with infinite amount of digits do not exist, while real numbers do?   This confusion is not restricted to me alone, see  for example


I'm using the default PDF viewer in Ubuntu 16.04 on a Dell XPS 13 9350. The link is a reference in a technical paper.  I get the error "Unable to open external link, Failed to execute child process "/opt/google/chrome/chrome" (Permission denied)"  I tried this solution without success:


Do you give gifts to your child's teachers and caregivers?

My 16 year old wants to give her teachers Christmas gifts. She is in 10th grade, so there are quite a number of teachers.  As a retired teacher, I do not think teachers need gifts. I would have loved a card or note with a comment or appreciative remarks. I taught special needs students and liked when a parent made snack for the entire class or contributed to the trip fund, but I never needed them to spend their hard-earned money on me.  I suggested my kid make cards -- she is very artistic, and add a heartfelt message. She disagrees and wants twenty dollar gift cards, which for the record, she cannot contribute to.  We are trying to find a compromise. I think that over $100 is ridiculous. It is also too much to 'lend' my kid.   (Deep background, this is not my own daughter but my godchild. When her parents died, I became her guardian. She was 4 when they died. So sometimes she uses that as her trump card. Teens aren't 'easy'.)  I said I'd ask what others think.


I want to install pencil 0.4.4b, on an ubuntu machine that is not connected to the internet.  Is there a way I can copy all the source files or preferably a .deb file and any dependencies to a usb and then install from there?


I wanna install windows 7 on ubuntu. When i boot windows 7 dvd then it stuck on boot screen. Help me to install windows 7 on ubuntu. Thanks in advance.


Question on intuition behind notation in u substitution

I have a question concerning u substitution for integrating. Suppose I needed to set $u = 3x^2 + 1$. Then $du = 6x dx$. So why are we incorporating the $dx$ with it?   I understand that $\displaystyle\frac{du}{dx} = 6x$, but I was under the impression that $\displaystyle\frac{du}{dx}$ could not be thought of as a fraction. Its just a way of symbolizing the derivative of $u$ with respect to $x$. But it seems like it is being treated like a fraction because both sides are being multiplied by $dx$.


Work done in rotating a dipole in NON uniform electric field

I understand that the torque on a dipole due to a non uniform electric field is given by the same expression as that of in a uniform electric field i.e. pEsinθ. Now,how do you calculate the work done in rotating this dipole. I tried to integrate pEsinθ.dθ from limits say θ1 to θ2. But since the electric field is not uniform how do you go about integrating the thing, or is E to be taken constant?   I was trying to calculate the potential energy of a dipole in a NON UNIFORM field and got stuck here. Also, since the force acting is non zero, work would have to be done in keeping the dipole at its position, apart from the work done in rotating it, how do you calculate that?


Almost sure convergence of the Poisson process

Let $N = \{N(t) \}_{t\geq 0 }$ be a Poisson process. I already know that $N(t)- \lambda t$ is a martingale where $\mathbb{E} [ N(t) ] = \lambda t$.   I want to prove that $$ \frac{N(t)}{t} \rightarrow \lambda, \quad t \rightarrow \infty \quad \text{ a.s.}. $$  To prove this I received a hint that I should use the martingale law of large numbers which states that:  Theorem: (Martingale LLN)  Let $S= (S_n = \sum_{k=1}^n X_k)_{n=1,2,\ldots}$ be a martingale with respect to the filtration $(\mathcal{F}_n)_{n=1,2,\ldots}$. Then $\sum_{k=1}^n X_k/k$ converges almost surely on the set $\left\{ \sum_{k=1}^\infty k^{-2} \mathbb{E}\left[ X_k^2 \mid \mathcal{F}_{k-1} \right] < \infty \right\}$. Hence $S_n/n \rightarrow 0$ a.s. on the same set.  Now to use this theorem I think I need to use Doob-Meyer to decompose $N(t)$ as the sum of a martingale and an increasing process. Which would be the martingale $M(t) = N(t) - \lambda t$ and increasing process $A(t) = \lambda t$. But how is $M(t)$ the sum of a martingale? And I do not know how this exactly relates to the thing I have to prove. Thanks for any help.


Automation script for Minimal Form Interface with dynamic ids

I am trying to automate a minimal form interface using Selenium to capture an element & later Java code.  But the challenge is the minimal form has only one input container which is constantly changing and the input container generates dynamic id's so finding the element by id name is not possible.  The input container cannot be mapped with xpath because xpath also uses the id  eg. //md-select[@id='select_15'].


Post-apocalyptic religious fiction containing water merchants

I am trying to remember the name of a paperback book that I was given by a friend in the United States sometime in the early 2000s.  The book was part of a trilogy that followed the story of a group of people who were surviving in a post-apocalyptic world where water was so scarce that there were "water merchants" or "watermen" or similar who sold water to small colonies.  I do remember that the book was religious fiction written for a Christian audience, and I think that it ended up being specifically marketed as young adult fiction.  I read only the prologue or part of the first chapter, and the only thing that definitely I remember about it was that there was a group of people waiting to meet someone (possibly a water merchant), and there was a guy who was so sick that he was coughing up blood as he spoke to the others in the group.  I also seem to recall that the government in the region was totalitarian and may have been the reason why the water was so scarce. Other details that I remember are that the cover of the book was mostly blue and contained a sort of cyberpunk-styled image (possibly of a person wearing a hoodie).  I seem to recall that it looked similar to the .  In the book was an advertisement for the other books in the trilogy, and I remember that other books had similarly stylized covers with different images of a different predominant color.  (I think one of the other covers was mostly green with an image of another person.) What I can say for sure is that it is NOT one of the books in the Left Behind series, but it was definitely something in the same general genre.


I was trying to quickly edit an .hgignore file from the Cygwin bash shell today, and I added a line that was a mistake. I'm not sure if this was the best way to do it, but I quickly thought of using head -1 .hgignore to remove the offending line (I had previously only had one line in the file). Sure enough, when executed it gives the first line as the only output.  But when I tried to redirect the output and rewrite the file using head -1 .hgignore > .hgignore, the file was empty. Why does this happen? If I try appending instead, head -1 .hgignore >> .hgignore, it appends correctly but this is obviously not the desired result. Why does a truncating redirect not work in this case?


Help installing document class for LyX on Mac, unsure on where to start

I'm trying to download a document class from a university, and would like to use this for my thesis. However I'm very new to all of this, and so really have little clue on where to start.  The document class package is located below, I've downloaded the 'ecsdocs.zip' file under the 'installation' heading:   When unzipped, I am able to extract 5 folders, but can't seem to find my the right local texmf directory to place them in.  I have previously placed the files in usr>local>texlive>texmf-local>tex>latex, but can't seem to find the document class after a lyx reconfigure. Is this even the right folder to place the files in? And once placed into the correct folder, what would be the next steps? Would very much appreciate some detailed guidance.   Thanks.


I ve downloaded Super Hot (for linux) at the official site, but i dont know how to run it

Heres the link:  [LINK REMOVED]  Please let me know if you know how to run it.


How do I log in to my personal Windows 10 using a FIDO2 key?

I'd like to user a FIDO2 key to log into Windows 10. There are various guides explaining how to add a key to a Microsoft web account, or to Windows 10 sign in options, but neither result in showing up as an option when I try logging into Windows.  How can I configure windows to use my FIDO2 key to log in?


python script error- with GetParameterAsText

I have a seemingly simple code which iterates through a list of feature classes and calculates an ID field in the attribute table that is equal to the first 5 characters of feature class name.  The script works fine if I hard code the workspace.  As soon as I change it to "Get Parameter as Text"  I receive this error:  ERROR 000539: Error running expression: expression : name 'expression' is not defined Failed to execute (CalculateField).  The script is:  import arcpy, sys, array, time, datetime  #Get feature dataset inws = arcpy.GetParameterAsText(0)  #Set geoprocessing environments arcpy.env.workspace = inws arcpy.env.overwriteOutput = True  #Iterate through the list of feature classes  fcList = arcpy.ListFeatureClasses()  for fc in fcList:     print str("processing" + fc)  #Define field and expression field = "SID" expression = str(fc[:5])  #Create a new field name and expression arcpy.AddField_management(fc, field, "TEXT") arcpy.CalculateField_management(fc, field, "expression", "PYTHON")   does anyone know what is going on here? Thanks!


Are these the only solutions to $a!b!=c!$?

Curious about  on,  $$6!7!=10!\tag1$$ a little Mathematica expt yielded, $$r!(r!-1)!=(r!)!\tag2$$     Q: Are the only non-trivial integer solutions to $\color{blue}{a!b!=c!}$ with $a,b>1$ given by $(1)$ and $(2)$?


Discrepancy in profiling Java application

I was trying to calculate the performance of my algorithm by first implementing it in Java and then calculating the processor time for different inputs. I used ThreadMXBean.getCurrentThreadCpuTime() to get the system time.  I profiled it first using the following code:  calculateProfile() {    for (int n = 10; n <= 200; n++) {    long time_beg = getCurrentThreadTime();    run_my_algorithm(n);    long time_end = getCurrentThreadTime();    System.out.println("Output = " + n + " " + (time_end - time_beg)); }   However, I was surprised to see that with an increase in the value of n, the time profile does not increase as expected. In some cases, the execution time actually decreased, although my algorithm has a time complexity of O(n).  To look into the problem, I changed this code to run my algorithm once on each execution, and manually checked the time profile for each execution instance. In this case, I find a linear increase in execution time with respect to n. So my question is: How are the two cases different? What is making this difference in profile patterns? And, how to best automate this profiling process in that case?


Unix Shell : Array assignment not working

I am learning array by following code  source_array_list[0]="a" source_array_list[1]="a" source_array_list[2]="a" source_array_list[3]="a" source_array_list[4]="a" source_array_list[5]="a" source_array_list[6]="a" source_array_list[7]="a" a=0 while [$a -le 6] do     echo "just before loop"     target_array[a]=source_array_list[$a]     echo "${source_array_list[$a]}"     a=`expr $a + 1` done   Now this is not working and giving the error [0:  not found.


What is the formal mathematical definition of a "layer" of a neural network?

Often you see diagrams like these.  Which makes me wonder what is the definition of a layer, because as it is drawn, it is very vague.  For example, when people say a fully connected layer, what do they mean by a layer?    From the diagram, it seems that:   The input layer is a set of components associated with your input vector, as well as the value of the weights going to the hidden layer, i.e., let your input vector $x = (x_1, \ldots, x_n)$, then the input layer is the set $$L_i = \{x_1, \ldots, x_n\} \cup \{w_{ij}\},$$ where $w_{ij}$ are the weights associated with the input layer.  The hidden layer as well as the output layer consists of a set of activation functions $a_i$ which transforms the input $x$ into a set of outputs $o_i$, along with the weights going into the next hidden layer,i.e.,  $$L_H = \{a_i\} \cup \{o_i\} \cup \{w_{ij}\} $$.   Is my interpretation correct?


I recently installed MiKTeX with the texmaker editor and cannot figure out how to update the packages. When I attempt to use the subfigure package with the following preamble  \documentclass[a4paper,12pt]{article} \usepackage[english]{babel} \usepackage{graphicx} \usepackage{subfigure}   I then get a prompt to install a new package, which I then set to the online directory at ctan. I then get the following error:   ! LaTeX Error: File `subfig.sty' not found.Type X to quit or <RETURN> to proceed,or enter new name. (Default extension: sty)Enter file name:! Emergency stop.<read >   How do I properly install packages to miktex? I'm absolutely confused. Thanks in advance for any help.


I would like to keep timestamps on the commands logged in my Bash $HISTFILE, is it possible?  I did not manage to set it up using man bash as an information source.   My other options are as follows:  function thebanana() {   local -r -a bash_commands=(     "ls"     # ... more coconut commands   )   for bash_command in "${bash_commands[@]}"; do     printf "${bash_command}"     printf ":"   done } export HISTFILE=banana export HISTIGNORE="$(thebanana)" export HISTSIZE=999999 export HISTFILESIZE=999999999 export HISTCONTROL=ignoredups:erasedups   I should have mentioned I am on OS X Mountain Lion (sigh). uname -a gives me:  Darwin CoconutMac.local 12.2.0 Darwin Kernel Version 12.2.0: Sat Aug 25 00:48:52 PDT 2012; root:xnu-2050.18.24~1/RELEASE_X86_64 x86_64   and echo $BASH_VERSION gives me:  3.2.48(1)-release   Tried adding this:  export HISTTIMEFORMAT='%b %d %I:%M:%S %p '   and it only prefixes this kind of timestamps to commands:  #1349057791   I try echoing back the variable (echo $HISTTIMEFORMAT), it has the right value.  Interesting!  I even removed .profile completely to debug this. Still only funny timestamps:  #1349058320   I don't know how to further troubleshoot this... :(  Solution: I was using a script that reads the $HISTFILE directly, not the history built-in so the epoch-based timestamp (secs since Coordinated Universal Time (UTC) of January 1, 1970) was not being translated using the date formatting string. Plain-old history works fine, I'll use that instead.


I'd like to write this formula with all parenthesis of the same size  N = \left( \frac{s}{2} \right)^2 - \left( \frac{d}{2} \right)^2   so I tried  N = \left( \frac{s}{2} \middle)^2 - \middle( \frac{d}{2} \right)^2   The two results are the following:    Is there a way to achieve my goal without using \big( and similar?  Thanks


How long until I can reapply after refusal of a UK Standard Visitor visa?

I am a Peruvian permanently resident in Australia. I have lived in Sydney for 27 years and want to travel to the UK to visit some friends. I applied online but my application was refused. I put a friend as a contact as I was planning to stay with him for a few days then maybe stay in different places.  The decision was that I didn't provide evidence of my friend's personal circumstances and that it was unclear I had a friend in the UK to visit. This mas my mistake as I only asked for his information, not a referral or invitation letter.  The other point was evidence of my financial circumstances. It was a bank letter and that showed the balance on one day but not the financial commitment of an applicant nor the source of funds in my account. I am a bit confused with this one as I don't know what to show.   Do they want six months of bank statements with all my transactions?  Isn't that going to be a lot of paper to print and send?  I also sent additional information such as my itinerary for the flights already purchased and a letter from my employer confirming the time I was going to be away (1st - 18th October).   So I don't know what to do.  Can I reapply with additional information?  Because the flight is quite close, what kind of extra information can I show to ensure the application is approved?  This refusal caught me unguarded. I didn't know this was going to happen as it is just a simple holiday. When I applied (14 August) I hadn't planned much and bought the ticket because it was cheap but they asked so many questions about where I was going to stay I just asked my friend for his address, as I was planning to stay there for a few days but for the others I wasn't sure - maybe look for places in Airbnb or similar.  I have recently acquired Australian citizenship. I just need to wait a few months to make the official pledge and I can apply for an Australian passport. I think with that I don't need to apply for any visitor visa. But that's not going help me with the flight booked for October.  What should I do? Can I reapply? Postpone everything?


Location Consent & undo Remeber This Setting

Like many, I found the Location Consent prompts to be annoying. I was excited when Google finally extended the option to 'remember this setting' in the latest update, but dismayed when I could only have the phone remember a 'yes' answer.  Unfortunately, when I handed the phone to a friend to coordinate GPS while driving she checked 'Remember this setting' and consented into the program. I would like to undo this, but cannot for the life of me find where this setting is stored on my phone. It does not appear to be listed in the 'Location' or by clearing the cache of the LocationServices app (which doesn't appear to actually work)  How can this be undone? Phone is a Motorola Razr HD running 4.4.2


Why can't I change directories using "cd" in a script?

I'm trying to write a small script to change the current directory to my project directory:  #!/bin/bash cd /home/tree/projects/java   I saved this file as proj, added execute permission with chmod, and copied it to /usr/bin. When I call it by: proj, it does nothing. What am I doing wrong?


SA passport holder with Schengen visa 5 year multiple entry (EU family member) wishes to travel to EU without spouse

I'm a non EU passport holder and have a valid Schengen visa (5 year multiple entry). When I applied for the visa I applied as a spouse on a UK passport holder. Have traveled to EU several times with my husband and child - no problems. I now wish to travel without my spouse (but with child who has UK passport) on this Schengen. Is this possible?   I realise that conditions for granting the family visa include travelling with partner but it's not clear if these conditions apply for all future travel too. Hoping a Schengen is a Schengen and other conditions can't be applied post issuing. Failing that, hoping my UK born child can be considered my family member.


I am a beginner in Blender, I know how to use the basic commands but don't have much experience creating models. I am trying to create a circle of ribbon-like DNA with the base pairs detached in the center like this, except with a few caveats.  The base pairs should be able to freely rotate around the "vertical" axis, and somehow I can control the loop so it can writhe/contort (like go from a circle to an "eight"). Could anyone please help me figure out how to do this or point me to some resources that could help?


How to go about selling digital files for printing and how to price them?

I have recently shared an album of my pictures in an online photography forum and someone contacted me, asking if I can sell them a print, or the digital file for them to print themselves.   I have never sold any prints before and at the moment, I don't have time to spend on that; also I don't have any calibration tools for my monitor or any experience in high quality printing, and I don't want to half-ass that, so I don't want to sell a print right now. However, I'd be fine with selling the digital file so that person can print the photo. But I have no idea how to price a digital file, and what exactly I should give out.  Do you normally just send out a high-quality JPG? Or the RAW file along with the XMP file containing my edits? (I edited the picture in Lightroom) If I should go with JPG, do I just send out the full size (6000x4000) or ask them what size they want to print it in and send an appropriatly downsized version? And how do I determine an approriate price for that? What are the relevant factors?  I've read online that I should factor in the image size as well as the editing time. I don't know how long I spent on it, probably less than 10 minutes. I'm just not sure how to approach this, any price I could come up with somehow feels ... random. Some insights are appreciated!


I keep getting a java.lang.NullPointerException when trying to open a txt file in eclipse. Basically, this is a main menu, and when you click the "Rules" button, the rules text file should open. Currently, the txt file is located in a package called "Resources" (which is where all of the other img files I've used in making the game are). Here's the code:  private List<String> readFile(String filename) {   List<String> records = new ArrayList<String>();   try   {     BufferedReader buff = new BufferedReader(new InputStreamReader(             Configuration.class.getResourceAsStream(filename)));     String line;     while ((line = buff.readLine()) != null)     {       records.add(line);     }     buff.close();     return records;   }   catch (Exception e)   {     System.err.format("Exception occurred trying to read '%s'.", filename);     e.printStackTrace();     return null;   } }  //action performed public void actionPerformed(ActionEvent ae) {     JButton b = (JButton)ae.getSource();     if( b.equals(newGameButton) )         {         flag = true;         controller.startGame();         buttonPressed = "newGameBtn";         }     if(b.equals(quitButton))     {         System.exit(0);     }     if(b.equals(ruleButton)){         readFile("../resource/riskRules.txt");     }   }  Appreciate the help!


Asymptotic expansion of $v_n = 2^nu_n$ where $u_{n+1} = \dfrac{1}{2}\arctan(u_n)$

Let $(u_n)$ be a real sequence defined $u_0>0$ and $u_{n+1} =\dfrac{1}{2} \arctan(u_n)$. We define $v_n = 2^n u_n$ and write $l = \lim v_n$.  Find an equivalent of $u_n - \dfrac{l}{2^n}$ as $n\to \infty$.  What I did:  I've shown that $(u_n)$ converges to 0, $(v_n)$ is convergent. So we get $u_n \sim \dfrac{l}{2^n}$. I don't know how to continue.


Is there a way to use other computers that are sitting idle on my network to render my images?   From google, I've found , however it appears that is designed to let everyone use your hardware, in exchange for using theirs. Also, there is no guarantee to how soon your project will start rendering.   I have a bunch of servers sitting around that were bit coin mining. Is there a way to use them for blender?


I had configured an ftp server in Centos 7, in which I used the vsftp package and in the vsftpd.conf file I used a command called deny_file in which I only indicated the file extensions that I would not allow to be uploaded to the server, however I saw that the ftp server was not safe and I wanted to put it secure with SSH, that is with SFTP, but despite having the deny_file in the vsftpd.conf it does not block the files by extension and I really want to know if any of you knows a way to do it  please help me,the other question is not explained clearly and I do not understand it.


Should SE move in the long term to SLACK / DISCORD or chat alike system?

I didn't see any discussion alike and hence would like to check it out in case it is being discussed in the background by the fathers of the site.  Many pro's and con's, personally I dislike it (real questions, no real answers, no order, tons of noice), but the way that things go, there has been a massive adoption for this chatting programs that are being pushed in with a "productivity" sales pitch.  Question is in the umbrella of the existing chat system that is used by SE, there is no reference in this question to -entertainment, fun or alike, hence do not consider it duplicate of


What's the difference between "will turn on" and "going to turn on "?

I was playing an  when I came across the following question:     You and your friend are reading. It's getting dark and you decide to turn on the light. You stand up and walk towards the light switch.      A: What are you doing?   B: __________________              I'll turn on the light.    I'm going to turn on the light.     I'm turning on the light.          According to  we use will when we make rapid decisions. Isn't this the case in the game? I am asking, because the right answer turned out to be "going to turn on the light" - am I missing anything obvious here or is it a mistake in the game?


while not changing the value of a variable outside of the loop. I need to make a method that shuffles the array in a random way. (C# pls)

The method takes 1 array and using random to shuffle the array the value of rndm1-4 didn't change. and after the loop, it acts normal. I think the problem is in the while loop. public static string[] Shuffle(string[] array) {     string str1, str2, str3, str4;     Random rnd1 = new Random();     Random rnd2 = new Random();     Random rnd3 = new Random();     Random rnd4 = new Random();     int rndm1 = rnd1.Next(3);     int rndm2 = rnd2.Next(3);     int rndm3 = rnd3.Next(3);     int rndm4 = rnd4.Next(3);          while ((rndm1 != rndm2) && (rndm1 != rndm3) && (rndm1 != rndm4)          && (rndm2 != rndm3) && (rndm2 != rndm4) && (rndm3 != rndm4))     {         rndm1 = rnd1.Next(3);         rndm2 = rnd2.Next(3);         rndm3 = rnd3.Next(3);         rndm4 = rnd4.Next(3);     }          str1 = array[0];     str2 = array[1];     str3 = array[2];     str4 = array[3];     array[rndm1] = str1;     array[rndm2] = str2;     array[rndm3] = str3;     array[rndm4] = str4;     return array; }


How to draw (and paint) the Voronoi regions of a series of points using Tikz?

How can I draw (and paint) Voronoi regions of a series of points in plane using Tikz? How about if the points are in 3d space?


Cannot Install anything on Kali Linux 2018

root@Kali:~# echo -e "deb http://http.kali.org/kali sana main non-free contrib\ndeb http://security.kali.org/kali-security/ sana/updates main contrib non-free" > /etc/apt/sources.list  root@Kali:~# apt-get update  Ign:1 h t t p : / / http . kali . org/kali sana InRelease                                      Err:2 h t t p : / / http . kali . org/kali sana Release                                          404  Not Found [IP: 192.99.200.113 80] Ign:3 h t t p : / / http . kali . org/kali-security sana/updates InRelease Err:4 h t t p : / / http . kali . org/kali-security sana/updates Release   404  Not Found [IP: 192.99.200.113 80] Reading package lists... Done  E: The repository 'http://http.kali.org/kali sana Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: The repository 'http://security.kali.org/kali-security sana/updates Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. root@Kali:~# apt-get update --fix-missing  Ign:1 h t t p : / / http . kali . org/kali sana InRelease                                      Ign:2 h t t p : / / http . kali . org/kali-security sana/updates InRelease                 Err:3 h t t p : / / http . kali . org/kali sana Release   404  Not Found [IP: 192.99.200.113 80] Err:4 h t t p : / / http . kali . org/kali-security sana/updates Release   404  Not Found [IP: 192.99.200.113 80] Reading package lists... Done E: The repository 'h t t p : / / http . kali . org/kali sana Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: The repository 'h t t p : / / security . kali . org / kali-security sana/updates Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.  root@Kali:~# apt-get install tor Reading package lists... Done Building dependency tree         Reading state information... Done  Package tor is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source E: Package 'tor' has no installation candidate


Limit account applicants with certain email addresses

Hi I am working on a website for a student organization of my college.  In order to prevent spams, I have been looking for ways to limit account applicants only with email addresses from the college but haven't figure out how


Discontinuities of the derivative of a differentiable function on closed interval

I have a question about the corollary to theorem 5.12 in Rudin's Principles of Mathematical Analysis (page 108):  Suppose $f$ is a real differentiable function on $[a,b]$ and suppose $f'(a)< \lambda < f'(b)$ then there is a point $x \in (a,b)$ such that $f'(x) = \lambda$ Corollary: If $f$ is differentiable on $[a,b]$ then $f'$ cannot have any simple discontinuities on $[a,b]$.  Can someone help me to show how he uses the result in the "main theorem" in the corollary?  (There are two cases of simple discontinuities  $f(x+) = f(x-) \neq f(x)$ and $f(x +) \neq f(x-)$


If $a,b,c,d,e$ are positive reals, such that $a+b+c+d+e=8$ and $a^2+b^2+c^2+d^2+e^2=16$,then the range of $e$ is?  I dont even know how to proceed with problems like these. I have an idea that $A.M-G.M$ might be helpful. Is it true? If yes, then how to go about it?


How to explain the equation about summation?

$$\frac{\sum_{i=0}^nx_iy_i-\bar y\sum_{i=0}^nx_i}{\sum_{i=0}^nx_i^2-\bar x\sum_{i=0}^nx_i}= \frac{\sum_{i=0}^n(x_i-\bar x)(y_i-\bar y)}{\sum_{i=0}^n(x_i-\bar x)^2}$$  Maybe it refers some calculation rules about summation. I cannot solve that. Thanks!


How can I make iPhone silent for a specific amount of time?

On Android phones, there are apps (not native functionality) to make the phone silent for the next N minutes starting right now. This is different than setting specific times of day like Do Not Disturb does.  The functionality I'm used to takes one of two forms:   An icon you click that then asks "how long should the silence last" Or, automatically detect that I turned off the sound to zero (via volume rockers or otherwise); and asks the same thing. However, I'm not dogmatic, if iPhone has some other approach to solve this problem I'm open to exploring it.   Is something like this available on iPhone? (6, OS version 10 if it matters).  I prefer native functionality if it exists. Otherwise, an App store app is OK as long as it's free (as in gratis) doesn't require jailbreaking and works on iPhone 6.  Extra plus if it supports both modes described above (trigger with the icon or with setting volume to zero); as well as supposed 100% silence or vibrate-only mode.


I am wondering which is better to use- utilize or use? What do you guys think? Does it depend on what are you using the word for?


How are Python metaclasses different from regular class inheritance?

This might be too much of an open ended question, but I'm just now learning about metaclasses in Python and I don't understand how a metaclass is any different than just having a child class inherit from the parent class, like  class child(parent):   Wouldn't this serve the same purpose of a metaclass?  I guess maybe I don't understand the purpose of a metaclass.


The use of \\ outside special circumstances

Several times I have seen this advice (or words to this effect): "Never use \\ to break lines outside special contexts such as tabular." (for example, ). I cannot find a source for this advice.   Indeed, "The LaTeX Companion" (page 104) has this:      "Other ways of typesetting paragraphs are flush right and centered, with the flushright and center environments, respectively. In these cases the line breaks are usually indicated with the \\ command, whereas for ragged-right text (the flushleft environment discussed above) you can let LaTeX do the line breaking itself (if you are happy with the resulting quality)."    Moreover, instances of the use of \\ to format paragraphs are legion. Why is this use of \\ ill-advised?


Is it really a good idea to put money in 401(k)?

Assuming your company doesn't have 401(k) match, is it really a good idea to put money in 401(k)? Everyone says it's a good idea but I don't think so.   Why not save your money and buy a house/apartment instead (can rent it out for extra money)?  Some people even suggest to max out your 401(k), which is insane to me. I feel like ANY investment is better than dumping it in 401(k) in the long run (eg: dump into S&P 500)


Connected to wifi but no internet access

I am using wpa_supplicant to manually connect to wifi after deleting network-manager on Ubuntu 14.04.  Now that I've finally managed to connect, I can't access any pages on the internet and I can't ping anything either. This wifi and my network adapter (usb wireless dlink) work perfectly since I was using that setup 2 days ago before removing network-manager.  I know its an improvement because just yesterday Ubuntu took 2-3 minutes to boot because it told me it couldn't find network settings until it timed out eventually. Now it boots normally so it does see it and I feel I'm a few commands away.  Here's the setup :     Now the iwconfig before connecting to the wifi manually    and the iwconfig after connecting manually  (Chouchoune is my home network)    lshw -C network:    route -n; cat /etc/resolv.conf; ping -c4 4.2.2.2; cat /etc/network/interfaces


SQL Server logins and users -- assign multiple logins to a single user?

In SSMS, since I can't assign multiple login objects to a single user object, what is a best practice to achieve an equivalent security model?   For example, I have 20 logins and want to give them all the same permissions on a single database:   Do I have to create 20 user objects in that database? Do I have to touch all 20 Login objects?


How can I match a quote-delimited string with a regex?

If I'm trying to match a quote-delimited string with a regex, which of the following is "better" (where "better" means both more efficient and less likely to do something unexpected):  /"[^"]+"/ # match quote, then everything that's not a quote, then a quote   or  /".+?"/   # match quote, then *anything* (non-greedy), then a quote   Assume for this question that empty strings (i.e. "") are not an issue. It seems to me (no regex newbie, but certainly no expert) that these will be equivalent.   Update: Upon reflection, I think changing the + characters to * will handle empty strings correctly anyway.


How to get a sharper image using Nikon D3200?

Just wondering if you have any tips on getting a sharper image with a Nikon D3200? I was using a kit 18-55mm but solved the problem by taking someone's recommendation and shot a pic at F8 while in 55mm and now my pic seems sharper now. I will have to learn more about "Stops" as for example at 55mm - max 5.6 and did 2 stops from that to F8 and pic quality improve better and yes I do agree in purchasing a better lense.


What slang words and colloquialisms are likely to embarrass an American in England or an Englishman in the U.S.?

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


Prove that the number of units of $\mathbb Z[\sqrt{3}]$ is infinite, i.e. $a^2 -3b^2=1$ has infinitely many integer solutions.  Can you help me?


I need the explanation of this syntax , does this mean that (+4) is the same as (4) ? I have tried many other operands and it completely works as if I disregarded the plus sign before the number .


Is it possible to deactivate/remove/uninstall a default client side webpart?

I'm trying to deactivate/remove/uninstall a default Client Side Web-Part (the Yammer one) in modern pages and I don't find a way to do it:    I would like the Yammer option to be not visible in the menu. Any ideas?  Thank you very much in advance!


I have a plot with a lot of measurement datapoints. I exported this plot from Matlab2tikz.  When I tried to compile, it said that the memory was exceeded. I found  and it tells me that I can export different tikzpictures to different files. Unfortunately, this didn't help me since I have only 1 tikzpicture causing the problem.  So I actually tried to increase the memory of TeX. I went to /usr/share/texlive/texmf/web2c then in texmf.cnf I changed main_memory = 3000000 to main_memory = 5000000. Then I ran texhash and tried to compile my TeX file again.  My problem is that after I increased the memory limit I got again the same error: ! TeX capacity exceeded, sorry [main memory size=3000000]. However I just changed it to 5000000. I presume that I did something wrong when increasing the memory limit. Did I?  -Edit-   Eventually I just used lualatex. This was due to the fact that I think there is something wrong with my texlive install: it is installed twice on my system for some reason. I think, however, that Heiko Oberdiek's answer is correct and hence marked it as the correct answer.


I need advice for my reapplication for UK Visit Visa

I’m an international college student in Hamburg, Germany. I have applied for Visitor Visa in 2017 and this is the refuse letter from my last application. There are a few changes in my application that I want to ask for advice.    In the last application I have stated that I have no friend in the UK. But this time my boyfriend will write me an invitation letter and I will be staying at his place during the trip. Do I have to clarify why did I say that i have no friend in the UK in the last application? I’m a non-working fulltime student and receive regular allowance only from my family. What documents do I have to provide beside my bank statement? Plus I have a cash deposit of 6000 Euro in my bank sent from my family 3 months ago. Do I have to prove its origin, if yes what documents do I need? The reason for the large amount of money is because my family only send me twice a year. First thing is that, I have a penalty fare ticket last year in Germany for the amount of 60Euro for not having the right ticket for the different zone in Berlin and I have transfered the fee right after. Second is when I flew back to Germany from Vietnam, I have a fine for bringing meat to Germany for 46 Euro and also have to pay tax not fine for bringing cigarettes. I have paid everything right after. So my question is do have to disclose them in the section: “Warning, caution, reprimand, or other penalty” in my application form?   Thank you for your help!


Is there a built-in text editor in the terminal on Lion?  (Like, for example, nano on Linux.)


How do i create a script to locate a public ip address of a network computer?

I am really struggling to find the solution to this problem. I would really appreciate It if you guys could put the script in nano.


Forwarding a subdomain to a Minecraft Server

I am trying to forward a subdomain to directly connect to a Minecraft server. The domain name is hosted at GoDaddy and the server requires the port at the end. These are the things I have tried so far:   I attempted to create an A record via GoDaddy's DNS manager. This worked in redirecting the IP, as the IP for the server is actually the IP for the server's control panel. I attempted to add this to Minecraft followed by :25602 which is the port number. Unfortunately that didn't work. I went to the GoDaddy domain management page and attempted to create a redirect to the subdomain but that did not work either. I entered the port name as well.   Does anyone know how to do this successfully? I mean to me, these things should have worked. I have done some research and can't seem to find anything other than what I have tried already.


I use this code to load images from folder:  $dirname = "media/images/iconized/"; $images = glob($dirname."*.png");  foreach($images as $image) {     echo '
'; }   Source:   Works perfect. But load images in alphabetic order (A-Z). My question is:  How to load images from folder by modification date or creation date? To get newest first.  Greetings.


Is there any way to tell a difference between a Squib and a Muggle?

If someone has no way to tell who a person's parents are/were (no paperwork), is there a way to tell for a Wizard if someone is a Squib or a Muggle? Or are they 100% functionally equivalent and only different as far as bureaucracy is concerned?


Alright. I'm trying to move my games (from one drive to another), but as you know there is close to no possible way to do so.. Without redownloading it. No thanks to the recent client updates, simply copying the files over (and uninstalling the old location) does not help at all.  So: Is there any way to get Steam to redownload, and then instantly make it complete (then copy the files over)? (That means not redownloading the game again. Instead, it downloads nothing and the game is marked as downloaded.. But no actual files are downloaded. Instead, the source is the game files, untouched, and NOT in as a "backup1")  1 Backup = .csd, .csm and .sku files in the [Game Name]\Disk_[# No.][ID]depotcache[# Num].csm etc. format and file structure.  Question: How do you trick Steam into starting a download, and then "instantly" finish it without downloading a thing? As the solution in  does not work. Or it may be because I'm on a beta build.


Why in $\mathbf{R}^2$ the only nontrivial subspaces are lines passing through the origin?

I wonder why in $\mathbf{R}^2$ the only nontrivial subspaces are lines passing through the origin? Why not some other function (parabola, etc.) passing through the origin? I understand that for $P$ to be a subspace, it has to contain null vector. I do not understand, why it has to be a straight line.


Did the Nazgûl retain their Rings of Power?

In The Fellowship of the Rings, Frodo sees the true appearance of the Nazgûl:      He was able to see beneath their black wrappings. There were five tall figures: two standing on the lip of the dell, three advancing. In their white faces burned keen and merciless eyes; under their mantles were long grey robes; upon their grey hairs were helms of silver; in their haggard hands were swords of steel. Their eyes fell on him and pierced him, as they rushed towards him.   The Fellowship of the Ring - J.R.R. Tolkien - chapter 11, A Knife In the Dark   There's no mention of the Nazgûl wearing the rings of power that Sauron gave them, although their hands are referenced. Did the Nazgûl retain their rings of power once they became wraiths? Or did something else happen to the rings once the Nazgûl emerged?¹  ¹ As an FYI, I am currently re-reading The Lord of the Rings trilogy and am just pages from being done with The Fellowship of the Ring. I'm very familiar with the Peter Jackson movies. So that's where I'm coming from as far as canon knowledge goes.


.htaccess RewriteRule for directory based with two parameters

I need to redirect my webpage in the likes of  /dir/script.php?a=123&b=foobar   to  /123/foobar   I've found many answers for questions like this in this site, but none of them work for my problem. The solution from  answer is almost what I need. It works fine for three parameters:  RewriteRule ^([^/]+)/([^/]+)/([^/]+)$ /letters.php?q=$1&d=$2&t=$3 [NC]   But if I try to rewrite it for two parameters, as need in my case:  RewriteRule ^([^/]+)/([^/]+)$ /dir/script.php?a=$1&b=$2 [NC]   I get a 500 Internal Server Error. My script is not even executed. I have tested the regex in Perl and it works fine. There is nothing wrong with it, but Apache somehow refuses to accept it.  I am using the following Apache version:  Server version: Apache/2.4.10 (Debian) Server built:   Nov 28 2015 14:05:48   Can someone help me get this working?  EDIT:  I can't see how this is a duplicate question. The referred question has no mention whatsoever of a dynamic directory based redirection. It mentions named directory redirection, but that is completely different from what I am trying to achieve.  As requested, the log from Apache shows the following:     AH00124: Request exceeded the limit of 10 internal redirects due to   probable configuration error. Use 'LimitInternalRecursion' to increase   the limit if necessary. Use 'LogLevel debug' to get a backtrace.   EDIT2:  It was actually re-matching the /dir/script.php and redirecting indefinitely. The solution was to add the flag END to the RewriteRule, as specified in the :     An alternative flag, [END], can be used to terminate not only the   current round of rewrite processing but prevent any subsequent rewrite   processing from occurring in per-directory (htaccess) context. This   does not apply to new requests resulting from external redirects.


Simulate multinomial logistic regression model

I want to simulate multinomial logistic regression model i have 3 independent continuous variable. I need to simulate a dependent variable which have 5 levels with suitable beta coefficients. Please can anyone help me?


Why does the equation $x^4 -17 = 2y^2$ have no rational solution?

I am interested in understanding why $x^4 - 17 = 2 y^2$ has no rational solutions.  My first approach was to show that every rational solution leads to an integral solution but that doesn't seem to be the case.


I was trying something like infographic design, typographic design...but I can't find lots of examples or tutorials, and it's weird because I've seen them everywhere!! With those headers and ornaments... If you know where to find these designs or how they're actually called, if they are called something, that would be great! Thank you!


How to add indent even for starting line of paragraph?

\documentclass[10pt, a4paper, oneside]{scrartcl} \usepackage{lipsum}  \title{\normalfont{Technical Report: Loren Ipsum}}  \author{{Alex Murphy}} \date{} \begin{document} \maketitle \section*{Introduction}  \lipsum[1-3] % Dummy text \end{document}  Above code generates below output,  But my supervisor forcing me to make indentation for all starting line of all paragraphs ( even for the initial line of section/subsection ). How can I do so?


Cyanogen's new c-apps dialer not working

I recently installed a CyanogenMod bases rom called AICP one my phone and everything was working fine. Then a couple months later I found CyanogenMod's new c-apps. I decided to flash that. Now whenever I try to make/receive calls the new cyanogen dialer app crashes. Anybody know what's causing this?


Derivation of expression for sagging of a beam

I read in my physics textbook that:     A bar of length $l$, breadth $b$ and depth $d$ when loaded at the   centre by a load $W$ sags by an amount given by the expression   $Wl^3/(4bd^3Y)$ where $Y$ is the Young's Modulus.   How is this expression derived?


Check whether the series is uniformly convergent or not?

which of the following series converges uniformly for $x\in (-π,π)$. 1.$\sum_{n=1}^\infty \frac{x^n}{n^n}$.     2.$\sum_{n=1}^\infty \frac{1}{((x+π)n)^2}$  I was trying to  put putting $x = 0$,then both are uniformly convergent.I'm confused. Please give me hints or any idea, or tell me the solution.I would be much thankful.


When milk is poured into cereal, what is it?

Is it a broth, a sauce, a beverage, or other? this was a question posed to me and I have clue how to answer this.


Given 5 arbitrary points in the plane from which no 3 are collinear, prove that you can always choose 3 that are vertices of obtuse triangle.

I have no idea how to prove it, any advice?


mysql dataSource remove quotes from parameter using select with IN clause

It seems that the mysql select parameter is being inserted with double quotes  string strEstablishments = String.Join(",", myEstablishments);   strEstablishments contains (from the VS2019  debug window)    "'1007','3'"   sqlDSselectEstablishment.SelectParameters.Add("Establishments", strEstablishments);  sqlDSselectEstablishment.SelectCommand = "SELECT EstablishID,Description FROM tblEstablishment WHERE EstablishID IN (@Establishments)";   But this doesn't give the result expected it only returns one result that the dropdown is populated with but should return two (establishments 1007 and 3)  It seems to me the double quotes around the string are being injected which would explain the returned results, I've tried removing them using strEstablishments.Replace("\"","") with no joy.  Running the below command from MySQL directly returns the results as expected:  SELECT EstablishID,Description FROM tblEstablishment WHERE EstablishID IN ('3','1007');   Any ideas how I can get the result as expected using asp.net


"autorun.inf" autogenerated in each drive generates EXE and PIF files in Windows CP

I have Windows XP SP2 installed on my laptop, its been infected by a virus, which creates autorun.inf in each of my drives as read-only, hidden and system file attribute being set, and which generates some EXE file and PIF file. I tried some free versions of anti-rootkit, anti-malware, registry scanning softwares but of no use. For most of them it denies installation. I also tried online scanning but it disconnects the process. Then I deleted them using Live Ubuntu running on a bootable USB. But after rebooting the laptop in Windows XP they were autogenerated again. I think the registry is being affected by the virus which is restoring them. I dont want to format my laptop. Earlier the safemode was also being disbled but anyhow I enabled it then, I tried deleting the autorun.inf files from there Is there any way to check what is causing them to be autogenerate.


How can I fix error 29 in iPhone 4s , I am using the Original battery of the iPhone and the phone was working then it became disabled as I tried flashing it it went to the error error 29 (gas Gauge error) any way to skip it and flash it


Is it possible for Gohan to transform into a super saiyan while in his ultimate form at the same time?

Please I would like to know if it is possible or stated in any official resource.


Simple way to visualize First Cousin marriage

I came across some blood relations / intra family marriages like first cousin marriages in some of my family history books that I have. They are all documented as text in a family history book, not as a pedigree. I tried  to draw such a tree, but no luck. I don't think I can loop back a child node to an ancestor and create a marriage relation, but has to create another duplicate tree.  Reading about , I came across such a . Is this the right way to show a family tree which has first cousin marriages or is there a better way? Is there a software or website where I can do something like this?


Drupal Error : The website encountered an unexpected error. Please try again later

I made a site locally and when I uploaded it to the hosting server, it worked fine except when I went to edit some content type. It showed this error:  The website encountered an unexpected error. Please try again later.   It was showing nothing except the above error. To get more error output, I added a few lines to my index.php file (these lines were added right after the first line):   error_reporting(E_ALL); ini_set('display_errors', TRUE); ini_set('display_startup_errors', TRUE);   The error output was now showing this error:      Fatal error: Uncaught exception 'PDOException' with message   'SQLSTATE[HY000]: General error: 2006 MySQL server has gone away' in   /home/a2682242/public_html/includes/database/database.inc:2171 Stack   trace: #0   /home/a2682242/public_html/includes/database/database.inc(2171):   PDOStatement->execute(Array) #1   /home/a2682242/public_html/includes/database/database.inc(683):   DatabaseStatementBase->execute(Array, Array) #2   /home/a2682242/public_html/includes/database/database.inc(2350):   DatabaseConnection->query('SELECT expire, ...', Array, Array) #3   /home/a2682242/public_html/includes/lock.inc(167): db_query('SELECT   expire, ...', Array) #4   /home/a2682242/public_html/includes/lock.inc(146):   lock_may_be_available('theme_registry:...') #5   /home/a2682242/public_html/includes/theme.inc(449):   lock_acquire('theme_registry:...') #6   /home/a2682242/public_html/includes/bootstrap.inc(446):   ThemeRegistry->set(Array) #7 [internal function]:   DrupalCacheArray->__destruct() #8 {main} thrown in   /home/a2682242/public_html/includes/database/database.inc on line 2171   The site was working fine locally. I am not having much clue as to where the problem is. Is it some problem with the mysql server setting of my hosting provider? Or something else?


Prove $\sum_{i=1}^{i=n}\frac{a_i}{S-a_i}\geqslant \frac{n}{n-1}$ and $\sum_{i=1}^{i=n}\frac{S-a_i}{a_i}\geqslant n(n-1)$.

Let $a_1,a_2,\ldots ,a_n$, be positive real numbers and  S = $a_1+a_2+a_3+\cdots+a_n$. Use the Cauchy-Schwarz inequality to prove that   $$\sum_{i=1}^{i=n}\frac{a_i}{S-a_i}\geqslant \frac{n}{n-1}$$ and $$\sum_{i=1}^{i=n}\frac{S-a_i}{a_i}\geqslant n(n-1)$$  Hint: Apply the inequality to:   $\sum \frac{S}{a_i}$ and $\sum \frac{a_i}{S}$ for one case,     and $\sum a_i(S-a_i)$ and $\sum \frac{a_i}{S-a_i}$ for the other case.


Why did Newt need to cross the Atlantic by steamer?

In Fantastic Beasts And Where To Find Them, we see Newt traveling across the Atlantic by muggle steamship. Isn't there some way for wizards to teleport that distance, or for some entrepreneurial wizard to set up an airline?  Edit:  If so, why wouldn't Newt have used it? Why would he still go by muggle steamer?


Adding Variables Inside Functions for Python

I have a variable a, and I want a to be added with b, like so:  a = a + b   Now, I have my program set up like so:  a = 2 b = 3  def add() :     a = a + b     print(str(a))  add()   Every time I run this, I get  Traceback (most recent call last): File "<stdin>", line 8, in <module> File "<stdin>", line 5, in add UnboundLocalError: local variable 'a' referenced before assignment   instead of  5   Please explain the obvious mistake that I am making.


What are the shell's control and redirection operators?

I often see tutorials online that connect various commands with different symbols. For example:  command1 |  command2 command1 &  command2 command1 || command2     command1 && command2   Others seem to be connecting commands to files:  command1  > file1 command1  >> file1   What are these things? What are they called? What do they do? Are there more of them?    .


How can I make the files created by one user readable/writable by another?

I have a user account I created with no password to run some daemons on my server. I want my user account to be able to read,write, and delete files created by this user. How do I do this? Both users are members of the group "users".


Send email to Google contact group with Inbox

Is it possible to send an email to a  from Inbox? In Gmail you could type the name of a group to automatically add all group members as recipients, but that doesn't seem to work anymore.   Is there no way to do this now?


Can't remember a story about people having unique knacks

There is a story where every one is shown to have a unique knack. For example, one man can make an ashtray-sized object vanish (but he can't bring it back). Another man's knack is to be able to transport a person/object between two cabinets. As far as I recall, this was a short story in some collection.  Thanks for the help!


UEFI install UBUNTU 14.04 Along Windows 8 (Dual Boot)

I have a preinstalled windows 8.1 with secure boot on. i installed ubuntu 14.04 in uefi after which it showed the boot menu for first time, then i booted into windows and then when i started the pc next day(following shutdown) it booted directly into windows. I need to install ubuntu 14.04 on it properly.Please help me through this by possibly giving a detailed order of steps to follow. Thank You


Javascript how to properly clone and not modify an object

I have an object, which i search the keys and modify the values if a key match is found:  var myData = // some http.get which returns a JSON object.   Imagine myData is:  myData : {     "suffix" : "mr",     "fname" : "jullian",     "lname" : "exor",     "dobGmt" : 145754294700000     "addressLine1" : "xxx",     "street" : "xxx",     "rentStartedGmt" : 145754294700000,     "deposit" : "50.00",     "occupation" : "math teacher",     "profession" : {          "careerStartedGmt": 1458755224800000,          "careerEndGmt": 1459854224800000,      } }  $scope.viewData = function() {     var objClone = _.clone(myData);     objClone = myFactory.ProcessData(objClone);     $scope.view = objClone; };  $scope.viewProducts = function() {  };   MyFactory:  myModule.factory('myFactory', function() {     return {         ProcessData: function(data) {             var tmp = data;              function findGmt(tmp) {                 for (var key in tmp) {                     var v = tmp[key];                         if (key.indexOf("Gmt") !== -1) {                             tmp[key] = tmp[key].format('DD-MM-YY HH:mm');                             }                         }                 }              findGmt(tmp);              return tmp;         }     } });   User can click on viewData button which calls $scope.viewData which displays the formatted JSON in a modal on the same page. User then clicks on viewProducts which calls $scope.viewProducts which displays a list of products in a modal on the same page.  However, after clicking viewProducts, if i go back to click viewData again, on debugging, i can see var objClone is already formatted, rather than taking a new clone of _.clone(myData);  Have a missed how to clone/not modifiy original objects?


IS or ARE? "The only thing that I want you to hit right now IS/ARE the books"

In this sentence, which is the right word?     The only thing that I want you to hit right now is/are the books.


Unable to get package manager to work in Ubuntu 11.04

I'm new to Ubuntu. I got a disk from a friend which contains release 11.04 but package manager does not work. How do I solve this?  Here is the error message:  E: Encountered a section with no Package: header E: Problem with MergeList /var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_natty_main_binary-i386_Packages E: The package lists or status file could not be parsed or opened. E: _cache->open() failed, please report.


Place of subdivision surface modifier in the workflow

Good evening everyone. Following BlenderGuru´s donut tutorial, i´ve repeatedly found the same error. These spikes appear around the time i start sculpting. My guess is that it has to do with the subdivision surface modifier (solidify is the only other one), either the values used or the place in the workflow- whether i used/applied it too soon or too late. Could anyone please clarify for me? Thanks a lot!


I know that this is convergent. I've proven it with mathematical induction but I want to know what is the exact limit.I have no idea what to do. can anybody help me?             Lim  $1+\frac{1}{4}+\frac{1}{9}\ldots \frac{1}{n^2}$


Evaluate $\int_0^1 \frac{\ln(1-x^2)\arcsin^2 x}{x^2} {\rm d}x$

Evaluate $$I=\int_0^1 \frac{\ln(1-x^2)\arcsin^2 x}{x^2} {\rm d}x.$$  Maybe, we can make a substitution $x=:\sin u, u\in [0,\pi/2]$. Then  $$I=2\int_0^{{\pi}/2}\frac{u^2\cos u\ln\cos u}{\sin^2 u}{\rm d}u.$$ Can we go on from here?


Someone wants to send me cash by DHL. How's this scam supposed to work?

This raises a bunch of red flags (also confirmed by googling the email address it came from), but I don't quite understand how this scam is actually supposed to work. So, here it goes:   I put up an ad (for a guitar, 90€) on LeBonCoin (the French equivalent of Craigslist). Someone contacts me by text message (anonymous with no actual phone number), saying they want to continue by email. I then get an email, with roughly the following content (rough translation):     OK, I will buy it, but I need to send you cash by "express DHL letter". The DHL driver will pick up the item when he gives you the cash. I need the following information: full name, postal address, price of the item, and your phone number.    I'm guessing that this works by them requesting some "delivery fee" in advance, but does anyone know how this actually works?


I just want to get the first result of this query but whenever I write down LIMIT. Oracle SQL Developer throws me this error   *ORA-00933: SQL command not properly ended 00933. 00000 -  "SQL command not properly ended" *Cause: Action: Error at Line: 6 Column: 7  Here is the Code:  SELECT IDBAR FROM ( SELECT PARRANDEROS.FRECUENTAN.ID_BAR as IDBAR,  COUNT(PARRANDEROS.FRECUENTAN.ID_BAR) c  FROM PARRANDEROS.FRECUENTAN GROUP BY PARRANDEROS.FRECUENTAN.ID_BAR ORDER BY c DESC )   LIMIT 1;   I've tried this method too:  SELECT IDBAR FROM ( SELECT PARRANDEROS.FRECUENTAN.ID_BAR as IDBAR,  COUNT(PARRANDEROS.FRECUENTAN.ID_BAR) c  FROM PARRANDEROS.FRECUENTAN GROUP BY PARRANDEROS.FRECUENTAN.ID_BAR ORDER BY c DESC LIMIT 1  );   Thanks a Lot.


I want to run a programme located in C, which can be run using command line using a line as follows  tclsh oommf.tcl avf2odt -average space -axis z -onefile  <filename>.txt  -headers none -ipat *.omf   This is the only thing I need to type in command line.  How can I run it using python?  Please be VERY relevant to the question. I have seen a lot of answers like: you can use 'subprocess' to realize it. However, none of them really solves the problem.


Benchmarking hosting providers IO with Bonnie

Ok, because of a bunch of projects I'm working on I've access to dedicated Servers on a 3 hosting providers.  As an experiment and for educational purposes I decided to see if I could benchmark how good the IO is with each.  Bit of research lead me to Bonnie++   So I installed it on the server and ran this simple command  /usr/sbin/bonnie -d /tmp/foo    The 3 machines in different hosting providers are all dedicated machines, one is a VPS, other two are on some cloud platform e.g. VMWare / Xen using some kind of clustered SAN for storage   This might be a naive thing to do but here are the results I found.      HOST A      Version 1.03c       ------Sequential Output------ --Sequential Input- --Random-                         -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--     Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP     xxxxxxxxxxxxxxxx 1G 45081  88 56244  14 19167   4 20965  40 67110   6  67.2   0                         ------Sequential Create------ --------Random Create--------                         -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--                   files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP                      16 15264  28 +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++     xxxxxxxx,1G,45081,88,56244,14,19167,4,20965,40,67110,6,67.2,0,16,15264,28,+++++,+++,+++++,+++,+++++,+++,+++++,+++,+++++,+++        HOST B      Version 1.03d       ------Sequential Output------ --Sequential Input- --Random-                         -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--     Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP     xxxxxxxxxxxx     4G 43070  91 64510  15 19092   0 29276  47 39169   0 448.2   0                         ------Sequential Create------ --------Random Create--------                         -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--                   files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP                      16 24799  52 +++++ +++ +++++ +++ 25443  54 +++++ +++ +++++ +++     xxxxxxx,4G,43070,91,64510,15,19092,0,29276,47,39169,0,448.2,0,16,24799,52,+++++,+++,+++++,+++,25443,54,+++++,+++,+++++,+++        HOST C      Version 1.03c       ------Sequential Output------ --Sequential Input- --Random-                         -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--     Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP     xxxxxxxxxxxxx 1536M 15598  22 85698  13 258969  20 16194  22 723655  21 +++++ +++                         ------Sequential Create------ --------Random Create--------                         -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--                   files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP                      16 14142  22 +++++ +++ 18621  22 13544  22 +++++ +++ 17363  21     xxxxxxxx,1536M,15598,22,85698,13,258969,20,16194,22,723655,21,+++++,+++,16,14142,22,+++++,+++,18621,22,13544,22,+++++,+++,17363,21   Ok, so first off what is the best way to read the figures and are there any issues with really comparing these numbers?    Is this in any way a true representation of IO Speed?  If not is there any way for me to test that?  Note: these 3 machines are using either Ubuntu or Debian  (I presume that doesn't really matter)


I just recently installed Ubuntu Server 16.04 LTS on VMware Workstation for a school project. OS installed beautifully; however, when I try to install SNMP on it, I am getting this message:  Media change: please insert the disc labeled 'Ubuntu-xxx 16.04 LTS _Xenial Xerus_ - Release amd 64 (20160420.3)' in the drive '/media/cdrom/' and press [Enter]"    I have tried running an update, re-installing Ubuntu, but still nothing.   I have a x64-big Intel Celeron processor on my PC but according to documentation, the image should be compatible. I did install from a USB-stick though. Could that be the reason why? Any advice would be greatly appreciated. Thanks in advance.


Is there a way to get back items after /clear command

I used the /clear command, and I accidentally got rid of a very important book. Is there a way to get it back without having to rewrite it?


Is it possible to install Nexus factory reset images on other Android devices

The device I want to install Nexus onto is the Onda VI10 tablet.  I found some Nexus factory images , and I would like to install them. Is this possible?