It seems that certain (not all) emoticons are missing in my Windows 7 Ultimate x64 SP1 installation. The table of emoticons from the  looks as follows on my system:    Windows Update  which should address this issue is installed.  What can I do to get the missing emoticons? Deciphering them in incoming E-Mails is getting old... :-)

Is there a specific font or something I need to install/download/configure in order to see emoji characters?   are picture characters/emoticons often used in Japanese webpages and messages.   People can post these from their phones to a site like Twitter, but when I try to read them on my PC (running Windows 7) it doesn't know how to display them.  If there's a reason I can't display them on my machine, is there a reason why not? They're part of unicode, after all.


I would like to merge a point vector layer with a polygon layer. There are some attributes in the polygon layer which I would like to be in the point layer!

I have a polygon layer without data, and a point layer with attributes.  Each point is contained in one polygon, and I would like to have the data from the point layer joint in the polygon layer, so every polygon has the data from the point contained in it.  Is this possible with QGIS?


Hartogs' Theorem states: If $X$ is a set, then there is an ordinal $\alpha$ such that there is no injection from $\alpha$ to $X$. The proof I am familiar with uses unique representation of wellorders by ordinals, which in turn requires the Axiom Scheme of Replacement. How do you prove the following without using Replacement or the Axiom of Choice?     For every set there is a wellorder such that there is no injection from the wellorder to the set.   I had the idea to separate from $\{X\}\times \mathcal P(X \times X)$ the set of all wellorders on $X$ and then to extend this wellorder, but as far as I understand, without the Axiom of Choice we do not know whether there even exists a wellorder on $X$.

I want to build an uncountable well-ordered set within the theory $Z^\textbf-$. So, I take $A=\omega$ (exists by infinity axiom) and define $$W:=\{(X,R)\in\mathcal{P}(A)\times\mathcal{P}(A\times A):\langle X,R\rangle\ \text{is a well-ordered set}\}$$  With this I consider the set $T:=W/\cong$ (where $\cong$ is isomorphism relation). Note that $W$ and $T$ are sets by power set axiom. So I define for each equivalence class $[x],[y]\in T$ the order  $$ [x]\leq_T[y]\Leftrightarrow \text{type}(x, R_x)\leq \text{type}(y,R_y) $$  Here, $R_x$ means the order of $x$ that make it belongs to $[x]$.   So, $T$ is well ordered by $\leq_T$ and it is uncountable.  Question: I don't pretty sure if I can build $\leq_ T$ without replacement axiom. Another doubt is, Can I take the $R_x$ without AC?


I can´t install Ubuntu with Wubi on my Windows 7 laptop, there is a pop up with the message      Could not retrieve the required disk image files

I tried to install Ubuntu 12.10 with the Wubi installer while running Windows, because my PC does not accept my BootCD as a bootable medium.  But Wubi showed me this error:  Ubuntu-Installationsprogramm (X) Ein Fehler ist aufgetreten: Could not retrieve the required disk image files Weiter Informationen finden Sie in der Protokolldatei: c:\users\username\appdata\local\temp\wubi-12.10-rev273.log   What can I do, because I want to get rid of my Windows 7 and use the way better Ubuntu 12.10?  Thanks for your huge answer, now my next problem after trying to install wubi with the .iso is, that the same error shows up again and i am not shure which part of the errorreport you need.  Can you tell me? Because i'm not that good at linux.


I am devloping an app in which i am getting value like mentioned in statement and i have a value in double as.I need to get three digit value after "." How can i do that  value  9.690000000000001

What I would like is a method to convert a double to a string which rounds using the half-up method - i.e. if the decimal to be rounded is 5, it always rounds up to the next number. This is the standard method of rounding most people expect in most situations.  I also would like only significant digits to be displayed - i.e. there should not be any trailing zeroes.  I know one method of doing this is to use the String.format method:  String.format("%.5g%n", 0.912385);   returns:  0.91239   which is great, however it always displays numbers with 5 decimal places even if they are not significant:   String.format("%.5g%n", 0.912300);   returns:  0.91230   Another method is to use the DecimalFormatter:  DecimalFormat df = new DecimalFormat("#.#####"); df.format(0.912385);   returns:  0.91238   However as you can see this uses half-even rounding. That is it will round down if the previous digit is even. What I'd like is this:  0.912385 -> 0.91239 0.912300 -> 0.9123   What is the best way to achieve this in Java?


The Observant feat states:  You have a +5 bonus to your passive Wisdom (Perception) and passive Intelligence (Investigation) scores.  To my knowledge, nowhere else in the rules is there discussion regarding a passive Intelligence (Investigation) score. Furthermore, on D&D Beyond, the Passive Intelligence (Investigation) is included under the character's Senses akin to Darkvision or Blind Sight. Several illusion spells include language along the lines of:  Can use its action to (do something to see through the illusion) and must succeed on an Intelligence (Investigation) check against your spell save DC.  Does the creation of a Passive Intelligence (Investigation) by the feat constitute a scenario of specific beats general rule whereby any illusion that can be defeated by an investigation check automatically fails if the save DC is lower than the passive score created by the feat?

I have been thinking about this for a few days (since taking the Observant feat specifically) and have now seen my logic backed up in .  Let's assume a character has 20 passive Investigation. A level 13 caster with 20 INT, has a DC of (8+5+5) = 18.  Does the character see through the illusion automatically?  I am prepared to consider that there is a range requirement on this, which would be answered by the linked question, so this question assumes the character is already within whatever range is required.


Ubuntu 14.04 to 16.04 upgrade got interrupted due to power failure. Now when I try to upgrade again I am getting the following message:  "Not all upgrades can be installed, run a partial upgrade"    What should I do to upgrade to 16.04?

Yesterday I started the upgrade from 12.10 to 13.04, but I interrupted it because it was taking too long. Now if I restart it, it doesn't proceed.  Is there any possibility to clean the mess it left when I interrupted it and make a clean restart of this update?


Can someone please put some highlights on this, How many slaves can be handled by Master.  I have 100+slaves for a single master, how this process will work?

I currently have a Master with 2 slaves, all running MySql 5.5.  What are the limitations on the amount of slaves I can connect to a single master? what parameters should be taken into affect?


I have a huge MySQL Dump with lots of insert statement using the multiple rows syntax. I need to search for specific content in each row, therefore I want to split the statement to have each row in a extra string.  INSERT INTO tbl_name (a,b,c) VALUES (1,2,'test1'),        (4,5,'test2 (test2a),        (test2b)'),(7,8,'test3');   Result should be a list of the 3 blocks  [     "1,2,'test1'",     "4,5,'test2 (test2a),(test2b)'",     "7,8,'test3'" ]   Question, what is the most efficient way to achieve this. Is it regular expression with some magic? Language does not matter for me. Can do with Java, PHP, Perl ...

I need a regular expression to select all the text between two outer brackets.  Example: some text(text here(possible text)text(possible text(more text)))end text  Result: (text here(possible text)text(possible text(more text)))


How can I write an asterisk symbol over a letter? Thank you very much

I'd like to put one symbol over another? There are some similar things in math, like $\binom{a}{b}$, but I don't want the parentheses, or $\frac{a}{b}$ without the division line.  The closest I've found is $\overset{a}{b}$ (from mathtools) but the a ends up smaller than the b.


Whenever I do 'sudo' I get an error saying 'sudo: unable to resolve host HP-Pavilion'. I recently change my hostname to "HP-Pavilion". I wonder if I screw up something.  $ sudo mkdir SourceCodePro sudo: unable to resolve host HP-Pavilion [sudo] password for mike:   Thank you for your help.

When I run sudo the terminal is stuck for a few seconds and then outputs an error message. My terminal looks like this:  ubuntu@(none):~$ sudo true sudo: unable to resolve host (none)   What can I do to solve it?


I just installed Wine and I realized the applications look terrible. I wanted the look and feel of Windows 8 on my Wine applications, how can I go about doing this? Thanks!

In many cases Windows programs run ok in Wine, but there is still the annoying problem of their appearance.  How to make things look better in Wine, especially fonts?


My phone was snatched. Its Activation Lock was turned off and it was not signed in on iCloud. However, I still see my phone as listed among the devices in iCloud.   Since the iPhone is still in my iCloud's device list, will the next user still be able to use my phone? Or would it be possible for them to add my phone to their iCloud?

Recently, my iPhone 5 was stolen, and while I have a new iPhone 6, I received a message from a number of someone claiming to be in possession of the device, with a new number.   All images, contacts, Outlook mail, you name it, are still on the device.  While I realize it's my fault for not having it connected to iCloud to wipe manually, is there anything I can do to have this sensitive information wiped from the device?


I have a random variable $X$ behave as $ U[0,\alpha]$.  Out of $n$ experiments, I would look at the new random variable $Y=\max(X_1,...X_n)$.  I ask for $E(Y)$.   I know it supposed to be $\alpha \cdot \frac{n-1}{n}$ or something like that (maybe $\alpha \cdot \frac {n}{n+1}$) and I understand why, but all this is intuitive and I don't understand how to prove it.  Thanks in advance for your answers

Let $X_i\sim\mathrm{Uniform}(0,\theta)$ be iid, what is $E[\max\{X_1,\ldots,X_n\}]$? Apparently the answer is $$\frac{n}{n+1}\theta,$$ but I do not see why?  It seems intuitive in that you would "expect" them to be spaced out evenly, hence the maximum would be $\frac{n}{n+1}$-of-the-way along the interval, but how can we prove this mathematically? I feel like it should be simple, but evidently $$E[\max\{X_1,\ldots,X_n\}]\neq\max\{E[X_1],\ldots,E[X_n]\}.$$ Thanks.


I am not being able to solve this question.  It is basically a high school level question and chapter I think is basic fundamentals of maths.  The value of $$\sqrt[3]{24+\sqrt[3]{24+\sqrt[3]{24+\cdots}}}$$ is equal to ...  an even number a prime number a composite number an even prime number

Find the value of the following infinite series: $$\left\lfloor\sqrt[3]{24+\sqrt[3]{24+\sqrt[3]{24+\cdots}}}\right\rfloor$$  Now, my doubt is whether it's $2$ or it's $3$. I'm not sure if it just converges to $3$ but not actually reaches it or if it completely attains the value of $3$.  I would to like to see the proof (formal) as well instead of just intuitions.


I have a Spring mvc form with input text field. I map that field with a java Date object. When I type the date wrong (For example 34/01/1985), in the backend it is auto correct the date and give it as 03/02/1985 (03 Feb 1985). I want to stop this auto correction to validate the in the backend.  Folks, give me a solution?   Update :  <form:input path="person.dateOfBirth" placeholder="DD/MM/YYYY"/>   public class Person  implements Cloneable{  @DateTimeFormat(pattern = "dd/MM/yyyy")     private Date dateOfBirth;     public Date getDateOfBirth() {         return dateOfBirth;     }     public void setDateOfBirth(Date dateOfBirth) {         this.dateOfBirth = dateOfBirth;     } }  public void  post(              PortletSession session,             ActionRequest request,             ActionResponse response,              @ModelAttribute("form") Form form,             BindingResult errors,             ModelMap mm) throws Exception {  print(form.getPerson().getDateOfBirth());  }

I find it curious that the most obvious way to create Date objects in Java has been deprecated and appears to have been "substituted" with a not so obvious to use lenient calendar.  How do you check that a date, given as a combination of day, month, and year, is a valid date?  For instance, 2008-02-31 (as in yyyy-mm-dd) would be an invalid date.


I'm trying to parse a simple Webservice and I'm receiving this error:      Apex Generation Failed:      Unable to find complexType for {.***}RelationshipReferenceTo   There are two lines in the WSDL file with the RelationshipReferenceTo:  <xsd:complexType name="EntityParticle"> <xsd:element name="ReferenceTo" minOccurs="0" type="tns:RelationshipReferenceTo" nillable="true"/>   And   <xsd:complexType name="FieldDefinition"> <xsd:element name="ReferenceTo" minOccurs="0" type="tns:RelationshipReferenceTo" nillable="true"/>   Can anyone help to solve this problem and allow me to parse this XML file?

My first post,pretty excited.I want to make a soap api call which insert multiple records. I am using 2 different salesforce instances. destination side  global with sharing class SoapDemo1 {    global class AccountWrapper    {       webservice string Name;       AccountWrapper(Account a)       {         this.Name=a.Name;       }    }     webservice static List<Account> CreateMultipleAccounts(List<Account> accs)    {        List<Account> FinalList=new List<Account>();         for(Account a:accs)        {           Account a1=new Account();           a1.Name=a.Name;            FinalList.add(a1);           }         if (FinalList.size() > 0)        {           Database.Insert(FinalList);        }         return FinalList;     }     }   I generated the class wsdl file and also partner wsdl file  ****source side:**** I upload the class wsdl file generated from destination, when I parse no errors, but when I click Generated Apex code, it shows error as:     Unable to find complexType for   {}anyType    I changed anyType to string and again repeated the process but it shows error as:     Unable to find complexType for   {}JunctionIdListNames   Please help me out


My current bike tyres are 26 x 2.0 (Manufacturer fitted tyres)  Is it possible to fit 26 x 2.1 or 26 x 1.95 on these wheels or is this going to cause an issue?

We often get questions on bicycles.stackexchange about fitting wider or narrower tires to bicycles. We have a large number of these with answers suiting the specific bike or style of bicycle in question, but I have been unable to find one that provides a generic answer covering off all things that need to be considered. For most bicycles, the answer is the same regardless of the specific style and sizes of tires in question.   This is intended as a canonical question that we can point closed questions to.


Could anyone clearly explain    what is Sharepoint authentication realm (the one set by  cmdlet)? In what cases do I need to set this realm equal for 2 (or more) farms, and in what cases do I have to set the realm ID different for the farms? What are the possible usage cases of the authentication realm values?   As SharePoint's documentation, as usual, only covers the simplest and superficial terms/notions and cases, this info would be very useful.

I have a SharePoint 2013 environment with several High-Trust Addins. This must now be upgraded to SharePoint 2016.  My Questions:   I was unable to find any documentation on the required steps. Links are welcome. Do i have to migrate App-Management Service and Subscription Settings Service?  don't even mention them.   say yes, but linked background is no longer available.  , i had to create a New-SPTrustedSecurityTokenIssuer. In this step, a RegisteredIssuerName had to be specified. This IssuerName consists of the Realm and the .   I think IssuerID can and should be migrated to SharePoint 2016, as it it also defined inside the High-Trust app. What about the Realm? This is by default the same value as FarmID. If i migrate this value, i have to change the Realm in SharePoint 2016. Or should i create the TST with a new Realm and existing IssuerID?


Consider a triangle with vertices $$(0,0),(a,0), (0,b)$$ where $a≥b>0$ The triangle contains $74$ lattice points in its interior (not including vertices). What is the sum of the areas of all such triangles? I have drawn a diagram but that is about all I am able to translate into math form this question

Here is a problem I was given: A lattice point in the plane is a point whose coordinates are both integers. Consider a triangle whose vertices are lattice points (0,0),(a,0) and (0,b), where b≤a. Suppose the triangle contains exactly 74 lattice points in its interior, not including those lattice points on the sides of the triangle. Determine the sums of the areas of all such triangles. The only way that I could see to do this problem was to try all possible values of a, checking to see which values of b gave 74 lattice points. I did this and gave up at a=5 so I suspect there must be an easier way. I was thinking Pick's theorem would be useful but I couldn't think of what to do with it. Can anyone provide a shortcut, or at least just give me the answer? By the way, I know it is less than 1000.


I am trying to read a simple text file into a String. Of course there is the usual way of getting the input stream and iterating with readLine() and reading contents into String.   Having done this hundreds of times in past, I just wondered how can I do this in minimum lines of code? Isn't there something in java like String fileContents = XXX.readFile(myFile/*File*/) .. rather anything that looks as simple as this?  I know there are libraries like Apache Commons IO which provide such simplifications or even I can write a simple Util class to do this. But all that I wonder is - this is a so frequent operation that everyone needs then why doesn't Java provide such simple function? Isn't there really a single method somewhere to read a file into string with some default or specified encoding?

I've been using the idiom below for some time now. And it seems to be the most wide-spread, at least on the sites I've visited.  Is there a better/different way to read a file into a string in Java?  private String readFile(String file) throws IOException {     BufferedReader reader = new BufferedReader(new FileReader (file));     String         line = null;     StringBuilder  stringBuilder = new StringBuilder();     String         ls = System.getProperty("line.separator");      try {         while((line = reader.readLine()) != null) {             stringBuilder.append(line);             stringBuilder.append(ls);         }          return stringBuilder.toString();     } finally {         reader.close();     } }


Came in from store but forgot to put up my Tyson fully cooked chicken patties. Never opened, seal not broken, 20 hrs later--do I trash em?

If I left food out of the refrigerator for some period of time, is it still safe? If I left it out too long, can I salvage it by cooking it more?


My bank has an app for Android phones, but that same app won't install on my tablet.  Is there a way to determine what capability or permission is blocking it from even being listed in the Play store?

I own a Motorola Flipout, Android 2.1 stock ROM. According to the market the app "" is not compatible with my phone. The required Android version is 1.5 or above. How can I tell why the app will not work for me?    The Flipout has a comparably small screen. Is it possible that the publisher just forgot to mark my phone's display resolution as supported?  Note: Users from outside Germany see a different message. I believe, those country-restriction are unrelated.


I am new to the ubuntu operating system and for some reason after installing it I do not see any wireless connections. My system uses:  02:00.0 Network controller [0280]: Broadcom Limited BCM43142 802.11b/g/n [14e4:4365] (rev 01)  So far I have tried   1.Turn off the secure boot  2.Remove bcmwl-kernel-source sudo apt-get purge bcmwl-kernel-source  3.Re-install bcmwl-kernel-source and the kernel header: sudo apt-get install linux-generic bcmwl-kernel-source  4.Reboot sudo reboot  After I reboot, nothing changes at all.  When I run: sudo lshw -C network  This is what I get for the network controller:    *-network UNCLAIMED             description: Network controller        product: BCM43142 802.11b/g/n        vendor: Broadcom Limited        physical id: 0        bus info: pci@0000:02:00.0        version: 01        width: 64 bits        clock: 33MHz        capabilities: pm msi pciexpress cap_list        configuration: latency=0        resources: memory:b0500000-b0507fff   I believe the network controller driver is not installed properly, therefore not working but I am not sure.   Can anyone suggest anything to try and get this to work.  Thank you!

This issue happens only on UEFI systems with enabled Secure Boot.  When I try to install DKMS modules like VirtualBox, Nvidia, or Broadcom drivers, they do not install and I get Required key not available when I try to modprobe them.  VirtualBox complains that vboxdrv is not loaded.  Broadcom wl driver is shown in lspci -k as a kernel module but is not in use. sudo modprobe wl throws Required key not available.  Also this issue may happen when I install some kernel modules from git sources.  This issue may appear after a kernel update as disabled wireless adapter, black screen after a reboot, etc.   How can I fix it?


I am learning Java from HeadFirst Java. When I run the app, it shows the circle first. But when I click the Button, it fires the below error. Below is the code and error:  import java.awt.*; import java.awt.event.*; import javax.swing.*; public class GUI implements ActionListener { JFrame frame;  public static void main(String[] args) {     GUI g = new GUI();     g.go(); }  private void go() {     JFrame frame = new JFrame("Title");     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);     JButton button = new JButton("Change Color");     button.addActionListener(this);      MyWidget my = new MyWidget();      frame.getContentPane().add(BorderLayout.SOUTH, button);     frame.getContentPane().add(BorderLayout.CENTER, my);     frame.setSize(300, 300);     frame.setVisible(true);  }  @Override public void actionPerformed(ActionEvent e) {     frame.repaint(); } } class MyWidget extends JPanel { @Override public void paintComponent(Graphics g) {     Graphics2D g2 = (Graphics2D) g;     int red = (int) (Math.random() * 255);     int green = (int) (Math.random() * 255);     int blue = (int) (Math.random() * 255);     Color startColor = new Color(red, green, blue);     red = (int) (Math.random() * 255);     green = (int) (Math.random() * 255);     blue = (int) (Math.random() * 255);     Color endColor = new Color(red, green, blue);     GradientPaint gradient = new GradientPaint(70, 70, startColor, 150, 150, endColor);     g2.setPaint(gradient);       g2.fillOval(70, 70, 100, 100); }   }   Here is what I getting on console:  Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException at HeadFirstJava.GUI.actionPerformed(GUI.java:32) at javax.swing.AbstractButton.fireActionPerformed(Unknown Source) at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source) at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source) at javax.swing.DefaultButtonModel.setPressed(Unknown Source) at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source) at java.awt.Component.processMouseEvent(Unknown Source) at javax.swing.JComponent.processMouseEvent(Unknown Source)

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


I tried to write my code with and without the syntax "@Override", and both times I receive the same output. Therefore, why should I bother to write the syntax "@Override" before my method in the subclass?  With:   Without:

What are the best practices for using Java's @Override annotation and why?     It seems like it would be overkill to mark every single overridden method with the @Override annotation.   Are there certain programming situations that call for using the @Override and others that should never use the @Override?


I have an animation where a cube goes from point A to B. When it reaches B, he will be out of sight from the camera.  How can I make a "cut", a.k.a., make the camera now show point B, where the cube is?  Kind of like transition from Scene 1 over to Scene 2; I don't have any scenes, though.

I have multiple cameras in a scene. What I want to do is to change which one is active. This way I can view the scene from different angles. How would I do this?


Hardware damage caused by USB Type-C cables by drawing too much power has been widely reported:                Can other  cause this type of damage? Is this issue entirely limited to Type-C?

There's a lot of press about how  - as I understand it, they have the wrong resistor, and that causes the device to draw too much power.  On the other hand, I'd like to get a cheap USB A to C cables for stashing around the house. I also currently have a probably nonstandard cable that came with the phone - designed to handle up to 5v 4A - I have a one plus three and its part of the dash charge quick charge system. I'm assuming that's safe for use with a PC though.  While "get cables that have been tested by " is a good idea, having a standard way to test my cables that do not involve having a nexus 5x or 6p would be nice.  From what I understand, the issue is with excessive current draw - would monitoring the current draw phone side, with an app like ampere be sufficient, and what current is 'safe' for a phone connected to a PC?   If I were to wish to check the resistance, where would it be?   In short, how, short of picking up another phone (a nexus- and using check), can I test to see if its safe for my current phone and pc(s)?  I'll be using a variety of possible charging sources - but more importantly, I want a cable spare I can use to connect my phone for data transfer. For my purposes, let's assume a windows 10 PC with a powered USB hub as a baseline for testing. I'd likely use legacy USB A -> USB C cables for the most part.   I'd also add, it's plausible that the problem might be specific to certain phone/pc combinations. The OP2 apparently would use any USB cable, in spec or not. The nexuses might not have. Hence testing for my hardware


I have a problem with a java plugin. I want to create a File with name "spawns.yml" in a Folder with the name of the main class. So i have 2 Classes.  The Main-Class called Tutorial:   import java.io.File; public class Tutorial extends JavaPlugin {   private static Tutorial plugin;   private File f;   private FileConfiguration fc;   public void onEnable()   {     f= YamlHandler.createFile("Spawns.yml");     fc=YamlHandler.createYamlFile(f);     YamlHandler.saveYamlFile(fc,f);     plugin=this;   }   public static Tutorial getInstance()   {     return plugin;   } }   And the YamlHandler, where the problem is:  import java.io.File; import java.io.IOException;  import org.bukkit.configuration.file.FileConfiguration; import org.bukkit.configuration.file.YamlConfiguration;  public class YamlHandler {     public static File createFile(String filename)     {         File dir=new File(Tutorial.getInstance().getDataFolder().getAbsolutePath()+File.separator+Tutorial.getInstance().toString());         dir.mkdir();         File f= new File(dir.getAbsolutePath() + File.separator + filename);         if(!f.exists())         {             try {                 f.createNewFile();             } catch (IOException e) {                 // TODO Auto-generated catch block                 e.printStackTrace();             }         }         return f;     }     public static FileConfiguration createYamlFile(File f)     {         FileConfiguration fc= YamlConfiguration.loadConfiguration(f);          return fc;     }      public static void saveYamlFile(FileConfiguration c,File f)     {         try {             c.save(f);         } catch (IOException e) {             // TODO Auto-generated catch block             e.printStackTrace();         }      }  }   The Exception says:        java.lang.NullPointerException                at YamlHandler.YamlHandler.createFile(YamlHandler.java:17)~[?:?]  which is this line:    File dir=new File(Tutorial.getInstance().getDataFolder().getAbsolutePath()+File.separator+Tutorial.getInstance().toString());`   Any ideas?


Now I just want to identify that disk again and merge with my MacOS disk so I can use the full 2TB again. That's my disk utility list :  /dev/disk0 (internal, physical): #:                       TYPE NAME                    SIZE       IDENTIFIER  0:      GUID_partition_scheme                        *2.0 TB     disk0  1:                        EFI EFI                     209.7 MB   disk0s1  2:         Microsoft Reserved                         16.8 MB    disk0s2  3:                 Apple_APFS Container disk1         1.0 TB     disk0s3  /dev/disk1 (synthesized): #:                       TYPE NAME                    SIZE       IDENTIFIER 0:      APFS Container Scheme -                      +1.0 TB     disk1 1:                APFS Volume MacOS - Data            7.4 GB     disk1s 2:                APFS Volume Preboot                 25.1 MB    disk1s2 3:                APFS Volume Recovery                525.4 MB   disk1s3 4:                APFS Volume VM                      8.6 GB     disk1s4 5:                APFS Volume MacOS                   11.0 GB    disk1s5

So I removed bootcamp and now there is a partition called "free space" that I can't remove.  Here is my output from diskutil list:    Here is the screenshot from disk utility showing the partitions:    And here is the error I get when I try to remove "free space":    Heres the output when I run   sudo diskutil apfs resizeContainer disk0s2 0


Given two (possibly infinite) sequences of complex numbers $\{a_1, a_2, \ldots\}$ and $\{b_1, b_2, \ldots\}$, I'm looking to find a closed form expression for each element of the sequence of complex numbers $\{c_1, c_2, \ldots\}$ where the sequences are related by  $$\frac{1+\sum_{n=1}^\infty a_n x^n}{1+\sum_{m=1}^\infty b_m x^m} = 1+\sum_{r=0}^\infty c_r x^r\,.$$  Essentially, I am looking for a rapid computational algorithm to find the Taylor series expansion coefficients of a general rational function.    Edit: The problem can be simplified to finding a series expansion of $(1+\sum_{m=1}^\infty b_m x^m)^{-1}$ since then the $c$ coefficients are given by the series product.

Let's say I have two power series $\,\mathrm{F}\left(x\right) = \sum_{n = 0}^{\infty}\,a_{n}\,x^{n}$ and $\,\mathrm{G}\left(x\right) = \sum_{n = 0}^{\infty}\,b_{n}\,x^{n}$.  If I define the function $\displaystyle{\,\mathrm{H}\left(x\right) = \frac{\mathrm{F}\left(x\right)}{\mathrm{G}\left(x\right)} = \frac{\sum_{n = 0}^{\infty}\, a_{n}\,x^{n}}{\sum_{n = 0}^{\infty}\, b_{n}\, x^{n}}}$, is there a general way to expand $\,\mathrm{H}$ such that $\,\mathrm{H}\left(x\right) = \sum_{n=0}^{\infty}\,c_{n}\,x^{n}$ ?.  I guess, what i'm asking is if there is a way to get the first few $c_{n}$ coefficients ?. I'm dealing with a physics problem in which I have two such functions $\,\mathrm{F}$, $\,\mathrm{G}$ and I'd like to get the first few terms in the power series $\,\mathrm{H}$.


I have figured out the base of the problem, but I have no idea how to fix it. I have a user configured named files, which has write permissions to /var/www/html/files/ and can write and read fine to it. However, when uploading a file, my apache server gets a 403 forbidden error upon viewing it. To fix it, I have to SSH into my server and chown the directory to the www-data user to see the file. Obviously, I don't want to do this every time I upload an image, since this is very frequently. How to fix?

I want to stop having to use sudo everytime I work in /var/www. How can I do that? I simply want to put all of my sites into this directory and work with them without too much pain.


I got the Ubuntu Unity desktop on my Chromebook through Chroot. I realized there was a update ready, 14.04 Trusty Tahr. I start the process, and it gets to where the computer restarts. When I boot the computer back up, the Chroot is unable to start again. Did the update make the Chroot invalid??

What is the proper way to upgrade Ubuntu chroot environment to a newer Ubuntu release? The chroot environment has been originally set up using debootstrap.  The proper way to upgrade a Ubuntu server is to use do-release-upgrade command.  Ubuntu is based on Debian. Debian can be upgraded by replacing the release name in /etc/apt/sources.list with the new release name and running apt-get update, apt-get upgrade and apt-get dist-upgrade.  Which one is the proper way to upgrade a Ubuntu chroot environment? What does do-release-upgrade do differently from the Debian way?


I have MATLAB 2016a installed on Ubuntu 16.4. I can launch MATLAB from the command line but I am unable to successfully launch it from the icon in 'Search' or if I try to create a shortcut. Does anyone have a solution that will allow me to create a working shortcut?

I've installed MATLAB R2011a on Ubuntu 11.10 today following . I've also followed the steps to create the launcher. It appeared, but when I click on it nothing happens. Does anyone knows what can I do to fix it? Additional info I can run it perfectly through terminal. My only problem is getting the launcher to work. To create the launcher I used :   Get an icon:  sudo wget http://upload.wikimedia.org/wikipedia/commons/2/21/Matlab_Logo.png -O /usr/share/icons/matlab.png   Get the launcher file:  sudo wget 'https://help.ubuntu.com/community/MATLAB?action=AttachFile&do=get&target=matlab-r2011a.desktop' -O /usr/share/applications/matlab.desktop


Show that $\sum_{k=1}^{\infty}\frac{k}{2^k}=2$   I have no idea to calculate this sum. I　try shift index since $k=0$ gives 0, tis won't change the sum. But I don't know how to keep going. Can someone give me a hint or suggestion to calculate this sum? Thanks

How can I evaluate $$\sum_{n=1}^\infty\frac{2n}{3^{n+1}}$$? I know the answer thanks to , but I'm more concerned with how I can derive that answer. It cites tests to prove that it is convergent, but my class has never learned these before. So I feel that there must be a simpler method.  In general, how can I evaluate $$\sum_{n=0}^\infty (n+1)x^n?$$


I have about 80 predictor variables (with some multicollinearity, I assume) and a non-normal count data response variable (n=570) which is arranged into groups (n=34). I need to reduce the number of predictors for the use of GLM and/or GLMM. Ideally, the number for regression model in this case would be about 4 or 5 predictor variables.  Spearman's correlation, linear or curvilinear trend line in excel would be an easy way (for me as a student) for looking the most obvious predictors, but I think I need to do that for each group separately, and that obviously will result in a large number of coefficients. Is it appropriate to use the highest correlation coefficient average to "judge" the best predictors for later use? So I would be comparing coefficient averages (got from a single grouped variable) of different variables.  I'm sure there are plenty of better ways to choose the best predictors and feel free to suggest methods. Just to mention every one of those 80 predictors could be important.

I would like to implement an algorithm for automatic model selection.  I am thinking of doing stepwise regression but anything will do (it has to be based on linear regressions though).   My problem is that I am unable to find a methodology, or an open source implementation (I am woking in java). The methodology I have in mind would be something like:   calculate the correlation matrix of all the factors pick the factors that have a low correlation to each other remove the factors that have a low t-stat add other factors (still based on the low correlation factor found in 2.). reiterate several times until some criterion (e.g AIC) is over a certain threshold or cannot or we can't find a larger value.   I realize there is an R implementation for this (stepAIC), but I find the code quite hard to understand. Also I have not been able to find articles describing the stepwise regression.


All I watch is crime documentaries. All I watch are crime documentaries.  I mean, I know "is" refers to one and "are" is for multiple, but does the "All I watch" at the start mean "is" makes more sense, seeing as that's what comes first. I think it would make more sense using "are" if you said: "Crime documentaries are all that I watch". I know you could rephrase the sentence in question, but for the two I have mentioned, which one is correct?

In one of Oasis's songs — Cigarettes and Alcohol — there are two sentences that make me confused:     All I found was cigarettes and alcohol   ...and...     All I need is cigarettes and alcohol   Why would is and was be correct in these sentences instead of are and were, since they're referring to more than one thing?


Given $f$ defined at $G$ and $f^3,f^2$ holomorphic at G prove $f$ holomorphic My try: $f^3-f^2$=$f^2(f-1)$ because the LHS is holomorphic so does the RHS and then we get that $f-1$ is holomorphic and $f$ is holomorphic, is this right?

Let $f: \mathbb{C} \to  \mathbb{C}$ be a continuous function such that $f^2$ and $f^3$ are both analytic. Prove that $f$ is also analytic.   Some ideas: At $z_0$ where $f^2$ is not $0$ , then $f^3$ and $f^2$ are analytic so $f = \frac{f^3}{f^2}$ is analytic at $z_0$ but at $z_0$ where $f^2$ is $0$, I'm not able to show that $f$ is analytic.


I need to merge two states in the Transition Matrix:  For example: I have the matrix below            A       B       C      D      E      F        A  0.5     0.4      0      0      0.1    0        B  0.5     0.1      0.2    0.1    0.1    0        C  0       0.1      0.9    0      0      0        D  0       0        0      0.7    0.3    0        E  0       0.2      0      0.7    0      0.1        F  0       0        0      0.5    0      0.5   And I want to join the states $D$ and $E$:            A      B        C    (D+E)    F        A  0.5     0.4      0      ?      0        B  0.5     0.1      0.2    ?      0        C  0       0.1      0.9    ?      0     (D+E) ?       ?        ?      ?      ?        F  0       0        0      ?      0.5   What are the formulas to obtain the row and column $(D+E)$?  Using the constraint: "the sum over column must be equal to $1$" is simple to calculate the elements: $$ (A,(D+E))=0.2 \\  (B,(D+E))=0.2\\ (C,(D+E))=0.1\\ (F,(D+E))=0.5\\ $$ How can I calculate the elements of row $((D+E),i)$?

I need to merge two states in the Transition Matrix:  For example: I have the matrix below        A       B       C      D      E      F    A  0.5     0.4      0      0      0.1    0    B  0.5     0.1      0.2    0.1    0.1    0    C  0       0.1      0.9    0      0      0    D  0       0        0      0.7    0.3    0    E  0       0.2      0      0.7    0      0.1    F  0       0        0      0.5    0      0.5   And I want to join the states D and E:            A      B        C    (D+E)    F        A  0.5     0.4      0      ?      0        B  0.5     0.1      0.2    ?      0        C  0       0.1      0.9    ?      0     D+E   ?       ?        ?      ?      ?        F  0       0        0      ?      0.5   What are the formulas to obtain the row and column (D+E)?  Using the constraint: "the sum over column must be equal to 1" is simple to calculate the elements:  (A,(D+E))=0.2  (B,(D+E))=0.2  (C,(D+E))=0.1  (F,(D+E))=0.5  How can I calculate the elements of row ((D+E),i)?


I'm playing grand theft auto 5. I needed to earn money from any character of GTA. So how can I earn money easily?

What are some of the most efficient ways to make money?   Based on:    time initial investment required progress (in the game) special equipment/gear


I kinda understand the logic and motivation behind the proof, but what bothers me is the fact, why is the base case (the first statement that we write) is always $P(1)$ when we are proving a proposition is true for all $\mathbb{N} $? Why can't it be anything other than $1$? What about $P(5)$ or something? Does it change anything?

I attempted a proof of mathematical induction using an arbitrary base case, but was unsuccessful (and hence this question). Below is what I was trying to do and along with my thinking; if anyone can point me in the right direction I'd appreciate it.  The induction I am using: Let $P$ be a property about the natural numbers $\mathbb{N}$ with $0\in\mathbb{N}$, and let $P(n)$ denote the statement that the property $P$ holds for $n\in\mathbb{N}$. Suppose $P(0)$. Furthermore suppose that for each natural number $k$, $P(k)$ implies $P(k+1)$. Then $\forall nP(n)$.  What I am trying to prove: Let $P$ be a property about the natural numbers $\mathbb{N}$ with $0\in\mathbb{N}$, and let $P(n)$ denote the statement that the property $P$ holds for $n\in\mathbb{N}$. Suppose for $n_0\in\mathbb{N}$, $P(n_0)$. Furthermore suppose that for each natural number $k\geq n_0$, $P(k)$ implies $P(k+1)$. Then $\forall n\geq n_0 P(n)$.  My attempted proof: define $Q(n)$ to be $n\geq n_0 \to P(n)$. Then we wish to prove $\forall nQ(n)$. We induct on $n$.  Base case (for ordinary induction): $Q(0)$ is $0\geq n_0\to P(0)$. Since $n_0\in\mathbb{N}$, $0\geq n_0$ implies that $n_0=0$. Since $P(n_0)$, $P(0)$, which proves the base case.  Inductive step: we want to show $\forall n(Q(n)\to Q(n+1))$. To do this, we assume $k\geq n_0 \to P(k)$ and try to show $k+1\geq n_0 \to P(k+1)$.  Since $k\geq n_0 \to P(k)$, we first prove the case where $k\geq n_0$ and $P(k)$. By the hypothesis of the proof, we see that $P(k+1)$, which proves the case for $k+1$.  This is where I am having trouble: For $k<n_0$, I am unable to show the implication for $k+1$.  So my questions would be: (1) is the overall approach for the proof correct? (2) If so, how might I go on to prove the case when $k<n_0$?  Thanks in advance. (This is not homework, by the way.)


I have a code where I try to get a path from an input so this program could append info to another text file. file1 = input("Input the file path:\n") file2 = file1.replace("\", "/")  file2 = file1.replace("\", "/")                               ^ SyntaxError: EOL while scanning string literal  I get this problem and it seems to be because the \ is not seen as a string (if I put \n for example it does work but I need to replace ) An alternative for replacing \ with / could also fix my problem. I used to use r"filepath" but I can't do that with an input I think. I just need to make the input into a raw string.

Technically, any odd number of backslashes, as described in .  >>> r'\'   File "<stdin>", line 1     r'\'        ^ SyntaxError: EOL while scanning string literal >>> r'\\' '\\\\' >>> r'\\\'   File "<stdin>", line 1     r'\\\'          ^ SyntaxError: EOL while scanning string literal   It seems like the parser could just treat backslashes in raw strings as regular characters (isn't that what raw strings are all about?), but I'm probably missing something obvious.


I have a multiple entry Schengen visa that is valid till June 8, 2019 from Dutch Embassy and I have to travel to Italy on June 9, 2019. Do I need to cancel my Schengen visa before applying for new visa?

I have an existing Schengen visa given by Netherlands and expires on April 27, 2019. I am applying again for a visa going to france, my flight schedule is on April 29-may 6 2019. Do I still need to process the cancellation of my existing visa where in fact it is expiring before my flight. Some said existing visa should be cancelled before you can apply for new visa.


I have recently been trying to refresh my memory on the Quantum Field Theory I learned 25 years ago while getting my Ph. D. At the time I did not study Chern-Simons modifications to QFT Lagrangians. Can someone point me to some good notes on the topic? I really want to understand the "utility" of those terms. Why do we want them there?

I'm interested in learning about topological QFT including Chern Simons theory, Jones polynomial, Donaldson theory and Floer homology - basically the kind of things Witten worked on in the 80s. I'm looking for pedagogical reviews rather than original articles. Though these things sit at the interface of mathematics and physics I'm interested in them more as a physics student. I remember someone asking for a suggested . The suggested papers were almost uniformly rigorous mathematics written by mathematicians. I am not looking for something like that.


In java we can create String in the following 2 ways -    String str1 = new String("first string");  //1  String str2 = "second string";  //2   Is there any difference in performance  with these 2 approaches? And in the second case is there any new String object created? Thanks in advance.

I'm a C++ guy learning Java. I'm reading Effective Java and something confused me. It says never to write code like this:  String s = new String("silly");   Because it creates unnecessary String objects. But instead it should be written like this:  String s = "No longer silly";   Ok fine so far...However, given this class:  public final class CaseInsensitiveString {     private String s;     public CaseInsensitiveString(String s) {         if (s == null) {             throw new NullPointerException();         }         this.s = s;     }     :     : }  CaseInsensitiveString cis = new CaseInsensitiveString("Polish"); String s = "polish";    Why is the first statement ok? Shouldn't it be   CaseInsensitiveString cis = "Polish"; How do I make CaseInsensitiveString behave like String so the above statement is OK (with and without extending String)? What is it about String that makes it OK to just be able to pass it a literal like that? From my understanding there is no "copy constructor" concept in Java?


A chocolate bar is divided into an m x n grid and one of the corner pieces is poisoned. In the chocolate bar game, two players take turns alternately dividing the chocolate into two pieces and choosing which of the pieces to eat. The players may only break the chocolate bar along a single grid line. The person who is forced to take the poisoned piece loses. For which values of m, n, does  (a) the first player have a winning strategy? (b) the second player have a winning strategy?  Prove your conjecture by induction. Hint: set k = min{m,n} and use induction on k.  Edit: This is an assignment question. I managed to reduce the question down into base cases of a 2x2 grid (where player 2 wins), a 2 x m grid where m >= 3 (player 1 wins), and a 3 x m grid where m >= 3 (player 2 wins). The loser for the larger grids can be determined by whoever is the last player to reduce the grid to 3 x m. The problem is I am unable to show this using an induction proof.

About two weeks ago, a friend of mine taught me the following game without his knowing the answer. It may be famous, but I haven't known it.  There are $N\ (\in\mathbb N)$ chocolate bars composed of $a_i\times b_i\ (i=1,2,\cdots, N)$ squares of chocolate. Here, suppose that $a_i$ is the length of the vertical edge of each square, and that $b_i$ is the length of the horizontal edge of each square. Also, let $a_i,b_i$ be natural numbers. (see below. $N=4$ case.)   $\ \ \ \ $  Two players $A, B$ take turns picking up a piece of chocolate and cutting it along the grid lines. A player cuts through and creates a new pieces. The first player $A$ always has to cut it horizontally. The second player $B$ always has to cut it vertically. One must not turn around the squares. A player that has no place to cut loses. (see below. $N=3$ case in which the game will be continued.)   $\ \ \ \ $  Examples : If there is a chocolate bar composed of $3\times 2$ squares of chocolate, then the player $B$ wins. If there is a chocolate bar composed of $4\times 2$ squares of chocolate, then the player $A$ wins.      Question : In what cases does the player $A$ win? Why?    I have a conjecture.   My conjecture : The player $A$ wins $\iff \sum_{i=1}^{N}\lfloor \log_2 a_i\rfloor\gt \sum_{i=1}^{N}\lfloor\log_2 b_i\rfloor$ holds.  This seems true for $N=1$ case and some other smaller cases, but I don't think I've succeeded in proving this strictly. Of course it may not be true. Can anyone help?  Edit : I edited the notation. I hope this time is not confusing.


I just added a comment . The poster (眠りネロク) has a non-western username, which I copy-pasted into the comment (I don’t have Japanese language input ability installed on my PC).   However, I notice that doing so failed to activate the "link-to-reference" kind of behavior I've come to expect on SE, meaning that it is unlikely that the poster will know I just tried to tag him with a note.  Is this a failing with the language on SE? (Japanese is well-within the BMP.) Or did I do something wrong?  edit  I do not consider this a duplicate of (above): the question is about using CJK characters with @, not whom can I ping (which I admit I did wrong).

How do the comment replies (aka "pinging users") work?  Who can I send an @reply to? How do I respond to a specific user when entering my comment? Will they be notified? What do people mean when they talk about "pinging" another user?  Related:


I have a code for submitting an article which in this form there is a title input and file input for the article file.   but problem is if in the title i write for ex : this is hi's article  this article would not submit and will fail. the code for replacing spaces in title is :   //pereventing spaces for article title $pdf_file=str_replace(" ", "_", $_FILES['msfile']['name']);  /* define the path to the upload folder */ $destination='../pdf/'; move_uploaded_file($_FILES['msfile']['tmp_name'], $destination.$pdf_file);    //inserting info into articles mysql_connect($host,$username,$password)or die("cannot connect"); $selected=mysql_select_db($db_name)or die("cannot select DB");        $sql1=mysql_query(" INSERT INTO `{$tbl_name}`  (`uname`,`title`,`fname`,`lname`,`email`,`mstitle`,`msfile`,`date`,`status`)  VALUES ('{$log_row["uname"]}' , '{$log_row["title"]}' , '{$log_row["fname"]}' , '{$log_row["lname"]}' , '{$log_row["email"]}' , '{$_REQUEST['mstitle']}','{$pdf_file}','{$mydate}','Awaiting Processing' )"); $result1=mysql_query($sql1);   any suggestion ?

If user input is inserted without modification into an SQL query, then the application becomes vulnerable to , like in the following example:  $unsafe_variable = $_POST['user_input'];   mysql_query("INSERT INTO `table` (`column`) VALUES ('$unsafe_variable')");   That's because the user can input something like value'); DROP TABLE table;--, and the query becomes:  INSERT INTO `table` (`column`) VALUES('value'); DROP TABLE table;--')   What can be done to prevent this from happening?


I am specifically creating a simple To Do app in C#. I have a public property in my "Item" class called "DateTimeCreated". I would like the current date/time to be set at the moment the new "Item" is created. I removed the relevant mark-up from the Create and Edit cshtml pages as I don't wish for it to be created or edited, but rather stamped when an instance of the Item class is created. Part of my Item class I have... public DateTime DateTimeCreated { get { Return DateTimeCreated; } set { DateTime timeStamp = DateTime.now; DateTimeCreated = timeStamp; } }  I get no errors when running the app, but as soon as I click "Create" in order to submit the creation of a new "Item", the browser crashes. And if I change it to simply public DateTime DateTimeCreated { get; set; }  the browser doesn't crash but the value is the default DateTime.now value of 01/01/0001 01:02 or something to that effect Am I doing this right but need a tweak or is my approach all wrong?

I know java and would normally put in getter/setter methods. I am interested in doing it in C# with the following code, but it throws a StackOverflow exception. What am I doing wrong?  Calling Code  c.firstName = "a";   Property Code    public String firstName; {     get     {         return firstName;     }     set     {         firstName = value;     } }


In Stranger Things Season 2, , and in Kick-Ass Chloe Moretz  her parents gave her permission to swear as well.  When the script is written and given to the children, do the parents read it and determine if it's okay for them to swear?   Are the children told by the production crew that these words should only be said on set of this movie and not in real life?

Some movies feature child characters put in violent situations. This can range from crude language to extreme horror (e.g. torture, gore, etc.). As an example,  and its sequel has plenty of those scenes. It looks like a paradox that children can be actors in movies that are definitely not for children.  Do the directors usually try and avoid exposing the very young actors to the violence of such scenes, e.g. by clever dubbing and editing? Are there laws that require them to do so, just like there are ratings that prevent children from seeing some movies?


suddenly, my wifi icon is missing, and showing wired icon instead; but there is no problem in connecting with wireless connection, though I'm not able to connect with wired connection! any help.. here is the screen shot of the problem

I am connected to a WiFi network but wired connection icon is shown:  Screen-shot of the problem:    I also can't see other available WiFi networks in order to connect to them.  Output for lspci -knn | grep Net -A2:  0c:00.0 Network controller [0280]: Broadcom Corporation BCM4312 802.11b/g LP-PHY [14e4:4315] (rev 01)     Subsystem: Dell Wireless 1397 WLAN Mini-Card [1028:000c]     Kernel driver in use: wl   What should I do?


I have a variable animals.  animals=lion*tiger*elephant**cat***dog   I just want to split by the delimiter * and store it into an array.   Expected:   animals[0]="lion"  animals[1]="tiger"  animals[2]="elephant"  animals[3]=""  animals[4]="cat"  animals[5]=""  animals[6]=""  animals[7]="dog"   I used awk command but I don't know how to store empty string for no value.  echo "$(awk -F* '{ for (i = 1; i <= 8; i++) print $i }' <<< "$animals")"   Result:  lion tiger elephant  cat   dog   Array:  Array=($(awk -F* '{ for (i = 1; i <= 8; i++) print $i }' <<< "$animals"))  # Null values get neglected

This is the output:  3,aac-lc, 93.8, aaclc, 77.3, h.264, 1024.6, h.264, 1029.1, 31, 31, 0,0,0.000000,31,31,0,0,0.000000,7,0,0,0.000000,30,1280 720,10,0,0,0.000000,30,1280 720   I tried with 2 scenario:   Storing in an array    @arr=split(',',$stats);   echo "statistics: $stats"  Storing in a variable   echo $stats | cut -d ',' -f | read s1  echo $s1    But neither scenario is working.


I have 2 functions fun_1 and fun_2 fun_1 → loops over fun_2 and stores the output of it in a variable named X. I want the return value of fun_1 to be the value of each iteration of the loop, so the return value I need is a tuple of 5 values, each value for X in one of the iteration instead of the value of only the last iteration. Note:fun_1 and fun_2 are just examples for functions just to demonstrate the idea and understand it so that I can apply it to complex function. def fun_1():     N = 0     while N <= 5:         X = fun_2()         N = N+1     return(X)

What is the use of the yield keyword in Python? What does it do? For example, I'm trying to understand this code1: def _get_child_candidates(self, distance, min_dist, max_dist):     if self._leftchild and distance - max_dist < self._median:         yield self._leftchild     if self._rightchild and distance + max_dist >= self._median:         yield self._rightchild    And this is the caller: result, candidates = [], [self] while candidates:     node = candidates.pop()     distance = node._get_dist(obj)     if distance <= max_dist and distance >= min_dist:         result.extend(node._values)     candidates.extend(node._get_child_candidates(distance, min_dist, max_dist)) return result  What happens when the method _get_child_candidates is called? Is a list returned? A single element? Is it called again? When will subsequent calls stop?   1. This piece of code was written by Jochen Schulz (jrschulz), who made a great Python library for metric spaces. This is the link to the complete source: [Module mspace][1].


For example, in the mathematical notation of a quotient space given an equivalence relation \sim, the rendering of X/\sim is different from X/\!\!\sim. In the former, there is a gap between the slash and the \sim, whereas in the latter, there is no such gap. I couldn't find meaningful entries on Google.

I know that \: in LaTeX produces a space when rendered.  Are there any alternatives, because my LaTeX renderer doesn't support \: (it renders it as text), and there is no help / FAQ that I can find.


I've been trying do put together a function that combines mkdir and cd. This is what I've been using: #!/bin/bash mk(){     mkdir "$1" && cd "$1" }  mk $1  However, when I run the script using ./mker.sh test , it'll create a directory with  but won't change into it. I'm brand new to Bash so I'm really at a loss as to why that part doesn't work. It doesn't return an error to the command line either. What's the issue here? Thanks!

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?


Saying that ice is slippery is like saying that water is wet -- it's something we've known for as long as we can be said to have known anything. Presumably, humans as a species knew ice was slippery before we knew fire was hot, or that it existed. But ask anyone why, and they won't be able to give you any better explanation than one of those cave people would have.

Some textbooks I came across, and a homework assignment I had to do several years ago, suggested that the reason we can skate on ice is the peculiar $p(T)$-curve of the ice-water boundary. The reasoning is that due to the high pressure the skates put on the ice, it will melt at temperaturs below $273 K$ and thus provide a thin film of liquid on which we can skate. It was then mentioned as fun fact that you could ice-skate on a planet with lakes of frozen dioxide because that gas has the $p(T)$-curve the other way round. My calculations at that time told me that this was, pardon my french, bollocks. The pressure wasn't nearly high enough to lower the melting point to even something like $-0.5$ degrees Celsius. I suppose it is some other mechanism, probably related to the crystal structure of ice, but I'd really appreciate if someone more knowledgeable could tell something about it.


Using the pigeonhole principle, prove that among any n+ 1 integers you can find two integers so that their difference is divisible by n.  You will want the “holes” to be the remainder when you divide a value by n.

Here's the full question:  Prove that, for any $n + 1$ integers, $\{x_0, x_1, x_2, . . . , x_n\}$, there exist two integers $x_i$ and $x_j$ with $i \neq j$ such that $x_i − x_j$ is divisible by $n$.  Now, the integers aren't necessarily consecutive, positive, or without repeats. I've tried breaking this into cases, such as "$x_i = x_j, \dfrac{0}{n} = 0$" etc. But I don't think it's possible to exhaust the cases.  I feel like there should be an easy way to contradict this one, by saying that $x_i - x_j$ isn't divisible by $n$. But I just wasn't getting anywhere with that one.  I thought about using induction, but I would have just as hard a time proving this for $n$ integers before $n+1$ integers, so I don't think it would be possible for me to do it that way.  If anyone could help out, that would be wonderful. I'm pretty stuck here.


When spell components are consumed or have a cost, they need to be provided and cannot be substituted by a spellcasting focus. The  spell has such components:  10 gp worth of charcoal, incense, and herbs that must be consumed by fire in a brass brazier  Now obviously, the charcoal, incense, and herbs have to be provided as they have a specified cost and are consumed. However, what about the brass brazier? Does the caster have to provide that as well, as there are components that have to be provided and they directly interact with the brazier? It doesn't logically seem like something a component pouch could replace, mostly those things are some small items. On the other hand it seems unreasonable to carry a brass brazier around, sounds heavy.  A related question about the brass brazier:

In our campaign, I play a warlock and brass braziers are hard to come by. I want to carry a brass brazier in case my familiar dies and I need to again cast find familiar.   How bulky is a small brass brazier? Can it be carried for several weeks without hindering long distance foot travel? That is, because of its shape or weight, does the typical brass brazier reduce my speed? What's the price of a small, simple brass brazier? How long would it take a brass worker to make a small, simple brazier? How long would it take the brass worker to make one specifically designed to be eminently portable? In both cases, assume the brass worker works nonstop exclusively on the brazier.     What I'm looking for are references, similar cases, and information that can help handle these issues properly and accurately. First and foremost in D&D 5e (especially RAW) and then other RPGs and even real world, if they could be used to make estimates about the answers to these questions when we compare how similar cases translate to D&D 5e mechanics.


I've a problem to get the IOP Conference Series template working with LyX. What I managed to do so far:   Download the necessary files from  Install the files like explained in    After that I'm able to compile the example file, so the installation to the TeX distribution worked. The thing I'm missing now, is a LyX ".layout" file to make the class available in LyX. I'm not familiar how to write these files - I tried to adept the file for the IOP article (provided by LyX) but failed. Could somebody provide a working ".layout" file for the IOP conference series class?  (I use MacTeX 2016, LyX 2.2.3)

I tried googling this elsewhere but I'm new to LaTeX and extremely confused about certain things. Basically I downloaded MikteX and I'm using the latest version of Lyx with it. Now all I basically know how to do is make pretty looking mathematics and add contents pages/titles/references/etc.  I'm looking to make a dissertation and my unviersity provides a template,  (available for download at that link).  So, what exactly do I need to do (and please be super specific as I am totally clueless to all the jargon I read).   Basically, I need to download ociamthesis.cls in the first line of that webpage. Does it matter where I save it? What exactly do I do next?


I'm wondering if there's a TeX package where I could find a proper command to type curl and divergence in equations. Any help? Cheers, Riccardo

Mathematical operators, such as function names, should be set in roman type, not italics. Latex already has commands for some operators, including \max, \min, and \log.  How can I define additional such commands?


The formula for drag force is $F_D=\frac{1}{2}\rho v^2 C_d A$. Why is the $\frac{1}{2}$ significant here? I think that the  $C_d$ already serves the purpose. Is it for a historical reason?

$$Drag = \frac{1}{2}C_d \rho Av^2$$ I understand that the strength of the drag depends on the density of the fluid the body passes through, the reference area of the body, the , and the velocity of the object. I don't, however, understand the 1/2 and the $v^2$ in the equation.


As far as I've read online, there isn't a good explanation for the . Is this the case? Why does taking the square of the wave function give you the Probability? Naturally it removes negatives and imaginary numbers, but why is it the square, not the fourth or some higher power?

Is the  a fundamental , or can it be inferred from unitary evolution?


These Edges from Edit Mode are screwing up my Subdivide. What are they and how do I get rid of them?

So recently, I have been noticing neon light blue lines on objects I import, in place of the the normal orange selection lines. Maybe I was supposed to be getting this variant of line before hand or maybe I just somehow haven't noticed it till now. But assumptions aside, I'm wondering what this line is for and how can I get rid of the light blue lines? Also Along with this my objects that are imported seem to  have their faces turn from gray to white.


I want to know how to just check for the permission of a file.   I know  ls -l yourfile   will show you it but I just need the nine permission letters.  Thanks

What is the command with which you can directly view the permission bits of a directory?


I have four different equations numbered as Eqs. (1), (2), (3), (4).   I want to refer them like Eqs. (1-4) in a text. How can I do it?


In this code, I drew a red rectangle. I was wondering how to make this rectangle clickable. That way, I can make it turn blue when I click on it.   public partial class Form1 : Form {     public Form1()     {         InitializeComponent();         this.Cursor = new Cursor(Application.StartupPath + "\\Cursor1.cur");     }      public Rectangle rect = new Rectangle(333, 333, 95, 95);      private void Form1_Paint(object sender, PaintEventArgs e)     {         System.Drawing.SolidBrush fillRed = new System.Drawing.SolidBrush(Color.Red);         System.Drawing.SolidBrush fillBlue = new System.Drawing.SolidBrush(Color.Blue);         e.Graphics.FillRectangle(fillRed, rect);     }      private void rect_Click(object sender, EventArgs e)     {         System.Drawing.SolidBrush fillBlue = new System.Drawing.SolidBrush(Color.Blue);         e.Graphics.FillRectangle(fillBlue, rect);     } }

Imagine I use the .NET graphic classes to draw a rectangle.  How could I then assign an event so that if the user clicks a certain point, or a certain point range, something happens (a click event handler)?  I was reading CLR via C# and the event section, and I thought of this scenario from what I had read.  A code example of this would really improve my understanding of events in C#/.NET.  Thanks


I'm building a MVC core IHtmlHelper extension to handle tables. Roughly speaking you provide the extension with an IEnumerable list of data records and a column layout and it produces an HTML table.  For the column layout I'd like some of the methods to be lambdas that accept a data record and return a value from it. For example for each row of the table the first column should contain such and such value from the data record.  So the MVC IHtmlHelper extension method will look like:  namespace TableStuff {     public class Column<T>     {         public Func<T, string> TDContent { get; set; }         // ... plus any other settings needed     }      public static class Table     {         public static IHtmlContent BasicTable<T>(             this IHtmlHelper htmlHelper,             IEnumerable<T> Data,             IEnumerable<Column<T>> Columns             )         {             return new HtmlString("just a mockup");         }            } }   To use it you:  public class Test {     class ListEntry     {         public string Id { get; set; }     }      public void DefineTable()     {         // fake a couple of things to make example minimal         IHtmlHelper t = null;         var Data = new List<ListEntry>();          // generate the table; in reality this would be a razor page via @Html.BasicTable(...)         var c = t.BasicTable(Data, new [] {             new Column<ListEntry> { TDContent = i => i.Id }         });     } }   What I'm wondering is why "new Column< ListEntry > { ... }" has to specify an explicit type. I'd really rather have it just be ""new Column { ... }" and have the type inferred as ListEntry.

C# doesn't require you to specify a generic type parameter if the compiler can infer it, for instance:  List<int> myInts = new List<int> {0,1,1,     2,3,5,8,13,21,34,55,89,144,233,377,     610,987,1597,2584,4181,6765};  //this statement is clunky List<string> myStrings = myInts.     Select<int,string>( i => i.ToString() ).     ToList<string>();  //the type is inferred from the lambda expression //the compiler knows that it's taking an int and  //returning a string List<string> myStrings = myInts.     Select( i => i.ToString() ).     ToList();   This is needed for anonymous types where you don't know what the type parameter would be (in intellisense it shows up as 'a) because it's added by the compiler.  Class-level type parameters don't let you do this:  //sample generic class public class GenericDemo<T>  {     public GenericDemo ( T value )      {         GenericTypedProperty = value;     }      public T GenericTypedProperty {get; set;} }  //why can't I do: int anIntValue = 4181; var item = new GenericDemo( anIntValue ); //type inference fails  //however I can create a wrapper like this: public static GenericDemo<T> Create<T> ( T value ) {     return new GenericDemo<T> ( value ); }  //then this works - type inference on the method compiles var item = Create( anIntValue );   Why doesn't C# support this class level generic type inference?


Can you give me some examples where "ain't" is used in place of "have not".  According to Oxford Dictionary, ain't=am not,is not,are not,has not,have not.

Sometimes I encounter ain't, but I really don't know how to translate it properly.    What does ain't stand for? If I really wanted to use it, in which contexts would you say it's acceptable using it?


Can someone please give me a hint as to how these two statements are different? Thank you!   ∀x ∈ S, ∃y ∈ T, P(x, y) ⇒ Q(x) (Statement 1)  ∀x ∈ S, (∃y ∈ T, P(x, y)) ⇒ Q(x) (Statement 2)

My book and my teacher both said that these two statements are different:  1) $∀x∈A,∃y∈B, F(x, y)⇒G(x)$  2) $∀x∈A,(∃y∈B, F(x, y))⇒G(x)$  How can just adding an extra parenthesis make the statement different? I am not quite sure I understand.  If they are different, how are there negation different? Would the negation be as follows:  1) $∀x∈A,∃y∈B, F(x, y) ∧ ¬ G(x)$  2) $∀x∈A,(∀y∈B, ¬ F(x, y)) ∧ ¬ G(x)$    SIDE NOTE: I tried taking contrapositives, but ended up with the same expression for both. So how and why are they diffrent? $¬ G(x) ⇒ ∃x∈A,∀y∈B, ¬ F(x, y) $    Thanks


I've been trying to format a field in a vector file in QGIS to be run in Time manager and, for some reason I can't figure out, it still is not running. I read the other threads here associated with this problem, and so I reformatted the date to conform to what Time Manager says is an acceptable format - YY-MM-DD. My cells currently look like: 07-01-01 for Jan 1, 2007. I created it as a string variable and then tried converting it to a date variable in field calculator. I still keep getting the same error message which is:   An error occured while trying to add layer scicafe_07-16-pointshapefile to TimeManager. Cause: Exception(UnsupportedFormatException('Could not match value PyQt4.QtCore.QDate(2015, 1, 1) with any of the supported formats. Tried:  ...lists lots of other formats..and  %Y-%m-%d.  But as far as I understand, the format 07-01-01 is %Y-%m-%d, so I'm not sure what I'm doing wrong? I also tried YYYY-MM-DD too by the way. Same error message.   How can I troubleshoot this problem?

I've been through associated answers but cannot quite seem to find something which works!  I'm having trouble getting TimeManager to recognise a simple data field (this is in QGIS2 - but I've had this error in earlier versions). I have these fields formatted in what appears to be one of the acceptable formats:    ... here is a screenshot of the field properties:    The format appears to be recognised in QGIS as I've worked out days difference between two dates (the "Time on Market" field shown in the image).  However ... I always end up with:   The Twitter.shp file works fine as a test, so I don't think this is an issue with the install / phyton conflict.  Any thoughts welcome!


private boolean  CharToString(){     String lineOfText = "XXXXXX";     String desiredResult = "X";     String actualResult = "initialised value";     for(int i = 0; i < lineOfText.length(); i ++){         actualResult = Character.toString(lineOfText.charAt(i));         }     if(desiredResult == actualResult){         return true;     } else{         return false;     } }   So basically, this code is a reproduction of what I have, but designed to highlight what I believe the problem to be after a long time diagnosing and testing.  As you can see, it sets the value of actualResult to the 'char' value of the character at the present location along lineOfText. Every value is intended to output "X" as a String (converted from char).  However, for reasons unknown to me, despite actualResult and desiredResult both outputting "X" to my debug drawText() method (I can't work out how to use console log...), the method returns false, indicating that the two String variables are NOT equal.  Strangely, if I were to change the if() else to a switch(), it would return true (i.e. work as intended).  I've tried Googling and searching StackOverflow but my search terms are probably poor/wrong as I'm getting no useful results :(  Any help would be greatly appreciated, and sorry if this is a stupid question - I have tried for ages to figure it out myself...  p.s.  Is there a good graphic map editor available online anywhere? Editing a .txt file to create a map seems overly complicated, and very difficult to maintain consistency or coherence in the development of large/intricate maps...  I figure there must be SOMETHING, how else would you make a 3D java game??

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


What are the complex solutions for $z^4+16=0$? I know that one solution is $z=a+bi=-2$. How can I figure out the other solutions?

Probably dumb question, but I would like to ask it anyway.  I was to solve this equation:  $z^4 = -16$  At first glance, the way to solve it would be (as any other equation):  $z^2 = \sqrt{-1} * 4 \lor z^2 = -\sqrt{-1} * 4$  $z^2 = 4i \lor z^2 = -4i$  $z = 2\sqrt{i} \lor z = -2\sqrt{i} \lor z = 2i\sqrt{i} \lor z = -2i\sqrt{i}$  However, in suggested answers, there are $z_1, z_2, z_3$ and $z_4$ found using trigonometric formulas. Is there something particulary wrong in my solution and the only proper one uses trigonometric form of complex number?


With object.GetType().GetMethods() you can list all methods of an object. How can you list all extensions of an object ?  For example :  I have this extension  public static void DoSomething(this MyObject obj, String param) {}   Is there a way to retrieve DoSomething method of object MyObject using reflections or an other method ?

In C# is there a technique using reflection to determine if a method has been added to a class as an extension method?  Given an extension method such as the one shown below is it possible to determine that Reverse() has been added to the string class?  public static class StringExtensions {     public static string Reverse(this string value)     {         char[] cArray = value.ToCharArray();         Array.Reverse(cArray);         return new string(cArray);     } }   We're looking for a mechanism to determine in unit testing that the extension method was appropriately added by the developer.  One reason to attempt this is that it is possible that a similar method would be added to the actual class by the developer and, if it was, the compiler will pick that method up.


I've read that arrays and objects are "being passed by reference". But I've encountered behavior, which confuses me.  In this piece of code, everything works as I would expect  let first = [1, 2, 3, 4, 5]; let second = first; first.push(10); console.log(first); //[ 1, 2, 3, 4, 5, 10 ] console.log(second); //[ 1, 2, 3, 4, 5, 10 ]   I have troubles understanding the following one  let third = [1, 2, 3, 4, 5]; let forth = third; third = [11, 12]; console.log(third); //[ 11, 12 ] console.log(forth); //[ 1, 2, 3, 4, 5 ]   I would expect both variables to be equal, but it works as I'm operating primitives, not an array.

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


Is there a difference between using a bagging classifier with base_estimaton=DecisionTreeClassifier and using just the RandomForestClassifier? This question refers to models from python library called sklearn.

I know that Random forest uses Bagging, but how does ensemble give a single prediction in sklearn Bagging vs Random forest? Also, I do not understand why in Bagging you not need to choose a tree estimator, while not in RF?  other than this, are the other steps the same? wht are main implementation differences in sklearn Bagging vs Random forest?  bonus points if you have "explain like I'm 5 years old" simple example using sklearn please.


I have two shapefiles, A (polygons) and B (points), and I need to select all features from shapefile B that have the same attribute (for example, "Name") as shapefile A, and I need to do this iteratively for a large number of features.  Normally I would browse the table of shapefile A using the Go2NextFeature plugin, select a record, copy its name and make a "select by attribute" selection on layer B.   It would be best if whenever I select a new feature in shapefile A, all features of shapefile B with the same name would automatically be selected.

I'm trying to make a species distribution project where I can select a species from a non-spatial list of species and the selection would highlight (select) all the counties to which the species has been attributed.  Simplified example data: species, a non-spatial table of species (CSV with header): "species" "Mus borealis" "Mus australis"  species_distributions, a non-spatial relation table (csv with header): "species","county" "Mus borealis","North" "Mus borealis","Central" "Mus australis","South" "Mus australis","Central"  counties, a spatial feature class representing county boundaries (first row = field name): "county" "North" "South" "Central" "West"  So if I select "Mus borealis" from the species table, the "North" and "Central" counties would be highlighted in the map. Seems like a simple scenario, but I have been unable to uncover a solution on my own. The closest I've found is a plugin "Select by relationship" but it doesn't appear to be available for QGIS 3 (I'm using QGIS 3.4.3). I have a PostGIS server available.


Without (at least a weak form of) choice, we cannot prove the existence of a basis for $\mathbf{R}$ over $\mathbf{Q}$.  But is there some vector space $V\supset \mathbf{R}$ that we can prove has a basis, without choice?  Note that it is not true in general that if $V$ has a basis and $U\subseteq V$ then $U$ has a basis; see

I would like to know if there are "interesting" equivalences to the statement "$\mathbb R$ has a Hamel basis over $\mathbb Q$". I am not interested in more general statements, like "every vector space has a Hamel basis" or "every vector space over (your favorite field) has a Hamel basis".  On the other hand, according to , such Hamel basis of $\mathbb R$ over $\mathbb Q$ may not exist, assuming the negation of the Axiom of Choice. Where can I find a proof of this fact?


Currently I'm using Bind9 for my DNS server.   It was set-up in such a way that the server respond differently depending on which IP the request came from. I'm using Bind's View to achieve this.   The conf file is something similar to this :   acl trusted { 192.168.7.0/24; localhost; }; acl guest   { 192.168.8.0/24; };  view trusted {     match-clients { trusted; };      allow-recursion { any; };      zone "myzone.example" {         type master;         file "db.myzone.example";     };     zone "7.168.192.in-addr.arpa" {         type master;         file "db.192.168.7";     }; };  view guest {     match-clients { guest; };      allow-recursion { any; }; };   My question is :    Is it possible to do the same with PowerDNS? If yes, What is the easiest way to have it implemented?

I've looked around the web for a solution and have found numerous threads with different suggestions.  Most of which I've found has been using LUA on the resolver to return records. Other posts suggest using GEO-IP or Pipe backends. All of the content I've read have used   I am curious to know if it is possible, via LUA to change the Forwarder based on the network range rather than using LUA to store zone information.  If I can get logic similar to the following to work I should be all set:  if sourceip comes from (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16) {      forwarder = 192.168.0.1; }else{      forwarder = 8.8.8.8; }   I don't see any examples of LUA from pdns that demonstrate changing any settings within PDNS itself, and am curious if that is even possible.


I am planning to build an 8 foot fence and will use galvanized post due to high moisture in the area. Looking for some advice regarding the depth of the post. These are 10 foot post so I was planning to place them 2- 2 1/2 feet deep and secure with up to 100 pounds of concrete mix. The post will be 6 feet apart and I will use 2x4x12 stringers. Due to the lumber shortage I will have to use 1x6x8 PT pine pickets instead of cypress. There is 125 feet to build. Any ideas on the depth to place the posts? Thanks

What is a reasonable depth and diameter for postholes dug in clay soil where the frost line is no more than 12” and that will support an 8 foot tall solid wood fence that uses PostMaster metal posts?  I hope to have someone else install an 8 foot high PT wood fence.  There will be no light or air passing through or under the fence and it will be heavier than average, given the additional height and board weight.  One side will run for 135’.  The attached diagram provides more detail.  The PostMaster Installation Instructions describe a 30” deep, sloped, 10” diameter hole, filled with 6” of gravel plus 24” of concrete for a 6 foot high fence.  They caveat that the “exact diameter and depth will be determined by local weather and soil conditions.”  Got it.  Huntsville, AL; very clay soil.  Maximum wind gusts of 65 mph.  (This is not in the normal tornado path and is not intended to withstand a tornado.)  In reviewing the StackExchange posts on fencing and post holes I came across the concept that the diameter of the pier may be increased to compensate for a shallower post hole.  I would like to know the recommended depth and diameter without relying on the 2 buttress posts, which are my small overbuild idea.  We will be able to walk under them.  26 APR 18 update: I just found a Master Halco youtube video specifying 6-8" diameter holes dug 36" deep for an 8' board-on-board fence, such as I would like to have.   - I also spoke to a fence builder experienced using PostMaster posts who opined that the 10" diameter and 30 deep holes were more than adequate, but that the gravel was of no value in our climate.  So, 30" x 10" dia inches of concrete vs. 36" x 8" dia of concrete.


My code works fine for characters a-z and .,?!. Is it possible allow all Cyrilic (Russian, Serbian) and Scandinavian characters as well as .,?!?  $('#myInput').bind('keydown', function(event) {   switch (event.keyCode) {     case 8: // Backspace     case 9: // Tab     case 13: // Enter     case 37: // Left     case 38: // Up     case 39: // Right     case 40: // Down       break;     default:       var regex = new RegExp("^[\wa-zA-Z0-9.,?!/]+$");       var key = event.key;       if (!regex.test(key)) {         event.preventDefault();         return false;       }       break;   } });

How can I use Unicode-aware regular expressions in JavaScript?  For example, there should be something akin to \w that can match any code-point in Letters or Marks category (not just the ASCII ones), and hopefully have filters like [[P*]] for punctuation, etc.


We are supposing in my mechanics course that forces add as vectors. But why, philosophically, should this be the case?

"We have focused our discussion on one-dimensional motion. It is natural to assume that for three-dimensional motion, force, like acceleration, behaves like a vector."- (Introduction to Mechanics) Kleppner and Kolenkow  We learn it very early in the course of our study that Force is vector; But, if I were the physicist defining the the Newton's second law (experimentally) and analysing the result F=ma, how would I determine whether Force is vector or scalar(especially in 3-D).   Actually, when I read the aforementioned sentences from the book, I wanted to  know why do the authors expect it to be natural for us to think that in 3-D "Force" behaves like a vector. I know a(acceleration ) is vector and mass a scalar and scalar times vector gives a new vector but is there another explanation for this?


Is there some command, or app, to show a visual indication about the state of special keys (Caps Lock, Num Lock, etc)?  It is intended to be used with some keyboards without the "standard" indicator leds.  I use Ubuntu Studio 18.04.1 and Gnome desktop enviroment.

I know there are many solutions to this problem like using indicator-keylock or using lks-indicator.  I have tried them both. However since I am on Ubuntu 18.04, these are not working.  Can someone help me with something new or help me in writing a new indicator which I can use for myself at least?


I'm new to the Ubuntu community and I have a question: I've noticed while downloading both 32 bit and 64 bit versions that the 32 is referred to as i386 (which I assume is an Intel reference) and the other is referred to as amd64.  Are they written specifically for each architecture? I have both a 64 bit Intel desktop and a 64bit AMD laptop. I installed the 32 bit on the laptop by accident, having made the install "pen" a while back for a 32 bit laptop and it worked fine. Then I installed the 64 bit version on top of that, again no problem.  But I rely more on my desktop (more powerful, for one thing) and it's running the aforementioned Intel, an i5 quadcore sandybridge 3.3Ghz to be exact.  So again, does it matter? Were the 32 and 64 written for different architectures?   Thank you.

I was told that computers with more than 2 gig's memory need a 64 bit operating system to utilize all RAM.  Is the 64bit Ubuntu download really JUST for AMD processors? I am asking because the disk image I downloaded says AMD64.  So will my new Intel 2.3Ghz Core i3 Dual Core processor work with 64 bit Ubuntu?  It runs the 64bit version of Windows without any qualm.


This three questions have been merged into this one. The following answers might have come from any of them, or might be a generic answer to all of them.  Is there any kind of tool to assist in loading an unloading servers? I realized that I lack both height and upper body strength to remove servers from the upper tiers of a rack? I could not find the name or type of equipment that folks are using to do this kind of work safely?  In  video can I see that they use a dedicated "server lift"  which looks quite expensive until you consider the cost of what your lifting. Does anyone know of cheap server lifts or other tools that can be used for this?  In this video:   3:18 into the video. I'm curious about Server Jacks and possibly ballpark costs for them.


After using ctrl+l to link highlighted text when writing and answer or question, I can no longer use my up/down keys unless I leave the page and come back to it.  I am having an issue in FireFox 47.0.1, although I have noticed this in all previous versions as well. Windows 7 x64 if that matters.  I disabled all of my add-ons and verified this issue before posting this report.

I found another odd bug... but I can only repro it in Firefox (40.0.2 for OSX). It doesn't occur in Chrome or Safari. I understand that, if it is a FF only thing, there's possibly nothing you guys can do about it, but I thought I'd put this out here anyway.  I use the magic hyperlink button to create links because they're pretty. Recently I've been noticing that, when I use it, I can't use ↓ until I click outside the text area.  The process is pretty simple:   Write two lines of text (to make sure you have a "down" to go to). Highlight some of the text on the upper line. Click the hyperlink button or use Ctrl + L. Paste the link into the text area. Hit Enter/Return to close the dialogue. (Hitting the OK button will not repro the issue.) Try to use the down arrow…. No response.   As long as you don't click out of the text input area, you will not be able to use the down button. Even using your mouse to move the cursor to another spot doesn't make it work. The other three direction arrows work fine.  This may or may not be related to ... I don't remember running into this issue until the last week or so.


I'm a beginner photographer. I'm 13. I'm not thinking photography for a job, but for a VERY nice hody. My father also loves photography, he is an expert but he don't have time in the last years to improve his hobby... (Is a doctor)  So he has stayed a little bit far from the thing and he can't answer me all my questions. :)   So, my question is:  1) Best camera for an expert-beginner guy. (Around 350-400  € ).   2) Best sources to learn all important stuff in cameras and in their settings  .....etc.  Thanks!!

I am thinking of buying a digital SLR camera. What things should I be looking for?


I am a student and I want to apply for a UK tourist visa. A month ago my parents sent me the money for my trip (as a gift). So if I apply for a UK tourist visa, is it okay that my only source of revenue is that money? And what should be on the bank statement?

The UK Visas and Immigration Directorate publishes  that provides helpful tips that can result in successful visa applications. Section 2 of this guidance opens is entitled "other documents you may want to provide" (emphasis mine).  Section 2: other documents you may want to provide – all visitors This section provides guidance on the types of documents that you may want to provide to help us consider your application against the Immigration Rules. Previous travel documents/passports, which show previous travel. Financial documents showing that you have sufficient funds available.  These must clearly show that you have access to the funds, such as:  bank statements building society book proof of earnings such as a letter from employer confirming employment details (start date of employment, salary, role, company contact details) where a third party (who is either in the UK or will be legally in the UK at the time of your visit) is providing financial support to you e.g. a business, a friend or a relative, documents to show that they have sufficient resources to support you in addition to themselves and any dependant family should be provided   The first item is "bank statements" and this ties in with the , which says...  evidence that you can support yourself during your trip, eg bank statements or payslips from the last 6 months  (Note 'eg' is a Latin abbreviation meaning "for example"; this appears to be optional rather than a fixed requirement.) Question: How should someone interpret this such that the chances of success are maximized? How many statements should I submit? What are they looking for and what do my bank statements tell about me?


I need a chip like the esp32 with an output  channel thats at least 48kHz. Also, it needs to be able to pair and connect to another esp32 over bluetooth, kind of like Airpods.  Basically, if I want to get a custom IC made, what so i do? What kind of company do I contact or who do i talk to, assuming I have the money (I dont but there's a reasonable chance I convince someone it's a worthy investment)? Any clue?

I have browsed several ASIC manufacturer's webs, but I haven't found an actual number. I assume there would be a fixed cost associated with creating masks and such and then there will be a cost per unit.     Note: that I don't actually want to have an ASIC made, I'm just curious.


Which is the correct one, and why?   How does this machine work? How does this machine works? How this machine works?

How does he does that?      How does he do that?   Which one is correct? This type of sentence sounds a little odd because of two do/does in a single statement. Is there an alternative which has the same meaning?


The integral given is: $$\int_{0}^{1}\big\lbrace\frac{1}{x}\big\rbrace \big\lbrace\frac{1}{1-x}\big\rbrace \big\lbrace1-\frac{1}{x}\big\rbrace dx$$ where  $\big\lbrace x\big\rbrace$ represents the fractional part of $x$  I first tried breaking it using a piecewise definition but I couldn't figure out how to do it as there wasn't any consistent pattern that I could spot.   I tried graphing it to get an idea but that also didn't get me anywhere.  Finally, I tried using the property of definite integral that $\int_{0}^{a}f(x)dx=\int_{0}^{a}f(a-x)dx$ but the first and seccond terms remained the same and the last term changed but not it did not lead to any noticeable changes.  I am stuck now. Any help would be appreciated.

$\int_{0}^{1}\left\{\frac{1}{x}\right\}\left\{\frac{1}{1-x}\right\}\left\{1-\frac{1}{x}\right\} d x=?$ Where $\{\mathbf{x}\}$ is fractional part of $\mathbf{x}$  I reduced $\{1-1/x\}$ to $\{1/x\}$ but after that I'm not sure how to proceed.


I'm trying to find a book I remember reading, one I'd like to re-read.  I saw it  probably decades ago.   Basic premise is that earth has been stuck in a zone that somehow suppresses intelligence.   When it leaves, everyday people go genius.      I remember a throw away line early in the book with a scene about a kid who was toying with high mathematics and saying later that day he had reinvented calculus.    I remember it causing chaos on Earth -- and I remember them doing some sort of space journey later in the book to test the theory that there was a zone of IQ suppression.   I think I remember reading it as a small paperback. There might have been something about some animals becoming sentient as well, unless I'm confusing still another story.  I don't remember the title or author.   I'm thinking it had a cover possibly with a chimp riding an elephant into a farm or low-urban area or something  -- unless my memory is mixing books.  This was long before Vernor Vinge's books.

The 'blurb' on the back of the book was that something had boosted the intelligence of every creature on earth, to the point that at least some animals were on par with humans. I'm not sure if humans were similarly enhanced or just animals. I'm not sure whether it was done by aliens, or a side effect of something humans did, or what.   This book was on the shelves in the mid/late 1980's, so it's nothing more recent than that.


I need something that does not need to be installed. It's on an embedded system with very little space on the HD. I can't instal anything. I need to do it with something that is already included.  I have a script that I want to run based on a certain line that appears in a log file. Currenty I placed this script to run every 5 minutes in the crontab and check the file for changes.  Is there a way that I can have the system call the script only if the file has changed? Like, to tell the system to fire the script in case a system call was made to open that file with write permission?

I want a script to sleep unless a certain file is modifed/deleted (or a file created in a certain directory, or ...). Can this be achieved in some elegant way? The simplest thing that comes to my mind is a loop that sleeps for some time before checking the status again, but maybe there is a more elegant way?