Angular momentum commutation relations
These two operators commute...but their eigenvectors aren't all the same. Why?
Split a string by spaces -- preserving quoted substrings -- in Python How do I restrict my kids' computing time? Why isn't the eigenclass equivalent to self.class, when it looks so similar? How can I generate isometric sprite sheets from 3D animations? What contributes to expanded company details being displayed in Google search results? For some results returned in Google Search, on the right side it displays the company details, logo, contact numbers, etc...   For example, see the following screenshot:    I'd like to know what contributes to this so that I can try to achieve it for my site too. How many stickers do I need to complete my FIFA Panini album? I'm playing the , which is an Internet adaption of the classic Panini albums that are usually published for the soccer world cup, European championship, and possibly other tournaments.  The album has placeholders for 424 different stickers. The purpose of the game is to collect all 424. The stickers come in packs of 5, which can be obtained through codes found online (or, in case of the classic printed album, bought at your local newsstand).  I make the following assumptions:   All stickers are published in the same quantity.  One pack of stickers does not contain duplicates.     How can I find out how many packs of stickers I need to acquire in order to be reasonably sure (let's say 90%) that I have all 424 unique stickers? String representation of an Enum I have the following enumeration:  public enum AuthenticationMethod {     FORMS = 1,     WINDOWSAUTHENTICATION = 2,     SINGLESIGNON = 3 }   The problem however is that I need the word "FORMS" when I ask for AuthenticationMethod.FORMS and not the id 1.  I have found the following solution for this problem ():  First I need to create a custom attribute called "StringValue":  public class StringValue : System.Attribute {     private readonly string _value;      public StringValue(string value)     {         _value = value;     }      public string Value     {         get { return _value; }     }  }   Then I can add this attribute to my enumerator:  public enum AuthenticationMethod {     [StringValue("FORMS")]     FORMS = 1,     [StringValue("WINDOWS")]     WINDOWSAUTHENTICATION = 2,     [StringValue("SSO")]     SINGLESIGNON = 3 }   And of course I need something to retrieve that StringValue:  public static class StringEnum {     public static string GetStringValue(Enum value)     {         string output = null;         Type type = value.GetType();          //Check first in our cached results...          //Look for our 'StringValueAttribute'           //in the field's custom attributes          FieldInfo fi = type.GetField(value.ToString());         StringValue[] attrs =            fi.GetCustomAttributes(typeof(StringValue),                                    false) as StringValue[];         if (attrs.Length &gt; 0)         {             output = attrs[0].Value;         }          return output;     } }   Good now I've got the tools to get a string value for an enumerator. I can then use it like this:  string valueOfAuthenticationMethod = StringEnum.GetStringValue(AuthenticationMethod.FORMS);   Okay now all of these work like a charm but I find it a whole lot of work. I was wondering if there is a better solution for this.  I also tried something with a dictionary and static properties but that wasn't better either. When you are performing time consuming operations in bash like installing new software, is it possible to write text that will appear at the prompt when the operation has finished.  E.g   Imagine running:  apt-get install eclipse-platform   Then it will use quite a while to finish while you see the installation log, meanwhile I want to create new folders (workspaces) which Eclipse later will use.  Is this possible without opening a new terminal (or tab)? What is the formula for percent of frame filled at a specific distance and focal length? Which is the right way to do something like 'description' list but with customizable and fixed-width labels? I.e. something like this:  Label:         Text text text text text text                text text text text. Longer label:  Text text text text text text                Text text text text.   The way I see it to use two-column table (first columt for labels and second column for descriptions), but this solution seems ugly. Is there any other way? how to create a roster sheet in sharepoint 2010 Disable automatic activation of Gnome Shell activities on mouse over How to display citations in text grouped as [1-3] in stead of [1,2,3] What can I do when getting “This question body does not meet our quality standards”? prove inequality through mean value theorem I am trying to understand the permission usage for the cp command in unix.   What are the permissions required for copying a file into a directory What are the permissions required for copying out of a directory?   I'm assuming for my first question, the directory will need execute permissions to perform the operation and the file will need read permissions to read the binary of the file and then the output file will need write permissions.  For the second the directory itself would need execute permissions to perform the copy operation and the file would need read permissions to extract the data from the file.  Can anyone tell me if my logic is flawed? "Planar" graphs on Möbius strips Bluetooth earphones work fine until sleep. After resuming from sleep however, they appear to connect for a brief moment before disconnecting. On blueman, the error given is Resource temporarily unavailable. This issue arose only after updating to 18.04 LTS.   Here's the terminal output for lsusb:  Bus 001 Device 002: ID 8087:8001 Intel Corp.  Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 003 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 002 Device 004: ID 1bcf:0002 Sunplus Innovation Technology Inc.  Bus 002 Device 003: ID 04f2:b477 Chicony Electronics Co., Ltd  Bus 002 Device 002: ID 0a5c:21f1 Broadcom Corp. HP Portable Bumble Bee Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Guests see the Protected notice , somewhat displaced:    Logged in, all is fine:    It actually belongs there, at the bottom, but then it has some design glitches, or it needs to be placed at the top.  Verified on Firefox and Chrome stable. I had a tin of golden syrup for a long time - longer than I care to admit. When I opened it up yesterday (to sweeten up some mulled wine), it was granular (a bit like honey can be), and black around the edges.   Is this 'bad', or just different?   Is the blackness the result of some chemical reaction with the tin?  And in general, does it eventually go off, or does it last indefinitely?