How can you construct a series $$\sum_{n=1}^\infty \frac 1{a_n}$$ which diverges very slowly to infinity where $a_n$ is always a positive integer and $a_{n+1}>a_n$? I know that if $a_n=p_n$, where $p_n$ is the nth prime, then the series diverges slowly. Is there a series that diverges even slower?

$$f(n)=\sum_{i=1}^n\frac{1}{i}$$ diverges slower than $$g(n)=\sum_{i=1}^n\frac{1}{\sqrt{i}}$$ , by which I mean $\lim_{n\rightarrow \infty}(g(n)-f(n))=\infty$. Similarly, $\ln(n)$ diverges as fast as $f(n)$, as $\lim_{n \rightarrow \infty}(f(n)-\ln(n))=\gamma$, so they 'diverge at the same speed'.   I think there are an infinite number of 'speeds of divergence' (for example, $\sum_{i=1}^n\frac{1}{i^k}$ diverge at different rates for different $k<1$). However, is there a slowest speed of divergence?  That is, does there exist a divergent series, $s(n)$, such that for any other divergent series $S(n)$, the limit $\lim_{n \rightarrow \infty}(S(n)-s(n))=\infty$ or $=k$? If so, are there an infinite number of these slowest series?


My dissertation has been cited in a few good journals, which Google Scholar indexes. I have added my dissertation to Google Scholar and Google Scholar has even linked it to the arXiv version of my dissertation, which I have recently updated. The issue is that none of the citations of my dissertation have shown up in Google Scholar. What could be the cause?

I have a paper that I uploaded to arXiv and google scholar listed it as a publication.  Since then the paper has been published in a nature journal several months ago.  The nature publication still hasn't showed up on my scholar profile, which still lists the arXiv version.  Is there any way to resolve this conflict?


Does it matter if a dependent variable has a normal distribution or not when it is used in a regression?

There are several threads on this site discussing  to determine if the OLS residuals are  normally distributed. Another way to evaluate the normality of the residuals with R code is provided in this excellent . This is another  on the practical difference between standardized and observed residuals.  But let's say the residuals are definitely not normally distributed, like in this . Here we have several thousand observations and clearly we must reject the normally-distributed-residuals assumption. One way to address the problem is to employ some form of robust estimator as explained in the answer. However I am not limited to OLS and in facts I would like to understand the benefits of other glm or non-linear methodologies.  What is the most efficient way to model data violating the OLS normality of residuals assumption? Or at least what should be the first step to develop a sound regression analysis methodology?


I have a requirement to send a specific report as an attachment on schedule basis.  So, i have created a schedule class with future annotation to send.But now when i'm trying to setup apex class I'm getting below error.     Error Message Methods defined as TestMethod do not support getContent   call   Apex class:  global class CallSubscriptionReportScheduler { @future(callout=true)     public static void SentSubscriptionData()     {         Id userdetail=[Select id from user where email='xyz@gmail.com'].id;         OrgWideEmailAddress[] owea = [select Id from OrgWideEmailAddress where Address = 'info@xyz.com' Limit 1];         ApexPages.PageReference report = new ApexPages.PageReference('/00O6F00000CGpHH?csv=1');         Messaging.EmailFileAttachment attachment = new Messaging.EmailFileAttachment();         attachment.setFileName('Data_Report.csv');         attachment.setBody(report.getContent());         attachment.setContentType('text/csv');         Messaging.SingleEmailMessage message = new Messaging.SingleEmailMessage();         message.setFileAttachments(new Messaging.EmailFileAttachment[] { attachment } );         message.setSubject('Data');         message.setPlainTextBody('The report is attached.');         message.setOrgWideEmailAddressId(owea.get(0).Id);         message.setReplyTo('sfdcadmin@xyz.com');         message.setTargetObjectId(userdetail);         message.setSaveAsActivity(false);         Messaging.sendEmail( new Messaging.SingleEmailMessage[] { message } );      } }   Test class:  @isTest public class TestWeeklySubscriptionData {     public static String CRON_EXP = '0 0 1 ? * MON';     static testmethod void testsubscription() {                     Test.startTest();             WeeklySubscriptionData uca = new WeeklySubscriptionData();             String jobId = System.schedule('ScheduledApexTest',CRON_EXP,new WeeklySubscriptionData());             Test.stopTest();             // after the testing stops, assert records were updated properly             //System.assertEquals(6, [select count() from Lead where Lead_Type__c='Insurance' AND RecordTypeId ='0126F0000016MZP']);     } }   Could someone help me.

My below test fails because of Run Failures: TestRangehoodObjectionSheet.RangehoodObjectionSheetTest Methods defined as TestMethod do not support getContent call. I added the Blob thinking it might resolve but it doesn't work. What could be the problem here? Have I used the Blob correctly?  @isTest public with sharing class TestRangehoodObjectionSheet {      static testMethod void RangehoodObjectionSheetTest() {             String Build                = NBATRecords.getIdFromDeveloperName('Plan_Reviews__c','Building_Plan_Review');             Account a = new Account(Name = 'Test1' ,Type = 'Lead Acct',BillingState = 'CA',Industry = 'Business Services');             insert a;              Establishment_Record__c er = new Establishment_Record__c(Account__c=a.Id ,Project_Name__c = 'TestPreet',PremiseStreet__c='Manhattan ave',PremiseBorough__c='Manhattan',PremiseState__c='NY',PremisePostalCode__c='11102',Referral_Source__c='311',Data_Source__c='CAMIS',Phase__c='Initiate',Business_Status__c='Open' );             insert er;              Application__c ap = new Application__c(Establishment_Record__c=er.Id,Job_Number__c='222222222');             insert ap;              Plan_Reviews__c pr = new Plan_Reviews__c(Application__c =ap.Id ,DOB_Job_Number__c='222222222',RecordTypeId =Build,Objections__c='Pipe size not indicated');             insert pr;             PageReference pageRef = Page.RangehoodObjectionSheet;              Test.setCurrentPage(pageRef);               Blob content = Test.isRunningTest() ? Blob.valueOf('UNIT.TEST') : pageRef.getContent();              Plan_Reviews__c              p   = new Plan_Reviews__c(id=pr.Id);                ApexPages.StandardController sc  = new ApexPages.standardController(p);             System.assertNotEquals(sc,null);             RangehoodObjectionExtention    ext = new RangehoodObjectionExtention(sc);              ext.Savecopy();       } }   Actual class for the test:  public with sharing class RangehoodObjectionExtention { private final ApexPages.StandardController controller; private final Id                           planreviewID; public String imageURL{get;set;} public List<String> objlist {get;set;}  public string currentdate {get; set;}    public RangehoodObjectionExtention (ApexPages.StandardController stdController) {         controller   = stdController;         planreviewID = (Id)controller.getRecord().get('Id');         Date dt = Date.today();         currentdate = dt.format();         list<Plan_Reviews__c> prlist = [select FDNY_Objections__c from Plan_Reviews__c where id = :planreviewID limit 1];         string obj;         for(Plan_Reviews__c pr: prlist){            obj = pr.FDNY_Objections__c;             }         if(obj!=null){            list<string> objections = obj.split(';');             integer i =1;            objlist = new list<string>();            for(string o : objections){               objlist.add(i++ +'. '+o);            }         }         imageURL='/servlet/servlet.FileDownload?file=';         List< document > documentList=[select name from document where Name='RangehoodObjectionLogo'];         if(documentList.size()>0)         {            imageURL=imageURL+documentList[0].id;         }       }          public PageReference Savecopy(){       PageReference p = Page.RangehoodObjectionSheet;       blob b = ApexPages.currentPage().getContentAsPDF ();       Attachment a = new Attachment();       a.body = b;       a.name = 'Rangehood Objection sheet Issued '+currentdate+'.pdf';       a.parentid = planreviewID;        insert a;        PageReference pref = new PageReference('/'+planreviewID);       return pref;    } }


I've just added an SSH key to my digital ocean droplet using their API, so I didn't ever connect to my droplet through SSH. Their  says that I should, after creating, I should just say 'yes' when connecting through ssh, like I did:  ssh -i id_rsa root@IP   the fact is that I don't know if this fingerprint is from my machine. Howevr, since I'm using private keys, I don't know if there s a risk of saying 'yes' without knowing if this fingerpint is the real one. Is there any risk, even using a private key? Why does the documentation tell me to say yes if that is a security risk?

I installed openssh-server and created a key with ssh-keygen. I then attempted to test it using local port forwarding by doing ssh -L 8080:www.nytimes.com:80 127.0.0.1. However, the key fingerprint that this command provides is not the key fingerprint I get when I do ssh-keygen -l. Even if I delete my .ssh directory, I still get the same fingerprint, which is not the one I created with ssh-keygen. Is there another key on my system? Where is this key? How can I select this key for use by openssh-server?


This story goes back to the 70s at least and was a short story in an anthology. I read this around 1971.  The protagonist was involved in an auto accident on a high speed "hyperway" of the future. He was tried in what I remember as a mobile court and I believe executed for this immediately.  It was a very short story and not an incident from a longer book. From what I remember the plot was what is the ultimate consequence of bigger and faster freeways and how can they be controlled.

I'm trying to locate a short story, probably written in the 1970s but likely before the oil crisis, about a day in the lives of two officers and one medic on a patrol car riding the highways of the U.S. and Canada at speeds of over 400 miles per hour.  They eat, shower and sleep in their vehicle as they patrol, rescue and arrest drivers over hundreds on miles of road. It's either a multi-national patrol or the two countries have merged in some fashion. I probably read this in an anthology, possibly in the 1980s or 1990s.


Do all votes have the same effect on reputation?   Is there any policy in which first n votes will increase/decrease the reputation by j, and after n votes reputation will increase/decrease by k votes?

On Stack Exchange, users may gain a certain level of reputation.  What does reputation do? How can a user gain or lose reputation?   See also   in the Help Center  - Maximum amount of votes a user can use in a day and reputation requirements to vote.  - How to get an exact overview of the actions that got you your reputation.  - A full list of all privileges granted at each reputation level on all sites.


Here is a screenshot of my "select your next badge" window.    As you can see in the screenshot, my rep was 1905 but I have 1/100 for proofreader badge. I took that screenshot recently, but I have been seeing that 1/100 for quite a long time now. I know that a user with less than 2000 rep doesn't have  Moderation Privilege. So, how was it possible for me to get that 1/100 for proofreader?  I have a suspicion though. I think that 1/100 came from  of mine. I get this suspicion because, as far as I remember I once edited that question without logging in. Also, you can see that the question was edited my .    I am tagging this question with "bug" tag, because I had to choose one from "discussion" and "bug", and the latter seemed right to me, though I want to think that this is not a bug!

I am a member of the  (in beta) and I have a 770 reputation points.  Recently, I was reviewing Close votes posts and found that a user with just  of suggested edits.  But the review page says I need a minimum of 1000 reputation points to review a suggested edit.    How could that user do that?  Is this a bug?


I upgraded from 16LTS to 18. Among other problems, I am stuggling with this interface. How can I go back to the old interface?

I recently installed Ubuntu 18.04 and I'm not keen on the desktop environment. I want the desktop env. I used to have in Ubuntu 14.04. How can I get it?  I've attempted to use , but when I try to install the Unity's 7.2.5 version using the command:  apt install unity=7.2.5   it gives me   E: Version '7.2.5' for 'unity' was not found   For sure I need to add a PPA for this, but which one!?


Consider a class that can be used as a member of multiple other classes:  class Customer {     public string FirstName {get;set;}     public string LastName {get;set;} } // Both "Order" and "Profile" have a "Customer" property class Order {     public Customer Customer {get;set;} } class Profile {     public Customer Customer {get;set;} }   I want to define a method that makes a checker for an object associated with a Customer. If I want an in-memory checker, I do it like this:  static Func<T,bool> Check<T>(Func<T,Customer> conv, string first, string last) {     return obj => conv(obj).FirstName == first && conv(obj).LastName == last; }   I can use my checker for in-memory sequences as follows:  var matchingOrders = orders     .Where(Check<Order>(x => x.Customer, "Foo", "Bar"))     .ToList(); var matchingProfiles = profiles     .Where(Check<Profile>(x => x.Customer, "Foo", "Bar"))     .ToList();   Now I want to do the same thing with Expression<Func<T,bool>>:  static Expression<Func<T,bool>> Check<T>(Expression<Func<T,Customer>> conv, string first, string last)   Unfortunately, the same trick does not work:  return obj => conv(obj).FirstName == first && conv(obj).LastName == last;   and use it like this:  var matchingOrders = dbContext.Orders     .Where(Check<Order>(x => x.Customer, "Foo", "Bar"))     .ToList(); var matchingProfiles = dbContext.Profiles     .Where(Check<Profile>(x => x.Customer, "Foo", "Bar"))     .ToList();   This triggers an error:     CS0119: Expression denotes a variable', where amethod group' was expected   Can I compose expressions the same way that I compose delegates?

I want to compose the results of two Linq Expressions. They exist in the form  Expression<Func<T, bool>>   So the two that I want to compose are essentially delegates on a parameter (of type T) that both return a boolean. The result I would like composed would be the logical evaluation of the booleans. I would probably implement it as an extension method so my syntax would be something like:  Expression<Func<User, bool>> expression1 = t => t.Name == "steve"; Expression<Func<User, bool>> expression2 = t => t.Age == 28; Expression<Func<User, bool>> composedExpression = expression1.And(expression2);   And later on in my code I want to evaluate the composed expression  var user = new User(); bool evaluated = composedExpression.Compile().Invoke(user);   I have poked around with a few different ideas but I fear that it is more complex than I had hoped. How is this done?


How do I decipher these cryptic COMExceptions that ArcObjects are throwing?  I got this exception System.Runtime.InteropServices.COMException: HResult: 0x8004151C and thats it, no more info no nothing. How do I go about debugging?  I managed to decipher the exception after hours of googling, talking to colleagues, searching ESRI's forums and resources and at last gis.stackexchange.com.  I found this resource  and some other resource I cant manage to find again, where I was supposed to use the calculator in scientific mode, and do 10 steps of stuff get a 10 digit error code.  While doing so I couldn't help but get annoyed and wonder if this is the way its meant to be, or if there is any solution, code or anything else out there that could ease the job.  Or do we developer really have to wait for an exception to happen, and then do a manually lookup on the internet and maybe, just maybe find the cause for the exception after a long period of time?  So thats why I'm asking here, hence the question in the top.

I'm trying to perform the following operation:    IPropertySet addressProperties = reverseGeocoding.ReverseGeocode(point, false);   And I get this error: Exception from HRESULT: 0x80040217  Is there some function to get a human readable form of this error?


In general,  'the + adjective' and 'the + past participle' could be used instead of a plural noun phrase.     The good die young.      The damned will bury the dead.   I think in certain cases that structure could be used instead of a singular noun.     'The Good, The Bad and the Ugly'      I was not the hunter but the hunted. (the hunted one)   Also, the structure is sometimes used with a possessive or an indefinite article instead of 'the'.     An accused      A condemned      God's chosen   Three questions:   Is this structure is ever used for non-humans? Is it ever used for non-living things? Is it ever used with a determiner other than 'the' when we don't have a past participle, but an adjective?

Some examples include:     We fear the damned.   He honored our fallen.   This is a given.   You are the chosen.   The lost were among us.   They obey the venerated.   My beloved kissed me. (TIL “beloved” is a verb thanks to RegDwight АΑA)   Is there a word to describe the past participle used as a noun? I’m hesitant to refer to it as a gerund, since it doesn’t end in -ing. Another possibility is adjectival noun, if you originally treat the word as a participle (e.g. “the damned man”) that has given up its modified noun.  Also, why does English tend to preface such nouns with the?


I recently added the relevant tags to my site and validated my email for Google Authorship. After around a week my image started showing up with results.   Today the image is no longer present and I haven't changed anything. The Structured Data Testing Tool  show that it should all be working.   Have I missed something or does anyone know why it would stop displaying?  Other questions ask about situations where the image has never appeared. My image has appeared but has since stopped appearing so is a different situation.

A few months back I set to the task of verifying my blog content for Google Authorship. I'm fairly confident I've ticked all the boxes and when I test my posts with the Google Structured Data tool it informs me that .   It has been like this for around 2 months but I am still not seeing my authorship profile in the search results. Do a search for "jQuery Parallax Scrolling Tutorial" and you will see my blog post near the top of the results but no authorship data.  Can anyone suggest why this is not appearing when Google itself tells me that everything is in order? Thanks


My laptop hard disk is running with Windows 10 and my old laptop hard disk is running with Windows 7, Can i just take them out and put it on my new laptop?

My laptop running Windows 7 Ultimate (non OEM) died on me today and it has tonnes of stuff on it - my projects, Visual Studio and office installations, etc. etc.  I am getting a new laptop from somewhere and was wondering if I could just unplug the hard disk from my original (dead) machine and plug it into the new one.  I remember trying this once with Windows Xp (on a desktop) and the OS crashed on boot and I had to reinstall everything again.  I have read about  but by the looks of it, it can be used only when the host computer is alive and kicking -- which mine isn't.  My old laptop was a Compaq Pressario v3000 (3 years old) on an AMD and the new one is going to be a new dual core Intel HP laptop.  Any ideas?  Thanks!


Hello I am pretty new to rust, is there a reason to use (0xFF, OxFFFF and so on) x: [u8; 0xFF] instead of x: [u8; 255]

Hey! I was looking at this code at   I noticed that in some situations they used hex numbers, like in line 134:  for (j = 1; val && j <= 0x80; j <<= 1, q++)   Now why would they use the 0x80? I am not that good with hex but I found an online hex to decimal and it gave me 128 for 0x80.  Also before line 134, on line 114 they have this:  small_n = (n & 0xffff0000) == 0;   The hex to decimal gave me 4294901760 for that hex number. So here in this line they are making a bit AND and comparing the result to 0??  Why not just use the number? Can anyone please explain and please do give examples of other situations.  Also I have seen large lines of code where it's just hex numbers and never really understood why :(


I had a file downloaded from torrent by a media center device on an external hard disk. The file has an invalid filename such as "Movie ** 480p ** NEW.wmv" (without the quotes). I cannot delete or rename the file in any way probably because of the asterisks "**" in the file name. Do you have any ideas what I can do?  Details: The external drive uses an NTFS file system. I tried Windows, Windows command line, OSX terminal, Ubuntu but could not delete it. I can see the file by "dir" or "ls" commands, but when I try to delete or rename I get "No such file or directory" or a similar error. So the file can be shown but cannot be operated on by all OSs I mentioned above. I thought I deleted it with Ubuntu Terminal commands but the file and the folder it is in is only moved to ".Trash" folder and it is stuck there.  I tried various suggestions in various forums:   rm -r rm * del * rmdir rmdir -r dir /x (does not work on Windows 8.1) find . -inum number_here -exec rm -i {} \; shell scripts in Linux to delete files rm "Movie ** 480p ** NEW.wmv" rm -- 'file_name_here' (and variants) chkdsk f: (This actually ended up with an error) Using 7Zip   ...and many other suggestions on different forums to similar problems, none of them work. My last option is using a hex editor and change the file name manually on disk but that may mess up the Master File Table. In addition, I could not locate what sector the MFT is.  One user on  solved this problem by connecting his drive to an Android system but my Android devices do not have USB connections and the original media center device cannot delete or rename the file either.  Any other suggestions?

I have a bunch of files on a Ubuntu box, which have various characters in their filenames that Windows doesn't accept (mostly ":" and "*", but possibly others).  What's the simplest way to get these all renamed and moved to a Windows machine? It's OK to replace these characters with something like "[colon]" and "[asterisk]".


I play in creative, and I basically had a house with things connected to it with a path. I used the same wood for the other rooms but every little bit of my house is gone! Even my 6-7 dogs are gone and their dog house!

I was playing Minecraft 1.6.2 survival mode (normal difficulty), and I built a house. Then I went far away to explore a cave. When I got back, part of my house had simply disappeared.     As you can see, a part of my house just vanished. There used to be walls and a roof, but not anymore.     The stranger thing is, the wooden floor just turned into a perfect square of dirt.    There also used to be a pond nearby, but part of the pond also turned into dirt. (as indicated by the redstone circuit.)    Fences are gone. My iron golem and a cat are nowhere to be found. The whole area encircled by the redstone simply turn into dirt.  I thought of a creeper explosion. Yes, I might have left the gate open, and yes a creeper might be able to sneak into the house, (if it managed to get pass my two cats). It seems unlikely that an explosion would occur. There is no hole on the ground, and the roof is gone too. I don't think the blast radius is that large. The house was fine when I left. Doesn't a creeper has to be near me to trigger an explosion?  I am really puzzled. Can somebody explain what happened? I would be very grateful.


When using "who" in a question, which is correct:  Is it I who has erred? Is it I who have erred?  The latter seems correct by test (take out who), but the former seems correct by question form (singular, but take out I).

Possible Duplicate:          Am aware it is correct to say "I have written..." and "I am a doctor who has writen..."  I have, however, severally come across the sentence "I, Tertius, who have written...". Shouldn't it be "I, Tertius, who has written..."?


If I refinance my mortgage with same lender, will I need to pay for new lender title insurance ?  I understand, I can ask the lender, but before I do I want to know how is the experience of other stack-flow readers?

I was wondering: if I refinance my home, will I need a new owner's title insurance, or will the previous title insurance still be valid?  I suppose the new lender will require new lender's title insurance, but my owner's title insurance should still be valid. I have standard (non-enhanced) title insurance.


For some reason, I can't break any blocks in Minecraft.  They break, but then they reappear and don't drop anything.  Iv'e tried restarting and updating, but nothing seems to work.  What do I try next?

I'm playing on a Survival world with cheats on, "easy" difficulty, and at night in-game. I didn't have a sword or anything to make a sword with, and I was starving, so I switched to Creative to give myself a stack of food and a bed to set my spawn point. When I switched back to Survival, I couldn't destroy or place blocks. I'm on single player, and my Internet is fine, and I can destroy blocks still if I switch to creative. I've tried resetting the button one, and reloading the map, and it still doesn't work. I've even tried deleting everything I gave myself in Creative. This happened before on a different world and I ended up deleting it.  This only happens on this world. How do I fix it?  If I know I'm in the correct game mode, what else can cause this?  Are there different causes in multiplayer?


My upgrade from 14.04 to 16.04 LTS gets stuck and hangs on one task way too long.  The job it seems to get stuck on is  [OK] Starting : start Samba LSB SMB/CIFS daemon (smdb).  The background IS black, but I have access to the terminal. and now through using nmcli I have my Wi-Fi connection back, but no apt.   The question that's supposed to be this duplicate is NOT the same case here. I provided much more detail, the install version and distro as well as my attempted fixes. In my comments I added updates as I tried something a bit different daily. Today I'll work w/ systemd and try that.

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


Is "I believe I am ready enough" the wrong way to say that I am ready enough?  I wish to write it with reasonable confidence that I am ready enough to take up a certain challenge. Is there another other way to convey the same?  Conversely - is "I believe I am ready enough" wrong way to say that I am ready enough?

He will understand that I was not joking.   He will understand I was not joking.  Which of the sentences is correct? Are there any specific rules about the use of "that" in the sentences I reported as example?


I have a problem which I can't solve by myself or haven't found anywhere:  I'm citing the same author (and year) with two different sources. In the bibliography the second entry only has a big dash instead of the author again, which I would prefer. Any suggestions to get the same author being displayed again there?  Code example:  \documentclass{article} \usepackage[utf8]{inputenc} \usepackage{blindtext} \usepackage[style=authoryear,maxnames=2,sorting=nyt,isbn=true,url=true,block=space,natbib=true]{biblatex} \addbibresource{bib.bib} \title{Hi} \author{MM} \date{November 2019}  \begin{document}  \maketitle  \section{Introduction}  \blindtext\citep{bundesregierung_klimaschutzgesetz_nodate}\citep{bundesregierung_klimaschutzprogramm2030_2019}  \printbibliography  \end{document}   In the bib.bib file there are these two entries:  @misc{bundesregierung_klimaschutzprogramm2030_2019, title = {Klimaschutzprogramm 2030}, url = {https://www.bundesregierung.de/breg-de/themen/klimaschutz/klimaschutzprogramm-2030-1673578}, language = {de}, urldate = {2019-11-04}, author = {{Bundesregierung}}, year = {2019}, }  @misc{bundesregierung_klimaschutzgesetz_nodate, title = {Klimaschutzgesetz}, url = {https://www.bundesregierung.de/breg-de/themen/klimaschutz/kimaschutzgesetz-beschlossen-1679886}, urldate = {2019-11-05}, author = {{Bundesregierung}}, year = {2019}, }   The output looks something like this:

I use biblatex with style=authoryear and when there are two references of the same author in the bibliography there is just a dash. How can I get the full name in the second entry too?


I'm trying to understand this proof that every group of order $30$ has a subgroup of order $15$:  By Example $37.12$, a group $G$ of order $30$ has a normal subgroup of order $5$ or of order $3$. Suppose that $G$ has a normal subgroup $H$ of order $5$. Then $G/H$ is a group of order $6$, which has a normal subgroup $K$ of order $3$ by Sylow theory. If $λ : G → G/H$ is the canonical homomorphism, then $λ^{−1}[K]$ is a normal subgroup of $G$ of order $3 · 5 = 15$. If $G$ has no normal subgroup of order $5$, then it has a normal subgroup $N$ of order $3$, so $G/N$ has order $10$ and has a normal subgroup $L$ of order $5$. Applying to $L$ the inverse of the canonical homomorphism mapping $G$ onto $G/N$ gives a normal subgroup of $G$ of order $15$  First, why the inverse image doesn't have the same number of elements as $K$ since $\lambda$ is a bijection? Also, why the inverse image has $3.15$ elements?

How do I find all the groups of order 30? That is I need to find all the groups with cardinality 30. I know Sylow theorems.


We have positive continuous function $f(x)$ defined on $\mathbb{R}$, such as $\int_{-\infty}^{+\infty} f(x) dx = 1$ let $\alpha \in (0,1)$ and $[a,b]$ is an interval  of minimal length amongst intervals for those holds: $\int_{a}^{b} f(x) dx = \alpha$. Task is to prove that $f(a) = f(b)$.    I managed to sum up following statements: $F(\infty) - F(-\infty) = 1$ $F(b) - F(a) = \alpha$ And one to prove is: $f(b) - f(a) = 0$ I am looking for hints to build a proof here.

$f(x)$ is positive and continuous function on $\mathbb{R}$ and, moreover, $\int_{-\infty}^{+\infty}f(x)dx=1$. $\alpha\in(0;1)$ and $[a;b]$ is the interval having a minimum length such that the $\int_{a}^{b}f(x)dx=\alpha$. Prove $f(a)=f(b)$.  With mean value theorem easy to show, that for every $\alpha\in(0;1)$, exist such $[a;b]$, so  $\int_{a}^{b}f(x)dx=\alpha$. The statement looks like Rolle's theorem, but I have no idea. I will be grateful for help.


Is there a white paper, or any long winded sob story already written why we desperately need to stop using Windows XP and upgrade to... well, anything other than XP really, 7/8/10. ?  I've searched, and you would have though Microsoft would be spamming the internet with reasons to upgrade, but I've come up with nothing, was/is it really that loved?  anyway, I really do need some sound reasons to get rid (I personally want to get rid due because of the limited memory support, can't use latest .Net framework and can't use latest SQL Express, but if I had a sound security reason.. well people would panic into upgrading right?)

Microsoft stopped updating Windows XP and the media warns us of security leaks. I actually just read that continuing to use Windows XP is "extremely" dangerous. Why exactly is this such a danger? I would believe that by now XP should be pretty safe to use after years of updates.   Are there particular things XP users have to look out for and perhaps take counter measures against?  I would also believe that all the interesting places for hackers will update to Windows 7/8 and serious threats will not be created anymore in the future, at least not specifically aimed at Windows XP.


I'm a Saudi citizen, holding a Schengen visa that expires on April 12, 2018. I'm planning to visit Romania, which allows multiple entries for Schengen visa holders. However my Schengen visa is expiring in 1 month and I'm planning to visa Bucharest on March 25 for 5 days.  Is it ok to enter that country with 15 days left on the visa?

I have a Vietnamese passport. I'm planning to visit Vietnam on July 7th and be back in the Czech Republic (in Schengen area) on August 29th. My visa is a multiple-entry, long-term, D type visa (for study purposes) and the expiration date is September 10th. I am afraid that the boarding officer will not allow me to enter EU since the arrival is so close to the expiration date.   Is it OK for me to enter Schengen on August 29th when I have only 12 days left until visa expiration?


I decided to take the product of each term in the sequence and add I to the result. My main issue is that I do not know how to show that this resulting number must have a Gaussian prime factor q which has a Split primagon. If I can show this, then my idea was to show that q*q' is a prime integer within the sequence where q' is the conjugate of q.  Showing the product has a Gaussian prime factor isn't difficult, but I'm not sure how to how it's split, nor am I sure why only the split case allows for q*q' to produce a prime within the sequence.

Question: Are there infinitely many primes of the form $4n+3$ and $4n+1$?  My attempt: Suppose the contrary that there exist finitely many primes of the form $4n+3$, say $k+1$ of them: $3,p_1,p_2,....,p_k$  Consider $N = 4p_1p_2p_3...p_k+3$, $N$ cannot be a prime of this form. So suppose that $N$=$q_1...q_r$, where $q_i∈P$  Claim: At least one of the $q_i$'s is of the form $4n+3$:  Proof for my claim: $N$ is odd $\Rightarrow q_1,...,q_r$ are odd $\Rightarrow q_i \equiv 1\ (\text{mod }4)$ or $q_i ≡ 3\ (\text{mod }4)$  If all $q_1,...q_r$ are of the form $4n+1$, then $(4n+1)(4m+1)=16nm+4n+4m+1 = 4(\cdots) +1$  Therefore, $N=q_1...q_r = 4m+1$. But $N=4p_1..p_k+3$, i.e. $N≡3\ (\text{mod }4)$, $N$ is congruent to $1\ \text{mod }4$ which is a contradiction.  Therefore, at least one of $q_i \equiv 3\ (\text{mod }4)$. Suppose $q_j\equiv 3\ (\text{mod }4)$  $\Rightarrow$ $q_j=p_i$ for some $1\leq i \leq k$ or $q_j =3$  If $q_j=p_i≠3$ then $q_j$ | $N = 4p_1...p_k + 3 \Rightarrow q_j=3$ Contradiction!  If $q_j=3$ ($\neq p_i$, $1\leq i \leq k$) then $q_j | N = 4 p_1...p_k + 3 \Rightarrow q_j=p_t$ for some $1 \leq i \leq k$ Contradiction!  In fact, there must be also infinitely many primes of the form $4n+1$ (according to my search), but the above method does not work for its proof. I could not understand why it does not work. Could you please show me?  Regards


I'd like to show the following: Let $a \in \mathbb{N}$ and $p \in \mathbb{P}$ with $gcd(a, p-1)=1$, then for every integer $b$, the congruence relation $x^a \equiv b$ mod $p$ has a solution.  If $p \mid b$, then this trivially holds. For the other case, I've started with showing that there exists a $c$ such that $a*c \equiv 1$ (mod $p-1$) and I think that $x = b^c$ should satisfy the relation, but I've not yet been able to show this. Can someone help me?  Thanks!

The question is about the encryption equation in asymmetric encryption.  For $c\equiv m^e\bmod n$, prove that for every unique $m$ there is a unique $c$.  Here $n=pq$ where $p$ and $q$ are primes larger than $m$ and the exponent $e$, is $\geq3$ and coprime with $p-1$ and $q-1$.  Thanks!


How to format HD 1TB in more than three gpt partitions without any operarations system. At least 7 partitions in gpt  There is a tutorial to do gpt partitions? 1 for Windows 10 and the others that are need for got style partitions.  2 for data, backup 3 for Ubuntu. 4 for home in separate partition. 5 for backup or data.

I'm absolutely new to Linux. I would like to know how to install Ubuntu alongside the pre-installed Windows 8+ OS.  Should I do it with Wubi, or through the Live USB/DVD?  What steps do I need to take to correctly install Ubuntu?


I did plot my graph with GeoGebra, but when I added it to Texmaker the graph isn't proper. That's why I'm trying to color the background of the graph with the same color as inside the other circle (grey). I'm trying to do this by adding the command   \addplot [draw=black, fill=grey] coordinates {(-3,-3) (-3,3) (3,-3) (3,3)};   Can someone solve my problem? Here is the full code for the tikzpicture:  \documentclass{article} \usepackage{pgf,tikz} \usetikzlibrary{arrows}   \begin{document} \definecolor{uququq}{rgb}{0.25098039215686274,0.25098039215686274,0.25098039215686274} \definecolor{ffqqqq}{rgb}{1,0,0} \begin{tikzpicture}[line cap=round,line join=round,>=triangle 45,x=1cm,y=1cm] \draw[->,color=black] (-4,0) -- (4,0); \foreach \x in {-4,-3,-2,-1,1,2,3,4} \draw[shift={(\x,0)},color=black] (0pt,2pt) -- (0pt,-2pt); \draw[->,color=black] (0,-3.9627039627039613) -- (0,4); \foreach \y in {-3,-2,-1,1,2,3} \draw[shift={(0,\y)},color=black] (2pt,0pt) -- (-2pt,0pt); \clip(-8,-3.9627039627039613) rectangle (8,4); \draw[line width=2pt,color=ffqqqq,smooth,samples=100,domain=-8:8] plot(\x,{(\x)});  \draw [rotate around={0:(-1,0)},line width=2pt,color=uququq] (-1,0) ellipse (1cm and 1cm);  \draw [rotate around={0:(0,0)},line width=2pt,fill=black,fill opacity=0.25] (0,0) ellipse (1.4142135623730951cm and 1.4142135623730951cm);  \begin{scriptsize}\draw[color=ffqqqq] (-3.2950340798442066,-3.655011655011654) node {$f(x) = x$};\draw [fill=black] (0,0) circle (2.5pt);  \draw[color=black] (0.6932814021421617,0.39160839160839206) node {$A = (0, 0)$};  \draw [fill=black] (-1,-1) circle (2.5pt);  \draw[color=black]  (-0.1947419668938657,-0.5967365967365961) node {$B = (-1, -1)$};  \end{scriptsize}  \end{tikzpicture} \end{document}

How to change the paper color(background color) in tikz class kindly help me to change color    \documentclass{scrartcl} \usepackage[usenames,x11names,dvipsnames,svgnames]{xcolor} \usepackage{graphicx,amsmath,latexsym,amssymb,amsthm,geometry} \usepackage{tikz} \usepackage{pagecolor}% http://ctan.org/pkg/{pagecolor,lipsum} \usetikzlibrary{decorations, decorations.text} % tight page \usepackage[active,tightpage]{preview} \PreviewEnvironment{tikzpicture} % \begin{document}%  \begin{tikzpicture}         % outer circle             \draw[line width=2 mm,color=black,fill=white!10] circle[radius=7cm];         % outer text             \path[                 postaction={                     decoration={raise=.1ex,                         text along path,                         text format delimiters={|}{|},                         text={%                             |\Huge\bfseries\color{black}|                           name name {\textbullet} name {\textbullet} name name name name name                         },                         text align=fit to path,                         reverse path                     },                     decorate                 }             ]              (0:6.2cm) arc (0:360:6.2cm); \draw[line width=2 mm,color=black,fill=white!10] circle[radius=5.8cm]; % central text \node[color=Brown3] at (0, 1){\includegraphics[width=4.5cm]{14}}; \end{tikzpicture}% \end{document}


Server Socket throwing this error and app completely crashes. I called this thread in my onCreate() method . When activity is running for the first time it is good but after finishing and get back to this activity is giving below error.        'java.net.Socket java.net.ServerSocket.accept()' on a null object reference    private class ClientConnectionThread implements Runnable {         ServerSocket serversocket;          public ClientConnectionThread(){             try{                 serversocket = new ServerSocket(5005);                 serversocket.setReceiveBufferSize(1024*1024);                 Log.v("BoardCastRunning","BoardCast Server Waiting");             }catch (IOException ex){                 Log.v("BoardCastError",ex.toString());             }           }          @Override         public void run() {              while(true){                 try{                      streamClientSocket = serversocket.accept();                     Log.v("BoardCast","New Connection");                     videoBroadcastSockets.add(streamClientSocket);                     runOnUiThread(new Runnable() {                         @Override                         public void run() {                             Utils.shortToast(context,                                     "Client connected from: "                                             + streamClientSocket.getInetAddress().getHostAddress()                                             + " " + streamClientSocket.getPort());                           }                     });                 }                 catch(IOException ex){                     Log.v("BoardCastError",ex.toString());                 }               }         }     }

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'm trying to use \ifthenelse from the ifthen package to vary the size of \headheight within a document. I'd like this to be larger for the first page and then smaller for each subsequent page.   I had thought I could accomplish this using code like the following in my preamble.  \ifthenelse{\thepage=1}   {\setlength\headheight{72pt}}   {\setlength\headheight{14pt}}    Unfortunately, that's not working for some reason. Below is some code that illustrates what I'm trying to do.   \documentclass{article}  %%%% Margins %%%%  \setlength{\textwidth}{6.5in} \setlength{\oddsidemargin}{0in}  %%%% Packages %%%%  \usepackage[usenames,dvipsnames]{color}  \usepackage[lastpage,user]{zref} \usepackage{fancyhdr} \usepackage{ifthen} \usepackage{parskip} \usepackage[pdfstartview=Fit]{hyperref}  %%%% Headers/Footers %%%%  \setlength\headheight{72pt} \renewcommand\headrule{{\color{BrickRed} \hrule height 1pt width\headwidth}} \pagestyle{fancy} \definecolor{light-gray}{gray}{0.65}  \lhead{\ifthenelse{\thepage = 1}               {\textcolor{light-gray}{My Name} \\ [4ex] \vspace{36pt} \textcolor{light-gray}{Telephone Number}}               {\textcolor{light-gray}{My Name}}}  \rhead{\ifthenelse{\thepage = 1}               {\textcolor{light-gray}{Page \thepage \ of \zpageref{LastPage}} \\ [4ex] \vspace{36pt}                \textcolor{light-gray}{Email Address}}               {\textcolor{light-gray}{Page \thepage \ of \zpageref{LastPage}}}}  \chead{\ifthenelse{\thepage = 1}               {{\large\bfseries MY NAME, TITLE} \\                Address Line 2 \\                Address Line 3 \\                Address Line 4 \\ [1ex]}               {}}  \cfoot{}  %%%% Main Document %%%%  \begin{document}  Some text  \newpage \setlength\headheight{14pt}  More text  \end{document}   This code produces the desired output. The drawback though is that I need to manually specify where the first page break should occur and then reset the headheight using:  \newpage \setlength\headheight{14pt}   Is there some way to automate this, using \ifthenelse or some other means? Setting things manually when the contents of the first page change doesn't require much effort, but I'd like to understand what's going wrong and how to do this properly.

I am trying to write a recommendation letter with a fancy heading at the top of the first page, using fancyhdr. I copy my code below.  The results are that the first page looks good but subsequent pages do not. Subsequent pages omit the logo (as desired) but leave enough space for it, and the text starts from the same place on every page. Starting from the second page, I would like the text to start higher.  It seems that the only code which could cause the text to appear lower is within the \fancypagestyle{firstpage}{...}, and I use \thispagestyle{firstpage} with the intent that this should only affect the first page -- but this is not what happens when I compile and view my document.  I read related posts  and , and attempted to modify my code based on what I read there, but without achieving the results I was looking for.  Thank you very much.  LaTeX code (which compiles):   \documentclass[11pt]{article} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsmath} \usepackage{color,hyperref} \usepackage{graphics} \usepackage{times} \usepackage{fancyhdr} \usepackage{datetime}   \definecolor{darkblue}{RGB}{0,0,50} \hypersetup{colorlinks,breaklinks,             linkcolor=darkblue,urlcolor=darkblue,             anchorcolor=darkblue,citecolor=darkblue}   %%%%%%%%%%%%%%%%%%date in format Sunday, October 25, 2011$$$ \usdate \def\theday {\dayofweekname{\day}{\month}{\year}} \def\mydate {\theday , \today}  %%%%%%%%%%return address%%%%%%%%%% \def\myname     {Frank Thorne} \def\mydeptname     {Department of Mathematics} \def\myaffiliation  {University of South Carolina} \def\mystreet       {1523 Greene Street} \def\mycitystatezip {Columbia,\ SC\ \ 29208} \def\myphone        {{\it Phone:} (803)404-4057 (home)} \def\office     {(803)777-4224} \def\fax        {{\it Fax:}(803)777-3783} \def\email      {thorne@math.sc.edu} \def\url        {http://www.math.sc.edu/$\sim$thornef} % NOTE: use $\sim$ for tilde %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%  %%%%%%%%%%%%%%%margins%%%%%%%%%%%%%%%%%% \oddsidemargin   0in \evensidemargin  0in \topmargin  -0.75in \textwidth   6.5in \textheight  6.25in \headwidth  \textwidth \parindent      0ex %controls how the indentation of new paragraphs behaves \parskip        6pt %controls the space between paragraphs \headheight     1.25in \headsep    1in %This controls how far below the letterhead the text of the letter will begin    \addtolength{\textheight}{.5in} %%%%%%%%%%%%%%%%letterhead%%%%%%%%%%%%%%%% \fancyfoot{} \renewcommand{\headrulewidth}{0pt} \renewcommand{\footrulewidth}{0pt}  %\thispagestyle{fancy} \fancypagestyle{firstpage}{ \fancyhf{} %%%usc logo \fancyhead[L]{\resizebox{2.5in}{!}{ %\includegraphics{USC_Linear.jpg} } \vspace{0.6in}}  %%%%%%%%%%return address on right%%%%%%% \fancyhead[R]{ \parbox[t]{3.1in}{ \footnotesize   \em \vspace{0.5in}                 \myname \\                 \mydeptname   \\                 \myaffiliation \\                 \mystreet \\                 \mycitystatezip \\                 \email \\ \\                  \mydate                 }\hspace{-1.3in} \vspace{0.2in}} }  \begin{document}  \thispagestyle{firstpage}  Blah blah blah.   Blah blah blah.  Blah blah blah.  Blah blah blah.  Blah blah blah.  Blah blah blah.  Blah blah blah.  Blah blah blah.  Blah blah blah.  Blah blah blah.  Blah blah blah.  Blah blah blah.  Blah blah blah.  Blah blah blah.  Blah blah blah.  Blah blah blah.  Blah blah blah.  Blah blah blah.  Blah blah blah.  Blah blah blah.  Blah blah blah.  Blah blah blah.  Blah blah blah.  Blah blah blah.  Blah blah blah.  Blah blah blah.  Blah blah blah.  Blah blah blah.  Blah blah blah.    \hspace{.5\textwidth}\parbox[t]{2.95in}{             Sincerely,\\              Frank Thorne\\             Assistant Professor of Mathematics            }  \vfill      \end{document}


Somehow suddenly Ubuntu is reading menu's to me - with a computer voice. How do I turn that off?  thanks

I accidentally opened Orca Screen Reader from the Dash when I was trying to open Screenshot. Now everything I type or click on is spoken out loud.  How do I make it stop?  For reference, here is a screenshot of Orca Screen Reader running:


I'm trying to add an if statement in add_resource of troposphere, but I can't. Is there any workaround to do so? s3_bucket = t.add_resource(Bucket(     "MyBucket",     if 2>1:        BucketName="bucket1",     else:        BucketName="bucket2",     CorsConfiguration=CorsConfiguration(         "CorsConfiguration",         CorsRules=[CorsRules(             "AllowOrganization",             AllowedMethods=["GET"],             AllowedOrigins=["*"],         )]     ),     Tags=Tags(         Environment="aa",     ) ))  Edit: I tried to use ternary operators as well, but it didn't work. BucketName= if 2 > 1: "bucket2" else: "bucket3",

If Python does not have a ternary conditional operator, is it possible to simulate one using other language constructs?


Given set A has n elements. Find  1) Number of all reflexive relations?  2) Number of all symmetric relations?  3) Number of all reflexive and symmetric relations? Why is enumeration of transitive relations difficult?  1) Relation could be viewed as a digraph hence after the self loop edge for each vertices. There are ${n \choose 2}$ edges hence two choices for each i.e either a relation or not Hence answer:$ 2 ^ {n \choose 2} $  2) Here another choice of self loop. There are ${n \choose 2}$ + 1  edges hence two choices for each i.e either a relation or not Hence answer:$ 2 ^ {{n \choose 2}+1} $   Is this correct? Third one I am very confused how to approach.

Consider a non-empty set A containing n objects. How many relations on A are both symmetric and reflexive?  The answer to this is $2^p$ where $p=$ $n \choose 2$. However, I dont understand why this is so. Can anyone explain this?


for (i=1; i < 9; i++) {         for (j=1; j < 9; j++) {             if ( board[i][j] == "o" ) {                 j = j-1;                  if ( board[i][j] == "x" ) {                     do {                         j--;                     }                     while (board[i][j] != "-");                     board[i][j] = ".";                 }             }         }     }   I have this piece of code as part of a method, there are two versions, one as written above and one where j = j-1 is replaced with j = j+1 and j-- is replaced with j++  The positive version works perfectly fine but if I put in the negative version, the code compiles fine but when I attempt to run it nothing happens, the console just hangs and I have to close and reopen it. Can anyone tell me what I am doing wrong? Thanks in advance.  edit:  for (i=1; i < 9; i++) {         for (j=1; j < 9; j++) {             if ( board[i][j].equals("o") ) {                 j = j-1;                  if ( board[i][j].equals("x") ) {                     do {                         j--;                     }                     while (!board[i][j].equals("-"));                     board[i][j] = ".";                 }             }         }     }   I have edited the code as indicated but the problem persists

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


The question I have is:  Define X,Y to be two independent uniform(0,1) random variables and $Z:=\frac{Y}{X}$  Compute $P(X<x|\sigma(Z))$  The answer given apparently by "straightforward elementary computations" is for $x\geq 0$  $P(X<x|\sigma(Z))$=min$\{{x^2,1}\}\mathbb{I}_{Z\leq 1}$ $+$ min$\{{x^2 Z^2,1}\}\mathbb{I}_{Z\geq 1}$.  My idea was to condition on the $Z\leq 1$ and ${Z\geq 1}$  then compute using the joint density of X and Y, but this seems to work for the first term but doesn't for the second? Any help would be much appreciated.

Supppse $X$ and $Y$ are standard uniformly distributed in $[0, 1]$, and they are independent, what is the PDF of $Z = Y / X$?   The answer from some probability theory textbook is  $$ f_Z(z) =  \begin{cases} 1/2, & \text{if } 0 \le z \le 1 \\ 1/(2z^2), & \text{if } z > 1 \\  0, & \text{otherwise}. \end{cases} $$  I am wondering, by symmetry, shouldn't $f_Z(1/2) = f_Z(2)$? This is not the case according to the PDF above.


I writing JSOM code to get interact with sharepoint 2013 lists and document libraries.Now I have requirement to allow anonymous users to insert the items for SharePoint Lists   list. Can any one help me in knowing how can I use SPSecurity.CodeToRunElevated in JSOM Code

Can I elevate Visitors Group users permission via javascript client object model code to do some list or library item updates ?


$n$ is assumed to be even. I assume I have to use the fact that $\dbinom{n}{\frac{n}{2}+k}=\dbinom{n}{\frac{n}{2}-k}$ for all $0 \leq k \leq \frac{n}{2}$, but I keep going in circles.

Question:  $$\sum_{k=1}^{n}k\binom{2n}{n+k}=\frac n2\binom{2n}{n}$$ is true for every $n\in \mathbb N$? If this is true, then how can we prove this?   When I was playing with numbers, I conjectured this. Though I found that this holds for many $n$s, I haven't found any proof. Can anyone help?


I bought an iPod off of ebay, and went to activate it. However, it was linked to another person's Apple ID and I have no contact with them. The ebay seller does not have the Apple ID either. Is there anyway around activating this iPod without contact with the original owner whose Apple ID this iPod is linked to?

I bought a used iPhone 4.  The previous owner re-set the phone, but did not remove the device from their iCloud.  It is asking me for their iCloud information when I try to set-up the phone.  I don't have contact with the previous owner anymore.  Is there a way to remove the device from their iCloud so I can use a new one?


I would like to access 'system volume information' folder of my external HDD (WD my book 2TB) to view results of chkdsk process. (I want to know the list of damaged file names) When I try to open the folder, the access is denied.  Right-click the folder -> properties shows that the user 'SYSTEM' has full permissions and there is no other user.  The OS is Windows 7 64bit and I have admin privilege and am the only user of this desktop computer.

My laptop got broken (by what it seems the graphics card burned) and it is so old that it is not worth fixing it.   I took the harddrive from it and tried to use it as external hard drive with other computer, however I cannot access all the data, ie anything that is inside my user folder (it shows it to be empty). Couldn't find anything to solve it.


I am travelling to the USA from england next month, after about 60 days travelling i am going to cuba for about a week, and then I'm hoping to go to cancun and from there to Hawaii, would i be able to spend another full 90 days in hawaii before having to leave, as I've previously left the US, or would it just be 30 days, to make up 90 from the time i already spent in the states? any advice would be very much appreciated!

I am currently visiting the USA from the UK (I am a UK citizen) and am intending on staying here for the full 90 days under the Visa Waiver Program.     How long would I have to stay out of the US at the end of this period before returning again?    Would I have to return to the UK, or could I stay with friends in another country (such as Canada) for a while?


As you can see on the pictures below Area51 top bar popup contains narrow strings in some cases:  Site switch:        Reputation change:

The content in the site switcher, inbox and achievements of the Area 51 are misaligned. I can verify the issue in recent Google Chrome and Mozilla Firefox browsers with 100% zoom.


I have an arraylist like below:  ArrayList<PhoneNumber> arrayListToSort    PhoneNumber have following properties  private String number;  private String numberType;  Number type is like MOBILE , HOME , OFFICE  I want to sort arrayListToSort by numberType of each.   I can do this with simple alphebetical order.   But my problem is how to sort the list by follwing order.   MOBILE HOME OFFICE

Assume you have some objects which have several fields they can be compared by:  public class Person {      private String firstName;     private String lastName;     private String age;      /* Constructors */      /* Methods */  }   So in this example, when you ask if:  a.compareTo(b) > 0   you might be asking if a's last name comes before b's, or if a is older than b, etc...  What is the cleanest way to enable multiple comparison between these kinds of objects without adding unnecessary clutter or overhead?   java.lang.Comparable interface allows comparison by one field only Adding numerous compare methods (i.e. compareByFirstName(), compareByAge(), etc...) is cluttered in my opinion.   So what is the best way to go about this?


Should the comma after "tacalcitol" go inside or outside the parenthesis?   "Rotate therapy with topical vitamin D analogues (calcipotriene, tacalcitol,) retinoids, anthralin, or tar preparations."

Where should the period go when using parentheses? For example:     In sentence one, I use this example (which has a parenthesis at the end.)   Should the period be inside, or outside of the parentheses? What about if the entire sentence is a parenthetical (as below)?     (Where does the terminal punctuation go here?)   Is there a hard and fast rule?


I have one field that calculates last year's sum of donation amount using a managed package. My requirement is to create a new field on Account object to calculate sum of total opportunity amount from today to past 12 months. I tried to create a roll up summary field but not sure how to handle date requirement.

Is there any way that we can put the date filter on child record (like created in last one year) while creating roll-up summary field? I want to count only those child records which are created within last one year. I tried it by creating formula field on child object  but it does not appear while filtering the records (As per the doc: Automatically derived fields such as current date or current user are not allowed in roll-up summary fields). Any workaround if someone face this issue before ?


For the code below, which is used for Leetcode #64 Minimum Path Sum, I tried to make the cache grid using " len(grid)" and it does not work for all test cases, but if I do "for i in range(len(grid))" it works perfectly. I'm wondering why this makes a difference if the grid has the same dimensions either way. My code works for the first 2 cases but fails at the third, the code that uses range is accepted in Leetcode. Thank you. class Solution:     def minPathSum(self, grid: list) -> int:         # cash = [[-1] * len(grid[0])] * len(grid)         cash = [[-1] * len(grid[0]) for i in range(len(grid))]         return self.recursion(grid, 0, 0, cash)      def recursion(self, grid, y, x, cash):          # first we check if the space is valid         if self.check(grid, y, x) is not True:             return 0          # then we check if that space has already been cached, if it has, we just return that space         if cash[y][x] != -1:             return cash[y][x]          # this is where the space currently is on the grid         current = grid[y][x]         # now check if we are currently at the rightmost or bottommost perimeters of the grid         if y == len(grid) - 1:  # if at rightmost, have to go down             cash[y][x] = current + self.recursion(grid, y, x + 1, cash)         elif x == len(grid[0]) - 1:  # at bottommost, have to go right             cash[y][x] = current + self.recursion(grid, y + 1, x, cash)         else:  # if the current value is not at a bottom or right perimeter, keep going             cash[y][x] = current + min(self.recursion(grid, y, x + 1, cash),  # compare the right block                                        self.recursion(grid, y + 1, x, cash))  # to the down block         print(cash)         return cash[y][x]      # check if this space exists in the grid using the grid boundaries     def check(self, grid, y, x):         return len(grid) > y >= 0 and len(grid[0]) > x >= 0   grid = [[1,3,1],[1,5,1],[4,2,1]] print(Solution().minPathSum(grid=grid))  grid = [[1,2,3],[4,5,6]] print(Solution().minPathSum(grid=grid))  grid = [[1,2],[1,1]] print(Solution().minPathSum(grid=grid))

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


New to Ubuntu 14.04.  How do I get to a terminal window?  Reason for question: I am wanting to do installs and workarounds with issues to do with DVDs and turning the music off when I close the music file.  Those routine-looking instructions come to a screeching halt for me when I am told to "open a terminal window" (to enter a sudo instruction).

What is a terminal? How do I open a terminal window? How do I use the terminal?


What is this line on water? What causes this difference in appearance? I often see it on lakes. Not sure if it appears in the sea too.

What causes the surface of the lake to appear darker in some places?   Firstly, I know that it's not fishes that cause it. Secondly, the dark surfaces move from time to time and thus are not associated with the depth of the water or the structure of the lake bottom. Lastly, I may say they are due to a kind of ripple distortion. What causes this distortion and what is its mechanism?  Please, provide more explanation than "the wind", for example.  In this photo, look at the far area; it's darker somehow.


In ArcMap, is it possible to automatically (through a tool) snap points in one point layer (A), to points in another point layer (B)?  I do not wish to snap the points to a line, nor do I wish to merge the points - I would like the end result to be a new layer (C) containing points from layer A that have been moved to match the nearest point in layer B.  If a separate layer cannot be created, but layer A is altered to match the locations of layer B, that is also fine.  I don't think a spatial join works for me, as far as I understand it, as I want the physical location of one of the point layers to move.    I also do not wish to merge the two sets of points, but keep them separate.

I have some points (370 points) in a layer . These points must snap to crossroad layer . I could'nt find any tools in arcmap to snap points to crossroad layer.   Is there any way to snap these points to the crossroads ?   I'm using ArcGIS Desktop 10.2.


Suppose I have a sample of $N$ numbers $a_1,\dots,a_N$ from $1,\dots,k$. How can I test whether they are equidistributed?  I'm not interested in a full randomness test as the order does not matter to me, so  is not relevant to me, neither are its dupes. For me, a sequence $1,2,3,\dots k,1,2,3,\dots,k,\dotsc$ is perfectly fine.  I would like to have a test just from the frequencies/counts, i.e., my input data really is the vector of number of occurrences $c_j=\#\{n\leq N:a_n=j\}$ for $j=1,\dots,k$. I was unable to google the way how to proceed.

How can I test the fairness of a twenty sided die (d20)?  Obviously I would be comparing the distribution of values against a uniform distribution.  I vaguely remember using a Chi-square test in college.  How can I apply this to see if a die is fair?


Suppose $X$ has two topologies $(X,T),(X,T')$ and both are compact and hausdorffs. Suppose $T \subset T'$. Prove that $T=T'$  Because of the compactness of both topologies and the fact that one is an open subset of the other, I can clearly see that we can use the same finite open coverings to cover these topologies. But how do i use the hausdorff definition in this question?  Kees Til

Say that a topological space is CH if it is both compact and Hausdorff.   Let $T$ and $T'$ be two topologies on the same set X that are comparable   but different, i.e., $T$ is either strictly smaller or strictly larger than $T'$.   Assume that $(\text{X}; T )$ is CH. Prove that $(\text{X}; T')$ is not CH.   I just can seem to get started, so I was wondering if anybody could give me a hint...  If $T' \subsetneqq T$, then the identity $id: (\text{X},T) \rightarrow (\text{X}, T')$ is continuous and surjective. This implies that $id(\text{X},T) = (\text{X},T')$ is also compact. So in order to show that $(\text{X},T')$ is not CH, I need to show that it is not Hausdorff, right? But I'm stuck...


I assume its speed doesn't change but the photons get absorbed and destructed by the materials' atoms and then they emit new photons. Is that true?

So light travels slower in glass (for example) than in a vacuum. What causes light to slow down? Or: How does it slow down? If light passes through the medium, is it not essentially traveling in the "vacuum" between the atoms?


Being that the Title sequence for Game of Thrones tells us a lot about each house, each city for that particular series or represents a place in the world of Game of Thrones. I keep on wondering what is the thing that looks like a lit up shield in the below picture;    Here it is again later on in the Title sequence;                                  And I don't think it is the sun as there is a place where they show what seems to be the sun in the picture below:    So what is it supposed to be, or what is it supposed to represent?

THe HBO intro to Game of Thrones starts with a ball of light encircled by several bands. Then it soars across a map of Westeros. Then in the middle of the intro is the ball of light again. Some more moving across the map, dwelling in this place or that. Then again, the ball of light encircled by bands at the end of the intro.  I recognize most of the imagery as being related to the story. But I still haven't figured out the ball of light encircled by bands. Is that related to the story somehow?


How can I modify the command in the answer to  to add a solid line at the descender height and make the baseline dotted?  I'd also like to be able to fill the page with guides and optionally add solid or outlined letters to one or more of the guides.

I am looking to create some handwriting drill sheets.  Similar to what can be found here    I also found this question:  But I'd like to be able to simply write a paragraph of text with a known font and have the lines placed behind, perhaps like a watermark.  I have found a git repo with some nice lines in both portrait and landscape here   From the kindergarten example, I would like to overlay "phantom" text (probably a dotted cursive font) over the lines that are generated.  Any thoughts?  \documentclass[10pt,letterpaper]{article}  \usepackage[latin9]{inputenc} \usepackage{geometry} \geometry{verbose,tmargin=1cm,bmargin=1cm,lmargin=1cm,rmargin=1cm} \pagestyle{empty} \usepackage{dashrule} \usepackage{forloop} \makeatother  \setlength{\parindent}{0pt}  \begin{document}  \newcounter{ct} \forloop{ct}{1}{\value{ct} < 13} { \vskip 10pt \rule[1.75ex]{7.5in}{1pt} \\ \hdashrule{7.75in}{1pt}{4mm} \\ \rule[-1.75ex]{7.5in}{1pt} \\ }  \vskip 1cm  \end{document}   *Edit: I also just found this source:    So some combination of these makes sense to me, I'm just not clear on how...  *Edit: Okay, So I've gotten pretty far here.  But it seems like several parameters need to be functions of each other some how.  The line spacing, the font size, etc.  Here is where I am:  \documentclass[10pt,letterpaper,english]{article}  \usepackage{babel}  \usepackage{blindtext}   \usepackage{setspace}  \usepackage[latin9]{inputenc} \usepackage{geometry} \geometry{verbose,tmargin=1cm,bmargin=1cm,lmargin=1cm,rmargin=1cm} \pagestyle{empty} \usepackage{dashrule} \usepackage{forloop} \makeatother  \usepackage{xcolor}  \newcommand{\baselinegrid}{%   \raisebox{0pt}[\height][0pt]{\makebox[0pt][l]{%   \begin{minipage}[t]{\textwidth}%     \begin{color}{red}%     \newcounter{ct}     \forloop{ct}{1}{\value{ct} < 11}     {     %\vskip 15pt     \rule[0.5ex]{7.5in}{1pt}     \\     \hdashrule[0.75ex]{7.75in}{1pt}{4mm}     \\     \rule[1.2ex]{7.5in}{1pt}     \\     }     \end{color}   \end{minipage}% }}}  \begin{document}    \baselinegrid%  \begin{spacing}{2.5}    \usefont{T1}{wela}{m}{n}   \fontsize{30}{15}\selectfont   \setlength{\parskip}{0pt}   \setlength{\parindent}{0pt}    DURING the whole of a dull, dark, and soundless day in the autumn of the year, when the clouds hung oppressively low in the heavens, I had been passing alone, on horseback, through a singularly dreary tract of country; and at length found myself, as the shades of the evening drew on, within view of the melancholy House of Usher.  \end{spacing}  \end{document}


$f: V \to W $ over $K$ with $a,b \in V$ and $k \in K$. Additivity: $f(a+b) = f(a) + f(b)$ Homogenity: $k*f(b) =f(k * b)$ I have a visual understanding that a function is linear if the structure is kept while projecting it with $f$ but why it is not enough to check if the function is additive? I would be glad to have some easy examples and an intuition why we would have to check both conditions.

A function $T:V \rightarrow W$ is additive if $T(x+y) = T(x) + T(y)$ for every $x, y \in V$. Prove that there exists an additive function $T: \mathbb{R} \rightarrow \mathbb{R}$ that is not linear.  My attempt: Let $T$ be the function $T: \mathbb{R}$ (over the field $\mathbb{Q}$) $\rightarrow \mathbb{R}$ (over the field $\mathbb{R}$). The set $\{1, \sqrt{2}\} \subseteq \mathbb{R}$ is linearly independent for the vector space $\mathbb{R}$ over $\mathbb{Q}$. Then, there must exist a linearly independent set $W \subseteq \mathbb{R}$ (over $\mathbb{Q}$) such that $\{1, \sqrt{2}\} \subseteq W \subseteq \text{span}(W) = \mathbb{R}$ (over $\mathbb{Q}$).  I have been told that the function defined as $T(1) = 1$ and $T(w) = 0$ for all $w \in \text{span}(W) \setminus \{1\}$ is additive but not linear, but I cannot see why this is? I can see why it is not linear, clearly $T(\sqrt{2} \cdot 1) = 0$ but $\sqrt{2} T(1) = \sqrt{2}$. But, why is $T$ additive? For example, $T(1+1) = T(2) =0$ but $T(1) + T(1) = 1+1 = 2$? Is there a mistake somewhere?


I've asked this question before but it was marked as a duplicate with  that didn't answer my question. My question is as follows: I have a 2-D probability distribution along the lines of this plot:  I know how to find the confidence interval for a 1-D probability distribution (by the definition of standard deviation or the 68-95-99 rule) but I don't know how to generalize that to 2-D to get a confidence region. I've been looking at Principle Component Analysis and covariance matrices, but most explanations or examples are for a 2D distribution of random vectors rather than a probability distribution so I'm not quite sure how to generalize it. How would I find the 1-$\sigma$/2-$\sigma$ regions for a 2D probability distribution? The question that was linked refers to random vectors, whereas what I have is a probability distribution from data, with a continuous 2-D probability function as opposed to random vectors. As such, I cannot find the covariance matrix between two vectors because I DO NOT HAVE TWO VECTORS, and therefore cannot apply the process described in the linked question. If I were to analogize to 1-D, my issue is the difference between the standard deviation for a random distribution of samples, $\sigma=\sqrt{\frac{1}{N}\sum (x_{i}-\bar{x})^{2}}$, and the standard deviation for a probability distribution $\sigma=\sqrt{\sum (x_{i}-\bar{x})^{2}P(x_{i})}$. As far as I can tell, the method involving the covariance matrix is a generalization of the former. I need a generalization of the latter. If I'm wrong in my understanding, please let me know, but I don't think the other question gives me what I need.

I have a 2-D probability distribution along the lines of this plot:  I know how to find the confidence interval for a 1-D probability distribution (by the definition of standard deviation or the 68-95-99 rule) but I don't know how to generalize that to 2-D to get a confidence region. I've been looking at Principle Component Analysis and covariance matrices, but most explanations or examples are for a 2D distribution of random vectors rather than a probability distribution so I'm not quite sure how to generalize it. How would I find the 1-$\sigma$/2-$\sigma$ regions for a 2D probability distribution? Edit: The question that was linked in the duplicate message refers to random vectors, whereas what I have is a probability distribution from data, with a continuous 2-D probability function as opposed to random vectors. As such, I cannot find the covariance matrix between two vectors because I DO NOT HAVE TWO VECTORS, and therefore cannot apply the process described in the linked question. If I were to analogize to 1-D, my issue is the difference between the standard deviation for a random distribution of samples, $\sigma=\sqrt{\frac{1}{N}\sum (x_{i}-\bar{x})^{2}}$, and the standard deviation for a probability distribution $\sigma=\sqrt{\sum (x_{i}-\bar{x})^{2}P(x_{i})}$. As far as I can tell, the method involving the covariance matrix is a generalization of the former. I need a generalization of the latter. If I'm wrong in my understanding, please let me know, but I don't think the other question gives me what I need.


I watched this English movie or TV show during 1980s in my childhood. The story was in a spaceship. Several people was in the spaceship, among whom the main character was a lady.  The villain appears as electric sparks near the ceiling of a room in the ship. He appears only when a lady remains alone. He then converts to a man in long black robe. He tries to penetrate his metallic long fingernail into her neck. The lady was so scared and tried to escape. One day he was successful to penetrate. Then her mind was converted and inclined to him. Then he took her away with a small space shuttle detached from the main spaceship.  He was driving the shuttle but suddenly he started to be melted down and finally destroyed. Then the lady went back to the main spaceship and met her friends.

Every once in a while this starts nagging me, I have really no idea and not much to go on so here goes...  A man wearing a blue? uniform walks into a town that looks abandoned and empty and all covered in dust.  The skies are brown/dirty with no sun.  He goes into the upstairs of one of the houses. He stops at I think a fireplace, examines something, or it’s like he’s remembering something.  Then downstairs in the street, a man/person wearing rags/robes with bandages covering his face starts banging on a fire hydrant with a stick/pipe. More people in bandages/robes start appearing, there's a chase in the town. I don't remember much but he's chased into wastes? through a gully or ditch and then a vehicle (only really remember that it was steel in colour) shows up and a woman comes and shoots one or two of the people chasing him.   That’s about all I remember. I was about 6 or 7 maybe and it was afternoon maybe a little later.  I thought maybe Star Trek, but after searching I don't think it is. I think it might be 80's, maybe early 90's. I think it's sci-fi rather than post-apocalyptic.


Let $V$ be a vector space of dimension $n$. Let $\omega\in A_n(V)$. Then for any linear map $T: V\rightarrow V$, $T^\ast\omega=\det(T)\cdot\omega$. Can anyone explain why the last sentence is true?

Let $V$ be a vector space of dimension $n$ and  $f: V\to V$ a linear operator. I need to show that $f^\ast:\Lambda^n(V)\to \Lambda^n(V)$ is multiplication by $\det f$.  My try:  Since $\dim \Lambda^n(V)$ is $1-$dimensional and $f^\ast$ is linear, $f^\ast$ must be multiplication by a constant.  Let $\omega\in \Lambda^n(V)$ and let $A$ be the matrix of $f$ with respect to a basis $e_1,\dots,e_n$. Then $$f^\ast\omega(v_1,\dots,v_n)=\omega(f(v_1),\dots,f(v_n))=\det A \cdot \omega (e_1,\dots,e_n)$$ The first equality is definition and the second is      4-6 $\ \ $ Theorem. $\ $ $\textit{Let }v_1,\ldots,v_n\textit{ be a basis for }V\textit{, and let }\omega\in\Lambda^n(V)\textit{. If }w_i=\sum\limits_{j=1}^n a_{ij}v_j\textit{ are }n\textit{ vectors in }V\textit{, then}$ $$\omega(w_1,\ldots,w_n)=\det(a_{ij})\cdot\omega(v_1,\ldots,v_n).$$   But I think this isn't what I what I need to obtain, namely $$f^\ast\omega(v_1,\dots,v_n)=\det A \cdot \omega (v_1,\dots,v_n)$$  Is there any mistake in my computations, or do I need some additional step?


I got this error while executing my batch job     Duplicate id in list: 0062800000AqfihAAB   Here is my batch job:  Global class OpportunityStageChanges implements Database.Batchable<sObject> {  Global Database.QueryLocator start(Database.BatchableContext BC) {    //String query = 'Select id,Amount, (Select OldValue, NewValue From Histories) From Opportunity where stage <> NULL';    //String query  = 'Select Id, CreatedById, CreatedDate, Field, NewValue, OldValue from OpportunityFieldHistory ';      String query = 'Select Id,Name,Amount,LightiningEd__Stage_change_from_Prospecting__c,(Select ID, CreatedDate,OldValue, NewValue from Histories)from Opportunity';             return Database.getQueryLocator(query); } Global void execute(Database.BatchableContext BC, List<Opportunity> scope) {   List<Opportunity> opplist = new List<Opportunity>();   for(Opportunity opp : scope) {      for(OpportunityFieldHistory opfh : opp.Histories){           system.debug(opfh.oldValue+'----'+opfh.NewValue+'-----'+opfh.CreatedDate );           if(opfh.OldValue == 'prospecting' && opfh.NewValue == 'Qualification '|| opfh.NewValue == 'Closed Won'){                opp.LightiningEd__Stage_change_from_Prospecting__c = opfh.CreatedDate;               System.debug('Date Value' + opp.LightiningEd__Stage_change_from_Prospecting__c);               opplist.add(opp);          }             }     if(opplist.size()>0){           update(opplist);      }    }  } Global void finish(Database.BatchableContext BC) {     } }

If you take a look into this issue     I have provide an answer of using set<Sobject> instead using list<Sobject>  i.e.  if( !contacts.values().isEmpty() ){   set<Contact> setContacts = new set<Contact>();   for( Contact objCon : contacts.values() ){     if(!setContacts.contains(objCon)){         setContacts.add( objCon );     }   }  update new list<Contact>(setContacts); }   even if(!setContacts.contains(objCon)) is not needed  if( !contacts.values().isEmpty() ){   set<Contact> setContacts = new set<Contact>();   for( Contact objCon : contacts.values() ){         setContacts.add( objCon );   }  update new list<Contact>(setContacts); }   So is there any condition/use case where this answer might fail?


Let $A$ be a real $n\times n$ matrix, with ones in the diagonal, and all of the other elements equal to $r$ with $0<r<1$.    How can I prove that the eigenvalues of $A$ are $1+(n-1)r$ and $1-r$,  with multiplicity $n-1$?

This question aims to create an ""  of numerous questions that ask about determinants of specific matrices (I may have missed a few):              The general question of this type is  Let $A$ be a square matrix of rank$~1$, let $I$ the identity matrix of the same size, and $\lambda$ a scalar. What is the determinant of $A+\lambda I$?  A clearly very closely related question is  What is the characteristic polynomial of a matrix $A$ of rank$~1$?


I just came across this sentence:      ...is expected to take five weeks to repair, according to Aurizon Holdings Ltd. Prices more than doubled last year, topping $300 a ton...   As I'm sure most people do, I come across situations like this one on an almost daily basis, and despite this it almost always throws me off. Because I am so used to the single full stop after "Ltd", "Co" etc. (pardon that pun?) simply representing a shortening of the words "Limited" and "Company", I naturally continue to read at the same pace, without noticing that a new sentence has in fact started, indicated by the capital letter. (In this case the capital "P" on "Prices".) I have to retrace the word.   Is this end-of-a-sentence behaviour simply convention, thus rendering it grammatically correct to rewrite this sentence as      ...is expected to take five weeks to repair, according to Aurizon Holdings Ltd.. Prices more than doubled last year, topping $300 a ton...   This would save me an annoyance! How about everyone else?  The reason I think it would be correct is simple: We use the first full stop to indicate the shortening of the word, and the second to indicate that we are ending the sentence.

I always stumble when using abbreviations in a sentence, as they inherently contain a period in them. How do I use a comma or a semicolon after an abbreviation? How about a period?  E.g. (This is an example of my quandary)


For features that are heavily skewed, the Transformation technique is useful to stabilize variance, make the data more normal distribution-like, improve the validity of measures of association.  I am really having trouble understanding the intuition behind Box-Cox transform. I mean how to configure data transform method for both square root and log transform and estimating lambda.  Could anyone explain in simple words (and maybe with an example) what is the Intuition behind Box-Cox transform

The Box-Cox transformation transforms our data into a normal distribution.  How is that even a proper technique? What if our data didn't come from a normal distribution? How could someone just blindly apply the Box-Cox transformation?  To re-phrase: why apply the Box-Cox transformation if our data isn't normally distributed?  Is the Box-Cox transformation used when our data SHOULD be normally distributed, but isn't?


The runtime indicates the exception occurs when giving temp = keysit.next(). I thought this had been taken care of when I redefined keysit = keys.iterator() for the 2nd time, but maybe I'm missing the point. Any suggestions?  Map<Integer, Set<String>> lhm = new LinkedHashMap<Integer, Set<String>>();  public void sortMap() {     Set<Integer> keys = hm.keySet();     Iterator<Integer> keysit;     int iterations = keys.size();     int smallest;     int temp;     for(int i=0; i<iterations; i++) {         keysit = keys.iterator();         smallest = keysit.next();         keysit = keys.iterator();           while(keysit.hasNext()) {             temp = keysit.next();               if(temp<smallest)                  smallest = temp;             lhm.put(smallest, lhm.get(smallest));             keys.remove(smallest);         }     }     System.out.println(lhm); }

We all know you can't do the following because of ConcurrentModificationException:  for (Object i : l) {     if (condition(i)) {         l.remove(i);     } }   But this apparently works sometimes, but not always. Here's some specific code:  public static void main(String[] args) {     Collection<Integer> l = new ArrayList<>();      for (int i = 0; i < 10; ++i) {         l.add(4);         l.add(5);         l.add(6);     }      for (int i : l) {         if (i == 5) {             l.remove(i);         }     }      System.out.println(l); }   This, of course, results in:  Exception in thread "main" java.util.ConcurrentModificationException   Even though multiple threads aren't doing it. Anyway.  What's the best solution to this problem? How can I remove an item from the collection in a loop without throwing this exception?  I'm also using an arbitrary Collection here, not necessarily an ArrayList, so you can't rely on get.


If $m$ varies then find the range of $c$ for which the line $y=mx + c$ touches the parabola $y^2 = 8(x+2)$ .  My Attempt:  Put the value $y = mx + c$ in the parabola equation and then done $\Delta = 0$ or $\Delta >0$  I am getting $16/(m^2 + 8m) >0$  But in this, how do I neglect $m$?

if m varies then find the range of c for which the line $y=mx + c$ touches the parabola $y^2 = 8(x+2)$ .  I tried Put the value $y = mx + c in$ the parabola equation and then done $D = 0$ or $D>0 $  I am getting $16/(m^2 + 8m) >0 $  But in this , how do I neglect m


As the influence of gravity is infinite throughout the universe.is the influence of its force on a body very far away faster than the speed of light.suppose a star dies...is the influence of its gravity on us proportional to the light the we are seeing or is its diminished gravity influencing us faster than the light that is reaching us

A thought experiment: Imagine the Sun is suddenly removed. We wouldn't notice a difference for 8 minutes, because that's how long light takes to get from the Sun's surface to Earth.   However, what about the Sun's gravitational effect? If gravity propagates at the speed of light, for 8 minutes the Earth will continue to follow an orbit around nothing. If however, gravity is due to a distortion of spacetime, this distortion will cease to exist as soon as the mass is removed, thus the Earth will leave through the orbit tangent, so we could observe the Sun's disappearance more quickly.  What is the state of the research around such a thought experiment? Can this be inferred from observation?


My cat keeps walking over my keyboard.  Is it possible to  with a keyboard short cut but leave the screen running and all apps visible?

I sometimes bring my external keyboard with me on the go and use it with my MBP. I would like to lay it over the macbook's current keyboard without having to worry about it pressing other keys.  Is there a way to temporarily enable/disable the onboard keyboard?


explains as it claims in its title: 'How To Send Text Messages to Multiple Recipients Using iPhone'. However, what do I do if I want to prevent each recipients from seeing all the other recipients in the address field (ie I want this to be a Blind Carbon Copy)?  For my iPhone 5s, I already tried , which claims:      The option you're looking for is located at Settings > Messages > Group Messaging. Turning this off will send all messages individually to their recipients.   I do see and can access (iPhone  Home Screen) > Settings > Messages, but just like the commenters below that answer, I can't find Group Messaging?

I want to send "Happy Thanksgiving!" to 35 different people, but I do not want it to be treated as a group message. How can this be accomplished on the iPhone 4S (with or without jailbreak applications, such as biteSMS) with iOS 5.1.1?  The reasons that I would not want it treated as a group message are:   I do not want the recipients to see the numbers of other recipients I do not want the recipients' replies to go to multiple people I do not want the recipients' replies to be grouped in a group message, but to instead be part of each individual thread depending on the message, I may specifically not want a given recipient to know that other recipients received the same message.   Optimally, the solution would also allow pictures to be attached and would automatically send iMessages instead of text messages to iOS users - but those parts are less important than being able to send plain text messages.


I am trying to use Flash for habbo.com. I cannot get it to download. Is it even possible? Any recommendations or tips would be highly appreciated.

I know, it's been asked before but I couldn't really get a satisfying answer for some details/backgrounds and I guess it's an important question for many.    Some application seem only to be running with Adobe Flash 15 (or at least I know it does, because I have that version on my Windows Partition).  The official Adobe website says:     NOTE: Adobe Flash Player 11.2 will be the last version to target Linux as a supported platform. Adobe will continue to provide security backports to Flash Player 11.2 for Linux.   Some search on the web like "Ubuntu Adobe Flash 15" or similar does not return any good websites.  I found something that says   (using a "pepper-based version"), and  .   Is it impossible to use this for Firefox too? Would it be a privacy risk?  Are there no alternative projects (I know it's closed source but there are so many so very bright people out there using something similar to wine but just for the plugin....)?  How about the Mac-Version? Shouldn't someone be able to port that one to Linux?


I have several constants that I use, and my plan was to put them in a const array of doubles, however the compiler won't let me.  I have tried declaring it this way:  const double[] arr = {1, 2, 3, 4, 5, 6, 73, 8, 9 };   Then I settled on declaring it as static readonly:  static readonly double[] arr = { 1, 2, 3, 4, 5, 6, 7, 8, 9};   However the question remains. Why won't compiler let me declare an array of const values? Or will it, and I just don't know how?

Compiler error  indicates that only the basic POD types (as well as strings, enums, and null references) can be declared as const. Does anyone have a theory on the rationale for this limitation? For instance, it would be nice to be able to declare const values of other types, such as IntPtr.  I believe that the concept of const is actually syntactic sugar in C#, and that it just replaces any uses of the name with the literal value. For instance, given the following declaration, any reference to Foo would be replaced with "foo" at compile time.  const string Foo = "foo";   This would rule out any mutable types, so maybe they chose this limitation rather than having to determine at compile time whether a given type is mutable?


I was wondering how third party libraries with LockerService enabled can work in the near feature. I work in a project where we use jQuery, AngularJs etc... and I'm afraid that we have to rewrite all the code that I have in my orgs, specifically for that code that manipulate DOM. Is there some risk in that sense? Thanks in advance.

Components often seem to work with external libraries until the Locker Service is enabled. What libraries work with locker service enabled and where can I go to find out?


We have an older iMac (Model A1311, Mid 2011). It has been running Yosemite. We have run into some of the WIFI issues associated with Yosemite.   Is it possible to upgrade to El Capitan but not Sierra?   El Cap has been out longer. Its my wife's computer, its older, and I really don't want to be debugging Sierra until a few  more "dot" releases come out.

Sometimes it's hard to search for older versions of macOS & OS X  on the App Store.  This is an attempt to provide the canonical QA for this issue, as per the Meta QA -  I expect it to be modified over time to hopefully become a complete information resource.  How can I get any older version of a Mac OS to be able to run as a VM, or to reinstall on my Mac?


I am doing the 8 queens problem and trying to implement the method which will check if there is any collision between queens. When it comes to the logic of the problem, I think I understand it, but I am getting NullpointerException and I can't figure out why. Any help would be highly appreciated.  private static boolean isOK(int[][] matrix) {         boolean isInCollision = false;         Queen [] queens = new Queen[8];         for (int i = 0; i < matrix.length; i++) {             for (int j = 0; j < matrix.length; j++) {                 if(matrix[i][j] == 1){                     queens[i] = new Queen(i, j);                  }             }         }           for (int i = 0; i < queens.length; i++) {             for (int j = i+1; j < queens.length; j++) {                 if(queens[i].getX()==queens[j].getX() && Math.abs(queens[i].getX()-queens[j].getX())==Math.abs(queens[i].getY()-queens[j].getY())){                     isInCollision = true;                 }             }         }         return isInCollision;     }   I get error in this line of code:  if(queens[i].getX()==queens[j].getX() && Math.abs(queens[i].getX()-queens[j].getX())==Math.abs(queens[i].getY()-queens[j].getY()))

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?


This suggests, as a shortcut notation, the concept of lowering indices; from any vector we can construct a (0, 1) tensor defined by contraction with the metric: $$A_\nu ≡ g_{\mu\nu}A^\mu$$  so that the dot product becomes $$g_{\mu\nu}A^\mu B^\nu = A_\nu B^\nu$$  We also define the inverse metric $g^{\mu\nu}$ as the matrix inverse of the metric tensor: $$g^{\mu\nu}g_{\nu\rho} = δ^\mu_\rho$$  where $δ^\mu_\rho$ is the (spacetime) Kronecker delta. (Convince yourself that this expression really does correspond to matrix multiplication.) Then we have the ability to raise indices: $$A^\mu = g^{\mu\nu}A_\nu$$ Note that raising an index on the metric yields the Kronecker delta, so we have $$g^{\mu\nu}g_{\mu\nu} = δ^\mu_\mu = 4$$  I don't understand why $δ^\mu_\mu = 4$. Shouldn't it equal 1?

I'm confused about the Kronecker delta. In the context of four-dimensional spacetime, multiplying the metric tensor by its inverse, I've seen (where the upstairs and downstairs indices are the same):  $$g^{\mu\nu}g_{\mu\nu}=\delta_{\nu}^{\nu}=\delta_{0}^{0}+\delta_{1}^{1}+\delta_{2}^{2}+\delta_{3}^{3}=1+1+1+1=4.$$  But I've also seen (where the upstairs and downstairs indices are different):  $$g^{\mu\nu}g_{\nu\lambda}=\delta_{\lambda}^{\mu}=\left(\begin{array}{cccc} 1 & 0 & 0 & 0\\ 0 & 1 & 0 & 0\\ 0 & 0 & 1 & 0\\ 0 & 0 & 0 & 1 \end{array}\right).$$  How can there be two different answers to (what appears to me to be) the same operation, ie multiplying the metric tensor by its inverse? Apologies if I've got this completely wrong.


I have seen this, but when I tried it did not work, I have one folder 'childFolder' in my current working directory, and inside that I have the module moduleName.py.       import cwd.childFolder.moduleName as mod     mod.someclass().method()

How can I load a Python module given its full path? Note that the file can be anywhere in the filesystem, as it is a configuration option.


I want to achieve the following behavior like in the image    So, I have a header with an arbitrary height and I want the container to fill the rest of the space. I have the following code:
         My header
 Arbitrary height (ex: 123px)

         Container
 Height = rest of the viewport
    Note: I don't want to use .container{ height: calc(100% - 123px) } because the in the future 123px may change, so I don't want to modify in two places.

I am working on a web application where I want the content to fill the height of the entire screen.  The page has a header, which contains a logo, and account information. This could be an arbitrary height. I want the content div to fill the rest of the page to the bottom.  I have a header div and a content div. At the moment I am using a table for the layout like so:  CSS and HTML    #page {     height: 100%; width: 100% }  #tdcontent {     height: 100%; }  #content {     overflow: auto; /* or overflow: hidden; */ }

...

...

     The entire height of the page is filled, and no scrolling is required.  For anything inside the content div, setting top: 0; will put it right underneath the header. Sometimes the content will be a real table, with its height set to 100%. Putting header inside content will not allow this to work.  Is there a way to achieve the same effect without using the table?  Update:  Elements inside the content div will have heights set to percentages as well. So something at 100% inside the div will fill it to the bottom. As will two elements at 50%.  Update 2:  For instance, if the header takes up 20% of the screen's height, a table specified at 50% inside #content would take up 40% of the screen space. So far, wrapping the entire thing in a table is the only thing that works.


In the following example, how is y given the value of 1?  I added some logging to see values and don't understand how/where y is assigned...   (function() {     function foo(x) {         var callNum = 0;         var baz = 3;         return function (y) {             callNum++;             console.log("callNum: " + callNum);             console.log("y: " + y);             console.log("baz: " + baz);             console.log("x: " + x);             console.log(x + y + (++baz));         }     } var moo = foo(2); // moo is now a closure. moo(1); moo(1); })();   Here's the fiddle output log:       callNum: 1        y: 1        baz: 3     x: 2      7      callNum: 2      y: 1      baz: 4      x: 2      8

How would you explain JavaScript closures to someone with a knowledge of the concepts they consist of (for example functions, variables and the like), but does not understand closures themselves?  I have seen  given on Wikipedia, but unfortunately it did not help.


To each vertex of a pentagon, we assign an integer $x_i$ with sum $$s=\sum x_i>0$$ If $x$, $y$, $z$ are the numbers assigned to three successive vertices and if $y<0$ , then we replace $(x, y, z)$    by $(x+y, -y, z+y)$. This step is repeated as long as there is a $y<0$. Decide if the algorithm always stop .  I know this question is already asked, but my question is, how much steps are needed until stop??

To each vertex of a pentagon,we assign an integer $x_{i}$ with sum $s=\sum x_{i}>0$. If x,y,z are the numbers assigned to 3 successive vertices and if $y<0$,then we replace $(x,y,z)$ by $(x+y,-y,y+z)$.This step is repeated as long as there is a y<0.Decide if the algorithm always stops.


I'm new to Apex code, got below error Error: Invalid Data.  Review all error messages below to correct your data. Apex trigger PositionTrigger caused an unexpected exception, contact your administrator: PositionTrigger: execution of AfterInsert caused by: System.FinalException: Record is read-only: Trigger.PositionTrigger: line 4, column 1  trigger PositionTrigger on Position__c (after insert) {   Position__c ThePosition = trigger.new[0];   if(ThePosition.Days_Open__c>90){     ThePosition.Educational_Requirements__c='Featured';     update ThePosition;   } }   please let me know the solution.

I'm writing a trigger for new opportunity products to populate  a field Product_Category__c (on opportunity lineitem) getting the value from Product_Category_new__c (on Product).  This is my trigger:  trigger SetProductCategory on OpportunityLineItem (after insert) {      for (OpportunityLineItem opplineitem: Trigger.new) {                    opplineitem.Product_Category__c =  opplineitem.PricebookEntry.Product2.Product_Category_new__c;     }      }   I get this error message:     execution of AfterInsert caused by: System.FinalException: Record is read-only   I have tried with before insert;in this case there aren't errors but the value Product category it's not saved on Opportunity Line item.  I have found that:  In a after insert trigger is not allowed change field using trigger.new  Please can you suggest a solution for this? i would like to copy the value Product category (Product) on Product Category (Opportunity Product)  after the insert of the new opportunity products.  Thanks in advantage for any advice.  Br