Transitioning to Ubuntu - Complete Newbie
What are the system requirements for each flavour of Ubuntu Desktop?
Better favourites organisation I don't know about anyone else, but I have a reasonable list of favourites now, and it can be rather difficult to find the relevant ones at any given time. Sometimes, I have a specific one in mind, others I just want to see all favourites relating to a specific topic. It would be nice if there were a way to organise my favourites by tag, or OP, or possibly just search them.  How can we improve the favourites feature?  Please post your ideas on how we might improve the favourites feature of the Stack&nbsp;Exchange sites. Try to keep each answer to one idea so that the votes reflect the popularity of a single idea. POST JSON data denormalization error Confirmation that (inner) classes are still not fully supported in @AuraEnabled methods? A very basic question concerning the $R^2$ of OLS regressions   run OLS regression y ~ x1, we have an $R^2$, say 0.3 run OLS regression y ~ x2, we have another $R^2$, say 0.4 now we run a regression y ~ x1 + x2, what value can this regression's R squared be?   I think it's clear the $R^2$ for the multiple regression should be no less than 0.4, but is it possible for it to be more than 0.7? Process Unicode files with BOM correctly with POSIX tools Why constructors will always have same name as of class and how they are invoked implicitly? Yes, I'm really sure I want to delete that post how to prove that $\ln(1+x)< x$ Was Severus Snape made a Death Eater before or after he told Voldemort about the Prophecy? Based on discussion in comments on , was Severus Snape a Death Eater (real one, with Dark Mark) before he overheard Sybil give the Prophecy to Dumbledore and relayed it to Voldemort? Or was he made a DE after that?  Canon sources only please (books/interviews/Pottermore) How to pick a specific symbol from a specific font? Where can you ask about Career Advice? The  specifically says not to ask  for career advice but people do it anyway.  Should I consider the Help Center outdated or only loosely enforced?    And what about a career advice site on the network?  There are 70+ sites, and most of them are for relatively narrow interests (which is not a criticism, I enjoy looking through the many sections).  A career section seems like it would be very popular.  Also, a careers section would help keep career questions off the other sites. How does one install PlayOnLinux? How do I install PlayOnLinux on Ubuntu? Users below 15 reputation can't effectively vote. It says:     Votes cast by those with less than 15 reputation are recorded, but do not change the publicly displayed post score   Does it mean that they will take effect after I reach 15 reputation or because they were cast before, they're recorded but ignored? i have created a schedulable class which has to trigger a batch job. The run method for the batch class will get list of data to process from a webservice callout. Now, i got the exception below. Any suggestions please.     System.CalloutException: Callout from scheduled Apex not supported.   global class scheduledDeltaBatchable implements Schedulable {    global void execute(SchedulableContext sc) {     ID batchprocessid = BatchUpsertSAPCustomerMasterBPSync.run(SAPServices.GetSAPCustomerMasterBPSync('Delta'));    } } What is a lambda (function)? A relative managed to change her password, yet can not input the correct password.  She does not want to reset the phone to avoid loss of data (pictures, contacts, messages, etc.).  Will the phone eventually stop accepting logon attempts? What's the last character in a file? I just read the answers to  and everyone said to delete the last character. My question is,  isn't the eof character the last one? $G$ simple group and there exists a subgroup of index $n$. Show that: $|G|$ divides $n!/2$ Let $G$ be a simple group and there exists a subgroup $H$ of index $n \in \mathbb{N}_{\ge 3}$. Show that: $|G|$ divides $n!/2.$ I saw a similar question .   There was written: "The proof is really simple. Let $X$ be the set of left cosets of $H$. Consider $\phi: G \to \text{Sym}(X)$ given by $\phi(x)(aH)=(xa)H$. Then $\phi$ is a homomorphism. Consider now $K=\ker \phi$. Then $K$ is a normal subgroup of $G$ contained in $H$. Finally, $G/K$ is isomorphic to a subgroup of $\text{Sym}(X)$, which has order $n!$, where $n=[G:H]$. Thus, $[G:K]$ is finite and divides $n!$."  In fact, I don't understand the last sentence. "Thus, $[G:K]$ is finite and divides $n!$." Also did I understand it right that $ker(\phi)=H$?  Can you also give me an advice how to proof it for $n \ge 3$. (maybe induction)  Thank you for taking your time. When I installed my SSD I just mounted with discard and didn't sweat it. However today I was reading about the pros and cons of using fstrim instead and decided to run the program to get an idea of how long it would actually take (still with my partitions mounted with discard). The command took several minutes on both my root and home partitions. For my home partition I used -v and got this:  $ sudo fstrim -v /home /home: 137494052864 bytes were trimmed   This is more than the amount of free space on the partition!  $ df -h /home Filesystem      Size  Used Avail Use% Mounted on /dev/sda2       206G   78G  118G  40% /home   Subsequent runs finish in less than a second, eg:  $ sudo fstrim -v /home /home: 0 bytes were trimmed   Surely if I have always had the partition mounted with discard, fstrim should not trim a large amount of data like that? The discard option is definitely enabled, here are the relevant fstab lines:  UUID=xxxxxxxx...    /          ext4   noatime,discard,errors=remount-ro  0      1 UUID=xxxxxxxx...    /home      ext4   noatime,discard,errors=remount-ro  0      2   And mount output lines:  /dev/disk/by-uuid/xxxxxxxx... on / type ext4 (rw,noatime,discard,errors=remount-ro,stripe=128,data=ordered) /dev/sda2 on /home type ext4 (rw,noatime,discard,errors=remount-ro,stripe=128,data=ordered)   The SSD is a TOSHIBA THNSNS256GMCP. Why does this happen? Correlation coefficient between a (non-dichotomous) nominal variable and a numeric (interval) or an ordinal variable I've already read all the pages in this site trying to find the answer to my problem but no one seems to be the right one form me...  First I explain you the kind of data I'm working with...  Let's say that I have an array vector with several names of city, one for each of 300 users. I also have another array vector with scores response to a survey of each user or a continuous value for each user.  I would like to know if exist a correlation coefficient that compute the correlation between these two variables so, between a nominal and a numeric/continuous or ordinal variables.  I've searched on the Internet and in some pages they suggest to use the contingency coefficient or Cramer's V or Lambda coefficient or Eta . For each of this measure the just say that they could be applied for such data in which we have a nominal variable and interval or numerical variable. The thing is that searching and searching, trying to understand every one of them, sometime is written or watching the examples that they are reasonable to use them if you have dichotomous nominal variable, except for Cramer's V, other time is not written any requirement for the type of data. A lot of other pages say that is right to apply regression instead, that is right, but I would just simply like to know if there is a coefficient like pearson/spearman for this kind of data.  I also think that is no so properly to use Spearman Correlation coeff since the cities are not sortable.  I have also built the function of Cramer'sV and Eta by myself (I'm working with Matlab) but for Eta they don't talk about any p-value to see if the coefficient is statistically significant...  In the matlabWorks site there is also a nice toolbox that says to compute eta^2 but the kind of input it needs is not understandable.  Is here someone that have done a test like mine? If you need more detail to understand the kind of data I'm using just ask me and I'll try to explain you better.