I'm one of these people who tends to leave a comment when I downvote and every now and then, the OP edits their post and pings me back they did and then I remove my downvote most of the time and even upvote every once in a blue moon...  :-)  However, I noticed that one of my comments on one of my downvotes was upvoted 3 times and the answer was downvoted for the same amount of times but now it's actually a good answer. (and I have no way of contacting the additional 3 downvoters)  Can we have an additional option¹ to be pinged whenever an edit was made on one of our downvotes for the few times that I don't leave a comment?  Note¹: Optional because there might be people who don't want any extra pings because they get too many already. Note²: It would be more welcoming to new users who generally don't know how the SE network works and get downvotes because of semantics and not because of their actual question or answer... Note³:  and highly upvoted, but that one is asking to make it mandatory, whereas this is broader and optional.
Problem: A lot of the time I downvote something that clearly shows lack of research or effort on OP's part, and when they edit to improve it, I usually find out pretty late, because there are no notifications to help with that.  Proposition: add a Get notified when this post is edited button/checkbox under a post which you have downvoted (per post, not just all posts ever), so that if there is a significant improvement, you could remove your downvote or even change it to an upvote to show you recognize the improvement.  I believe this would improve public thinking about votes, and make people (who choose to participate like this on the SE sites more often) vote more freely and more often, and everybody else would not think of a &lt;0 post score as a death sentence for their contribution.  I'm not asking to enable this on SO (for a number of obvious reasons), and that's why I propose an opt-in subscription. This would be most useful on lower activity sites like the SE, in my opinion, but who knows.    I want to know if someone has improved their post after a downvote to reinforce the positive behavior and I get -4 on my good intentions? What kind of culture are you trying to cultivate? Please, explain why you disagree without silently downvoting. If you think there's a better way, yes, I want to know your thoughts.
How to implement Enums in Ruby? What's the best way to implement the enum idiom in Ruby? I'm looking for something which I can use (almost) like the Java/C# enums. Ubuntu 17.10 Upgrade Broke VMWare Workstation 12.5 Hi after upgrading to Ubuntu 17.10, vmware is now not starting.    I get the message:    /usr/lib/vmware/bin/vmware-modconfig: Relink `/lib/x86_64-linux-gnu/libbsd.so.0' with `/lib/x86_64-linux-gnu/librt.so.1' for IFUNC symbol `clock_gettime'   I am aware that there are patches available and I am attempting to apply these and recompile. I have run from the solution at :    cd ~   #Copy the vmmon source tar ball to your temporary location cp /usr/lib/vmware/modules/source/vmmon.tar .    #Extract the tar ball tar xf vmmon.tar    #Download the modified file that mkubecek posted and overwrite the one from the tar ball for VMware Workstation 12.5: wget -O ./vmmon-only/linux/hostif.c https://raw.githubusercontent.com/mkubecek/vmware-host-modules/b50848c985f1a6c0a341187346d77f0119d0a835/vmmon-only/linux/hostif.c     #Wrap up the newly modified files into a tar ball replacing the original one sudo tar cf /usr/lib/vmware/modules/source/vmmon.tar vmmon-only    #Rebuild the VMware kernel modules sudo vmware-modconfig --console --install-all   Failed to get gcc information.  gcc --version gcc (Ubuntu 7.2.0-8ubuntu3) 7.2.0 ...   Unforunately, vmware-modconfig is failing because of a dependency it seems on a particular gcc version. Am I on the right track? Any help with this issue would be much appreciated.  EDIT Thank you Steve, the below has gotten vmware going again. I've included minor correction. Tested and confirmed I could run a virtual machine.   sudo su    # do all below as root cd /usr/lib/vmware/modules/source tar xvf vmmon.tar  tar xvf vmnet.tar wget -O ./vmmon-only/linux/hostif.c https://raw.githubusercontent.com/mkubecek/vmware-host-modules/b50848c985f1a6c0a341187346d77f0119d0a835/vmmon-only/linux/hostif.c vim vmnet-only/bridge.c cd vmmon-only/ make cd ../vmnet-only/ make cd .. mkdir /lib/modules/4.13.0-16-generic/misc cp *.o /lib/modules/4.13.0-16-generic/misc insmod /lib/modules/4.13.0-16-generic/misc/vmmon.o insmod /lib/modules/4.13.0-16-generic/misc/vmnet.o rm /usr/lib/vmware/lib/libz.so.1/libz.so.1 ln -s /lib/x86_64-linux-gnu/libz.so.1 /usr/lib/vmware/lib/libz.so.1/libz.so.1 vmware-networks --start exit  # run vmware as normal user /usr/lib/vmware/bin/vmware Why does $\sqrt{n\sqrt{n\sqrt{n \ldots}}} = n$? Ok, so I've been playing around with radical graphs and such lately, and I discovered that if the   nth x = √(1st x √ 2nd x ... √nth x);   Then  $$\text{the "infinith" } x = x$$  Example:   $$\sqrt{4\sqrt{4\sqrt{4\sqrt{4\ldots}}}}=4$$ Try it yourself, type calc in Google search, hit  then a number, such as $4$, and repeat, ending with $4$, (or press the buttons instead).  I'm a math-head, not big enough though, I think this sequence is divergent or convergent or whatever, too lazy to search up the difference.  However, can this be explained to me? Like how the Pythagorean Theorem can be explained visually. On the usage of "the" article with acronyms and initialisms I've read  and  I know that  1. The article is often used with initials that are pronounced letter by letter (initialisms).  2. The article is often NOT used with initials that are pronounced as a word (acronyms).  I used 'often' because I'm not sure about possible exceptions.  In my field of study (Operations Research), initials are frequently used to represent optimization problems (e.g., the TSP). I discussed this point with my university supervisor who makes comments on my reports (English is not his native language). He responded that:  "What I learned from [...] was that whenever we use (specific) acronyms, we don't use 'the' when they are within a sentence, and we use 'the' when a sentence starts with them. For instance,  (i) The HCP is an NP-Complete problem.  (ii) We developed a new algorithm to solve HCP."  HCP stands for the Hamiltonian Cycle Problem. It is really confusing me because I do not know when to use and when not to use the article. For example, on , the author Jane Watson writes:     Use a definite article with an initialism if the spelled out term begins with “the” but is not covered in the initialism.   which implies that I should use the article with "HCP". What do you think? TikZ: remove margin, padding, border around nodes containing images Rank correlation statistics comparison I am trying to understand the relative behavior of the following rank correlation statistics:   Spearman coefficient Kendall Tau / Concordance percentage Normalized Gini coefficient (area under curve of percentage captured versus percentage observations) Normalized Area under ROC curve (for binary classifiers)   I don't believe any of these are functionally related to the others.  The accepted answer  references  and Spearman and Kendall are highly correlated (as one would expect).  Are there good intuitions behind/discussions of relative (across datasets) or absolute (for a given dataset) differences for (any pair of) these measures? How to find the 'sizeof' (a pointer pointing to an array)? I would like to search an entire MS SQL 2000 database for one value. This would be to aid development only. Keep that in mind when considering this question.   This will get all the table names and the column of the data type I'm looking for:  SELECT Columns.COLUMN_NAME, tables.TABLE_NAME FROM INFORMATION_SCHEMA.Columns as Columns  JOIN INFORMATION_SCHEMA.TABLES as tables  On Columns.TABLE_NAME = tables.TABLE_NAME WHERE Columns.DATA_TYPE = 'INT'     I was thinking something like this:  -- Vars DECLARE @COUNTER INT DECLARE @TOTAL INT DECLARE @TABLE CHAR(128) DECLARE @COLUMN CHAR(128) DECLARE @COLUMNTYPE CHAR(128) DECLARE @COLUMNVALUE INT  -- What we are looking for SET @COLUMNTYPE = 'INT' SET @COLUMNVALUE = 3 SET @COUNTER = 0  -- Find out how many possible columns exist SELECT @TOTAL = COUNT(*)   FROM INFORMATION_SCHEMA.Columns as Columns  JOIN INFORMATION_SCHEMA.TABLES as tables  On Columns.TABLE_NAME = tables.TABLE_NAME WHERE Columns.DATA_TYPE = @COLUMNTYPE PRINT CAST(@TOTAL AS CHAR) + 'possible columns' WHILE @COUNTER &lt; @TOTAL BEGIN     SET @COUNTER = @COUNTER +1     -- ADD MAGIC HERE END   Any ideas?  UPDATE I recently found this  that works quite well. World edit wood rotation Solving linear congruences by hand: modular fractions and inverses When I am faced with a simple linear congruence such as  $$9x \equiv 7 \pmod{13}$$ and I am working without any calculating aid handy, I tend to do something like the following:  "Notice" that adding $13$ on the right and subtracting $13x$ on the left gives: $$-4x \equiv 20 \pmod{13}$$  so that $$x \equiv -5 \equiv 8 \pmod{13}.$$  Clearly this process works and is easy to justify (apart from not having an algorithm for "noticing"), but my question is this: I have a vague recollection of reading somewhere this sort of process was the preferred method of C. F. Gauss, but I cannot find any evidence for this now, so does anyone know anything about this, or could provide a reference? (Or have I just imagined it all?)  I would also be interested to hear if anyone else does anything similar. Division ring if and only if it has no proper left ideals. For any prime $p > 3$, why is $p^2-1$ always divisible by 24? Apply for Schengen visa in a third country Can a Kenyan citizen studying in Russia and temporarily visiting family in Kenya apply for a Schengen visa in Nairobi and not in Russia, where he has his residence? Trigger an event with Prototype I have noticed a significant number of suggested edits that attempt to fix code, or change the original meaning of someone else's post.    Is this really a good idea?    I've been on StackOverflow awhile, and among the editors who have sufficient reputation to edit without approval, I've never seen anyone modify the technical content or meaning of someone else's post.   I would consider obvious syntax and spelling errors OK to change, but I have seen many suggested edits that change the meaning of the code that was posted, or add things to the code that have nothing to do with the original question. A good example of this would be adding parameters to a SQL command, when the question was not asking about SQL injection. Many to Many and Weak Entities I have an entity that cannot exist without being defined by another, and I want this entity to participate in a many-to-many relationship.  Example: An artist has an album (the album cannot exist without an artist), the album also has many tracks, but the same track can exist in many albums.  So we have a many-to-many relationship between the album and the tracks.  If the album is a weak entity, then its primary key is a foreign key referencing the artist, thus it cannot be a foreign key to another table representing a many-to-many relationship.  The question is: is it possible to have this kind of relationship in SQL, and if so, how do I express it? Prove $g$ is a generator if $g^q=1 \pmod p$ Let $p$ be an odd prime and let $q=\frac{p-1}{2}$. If $g^q=-1\pmod p$ and $q$ is a prime, show that $g$ is a primitive root mod $p$.  I want to show $\{g,g^1,...,g^{p-1}\}=\{1,2,...p-1\}$. I argue by contradiction that if there're $x,y\in \{1,2,...p-1\},x&lt;y,g^x=g^y\pmod p$. Then $g^{y-x}=1\pmod p$. I don't know how to use the fact that $q$ is prime to lead to a contradiction. Let $f: \Bbb R \to \Bbb R$ be a differentiable function such that $\sup_{x \in \Bbb R}|f'(x)| \lt \infty$. Then (UGC CSIR-2015, DECEMEMBER, MATHEMATICAL SCIENCES)        $f$ maps a bounded sequence to a bounded sequence.   $f$ maps a Cauchy sequence to a Cauchy sequence.   $f$ maps a convergent sequence to a convergent sequence.   $f$ is uniformly continuous.      I choose all of the options as possible answers because the condition $\sup_{x\in \Bbb R}|f'(x)| \lt \infty$ forces $f$ to be uniformly continuous.(Because $f$ becomes Lipschitz and Lipschitz condition implies uniform continuity)  i.e. $\frac {|f(x)-f(y)|}{|x-y|} \le \sup_{x\in \Bbb R}|f'(x)|$ $ \forall x,y$.  Hence all other options are bound to be true.  Am I correct? Show that the set $\mathbb{Q}[\sqrt{2}] = \{a + b \sqrt{2} \mid a, b \in \mathbb{Q}\}$ is a field with the usual multiplication and addition. Show that the set $\mathbb{Q}[\sqrt{2}] = \{a + b \sqrt{2} \mid a, b \in \mathbb{Q}\}$ is a field with the usual multiplication and addition.  It is easy enough to show that it is closed under addition and multiplication ( $\forall a,b \space)$ we have $a+b \in \mathbb{Q}\sqrt{2}$ and $a * b = ab \sqrt{2} \in \mathbb{Q}\sqrt{2}$.  However, I had trouble proving the other axioms (associativity, commutativity, unique neutral element, unique inverse, and distributivity of multiplication over addition). I would really appreciate it if someone could help me with those. Symbolic links error while creating Ubuntu UEFI bootable USB I have tried to create UEFI bootable USB drive within Ubuntu 14.10 (Startup disk creator didn't help nor I am interested in using it.). I have formated USB with FAT32 and GPT. So the only thing left to do would be just to copy all files from ISO to USB. That method worked when it comes to Linux Mint 17.1 and Clonezilla live CD, but when I tried to create bootable USB for Ubuntu 14.04 or Kubuntu 15.04 beta 1 there was an error copying files. Actually, on several occasions (4 or 5) pop-up window appeared.   After ignoring this errors, both Ubuntu and Kubuntu USB boot-up just fine, with no apparent problems in Live mode.   Can someone please elaborate what this symbolic links presents? Will this cause some problem when OS is installed?