How to delete a custom tableview cell?
Smooth reload of uitableview data when rows are deleted
Getting the ID of the element that fired an event Is there any way to get the ID of the element that fires an event?  I'm thinking something like:    $(document).ready(function() {   $("a").click(function() {     var test = caller.id;     alert(test.val());   }); }); &lt;script type="text/javascript" src="starterkit/jquery.js"&gt;&lt;/script&gt;  &lt;form class="item" id="aaa"&gt;   &lt;input class="title"&gt;&lt;/input&gt; &lt;/form&gt; &lt;form class="item" id="bbb"&gt;   &lt;input class="title"&gt;&lt;/input&gt; &lt;/form&gt;     Except of course that the var test should contain the id "aaa", if the event is fired from the first form, and "bbb", if the event is fired from the second form. As the title says. How do I get from  $\frac{n}{\varphi(n)}$ to $\sum\limits_{d \mid n} \frac{\mu^2(d)}{\varphi(d)}$?  I know that $$\frac{n}{\varphi(n)}=\frac{\sum\limits_{d \mid n} \varphi(d)}{\sum\limits_{d \mid n} \mu(d)\frac{n}{d}},$$ and I suspect it is down this road I should go. But I get totally confused by the sums and I have no clue on how to divide them and "combine" them into one again. Any hints or advice would be much appreciated. Proof of the square root inequality $2\sqrt{n+1}-2\sqrt{n}<\frac{1}{\sqrt{n}}<2\sqrt{n}-2\sqrt{n-1}$ DC Motor as a Generator Voltage and Current Convert quaternion to a different coordinate system OSVR has a right-handed system: x is right, y is up, z is near.  I need to convert orientation data from a sensor in OSVR to a different right-handed system in which x is forward, y is left, and z is up.  I need to calculate the transformation that will convert a quaternion from one system to the other.  I naively tried:  void osvrPoseCallback(const geometry_msgs::PoseStampedConstPtr &amp;msg) { // osvr to ros     geometry_msgs::PoseStamped outputMsg;      outputMsg.header = msg-&gt;header;     outputMsg.pose.orientation.x = msg-&gt;pose.orientation.y;     outputMsg.pose.orientation.y = msg-&gt;pose.orientation.z;     outputMsg.pose.orientation.z = msg-&gt;pose.orientation.x;     outputMsg.pose.orientation.w = msg-&gt;pose.orientation.w;      osvrPosePub.publish(outputMsg);     ros::spinOnce(); }   But that made things really weird. Facing north pitch is pitch, facing west, pitch is yaw, facing south, pitch is negative pitch...  How can I convert my OSVR quaternion to the a corresponding quaternion in the new coordinate system? Find $ \lim\limits_{ x\to 100 } \dfrac { 10-\sqrt { x } }{ x-100 }$  (without using a calculator and other machines...?) In Windows Vista, I have tried to set the setting 'the following number of lines at a time' to zero. I assumed my scroll wheel would not scroll anymore. But it still works.  I'm trying to disable the wheel because my RSI complaints worsen when using the scroll wheel often.  Does anyone have an idea on how to achieve this? What does the draft mode change? How to identify if a webpage is being loaded inside an iframe or directly into the browser window? I am writing an iframe based facebook app. Now I want to use the same html page to render the normal website as well as the canvas page within facebook. I want to know if I can determine whether the page has been loaded inside the iframe or directly in the browser? Sometimes it’s possible to use either a noun adjunct or the possessive case.     the shop door   the shop’s door   However, in certain phrases it’s not OK to do so.     the ship’s crew (the ship crew is wrong)   The questions are:   How can one find out what to use in such cases as “the shop(’s) door” when a noun adjunct option and the possessive case option are available?  How can one know which option is wrong in order to avoid the construction “ship crew”? Is there a difference in meaning between (a) the shop door (b) the shop’s door? I've read a number of the helpful Q&amp;As on photons that mention the mass/mass-less issue. Do I understand correctly that the idea of mass-less (a rest mass of 0) may be just a convention to make the equations work?  From a layperson's view, it's difficult to understand how a particle of light (photon) can be mass-less. A physical object (everyday world-large or quantum-small) must have a mass. Yet, if my understanding is correct, the mass of a moving object/particle increases in proportion to its speed/velocity...so that at the speed of light, its mass would be infinite. A photon travels at the speed of light, but it obviously doesn't have infinite mass, right? Can someone formulate a practical explanation that can be understood by middle-school to high school kids? Much thanks for the help.    Wow--your answers to my original Q below clear up much of my confusion. I now have the daunting task of going over these nuggets and working up an equation-less (hopefully) explanation of the mass-less photon for non-physicist types.  Yes, from a layperson's view, it does seem remarkable that an existing piece of matter-- which has to be made of physical substance--could have zero mass at rest (though a photon is never at rest). It would be almost understandable if a piece of matter made of nothing had zero mass, but that  seems to be an oxymoron, and "nothing" would equate to nonexistent, right?  In case you might find it interesting: I'm working on a writing project that posits we inhabit a universe that consists of matter (physical stuff) only, and that the NON-physical (aka supernatural) does not (and cannot) exist. For instance, if a purported supernatural phenomenon is found to actually exist, then by definition, its existence is proof that it is mundane/natural. All it would take to disprove this premise is reliable proof that ONE supernatural event has occurred. Despite thousands of such claims, that's never yet happened.  Who else better than physicists to confirm my premise? However, I do wish the TV physicists would explain the terms they throw about, some of which mislead/confuse their lay viewers. Case in point: "The universe is made up of matter and energy" (without properly defining the term "energy" as a property of matter).  The result is that laypersons are left with the impression that energy must therefore be something apart from or independent of matter (ie, nonphysical). Their use of the term "pure energy" without specifying exactly what that means adds to the confusion. (Thanks to your replies on this forum, I now understand that "pure energy" refers to photon particles.) However, "psychics" and other charlatans take advantage of such confusion by hijacking terms like energy (as in "psychic energy"), frequencies, vibrations, etc to give perceived scientific legitimacy to their claims that a supernatural spirit world, etc., exists. As you may realize, the majority of people in the US (per 2009 Harris Poll) and around the world believe in the existence of nonphysical/supernatural stuff such as ghosts and spirits.  My purpose is to give laypersons the information they need to distinguish what's real from what's not.  Thanks so much for help...And, PLEASE, add any further comments you think might be helpful/insightful to better inform laypersons. How do I get my Broadcom BCM4313 working correctly? This is an idea I have seen around, but I have not seen a feature request for it, so here it is.  Downvotes that have no comments are frustrating and difficult to manage.  This is a way to help improve that:   Have a downvote initially cost more to cast for the downvoter (5 points for example) When a comment (from the downvoter) on the downvoted question/answer gets an upvote, you get your points back.   All points (ie all 5) could be refunded or just up till the traditional -1 that is in place now (ie 4 points refunded).    This would encourage good comments and downvotes for real reasons.  (Because comments for questions/answers that are bias related will not get the upvotes as readily.)  This could/should be limited to non-subjective tags.  (ie tags where a downvote just because you "don't like it" is not appropriate.) Spoilers for the end of the second film      Towards the end of the fight against Ego, we see that the bomb Groot set off blows up Ego's core. Shortly thereafter, it cuts to a scene where Quill is shown apparently losing his powers.   Given that the movie builds up this finale so much, I'm left wondering:      Did Quill lose his powers or merely the means to access them after Ego's apparent death?   Answers from the film or comics are very much welcome. Why is super.super.method(); not allowed in Java? I read  and thought that would easily be solved (not that it isn't solvable without) if one could write:   @Override public String toString() {     return super.super.toString(); }   I'm not sure if it is useful in many cases, but I wonder why it isn't and if something like this exists in other languages.  What do you guys think?  EDIT: To clarify: yes I know, that's impossible in Java and I don't really miss it. This is nothing I expected to work and was surprised getting a compiler error. I just had the idea and like to discuss it. Do I need to have antivirus software installed? I am new to blender. Pressing &#9096; Ctrl&#9095; AltQ opens the quad view. How to maximize any one of the four views of the quad view? Rules for refreezing food What are the general rules regarding when can you refreeze food that was frozen and then thawed in the fridge? and what are the reasons behind them? (Hygiene? Food quality?). Let's assume for the sake of the argument that the items were in a non-frozen state only a few hours.  To be more specific, I'm interested in the application of these rules for  - Ginger garlic paste - Dough - Indian Curries - Green Chilly paste - Frozen green peas Why won't Amanita move in and settle down? I keep getting an alert that Amanita would like to settle down. I have a house ready for them however they still won't move in. Who is this NPC and why won't they settle down? How to see this improper integral diverges? $$\int^\infty_1\frac{1}{x^{1+1/x}}dx$$  I'm preparing for exams. I would also like to know what are some commonly used methods to show an improper integral diverges?