Why do droids in Star Wars all have random alphanumeric designations?
Do all droids have a four alphanumeric character name and does this have any significance?
What is a good asymptotic for $f_n = f_{n-1}+\ln(f_{n-1})$? Which preposition is correct in the phrase "proficient in/at/with English"? Do the Imperials know they are evil? I am trying to make a custom food recipe. I'm using spawn eggs with /replaceitem because spawn eggs are not obtainable in survival. This works fine when the player crafts only one spawn egg, but when I scroll over multiple spawn eggs, I receive only 1 of the custom food. BTW this food uses custommodeldata, so I can't simply add it into the crafting recipe. I cannot seem to find a way around this. If I make the item non-stackable, such as a piece of armor, mass crafting would be impossible. If I make an item.dropped scoreboard, the player could keep the item and use it to spawn mobs (griefing or for own profit.)  My command:    execute as @a[nbt={SelectedItem:{id:"minecraft:villager_spawn_egg"}}] run replaceitem entity @s weapon  minecraft:melon_slice{CustomModelData:10000101,display:{ Name:"{\"text\":\"Blue Melon Slice\",\"italic\":\"false\"}"}}     My problem is that the command does not see item count, as it is often used for weapons and armor only.    One way I thought to fix this issue is by storing the amount of custom food crafted in a scoreboard item and then giving the player that same count of the custom food, but I do not know how to do this; consequently, I don't know if this works.    Is there a way to do this method, or is there another, simpler method possible? Chi-squared test when two vectors have different lengths I want to compare two groups (vectors) having different lengths to see if their distributions differ considerably. However, when I use chisq.test, I get an error due to inequalities of lengths:  &gt; chisq.test(factor(Group1), factor(Group2))   results in:  Error in chisq.test(factor(Group1[, col]), factor(Group2[, col])) :  'x' and 'y' must have the same length   Could someone help me with this? Thanks. Allowed Wave Functions of System Given a single-particle system with Hamiltonian $H$, what constraints can be put on the wave function at a particular point in time $\psi(x)$? Of course $\psi(x)$ must obey boundary conditions given by $H$. However, in situations where $H$ does not yield strict boundary conditions (e.g. the harmonic oscillator) can $\psi(x)$ be any normalised function? My intuition says no for the following reason: QM textbooks say that any valid wave function can be represented as a linear combination of the eigenstates of $H$. In the case of the harmonic oscillator, the eigenstates of $H$ are a countably infinite set. However the set of all normalised functions is uncountably infinite. It seems to me that one cannot change between one complete set of basis functions to another and reduce the "dimensionality" somehow. This makes me think that the eigenstates of $H$ are not complete, that they imply some constraints on $\psi(x)$. This is not an area of mathematics that I understand well. Can somebody help me out? How to reduce space between image and its caption? I want to use the get_option() function of wordpress in one of my theme's files, which is not related to WP, it is just located in the same directory of the other theme files. I need this file because of some extra IPN paypal related actions, but I need some values from the options table that exists in WP to be called in this page in order for it to work. I know I can't just use get_option() as this file is overlooked by wordpress. Is there any approach by including some parts of wordpress in my theme to make this functionality only work? We've all wanted to express certain questions, rhetorical or not, with annoyance, excitement, surprise, frustration and so on. What better way than with both a question mark (?) and an exclamation mark (!), right? I've seen two ways of punctuating such questions:  Where is this place?!    Who do you think you are!?  (Things like ?!?, !?!, ?????!!!!!, ??!?!!?!?!!??, etc are irrelevant here.) Which is the proper way to order the two symbols? Or does each of the above two have a distinct and grammatically correct meaning? Or is the interrobang (‽) the clear winner here? ;) I have noticed that some browsers (in particular, Firefox and ) are very zealous in using cached copies of .css and .js files, even between browser sessions. This leads to a problem when you update one of these files, but the user's browser keeps on using the cached copy. What is the most elegant way of forcing the user's browser to reload the file when it has changed? Ideally, the solution would not force the browser to reload the file on every visit to the page.  I have found  and  suggestion to be useful. It turns out there is a term for this: auto-versioning. I have posted a new answer below which is a combination of my original solution and John's suggestion. Another idea that was suggested by SCdF would be to append a bogus query string to the file. (Some Python code, to automatically use the timestamp as a bogus query string, was .) However, there is some discussion as to whether or not the browser would cache a file with a query string. (Remember, we want the browser to cache the file and use it on future visits. We only want it to fetch the file again when it has changed.) Are primes (ignoring $2$) equally likely to be $1~\text{or}~3\pmod 4$? For all primes $p\neq 2$, it's easy to see that $$p\equiv 1~\text{or}~3\pmod 4$$ I was wondering if it's equally likely ($50\%-50\%$) that prime modulo $4$ is $1$ or $3$. And if so, is there a simple proof? Make the MSE favicon grayscale (like all other meta icons are) The new  for Meta Stack Exchange looks exactly the same as the one for the  site:        This can get a bit confusing, especially if you happen to have many tabs open from both sites.  It also looks a bit silly in the site switcher menu:  All the per-site metas (and MSO, even before the MSO/MSE split) have favicons that are grayscale versions of the main site icons.  Why not do the same for MSE? Conveniently, michaelb958 already wrote a nice  to do just that (and I  it to apply to the menu too), so you can easily see for yourself how it would look.  Or just see the screenshot below:  So here's my proposal: Let's make this gray icon the official MSE favicon.  Update: The meta.SE favicon has recently been changed to a simplified outline version of the SE logo:  I'm not sure how much I like the new logo (for one thing, it doesn't seem to match the dimensions of the main SE logo), but at least it's different, which was the main point of this request. Is it a good practice to place C++ definitions in header files? My personal style with C++ has always to put class declarations in an include file, and definitions in a .cpp file, very much like stipulated in . Admittedly, part of the reason I like this style probably has to do with all the years I spent coding Modula-2 and Ada, both of which have a similar scheme with specification files and body files. I have a coworker, much more knowledgeable in C++ than I, who is insisting that all C++ declarations should, where possible, include the definitions right there in the header file. He's not saying this is a valid alternate style, or even a slightly better style, but rather this is the new universally-accepted style that everyone is now using for C++. I'm not as limber as I used to be, so I'm not really anxious to scrabble up onto this bandwagon of his until I see a few more people up there with him. So how common is this idiom really? Just to give some structure to the answers: Is it now The Way™, very common, somewhat common, uncommon, or bug-out crazy? How can I tell which cards or sets are currently legal in various formats? I haven't played Magic: the Gathering since the days of Onslaught and Mirrodin, and I would like to try to catch back up. Since all my cards are quite dated now, I may be more interested in formats other than the most up-to-date one.  Rather than ask what is currently legal in various formats (since that is likely too localized), I would rather pose the question of how can I tell which sets/cards are legal in each format. Disable key when program is running What does first authorship really mean? In my field (theoretical computer science), authors of any paper are always listed alphabetically; our papers .  (Well... hardly ever.)  In most other disciplines, at least within science and engineering, the ordering of authors is a signal about their relative contributions to the paper, with the first author indicating the most significant contributor.  Hiring and promotion committees do give extra weight to "first-author papers" (and sometimes have to be reminded that not all areas have them).  As an outsider, I find this practice confusing.  What does first authorship actually mean in your discipline? I understand vaguely that the first author is supposed to be the one who "", but what counts as "work" in this comparison?  Does "most" mean "more than all the other coauthors together" or just "more than any other coauthor"?  What happens when the comparison is unclear?   How often is "did the most work" the actual truth, versus a cover story for a more complex political decision?  I realize that the precise answer is different for every paper.  I'm looking for general guidelines for how an outsider (like me) should interpret first authorship in your field.  Pointers to guidelines from journals or professional societies would be especially helpful.  Please give only one answer per discipline. I updated MacOS Sierra's Apache and PHP, and now whenever I $ sudo apachectl restart I get this:  AH00557: httpd: apr_sockaddr_info_get() failed for My-MacBook-Pro.local AH00558: httpd: Could not reliably determine the server's fully qualified domain name, using 127.0.0.1. Set the 'ServerName' directive globally to suppress this message   Things I've tried so far that didn't work:   Setting ServerName localhost in /etc/httpd.conf Setting ServerName localhost:80 in /etc/httpd.conf Setting ServerName 127.0.0.1 in /etc/httpd.conf Setting ServerName 127.0.0.1:80 in /etc/httpd.conf Ensuring 127.0.0.1       localhost is set in /etc/hosts Repeatedly restarting Apache Quotient rings of Gaussian integers Simple homework question about normally distributed variables The question states:      Consider a set of random variables $X_i$, where $i=1,...n$. Each $X_i$ is   normally distributed with mean $0$ and variance $1$, i.e. $X_i$ are $\mathcal N(0,1)$.   What is the mean and the variance of the random variable $Y$, where   $Y=X_1+...+X_n$.   How do I do this? I'm using Chrome 32 on an Android tablet (not phone) and just can't figure out how to close all open tabs in one go.