How can I center divs vertically and horizontally in a container
How can I vertically center a "div" element for all browsers using CSS?
"He is king" vs "He is a king." I'm reading a book and encountering the phrase "insert name is king" a lot. I'm wondering, what's the difference between them? When and why should I use "He is king" instead of "He is a king"?   Examples:        Tommen is king now   Yet if neither one is king, still, how could it be Lord Renly?   And he is a king, and you’re just a spy   Everyone else is a king or prince these days      Same with other words:        They elected him president.   They called him a thief. When should I use a List vs a LinkedList Glucagon stimulates glycogenolysis and gluconeogenesis, thus increasing the plasma glucose concentration — so that tissues get enough glucose in the fasting state. However glucagon also inhibits glycolysis. In this case, what is the point of having high blood glucose if it cannot be catabolized? How to count occurrences of one field grouped by values of another? Inverse Green's Function identity in derivation of Hedin's equations I'm trying to work through a derivation of Hedin's Equations in Effect of Interaction on One-Electron States by Hedin and Lundqvist (1969) and I've come across an identity that is given without much explanation that I'd like to understand.   We start with an equation of motion with single particle Green's functions G:   $\left[ i\frac{\partial}{\partial t_1} - h(1) - \phi(1) - V_H(1)\right] G(1,2) - i\int v(1^{+},3) \frac{\delta G(1,2)}{\delta \phi(3)} d3 = \delta(1,2)$  where $1=(x_1,t_1)$, $h$ is the one-electron kinetic energy and ion interaction, $\phi$ is a small perturbing field that is set to zero at the end, $V_H$ is the Hartree potential, and $v$ is the Coulomb interaction.  They then insert the identity  $\frac{\delta G(1,2)}{\delta\phi(3)} = -\int G(1,4) \frac{\delta G^{-1}(4,5)}{\delta\phi(3)} G(5,2) d(4,5)$  which is then used to define the self energy  $\Sigma(1,2) =  -i \int v(1^+,3) G(1,4)\frac{\delta G^{-1}(4,2)}{\delta\phi(3)} d(3,4)$.  I know this identity is related to the definition of the inverse Green's function  $ \int G(1,3) G^{-1}(3,2) d(3) = \delta(1,2)$  but I can't figure out how to get from this definition to the identity that is inserted into the equation of motion. Any ideas?  Thank you! Short story that takes place off planet, involving sun and rain I read this short story about 20 years ago, and I'd love to find the title and author. This is what I can recall about the story:   It takes place in a classroom full of kids (around 10 years old?) The planet always gets rain The kids lock the main character (a girl, I think) in the closet during the very rare occurrence of sunlight and she misses the entire event.    I know it's not much to go on, but I hope it rings a bell for someone! I was so excited about the Spring '14  as a way to present data visualizations on a public site, and now it looks like that's not possible.  I created a page that looks basically like the release notes sample:  &lt;apex:page &gt;     &lt;analytics:reportChart reportId="00OW0000000Spru"&gt;&lt;/analytics:reportChart&gt; &lt;/apex:page&gt;   I tested it inside the authenticated environment, where it works fine, then added it to a Site. There, I get the error: To view the report chart, you need both the Run Reports permission and access to the report's folder. But, Run Reports is not a permission I can grant to the Site Guest User.  Anybody have any ideas for a workaround? Or is it not going to be possible to show report charts on a public site? Where is the Layers panel in Blender 2.8? I am starting working on Blender 2.8, but I can't find the layer panel. Where is it? How do I figure out what package something is in without resorting to Google? I often find myself wanting to install something, but I'm unsure of what package it's in. This is a very common occurrence for me:  $ make html sphinx-build -b djangohtml -d _build/doctrees   . _build/html make: sphinx-build: Command not found make: *** [html] Error 127  $ sudo apt-get install sphinx E: Unable to locate package sphinx  $ sudo apt-get install sphinx-build E: Unable to locate package sphinx-build   googles  $ sudo apt-get install python-sphinx   Is there a better way? Suppose I sold an option on stock X, with strike price Y, and expiry date Z. Suppose I later buy an option on the same stock, with the same strike price, and the same expiry date. Do these two positions cancel out each other (i.e. both contracts cease to exist anywhere), or will I end up with two separate contracts?  Is it the same with the reverse situation? e.g. I bought an option on stock A, with strike price B, and expiry date C. If I later sell an option on the same stock, with the same strike price and expiry date, will I end up with two contracts (one long position, one short position)? How do I get my Epson Scanner working on Ubuntu 13.10 I have the Epson SX218 with a built-in scanner. The printer works fine but if I want to scan something simple scan says no scanner found.  Any ideas what I can do?  By the way, how can I check the ink level of the printer?? Have men and women in the Wizarding World always had relatively equal rights? There are racial struggles and examples of racism, (Muggle-borns, centaurs, hous-elves, goblins, etc.) but are there any examples in the Wizarding World of sexism?  Have witches and wizards always had equal rights? i want to write a device driver but not able to find the header file can someone please help me find them?Also if someone can point out some important site links that would be really appreciated Solution of limit $\lim\limits_{x\to 0} \frac {e^{-1/x^2}}{x} $ Small question, I'm trying to solve this limit but I just can't wrap my head around this problem.  $$\lim_{x\to 0} \frac {e^{-1/x^2}}{x} $$  L'Hopital just seems to make it messier.   It's probably pretty simple - I'd like to hear what I'm missing. First quick glance at a dataset Please pardon my ignorance, but...  I keep finding myself in a situation, where I'm faced with a bunch of new data I managed to find. This data usually looks something like this:  Date     Number1  Number2  Category1  Category2 20120125      11      101        Dog      Brown 20120126      21       90        Cat      Black 20120126      31      134        Cat      Brown (...)   Usually at first glance I can't really tell if there are any trends here. The correlations between the various columns may not be very significant, but I would be delighted if I didn't have to manually create a plot for every possible combination of columns/categories.  Is there a tool out there which would accept a table of data along with information which columns should be treated as numbers, dates and categories and then proceed to plot:   correlations between each two numerical columns correlations between each two numerical columns, with separate trend lines for each category each number column as a time series, each number column as a time series, separated by category, etc.   In the end this would generate a large number of plots, most of which would show only noise. Ideally, the tool could score the plots by correlation and in the end display a slideshow starting with the highest scoring plots. This would be a very imperfect, but useful first glance at the dataset.  So? Is there a tool everyone uses for this and I just don't know about it, or is this something we need to make? PHB says 'once per turn,' so, it would seem that a Rogue with Sentinel, for example, could "consistently" deal Sneak attack twice per round (whether the enemy triggers an OA or the melee weapon attack provided by the Feat).  So, can rogues deal sneak attack damage with any weapon attack outside their turn? (obv. one that meets the standard requirements--finesse, adv or adj ally) The problem:  Assume $f: \mathbb{R} \rightarrow \mathbb{R}$ satisfies $|f(t) - f(x)| \leq |t - x|^2$ for all $t, x$. Prove $f$ is constant.  I believe I have some intuition about why this is the case; i.e. if $t$ and $x$ are very close, ($|t - x| = \epsilon$), then $\sqrt{\epsilon}$ will converge to 0, so $|f(t) - f(x)|$ will also converge to zero if you keep taking $t$ and $x$ closer and closer to each other. However, how do I formalize this argument? Thanks. Removing nodes from graphs such that one is dependent on other - ZIO $2010$, P$1$ Greetings Community! The above problem you see is a combinatorics problem I could not solve. :( This problem is from ZIO $2010$, P$1$.     Here is what I did: Observe that every graph can be divided into "sub-groups" which may help in solving. We first remove the empty set. Then the singleton set. Consider the bigger but smaller than the sub-parts example:    The singleton sets are $\{4,5,6\}$ which are at the least position in the graph.   The dual sets are $\{2,4\}, \{3,5\}, \{3,6\}$, the bottom - two portions in the graph. The triplet sets are $\{2,4,5\}, \{4,5,6\}$ which we may manually count but for the bigger graphs in the sub-part, this may prove to be difficult and this is where I am stuck.   Any help would be appreciated. Thanks. Find all solutions to the functional equation $f(x) +f(x+y)=y+2 $ I have been texture painting in look dev mode. But when i try to render it, everything looks very dark. I have 3 sun lights in my scene, ambient turned on in Eevee settings. What am i missing? I really like the look of my scene in Look Dev mode, how can i achieve the same look when my scene is rendered too?