I've been given the following design for an error modal dialog (the rest of the page is grayed out and can't be clicked):    To me, instinctively, it seems redundant having two ways (close button and ok button) to do the same thing (close the dialog).  I don't see the need to have the close button.  Can you provide some more solid reasons to avoid that, or good reasons to have both if I am wrong?
I am working with a basic  which is a popular modal used on many sites. I noticed that the default template comes with both a close button on the bottom, as well as an x on the top, these two buttons essentially having the same purpose. Are the two redundant and the close button completely unnecessary and just taking up extra space? Or, is having multiple usage options more user friendly?   To make this even more fun, suppose I throw in a Save button:   Is it now clearer that if you don't press save and just press the x, your changes will be canceled, or is there now more of a need for a cancel button for users who are scared that a mistake will become permanent? Update: To clarify for those who feel this question is similar to  - That question is asking if a clickable background is sufficient to close a popup. I'm using buttons and it is just a matter of how many buttons to use. (I do also have a clickable overlay and ESC key enabled, but that is irrelevant to my question)
Why was Gotham City changed from a mostly fictional city to New York City in the Nolan trilogy? In Batman Begins, Gotham City has a futuristic/fictional and run down look: think of Oldtown, the trains built by the Wayne Corporation etc.   In The Dark Knight Rises, Gotham City looks like plain old real world New York City — we don't see the trains anymore. Oldtown is just a standard poor neighborhood. Lots of the locations used in the movie are easily identified as real world NYC locations: the stock exchange or East River bridges for example.   My question is: Why did Nolan change Gotham city from a shady fictional more cartoon-like town to plain old NYC?   Edit: The examples from Batman Begins and The Dark Knight Rises were just for illustration; I didn't intend to limit the question to those two movies.  Edit 2: I specifically want to know why Gotham City was changed from a cartoon-like city in Begins to an almost real-world NYC in The Dark Knight Rises (via not so cartoon-like but not yet real-world like Chicago in The Dark Knight Rises). Why it's NYC or Chicago is not so important for me. But why, e.g., were the trains which featured prominently in Begins gone in The Dark Knight Rises? There was only a very short in-universe time-span between the events of the two movies, yet Gotham changed drastically. Browser back leaves page after going fullscreen in stack snippet Opening a Stack Snippet in full screen should use history.pushState() to add an entry to the browser history stack. Clicking back will then close the snippet rather than leave the page completely. Proof for $e^z = \lim \limits_{x \rightarrow \infty} \left( 1 + \frac{z}{x} \right)^x$ Q1: Could someone provide a proof for this equation (please focus on this question):   $$e^z = \lim \limits_{x \rightarrow \infty} \left( 1 + \frac{z}{x} \right)^x$$  Q2: Is there any corelationn between above equation and the equation below (this would benefit me a lot because i at least know how to proove this one):  $$e = \lim \limits_{x \rightarrow \infty} \left( 1 + \frac{1}{x} \right)^x$$ What's the best blog post/video/tweet/whatever to explain how the Stack Exchange system works to regular people? I am trying to gauge interest for a new Stack Exchange site, but I want to explain it to people as best (and preferably) as visually as I can. Any YouTube clips breaking it down?  anyone?  Note: I am fully aware of , but mine is about Stack Exchange, not Stack Overflow.  Most people think I'm describing traditional forum software, which they know sucks. Is there some way to describe the magic of how the design of the Stack Exchange system actually produces useful results very quickly? I can describe generally that it is a Q&amp;A site that users vote on the answers, but Stack Overflow feels like so much more. Am I perhaps thinking too big about this? Should not we apply pseudo-forces all the time as the Earth is a non-inertial frame of reference? $M= \{ A \in Mat_{2 \times 2}{\mathbb{R}}| \det(A)=1 \}$ is homeomorphic to $S^{1} \times \mathbb{R}^{2}$ Time Capsule cryptography? Does there exist any cryptographic algorithm which encrypts data in such a way that it can only be decrypted after a certain period of time?  The only idea that I can think of, is something like this: Seed a PRNG with a public value. Run the PRNG for a week and use the final value it produces to encrypt the message. Now anyone who runs that PRNG for a week starting from the seed value you made public can decrypt the message. Obviously this breaks down since they could use more computational power than you; if the time span was years then Moore's Law would apply, etc.  Is there anything like this other than physically burying a private key on a USB stick in a literal time capsule? I would like to show that the function $\frac{1}{x}$ is not uniformly continuous on $(0,1)$ using two approaches.   First Approach:   We have the fact that if a function $f$ is uniformly continuous on an open interval $(a,b)$, then the function $f$ is bounded on $(a,b)$. By using its contrapositive, since $\frac{1}{x}$ is not bounded on $(0,1)$, it is not uniformly continuous.  Second Approach:  Proof by definition. Note that the definition of non-uniform continuity is:  There exists an $\epsilon_0&gt;0$ such that for all $\delta&gt;0$, there exists $x,y \in (0,1)$ such that $|x-y|&lt;\delta$ but $|\frac{1}{x} - \frac{1}{y}| \geq \epsilon_0$.  Assume that $\delta &lt; 1$. Let $x = y + \frac{\delta}{2} \in (0,1), y &lt; \frac{\delta}{2} \in (0,1), \epsilon_0 = 1$. Then we have   $$|\frac{1}{x} - \frac{1}{y}| = |\frac{1}{y + \frac{\delta}{2}} - \frac{1}{y}| = \frac{\frac{\delta}{2}}{|y(y + \frac{\delta}{2})|} &gt; \frac{\frac{\delta}{2}}{(\frac{\delta}{2})(\delta)} = \frac{1}{\delta} &gt; 1 = \epsilon_0 $$  If $\delta \geq 1$, then let $\delta^{\prime} = \frac{1}{\delta}$ so that $\delta^{\prime} \leq 1$. The rest proceeds the same as above.   Question: Are my two approaches correct? Where can I find every gnome? Infinite Series $\sum\limits_{n=1}^{\infty}\frac{1}{4^n\cos^2\frac{x}{2^n}}$ How to prove that  $$\sum_{n=1}^{\infty}\frac{1}{4^n\cos^2\frac{x}{2^n}}=\frac1{\sin^2x}-\frac1{x^2}$$ Using PyQGIS to transform layer of polygons into layer of holes inside bbox? I'm using python in QGIS. I have a layer of polygons (its a result of some earlier dissolving and has no overlapping polygons but some holes and islands in holes etc). I want to build a new layer which contains one polygon representing a bbox of the first layer with each polygon cut from it.  Essentially I want to "invert" the layer I have so that where the was polygon, now there is not, and where there was not polygon now there is. All inside a bounding box of the original layer.  I can build a bbox easily and I tried to "subtract" the polygon layer from my new bbox polygon layer but the process slows to a stop and then crashes my PC. Here's the algorythm  processing.runalg("qgis.difference","path/to/polygon.shp","path/to/bbox.shp","path/to/result.shp")   I dont care about attributes (obviously). I just need to cut one set of polygons from one larger polygon.  It seems so simple, I wish I could find a simple command or script to acheive this. As stated at the top I'm looking for a solution in python in QGIS. For a while now I've noticed that if I take a cup of hot tea and pour it into two cups and leave it then both cups will cool faster than the single cup.  How is it that nature cools two cups of tea in parallel more quickly? It's still the same amount of tea but it gets cooled quicker if I have two cups. What is -crf used for in ffmpeg When converting an array of jpegs to a video file (ogg format) I have been using the -crf option.  What are the valid ranges for -crf? Currently I am using 23.    I cannot find the bookmark I read to know what this flag does and I have spent some time Googling around.  These are the arguments I am using at the moment:  -f image2 -r 10 -i " + _sourcePath + @"\img%05d.jpg -crf 18  -y -r 10 " + _destPath + "\\" + _filename + ".ogg" 9 pirates have to divide 1000 coins... A band of 9 pirates have just finished their latest conquest - looting, killing and sinking a ship. The loot amounts to 1000 gold coins.  Arriving on a deserted island, they now have to split up the loot. You, as the captain of the band, have to propose a distribution plan (who gets what). What's your proposal?  Consider that this bunch is a democratic lot. If your proposal is accepted by half of the group, then everybody adheres to it. However, if folks feel you are getting greedy, and less than half of the band agrees to your proposal, then they kill you, and then your First Mate gets to make a proposal. And so it goes in decreasing order of hierarchy/seniority. What is a good introductory book on quantum mechanics? How can I save the world from the spread of Hallow and Corruption/Crimson? After the Wall of Flesh, the Hallow appears and Corruption/Crimson spreads even faster.   Corruption/Crimson spreads through everything   Except Hallow  Hallow spreads through everything   Except mud (jungle) Except synthetic blocks like gray-brick  The results of Hallow and Corruption meeting are unpredictable   How can I stop them both permanently and effectively from taking over the world, considering both the top layer and underground?  (Eg, simply placing gray brick on top of the surface won't stop the underground spread?)  And, is it worth the effort? Series $\frac{x^{3n}}{(3n)!} $ find sum using differentiation Should we use 'Title Case' or 'Sentence case' for headlines and buttons? I am wondering if we should use  or  for buttons and headings in websites and web/mobile apps? Title Case: Manage my Account Delete my Account  Sentence case: Manage my account Delete my account  In  I found the recommendation 'choose your style and be consistent'. This is it? Aren't there any other (additional) recommendations or sources. Like for specific use cases or apps where the one style would be preferred over the other? Edit: The question refers primarily to English, but differences in other languages are also good to know. Workflow rule order of execution Can I disable full-disk encryption?