Why isn't my program interpreting the user's input correctly?
What is a "callable"?
Can I run PC steam games on a Mac? I recently downloaded 'Blood Bowl' on Steam to my Mac, not realizing that it was not Mac-compatible. Is there any software or any way that will allow me to play it, as obviously I've already paid for it? Cheers. What is "Best Practice" For Comparing Two Instances of a Reference Type? I came across this recently, up until now I have been happily overriding the equality operator (==) and/or Equals method in order to see if two references types actually contained the same data (i.e. two different instances that look the same). I have been using this even more since I have been getting more in to automated testing (comparing reference/expected data against that returned). While looking over some of the  I came across an  that advises against it. Now I understand why the article is saying this (because they are not the same instance) but it does not answer the question:  What is the best way to compare two reference types? Should we implement ? (I have also seen mention that this should be reserved for value types only). Is there some interface I don't know about? Should we just roll our own?!  Many Thanks ^_^ Update Looks like I had mis-read some of the documentation (it's been a long day) and overriding  may be the way to go..  If you are implementing reference types, you should consider overriding the Equals method on a reference type if your type looks like a base type such as a Point, String, BigNumber, and so on. Most reference types should not overload the equality operator, even if they override Equals. However, if you are implementing a reference type that is intended to have value semantics, such as a complex number type, you should override the equality operator. How can I quickly know the rank of this / any other matrix? One way to prove that there is an infinity of consecutive powerful integers is to just note that there are infinite solutions to the equation $x^2-8y^2=1$, because clearly $x^2$ and $8y^2$ are clearly powerful. But this uses a bit of theory.  I found this problem under an induction worksheet, and all of the surrounding problems are easy. Is there really an elementary solution to the problem?  All of my attempts have been fruitless.  Note: a number is powerful if whenever a prime $p$ divides it we have that $p^2$ also divides it. What problem does oversampling, undersampling, and SMOTE solve? Fast, accurate 2d collision I'm working on a 2d topdown shooter, and now need to go beyond my basic rectangle bounding box collision system.  I have large levels with many different sprites, all of which are different shapes and sizes. The textures for the sprites are all square png files with transparent backgrounds, so I also need a way to only have a collision when the player walks into the coloured part of the texture, and not the transparent background.  I plan to handle collision as follows:   Check if any sprites are in range of the player Do a rect bounding box collision test Do an accurate collision (Where I need help)   I don't mind advanced techniques, as I want to get this right with all my requirements in mind, but I'm not sure how to approach this. What techniques or even libraries to try. I know that I will probably need to create and store some kind of shape that accurately represents each sprite minus the transparent background.  I've read that per pixel is slow, so given my large levels and number of objects I  don't think that would be suitable. I've also looked at Box2d, but haven't been able to find much documentation, or any examples of how to get it up and running with SFML. If $x_1,x_2,\ldots,x_n$ are the roots for $1+x+x^2+\ldots+x^n=0$, find the value of $\frac{1}{x_1-1}+\frac{1}{x_2-1}+\ldots+\frac{1}{x_n-1}$ When you review papers submitted for publication, is there an “optimal” length for reviews? In my experience as an author and referee, I have seen a large range of review lengths (for reference, a paper in my field is typically between 3 and 8 printed pages):   Zero length: for some of the papers I have authored, the reviewer just clicked the “accept as is” or “reject” checkmark on the review sheet, without adding any comment (at least, not any comment visible to me). It's not so common, but it has happened. Short length: a lot of time, I received reviews who consisted of a single paragraph. Medium: one full page, maybe two pages.   Although I have never received any such long reviews, I have myself written on a few occasions reviews that exceed two pages, including once or twice a four or five-page review.  These were cases where the paper was good, but could be (in my view) much improved and some of the aspects/consequences had escaped the authors' consideration.  I am wondering how useful reviews of various length are to editors. I often consider that “unmotivated” reviews are useless, as they do not give any real insight about the paper to the editor. For example, if the editor gets two conflicting non motivated reviews, how is she to decide?  On the other hand, although I write some from time to time, I have never received long reviews, so… is this something frowned upon? Where should I put  tags in HTML markup? Can I see things that I've said in chat that have been starred? I was reviewing the star on chat.SE list this morning and I noticed that quite a few of the items on the list were mine.  I was curious as to how often people enjoy the things I post there enough to star them, but I can't seem to find statistics about this anywhere.  Mana told me that no such feature exists.  (the best we could come up with is ) So here's my request - can I filter/search the chat history for things I've said that other people have starred? Is it possible to detect 32 bit vs 64 bit in a bash script? I am writing a bash script to deal with some installations in an automated way... I have the possibility of getting one such program in 32 or 64 bit binary... is it possible to detect the machine architecture from bash so I can select the correct binary?  This will be for Ubuntu machines. Can a pixie fly higher than their altitude of one? In the pixie description on the compendium:     Altitude Limit: You fall at the end of your turn if you are using your racial fly speed and are more than 1 square above the ground (see the rules for flying and falling in the Rules Compendium).   So can a pixie choose to go two or more squares above the ground?   Here are the relevant rules from the compendium:  Fly speed:     A creature that has a fly speed can fly a number of squares up to that speed as a move action. If it is stunned or knocked prone while flying, it falls. See also “Flying” and "Hover".   Flying:     Flight      Some creatures have the innate ability to fly, whereas others gain the ability through powers, magic items, and the like. The rules for flight in the DUNGEONS &amp; DRAGONS game stress abstraction and simplicity over simulation. In real life, a flying creature’s ability to turn, the speed it must maintain to stay aloft, and other factors put a strict limit on flight. In the game, flying creatures face far fewer limitations.      FLIGHT      Flight follows the basic movement rules, with the following clarifications.         Fly Speed: To fly, a creature takes the walk, run, or charge action but uses its fly speed in place of its walking speed. A creature that has a fly speed can also shift and take other move actions, as appropriate, while flying.   Moving Up and Down: While flying, a creature can move straight up, straight down, or diagonally up or down. There is no additional cost for moving up or down.   Falling Prone: If a creature falls prone while it is flying, it falls. This means a flying creature falls when it becomes unconscious or suffers any other effect that knocks it prone. The creature isn’t actually prone until it lands and takes falling damage.   Remaining in the Air: A flying creature does not need to take any particular action to remain aloft; the creature is assumed to be flying as it fights, moves, and takes other actions. However, a flying creature falls the instant it is stunned, unless it can hover.   Landing: If a creature flies to a surface it can hold onto or rest on, the creature can land safely.   Terrain: Terrain on the ground does not affect a flying creature if the terrain isn’t tall enough to reach it. Because of this rule, flying creatures can easily bypass typical difficult terrain, such as a patch of ice on the ground. Aerial terrain can affect flying creatures.      Crashing        Falling while Flying: If a creature falls while it is flying, it descends the full distance of the fall but is likely to take less damage than a creature that can’t fly. Subtract the creature’s fly speed (in feet) from the distance of the fall, then figure out falling damage. If the difference is 0 or less, the creature lands without taking damage from the fall. For example, if a red dragon falls when it is 40 feet in the air, subtract its fly speed of 8 (8 squares = 40 feet) from its altitude. The difference is 0, so the dragon lands safely and is not prone.         If a creature is flying when it starts a high-altitude fall, it has one chance to halt the fall by making a DC 30 Athletics check as an immediate reaction, with a bonus to the check equal to the creature’s fly speed. On a success, the creature falls 100 feet and then stops falling. On a failure, the creature falls as normal.         High-Altitude Falls: Some encounters take place very high above the ground. In such an encounter, it is possible for a creature to spend more than one round falling to the ground. As a rule of thumb, a creature falls up to 500 feet during its first turn of falling. If it is still falling at the start of its turn, it can take actions on that turn as normal, then falls up to 500 feet at the end of the turn. If none of those actions expressly halts a fall, the creature falls up to 500 feet at the end of the turn. This sequence continues until the creature lands. How to find out which (not installed) Debian package a file belongs to? On Debian systems (and derivatives):  $ dpkg --search /bin/ls coreutils: /bin/ls   That is, the file /bin/ls belongs to the Debian package named coreutils.  But this only works if the package is installed. What if it's not? How do I set environment variables? I'm trying to set up Apache Tomcat on my pc, and it wants me to set up an environment variable for CATALINA_HOME.  Does any know how to do this? As in the title I have to evaluate this triple integral: $$\iiint_{[0,1]^3}\frac{dx\,dy\,dz}{(1+x^2+y^2+z^2)^2}$$ I've been trying to solve this since a week ago. The first thing I've done was understand the meaning of the integral. I think this integral represents the mass (as an example) of a unitary cube which contains materials of different density. The values of the materials density are, point for point, the inverse of the square of spheres centered in the origin plus one. The max value of the density is $1$ in the origin of the cube and the min value is $\frac{1}{16}$ on the opposite vertex. I suppose that the value of the integral is $\frac{\pi^2}{32}$ I've tried to use simple substitutions without any results, so I tried to change the coordinates with spherical and cylindrical systems. The spherical coordinates give me an incredibly long sum of integrals and I doubt that they're all integrable as elementary functions. The cylindrical gives me the following result $$\frac{\pi^2}{16}-\int_0^\frac{\sqrt2}{2}{\frac{\arctan{\sqrt{\frac{u^2-1}{u^2-2}}}}{\sqrt{2-u^2}}du},$$ which I'm not able to solve. My instinct tells me that there is a trick in some steps where I can observe that a difficult integral actually is exactly half of another one simpler but I can't figure out where. I'll appreciate any kind of suggestions. I have a collection of articles written in latex, and I would like to "merge" them into a larger thesis document, in which each article will be a chapter. I have been looking at include and input, which are great if you start with the meta-document in mind. However in my articles I have sometimes a bit exotic dependencies, such as dot2texi, and using the naive approach fails rather abysmally with all kinds of broken paths.  So I was wondering, do you recommend any "best practices" for merging non-trivial documents -- which packages to look at, or to avoid at all cost, etc.  Thanks Invite people who liked my first page to like another one in Facebook How to create a table with long text and which packages use What governor limits impact Apex Describe methods? It's not like there's anything else to do.   Shouldn't the speaker say: "There's something else to do." ? so what's the meaning of the sentence and what's the difference between the two of them? Thank you,