Ps4 controller problems/issues
PS4 Controller not connecting to PS4 and won't reset?
Show that if $n$ is not divisible by $2$ or by $3$, then $n^2-1$ is divisible by $24$.   I thought I would do the following ... As $n$ is not divisible by $2$ and $3$ then $$n=2k+1\;\text{or}\\n=3k+1\;\text{or}\\n=3k+2\;\;\;\;$$for some $n\in\mathbb{N}$. And then make induction over $k$ in each case.$$24\mid (2k+1)^2-1\;\text{or}\\24\mid (3k+1)^2-1\;\text{or}\\24\mid (3k+2)^2-1\;\;\;\;$$This question is in a text of Euclidean Division I'm reviewing, and I wonder if there is a simpler, faster, or direct this way. Why were the people of Rhun and Harad allied with Sauron?  Did they join him out of fear, or did Sauron say he would give them something if they joined him?  I know the men of Dunland were angry at Rohan; did Rhun and Harad have something against Gondor? Endpoint of a line knowing slope, start and distance In a Cartesian system, I've got the slope, start point and distance of a line segment.  What's the formula to find the endpoint? Extract all the polygon coordinates from a SpatialPolygonsDataframe? I want to do something relatively simply but it seems to be very difficult to do, though I am very new to using R for spatial data so apologies if I've missed something obvious.  I have a list containing 161 shapefiles of bird distributions in the world, they are each in the format of a SpatialPolygonsDataFrame. I also have world climate data in a raster stack format for 8 variables. Both sets of files are in the same projection (lat and long WGS84). I want to create new columns for the climate data with 1's where the species polygon overlaps with the climate data and 0 where it doesn't. I tried various functions to do this, quite a few initial options didn't work, the best option appeared to be:  pnt.in.poly(XY coordinates of climate data points, XY coordinates of species polygon)   I changed my raster of climate data into points to get the XY coordinates. I unified the polygons for each species shapefile and then used:  species@polygons[[1]]@Polygons[[1]]@cords   to get the coordinates for my species polygons as a matrix. However, I discovered that:  species@polygons[[1]]@Polygons[[1]]@coords    wasn't actually getting all the coordinates of the polygons only some of them.  I tried using fortify from the ggplot package, and it gives me a dataframe with coordinates but some of them are for holes in the polygons. I ran that with the pnt.in.poly function excluding the holes but it took an hour to run and when I looked at the output maps after it matched for some of the range but not all of it- there were holes in the distribution where there shouldn't be holes.   I also tried this method that I found somewhere else:  lonlat &lt;- lapply(slot(species, "polygons"), function(x) lapply(slot(x,"Polygons"), function(y) slot(y, "coords")))    which gives me a list with 436 items- but I'm still not sure how to get the coordinates into a matrix form that will work in pnt.in.poly.  I'm sure this should be easier to do! Does anyone know a better way? How to make a Snap application (ksnip) appear in "open with other application" context menu? For editing screengrabs, I prefer to use , since  was no longer installable without hassles on Ubuntu 18.04 and 20.04 However ksnip is available as a Snap App on my 20.04 ○ → snap list | grep ksnip ksnip                    1.8.0                       265    latest/stable    dporobic                 Unfortunately I have to start ksnip from the command line, then use the File-Open Dialog to pick a screengrab/PNG, then edit it in ksnip. This is should be easier. What I want is to use Nautilus File manager, then select the &quot;Open with other Application&quot; context menu item to select ksnip, and the have ksnip open the file I picked with nautilus. Nautilus Context Menu, selecting a PNG:  &quot;Select Application&quot; Dialog:  How can I achieve this? There is a &quot;View all Applications&quot; Button, but after clicking, ksnip does NOT appear in this list of apps. &quot;Find new applications&quot; does not work either. Maybe this is a duplicate, but I think we did not have the combination yet (Hack the dialog and Snap App)  (Note to self: maybe Shutter is usable again. Development had stalled for a while, or it needed a lot of deprecated versions of gnome libs as dependencies) . Before proposing reviewers, should I notify them? Some journals require the author to propose potential reviewers. Should I just propose reviewers and let the editor contact them? Or should I first contact the potential reviewers myself and ask if they agree? If $\omega \in \Omega^q(M)$, and $(\omega|_{U})_p = 0$, is $\omega_p = 0$? If I have a manifold $M$ and $\omega \in \Omega^q(M)$, considered an open subset $U$ of $M$, and choose a point $p \in M$, is it true that $(\omega|_{U})_p=0 \rightarrow \omega_p=0$? With $\omega|_{U}$ I mean the pull-back of $\omega$ by the embedding $F:U\to M$. The converse is obviously true, but this implication? Is there a way to view the site without having to look at reputation information? I do not want to track my rep information or see anyone else's.  I think that'll let me focus more on the questions themselves.  Is anyone else interested in this feature? I don't see anything on Stack Overflow itself, but are there any add-ins or  scripts that do this? How can I typeset this accented, dotless i? See the rough sketch above. I am able to typeset the accented i shown in the middle (for which I used the \v macro) and, obviously, the plain and simple i shown on the left also. However, I can't figure out how to typeset the one shown on the right. How can I do that? How to merge two arrays in JavaScript and de-duplicate items I want to open a file for reading, the C++ way. I need to be able to do it for:   text files, which would involve some sort of read line function. binary files, which would provide a way to read raw data into a char* buffer. In addition to the .tex and .dvi or .pdf files, TeX/LaTeX/ConTeXt produces and uses lots of other files. What do they do? Which ones are used to create the document and which ones are automatically created by the compiler. What files can I safely delete? JUnit Testing Exceptions Finding $\int_0^\infty \frac{\cos(ax)-\cos(bx)}{x}dx$ I am practicing calculus section of GRE Math Subject test, and I can't figure out a way to do the following integral: $$\int_0^\infty \frac{\cos (ax) - \cos (bx)}{x}dx.$$  I absolutely have no clue how to do this. Can someone show me the solution explicitly? Thank you. using underscore's “difference” method on arrays of objects Rotate Geographic map Why do the Localization of a Ring This question may be a bit vague, but neverthless, i would like to see an answer. Wikipedia tells me that:   In abstract algebra, localization is a systematic method of adding multiplicative inverses to a ring.   It is clear that for integral domains, we have the Field of Fractions, and we work on it. It's obvious that a Field has multiplicative inverses. Now if we consider any arbitrary ring $R$, by the definition of localization, it means that we are adding multiplicative inverses to $R$ thereby wanting $R$ to be a division ring or a field. My question, why is it so important to look at this concept of Localization. Or how would the theory look like if we never had the concept of Localization. Is $\operatorname{lcm}(a,\gcd(b,c))=\gcd(\operatorname{lcm}(a,b),\operatorname{lcm}(a,c))$ Central limit theorem and the law of large numbers I have a very beginner's question regarding the Central Limit Theorem (CLT):  I am aware that the CLT states that a mean of i.i.d. random variables is approximately normal distributed (for $n \to \infty$, where $n$ is the index of the summands) or the standardized random variable would have a standard normal distribution.  Now the Law of Large Number states roughly speaking that the mean of i.i.d random variables converges (in probability or almost surely) to their expected value.  What I don't understand is: If, as the CLT states, the mean is approximately normally distributed, how then can it also converge to the expected value at the same time?   Convergence would imply for me that with time the probability that the mean takes a value which is not the expected value is almost zero, hence the distribution would not really be a normal but almost zero everywhere except at the expected value.  Any explanation is welcome. This is a somewhat bizarre question. My objectives are to understand the language design decision and to identify the possibilities of reflection in C++.   Why C++ language committee did not go towards implementing reflection in the language? Is reflection too difficult in a language that does not run on a virtual machine (like java)? If one were to implement reflection for C++, what will be the challenges?   I guess the uses of reflection are well-known: editors can be more easily written, program code will be smaller, mocks can be generated for unit tests and so on. But it would be great if you could comment on uses of reflection too.