How can I typeset this equation (standard model of physics)?
How to strike through obliquely, e.g. to indicate cancellation?
How to prepare files for rsync on a case insensitive filesystem? I am transferring a large number of files on a HFS+ filesystem.  The files are currently on ext2 partitions.  I have conflicts due to case insensitivity of the target partition (HFS+).  I want to identify the files that have duplicates filenames once they are in lower case, and delete them if they are actually duplicates.  I also found that I will have duplicate folder names if I convert everyhing to lower case. Basically these hard drives contain years of unsorted data, and I happen to have this problem with folder names too.   Does this seem reasonable:  find . -type f | while read f; do echo $f:l; done | sort | uniq -d    $f:l is ZSH for convert to lower case.  Now I want to keep only one instance of each file that have duplicates. How to do this efficiently ?  I do not want to find files with duplicate content, unless they have the same lower case filename. I will deal with duplicates later. The documentation for the  function states that you pass it a number, and the positions past the decimal to round. Thus it should do this:  n = 5.59 round(n, 1) # 5.6   But, in actuality, good old floating point weirdness creeps in and you get:  5.5999999999999996   For the purposes of UI, I need to display 5.6. I poked around the Internet and found some  that this is dependent on my implementation of Python. Unfortunately, this occurs on both my Windows dev machine and each Linux server I've tried. .  Short of creating my own round library, is there any way around this? Changing order of features in shapefile I have a shapefile and I want to change the order of the features. Is that possible? I want to sort the features in the shapefile because I'm embedding this shapefile in a mobile app. The app will display a list of features, and although I could do the sorting at load time, I'd prefer to have them sorted. Imagine a standard machine-learning scenario:     You are confronted with a large multivariate dataset and you have a   pretty blurry understanding of it. What you need to do is to make   predictions about some variable based on what you have. As usual, you   clean the data, look at descriptive statistics, run some models,   cross-validate them etc., but after several attempts, going back and   forth and trying multiple models nothing seems to work and your   results are miserable. You can spend hours, days, or weeks on such a   problem...   The question is: when to stop? How do you know that your data actually is hopeless and all the fancy models wouldn't do you any more good than predicting the average outcome for all cases or some other trivial solution?  Of course, this is a forecastability issue, but as far as I know, it is hard to assess forecastability for multivariate data before trying something on it. Or am I wrong?   Disclaimer: this question was inspired by this one  that did not attract much attention. It would be nice to have detailed answer to such question for reference. Why aren't Christoffel symbols tensors? - asked from a fibre bundle perspective Suddenly, to everybody's surprise, the silent Mr.Smith swung around and addressed Barbara.   The dinner was served by a silent Mrs. Keats.   I saw an infuriated Jennifer, who started shouting at me the moment I opened the door.   It seemed Walter didn't pay any attention to a tearful Kitty.   She hasn't got lovely eyelashes like marvellous Monica.   I bet your Mum kept you well clear of horrible Jesse.      The rule I learned at university said that the is used when the adjective a permanent quality of the person in question. E.g. 'I met the wicked Matilda the other day' would suggest that Matilda is inherently wicked.  The indefinite article a/an, on the other hand, would denote the mood or an unusual quality of the person described.  However, recently I've come across a lot of examples where no article is used with names modified by adjectives (see examples 5 and 6 above).   Can anyone explain why there are no articles in sentences 5 and 6? When you click on the Opportunities tab, (assuming you haven't modified standard salesforce layout), you see a "Recent Opportunities" list. At the top of the list, there is a "New" button.     Is there a way to hide the "New" button displayed on this page? I have tried disabling the button on the "Opportunity List View" Search Layout[Setup -> App Setup -> Opportunities -> Search Layouts], but it does not remove the button from this particular view. How do I pick a part that goes into a breadboard when I order it? I have just bought some 555 timers and they are timers for microelectronic circuits...could anyone tell me what I need to search for in order to get larger ones which will fit a breadboard? Thanks Drift velocity in Drude model If $T^n$ is $q$-contractive, $T$ exactly has one fixed point Consider a complete metric space $(X,d)$ and $T\colon X\to X$. Suppose there exists $n\in\mathbb{N}$ such that the n-th power of $T$ is $q$-contractive. Show that then $T$ has exactly one fixed point $\overline{x}\in X$.      The n-th power is defined inductively: $$ T^{n+1}(x):=T(T^{n}(x)), n\in\mathbb{N}. $$ And for a function $T\colon X\to X$, $q$-contractive means  $$ \exists 0\leq q&lt;1~\forall~x,y\in X: d(T(x),T(y))\leq q d(x,y). $$    Now to the proof.  I think I have to show, that $T$ is q-contractive, because then it follows with Banach, that $T$ does have exactly one fixed point. So I have to show, that there exists a $0\leq q&lt;1$ so that for all $x,y\in X$ it is $$ d(T(x),T(y))\leq q\cdot d(x,y). $$ And most likely I have to use the q-contractivity of $T^n$, i.e. that there exists a $0\leq q &lt;1$ so that for all $x,y\in X$ it is $$ d(T^n(x),T^n(y))\leq q\cdot d(x,y). $$  Can you help me? How to insert a figure between two texts? I'd like to create something similar to what is give below: text on either side of a vertically centred image: Seven-sided dice from five-sided dice with finite rolls I have a 5-sided dice, and I want to use it to simulate a 7-sided dice. Is there a way to do this with a finite number of rolls? How to connect Nokia Lumia 730 to Ubuntu 15.04? My Nokia Lumia 730 (WP8.1) is not getting detected on Ubuntu 15.04.  Can anybody tell me how to fix this? Trying to identify a story about breaking out of a predefined path and no one notices I vaguely remember reading a short story many years ago where something happens and the protagonist gets a bit "out of step" with the rest of the world.  Everyone else keeps acting as if he's still doing what he would have been doing before the event, to the point of carrying on one-sided conversations and the like.  I can't remember much of the plot, but the premise stuck with me.  Edit: To try and explain it more clearly, based on the comment I just wrote, I think everyone else was effectively acting like they were robots with a prerecorded program.  If someone would normally wake up, drink coffee, put on pants, then walk out the door to catch a bus, then if the protagonist broke his coffee cup, stole his pants, and jammed the door, the victim would pour coffee into a broken/nonexistent cup, walk out pantsless, but when he got to the jammed door he might suddenly realize something was up (and thus being "out of step" spreads) or he might continue to go through the motions.  In either case, no one else would notice that the victim was pantsless (or that he didn't make it to work)...  How much of this actually came up in the story, I don't remember. What is the difference between Shrink Database and File? DBCC ShrinkDatabase() DBCC ShrinkFile()    Do I need to run both DBCC commands in order to shrink the database? What is the difference between these two above? Why is the network configuration I set in /etc/network/interfaces ignored on Ubuntu 17.10? Routing Applications sound to different sound device? (Windows) Working in an enterprise system. We need to determine if everyone needs to update to 10.6 at the same time for mxd cross-compatibility or can we update from 10.5 as needed. Best practices for catching and re-throwing .NET exceptions Need a proofreading why all the units are satisfied $a^2-2b^2 =\pm1$ for $\mathbf{Z}[\sqrt{2}]$ All the units are satisfied Pell's equation $a^2-2b^2=\pm1$  for $\mathbf{Z}[\sqrt{2}]$, $a,b\in\mathbf{Z}$.  Here is my proof:  Let $a+b\sqrt{2}$ be a unit $\in\mathbf{Z}[\sqrt{2}]$. This implies $$(a+b\sqrt{2})(c+d\sqrt{2})=1, c+d\sqrt{2}\in\mathbf{Z}\sqrt{2}$$ $$\implies \mathrm{norm}((a+b\sqrt{2})(c+d\sqrt{2}))=1$$ $$\implies \mathrm{norm}(a+b\sqrt{2})\cdot \mathrm{norm}(c+d\sqrt{2})=1$$ $$\implies (a+b\sqrt{2})(a-b\sqrt{2})(c+d\sqrt{2})(c-d\sqrt{2})=1$$ $$\implies (a^2-2b^2)(c^2-2d^2)=1$$ $$\implies \left[ a^2-2b^2=1\text{ and } {c}^2-2{d}^2=1\right]\text{ or } \left[ a^2-2{b}^2=-1\text{ and }{c}^2-2{d}^2=-1\right]$$ $$\implies {a}^2-2{b}^2=\pm1$$