I rarely use '' ( or ) and use '' () all the time as part of my signature on emails and so forth.  I realize the Swung Dash (⁓) and Tilde (~) are very similar, I just find the longer one more aesthetically pleasing for signatures and stuff like that.  Is there a way I can remap ^ to ⁓ ? Or when remapping keys is it all or nothing?  Any advice is welcomed!   ⁓ Ev   PS ⁓ See, there it is.  Twice.  In the signature and PS!
I cannot make xmodmap run on login in Ubuntu 13.04. I have searched around, including in askubuntu and all answers I found do not work.  I have a file named .Xmodmap in my home folder which contains the desired mappings. If I run it manually it works fine, so there is no error there. In order to make it run on startup, I have tried:     Using various .xinitrc containing one of the following commands:      xmodmap .Xmodmap xmodmap ~/.Xmodmap   /usr/bin/xmodmap /home/NAME/.Xmodmap if [ -s ~/.Xmodmap ]; then xmodmap ~/.Xmodmap fi  Using .Xresources instead of .xinitrc with the same variations. Setting it as a startup application.   None of the above works in Ubuntu 13.04 (64-bit). I also saw a few ideas about globally changing the keyboard mappings, but most of them were not applicable in Ubuntu 13.04 (i.e. the corresponding files did not exist where specified) and I prefer not to touch the global settings anyway.
I have a table:  table votes (     id,     user,     email,     address,     primary key(id), );   Now I want to make the columns user, email, address unique (together).  How do I do this in MySql?  Of course the example is just... an example. So please don't worry about the semantics. Alien invasion movie, giant robot aliens with long legs capturing people So I saw this movie about 10 years ago, when I was about 5 years old. Since I was really young, my memory of it isn't really that great.   I think it may have been an alien invasion movie, but the only scene I remember is that there were these giant robot-alien things:   I think they had several long legs. They had a big glass dome on top of them They would grab civilians and drop them in their glass dome.   That's all I remember. If you could please help me out, that would be great.   Again, I was about 5 years old when I watched it, so my memory of it isn't that great, but I hope you know what I'm talking about. Thanks so much :) How to recover deleted files? Delta-like symbol in LaTeX I'd like to write a majuscule delta-like symbol in LaTeX but I can't find it's syntax anywhere. You can see the symbol on equation (12) of the following paper:  "". I want to run a ppp connection when my USB modem is connected, so I use this udev rule:  ACTION=="add", SUBSYSTEM=="tty", ATTRS{idVendor}=="16d8",\     RUN+="/usr/local/bin/newPPP.sh $env{DEVNAME}"  (My modem appears in /dev as ttyACM0)  newPPP.sh:  #!/bin/bash /usr/bin/pon prov $1 &gt;/dev/null 2&gt;&amp;1 &amp;   Problem:  The udev event fires, and newPPP.sh is running, but newPPP.sh process is killed after ~4-5s. ppp does not have time to connect (its timeout is 10s for dial up).  How can I run a long time process, that will not be killed?  I tried using nohup, but it didn't work either.  System: Arch Linux  Update  I found a solution , thanks to .  I use at now to run my job detached from udev process.  But the one question remains unanswered: Why do nohup and &amp; not work? Why isn't reflexivity redundant in the definition of equivalence relation? An equivalence relation is defined by three properties: reflexivity, symmetry and transitivity.  Doesn't symmetry and transitivity implies reflexivity? Consider the following argument.  For any $a$ and $b$, $a R b$ implies $b R a$ by symmetry. Using transitivity, we have $a R a$.  Source: Exercise 8.46, P195 of Mathematical Proofs, 2nd (not 3rd) ed. by Chartrand et al Where did Magister Illyrio Mopatis get the dragon eggs from? How do I get:  $$\cos{\theta} \lt \frac{\sin{\theta}}{\theta} \lt 1$$ I'd love your help with finding the sign of the following integral: $\int_{0}^{2 \pi}\frac{\sin x}{x} dx$,I know that computing it is impossible.  I tried to use integration by parts and maybe to learn about the sign of each part and conclude something but It didn't work for me.  Any suggestions? I read this at least 20 years ago, and I believe it was originally published in the '60s.   The main character is a human, but somehow "inherits godhood" from an alien, whose species is very long lived. IIRC this is one of the old-style god thingies, i.e. "god of thunder" not "omniscient omnipotent omnipresent transcendent being".  The plot somehow revolved around identifying and fighting some enemy which, I believe, was in turn a member of the alien species who acted as the avatar of the opposite god in the alien pantheon.  The only thing I remember for sure is that the enemy was identified as "green green" or "gringrin" (sadly, I read this in translation so I am not sure what the original meant) I have seen this many times, a question is being asked because a previous, duplicate question was asked and answered a few years ago and has no longer relevant answers.  The  is to edit the old question, or add new answers to it, but it is not always happening.  I was wondering, should I still mark it as duplicate and vote to close it? Or just leave it as is? What is the difference between test set and validation set? I found this confusing when I use the neural network toolbox in Matlab. It divided the raw data set into three parts:   training set validation set test set   I notice in many training or learning algorithm, the data is often divided into 2 parts, the training set and the test set.  My questions are:   what is the difference between validation set and test set?  Is the validation set really specific to neural network? Or it is optional. To go further, is there a difference between validation and testing in context of machine learning? After a lot of messing around today I curiously observed that $a^2+b^2$ is only divisible by 3 when both $a$ and $b$ contain factors of 3.  I am trying to prove it without using modular arithmetic (because that would be way too easy), but finding it very difficult to do so.  Is there an easy way to prove this without using modular arithmetic?  I am also interested in a more general statement.  Namely, I want to find the values of $Z$ for which $Z \mid \left( a^2+b^2 \right)$ necessarily implies that $Z \mid \gcd \left( a,b\right)$.  We know that $Z$ cannot be 5, because $3^2+4^2=5^2$.  More generally, if $Z$ is the largest element of a pythagorean triple then the above implication does not hold. Understanding my electrical panel I just purchased .  I'll be installing it in my RV.  Current will be supplied by a 12VDC to 120VAC, 3000W inverter.  I'll be using Single-Pole Type BR breakers.  Here's a picture of the box:    My current understanding is that I must install a grounding bar to the box.  This is my current understanding of how to connect the breaker to the main supply.:    Here is my understanding of how I would wire in new circuits:    Does this look right?  I would really appreciate your help -- I've been beating myself over the head about this. "Print" and "ui.Label" return different strings in console and in the UI in Google Earth Engine I am working on a variable label in Google Earth Engine and noticed that the label as printed in the console is not the same as the label shown on the map. Why is that? Code below:  var aoi = ee.Geometry.Polygon([[[-106.75701284923326, 42.31332966408458],           [-106.75701284923326, 42.003856624775146],           [-106.31755972423326, 42.06913460511273]]]);  var chirpsSelect = ee.ImageCollection("UCSB-CHG/CHIRPS/DAILY")             .filterDate('1985-01-01','2018-01-01')             .filter(ee.Filter.dayOfYear(3,6))             .filterBounds(aoi)  var chirpsStartImage = ee.String(chirpsSelect.first().get('system:index')) var dateStartString = ((((chirpsStartImage.slice(6,8)).cat('/')).cat(chirpsStartImage.slice(4,6))).cat('/')).cat(chirpsStartImage.slice(2,4))   var sortChirpsSelect = chirpsSelect.sort('system:index',false)  var chirpsEndImage = ee.String(sortChirpsSelect.first().get('system:index')) var dateEndString = ((((chirpsEndImage.slice(6,8)).cat('/')).cat(chirpsEndImage.slice(4,6))).cat('/')).cat(chirpsEndImage.slice(2,4)) var dateTitle = ee.String((dateStartString.cat(' to ')).cat(dateEndString))  print(dateTitle)  var dateLabel = ui.Label({   value: dateTitle })  var panel = ui.Panel() panel.add(dateLabel) Map.add(panel) I'm trying to model an , but it's not going so well when it comes to the magazine of the weapon.   Next to the magazine is a mesh. I want to cut holes in the mag with that mesh. But the magazine just goes invisible or connects with the mesh when trying to execute the Boolean Modifier. I have tested to invert the normals and some other stuff, but it isn't working. Is setting a higher nice level for a process an effective way to reduce its impact on system load/CPU time? I have an rsync cron job which is pushing the server load and triggering monitor alerts.  If I set the job to be run with a high nice level, would that effectively reduce the impact it has on system load values? I recently printed a paper that asks to prove the "amazing" claim that for all $a_1,a_2,\dots$  $$\sum_{k=1}^\infty\frac{a_1a_2\cdots a_{k-1}}{(x+a_1)\cdots(x+a_k)}=\frac{1}{x}$$  and thus (probably) that  $$\zeta(3)=\frac{5}{2}\sum_{n=1}^\infty {2n\choose n}^{-1}\frac{(-1)^{n-1}}{n^3}$$  Since the paper gives no information on $a_n$, should it be possible to prove that the relation holds for any "context-reasonable" $a_1$? For example, letting $a_n=1$ gives  $$\sum_{k=1}^\infty\frac{1}{(x+1)^k}=\frac{1}{x}$$  which is true.  The article is This is a pretty simple question, at least it seems like it should be, about sudo permissions in Linux.  There are a lot of times when I just want to append something to /etc/hosts or a similar file but end up not being able to because both &gt; and &gt;&gt; are not allowed, even with root.  Is there someway to make this work without having to su or sudo su into root? What does the dot product of two vectors represent? I know how to calculate the dot product of two vectors alright. However, it is not clear to me what, exactly, does the dot product represent.  The product of two numbers, $2$ and $3$, we say that it is $2$ added to itself $3$ times or something like that.  But when it comes to vectors $\vec{a} \cdot \vec{b}$, I'm not sure what to say. "It is $\vec{a}$ added to itself $\vec{b}$ times" which doesn't make much sense to me.