I can't seem to figure out how to input a root that isn't square in Ubuntu's default calculator. I know I can input 4^(1 / 3) but I'd prefer to input them in a more.. "natural" way.  (I can't think of a good way to put it.)  Is there a  way to work with non-square roots in the advanced mode of the calculator without using exponents?
I don't know which buttons I have to click or what key combination to type to calculate a cube root.
Can anyone tell me how to interpret the 'residuals vs fitted', 'normal q-q', 'scale-location', and  'residuals vs leverage' plots?  I am fitting a binomial GLM, saving it and then plotting it. How can I solve this integral using the Residue theorem? $$ \int_{-\infty}^\infty \frac{\sin(x)}{x^2 + 4x + 5}dx$$  What I now is you can use residue theorem, and evaluate this integral  $$ \oint \frac{e^{iz}}{z^2 + 4z + 5}dz$$ and through calculating the residues and using the residue theorem I get that the answer for the above integral is $$\pi e^{-1-2i}$$  However after this I am completely lost.  Any guidance will be much appreciated. I would like to know why I can evaluate the integral as an exponential integral as well. Holomorphic function has at most countably zeros What is the most CPU efficient way to ensure that NumLock is on? Situation: I have a script watching over NumLock status, well not really watching, but turning it On every 1 second. The script is running in the background.  Reasoning: I often accidentally turn off NumLock. And I have no indicator of NumLock status on the keyboard.  OS, DE, DM, WM, xmodmap:  :  $ lsb_release -a  No LSB modules are available. Distributor ID: LinuxMint Description:    Linux Mint 18 Sarah Release:    18 Codename:   sarah   :  echo $DESKTOP_SESSION  cinnamon   :  cat /etc/X11/default-display-manager  /usr/sbin/mdm   :  wmctrl -m | head -n 1  Name: Mutter (Muffin)   :  xmodmap -pm  xmodmap:  up to 4 keys per modifier, (keycodes in parentheses):  shift       Shift_L (0x32),  Shift_R (0x3e) lock        Caps_Lock (0x42) control     Control_L (0x25),  Control_R (0x69) mod1        Alt_L (0x40),  Alt_R (0x6c),  Meta_L (0xcd) mod2        Num_Lock (0x4d) mod3       mod4        Super_L (0x85),  Super_R (0x86),  Super_L (0xce),  Hyper_L (0xcf) mod5        ISO_Level3_Shift (0x5c),  Mode_switch (0xcb)   My original Bash script follows:  #!/bin/bash  while true do    numlockx on    sleep 1s  done   As you can see, the script does not care about current status of NumLock. It just keeps turning it on.  Goal: I would like to make the script at least somewhat CPU efficient.  Question: What is the most CPU efficient way to ensure that NumLock is On in Linux (Mint 18)? Recently I installed Ubuntu 12.10 x64 Server Edition on my PC. Unfortunately, I attempted to install a lightweight desktop but due to the fact that I have an old graphics card, the PC does not perform so well. I am thinking of re-installing an Ubuntu version but I do not want to lose the contents in my home folder. Is there any way to do that with a Live CD? If I chose "Replace Windows with Ubuntu", do I lose the other partition too? I am a newbie in linux. I wanted to install ubuntu to my desktop. I currently have two partitions, Windows 8 in installed on one, and i have some important files in another partition. While installing ubuntu, if I chose "Replace Windows 8 with Ubuntu", do I lose the other partition too?   And are there other ways to leave the other partition as it is, and install ubuntu in the partition  where windows was installed. Variable wavelength IR Diode? I was thinking of building a DIY IR Spectroscope but for this, I need to find an IR diode that can do variable wavelengths. So far I have looked at Farnell and Mouser but all the diodes I have looked at seem to be fixed on a wavelength.   Is this possible? or would I need some sort of filters and optical equipment, if so which parts would I need?  Thanks. Cancelling a Schengen Visa via the Italian Consulate I am trying to get an intuitive idea of how the  affects Quantum computation. My understanding is that given a qubit $Q$ in superposition $Q_0 \left| 0 \right&gt; + Q_1 \left| 1 \right&gt;$, NCT states another Qubit $S$ cannot be designed such that $S$ is equivalent to the state of $Q$.   Now the catch is, what does Equivalent mean? It could mean either that:   $S = S_0 \left| 0 \right&gt; + S_1 \left| 1 \right&gt;$ such that $S_0 = Q_0, S_1 = Q_1$. Or it could mean that $S = Q$, meaning that if $S$ is observed to be some value ( for example 0) then $Q$ MUST be that same value, and vice versa.    So it seems that point 2, occurs anyways in entangled systems (particularly cat-states), so I can eliminate that option and conclude that that No Cloning states, given a qubit $Q$, it's impossible to make another qubit $S$ such that:  $S = S_0 \left| 0 \right&gt; + S_1 \left| 1 \right&gt;$ such that $S_0 = Q_0, S_1 = Q_1$.  Is this correct? Understanding dummy (manual or automated) variable creation in GLM If a factor variable (e.g. gender with levels M and F) is used in the glm formula, dummy variable(s) are created, and can be found in the glm model summary along with their associated coefficients (e.g. genderM)  If, instead of relying on R to split up the factor in this way, the factor is encoded in a series of numeric 0/1 variables (e.g. genderM (1 for M, 0 for F), genderF (1 for F, 0 for M) and these variables are then used as numeric variables in the glm formula, would the coefficient result be any different?  Basically the question is: does R use a different coefficient calculation when working with factor variables versus numeric variables?  Follow-up question (possibly answered by the above): besides just the efficiency of letting R create dummy variables, is there any problem with re-coding factors as a series of numeric 0,1 variables and using those in the model instead? Which derivation of drift velocity is correct? In the derivation of drift velocity I have seen two variations and want to know which one's correct.   $s=ut+\frac{at^2}{2}$ Assume that the drift velocity of any electron in any conductor is : $$\vec{v_d}=\frac{\vec{l}}{t}$$ Due to the electric field the acceleration of electrons in any conductor is: $$a=\frac{-e\vec{E}}{m}$$ Now the distance travelled by an electron after a long time (initial thermal velocity = 0) $$l=\frac{at^2}{2}\implies \frac{-e\vec{E}t^2}{2m}$$ the time between the collisions is $\tau$ $\therefore$ $$l=\frac{-e\vec{E}\tau^2}{2m}$$ thus the velocity is $$\vec{v_d}=\frac{-e\vec{E}\tau}{2m}$$ In another proof I saw the author using $v=u+at \implies v_d=\frac{-e\vec{E}\tau}{m}$   My question is which of the the two equations of motion can be used in the proof? Can they be used at all. I've set my Units (in scene properties) to Metric, and the Scene Scale to 0.01 hoping to get the Blender dimensions it mm's. While the (normal) scale is 1 for x,y,z, the standard cube has the dimensions 2x2x2 cm. When I export this to an STL and open it in a slicing program (Netfabb, Slic3r or Cura) they all give the dimensions: 2x2x2 mm. While exporting, the scale is 1.  What am I doing wrong? I hope you can help me.  Thanks! Use a variable reference "inside" another variable I'm sure it is relatively simple, I just don't know how to do it.  #!/usr/bin/ksh set `iostat` myvar=6   I want to something like echo ${$myvar} which i want interpreted as ${$myvar} -> ${6} -> value LaTeX packages: automatic versus manual installation, and related issues I often run into problems in LaTeX with packages. I did a reinstall (MiKTeX) and it seemed to fix some issues with knowing where packages coming from or going. In general, I am not sure what should or does happen when using \usepackage command.  Is it standard that these packages are automatically pulled from the internet? Where do they go (by default)? Is there a better place to put them?  If I am troubleshooting, and if we can say packages are usually installed automatically, when, and should I ever, install packages manually? If so, where would I put them?  For instance, I believe the package easylist is installed on my computer. I was able, with some difficulty, to get into the roaming folder, looked around, and really the only package I saw, was several easylist files, such as .sty, and an associated readme file. I did a windows search for easylist, and only found one, with suffix .tpm and in the Program Files (x86)\MiKTeX 2.9\tpm folder.  My problem currently, is that I am trying to use the todonotes package. It seems to require the xcolor package. But this "can not be found". It asks to choose a place to get it. I think default was "choose random", but I just switched it to internet, and some random mirror site in country (USA). That didn't work, and I'm afraid I've now fiddled with the default settings for getting packages, which will create problems later.  Here are some other threads I have been fishing through:             In lieu of picture, I have this:    miktex-pdftex.exe: No connection could be made because the target machine actively refused it.  miktex-pdftex.exe: Data: connect failed in tcp_connect() {}======================================================================  ! LaTeX Error: File `xcolor.sty' not found.  Type X to quit or &lt;RETURN&gt; to proceed, or enter new name. (Default extension: sty)  Enter file name:    and from clipboard:    MiKTeX Problem Report Message: No connection could be made because the target machine actively refused it.  Data: connect failed in tcp_connect() Source: Libraries\MiKTeX\PackageManager\PackageManager.cpp Line: 2461 MiKTeX: 2.9 OS: Microsoft Windows 7 Home Premium Edition, 64-bit Service Pack 1 (build 7601) Invokers: explorer SystemAdmin: no PowerUser: no Root0: C:\Users\aUserName\AppData\Roaming\MiKTeX\2.9 Root1: C:\Users\aUserName\AppData\Local\MiKTeX\2.9 Root2: C:\ProgramData\MiKTeX\2.9 Root3: C:\Program Files (x86)\MiKTeX 2.9 UserInstall: C:\Users\aUserName\AppData\Roaming\MiKTeX\2.9 UserConfig: C:\Users\aUserName\AppData\Roaming\MiKTeX\2.9 UserData: C:\Users\aUserName\AppData\Local\MiKTeX\2.9 CommonInstall: C:\Program Files (x86)\MiKTeX 2.9 CommonConfig: C:\ProgramData\MiKTeX\2.9 CommonData: C:\ProgramData\MiKTeX\2.9    (from "Package Installation" window below)   The required file        tex\latex\xcolor\xcolor.sty  is missing. It is part of the following package:        xcolor  The package will be installed from:  ftp://... [Change...] The package will be installed for... Which Stack Exchange website for machine learning and computational algorithms? I'm currently working on many machine learning and computational algorithms, such as Singular Value Decomposition, Support Vector Machines, and others.  I'd like to ask questions about these topics, but I don't know which Stack Exchange website to use to post my questions.   Should I use ? Should I use ? Should I use ? Should I use ?   How do I tell?  What criteria do I use? In the beginning of the series, it's mentioned that Muggle-born wizards/witches are identified due to inadvertent spell-casting. However, it seems like later in the book, disarmed wizards/witches are completely helpless.   What is the explanation for why some spells can be cast without a wand and is there an in-universe explanation for why this isn't done? Also, are there spells that can be cast non-verbally (with/without a wand)? Why are local variables not initialized in Java? Was there any reason why the designers of Java felt that local variables should not be given a default value? Seriously, if instance variables can be given a default value, then why can't we do the same for local variables?  And it also leads to problems as explained in :     Well this rule is most frustrating when trying to close a resource in a finally block. If I instantiate the resource inside a try, but try to close it within the finally, I get this error. If I move the instantiation outside the try, I get another error stating that a it must be within a try.      Very frustrating. For some reason, I have a server that if ssh into another server...you don't need to enter the  password.  How is this done? Can someone give me step by step instructions please? Story where the main character learns to perceive time out of order from the aliens I read a story several years ago in which aliens come make first contact with Earth, and a bunch of scientists set to work trying to establish communication with them in various fields. The main character is a linguist and her team is working to try to figure out their written language, which doesn't have any sort of linear structure and can be read starting from any place.  It contains some explanation of quantum physics as an analogy for how they view time.  In the end, it turns out that the aliens don't perceive time in a linear fashion, and sort of see the future on equal terms with the past, etc. The main character learns to see time this way by studying their language, and the story is interspersed with her talking about what her child is going to do / is doing / has done.  I think I read it in a science fiction magazine but I'm not sure about this part. I'm using the following syntax for my code snippets  \begin{minipage}{\textwidth} \begin{lstlisting}[caption=&lt;something&gt;, label=&lt;something&gt;] The REST Endpoint URL     is http://api.flickr.com/services/rest/  To request the flickr.test.echo service,     invoke like this:    http://api.flickr.com/services/rest/       ?method=flickr.test.echo&amp;name=value  By default, REST requests will send a REST response. \end{lstlisting} \end{minipage}   and I would like to have  \begin{code}[&lt;caption&gt;, &lt;label&gt;] ... code ... \end{code}   which would behave exactly the same.   So I tried this thing but it won't compile and I can't spot the problem  \newenvironment{code}[2][]%     {         \minipage{\textwidth}          \lstset{             basicstyle=\ttfamily,             breaklines=true,             captionpos=b,             frame=bottomline,             extendedchars=true         }         \begin{lstlisting}[caption=#1, label=#2]     }     {         \end{lstlisting}         \endminipage     }   Error when running pdflatex  ! Package inputenc Error: Unicode char \u8:�\expandafter not set up for use with LaTeX.  See the inputenc package documentation for explanation. Type  H &lt;return&gt;  for immediate help.