Do I need a visa to transit Canada?
Is there a way to find out if I need a transit visa for Canada?
PyQGIS toggle group visibility (and recursively subsub...group visibility) I would like to set visibility of a layer group and all of its children (and grand-children and so on...) using PyQGIS (QGIS 2.14.1).  Assume the groups name is g0 with subgroups g0[1...n] and subsub...groups g0[1...n][1...n][...].  QgsProject.instance().layerTreeRoot().findGroup('g0').setVisible(False)   sets the group and ALL what comes beneath invisible, so far so good:    But vice versa  QgsProject.instance().layerTreeRoot().findGroup('g0').setVisible(True)   sets the group visible and leaves all its children untouched, wich results in nothing visible at all:    QgsProject.instance().layerTreeRoot().findGroup('g0').updateChildVisibility()   only touches the direct children and not recursively all the descendants:    I wonder why manually setting the root groups (g0) visibility does result in recursively setting the visibility of all beneath it at all.  Question: Do I have to implement some recursive function to set the visibility of a group and its whole big family, or is there a more convenient way to accomplish this? Or is here something buggy? I have a Dell Inspiron 1525 laptop and I am planning on purchasing a mac mini, new version , I am tight on money for a while and want to use my current laptop screen as monitor for mac mini, I just want to know if it is at all possible to do, I have windows 7 and ubuntu 11.04 installed in my laptop, and I don't really care if need to wipe them out, or purchasing a monitos is the only option left, also I am planning to use it for coding and stuff, so VNC is probably not a good choice. I just installed Solaris 11.3 on the laptop. This laptop have Broadcom BCM4312 WiFi card.  It looks like the install does not have a driver for this card just like 11.1 version.  I have a Linux installed on this same machine (Gentoo) and this OS does have a driver.  Is it possible to get the driver for this card somewhere? Maybe broadcom.com? Failing that is it possible to use Linux driver inside Solaris?  On the kind of related side - I tried to connect a wire and run Driver Manager, but it does not want to finish. All controls are  still disabled. Any idea?  Thank you for any pointers you can provide. If $\left(1+\sin \phi\right)\cdot \left(1+\cos \phi\right) = \frac{5}{4}\;,$ Then $\left(1-\sin \phi\right)\cdot \left(1-\cos \phi\right)$ If $\displaystyle \left(1+\sin \phi\right)\cdot \left(1+\cos \phi\right) = \frac{5}{4}\;,$ Then $\left(1-\sin \phi\right)\cdot \left(1-\cos \phi\right) = $  $\bf{My\; Try::}$ Given $\displaystyle \left(1+\sin \phi\right)\cdot \left(1+\cos \phi\right) = \frac{5}{4}\Rightarrow 1+\sin \phi\cdot \cos \phi+\sin \phi+\cos \phi = \frac{5}{4}.$  So $\displaystyle \sin \phi+\cos \phi+\sin \phi \cdot \cos \phi = \frac{1}{4}\Rightarrow \left(\sin \phi+\cos \phi\right) = \frac{1}{4}-\sin \phi \cdot \cos \phi.$  Now $\displaystyle \left(1-\sin \phi\right)\cdot \left(1-\cos \phi\right) = 1-\left(\sin \phi+\cos \phi\right)+\sin \phi \cdot \cos \phi =\frac{3}{4}+\sin 2\phi$  Now How can I calculate $\sin 2\phi.$  Help me, Thanks Where do I find the current C or C++ standard documents? For many questions the answer seems to be found in "the standard". However, where do we find that? Preferably online.  Googling can sometimes feel futile, again especially for the C standards, since they are drowned in the flood of discussions on programming forums.  To get this started, since these are the ones I am searching for right now, where are there good online resources for:   C89 C99 C11 C++98 C++03 C++11 C++14 C++17 I'm rewiring a a small part of a wall and I'm confused about a combination of the NEC and the products that I'm able to find.  I'm working on a 20 amp circuit (with 12g wire of course).  I'm connecting 4 receptacles each in their own box, 15 amp receptacles for normalcy.  But the terminals don't seem to accept 12g wire, even on the screws.  My first reaction was to make pigtails 14g pigtails, so that the 14g tap goes directly to the receptacle and is not used to feed the rest of the circuit.  12g in the box, 12g out of the box, and 14g inside the box only.    Is that type of splice allowed, or should I look harder for a 15 amp outlet that can more easily accept 12g wire? Inverse Green's Function identity in derivation of Hedin's equations I'm trying to work through a derivation of Hedin's Equations in Effect of Interaction on One-Electron States by Hedin and Lundqvist (1969) and I've come across an identity that is given without much explanation that I'd like to understand.   We start with an equation of motion with single particle Green's functions G:   $\left[ i\frac{\partial}{\partial t_1} - h(1) - \phi(1) - V_H(1)\right] G(1,2) - i\int v(1^{+},3) \frac{\delta G(1,2)}{\delta \phi(3)} d3 = \delta(1,2)$  where $1=(x_1,t_1)$, $h$ is the one-electron kinetic energy and ion interaction, $\phi$ is a small perturbing field that is set to zero at the end, $V_H$ is the Hartree potential, and $v$ is the Coulomb interaction.  They then insert the identity  $\frac{\delta G(1,2)}{\delta\phi(3)} = -\int G(1,4) \frac{\delta G^{-1}(4,5)}{\delta\phi(3)} G(5,2) d(4,5)$  which is then used to define the self energy  $\Sigma(1,2) =  -i \int v(1^+,3) G(1,4)\frac{\delta G^{-1}(4,2)}{\delta\phi(3)} d(3,4)$.  I know this identity is related to the definition of the inverse Green's function  $ \int G(1,3) G^{-1}(3,2) d(3) = \delta(1,2)$  but I can't figure out how to get from this definition to the identity that is inserted into the equation of motion. Any ideas?  Thank you! Installing Kali on a USB drive - NOT Live USB or Persistence partition Greeting's, to clarify; my question is not creating a Live USB drive or a persistence partition but creating a USB with GRUB bootloader (or other) and Kali which can be used on any machine. This is similar to running other linux OS directly from USB. I am currently running Ubuntu from a pen drive. I installed the OS (Ubuntu) and the bootloader on the pen drive and I can boot off it anywhere. Here is a video explaining the same (video is not by me: )  Since, Kali's installer doesn't give option to select which drive to write the booloader to and directly writes on the HDD (sda1). This means even if I partition and install Kali on a pen drive since the bootloader will be installed on the machines fixed primary drive, the USB drive will fail to boot on a different device.  I have two questions:   Anyone has any idea how to write bootloader to a USB drive and what parameters should be given so that it boots with Kali installed on it. I am using graphic install mode for installing Kali on the USB drive, however there is no option for the install to be encrypted (Full disk encryption or at least /home folder to be encrypted). Does anyone know how can I install Kali with full disk / home folder encryption? Or enable is post install?   Thank You! I need to find node voltage at A. This seems like a trivial question, but when I set up the resistive voltage divider equations they are not equal to each other. Am I doing something wrong?  My equations are \$V_A = V_1(R3/(R3+R1)) = V_2(R3/(R3+R2))\$      I tried solving this problem with an LTSpice simulation and with the superposition method, but my answers did not match (although very close to each other). Is this because the simulator uses an approximation? Can someone compare results? I have created screenShot() method to take the screenshot of the web page. When I used this method in my code first time it will capture the screen and it will save the image with image1 name. When I used the same method screenShot() to capture screens for other pages with the use of this.screenShot(); this will again capture the current web page screen but it stores With the same name image1 in the same folder (which overrides to previously captured screen image1).  Now, I have to take screenshots for the number of web pages &amp; want to store it into the same folder with different names like image1, image2, image3...etc. by using the same method screenShot().  public void screenShot() throws IOException, InterruptedException {     File scr = ((TakesScreenshot)driver).getScreenshotAs(OutputType.FILE);     File dest = new File("filPath/image1.png");     FileUtils.copyFile(scr, dest); }   Any workaround to achieve this scenario? Emoji Characters I'm trying to display Emoji Characters inside my XeLaTeX Document. It seems to work for some glyphs like the numbers and pound sign but not for all. Here is a MWE:  \documentclass{scrartcl}  \usepackage{fontspec}  \setmainfont{Apple Color Emoji} % The emoji Font   \begin{document} \char"0030{}  %Works \char"1F60D{} % Doesent Work should out put SMILEY FACE WITH HEART SHAPED EYES \end{document}   What is the reason for this strange behavior and is there a way to include Emojis in XeLaTeX?  Edit:   It seems the Character is there. It is selectable but not visible. I can copy&amp;paste it. I have just asked a question on   I read from this meta answer  that suggested     From a desktop support perspective there are certainly cases where a   large(r) number of machines will be affected by something, in which   case it's appropriate for SF. There are then others that are isolated   to a single computer, these tend to be the ones I vote to move to SU.   Since my question is clearly not about a single computer and is external to a single computer, I turned to ServerFault. I thought the question is about how to replicate a network admin strategy on my own (home) network. My question is, however, marked as off-topic, and I did see that homenetwork questions are off-topic. But this is not a single computer issue either.  My question is:  Where should such home/small network questions be asked?  What's the real difference between "professional" networks and the smaller networks that I build for my home or lab with a handful computers?  -- UPDATE --  The question asked here is different from the said duplicate question  as that question is about the difference among computer science and programming SE sites. It has nothing to do with network administration, whether it's large or small networks. None of the two SE sites in question (Server Fault and Super User) is even mentioned in the question or in the 2 cited answers.  -- UPDATE2 --  This question is not a duplicate of , which was cited in the OP and was the cause of this question. That question does not cover the overlapping area of small networks, which could both be for work and for home network. Negative energy levels in the diagram for a hydrogen atom How do I disable "Link Preview" in Chrome? In my program I have one array with 25 double values 0.04 When I try to sum these values in a loop I get following results:  0.0 + 0.04 = 0.04 0.04 + 0.04 = 0.08 0.08 + 0.04 = 0.12 0.12 + 0.04 = 0.16 0.16 + 0.04 = 0.2 0.2 + 0.04 = 0.24000000000000002 0.24000000000000002 + 0.04 = 0.28 0.28 + 0.04 = 0.32 0.32 + 0.04 = 0.36 0.36 + 0.04 = 0.39999999999999997 0.39999999999999997 + 0.04 = 0.43999999999999995 0.43999999999999995 + 0.04 = 0.4799999999999999 0.4799999999999999 + 0.04 = 0.5199999999999999 0.5199999999999999 + 0.04 = 0.5599999999999999 0.5599999999999999 + 0.04 = 0.6 0.6 + 0.04 = 0.64 0.64 + 0.04 = 0.68 0.68 + 0.04 = 0.7200000000000001 0.7200000000000001 + 0.04 = 0.7600000000000001 0.7600000000000001 + 0.04 = 0.8000000000000002 0.8000000000000002 + 0.04 = 0.8400000000000002 0.8400000000000002 + 0.04 = 0.8800000000000002 0.8800000000000002 + 0.04 = 0.9200000000000003 0.9200000000000003 + 0.04 = 0.9600000000000003   Why on earth could that happen?! How can I get my graphics card to be recognized in System Info? I am new to Linux/Ubuntu. I installed Ubuntu 11.10 on my Lenovo IdeaPad y510.   System info says    Graphics: unknown.   Driver: unknown,   Experience: Standard.   What should I do to use all my laptop hardware components to work properly with Ubuntu? Screenshot: A Google search spewed forth millions of hits on how to find tables without clustered indexed, the PK normally being the clustered index of a table. However, a table could easily have a natural key as a clustered index, and a non-clustered surrogate index, like an identity column.  How do I find all tables in a DB without a primary key defined? I have 245 tables in this DB: manual inspection is grossly inefficient. I was speaking to an English learner and said, “All you have to do is read a lot.” And they thought that sentence wasn’t grammatically correct because I dropped the word to between is and read.  They thought it should be “All you have to do is to read a lot.” That sounds weird to me.   How do I explain to them the reason you drop the to? Or am I incorrect and it really should have a to? The comment with the Flagged Posts that seems to be new as of today states there are posts with flags awaiting my attention but the counter shows zero and when I go into flagged posts there is nothing waiting for me. I have just updated MiKTeX and have found that pstricks now appears to cause a problem. The error message I'm getting is     ("C:\Program Files\MiKTeX 2.9\tex\generic\pstricks\pstricks.tex"      ! Undefined control sequence.      l.31 \if@check@engine   Not sure what's happening here. If I stop pstricks from being loaded things work ok.  Is there a known problem with the latest pstricks?