Target Packages (main/binary-amd64/Packages) is configured multiple times with Ubuntu 16.04
How can I fix apt error "W: Target Packages ... is configured multiple times"?
Problem requiring/including plugin files with plugin_dir_path( __FILE__ ) I am trying to write a WordPress plug-in. In my project I have three PHP files.   My plug-in file Widget for the plug-in Data installation   I need to install data table on plug-in activation. For that sake I wrote code to create table for my plug-in in data installation file. But I am not able to create data table using this file.  My code for include data installation file and widget file in my plug-in file is  define ( 'OTHER_FILES_PATH', plugin_dir_path( __FILE__ ) ); require_once( OTHER_FILES_PATH . '/data_installation.php' ); require_once( OTHER_FILES_PATH . '/plugin_widget.php' );   My problem is when I put my data installation code in my plug-in file it's working fine but when I put it in separate file (data installation) I am unable to create tables for my plug-in.  Please let me know if I am making any mistake. I need to add a specific column if it does not exist. I have something like the following, but it always returns false:  IF EXISTS(SELECT *           FROM   INFORMATION_SCHEMA.COLUMNS           WHERE  TABLE_NAME = 'myTableName'                  AND COLUMN_NAME = 'myColumnName')    How can I check if a column exists in a table of the SQL Server database? Proving a direct product of groups is a group How can I find the value of the sum $\sum_{k=1}^{\infty}\frac{k^n}{k!}$? for example for $n=6$, we have $$\sum_{k=1}^{\infty}\frac{k^6}{k!}=203e.$$ Sharepoint Online/O365 custom fonts How to prove that a continuous function, homotopic to the constant map $f:S^1\to S^1$  (a) has a fixed point and that (b) has a point $x$, such that $f$ maps $x$ to its antipodal point $-x$? How to run a scheduled job every 15 minutes? Using the salesforce GUI it seams impossible to schedule a job every 15 minutes. Or more than once a day. In my student book they separate these two and indicate that sparks need high voltage to occur while arcs need low voltage with normal or low pressure and electric arcs CAN come with heat and bright light. But when I search on the web many people said that arc is just a hotter version of spark. So what is the difference between them? How do favored classes work in Pathfinder? I'm working on creating a half-elf paladin character for a Pathfinder game.  Full disclosure: this is the first time I've tried creating a character; I've used ones other people created before.  In the text, it mentions something about "favored classes" I believe.  What is this? I need to find a bottleneck and need to accurately as possible measure time.  Is the following code snippet the best way to measure the performance?  DateTime startTime = DateTime.Now;  // Some execution process  DateTime endTime = DateTime.Now; TimeSpan totalTimeTaken = endTime.Subtract(startTime); Why does $x$ divided by zero not equal $x$? Why don't my female dwellers give birth to children? I need to end my visa waiver period when leaving States to Canada so that I don't exceed the period of 90 days. But form I-94 is no longer a physical card, it's only online.  How do I know or ensure that it will be terminated and will not continue counting the days once I leave to Canada? velocity of an object after leaving a ramp Fonts larger than \Huge? How can I make text that is larger than the size of the output of {\Huge ...}?   I would like to be able to make text arbitrarily large (even if that is done by some suboptimal scaling routine). I'm currently reading Evans' PDE book. In it he claims that for $f \in C^2_c(\mathbb{R}^n)$ $$\frac{f(x + he_i) - f(x)}{h} \to \frac{\partial}{\partial x_i}f(x)$$ and $$\frac{\frac{\partial}{\partial x_i}f(x + he_j) - \frac{\partial}{\partial x_i}f(x)}{h} \to \frac{\partial^2}{\partial x_jx_i}f(x)$$ uniformly as $h \to 0$.  My question is why must the convergence be uniform?  Thanks in advance. Lagrangian and Hamiltonian EOM with dissipative force I am trying to write the Lagrangian and Hamiltonian for the forced Harmonic oscillator before quantizing it to get to the quantum picture. For EOM $$m\ddot{q}+\beta\dot{q}+kq=f(t),$$ I write the Lagrangian  $$ L=\frac{1}{2}m\dot{q}^{2}-\frac{1}{2}kq^{2}+f(t)q$$ with Rayleigh dissipation function as   $$ D=\frac{1}{2}\beta\dot{q}^{2}$$ to put in Lagrangian EOM $$0 = \frac{\mathrm{d}}{\mathrm{d}t} \left ( \frac {\partial L}{\partial \dot{q}_j} \right ) - \frac {\partial L}{\partial q_j} + \frac {\partial D}{\partial \dot{q}_j}. $$  On Legendre transform of $L$, I get $$H=\frac{1}{2m}{p}^{2}+\frac{1}{2}kq^{2}-f(t)q.$$  How do I include the dissipative term to get the correct EOM from the Hamiltonian's EOM? right (opposite of left) connected to right (legal term)? Show JDBC ResultSet in HTML in JSP page using MVC and DAO pattern In a complete metric space with no isolated points, any countable intersection of open dense sets is uncountable?