Looking for a app for ubuntu 14.04  I need a app to download the songs and video from  youtube.com.  Is there any way to get the sign of download on youtube while watching any favourite songs or videoes?  In my friends computer the download option comes on youtube while watching any movie or song on youtube.com,  he was using Windows7. But I am using Ubuntu 14.04 LTS.  By clicking on download, he was able to download that songs from youtube directly?  I need a best app or website in Ubuntu to download the songs from youtube.com
What are instructions on how to download videos from YouTube?    Notice: Terms of Service Violation  Please be aware that by following any of the answers below, you will be violating YouTube's . In particular, from Section 5.B.:     Content is provided to you AS IS. You may access Content for your information and personal use solely as intended through the provided functionality of the Service and as permitted under these Terms of Service. You shall not download any Content unless you see a “download” or similar link displayed by YouTube on the Service for that Content. You shall not copy, reproduce, distribute, transmit, broadcast, display, sell, license, or otherwise exploit any Content for any other purposes without the prior written consent of YouTube or the respective licensors of the Content. YouTube and its licensors reserve all rights not expressly granted in and to the Service and the Content.
Let $R= \mathbb{Q}[x^2 ,x^3 ]$, the set of all polynomials over $\mathbb{Q}$ with no $x$ term. Show that the $\gcd$ of $x^5$ and $x^6$ does not exist What's the difference between anonymous methods (C# 2.0) and lambda expressions (C# 3.0)? Origins of possessive pronouns Is there a word to describe a highly desirable cursed treasure? Create an encrypted ZIP file in Python Using ReplaceAll on SparseArray Most of the time, it should be really easy to determine who is my ally and who is not. The people who try to kill me are most likely my foes, whereas the people who entered the dungeon with me are probably my allies.   But sometimes it’s not that simple. What if one of my party members got replaced by an evil doppelganger, who plans to kill me in the near future? What if one of my allies infiltrated the court of the evil king and I accidentally have to fight her, while she is (unbeknownst to me) under the effect of a  spell? What if a character fell in love with the BBEG and just wants to save him from himself, while the BBEG hates the character and actively tries to murder him?  Most spells and abilities that affect others specify the targets as “creatures” or “willing creatures”. Some explicitly affect allies only. That’s why I want to know, how to determine who’s allied with whom. Do I have to think that someone is my ally for someone to count as my ally? Does someone else have to believe to be my ally in order to count? Do both of us have to agree on being allies? Is there an objective observer who determines who’s allied? Can Person A be the ally of Person B, while Person B is not the ally of Person A?  There are many examples for spells/abilities that care about allies, among others:   the Exalted Champion feature from the  (SCAG, p. 132-133), that grants allies within 30 feet advantage on Wisdom saving throws. the Inspiring Surge feature from the  (SCAG, p. 128), that allows one or two allies within 60 feet to make a melee weapon attack as a reaction.   With features like this, you could accidentally affect someone who’s not actually your ally. You could fail to affect someone who is actually your ally, but you don’t know it (yet). Or you could affect someone who doesn’t want to be affected (because they don’t want to be allied with you). This all depends on the interpretation of the word “ally”. I’m not sure if "ally" is a defined game term (but I don’t think so), or if I have to rely on the dictionary definition. That’s why I want to ask:  How do I determine who’s allied with whom? Is there a clever way to show that  $$|x| - |y| \leq |x-y|$$  I believe I can think of a way to solve this using cases, but the book I'm working out of said that "A very short proof is possible if you write things in the right way" which has motivated me to figure out this quick way, but I've failed thus far and any help would be appreciated XGBoost Loss function Approximation With Taylor Expansion As an example, take the objective function of the XGBoost model on the $t$'th iteration:  $$\mathcal{L}^{(t)}=\sum_{i=1}^n\ell(y_i,\hat{y}_i^{(t-1)}+f_t(\mathbf{x}_i))+\Omega(f_t)$$  where $\ell$ is the loss function, $f_t$ is the $t$'th tree output and $\Omega$ is the regularization. One of the (many) key steps for fast calculation is the approximation:  $$\mathcal{L}^{(t)}\approx \sum_{i=1}^n\ell(y_i,\hat{y}_i^{(t-1)})+g_tf_t(\mathbf{x}_i)+\frac{1}{2}h_if_t^2(\mathbf{x}_i)+\Omega(f_t),$$  where $g_i$ and $h_i$ are the first and second derivatives of the loss function.   What I'm asking for is convincing arguments to demystify why the above approximation works:  1) How does XGBoost with the above approximation compare to XGBoost with the full objective function? What potentially interesting, higher-order behavior is lost in the approximation?  2) It's a bit hard to visualize (and depends on the loss function) but, if the loss function has a large cubic component, then the approximation will likely fail. How is it that this doesn't cause problems for XGBoost? Is there a way to use the covariance matrix to find coefficients for multiple regression? For simple linear regression, the regression coefficient is calculable directly from the variance-covariance matrix $C$, by  $$ C_{d, e}\over C_{e,e} $$ where $d$ is the dependent variable's index, and $e$ is the explanatory variable's index.  If one only has the covariance matrix, is it possible to calculate the coefficients for a model with multiple explanatory variables?   ETA: For two explanatory variables, it appears that $$\beta_1 = \frac{Cov(y,x_1)var(x_2) - Cov(y,x_2)Cov(x_1,x_2)}{var(x_1)var(x_2) - Cov(x_1,x_2)^2} $$ and analogously for $\beta_2$. I'm not immediately seeing how to extend this to three or more variables. Using k-fold cross-validation for time-series model selection Question: I want to be sure of something, is the use of k-fold cross-validation with time series is straightforward, or does one need to pay special attention before using it?   Background: I'm modeling a time series of 6 year (with semi-markov chain), with a data sample every 5 min. To compare several models, I'm using a 6-fold cross-validation by separating the data in 6 year, so my training sets (to calculate the parameters) have a length of 5 years, and the test sets have a length of 1 year. I'm not taking into account the time order, so my different sets are :   fold 1 : training [1 2 3 4 5], test [6] fold 2 : training [1 2 3 4 6], test [5] fold 3 : training [1 2 3 5 6], test [4] fold 4 : training [1 2 4 5 6], test [3] fold 5 : training [1 3 4 5 6], test [2] fold 6 : training [2 3 4 5 6], test [1].   I'm making the hypothesis that each year are independent from each other. How can I verify that? Is there any reference showing the applicability of k-fold cross-validation with time series. Show that $$\lim_{x \to \infty} \frac{\log(1 + e^x)}{x} = 1$$ How do I prove this? Or how do we get this result? Here $\log$ is the natural logarithm. How could it be that the entropy of gas is not infinite?  If we use the formula $S=k\ln(\Omega)$ we get infinity because there are an infinite number of possible situations (because there are infinite possibilities of position and momentum for each molecule). Make Launchpad Appear on screen with mouse I'm planning to travel to France a few times in the next few months (tourist). Since I need a Schengen visa, I just don't know how to fill out the forms (which only have questions about travel dates of ONE single trip).  How do I report that I am traveling a few times, because if I don't they might only give me a single entry visa (or a visa not valid long enough for my next trips). I can only see that I'm requesting a multiple entry visa, nothing else about how long I need it to be valid.  Do I need to provide proof of hotel/flight reservations and travel insurance for all the trips or would the first one suffice?  How do I approach this issue so that I get a Schengen visa for at least 4.5 months? I am applying in the UK at their London application centre. Why is an orthogonal matrix called orthogonal? Why are there two sets of the Ctrl, Alt, and Shift modifier keys when only one of each is necessary? Can we raise the bar for reputation for late answers to bypass the review queue? I would like to raise the bar for late answers to enter the Late Answers Review Queue to 50 rep, which is the threshold after which users gain the ability to comment. Here are some answers that were posted by users with between 10 to 50 rep (yes, there's a little selection bias to be sure. I suspect most/all of these will be 10k links only by the time you're reading this. Note, all of these are from the last 5 hours.  These are all from Stack Overflow, where I have the most experience, but since Late Answers have a much higher probability to be bad across all stacks, I think this applies generally. Also, I have bolded all the users references to the inability to comment, that were not in their original answers:    (23 rep)     Solution provide by @brandonyang works for me too! (I can't add comments in a response 'cause my low reputation, sorry).   (47 rep)     I tried your answer but it doesn't work in office 365 outlook online. Do you have any suggestions?   (26 rep)     My question is somehow related to the same issue. I am fairly new to C# and have been doing JAVA for quite a long time. When I am coding in C# with .Net framework 4.5.1 using visual studio 2013, I get errors for using certain libraries but I donot know which dll should I reference in my project How do C# people figure that out? For example I wanted to code to draw an ellipse and needed system.Windows.Media and System.Windows.Controls both of which were giving me errors, after googling for quite sometime I got to know that we need to reference PresentationFramework.dll, is this the only way to figure it out?      PS >> I am unable to post this as a comment hence putting it as answer.      Thanks.   (19 rep)     i like  video. It explains the differences between int and Integer and cautions of using Integer   (21 rep)     I have a question, i am actually trying to copy the database from Prod server to test server ( SQL server 2008R2). I am wondering would it copy the users logins, roles and permission as well ?      I know I suggested 50 rep above, but while I was compiling that, I . Perhaps it should be 100 rep, not 50. I am less confident about this, but I thought I'd add it as an addendum for discussion.     The answer posted  is the simplest solution that you are looking for to solve your problem, so take a look ;) sed : Ignore line starting whitespace for match I want to replace the default listening port of httpd to 9090. I can edit the line in httpd.conf file using below  sed -i "/^Listen/c\Listen 9090" /etc/httpd/conf/httpd.conf   But the line   Listen 80   may have white space before it.  How do I ignore this white space to match this line? need to move a domain controller, the first in the forest that holds all the fsmo roles, to another location in a clients building. it will require turning off this dc, call it dc1 for this question. i want to transfer the fsmo roles to a new domain controller call the new one dc2. dc2 is already on the network and has been promoted and made a domain controller, it's dns settings are set and it is also a global catalog (GC). the work is scheduled to be done after hours and i am also planning on moving the dhcp server to dc2.  i am looking for a best practices checklist of things to verify prior to moving fsmo roles and turning dc1 off? as far as i know there are no issues with replication between the dc's. my biggest worry is if i turn on dc1 after moving it and i have hardware issues or boot issues, i would rather move the fsmo roles to a known good one that is a few months old (dc2) vs still using a 5yr old box (dc1), this is part of my migration strategy too.   thanks for the help.