Just bought a brand new HP pavillion all in one desk top. I saved the current Ubuntu to a USB stick and Im not sure once im in setup what to do to have it boot up using the USB stick ?
This is the third time I've tried to install Ubuntu Server 14.04.03 64-bit on the same laptop, and each time it caused different problems.  Each time I wrote the same iso image to a USB flash drive by using a different application and OS.   Universal USB Installer (pendrivelinux.com) from Windows WinImage writer from Windows built-in image writer from Linux Mint 17.2    The iso image is the same in all three cases, the USB flash drive is the same, and the laptop is the same. However each time the installation of Ubuntu gave me different installation options. For example, the last time I installed Ubuntu, it didn't show all the packages to choose while installing (Basic Ubuntu server, etc.).
Initializing K-means centers by the means of random subsamples of the dataset? If I have a certain dataset, how smart would it be to initialize cluster centers using means of random samples of that dataset?  For example, suppose I want 5 clusters. I take 5 random samples of say, size=20% of the original dataset. Could I then take the mean of each of these 5 random samples and use those means as my 5 initial cluster centers? I don't know where I read this but I wanted to know what you guys think about the idea.    UPDATE: Please see this thread  for the general discussion about the various initialization methods. When is a review task "completed" or "invalidated"? I've noticed that the number of reviews required to remove a post from a queue varies. For example, to accept/reject a suggested edit, you need two votes of the same kind. If the votes are conflicting, the number goes higher. This seems to be the case for the other queues as well. (Additionally, I think that a mod-review is binding) So, my question is: what are the criteria for a review to be marked as a &quot;completed&quot; review? Also, when is a review considered invalidated (i.e. &quot;no longer reviewable&quot;)? Formerly When is a post removed from a review queue?. In the movie Harry Potter and the Goblet of Fire, there's a scene where the students are preparing for the Yule Ball.   Professor McGonagall is instructing the boys and girls, while Filch is choosing a vinyl record to place in an enormous turntable phonograph with a horn as big as Hagrid.   This has me wondering if the wizarding world, in general, plays vinyl records. Or, if this was just a Muggle artifact that Hogwarts kept as a novelty.   Are there other instances of witches or wizards using or owning phonographs or record players in either the books or movies? If so, what are they? (Examples help to illustrate if this was a one-off or a trend) Refreshing Formula Fields Dynamically (without save) I have an "invoice" custom object which has a couple of summarising formula fields in. I also have a complicated and dynamic visualforce page for building the invoice objects.  As the user is completing this form, different areas are dynamically updated to show "latest" values. This is all fine where I am copying data about or performing bespoke lookups and maths, but - in what is really the simplest case - a formula field, I can find no way to get the value to update, without performing some weird cyclic save + reload of the whole object.  This is inappropriate for a couple of reasons (the object should not be saved until the invoice is complete + accepted) and the other option I have found online is to spoof the value by duplicating my formula field maths into the custom controller and re-executing them there - also unacceptable from a code/logic location/duplication perspective.  Is there anyway to "force" an object/page to recalculate it's formula fields, either through standard or extended controllers? If I recall it correctly, this book has two main characters, both male, one of them big and well muscled. During the novel, they found evidence that the current human race descends from ancient Martian astronauts who traveled to Earth in prehistory, causing the extinction of prehistoric Earth humans, (which explains the Missing Link in human evolution).  Later in the novel the big guy travels back in time (no idea of how or why) to Prehistory.  And near the end of the book, the other main character, during an archaeological field research, finds remains of a human being who lived thousand of years ago, a human with large bones, and who holds an item that could not be made in that era (a gold plaque? A metal rod?)  That's all I can remember. I know it is not from the ABC, Asimov, Bradbury or Clarke.  Thanks in advance. How do I extract text that lies between parentheses (round brackets)? I have a string User name (sales) and I want to extract the text between the brackets, how would I do this?   I suspect sub-string but I can't work out how to read until the closing bracket, the length of text will vary. A curious integral The following integral has been on my mind for a while $$\int_0^\infty \frac{\sin(x)}{e^x-1}\,\mathrm d x \tag{$\dagger$}$$    Let us indicate the integrand as $f(x)=\frac{\sin(x)}{e^x-1}$. The following are a couple of observations.   The integrand can be extended by continuity in $0$ since $$\lim_{x\to 0}f(x)=\lim_{x\to 0}\frac{\frac{\sin(x)}{x}}{\frac{e^x-1}{x}}=1$$ This is the original reason I started playing around with this integral. Mathematica yields the result $$\int_0^\infty \frac{\sin(x)}{e^x-1}\,\mathrm d x=\frac{\pi}{2}\textrm{Coth}(\pi)-\frac 12 \approx 1.076674047$$ which, following numerical evidence, seems correct. Complex analysis may be useful here, since the integrand is a holomorphic function on $\mathbb C$. I tried writing $\sin(z)=\frac{e^{iz}-e^{-iz}}{2i}$, but I was not able to find an appropriate integration contour to solve the problem. The $-1$ in the denominator breaks the simmetry of the expression. This made most of my substitutions useless.   Can this integral be evaluated correctly, preferrably through complex analytic methods? In unix server grep -r option is not working. OS is HP-UX.  If grep -r is not working any alternative way to do recursive search without -r option? Why is my Wi-Fi connection speed much slower than a wired connection? When I plug my laptop via LAN cable and check speed on speedtest.net I have over 32 Mb/sec. When I unplug the cable and connect to the same router I have less than 15 Mb/sec. I tried to change channels already but this didn't help. I'm sitting just near the router.   What can it be? The router is a Dlink 400. If I have the following enum:  public enum ReturnValue{     Success = 0,     FailReason1 = 1,     FailReason2 = 2     //Etc... }   Can I avoid casting when I return, like this:  public static int main(string[] args){     return (int)ReturnValue.Success; }   If not, why isn't an enum value treated as an int by default? Prove that if the positve term series $\sum^{\infty}_{n=1}a_n$ is convergent, also $\sum^{\infty}_{n=1}\sqrt{a_na_{n+1}}$ is convergent.  Prove that if the positive term series $\sum^{\infty}_{n=1}a_n$ and $\sum^{\infty}_{n=1}b_n$ are convergent, also $\sum^{\infty}_{n=1}a_nb_n$ is convergent.  I've tried to solve it using comparison test, but no results. I need to find the cardinality of the set $S$ of all infinite subsets of $\mathbb{Q}$.   It's easy to prove $\operatorname{card} S=\mathfrak c$ if you first prove that the cardinality of the set of all finite subsets of $\mathbb{Q}$ is $\aleph_0$.   But is there some other proof for the statement without using the second one (about finite subsets)? Probably there is =) Recolor Artwork: single swatch to multiple swatches I have an Illustrator document with a lot of objects. All the objects are black, same swatch.  I have a swatch group with a few dozen coloured swatches. I wish to apply these swatches to all the many black objects. It doesn’t have to be in any particular order, but each object should be coloured individually—I don’t just want to change black into some other colour, but to dozens of other colours. What I really want to avoid is having to select each object individually and then applying a different swatch to each.  I’ve never quite managed to get my head properly around the Recolor Artwork feature in Illustrator, and I cannot for the life of me get it to do anything like this. The “New” box in the Recolor Artwork dialogue box appears to accept only one colour.  Is there some way to do this using the Recolor Artwork feature? Or using some other feature that I’m not aware of? Bonus points if there’s a way to control the order in which the colours are applied; e.g., specifying an order and then click on each object in turn to apply each swatch being ‘iterated’ through in that order.  (I would prefer to avoid having to script it, but I will if there’s no other way.) Am trying to Update Leads.  When Lead converted flag is true.  Lead Status is Contacted. I have to update all the contacted leads to Converted.  Am Getting this error on the data loader:     ERROR: cannot reference converted lead   Maybe because converted leads cannot be updated because they are locked out once they are converted?  Is there a workaround to update Lead Status to Converted from Contacted? Is exponential map locally a diffeomorphism w.r.t. base point? Let $M$ be a riemannian manifold and $\exp_p: T_pM \rightarrow M$ the exponential map at $p \in M$.  At each point $p\in M$, $\exp_p$ can be restricted to a neighborhood $V$ of $0\in T_pM$ so that $\exp_p|_V$ is a diffeomorphism. Let $U\subset M$ denote image of $V$ under this map.  Choosing an orthonormal basis $\{E_i\}$ for $T_p M$ and using the isomorphism $E: \mathbb R^n \rightarrow T_pM$, where $E(x^1, \dots, x^n)= x^iE_i$, gives normal coordinates $(U, \phi)$, where  $$ \phi := E^{-1} \circ \exp^{-1}_p: U \rightarrow \mathbb R^n $$  My question is: can we fix some $z\in \mathbb R^n$ (small enough) and take some small neighborhood $\widetilde{U}$ of $p$ so that the function $\widetilde \phi$, defined as $$ \widetilde{\phi}_z (p) := \exp_p ( E(z)) $$ is a diffeomorphism when restricted to  $\widetilde{U}$?  (In the definition of $\widetilde \phi$, the isomorphism $E$ will also vary with $p$.) Tag links in tag excerpts not shown properly If a tag excerpt contains a link to another tag with the [tag:foobar] syntax, this link is not properly shown in every context. For an example see . The link is shown as [tag:school-libraries] but it should be  or at least "school-libraries". If I reboot Ubuntu, then I need to log on each site and into Google Chrome account. What is the reason?  My system is Ubuntu 16.04 and Google Chrome 53.0.2785.101 (64-bit). I would like to cook frozen chicken breasts in a pressure cooker for shredding and making chicken mole.  I do not want to add anything except water, but I'm having a hard time finding specific guidelines on the time to cook frozen meats with no added ingredients or steps.   In my case, I have 3 pounds of frozen chicken breasts to cook.  What are the general rules to follow for frozen meats and, in my case, how long and at what heat should I cook this for? How to obtain a confidence interval for a percentile? I have a bunch of raw data values that are dollar amounts and I want to find a confidence interval for a percentile of that data.  Is there a formula for such a confidence interval? I updated the image in my Gravatar but my old picture still shows up.  Is this a cache issue?  Do I need to log out and then log back in?