I have 320GB HDD messed with Ububtu 10.04 and Windows Developers preview. I formated Windows partition and deleted the Linux boot folder from the disk, I thought it may help me to install newer version of Linux because my Windows installation was messed up with a problem and I can't install Windows on Linux .  Now I get a grub rescue terminal and after searching a lot I got someway out but there was another a problem when I insert the windows 7 disc. It does not give anything just a paused Starting Windows screen.  I tried the Ubuntu Live CD but same problem occurred so I starting to mess with GRUB rescue terminal when I ran the commands:  set root=(hd0,12) set prefix=(hd0,12)/boot/grub insmod /boot/grub/linux.mod   I got the message file not found  How would I fix this problem?
I installed Windows 7, which ate Ubuntu's boot file. When starting up the computer, it now goes straight to Windows, without giving me the option of booting Ubuntu.   How can I get Ubuntu back?
possible to access custom labels dynamically? Since the version of the word "that" might matter to the correct answer, I'll provide the actual title in question:  Title:  Existing Solutions that Didn't Work  If someone could explain the why of the answer, I would be appreciative.  EDIT:  It has been suggested that this is a duplicate, and that may be, in a sense.  However, the after reading the suggested prior question, I'm no closer to my answer.  I think it may have to do with my use of the word "that."  Perhaps it is incorrect?  Using these definitions of the word "that:" I'm having trouble figuring out which definition of that matches my title.  Am I even using it correctly?  Perhaps I should use which instead:  Possible Title:  Existing Solutions which Didn't Work  If my original usage is incorrect, and I should use which, then the answer is simple since which is always a pronoun or adjective, and those are both capitalized in a title.  However, I'm having difficulty understanding which part of speech that is in my original title. Why was the DeLorean in Back To The Future not always covered in ice after time travel, and why didn't it fly in 1885? Reproject GeoJSON from EPSG:3857 to EPSG:4326 I want to know if I can pass an argument with an alias command.  for example:  alias d="dmesg|grep -iw usb|tail -5"    Now d will print the last 5 lines. If I want to use d to print a different number of lines, I have to make change in the alias command declaration of d again.  Is there any way I can modify the declaration of an alias so that I don't have to retype the declaration to change the number of lines. Like incorporating passing the number of lines as an argument while declaring alias for d? Or is there some other method to solve this? What is the word for the emotion I feel when I see someone being humiliated? When I see someone else being embarrassed / humiliated, for example a singer forgetting their words in a concert, I would say something like "I feel embarrassed for them". But is there a better word to describe this feeling?  I would say it's a mix of:   Empathetic discomfort for someone else's humiliation Tension; hope that spectators will be forgiving Frustration that I cannot help them   Other scenarios I would feel the same emotion:   Seeing someone make a presentation, the slides are all out of order, and their face gets red with embarrassment while there's a tense silence in the room. Seeing someone make an embarrassing social blunder in front of unforgiving people. Seeing a speaker who keeps making a distracting and annoying gesture, and they don't realize that the whole audience is annoyed. Seeing someone be taken advantage of, like seeing someone naively and happily accept a terrible offer on a car. Seeing a person of strong image (for example the CEO of your company) do something like accidentally leave their webcam on after a conference call, and employees see him/her let out a big burp and pick their nose or something.   In these cases it's important that the audience is not forgiving, even if they don't confront the person about it. The person may or may not know they are being humiliated.  "Pity" as proposed in an answer seems very close, but I think it lacks a few components. I think "pity" has a chronic connotation - that you are referring to the general state of things rather than a specific event.  I think "pity" also depends on the subject suffering, but in my example they are often oblivious.  It could very well be that there is no word for this at all.  NOTE: Some people do not feel the same way I do in this scenario, so you may not think this question makes any sense. 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. Degree of minimum polynomial at most $n$ without Cayley-Hamilton? Significance of starting the Fibonacci sequence with 0, 1.... DISCLAIMER: I do not deal with in-depth mathematics on a daily basis as some of you may, so please pardon my ignorance or lack of coherence on this topic.  QUESTION: What is the significance of starting the Fibonacci sequence with $0,1$ ?  For instance, if I picked any two random integers, say 2 and 7, to start a sequence would I actually be creating some multiple or derivation of the Fibonacci sequence?  Is there a general mathematical explanation for the relationship between any sequence represented by $a[0] = x, a[1] = y, a[n] = a[n-1] + a[n-2]$ and the Fibonacci sequence?  Or, back to my example sequence, is there a general mathematical relationship between:  $2,7,9,16,25,41,66,107,173,280...$  and  $0,1,1,2,3,5,8,13,21,34...$  Perhaps the Golden Ratio explains it somehow?  Any help would be appreciated. Suppose $f$ and $g$ are entire functions, and $|f(z)| \leq |g(z)|$ for all $z \in \mathbb{C}$, Prove that $f(z)=cg(z)$. Suppose $f$ and $g$ are entire functions, and $|f(z)| \leq |g(z)|$ for all $z \in \mathbb{C}$, Prove that $f(z)=cg(z)$.   My try :  I consider $h(z)=\frac{f(z)}{g(z)}$. If I prove that $h(z)$ is entire, using the fact that $|h(z)|\leq 1$, the result follows immediately from Liouville's theorem.  To prove that $h(z)$ is entire, I have to prove that $h(z)$ has removable singularities at possible zeros of $g(z)$.  Suppose $g(z_0)=0 \Rightarrow |g(z_0)|=0 \Rightarrow |f(z_0)|=0$, BUT what if $z_0$ be a root of of order $k$ of $g(z)$ (i.e. $f^{(n)}(z_0) = 0 $ for all $ 0 \leq n \leq k-1$) and be a zero of order $m$ of $f(z)$ and $k&gt;m$ ?  And if that's not the case, how to rigorously show that $z_0$ is a removable singularity ?  Thank you all in advance. Pokemon Egg Disappearing So my Pokemon eggs are reaching "maturity" then they just disappear. I don't get a new Pokemon. The egg just disappears. I had this happen with a 2k and a 5k now. Is this happening to anyone else? Is there a difference in meaning among 'should', 'happens to', or 'should happen to'? What is the probability that all three tosses result in the same outcome? A coin is tossed three times: The probability of zero heads is 1/8 and the probability of zero tails is 1/8.  And my question is: What is the probability that all three tosses result in the same outcome?   So, if P(zero heads)= 1/8 , then that should be the same of p(all tails)?  If so, we could use the Addition Rule which is $P(A \cup B) = P(A) + P(B)$  where A and B are disjoint events, i.e. $A \cap B = \emptyset$, A is the event of tossing all heads and B is the event of tossing all tails.  I'm not sure how to continue after that... would the complement be used? Installing Ubuntu 13.04 on a MSATA SSD I am trying to install Ubuntu 13.04 on my 24Gb MSATA SSD. In my laptop, I've also got a 500Gb SATA HDD. I realize that in order for this to work I need to put my /home directory on the 500Gb HDD.   I've tried installing it by creating a ext4 partition on the SSD and a 8Gb swap partition on my HDD. This resulted in an error saying something similar to Cannot install bootloader, please select an other location for the bootloader.   Now before I waste any more time trying to get it to work I'm going to ask a bunch of questions:   Where should I put the swap partition? How big should I make the swap partition? (I've got 12Gb RAM) My 500Gb HDD is currently in Raid mode. Should I change that (to AHCI or IDE)? Where should I put the bootloader if the error message occurs again? How do I make the home directory point to the HDD instead of the SSD? Can I configure Ubuntu to install software/packages on the HDD instead of the SSD? Some questions and answers are marked Community Wiki and are owned by a community wiki user:  (In fact, this very question is one of them)  Why have Community Wiki posts? How do Community Wiki posts work? How does a post become a Community Wiki post? How can the Community Wiki status be removed from a post? How can I find Community Wiki posts? "It was my op" what does it mean? I heard this in  movie. It was my op. What does it mean? Googling gave me : 'Original Poster'. But that doesn't seem very meaningful. How do I suppress the whitespace above an equation block at the page top? How do I suppress the whitespace above the equation block at the page top ? It is added to the top margin, and I don't want that to happen. I know that \abovedisplayshortskip controls this for the whole document, but how can I change this for this particular equation block and NOT for any others ? Negative vspace doesn't work.  \documentclass[pdftex,12pt,a4paper,english,dutch,leqno]{article} \usepackage[top=1cm,right=1cm,bottom=1cm,left=1.5cm,noheadfoot]{geometry}         \usepackage{babel} \usepackage{amsmath} \usepackage{amssymb} \usepackage{empheq}  \begin{document}  \abovedisplayskip=6pt \abovedisplayshortskip=3pt % This should NOT be changed \belowdisplayskip=6pt \belowdisplayshortskip=3pt  \begin{equation*} \left.\begin{array}{r} a_{31}'=a_{11}\cdot a_{31}-a_{31}\cdot a_{11}=0\\ a_{32}'=a_{11}\cdot a_{32}-a_{31}\cdot a_{12}\\ a_{33}'=a_{11}\cdot a_{33}-a_{31}\cdot a_{13}\\ a_{34}'=a_{11}\cdot a_{34}-a_{31}\cdot a_{14}\\ b_{3}'=a_{11}\cdot b_{3}-a_{31}\cdot b_{1} \end{array}\!\!\right\} \Longrightarrow\; \begin{matrix*}[l] \text{Pseudo-code :}\\ a_{11}\cdot b_{3}-a_{31}\cdot b_{1}\mapsto b_{3}\text{.}\\ \forall\;i\in\{4,3,2,1\} : a_{11}\cdot a_{3i}-a_{31}\cdot a_{1i}\mapsto a_{3i}\text{.} \end{matrix*} \end{equation*}  \end{document} example:   Does Chocolatey run the native program installer? If I prefer simplicity, should I avoid packages with (Install) in their name? After cruising through a lot of material online, and answers over here, my understanding of contravariant and covariant vectors are, in a finite-dimensional vector space, suppose we have a vector, which is contravariant to its basis. However, using the metric tensor, we can map this vector to a one form in the dual space, which acts as a vector space for this example. This one form, or covactor, varies similarly to the basis in our original vector space. However, the covectors have a different basis, which is the dual basis, and are expanded in terms of those. Here's where my confusion arises : Many diagrams over the internet give a geometric picture of the scenario, by claiming that contravariant components of an 'arrow' are found by drawing parallel lines along the axes, and checking where they intersect. Co-variant components could be found by sketching the perpendicular lines on these axes. So, these materials are treating covariant and contravariant as different representations of the same arrow, while I'm inclined to believe they are completely different. However, if we let go of rigour, in exchange for a 'more' geometric understanding, I think we are allowed to do this. The diagrams are usually of the form :  However, even if we assume that contravariant and covariant are different representations of the same object, this particular diagram still seems wrong to me. Particularly the locations of $x_1,x_2$. In this diagram, they are located on the span of the original basis. Shouldn't covector components be located on the span of the dual basis ? This diagram suggests to me, that co-variant components have the same basis, as the contravariant ones. Shouldn't the diagram look more like this ?  This second diagram seems to fit the concept better according to me. This is because the dual vector must be 'contravariant' with respect to the 'dual basis'. This means, their components must be found out by sketching parallel lines along the span of the dual basis. These lines intersect the original axis at a right angle, which is to be expected, as dual bases are orthogonal to the original bases. Moreover, this second picture can also show in a much better way, how scaling up of the original basis, scales down the 'contravariant components' and the 'dual basis', which in turn scales up the 'covariant' components.This shows that the components of the dual vector are covariant to the original basis. This is something that is not readily visible in the first diagram. So, am I correct in assuming this second 'geometrical' representation is correct ? I know this doesn't make much sense, because as the mathematicians said, that vectors are completely different from one forms, and one forms should be represented using the number of hyperplanes intercepted by our arrow. However, I've seen most course material refer to it in this way, and frankly it is easier to visualize. However, most of this material used the first picture. Can anyone point out my mistakes, if any, and tell me if the first picture is correct, or the second one ? Or in this case 'less-flawed'. Difference between “with”, “at” and “for” with a business title and a company name The prepositions “with”, “at” and “for” are also used to associate a business title with a company's name. It seems that they are interchangeable, with no (significant) difference in meaning. The following examples taken from The New York Times website seem to confirm that:      Until now, said Justin Nielson, a senior analyst for the media   research firm SNL Kagan, “there really hasn't been any direct   competitor . . .      “The consumer is still deleveraging,” said Jason Goldberg, a senior   analyst with Barclays. “It's not a lack of supply; it's a lack of   demand.”      “There’s the party of fear and the party of despair,” Nikos Xydakis, a   political analyst and an editor at Kathimerini daily, said.   Are they really the same as for meaning? If it isn't so, what is the difference between them?