I upgraded to 18.10 from 18.04 using do-release-upgrade. The upgrade was successful, but on rebooting, the system seems to freeze after the Plymouth splash screen and systemd (OK/FAIL) status output, but before the desktop. I don't get a tty login either. This happens with both the 4.18.0-10-generic and 4.15.0-10-generic kernels.  Updates:  Using another PC, I can ssh into the host and then run sudo lightdm to bring up the desktop.  Changing grub options from quiet splash to nomodeset did not fix the problem.  Renaming /etc/X11/xorg.conf to xorg.conf.bak did not fix the problem.
I am trying to boot Ubuntu on my computer.  When I boot Ubuntu, it boots to a black screen.  How can I fix this? Table of Contents:
"Economic" vs. "economical" Find conditional expectation from a 3-dimensional random vector? Equation mode, labelling equations I have the following   \[K^{-1}\left\|\sum\limits_{n=1}^N a_ny_n\right\|    \leq \left\|\sum\limits_{n=1}^N a_nx_n\right\|    \leq K\left\|\sum\limits_{n=1}^N a_ny_n\right\| (\dagger)\]   But the dagger doesn't appear at the right hand end of the page. How can I Get it so that it does appear on the end of the page? the \hfill command doesn't seem to work. Thank you. Graphical interface for generating presentation slides Is there a good graphical interface, similar to PowerPoint or LibreOffice Impress, for generating presentation slides?  When writing documents I prefer to write my text and LaTeX-markups using a text-editor and not using a graphical tool like LyX. However, in the case of presentation slides I want to see the layout and to have the ability to immediately see what you get e.g. by moving a picture with arrow keys.  ADDITION: The background to my question is as follows. I have used PowerPoint for more than a decade and like to use a WYSIWYG tool when making presentation slides. However, I can not use PowerPoint on my current computer and I think the output from LibreOffice Impress is inferior. As a long-time user of LaTeX, I have considered using SliTeX or Beamer but unfortunately I do not like the way of working. The end result is of course superior, but I found it very time-consuming and tiresome to e.g. adjust the position and size of pictures. Is $2^\sqrt{2}$ irrational? Is it transcendental? Is there a term for words that when reversed, form other words? I'm aware of what a palindrome is. What do you call words that, when reversed, form other words, such as ton (not) and part (trap)? Why can't the indefinite integral $\int\frac{\sin(x)}{x}\mathrm dx$ be found? I came across a list of functions in my calculus textbook whose indefinite integral cannot be found. It was written that the integral $$\int \frac{\sin(x)}{x} dx$$ cannot be evaluated without any explanation as to why.  I did some research over the internet and found out that the definite integral $$\int_{0}^{\infty} \frac{\sin(x)}{x} dx$$ can be evaluated using Laplace transformation and is equal to $\pi /2$. But I still couldn't find answer to my original question. I read somewhere that the integral cannot be expressed using 'elementary functions'. A little help is appreciated, I'm in Calc 1 going advanced than my course but I am sorry if my post shows lack of research. Thank you! The derivative of $x!$ and its continuity is the factorial of fractions and negative numbers defined? If yes, then what is its graph? Also please find its domain.  Our teacher said the factorial of a fraction is the fraction itself. He also said the graph is continuous but could not determine the derivative of $x!$. How do I rename all folders and files to lowercase on Linux? Does anybody know which files I need to save in order to have a simple backup?   Reason for my question is, that my Galaxy Android smartphone lost all calendar data without any interaction. I found tons of apps, tons of sync stuff, but NO simple list of files to save. I do NOT want to save my data remotely on Google.  There must be at least one local file (database?) on my phone containing the synced calendar file (on my server, using ICSSync) Can I run Android apps on Ubuntu? Arguments for/against same birthday for siblings? My son is born on October 1st three years ago. My wife is pregnant again and the calculated delivery date is October 22nd. Both children are boys, 3 years apart. We might end in a situation where the delivery is earlier, for reasons irrelevant to this question.   I believe that around their birthdays is the only time in the whole year that the actual date matters. It really does boil down to practical considerations around patience (gifts) and planning. I think that if there is, say, a week or more between the birthdays then it's easy to separate but if the difference is only a very few days then it gets complicated, and that's the situation I'd like to avoid.  I know from friends that having the same birthday makes events easier to plan, from the parents' perspective. It would also remove the unhappiness of a small child saying "why does he get presents today and I don't." Being a twin, and married to one, I know that there's nothing problematic in sharing a birthday as long as both get their fair share of attention.    What are practical arguments for, and against, choosing the same birthday for the second child? What considerations apply when the second child's birthday is only a very few days after the elder sibling's? I have the loop tools addon enabled and when I click the circle button with these verts selected, it just disappears. Why is that?  You can see the selected options in the bottom screenshot. It is worth noting that all the verts are flat on the x plane. Locking in X or not does not change the effect.   When I use the to sphere operator it squishes the verts on Z and stretches super wide on Y, not making a cirlce.    EDIT:  here is the blend Automatically building a database of forward and backward citations My goal is to produce a graph showing the linkages (and lack there of) between several fields that share a common subproblem by showing who cites whom.  There are many databases that show citations between papers: , , and Google Scholar.  However none allows me to download even part of their database.  Is there some database I have overlooked?  Has someone written a scrapper for one of these websites?    For reference, the fields I'm considering are Mechanics, Magnetic Resonance Imaging, Signal Processing, Geophysics, and several others. Why should I put a ~ before \ref or \cite? My question is in the title of this post, but extends to other referencing commands like \eqref, \citep, \citet (and the like) as well. Show that the LU decomposition of matrices of the form $\left[\begin{smallmatrix}0& x\\0 & y\end{smallmatrix}\right]$ is not unique How can I show that every matrix of the form $\begin{bmatrix}0&amp; x\\0 &amp; y\end{bmatrix}$ has an $LU$ factorization and that even if $L$ is unit lower triangular there is not a unique factorization?  I am completely stuck. Any ideas would be greatly appreciated "Me and my wife" or "my wife and me" running a bash file states:date: command not found I've installed a version of Ubuntu Server and although I'm fairly still fresh with Ubuntu, I'm trying to create a bash file to run a program in the background. More importantly, I'm trying to get a file nameto display correct and create it before I start running the program (I like my debug stuff).  However, here is my bash script:    #!/bin/bash  PATH="/var/log/servers/Game/"  FILENAME="startup"  EXT=".log"  DATE=$(date +%d-%m-%Y)  NEWFILE=${PATH}${FILENAME}_${DATE}${EXT}   I have verified that the file does exist in the PATH directory. However, the issue is with the date command. When I run the script bash -x game.sh this is what is displays.   + PATH=/var/log/servers/Game/  + FILENAME=startup  + EXT=.log  ++ date +%d-%m-%Y  game.sh: line 5: date: command not found  + DATE=  + NEWFILE=/var/log/servers/Game/startup_.log  + echo /var/log/servers/Game/startup_.log   I don't understand why it would say the command doesn't work, when I can go to the main console and run date and get a valid response.  Any help is greatly appreciated! Cannot remove any bluetooth device Texstudio + Biber + build folder I used  to export my auxiliary files into a different directory. Basically i just add -aux-directory=build in Options -&gt; Configure -&gt; Commands and added the build folder into Options -&gt; Configure -&gt; Build -&gt; Build Options -&gt; Additional Search Paths -&gt; Log. This succesfully generates all the auxilliary files in the build folder and it's also possible to generate the pdf. Unfortunately biber has a problem with this setup:  Prozess gestartet: biber.exe &quot;MyFile&quot; INFO - This is Biber 1.7 INFO - Logfile is 'MyFile.blg' ERROR - Cannot find control file 'MyFile.bcf'! - did you pass the &quot;backend=biber&quot; option to BibLaTeX? INFO - ERRORS: 1  I guess i have to specify the correct path for biber somewhere in Texstudio. Does anyone know where i have to update the path?  someone had similar problems. Also i'm not sure if the solution of   applies to my situation.