I need to be able to use Ubuntu on different computers with my external hard drive, with varying devices. And it needs to be a full (normal..ish) install. (No bootable+overlayfs persistence for me!)  I'll probably be using computers with an i386 architecture, but the 32/64-bit could change.  Or, I'll just hope for the best and just repart my drive and install.
OS: Windows 7. I want install Linux Ubuntu on portable external Hard Drive USB 2.0. I read a variety of methods, but I'm confused by contradictory advices and methods. Actually, installing Ubuntu on anything other than clean PC looks much more complicated than installing Windows. I need to have Ubuntu package + Python 2.7 + C compiler installed. My external hard drive is partially filled, I need to keep all files.   Will Ubuntu run entirely on external hardrive, without writing anythinhg to Windows system folders and to registry?  Can anyone post detailed guide how install Ubuntu on external hard drive?
Validation Error: Value is not valid How do you subtract Dates in Java? Regarding ,  it is not possible to combine complex powers in the usual way:  $$ (x^y)^z = x^{yz} $$  There was mention of multi-valued functions, is there some theory that makes this all work out correctly? I have a trained logistic regression model that I am applying to a testing data set. The dependent variable is binary (boolean). For each sample in the testing data set, I apply the logistic regression model to generates a % probability that the dependent variable will be true. Then I record whether the acutal value was true or false. I'm trying to calculate an $R^2$ or Adjusted $R^2$ figure as in a linear regression model.  This gives me a record for each sample in the testing set like:  prob_value_is_true         acutal_value    .34                          0    .45                          1    .11                          0    .84                          0     ....                        ....             I am wondering how to test the accuracy of the model. My first attempt was to use a contingency table and say "if prob_value_is_true > 0.80, guess that the actual value is true" and then measure the ratio of correct to incorrect classifications. But I don't like that, because it feels more like I'm just evaluating the 0.80 as a boundary, not the accuracy of the model as a whole and at all prob_value_is_true values.  Then I tried to just look at each prob_value_is_true discrete value, as an example, looking at all samples where prob_value_is_true=0.34 and measuring the % of those samples where the acutal value is true (in this case, perfect accuracy would be if the % of samples that was true = 34%). I might create a model accuracy score by summing the difference at each discrete value of prob_value_is_true. But sample sizes are a huge concern here, especially for the extremes (nearing 0% or 100%), such that the averages of the acutal values are not accurate, so using them to measure the model accuracy doesn't seem right.  I even tried creating huge ranges to ensure sufficient sample sizes (0-.25, .25-.50, .50-.75, .75-1.0), but how to measure "goodness" of that % of actual value stumps me. Say all samples where prob_value_is_true is between 0.25 and 0.50 have an average acutal_value of 0.45. Is that good since its in the range? Bad since its not near 37.5% (the center of the range)?  So I'm stuck at what seems like should be an easy question, and hoping someone can point me to a resource or method to calculate an accuracy stastic for a logistic regression model. I am studying statistics and I am wondering when it comes to standard error or a sampling if the calculation changes when there are weights added.   I have a weighted mean:  $$\mu_{w} = \dfrac{\sum_{i=1}^Nw_ix_i}{\sum_{i=1}^Nw_i}$$ and a weighted variance calculated by:  $$s^2_{w}=\dfrac{\sum_{i=1}^Nw_i}{(\sum_{i=1}^Nw_i)^2-\sum_{i=1}^Nw_i^2}\cdot \sum_{i=1}^N(x_i-\mu)^2$$  is the sampling error still calculated as  $$\text{SE}=\sqrt{\dfrac{s^2_{w}}{n}}$$ Why is 'ls' suddenly wrapping items with spaces in single quotes? I just noticed that on one of my machines (running Debian Sid) whenever I type ls any file name with spaces has single quotes surrounding it. I immediately checked my aliases, only to find them intact. wyatt@debian630:~/testdir$ ls 'test 1.txt'  test1.txt wyatt@debian630:~/testdir$ alias alias ls='ls --color=auto' alias wget='wget --content-disposition' wyatt@debian630:~/testdir$   Another test, with files containing single quotes in their names (also answering a request by jimmij): wyatt@debian630:~/testdir$ ls 'test 1.txt'  test1.txt  'thishasasinglequotehere'\''.txt' wyatt@debian630:~/testdir$ touch &quot;'test 1.txt'&quot; wyatt@debian630:~/testdir$ ls ''\''test 1.txt'\'''  test1.txt 'test 1.txt'          'thishasasinglequotehere'\''.txt'   update with new coreutils-8.26 output (which is admittedly much less confusing, but still irritating to have by default). Thanks to Pádraig Brady for this printout: $ ls &quot;'test 1.txt'&quot;   test1.txt 'test 1.txt'    &quot;thishasasinglequotehere'.txt&quot;  $ ls -N 'test 1.txt'  test1.txt test 1.txt    thishasasinglequotehere'.txt  Why is this happening? How do I stop it properly? To be clear, I myself set ls to automatically color output. It just never put quotes around things before. I'm running bash and coreutils 8.25. Any way to fix this without a recompile? EDIT: Appears the coreutils developers  to break with the convention and make this the global default.  UPDATE - October 2017 - Debian Sid has re-enabled the shell escape quoting by default.  And at the bottom of the reply chain to the previous bug report, &quot;the change was intentional and will remain.&quot;  I thought this had already been settled, but apparently it was just reverted so that the &quot;stable&quot; Debian branch could keep its &quot;feature freeze&quot; while getting the other fixes, etc. from the newer version. So that's a shame (in my opinion). UPDATE: April 2019: Just found a  that was caused by this change to ls. When you're confusing developers and generating false bug reports, I think it might be time to re-evaluate your changes. Update: Android toybox ls is now doing something similar to this but with backslashes instead of quotes. Using the -q option makes spaces render as 'question mark characters' (I have not checked what they are, since they're obviously not spaces), so the only fix I have found so far without rooting the device in question is to add this to a script and source it when launching a shell. This function makes ls use columns if in a terminal and otherwise print one-per-line, while tricking ls into printing spaces verbatim because it's running through a pipe. ls() {     # only way I can stop ls from escaping with backslashes     if [ -t 1 ]; then         /system/bin/ls -C $@ |cat     else         /system/bin/ls $@ |cat     fi } What is this heart in the crimson biome? I found this heart while exploring the crimson biome - what is it? How to place an image at the right top of a document? I've been learning LaTeX and this community has been very helpful. Currently, I'm trying to set up corporate letters but as a newbie I'm encountering a  of , so I'm posting them one by one instead of putting it in the comments... maybe this helps others as well.  Anyway, I am trying to implement this  that indicates that I can use vbox to float an image to the right of my header. I almost have this working, but I now try to adjust this to get my logo to stick to the top of the page. So I want to have this at the right top of my document. This is quite difficult! When I place the vbox, it creates unwanted spacing, for some odd reason. So I can not get the logo to be at the right top, even though I 'reset' every possible margin to 0 (in my opinion). Here is my distilled code:  \documentclass[a4paper]{article} \usepackage{graphicx} \graphicspath{{./img/}} \usepackage{color} \usepackage{xcolor} \definecolor{orange}{HTML}{DD4616} \definecolor{white}{HTML}{FFFFFF} \usepackage{fullpage} \usepackage[margin=0cm, paperwidth=215.9mm, paperheight=30mm,top=0cm]{geometry} \parindent=0pt  \begin{document} \fboxsep0pt  \pagecolor{orange}   \fbox{\vbox to 0pt{\hfill\fbox{\includegraphics[height=3cm]{logo}}}}  \end{document}   I've used a full black logo for illustrative purposes. Here you can see this:    The black line is the vbox border. For some reason, it jumps down. The only way to get rid of this that I found out about is this:    Which means that I need to add:  \edef\theprevdepth{\the\prevdepth}\nointerlineskip \vbox to 0pt{...}\prevdepth=\theprevdepth   But there are two problems with this:   I get an error with I try this (Improper \prevdepth.) More importantly, I really want to understand my code at this point, and get to master the basics of positioning elements. This feels overcomplicated and I do not understand it at all.    Is there any easy way to position an image at the right top of a document? Are aerosol cans allowed and safe, in checked luggage? Why don't the White Walkers take the sea route to Westeros event.returnValue is deprecated. Please use the standard event.preventDefault() instead Missing argument 2 for wpdb::prepare() Issue I'm having to update a WP installation for a community organisations from version 2.9.1 to the current 3.9.1.   The installation has a couple of custom built plugins that aren't documented.  I've just performed the WP version update and now I see a warning (Missing argument 2 for wpdb::prepare()) on every page that relates to the following line in the code of one of these custom built plugin:  $rows = $wpdb-&gt;get_results($wpdb-&gt;prepare("SELECT id, name FROM ".$table_name));   From what I've read online, this is due to a change in the coding, that requires 2 values to be sent to wpdb::prepare(), but I've no idea how the line of code given above, needs to be changed.  If someone could help me out, I'd really appreciate it. I know the "textbook" estimate of the standard error of a proportion is $SE=\sqrt{\frac{p(1-p)}{n}}$, but does this hold up when the data are weighted? Secure an Ubuntu OpenSSH server from Brute force attacks but without a firewall or SSH key pair? I use Ubuntu 16.04 and seek to harden my SSH authentication in a special manner.  The current situation:  I have a machine with a minimal Ubuntu server I use mainly to transfer files to via its local OpenSSH server. Now, I don't have a firewall on that machine from a few reasons and I also avoid using a key pair hence I use only a password. One of the only ways I have left to defend from brute force attacks, and the one I most desire at the moment, is using a mechanism that blocks a user for X amount of hours, after Y amount of connection tries.  The desired situation:  I wish to have a standalone mechanism (that is, not as part of a firewall) that blocks a user for X amount of hours, after Y amount of connection tries as a way to defend from brute force attacks.  My Question:  Do you know a utility (and specific configuration) that will let me achieve the desired situation? How can you handle an IN sub-query with LINQ to SQL? Can an LC oscillator be used to generate visible light? The LC oscillator is most commonly used to generate radio waves for practical use and the frequency $\omega$ of the LC oscillator equals that of the electromagnetic wave so produced. So, can they in principle be used to emit visible light?  The frequency of visible light is on the order of a few hundred terahertz, and the frequency of an LC oscillator is   $$\omega = \frac{1}{\sqrt{LC}}$$  I admit, the  product $LC$ does become very small (on the order of $10^{-30}$) when the numbers are plugged in, but making an inductor and a capacitor with small values isn't difficult, is it? What is an observer in quantum mechanics? My question is not about (pseudo) philosophical debate; it concerns mathematical operations and experimental facts.  What is an observer? What are the conditions required to be qualified of observer, both mathematically and experimentally? How can I implement a comprehensive apa-style citation and bibliography I am really new to LaTeX and I need a comprehensive solution for my Thesis  I have this problem since two days and I couldn't find any solution in any other post.  I work with BibDesk on Mac  And I used Packages apacite and natbib  @article{Ha89, Author = {Peter M. Haas}, Date-Added = {2017-02-06 21:15:57 +0000}, Date-Modified = {2017-02-06 21:45:06 +0000}, Journal = {International Organization}, Lastchecked = {03/02/2010 12:54}, Number = {3}, Pages = {377-403}, Publisher = {Peter Haas}, Read = {0}, Title = {Do regimes matter? Epistemic communities and Mediterranean pollution control}, Urldate = { http://www.jstor.org/stable/2706652}, Volume = {43}, Year = {1989}}   this is a stripped version of my document:  \documentclass[11pt, oneside]{article}  \usepackage{lipsum} \usepackage[margin=1in, left=1.5in, includefoot]{geometry}   \usepackage{ragged2e} % REFERENCE PREAMBLE %\usepackage{url} \usepackage{apacite} \usepackage{natbib} %\usepackage{biblatex-apa}                                                   % Bullet preamble \renewcommand{\labelitemi}{$\bullet$} \renewcommand{\labelitemii}{$\diamond$} \renewcommand{\labelitemiii}{$\circ$} % graphics preamble \usepackage{graphicx}   %Allows you to import images \usepackage{float}      %Allows for control of float positions %HEADER AND FOOTER STUFF \usepackage{fancyhdr}  \pagestyle{fancy} \usepackage{graphicx}        \usepackage{amssymb} %Zeilenabstand 1,5 wenn aktiviert  \usepackage{setspace}\makeatletter\newcommand{\MSonehalfspacing}{\setstretch{1.44}\ifcase \@ptsize \relax\setstretch {1.448}\or\setstretch {1.399}\or\setstretch {1.433}\fi}\newcommand{\MSdoublespacing}{\setstretch {1.92}\ifcase \@ptsize \relax\setstretch {1.936}\or\setstretch {1.866}\or\setstretch{1.902}\fi}\makeatother\MSonehalfspacing %Zeilenabstand Code fertig \usepackage[hidelinks]{hyperref}   %allows for clickable reference %                       BEGIN OF DOCUMENT \citeA{source} %                       REFERENCES  \renewcommand{\sectionmark}[1]{\markright{\thesection\ #1}} \fancyhf{} \rhead{\fancyplain{}{Identifying the Regime}} \lhead{\fancyplain{}{List of References}} \cfoot{\fancyplain{}{\thepage}}  \setlength\bibitemsep{1.9\itemsep} \bibliography{/User/Desktop/Thesis/references/mybib.bib}                   \bibliographystyle{apa} \addcontentsline{toc}{section {\numberline{}References}                                                       \end{document}   I would like to have the bibliography entry include a retrieved from    I tried to deactivate hyperref – as suggested in another post – but it didn't work. I also tried to activate and deactivate natbib and apacite as well.   I would really appreciate any help... Find a plane that passes through a point and is perpendicular to 2 planes Find an equation of a plane that passes through $p(1,5,1)$ and is perpendicular to planes $2x+y-2z = 2$ and $x+3z=4$.  I basically need the 2 other points to make the vector and perform the cross product.  Since $ax+by+cz+d=0$ is the form of a plane. Can I obtain the points as $(a,b,c)$ of the 2 planes given? Also, how can I set them up to obtain the points? So I have a generic list, and an oldIndex and a newIndex value.  I want to move the item at oldIndex, to newIndex...as simply as possible.  Any suggestions?  Note  The item should be end up between the items at (newIndex - 1) and newIndex before it was removed.