This is a possible duplicate of   When I copy files from C:\...\Downloads\ to C:\...\Desktop\ it happens instantly, but if I copy the same file (1.12 GB) to D: it takes quite some time. Why so?
If a drive doesn't know about partitions and files systems why moving a file from one partition to another takes relatively long time, unlike the instantaneous move on the same partition? Is that file system inefficiency? In this case, NTFS. It seems like the file is being copied and then original is erased, instead of removing the entry about that file in one partition and making it in another?
Recursive bash script to collect information about each file in a directory structure How do I work recursively through a directory tree and execute a specific command on each file, and output the path, filename, extension, filesize and some other specific text to a single file in bash. i am finding nowhere a solution I am running UBUNTU 12.04 and using GNOME desktop, which I installed additionally. Logging into classic GNOME I see the following:     WHAT is this "earth globe" icon coming from?Seems to be named "starter". It is configured to open a website, from my bookmarks. WHY is it not showing the TIME?   Using dconf-editor I had no luck in answering the above questions.  Any idea? Testing for coefficients significance in Lasso logistic regression [A similar question was asked  with no answers] I have fit a logistic regression model with L1 regularization (Lasso logistic regression) and I would like to test the fitted coefficients for significance and get their p-values. I know Wald's tests (for instance) are an option to test the significance of individual coefficients in full regression without regularization, but with Lasso I think further problems arise which do not allow to apply the usual Wald formulas. For instance, the variance estimates neded for the test do not follow the usual expressions. The original Lasso paper:  suggests a bootstrap-based procedure to estimate the coefficients variance, which (again, I think) may be needed for the tests (section 2.5, last paragraph of page 272 and beginning of 273):  One approach is via the bootstrap: either $t$ can be fixed or we may optimize over $t$ for each bootstrap sample. Fixing $t$ is analogous to selecting the best subset (of features) and then using the least squares standard error for that subset  What I understand is: fit a Lasso regression repeatedly to the whole dataset until we find the optimal value for the regularization parameter (this is not part of the bootstrap), and then use only the features selected by the Lasso to fit OLS regressions to subsamples of the data and apply the usual formulas to compute the variances from each of those regressions. (And then what should I do with all those variances of each coefficient to get the final variance estimate of each coefficient?) Furthermore, is it correct to use the usual significance tests (for instance Wald's test which makes use of the estimated betas and variances) with the Lasso estimates of the coefficients and the bootstrap-estimated variances? I am fairly sure it is not, but any help (use a different test, use a more straightforward approach, whaterever...) is more than welcome. According to the answers  I suspect inference and p-values just cannot be obtained. In my case, p-values are an external requirement (although the use of L1 regularization was my choice). Thanks a lot EDIT What if I fit an OLS logistic regression using only the variables selected by a previous run of the Lasso logistic regression? Apparently (see ),  There's no need to run the model again after doing cross-validation (you just get the coefficients from the output of cv.glmnet), and in fact if you fit the new logistic regression model without penalisation then you're defeating the purpose of using lasso  But what if I do this with the sole purpose of being able to compute p-values while keeping the number of variables low? Is it a very dirty approach? :-) Understanding reference counting with Cocoa and Objective-C I'm just beginning to have a look at Objective-C and Cocoa with a view to playing with the iPhone SDK. I'm reasonably comfortable with C's malloc and free concept, but Cocoa's references counting scheme has me rather confused. I'm told it's very elegant once you understand it, but I'm just not over the hump yet.  How do release, retain and autorelease work and what are the conventions about their use?  (Or failing that, what did you read which helped you get it?) Blender 2.78 with Windows 10 lags when interacting with the UI How prove this nice limit $\lim\limits_{n\to\infty}\frac{a_{n}}{n}=\frac{12}{\log{432}}$ Nice problem:  Let $a_{0}=1$ and $$a_{n}=a_{\left\lfloor n/2\right\rfloor}+a_{\left\lfloor n/3 \right\rfloor}+a_{\left\lfloor n/6\right\rfloor}.$$  Show that  $$\lim_{n\to\infty}\dfrac{a_{n}}{n}=\dfrac{12}{\log{432}},$$  where $\lfloor x \rfloor$ is the largest integer not greater than $x$.  It is said this problem was created by Paul Erdős, and I can't find this problem's solution, does anyone have any nice methods? Thank you. Korean characters scrambled [XeLaTeX; Noto Sans Korean]? I was trying to find a font which has obsolete jamo and the right combining behaviour. Yesterday I found out about , which seems to have both of these. However, when I use it in XeTeX, I get some seemingly-arbitrary hanja (or blank spaces) instead of the expected characters.  (I’m guessing the composing behaviour will fix itself when the right characters are selected. And yes, I know that Code2000 is working perfectly in this example, but unfortunately it is the ugliest font in the world. :p)  MWE:  \documentclass{article} \usepackage{fontspec}  % 1. precomposed: U+BB47 % 2. separate jamo: U+1106, U+116E, U+11BA % 3. obsolete [separate jamo]: U+113B, U+119F, U+11EB \newcommand\test[1]{#1 &amp; {\fontspec{#1}{뭇; 뭇; ᄻᆟᇫ}} \\}  \begin{document}  \begin{tabular}{rl} \test{Arial Unicode MS} \test{Batang} \test{Code2000} \test{Gulim} \test{GungSeo} \test{HeadLineA} \test{Nanum Brush Script} \test{Nanum Myeongjo} \test{Nanum Pen Script} \test{Noto Sans Korean} \test{PCMyungjo} \test{PilGi} \test{Adobe Gothic Std} \test{Adobe Myungjo Std} \test{Apple SD Gothic Neo} \test{AppleGothic} \test{AppleMyungjo} \end{tabular}  \end{document} Is every compact subset of $\Bbb{R}$ the support of some Borel measure? I have tried to prove the exercise 2.12 in Rudin's RCA:     12 Show that every compact subset of $\Bbb{R}$ is the support of a Borel measure.   For perfect (i.e. no isolated point) compact $K$ with non-zero Lebesgue measure, we just take the Lebesgue measure. However I struck on the general case.  My attempt is as follows: For every compact $K$, we can find a decreasing sequence of open set $\langle W_n\rangle_n$ s.t. $\bigcap_n W_n =K$ and $m(W_n-K)&lt;1/n$. Find a continuous function $h_n$ s.t.   $h_n(x) = 1$ for $x\in K$ and $h_n(x) = 0$ outside of $V_n$.   (such function exists by Urysohn's lemma.) For continuous function $f$ with compact support define $$\Lambda f = \lim_{n\to\infty}\frac{\int_\Bbb{R} fh_ndm}{\int_\Bbb{R} h_ndm}.$$  I can not certain that the $\Lambda$ is well-defined. But if it is well-defined, then it gives an regular Borel measure (by Riesz representation theorem) $\mu$ s.t. $\mu(K)=1$. I guess that the $\mu$ has a support $K$ but I don't know how to get it. Thanks for any help! Prove that $\sum\limits_{k=0}^m\binom{m}k\binom{n}{r+k}=\binom{m+n}{m+r}$ using combinatoric arguments. Prove that $$\sum\limits_{k=0}^m\binom{m}k\binom{n}{r+k}=\binom{m+n}{m+r}$$ using combinatoric arguments.   I prefer you to answer using an analogy to a combinatoric problem or else I'll have trouble understanding.  I tried:  Let $m$ represent a group of boys and $n$ represent a group of girls. We want to form a committee with the condition that there must be $r$ more girls than boys on the committee. There's two ways of doing this. (I'm having trouble with the right-hand side.)  The left-hand side is one way of doing this. So we split the problem to different cases. One such case is where there are no boys on the committee, and so, there's $\binom{m}0\binom{n}{r+0}$ ways of forming a committee. Next, we can have 1 boy on the committee. There's $\binom{m}1\binom{n}{r+1}$ ways to do this. We repeat this process until we have $\binom{m}k\binom{n}{r+k}$ ways of forming a committee. Summing up the cases will result in the right-hand side. However, as stated before, I don't really know how to explain the right-hand side. Maybe I used the wrong analogy? What happened to the ia32-libs package? The ia32-libs package is no longer present in Ubuntu 12.04 repositories for a 64bit system. Are there any available replacement packages available for download? Eigenvectors of real symmetric matrices are orthogonal Can someone point me to a paper, or show here, why symmetric matrices have orthogonal eigenvectors? In particular, I'd like to see proof that for a symmetric matrix $A$ there exists decomposition $A = Q\Lambda Q^{-1} = Q\Lambda Q^{T}$ where $\Lambda$ is diagonal. Citation colour with Beamer + Hyperref + Natbib I'm using natbib for citation with a custom bibstyle. I'm working on a presentation using LaTeX beamer and for some reason the citation marker doesn't have the colour that is specified to hyperref. The citation marker is black instead of green. I'll give you a MWE:    \documentclass{beamer} \hypersetup{   colorlinks,   citecolor=green,   linkcolor=red }  \usepackage{filecontents} \begin{filecontents}{mybib.bib} @ARTICLE{Bar2011,   author = {F. Foo and F. Bar},   title = {Foo and Bar},   journal = {Journal of Foo},   year = {2011},   volume = {1},   pages = {1--3} } \end{filecontents}  \usepackage[comma,numbers,sort&amp;compress]{natbib} \bibliographystyle{plain}  \begin{document} Dummy referefence to~\cite{Bar2011} \bibliography{mybib} \end{document}   For the purpose of the MWE I have selected the plain bibstyle, however, changing that to something else (including the custom style I want to use) doesn't affect the label colour.    Is there any patch for this problem? Say an airplane flies at Mach 1. The doppler effect causes the front of the sound emitted by the plane to reach infinite frequency:    $f = \left ( \frac {343+0}{343-343} \right ) f_0 = ∞$  If the plane suddenly stopped, and there was an observer in front of the sound waves to receive the sound, what would the bunched up waves sound like to the observer? Would they cancel each other out and cause no sound? I am a bit lost how one has deduced the formula for electric field with electric dipole because of some inconsistency between different sources. The  contains a delta function in the formula, but  gives only the formula without the delta function,  $$\bar{E} = -\nabla \phi = \frac{-p}{4\pi \epsilon_{0} r^{3}} ( \hat{e}_{z}-3\hat{u}_{r}(\hat{u}_{r} \cdot \hat{u}_{z}) ) $$  Is it intentionally left out?  My notes mention that the dipole is with a circular thing $P=Q d$ where $d$ is distance and $Q$ is charge. I have a number of tiff files named:    sw.001.tif sw.002.tif ...   and I want to remove the .tif at the end of each of the files.  How can I use the rename command to do this? How to pronounce "Stannis's"? I know that the &quot;s&quot; becomes &quot;z&quot; when it comes after a voiced sound. And it is pronounced as &quot;s&quot; when it comes after a voiceless sound. I also know rules about possessives but I don't know how natives pronounce a word when it ends in S and &quot;apostrophe S&quot; is added to it. For example: &quot;Stannis's army&quot;. Do you add another syllable to it? Like Stannisiz? or just Stannis and ignore the possessive S? I really have difficulty in pronouncing words that end in S and possessive S is attached to it. Can I bake in a convection microwave? I have microwave oven, but I can't bake cakes and cookies in it. So I need an electric oven, but people are suggesting I buy a convection microwave to do both baking and normal microwaving. Will that work? Or do I really need to get an electric oven to bake? I just updated my iPhone 7 Plus to iOS 13 tonight and noticed that the post menu in the Stack Exchange app became close to unreadable, because the font/text is too large to be properly displayed. Luckily we can still recognize the icons...    (Yes, app development has been frozen for quite a while but the app continues to serve me well.) Is my proof of convergence for $\sum\limits^{\infty}_{n=1} \frac {2^n} {n^n}$ true? I want to prove that $\sum\limits^{\infty}_{n=1} \frac {2^n} {n^n}$ is convergent.  Therefore I want to use that it will be convergent if $\lim\limits_{n \to \infty}|\frac {2^{n+1}} {n^n}| &lt; 1$ is true.  But I am not sure if all of my steps are legal to do in order to do it. Here is what I came up with:  $$\lim_{n \to \infty}|\frac {2^{n+1}} {n^n}| &lt; 1$$ $$\lim_{n \to \infty}|\frac {\sqrt[n]{2^{n}} \sqrt[n]{2}} {\sqrt[n]{n^n}}| &lt; \sqrt[n]1$$ $$\lim_{n \to \infty} \frac {2 \sqrt[n]2} {n} &lt; 1$$ $$0&lt;1$$  $\Rightarrow$ It is true. Symbols instead of numbers as footnote markers How can I make LaTeX use symbols (*, †, ‡, and so on) instead of numbers to mark footnotes?  (The numbers are confusing because I use superscripted numbers for citations.)