Disclaimer. I'm a long-time Windows user and just starting to get my head around the Linux paradigm. While excited by it, I understand that my formulations might be poorly chosen due to ignorance.  I've received , the contents of which included the following line, which I need help interpreting (after a while of googling I've got a pretty good guess but I'd like to make it more reliable).  curl -sL https://blabla | sudo -E bash -   I understand that we first create a web call to the URL blabla and then (here's the pipe magic popping up) execute a command with admin elevated privileges to open a new terminal window instance.  However, when I try to digest the command, I learn that it's equivalent to the following sequence.  curl --silent --location https://blabla sudo -E bash -   Question 1: Is that correctly understood?  Further on, I tried to learn what the switches for the second line are and used the statement as follows.  man bash | sed -n '/-E/,+1p'   However, I can't really see what "-E" is shorthand for (is it --empty or is it -- or maybe --err) and get stuck on the interpretation. Also, I can't figure out what the alone dash character does and I'm not sure how to look it up in the manual using the statement above.  Question 2: How do I look up the verbose syntax for the switches?  Question 3: What is the meaning of the dash character without the switch?
I was wondering what is the purpose of piping the downloaded file by curl into sudo -E bash - in the following shell:   curl -sL https://deb.nodesource.com/setup_5.x | sudo -E bash -
What is the easiest way to resolve apt-get BADSIG GPG errors? I frequently cross this issue, and always have to google for an answer. Does anyone have a permanent fix for BADSIG errors from apt-get?     W: GPG error:    lucid   Release: The following signatures were   invalid: BADSIG 54422A4B98AB5139   Oracle Corporation (VirtualBox archive   signing key) X Windows special programs: do some of these still exist? "This product is good value" vs "This product is of good value" in a sentence 1.This product is good value. 2.This product is of good value.    Are there any difference in meaning between "good value" and "of good value"? Showing that $f_0 (x_1, \ldots, x_m) \mathrm tr A =\displaystyle{ \sum_{i=1}^n} f_0(x_1, \ldots, Ax_i,\ldots, x_m)$ Question:  Consider $f: (-\epsilon, \epsilon) \to \mathbb R^{m^2}$ a differentiable path of matrices $m \times m$ such that $f(0) = I_m$ and the function $g: I \to \mathbb R$ is defined by $$g(t) = \det f(t)$$  Show that $g'(0) = \mathrm{tr} \,a $ (trace of the matrix $a$), where $a = f'(0)$.   Attempt:  First we use that $\det f(t) = \det (f_1(t), \ldots, f_m(t)) $, where $f_i$ is the $i$-th row of the matrix $f(t)$ $m \times m$. Considering the operator $': \mathbb R^m \to \mathbb R^m$, $f(t) \mapsto f'(t)$  With this in mind $$\begin{align}g'(t) = \det'f(t) &amp;= \sum_{i=1}^{m} \det (f_1(t),\ldots,f'_i(t),\ldots, f_m(t)) \\&amp;\underbrace{=}_{(*)}\det(f_1(t), \ldots, f_m(t))\, \mathrm tr f'(t) \end{align}$$  For $t = 0$ we have   $$\begin{align}g'(0) &amp;=\det(e_1, \ldots, e_m) \,\mathrm tr f'(0) \\&amp;= 1 \dot\, \mathrm tr \,a \\&amp; = \mathrm tr \, a\end{align}$$  I'm trying to come up with a proof using the fact that $\det$ is a $m$-linear form.   In order to prove $(*)$ I need the following equality, which according to this  holds.   If $A: V \to V$ is a linear operator and $f_0$ is a alternated $m$-linear form, such that $f_0 (e_1, \ldots, e_m) = 1$ then   $$f_0 (x_1, \ldots, x_m) \mathrm tr A = \sum_{i=1}^m f_0(x_1, \ldots, Ax_i,\ldots, x_m) $$  Could someone give a proof to this? Is the Cantor set made of interval endpoints? We hold an L1 visa (Citizens of India) and are planning a cruise to the Bahamas this summer. Are there any Visa requirements to enter Bahamas. A Putnam Integral $\int_2^4 \frac{\sqrt{\ln(9-x)}\,dx}{\sqrt{\ln(9-x)} + \sqrt{\ln(x+3)}}.$ This is a Putnam Problem that I have been trying to solve (on and off) for two years, but I have failed. I am in Calculus BC. This problem comes from the book "Calculus Eighth Edition by Larson, Hostetler, and Edwards". This problem is at the end of the first section of the chapter 8 exercises. Here's the problem:  Evaluate $$\int_2^4 \frac{\sqrt{\ln(9-x)}\,dx}{\sqrt{\ln(9-x)} + \sqrt{\ln(x+3)}}.$$  Please. Any help is very much appreciated. So are solutions. Thank you!  Edit: I like the solution given, but I was interested to see if there is any other way of doing the problem? I'm excited to see the results. Can I travel to the UK unaccompanied on an accompanied child visa now that I am over 18? Converting FLV to MP4 Using FFMPEG and Preserving the Quality Im trying to use ffmpeg to convert my flv files to mp4 to play them on iOS devices but the converted video has a much worse quality than the original one.  Here is the command i use:  ffmpeg -i input.flv -ar 22050 output.mp4   I would really appreciate if someone could provide me with the best settings for flv to mp4 conversion. The Chinese government has a really specific list of requirements for visa photos:    I had an old unused photo from last time I applied for a visa or passport, and compared it to the requirements (decided not to use it because it was damaged). It seemed to match most of the requirements, except that it seems that they want a photo which isn't square: The required width is less than the required height.  Assuming most drugstores are still providing square passport photos, the question becomes: Should I cut the photo to match the specified width?   What adds to the confusion is if you look at the  the box for the photo is nearly square, not the oblong shape in the requirements. And I have seen other advice that you need to make sure it fully fits the box.  Any advice about what to do here? Can I use an "if" clause without "then"? Markov chains, cellular automata, and raster algebra I need to build a probabilistic cellular automaton for simulating land-use changes and am wondering how to implement this in a GIS. I understand that Markov chains are a way of doing this, and IDRISI has some sort of module for Markov chains, but I have no access to IDRISI.  that, with raster data, this can, in theory, be done with any GIS that can do raster algebra. Presumably this means that it can even be done in ArcGIS, and I think I've figured out how to build cellular automata in ModelBuilder (once I know with certainty how to make iteration work there).  Still, I can find next to no practical advice on this. Once I have two datasets, one showing the land use at a certain point in time (time A) and the other at a later time (time B), I imagine doing the following (correct me if I'm wrong):   If there are (for example) 3 types of land use, then there are 9 possible things that can happen to a cell from time A to time B; thus, reclassify each dataset such that each land use is represented by a different number (for example, 9, 11, and 14 at time A and 3, 4, and 5 at time B); Divide one raster by the other, obtaining a raster with 9 possible cell values. Determine the percentage of cells in the new raster that has each of the 9 values (I forgot, how does one do this in ArcGIS?); those will be the probabilities of each type of change (or lack thereof) in land use.   What I cannot figure out, though, is how to apply these probabilities during the next iteration. Finally, I wonder if there is a way of making an external factor (say, proximity to roads) influence the spatial distribution (not the overall likelihood) of change in my model.  Can anyone recommend where to find information on how to do this in ArcGIS? Does Python have a ternary conditional operator? If Python does not have a ternary conditional operator, is it possible to simulate one using other language constructs? heredoc for Windows batch? No such file or directory? But the file exists! I've downloaded a game (Shank) but the bin file doesn't run. The error that is shown when I try to launch the executable is:  bash: ./shank-linux-120720110-1-bin: No such file or directory I just created a plane and added a wave modifier to it, to simply make it look like something fluid. Now, I have an Object that I want to place on the surface of this fluid plane. But how do I do that?  I thought of adding a driver to my Objects location, but I have no clue how to get the location of a certain vertex in runtime. I have added the png transparent image with the setting and its not showing transparent black background is seen. I have the base color aluminum and i want to add that logo of png on to it. The image is black letter with transparent background why its showing in white letters and black background. May i know where im going wrong any suggestion or help. How do I generate a random int value in a specific range? I have tried the following, but those do not work: Attempt 1: randomNum = minimum + (int)(Math.random() * maximum);  Bug: randomNum can be bigger than maximum. Attempt 2: Random rn = new Random(); int n = maximum - minimum + 1; int i = rn.nextInt() % n; randomNum =  minimum + i;  Bug: randomNum can be smaller than minimum. Show that$\displaystyle\sum_{n=1}^\infty\frac{\sin( nz)}{n}$ diverges if $\mathfrak{Im} \,(z)\neq0$ We have to show that$\displaystyle\sum_{n=1}^\infty\frac{sin( nz)}{n}$ diverges if $Im\,(z)\neq0$  My try:$$\sin (nz) = \mathfrak{Im}(e^{nzi})$$  $$\sum_{n=1}^{\infty} \frac{\sin nz}{n} = \mathfrak{Im} \sum_{n=1}^{\infty} \frac{(e^{zi})^n}{n} = - \mathfrak{Im} \ln\left(1-e^{zi}\right). $$ Then how to proceed? Can you determine a formula for this problem?