How to Install Xfce Desktop Environment from "xfce-4.6.1-src.tar.bz2"?
How can I install software or packages without Internet (offline)?
How to get the IPV4 address for an interface from /proc Is there a clean, simple way to get an IP address for a network interface from /proc, similar to the way I can get the MAC address for a network interface? Ideally I would just type cat /proc/&lt;foo&gt;/{interface_name} and get the IPv4 address.  I'd rather not run anything other than cat. How can I extract a predetermined range of lines from a text file on Unix? I have a ~23000 line SQL dump containing several databases worth of data. I need to extract a certain section of this file (i.e. the data for a single database) and place it in a new file. I know both the start and end line numbers of the data that I want.  Does anyone know a Unix command (or series of commands) to extract all lines from a file between say line 16224 and 16482 and then redirect them into a new file? My understanding is that GPUs are more efficient for running neural nets, but someone recently suggested to me that GPUs are only needed for the training phase. Once trained, it's actually more efficient to run them on CPUs.  Is this true? Currently using ubuntu 15.10 on azure and installed the gnome and vnc4server latest version on ubuntu. Please find log file below:  Current VNC client screen:    $ cat .vnc/myhost1\:1.log    --cut-- VNCSConnST:  Server default pixel format depth 16 (16bpp) little-endian rgb565 VNCSConnST:  Client pixel format depth 8 (8bpp) colour-map Window manager warning: Invalid WM_TRANSIENT_FOR window 0x20000c specified for    0x20000b (I        nitialization error). Error org.freedesktop.DBus.Error.NameHasNoOwner: Could not get owner of name    'org.gnome.ze        itgeist.Engine': no such name amdxdg-su: no graphical method available for invoking '/usr/bin/amdcccle' as 'root'  $ cat .vnc/xstartup unset SESSION_MANAGER  [ -x /etc/vnc/xstartup ] &amp;&amp; exec /etc/vnc/xstartup [ -r $HOME/.Xresources ] &amp;&amp; xrdb $HOME/.Xresources  vncconfig -iconic &amp;  gnome-panel &amp; gnome-settings-daemon &amp; metacity &amp; nautilus -n &amp; gnome-terminal &amp;   How to get 24bit color with wide screen (Now I getting square screen in vnc client) What, if anything should one do if a user's "about me" profile section contains extremely inflammatory terms (racist, etc.) I don't think anyone wants to be the thought police, and I'm particularly wary of censorship on a part of the site that is a user's personal self-statement, and is a little off the beaten path.  On the other hand, I'm also concerned that we may not want a site where clicking on a user to see their other posts would expose folks to racist or other bigoted terms that almost everyone would agree are inappropriate for civil discourse.    Don't forget the "be nice" rule".  Note that I don't want a "flag user" rule, which I know has been beaten to death already, and further think that swears and semi-inflammatory opinions, etc. should generally just be ignored - I'm only asking about terms that provoke serious emotions around racial, religious, ethnic, or sexual orientation issues.  What, if anything, is the appropriate response in such cases? Skewness, kurtosis and how many standard deviations values are from the mean As is well known for the normal distribution, 68% of the probability mass is within one standard deviation of the mean, 95% within two standard deviations and 99.7% within 3 standard deviations.   However, I have some empirical distributions that are leptokurtic and negatively skewed. In such circumstances is there a formula based on their higher-order moments to calculate how much of the probability mass is within so many standard deviations of the mean?   I have a measurement and would like to give some sense of how far it is from the midpoint (mean or some other measure of central tendency).  Can this be done? Is $\sin^2(z) + \cos^2(z)=1$ still true for $z \in \Bbb{C}$? Is $$\sin^2(z) + \cos^2(z)=1$$ still true for all $z \in \Bbb{C}$? I've tried rewriting it using complex definitions of $\sin$ and $\cos$, and I don't see why it wouldn't, but the text I'm reading asks this question as if it shouldn't hold? I'm looking for a word which indicates that a person has adopted a quality suggested by their name, e.g. a person named Grace who is indeed graceful, or perhaps someone named Shepherd who has become a shepherd.  I have a strong notion that I once learned such a word, but I have forgotten it and have never re-discovered it. Foobar2000-like music player? sed -i - edit files in place does not work in compound commandq Given two functions $f$ and $g$, is there a formula for the Fourier transform of $f \circ g$ in terms of the Fourier transforms of $f$ and $g$ individually?  I know you can do this for the sum, the product and the convolution of two functions. But I haven't seen a formula for the composition of two functions. Chinese Passport Holder Transit in South Korea A Chinese passport holder with a US visa has a flight scheduled from Beijing to Los Angeles in mid-November.  This person wants to go to South Korea for a 3 day conference; the conference is one week prior to the PEK-LAX flight.  If this person buys a round-trip ticket from China to Korea, will the transit visa be sufficient? Or will they need a regular visa?    Extra info:  What if the original ticket were modified to make it ICN-PEK-LAX?  . It says "Holding a confirmed onward flight ticket for departure within 30 days." Would a return ticket to China than a flight to LAX a week later be sufficiently "onward"? Prove that if $\sum{a_n}$ converges absolutely, then $\sum{a_n^2}$ converges absolutely I'm trying to re-learn my undergrad math, and I'm using Stephen Abbot's Understanding Analysis. In section 2.7, he has the following exercise:  Exercise 2.7.5 (a) Show that if $\sum{a_n}$ converges absolutely, then $\sum{a_n^2}$ also converges absolutely. Does this proposition hold without absolute convergence?  I'm posting about this here because my answer to that last question about whether the proposition holds without absolute convergence is "Yes", but my suspicions are raised by him merely asking the question. Usually questions like this are asked to point out that certain conditions are necessary in the statement of propositions, theorems, etc. I just want to see if I'm missing something here.  Anyway, here's how I prove the absolute convergence of $\sum{a_n^2}$, and note that I never use the fact that $\sum{a_n}$ is absolutely convergent:  Proof: Let $s_n = \sum_{i=1}^n{a_n^2}$. I want to show that $(s_n)$ is a Cauchy sequence. So, let $\epsilon &gt; 0$ and $n &gt; m$, and consider, \begin{equation}   \begin{aligned}     |s_n - s_m| &amp;= |(a_1^2 + a_2^2 + \cdots a_n^2) - (a_1^2 + a_2^2 + \cdots a_m^2)|\\                 &amp;= |(a_{m+1})^2 + (a_{m+2})^2 + \cdots + a_n^2|\\                 &amp;= |a_{m+1}|^2 + |a_{m+2}|^2 + \cdots + |a_n|^2\\   \end{aligned} \end{equation} Now, since $\sum{a_m}$ converges, the sequence $(a_m)$ has limit 0. Therefore I can choose an $N$ such that $|a_m| &lt; \sqrt{\epsilon/n}$ for all $m &gt; N$. So for all $n &gt; m&gt; N$,  we have, \begin{equation}   \begin{aligned}     |s_n - s_m| &amp;= |a_{m+1}|^2 + |a_{m+2}|^2 + \cdots + |a_n|^2\\                 &amp;&lt; \left(\sqrt{\frac{\epsilon}{n}}\right)^2 + \left(\sqrt{\frac{\epsilon}{n}}\right)^2 + \cdots + \left(\sqrt{\frac{\epsilon}{n}}\right)^2\\                 &amp;&lt; \left(\sqrt{\frac{\epsilon}{n-m}}\right)^2 + \left(\sqrt{\frac{\epsilon}{n-m}}\right)^2 + \cdots + \left(\sqrt{\frac{\epsilon}{n-m}}\right)^2\\                 &amp;= \epsilon   \end{aligned} \end{equation} Therefore $(s_n)$ is Cauchy and $\sum{a_n^2}$ converges. And since $\sum{a_n^2} = \sum{|a_n^2|}$, the series $\sum{a_n^2}$ is absolutely convergent. &#x220E;  Am I doing something wrong here? Am I right in thinking that $\sum{a_n}$ need not be absolutely convergent for $\sum{a_n^2}$ to be absolutely convergent? Booting a Windows 7 installation on different hardware I'm in a situation where I could do with very quickly migrating a Windows 7 (RTM x64) installation from one machine to another.  What options are open to me in terms of getting W7 to boot after the drive is picked up and moved from one box to another? I thought it was supposed to be a little less sensitive to this kind of move than XP, but it doesn't work - it is stuck in a reboot loop and never reaches a GUI.  Tried a few things so far, none of which have worked:   Changed SATA mode in the BIOS of the target machine between ATA and AHCI run Windows 7 Startup Repair tried safe mode, no change   (I will keep this list up to date as suggestions come in)  UPDATE: I can confirm this reboot loop is due to STOP error 0x0000007B, and these codes follow:  0xFFFFF880009A98E8 0xFFFFFFFFC0000034 0x0000000000000000 0x0000000000000000    UPDATE: I didn't get anywhere on this and I ended up just rebuilding the machine. I think it should be theoretically possible, so I'm going to leave the question open in case someone comes along in future with an answer. What is the connection between Poisson brackets and commutators? The Poisson bracket is defined as:  $$\{f,g\} ~:=~ \sum_{i=1}^{N} \left[  \frac{\partial f}{\partial q_{i}} \frac{\partial g}{\partial p_{i}} - \frac{\partial f}{\partial p_{i}} \frac{\partial g}{\partial q_{i}} \right]. $$  The anticommutator is defined as:  $$ \{a,b\} ~:=~ ab + ba. $$  The commutator is defined as:  $$ [a,b] ~:=~ ab - ba. $$  What are the connections between all of them?  Edit: Does the Poisson bracket define some uncertainty principle as well? Here's my proof in my own words, does it stack up?   Showing $A$ is complete implies $A$ is closed. Let $(x_n)$ be a convergent sequence in $A$. $A$ is complete $\implies (x_n) \to p \in A$. Hence $A$ is closed. Showing $A$ is closed $\implies$ $A$ is complete. Let $(x_n)$ be a convergent sequence in $A$. $A$ is closed $\implies (x_n) \to p \in A$. As every convergent sequence is a Cauchy sequence, $(x_n)$ is a Cauchy sequence in $A$ that converges to $p \in A$ and hence $A$ is complete.   That sound ok?  As an aside, it seems to me that the definition of completeness and closed are basically identical, why are there two definitions for the same thing? Am I missing something here? How do websites block selecting text and how do I unblock that? There's a website () that somehow blocks selecting text. Also it blocks Ctrl+A to select everything, there is also no “Copy” in the popup menu.  What I have tried:  Some sites use JavaScript to block selection. So I disabled all JavaScript sources in no-script addon in Firefox. I tried the same site in Google Chrome with the Script Safe addon. Made sure that everything is blocked, still can’t select text. Mousepointer remains an arrow and not a text cursor also on the whole site.  Used about:config to disable JavaScript completely in Firefox. Still no effect.  I read that some sites use DIVs with the style display:block so I used Inspect to examine the styles of the site. There is not one mention of "block" on the whole website, not in embedded CSS nor in object style=-attributes.  The text is not an image or flash or some HTML5 canvas ect. Everything is within DIV and P tags but no style was found that might block the text selection.  How can the website still block any selection of text? Not to mention why browsers support such behaviours at all. I just want to use a selected word or sentence and want to search google for it using right mouse click. It’s pretty annoying when a website does such things and forces me to type technical terms and names into google by hand. It disturbs my workflow. If we have two circles in the plane described by $(x_1, y_1, r_1)$ and $(x_2, y_2, r_2)$ we can determine if they are completely disjoint by simply:  $$(x_1 - x_2)^2 + (y_1 - y_2)^2 &lt; (r_1 + r_2)^2$$  Assume this is not the case, we now want to know if one completely overlaps the other.  (That is: if the second circles interior is a subset of the first circles interior.)  If $(x_1, y_1) = (x_2, y_2)$ than we can trivially compare radii, so lets assume their centers are distinct.  The way I have imagined is to create a parametric equation of the line that connects the two centers:  \begin{align} x_p(t) &amp;= x_1 + t(x_2 - x_1) \\ y_p(t) &amp;= y_1 + t(y_2 - y_1) \end{align}  Then we calculate the two line segments (represented as two pairs of t values) where the circles intersect this line.  One is a subset of the other if and only if the corresponding circles are subsets of each other.  Is there a simpler approach I am overlooking? Indiscernible to create descending chain of elementary models This is actually a two part question:   Which methods are there to calculate average slope by unit (say km²) for a given area? Are there any special requirements on the data - like additional information besides height measurements? Which open source GIS implement methods usable to calculate average slope on a grid (e.g. TIF file)?