This will be a very dumb question to the gurus I'm guessing but here goes. I am trying to keep track of the number of threads on my system and I need to add timestamp somewhere with each output. Here is my current command to check number of threads : watch -n1 'ps -eLo pid,cmd,nlwp | wc -l &gt;&gt; test.txt'  I would like the timestamp to be added on each line in test.txt as the number of threads gets written How do I get the output to look like 2020-12-14 07:08:10 5431 (where 5431 is the number of threads) ?
When I ping I have this display:  &gt; ping -i 4 www.google.fr  64 bytes from wi-in-f94.1e100.net (173.194.67.94): icmp_seq=503 ttl=46 time=45.5 ms ....... ....... 64 bytes from wi-in-f94.1e100.net (173.194.67.94): icmp_seq=508 ttl=46 time=44.9 ms 64 bytes from wi-in-f94.1e100.net (173.194.67.94): icmp_seq=509 ttl=46 time=45.1 ms   I'd like to have the time of the ping before.   Something like:  &gt; (right functions) + ping -i 7 www.google.fr  mardi 15 mai 2012, 10:29:06 (UTC+0200) - 64 bytes from wi-in-f94.1e100.net (173.194.67.94): icmp_seq=503 ttl=46 time=45.5 ms ....... ....... mardi 15 mai 2012, 10:29:13 (UTC+0200) - 64 bytes from wi-in-f94.1e100.net (173.194.67.94): icmp_seq=508 ttl=46 time=44.9 ms mardi 15 mai 2012, 10:29:20 (UTC+0200) - 64 bytes from wi-in-f94.1e100.net (173.194.67.94): icmp_seq=509 ttl=46 time=45.1 ms   How would you do this in a command line (if it's possible)?
Show that the determinant of $A$ is equal to the product of its eigenvalues Show that the determinant of a matrix $A$ is equal to the product of its eigenvalues $\lambda_i$.   So I'm having a tough time figuring this one out. I know that I have to work with the characteristic polynomial of the matrix $\det(A-\lambda I)$. But, when considering an $n \times n$ matrix, I do not know how to work out the proof. Should I just use the determinant formula for any $n \times n$ matrix? I'm guessing not, because that is quite complicated. Any insights would be great. Issues with win key and right alt key after Windows Update (Polish diacritical signs not working) With the new  and the upcoming release of  film, JK Rowling has been awesome and given us new writing on the .  In the introduction it is stated that there are eleven established/registered schools. There are writings for six of them. I don't think we need a new writing for Hogwarts... so that means seven have been located and defined.   Hogwarts School of Witchcraft and Wizardry - Great Britain  - France  - Northern Europe (possibly Estonia, Latvia, or Belarus)  - Japan  - Africa (possibly Congo/DRC)  - Brazil  - United States   Do we know anything of possible location or names of the other four schools? I know Koldovstoretz was mentioned as school in Russia, but is that still canon?   Koldovstoretz - Russia (maybe depending on current canon)   The final three are my guesses based on the population and geography on the world.   Name Unknown - China (based on population) Name Unknown - India (based on population) Name Unknown - Australia (based on geography)   Related: Standalone python app that uses qgis.core without installing qgis I tried to find this question somewhere else on here, and found a couple that were similar to it -- but all the answers seemed pretty convoluted, and I think it was surprising to me because I just imagined that SQL would have a way easier way to do this.  Essentially, I'm using a GROUP BY to group two values on top of each other. The coding is simple and works well, where I get these results using WITH ROLLUP at the end:  Type    Person  Count Type A  Person 1    10 Type A  Person 2    91 Type A  Person 3    13 Type A  Person 4    10 Type A  Person 5    2 Type A  NULL        126 Type B  Person 6    16 Type B  Person 7    63 Type B  Person 8    15 Type B  Person 9    22 Type B  Person 10   16 Type B  Person 11   3 Type B  Person 12   20 Type B  Person 13   44 Type B  NULL        198 NULL    NULL        360   Is there an easy way to substitute something saying if "NULL" is in the "Person" column, then make NULL AS "Subtotal" and if "NULL" is in the "Type" column, NULL AS "Grand Total?"  And if that's weirdly complicated, I'd be totally fine with just calling all of them "Total."  Thanks! A Good Book for Mathematical Probability Theory In Guardians of the Galaxy vol. 2, we see long-distance space travel. It involves piloting your ship into some sort of "jump point" that opens up in space, taking the shape of a honeycomb-like structure with a single hex missing.  The way it's describe, these points are fixed in space: early in the movie, the Guardians have to out-run an enemy fleet to reach the one they need; later on, we see them fly through a very long series of them in sequence. It's also made clear that doing too many of these "jumps" in a row has consequences for the passengers.  The process seems to be similar to, say, the Mass Effect relay setup, mixed with a bit of Star Wars hyperspace travel.  Is this the first time we have seen long-distance space travel in the MCU? Is there anything from the source material that explains how this works from a logistical standpoint? If there's any information on the "science" behind it, that would also be helpful. How can I display a short chapter name in the header and a long chapter name in the ToC? I am writing a book and one of my chapters has a very long title. As it can't be displayed correctly on the top of even pages, I provide a "short title name" via the   \chapter[short title]{long title}   command. But then, "short title" appears in the table of contents instead of the original/true/long one.  How can I have the "short title" in the header of even pages, and the "long title" in the ToC and in the "Title header"?  For reference, here is the code I use:  \documentclass[11pt,a4paper]{book} \begin{document} \tableofcontents  \chapter[Short title]{Very vey very very very very very very long title     i can't display in the header} Lorem ipsum dolor sit amet, consectetur adipiscing elit. \end{document} How to output string completions to stdout? Let $f(z)=\frac{1}{(z-1)(z-2)}$ and $g(z)=\frac{z}{(z-1)(z-2)}$. Let $\gamma$ be the circle of radius 4 centered at the origin and traveled once in the counterclockwise direction. Let $A=\{ z \in \mathbb{C}: |z|&gt;3 \}$  1) I need to show there is no analytic function $G: A \to \mathbb{C}$ such that $G'(z)=g(z)$ for all $z$ in $A$.   2) I also need to show that there is an analytic function $F:A \to \mathbb{C}$ such that $F'(z)=f(z)$ for all $z$ in $A$.  Do I have to integrate to find such function? Let's assume a very simplified situation. There is only one seller asking for 10$ and there is only one buyer bidding 20$. At what price would the transaction go?   Some answers say it won't, because the ask price has to match the bid price. () Other answers say, that the time ordering is important. () Which answer is correct? What is the final price in the presented situation? Is having a skills bar chart on a resume a good idea? I read a story once about a man who escapes from his pursuers by doing an uncontrolled jump into hyperspace. If I'm not mixing my stories up he was blind but could see through the eyes of other sighted people/animals nearby. He was able to see through his pet but it dies and he thinks he's finished - he's blind and lost in hyperspace but there's a rat on board which he eventually catches by turning off gravity and then he can see through the rat's eyes. He works out how hyperspace operates and can hop back to where he came from.   Can anyone remember the name of the story and the author? I enjoyed it when I was a kid and would like to read it again. Impact of hyperref, when varioref and cleveref are used I have no idea how to do this. Any help would be appreciated. The chapter I'm on is about differentiation and the mean value theorem.  Prove $a^\alpha b^{1-\alpha} \le \alpha a + (1 - \alpha)b, \; a,b &gt; 0,\; 0 &lt; \alpha &lt; 1$ Diminishing returns / non-linear reputation from “great” answers Over time I realized a very annoying property of the Stack Overflow reputation system: Easy answers to popular question are rewarded with a lot more reputation points than actually great answers. In case anybody actually needs examples for this, here are two examples from :   gained me 420 rep, I invested 2 minutes writing it, and it only was a wild guess.   took me about an hour for the research and the math and gained me 40 rep.  Now I know that you are bound to get more rep for answers that are useful to more people, and I'd say that's fine. But the current situation is quite extreme: 30% of my reputation is from 5 of my 330 answers, and they are definitely far from being my best ones.  A final example that is not from my profile, but more extreme: Do you really think  is worth 40000 reputation?  My proposition to improve that situation would be to make the reputation gain from a single answer non-linear, maybe even have it capped at a certain point. I'm not sure on how that non-linear function should look exactly, and would leave good proposals for that to users with more experience than me. Why does polynomial factorization generalize to matrices I'm reading about linear algebra and I came across with the following theorem where I have a problem convincing myself:      Theorem 2.1 $\,$ Every linear operator on a finite-dimensional complex vector space has an eigenvalue.      Proof:       To show that $T$ (our linear operator on $V$) has an   eigenvalue, fix any nonzero vector $v \in V$. The vectors $v, Tv,  T^2v,..., T^nv$ cannot be linearly independent, because $V$ has   dimension $n$ and we have $n + 1$ vectors. Thus there exist complex   numbers $a_0,...,a_n$, not all $0$, such that      $$a_0v + a_1Tv + ··· + a_nT^nv = 0.$$ Make the $a$’s the coefficients   of a polynomial, which can be written in factored form as $$a_0 + a_1z  + ··· + a_nz^n = c(z − r_1)\cdots(z − r_m),$$ where $c$ is a non-zero complex number, each $r_j$ is complex, and the equation holds for all   complex $z$. We then have      $${\color{red}{ 0=(a_0I + a_1T + ··· + a_nT^n)v= c(T − r_1I)\cdots(T −  r_mI)v}},$$ which means that $T − r_j$ I is not injective for at least   one $j$. In other words, $T$ has an eigenvalue.$\;\blacksquare$   I'm having trouble with the factorized form of the matrix polynomial (in red). I understood that the factorization holds for a polynomial by the fundamental theorem of algebra but why does this also hold for matrices?  In other words, why is the the part I highlighted true? Does such an factorization always exist?    Could I have some help to see this? Thank you =)   P.S.  is my reference (page 3).  UPDATE:   Someone else also has asked the  before it seems. UK Visa in an expired Nigerian passport - what to use? I am in Nigeria, my passport will expire in 4 months and I have a document to apply for a UK visiting Visa with that passport number.  Should I use it like that or go for another passport. If I choose to get another passport, how will I use it because of the passport number on the about to expired one in the document I want to use for Visa. Using Iterator with ModelBuilder for clipping and splitting in ArcMap? Schengen Business visa without a business invitation letter