For example, a question about physics education is seemingly not on-topic on Physics. But there is no Physics Education nor Science Education, so it seems there is nowhere on SE that a question about physics education would be on-topic. So why not make room for such a question on Physics?

Is there a catch-all place somewhere on the Stack Exchange sites where one can post a (any) question that does not obviously belong to any of the Stack Exchange sites?  Sometimes I have questions but I don't want to ask them on other sites (no need for names). I prefer to post it on the Stack Exchange network for various reasons.  If there isn't, are there plans for one? I imagine that if such a site exists, questions on that site can also be moved to other more specific sites when they exists, and it's not to be used to post questions which obviously belong to a specific Stack Exchange site.


I have recently created an Ubuntu Virtual Machine, but the resolution is way off, and I am not able to change it to a more appropriate size.   My host machine is a MacBook pro running 10.7.5 with a 1280x800 resolution. My virtual machine is running Ubuntu 14.04 and everything except the resolution is working fine. The resolution is not just "not ideal" but it is impossible to work with at 640x480.   I have researched a lot and looked all over askubuntu, but none of the answers I have found work for me. And I do have guest additions installed.   What I have tried    seems to be a very informative and exhaustive answer, yet none of the solutions he has offered have worked for me.  1. Use Mouse to adjust screen size     Adjusting the screen by resizing the Virtual Box Windows with the mouse allows for any screen resolution up to the host screen resolution.   I have tried that but the resolution remains the same and gray bars are added around the outside of the window.   2. Use predefined standard screen sizes      If you need a fixed (standard) resolution you may also choose System Settings -> Monitors (for 11.04) or Displays (for 12.04) for a selection of fixed resolutions (here shown for 12.04):        For maximum host screen resolution you will need to run Virtual Box in Fullscreen mode (Host + F)   For a fixed host screen resolution we need to disable Auto-resize Guest Display (HOST+G) from Virtual Box Manager View menu.   1: The only option I have is 640x480.  2: When I go to fullscreen, it just makes the gray bars larger without affecting the  resolution.  3: Auto-resize Guest Display is grayed out and I am unable to disable it. Host+G also does nothing.  3. Define new geometry with xrandr     If you need a fixed geometry that is not in the list of resolutions for monitors you will have to use xrandr to define a new resolution:      First we use gtf for calculating the modeline of possible resolutions:   gtf <xres> <yres> <refresh> [-x]      Give the desired values for x-resolution, y-resolution and refresh rate. The flag -x is default and can be omitted. For a portrait resolution 480x640 at 60 Hz you will get the following output:   $ gtf 480 640 60 -x $ 480x640 @ 60.00 Hz (GTF) hsync: 39.78 kHz; pclk: 24.82 MHz Modeline "480x640_60.00" 24.82 480 504 552 624 640 641 644 663 -HSync +Vsync      From this we can copy & paste the modeline to add it to xrandr list of known resolutions:   xrandr --newmode "480x640_60.00" 24.82 480 504 552 624 640 641 644 663 -HSync +Vsync      and add this for the Virtual Box Monitor:   xrandr --addmode VBOX0 480x640_60.00      Replace VBOX0 with the appropriate monitor if you have setup Virtual Box with multiple monitors (or any other output name the driver reports).      We can now switch to the newly defined geometry as described above (2.).   I have done as he said ^ there. Here is what I wrote in the terminal and what the terminal said back.  VirtualBox:~$ cvt 1280 800 # 1280X800 59.81 Hz (CVT 1.02MA) hsync: 49.70 kHz; pclk: 83.50 Mhz Modeline "1280x800_60.00" 83.50 1280 1352 1480 1680 800 803 809 831 -hsync +vsync VirtualBox:~$ xrandr --newmode "1280X800" 83.50 1280 1352 1480 1680 800 803 809 831 -hsync +vsync xrandr: Failed to get size of gamma for output defualt  VirtualBox:~$ xrandr --addmode default 1280X800_60.00 xrandr: Failed to get size of gamma for output defualt xrandr: Cannot find mode "1280X800_60.00"   Any help would be appreciated, I'm pulling my hair out over this!

Running 11.04 beta in a Parallels 5.0 virtual machine, but this question will apply to any virtualization software.  Parallels 5 Linux tools (guest additions) don't work for 10.10 and 11.04 and I don't want them. I like how the VM is integrated as is. The only thing that needs tuning is the screen geometry.  None of the options in the Systems -> Preferences -> Monitors fit my display perfectly. I need it at 1080 x 1920 (9:16) or 1920 x 1080 (16:9).  Many different resolutions work (see screen-shot bellow), among which are:   1680 x 1080 (too narrow horizontally and a bit too short vertically) 1920 x 1200 (perfect horizontally, but a bit too tall vertically)   How can I adjust the screen resolution (display/monitor size) manually?  What I tried so far  $ cvt 1920 1080 # 1920x1080 59.96 Hz (CVT 2.07M9) hsync: 67.16 kHz; pclk: 173.00 MHz Modeline "1920x1080_60.00"  173.00  1920 2048 2248 2576  1080 1083 1088 1120 -hsync +vsync $ sudo xrandr --newmode "1920x1080"  173.00  1920 2048 2248 2576  1080 1083 1088 1120 -hsync +vsync xrandr: Failed to get size of gamma for output default  $ cvt 1080 1920  # 1080x1920 59.96 Hz (CVT) hsync: 119.26 kHz; pclk: 176.50 MHz Modeline "1080x1920_60.00"  176.50  1080 1168 1280 1480  1920 1923 1933 1989 -hsync +vsync $ sudo xrandr --newmode "1080x1920"  176.50  1080 1168 1280 1480  1920 1923 1933 1989 -hsync +vsync  $ sudo xrandr -q xrandr: Failed to get size of gamma for output default Screen 0: minimum 640 x 480, current 1920 x 1200, maximum 1920 x 1200 default connected 1920x1200+0+0 0mm x 0mm    1920x1200       0.0*     1600x1200       0.0      1680x1050       0.0      1400x1050       0.0      1280x1024       0.0      1440x900        0.0      1280x960        0.0      1280x800        0.0      1024x768        0.0      800x600         0.0      640x480         0.0     1920x1080 (0x11d)  173.0MHz         h: width  1920 start 2048 end 2248 total 2576 skew    0 clock   67.2KHz         v: height 1080 start 1083 end 1088 total 1120           clock   60.0Hz   1080x1920 (0x11e)  176.5MHz         h: width  1080 start 1168 end 1280 total 1480 skew    0 clock  119.3KHz         v: height 1920 start 1923 end 1933 total 1989           clock   60.0Hz   The 2 new resolutions do not show up in the Monitor Preferences GUI:   Trying Takkat's Solution  Here is what I do and get:  $ gtf 1920 1080 60 -x    # 1920x1080 @ 60.00 Hz (GTF) hsync: 67.08 kHz; pclk: 172.80 MHz   Modeline "1920x1080_60.00"  172.80  1920 2040 2248 2576  1080 1081 1084 1118  -HSync +Vsync  $ sudo xrandr --newmode "1920x1080_60.00"  172.80  1920 2040 2248 2576  1080 1081 1084 1118  -HSync +Vsync  $ sudo xrandr --addmode default 1920x1080_60.00  $ xrandr  xrandr: Failed to get size of gamma for output default Screen 0: minimum 640 x 480, current 1680 x 1050, maximum 1920 x 1200 default connected 1680x1050+0+0 0mm x 0mm    1920x1200       0.0      1600x1200       0.0      1680x1050       0.0*     1400x1050       0.0      1280x1024       0.0      1440x900        0.0      1280x960        0.0      1280x800        0.0      1024x768        0.0      800x600         0.0      640x480         0.0      1920x1080_60.00   60.0     I also tried gtf 1920 1080 60 -x.  In both cases I can't switch to that resolution and get:   Could not set configuration for CRTC 262     All the other resolutions work.


We have over 10000 servers to patch for bash vulnerability (shellshock) bug. Now my question is what is the command to patch this bug ? And how we can check whether the patch has been installed and the bug has been fixed ?

Some context about the bug:      Bash supports exporting not just shell variables, but also shell   functions to other bash instances, via the process environment to   (indirect) child processes.  Current bash versions use an environment   variable named by the function name, and a function definition   starting with “() {” in the variable value to propagate function   definitions through the environment.  The vulnerability occurs because   bash does not stop after processing the function definition; it   continues to parse and execute shell commands following the function   definition.  For example, an environment variable setting of    VAR=() { ignored; }; /bin/id       will execute /bin/id when the environment is imported into the bash   process.   Source:   When was the bug introduced, and what is the patch that fully fixes it? (See )  What are the vulnerable versions beyond noted in the CVE (initially) (3.{0..2} and 4.{0..3})?  Has the buggy source code been reused in other projects?  Additional information is desirable.    Related:


As seen here, my iTunes is splitting my albums up. More specifically, albums that contain songs that have different artists names in the tags. Those "Avengers - Age of Ultron" albums are supposed to be one album.  Rocket Music player, as well as every other multimedia application I have used besides iTunes, all recognize and sort my albums correctly.  This is extremely frustrating and I was wondering if there was a way I could solve this without resorting to incorrectly tagging my music with the same artist as other songs in the album.

tl;dr Is there an easier way / hack to get iTunes to display albums by album name? Currently it splits albums up by artist, then sorts the album names A-Z. Going through and manually changing the Album Artist will take way to long...    I recently upgraded to iTunes 11 and for the most part I like it. However one issue I have come across (and it would seem many others are in the same boat) is that iTunes is grouping albums by artists. For the most part this is fine, but when it comes to soundtracks and compilations things get hairy...    As you can see soundtracks for games or movies (eg the Shutter Island or Sin City soundtrack) is a compilation of different songs by various artists and iTunes is displaying albums in A-Z order but grouping them by Artist...  I've found that you need to set the 'album artist' to something like Soundtrack or Various Artists to get the grouping to work correctly. However this would take hours to do manually!!   Is there an easy fix for this behavious? Either by automating the Album Artist or by hacking iTunes to display albums grouped by album name?  iTunes 11.0.3


How can I save the output of this command into a var and still remove the files?  rm -vri files | wc -l

I want to assign the result of an expression (i.e., the output from a command) to a variable and then manipulate it – for example, concatenate it with a string, then echo it.  Here's what I've got: #!/bin/bash cd ~/Desktop; thefile= ls -t -U | grep -m 1 "Screen Shot"; echo "Most recent screenshot is: "$thefile;  But that outputs: Screen Shot 2011-07-03 at 1.55.43 PM.png Most recent screenshot is:   So, it looks like that isn't getting assigned to $thefile, and is being printed as it's executed. What am I missing?


I have a Polyline layer in QGIS which is split into multiple segments using the explode lines tool (the black lines in the image). There are nodes created from the 'extract vertices' tool (the red circles in the image). I want to merge the segments but keep 3-way or greater intersections split. Dead ends can be ignored but must be kept. When splitting the features I could not find a way to split exclusively at vertex intersections of 3 or more. I then decided to explode the line and try merging intersections with less than 3 segments, but I'm stuck again. Ideally this method can be automated.

I have a shapefile of city streets. I tried to run the Road Graph tool on them but the select box does not populate with the layer. I ran the Topology Checker on the layer and found that there are 2,000 pseudo nodes. I then ran the Dissolve tool on them and reduced the number to about 700 (these are pseudo nodes that are not in straight line segments in the layer).   I have also tried importing to GRASS, which fixes topology errors, but the layer results do not display on the map. Don't know why, tried several times.  Any suggestions for getting rid of all of these pseudo nodes in QGIS? I'm using QGIS 2.4, Chugiak.  This link:     ...describes pseudo nodes as  The definition of Pseudo node is "Pseudo nodes occur where a single line connects with itself or where only two Polylines intersect."  In QGIS, they look like points on the lines between legitimate intersecting nodes.


To show that Egoroff's Theorem continues to hold if the convergence is point-wise a.e. and  $f$ is finite a.e. on  $E$.  And Egoroff's Theorem states that if $E$ is a set of finite measure and $\{f_n\}$ is a sequence of measurable functions that converges pointwise on $E$ to the real valued function $f$, then there exists a closed set $F$ that is roughly the same size as $E$ on which $\{f_n\}$ converges uniformly.

The following question is taken from Royden's Real Analysis $4$th edition, Chapter $3,$ question $28,$ page $67:$     Question: Show that Egoroff's Theorem continues to hold if the convergence is pointwise a.e. and $f$ is finite a.e., that is.       Assume $E$ has finite measure. Let $\{f_n\}$ be a sequence of measurable functions on $E$ that converges pointwise almost everywhere on $E$ to the real-valued function $f$ which is finite almost everywhere. Then for each $\varepsilon>0,$ there is a closed set $F$ contained in $E$ for which    $$\{f_n\}\to f \text{ uniformly on }F \text{ and }m(E\setminus F)<\varepsilon.$$   My attempt:   Let $A = \{ x\in E: f_n\not\to f \text{ pointwise} \}$ and $B=\{ x\in E: |f|=\infty \}.$  By assumption,  $$m(A)=m(B)=0.$$ So $A$ and $B$ are measurable.  Note that  $$m[E\setminus (A\cup B)] = m(E) - m(A\cup B) = m(E).$$ Fix $\varepsilon>0.$ Since $\{f_n\}$ converges to $f$ pointwise on $E\setminus (A\cup B)$ to the real-valued function $f,$ by Egoroff's Theorem, there exists a closed set $F$ contained in $(E\setminus (A\cup B))\subseteq E$ for which  $$f_n\to f \text{ uniformly on } F \text{ and }m[(E\setminus(A\cup B)) \setminus F] < \varepsilon.$$ Since $E$ has finite measure and $F\subseteq E,$ by monotonicity,  $F$ has finite measure. As $F$ is closed, it is also measurable.  Therefore, by Excision property, we have $$m(E\setminus F) = m(E) - m(F) = m[E\setminus(A\cup B)] - m(F) = m[(E\setminus(A\cup B)) \setminus F]<\varepsilon.$$  Is my proof correct? I ask for verification because in this  Kenny's comment about countable union of null sets. I do not use this anywhere in my proof. So I wonder whether my proof miss out something.


How can $\pi$ be an irrational number if it is a ratio of the circumference over the diameter?    Thanks!

$\pi$ can be represented as $C/D$, and $C/D$ is a fraction, and the definition of an irrational number is that it cannot be represented as a fraction.   Then why is $\pi$ an irrational number?


I think that dimensional regularisation only regularises logarithmic divergences and not quadratic divergences. If you agree, or know someone who does, please comment.

I have followed two courses on QFT, which both involved renormalization by dimensional regularization. My confusion is that one of the professors claimed that dimensional regularization can only be used to regularize logarithmically divergent integrals, whereas the other professor claimed that the scheme can renormalize higher order divergencies. Let me make my question more precise.  Consider the standard integral which is computed in a dimensional regularization scheme: $$ I(n,\alpha) = \int \frac{d^np}{(p^2 + m^2)^{\alpha}} = i\pi^{n/2}\frac{\Gamma(\alpha-n/2)}{\Gamma(\alpha)}(m^2)^{n/2 - \alpha}. $$ For $\alpha=2$ and $n=4\pm\epsilon$ (depends on convention) the integral is logarithmically divergent and we can continue standardly by expanding the gamma, obtaining a $1/\epsilon$ pole and adding a counterterm to the Lagrangian. Generally, the integral is only convergent for $\alpha > n/2$. In the case of $\alpha = 1$ for example my first professor claimed that one has to introduce a Pauli-Villards cut-off in order to renormalize correctly.  My second professor claims that one may use: $$ \int d^n q \frac{\partial}{\partial q^{\mu}}(q^{\mu}f(q)) = \int d^n q q^{\mu}\left(\frac{\partial}{\partial q^{\mu}} f(q)\right) + n\int d^n q f(q), $$ such that one throws away the boundary term as it is a surface integral by Gauss' theorem. He states explicitly that this may be done if $f(q)$ vanishes quickly enough at infinity, but also that "analytic continuation will be implemented by ignoring the surface term irrespective of the asymptotic behaviour of the integral." If this is true/legit, one may write: $$ \int d^n q q^{\mu}\left(\frac{\partial}{\partial q^{\mu}} f(q)\right) = - n\int d^n q f(q), $$ such that one can express divergent integrals in terms of finite ones.  Is the last approach correct? Is the first approach wrong? Could you comment on these two approaches?


How many 10- digit numbers containing digits 1,2&3 can be formed such that the first & the last digits are same and no two consecutive digits are same?

How many 10-digit numbers can be made by using the digits {5,6,7} (all of them) and with the additional constraints that no two consecutive digits must be the same and also that the first and last digits of the number must be the same?   I am trying to find a solution by using combinatorics. I start from the 1st leftmost digit, which can have any value from {5,6,7} (3 possibilities).  Then we move to the 2nd digit, which can have 2 values (since it can't be the same with the 1st) and so on, and for the last digit we only have 1 option. But this is not correct, because for the 9th digit we have the restriction that it must be different from the 8th and also different from the 10th, which, in turn, is equal to the 1st.  I don't know how to express this.  I therefore tried to find a recursive relation.  I found that the general relation is $a(n) = 2*a(n-1)$ if n odd and $2*a(n-1) + 6$ if n is even.   For n=4, we have 6 such numbers (4-digit numbers, but with the given restrictions). Then if we add one more digit to the right, we remove the rightmost (4th) digit, which had to be the same with the first, and now for the 3rd digit we have 2 options instead of 1 (we can also add the options that were rejected because they were neighboring with the 4th digit). So in total we now have $2 x 6 = 12$ options. Therefore, $a(4)=6$ and $a(5)=12$. I don't understand, however, where this $+6$ (in the recursive relation) comes from!  By the way, the correct answer is 510.  Many thanks in anticipation.


I've been working my way through Rudin's PoMA, and I was thinking about subsequential limits. If you take a sequence with finitely many subsequential limits, then the set of subsequential limits is clearly closed and compact. Theorem 3.17 in Rudin states that the upper limit of a sequence is the limit of some subsequence. This gives me the feeling that perhaps the set of subsequential limits for a divergent sequence with infinitely many subsequnetial limits is also closed or compact. Admittedly, however, I don't think this follows directly from theorem 3.17. I've toyed with this idea for a bit, but I haven't been able to come up with a proof or a counter-example. Is this true or false, and what's the proof? Does this have any other interesting extensions/implications?

I have tried to prove the following result, but it looks a bit messy in my opinion. How can it be improved?     Proposition. Let $a_n$ be a bounded sequence with values in $\mathbf{R}$.   Let $A=\{l\in\mathbf{R} \mid \text{ there exists a subsequence of $a_n$ >converging to }l\}$. Then $A$ is closed.   Lemma: For each subsequence of $a_n$ which converges to $l$ it is true that $\forall {\varepsilon}>0$ $a_n\in B(l,{\varepsilon})$ for arbitrarily large $n$ -- that is, for each $m\in\mathbf{N} \; \exists M\geq m \mid a_M\in B(l,{\varepsilon})$.  Let $a_{k_n}$\,be such a subsequence. By definition, for each $\varepsilon>0 \; \exists N$ such that $\forall n\ge N \; a_{k_n}\in B(l,\varepsilon)$. Let $m\in\mathbf{N}$. Then $k_m\ge m$, since $a_{k_n}$ is a subsequence of $a_n$.   if $m\ge N$, take $M:=k_m$; if $m<N$, take $M:=k_N$.   Proof. Let $x$ be a closure point of $A$. By definition, $\forall \varepsilon>0 \; B(x,\varepsilon)\cap A\neq\varnothing$, which means that $\forall \varepsilon>0$ there exists a subsequence $a_{k_n}$ which converges to ${l}_\varepsilon\in B(x,\varepsilon)$.  This means in particular that for all $m\in\mathbf{N}$ there exists a subsequence $a_{k^{(m)}_n}$ that converges to $l_m\in B(x,1/2^{m+1})$ .  Define the sequence $x_n$ inductively:   $x_0=0$; $x_n=\min\{m>x_{n-1} \mid a_m \in B(l_m,1/2^{m+1}) \}$.    The sequence is well-defined, because there exists a subsequence converging to $l_m$, and by the lemma there are infinite indices for which the sequence lies in the neighborhood. So the set is not empty and by well-ordering there exists a minimum element.  It follows that for each $n\in\mathbf{N}$ $$x-1/2^{m}<l_m-1/2^{m+1}<a_{x_n}<l_m+1/2^{m+1}<x+1/2^{m},$$  so by squeeze theorem (strict inequalities imply non-strict inequalities) $a_{x_n}\to x$.


If I evaluate a surface $f$$($$x$$)$, that is subjected to a constraint $g$$($$x$$)$, for it's maximum and minimum values using Lagrange Multipliers then how do I know that the solution that is found is maximum or minimum. For example $f$$($$x$$)$= $x^2$+$y^2$+$z^2$ and $g$$($$x$$)$=$x^3$$y^2$$z$=  $6$$\sqrt{3}$ The solution using Lagrange multiplier is ($\sqrt{3}$,$\sqrt{2}$,$1$) But is this point a maxima or minima?

My book tells me that of the solutions to the Lagrange system, the smallest is the minimum of the function given the constraint and the largest is the maximum given that one actually exists.  But what if we only have one point as a solution? How to know whether Lagrange multipliers gives maximum or minimum?


Every time I try to use sudo I get this:  sudo: unable to resolve host ubuntu-server   My /etc/hosts file:  127.0.0.1       localhost 127.0.1.1       ubuntu-server  # The following lines are desirable for IPv6 capable hosts  ::1     ip6-localhost ip6-loopback fe00::0 ip6-localnet ff00::0 ip6-mcastprefix ff02::1 ip6-allnodes FF02::2 ip6-allrouters   /etc/hostname has:  ubuntu-server   I think there is some other setting that causes the unable to resole host error, but I cannot find these.

When I run sudo the terminal is stuck for a few seconds and then outputs an error message. My terminal looks like this:  ubuntu@(none):~$ sudo true sudo: unable to resolve host (none)   What can I do to solve it?


Long story short I just had two exams - one after the other. One required me to use LockDown Browser and the other one was in CANVAS. The second class is Finances and I asked a friend who already graduated from the same campus on Finances to help me out answer some questions. With that being said, the final question allowed us to attach a file with the procedure and I sent a PDF file of the excel sheet. The excel file has my friend as an author and I completely forgot to change/remove such a basic thing- later on there is a modification done by me. I sent an email right away after noticing the pdf was a mess just to notice the author thingy. I tried recalling the email but hey, 2021 and we still cannot edit tweets nor delete sent emails. I sent like two additional emails explaining that I messed up not adding my name on it and bla bla bla. Additional information. Teacher asked us to join the zoom meeting via phone and record our screen, hands and desk at ALL-TIME. Update: Teacher just replied to the email with the correct file that has name and no friend author. In case, just in case the teacher finds out about the author what could be a good excuse? "Teacher I had an exam before this one that required me to use Lockdown and my friend's laptop already had it so I proceeded to do the exam in the same laptop" "Teacher at that time my friend was at my house- my laptop had a BSOD so I proceeded to use his laptop" "Teacher I visited my friend and had no laptop- proceeded to use his and do the exam" I am so nervous- I am such an idiot because I graduate next semester... way to freaking go and messing up things. Finally, I would also like to add that the teacher said "it is not necessary to upload any file but if you want to overview something then you won't be able to". I simply do not what to think, do or say... I am shocked and worst thing is that they upload grades this weekend but I have classes with her once a week (THU). Also my friend lives like 3 hours away from me.

I got caught cheating in a two-hour engineering exam consisting of 100 multiple choice questions which was done online through the  e-learning software. I feel like my life is almost over.  Having not studied well and having no time to study, I decided to cheat. I know there are no excuses for cheating. Before the exam I dug up research about moodle exams, and it turned out you can take the exam anywhere you want to as long as you have the quiz password. Taking advantage of this, I went up to my engineering library and asked a close friend who was taking the exam to send me the quiz password before he starts.  What I had prepared:   Calculator (was not allowed during the quiz). Printed material (consisted of more than 200 pages). Google search engine (on a laptop ready to help). Whatsapp (to ask questions for a friend who took the quiz last year).   As I sat down, I did the first 50 questions, suddenly the quiz froze and moodle told me:      you are not allowed to take the exam from this location.   While I was leaving, one instructor responsible for the course (there are 5) came and found me. She accused me of cheating, took my mobile and made come with her to a huge office where two instructors searched all my mobile (took the name of my friend who gave me the password), and started talking to me, asking for all details of this crime. They took and confiscated my phone and looked at everything: Whatsapp conversations, all my emails, and images. The instructor took the mobile from my hand without asking me and kept it with her. It seems that the instructors are going to report me as well as my friend who sent me the password for the exam.  The university's Student Code Conduct said that cheating will result in one of the following: a Dean's Warning, Suspension, or Expulsion. If any of that happens, my future is over. A dean's warning will cancel my financial aid. A suspension would be for at least two years, and coming back would require a lot of work. An expulsion will be definite.  I've learned the lesson about cheating, now how can I fix this? How can I prevent the five instructors from reporting me? It's obvious that I should speak to them, but what should I say? What can I do? My future is almost over, but many of you are teachers and instructors here, what can I do to fix this?    EDIT: Wow, it has been almost 3 years. I would like to update on how I dealt with the situation.   Lesson: It was obvious to never ever cheat under any circumstances, and it was not whether you'd get caught or not.    Consequences: I received a Dean's warning but the financial aid wasn't revoked. However, I couldn't stay in the department as engineering was not for me and I was even ashamed to stay in the university.  What happened next: I transferred to an ABET-accredited Computer Science institution and I graduated with distinction in 2.5 years. It was extremely stressful as I had taken 6 major courses (18 credits) in one semester, but I had to do it.  Future plans: I'm going for an MSc in Computer Science in St Andrews next year.


A mutual fund I have (Vanguard Health Care Inv - VGHCX) dropped around 8% in one day...which is kind of unusual for a fund.  All the while the general stock market rose slightly.  Which brings me to my question...  How do I research why it went down?  What specifically caused it to do so.    I don't have any specialized tools other than Google/Yahoo/MSN finance sites...

I have no prior experience with stocks so please forgive me if this is a dumb question but I don't even know what to try googling. Two days ago I signed up with scottrade. I put $1000 into ICENX mutual fund. It got me ~56 shares. Today I log in and I see this:    What has happened? Apparently the share price took a huge plunge but my shares magically multiplied? Why does it say I lost $258 if I actually gained $12? Thank you guys so much!


I need to prove that for each natural n:  $$ 1^3+2^3+... +n^3 = (1 + 2+  ...+n)^2 $$  How do I do that? how do I know whether I should choose strong induction or simple induction?

How can I prove that     $$1^3+ 2^3 + \cdots + n^3 = \left(\frac{n(n+1)}{2}\right)^2$$    for all $n \in \mathbb{N}$? I am looking for a proof using mathematical induction.  Thanks


I am new to Linux and I am trying to install Ubuntu on my mac book pro without deleting the existing mac OS. I am roughly following this tutorial () to install Ubuntu 17.10 and I have installed rEFInd from my mac OS.  When I try to install Ubuntu on my computer, I select the partition I already created with the ext04 file system and for the boot loader option I have tried multiple options but they all give the following error "the grub-efi-amd64-signed package failed to install into /target/. Without the grub boot loader, the installed system will not boot."

I am installing Ubuntu 16.04 in an Intel NUC computer with UEFI enabled. I am using an SSD from another computer. During the installation I chose Erase the disk and make a new full install  At the end of the process I see:  grub-efi-amd64-signed failed installation /target/ Ubuntu 16.04    And the system does not boot.  I tried to use boot-repair but apparently it does not solve the problem.


After the destruction of the Two Lamps (Ormal and Illuin), the Valar created two massive Trees (Laurelin and Telperion) in Valinor and gave them light that was left over from the Lamps that gave Elves who arrived in Valinor a more enhanced power until they were destroyed by Morgoth and Ungoliant some time after.  Did the light of the Two Trees pass beyond Valinor and light up the whole of Arda, or just illuminate Valinor?

It is Known that Melkor (Morgoth) destroyed the Two Lamps, Ormal And Illuin. Meanwhile Valinor was lit by the Two Trees, and in Middle-earth the first light that Elves-Quendi beheld was that of the stars, when they awoke In Cuiviénen. My question is: what lit Arda during that, and before the Sun and Moon appeared? Only the Stars?


Is QGIS CLoud still missing off QGIS 2.0.  I am having a lot of issues with 2.0. on another matter I cannot load print templates without the system crashing. Are templates non compatible.  When i am also loading projects into 2.0 from 1.8 some raster layer properties have reset to default values....eg greyscale back to colour.

Will these plugins no longer be available in QGIS 2.0.1?


I read on MOZ that a domain name should ideally be less than 15 characters. My current domain name for a WIP website is ANightInBurlington.com, which is 18 before the .com, and without http:// or www. My thoughts:   While ANightInBurlington.com is a bit long, it contains both "Night" and "Burlington", the focus of my website (night life / tourism in Burlington, Vermont). "Burlington" is also a little long as it is, so it's only natural that anything with "Burlington" in it will be a tad long. My domain name, while long, is catchy and capable of branding. The primary reason to not go beyond 15 characters, is because users may not remember the name / may typo the URL when writing it. I don't think this is an issue with it mostly containing 2 words (not counting a and in).   My alternative URL is anibvt.com, which is an acronym for ANightInBurlington (adding VT to the end to specify Vermont / grab an available domain). My thoughts on this:   Much shorter domain, only 6 characters! It's slightly catchy, though I'm not sure how memorable it is. It's not at all clear to search engines / users what the site is about by the domain name alone.   So with that information, I'm just wondering if anyone can weight in. I'm pretty happy with ANightInBurlington.com, but I just want some reassurance that the domain isn't too long, "Burlington" in the name has some value (to search engines and users), and that I'm essentially good to carry on as I am. If not, I'll gladly switch the name.

I need a counsel about my websites' domain.  Let's say I have just bought two domains: xyz.com and xyzphotography.com.  As we can see, the first one is shorter but way less meaningful than the second one. The second one contains a photography keyword but it's longer.  I have only one website which is my photography portfolio. Can you advise me how to set those domains to make it all as SEO-friendly as possible? Which one should be the main one, does the rest should work on their own or have some kind of SEO-friendly redirect to the main domain?


I'm used to forums, where you talk about posters and OPs.  In SE, what can we call someone who asks a question - an OP, a questioner, something else?  What should we call someone who answers - an answerer?  I often want to refer to one or the other in a comment. I haven't been able to spot what others do. Are they using something like OP or do they just skirt around it?  Addendum  I see that my question has been marked as a duplicate.  I'll appeal on the basis that the other question is much more specific.    It asks for a straight 'translation' of the term "OP" - that's all. There is no request for a discussion as I have indicated in my tags and now in the title itself. It does not ask about what an 'Answerer' should be called. Although someone does address that point, it doesn't appear in the title and so wouldn't be found by a simple search. Although I say it myself, my question title is much clearer (and therefore more easily searchable) than the other. I believe that the other question is completely subsumed by mine. If that question is to stand then perhaps it should be edited so that the title reflects the contents.

As in "Original Poster". How do I refer to the user who asked the question in the third person, other than by account name?


I am trying to center my divs with bootstrap  html

             //stuff

             //stuff

   it shows   ---------------------------- |                            | ||left  | |       right      | ||      | |                  | ||      | |                  | | |   I want to have    ---------------------------- | |     |left|  |  right  | |     |    |  |         |  | |   with Left and Right divs centered within wrapper all the time.  What is the best way to do this with bootstrap class only?

How can I horizontally center a
 within another
 using CSS?

Foo foo


Page 358 of Introduction to probability, second edition, by Blitzstein and Hwang, defines the sample covariance as $$r = \dfrac{1}{n} \sum_{i = 1}^n (x_i - \bar{x})(y_i - \bar{y}),$$ where $\bar{x} = \dfrac{1}{n} \sum\limits_{i = 1}^n x_i$ and $\bar{y} = \dfrac{1}{n} \sum\limits_{i = 1}^n y_i$ are the sample means. However, I have also seen the sample covariance (matrix) defined as $$S = \dfrac{1}{n - 1} \sum\limits_{i = 1}^n (\mathbf{X}_i - \bar{\mathbf{X}})(\mathbf{X}_i - \bar{\mathbf{X}})^T.$$ Why is $n$ used in the denominator of the first definition, but $n - 1$ is used in the denominator of the second definition? I would greatly appreciate it if people would please take the time to explain this. EDIT: My understanding is that this is a matter of convention, but why does this difference exist at all? Obviously, these do not produce the same value, so there is clearly a difference between one choice or the other.

I was asked today in class why you divide the sum of square error by $n-1$ instead of with $n$, when calculating the standard deviation.  I said I am not going to answer it in class (since I didn't wanna go into unbiased estimators), but later I wondered - is there an intuitive explanation for this?!


I got a notice once I acquired a musket that "Deshawn", my arms dealer, was ready to settle. I have built a house with walls, background, light source, door, chair and table and he simply will not spawn.  I haven't seen any other notice regarding him again yet. Can anyone give me any advice on what I should do?

I read on the wiki that people will move in under the following conditions:   You do something to please them An empty house is available with a light source, table, and chair (also with walls).   I have a house which is about 7x8, then a roof space above that; about half the area. I could put furniture up there too, but will anyone move in?


Distribution of the sine of a continuous, non uniform random variable?  I was trying to solve a simple exercise about univariate transformation of univariate continuous random variables. I'd like to know if my computation is wrong and to have some suggestions about the way of solving such exercises.  Let X be a random variable with the following density function: \begin{align} f_X(x)=\pi^{-2}2x\mathbb{I}_{\left[0,\pi\right]}( x ) \end{align} This exercise required to compute the density of \begin{align} Y=\sin X \end{align} Firstly, this is not uniform distribution, hence the distribution of this transformation won't be the Arcsine distribution, am I right? First of all, I'm sorry if my questions will seem so trivial, indeed I'm a beginner. Since I used the cdf method, \begin{align} \Pr(Y\le y)= \end{align}  \begin{align} \Pr(sin(X)\le y) & = \Pr(X\le arcsin(y)) + \Pr(X\ge π-arcsin(y))\\[10pt] \end{align}  Hence I computed:  \begin{align} \Pr(X\le arcsin(y)) & = \int\limits_{-\infty}^{arcsin(y)} \frac{1}{π^2}2x\mathbb{I}_{\left[0,\pi\right]}( x ) dx \end{align}  \begin{align} \Pr(X\ge π-arcsin(y)) & = \bigg[1-\int\limits_{-\infty}^{\pi-arcsin(y)} \frac{1}{π^2}2x\mathbb{I}_{\left[0,\pi\right]}( x ) dx \bigg] \end{align}  Now, I could change the extremes of integration, by evaluating the intersection between them and the interval $0\text{-}\pi$. Since the arcsin function lies between the interval \begin{align} [-\frac{π}{2}, +\frac{π}{2}]\ \end{align}  I can rewrite the integral as (is this correct?)  \begin{align} \int\limits_{0}^{\arcsin(y)} \frac{1}{π^2}2x dx + \bigg[1-\int\limits_{0}^{\pi-arcsin(y)} \frac{1}{π^2}2xdx \bigg]& = \frac{1}{\pi^2}2\bigg[\frac{x^2}{2} \bigg]_0^{\arcsin(y)} \ +1-\frac{1}{\pi^2}2 \bigg[\frac{x^2}{2}\bigg]_0^{\pi-arcsin(y)}\ & = \end{align}  \begin{align} \frac{1}{\pi^2}arcsin^2(y)+1-\frac{1}{\pi^2}(\pi-arcsin(y))^2 \end{align}  This is the cumulative distribution function of the transformation between \begin{align} (0,1]\ \end{align} The computation of the density just requires to compute the derivative of this function (...)

I'm learning about functions of random variables and am trying to work out an example I made up. If $y = \sin(x)$ and $x$ has domain $[0, 4\pi]$, is the following the correct expression for the pdf of $y$: $$\begin{align*} f_Y(y) &= \frac{d}{dy}F_Y(y)\\ &= \frac{d}{dy}[F_X(2\pi) - F_X(\pi) + F_X(4\pi) - F_X(3\pi)]\\ &= \frac{d}{dx}F_X(2\pi)\left|\frac{dg^{-1}(y)}{dy}\right| - \frac{d}{dx}F_X(\pi)\left|\frac{dg^{-1}(y)}{dy}\right| + \frac{d}{dx}F_X(4\pi)\left|\frac{dg^{-1}(y)}{dy}\right| - \frac{d}{dx}F_X(3\pi)\left|\frac{dg^{-1}(y)}{dy}\right|\\ &=f_X(2\pi)\left|\frac{1}{\sqrt{1-0}}\right| - f_X(\pi)\left|\frac{1}{\sqrt{1-0}}\right| + f_X(4\pi)\left|\frac{1}{\sqrt{1-0}}\right| - f_X(3\pi)\left|\frac{1}{\sqrt{1-0}}\right|\\ &= f_X(2\pi) - f_X(\pi) + f_X(4\pi) - f_X(3\pi)\\ \end{align*}$$


Can anyone suggest a program that can tell me which process is using which files? I need a GUI program that I can run on Windows Server 2008.

How can I find out which process is locking a file or folder in Windows?  For instance, when trying to delete a folder, Windows reports this:     The action can't be completed because the folder is open in another program   Happens the same with a file, but how do I find out what program or application is currently using it and preventing me from deleting the file or folder?


My last name is Mayberry and for years I have spelled it "Mayberries"on our Christmas cards because I like it that way. I realize that the normal rule of pluralizing nouns doesn't apply to proper names. I just figured since it was my last name then I should get to decide how I sign it or pluralize it. This wasn't an issue until a sister in law of mine decided to point out this year that I was spelling it wrong. So I took to the internet to see what it had to say. I found this  about the same thing but its a few years old.  Any thoughts on whether or not I should stop using it the way I like and go with the "correct" way of Mayberrys?

Frequently when I refer to or address a family, I do so by pluralizing their last name, e.g., The Smiths, or The Ramones. But suppose I want to address a family whose last name ends in a "y", e.g., Kennedy. Normally in English, I reflexively change the "y" to an "ies" when pluralizing words in this form, but as a proper noun, I'm not sure this is the right thing to do. On the other hand, The Kennedys doesn't seem right either--the "dys" looks like it would lead to a dysfunctional prononciation. I'm also pretty sure an apostrophe belongs nowhere near here.  So how do I properly pluralize a name ending in a "y"?


What directories on my Ubuntu computer aren't actually on my hard drive? I am making a personal backup software, and some of the directories are not "real" Which directories aren't actually on my hard drive?  Thanks

I'm looking for a list which paths/files are safe to exclude for a full system/home backup.   Considering that I have a list of installed packages.   /home/*/.thumbnails /home/*/.cache /home/*/.mozilla/firefox/*.default/Cache /home/*/.mozilla/firefox/*.default/OfflineCache /home/*/.local/share/Trash /home/*/.gvfs/ /tmp/ /var/tmp/ not real folders but can cause severe problems when 'restoring'   /dev /proc /sys    What about...   /var/ in general? /var/backups/ - can get quite large /var/log/ - does not require much space and can help for later comparison /lost+found/


My grandma is trying to request compensation under  from Air Transat, as her flight from England landed 4 hours past the scheduled arrival time in Canada. She recorded the time, but her telephone obviously isn't probative evidence.   But Air Transat refused, and countered:     The delay of your flight was under the 4-hour mark. Regulation EC261/2004 does not apply.   So how can she prove the delay of more than 4 hours, free of charge?

Suppose that a layperson no longer trusts an airline or the airline refuses to supply such details of time. How can she cost-effectively obtain trustworthy  evidence of such times?


We can know clearly from  $$(1+X)^n=\sum\limits_{i=0}^{n}C(n,i)X^n$$ that $$ \sum\limits_{i=0}^{n}C(n,i)=2^n.$$  Whereas, I want to know if there are any researched results about permutations in the similar case, i.e., what can we know about  $$ \sum\limits_{i=0}^{n}P(n,i).$$  I’m really curious about that, but have found no answers elsewhere. Any help will be sincerely appreciated!

In a question I asked on algorithms with time complexity of $f(x) = n^n$ I was told that enumerating the number of strings that can be formed from a string of length $n$ qualifies.   I.e the sum of all permutations of $n$ from $n$ to $0$ is $n^n$  $\sum ^n_{i=0} nPi$ $= n^n$  Can I please see an easy to understand derivation of that formula.   EDIT The above identity is wrong. I just tested it. Can I get a derivation of the formula for the sum of permutations.


Does there exist any monotone function $f : \Bbb R \longrightarrow \Bbb R$ which takes connected sets to connected sets without being continuous? If the answer is "no" then can we extend this result to arbitrary topological space?

Let $f:\mathbb{R}\to\mathbb{R}$ be a map sending closed intervals to closed intervals. Prove that $f$ is continuous or find a counter example.  WLOG we just have to prove continuity at $0$ and we can also assume that $f(0)=0$ and $f(1)=1$ (by considering $x\mapsto (f(x)-f(0))/(f(1)-f(0))$ ).  I build up this question while thinking of the question .


I have a content type with a file field.  Is there a way to create an exposed filter in a view for the filename of a document in a file field?  I can get the filename to display in the view by using a file formatter or PHP, but I can't figure out how to allow the user to filter on the document filename.  I also need the filtering to be a contains, not an equal to, so they can enter partial filenames and get results.

We have a view for a type of node that includes a Private File.  We cannot see a way to add an exposed filter, such as "Contains any word", and have it filter based on the file's name.  Are we missing something obvious?


I'd never encountered a problem like "show that $2^{50}<3^{33}$" but I think I ended up solving it after doing some weird stuff with logs and Maclaurin series:  $$ \begin{align*} 2^{50}&<3^{33}\\ \ln2^{50}&<\ln3^{33}\\ 50\ln2&<33\ln3\\ \frac{50}{33}&<\frac{\ln3}{\ln2}\\ \end{align*} $$  When I got to this point I thought I might be able to use the result $\ln(1+x)=x-\frac{x^2}2+\frac{x^3}3-\cdots$ to rewrite the right-hand side into something like a fraction. $$ \begin{align*} \frac{50}{33}&<\frac{\ln3}{\ln2}\\ &<\frac{\ln(1+2)}{\ln(1+1)}\\ &<\frac{2-\frac{2^2}2+\frac{2^3}3-\cdots}{1-\frac12+\frac13-\cdots}\\ \end{align*} $$  Here I noticed that actually, the bottom is clearly greater than a half, because the sum of all the terms is greater than the sum of the first two, $1-\frac12+\frac13-\cdots>1-\frac12$.  So I actually went back a step:  $$ \begin{align*} \frac{50}{33}&<\frac{\ln3}{\frac12}\\ \frac{50}{33}&<2\ln3\\ \end{align*} $$  Here I think I've proved that $2^{50}<3^{33}$, because the above inequality ($\frac{50}{33}<2\ln3$) is clearly true:  $$ \ln3>1\implies 2\ln3>2.\\ \frac{50}{33}<2\implies \frac{50}{33}<2\ln3. $$  However, I'm not sure if I've done this the "right" way. I'm pretty sure there must be alternative, simpler, "more elegant" ways to prove $2^{50}<3^{33}$.  Can people show me how they would prove this result?

Could you generalise the question and get something along the lines of $n^{50} < (n+1)^{33}$ ?


I seem to be having trouble with Apache's mod_rewrite to rewrite URL requests while using it with mod_proxy to act as a reverse proxy. In summary, I'm trying to redirect requests to unminified CSS to my minified CSS located in another directory.  I currently have a web app requesting it's CSS at https://example.com/assets/css/styles.css. I have my minified CSS stored at https://example.com/assets/css/min/styles.min.css. Because I can not change the code where the CSS is linked, I want to use Apache's mod_rewrite to turn all requests for assets/css/styles.css to assets/css/min/styles.min.css.  Also, the web app is currently running on a separate backend server, 192.168.1.100,  so I have ProxyPass and ProxyPassReverse set up as  ProxyPass / http://192.168.1.100/ ProxyPassReverse / http://192.168.1.100/   Currently, I've tried adding  <Location /assets/css>     RewriteEngine On   RewriteBase /assets/css   RewriteCond %{REQUEST_URI} ^/assets/css/((.+)\.css)$   RewriteCond %{DOCUMENT_ROOT}/assets/css/min/%2.min.css -f   RewriteRule ^(.+)$ min/%2.min.css [L] </Location>   I've also tried adding a trailing slash at the end of /assets/css but that didn't do anything. I'm currently at a loss, as I'm not the best at mod_rewrite.    I think it is likely due to the interactions between Mod_Proxy and Mod_Rewrite that is causing the issue. I've taken the Location block snippet from another one of my projects and adapted the file paths appropriately. It was working correctly on that project, which was not using Mod_Proxy and was serving the content directly.

This is a  about Apache's mod_rewrite.   Changing a request URL or redirecting users to a different URL than the one they originally requested is done using mod_rewrite. This includes such things as:   Changing HTTP to HTTPS (or the other way around) Changing a request to a page which no longer exist to a new replacement. Modifying a URL format (such as ?id=3433 to /id/3433 ) Presenting a different page based on the browser, based on the referrer, based on anything possible under the moon and sun. Anything you want to mess around with URL   Everything You Ever Wanted to Know about Mod_Rewrite Rules but Were Afraid to Ask!  How can I become an expert at writing mod_rewrite rules?   What is the fundamental format and structure of mod_rewrite rules? What form/flavor of regular expressions do I need to have a solid grasp of? What are the most common mistakes/pitfalls when writing rewrite rules? What is a good method for testing and verifying mod_rewrite rules? Are there SEO or performance implications of mod_rewrite rules I should be aware of? Are there common situations where mod_rewrite might seem like the right tool for the job but isn't? What are some common examples?   A place to test your rules  The  web site is a great place to play around with your rules and test them. It even shows the debug output so you can see what matched and what did not.


I read a science fiction story as teenager, over 20 years ago, these are the details I remember:   Earth is controlled by an alien race who conquered it. The situation is really desperate, the technology gap is huge. Earth people became mostly slaves, sending materials to the home planet of the invaders.  The small resistance group on Earth succeeds to send a nuclear bomb to the invader's home planet, causing them to retreat from Earth after it caused major damage, maybe even destroyed the whole planet in a chain reaction of some kind.   I think this was written by Robert Heinlein, but not sure about it.  Can anyone help me remember what story this might be?

I saw this movie a while back. I don't remember how it starts, but from where I remember watching it, it may have not been too far from the start. Apparently, Earth has been conquered by some alien empire or something and humanity are basically cavemen being used as slaves. From what I remember, the main antagonist alien is seen taking one of the slaves to a room where a machine is used on him to make him smart; this is apparently a big no-no so the main antagonist and his sidekick have to keep it quiet. The idea was that by making one of the slaves smart, it could increase the work output of the others. Apparently the antagonist is using the slaves on Earth to gather gold bullion  which is apparently still very valuable to the aliens but he's doing it illegally (not the slave labor; that's apparently ok). The protagonist who had the machine used on him becomes the intermediary between the slaves and the aliens and begins teaching the other slaves. I remember him teaching them mathematics and I remember him saying that it was universally accepted (I think he may have been referring to algebra or trigonometry). At some point he becomes aware that they are slaves and organizes a plan to free not only his fellow slaves but the Earth. Some escape and find an old museum which has old flight simulators, and shows that humanity wasn't always a slave race and that it may have been modern times in which Earth was invaded (i.e. no lasers or starships). I think they also find Fort Knox as there is a huge collection of gold bricks and weapons. The protagonist comes up with a plan to destroy some sort of teleporter the aliens use to transport stuff to and from Earth, however that alone wont be enough as they could fight back, which will be bad for humanity, which is still undeveloped. So the plan also includes using the teleporter before destroying it to to transport and detonate a nuclear warhead on the alien home world which apparently cripples any attempt to immediately send a fleet but also as a show of strength. After executing their plan, the main antagonist is captured by the humans and as an insult is locked in a cage surrounded by the gold he sought. If I recall correctly the place is set to detonate as to destroy the precocious gold and that will be used against the aliens should they mobilize a fleet in the future (i.e. attack us and we destroy Earth's supply of gold). The antagonist's side kick for some reason I remember as a big black man from whom the antagonist had removed his hand at some point and also apparently the antagonist was cruel to him. After the antagonist is locked up, he is trying to appeal to his sidekick's loyalty, however the sidekick takes the humans' side, I'm also getting an image that apart from treating him kindly the sidekick's missing hand was restored.


Are Docker questions on-topic? A question was closed some time ago: . Since Docker doesn't relate to programming, should the tag be deleted?  Should a new one, , be added? This tag would be about the files that are used with Docker instances, and I don't see this as ontopic at Server Fault.

This question is clearly not off topic, as it directly pertains to Docker. I think this belongs on here, possibly Server Fault, but there is a tag for it here. I had to remove all references to my use-case because people thought it was off-topic.


My teacher says these two functions are different, why though?  $$\sin : \mathbb{R} \to [-5,5] \tag{1}$$  $$ \sin : \mathbb{R} \to \mathbb{R} \tag{2} $$  Both have the same domain and range. What difference does changing the codomain make here, so long as I keep the codomain as a superset of the range?  More generally speaking, $f : A \to B $ and $f: A \to C$ where $B$ and $C$ are the codomain of the same function $f$ and are supersets of range of $ f$  What difference would that make? How would changing the codomain (in this case) mean the functions are different? Isn't the function $f$ the same?

Or, in other words, why aren't all functions surjective? Isn't any subset of the codomain which isn't part of the image rather arbitrary?


During my elementary years, I remember a book about a group of humans venturing off of Earth to colonize a new planet. One of the things I specifically remember is how they had the youngest member of the colonization team name the planet. Another thing I remember is how the planet did not have rain, rather having lots of dew in the mornings. The book ended with who I believe to be the youngest member (who named the planet) telling the story of the colonization to the new generation of children.

I read a story back in the early 90s about a group of colonists who landed on a planet where the wheat (or wheat-like equivalent) is some kind of crystalline plant. The colonists face starvation until one of them figures out how to process the wheat.  I think it was by Asimov but so far I haven't found it by looking for his works.  I also cannot remember if it was a novel or a short story.


I have vim-athena package (the same is observed for vim-gtk) in my Debian machine.  Running vim spawns Vim in the terminal. Running gvim spawns a new window with Vim in a Athena GUI.  But what is vim and gvim? Symlinks pointing to a same target. $ readlink -e "$(type -p gvim)" /usr/bin/vim.athena $ readlink -e "$(type -p vim)" /usr/bin/vim.athena  And that final target is a binary. $ file --brief /usr/bin/vim.athena ELF 64-bit LSB shared object, ...  How can it be that vim and gvim do different things if both resolve to the same binary? Background: I was changing my default editor via update-alternatives --config editor. In the list, there are vim.tiny and vim.athena, but even if I select the latter, Vim always opens in the terminal, not in a separate GUI.

In Arch Linux, if I do ls -l in /sbin, I can see that reboot, shutdown and poweroff are all symlinks to /usr/bin/systemctl. But issuing reboot, shutdown and systemctl commands obviously does not all have the same behaviour.  Is ls -l not showing me full information regarding symlinks? How can I, for example, know what the real symlink of reboot is?


To be more fun. If you are 2 people to play, would you play each 2 characters? With only 2 characters into play, I fear that we would lack some expertise.

What are the mechanical/strategic differences in playing Pandemic Legacy: Season 1 with just two characters, as opposed to three or four?  If discussing Season 1 spoilers is unavoidable, please remember to use the spoiler notation (>! hidden text) and clearly mark them.


I would like to make this tikz picture fancier.    First of all, is it possible to smooth the junction between the different parts of the graph, for istance between the half circle and the line?  Then, is it possible to color the part of the graph under the curve, i.e. between the curve and the x-axis? ONLY THIS SECOND PART WAS ALREADY ANSWERED IN A PREVIOUS QUESTION.  Here is my code until now:  \documentclass[a4paper]{article} \usepackage[english]{babel} \usepackage{tikz} \usepackage[]{xcolor}  \begin{document}  \begin{tikzpicture} %\draw [help lines] (-10,0) grid [step=3] (10,10);  \draw plot [domain=0:3] (\x, {(0.7*\x)^2}); \draw plot [domain=-3:0] (\x, {(0.7*\x)^2});  \draw (4,4.41) arc (0:180:0.5); \draw (-3,4.41) arc (0:180:0.5);  \draw plot [domain=4:10] (\x, 4.41); \draw plot [domain=-4:-10] (\x, 4.41);  \draw [->, line width=5pt] (0,-2) -- (0,7); \draw [->, line width=5pt] (-10,0) -- (10,0);  \draw [inner color=blue!20, outer color= blue!50!black] (0,0.5) circle (0.5);  \end{tikzpicture} \end{document}

How to fill the area under a function using the package tikz? Only tikz. Is it possible? This is what I have:  \begin{tikzpicture} \draw[very thin, gray!30, step=1 cm](-4.9,-3.9) grid (4.9,3.9);  \draw [thick] [->] (-5,0)--(5,0) node[right, below] {$x$};  \foreach \x in {-4,...,4}    \draw[xshift=\x cm, thick] (0pt,-1pt)--(0pt,1pt) node[below] {$\x$};  \draw [thick] [->] (0,-4)--(0,4) node[above, left] {$y$};  \foreach \y in {-3,...,3}    \draw[yshift=\y cm, thick] (-1pt,0pt)--(1pt,0pt) node[left] {$\y$};  \draw [domain=-2:2, variable=\x] plot ({\x}, {\x*\x}) node[right] at (1.5,2) {$f(x)=x^2$};   \end{tikzpicture}   Please tell me, how do I fill the area under the function I drew? I mean the area between x axis and the curve.


I've recently had to switch to Ubuntu and am fumbling my way through. That being said, please help me be explaining each acronym.   I was directed to  this page in order to get everything for running Netflix on Ubuntu. I did download Wine, but when I went to the Dash Home and opened Netflix through there, nothing happens. Wine doesn't load to get the add-ons, Netflix doesn't load-nothing happens.   Any help would be appreciated.

Is there a way to stream Netflix content to my Ubuntu machine?


I am trying to mimic the behavior of Gedit's code highlighting in listing. For example, Gedit makes all numbers (int, float) in Python pink, but I have trouble implementing this. I tried numberstyle in \lstset, but it does not work. (In the example below, the "10" and "2" are not colored correctly)  \documentclass[11pt]{article} \usepackage{listings} \usepackage{courier} \usepackage{xcolor}  \lstset{     basicstyle=\ttfamily,     tabsize=4,         columns=fixed,     extendedchars=false,     breaklines=true,     keywordstyle=\bfseries\color[HTML]{a52a2a},      keywordstyle=[2]\color[HTML]{008a8c},     commentstyle=\color[HTML]{0000ff},     stringstyle=\color[HTML]{ff0bff},     numberstyle=\color[HTML]{ff0bff}, }  \begin{document} \begin{lstlisting}[language=Python, gobble=4, basicstyle=\ttfamily]     for i in range(10) :         print('%d' % i**2) \end{lstlisting} \end{document}

With the listings package, I would like to color the integers out of strings and comments and out of keywords too. The question for coloring numbers     . Some answer handle the numbers occurring within comments, strings or barewords, but no solution given work when a keyword contain a number. Which is annoying because C and C++ have a lot of types with a number in them, like uint32_t.  Here is a small example.  \documentclass{standalone} \usepackage{xcolor} \usepackage{listings}  \definecolor{darkgreen}{rgb}{0.18,0.54,0.34} \definecolor{maroon}{rgb}{0.64,0.16,0.16} \definecolor{darkpink}{rgb}{0.75,0.25,0.5}  \lstdefinestyle{myc++}{     language=[ISO]C++,     keywordstyle=\color{darkgreen}\bfseries,     commentstyle=\color{blue}\textit,     stringstyle=\color{darkpink}\ttfamily, %     literate=*     {0}{{{\textcolor{red}0}}}1     {1}{{{\textcolor{red}1}}}1     {2}{{{\textcolor{red}2}}}1     {3}{{{\textcolor{red}3}}}1     {4}{{{\textcolor{red}4}}}1     {5}{{{\textcolor{red}5}}}1     {6}{{{\textcolor{red}6}}}1     {7}{{{\textcolor{red}7}}}1     {8}{{{\textcolor{red}8}}}1     {9}{{{\textcolor{red}9}}}1,     escapeinside={|}{|}, %     morekeywords={int32_t} }  \begin{document}  \begin{lstlisting}[style=myc++] // In comment: 42 int32_t in_keyword = 80085; char *in_identifier|2| = "And in string 1337\n"; \end{lstlisting}  \end{document}   And the result:    The star for literate avoid to coloring the digits inside comments or strings. The escapeinside avoid coloring the digits inside a bareword when specifically marked. But I have yet to find how to color int32_t as a keyword.


For complicated reasons, I have been forced to make an identical copy of cmd.exe and rename it to cmd-2.exe, which I put a shortcut to in the Taskbar. The reason is purely to have them "grouped" in different "taskbar groups", and nothing else.  Sometimes, I forget about this, and to open a new cmd.exe, I simply middle-click that Taskbar icon to open a new cmd.exe. Then I type a command such as "dir", and then it spits out a bunch of nonsense, including:  DNS bad key.   This only happens if I accidentally use the cmd-2.exe. Not if I open the "real" cmd.exe. So it's not a "practical" problem.  However, I wonder why that message is ever printed at all. It's apparently failing to do some kind of DNS lookup or something? Why is DNS involved at all with me typing "dir" to list files in my local computer? I have no network set up, no "cloud drives", nothing like that whatsoever. It scares me that (apparently) there are DNS queries being made when I type "dir".  Or maybe "DNS bad key" refers to something completely unrelated to the Domain Name System? I don't know what a "bad key" would even be in that context...

For complicated reasons, I have been forced to make an identical copy of cmd.exe and rename it to cmd-2.exe, which I put as a shortcut on the Taskbar to have them "grouped" in different taskbar groups.  Sometimes, I forget about this, and to open a new cmd.exe I middle-click that Taskbar icon to open a new cmd.exe. I then type a command such as dir and it spits out a bunch of nonsense, including: DNS bad key, which only happens if I accidentally use cmd-2.exe, not if I open the "real" cmd.exe, so it's not a "practical" problem.  However, I wonder why that message is ever printed at all. Is it apparently failing to do some kind of DNS lookup or something? Why is DNS involved at all with issuing dir to list files on my local computer? I have no network set up, no cloud drives, nothing like that whatsoever. It scares me that (apparently) there are DNS queries being made when I issue dir.  Maybe DNS bad key refers to something completely unrelated to the Domain Name System? I don't know what a "bad key" would even be in that context.


I was trying to export the layout, which was supposed to be like this:    However, the exported image became untidy and unclear because of many secondary information were added, such as those tiny road names or county names.    How do I print the image as it appears in print composer layout?  The basemap is Bing Map from plugin `QuickMapService’.

I use tiled background map, from online source with 512-pix tiles and try to use it as background for printed map, using Print Layout and PDF export features. Problem: it seems that the choice of tile zoom levels depends automatically from the DPI setting.  Basemap layer is defined simply as "XYZ tiles" layer with following URL: http://1.basemaps.cartocdn.com/rastertiles/voyager/{z}/{x}/{y}@2x.png    In the preview it uses screen dpi (70 perhaps), and I see this map on both map window and Print Layout. Tiles are here from zoom 16. And the street names are big and readable, as I need.  Now for for print I need 600 (or more) DPI PDF-s. When I set this as Export resolution of Layout and create PDF, then suddenly exporter takes tiles from zoom 18, so exported PDF has different map, as below. Probably QGIS tries to match print resolution with tile raw resolution, but this is bad idea for such raster tiles, as you end up with very small texts. This rescaling probably makes sense for satellites, but not with maps with scale-dependent styles like texts. The pattern is that with 300 DPI there is +1 zoom, with 600 +2 zoom etc.    In screenshots here the difference is not maybe so visible as it is in real printouts, but it is quite terrible.  Question: is there a way to adjust this multi-resolution raster layer resolution matching magic in QGIS Print Layouts?  This WMS question seems similar, maybe core issue is same:   Btw, my quick remedy is now to use raster screenshot from Print Layout, but then I loose PDF vector with this, which would give much clearer vector texts and SVG vector icons on top of map.


I'm using the following to write a value to a field.  arcpy.CalculateField_management (newPha, "PHACODE", """'{}'""".format(name), "PYTHON_9.3")   The only problem is that the string I'm attempting to write to the table has an apostrophe. (ex. "Saint Anne's Bay").  The single quote is clearly throwing off the expression, but the triple-double quote solution isn't working. Any ideas on how to deal with this???

I'm using arcpy.CalculateField_management to populate a field.  The expression:  "'https://anystate.gov/someportal/DisplayQueryResults.aspx?Prompts=Spill%20Number="!ID!"&Database=OfficeDocs&Query=DEP_Spill_Projects&QuerySet=Portal_Queries&User=Portal.DEP&Password=DEPPortal1'"   will work when entered into the Calculate Field Tool.  The url is completed by pulling in values from the ID field.  However, the Python code snippet pasted into my script results in a syntax error. It's worth noting the expression is bounded by """"'....'"""" (4 double quotes outside a single quote.  I tried Midavalo's suggestion a couple of different ways. First attempt set  expression = 'https://anystate.gov/someserver/…{0}&Database=OfficeDocs&Query=DEP_Spill_Projects&QuerySet=Portal_Queries&User=Portal.DEP&Password=DEPPortal1'.format(!ID!)   Resulting in invalid syntax  Based on the Python link, the second try included single quotes:   'https://....'.format('!ID!')    But the result was a syntax error


I've found some questions here about the can+have+V3 possibility when speaking about possible situations in the past. But there was nothing said about future perfect usage, and I wonder if we can use it to speak about some actions that can become accomplished in the future.  I know that we can use will or may/might in this case, but I feel that the meanings may be slightly different:   I will have done it by tomorrow. - It sounds like a promise to me: I'm quite sure that I will accomplish it today. I may/might have done it by tomorrow - a possibility: I probably will accomplish it today, but I'm not sure at all *I can have done it by tomorrow - an ability: I have an opportunity to accomplish it today (but I may not use it)   Is the third sentence possible, and does it all make sense?

When talking about possibilities in the past, You often use "could have done".     "She could have gone to the theatre with him."   "He couldn't have done such a thing!"   "I could have saved them."   "You could have borrowed the car from him."   I understand "can have done" is used in negative and interrogative statements.     "She can't have eaten all the food."   "Can he have told them all the secrets?"   But I've not seen an affirmative sentence like,     "She can have gone to the theatre with him."   "He can have told them all the secrets."   "I can have saved them."   "You can have borrowed the car from him."   Why is it? As far as I know, "can" sometimes refers to possibilities as follows.     "It can be boiling hot in summer."   "She can be nasty."   Did "can have done" in affirmatives used to exist before? Or is it still possible but only used in limited contexts? If it is, when do you use the structure? If it's not used at all, what do you think is the reasons? Should I just think of it as an exception or an irregularity? ※. I've already read this link:  ※. One thing added: I looked up 'can' in Oxford Advanced Learner's Dictionary of Current English       (Third Edition, 1974, A.S. Hornby), and here are the examples:     a. One of the prisoners escaped yesterday; he can/could(=may) be anywhere by now.   b. He's an hour late; he can have been delayed by fog, of course.   Now I'm thinking "can" really used to express speculations about the past, and the meaning was more or less the same as "could" or "may". if the interesting affirmative "can" was still alive in some dialects, I'd love to know about them and to know whether the choice between "can" or "could" might be a matter of lowering possibility in the dialects. I really want to hear different opinions on this "can".


What would this integral come out as? $$\int_{-1}^1\frac{1}{x}\ dx $$  Since the areas on both sides of the y-axis are equal, with one being negative, does that mean that the answer is $0$?

Does $\int_{-1}^1 \frac 1 x dx$ equal zero? My contention is that it should, however several sources have said that it does not. I would think that the two areas on the left and the right of $x=0$ should be inverses and thus cancel, even if their areas are each infinite.


I think it is safe to say that flying on the weekend is probably going to be more expensive than during the week. Releated:   I am also not asking about  which talks about getting the first available tickets.  I am curious about booking, specifically, about tickets which were already available. Is there a specific time and day of the week which is the cheapest to book during?  I only ask because I saw an interview once where it was implied that the bookings held for the week which were not actually booked are released at a certain point. This person had said theirs were released Tuesday at noon EST and that the resulting increase in available bookings dropped prices compared to the previous day.  Is there any truth to this? Is there a best time of the week to book (as in actually purchase the tickets, not as in the arrival time/date)?

Is there any day of the week when airfares are statistically the cheapest to buy?


Is it ever OK to use we as a substitute for you? Let me illustrate:  I am increasingly receiving emails from colleagues that contain sentences such as:   Can we have a look at this tomorrow please? Can we ensure that we do not...   Now these emails seem innocuous enough, but I know full well that these co-workers have no intention of partaking in the tasks in question.  Would it not be better to say:   Can you have a look at this tomorrow please? Can you ensure that you do not...?   Are these people trying to be considerate of my feelings by indirectly giving orders?  I find this use of we to be particularly grating, so some clarity regarding its correct use would be much appreciated.

What is the term for the condescending usage of "we" that essentially means "you"?  For example, when talking to a child, you might say "we need to be on our best behavior."  A slight variant could be the instructive tone commonly found in mathematical proofs, e.g. "we see from (xxx) that (yyy), which tells us that (zzz)..."  I thought for quite some time that this was the meaning of "the ", but it turns out that is a different thing.  What is the condescending usage actually called?


Problem Evaluate $$ \int_0^{\frac{\pi}{4}}\arctan\frac{\sqrt{2}\cos 3x}{(3+2\cos 2x)\sqrt{\cos 2x}}{\rm d}x.$$ The integrand is complicated.  outputs the result is zero. If we consider making a subsitution, let $x=\dfrac{\pi}{4}-u$, then $$\int_0^{\frac{\pi}{4}}\arctan\frac{\sqrt{2}\cos 3x}{(3+2\cos 2x)\sqrt{\cos 2x}}{\rm d}x=\int_0^{\frac{\pi}{4}}\arctan\frac{\sqrt{2}\cos\left(3u+\dfrac{\pi}{4}\right)}{(3+2\sin 2u)\sqrt{\sin 2x}}{\rm d}u,$$ which seems to be helpless.

Evaluate the integral:  $$\displaystyle \int_{0}^{\frac{\pi}{4}}\tan^{-1}\left(\frac{\sqrt{2}\cos3 \phi}{\left(2\cos 2 \phi+ 3\right)\sqrt{\cos 2 \phi}}\right)d\phi$$   I have no clue on how to attack it. The only thing I noticed is that there exists a symmetry around $\pi/8$, meaning that from $\pi/8$ to $\pi/4$ is the negative of zero to $\pi/4$. But, there exists a root of the integrand at $\pi/6$ and the limit of the integrand at $\pi/4$ is $-\infty$.  Conjecture: The integral is $0$ for the reason of symmetry I mentioned above.  However I cannot prove that. I would appreciate your help.


I have bought a car camera with LCD monitor, exactly this one   It is powered by 12V.  Can I try it out at home by connecting it to my PC power supply? There is 12V available in the molex connector.  Thanks

Power supplies are available in a wide range of voltage and current ratings.  If I have a device that has specific voltage and current ratings, how do those relate to the power ratings I need to specify?  What if I don't know the device's specs, but am replacing a previous power supply with particular ratings?  Is it OK to go lower voltage, or should it always be higher?  What about current?  I don't want a 10 A supply to damage my 1 A device.


In a Google Spreadsheet, I have a column of task IDs, with values like T1, T2, T13 (i.e. all values starting with the same text). I would like to use a formula on the values of these cells (for conditional formatting). Can I somehow apply it only to the numeric part of the value, i.e. 1, 2, 13? Something like =max((A1:A100)[2:end])?

In a Google Spreadsheet, I have a column with values like T1, T2, T13 (i.e. all values starting with the same text prefix). I would like to use a formula on the numerical part of the values of these cells (for conditional formatting). Can I somehow apply it only to the numeric part of the value, i.e. 1, 2, 13? I would like to change the background colour for the cell containing the maximum numeric part of the value?  I know how to extract the numeric part. E.g., if the T-values are in column A, cell B3 can contain this equation:  =if(len(A3)>1,value(right(A3, len(A3)-1)),0)   However I fail to apply any further formula to this. E.g. this doesn't work:  =max(if(len(A2:A)>1,value(right(A2:A, len(A2:A)-1)),0))


Hi I am running Athlon X2 with 6 gig of ram and a gtx75o card I just bought.  I try and render and it says  CUDA error: Out of memory in cuMemAlloc(&device_pointer, size)

My GTX 960 is reporting there there is not enough memory, even when another person the same card is able to render it fine. The other person had the same set up as I do and rendered the same scenes. He did not have this issue.   I'm a render farmer for black plasma studios and I have come across this problem with my rendering recently. I was doing a benchmark test for them and blender gave the error (in the title).  My first test went good:    But I got the error on my second test:   as you can see it renders the first square but then runs out of memory after that. It did not render at all until I updated my graphics drivers with GeForce Experience. This helped a little but the render still didn't finish.  I seem to get this error a lot now and I would assume a better graphics card would be needed but someone else in the group has the same one that I have and he can do it just fine.  Computer info:  Display Device: name: NVIDIA GeForce GTX 960 DAC type: Integrated RAMDAC Device Type: Full Display Device Approx Memory: 6091 MB    System: OS: Windows 10 Home 64-bit processor: Intel Core i5-6600K CPU @ 3.50GHz (4 CPUs), about 3.5GHz Current Display Mode: 1920 x 1080 (32 bit) (60Hz) Memory: 8148MB RAM  How do I fix this?


Let us suppose that I am following my MSc studies. At the end of my compulsory courses I have an accepted article for being presented in a conference with my advisor. For graduating, I need to prepare a thesis, and I want to include this article as the main part of my thesis (80% of the thesis). So I have the following questions (I believe it is not necessary to open another thread for this): a) How should I do this thesis? Should it be an extended version of the article that is about to be published? b) How should I cite the article that will be published in my thesis if most of it is based on my article? I believe it would be somewhat troublesome to cite one's work at every moment in the thesis? c) What would happen if, after the article is published and my thesis is in the digital library of my university, somebody passes a plagiarism checker (like Turnitin) to it? It would detect my thesis in the university repository. I could be blamed for self-plagiarism or even plagiarism (because my supervisor's name would not appear like an author in the thesis document, but as a supervisor). Any help would be much appreciated. Thank you very much.

I'm aware that some institutions offer something that is called 'Thesis by Publication' (sandwich thesis) but that's not available to me. I'm trying to work out what pitfalls there may be to simply copying from papers that I have previously published in order to form large sections of my thesis.  The papers that I've published were largely designed to solve major problems encountered within the larger frame of research, so altogether they should follow a single coherent line of thought.  Must one's own work be cited in a thesis? This would be standard when submitting a paper for publication, but there is a stipulation when publishing papers that that work has not been already published elsewhere, and the same sort of thing does not really crop up with a thesis, does it?  Are there any other potentially pitfalls in this course of action?


Assume I make a custom Object:  function MyObject() {   // define some properties }   Now I want define a private method in the prototype:  MyObject.prototype = {   // by doing this I defined a public method, how can I define a private method?   myMethod: function() {     //some code   } }   Then I want to call the function in the constructor like this:  function MyObject() {   // define some properties   call myMethod() }   How can I do it?

To make a JavaScript class with a public method I'd do something like:  function Restaurant() {}  Restaurant.prototype.buy_food = function(){    // something here }  Restaurant.prototype.use_restroom = function(){    // something here }   That way users of my class can:  var restaurant = new Restaurant(); restaurant.buy_food(); restaurant.use_restroom();   How do I create a private method that can be called by the buy_food and use_restroom methods but not externally by users of the class?  In other words, I want my method implementation to be able to do:  Restaurant.prototype.use_restroom = function() {    this.private_stuff(); }   But this shouldn't work:  var r = new Restaurant(); r.private_stuff();   How do I define private_stuff as a private method so both of these hold true?  I've read  a few times but it doesn't seem like "private" methods can be called by public methods and "privileged" methods can be called externally.


We can express a square number as the repeated addition of that number in this manner:  $1^2 = 1$  $2^2 = 2 + 2$  $3^2 = 3 + 3 + 3$  Generalising this, we get:  $x^2 = x + x + x...$ $x$ $times$  If we differentiate with respect to $x$ on both sides, we get:  $2x = 1 + 1 + 1...$ $x$ $times$  $2x = x$  $2 = 1$  This is obviously wrong. What's the mistake in my proof?

Consider the following:   $1 = 1^2$ $2 + 2 = 2^2$ $3 + 3 + 3 = 3^2$   Therefore,   $\underbrace{x + x + x + \ldots + x}_{x \textrm{ times}}= x^2$   Take the derivative of lhs and rhs and we get:   $\underbrace{1 + 1 + 1 + \ldots + 1}_{x \textrm{ times}} = 2x$   Which simplifies to:   $x = 2x$   and hence    $1 = 2$.     Clearly something is wrong but I am unable pinpoint my mistake.


I want to define a new command using the package tikz-cd.  For example, suppose I want to define:  \newcommand{\simplearrow}[3]{\begin{tikzcd}  #1\arrrow[r, "#3"'] & #2 \end{tikzcd}}   This would give an arrow #3 from #1 to #2, but it does not work.  I guess the problem has to do with the double quotes in "#3" ' (the extra ' is for positioning the label below the arrow so it is important).   How to solve this?  Thanks

I’m using tikz-cd for diagrams, and have a medium-sized diagram that I want to re-use several times.  However, when I try using a definition like:  \newcommand{\myarrow}{$\begin{tikzcd} A \ar{r} & B \end{tikzcd}$   I get an error:  ERROR: Package pgfbasematrix Error: Single ampersand used with wrong catcode.   Is it possible to put a tikz-cd diagram into a defined command somehow?


I am unable to login again after rebooting my laptop which runs Ubuntu 14.04. I am 100% sure the password I type is correct ( see below - I also ruled out a keyboard issue) so it's not the case that I have forgotten it and would need to reset it.  I have both Unity and KDE but it doesn't work with either of them.  I looked at various suggestions like:   typing my password in the login field to make sure this is not a keyboard issue open a tty. My password still doesn't get recognized at the prompt so I can't go any further. boot to GRUB and open a root terminal but I don't have the root password on my machine so it didn't take me very far. I have also found it very hard to boot into GRUB as holding SHIFT while booting has worked a few times only and I can't get it to work anymore.   Also, not sure this is relevant but from the unity/kde login screen I am unable to connect to wireless (I get a permission error)  What should I try next?

I'm working on a Ubuntu system, and my client has completely forgotten his administrative password. He doesn't even remember entering one; however it is there.  I've tried the suggestions on the website, and I have been unsuccessful in deleting the password so that I can download applets required for running some files. Is there a solution?


I have some code which produces a sort of grid of letters that I want to scroll across- (that bit's not important I don't think). At the moment the 'scrolling' function works but only if you type in 'r' and then the  key.  Is there a way of making it so that as soon as you hit 'r' it's 'entered' and the program responds?      This is a tiny bit of the code.  print('Enter [r] for right and [l] for left:')             input_val = raw_input('Left or Right: ')              if input_val == 'r':                 a += 10                 b += 10

Is there a way of reading one single character from the user input? For instance, they press one key at the terminal and it is returned (sort of like getch()). I know there's a function in Windows for it, but I'd like something that is cross-platform.


It's fairly easy to see, using the ratio test, that the series  $$\sum_{n=0}^\infty\frac{n!!}{n!}$$  converges, where $n!!$ is the double factorial.  However, I'd be interested if there is a way of calculating its value analytically. I've tried around a little with WolframAlpha and I know that   $$\sum_{n=0}^\infty\frac{n!!}{n!}\approx 4.05941$$  Wolfram also suggests a couple of possible closed forms, which look very different. Since this sum is related to $e$ somehow, the following two are what I'd find most likely:  $$\sum_{n=0}^\infty\frac{n!!}{n!}=-8-e+2e^2$$ $$\sum_{n=0}^\infty\frac{n!!}{n!}=\Gamma(e+1)+e-2-\frac{5}{2e}$$  However, I have no clue if either of the two is actually correct, and if it were, how one would go about proving this result to be true - none of the approaches to series that I know seem to be getting me anywhere.     Is there a way to find a closed form for this series, and if so, how would one go about deriving it?

My question is pretty simple.  Since $n! \gt n!!$, it's clear by the comparison test that $\sum_{n=0}^\infty \frac {1}{n!!}$ converges.      But what value does the sum converge to? How does one go about determining its value (if possible)?


In the movie Star Wars, one of Mace Windu(S.Jackson)'s line reads such that:     I think it is time we informed the Senate that our ability to use the Force has diminished.   Is saying 'inform the Senate' rather than 'informed the Senate' technically wrong?

I'm watching Suits TV Series, and there was something that caught my attention. 2 guys meet, have a drink, chat, and then one guy says:     I mean it's time I told you. I made a deal with Darby to take over the   firm from Jessica.   Why is "told you" in paste tense? What exactly does it mean? He is saying that news right now. If I were to say that, I would say "it's time to tell you" or "it's time I'm gonna tell you".  Thanks!


When teaching a course based a text book, is using the proofs of theorems and examples from a text book considered reproducing the material from the textbook, while providing the study lecture notes?

I'm trying to change the numbers in problems I write for examples I use in my class as well as assignments. However the problems are still inspired by the textbook. Are the problems sufficiently different from the textbook problems to not have copyright issues? There is also an issue of theorems and definitions. Authors of the calculus textbook certainly did not come up with these things. Is it OK to just copy them down in my lecture notes?  By the way I do share my lecture notes on Piazza and the course I'm teaching is multivariable calculus.


I've got lines set up something like this:  A a-type_value B b-type_value C c-type_value B b-type_value C c-type_value C c-type_value A a-type_value   My Java code is reading lines like those from a file like so:  BufferedReader reader = new BufferedReader(new FileReader("C:\\Path\\to\\File.txt"));         try {           while (true) {             String line = reader.readLine();             if (line == null) break;             String[] fields = line.split("\t");             LineProcess(fields);           }         } finally {           reader.close();   The LineProcess() method looks like this:  public static void LineProcess(String[] input)     {         int result = 0;         String datetime = null;         System.out.println(input[0]);         if (input[0] == "A") {             result = Integer.parseInt(input[1]);             System.out.println(result);         }         if (input[0] == "B") {             bvalue = input[1] + input[2];             System.out.println(bvalue);         }         if (input[0] == "C") {              System.out.println(input[1]);         }         //System.out.println(input.length);         //for(int i = 0; i < input.length; i++)          //  System.out.print(input[i] + " ");         //System.out.println("");     }   Although there are A's, B's, and C's in my input, the if statements are never catching them.  I'm sure I'm making a simple mistake.  Thanks

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


I need to change the address of one of the pages of my site. I will create a new page with absolutely the same content and the same structure of the page (no changes to the content of the page at all, 100% copy), and then I will do 301 redirect from the old page to the new one.  So for example: example.com/somegoodpage (the old page) Will 301 redirect to: example.com/goodpage (the new page, exactly the same as the old one, except the URL).  How will Google respond to this kind of URL change in terms of search result positions?  Maybe this shouldn't be done at all because Google does not like this kind of redirect and heavily punishes for it? If so, maybe there is another way to do this?

I recently submitted a sitemap.xml in Google's Webmaster Tools and some of the pages already got indexed. The problem now is, that I cleaned my URLs with MOD_REWRITE in the .htaccess file afterwards and I would like the new ones to be indexed. The old ones should be removed from the Google Index.  Indexed Page:  www.example.com/article.php?=article=this%is%an%example   New URL:  www.example.com/article-this-is-an-example   Do I even have to remove them manually from the index in any way or do they refresh if Google crawls my new sitemap? I really wan't to prevent duplicate content.  Thanks in advance.


What items, gear, or other content is only available on the IOS version of Terraria?

I love the game Terraria for PC and played it for ages. Now I saw Terraria on the PS3-Store and gave it a shot. After some wandering around I saw something like a snow-biome and realised later on, that I was on a floating Island. I haven't played much of Terraria the last months, but this stuff seems kind of new. In addition I haven't found the (current) differences between the PC and the Consoleversion. Is there just one (upcoming?) Patch missing on the PC? What's included or - like the title said - what are the current differences (besides the splitscreen-feature of course)?


As the title says, I don't get pointy triangle bullet lists.  \documentclass{beamer}  \usepackage[utf8]{inputenc} \usepackage[ngerman]{babel} \usepackage{svg} \usepackage{tikz} \usetikzlibrary{chains, positioning, shapes.symbols} \usepackage{etoolbox} \usepackage{enumitem}  %\usepackage{gensymb} %\usepackage{siunitx}  %\sisetup {     %locale = DE,     %per-mode = symbol %}  % THEME AND COLOR SETUP \usetheme{CambridgeUS} \usecolortheme[RGB={205,0,0}]{structure} \setbeamertemplate{items}[triangle] \setbeamertemplate{sections/subsections in toc}[square]  \newcommand{\quoted}[1]{     \glqq#1\grqq } \date{27. June 2018}  \mode<presentation>{}  \begin{document} \beamertemplatenavigationsymbolsempty   \title{I'm not yet getting the hang of this} \author{Narusan}  \begin{frame}     \frametitle{Blabla}             \begin{itemize}                      \item {\color{black}{no bullet point}}                      \item here neither                                  \end{itemize}    \end{frame} \end{document}     I don't understand why, it used to work before in other presentations and I haven't really touched anything (I probably did, but nothing I'm aware of).

this is my first time using beamer.  I copied a template from the sharelatex page on Beamer  Which works, and \begin{itemize} shows bullets     But after adding a few more packages that I need, all the bullets are gone!    What is going on and how can I fix this?  \documentclass{beamer}  \usepackage[utf8]{inputenc}    \usepackage{amsmath}  \usepackage{amsthm}     %Theorem Environment  \usepackage{amssymb}  \usepackage{multirow}  \usepackage{cancel}  \usepackage{amsfonts}  \usepackage{graphicx}  \usepackage{subfigure}  \usepackage{upgreek}     \usepackage{mathtools}  \usepackage{thmtools}  \usepackage{enumitem}       %Information to be included in the title page: \title{Sample title} \author{Anonymous} \institute{ShareLaTeX} \date{2014}  \begin{document}    \frame{\titlepage}    \begin{frame}  \frametitle{Sample frame title}  \begin{itemize} \item  This is a text in first frame.  \item This is a text in first frame. \item This is a text in first frame.  \end{itemize}  \end{frame}  \end{document}


The following code does not yield the correct references with cleveref, but it does work as desired with regular references.  What is the easiest solution?  (See also  which highlights a similar problem but the solution provided there doesn't help here)  \documentclass{article}  \usepackage{amsmath} \usepackage{cases} \usepackage{cleveref}   \begin{document} \begin{subnumcases}{}  x=y, \label{eq:x=y}\\  z=a  \label{eq:z=a} \end{subnumcases} Equations \cref{eq:x=y,eq:z=a}...  \cref{eq:x=y} doesn't work. But \ref{eq:x=y} works well. \end{document}

I need something like this:  \left\{ first line  (1a) second line (1b) third line  (1c) \right.   all lines should be aligned to left


Me and some friends developing simple 3D rendering engine as practice for the university. We used Ogre 3d as prototype and now we are developing it from base  The engine is wrapped up in simple game that asks the user to select shape (circle, triangle, square...), color and dimensions and renders the image to the screen. It also enables to move and rotate the shape on screen using mouse.  We would like to test automate the view rendering. I could not find any test framework for this issue and I would like to know how 3D test is done in non manual matter

I've been embracing Test-Driven Development (TDD) recently and it's had wonderful impacts on my development output and the resiliency of my codebase. I would like to extend this approach to some of the rendering work that I do in OpenGL, but I've been unable to find any good approaches to this.  I'll start with a concrete example so we know what kinds of things I want to test; lets say I want to create a unit cube that rotates about some axis, and that I want to ensure that, for some number of frames, each frame is rendered correctly.  How can I create an automated test case for this? Preferably, I'd even be able to write a test case before writing any code to render the cube (per usual TDD practices.) Among many other things, I'd want to make sure that the cube's size, location, and orientation are correct in each rendered frame. I may even want to make sure that the lighting equations in my shaders are correct in each frame.  The only remotely useful approach to this that I've come across involves comparing rendered output to a reference output, which generally precludes TDD practice, and is very cumbersome.  I could go on about other desired requirements, but I'm afraid the ones I've listed already are out of reach.


I've been trying to find Fourier transform of that function.  What I got so far: - The function is even, so the FT is of order $2$, and an involution. - When we integrate the FT of that function over $\mathbb{R}$, we get $1$  (because FT of FT is the function itself, we put argument$=0~$ and $$\lim_{x\to 0}  \frac{\sin (x)}{x}=1$$ well known.   But I don't know how to precisely calculate FT of that function given as a  combination/mix of elementary functions. I tried also changing variables etc. yesterday but nothing worked.  Thanks in advance for help.

We know that the Fourier transform of the sinc function is the rectangular function (or top hat). However, I'm at a loss as to how to prove it. Most textbooks and online sources start with the rectangular function, show that   $$\int_{-\infty}^\infty \text{rect}(x)e^{i\omega x}dx=\int_{-1/2}^{1/2}e^{i\omega x}dx=\left.\frac{e^{i\omega x}}{i\omega}\right\vert_{-1/2}^{1/2}=\text{sinc}(\omega/2)$$  and then just invoke duality and claim that the Fourier transform of the sinc function is the rectangular function. Is there any way of deriving this directly? i.e., starting with the sinc function?   I've tried, but I'm not sure as to how to proceed. I know that the sinc is not Lebesgue integrable and only improper Riemann integrable. Some vague recollection of these being important in the Fourier transform hinders my thought process. Can someone clear things up for me?


What is the difference between the following?  I don't know nothing else  and  I know nothing else  There's a don't in the first sentence, however both sentences translated the same in google translator. So, are they used interchangeably?

Is "not unpleasant" a double negative, and hence bad grammar?  See the first answer (by Ham and Bacon) to , for the basis of this question:     "Did you enjoy the movie?"      "Well, I didn't not enjoy it, but..."   Are all "not un..." forms incorrect?  They are very widely used, much more so than the blatant "not not" or "didn't not", etc.


I had applied for a UK visitor visa and it got refused saying there were not enough funds and also they thought I would not be able to take care of my wife and child. I checked the mistakes and reapplied with more precise information and proof of funds.  The first time I had applied I got the reply in 10 days however this time it has already been 14 days and there is no reply. Only I got an email on 16 August, 2016 informing that it is reached British High Commission, Chennai.  Could anyone help me how much time will this take?  In the email they mention with 15 working days. August 18 was a holiday as it was Raksha Bandhan and also September 5. I wanted to know how much time could it take as i applied for Visitor Visa for 6 months and do i need to count 15 working from the day I got the email or from the next date ? Any help could be great.  My brother is in UK as he is a citizen so attached sponsorship letter too.

I have applied for visa to UK on 28th June, 2016. I have to travel on 17th July, 2016. But still my visa request is pending. Who can be requested to expedite my application? What can someone do in situations like these?


I have a string and I want to split it every time the char ',' appears. I want to save the result in a vector of pointers to string. What is the best way to do this?

I'm trying to iterate over the words of a string.  The string can be assumed to be composed of words separated by whitespace.  Note that I'm not interested in C string functions or that kind of character manipulation/access. Also, please give precedence to elegance over efficiency in your answer.  The best solution I have right now is:  #include <iostream> #include <sstream> #include <string>  using namespace std;  int main() {     string s = "Somewhere down the road";     istringstream iss(s);      do     {         string subs;         iss >> subs;         cout << "Substring: " << subs << endl;     } while (iss); }   Is there a more elegant way to do this?