Reset test in r I have two questions about this test in R:   How do you read the result of p-value? I assume that the bigger it is the more successful it is. When I do a multiple dummy variable regression, I get a p-value of 0.02758. How to understand this number with my result? When using the lm function to fit a model, I'm not able to draw the fitted line on the scatterplot. I am using the lines function like this:   lm8 &lt;- lm(H$weight~lga, data=H) summary(lm8)  reset(lm8, power=2, type=c("fitted"), data=H) Fit8 &lt;- data.frame(predict(lm8)) lines(Fit8, data=H)    And what do Fit8 and predict(lm8) mean essentially?
What is the meaning of p values and t values in statistical tests? After taking a statistics course and then trying to help fellow students, I noticed one subject that inspires much head-desk banging is interpreting the results of statistical hypothesis tests.  It seems that students easily learn how to perform the calculations required by a given test but get hung up on interpreting the results.  Many computerized tools report test results in terms of "p values" or "t values".  How would you explain the following points to college students taking their first course in statistics:   What does a "p-value" mean in relation to the hypothesis being tested?  Are there cases when one should be looking for a high p-value or a low p-value? What is the relationship between a p-value and a t-value?
PHP script not executing on Apache server What makes a Feynman diagram real or virtual? Simple question: as the title says, what makes a real Feynman diagram real, and what makes a virtual diagram virtual? Or in other words, how do I tell whether any given diagram is real or virtual? I've never gotten a really satisfying explanation of this. I would imagine it has something to do with virtual particles, but all internal propagators are virtual particles and I know for a fact that having internal lines doesn't make a diagram virtual. Are there any way to execute a query inside the string value (like eval) in PostgreSQL? While traveling in the Berlin Tegel airport (TXL), I wanted to get on Wi-Fi. I found three unsecured networks in addition to a number of password-protected networks.   _Free_TXL_WiFi airberlin Berlin Tegel Airport WiFi   I had no idea which of these were an official Wi-Fi network provided by the airport and which were provided by other people, potentially for malicious purposes like capturing my network traffic. Presumably the official one uses a captive portal to allow internet access.  Is there any way to determine which Wi-Fi network is the official one provided by the airport? Would airport staff such as at the ticketing booths know? Are there official lists available somewhere?  I’d like an answer that is applicable to airports generally, rather than specific to the Berlin Airport. Also, please don’t just give a blanket “don’t use any public Wi-Fi network” answer; I know there are risks associated with it, but sometimes it is a necessity and so I want to know how to identify the airport-provided one.   suggests there are no official Wi-Fi networks, but the answers are six years old, so it’s not clear if things have changed or if none of the networks I saw were official. Proper Way to Combine Feature Selection and Hyperparameter Tuning? On a plane, there are two congruent circles, $O_1, O_2$. One line intersects $O _1$ and A and B and $O_2$ at C and D such that AB=BC=CD=14. Another line intersects $O _1$ and E and F and $O_2$ at G and H such that EF=FG=GH=6. What is the radius of the circle.   The configuration was hard to draw. . You can reflect the lines over the centers, but it is still the same. Cleary, $\widehat{AB}=\widehat{CD}$ and $\widehat{EF}=\widehat{GH}$. I have no idea how to proceed. Let $trcA=0$.why $A=M+N$ where $M$ and $N$ are nilpotent matrices? The number of books in economics that we need to buy (is/are) three 1) The number of books in economics that we need to buy (is/are) three.   or       2) A number of books in economics that we can buy for the course (is/are) available in the college book store.   Possible answers:  a)is  b)are  My approach:  I am confused here why is and are are used in the 1 and 2 sentence.  What they exactly mean according to subject verb agreement rules. How to calculate $\int \frac{x^2 }{(x^2+1)^2} dx$? I'm trying  to calculate $\int \frac{x^2 }{(x^2+1)^2} dx$ by using the formula: $$ \int udv = uv -\int vdu $$  I supposed that $u=x$ s.t $du=dx$, and also that $dv=\frac{x}{(x^2+1)^2}dx$, but I couldn't calculate the last integral. what is the tick here?           the answer must be: $ \frac{1}{2}arctan\ x - \frac{x}{2(1+x^2)} $ + C I have a lot of filesystems:   / on a PCI-E SSD swap on a SATA SSD /media/ned is a RAID5 array /tmp lives on RAM Parts of /home/oli are symlinked and bind-mounted in from ned I also have /media/jeff/ which is RAID1 that I store backups and bind-mount ~/.wine in off.   It's actually a lot more complicated than that. There are all sorts of extra symlinks that I need to untangle in the long run but for now I just need a nice way of taking a path and finding out where it physically lives. Why does a 'sudo -i' login shell break a here-doc command string argument? In the sequence of five commands below, all depend on single-quotes to hand off possible variable substitution to the called bash shell rather than the calling shell. The calling user is xx, but the called shell will be run as user yy. The first command substitutes $HOME with the calling shell's value because the called shell is not a login shell. The second command substitutes the value of $HOME loaded by a login shell, so it is the value belonging to user yy. The third command does not rely on a $HOME value and creates a file in the guessed home directory of user yy.  Why does the fourth command fail? The intention is that it writes the same file, but relying on the $HOME variable belonging to user yy to ensure it actually does end up in her home directory. I don't understand why a login shell breaks the behaviour of a here-doc command passed in as a static single-quoted string. The failure of the fifth command verifies that this problem is not about variable substitution.  xx@host ~ $ sudo -u yy bash -c 'echo HOME=$HOME' HOME=/home/xx xx@host ~ $ sudo -iu yy bash -c 'echo HOME=$HOME' HOME=/home/yy xx@host ~ $ sudo -u yy bash -c 'cat &gt; /home/yy/test.sh &lt;&lt; "EOF" &gt; script-content &gt; EOF &gt; ' xx@host ~ $ sudo -iu yy bash -c 'cat &gt; $HOME/test.sh &lt;&lt; "EOF" &gt; script-content &gt; EOF &gt; ' bash: warning: here-document at line 0 delimited by end-of-file (wanted `EOFscript-contentEOF') xx@host ~ $ sudo -iu yy bash -c 'cat &gt; /home/yy/test.sh &lt;&lt; "EOF" &gt; script-content &gt; EOF &gt; ' bash: warning: here-document at line 0 delimited by end-of-file (wanted `EOFscript-contentEOF')   These commands were issued on a Linux Mint 18.3 Cinnamon 64-bit system, which is based on Ubuntu 16.04 (Xenial Xerus).  Update: The here-doc aspect is just clouding the issue. Here's a simplification of the problem:  $ sudo bash -c 'echo 1 &gt; echo 2' 1 2 $ sudo -i bash -c 'echo 1 &gt; echo 2' 1echo 2   Why does the first of those two commands preserve the linebreak and the second does not? sudo is common to both commands, yet seems to be escaping/filtering/interpolating differently depending on nothing but the "-i" option. Commuting: How to carry office clothing so it doesn't get crushed? I have the bike, I have the best route; but now I want to know, how do I transport my clothing in each day? I typically wear suit pants and a business shirt, but not a suit jacket.   Am I better off leaving my clothes at work, or is there a special bag that would let me carry in shirt/pants without them getting crushed? How to properly play .mkv files? I am having a problem while playing .mkv files. Every time I play a .mkv file, the audio can be heard but video cannot be seen. The only way to see the video if I actually right click on it or put a window in front of it and it displays one part of the video but not all.    The link of the picture above basically describes what I am saying. While I was trying to take the screenshot, the window for the screenshot disappeared and displayed part of the video. I hope someone could help me on this. Thank you!   EDIT: I was running Unity 2D when I have the problem but when I run Unity 3D, it works. So I need to make this work on 2D. Please help. A colleague and I recently submitted a paper to a journal with an impressive-sounding name, the "International Journal of Artificial Intelligence and Computational Research". According to ,      IJAICR is a referred [sic] journal in the field of computer science, artificial intelligence and soft computing methods.   It was accepted two days after we submitted it. That's too fast. We were suspicious. Although the journal said that all papers are peer-reviewed, we could not see how that was done in two days. Plus, we received no comments from the reviewers. Also, the submission guidelines didn't ask for a "blind" copy (without our names or any references to who we were).   But wait, there's more.  The acceptance letter asked us to send them US$300 to publish it. We did not. We've withdrawn our submission and will submit a new version of the paper to a more reputable journal in the coming months.  How might we make a better choice of respectable journals before we submit next time? Idiom/Phrase for "results without work/effort" I'd be greatly appreciative of a cleverly devised idiom/phrase that depicts the following concept:     Results without work/effort.   ...and/or...     My Work/Effort; Your Result.   Any idioms/phrases you can recount or conceive would be of use.    Contextual Edit:  The idiom/phrase should be in the context of service offering/hiring or task delegation, not free-loading as most answers thus far have understandably assumed. E.g.     [You hire me for] My Work/Effort; [My work/effort produces] Your   Result. Subsurf modifier rounding sharp edges I tried to apply a Subdivision Surface on a part of my object. I can't keep the angles sharp, they all turn into rounded angles.  The angle before applying the Subdivision surface...   ...And after Showing that $\sqrt[3]{2}\notin\Bbb Q(\alpha_1,...,\alpha_k)$ where $\alpha_i^2\in\Bbb Q\ \forall i$ Let $F$ be the field $\Bbb Q(\alpha_1,...,\alpha_k)$ where  $\alpha_i^2\in\Bbb Q\ \forall i$  I want to show that $\sqrt[3]{2}\notin F$  I thought if $\sqrt[3]{2}\in F$ then $\sqrt[3]{2}\in\Bbb Q\cup(\alpha_1,...,\alpha_k)$ but this is not a disjoint union so I'm not sure what to do... taking the square of $\beta:=\sqrt[3]{2}$ gives $2^{2/3}=\sqrt[3]{4}\notin\Bbb Q$ but that doesn't really advance things  So I'm looking for a hint Linux/Bash: Create relative soft links to files in directory tree? My earliest PhD graduation date is 10 months away. Funding permits me to stay 1–3 months longer, so the final date is still uncertain.  It is never too early to make contacts for possible post-docs. But how long in advance is too early to formally apply to post-doc job openings or funding opportunities? Depending on the bureaucracy, the path from applying to starting can probably be anything from a week up to a year — someone I know is applying with  which had the opening advertised in August, application deadline in October, will have interviews in December/January, and the commencement of work only in September, 13 months after the initial job advertisement. My personal guess is that the long time between interviews and starting is to create a level playing field between those who do and those who don't need to go through a visa application procedure.  If I'm too early in applying for a post-doc, a hosting institution might prefer someone who can start earlier and where the graduation date is more certain. For example, in my case the graduation date is still uncertain, so there is a risk in accepting even if they are willing to wait. Project funding might also require the money to be spent rather soon.  If I wait too long, there might be a considerable period where I'm between jobs. Having a long (>6 months) period between jobs is a disadvantage for me. Maybe it's also a disadvantage for a hosting institution (I'm not sure).  How do I find the balance? For example, considering the duration of funding and visa applications, does it make sense to apply e.g. ? Or is it in any case virtually inevitable to have at least several months before my PhD graduation and the start of a post-doc? How should we treat questions that are, or have seeds of, evil or malicious purposes and actions, such as writing spambots and malware?    Should they be answered like regular "everybody keeps their pants on" questions? Or should there be some other type of response to this bad behaviour lot?