I am trying to restore a database with the following command:  $ sudo -u postgres pg_restore -C -d dvdrental dvdrental.tar  [sudo] password for t:    However, I am receiving the following error message:      could not change directory to "/home/t/mydata/.../relation model/SQL/implementations/Implementations, i.e. relational database management systems/postgreSQL/general/web/postgresqltutorial/databases": Permission denied      pg_restore: [archiver] could not open input file "dvdrental.tar": No such file or directory   I was wondering why I can't change directory to the current directory with permission denied?  File permission bits are:   -rw-rw-r-- 1 t t 2838016 May 26  2013 dvdrental.tar
I am trying to restore a database with the following command:  $ sudo -u postgres pg_restore -C -d dvdrental dvdrental.tar  [sudo] password for t:    However, I am receiving the following error message:      could not change directory to "/home/t/mydata/.../relation model/SQL/implementations/Implementations, i.e. relational database management systems/postgreSQL/general/web/postgresqltutorial/databases": Permission denied      pg_restore: [archiver] could not open input file "dvdrental.tar": No such file or directory   I was wondering why I can't change directory to the current directory with permission denied?  File permission bits are:   -rw-rw-r-- 1 t t 2838016 May 26  2013 dvdrental.tar   Is it because one of its ancestry directory is not both readable and executable by any one?  The file has  many ancestry directories, and how can I verify that?
How does a Pokémon gain CP when evolving? How can I get the source directory of a Bash script from within the script itself? How do I get the path of the directory in which a  script is located, inside that script? I want to use a Bash script as a launcher for another application. I want to change the working directory to the one where the Bash script is located, so I can operate on the files in that directory, like so: $ ./application How do the tens­es and as­pects in English cor­re­spond tem­po­ral­ly to one an­oth­er? Find a plane that passes through a point and is perpendicular to 2 planes How to select the most recent set of dated records from a mysql table How to connect portable monitor USB Type-C to graphic card with display port or hdmi How to make traces on an universal PCB? I hope this question won't be closed as too subjective. I'd like to know best practice - how to make traces on universal PCB's with individual holes without traces (like the following image). My idea is to bend the ends of discrete components and use them to make traces to other components. Is this approach acceptable, or nasty? Although this is called "prototype" PCB, I'd like to use it for my simple final circuits (low frequency, low current applications), because I hope it will save time. Recently I began studying machine learning, however I failed to grasp the intuition behind .   The following are the facts about logistic regression that I understand.   As the basis for hypothesis we use . I do understand why it's a correct choice, however why it's the only choice I don't understand. Hypothesis represents the probability that the appropriate output is $1$, therefore the domain of our function should be $[0,1]$, this is the only property of sigmoid function I found useful and appropriate here, however many functions satisfy this property. In addition, sigmoid function has a derivative in this form $f(x)(1-f(x))$, but I don't see the utility of this special form in logistic regression.   Question: what so special about sigmoid function, and why we cannot use any other function with domain $[0,1]$? The cost function consists of two parameters ${\rm Cost}(h_{\theta}(x),y)=-\log(h_{\theta}(x))$ if $y=1, {\rm Cost}(h_{\theta}(x),y)=-\log(1-h_{\theta}(x))$ if $y=0$. In the same was as above, I do understand why it's correct, however why is it the only form? For example, why couldn't $|h_{\theta(x)}-y|$ be a good choice for the cost function?  Question: what is so special about the above form of cost function; why cannot we use another form?   I would appreciate if you could share your understanding of logistic regression. Creating vimrc breaks vim I'm currently logged into a server via ssh with ssh -Y and running a tmux session. If I start vim and run :colorscheme elflord the color scheme is changed. (Although the colors are not exactly what I would expect although they are I think 256 color. If I create a ~/.vimrc file and put a single line colorscheme elflord  in it then when I run vim it shows no color (just white text) and I cannot change the color with the :colorscheme command. $A$ abelian variety. Is the multiplication by $n_A$ surjective? Similar matrices and field extensions I currently have a Yongnuo YN560-TX trigger and a Yongnuo YN-560 Mark III. I would like to get a iTTL flash that also works with remote triggering.  How compatible are are different flash brands (Neewer, Yongnuo, etc.) when it comes to things like setting zoom, etc. ? When looking at my Apache2 access logs, I occasionally see GET requests asking my server for a page on a completely different server. For example:  xx.xx.xx.xx - - [18/Jan/2012:07:12:10 -0500] "GET http://someotherserver.com/?sometimesmorestuff=likethis HTTP/1.1" 200 389 "-" "Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.8.1.12) Gecko/20080201 Firefox/2.0.0.12"   I remembered reading something about that in the past, but at the time I had never seen that on my server, so I didn't worry about it.   Now that I am seeing it on my server, I just ran a test and it appears that my site does indeed serve requests for content from other servers. This seems like a bad thing. So, two questions:  A) Is this something I should be worrying about?  B) How can I fix it?  I've tried a little Googling, but I don't even know what this sort of thing is called, and that makes it difficult. Explicit solution for linear regression with two predictors I have some samples of data of the form $x,y$ and $z=f(x,y)$. I wish to fit a plane $$z = Ax + By + C$$ to the data with the smallest mean square errors.  I have found an "answer" in section 3 of  document, but it is left in the form of some equations left to be solved. I just about have the ability to solve these equations, but the process gets so messy that the likelihood of me making a mistake is quite high. Surely someone has written out the full solution longhand somewhere (it might be called "closed form") anyway, in the form $$A=\ldots,$$ $$B=\ldots,$$ $$C=\ldots.$$  EDIT: Maybe "closed form" is the wrong phrase. So let me be clear. I want an explicit solution for $A$, $B$, and $C$, and not a solution that ends with "So now if you can solve these equations then you can discover the values of $A$, $B$ and $C$". Proving that all entire & injective functions take the form $f = ax + b$? I'm a little confused at both the overall logic in this proof. Are we simply using $g(z)$ to make conclusions about $f(z)$, because $g(z)$ is the reciprocal of $f$? Is the proof assuming that $f$ is injective and entire (all the while knowing that it has some sort of singularity at $z = 0$), and then trying to reach contradictions in the essential singularity and removable singularity cases? Then, once it concludes that $z = 0$ is a pole singularity, it reaches the conclusion that $f$ must be of the form $f(z) = az + b$?  Also, more specific questions about the different cases:   Removable singularity case: Why is $f$ bounded on the closed circle if $f$ is continuous? Am I missing something simple? Essential singularity case: Why exactly is $f(\{|z| &gt; r \} \cap f(\{|z|&lt;r\}) \neq \emptyset$? $f(\{|z| &gt; r \})$ is dense, but how does $f(\{|z|&lt;r\}$ being open guarantee that their union is non-empty? Notify close voters when a closed question gets edited As mentioned in , a question closed because it was not well-phrased is currently very unlikely to be reopened after an edit clarifying the issues. Those who voted to close should at least be asked to reconsider and reopen the question after such an edit. Age and Graduate school I am 33. I live in the US. I am a neither a US citizen, nor a green card holder. I have worked in various jobs as a research assistant (physics, biology, economics) usually involving programming, mathematics or statistics.  As a newly minted undergraduate, I didn't really have much confidence in myself and I completely ruled out graduate school as pointless.  I didn't think of myself as smart enough.  I drifted into working in labs, because those are some of the easiest ones for which one can get a work permit in the US as a non-American.  Having worked in academia for a while now, I've had a chance to leap into various fields and help build solutions to complex problems.  I think I have literally gone as far as I can go researching in academia with no higher degree.  I work at one of the top universities in the world.  (If you looked at US News rankings or the Academic Ranking of World Universities, it's in the top 5.)  Lately, I've been thinking about applying for graduate school.  I do have a few papers in various fields.  I'm thinking of a PhD in either pure mathematics, applied mathematics, statistics or computer science.   I see two big minuses to applying to graduate school:   Most people applying are more than a decade younger than I am.  (Alas, more than a few gray hairs have made an appearance in recent years.) Perhaps my achievements would look good for someone younger, but partially my achievements are the result of a long career rather than any special brilliance. So, I wonder how my record will be perceived.  I did take GRE and I scored 800 quantitative, 800 verbal and a 5 on the essay.  (I would most likely have to do a GRE subject test depending on what field I ultimately decided.)   Please advise on how accomplished, but older candidates, are viewed in the graduate school application process. How is the /tmp directory cleaned up? Is it automatic? If so, how frequently is it cleaned up? extract the 4th column from a csv file using unix command I have a csv file formatted as below.  "col1","col2","col3","col4" "1","text1","&lt;p&gt;big       html      text&lt;/p&gt; ","4th column" "2","text2","&lt;p&gt;big2       html2      text2&lt;/p&gt; ","4th column2"   I want to extract the 4th column using.  I think that awk is the best tool for this ( let me know if I am wrong). I tried this   awk -F, '{print $4}' myFile.csv    but it fails.  I think because the 3rd column is multiline one.  How can I use awk or any other unix command to extract the 4th column.  I am looking for an efficient solution since my real file is big (> 2GB) Local colormaps in global coordinate system I am trying to get a surface graph with two colormaps.  Instead of using the full Z range i want to give the first surface its own colormap  and the second surface should receive its own colormap too (it may be even the same)... however the current version takes the full range of Z-Data and calculates the colormap. Is there any way?  \begin{tikzpicture}     \begin{axis}[grid = major, colormap={bw}{gray(0cm)=(0); gray(1cm)=(1)}, view={-30}{15}]   \addplot3[surf]    table     {DATA1.dat};   \addplot3[surf]    table     {DATA2.dat};  \end{axis} \end{tikzpicture}   Right now it looks like that:   I want each of the surface to be scaled individually... just to see more clearly how the amplitude changes :)  Any ideas?  Thanks, Alex