I want to put both nodes and pics along a path. This works perfectly well:  \documentclass{article} \usepackage{tikz} \begin{document} \tikzset{p/.pic={\node [circle, draw] at (0,0) {};}} $\tikz{   \draw (0,0) node {x} pic {p}     to (1,1) pic {p}; }$ \end{document}   I get a path from (0,0) to (1,1), with a node labelled 'x' and my pic p at (0,0), and my pic p at (1,1).  But if I change my tikz picture to the following, I get errors:  $\tikz{   \draw (0,0) node {x} pic {p}     to (1,1) node {y}; }$   In fact, it seems that I can place some nodes, and then I can place some pics, but then I cannot place any more nodes along the path.  How can I achieve what I want? Is this a bug with PGF 3.0?
Why the shape (sB) is unknown in the following code ? How to avoid this ?  \documentclass[]{standalone} \usepackage{tikz,xparse} \usetikzlibrary{calc}  \tikzset{pics/.cd,     % Marque croix     Cross/.style args={#1 and #2}{%         code = {%         \draw[#2,rotate=45,scale=1.4] (0,#1 pt) -- (0,-#1 pt) ;         \draw[#2,rotate=-45,scale=1.4] (0,#1 pt) -- (0,-#1 pt) ;         }     },     Cross/.default={2 and black} }  \NewDocumentCommand{\Segment}{mO{}}{%     \begin{scope}[#2]     \path    (0,0) coordinate (sA) pic {Cross={1.5 and gray}}         -- (#1,0) coordinate (sB) pic {Cross={1.5 and gray}} ;     \draw (sA)--(sB) ; % Can't reuse (sB)     \end{scope} }   \begin{document}     \begin{tikzpicture}     \Segment{1.5}     \end{tikzpicture} \end{document}
Is it normal to get hundreds of break-in attempts per day? I just checked my server's /var/log/auth.log and found that I'm getting over 500 failed password/break-in attempt notifications per day! My site is small, and its URL is obscure. Is this normal? Should I be taking any measures? I'm planning on selling a USB external hard drive that currently contains an old Ubuntu installation with stored passwords and banking information.  How can I securely erase the drive before selling it? We  that there's a difference in meaning between try used with the infinitive and  try used with the gerund:     I tried sending her flowers. (Meaning: An experiment: I sent her flowers to see what will happen).   I tried to send her flowers. (Meaning: I tried to go through the procedure necessary to send flowers to her. The procedure might have been difficult.)   (per Michael Swan's PEU, Unit 299.6)   Will the same distinction hold if we use trying:     A man is trying setting up a password on his computer. (Is he experimenting, wanting to see what will happen?)   A man is trying to set up a password on his computer. (Is he trying to go through all the necessary steps, probably difficult, of setting up a password?) What do potential postdoc advisers seek in research statement letters? I am putting together my application for a postdoctoral position in theoretical condensed matter physics. The position is not a fellowship and is a regular postdoc position. If you have gone through the process of applying for such positions a number of times, or, even better, if you have reviewed such research statement letters, what are the main points that are sought/you seek in such letters? Specifically, should I put more emphasize on my PhD research to demonstrate my "depth of knowledge" on projects I have worked on (past research), or dwell more on things that I want/am capable to do (future research)? How can I get dramatic shallow DOF with a kit lens? Undefined control sequence \documentclass First of all I would like to thank you because you helped me out a lot with all your answers to the already online questions.  Now, here is my problem. I am trying to do a bibliography file with TeXworks but I get this error when I try to compile (pdfLaTeX+MakeIndex+bibTeX):      This is pdfTeX, Version 3.1415926-2.4-1.40.13 (MiKTeX 2.9 64-bit)     entering extended mode     ****PATH here******     ! Undefined control sequence.     l.1 \documentclass         [a4paper,11pt]{report}   I've been reading some similar questions but I don't find the way to fix it (maybe I am missing something). I found one that says that I am trying to compile a LaTeX file using TeX compiler but I don't know how to change the configuration.  This is the .bib fiel content:      \documentclass[a4paper,11pt]{report}     \usepackage[english]{babel}     % faire de l'anglais     \usepackage[latin1]{inputenc}   % accents dans le source     \usepackage[T1]{fontenc}        % accents dans le DVI     \usepackage{url}     \begin{document}      @Article{ref11, author={Danihelka, Jiri and Kencl, Lukas}, journal={Cloud Futures Workshop 2012 }, title={Colaborative 3D Environments over Windows Azure}, year={2012}, month={May}, pages={}, note={}     }      @book{ref12, author = {Lee, Henry and Chuvyrov, Eugene},     title = {Beginning Windows Phone 7 Development},     publisher = {Apress},     volume = {},     number = {},     series = {},     address = {},     edition = {Second edition},     year = {2011},     month = {July},     note = {}     }      @Article{ref13, author={}, journal={}, title={Cloud computing}, year={}, month={}, pages={}, url={\url{http://en.wikipedia.org/wiki/Cloud_computing}}     }      \end{document} How to call Apex REST API from Javascript? I have two different developer orgs. One contains apex REST web service, and I want to call that REST service from my second org. I have tried to call that REST service using normal ajax post request and forcetk.js, But I got following error     XMLHttpRequest cannot load   . Origin    is not allowed by   Access-Control-Allow-Origin.   I searched about this problem then I got to know that Salesforce never allows CORS (Cross-Origin-Resource-Sharing).  Initially I was using apex to call that REST web service, that time I was able to post data from apex. But as we have callout limitation in salesforce, I want to use javascript.  Can anybody please help me? How do I disable network manager permanently? I'm using Ubuntu 18.04.1 LTS. I want to disable network manager on an Ubuntu machine, because (1) I don't need it, (2) I prefer having hardcoded configuration, and (3) network manager regularly causes issues by changing the DHCP configuration. I tried to follow :  Stop network manager sudo systemctl stop NetworkManager.service  Disable network manager (permanently) to avoid it restarting after a reboot sudo systemctl disable NetworkManager.service   Despite this, the network manager is back again every time I reboot the machine. How can I make it go away? What are the assumptions for applying a quantile regression model? The question has been asked (one time) on CV before, but the answer is really imprecise and does not really answer the question in my opinion.  So: What are the assumptions for estimating a linear regression model via quantile regression?  To my understanding (and as several CV users have mentioned), quantile regression does not assume any specific distribution of the error terms - does that mean that, in a time series model, autocorrelation and heteroscedasticity do not have to be accounted for?  What about the other Gauss-Markov assumptions? I would assume that the assumption of no perfect multicollinearity has to be met when applying quantile regression, but do the parameters have to be linear? The linearity assumption only has to hold for the specific quantile I would assume.  Anyways - I do not find any backup for any of my thoughts in the scientific literature and I would appreciate a comprehensive answer. Thank you! Find number of files with a specific extension, in all subdirectories Is there a way to find the number of files of a specific type without having to loop through all results inn a Directory.GetFiles() or similar method? I am looking for something like this:  int ComponentCount = MagicFindFileCount(@"c:\windows\system32", "*.dll");   I know that I can make a recursive function to call Directory.GetFiles , but it would be much cleaner if I could do this without all the iterating.  EDIT: If it is not possible to do this without recursing and iterating yourself, what would be the best way to do it? in QGis 1.8 were lots of predefined coordinate systems (national projections). Where have they all gone in qgis 2.0? I specifically need the Gauß-Krüger-Projections Zone 1 to 5.  Is there any plugin to load those coordinate systems? Calculating roundness/compactness of polygon? I am trying to find ways to quantitatively describe the shapes of various polygons. For my project, these polygons represent lakes, rivers, lagoons, and parks. So they can be almost any shape. One easy metric is to calculate perimeter vs. area, which is at best an only slightly useful metric. But I would also very much like to be able to say something about the 'roundness' of a polygon. Or how 'compact' the shape is on a map.  The only way I can think of doing this easily is to calculate the area of each polygon in relation to a bounding box for that polygon (which I already have). But this seems like a poor solution.  So now I am thinking of something more like this - take the centroid of the polygon, add on a series of buffers of increasing areas (say 50%, 100%, 150%), then compare how much overlap there is between each buffer and the original polygon. A perfect circle will have perfect overlap at 100%, and I can use the 50% and 150% buffers to judge how much and in what way each polygon differs.  But even that feels cumbersome, and like a poor workaround for what somebody else has probably already figured out far better.  For reference, at a minimum I will need to be able to look at the resulting indices for the shape of various polygons, and be able to make an educated guess as to their source (River? Reservoir with dendritic shape? Lake/Lagoon? Park?) Seatpost Overextension I've been riding with my very short seat post extended well past its maximum extension line for quite a while now. Looking at the seat post itself I don't see any signs of deformation or damage other than some very minor surface rust.   Could my bike frame have been damaged? Could the lever force have damaged the frame? I can post some pictures of the frame if needed. My bike is all aluminum. How do I sort custom objects alphabetically in an array in Java? I have been reading about depth-of-field and presume to have a sufficient understanding of what it means and how it is related to lens properties, lens aperture, focal length, sensor format size and probably even print dimensions in case the picture is being printed. I do have a question about how/if depth-of-field depends on the dimension of a pixel. Let me elaborate:  Given two sensors with differing pixel sizes: x and 4x, the latter sensor integrates more light per-pixel than the former, however, it might have a lower resolution if the sensor dimensions remain fixed. Theory suggests that the depth of field is determined by those circles-of-confusion which are very close to being an in-focus point, and this perhaps also means that these very small CoCs fall within the integration area of the same pixel. Now when a CoC becomes larger than a pixel (like also in the case of diffraction blur), there is some spreading of intensities among neighboring pixels and this would clearly lead to blur. However, if one was using the 4X sized pixel, even with a slightly larger CoC, the intensity would still integrate into the same pixel area, and would thus perhaps be in-focus? Is this the right assumption? And if so, is there any analysis of pixel-area dependence of depth-of-field? Moreover, depth-of-field is in some sense independent of the integration medium as it clearly occurs in analog film devices as well, so is there a trade-off or a difference in depth-of-field between film and digital cameras?  Please point me to the correct references for this question. Please correct me if there seems to be a fundamental issue with the assumptions made above. An unclear sentence in the book "Griffiths, Harris-Principles of algebraic geometry" Let $X$ be a complex manifold and consider a holomorphic vector bundle $\pi:E\to X$ of rank $r$. By the usual correspondence between vector bundles and locally free sheaves, we consider $E$ as a sheaf by abuse of notation. We denote with $\mathscr A_X^{p,q}$ the sheaf of $C^\infty$ $(p,q)$-differential forms on $X$ and we define: $$A^{p,q}(E):=\Gamma(X,\mathscr A^{p,q}\otimes_{\mathscr O_X} E)$$ $$A^k(E):=\bigoplus_{p+q=k}A^{p,q}(E)$$  Now suppose that $\nabla:A^\bullet(E)\to A^\bullet(E)$ is a linear connection on $E$, then the curvature operator is defined as: $$\nabla^2:A^0(E)\to A^2(E)$$ where $\nabla^2$ is the composition of the maps $\nabla: A^0(E)\to A^2(E)$   and $\nabla: A^1(E)\to A^2(E)$. One can show that $\nabla^2$ is $C^\infty(X)$-linear.    I don't understand the following sentence from the Griffiths-Harris book at page 75 (I rephrase it by using my notation):     Since $\nabla^2$ is $C^\infty(X)$-linear, then it is induced by a bundle map $E\to\bigwedge^2T^*X\otimes E$, or in other words, $\nabla^2$ corresponds to a global section $\Theta$ of the bundle $\bigwedge^2T^*X\otimes\operatorname{Hom}(E,E)$.   I absolutely don't understand how I can see the operator $\nabla^2$ as the section $\Theta$. Unable to change payment information to NONE in iOS Appstore Ever since adding an iTunes gift card to my account, I'm getting verification requests like crazy. I can't even download free apps. It takes me to my payment info and when I try to select none, I continually get a message under the payment info that says "you must verify your payment info to continue"  I don't want a credit card on file and would really like the none option to work. My ID shows I still have iTunes credit. Me and my friends want to listen to music together. Two of us have Bluetooth Headphones (Beats Solo2 Wireless, Beats Studio Wireless) and one has a wired headset. Is there any way to use all three of these together? How can I check the SMART status of a SSD or HDD on current versions of Ubuntu 14.04 through 20.04? How can I check the SMART status of a drive under 14.04 and beyond? I've seen  but it doesn't seem to apply under 14.04 and later. How variance is defined?