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In Java, how do I call a base class's method from the overriding method in a derived class? I have two Java classes: B, which extends another class A, as follows :  class A {     public void myMethod() { /* ... */ } }  class B extends A {     public void myMethod() { /* Another code */ } }   I would like to call the A.myMethod() from B.myMethod(). I am coming from the , and I don't know how to do this basic thing in Java. Datasets constructed for a purpose similar to that of Anscombe's quartet I've just come across  (four datasets that have almost indistinguishable descriptive statistics but look very different when plotted) and I am curious if there are other more or less well-known datasets that have been created to demonstrate the importance of certain aspects of statistical analyses. Do natural weapons count for two weapon fighting? Do natural weapons such as those granted by being a Tabaxi or an Aarakocra count for the purposes of two weapon fighting? Would they have the light property to allow it and if not what about if you take the dual wielder feat that removes the restriction on them being light?  From a logical perspective I would think claws or talons would be light enough to count and with them being "natural weapons" this means they are definitely weapons so it would make sense for them to be considered light and one handed. I know that it can be done with graphics packages like TikZ, but it seems to be a bit of an overkill. And for those not already familiar with the TikZ system, learning it can be a bit of a barrier. So my question is     Assuming the advanced graphics capabilities are not necessary, and I just need a bare-bones flow chart (which should be implementable just using the picture environment), is there a LaTeX package for simply making a flow chart? How to find string position within another string in C recursively? Printing a .NET DataGridView I am fairly new to .NET and C#, but I have a DataGridView that I would like to print.  What would be the best way to go about doing so? Maximum and Minimum values for ints How To Get Notified When Hard Drives Fail In Dell PowerEdge Servers I have a Dell PowerEdge R415 and R515 and wondering how I can be alerted remotely when a hard drive fails in either server? Both are running RAID, so I need to be notified, so I can swap out the drive. Both servers only have the basic Baseboard Management Controller. Is this possible with a third party tool/software? Blackboard bold variants for Greek letters It is common (or it used to be) to use a blackboard-bold variant of \mu to denote roots of unity in some mathematical papers.  However, despite searching (several times, periodically over several years) I have never been able to locate any package or technique that makes this possible, other than using Metafont or possibly hunting through the font definitions to see if it is something I can create a variant of (along the lines of the suggestions in Section 8 of the Comprehensive LaTeX symbol list).  Thus far, I haven't been sufficiently motivated to learn how to do any of this (although it probably would have resulted in a net time savings), and I feel like I cannot be the only person who would have tried.  Is anyone aware of an existing way to produce this character? Best technique to create oldschool (fake 3D) racing game? What would be a good approach to develop the render system for an oldschool type racing game that uses a pseudo 3D scenery, like for example Outrun or Lotus Esprit Turbo Challenge? There's an endless scrolling road and scenery graphics are placed like billboard items, etc. I think you get the idea.    Are these developed in a similar way like  or is there a different technique behind it? Does the technique has a specific name I could search for on the web? I need to develop something like that in Flash. removeClass and fade animation Possible Duplicate:             In the itemize environment, how do I use the ampersand symbol &amp; without LaTeX trying to use it as a command? Under which assumptions a regression can be interpreted causally? First, don't panic. Yes, there are many similar question on this site. But I believe none gives a conclusive answer to the question below. Please bear with me.  Consider a data generation process $\text{D}_X(x_1, ... , x_n|\theta)$, where $\text{D}_X(\cdot)$ is a joint density function, with $n$ variables and parameter set $\theta$. It is well known that a regression of the form $x_n = f(x_1, ... , x_{n-1}|\theta)$ is estimating a conditional mean of the joint distribution, namely, $\text{E}(x_n|x_1,...,x_{n-1})$. In the specific case of a linear regression, we have something like $$ x_n = \theta_0 + \theta_1 x_1 + ... + \theta_{n-1}x_{n-1} + \epsilon $$ The question is: under which assumptions of the DGP $\text{D}_X(\cdot)$ can we infer the regression (linear or not) represents a causal relationship? It is well known that experimental data does allow for such interpretation. For what I can read elsewhere, it seems the condition required on the DGP is exogeneity: $$ \text{E}(x_1, ... x_{n-1}|\epsilon) = 0$$ The nature of randomisation involved in experimental data ensures the above is the case. The story goes then to argue why observational data normally fails in achieving such condition, reasons including omitted variable bias, reverse causality, self-selection, measurement errors, and so on. I am however uncertain about this condition. It seems too weak to encompass all potential arguments against regression implying causality. Hence my question above. UPDATE: I am not assuming any causal structure within my DGP. I am assuming that the DGP is complete, in the sense that there must be some causality (an ontological position it could well be debated), and all relevant variables are included. The key is to identify the set of assumptions which ensure me causality goes from certain variables to the other, without assuming from the outset such direction of causality.  Many similar posts on the site spend time mentioning why correlation does not imply causation, without providing hard arguments about when it does. That is the case, for instance, of  very popular post. Additionally, in the  on the site about the topic, the accepted answer gives the very vague answer:  Expose all hidden variables and you have causation.  I do not know how to translate that to my question above. Neither is the second most upvoted answer. And so on. That is why I believe this post does not have an answer elsewhere. Consider the partial sum of the divergent Harmonic series $H_n = \sum\limits_{k = 1}^{n}\frac{1}{k}$. I recently saw a question which required finding out the asymptotic bounds of $H_n$. Now, I could not find any bound closer than $O(n)$. So I looked up the series and found  Wikipedia article which says that $H_n - \ln n$ approaches a constant (the ). This clearly shows that $H_n = \Theta(\log n)$.  However, considering the question was in an beginners undergraduate algorithms course in CS, I was wondering if there is a simpler proof of this? Is there some clever proof requiring elementary mathematics to show $H_n = \Theta(\log n)$?  PS: This is not homework in the sense that it is not my homework, and the actual question does not ask for a proof, but rather asks a lot of functions to be arranged asymptotically. Is there a fairly simple way to divide a circle into equal parts using Adobe Illustrator CC? MAC addresses in JavaScript I know that we can get the MAC address of a user via IE (ActiveX objects).  Is there a way to obtain a user's MAC address using JavaScript? Why does a free-falling body experience no force despite accelerating? Anonymous questions and Avatars Some Stack Exchange sites allow to ask an anonymous question by specifying a one-time user name and an email which is "required, but never shown". However the Gravatar attached to the email is shown anyway. Anonymous users do not want their picture to appear - someone can find their identity via google image search or someone that knows them.  Example: open incognito window and : How do you clear a stringstream variable? I've tried several things already,  std::stringstream m; m.empty(); m.clear();   both of which don't work. VBox on 14.04, Kernel driver not installed (rc=-1908) On Installing Virtual box on Ubuntu 14.04, I got following message:     Kernel driver not installed (rc=-1908)      The VirtualBox Linux kernel driver (vboxdrv) is either not loaded or there is a >permission problem with /dev/vboxdrv. Please reinstall the kernel module by executing      '/etc/init.d/vboxdrv setup'      as root. If it is available in your distribution, you should install the DKMS package >first. This package keeps track of Linux kernel changes and recompiles the vboxdrv >kernel module if necessary.   Then on following the   I entered these commands:  sudo apt-get install linux-headers-generic build-essential dkms sudo apt-get remove --purge virtualbox-dkms sudo apt-get install virtualbox-dkms   On Running the last command   sudo apt-get install virtualbox-dkms   I get an error:  Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable  distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies: virtualbox-dkms : Depends: virtualbox (&gt;= 4.3.10-dfsg-1) E: Unable to correct problems, you have held broken packages.   Just for reference, I checked the version of the Virtual Box, I got 4.3.16 r95972  It worked using the solution  sudo apt-get install build-essential module-assistant sudo m-a prepare   Second as mentioned in the error reinstall kernal module.  sudo /etc/init.d/vboxdrv setup   More Details are from