I did not find my answer in the questions I searched , that's why I am asking it .  class outer  { class inner  // non static . { } }  For creating object of inner class I am unable to understand the logic of the part to the right of assignment operator .  outer o = new outer () ; outer.inner y = o. new inner () ; //  I have doubt in this line .   Here outer.inner is the return type but what about the right portion ?  Thing I know : We cant write outer.inner y = new outer.inner () ; since inner is non static .
What is the main difference between an inner class and a static nested class in Java? Does design / implementation play a role in choosing one of these?
I want a green for "correct answer" and a red for "wrong answer". My current choice is rgb(144, 238, 144) for the green and rgb(250, 128, 114) for the red. (See wikilearner.net/wiki for the colours in action.)  I have been told that these colors are very close in contrast, making it difficult for a person with red-green color-blindness. What would be a better choice? What Happens When A Gravitational Wave Interacts With Another One? If two gravitational waves came in contact with each other what would happen? In another question entirely, what happens when a higher gravitational field interacts with a weaker one. Swapping two variable value without using third variable Related questions with over 99 score display incorrectly Using Ubuntu 12.04. is there any way to hide a running process ?  That process shouldn't' display in system monitor,top,htop . There is no problem to remember the process id (PID) so observation of the process can be done easily .but i want to hide the process completely . is there any way ? Is $\exists x(x=a)$ a valid formula in first order logic with equality? Under , is $\exists x(x=a)$ true in every interpretation in first order logic (FOL) with equality? If so, could $\exists x(x=a)$ be considered a tautology? This question was motivated by  which was closed for lacking clarity. Here I have attempted to add that clarity myself so that the same question can be useful to others who are wondering a similar thing. This is a self answer question. Light Presets .exr I would like to install light presets for Blender to automate my lightning in my scenes. I have some .exr files (from Greyscalegorilla) but I don't know how to do it on Blender to make it work. Can someone help me? Thank you Intermediate fields between $\mathbb{Z}_2 (\sqrt{x},\sqrt{y})$ and $\mathbb{Z}_2 (x,y)$ In The Dark Knight Rises, at the beginning of the film Bane kidnapped a guy from the plane, then he drew blood from the guy he kidnapped. And then throughout the movie I didn't see any news regarding this kidnap scene. But, before the end of the movie we find out that the guy kidnapped by Bane was Dr Pavel. Bane needed him to convert the fusion project into a nuclear bomb and Dr Pavel was the only guy who could have done it.   But I don't understand, why did he draw blood from Dr Pavel? Windows 10 doesn't shut down properly External program from our Java program How can I write a program in Java that will execute another program? Also, the input of that program should be given from our program and the output of that program should be written into a file.  This is my small set of code to get its output:  Process p = Runtime.getRuntime().exec("C:\\j2sdk1.4.0\bin\\helloworld.java"); BufferedReader input =         new BufferedReader(new InputStreamReader(p.getInputStream())); while ((line = input.readLine()) != null)    System.out.println(line);  input.close();   This was my set of code but this throws an IOException. How to delete file with this name on linux: -]???????q Somehow a file named -]???????q got created on my terminal. I tried  rm -f "-]???????q"  (in double quotes), but it did not get deleted. (Error::  rm: invalid option -- ]).  How do I delete it? In the Stack Overflow podcast #36 (), this opinion was expressed: Once you understand how easy it is to set up a state machine, you’ll never try to use a regular expression inappropriately ever again. I've done a bunch of searching.  I've found some academic papers and other complicated examples, but I'd like to find a simple example that would help me understand this process.  I use a lot of regular expressions, and I'd like to make sure I never use one &quot;inappropriately&quot; ever again. Load your bag or Load your bike? Probably, another debatable question from my side.  When carrying items while riding, like water bottle, repair kits, pumps, or other stuffs that you might need, What is the best option.... to carry them?   On your cycle at saddle bag, handlebar bags, or pannier bags or etc.  or, On backpacks, like hydrant pack, or simple travel pack.   While loading on cycle, it will increase the weight of the bike, thus affect a lot of things, like speed, traction, more reactive on corners. Like while using pannier bags.. it will increase rear weight, making it difficult on uphill.   Also while loading on backpack, it will tire you down fast if its a big load, decreases your flexibility, agility &amp; etc.  So what is right way to do it?  Update:  The type of ride I generally, go to are commuting, mountain biking, &amp; trailing. And the items I generally carry are   Commuting: Water bottle(x2), Laptop (17"), books, copies, repair kits, hand pump, few other accessories. Mountain Biking &amp; Trailing: Water bottle(x2), repair kits, extra tubes, hand pumps, candybars &amp; few other accessories After I installed Ubuntu 13.04, I can't mount my NTFS partition.  Error mounting /dev/sda5 at /media/mrxfly/xFLyDiskData: Command-line `mount -t "ntfs" -o "uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000,dmask=0077,fmask=0177" "/dev/sda5" "/media/mrxfly/xFLyDiskData"' exited with non-zero exit status 14: The disk contains an unclean file system (0, 0). Metadata kept in Windows cache, refused to mount. Failed to mount '/dev/sda5': Operation not permitted The NTFS partition is in an unsafe state. Please resume and shutdown Windows fully (no hibernation or fast restarting), or mount the volume read-only with the 'ro' mount option. Proving the countability of algebraic numbers I am trying to prove that algebraic numbers are countably infinite, and I have a hint to use: after fixing the degree of the polynomial, consider summing the absolute values of its integer coefficients, and setting the sum less than or equal to $m$, for each $m \in \mathbb{N}$. I am also allowed to use the fact that every polynomial has a finite number of roots. I am not sure where to begin... Perhaps after fixing the degree of the polynomials, I could try enumerating them, and after proving countability of the set that contains the roots of all polynomials of a certain degree, I could state that the union of infinitely many ($\bigcup_{n=1}^{\infty}$, $n \in \mathbb{N}$) countably infinite sets is countable, and thus the algebraic numbers are countably infinite, too, but I am not sure if this is a good approach/how to enumerate the polynomials. Thanks! Every natural number $n$ can be written as $n=s-t$ with $\omega(s)=\omega(t)$ Can we prove the following statement ?  Let $\omega(m)$ denote the number of all distinct prime factors of a positive integer $m$. Prove that every  natural  number $n$ can  be  written  as $n=s-t$, where $s$ and $t$ are positive integers with $\omega(s)=\omega(t)$, in other words, as the difference of two positive integers with the same number of distinct prime factors.   If $n=1$ , we can choose $\ s=3\ $ and $\ t=2$.  If $n$ is even , we can choose $\ s=2n\ $ and $\ t=n$. Non-perpendicular hyperplane decision trees The usual implementation of decision trees, and estimators based on ensembles of decision trees, use decision trees that threshold on a single predictor at each split. So they divide the feature space into perpendicular hyperlanes.  Is there any benefit to generalizing this a tiny bit. So at each split, the decision tree uses 2 features, and thresholds based on whether $ax_1 + bx_2 \ge T$. In other words, the feature space is now getting divided into hyperplanes that are not necessarily perpendicular.   I think the main disadvantages would be:    increased computation, and  overfitting since now using more degrees of freedom   I guess to help both of these issues, randomization could be used analogous to extra trees. The pair of features could be randomly selected, instead of exhaustively trying every pair, and the threshold T and parameters a and b could be chosen randomly as well (perhaps from a set of few discrete values such that the hyperplanes could have a few orientations).  Are there some cases where you think these non-perpendicular decision trees would be an improvement over the regular implementation of various decision tree algorithms? How strong is Superman on Krypton? When Superman goes back to visit his home planet (using his ability to travel through time, I guess), is he:    an exceptionally strong and athletic Kryptonian? just an average Kryptonian male? a weakling on account of spending a lifetime in the comparative microgravity of Earth?   A possibly related question: why is Superman so muscular? What kind of weights does he lift to stay in shape?  The answers to  are all about Superman's superpowers on Earth compared with other visitors from Krypton; I'm asking about Kal El without his superpowers.  Clarification: I'm asking about the "classic"  Superman, say late Golden to early Silver Age, roughly 1945-1960. (Yes, I know the concept evolved during those years.) I'm not sure what that would be in terms of "numbered Earths", those came along after my time. I'm pretty sure the Kryptonians of that era had no superpowers in their native milieu, nor would Kal El if he were deported in space-time to his native world. Was Dumbledore aware that Professor Snape took points from Harry/Gryffindor unfairly? In many situations, we see Professor Snape behave in an unfair manner.   Snape unfairly and arbitrarily takes house points away from Harry/Gryffindors.  Was Dumbledore aware of this and, if so, did he just not care, or did he support this to somehow help Snape's double agent role?