When a question is deleted the same vote-day as it was closed, refund the close votes cast on the question.  There are three situations where this comes up:   Question has a close vote or two, a comment tells the OP that this is off topic (or about issues with the question) and the OP self deletes the question.     Note this would also cover a narrower feature request:   Question is crap.  It gets a bunch of fast close votes and down votes and then 3x fast delete votes from 20k users.  The question is gone. Question is deleted by moderator   In these situations, the close votes were either unneeded or a means to an end of getting rid of the crap (and if the close to allow the speedy delete votes wasn't done a moderator might have just nuked it).  So, refund these close votes.  Part of the issue is that I sometimes find myself holding back on closing obvious crap (its at -4 and 3 close votes) because I won't be able to address other questions that need closing.  Or a question about career advice (close it quickly so it doesn't get any answers that make janitorial work later harder) close and comment? or just comment hoping the OP will self delete it? And if I just comment someone else might answer when its sitting at 4 close votes and I didn't close it...  A classic example of such where refunding the close votes spent is:    though having days where my close vote history looks like:    or for the first 12 of my 24 daily close votes, five being deleted already:    and then a few hours later...    On sites where close votes or community moderation is a scarce resource, the ability to get back close votes of things that were closed and deleted rapidly can help facilitate better and more prompt (closing the question) feedback to the original poster and improve (or maintain) the quality on the site.

We should recover close votes cast on questions which are deleted by the owner before actually being closed.   For example, a user posts a question, and I think to myself that it looks familiar. A search turns up one (or several) pretty clear duplicates, so I vote to close and provide the link to the older question(s). A short time later, the OP comes by and realizes that their question is, indeed, a duplicate and decides to delete it.  What I don't like about this is that I've essentially "wasted" a close vote. Now I'll admit, I've never actually used all my allotted close votes in a day yet, but it's a little disappointing to know that I've effectively squandered a vote pointlessly when it could have been used for something more productive instead (i.e. a question that really ought to be closed for whatever reason).  I suppose there's also some hypothetical room for abuse of this current mechanic (trying to force people to waste votes), but with moderators on the boards I think that's a non-issue.


Recently i read that ( i cannot remember where though)   $$\sum_{k=0}^{\infty}\frac{1}{(2k)!!} = \sqrt{e} $$  Wolfram also confirms this , but I have been looking everywhere to find a proof and i cannot. Could anybody provide one or direct me to a site that provides one?   Thank you very much in advance for your time and help!!

Proving that $$\sum_{n=0}^{\infty }\frac{1}{(2n)!!}=\sqrt{e}$$ Firstly, I tried to check the value with the exponential function at $x=.5$ but I found its terms not equal to the series terms.


I know how to set a background colour for the whole slide, but can I make one column have a different background (and font) colour? Ideally not just by setting a static two-colour background, as I might want to change the column width and not have to remake the background image.

How do I change the background color of a column in Beamer? (the entire column)  (This is a simple question, but for the life of me, I cannot not find an answer.)  Example:  \documentclass[t]{beamer} \setbeamersize{text margin left=1em, text margin right=1em} \begin{document}  \begin{frame}{Test} \begin{columns}[t,onlytextwidth] \begin{column}{0.5\textwidth} Some text. \end{column} \begin{column}{0.5\textwidth} Some question. \[1+1=2\] \end{column} \end{columns} \end{frame}  \end{document}   What I would like:


I am talking about converting floats that already store integer values (like 10.0) I need to do this because I want to create a simple function that reverses a given integer, and it uses a line of code that looks something like this: ans += x % (int)pow(10, i); (the % operator needs both arguments to be integer, and pow returns a double)  C++ is not very happy doing this conversion properly. For pow(10, 4), I get a value of 9999, which is very irritating. Why this error occurs is obvious, 10^4 must have been stored as 9999.999999... or something like that. I could possibly fix this error by using the lround() function, but that would be a less than optimal solution because what if I overlook a similar error like this?  Is there a way to do mathematics in C++ without worrying about such trivialties? If not, what language should I choose to do computation like this? I have briefly used the bigInt library in python. Any suggestions regarding which language and library to use to tackle this issue would be very helpful.

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


I wiped my computer a while ago and I re installed a new version of Ubuntu, I believe I was on 11.10 now 12.04. Downloaded the Flash player as usual from the Software Center.    This is what I get when I try to go to a Youtube video (The size of the screen cap is how large the video should be.) When I encountered this, I looked through and found the extra Flash add on that Firefox said it needed being Gnash SWF Viewer, that was a waist, no change.  Downloaded Chromium, same thing happened. Re-installed the Flash player, nothing. I'm stumped frankly, can't find anything around with an answer for this so far, maybe I'm looking for it in a wrong way?

I recently installed Lubuntu but I have a problem with Adobe Flash Player. I always see something that looks like this when I open a video:    (source: )    The video is small, grainy, and is green and purple.  I tried to reinstall Flash and to test it in multiple browsers without success. I installed an older version of Flash but no result.  [0300]: Intel Corporation 82865G Integrated Graphics Controller [8086:2572] (rev 02)     Subsystem: Hewlett-Packard Company D530 sff(dc578av) [103c:12bc]     Kernel driver in use: i915


I've started by saying $a_n$=$1+a+a^2+...+a^n$=$\frac{1-a^{n+1}}{1-a}$  Now I think I need to do: $lim_{n\to \infty}$$\frac{1-a^{n+1}}{1-a}$  Should let $a=2$ and then solve the limit, then write a proof for it using $\epsilon$?  I've also considered that $1+a+a^2+...+a^n$=$1+a^n$. But I'm not sure what to do with this information.  I'd like to understand how to start this problem properly.

So what I am trying to prove is for any real number x and natural number n, prove $$x^n-1=(x-1)(x^{n-1}+x^{n-2}+...+x+1)$$   I think that to prove this I should use induction, however I am a bit stuck with how to implement my induction hypothesis. My base case is when $n=2$ we have on the left side of the equation $x^2-1$ and on the right side: $(x-1)(x+1)$ which when distributed is $x^2-1$. So my base case holds.   Now I assume that $x^n-1=(x-1)(x^{n-1}+x^{n-2}+...+x+1)$ for some $n$. However, this is where I am stuck. Am I trying to show $x^{n+1}-1=(x-1)(x^n + x^{n-1}+x^{n-2}+...+x+1)$? I am still a novice when it comes to these induction proofs. Thanks


For example, instead of testing the difference in mean, I want to test the difference in the 75th percentile of the 2 groups.  Does the central limit theorem hold? and what would be the equation for the standard error?

I am using r and have ~400 observations divided into 3 groups.  Group A contains 199 observations, while B contains 173 and C contains 24. I have generated a boxplot of their corresponding measures and would like to compare the 3rd quartile between them to see if they are significantly different. I've included the boxplot here.  I'm not sure what test I should use to compare the 3rd quartile. Does anyone know?


I'm using black felt at the bottom, a small tin can, and black sponge around the inside of the can. I hot glued them onto the can, and then put 91% isopropyl alcohol in it. Afterwards, I used some clear wrap and put it over the top, then put a rubber band over it to make sure nothing came out. Instead of dry ice, I used a can of compressed air, and the bottom of the can has ice molecules on it, but I can't see any vapors. Any tips? Thanks

My setup:   plastic box (~1l) with the cover painted black mat the bottom of the box covered with sponges saturated with ethyl alcohol (90%) to the limit (all over sponge capacity poured back to bottle) turned upside down and placed on ~0.5kg of dry ice.   I can see a 'rain' of particles of alcohol, but no traces.  I disassembled smoke detector and attached the sample of americium to the box. No effect.  Here is the 'rain':   Here are some pictures of the setup:          Any help appreciated.


I just watched a  about the laboratory production of [solid] metallic hydrogen for the first time. I was surprised to find the researchers predicting that, once produced, it might remain solid at atmospheric pressure. The video says they will test this in a couple of weeks, so I guess we'll know then, but in the mean time I'm curious about how plausible this is.  As noted in the answer to  it seems this prediction was made in the 1970s, and it seems that people have speculated since then about possible applications if it is the case. (For example, it would be a revolutionary rocket fuel.) However, it isn't clear to me whether that early result has been backed up or made less plausible by more recent calculations. Does anyone know the current state of the art in terms of predictions about the stability of metallic hydrogen at low pressures?

Below the question  there is a  that directed me to the BBC News summary . In their attempt to balance the skepticism of this particular reported observation with the potential implications of producing metallic hydrogen in a laboratory, the BBC included some far-reaching possibilities:  If that is true - and it is a controversial claim - it fulfills a more than 80-year quest to produce what many have said would be a wonder material. Theory suggests metallic hydrogen could be used to make zero-resistance electrical wiring and super-powerful rocket fuel, among many applications.  At the end of the article:  "The scepticism here is probably a good thing, in that it will drive many groups towards attempting to reproduce this experiment. This publication will certainly incite the field. Again, if it holds up, this is an exciting result. I think in this case time will tell," he told BBC News.  ...referring to Marcus Knudson from Sandia National Laboratories.  And Jeffrey McMahon from Washington State University concurred: "With respect to the tiny sample amount: Such experiments are performed in small diamond anvil cells. One challenge would be to make a larger quantity (at once); another, perhaps bigger challenge is to recover even the small sample (ie, remove it from the extreme pressures that it is under in the diamond anvil cell). "Whether the latter is possible is an important open question."  Question: Are there published, peer-reviewed predictions that hydrogen could remain metallic at ambient pressure? A link or reference would be appreciated. If it's still in pre-print form (AeXiv) that's OK too. If it's possible, a little help understanding the prediction would be great as well: I know there are many predicted crystalline forms of water ice at elevated pressures and/or reduced temperatures, and many or most of these have been observed, but I think most of them revert once pressure is reduced to ambient. Also the  comes to mind. If there is such a prediction of the possibility of hydrogen remaining metallic at ambient, is there an analogous example of this with a material I'm more familliar with, or is this something quite new?


I've created an operator that uses a keymap to activate it.  While it works in object mode, it is not being called in edit mode.  Is there a way to get this to run in edit mode too? import bpy   class GridRescale(bpy.types.Operator):     """Change grid scale"""     bl_idname = "kitfox.grid_rescale"     bl_label = "Grid Rescale"     bl_options = {'REGISTER'}      def invoke(self, context, event):         scale = bpy.context.space_data.overlay.grid_scale                  if event.type == "LEFT_ARROW":             scale /= 2         elif  event.type == "RIGHT_ARROW":             scale *= 2                  bpy.context.space_data.overlay.grid_scale = scale         self.report({'INFO'}, "Grid scale: %f" % (scale))         return {'FINISHED'}   # store keymaps here to access after registration addon_keymaps = []   def register():     bpy.utils.register_class(GridRescale)      # handle the keymap     wm = bpy.context.window_manager     km = wm.keyconfigs.addon.keymaps.new(name='Object Mode', space_type='EMPTY')      kmi = km.keymap_items.new(GridRescale.bl_idname, 'LEFT_ARROW', 'PRESS', ctrl=True, shift=False)     kmi = km.keymap_items.new(GridRescale.bl_idname, 'RIGHT_ARROW', 'PRESS', ctrl=True, shift=False)      addon_keymaps.append(km)            def unregister():     bpy.utils.unregister_class(GridRescale)      # handle the keymap     wm = bpy.context.window_manager     for km in addon_keymaps:         wm.keyconfigs.addon.keymaps.remove(km)     # clear the list     del addon_keymaps[:]   if __name__ == "__main__":     register()

How can I create a keyboard shortcut for a specific operator with using the python API?


I'm using live mode to boot Ubuntu from an USB. Every time I restart the computer all files are gone. How can I store files on the USB running the live install?

Persistent live drive with a partition for persistence There are some web sites describing  new tools new features in [new versions of] old tools  that can create a persistent live drive from an iso file with Ubuntu 19.10 and the corresponding Ubuntu family flavours.  Why and how does it work? How is it different from earlier methods for persistent live drives? Isn't live the default for a cloned drive?


I updated Winamp today from the market and now I'm having troubles playing shoutcast stations and some mp3's. Is it possible to rollback only the update I installed this morning? or am I out of luck?

I have an app installed on my phone, which I've installed from the Google Play Store.  If I update the app and don't like the upgraded version, is there a way to undo the update and downgrade back to the version of the app that I had previously installed?  I tried searching a bunch on this site, and I found lots of questions about downgrading the OS/ROM/firmware, but nothing about downgrading app versions or reverting an app update.


I read the following sentence, "My mother won't put up with my sister or I swearing." My question is, should the sentence say, "my sister or I" or "my sister or me"?

I just stumbled upon a :     My wife and I's seafood collaboration dinner. How does it look?   Sure enough, the top comment immediately points out that it should be "my wife's and my". However, a cross-post to the Grammar subreddit produced :     It's fine as it is written. "my wife and I" is a noun phrase, functioning as a subjective pronoun in the singular and made possessive with the apostrophe. It is exactly the same as "our".      It seems weird because you would never use "I's" on its own but it is not on its own here - it is part of a noun phrase.   That's a rather intriguing argument. Does it hold any water?


I am getting very low space please help. I want to install or transfer apps on external SD card completly.

I've installed an Android ROM on my HTC HD2, and it's working smoothly and responsively. I've gotten calling, SMS, MMS and internet to work flawlessly. I do however have one small problem. With only Android installed, my phone only has a few hundred kilobytes of space left in it's internal memory. I have an SD card inserted with 16GB available that's not being used.  After 6 hours of use I'm already getting error messages about SMS message memory being full, and I can't download apps due to the lack of space.  Any way I can get my Android phone to treat the SD card as "default" location for saving files, including images from the camera, images recieved from MMS, apps, text messages, mails and application data?


I want to find the PDF of $Y = \sin^2(X)$, where $X ∼ \text{Exponential}(\lambda)$ is a random variable. I thought i had solved this correctly by simply finding the inverse $h(Y) = X$ and taking the derivative via the chain rule. However, I was told that the solution of this problem would involve an infinite sum, but my solution did not, so I assume it was wrong. I can see why there would be an infinite sum due to the adding up of all the sine intervals, but I could not seem to figure out how to find an expression for each of these intervals that I can then sum up.  Any help would be greatly appreciated, thank you very much in advance!

Suppose X ∼ Exponential(λ). Find the PDF of $$Y = sin^2(X)$$ Note: While the solution involves an infinite sum, it is an example of a geometric series and so can be evaluated.  My answer so far: I was able to go as far as finding the bounds, and now I am stuck on the integral itself. As in the directions, we are told to use a geometric series, but I don't know how to proceed from here.   The integral which will give me the CDF   I also have the piece $$P(0 <= x <= arcsin(\sqrt t))$$ I know this does not included in the integral, but I don't know how to incorporate it into my CDF.   $$\int_a^b \lambda\ e^-\lambda x\ \,dx,$$  $$ a = k \pi\ - arcsin(\sqrt t)$$  $$ b = k \pi\ + arcsin(\sqrt t)$$


I tried to use  on Ubuntu 12.04 to create an application, but it does not behave as described in that linked page. I don't get a popup when creating the application (see error below).  % quickly create ubuntu-application foo Creating project directory foo Creating bzr repository and committing Launching your newly created project!  (foo:16847): GLib-GIO-ERROR **: Settings schema 'org.gnome.desktop.interface' is not installed  Congrats, your new project is setup! cd /tmp/foo/ to start hacking.   It creates a project, but when I try to run, it crashes and burns:  % cd foo  % quickly run  (foo:22639): GLib-GIO-ERROR **: Settings schema 'org.gnome.desktop.interface' is not installed   Is this because I'm not using gnome-shell? What can I do to get a working project?  (Edit: As a side note, I'd be willing to debug this myself, but I don't even get a traceback. What do I have to do to get quickly to give me a traceback?)

Getting an error while running quickly app:  Creating project directory sata Creating bzr repository and committing Launching your newly created project!  (sata:2701): GLib-GIO-ERROR **: Settings schema 'org.gnome.desktop.interface' is not installed  Congrats, your new project is setup! cd /home/blacksaint/sata/ to start hacking.   Actually after this the app should pop - up but it really doesn't do so!


First time asking a question on stackoverflow. I am stuck trying to solve this. This is my code:   a = int(input())  b = int(input())   Given two non-zero integers, print "YES" if exactly one of them is positive and print "NO" otherwise.  if (a > 0) or (b > 0):     print('YES')  else:     print('NO')

How do you get the  of two variables in Python?  For example, I have two variables that I expect to be strings. I want to test that only one of them contains a True value (is not None or the empty string):  str1 = raw_input("Enter string one:") str2 = raw_input("Enter string two:") if logical_xor(str1, str2):     print "ok" else:     print "bad"   The ^ operator seems to be bitwise, and not defined on all objects:  >>> 1 ^ 1 0 >>> 2 ^ 1 3 >>> "abc" ^ "" Traceback (most recent call last):   File "<stdin>", line 1, in <module> TypeError: unsupported operand type(s) for ^: 'str' and 'str'


I am new to group theory, and I observed that some multiplicative mod-n groups are cyclic and some are not . For ex :   $U(8) = (1,3,5,7)$ is not cyclic , but  $U(10) = (1,3,7,9)$ is cyclic and its generators are $(1,3,9)$.  How do we find which multiplicative group is cyclic, which is not?

When can we say a multiplicative group of integers modulo $n$, i.e., $U_n$ is  cyclic?   $$U_n=\{a \in\mathbb  Z_n \mid \gcd(a,n)=1 \}$$  I searched the internet but did not get a clear idea.


I have this idea and maybe it is not feasible, but I think it worth asking.  Let's say a user is running this command:  cat ~/file.txt   Whenever something tries to read from this file, I would like to run a script or command in the background instead and return the response of that script as content.  Somehow like doing:  ln -s /folder /symlink   But for scripts (idea of what I have in mind):  symlinkcommand /filepath/file.txt "command to run"   Hope I made myself clear. Please reply with your ideas and suggestions if any.  Thanks.

Is there any way to create a virtual file, such that reading from the file actually reads from the stdout of a command; writing to the file is acually writing to the stdin of a command?  So far I have kludged this with an inotifywait on a file, which calls a command when the file is modified, taking it's input from the file and writing back to it.  I don't like that the inotifywait has to be constantly restarted though (and I have to ensure that it is always running). I only use this file perhaps twice a week.


I have been working on a project and when I started using the camera I noticed its view did not go very far, any way of increasing this?  here is what I mean, you can see the view is curving around the Minecraft blocks and not showing the scene.

I have created a simple model here   When rendering it the end of it is cut off   How can I get the camera to render a longer distance?


I have been using a location allocation model for several months now, with no issue. The load location feature is extremely slow, minutes for 1 point.   There is a spatial index and i have deleted and updated them several times. I have tried older versions and used older (faster) networks. All to no success.  I have seen this question and answer:    Is there anything else to be done?

I am currently using ArcGis Network Analyst to calculate an OD cost matrix.  I was wondering whether there is a faster way to  (origins, destinations and barriers) because my current rate is around 10 locations loaded per second (which is quite slow for I have about 7.000 points to load).  Moreover, is there a way to save these locations in order to use them later?   I think of origins/destinations but also of the barriers. I didn't find anything about this in the ArcGIS documentation.


This is a question about the comics - as it relates to the Captain Marvel 2019 movie.  My understanding of the Marvel comic history (which is admittedly limited) is that Skrulls are evil conquerors. This is played heavily on throughout the movie as well.      However, in the movie, we learn that Carol has been deceived and that the Kree she had been working for were actually evil. The Skrulls she spent the movie fighting were actually innocent refugees or something similar and apparently good, just looking for a way off the planet to find a new home.   So I'm curious if the Skrulls' society in the comics is more complex than just simple shape-shifting conquerors, if there are pockets of peaceful Skrulls disloyal to their cause, or      is the movie adaptation just a major deviation from the comics, showing that the Skrulls are good guys all along?

It is my understanding that in Marvel Comics, Skrulls are considered evil. For instance, in The Skrull Invasion, the Skrulls are the bad guys kidnapping people and such. I thought the Skrulls were evil. At least, that was my understanding until very recently. In Captain Marvel,      the Skrulls are portrayed as the ones who are actually the good guys, instead of the Kree.   This came as a total shock to me, as I always thought the Skrulls were totally evil. While comic book movies/TV generally don't always adapt things perfectly from the comics (Civil War, or The Trial of the Flash are good examples), I don't think they usually go that far off.  So, what I guess I'm asking is, while the Kree and the Skrulls are definitely enemies, does Marvel usually take the side of the Kree and designate the Skulls as "evil", or is it usually more complicated than that?


This one should be simple.  I want to match any numbers that do NOT have a series of numbers in the front.  I have the regex, but it does the exact opposite. I need an inverse of it.  Examples:  123456 - NOT MATCH 456789 - MATCH 451236 - MATCH   Right now, it's the opposite of the above.  The regex: ^(123)

I'm using RegexBuddy but I'm in trouble anyway with this thing :\  I'm processing line by line a file. I built a "line model" to match what I want.  Now i'd like to do an inverse match... i.e. I want to match lines where there is a string of 6 letters, but only if these six letters are not Andrea, how should I do that?    EDIT: I'll write the program that uses this regex, I don't know yet if in python or php, I'm doing this thing first to learn some regex :) There are different types of line, I wanted to use regex to select the type i'm interested in. Once I got these lines I've to apply an other filter just to do not match a known value, I need all the others, not that. The (?!not-wanted) is working pretty fine, thank you. :-)  I hope this clarifies the question :)


I own an old Asus P50IJ laptop .  CPU: Intel Core 2 Duo processor, 2.2 GHz ~ 2 GHz RAM: DDR2 800 MHz SDRAM, 2 x SO-DIMM sockets for expansion up to 4 GB SDRAM OS: Windows 7 preinstalled  Since I'm about to install an SSD to run the OS is it feasible to think about installing Ubuntu 20.04 on this old laptop?

For a given hardware configuration, how do I find out if Ubuntu will run on it? What considerations should I take into account when choosing an Ubuntu version and  such as:    with a lighter desktop than the usual Gnome and Unity  with the even lighter LXDE desktop   Obviously Ubuntu does not run on some processor architectures. So how do I go about choosing the right version and derivate. How can I find out the minmal system requirements?


Is there a general method to find the number of non-negative integral solutions for $$ \sum_{i=1}^k i\cdot x_i = n $$

Suppose $n$ be a given positive integer. Then the Diophantine equation $x=n$ has only $1$ solution. Just by inspection, I found that the Diophantine equation $x+2y=n$ has $\left\lfloor \dfrac{n}{2}+1\right\rfloor$ non-negative solutions for $(x,y).$ Also, according to  the Diophantine equation $x+2y+3z=n$ has $\left\lfloor \dfrac{n^2}{12}+\dfrac{n}{2}+1 \right\rfloor$ non-negative solutions for $(x,y).$  Is there any closed form for the number of non-negative integer solutions for $(x_1,x_2,\cdots,x_k)$ of $$x_1+2x_2+3x_3+\cdots+kx_k=n$$ for a given $k\in\Bbb{N}$? How can I prove these formulas rigorously?  EDIT After a very tedious calculation I found that the equation $w+2x+3y+4z=n$ has  $\left\lfloor \dfrac{n^3}{144}+\dfrac{5n^2}{48}+\dfrac{(15+(-1)^n)n}{32}+1 \right\rfloor$ solutions. This solution completely agree with the approximation given by Rus May. However still I believe that we can do something more than this.


Suppose there is an object of weight 'mg'. If we apply a force equal to mg, why the object is lifted up as its weight and the force applied are equal and opposite in direction should be cancelled out and the object should not move at all?

If the friction on an object is 200 N and you apply 200 N, it seems, the forces should immediately cancel each other out since the friction and your applied force go in opposite directions, leaving you with an object that is motionless. Yet, from what I've read, that's not the case. I feel like I'm misunderstanding something. Could it be I'm wrong about needing to apply 200 N initially? Might the amount of force I actually need be greater, but instantaneously decrease to 200 N?


I've been visiting this site for a while and while I'm really curious about UX, I've become really frustrated switching between reading about theory and usability. I'm asking this question with the assumption that what I can do about implementing UX knowledge is mostly by wireframing and communicating the problems I am solving, but it seems like a nontrivial task when you don't have any direction.

Presenting your UX design on the portfolio is more than just showing off some screenshots of the wireframe or finished graphics. I am just wondering what your thoughts are on the ideal way to display your UX work on a web portfolio.   At the moment I am thinking about a combination of slideshow with sufficient amount of text to showcase the interface along with the thought process behind key design decisions.   Is this a good idea, or is there a better alternative approach?


I am currently trying to debug an application and I am passing debug command line arguments via Visual Studio when starting the application as this is the only way available to me to debug this.  When I use either the > or < symbols in the command line arguments they are simply ignored. This does not happen when the application is called via command prompt however.  I have tried using 'ampersand' gt; , but this did not work. Can anyone please advise?  EDIT: The code I'm using is    Processor.CommandLineArgs = My.Application.CommandLineArgs    An example of it being used is me passing "/output.txt />3"    My.Application.CommandLineArgs has 2 items, "/output.txt" and "/3"

I need to echo a string containing angle brackets (< and >) to a file on a Windows machine.  Basically what I want to do is the following: echo some string < with angle > brackets >>myfile.txt  This doesn't work since the command interpreter gets confused with the angle brackets.  I could quote the whole string like this: echo "some string < with angle > brackets" >>myfile.txt  But then I have double quotes in my file that I don't want.    Escaping the brackets ala unix doesn't work either: echo some string \< with angle \> brackets >>myfile.txt  Ideas?


I couldn't find any solution to this. I need to remove the power off menu button (not the entire panel but just button highlighted in yellow hexagon) from the UI.     How can it be done?

I have an Ubuntu 10.04 LTS Desktop PC with GNOME.   How can I fully disable the reboot/shutdown/suspend/hibernate functions in GNOME or even with root? So that the root gives out the "reboot" or "pm-suspend" command it doesn't do anything, and the machine goes on. How can I fully disable these basic "features"?


"Change the default branch on github." is correct?  Isi a technical sentence. Github is a website. Need I use "in" or "on" for a website? I do not care what is more appropriate. I care about what is right and why.

What's the difference between say:     "The project will be on GitHub",      "The project will be in GitHub" and      "The project will be at GitHub"?


I am attempting to evaluate the following integral: $$\int_0^\infty \frac{(ln(x))^2 }{1+x^2}dx$$  Using the substitution $x=e^u$ and $dx=e^u du$, I get: $$\int_{-\infty}^\infty \frac{u^2}{e^{-u} + e^u} du$$  It's suggested that I evaluate this integral in the complex plane. How do I complete this problem?  The problem is found in Arfken.

How do I compute      $$\int_0^\infty \frac{(\log x)^2}{1+x^2} dx$$   What I am doing is take   $$f(z)=\frac{(\log z)^2}{1+z^2}$$  and calculating   $\text{Res}(f,z=i) = \dfrac{d}{dz} \dfrac{(\log z)^2}{1+z^2}$ which came out to be $\dfrac{\pi}{2}-\dfrac{i\pi^2}{8}+\dfrac{i\pi}{2}$  Im not too sure how to move on from here. the given answer is $\dfrac{\pi^3}{8}$  Any help will be appreciated. thank you in advanced.


I have a button which simulates the heatmap. I use setInterval function when the button onclicked    <button onclick="setInterval(function(){update_map()},50);">simulate</button>   My function is below:  function update_map(){   counter+=50;   var i =1   for(i=counter-50;i<<?php echo json_encode($lat); ?>.length & i<counter;i++){   taxiData.push(new google.maps.LatLng(<?php echo json_encode($lat); ?>[i],<?php echo json_encode($log); ?>[i]));  }   var pointArray = new google.maps.MVCArray(taxiData); heatmap = new google.maps.visualization.HeatmapLayer({     data: pointArray   });    heatmap.setMap(map);   if(i==<?php echo json_encode($lat); ?>.length )   clearInterval(setInterval(function(){update_map()},50)); }   Any kind of help or suggestion will be appreciated.

I am using setInterval(fname, 10000); to call a function every 10 seconds in JavaScript. Is it possible to stop calling it on some event?   I want the user to be able to stop the repeated refresh of data.


I've downloaded a free 3d car model, and everything seems to be fine except one thing: the windows act very weirdly. When in texture view, some of the faces seem like they are missing, while in the non texture view the surface looks solid. The texture is a solid grey square. I'd be very appreciative if someone could help me to fix this. I provided a few screenshots, so it would be easier to understand the issue.  Non textured and textured views   This is how it's rendering in Blender AND on a game engine (very badly)

I was following  on creating a watch and noticed that when I rendered the watch, some pieces were messed up.  I'm new to 3D modeling and I've just learned Blender, I can't explain it well, so here's a picture:    Other examples:     I don't know if it's a problem with my World texture, the object, or the object's texture/material, so I can't even guess how to fix it. What causes this? Is it possible to fix it?


Is it possible, to turn this into a one-liner with a nested expression? simpler put: stuffing the first line into the second. scriptPath="$(readlink -f ${BASH_SOURCE[0]})" containerDir=${scriptPath%/*}  If it had to be , that's fine, too. Although I would prefer without.

I would like to use variable substitution on a particular string that I access via a command. For example, if I copy something into my clipboard, I can access it like this.  $ xclip -o -selection clipboard Here's a string I just copied.   If I assign it to a variable, then I can do variable substitution on it.  $ var=$(xclip -o -selection clipboard) $ echo $var Here's a string I just copied. $ echo ${var/copi/knott} Here's a string I just knotted.   However, is there a way to do variable substitution without assigning it to a variable? Conceptually, something like this.  $ echo ${$(xclip -o -selection clipboard)/copi/knott} bash: ${$(xclip -o -selection clipboard)/copi/knott}: bad substitution   This syntax fails, because var should be a variable name, not a string.


I have a single table in which there is a column "Name" and want to find the total area of all those polygons where value of Name is Cardiff. I have more than one polygons with this name.

I have a vector layer of habitats. Each feature belongs to a category and has its area calculated. I'm trying to find out the total area of each type of habitat.  I've looked at QGIS "Statistics by categories" which gives everything but the Sum of each category.  The GroupStats plugin looks like it would do it, but I can't get the "calculate" button to activate.  I'm new to QGIS tools/scripts etc but happy to try to modify an existing tool but haven't yet found where they are or how to do this.


Every time I Google for any CSS property, the first result is always on w3schools.com (a.k.a. the most useless, bogus and misleading site around).  Is there a way to add it to some sort of a black list, to get useful results first instead?

I regularly find sites that copy content from elsewhere (mailing lists, etc) while not providing any added value. Quite to the contrary, they are pretty heaped with ads.  I'd like to remove those sites as permanently as possible from my Google search results. Any ideas?


Prove that if $F_1, F_2, ..., F_k$ are closed sets in $R^{n},$ then $\cup_{i = 1}^{k}F_i$ is also a closed set in $\mathbb{R}^{n}.$

Let $X$ be a metric space.  If $F_i \subset X$ is closed for $1 \leq i \leq n$, prove that $\bigcup_{i=1}^n F_i$ is also closed.  I'm looking for a direct proof of this theorem.  (I already know a proof which first shows that a finite intersection of open sets is also open, and then applies De Morgan's law and the theorem "the complement of an open set is closed.")  Note that the theorem is not necessarily true for an infinite collection of closed $\{F_\alpha\}$.  Here are the definitions I'm using:  Let $X$ be a metric space with distance function $d(p, q)$.  For any $p \in X$, the neighborhood $N_r(p)$ is the set $\{x \in X \,|\, d(p, x) < r\}$.  Any $p \in X$ is a limit point of $E$ if $\forall r > 0$, $N_r(p) \cap E \neq \{p\}$ and $\neq \emptyset$.  Any subset $E$ of $X$ is closed if it contains all of its limit points.


I'm looking for dictionaries for download. I have found word lists from some , etc. but these lists are incomplete and do not cover word definitions and, perhaps, a thesaurus.  I also know about dictionary APIs, unfortunately they either have query limitations or do not allow downloading their database.  I should mention that my interest in this is strictly personal.    ** NOTE **  I should also mention that this question is not about a program (or software), but the raw files. I am hoping something like XML, JSON, MySQL dump, text, etc. But not necessarily limited to this.    I know it's a bit to ask, but I'd like to know if such thing even exists? Is there anyone who would know where I can download en entire dictionary database, with word description, etc. (and possibly the synonyms)?  Thank you.

I would like to download an English dictionary -- not just a  -- in a structured format such as TXT, XML, or SQL.   Specifically, I need phonetic pronunciation and parts of speech (definition is not required).  Surprisingly, I can't find this online anywhere.  is available , but it only the mediawiki articles themselves. Crawling all articles and extracting the phonetics and parts of speech would be a huge exercise.   Is this available anywhere? I don't mind paying.   Note: cross-posted .


first question to this forum and i would be happy if someone could help me.  I am building a PC and i have bought some components. I already bought the motherboard MSI H170 GAMING M3 with these specs:  -Supports 6th Gen Intel® Core™ / Pentium® / Celeron® processors for LGA 1151 socket  -Supports DDR4-2133 Memory. Supports ECC, un-buffered memory  -DDR4 Boost: Give your DDR4 memory a performance boost  So i tend to buy a kingston RAM 8GB at 2400mHZ  My questions are:  1)The motherboard specs mention that it supports DDR4 2133MHZ, will this ram run smoothly on this motherboard? Can it run at full 2400Mhz?  2) In the near future i plan to buy one more RAM of the same type. Will it run on dual channel?  Thanks in advance

If I want to add more RAM to my computer, how can I buy something compatible? What kinds are there? How do I determine which kind my computer will accept and how much I can add?


I have two directories with same files but with some difference in their contents. I want to list down those files which are differing. For example  There are two folders Folder1 and Folder2 with files file1,file2,file3,etc. file2 of Folder1 is not similar to file2 of Folder2.   So my command should list file2.  How can I do that ?

Suppose I have same version of linux kernel but I changed some driver lines. Is there any way to compare these kernels and list the results. The result would be helpful to go back if I changed a lot in original drivers.


when I select an option in jcombobox, it doesn't get close and throws null pointer exception... the code is given below....  public void itemStateChanged(ItemEvent e)  {     String[] selectedItem=null;     int i=0;     ArrayList<String> sub_list = new ArrayList<>();     try {         connection();         String s1="select subnm from subject where branch='"+combobranch.getSelectedItem()+"'";         System.out.println(s1);         rs = st.executeQuery(s1);          rs.first();          while(rs.next())         {             selectedItem[i] = rs.getString("subnm");             System.out.println(selectedItem[i]);             if(!sub_list.contains(selectedItem))             {                 sub_list.add(selectedItem[i]);             }         } DefaultComboBoxModel(sub_list.toArray()));     } catch (SQLException ex) {         Logger.getLogger(admin.class.getName()).log(Level.SEVERE, null, ex);     }   and the exceptions message shown below...!  Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException     at admin.itemStateChanged(admin.java:1201)     at javax.swing.JComboBox.fireItemStateChanged(JComboBox.java:1223)     at javax.swing.JComboBox.selectedItemChanged(JComboBox.java:1271)     at javax.swing.JComboBox.contentsChanged(JComboBox.java:1327)     at javax.swing.AbstractListModel.fireContentsChanged(AbstractListModel.java:118)     at javax.swing.DefaultComboBoxModel.setSelectedItem(DefaultComboBoxModel.java:93)     at javax.swing.JComboBox.setSelectedItem(JComboBox.java:576)     at javax.swing.JComboBox.setSelectedIndex(JComboBox.java:622)     at javax.swing.plaf.basic.BasicComboPopup$Handler.mouseReleased(BasicComboPopup.java:834)     at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:290)     at java.awt.Component.processMouseEvent(Component.java:6527)     at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)     at javax.swing.plaf.basic.BasicComboPopup$1.processMouseEvent(BasicComboPopup.java:498)     at java.awt.Component.processEvent(Component.java:6292)     at java.awt.Container.processEvent(Container.java:2234)     at java.awt.Component.dispatchEventImpl(Component.java:4883)     at java.awt.Container.dispatchEventImpl(Container.java:2292)     at java.awt.Component.dispatchEvent(Component.java:4705)     at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4898)     at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4533)     at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4462)     at java.awt.Container.dispatchEventImpl(Container.java:2278)     at java.awt.Window.dispatchEventImpl(Window.java:2739)     at java.awt.Component.dispatchEvent(Component.java:4705)     at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:746)     at java.awt.EventQueue.access$400(EventQueue.java:97)     at java.awt.EventQueue$3.run(EventQueue.java:697)     at java.awt.EventQueue$3.run(EventQueue.java:691)     at java.security.AccessController.doPrivileged(Native Method)     at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)     at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:86)     at java.awt.EventQueue$4.run(EventQueue.java:719)     at java.awt.EventQueue$4.run(EventQueue.java:717)     at java.security.AccessController.doPrivileged(Native Method)     at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)     at java.awt.EventQueue.dispatchEvent(EventQueue.java:716)     at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)     at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)     at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)     at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)     at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)     at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)     }   plz help me out!!!

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


My Great Grandmother is Half spanish what percent would that make me?

My sister, cousins, and other relatives speculate that my mom's grandmother was Jewish (for various reasons). I've heard people say at times things like, for example, "I'm 50% German" or "I'm 25% Swedish." This has to do with their ancestry. But, how exactly is this calculated? Say for example that my mother's paternal grandmother was indeed 100% Jewish, what would that make me and my siblings, and how is it calculated?


I have two functions in Javascript shown below:  function Add(){      $("#tbl tbody").append(         "
"+         "<input type='text'/>	"+         "<input type='text'/>	"+         "<input type='text'/>	"+         "<button class=\"btn btnSave\"></button><button class=\"btn btnDelete\"></button>	"+         "
"      );      $(".btnSave").bind("click", Save);           $(".btnDelete").bind("click", Delete);  };   and   function Delete(){      var par = $(this).parent().parent();      par.remove();  };   and finally these two lines after the functions:  $(".btnDelete").bind("click", Delete); $("#btnAdd").bind("click", Add);   The function Add() adds a new row to the table with id tbl. The last column in a newly added row has two buttons btnSave and btnDelete. btnDelete is supposed to delete that particular row as is evident from the Delete() function. (I have not started to implement the 'save' function yet). But, whenever I click the 'Delete' button, nothing happens. Is there a problem with the code?  I am using  for my UI.  Function Add() works properly by the way.   Edit: Here is a screen capture. The highlighted button cross is not working.

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


I am looking for general instructions on remapping keys.  Can someone tell me how to remap F9 to PrtScr and F10 to ScrollLock button?  I have looked through every thread here and none of the suggestions worked.  I am using a Swedish keyboard setup and Ubuntu 12.04.

I cannot make xmodmap run on login in Ubuntu 13.04. I have searched around, including in askubuntu and all answers I found do not work.  I have a file named .Xmodmap in my home folder which contains the desired mappings. If I run it manually it works fine, so there is no error there. In order to make it run on startup, I have tried:     Using various .xinitrc containing one of the following commands:      xmodmap .Xmodmap xmodmap ~/.Xmodmap   /usr/bin/xmodmap /home/NAME/.Xmodmap if [ -s ~/.Xmodmap ]; then xmodmap ~/.Xmodmap fi  Using .Xresources instead of .xinitrc with the same variations. Setting it as a startup application.   None of the above works in Ubuntu 13.04 (64-bit). I also saw a few ideas about globally changing the keyboard mappings, but most of them were not applicable in Ubuntu 13.04 (i.e. the corresponding files did not exist where specified) and I prefer not to touch the global settings anyway.


I booked ticket on jet airways from Rajkot to Nagpur ( One stop is in Mumbai),I have to change the plane to another both are jet airways only. Ticket booked direct from Rajkot to Nagpur The changing time is only 30 min. As per procedure check-in time closing before 45 min. Then how can I change the flight

I will be travelling from Udaipur to Bangalore via connecting flights. My first flight will land in Mumbai at 8:15 AM and the second one will depart from Mumbai at 8:45 AM. Both are Jet Airways flights.   Actually these tickets have been provided to me by my employer. I shared my concern with them that the layover time is very short, and the chances of missing flights are high. But they are saying that Jet Airways will make sure that I make it to the second flight. But still I have my doubts.   Can you please tell me if this is a fine arrangement. Thanks in advance.


I'm planning my first network with 2 subnets and came up with the following schema:    I'd like to know...   Would this work? Did I use the right amount of routers? Did I configure everything correctly? Plus, do I need to configure static routing here, so that every host within the subnets has internet access?

This is a  about IPv4 Subnets.      Related:               How does Subnetting Work, and How do you do it by hand or in your head?  Can someone explain both conceptually and with several examples? Server Fault gets lots of subnetting homework questions, so we could use an answer to point them to on Server Fault itself.   If I have a network, how do I figure out how to split it up? If I am given a netmask, how do I know what the network Range is for it? Sometimes there is a slash followed by a number, what is that number? Sometimes there is a subnet mask, but also a wildcard mask, they seem like the same thing but they are different? Someone mentioned something about knowing binary for this?


I last read the book in the early 90's, so it would have been written before then. The main plot is about an Earth person being sent on an undercover mission to an alien planet of extraordinarily handsome/beautiful people who resemble humans in every detail but one- the cartilage in their nose. These aliens are either trying to avoid contact with humans, or invade (I can't remember which), but their leader is not 100% decided. Their leader is appointed by being the best player on their world of a game very similar to chess. The human agent is a grand master of chess, and is sent there undercover, to play and win the title of leader, so that he can facilitate contact or avoid the forthcoming war.

I'm looking for this short story:  A game-playing man is recruited to voyage to an alien species which humanity doesn't know much about. They are very similar to humans, except something about their nose is different - it can be bent inwards.  They play a chess-like game which this human is good at.  He plays them, gradually meeting tougher and tougher opponents, until he gets to one who really challenges him, and he tries something that's never succeeded before - a "triple fake".  It turns out the aliens knew who he was all along and admire his effort.  It is not "Player of Games".  It's a short story from the 90s or earlier.


I have the following tikz picture in my tex document:  \documentclass{article} \usepackage{tikz} \usetikzlibrary{arrows,arrows.meta,shapes.misc} \usepackage{xifthen} \begin{document} \begin{center} \begin{tikzpicture}[>={Stealth[inset=0pt,length=8pt,angle'=28,round]}]   \def \n {8}   \def \radius {2cm}   \def \margin {8} % margin in angles, depends on the radius   \def\inittimes{{"1", "8", "3", "2", "6", "5", "7", "4"    }}%   \tikzset{cross/.style={cross out, draw,             minimum size=2*(#1-\pgflinewidth),             inner sep=0pt, outer sep=0pt, thick}, cross/.default={6.5}}   \foreach \s in {1,...,\n}   {     \pgfmathsetmacro\l{\inittimes[\s - 1]}     \ifthenelse{\s = 3}{ \pgfmathsetmacro\fcolor{"lightgray"}}{ \pgfmathsetmacro\fcolor{"white"}}     \node[draw, circle, fill=\fcolor ] (n\l) at ({360/\n * (\s - 1) + 90 }:\radius) {$\l$} ;     \ifthenelse{\l = 5 \OR \l = 8}{\draw ({360/\n * (\s - 1) + 90 }:\radius) node[cross] {}}{};   }   \foreach \d in {4,...,\n}   {     \ifthenelse{\d = 5 \OR \d = 8}{}{       \pgfmathsetmacro\l{\d + 1]}       \foreach \k in {\l,...,8}        {         \draw[->]            (n\d) edge node[fill=none,draw=none]{\tiny election} (n\k);       }     };   } \end{tikzpicture} \end{center} \end{document}   Which is rendered like this:    The problem is that the incoming arrows at nodes 5 and 7 don't align  nicely with center of the nodes, but are off-center.  Is it possible to fine-tune the arriving positions of the arrows, so they look like they point to center?

I am trying to use \pgfmathsetmacro inside a foreach loop to connect nodes which are adjacent and named according to position as follows:  \foreach \src in {0,...,\T}{     \pgfmathsetmacro{\dest}{\src+1};     \path (n-\src-1) edge[<-] (n-\dest-1); };   This however leads to the following error during compilation:  ./nn.tex:54: Package pgf Error: No shape named n-1 is known. [    }] ./nn.tex:54: Package pgf Error: No shape named n-2 is known. [    }] ./nn.tex:54: Package pgf Error: No shape named n-3 is known. [    }] ./nn.tex:54: Package pgf Error: No shape named n-4 is known. [    }]   which makes it seem as though the \dest value is not available. How do I get around this issue?  Thanks in advance!


The following code and its output shows that although the line drawn is scaled, the rectangle node is not scaled.  \documentclass{article} \usepackage{tikz} \begin{document}  \section*{Without Scaling} \begin{tikzpicture} \node at (0, 0) [rectangle,draw,minimum size=5cm] {A}; \draw (-2.5, 1) -- (2.5, 1) node[midway,below] {B}; \end{tikzpicture}  \section*{With Scaling} \begin{tikzpicture}[scale=0.5] \node at (0, 0) [rectangle,draw,minimum size=5cm] {A}; \draw (-2.5, 1) -- (2.5, 1) node[midway,below] {B}; \end{tikzpicture}  \end{document}     What is the right/recommended way to scale a tikzpicture such that:   All drawings are scaled. All nodes are scaled. But text is not scaled.

It seems that the scale option scales only the length of lines, but not the size of texts. For instance, 1 and true and not scaled in the following code.  \begin{tikzpicture}[thick, scale=0.6] \draw [dashed] (1,12) -- (11,12); \node[above] at (4,11) {1}; \node[above] at (8,11) {true}; \end{tikzpicture}   Could anyone tell me how to scale everything together within a tikzpicture? Thank you very much!  PS: It is a picture in a presentation with Beamer.


In the Cracking the Coding Interview Linked List question: Write code to remove duplicates from an unsorted linked list, the solution is  public static void deleteDups (LinkedListNode n){   Hashtable table = new Hashtable();   LinkedListNode previous = null;   while(n!=null){       if(table.containsKey(n.data)){           previous.next = n.next;       } else {           table.put(n.data, true);           previous = n;       }       n = n.next;   } }   My question is why does n = n.next not alter the linked list passed into the function, but doing previous.next = n.next and previous = n do alter the linked list passed in?

I always thought Java uses pass-by-reference. However, I've seen a couple of blog posts (for example, ) that claim that it isn't (the blog post says that Java uses pass-by-value). I don't think I understand the distinction they're making. What is the explanation?


I am trying to use python to solve Project Euler's questions.  The question i met is to add to all prime number below 2 millions.  My codes:  import math  def isPrime(number): if number == 2:     return True for x in range(2,number):     if number % x ==0:         return False return True  number = 3 ans = 2  while number<=2000000:     if(isPrime(number)):        print(number)        ans+=number     number+=2   I think it is working, however it is processing too slow. Is there any way to enhance it? (Without using a prime number set in memory). Thank you!

Could someone please tell me what I'm doing wrong with this code? It is just printing 'count' anyway.  I just want a very simple prime generator (nothing fancy).   import math  def main():     count = 3     one = 1     while one == 1:         for x in range(2, int(math.sqrt(count) + 1)):             if count % x == 0:                  continue             if count % x != 0:                 print count          count += 1


I have problems with my Tilgin Vood Router. As I try to start my router by turning the power on (captain obvious), it generally doesn't work the first 3-4 times. This is getting very annoying.  Five minutes after turning the power on the router's signal LEDs don't blink in the way they should do in a connected state. I can connect to my routers web configuration interface through my PC connected to it via LAN though I can't access the internet.  It usually takes the router five minutes to get to the point where it should be connected to the internet but as it doesn't work the first times.  So I turn on my router 3-5 times, let him work 5 minutes and then suddenly, after turning the power off and on again it all works.  The problem is regarding startup only, when I get it to work everything runs as smooth as a 1980-s text-based C++ game on a 3ghz machine.  I also have to restart my PC too in order for everything to work.   How can I solve this problem? Just leave the router turned on all time? I prefer a daily IP switch, though. May the problem have something to do with my PC? There is another one connected to the router too and it doesn't work there either.

I have problems with my Tilgin Vood Router. As I try to start my router by turning the power on (captain obvious), it generally doesn't work the first 3-4 times. This is getting very annoying.  Five minutes after turning the power on the router's signal LEDs don't blink in the way they should do in a connected state. I can connect to my routers web configuration interface through my PC connected to it via LAN though I can't access the internet.  It usually takes the router five minutes to get to the point where it should be connected to the internet but as it doesn't work the first times.  So I turn on my router 3-5 times, let him work 5 minutes and then suddenly, after turning the power off and on again it all works.  I also have to restart my PC too in order for everything to work.   How can I solve this problem? Just leave the router turned on all time? I prefer a daily IP switch, though. May the problem have something to do with my PC? There is another one connected to the router too and it doesn't work there either.


$\sum a_n = \sum{(\sqrt{n+1} - \sqrt{n})}$. I want to show that this diverges. I think the only way I can do it, is by using the comparison test, and finding a series less than it that diverges, but I can't think of a series that is used often/ easy to prove divergence for that is less than this one for all $n$. I was origionally thinking something like $\frac{1}{\sqrt{n}}$ or $\frac{1}{n}$, but those don't work

$$(\sqrt 2-\sqrt 1)+(\sqrt 3-\sqrt 2)+(\sqrt 4-\sqrt 3)+(\sqrt 5-\sqrt 4)…$$  I have found partial sums equal to natural numbers. The first 3 addends sum to 1. The first 8 sum to 2. The first 15 sum to 3. When the minuend in an addend is the square root of a perfect square, the partial sum is a natural number. So I believe this series to be divergent.  Am I right? Have I used correct terminology? How would this be expressed using sigma notation? Is there a proof that this series diverges?


I know that $a(b)^{-1}  b(b+d)^{-1} + c(d)^{-1}  d(b+d)^{-1} = (a+c)(b+d)^{-1}$.  Can this identity help me to prove the inequality?

We were trying to come up with an easy way to generate a rational number in between two existing rational numbers with a fairly low numerator and denominator (the way we were doing this earlier was to find the average of the two rationals, but that results in a denominator of up to $c * d$. Does this inequality hold for all values of $a, b, c, d$?


What is the right way to embed one question inside another?  For example:        "Do you know what is it?"    "Do you know what it is?"      Are they both grammatical? If one of them isn't, then why is it ungrammatical?  I can say the question "What is it?", so I assume I can also say the question "Do you know what is it?" Can't I?

Which of the following is a correct sentence:   Does anyone know where's Linda?  Does anyone know where Linda is?    Does anyone know why and how to use above usage if #2 is correct. Also please let me know this kind of specific structures.


I am having some difficultly establishing a bijection from the set of functions $ f: A\rightarrow  \{0,1\},$ to the power set of $A.$   For the case where $A$ is finite, I found that $2^{|A|}$ is the total amount of functions from $A$, and that $|P(A)| = 2^{|A|}$ as well. For the cases where $A$ is denumerable or uncountable I am unsure how to proceed. I know by Cantor's theorem that $|A| < |P(A)|$.

Given any set $X$, let $P(X)$ be the set of all subsets of $X$, and let $\{0,1\}^X$ be the set of all functions $X \rightarrow \{0,1\}$. Construct a bijection (and its inverse) between P(X) and $\{0,1\}^X$.    Let us define $f: P(X) \rightarrow \{0,1\}^X$ by $f(\alpha) = g_{\alpha}$ where $\alpha \in P(X)$ and $g_{\alpha} : X \rightarrow \{0,1\}$ is defined by  $$g_{\alpha}(x) =\begin{cases}        1 & x \in \alpha \\       0 & x \in X-\alpha     \end{cases}$$  We need to check if this function is well-defined. Let $\alpha, \beta \in P(X)$. If $\alpha=\beta$, then $\alpha$ and $\beta$ correspond to the same set, and so correspond to the same function since both $g_{\alpha}$ and $g_{\beta}$ send that set to 1 and the ($X-$that set) to 0.   If we have a function $g_{\alpha} \in \{0,1\}$, then $\alpha$ is a set in $X$ that is sent to 1. But since $P(X)$ is the set of all sets of $X$, we must have $\alpha \in P(X)$. So the function is surjective.  Finally, if $g_{\alpha}=g_{\beta}$ then both $g_{\alpha}$ and $g_{\beta}$ send the set $\alpha$ or $\beta$ to 1. So $\alpha$ and $\beta$ must be same set. In other words, the function is injective; and hence bijective.   The inverse function is $f^{-1}: \{0,1\}^X \rightarrow P(X)$ where $f^{-1}(g_{\alpha}) = \alpha$.     Another way to prove this is to first construct the inverse function, show that it is well defined, and then show that $ff^{-1}$ and $f^{-1}f$ are the identity functions, right?  So if we let $g_{\alpha}=g_{\beta}$, then $\alpha=\beta$, because otherwise $g_{\alpha} (\beta)=0$ and $g_{\beta} (\beta)=1$; a contradiction.   Now we have $f \circ f^{-1} (g_{\alpha}) = f(\alpha) = g_{\alpha}$ and $f^{-1} \circ f(\alpha) = f^{-1}(g_{\alpha}) = \alpha$ , and so $f$ and $f^{-1}$ must be bijective.


I created a round function and it works fine in simple rounding.  If I round two numbers A and B, and then I add them, the result is fine.  But, if I "subtract" them, the result is weird. It is not rounded like it should.  I show you the function:  function round(x, p) {     return parseFloat(x.toFixed(p)); };   Weird result:  var a = 5.0007; var b = 2.048 var result = round(5.0007, 3) - round(2.048, 2);  // expected result: 2.951 // obtained result: 2.9510000000000005   Here is a !  Would you please help me understand why this subtraction shows a weird result?  Thanks

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


I wonder if it is possible to convert text to C# code for dynamic validation. For example, I'd love to be able to store a string in my DB like this:  ((Value.StartsWith("CR") || Value.StartsWith("TRC")) && Value.Length == 10)   Then - pull it from the DB and use it to validate data. If would automatically swap out Value for the piece of data I'm trying to validate.  All validations would return a boolean that I would use in the code to see if the data being tested passed or failed.  I would have numerous variations of validations similar to the one above like this stored in my DB.  I've tried researching various phrases on Google but can't seem to think of what this might be called?

Is there a way to Deserialize Expressions in C#, I would like to store Expressions in a Database and load them at run time.


It's been a while since I've read the first Harry Potter book but I can't help noticing that it is generally accepted that the DADA job is cursed and no teacher lasts longer than one year. In fact, Dumbledore confirms that in The Half-Blood Prince when viewing the memory of Tom Riddle asking for the DADA job, suggesting that after he was rejected, he immediately cursed the position and from then on, no professor has lasted longer than one year.  If so, not only why has nothing been done about it- because hey all books have plot holes, but more importantly, when Harry meets Quirrell in the Leaky Cauldron with Hagrid, Hagrid says that Quirrell took a year off to get some first hand experience, but that implies that he was the previous DADA teacher.  Hagrid also mentions that he is 'always trembling' and is 'scared of the students, scared of his own subject' but if he went to the Black Forest and was possessed by Voldemort in 1990 and has come back to teach in 1991 when Harry joins Hogwarts, then there hasn't been any time for him to be faced with any students or any opportunities for anyone, least of all Hagrid, who has no reason to be in the castle at all, to see how he interacts with his subject.  This suggests Quirrell's attitude predates his 1991, which can't be true since there is only a small window between the end of his sabbatical and the beginning of term. This also fails to answer how Quirrell has miraculously survived the curse for at least two years.  I have read of Harry Potter Wiki that Quirrell was the old Muggle Studies teacher but then switched to DADA upon his return from sabbatical. But that also doesn't explain why he would take a sabbatical to 'get some first hand experience' in the Black Forest if he was a Muggle Studies professor.  So my question is, how was Hagrid able to provide such a comprehensive description of Quirrell, if he had only begun his DADA job, and if he had been a teacher for longer- how did he avoid the curse?

It's well seen throughout the series that there is a “curse” on the DADA teacher position, that no one can hold that post for more than a year. But it seems like Quirrell has been around for longer than a year. What's up with that?


I use ubuntu 14.04 LTS. I used Ubuntu screenshot application in my computer. But it can maximum take a screenshot of whole screen.  What can I do if I want to take screenshot of a page which is larger than the screen i.e. webpage?

I have been testing various Firefox extension for screenshot grabbing, but none of them suited my needs.  Then I have found Shutter (0.86.3), and it is really nice. I use exporting to imageshack and FTP a lot.    The only thing I miss is grabbing the whole web page area (not just the part currently visible on the screen). Is there any Shutter extension for this or similar app with such a feature?


Error terms are calculated when you already have a model, and you calculate them as predicted values - actual values. Now you want to fit MA process to predict future data points (means you still don't have any MA model, so don't have predicted values and thus don't have past forecast errors)  MA model says ...   The model will try to learn parameters theta's, but how do derive these error terms?  (Please refrain heavy mathematical equations to answer this question, if possible, please provide answer with simple example; lets say my time series is 2,5,7,9 ..how the fifth element will be calculated based on MA(1) process?)

This is a basic question on Box-Jenkins MA models. As I understand, an MA model is basically a linear regression of time-series values $Y$ against previous error terms $e_t,..., e_{t-n}$. That is, the observation $Y$ is first regressed against its previous values $Y_{t-1}, ..., Y_{t-n}$ and then one or more $Y - \hat{Y}$ values are used as the error terms for the MA model.  But how are the error terms calculated in an ARIMA(0, 0, 2) model? If the MA model is used without an autoregressive part and thus no estimated value, how can I possibly have an error term?


How do I edit line of a file in while loop, Code works except for what is inside the "if" statement, anyone done this before? (second question today, thank you)  #!/bin/bash export ELMS_STORAGE="/loc1/f1.csv"  export CUSTOMER_LIST="/loc2/f2.csv" while read -r ELMS_SIZE ELMS_NAME ELMS_ENV do while IFS=, read -r CUSTOMER_ENV CUSTOMER_URI CUSTOMER_NAME CUSTOMER_SCHEMA_OWNER CUSTOMER_DB_INSTANCE OTHER do   if [ "${ELMS_NAME}" = "${CUSTOMER_URI}" ]; then #### add a new item to the f2.csv  ${ELMS_STORAGE}.${ELMS_ENV}="${ELMS_ENV} ${CUSTOMER_URI}"   ### doesn't work  fi   done < <(tac $CUSTOMER_LIST) done < <(tac $ELMS_STORAGE)  exit   f2.csv before edit  monkey dog tiger   f2.csv after edit  monkey brown  bird green  cat yellow

What's the simplest way to do a find and replace for a given input string, say abc, and replace with another string, say XYZ in file /tmp/file.txt?  I am writting an app and using IronPython to execute commands through SSH — but I don't know Unix that well and don't know what to look for.  I have heard that Bash, apart from being a command line interface, can be a very powerful scripting language. So, if this is true, I assume you can perform actions like these.  Can I do it with bash, and what's the simplest (one line) script to achieve my goal?


So, I figured something out and I'd appreciate it if you guys could try to prove it. $$ F(n+2) = 1 + n + (n-1)C_2 + (n-2)C_3 + (n-3)C_4 +\ldots $$ where $F(n+2)$ is the $(n+2)^{th}$ Fibonacci number.  Here's how I kinda proved it: I got a question in class which was : a fair coin is tossed n times. Let $A(n)$ denote the number of cases in which no two heads occur consecutively and they'd asked different values like $A(5), A(8)$, etc.    Two different approaches to this problem gave me the result I've put.   My teacher took 2 cases-   Last toss is a $T$. This means that the sequence of $(n-1)$ coins behind it have no two consecutive heads. So basically $A(n-1)$. Last toss is a $H$. This means that the toss just before it has to be $T$. This means that the sequence of $(n-2)$ coins before the $TH$ has no two consecutive heads. So $A(n-2)$. Using this, we get $A(n) = A(n-1)+A(n-2)$. $A(1)$ is $2$ and $A(2)$ is $3$. So we basically get the Fibonacci series.  I took several cases and for each case, I used the Gap method. Basically, if there are $x$ times $H$ and $(n-x)$ times $T$, I have $(n-x+1)$ gaps where I can put the $x$ times $H$ = $(n-x+1)C_x$. So, for $0 H, n T$, we get $1$  $1 H$ and $(n-1) T \ge nC_1$  $2 H$ and $(n-2) T \ge (n-1)C_2$  And so on. $$ A(n) = 1 + n + (n-1)C_2 + (n-2)C_3 + \ldots $$   I was looking for a more valid proof for this. I'd appreciate all the help I can get.

The binomial sum   $$s_n=\binom{n+1}{0}+\binom{n}{1}+\binom{n-1}{2}+\cdots$$   satisfies the Fibonacci relation.   I failed to prove that $\binom{n-k+1}{k}=\binom{n-k}{k}+\binom{n-k-1}{k}$... Any hints or suggestions?


Does anybody know the title of a film that features robots or androids I think they were called and the humans, I think being chased by these androids, jumping through a time travel machine that speeds up and replays almost the whole film 2 or 3 times becoming faster each time.  It is a bit fuzzy as I was a child when it was shown on TV and this is all I can recall.

I’m trying to identify a movie I saw when I was very young.  It was a “Saturday Matinee” playing on one of the local stations, and I likely watched it in the late 60’s.  So I expect that the movie is from the 50’s or 60’s.  I watched it in black and white, but it could have been a color movie on a black and white set. I clearly recall a scene where scientists enter a lab and some see something move past them in a blur.  Later in the movie, they come upon themselves in the same lab where they appear to be frozen and not moving.  Then they notice that their “other selves” are moving, just almost inperceptibly slowly.  They are encountering themselves but at a completely different time scale. Unfortunately, I don’t recall much else about the movie, just the idea that they encounter themselves once with the others flashing past, and again seemingly not moving at all.  If this rings any bells with anyone, I’d love some pointers to try to track this movie down.


I want to start using Ubuntu so I went to software shop today, asking for Ubuntu Desktop installation media.  There were some Ubuntu boxes, like Windows ones. I was told that I should enter a product key from some label when installing Ubuntu. I have never seen copy protection in free software.  I was allowed to copy an .  I am unable to download Ubuntu from official website because my computer doesn't have operating system installed and I don't have any other devices.  Where can I purchase genuine Ubuntu?

Is Ubuntu an open source software (OSS)?


If p is a prime, show that the only solutions of  $x^2\equiv 1 \pmod p $ are $x=1$ and $x\equiv -1 \pmod p$. (from herstein's abstract algebra chapter2 section4 lagrange's theorem problem 15, this section is unfamiliar to me, and the questions are all damned hard!)

The proof is a follows:  Let $p$ be a prime number and $x$ in Z. If $x^2\equiv1\pmod p$ then $x\equiv\pm1\pmod p$.  Proof: By assumption, $p | x^2 - 1 = (x + 1)(x - 1)$. Thus $p | x + 1$ or $p | x - 1$. This completes the proof.    However if $p | x + 1$ then $x$ is congruent to $-1 \mod p$. However why is $p$ congruent to $1 \mod p$ ??   I'm struggling seeing this, and been sitting for some hours now trying to figure it out - please help.


How to I prove this?? The questions asks "Observe this function is differentiable on $\mathbb{R}$."

Show that the function $g(x) = x^2 \sin\left(\frac{1}{x}\right) ,(g(0) = 0)$ is everywhere differentiable and that $g′(0) = 0$.


I wrote some luacode in my main.tex and I'm a adding several other files due to \input{code.tex} I already asked this question  and it works on a standalone environment but not in my case. I can't figure out why. There is no problem in plotting a function due to tikz with declare function = {test(\x)=\x*\x;}  but it is neither drawing anything nor using the correct samples on the axis when I use declare function = {nbin(\t) = \directlua{tex.sprint(nbin(\t))};}  Here are parts of the files: main.tex: \documentclass[14pt]{book}   \usepackage[german]{babel}   \usepackage{graphicx} \usepackage{float}  \usepackage{hyperref}   \emergencystretch=0em   \usepackage{marginnote} \usepackage{amsmath} \usepackage{multicol} \usepackage{amsfonts}  \usepackage{amssymb} \usepackage{stmaryrd} \usepackage{amstext} \usepackage{siunitx}  \usepackage{tikz} \usetikzlibrary{trees} \usepackage[utf8]{inputenc}  \usepackage[T1]{fontenc}  \usepackage{amsthm} \usepackage{amssymb} \usepackage{mathtools} \usepackage{enumerate} \usepackage{dsfont} \usepackage{calrsfs} \usepackage{calligra} \usepackage{verbatim} \usepackage{mathpazo}  \usepackage{mathptmx} \usepackage[autostyle=true]{csquotes}  \usepackage{currvita} \usetikzlibrary{matrix} \usetikzlibrary{calc} \usetikzlibrary{positioning,shapes} \usepackage{pgfplots}     \pgfplotsset{compat=newest} \usepackage{delarray} \usepackage{pifont} \usepackage{polynom} \usepackage{stmaryrd} \usepackage{varwidth} \usepackage{fancyhdr}  \pagestyle{fancy}     \usepackage{pdfpages} \usepackage{pgf} \usetikzlibrary{tikzmark}  \usetikzlibrary{arrows} \usetikzlibrary{intersections} \usepackage{extarrows}  \usepackage{cancel} \usepackage{calc}   \usepackage{caption}  \captionsetup{     font={ sc, bf, footnotesize},     skip=0pt,   justification=centering, }     \usetikzlibrary{decorations.pathreplacing} \tikzstyle{abstract}=[rectangle, draw=black, rounded corners, text centered, anchor=north, text=black, text width=2.7 cm] \tikzstyle{comment}=[rectangle, draw=black, rounded corners, fill=green,  text centered, anchor=north, text=white, text width=3cm] \tikzstyle{myarrow}=[->, >=open triangle 90, thick] \tikzstyle{line}=[-, thick]  \usepackage{luacode} \begin{luacode*} function factorial(n)     if (n == 0) then             return 1     else         return n*factorial(n-1)     end end  function binom(n,k)     return factorial(n) / (factorial(n-k) * factorial(k)) end  function nbin(t)     local res = 0     for k = 0, math.floor(t), 1 do         res = res + (binom(k+2,2) * 1/8 * (1/2)^k)     end     return res end \end{luacode*}   \begin{document} \setcounter{secnumdepth}{4} \tableofcontents  \input{code.tex}\fontsize{12pt}{16pt}\selectfont \setlength{\parindent}{0cm}  \setlength{\parskip}{3mm plus1mm minus1mm} \sloppy \end{document}  And here is the part of code.tex \begin{center} \begin{tikzpicture}[  declare function={nbin(\t) = \directlua{tex.sprint(nbin(\t))};}   ]   \begin{axis}[     use fpu=false,     height=8 cm,     width = 8 cm,     samples at={0,1,...,40},     ]     \addplot[no markers]{nbin(x)};   \end{axis} \end{tikzpicture} \end{center}  It doesn't give any errors, just a clear Diagram with both axis going from 0 to 1 in 0.2 steps.

hopefully you can help me. I tried to plot a function with Tikz and Lua in the following way \documentclass[14pt]{book} \usepackage{marginnote} \usepackage{amsmath} \usepackage{multicol} \usepackage{tikz} \usetikzlibrary{trees} \usetikzlibrary{matrix} \usetikzlibrary{calc} \usetikzlibrary{positioning,shapes} \usetikzlibrary{tikzmark}  \usetikzlibrary{arrows} \usetikzlibrary{intersections} \usepackage{pgfplots}     \pgfplotsset{compat=newest}  \tikzstyle{abstract}=[rectangle, draw=black, rounded corners, text centered, anchor=north, text=black, text width=2.7 cm] \tikzstyle{comment}=[rectangle, draw=black, rounded corners, fill=green,  text centered, anchor=north, text=white, text width=3cm] \tikzstyle{myarrow}=[->, >=open triangle 90, thick] \tikzstyle{line}=[-, thick]  \usepackage{luacode}  \begin{luacode*} function factorial(n)     if (n == 0) then         return 1     else         return n*factorial(n-1)     end end  function binom(n,k)     return factorial(n) / (factorial(n-k) * factorial(k)) end  function nbin(t)     res = 0     for k = 0, math.floor(t), 1 do         res = res + (binom(k+2,2) * 1/8 * (1/2)^k)     end     return res end  \end{luacode*}  \begin{document} \input{code.tex} \sloppy \end{document}  And the picture is in code.tex using \begin{tikzpicture}[  declare function={nbin(\t) = \directlua{nbin(\t)};}   ]   \begin{axis}[     use fpu=false,     height=8 cm,     width = 8 cm,     samples at={0,1,...,40},     ]     \addplot{nbin(x)};   \end{axis} \end{tikzpicture}  I'm kind of new to all that Tikz stuff, but I can't find solutions here :-/ This prints just a white box with 0, 0.2, ..., 1 at the axis and no errors. What's wrong here? I edited my question because it is running in the standalone environment but not in my setting.


I don't grasp .  An example of (3) might be  (from a 15th-century will):  I now the seid John Smyth, for diu[er]se causez and consyderacyonys shevyd vnto me, will ordeyne and declare ...  Here, "consideration" means "something to be considered, a reason".  The semantic sense has shifted from the act of considering to the thing considered.  A parallel might be the word "obligation", where the shift is from the act of obliging, to the thing one is obliged to do.  These semantic shifts are too apart, far-reaching, far-fetched for me to grasp! To the common Anglophone, "the act of considering" plainly differs from "the thing considered". For instance, rational humans perform "the act of considering", while "the thing considered"    is an inanimate valuable object like money. How can I interpret these semantic shifts so they feel natural, intutitive common sense? How can these semantic shifts be bridged?

What semantic notion connects the bolded meaning beneath with all the others that aren't related to recompense? To me,  nouns like  fit the bolded meaning more intuitively. I'm asking about , not its meaning in contract law. Which  is this?       mid-14c., consideracioun, "a beholding, looking at," also "a keeping in mind," also "contemplation, reflection,"    from Old French consideracion (12c., Modern French considération) and directly from Latin considerationem (nominative consideratio) "consideration, contemplation, reflection," noun of action from past-participle stem of considerare "to look at closely, observe" (see ).      Meaning "a taking into account, act of paying attention to" is from late 14c.; that of "examination, observation" is from early 15c.. Sense of "thoughtful or sympathetic regard" is from c. 1400. Meaning "that which is or should be considered" is from late 15c. Meaning "something given in payment" (as recompense for service) is from c. 1600.


How to Prove the triangle inequality which says for all x (no matter how big or small) and for all y (no matter its size) in the set of irrational+rational numbers, this holds: $|x+y| \leq |x|+|y|$

I understand intuitively that this is true, but I'm embarrassed to say I'm having a hard time constructing a rigorous proof that $|a+b| \leq |a|+|b|$. Any help would be appreciated :)


Very very very new to blender but is it possible to colour different parts of an object? (.obj import from fusion). if so; how do I change the colour of different areas of my object?

How do you add more than one material to a mesh?   I have tried adding two materials to the object, and then assigning one of the materials to a vertex-group, but I could not find a place to assign it.  I am making a striped bouncy ball that I want to deform, so adding a different material by separating the mesh into different objects would not be ideal.


RBCs don't have mitochondria so there is no Respiratory chain in them. But how does they get energy from Lactate. Because Lactate produce NADH which gives energy only in respiratory chain.

I have read that red blood cells (RBCs) metabolize glucose. However they don't have any mitochondria because there is just so much hemoglobin that there is no room for mitochondria without expanding the cell.   So how is it possible for them to metabolize glucose if it is mainly O2, CO2, H2O, fatty acids (in cell membrane), and hemoglobin?


I was wondering if the finding of gravitational waves proves M theory. I know at Fermi Lab scientists were looking for gravitons in distant places in our universe so that they can prove string theory. I'm very interested to see if the LIGO finding would be this revealing. Please let me know your thoughts.

The rumor spreads that .  I am far from being an experimentalist, but I want to know if there is any chance that the mentioned observations will reveal any experimental evidence for quantum gravity.  Personally, I feel like this is merely impossible as gravitational waves should propagate in agreement with classical General Relativity. But I might very well not see pitfalls if there are any.  UPDATE: by "evidence for quantum gravity" I mean experimental results which don't agree with predictions of General Relativity or its classical generalizations. They might be coming from string theory or loop gravity or from a completely different approach which we haven't discovered yet. I want to understand what are the chances that new physics will show up during the upcoming  gravitational wave observations.  Also, I expect gravitational waves to be in a highly coherent state, thus making the individual gravitons unobservable. Is this true?


I have a situation where I'd like, in bash, to loop over all of the .h and .c files in a directory.  I.e., for file in *.{h,c}; do     ... done  However, if I have a directory that has, for example, no .h files, *.h is one of the "files" iterated over by the for loop.  I've read  and I believe I understand why it is not expanding. So, how should such a loop be carried out?

In bash I often use for-loops such as the following  for file in *.type; do    sommecommand "$file";  done;   to perform an operation for all files matching *.type. If no file with this ending is found in the working directories the asterisk is not expanded and usually I will get an error message saying that somecommand didn't find the file. I can immediately think of several ways to avoid this error. But adding a conditional does not seem to be very elegant. Is there a short and clean way to achieve this?


I added a user to the root group, but the user is still not able to perform operations that require root's permissions. What is the problem?

When I'm doing something that requires root be typed in dozens of times in a row, I prefer to switch my session to a root session. In the various tutorials and instructions I have used on the Internet, I see sudo su, sudo su -, sudo -i and sudo /bin/bash being used to open a root session, but I'm not clear on the difference between these and when or if that difference matters.  Can someone clear this up for me?


How is it possible to add comments in LaTeX and in the produced pdf show them with a different color?

Is there a simple way to add todo notes to LaTeX documents ?  I would like to have these notes in red in the generated pdf and a simple syntax to write them.


Taking this example,     Everyday is an adjective that means commonplace, ordinary, or normal.      Every day means "each day."   or numerous other similar words which have a different meaning when extra spaces are added, is there a particular term to describe these?  E.g. psychotherapist and psycho the rapist have two very different meanings, maybe and may be, or between and be tween.  I know that some of these words can be homophones, homographs, or homonyms, but the closest I can find is something like , which describes words that share the same spelling but have different meanings when capitalised e.g. polish/Polish, march/March.  Is there a particular term to describe words which look the same, but change meaning (and perhaps pronunciation) when a space is added?

For example, therapist may be split into the + rapist, neither of which (arguably) has anything to do with the original words.  Another example would be conflagration: con + flag + ration. Or weather: we + at + her.  Note that words like threesome and purebred would not qualify, because the parts are intentional and contribute to the original word's meaning.  It seems to me there might be a word for this, which I would describe as "accidental lexical componentry" — but I'm not sure there is one. And if I do think of one I will be sure to add a supplemental (supple + mental) section (sect + ion) to this question (quest + ion).


So i converted a JSOn object and compared the value with something,and even though the value matches with whats there in the string,the loop is not getting invoked,this what i've written Any help would be appreciated  @Override         protected void onPostExecute(String s) {              JSONObject obj = null;             try {                 obj = new JSONObject(s);                 String error_desc = obj.getString("error_desc");                 writeToFile("responseONP="+error_desc);                 if(error_desc == "Invalid Credentials") {                     Context context = getApplicationContext();                     CharSequence text = error_desc;                     int duration = Toast.LENGTH_SHORT;                      Toast toast = Toast.makeText(context, text, duration);                     toast.show();                 }                  else{                      Intent intent = new Intent(getBaseContext(), HomepageNormal.class);                      startActivity(intent);                 }              } catch (JSONException e) {                 e.printStackTrace();             }

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


Which is correct?:  "One in seven people worldwide is living on $x per day."  "One in seven people worldwide are living on $x per day."

Take the examples:   "One in ten children are dyslexic."  "One in ten children is dyslexic." "One in ten children has dyslexia." "One in ten children have dyslexia."   The "one" is singular so 2 and 3 should be correct. But the "one in ten" is a fraction" so 1 and 4 should be correct. And yet I think I usually say 1 and 3. Which is/are correct?!


I've been trying to render a scene with a dark infinite background, but when I use a vignette effect it looks posterized. I thought that it might be something I did in my Blender file, but then I started a new file just to test it and it seems like that's the way it works... Bright background (no posterize effect)  Dark background (posterized) Open the image to visualize it better  I tried adding a blur filter but it makes it worst:  Blend file:

If I just render the default cube it will look like this:   It is rendered with color depth 16. I can see there are artefacts consisting of visible "line strokes" on some of the cube faces.  The bands seems to not go darker and darker, but alternates between light and dark, or is my eye fooled?  Why?  Edit  Here comes a gradient created by gimp without banding, using the same computer:


I would like to understand how to use geometry to solve the problem 7.8 from Reid's book Undergraduate Commutative Algebra. The problem is the following     Let $k$ be a field and consider the ideal $I = (xy, x - yz) \subset k[x,y,z]$. Find a primary decomposition of $I$.   So the vanishing locus $V(I)$ is the two axis $Y$ and $Z$, and if $I = q_1 \cap \cdots \cap q_n$ with all $q_i$ being $p_i$-primary, we could guess that we can take $p_1 = (x,z)$ and $p_2 = (x,y)$. Moreover, the vanishing of $xy$ is the $Z$-axis, but with double multiplicity (is this true ?), so we could guess to take $q_2 = (x,y)^2$, but we need $x - yz$ to be in there, so I think that $q_2 = (xy, y^2, x - yz)$ and $q_1 = (x,z)$ would give a decomposition into primary ideals ($x^2$ is automatically in $q_2$, don't need it).  Question 1 : How to make sure that these primes $p_1$ and $p_2$ are the only ones ? We can compute them by $\operatorname{Ass}(k[x,y,z]/(xy,x - yz))$, but wasn't able to do it.  Question 2 : Is $(x,z) \cap (xy, y^2, x - yz)$ a primary decomposition of $I$ ?  Question 3 : What is a better way to get to this answer with geometric intuition and not algebraic brute-force ?  Thanks

Given the ring $k[x,y,z]$, where $k$ is a field, and an ideal $I=(xy,x-yz)$, find a primary decomposition of $I$.    I tried to draw the graph of the variety of $I$ and get a decomposition of $(x,y)\cap(x,z)$ (the two prime ideals corresponds to the irreducible components of the variety), but apparently these two ideals are not the primary decomposition of $I$, and I don't know how to fix this.  I would really appreciate it if someone can help me. thx


What's the travel time, by tube, from Heathrow to King's Cross Station in London and how often does the tube run between those locations?

My wife and I will be arriving in London via Heathrow Airport (LHR) and are staying at a hotel near King's Cross station. So, we were wondering what the best (which means fastest but also easiest when carrying two large pieces of luggage and two carry-ons) way to get from LHR to King's Cross?  I gather that, with only one changeover, we can take the Tube. However, in the interest of other passengers, we thought it would be best to take a taxi, or maybe a bus?  Thoughts?


I am using an Asus C200 chromebook running Ubuntu 16.04, and I want to know how to remap the F10 button to Volume up, and F9 button to volume down.  Thanks.

I want to change the key bindings on some of the keys on my keyboard.  I want some to run commands and others to activate different keys.  What applications can I use to do this?      Index:       (from within System Settings)             I'm still looking for answers using dconf and any other method.


I try to install make on Ubuntu 12.04 LTS Server  apt-get install make   But I observe error:  Temporary failure resolving 'de.archive.ubuntu.com   Failed to fetch http://de.archive.ubuntu.com/ubuntu/pool/main/m/make-dfsg/make_3.81-8.1ubuntu1.1_i386.deb   Could you describe me what happened?

Err http://archive.canonical.com natty InRelease     Err http://security.ubuntu.com oneiric-security InRelease                Err http://extras.ubuntu.com natty InRelease                             Err http://security.ubuntu.com oneiric-security Release.gpg   Temporary failure resolving ‘security.ubuntu.com’ Err http://archive.canonical.com natty Release.gpg   Temporary failure resolving ‘archive.canonical.com’ Err http://extras.ubuntu.com natty Release.gpg   Temporary failure resolving ‘extras.ubuntu.com’ Err http://gb.archive.ubuntu.com oneiric InRelease Err http://gb.archive.ubuntu.com oneiric-updates InRelease Err http://gb.archive.ubuntu.com natty-backports InRelease Err http://gb.archive.ubuntu.com oneiric Release.gpg   Temporary failure resolving ‘gb.archive.ubuntu.com’ Err http://gb.archive.ubuntu.com oneiric-updates Release.gpg   Temporary failure resolving ‘gb.archive.ubuntu.com’ Err http://gb.archive.ubuntu.com natty-backports Release.gpg   Temporary failure resolving ‘gb.archive.ubuntu.com’  Reading package lists... Done W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/oneiric/InRelease       W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/oneiric-updates/InRelease   W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/natty-backports/InRelease   W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/oneiric-security/InRelease   W: Failed to fetch http://archive.canonical.com/ubuntu/dists/natty/InRelease   W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/natty/InRelease   W: Failed to fetch http://archive.canonical.com/ubuntu/dists/natty/Release.gpg  Temporary failure resolving ‘archive.canonical.com’ W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/oneiric-security/Release.gpg  Temporary failure resolving ‘security.ubuntu.com’ W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/natty/Release.gpg  Temporary failure resolving ‘extras.ubuntu.com’ W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/oneiric/Release.gpg  Temporary failure resolving ‘gb.archive.ubuntu.com’ W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/oneiric-updates/Release.gpg  Temporary failure resolving ‘gb.archive.ubuntu.com’ W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/natty-backports/Release.gpg  Temporary failure resolving ‘gb.archive.ubuntu.com’ W: Some index files failed to download. They have been ignored, or old ones used instead.   This is what I'm seeing when I try to run sudo apt-get update. I did an update on my instance yesterday and am now experiencing this.


i have file test.txt  hi hello good luck   i want in this test.txt  hi hello good luck lms localhost   how to add last two lines in terminal command ?

I want to append this text:  <Directory "/var/www/*">     Order allow,deny     Allow from all     AllowOverride All </Directory>   to the file /etc/apache2/apache2.conf  I have access via SSH but I don't know how to use VIM. I would like to do this via a command.


I have to create a Polygon from a lineString and a width. Ex: Given a street as a lineString (Or a list of points) and a width, create the polygon (the road). I am using Geotools, but I couldn't find anything helpful in the API.  The math for doing this manually is requiring to much work. Is there a simpler solution for this kind of problem?  Thanks.

I want to develop a simple GIS application using GeoTools. I have looked at the tutorials but i could get to much meaningful from them.   I have a simple JMapFrame to which add can add a featureLayer from a shapefile  public void action(ActionEvent e) throws Throwable{     sourceFile = JFileDataStoreChooser.showOpenFile("shp", null);     if (sourceFile == null) {         return;     }     FileDataStore store = FileDataStoreFinder.getDataStore(sourceFile);     featureSource = store.getFeatureSource();      Style style = SLD.createSimpleStyle(featureSource.getSchema());     Layer layer = new FeatureLayer(featureSource, style);     map.addLayer(layer); }   Now, lets say I want to create a buffer around my features. From what I have understood I have to get the featureSource, then create a featureCollection, iterate through the features and for each of those feature I have to cast them to a Geometry, then create a buffer.   When I have created a buffer should I go all the way back to featureLayer and add it to my map?


Problem: Show that if $\Bbb R$ is given the half-open interval topology, then $\Bbb R\times\Bbb R$ is not normal.  I can't start solving this problem. Please help me.

Is there a simple method to prove that the square of the Sorgenfrey line is not normal?  The method in the book is a little complex.  Could someone help me?


How can i calculate the limit $\lim_{x \to \infty}\frac{\ln x}{x}$ without the use of delhospital rule. I have tried using the fact that $\ln x \leq x-1$ but i couldnt solve this, any help?

It seems i'm not gonna find an answer for this question which does not use LHopital's rule. How do you prove limit of (lnx)/x approaches 0 as x moves toward infinity WITHOUT using LHopital's rule?


what is the difference between these two? put out the fire and put the fire out what are the use cases? do they mean the same or not? another example is take off take it off or take off it => here it seems the first one is correct

I have often heard the following statements when someone talks about shoes, cloths, etc. I don't know which one is more appropriate or grammatically correct.   Hey, put your shoes on.  Hey, put on your shoes.  Take off your coat, please.  Take your coat off, please.    Any thoughts? Can we also say "take out your coat"?


So this is strange. If I have the following:  function noTypo(){return;} fucntion doSomething(){return;} fucntion doSomethingElse(){return;}   And I highlight and yank function in function noTypo(), and I invoke visual mode and paste over fucntion with p, it pastes function. Good. But Vim then copies the value that was just pasted (fucntion) into my clipboard, such that when I paste a second time, the value that gets pasted is fucntion. How do I keep the original function value in the clipboard? Am I crazy?

I use the highlight mode in vim to copy a few characters.  I then want to paste more than once.  My current technique does not work well.  Sample text: Linux Solaris Irix HP-UX  Suppose I want to copy the word Linux, then paste over Solaris and Irix.   Place cursor at L in Linux Command v (for visual hilite), then e (for end-of-word), then y (for yank/copy) Now Linux is on my "vim clipboard" Move cursor to S in Solaris (first instance) Command v (for visual hilite), then e (for end-of-word), then p (for paste) Text is now: Linux Linux Irix HP-UX, but now Solaris is on my "vim clipboard" Move cursor to I in Irix (second instance) Command v (for visual hilite), then e (for end-of-word), then p (for paste) Text is now: Linux Linux Solaris HP-UX which is not what I expected.   I resort to using highlite/paste with the mouse (via X Terminal).  Surely, I can do this better.  How?