First at all, I know that this question is duplicate, but I have tried every solution of all the other "compiz/unity issue after upgrading 16.04 LTS" questions with no luck. I have been hours trying things and in the end I have switched to Gnome with metacity to be able to work a bit.  To be honest, I think I have the same problem that this question:    but I can't post a comment there and I can do a new question (weird, isn't it?). I have tried all the things Samvid tried except downgrading Mesa (I have not it installed) and still nothing.  That question remains unsolved and communication finished the 3rd of March, so I wonder if there is any other solution not documented there.  If you need any data of my computer, please ask it. I'll be happy to help.  Thanks in advance.  PS: I suspect that the solution to this bug   is what has broken my current version.  PS 20180313: Not sure if it is because I have applied the answer of N0rbert, but now i have tried (for sixth or seventh time) the "setsid unity" command in a terminal of a metacity session and after rebooting I have Unity and Compiz (with reset values) working again! Thanks a lot

This  forced removal of unity and ubuntu-desktop on my 16.04 Ubuntu system.   The offending package that is missing, but unity needs, seems to be compiz-core-abiversion-20151010. It seems to be a , and I can't find it to download.    As it happens, I mostly use LXDE on this system, but I'd be very unhappy if I used Unity...  Since I do occasionally use the Unity desktop, is there a fix for this?  Edit: related questions are rolling in. Looks like a major quality escape          Edit 2:


It seems this question has been marked  but I believe the answers given here is much more in detail. Why we are still using AC voltage for long distance voltage transmission. As we know with our current technology we could step up and and step down DC voltage thus reducing the Amps and losses. Dc current would have no harmonics or frequency issues. We may convert DC back to AC at receiving end.   Reasons for my arguments are

Is there a good reason why we are not in the process of completely converting our electrical transmission system to DC? The main reason for using AC on the grid (no offense Tesla, I love you man) was to enable transformation to higher voltages in order to drop line losses (\$P=IE=I^2R\$) and if the conductor size remains the same, when \$E\$ is increased in the equation \$E=IR\$ then \$I\$ must necessarily decrease, in turn decreasing losses as the square of \$I\$). But now we have the ability to transform AC (at all thermal, hydro and wind generators) and DC (at solar generators) to any level of DC we desire and transmit, usually to residential or commercial loads which tend to use DC anyway. If need be it can be converted back to AC at industrial loads (motors usually).  In this way many transformers, capacitors, spacing issues, etc. can be eliminated from the electrical grid, increasing efficiencies dramatically, and in turn decreasing emissions and costs.  Am I missing something here?


I'm trying to install g++ 14 after removing the existing version. the error message: $ sudo add-apt-repository ppa:ubuntu-toolchain-r/test  Toolchain test builds; see https://wiki.ubuntu.com/ToolChain   More info: https://launchpad.net/~ubuntu-toolchain-r/+archive/ubuntu/test Press [ENTER] to continue or Ctrl-c to cancel adding it.  Hit:1 http://al.archive.ubuntu.com/ubuntu focal InRelease Hit:2 http://dl.google.com/linux/chrome/deb stable InRelease                    Hit:3 http://al.archive.ubuntu.com/ubuntu focal-updates InRelease               Ign:4 http://ppa.launchpad.net/snaipewastaken/ppa/ubuntu focal InRelease        Hit:5 http://linux.teamviewer.com/deb stable InRelease     404  Not Found [IP: 91.189.95.83 80] Reading package lists... Done E: The repository 'http://ppa.launchpad.net/snaipewastaken/ppa/ubuntu focal Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.

When updating, I get the following error message:   W: The repository 'http://ppa.launchpad.net/mc3man/trusty-media/ubuntu xenial Release' does not have a Release file.   Here, I find another statement on this error:   This recommends removing certain PPAs; and, I'm not sure if I should do that since it might mean not getting the updates that I need.    Is this what I should do?


Everytime I sudo apt-get update it always not complete and will say in the end  E: Read error - read (5: Input/output error) E: The package lists or status file could not be parsed or opened.   Same goes, when I try to install something and do sudo apt-get install <some app>  What should I do ? I admit, that my drive has bad sectors, could that be the reason? Is there anything else I can do?

The computer gave me this output in a window:  E: Encountered a section with no Package: header E: Problem with MergeList /var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_natty_main_binary-i386_Packages E: The package lists or status file could not be parsed or opened.   How can I fix this?


I have a usb drive that is read by the computer as a CDFS  of the usb drive, and I want to have it as a usb storage device.  I tried diskpart in cmd.exe, and then tried to clean it there, but I've got the following error: virtual disk service error:there is no media in the device

After upgrading to Windows 10, I remember that I had an old bootable recovery usb drive from the manufacturer that I no longer needed. I want to format it but it's showing up as a CD-ROM and format options are not available.  I also tried formatting it in a live linux mint environment, but linux cannot even mount the cd-rom.  How can I format this recovery usb that is showing up as a cd-rom?


I'd like to know whether flame retardant epoxy resins, the FR-4 brominated type for instance, are used in the outer molding for integrated circuits or whether it's just a plain epoxy resin. Additionally, if anyone can direct me to any literature or textbooks that rigorously cover materials of construction for circuit boards I would greatly appreciate it!

ICs are typically  (encapsulated) in a black "plastic". What is this packaging material made of?  ()


I have MongoDB 3.0.0 running on a Digital Ocean droplet.  How can I tell which storage engine it is using?

I'm upgrading to 3.0 and ran into some issues with the upgrade. Specifically, I got an error when trying to start up mongod via ssh, it tried to use the default dbpath instead of the one I specified in my new YAML config file. I went ahead and rebooted the machine and now mongod is up and running again. I'm a bit paranoid at this point and would like to know if there's a way to make sure the storage engine is wiredtiger from the shell.


I need to include '(r)' in my document, but it defaults to the registered trademark sign, ® .   How can I override this?

I am having a bit of trouble finding a solution. When I type (R) TeXShop changes it into circled R. I changed the setting in Language & Text, disabling "Use the symbol and text substitution." However, TeXShop still converts my (R) into circled R. I was not able to find an option in TeXShop. I feel like it is somewhere I just can't find it.


I connected a machine via ssh and ran a programme. It took too long to run the programme and I have to turn off my local machine. How can I run the programme background even close the ssh connection?  I am running the code but if I rerun the code, it took a lot of the time, if I close the ssh, the program will be closed, so there are there any method to make the running program still running background even I close the ssh connection.

Let's say I launch a bunch of processes from a ssh session. Is it possible to terminate the ssh session while keeping those processes running on the remote machine?


I'm interested in the usage of the word pluperfect in the following passage from Thomas Harris’s crime thriller, The Silence of the Lambs.  Jerry Burroughs of the National Crime Information Center makes a comment to Jack Crawford, an FBI special agent, regarding Dr. Frederick Chilton, the administrator of the Baltimore State Hospital for the Criminally Insane:     “Chilton was blowing off about “The Search for Billy Rubin.” Then he   went to dinner with a television reporter. That’s where he was when   (Hannibal) Lector took a walk. What a pluperfect asshole.” - Page   272.   Though several online dictionaries define pluperfect only as a grammatical term equivalent to “past perfect tense”, Readers-Plus English-Japanese Dictionary defines it as        (grammar) n.a. past perfect. 2.(slang) a. perfect, extraordinary.      I’m curious to know how the slang usage of pluperfect to mean “perfect, extraordinary” came about. What is the etymological background for the appropriation of the grammatical term to this slangy use? Is it common to use the word like this?

From The Silence of the Lambs (1988):  "Marilyn Sutter saw it upstairs. Chilton was blowing off about "The Search for Billy Rubin." Then he went to dinner with a television reporter. That's where he was when Lecter took a walk. What a pluperfect asshole."  While I am aware of the pluperfect tense, the above usage of the word strikes me as rather exotic. ODO only lists the grammatical definition in its . But it provides an additional definition under its :  [as modifier] more than perfect: they have one pluperfect daughter and are expecting an ideal little brother for her   defines its alternate sense as utterly perfect or complete along with a note on its origin:  late 15th century: from modern Latin plusperfectum, from Latin (tempus praeteritum) plus quam perfectum  I'm curious as to how this odd-sounding construction made its way from the grammar book into common parlance. Is it used in this sense only in the US? Is it still in use? (Although I see it used in other languages, I believe that pluperfect is no longer the term of choice in English grammar.)


I am using   /^[a-zA-Z0-9\-_]+(\.[a-zA-Z0-9\-_]+)*@[a-z0-9]+(\-[a-z0-9]+)*(\.[a-z0-9]+(\-[a-z0-9]+)*)*\.[a-z]{2,4}$/  to validate my email IDs , but it has some issues like it is allowing below type mail ID which are invalid.  EX:   1.  1234@1234.com 2.  12deepak@abc.com 3.  _deepak@abc.com   I have tried a lot by modifying the regular expression but not succeeded. Any one please suggest me a correct regular expression ?

Over the years I have slowly developed a  that validates MOST email addresses correctly, assuming they don't use an IP address as the server part.  I use it in several PHP programs, and it works most of the time.  However, from time to time I get contacted by someone that is having trouble with a site that uses it, and I end up having to make some adjustment (most recently I realized that I wasn't allowing 4-character TLDs).  What is the best regular expression you have or have seen for validating emails?  I've seen several solutions that use functions that use several shorter expressions, but I'd rather have one long complex expression in a simple function instead of several short expression in a more complex function.


I want to make shortcut that after double-click will open terminal and execute script. The problem is after make file and after d-c it open vim edit instead of execute it. File code:  #!/bin/bash cd ~/some_path/ python3 main.py   I try command chmod -x and chmod 755 but it don't work. In file property is set allow executing file as program. I did try use this   but "Type dconf-editor and hit Enter." give error Command not found. In terminal file is working, how make d-c work?

I have a bash script that has permission to execute, but when I double click it in nautilus it won't execute, instead it opens as text in gedit.   In properties it says open with: gedit, and that doesn't change when I click the reset button.  What do I have to do to make it execute? I'm running Ubuntu 13.04. I never had an issue like this one with 12.04 or with any other distribution in general.  EDIT If I go in terminal and type: ./bashscriptname it runs just fine.


My teacher explained entropy like this:  It is increase in disorderliness. Take a glass jar put three layers of blue marbles in it then put three further layer of red marbles, now shake the jar, after some time you will find all the marbles get mixed up equally, after this, however much you shake there will NEVER be a time when the blue marbles come back to their original position and the red marbles to theirs.  The mixing of the marbles to a maximum extent is the highest entropy, and it always increases until it reaches its maximum, if you have to decrease entropy you have to introduce some external force. And this is what I have read else where   Although it doesn't seem to contradict but I want to confirm if this is the right analogy for the explanation?

So I though, and was told, that entropy is the amount of disorder in a system. Specifically the example of heat flow and it flows to maximize entropy. To me this seemed odd. This seemed more ordered to me, from two things (hot and cold) to one thing (lukewarm).   So as I have read today on wikipedia        In recent years the long-standing use of term "disorder" to discuss   entropy has met with some criticism.[20][21][22]      When considered at a microscopic level, the term disorder may quite   correctly suggest an increased range of accessible possibilities; but   this may result in confusion because, at the macroscopic level of   everyday perception, a higher entropy state may appear more homogenous   (more even, or more smoothly mixed) apparently in diametric opposition   to its description as being "more disordered". Thus for example there   may be dissonance at equilibrium being equated with "perfect internal   disorder"; or the mixing of milk in coffee being described as a   transition from an ordered state to a disordered state.      It has to be stressed, therefore, that "disorder", as used in a   thermodynamic sense, relates to a full microscopic description of the   system, rather than its apparent macroscopic properties. Many popular   chemistry textbooks in recent editions increasingly have tended to   instead present entropy through the idea of energy dispersal, which is   a dominant contribution to entropy in most everyday situations.    So what this is saying basically many people mistake the macroscopic outcome of entropy in the same manner as I have above. Seemingly two dissimilar things combining and becoming one.   They say to understand it microscopically. But this still is odd to me, take for example the particles in a box, when they come to thermal equilibrium they are said to have the most entropy they can within their system (from wiki again)     Entropy – in thermodynamics, a parameter representing the state of   disorder of a system at the atomic, ionic, or molecular level; the   greater the disorder the higher the entropy.[7]   What is disorder in the molecular sense I guess is my question. When the particles all come to thermal equilibrium they all seem to be uniform, which I equate with ordering.  I feel disorder in the molecular sense would be fast moving particles, making a mind boggling amount of interactions with each other. Such as in a hot gas, hot gas seems super disordered, but put cold gas in thermal contact with it, let them come to thermal equilibrium, and now they are more ordered!?


I'm designing a signup form and got stuck in a ux discussion on how to handle user input error handling. Which would you prefer of the following two scenarios? Or is there a third, better option?  Method 1: The submit button is always enabled. When clicking the submit button the form is either posted (if all fields are correct) or the wrong fields are marked for the user to correct.   Method 2: The submit button is disabled from start. When the user interacts with one of the form fields the rest of the fields are marked (with an error or are just highlighted) in order to emphasize that those fields also have to be filled out. When all fields are filled out correctly the submit button is enabled.

We have a few different forms as part of a web-based medical application. These forms have quite a few fields - 10-20 depending on the form. Each has at least 5 or so required fields. We currently disable the save button until those required fields are all completed.  We've been debating whether it's a better user experience to make the submit button enabled by default and then display an error message (and highlight missing required fields) if the submit button is clicked before all required fields are filled out.  Any research or sound opinions on what might be better? We're leaning towards the latter approach since our forms are pretty long -- allowing them to submit then find errors might be more efficient than the cognitive load of searching through the form to see why the button isn't enabled.


I'm doing a project in the field of multilevel marketing on .Net and SQL server.  In the database it should save like a binary tree. How should i design a database?

What are the ways that you use to model and retrieve hierarchical info in a database?


I'm using qgis Brighton  I have a dataset of 1500 points. I want to create polygons, where each polygon contains n=3 points from the dataset.  The aim of this is to have clusters of 3 points, which can be used for analysis, qua I can't show information on point level.  I have tried using heatmaps, but I'm not sure if this is the right tool for this analysis.  Here's a picture of my dataset.    Now, I want to create clusters of 3 points like this:   (Sorry for the amateur cutting)  I want to this, so I can make analysis of the clusters (with 3 points) e.g. energy demand, house characteristics, socioeconomics and so on.

Given a large (~ 1 million) sample of unevenly distributed points - is it possible to generate irregular grid (in size, but could also be irregular in shape if that is possible?) that will contain specified minimum amount of n points?   It is of less importance for me if genereted 'cells' of such grid contain exactly n number of points or at least n points.  I'm aware of solutions like  in ArcGIS or  in QGIS/mmgis however they will all create regular grids which will result in an output with empty cells (smaller problem - I could simply discard them) or cells with count of points less than n (bigger problem since I'd need a solution to aggregate those cells, probably using some tools from ?).  I've been googling around to no avail and am open to both commercial (ArcGIS & extensions) or free (Python, PostGIS, R) solutions.


April 20 I asked this a question. It got one up vote and one down vote and then was migrated to Meta Server Fault. Only today, the a month later, I saw:

I had a  that was migrated to Area 51 on 23rd January, after receiving 3 upvotes here. However, I suddenly lost the 15 rep from the upvotes today(almost a month later).     If I understand this  correctly, then that is not supposed to happen and rep gained on the original site is to be retained on the original site. Is this correct ?  What happened to my rep ?


It charged me a amount of 50 does it take a single time or for every purchase and y is this money taken and will I get the amount back and if there any one with the return of the money

Today I bought Temple Run: Oz from Google Play. When I filled all the credentials in to pay rupee 53.18 for this application then it automatically deducted rupee 50.00 from my credit card and after submitting it again deducted rupee 53.18 from the credit card. But the original price of this game is rupee 53.18, why did the extra rupee 50.00 deduction happen?  How can I get this money back?  Is buying an application on Google Play not secure?


What is the difference between 'int' and 'int?'.  For example:  public int? GoalPR { get; set; } public int AnchorPR { get; set; }

I am 90% sure I saw this answer on stackoverflow before, in fact I had never seen the "int?" syntax before seeing it here, but no matter how I search I can't find the previous post, and it's driving me crazy.  It's possible that I've been eating the funny mushrooms by accident, but if I'm not, can someone please point out the previous post if they can find it or re-explain it?  My stackoverflow search-fu is apparently too low....


I understand how to prove that for the set M = {f ∈  C([0,1]) : f(1) = 0} is closed in (C([0,1]),d(infinity)) using sequence of characterization but not sure how to prove it is not closed with respect to the d1 metric. There was a hint to draw a function fn and a function f (which is just f=1) and I am not sure how to a) know that this set F is not closed in the first place (so I know that I have to prove it is not closed) and b) how do I know what kind of graph to draw. I also know I need to show three things:  (fn)n ∈ M f ∉ M d1(fn,f) → 0  Thank you for all of the help!

I'm trying to solve this question:  Let $$M=\{f\in C([0,1])\ | \ f(1)=0\}.  $$  Is $M$ closed in $(C[0,1]),d_1)$?  At first, I assumed that $M$ was closed, so I tried to prove that if there is a sequence $f_1,f_2,f_3,...\in M,$and $\ f_n\rightarrow f\,$ with respect to $d_1$, then $f \in M$.    However, I got stuck and checked out the answers, and the answer I was given was just a counterexample of a sequence $(f_n)_n$ where $f_n \in M,\ f_n\rightarrow f$ wrt $d_1$, and $f\notin M$.    I understand that it's a lot easier to give a counterexample, but unfortunately I suck at analysis and cannot tell whether a set is closed or not upon inspection or come up with a counterexample right away.  Are there other ways of proof, like proof by contradiction, to show that this set is not closed?


This regex:      import re     string = 'I am a long string with many regexes matching'     pattern = '.*(?:with|regexes)'     print(re.findall(pattern, string))   returns   ['I am a long string with many regexes']   How can I instead make it return:  ['I am a long string with']   i.e. when both the short and long version of the regex is present, return the shorter string.

I have this gigantic ugly string: J0000000: Transaction A0001401 started on 8/22/2008 9:49:29 AM J0000010: Project name: E:\foo.pf J0000011: Job name: MBiek Direct Mail Test J0000020: Document 1 - Completed successfully  I'm trying to extract pieces from it using regex. In this case, I want to grab everything after Project Name up to the part where it says J0000011: (the 11 is going to be a different number every time). Here's the regex I've been playing with: Project name:\s+(.*)\s+J[0-9]{7}:  The problem is that it doesn't stop until it hits the J0000020: at the end. How do I make the regex stop at the first occurrence of J[0-9]{7}?


When you want to return a command line output, you may consider using two methods: `cat file` or $(cat file). As far as I know, they are equivalent before my eyes.  Is there a difference between both? If so, what's the difference please?

There are two syntaxes for command substitution: with dollar-parentheses and with backticks. Running top -p $(pidof init) and top -p `pidof init` gives the same output. Are these two ways of doing the same thing, or are there differences?


I have a rescued 2013 MacBook Air with a broken screen backlight due to a beverage spill and missing its internal SSD. I don't yet have any OS installed on it. I have access only to (32 bit) Windows PCs otherwise.  I believe there are bootable live USBs these days like we used to use live CDs back in the day. For a Mac live USB stick I'm not sure what partitioning / formatting / filesystem is needed for it to be bootable by Mac firmware. Thus I'm not sure if or how I can create one using a Windows box.  Existing questions that I originally thought were identical are about creating a USB key from an Intel machine running Linux. I currently don't have Linux on any of my Intel machines, all are running only Windows. Thus it appears mine is a novel question here.

we can create bootable windows 7 on usb drive using windows command line, is it possible to create bootable linux using windows command line? ( i.e. not using any software)  I've entered the following commands in diskpart and copied the linuxmint files in usb falsh drive , but cannot boot from it.


I have 3/8" wire that needs to be tight (not sagging) between two wooden posts with screw eyes. I don't want to purchase turnbuckles if I don't have to.  How can I pull them and then secure it with a crimp sleeve?  This is different to the other question because in the other one I was asking about regular polyester rope.

I have two 4-ft x 4" x 4" wood posts, and each post has a screw eye. There's 12 feet of distance between each post.  How can I tighten a piece of 1/2" diameter rope that goes through each screw eye and it's stretched tightly without having to buy turnbuckles?  There has to be a knot just for this.


I'm trying to understand the connection between The Equivalence principle and the Rindler space. According to Einstein the inhabitants of the elevator should feel the acceleration. However, for an observer in outer space (far the homogeneous field) should observe the elevator (and its inhabitants) as free-falling objects in the curvature of spacetime. This implies the they dont accelerate and thus describe the motion of a geodesic. Shouldn't the observer obtain a geodesic equation With vanishing Christoffel symbols ? is there something wrong with my reasoning? if not, How to obtain such geodesic equation for an observer in outer space for which the Christoffel symbols vanish and thus represents a 'free-falling' object.

Consider a scientist who is accelerating at a constant rate along the x direction, in flat minkovski space. The relevant coordinate transformations are  $$\begin{cases}t'=t \\ x'=x+\frac{1}{2}at^2 && a=\text{const}  \\ y'=y \\ z'=z\end{cases}$$  The question is, do you expect the curvature tensor to vanish in the primed coordinates?   One argument is that the curvature tensor is indeed a tensor. Since the space is flat, the curvature tensor will vanish for a stationary observer and hence will vanish in all coordinate systems. This makes sense because the curvature of space-time is an intrinsic property of the manifold and doesn't  care about which reference frame (RF) we measure it in.  But when i try to apply the equivalence principle (EP) to answer the same question i wind up contradicting myself. Which is worrying because it likely means that my basic understanding of the concept is flawed.   The EP says that the scientist cannot decide whether his laboratory is uniformly accelerating in flat space or if his laboratory is fixed on the surface of his home planet, who's surface conveniently results in an acceleration of 'a' outward from the planet (recalling that a freely falling observer is now the definition of unaccelerated). So actually, the primed coordinates aren't those of someone who is accelerating uniformly in flat space, they're  equivalently the coordinates of someone fixed in a gravitational field, the space of which is curved and so has a non zero curvature tensor.   Please correct where my logic fails, it's something quite basic and fundamental so i would really like to straighten it out. Thanks.


I'd like to render a frame with OPENGL and I want to save to a byte array variable without file save/load. What can I do?

Render Result exists in bpy.data.images["Render Result"] but it contains no data.  Also bpy.data.images["Render Result"].size[0] is 0, even if the render shows as an image in the UV/Image Editor with a width of 1366.  Maybe the render result cannot be accessed as an image or I missing some update or refresh call somewhere but I can't find such a thing in the 2.68 API documentation.  Any tip in the correct direction appreciated.


Suppose we have a ring R that contains the complex numbers, $\mathbb{C}\subset R$ and is not finitely generated as a ring. Can R be Noetherian?

I have the following questions:   (i) must every subring of the polynomial ring in two variables over the complex plane, containing the complex plane itself, be Noetherian?  (ii) Are there Noetherian rings containing the complex field which are not f.g. as a ring over the complex field (maybe the field of rational functions over the complex plane? is this f.g. as a ring over the complex field?)?


I know this is a terrible way to start a presence on a new community forum, but frankly, I'm frustrated that Stack Overflow is so restrictive regarding the ability to comment or vote on the feedback of others.  New users need 50 reputation points to comment on a thread, and 15 reputation points to 'vote' up or down a response to a topic. It is a bit ridiculous when considering how unfriendly this approach is for newer users. You're basically denying users any ability to participate on your forums until they've created several help topics.  I don't want to create new threads, as I'm doing now, for issues that many others have discovered and provided insight toward. I'd prefer to vote up or down comments that I found helpful, or provide my own related feedback or questions.  Overall, I find this a terribly unfriendly approach for reaching out to a community of developers. You should be mindful of the newer members who ACTUALLY want to become an active part of the Stack Overflow community. Sure, you're concerned some 'bot' will spam your forums with nonsense, or a n00b will ask dumb questions. But there are better ways to handle those problems than denying everyone the ability to participate in your forums until you've decided they are privileged enough.  I digress. My initial inquiries and issues regarding JQuery functionality were acknowledged and resolved in another topic; I was unable to participate in or thank the authors for their helpful responses likewise.

I think more reputation points should be required to add a new answer than to upvote an existing answer.  I don't continually watch for new questions, so usually when I find a question it has already been answered.  It seems bit inappropriate to answer an already-answered question in order to contribute to the conversation, but until you earn reputation, you can't upvote or comment; you can only add new answers, which prevents me from contributing at the moment as much as I would like to.  This seems backwards to me. If someone incorrectly upvotes a bad answer, the damage is minimal, as other users can down vote it and upvote the correct answers. On the other hand, an incorrect answer wastes the time of everyone who reads it.  So, IMHO, it should require more reputation points to add an answer than to upvote or comment on an existing answer.  I wouldn't say say that users should be prevented from answering unanswered questions until they have x reputation points, as that might prevent users who have answers from providing them, but perhaps it should be required if the question is already answered, to discourage users from reiterating previously given answers.  What do you think?


I'm planning to setup a Hyper-V virtual machine with Windows 10 and try to migrate some business applications. If everything works, I plan to activate with a Win 10 Professional license key. Unfortunately, I only see the  available for download.  Is it possible to switch the version later during activation?  Or can I get an official Professional evaluation ISO somewhere?

This is a  about Licensing.    Questions on licensing are off-topic on Server Fault.  If your question has been closed as a duplicate of this question, then this is because we want to help you understand why licence questions are off topic rather than just telling you "it just is". In all likelihood, this question will not address your question directly, it was not meant to.    I have a question regarding software licensing. Can the Server Fault community please help with the following:   How many licenses do I need? Is this licensing configuration valid? What CALs do I need to be properly licensed? Can I run this product in a virtual environment? Can I downgrade this product to an earlier version? Am I entitled to feature X with license Y?


I would like to know what the distribution is of linear combinations of Poisson random variables.  I know that a linear combinations of Poisson random variables is not always a Poisson random variable, namely   $Y : = \sum_k a_k X_k$  with $X_k \sim Pois(\lambda_k)$. Now, $Y$ is only Poisson if all $a_k$ are 1 and else $Y$ is a not Poisson random variable but follows a 'compound Poisson distribution'.  My question is can I still find an expression for this distribution or can I generate it using for instance Matlab?  Kind regards,  Michel

Using wikipedia I found a way to calculate the probability mass function resulting from the sum of two Poisson random variables. However, I think that the approach I have is wrong.  Let $X_1, X_2$ be two independent Poisson random variables with mean $\lambda_1, \lambda_2$, and $S_2 =  a_1 X_1+a_2 X_2$, where the $a_1$ and $a_2$ are constants, then the probability-generating function of $S_2$ is given by $$ G_{S_2}(z) = \operatorname{E}(z^{S_2})= \operatorname{E}(z^{a_1 X_1+a_2 X_2}) G_{X_1}(z^{a_1})G_{X_2}(z^{a_2}). $$ Now, using the fact that the probability-generating function for a Poisson random variable is $G_{X_i}(z) = \textrm{e}^{\lambda_i(z - 1)}$, we can write the probability-generating function of the sum of the two independent Poisson random variables as $$ \begin{aligned} G_{S_2}(z) &= \textrm{e}^{\lambda_1(z^{a_1} - 1)}\textrm{e}^{\lambda_2(z^{a_2} - 1)}  \\ &= \textrm{e}^{\lambda_1(z^{a_1} - 1)+\lambda_2(z^{a_2} - 1)}. \end{aligned} $$ It seems that the probability mass function of $S_2$ is recovered by taking derivatives of $G_{S_2}(z)$ $\operatorname{Pr}(S_2 = k) = \frac{G_{S_2}^{(k)}(0)}{k!}$, where $G_{S_2}^{(k)} = \frac{d^k G_{S_2}(z)}{ d z^k}$.  Is this is correct? I have the feeling I cannot just take the derivative to obtain the probability mass function, because of the constants $a_1$ and $a_2$. Is this right? Is there an alternative approach?  If this is correct can I now obtain an approximation of the cumulative distribution by truncating the infinite sum over all k?


I work on a system that automates signature generation for outlook. The part to generate the .htm files works great. But now I need to also add files in .txt format. If I use the content without any change in the encoding, all my accentuated characters are converted to a different value for example : "é" becomes "Ã©" or "ô" becomes "Ã´".  This issue clearly looked like an encoding conflict of some sort. I tried to correct it by converting the text value input to the "Windows-1252" encoding.  $myText = iconv( mb_detect_encoding( $myText ) , "Windows-1252//TRANSLIT", $myText);   But it didn't change anything. I also tried with :  $myText = mb_convert_encoding($myText, "Windows-1252");   And it didn't work either. For both of these tests, I checked the file type with Atom (my IDE) and it recognise these files as UTF-8. But when I check on terminal with file -I signature.txt it responds with this encoding signature.txt: text/plain; charset=iso-8859-1  Note that if I manually change the encoding to Windows-1252 in Atom, the characters are correct.  Has anyone met the same problem ? Is there another way in php to specify the encoding of the file ?

I'm setting up a new server and want to support UTF-8 fully in my web application. I have tried this in the past on existing servers and always seem to end up having to fall back to ISO-8859-1.  Where exactly do I need to set the encoding/charsets? I'm aware that I need to configure Apache, MySQL, and PHP to do this — is there some standard checklist I can follow, or perhaps troubleshoot where the mismatches occur?  This is for a new Linux server, running MySQL 5, PHP, 5 and Apache 2.


I removed gnome and gconf2 unknowingly and I am unable to login into Ubuntu.Please help me.

I accidentally removed all the packages starting with the name jpeg with:  sudo apt-get remove jpeg*   This screwed up a lot of things, removed Unity, Firefox, Flash player etc.  I somehow managed to recover the desktop and unity but then a lot of things are still buggy. For example .rpm files and .tag.gz just won't open up at all.  What I want is a way to fix everything that's amiss. Something that is the equivalent of a 'repair installation' with a windows disc.  Any tips, anyone?


I'm remodeling my home and I wanted to hardwire some extensions of my ethernet near my 220v outlet, by near at least a foot away from it. I was wondering, would I be able block the interference if I layer the patch extensions with copper tubes and PVC tubes to prevent EMI from the 220v line? If not, what do I do?

I am building a new house and am planning to hardwire network cables into each room.   Can I run CAT5/6 cables parallel to electrical wires without introducing any general safety issues or losing much in connection quality?  Wiring runs for up to 25 metres from patch panel and distribution board in garage to rooms.   My research indicates that is should be fine if they are in separate conduits or if the CAT cables are shielded.


Can someone help me by providing the correct set of steps to rename a SharePoint 2010 Web server machine name? It's a two-server farm. Are there know issues associated with this? I've researched this and found much  . I do not want to use alternative access mappings. It is a publishing site based Intranet.  I'm aware of the STSADM  command. But what else is involved? IIS? Remove Web app? Does it break anything? etc...

we have installed sharepoint server 2013 on 2008 server machine and configured few sites. and after couple of days the server name has changed. (Eg: servername1 to servername2).  So when i go to database, the instance name changed to servername2 and IIS as well.  But when i run the sharepoint site url with latest servername it saying error in database. please configure from sharepoint products. then i tried to launch configure the existing server farm with latest sql server instance and database as server_config db but it saying not able to proceed.  could you please help me on this because we do not want to loose the sites which we configured previously.  Thanks in advance!


I'm completely new to the entire D&D scene, so I thought it would be good to start out by getting the 5e starter set. But, after reading some more information about what's needed to start a campaign (as well as a review of the starter set), I'm starting to think the starter set might not be what I want.  It seems like nearly every website is recommending the 3 core books (Dungeon Master's Guide, Monster Manual, and Player's Handbook), but the Starter Set doesn't seem to contain any of these. Also, it seems that one of the Starter Set's main components is a pre-made adventure, and while that might be great for some, I think that my friends and I would enjoy having a unique adventure in an original world much more. That combined with the fact that the set seems to lack instructions on creating a character and only supports players though levels 1-5, it seems like the Starter Set would be the wrong way to go.  So I assume that I'll have to get my hands on the core books to start DMing, but is it necessary to get the Player's Handbook if I'm just going to be the DM? And since I'm still only in high school, I don't exactly have a huge budget for this, so I was wondering what the best way to get the books would be, budget-wise (sorry if this type of question is taboo, this is my first question).

I have GM'd several RPGs before that are not D&D (Fate, Deathwatch, Star Wars). We first tried to play D&D using the 3.5 edition and it went horribly — too many books and too many options with no idea of where to start.  I have been told that 5E takes care of all that and is easier and more fun so I want to try that but I would like a definitive list of what I need.  I expect that the kinds of books we need divide up like this:   Rulebook for me as GM Rulebook for players Fluff for everyone Monster book for me as GM   Links to these would be helpful as we got very confused with the 3.5 books — who should use what books confused us.  What other things do we need to play a campaign? I expect things like:   Dice: what kinds and how many of each kind, roughly. Models and maps. Do we need these? Does 5E need models and a grid or can it be played without (which is preferred)?   Is there anything else that we need that I haven't anticipated?


In season 2, episode 7 of The Mandalorian, Din is fighting some pirates and his blaster appears to either run out of ammo or jam up such that he can no longer use the blaster. Out-of-universe, I realize the explanation for this is the  as well as forcing our hero to physically engage with the Bad Guys. But I was wondering if there was an in-universe precedent for blasters suddenly failing to work (whether it be running out of ammo or jamming up).

I've been looking into the inner workings of blaster weapons primarily using Wookieepedia. While most of it I understand, I still can't figure out how many rounds a gun would fire before needing the ammunition component replaced/reloaded. Is there any solid answer?  I'm someone who likes to design and draw his own weapons and such, but likes to keep to how the technology of an era is in mind. While Star Wars weapons don't really have magazines (and you don't really see them reloading during battle), other people's work still has magazines and treat ammunition consumption as though it's pretty much the same as our modern era.  I guess that I just find it hard to believe, with the technology of the Star Wars Universe, that characters would need to carry lots of ammunition (hence why clones/storm troopers/battle droids don't visually seem to carry very much).  Example: DC-15A     "The weapon's tibanna gas cartridge carried enough gas for up to 500 shots, depending on the power settings of the weapon, while the charge pack lasted about 50 shots"   Source:   I've read in several places that this can be seen in two different ways.  1. Which ever ran out first, had to be replaced before the weapon could fire again. 2. The weapon contained two different sources of ammunition (so I guess you could switch between the two)


I'm using reflection and rotation from the graphics package. Depending on the number of characters I get an unwanted landscape output in the PDF file. [latex->dvips->ps2pdf]  \documentclass{article} \usepackage{graphics}  \begin{document} %%%%%%%%%%%%% comment A out REFLECTION\\% A %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% comment out B or C \rotatebox{90}{\scalebox{-1}[1]{REFLECTION}}%%%%% B %\rotatebox{90}{\scalebox{-1}[1]{REFLECTIONXX}}%% C \end{document}

Consider the following example:  \documentclass{article}  \usepackage{pstricks-add}  \def\RPut(#1)#2{%   \rput[r]{90}(!#1 1980 sub 2 div 0){#2 \quad}   \rput[l]{90}(!#1 1980 sub 2 div 0){\quad #1} }  \begin{document}  \psset{unit=0.78} \begin{pspicture}(-0.1,-2.9)(14.7,1.3)   \psaxes[     labels = none,     Dx = 2,     dx = 1,     Ox = 1980,     yAxis = false   ]{->}(15,0)   \RPut(1980){Lake Placid}   \RPut(1984){Sarajevo}   \RPut(2006){Torino} \end{pspicture}  \end{document}   If I compile using xelatex everything is fine but if I compile using latex --> dvips --> ps2pdf the figure is rotated 90 degrees clockwise.  How do I compile using latex --> dvips --> ps2pdf but without getting the rotation?


I'm writing my thesis using LyX editor. I use bibtex biography for citing papers. I use 'unsrt' style. When I cite multiple references on pdf I get them listed like [1,2,3,4,5] etc. not [1-5] like in most papers. How do I get it in latter style? Thanks.  PS: I'm using 'thesis' template from examples for writing my thesis.

Possible Duplicate:          In Latex I am using BibTex for the bibliography and use \bibliographystyle{unsrt} to manage my references.   When I use multiple references i.e. \cite{article1,article2,article3} I would love to see this appear in the text as:  blah blah [1-3] blah blah   instead I get:  blah blah [1, 2, 3] blah blah   I use the format of \bibliographystyle{unsrt} because it numbers the references in the order they appear and would like to keep this feature but I could be flexible on which style I use.


As of a few minutes (hours?) ago, all SE sites except chat present a TLS error in Firefox:     An error occurred during a connection to superuser.com. A required TLS feature is missing. Error code: MOZILLA_PKIX_ERROR_REQUIRED_TLS_FEATURE_MISSING   A bit of searching suggests that this occurs when a certificate specifies OCSP must-staple but there is no stapled response.  seems to  this conclusion.  Toggling security.ssl.enable_ocsp_must_staple in Firefox from its default of true to false allows access to the site again (please don't actually do this! I only did so to test it!), again suggesting a stapling issue.  I have at least one other person in chat confirming this is an issue in Firefox. It currently does work in Chrome, which is presumably not honouring the must-staple.

I suddenly started getting the following error message when using Firefox to access Stack Exchange sites:     An error occurred during a connection to math.stackexchange.com. A required TLS feature is missing. Error code: MOZILLA_PKIX_ERROR_REQUIRED_TLS_FEATURE_MISSING      The page you are trying to view cannot be shown because the authenticity of the received data could not be verified.      Please contact the website owners to inform them of this problem.   I should add that I am connecting just fine using Chrome.


How to find $\sum\limits_{n=1}^\infty q^n \sin(nx)$, where $|q|<1$ and $x \in \mathbb{R}$? I was thinking about rewriting it as $\sum\limits_{n=1}^\infty (q(\Im(\cos x+i\sin x)))^n$. It is a geometric series with the first term $q \cdot \sin x$, but what is the quotient? I can find $\sum\limits_{n=1}^\infty \sin(nx)$, but how to deal with the imaginary part, when multiplied by $q$?  Thanks!

I need to prove that $\dfrac{a \sin(bx)}{1 - 2a \cos(bx) + a^2} = \sum_{n=1}^\infty a^n \sin(nbx)$ where $|a| < 1$.  It seems that this can be proved by using Euler's formula identities for $\cos(bx)$ and $\sin(bx)$ and substituting $z = e^{ibx}$. From that, I get $$ \dfrac{a \sin(bx)}{1 - 2a \cos(bx) + a^2} = \dfrac{a (z - 1/z)}{2i(1 - a(z + 1/z) + a^2)}$$ $$= \dfrac{a (z^2 -1)}{2i(z - a(z^2 +1) + za^2)}$$ $$= \dfrac{a (z^2 -1)}{-2ai(z^2 - z(1-a^2)/a + 1)}$$  I don't understand what I am supposed to do next.


I looked at the other questions like this but I couldn't find one that worked. I'm trying to check if the person replied with something meaning "yes", so I'm checking for several words that mean yes. But if they reply with "yEs", my code won't work because its case sensitive, and I don't know what to do.  Code:  String fq = JOptionPane.showInputDialog(null, "Welcome to RadinBot! Would you like to continue?", "RadinBot", JOptionPane.YES_NO_CANCEL_OPTION);  if (fq.contains("yes") ||     fq.contains("Yeah") ||     fq.contains("Yup") ||     fq.contains("mhm") ||     fq.contains("Yea") ||     fq.contains("sure"))

Say I have two strings,  String s1 = "AbBaCca"; String s2 = "bac";   I want to perform a check returning that s2 is contained within s1. I can do this with:  return s1.contains(s2);   I am pretty sure that contains() is case sensitive, however I can't determine this for sure from reading the documentation. If it is then I suppose my best method would be something like:  return s1.toLowerCase().contains(s2.toLowerCase());   All this aside, is there another (possibly better) way to accomplish this without caring about case-sensitivity?


i have a table named tblStockManagement in my database. i have two columns named Client_ID and FoldingID.   i want to insert values to the columns, but first check the value if it is already exist in table or not. because then i will update the quantity of item instead of making new row in table.   i have method in my mind that select all data by given foldingID and Client_ID and see if dataset has 0 rows then data is not present already in table. but suggest me any easiest and reliable way to check that..

Assume a table structure of MyTable(KEY, datafield1, datafield2...).  Often I want to either update an existing record, or insert a new record if it doesn't exist.  Essentially:  IF (key exists)   run update command ELSE   run insert command   What's the best performing way to write this?


I arrived in the states in July. I got admitted. Now I want to fly from NY to LA in Sept. I will have problems at entering again back to the country if my passport ( Hungarian ) is stamped till October?

I understand that ESTA travellers are allowed to travel and can also go the Automated Passport Control (APC) in certain airports. But once I have arrived in a state (e.g. NY) and then would like to go to another state e.g. IL - How does this work? Do I need to treat this as an international travel i.e. do the ESTA based checks again?


I have dual boot system with Ubuntu 14.10 and Windows 8.1, both 32bit, with  5 partitons in windows 8.1.  I have insatalled Ubuntu 15.04 64 Bit. Now the 5 windows partitions are not visible and I cannot boot into Windows 8.1. How can I recover my partitons without loosing data.  Note that GRUB Menu is not showing the option to boot into Windows 8.1.  Here's the output of sudo parted -l, run from a live Ubuntu:

I am on Ubuntu 12.04 64-bits  I accidentally deleted a NTFS 255 GB partition using Gparted, and yes it contains LOTS of important data.  Upon realizing the deletion I haven't yet created any file-system on it. So it still shows Unallocated.    I tried Testdisk , but it shows entire partitions created from the beginning.  This sdb is my secondary drive with Xubuntu and Kubuntu on it. And that 255 GB NTFS  partition was cross platform storage drive.  I am currently in sda with Ubuntu and Win7 in dual boot, which enables me to use it as Safe recovery option rather then Live USB drive.   First ,  should i allocate it to ? file-System for better recovery .  Second , i really need to recover data from this drive so please give me possible  suggestions and proven methods of data recovery.  Third ,does Testdisk requires deleted partition to be allocated for its recovery .  I am currently trying the answer seen here  with Testdisk scanning for partition second time, hoping to recover it.   It looks a duplicate but i can't confirm if the OP got it right. Since my first doubt is to allocate it or not.  If any clarification required please do comment ,i will add it.  Edit: TestDisk deeper search results.      The following partitions can't be recovered:          Partition               Start        End    Size in sectors     >  HPFS - NTFS          22241 107 11 55592   3 27  535777280        FAT32 LBA            274460 158 19 460576 228 16 2989957948  NTFS, 274 GB / 255 GiB & for FAT32 LBA 1530 GB / 1425 GiB


I can compile the ""  but it doesn't look like the one given there. (Neither the dashed meridians, nor the cylinder)  The file:   Is it related to the "Missing character: There is no . in font nullfont!" Messages? How can I get the same picture as in the example?  I'm using the 2.02 release of TeXnicCenter with MikTex 2.9 64 Bit

I copied Tomasz M. Trzeciak's code from  to draw a shaded sphere with parallels and meridians. Only the sphere was drawn - no parallels or meridians. When I changed the \tikzset(#1/.estyle to \tikzset(#1/.style in the LongitudePlane and LatitudePlane macros the lines were correctly drawn. I am running the latest version of OS X 10.9.3 and have the full Mac Latex install with the latest updates (as far as I can tell).


I would like to test the execution of a php script that redirect its stdout and stderr to a file with tee.  php /path/to/script --param 2>&1 | tee -a  /path/to/log if ( test $? -ne 0 ); then     exit 2 fi   The last code tests the execution of the tee -a even if the php ocmmand fails.  How can I exploit $? or something similar to test the php script not the whole line ?

I have two processes foo and bar, connected with a pipe:  $ foo | bar   bar always exits 0; I'm interested in the exit code of foo. Is there any way to get at it?


I have a Windows 10 Home machine (Lenovo Y520) with a Core i7-7700HQ processor. Windows 10 and the BIOS are up to date. So is Oracle Virtualbox.  Until recently it was running VMs just fine with Oracle Virtualbox (doing what I bought it to do). Then it stopped doing that. VirtualBox's New VM feature stopped offering me 64-bit VMs. The ones I already had in place stopped running.  I have tried the instructions in these answers:      Specifically, I've tried upating the BIOS, reloading BIOS default settings, turning on Intel Virtualization in the BIOS, rebooting, powering off and back on again, etc etc ad nauseam. W10 Home doesn't have the Microsoft virtualization features that often interferes with VirtualBox, and I've made sure Windows Hypervisor Platform is shut off.  Still, no 64-bit vms.  What next?

Recently I started having an issue with VT-x on my Windows 10 running on HP EliteBook. I was using Oracle VirtualBox to run some VMs on it before and VT-x was enabled in BIOS and was working fine.  I started getting VT-x is not available error every time I was trying to start any of my VMs. That started happening after I installed Docker on my machine, so I tried uninstalling it and rebooting. Didn't help.  I checked BIOS settings and it says VT-x is enabled but checking with Intel(R) Processor Identification Utility shows that VT-x is not supported and Oracle VirtualBox also doesn't see it.  There were no hardware changes and the only software change was installing/uninstalling Docker.  How can this issue be fixed?


I had recently installed ubuntu 14.04.2 LTS using the option replace windows xp using ubuntu. So all my partitions lost. But i had the very important contents and backups please help me how to retrieve the deleted partition. Pls help me.  its in my Office so pls help me guys.

I have a Toshiba satellite A-200 laptop with a Vista OS on it with 4 NTFS partitions  (C:) Vista  (D:) Entertainment  (E:) Work  (F:) Sources   and I wanted to start using Ubuntu instead. So I tried it first from the live CD and everything was OK and all the partitions were shown and working and so I decided to install Ubuntu to replace Vista on the (C:) drive. After I did that I can no longer find my folders and files on the (D:), (E:), (F:) partitions and the only file system that is shown is one 198 GB although my HDD is 320 GB.  I can't access the lost data on the remaining 120 GB which I hope is still there and not totally lost  I am now working from the live CD but I am unable to install testdisk. Can I recover the Vista partitions by the product recovery CD to get my laptop back to the factory settings? Can I recover the NTFS partitions using a recovery program for Windows or will that make the problem worse?   I need these data badly as I don't have a backup for them.


This question is puzzling me since I learnt about the gravitation law in school. Why did Newton guess/assume that gravitational force is inversely proportional to the square of distance?  Did he verify that experimentally? (I remember hearing that the first experimental verification of the law of gravitation was after Newton's death.)  If the answer to the above question is no, is it for example more plausible to suppose that $F\propto1/r^2$ than to suppose that $F\propto1/r^4$? Did Newton carry out a thought experiment that makes $F\propto1/r^2$ a plausible guess?  So in summary: Why did Newton choose exponent of $-2$ instead of any other exponent? Was it a guess that depended on pure luck or an educated guess?

When I was in the university (in the late 90s, circa 1995) I was told there had been research investigating the $2$ (the square of distance) in the Newton's law of universal gravitation.  $$F=G\frac{m_1m_2}{r^2}.$$  Maybe a model like   $$F=G\frac{m_1m_2}{r^a}$$  with $a$ slightly different from $2$, let say $1.999$ or $2.001$, fits some experimental data better?  Is that really true? Or did I misunderstand something?


Suppose I have an itinerary A - C with 1 stop at B, booked under a single ticket number on the website of airline X, where the leg A - B is operated by airline Y and B - C is operated by X.   If the flight A - B is delayed to a point where I miss my connection, whose responsibility is it to see that I'm fed, watered, and eventually delivered to destination C? Is it Y or X?   Apart from an academic interest in the answer, I'm going to be travelling on such an itinerary soon, and would like to known with whom I should be having a polite but firm conversation in case things go wrong. In my particular scenario, the leg B - C is only operated a few times a week, not daily, so a missed connection would be quite inconvenient.

I have flight booked through United Airlines (PRG -> FRA -> YYZ -> MCI), checked-in using the Lufthansa website (first flight PRG -> FRA is operated by Lufthansa), and the flight (FRA -> YYZ) has an Air Canada number. My flight to Toronto is delayed, and I will miss my connection flight (YYZ -> MCI) that has Air Canada number, and is operated by Air Georgian.  Who should I contact and ask to get me on the next flight? I am little bit confused by all those airlines involved.  Update: YYZ -> MCI was cancelled, and I got another flight (YYZ -> ORD -> MCI). This was promptly arranged by Air Canada.


The following Python script is extracted from /usr/lib/python2.7/dist-packages/Mailnag/plugins/libnotifyplugin.py  In the script, the command ('zenity --info --text="You got new mail"') is not run.  How do I make it run? I want it to run when mail_count > 0 The lines under if mail_count > 1: are run properly.  if mail_count > 0:     import os     os.system('zenity --info --text="You got new mail"')     if mail_count > 1:     summary = _("{0} new mails").format(str(mail_count))     if (mail_count - i) > 1:         body = _("from {0} and others.").format(senders)     else:         body = _("from {0}.").format(senders) else:     summary = _("New mail")     body = _("from {0}.").format(senders)   I put the following "Testing.py" script into /usr/lib/python2.7/dist-packages/Mailnag/plugins/Testing.py and ran it, which did bring up the "You got new mail" message.   #!/usr/bin/env python2 import os os.system('zenity --info --text="You got new mail"')

I'm currently studying  and Python programming. I just want to know how I would go about executing a Linux command in Python. The commands I want to execute are:  echo 1 > /proc/sys/net/ipv4/ip_forward iptables -t nat -A PREROUTING -p tcp --destination-port 80 -j REDIRECT --to-port 8080   If I just use print in Python and run it in the terminal will it do the same as executing it as if you was typing it yourself and pressing Enter?


I have this code which I understand is vulnerable but I'm having trouble making a safe prepared statement out of it. Anyone with any idea of how to arrive to the point of getting an array of member records stored in variable $userrecord and number of rows stored in $rowsnumber help me out. I've not used MySQLi prepared statements before  /*This query returns member records in an array format*/ $querymember = "SELECT * FROM members WHERE phone='$providedphone' ";  $member = mysqli_query($conn,$querymember);  // Number of rows $rowsnumber = $member->num_rows;  // User record (Entity) $userrecords = $member->fetch_array(MYSQLI_NUM);   What I've tried  $stmt = $mysqli->prepare("SELECT * FROM members WHERE phone = ?"); $stmt->bind_param("s", $providedphone); $stmt->execute();  // To get number of rows $rowsnumber = $stmt->num_rows;  // To get user records $userrecords = $stmt->get_result();

If user input is inserted without modification into an SQL query, then the application becomes vulnerable to , like in the following example:  $unsafe_variable = $_POST['user_input'];   mysql_query("INSERT INTO `table` (`column`) VALUES ('$unsafe_variable')");   That's because the user can input something like value'); DROP TABLE table;--, and the query becomes:  INSERT INTO `table` (`column`) VALUES('value'); DROP TABLE table;--')   What can be done to prevent this from happening?


I'm trying to make an animation inside Freddy Fazbear's Pizza, but when I rendered the image to see how it looked, I got THIS.  I don't know how the heck this happened. for reference, this is what it looked like before the render.   What's going on and how do I fix it?

When I zoom out they look like faces eat each other. (also when rendering)    But when I zoom in they are normal... I don't know why?


Err:10 http://download.opensuse.org/repositories/home:/strycore/xUbuntu_ ./ Release   404  Not Found [IP: 2001:67c:2178:8::13 80] Ign:11 http://ppa.launchpad.net/wine/wine-builds/ubuntu bionic InRelease  Err:12 http://ppa.launchpad.net/wine/wine-builds/ubuntu bionic Release      404  Not Found [IP: 2001:67c:1560:8008::15 80]                            E: The repository 'http://download.opensuse.org/repositories/home:/strycore/xUbuntu_ ./ Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. W: Skipping acquire of configured file 'main/source/Sources' as repository 'http://dl.winehq.org/wine-builds/ubuntu artful InRelease' does not seem to provide it (sources.list entry misspelt?) E: The repository 'http;/ppa,launchpad,net/wine/wine-builds/ubuntu bionic Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.

When updating, I get the following error message:   W: The repository 'http://ppa.launchpad.net/mc3man/trusty-media/ubuntu xenial Release' does not have a Release file.   Here, I find another statement on this error:   This recommends removing certain PPAs; and, I'm not sure if I should do that since it might mean not getting the updates that I need.    Is this what I should do?


I spend a lot of time on math.se and even though I don't understand many of the questions posed, I try to understand what is being said or atleast wiki something to get some gist of the question and the answers. However, I never understood what "rigour" meant or what people mean when they say "is this a rigorous solution?". So can someone please explain to me what rigour in mathematics is?.  Thanks!

I am a programmer moving up to computer science and even in my past life as a mechanical engineer I used sufficient maths to get by but I have always wondered what exactly is this thing called rigor.  Please make me understand it.


I'm looking for a possible idea to restrict the visibility ec2 instances to certain IAM users under the same root account.  custom policies doesn't seem to work because describeInstances doesn't support resource-level permissions.  Is there any way to hide instances created by different IAM users from one another. Is this currently possible?

I'm looking for a way to restrict the visibility ec2 instances to certain IAM accounts. I'd really like a way for a particular account to only be able to see the instances that it has created i.e. when it does a describeInstances only those it has created are present.   I've been looking into using custom IAM policies based on resource tags to do this and while the management looks to be ok, each account can still see instances created by other users using describeInstances.  Really I'm looking for a way to hide resources created by different IAM accounts from one another. Is this currently possible?


i have an algorithm to upload an image with automatically naming, but i give the name with id from database, but the data in database isn't exist yet, so i insert the data first, then i get the max id as name of image (you can find it out clearly in my attachment code below and id is auto-increment), and the problem is i think if the server get much request to upload image, the image will have wrong name or name with id that doesn't belong to it. is there best practice regard to my problem?? or you have better algorithm about it?? please help me  This code written in php with codeigniter  if(isset($_FILES['gambarProduk'])){     $this->db->select_max('idProduk','maks');     $this->db->insert('gambarProduk',array('idProduk'=>$this->db->get('produk')->result()[0]->maks));     $config['upload_path']          = 'images/produk/';     $config['allowed_types']        = 'gif|bmp|jpg|png|jpeg';     $this->db->select_max('idGambar','maks');    $config['file_name'] = $this->db->get('gambarProduk')->result()[0]->maks;     $extension = pathinfo($_FILES["gambarProduk"]['name'], PATHINFO_EXTENSION);     $fullpath = $config['upload_path'].$config['file_name'].'.'.$extension;      if(file_exists($fullpath)){         unlink($fullpath);     }     $this->db->where('idGambar',$config['file_name']);     $this->db->update('gambarProduk',array('extension'=>$extension));     $this->load->library('upload',$config);     if(!$this->upload->do_upload('gambarProduk')){         $this->session->set_flashdata('uploadGambarProduk',2);     } }

I need to convert some files to PDF and then attach them to an email.  I'm using Pear Mail for the email side of it and that's fine (mostly--still working out some issues) but as part of this I need to create temporary files.  Now I could use the  function but it sounds like it creates a file on the filesystem, which isn't what I want.  I just want a name in the temporary file system (using ) that won't clash with someone else running the same script of the same user invoking the script more than once.  Suggestions?


I try to be a better programmer every day, and a big part of that is learning from people who are more experienced than me. (You are all awesome teachers!)  For example, in Java, if I want to know if, in general, I should set a field by passing in an argument when I create it or setting the field in the constructor, how do I find that out? This assumes I always know what to initialize the field to, such as setting something to a random position. It is an opinion based question, but there is a generally accepted practice (dependency injection). I would expect the question to be closed as being "primarily opinion based".  This answer may be opinion based, but someone who is asking this question does not have enough knowledge to form an educated opinion of his or her own. The asker would not know dependency injection is a thing, so would not know to read up on it.  The inability to ask questions like this, for me at least, slows my improvement as a computer scientist.  So my question is, where can I ask questions about programming conventions? This is a followup to my earlier question:

There seems to be more than a few computer science/programming Stack Exchange networks (is that the correct term?). Stack Overflow, being the first, has by far the most users, questions, and answers.  What is the reasoning for creating the others, and are there clear guidelines for which kinds of questions should be posted? I can see a large amount of potential overflow, many cases of people not getting a good answer to their question, because the person who has the answer isn't browsing that particular network at the moment.  I understand that they were probably created for organizational purposes, but wouldn't it almost make more sense to just have them as categories under Stack Overflow, keep them separated but still connected, instead of making people have to create multiple 'account's, one for each network?  I am sure there was a very good reason to break them up, but as someone that is new to SE, it can be somewhat intimidating to decide which one to post in to ensure you get a good answer. For example, if I am a computer science student, my first instinct might to be to post in the computer science network, until I see that it literally has 1% of the users as the Stack Overflow network, which still seems to be for programming/computer science related questions.  So my second instinct would then to be to post it into the Stack Overflow site on the basis that I have a significantly higher chance of my question being seen and getting a good answer. Then I notice that there is also a 'programmers' network, and I don't even begin to know where that fits in. I, and I am assuming most people, will probably just post on Stack Overflow to be safe.  My question is, other than the short little description blurb of each one, is there a clear cut set of guidelines which what each network is intended for, what kinds of questions should go to each one, and is anything being done to encourage people to post in these newer, smaller (more specialized?) networks as opposed to just posting in big daddy Stack Overflow?  Now again, this is for computer science/programming/"why isn't this code doing what I want?" related questions, I am not saying that if I had a question about Linux or WordPress or something I would have the same confusion.


What actually causes a rocket to move? Is it the pressure in the rocket engine or the amount and velocity of mass that is being ejected out.  The reason I am asking is, I found these two explanations for a rocket motion. Are they same or different. If same, is there any correlation between them?

We know, the rockets in space use Newton's 3rd law to increase their velocity and hence move. What I don't understand is how it is possible in space aka vacuum-state without air? From what I know, Joule's "Free Expansion of Gas" says that free-expansion compresses the gas and is therefore "affected" by vacuum so it can't make the rocket move as the gas will have zero press/force. Could someone please explain me how rockets do really work and the above-mentioned statement?   Actually, please have a look at this site:   Not: The site appears to include some conspiracy theory thingummies, but made me wonder anyway.


Why is Ubuntu 18.04 using Kernel 4.15 although that's not an LTS-Kernel?  Since 18.04 is supported for at least 5 years that seems like a strange choice.

I only recently became aware that LTS wasn't just an Ubuntu thing - there's LTS kernel versions too. Yet the kernel version used (3.13) in Ubuntu 14.04 LTS is not an LTS kernel version. Is it considered unimportant whether or not a kernel version is LTS?


Please fellows, how and what is the best usage, application and difference between the word "Am" and "I am"

I want to know firstly if it's grammatically correct to start a declarative sentence with "Am". For example:     Am excited about the game today.   Secondly, if it is grammatically incorrect, then I wanted to ask how much "head room" there is for the above usage. I can't think of an example now, nor find one here at english.stackexchange. However I imagine there are usages of the english language that grammatically are illegal, yet have somehow become accepted as colloquial or idiomatic perhaps.


I am new to Salesforce. I have Account (Master) and Keys (Detail). I created a trigger on Keys. Now I need to get reference to the Account object  to do some manipulations.   I tried ApexPages.currentPage().getParameters().get('Id'); but it throws System.NullPointerException: Attempt to de-reference a null object:   Any help is greatly appreciated -Thank you

I'm sure this has been addressed before but I can't seem to find the answer. In a trigger on a record, aside from the actual fields on the record, what do I have access to? The parent info? that record's children? Do you just add the fields by re querying in your handler?


I use emacs a lot, and type C-x s to save there. When I am in vim running inside tmux on a remote machine, if I accidentally type C-x s, the vim instance completely freezes up, and the only way out is to send tmux the kill-pane command.  How can I configure vim/tmux to block this from happening?

It's a situation that has happened quite often to me: after I press (with a different intention) Ctrl-S in a terminal, the interaction (input or output) with it is frozen. It's probably a kind of "scroll lock" or whatever.  How do I unfreeze the terminal after this?  (This time, I have been working with apt-shell inside a bash inside urxvt--not sure which of them is responsible for the special handling of Ctrl-S: I was searching the history of commands backwards with C-r, as usual for readline, but then I wanted to go "back" forwards through the history with the usual--at least in Emacs--C-s (, , ), but that caused the terminal to freeze. Well, scrolling/paging to view past things still works in the terminal, but no interaction with the processes run there.)


I have a perplexing issue that I can't seem to comprehend...  I have two SQL statements:   The first enters information from a form into the database. The second takes data from the database entered above, sends an email, and then logs the details of the transaction   The problem is that it appears that a single quote is triggering a MySQL error on the second entry only! The first instance works without issue, but the second instance triggers the mysql_error().  Does the data from a form get handled differently from the data captured in a form?  Query 1 - This works without issue (and without escaping the single quote)  $result = mysql_query("INSERT INTO job_log (order_id, supplier_id, category_id, service_id, qty_ordered, customer_id, user_id, salesperson_ref, booking_ref, booking_name, address, suburb, postcode, state_id, region_id, email, phone, phone2, mobile, delivery_date, stock_taken, special_instructions, cost_price, cost_price_gst, sell_price, sell_price_gst, ext_sell_price, retail_customer, created, modified, log_status_id) VALUES ('$order_id', '$supplier_id', '$category_id', '{$value['id']}', '{$value['qty']}', '$customer_id', '$user_id', '$salesperson_ref', '$booking_ref', '$booking_name', '$address', '$suburb', '$postcode', '$state_id', '$region_id', '$email', '$phone', '$phone2', '$mobile', STR_TO_DATE('$delivery_date', '%d/%m/%Y'), '$stock_taken', '$special_instructions', '$cost_price', '$cost_price_gst', '$sell_price', '$sell_price_gst', '$ext_sell_price', '$retail_customer', '".date('Y-m-d H:i:s', time())."', '".date('Y-m-d H:i:s', time())."', '1')");   Query 2 - This fails when entering a name with a single quote (for example, O'Brien)  $query = mysql_query("INSERT INTO message_log (order_id, timestamp, message_type, email_from, supplier_id, primary_contact, secondary_contact, subject, message_content, status) VALUES ('$order_id', '".date('Y-m-d H:i:s', time())."', '$email', '$from', '$row->supplier_id', '$row->primary_email' ,'$row->secondary_email', '$subject', '$message_content', '1')");

If user input is inserted without modification into an SQL query, then the application becomes vulnerable to , like in the following example:  $unsafe_variable = $_POST['user_input'];   mysql_query("INSERT INTO `table` (`column`) VALUES ('$unsafe_variable')");   That's because the user can input something like value'); DROP TABLE table;--, and the query becomes:  INSERT INTO `table` (`column`) VALUES('value'); DROP TABLE table;--')   What can be done to prevent this from happening?


I had answered someone who asked a very lazy question (-5 votes, link below) that had a real-value answer (+9 votes) and due to three users deleting the question I lost all of those reputation points - that's not the main issue. Reputation points aside it was a frequently asked question by folks who were inexperienced or new to the Apple Developer Portal as navigating to the beta content within that portal isn't always inherently obvious out of the gate.  With that being said as a semi-new user I'm having trouble comprehending why a question (lazy or not) that has a real-value answer that is helping people with the same question would still be closed. From a community based on sharing & learning that seems counter intuitive to me.   (for those with access)  EDIT: My last post on this just to prove how short-sighted the bureaucrats can be on this site. Googling "download xcode 5" reveals that the deleted question I'm complaining about is the 4th hit. Way to drive that site traffic Stack moderators!

I frequently come across a really useful answer on StackOverflow which has been closed because it doesn't match the Q&A format.  Examples include  ,  ,   ,  and there are others.  Where should this information be exchanged if it's not on stackoverflow?  It seems the moderators are often somewhat overzealous...  ---edit  When I say best, I mean they are informative and useful for someone who's looking for an answer to them.  Even if they do become a bit of a discussion, I value other people's opinions on the relative merits of the different JPA frameworks.  I come here looking to choose one and the answer helps me.  So what if it's not a definitive answer?  ---edit  I don't care how popular a question is, nor how interesting it is.  Users are interested in stuff that's useful to them.  Plenty of those were useful (as judged by the upvotes on the answers: 'This answer is useful'), but closed because they didn't have a definitive answer, as far as I can tell.  ---edit  Seems I'm not the first person to think this: there are various similar questions to mine like this one:   In it the user lists lots of other useful questions which have been closed:                    So isn't there a place on stackoverflow for these questions?  A discussion section, maybe?


I have 5 different email accounts: iCloud, GMail, Hotmail and two others which my iPhone does not give the option to sync its contacts.   So, I have only synced my contacts with iCloud and since barely a month ago, when I edit a contact it appears immediately a copy of it and if I delete one, both of the are deleted.  Does anyone know what is going on?

I have two exchange accounts on my iPhone 4. One that connects to my gmail, the other connects to my work's Lotus Notes. There are no overlapping contacts in the two accounts. There are also no contacts saved locally on my phone.   When I enable contacts in both accounts, I get two identical entries for each of the contacts in my gmail. If I disable the Notes exchange account, then there are no more duplicates. If I have Notes contacts enabled, and gmail contacts disabled then I have no contacts at all.  Does anyone know what is going on? Is this a problem with having multiple exchange accounts or is it a Lotus Traveler problem? (I tend to blame Notes for all the trouble in the world, but that is just my bias)  Thanks all.


This is exercise 1.3.8 in Hatcher:  Let $\tilde{X}$ and $\tilde{Y}$ be simply-connected covering spaces of path connected, locally path-connected spaces $X$ and $Y$. Show that if $X\simeq Y$ then $\tilde{X}\simeq \tilde{Y}$.  I tried applying the lifting criterion, but I seem to be hitting a dead end. Any help would be much appreciated.

As part of am exam question (Q21F ), I'm trying to prove that if $X$ and $Y$ are path-connected, locally path-connected spaces with universal covers $\widetilde{X}$ and $\widetilde{Y}$, respectively, then if $X \simeq Y$ then $\widetilde{X} \simeq \widetilde{Y}$.  My attempt might be correct, but it seems too complicated and amongst the jumble I may have made some incorrect assumptions. So what I'm looking for is (a) verification or correction; and (b) ideas as to how I could simplify my argument.    My argument:  Let $p:\widetilde{X} \to X$ and $q:\widetilde{Y} \to Y$ be the covering maps, and let $X \overset{f}{\underset{g}{\leftrightarrows}} Y$ be a homotopy equivalence.  Fix a point $\widetilde{x} \in \widetilde{X}$, let $x=p(x) \in X$ and $y=f(x) \in Y$, and fix $\widetilde{y} \in q^{-1}(\{y\}) \subseteq \widetilde{Y}$. Also let $x' = g(y) \in X$ and fix $\widetilde{x'} \in p^{-1}(\{x'\}) \subseteq \widetilde{X}$.  Define a map $\widetilde{f} : \widetilde{X} \to \widetilde{Y}$ as follows. For $\widetilde{z} \in \widetilde{X}$ let $\widetilde{u}:[0,1] \to \widetilde{X}$ be a path from $\widetilde{x}$ to $\widetilde{z}$. Let $z=p(z)$ so that $u=p\widetilde{u}$ is a path in $X$ from $x$ to $z$. Let $v=fu$, so that $v$ is a path in $Y$ from $y$ to $f(z)$. Lift $v$ to a path $\widetilde{v}$ in $\widetilde{Y}$ with $\widetilde{v}(0) = \widetilde{y}$. Define $\widetilde{f}(\widetilde{z}) = \widetilde{v}(1)$.  Notice that $q\widetilde{v}=v$ so that $q\widetilde{f} = fp$.  Define $\widetilde{g}:Y \to X$ analogously: For $\widetilde{z} \in \widetilde{Y}$ let $\widetilde{a}:[0,1] \to \widetilde{Y}$ be a path from $\widetilde{y}$ to $\widetilde{z}$. Let $z=q(z)$ so that $a=q\widetilde{a}$ is a path in $Y$ from $y$ to $z$. Let $b=fa$, so that $b$ is a path in $X$ from $x'$ to $g(z)$. Lift $b$ to a path $\widetilde{b}$ in $\widetilde{X}$ with $\widetilde{b}(0) = \widetilde{x'}$. Define $\widetilde{g}(\widetilde{z}) = \widetilde{b}(1)$.  Likewise, notice that $p\widetilde{g}=gq$.  Claim: $\widetilde{X} \overset{\widetilde{f}}{\underset{\widetilde{g}}{\leftrightarrows}} \widetilde{Y}$ is a homotopy equivalence.  We have $p\widetilde{g}\widetilde{f} = gq\widetilde{f}=gfp \simeq p$ and $q\widetilde{f}\widetilde{g} = fp\widetilde{g} = fgq \simeq q$.  This shows that $\widetilde{g}\widetilde{f}$ and $\widetilde{f}\widetilde{g}$ are covering translations (deck transformations) and are therefore homotopic to the respective identity maps. So we have a homotopy equivalence.    Any comments would be appreciated.


Do spells such as Hex or enhance ability affect attack rolls made using the affected ability score?  These spells reference advantage/disadvantage on ability checks, but I am unsure whether an attack roll constitutes an ability check.  I did reference these spells specifically in case there is a difference between a specific ruling and the general rule.

The Barbarian's Rage ability gives advantage on Strength checks and saving throws.  Does this mean that the Barbarian gets advantage to attack rolls as well? Is an attack a check, or since saving throws are mentioned, that means it does not apply to attacks?


After a while you start getting to the point where you've asked a lot of questions - finding the ones that don't have an answer starts to become a little laborious. I currently only have 11 pages of questions but this is going to continue growing over time. Some of these questions don't have an answer.  From a usability point of view, it would be nice to have an "unanswered" option alongside the existing "votes", "activity", "newest" and "views" options on users/current?tab=questions.  The way I would expect this to behave is that selecting this view would result in all questions that have not got an accepted answer would be listed, in date sorted order (newest to oldest). This would include any questions that have answers posted on them (regardless of the number of upvotes on the answer). Think of it as a checkmark filter.  I can't imagine it would be particularly difficult to implement and there's plenty of space to fit an additional button here without having to move anything around.   Would this be possible?  Note:  has been asked many years ago without defining exactly what was needed in specifics, and it doesn't have an official response from Stack Exchange on it, this is a feature request after all.

To help users keep track of (and hopefully get answers to) unanswered questions, it would be useful to have an "unanswered" sort order on a user's profile page.  It would order the list of questions with unanswered questions first.   This would be in addition to the "recent," "views," "newest," and "votes" sort orders.


How to get my dhcp ip address, whether i am in a local network?  I.e. if we have internet access in local network, but i want to know my dhcp server IP .. like " what is my IP" ..

If I check with , I can see my public IP. Is there something on the Ubuntu command-line which will yield me the same answer?


I need someone to help me  I got this iphone5 a months ago from my cousin and I already have my own appleID and also my iCloud, and I could download the apps and everything but now when I got a notice to update whatsapp it requires the old password :/ is the only solution to delete whatsapp or is there anything else I could do? P.S my cousin doesn't know the password  Thank you

So the problem is that I have an iPhone5 from my cousin, and yesterday I got a messages in WhatsApp from friends but I couldn't open WhatsApp. It said that I need to update WhatsApp. I went to the App Store and it required the password of iTunes Store but old email and password from my cousin, and I don't know the password.  Does someone have a solution for this? I also don't want to delete my WhatsApp because I cannot backup my chat history and also will not see the new messages that come in my WhatsApp.


The thing that made me ask this question was that most of Stark family are dead and Bran is now the "heir" to Winterfell. So I guess he should have children to succeed him, otherwise the Stark line will end. (I'm assuming Arya will not come back to Westeros and Rickon's fate is sealed, though I could be wrong.) I don't remember reading anything about it.

According to the family tree in A World of Ice and Fire Ned Stark's children are in fact the only surviving Starks. And as of S06E09;      Bran is the only legitimate, male Stark.   In the Season Six Finale it is revealed that;      Jon is in fact the Son of Lyanna Stark and most likely, Rhaegar Targaryen.   This means that if Jon was legitimised and there was record of his birth in the Citadel;      He would become a Targaryen.   So I guess my big question is: Can Bran father children? I find it to be quite an important issue considering House Stark's long term survival depends on it.  In season 4 (I can't remember which episode) Locke Bolton gives Bran a cut on the leg to confirm his identity. Bran reacts only with fear and not pain, indicating that he has no feeling below his waist.  Does this mean that he wouldn't be able to...get it up? And if so, why hasn't the show addressed House Stark's impending doom?


I am trying to extract parameters from video files with ffprobe and process depding on these results. However i am not able to pass the files properly to ffprobe if they contain whitespaces. echo $1  inputfile=$(printf '%q' "$1") #inputfile=${1@Q}  echo $inputfile  ffprobeout= ffprobe -v error -select_streams v:0 -show_entries stream=width,height,bit_rate -of csv=s=x:p=0 $inputfile  when i now call a smaple file  with files2reenc.sh "test file with spaces.mp4" it results test file with spaces.mp4 test\ file\ with\ spaces.mp4  Argument 'file' provided as input filename, but 'test' was already specified.  So ffprobe sees every part of the name as seperate file and does not recognize it as one parameter. I'm not sure how to pass/escape my input so it would work as expected. I'm not sure if the problem is already when invoking my bash script or with the way i try to handle input paramter. I also tried using echo $inputfile | xargs -0 ffprobe ... with no success.

Or, an introductory guide to robust filename handling and other string passing in shell scripts.  I wrote a shell script which works well most of the time. But it chokes on some inputs (e.g. on some file names).  I encountered a problem such as the following:   I have a file name containing a space hello world, and it was treated as two separate files hello and world. I have an input line with two consecutive spaces and they shrank to one in the input. Leading and trailing whitespace disappears from input lines. Sometimes, when the input contains one of the characters \[*?, they are replaced by some text which is is actually the name of files. There is an apostrophe ' (or a double quote ") in the input and things got weird after that point. There is a backslash in the input (or: I am using Cygwin and some of my file names have Windows-style \ separators).   What is going on and how do I fix it?


The polynomial $p(z)= z^n +a_{n-1}z^{n-1}+a_{n-2}z^{n-2}+...+a_0$ maps the closed unit disc to the closed unit disc. Then prove that all coefficients of $p(z)$ except the leading coefficient are zero. I have no idea because Schwartz lemma cannot be applied unless $p(0)=0$. Help please.

Given a polynomial $ P(z) = z^n + a_{n-1}z^{n-1} + \cdots + a_0 $, such that   $\max_{|z|=1} |P(z)| = 1 $      Prove: $ P(z) = z^n $      Hint: Use cauchy derivative estimation    $$ |f^{(n)} (z_0)| \leq \frac{n!}{r^n} \max_{|z-z_0|\leq r} |f(z)| $$ and look at the function $ \frac{P(z)}{z^n} $     It seems to be maximum principle related, but I can't see how to use it and I can't understand how to use the hint.


I collect numbers from generators that yield different ranges of whole numbers with an unknown distribution. I want to estimate the mean of the numbers outputted by this generator. I'm convinced the distributions are symmetric (more specifically, uniform) though, so I can just average the min and max after I have a decent sample size. What would be the best way to test that the distribution of numbers is symmetric or uniform?  Things I've tried: -Checked that the mean, median, and midpoint converge to the same values, but I can't quantify how close the values would have to be. -Histogram, but my sample sizes (n<100 because I must manually collect) are too low for me to tell -Chi-square test with the frequencies of each number in the range and testing them against the expected value for a uniform distribution, but I've read there are problems with this in other posts -Pearson's skewness coefficient and comparing that with the standard error of skewness, but I think there are limits to this kind of approach -Comparing kurtosis of data with that of a uniform distribution  I've also read about the Kolmogorov-Smirnov tests and Shapiro-Wilk tests but these seem too complicated for such a simple seeming task..  Thanks

We can test the symmetry of a distribution around $0$ by Wilcoxon sign rank test, based on its sample.   But if we want to test if a distribution is symmetric around its mean, based on its sample $X_1, \dots, X_n$, is it valid to first normalize $X_i$ by the sample mean as $Y_i := X_i - \bar{X}$, and then apply Wilcoxon sign rank test to $Y_i$'s?  If not, what are some ways?  Thanks and regards!


This may be a weird topic for SU but for those of us who are on the go a lot proving tech support or just carry our gear because we can and it is nice to always have around and with us, is storing hardware and electronics in 90F+ degree car trunks in backpacks a bad idea? Hardware meaning: switches, hard drives, routers, and other little devices with circuits.  I know they should never operate in those temperature ranges but is storing the same thing?  I understand that laptop batteries are effected by heat due to how they are built, but not sure about electronics that are not running.

It's now summer around here, with temperatures ranging from 20C to 30C in the summer. Occasionally, I have a situation where I can carry my laptop indoors, or just leave it in the car for a few hours.  My question is: will it cause any sort of damage if I leave it in the car for several hours? I usually bring it indoors just in-case, but I thought I'd ask. Note that the laptop is always off at this time.


I posted a question on StackOverflow:    Then I got spam from a 3rd party trying to get me to go to their site to get an answer, instead of SO. I know SO can't stop the email spam from a 3rd party, but is there someway to find if they have any SO accounts and nuke this f'ing spammer?

Well today as I was going home I got a strange email, in my private inbox (email associated with S.O.) asking me if I had solved a question on S.O. that I didn't ask. To be more precise I had given an answer.   After reading:       and several other email related issues on S.O. I decided to let you all know about this because probably I am not the only one.   So the mail subject was:     Re: Deleted facebook account - Cannot access my apps?   which refers to   And the body (masked last name of sender):      Hi Jimmy,      Just wondering if you ever got this question answered.  If not, maybe   a brief chat with a html wizpert could help: link   .      Good luck getting this resolved!      Cheers,      Michael      ------------------------- Michael W%^%^GF Founder, CEO @ Wizpert   Now I know that my email address is not visible and I read about the MD5 regarding gravatar but I don't think this is the case. I thought about some methods and sure it's possible via metadata, github, etc for someone to get my mail, but I do not dare to think that this has reached an automated level, so that some service could easily get the email of S.O. members.   I didn't get annoyed by the message, since the CEO took the time to contact me :-p but someone else could get annoyed by these kinds of messages, since they come in the important inbox of gmail.   What is more strange is that Wizpert seems to be a nice site and also is active in the Careers 2.0 if I am not mistaken.   Another thing that crossed my mind is that since Wizpert needs unanswered questions to promote their services, possibly this is an action of Wizpert trying to attract people into their services.   Well that's it, I hope I did good to let you know (maybe I did't include the correct tags).


I'm trying to find a word that describes movies, books, poems, plays, and basically anything that is either fiction or non-fiction. "Media" doesn't work because that includes songs and paintings.  Anyone have any ideas?

What is the most appropriate word or phrase to call all the books, theater plays, movies, etc. that a culture has produced and is still producing? For example, "the products of the French culture."


I think that is how astronomers hunt for these elusive objects using radio telescope and also gravitational lensing, I'm wondering how these photons lose their energy while encountering black hole or some massive objects and I remember energy cannot be created or destroy so what gives?

I think the title says it. Did expansion of the universe steal the energy somehow?


As far as I know, standard format allows cards released within the last two year before the release of the current edition e.g. for now, Rivals Of Ixalan.  During the Ixalan edition, there was a new Duel Deck edition (Merfolk, Goblins) containing re-prints of much older cards. Are they legal in standard format although they were firstly released more than two years ago from now on?

I haven't played Magic: the Gathering since the days of Onslaught and Mirrodin, and I would like to try to catch back up. Since all my cards are quite dated now, I may be more interested in formats other than the most up-to-date one.  Rather than ask what is currently legal in various formats (since that is likely too localized), I would rather pose the question of how can I tell which sets/cards are legal in each format.


I'm trying to find the name of a sci-fi story in which two competing orbiting AI send down AI probes to the surface of the earth and end up putting those probe AI's into bodies of frozen humans so that those space based AI can be given new instructions.

Eventually grows a person in a lab and transfers his consciousness, and so does a/the other AI present on the Earth.


Let $G$ be simple group, $|G|$ is not 2, and $ ϕ $ a homomorphism from $G$ to $H$. If $H$ contains a normal subgroup A of index 2, then $ ϕ(G) ≤ A $ .  I have been trying the following: $A$ is normal and maximal in $H$ since its index is 2(basic fact + correspondence theorem). $G$ is simple so it is isomorphic to its image so its image is a simple subgroup of $H$. Now I have to show somehow that its image must be a subgroup of $A$ and I can't find any reason it has to. I would very appreciate if someone could help me with this.

I am currently working my way through The Theory of Finite Groups by Kurzweil and Stellmacher and came across the following question in the first chapter:  Let $G$ be simple, $|G| \ne 2$, and $f : G \to H$ be a homomorphism. If $A \unlhd H$ is a normal subgroup of index $2$, then $\text{range}(f) \le A$.  Please could someone help me to prove this statement? It doesn't seem like it should be too difficult but having spent some time on it I'm still getting nowhere.  Thanks!


I know this question has been asked a lot, and I tried at least 10 different codes to run this without success.  I'm trying to upload a single file with , but it doesn't work. The code below always outputs:     please choose a file' because the file's name is not set or something     HTML  <form enctype="multipart/form-data">   <input name="file" type="file" />   <input type="button" value="Upload" /> </form>

   jQuery  $(function(){   $(document).ready(function(){     var files;      $('input[type=file]').on('change', prepareUpload);     function prepareUpload(event){       files = event.target.files;     };     $(':button').click(function(){         var formData = new FormData();         $.each(files, function(key, value){           formData.append(key, value);         });         alert(formData);         $.ajax({           url: 'check.php',             type: 'GET',           data: formData,           success: function(data){ $('#result').html(data); },            cache: false,           contentType: false,           processData: false         });     });   }); });   PHP  if(isset($_GET['file'])){     $filename = $_FILES['file']['name'];     if(isset($filename) && !empty($filename)){         echo 'sup my man?!';     }else{         echo 'please choose a file';     } }else{     echo 'not set'; }   I don't know what the problem is, I know it's in the FormData object creation because the alert - good to go, doesn't work.  BTW it is really important for me that it would be written in jQuery.

I would like to upload a file asynchronously with jQuery.     $(document).ready(function () {     $("#uploadbutton").click(function () {         var filename = $("#file").val();          $.ajax({             type: "POST",             url: "addFile.do",             enctype: 'multipart/form-data',             data: {                 file: filename             },             success: function () {                 alert("Data Uploaded: ");             }         });     }); });  File <input type="file" id="file" name="file" size="10"/> <input id="uploadbutton" type="button" value="Upload"/>     Instead of the file being uploaded, I am only getting the filename. What can I do to fix this problem?