Check: For the integers $a,b,c$ show that $\gcd(a,bc)=\gcd(a,\gcd(a,b)\cdot c)$

For the integers $a,b,c$ show that $\gcd(a,bc)=\gcd(a,\gcd(a,b)\cdot c)$  Proof:  Let $u$ and $v$ be integers. Then $\gcd(a,b)=au+bv$. Then $c\cdot \gcd(a,b)=c\cdot(au+bv)=acu+bcv$ Let $x$ and $y$ be integers. Then $\gcd(a,\gcd(a,b)\cdot c)=ax+(acu+bcv)y=ax+acuy+bcvy=a(x+cuy)+(bc)(vy)$.  Let $d$ and $e$ be integers. Then $\gcd(a,bc)=ad+bce$.   Since $d$ and $e$ are integers let $d=x+cuy$ and $e=vy$. Hence $\gcd(a,bc)=\gcd(a,\gcd(a,b)\cdot c)$


Return stream from array as int[] instead of Integer[]

I have this array:   Integer[] originalItems = itemsArray.stream()             .distinct()             .sorted()             .toArray(Integer[]::new);   I would like to return it as int[] rather than as Integer[].  I have tried to call .toArray(int[]::new) but I get this error:     no instance(s) of type variable(s) A exist so that int[] conforms to A[]


Are states of a quantum system represented by vectors in a Hilbert space?

Is it true that the states of a quantum system are represented by vectors in a Hilbert space?   When does the term "ray" come into play in this context?


"Without his telling me" vs. "Without him telling me"?

I was reading a book and encountered this sentence (emphasis added by me):        I know it without his telling me.      Despite being grammatically correct, it seemed a little strange to me. What came to my mind was this sentence instead:        I know it without him telling me.      Another case was this:        I can’t control the fact of temptation, but there’s no chance of my giving in to it.      QUESTION: Is using "me" here in #3 (or "him" as done in the previous one) correct? If so, what's the difference between the two?


Does anyone know a good safe way to redirect the output of a printf-style function to a string? The obvious ways result in buffer overflows.  Something like:  string s; output.beginRedirect( s );  // redirect output to s  ... output.print( "%s%d", foo, bar );  output.endRedirect();   I think the problem is the same as asking, "how many characters will print produce?" Ideas?


Making selection color transparent when in editing mode in QGIS

in QGIS, how do I make the selection color transparent? I need to split a polygon and i want to see the layer underneath it. But I have to select the polygon in order to cut it, and when i do that it turns yellow!


What font and style of this document is?

Does anyone has a way to produced something alike the following, I saw this first .  and the titles have this presentation (like centered):


Apparent depth and virtual image position

Why does the virtual image appear right on top of the object and not a little to the right, for example? Is it explained by some formula or just symmetry of the geometry?


Removing the element in a list occuring more than once

I have a list and don't know all the values but I want to remove all the values which occurs more than once and only one of that value is left.Suppose here is the list:  lst = ['one', 'two', 'three', 'four','four','five','five','five']   This is what I need:  lst = ['one', 'two', 'three', 'four','five']   Here is what I have tried:  i=0 for ele in lst: if ele[i] in lst:     lst.remove(ele[i])   but it's not working.


How to remove "site email address on behalf of" and just keep the sender email address in "from:" part of a mail from drupal 7

I am getting from part of a mail sent from my drupal 7 website like below  From: (site mail address) On Behalf Of (sender mail address)  Here I want to remove everything except sender email address, how can I do this?  I have found following url but it is expired    Any help???  Thanks


A word for someone who you share a half-sibling with

This is probably best explained with an example.  Alice and Bob have a child, Erin. Bob and Carol have a child, Frank. Carol and Dan have a child, Grace. Clearly, Erin and Frank are half-siblings, because of their father, Bob. Similarly, Grace and Frank share their mother, Carol.  Erin and Grace have no parents in common, and are thus not half-siblings. However, is there a term for their relation?


Prevent admin users from reading my files

My surface tablet is shared with a friend. She uses a separate account, with admin rights.  Being an admin, she is able to gain access to all my files. Even my OneDrive files.   I guess I could follow  to prevent this (it basically states that you'll need to disable access for the targeted administrator), but the same scenario would be present if I were to create another administrator account.  You could say "don't make her administrator", but I don't want to mess with her personal files as well.  Somehow this feels as a security flaw... or am I mistaken?  Is there any way to protect private files from "administrator eyes" by default?


Suppose I have perfect planar fragments of a big image. How to stitch them automatically?  Software should detect edge features but should not expect camera calibration.


How do I convert a python string that I'm getting from the user to a function name

I'm taking in an input from the user and storing it in a variable called videoType.  My question is, how do I take the string the user gives to videoType and convert that into a function name that I already have defined along with many others in python?  Ex. user input: "get_MPEG()" which is stored in videoType  And I would use that input as a function name.


Exporting Data From Salesforce - REST or SOAP?

We have a requirement where we need to export records from salesforce tables into our application programmatically. I am reading on the various API's for data integration from salesforce mainly SOAP vs REST API's.  From what I understand, REST should be used when the web service requests are from mobile devices or browser based clients (since they understand JSON). Is that true? If that's the case how do Bulk REST API's fit the bill (since they are meant for bulk data transfers)?  I would like to get your thoughts on what are pros and cons in using SOAP or REST API's to export data records. Note that the requests are being made a java ee server application programmatically. After retrieving the records (probably in batches) from salesforce records we process (validate, filter etc) them and load them in our internal tables.  Thanks.


What is this array called... and how to remove items from it

I have an array that I am using, I am having difficulties describing what kind of an array it is, which is making it hard for me to work with it. So far it works for me. I am just curious.  I eventually want to remove the end of this array.  I tried .pop() and  .grep(). Its not working.  Here is an example of my code.  var options = {}; $('.option:visible').each(function(){      var option_label = "";      var option_selected = [];      var option_img = "";       ...        options[option_label] = {          option_selected: option_selected,          option_image : option_img      }; });   What I am trying to do is:  if(option_label.indexOf("something") != -1) {    //then pop off options }  //continue about your business   For clarification I wont know the exact title of the option_label.


Should I mention my Canadian visa refusal in my UK visa application?

My Canada visa was refused; I got a refusal letter but nothing was stamped in my passport. I got rejected under section 205(a) and 186 for not demonstrating specialized knowledge.   Do I have to mention the Canadian refusal in my UK work permit visa application? Will it affect my application (it is not an offense or criminal case)?


How do I copy one side of a box and paste it on the rest of the sides?

As you can see from the picture below, I have a box with a plating on one side. How do I copy/paste it so that I can get it placed precisely on the rest of the sides?


How to do nothing forever in an elegant way?

I have a program which produces useful information on stdout but also reads from stdin. I want to redirect its standard output to a file without providing anything on standard input. So far, so good: I can do:  program > output   and don't do anything in the tty.  However, the problem is I want to do this in the background. If I do:  program > output &   the program will get suspended ("suspended (tty input)").  If I do:  program < /dev/null > output &   the program terminates immediately because it reaches EOF.  It seems that what I need is to pipe into program something which does not do anything for an indefinite amount of time and does not read stdin. The following approaches work:  while true; do sleep 100; done | program > output & mkfifo fifo && cat fifo | program > output & tail -f /dev/null | program > output &   However, this is all very ugly. There has to be an elegant way, using standard Unix utilities, to "do nothing, indefinitely" (to paraphrase man true). How could I achieve this? (My main criteria for elegance here: no temporary files; no busy-waiting or periodic wakeups; no exotic utilities; as short as possible.)


Must attributive nouns always be singular in form?

I want to speak in English that I have a list with car names. Should I say "cars list" or "car list"? What if I have more than one attributive noun. Should all be singular? For example I have two lists with commands. Each list has a different language and I want to merge them. Should I say  merged two different language commands lists or merged two different language command lists?


Compare equality between two objects in NUnit

I'm trying to assert that one object is "equal" to another object.   The objects are just instances of a class with a bunch of public properties. Is there an easy way to have NUnit assert equality based on the properties?  This is my current solution but I think there may be something better:  Assert.AreEqual(LeftObject.Property1, RightObject.Property1) Assert.AreEqual(LeftObject.Property2, RightObject.Property2) Assert.AreEqual(LeftObject.Property3, RightObject.Property3) ... Assert.AreEqual(LeftObject.PropertyN, RightObject.PropertyN)   What I'm going for would be in the same spirit as the CollectionEquivalentConstraint wherein NUnit verifies that the contents of two collections are identical.


Can I sign up to a Windows 10 free upgrade now and defer the actual install until after the July 29 deadline?

I'm currently somewhere with poor quality internet connections, working on some time-sensitive projects. I'd like to update from Windows 8.1 to Windows 10 at some point, but not for a month or so until I'm somewhere with better internet connections, with more time to fix any bugs, glitches or compatibility issues.  Is this possible? Is there any way I can sign up for the free install now before the deadline, but defer performing the install until later when I've got the time and facilities to make sure it happens smoothly?


When I signed up, I gave my desired screen name in the place where John Doe was used as an example. Instead of that name, I got the wimpy user70330 instead.    How can I fix this?


What's the consultant result of $x_1(t)=3\cos(2t+\pi/2)$ and $x_2(t)=4\cos(2t)$?

$x_1(t)=3\cos(2t+\pi/2)$ and $x_2(t)=4\cos(2t)$ given. What is the result of $x(t)=x_1(t)+x_2(t)$? When I do the calculations, I get the result as below. $$x(t)=x_1(t)+x_2(t)=3\cos(2t+\pi/2)+x_2(t)=4\cos(2t)$$ $$x(t)=3\left[\cos(2t)\cos(\pi/2)-\sin(2t)\sin(\pi/2)\right]+4\cos(2t)$$ $$x(t)=-3\sin(2t)+4\cos(2t)$$ I wonder If I can simply the result in $x(t)=A\cos(\omega t + \phi)$ form.


ping: unknown host google.com in UBUNTU SERVER

I use Ubuntu Server 12.10. Why if I try:  ping google.com ping bitbucket.org  or any other website I have:  ping: unknown host google.com ping: unknown host bitbucket.org  EDIT: ping 8.8.8.8 PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data. 64 bytes from 8.8.8.8: icmp_req=1 ttl=47 time=6.01 ms 64 bytes from 8.8.8.8: icmp_req=2 ttl=47 time=5.99 ms 64 bytes from 8.8.8.8: icmp_req=3 ttl=47 time=5.99 ms 64 bytes from 8.8.8.8: icmp_req=4 ttl=47 time=5.98 ms  nano /etc/resolv.conf is empty file


winbind not working after upgrading to 14.04 (from 12.04LTS)

Winbind stopped working after I upgraded to Ubuntu 14.04 (from 12.04 following the automatic upgrade prompt). This is on a home LAN with my router providing dynamic IP addresses to my machines. Specifically mount does not recognize my network file server by name, and requires the IP address. Also I noticed my dhclient.conf file is empty. Is this how it should be?


How to change "and" to ampersand, & in citations using BibDesk?

So I have TeXShop for mac, and this comes with BibDesk. Have used BibDesk to create a database with all my references in, and am using this with TeXShop in my LaTeX document. My advisor wants me to use an ampersand instead of "and" in my citations, and also possibly my bibliography. Have found many answers saying to edit the .bst file etc, all for use with biblatex, which I am not using.   At the moment I am using natbib, which I like. But the main problem is that I do not have a .bst file to edit, nor even a .bbl file as I am using this BibDesk- I do not even know how to edit the file BibDesk produces. Also not great at programming so getting very confused! Please please help I would appreciate it so much.


I understand that the function of melanin is to protect individuals from sunlight, and that people living in sun exposed areas are darker due to increased production of melanin. But why is the melanin pigment black in color? Wouldn't it have been more useful if melanin was white?  From my understanding, black absorbs more sunlight than white, so if melanin is black, it will tend to absorb more heat (which isn't a good thing in areas with a lot of sun exposure). This will lead to production of more melanin (tanning).  Instead, evolutionarily wouldn't it have made more sense if melanin were white, since not only would the pigment protect the person from sun exposure, but also prevent more sunlight from being absorbed?


How to remove duplicate values from a multi-dimensional array in PHP


i have been looking at this for an hour without figuring out what the problem is. The else statement is not working for some reason.   #!/bin/bash if [ $#=3 ] then echo $* else echo "error" 1>&2 exit fi


Should SQL Server files on Hyper-V be on separate drives?

I am working with a database on a virtual server on Hyper-V where the mdf and ldf files are on C:.  It's my understanding that these files should not be on C: and would perform better if on separate drives.  Is there good information that I can use to support my understanding?


Why does an object with a particle system not appear in the render?

I have a project, and it has an object that has always rendered correctly, but one day when I open the project and make a test render, the object has disappeared. All the settings are normal, the object, and all of its children render display in the object outliner set to true. I really don't know what happened to it. Can someone tell me what I should look through to diagnose it? Sorry I cannot provide much detail. What I've explained is all I know. Edit: I am uploading the .blend file at  This is a Minecraft scene. It is the wolf that doesn't render. At one point it did, but now it just won't. The wolf has particle properties. I don't know if that matters, but it could. Look through all the wolf's properties to try and figure it out.


Trying to dual boot Windows 8.1 and Debian Jessie

I've been trying for a month now to dual boot Windows 8.1 and Debian Jessie now. I thought it was about time I asked for help as I'm becoming a little crazy.  I've tried following a lot of tutorials, I'll link a few:      I can't post more links, a shame, because I've tried a lot. There were some really easy tutorials, like the first one, where I couldn't continue, because sudo modprobe efivars failed. sudo modprobe efivarfs did succeed though. But when I continued after using efivarfs, there wasn't a new entry.   I also tried using EasyBCD, setting it on GRUB 2 and "automatically choose and load", but it would choose "/NST/AutoNeoGrub0.mbr". Which is of course is not correct. So basically, to sum up my problem: modprobe efivars doesn't work, and because a lot depends on that, every tutorial I follow, fails.  How I can start Linux and some background information: I had Windows 8 first and still want to keep it and use its bootloader, because it already loads windows 8 a bit. I've got Secure Boot off and UEFI on with Legacy boot options on. I can boot Debian by going into boot menu and choosing Hard Drive under Legacy Boot.  Oh yeah, Almost forgot, when I wanted to install Debian, using an USB stick with some nice Windows programs didn't work, so I had to use a DVD+RW to install it.  I've tried this order a few times now:  sudo mount /dev/sda1 /boot/efi sudo modprobe efivarfs sudo grub-install /dev/sda sudo update-grub   Sometimes I had to use --force, I don't remember why anymore, I have tried so much stuff...  I really hope some of you have got a solution for me!


Is there a program I can download to add an option to create a new file to the contextual menu of finder?  doesn't seem to work in Snow Leopard.


I'm having trouble downloading steam to Ubuntu, his is my first time trying this I have a Google Chromebook and i tried to YouTube how to download steam and i pretty much have it, but it says that i'm missing some files steam needs in order to download. I've tried everything i don't know what to do or what i'm doing honestly. I need some help


Issue: When I try to run a java program on my personal machine I recieve the following error:   Exception in thread "main" java.lang.NoClassDefFoundError: ecs100/UI     at BallDrop.<init>(BallDrop.java:37)     at BallDrop.main(BallDrop.java:63) Caused by: java.lang.ClassNotFoundException: ecs100.UI     at java.net.URLClassLoader.findClass(URLClassLoader.java:381)     at java.lang.ClassLoader.loadClass(ClassLoader.java:424)     at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)     at java.lang.ClassLoader.loadClass(ClassLoader.java:357)   Explanation: I am required to write a program using an external library 'ecs100'. It has been supplied as a .jar mime-type file.  I have the file test.java:   import ecs100.*; class test{     public static void main(String args[]){         System.out.println('Test string');         UI.initialise(); //this is just how the library is supposed to be used     } }   I have tried compiling with the command: javac -cp esc100.jar test.java, which appears to load correctly.  Then when I attempt to run with the command java test it gives the error I specified.  Details: I have been told that the library was written for oracle java 8. I have attempted to compile and run with oracle java 8 JDK, oracle java 9 JDK and openJDK 9 or 8.  I am running ubuntu 16.10. And I do not have any nVidia drivers installed (apparently that can cause problems).  I have tried running files compiled successfully from another computer. Even if they ran on that computer, no luck with mine.  The command java -version outputs:   java version "1.8.0_121" Java(TM) SE Runtime Environment (build 1.8.0_121-b13) Java HotSpot(TM) 64-Bit Server VM (build 25.121-b13, mixed mode)  The command javac -verison outputs:  javac 1.8.0_121  Conclussion: I would greatly appreciate any feedback or suggestions.  I imagine I'm either doing something wrong with:   The classpath in compilation The import statement A missing dependancy Wrong use of one of the commands   I am basically positive the problem is not one of the following:   An issue with the way I am using the library


"... to apply for a visa" or "... and applied for a visa"?

Here are two sentences:        Once he got the passport, he went to the Chinese consulate in Toronto and applied for a visa.   Once he got the passport, he went to the Chinese consulate in Toronto to apply for a visa.      Are the two sentences grammatical, and do they sound natural?  If they are both fine, what's the difference?


How could I retrieve the exact duplicate value from conditionally formatted list that highlight duplicates?

I have imported a webpage table in to Google Sheets. It frequently being updated. A series of calculations has been conducted on the sheet named Shawn Of the link spreadsheet.  I have filtered the my desired results into the Calculation sheet of that linked document... which is in columns A5:A. I then applied =ARRAYFORMULA(if(A5:A200="",,A5:A200*{12,13,37,101,111})) in columns B5. The Results of the formula extends from B5:F. This results from a5:F was subsequently conditionally formatted to highlighted duplicates in the aforementioned, i.e. a5:f using the lists of values in K5:K and I5:5. In Columns A5:F, is it possible to generate/place values in the range A5:f with matching name of states and aligned values in J5:K and H5:I?


When I go to type a new question in any Stack Exchange site, it automagically suggests 'Questions that may already have your answer'. What technology is this leveraging to generate these results on the fly? Boolean search? Word or doc2vec?  Example:


Is it grammatically acceptable to write, "by March of 2015"?

The entire sentence would be something like:     The Center will be established by March of 2015.   I feel confident writing "in March of 2015", but this sentence must convey the fact that at any time up to and including March the Center may be established, but not after.


Is virtual box as effective as dual booting windows? If I am able run windows in linux and do everything I can in windows I might as well as get rid of win 8.


I'm having trouble finding a generic code that work, here, for both CentOS 5/6 and CentOS 7 versions pc the /proc/meminfo file. I Want to compute the "Real Used memory" like free does.  (amounts divided by 1024 for easier mental calculus)  CentOS 6 :  [root@web2-1 ~]# cat /proc/meminfo | gawk '{ $2=int($2/1024) ; print $0}' && free -m MemTotal: 3038 kB MemFree: 2580 kB Buffers: 34 kB Cached: 350 kB SwapCached: 0 kB Active: 216 kB Inactive: 189 kB Active(anon): 21 kB Inactive(anon): 1 kB Active(file): 195 kB Inactive(file): 188 kB Unevictable: 0 kB Mlocked: 0 kB HighTotal: 2185 kB HighFree: 1807 kB LowTotal: 852 kB LowFree: 772 kB SwapTotal: 4095 kB SwapFree: 4095 kB Dirty: 0 kB Writeback: 0 kB AnonPages: 21 kB Mapped: 12 kB Shmem: 1 kB Slab: 30 kB SReclaimable: 22 kB SUnreclaim: 8 kB KernelStack: 1 kB PageTables: 1 kB NFS_Unstable: 0 kB Bounce: 0 kB WritebackTmp: 0 kB CommitLimit: 5615 kB Committed_AS: 145 kB VmallocTotal: 120 kB VmallocUsed: 6 kB VmallocChunk: 99 kB HugePages_Total: 0 HugePages_Free: 0 HugePages_Rsvd: 0 HugePages_Surp: 0 Hugepagesize: 2 kB DirectMap4k: 9 kB DirectMap2M: 876 kB              total       used       free     shared    buffers     cached Mem:          3038        458       2580          1         34        350 -/+ buffers/cache:         72       2966  Swap:         4095          0       4095    Desired output : 73 which is MemTotal - MemFree - Buffers - Cached  CentOS 7 :  [maxime@g7r0x64-pkgbuild-mock-dev libexec]$ cat /proc/meminfo | gawk '{ $2=int($2/1024) ; print $0}' && free -m MemTotal: 993 kB MemFree: 89 kB MemAvailable: 710 kB Buffers: 0 kB Cached: 681 kB SwapCached: 5 kB Active: 341 kB Inactive: 361 kB Active(anon): 4 kB Inactive(anon): 23 kB Active(file): 336 kB Inactive(file): 337 kB Unevictable: 0 kB Mlocked: 0 kB SwapTotal: 4095 kB SwapFree: 4072 kB Dirty: 0 kB Writeback: 0 kB AnonPages: 16 kB Mapped: 11 kB Shmem: 7 kB Slab: 134 kB SReclaimable: 111 kB SUnreclaim: 23 kB KernelStack: 2 kB PageTables: 3 kB NFS_Unstable: 0 kB Bounce: 0 kB WritebackTmp: 0 kB CommitLimit: 4592 kB Committed_AS: 174 kB VmallocTotal: 33554431 kB VmallocUsed: 145 kB VmallocChunk: 33554275 kB HardwareCorrupted: 0 kB AnonHugePages: 2 kB HugePages_Total: 0 HugePages_Free: 0 HugePages_Rsvd: 0 HugePages_Surp: 0 Hugepagesize: 2 kB DirectMap4k: 39 kB DirectMap2M: 984 kB               total        used        free      shared  buff/cache   available Mem:            993          87          89           7         816         710 Swap:          4095          23        4072   Problem is, free gives me 816 MB for buffer + cache at the same time. Where are the missing 130 MB~?  I know I could do MemTotal - MemAvailable to get my real used, but MemAvailable doesn't exist on the previous version, and I would like my code to work with both versions of the meminfo file...  EDIT : by "portable" I mean I'd like the code to work for both 2.6 and 3.10 kernels (which means versions 5-7 of CentOS/RHEL), but I think I'll just have to make a big "if" in my code...


What is the object in "he lent me a book"?

It's a very simple question actually, but someone asked this to me suddenly and I got confused       He lent me a book.      In this sentence, is the object book (the thing being lent) or me (the one who is being lent the book)?    How can we determine the object in this sentence?


How can time-travel be possible if speed is relative?

I have heard that .  So, as I understand it, the following example would be accurate:  There are two twins- TwinA and TwinB. Both have very accurate clocks, that are exactly synchronised. TwinA leaves earth on a rocket, which travels at approaching the speed of light. After he has counted 24 hours, he comes back to Earth, only to find that more time has passed there, and his clock is now behind TwinB's.  However what confuses me is that speed is relative. So who is to say that TwinA was the one who was moving fast?


Limit of sequence with relation $x_{n+1}=x_n-x_n^2$

Let the sequence of real numbers is defined as follows: $x_1=\frac{1}{2}$ and $x_{n+1}=x_n-x_n^2$. Show that $\lim_{n\to \infty}nx_n=1$.  I've shown that the limit of $x_n$ is zero since this sequence  is bounded and monotone. How to show that $nx_n\to 1$ as $n\to \infty$?  I have no ideas how to handle this problem.  It would be interesting to see approach.


I have a very peculiar problem, following an answer in  I am trying to rename some files. This is the code I am using #!/bin/bash for file in *.HHZ_00; do mv $file ${file/${file:14:2}/00}; done  What I understand this to do is to replace the 2 characters following character index 14 (starting from zero) to 00. I am using 2 subsets of files to test it, one is this 2018113154211.25.AGCC.HHZ_00 2018113154211.25.APAC.HHZ_00  When running the code these successfully rename to 2018113154211.00.AGCC.HHZ_00 2018113154211.00.APAC.HHZ_00  The second subset fails at this, this subset is 2018070220829.28.AGCC.HHZ_00 2018070220829.29.APAC.HHZ_00  These rename unsuccessfully to 2018070220829.00.AGCC.HHZ_00 2018070220800.29.APAC.HHZ_00  Notice how the indices 11 and 12 are changed for the second file, not the 14 and 15 as I want it to, very curiously now the SECOND time I run it, using the last files as input, I get 2018070220829.00.AGCC.HHZ_00 2018070220800.00.APAC.HHZ_00  This is partially successful, but now the second filename is ruined...what am I doing wrong? Is it because the 29 is repeating in these files? If someone has a solution using the rename command that would be great too, I tried using it but I am unfamiliar with the syntax.


What is the canonical way to determine commandline vs. http execution of a PHP script?

I have a PHP script that needs to determine if it's been executed via the command-line or via HTTP, primarily for output-formatting purposes. What's the canonical way of doing this? I had thought it was to inspect SERVER['argc'], but it turns out this is populated, even when using the 'Apache 2.0 Handler' server API.


Weird stepping in bump map despite using 32-bit bump map image

i am trying to get rid of these steps in my bump map. Someone told me these steps occur because 8 bit isnt enough because it only contains 256 colors. So I increased the bit depth to 32 and tried several noise removing and gaussian blur methods but these steppings are still there and I don't know how to smooth them out. Even setting the Texture interpolation to Cubic only removes some steppings but not all. How do I get rid of these steppings?  This is my problem. This is when interpolation is set on Linear  And this is when interpolation is set on Cubic or Smart. Only a few steppings got smoothed out but not all.


"There are so many" vs. "There is so many"

There are so many questions on this website. There is so many questions on this website.  The former "sounds right," but the contracted form of the latter does as well:  There's so many questions on this website.  Which is correct?


Free PDF Editor software for Ubuntu 20.04 is needed

I am new user of Ubuntu 20.04. I need free PDF editor software for creating and editing PDF files, and for exporting the pages from the PDF files and the PDF files itself, in another format (docx, e.t.c.). I will appreciate your help.


I have a Schengen visa that has a 90 days validity and will be expiring by the 25th of February, 2015. I got an Internship and thought I could renew or extend my visa from here (Geneva) but was told that I have to go back to my country (Nigeria) for a new visa. The visa procedure takes a month and there is a conference that I would like to attend by March which means if I should go back end of this month, I may not make it to the conference due to the long application period. Is there any way possible for me to have the extension here until March?


Prove that there isn't such a function, which would be continuous at each rational point and discontinuous in each irrational point.    I find this question very challenging and have no idea even how to start off with the proof. Please suggest a proof or any hint.


Principal component anaylsis, what do obtained coefficients tell me?

I have already posted my problem in stackoverflow, I am not sure if this might be problematic, and I am not sure, if the post is shown in both communities. If so I will delete.  I am trying to apply principal component analysis, to reduce the dimensions of my data. 200x146 , 200 observations(samples) with 146 features(dimensions), each observation can belong to one of three classes. What I am trying to do is to visualize the data, to see how the class centroids move after adding new samples to my data. Since it’s impossible to plot such high dimensional data, I am looking for a dimension that would represent my data in almost separate classclusters.  I know that PCA, calculates the eigenvalues of the eigenvectors, while the eigenvalues represent the variance. The higher the variance the more the data is spread out and better to visualize. The eigenvector with the highest eigenvalue is the principal component, an axis orthogonal to this component is then found by the PCA. (Did I understand the basic idea of PCA correctly?)  However I don’t understand, what information I do get when I use the matlab function pca() I get the coefficient, but what do they tell me and how to I proceed afterward?


Why do eukaryotic organisms have introns in their DNA?

We touched on introns and exons in my bio class, but unfortunately we didn't really talk about why Eukaryotes have introns. It would seem they would have to have some purpose since prokaryotes do not have them and they evolved first chronologically, but I could easily be wrong. Did the junk sections of DNA just evolve there by some sort of randomness or necessity as opposed to an actual evolutionary advantage? Why hasn't evolution stopped us from having introns since they seem to be a 'waste' of time and DNA? Why do prokaryotes not have introns?


What happens when a tmpfs volume is full and swap is full? Is Linux's OOM-killer involved?

I understand that if a persistent / disk-based volume is full, files need to be explicitly deleted to free up space before more can be added.  Further, I understand that if memory is exhausted, the Linux kernel's OOM-killer will begin terminating processes in order to free up memory.  As tmpfs is an in-memory file-system, it occurred to me that there may or may not be some cross-over between regular volume behaviour and Linux's memory management.  Does the OOM-killer automatically start removing files based on some criteria (either by default or with configuration)?  Or is tmpfs in all respects just like other file-systems when it is full (and swap is full)?  EDIT #1  I've read  but it doesn't even mention "tmpfs" which is what this question is about.  EDIT #2  I've read  and this answers the question well enough that I think my question is practically a duplicate.


Finding the exact coordinates of circle's extreme east and west points on a sphere

I'm currently implementing the Bentley-Ottman algorithm applied to spheres, involving intersections of many spheres on one sphere, circles in most cases of course. This requires locating "event" points on the sphere (ie: points where something "special" happened, such as extreme points of intersection circles or intersections between these).  My question is very similar to , mainly because I'm asking for the exact same thing : the eastmost and westmost points of a circle on a sphere, in my case named the start and end points of the circle. These points have the particularity of being the tangency points between the circle and a special longitude. The problem resides in finding these as exact coordinates.  I'm working with the  library, which provides a great deal of exact intersection primitives, and these are in my opinion probably the most appropriate way to find the exact start-end points.  So far I've tried to reduce the problem to a simpler one : instead of finding the longitudes of these points, I'm trying to find the height of the horizontal plane which contains these two points. Using the following notations :   S : start point E : end point C : center of the circle (not on the sphere of course) r : radius of the circle O : center of the sphere R : radius of the sphere h : height of the horizontal plane containing the start-end points H : intersection between the pole axis and the horizontal plane containing the start-end points phi : the latitude containing C phi' : the latitude containing the start-end points.   Starting out from the formula based on the Law of Sines, from the last post :  sin(phi') = sin(phi) cos(r/R)   We notably have :  h = R sin(phi') sin(phi) = OC / R   Giving finally :  h = OC cos(r / R)   This is as far as I've gotten, and I'm stuck on finding an algebraic form of this cosine.


What is the minimum number of nodes required for MAAS?

We have an Ubuntu VM with a MAAS controller and only 1 node. We are not able to install juju.   Is there a minimum node requirement for MAAS?


How can I call a method from an inherited class?

public class TimsOrder {      private int size;     private String name;     private static TimsProduct[] items;      private TimsOrder(String name, int size) {         this.name = name;         this.size = size;     }      @Override     public double getRetailPrice(){         return price;     }      private static void orderItem(TimsProduct item) {         Donut chocolate = Donut.create();         item = chocolate;     }      public static TimsOrder create() {         items = new TimsProduct[size];         for (int i = 0; i < items.length; i++) {             orderItem(items[i]);         }         TimsOrder order = new TimsOrder("OrderName", 1); //Where 1 is the # of items     }      public double getAmountDue() {         double total = 0;         System.out.println("Testpoint");         for (int i = 0; i < items.length; i++) {             total = total + (((TimsProduct) items[i]).getRetailPrice()); //Line with issue         }         return total;     } }  public abstract class TimsProduct extends Commodity {     private String name;     private double cost;     private double price;      @Override     public double getRetailPrice(){         System.out.println("Testpoint2");         return price;     } }  public class Donut extends TimsProduct {     private String description;     private int calorieCount;      private Donut(String name, String description, double cost, double price, int calorieCount) {         super(name, cost, price);         this.description = description;         this.calorieCount = calorieCount;     }      public static Donut create() {         Donut chocolate = new Donut("Chocolate", "Glazed", 0.30, 0.99, 500);         return chocolate;     } }   Test Code:  TimsOrder t = TimsOrder.create(); System.out.println(t); System.out.printf("Total Price: $%.2f\n", t.getAmountDue());   I realize that t.items has 0 values which is the problem here. What I do not know is why these values are not there.  If anyone wants to see the files: Commodity.java   TimsProduct.java extends commodity   TimsOrder.java   Donut.java extends TimsProduct


Constructing self-complementary regular graphs

It can be easily shown that if a graph is self-complementary and regular then the number of vertices, $n$, is equal to $4k +1$ for some $k \in \mathbb{Z}$.   But, how to we prove (prove by constructing) that there is a self-complementary regular graph for $n = 4k +1$


My application was working normally but then when I added the splash screen an error has been appeared and I don't know what to do or how t solve it   the error is   java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setOnClickListener(android.view.View$OnClickListener)' on a null object reference   my MainActivity  public class MainActivity extends AppCompatActivity {  private final int SPLASH_DISPLAY_LENGTH = 4000;  @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);      setContentView(R.layout.activity_splash);       new Handler().postDelayed(new Runnable() {          @Override         public void run() {             Intent splashIntent = new Intent(MainActivity.this , SplashActivity.class);              MainActivity.this.startActivity(splashIntent);             MainActivity.this.finish();         }     },SPLASH_DISPLAY_LENGTH);         // Find the View that shows the numbers category     TextView numbers = (TextView) findViewById(R.id.numbers);      // Set a click listener on that View     numbers.setOnClickListener(new OnClickListener() {         // The code in this method will be executed when the numbers category is clicked on.         @Override         public void onClick(View view) {             // Create a new intent to open the {@link NumbersActivity}             Intent numbersIntent = new Intent(MainActivity.this, NumbersActivity.class);              // Start the new activity             startActivity(numbersIntent);         }     });   and the activity_splash    <?xml version="1.0" encoding="utf-8"?>   <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:background="@color/category_phrases" tools:context="com.example.android.miwok.SplashActivity">  <ImageView     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:src="@mipmap/nemo"     />  <TextView     android:layout_width="match_parent"     android:layout_height="wrap_content"     android:text="HELLO NEMO"     android:textColor="#FFF"     android:textSize="40sp"     android:layout_alignParentBottom="true"     android:layout_marginBottom="30dp"     android:layout_marginLeft="40dp"     android:fontFamily="casual"     android:textStyle="bold|italic"      />     SplashActivity   public class SplashActivity extends AppCompatActivity {  @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.activity_splash); } }   anything to solve it?


Converting from ascii to utf-8 format - iconv not working

I have a requirement to convert from ASCII text format to UTF-8.  Below is what I am performing through the iconv command:   [root@main tmp]# cat File1 1 5 6 [root@main tmp]# file File1 File1: ASCII text [root@main tmp]# iconv -f ascii -t utf-8 File1 > File2 [root@main tmp]# file File2 File2: ASCII text   (Still ASCII not utf-8)  Any suggestions on how to convert it from ascii to utf-8?


How do I pass a string into subprocess.Popen in Python 2?

I would like to run a process from Python (2.4/2.5/2.6) using Popen, and I would like to give it a string as its standard input.  I'll write an example where the process does a "head -n 1" its input.  The following works, but I would like to solve it in a nicer way, without using echo:  >>> from subprocess import * >>> p1 = Popen(["echo", "first line\nsecond line"], stdout=PIPE) >>> Popen(["head", "-n", "1"], stdin=p1.stdout) first line   I tried to use StringIO, but it does not work:  >>> from StringIO import StringIO >>> Popen(["head", "-n", "1"], stdin=StringIO("first line\nsecond line")) Traceback (most recent call last):   File "<stdin>", line 1, in ?   File "/usr/lib/python2.4/subprocess.py", line 533, in __init__     (p2cread, p2cwrite,   File "/usr/lib/python2.4/subprocess.py", line 830, in _get_handles     p2cread = stdin.fileno() AttributeError: StringIO instance has no attribute 'fileno'   I guess I could make a temporary file and write the string there -- but that's not very nice either.


× 5207  The action would require the installation of packages from not authenticated sources.  mplayer-gui mplayer-skins  from the ubuntu software center  I could not watch any .AVI without it, and rest of the software also require some packages to watch .AVI which is impossible to get?  thanks in nadvance


Pages in beamer are incorrectly numbered when using "show notes on second screen"

I'm using beamer to create a presentation, and want to use the mode "show notes on second screen". Unfortunately, there seems to be a bug: when I turn it on, the page numbers are shifted one page up, so page 1 becomes 2, 2 becomes 3, and so on, with the last page number being repeated. With overlays, the numbers also shits one position, so the previous page of the overlay, and the last one has incorrect number.  I attach a minimum sample file: just check the PDF page numbers. By commenting the line \setbeameroption{show notes on second screen=left}, the numbers work fine; when adding it, the numbering fails.  \documentclass{beamer}  \usepackage[spanish]{babel}  \usepackage{pgfpages}  \setbeameroption{show notes on second screen=left}  \begin{document}  \begin{frame} First frame (should be 1) \end{frame}  \begin{frame} Second frame (should be 2) \end{frame}  \begin{frame} Third frame (should be 3)\\  \pause Also third frame (should also be 3) \end{frame}  \begin{frame} Fourth frame (should be 4) \end{frame}  \end{document}


Windows 10 - Cannot remove one display language

A friend's Laptop came with windows 10 but, for some reason, had Polish language installed by default.   I added the English and Greek language (these are the ones he needed) and setup English as default. I logged out and back in. The problem is that, every know and then, it reverts to Polish, so I need to remove it. Here are the details:   Settings -> Time & Language -> Language:   It shows English as windows display language but there is also Greek and Polski in the drop down menu In the preferred languages, Polski is not shown so there is no way to remove it. I actually added polski (using "add a preferred language") and removed it but still it remained as one of the 3 windows display languages.  lpksetup /u shows the GUI shown here:    Although Polish is not the display language, it shows it as system language   Using Get-WinUserLanguageList in the powershell shows only English and Greek   So, I think I exhausted any methods I could think of (apart from reinstalling). Is there a possible solution?


What is the point of creating a typedef of an anonymous structure?

I am relatively new to C and I came across a typedef for a structure with no name.   What is the point of it?  #define POLY(name,deg)    \     term name[deg] = {0};  typedef struct {   int coeff;   int exp; } term;


I am trying to proof the following expression (without a calculator of course).  $\log_{12}{18}\times\log_{24}{54} + 5(\log_{12}{18}-\log_{24}{54})=1$  I know this isn't a difficult task but it's just killing me. I have tried many things, among which was base transformation to 12 and expressing every logarithm in terms of $\log_{12}{3}$ and $\log_{12}{2}$ but every time I try to do it, I mess up something. I don't know if my concentration is terrible or  I'm doing something wrong.   Thanks ;) ( if there are more levels to this task, I'd like a hint, not a complete solution)


Showing that a collection of sets is a $\sigma$-algebra: either set or complement is countable

I wish to show that $$\mathcal{F} = \{A \subset \Omega: A \text{ countable or }A^c\text{ countable}\}$$ is a $\sigma$-algebra.  We have $\Omega^c = \emptyset$, so obviously $\Omega \in \mathcal{F}$.  Suppose $A \in \mathcal{F}$. Assuming $A$ is countable, $(A^c)^c = A$ is countable, so $A^c \in \mathcal{F}$. If we assume $A^c$ is countable, $A^c \in \mathcal{F}$ follows trivially.  Now let $A, B \in \mathcal{F}$. I wish to show that either $A \cap B$ or $(A \cap B)^c = A^c \cup B^c$ is countable. How would I start this part? I am only looking for hints.


Prove that $2\int_a^b \int_a^x f(x)f(y) \, dy \, dx = \left[ \int_a^b f(x) \, dx \right]^2$

Suppose $f$ is a continuous single-variable function, prove that:  $$2\int_a^b \int_a^x f(x)f(y) \, dy \, dx = \left[ \int_a^b f(x) \, dx \right]^2$$  This question was just on my Calculus III final exam and I couldn't figure it out, could someone provide some insight, please?


Internet over mobile-data while connected to WLAN network

I have a WLAN network that is not connected to the internet. There is a DHCP server on that network and that assigns its clients an IP and subnet mask, but no default gateway.  When I connect to this network on an android device mobile data will automatically be disabled, so that the device will loose internet connectivity.  Most operating systems, when they are connected to multiple networks use the fastest connection that has a default gateway to connect to IP outside its respective subnet. However Android doesn't seem to get to that stage, because once it connects to a wi-fi network, it will disconnect the mobile-data - to save battery power, presumably. It doesn't care to check if there is gateway on the wi-fi network.  Is there a way to disable this "feature" of disconnecting mobile data when a wi-fi is connected?  Or better: is there a way to prevent disconnecting mobile data when the wi-fi has no default gateway?  Thank you in advance.


$f(x)=f(x^2+ 1/4)$ , $f$ is continuous from $\mathbb{R}$ to $\mathbb{R}$

Find all continous functions $f\colon\mathbb{R}\rightarrow\mathbb{R}$ satisfying  $f(x)=f(x^2+ 1/4)$  What I've tried so far:    suppose that $f$ is one-one thus $x=x^2+1/4$ ... $x=1/2$ then $f(x)=f(1/2)$ is constant   That's it, I'm stuck here.


Windows bounce to the first monitor after hibernate (in windows 7)

I have a windows ultimate 32 bit with 2 monitors, multiple displays set to: "Extend these displays" After hibernate, all the windows are back in the first monitor, and I need to re-drag them (or Win-shift-arrow them) all over again.  Any ideas?  it seems like a duplicate of:  but I didn't see a clear answer in there...


What is the intuition behind mapping one range of numbers onto another range?

If I have a range $x \to y$ and I want to map it to $x' \to y'$, what is the logic behind the mapping process? I found the formula online as:  $$R = (y' - x') / (y - x)$$  $$\text{output} = (\text{input} - x) * R + x'$$  I understand that $R$ is the ratio of both ranges, but I don't understand the second part where we subtract $x$ from the input? Why do we do this, I can't seem to wrap my head around this.


When I do more filename and less filename, it would seem that the resulting terminals are quite similar. I can navigate and search through my files identically (j, Space, /pattern, etc.).  I find it hard to believe that less is more and vice versa. Are there any differences between the two?


How to show that the modulus of $\frac{z-w}{1-\bar{z}w}$ is always $1$?

Let's suppose that $|z|<1$ and $|w|=1$. Show that the modulus of $\displaystyle \frac{z-w}{1-\bar{z}w}$ is always $1$. Some hint.


1970s: Student creates complex program, forgets about it, and it becomes intelligent and finds him years later

This book came out of the 1970s (early 1980's) at the latest. In it the protagonist, a not so diligent student, gets turned on to computer programming and creates (I think..) a weather program.   Eventually he moves on and years later the program contacts him. It has become an AI and he is its creator.  I forget what the setup is post contact which is not helpful at all..


I have the following code for inserting new row into the database:  $query = "INSERT INTO files_requests VALUES (NULL, ?, ?, ?, ?, ?, ?, {$userinfo['id']}, 0, ". time() .", 0)";     $stmt = $mysqli->prepare($query);     $stmt->bind_param('isssss', $listID, $files, $filesize, $audio, $subtitles, $fansub);     $stmt->execute();   Is there a way to see the query after the bind_param is done?  I know I can use echo to view and see the variables: echo "('isssss', $listID, $files, $filesize, $audio, $subtitles, $fansub)"; , I would like to view the query itself with the variables inside it. Is there any function I can run on the stmt object or mysqli, to display the query before it is executed, beside create an echo statement myself?


In my web app, I submit some form fields with jQuery's $.getJSON() method. I am having some problems with the encoding. The character-set of my app is charset=ISO-8859-1, but I think these fields are submitted with UTF-8.   How I can set encoding used in $.getJSON calls?


Why are radians more natural than any other angle unit?

I'm convinced that radians are, at the very least, the most convenient unit for angles in mathematics and physics. In addition to this I suspect that they are the most fundamentally natural unit for angles. What I want to know is why this is so (or why not).  I understand that using radians is useful in calculus involving trigonometric functions because there are no messy factors like $\pi/180$. I also understand that this is because $\sin(x) / x \rightarrow 1$ as $x \rightarrow 0$ when $x$ is in radians. But why does this mean radians are fundamentally more natural? What is mathematically wrong with these messy factors?  So maybe it's nice and clean to pick a unit which makes $\frac{d}{dx} \sin x = \cos x$. But why not choose to swap it around, by putting the 'nice and clean' bit at the unit of angle measurement itself? Why not define 1 Angle as a full turn, then measure angles as a fraction of this full turn (in a similar way to measuring velocities as a fraction of the speed of light $c = 1$). Sure, you would have messy factors of $2 \pi$ in calculus but what's wrong with this mathematically?  I think part of what I'm looking for is an explanation why the radius is the most important part of a circle. Could you not define another angle unit in a similar way to the radian, but with using the diameter instead of the radius?  Also, if radians are the fundamentally natural unit, does this mean that not only $\pi \,\textrm{rad} = 180 ^\circ$, but also $\pi = 180 ^\circ$, that is $1\,\textrm{rad}=1$?


I know it is defined as $ dP \wedge dx  $ or explicitly,  $$ \frac{\partial P }{\partial y } dy \wedge dx   . $$  The question is, could it be $dx \wedge d P $?  Or  $$  \frac{\partial P }{\partial y }  dx \wedge dy ?    $$  I know the question must be very naive or even stupid. But I am indeed confused.


The favicons on stackexchange.com/users/ seem to be stacked on top of one another

When I look at e.g. , I see the following under "Top Questions":  It appears that the MSO sprite is being stacked on top of the sprite for some beta site which I can't identify. I have cleared my cache and hard-refreshed, so this probably isn't a problem on my end. This appears to be related to the fact that favicon.css specifies a background-image for .favicon.


I'd like to know the correct order of this sentence:  Is it:     I and my friends plan for a movie months before the release.   or     My friends and I plan for a movie months before the release.


What is the name of this kind of visualization, with arrows showing count of different subsets?

What is the name of this kind of visualization? It uses arrows to show the count of parts of the sample set of an experiment.    This is from     "." Christian Collberg, Todd Proebsting, Gina Moraila, Akash Shankaran, Zuoming Shi, Alex M Warren. March 21, 2014.


Need to writing a valid regular expression (regex)

I have an input field on my website which uses pattern matching in the HTML It needs to have - Lowercase a-z (not upper) - All numbers (0-9) - Allows underscores (_) but NOT spaces - Minimum of 4 characters with a max of 12. - Does not allow special characters such as @, #, $, %, ^, * etc.  Right now I have pattern="(?=.*[a-z0-9_]).{4,12}" The problem seems to be that it does allow special characters.


Orbit space of torus homeomorphic to mobius strip

Let $\mathbb{T}^2$ be the torus and have $\mathbb{Z}_2$ action on the torus by permuting the coordinates. I am trying to prove the orbit space is congruent to the mobius strip $\mathbb{T}^2/\mathbb{Z}^2 \cong M$.  I am writing $M\cong I^2/\alpha$, where $I=[0,1]$, $\alpha(x)=1-x$ and we identify the points $(x,0)\sim (\alpha(x),1)$. I know it is useful for this problem to identify the torus as the quotient $I^2/\sim_0$ with left glued to right and top glued to bottom (referring to sides) and then the action on the torus corresponds to switching coordinates on the square, which is reflecting over the diagonal $(x,x)$. What I don't understand is how to combine these relations of gluing and permuting to show this space is homeomorphic to the quotient above with $\alpha$.   I think that with both relations we will identify the edges together since $(x,0)\sim_0(x,1)\sim(1,x) \sim_0(0,x)$. Then points not on the edges will either be identified with themselves if they are on the diagonal or just their permutation. But I can't figure out how to map this to the Mobius strip...  How do you proceed formally with proving these spaces are homeomorphic? Obviously I'm not looking for all the details but I'm stuck both trying to visualize it (i get to folding the square over the diagonal $(x,x)$ but then I cant picture how to get the mobius strip from there on). Any help is appreciative.   Also a different generalization than the natural one: instead of permuting the coordinates in $\mathbb{T}^k$ and taking the action by $S_n$ consider the action by reversing the coordinates, which can still be done by using $\mathbb{Z}_2$. What is this orbit space homeomorphic to? Would it be $M^k$ when $k$ is even and something else for odd $k$?


Missing Space on Drive using Core Storage after Boot Camp Assistant Failure

Using Boot Camp Assistant, I started to create a 50 GB partition, but it hung on partitioning. After waiting about 30 minutes without the progress bar moving, I quit the Boot Camp Assistant, thinking I would be able to fix the partition either by using the Boot Camp Assistant or the Disk Utility. However, the partition doesn't appear in either. Instead, my drive has just become 50 GB smaller. Looking for other solutions, people were generally able to find the partition by using Terminal application commands, however I haven't even been able to do that. (Notice in Disk Utility, it says Macintosh HD is 441.65GB, but "Capacity" is 500.28GB):    I tried booting in Recovery mode and doing First Aid in the Disk Utility. This resulted in the same "All's Fine," but still haven't gotten my 50GB back. I spent all day clearing 100GB to make room for a Windows partition, and now in the Finder I'm down to 43GB :/.  Any help would be greatly appreciated, thank you!


Field names change when selecting by attribute/location and then copying feature in ModelBuilder?

I am trying to create a tool to make my workflow faster for a routine job task.  Basically, I have a USGS 7.5 min quad layer and a feature (species) layer, and I want to ultimately create a shapefile (must be a shapefile, because I am sending these out to people who use them in a variety of GIS programs) of the species found in a certain quad and that contain the associated attribute data.  I am using ModelBuilder, and I have gotten it to go through the process of selecting the quad of interest (with Select by Attribute), use this quad selection to select the species that intersect that quad (with Select by Location), and export as a shapefile (with Copy Features).  The problem is that the resulting shapefile, while it contains all the attribute data, has lost its field names.  The field names become 'Request1', 'Request2', and so on (instead of 'Species Name', 'Common Name', etc. respectively).    I have tried using the 'Make Feature Layer' and 'Feature to Feature' tools, but without any change.  I have a Basic license, and so do not have access to the 'Alter Field Names' tool.    Any thoughts on what I'm missing or on a workaround?


Intuition behind the definition of conditional probability: why $\textbf{P}(A\cap B) = \textbf{P}(A|B)\textbf{P}(B)$

I have learned that the conditional probability is expressed as  $P(A|B) = \frac{P(A,B)}{P(B)}$.  My teacher told us that given an probability of event, we can know the probability of consequence.  However, I do not get the intuition behind this formula. Especially, why the joint probability is divided by  another probability? So I want to know the essence of division of probability.


Why are low-rep users rate-limited when posting questions?

I just encountered the following error:  Oops! Your question couldn't be submitted because: users with less than 125 reputation can only post questions every 20 minutes; try again later.  Why do you have this rule? Why 20 minutes?


If there are 2 independent event A and B, we find the probability of their intersection as product of their respective probability. Though I know how it is deduced but I don't seem to find proper intuition behind it. I don't expect any derivation. Kindly someone help.


transferring data from an app that hides it

I'm transferring data from an older phone (LG G5 running Android 7) to a newer phone (Nokia 8.3 running Android 11).  I've transferred most of it using backup + restore, or manually using syncthing.  But I have one app where I can't find the data.  The app is called . guidebook has a dir /Android/data/com.guidebook.android . But I don't see any actual files there, either under internal storage or on the external SD card. I tried to download the guidebooks again on the new phone.  But my old guidebooks are no longer available to download.  Probably because guidebook is now charging the orgs per download.  They don't even give me an option to buy them. I know that the guidebooks are being stored locally because I can access them offline, with wifi and mobile data disabled. I contacted guidebook support.  They say they don't support transferring the guidebooks between devices. Anyone know how to transfer them?  Or how I can even go about finding where they are hiding the files? I tried the Android debugger, but that won't run because I don't have symbols for libraries. NB: if others want to play with this, the app is free, and it's possible to download current guidebooks for free.


Why do lower case mathcal letters show up as random symbols?

amsfonts doesn't have lowercase caligraphic letters, so when you do $\mathcal{Hello World}$ you get some odd results. (Likewise for \mathbb I believe)  Now, what surprises me is not that there aren't lowercase mathcal letters, but that given this, the document compiles at all! What is going on that means that \mathcal{lowercase} is interpreted as being a string of random symbols? It seems what letter gets turned in to what symbol is constant, so this isn't just random: there's a reason why this happens as it does.  What is going on? Can some explain the details of what's happening beneath the surface that means that LaTeX interprets lowercase letters inside \mathcal as a variety of mathematical symbols?  [I don't understand enough to work out what tags would be relevant here...]


Sending SPAM free mail through my website

I've been battling with this issue for couple of months. I need to send bulk mail (not spam) through my social network to users in situations like newsletters, site invitations (when user imports their address book contacts)  I'm using shared hosting and it limits 500 mails per hour. Even though i manage to send mails most of them end up in user's spam box.  After researching these are the solutions that i finally came up with.    Use Google Apps SMTP () Move into VPS Use shared hosting with throttle enabled   Please advise me on what to choose.   Will using Google Apps prevent mail being sent as spam? I can't use other 3rd party SMTP like iContact or Aweber as "invitation sending script" will send emails to thousands of contacts, depending on user's addressbook.   Thanks in advance


QGIS won't read table columns in CSV import on Mac OS

I am trying to import a CSV file into QGIS, but it ends up looking like my print screen below (program is in Swedish but in the preview window you can see how QGIS won't read my data correctly). I can't load the data since for some reason, QGIS reads my CSV table columns as one single row. What is wrong? I want QGIS to read my data as numbers, so I have created an additional csvt-file with the code "String","String","Integer". Is there something else that I need to to in order for QGIS to read the third column as numbers?      Still, after doing that it loos like this...


Why I can't call a function inside another function in Javascript?

I have a problem with a  function Execution ,   I  call a function   inside another function but it appears an error like "Invoice is not defined" I tried  some methods but didnt' work , also some value  from objects not appearing on table  when i want to post Any solution for this ? It will helps me so much Thanks   let bill = [  {    name : "Sandra",      price : 50,      payment : "visa",      cardnumber:"1234 xxxx xxxx xxxx"  },   {    name : "Johnson",      price : 200,      payment : "master",      cardnumber:"1234 xxxx xxxx xxxx"  },  {    name : "Maria",      price : 500,      payment : "master",      cardnumber:"1234 xxxx xxxx xxxx"  },  {    name : "Bueno",      price : 1000,      payment : "american-express",      cardnumber:"1234 xxxx xxxx xxxx"  }, ]  let get  = document.querySelector(".get"); let first =  document.querySelector(".first"); let second =  document.querySelector(".second"); let third =  document.querySelector(".third"); let counter = document.querySelector("b"); let add = 0; let table = document.querySelector("table"); table.style.display="none"; let fourth=  document.querySelector(".fourth"); let result = document.querySelector("h2"); let reven = document.querySelector("strong");  GetBills = () => {   get.addEventListener("click" , ()=> {       table.style.display = "flex";     UpdateDOM();     let invoice= bill[Math.floor(Math.random()* bill.length)];     let store = parseInt(bill[0].price) + parseInt(bill[1].price +                    parseInt(bill[2].price + parseInt(bill[3].price)));       add++;     if(add>bill.length) {       add--;            result.innerHTML = `You have only ${bill.length} Bills,</br>buy to store to add more` ;         reven.textContent = `Total Revenue from bills:${store} $ `;     } else {       console.log("Very Good")     }   }) } GetBills();  UpdateDOM = () => {   GetBills();     counter.innerHTML=add;   first.innerHTML =  invoice.name;   second.innerHTML = invoice.price;   third.innerHTML =  invoice.payment;   fourth.innerHTML =  invoice.cardnumber;    if(get) {     console.log("Invoice Transacted")   } else {     console.log("Invoice not transacted")   } }  console.log(UpdateDOM()); body {  font-family:"Lato",sans-serif; display : flex; align-items:center; justify-content:center; background-color:#f4f4f4; flex-direction:column; }  .get { border:1px solid lightgray; padding:10px 50px; background-color:white; box-shadow:2px #fff; margin:20px 0; } <!DOCTYPE html>         <meta charset="utf-8">     <meta name="viewport" content="width=device-width">     <title>repl.it</title>     <link href="style.css" rel="stylesheet" type="text/css" />
 Get latest Bill
 <button class="get">Get</button>

     Name	     Price	      Payment	             Card Number

     All Bills: 0;
       Result


Proving a fact: $\tan(6^{\circ}) \tan(42^{\circ})= \tan(12^{\circ})\tan(24^{\circ})$

Prove that $\tan(6^\circ)\tan(42^\circ) = \tan(12^\circ) \tan(24^\circ)$.   I don't know how to approach this problem. One approach might be to note that $42-6= 24+12$, and then apply the identities for $\tan(A+B)$ and $\tan(A-B)$, but it just makes it more complex: $$\frac{\tan(42^{\circ}) - \tan(6^{\circ})}{1+\tan(42^{\circ})\tan(6^{\circ})}= \frac{\tan(24^{\circ}) + \tan(12^{\circ})}{1 - \tan(24^{\circ})\tan(12^{\circ})}.$$  Can anyone here please provide a hint?


TL;DR  When we take the transpose of two Grassmann-valued spinors (fermions), should we add a minus sign because we end up anticommutating the two spinors?    More details.  I'm studying the behavior of 1+1-dimensional Majorana fermion. I use the same representation for the gamma matrices as in Lectures on string theory by Lüst and Theisen, chapter 7 appendix B. That is  $$\gamma^0 = i \sigma^2 \qquad \gamma^1 = \sigma^1 \qquad C= \gamma^0 \qquad \eta^{\mu\nu}=diag(-1,+1)$$  Equation B.3 of these lectures says that Majorana fermions obey the following indentity:  $$ \bar{\psi}_1 \gamma^{\alpha_1} \gamma^{\alpha_2} ... \gamma^{\alpha_n} \psi_2 = (-1)^n \bar{\psi}_2 \gamma^{\alpha_n} ... \gamma^{\alpha_2} \gamma^{\alpha_1} \psi_1.$$  However I cannot prove this identity, I always get the wrong sign on the RHS, even for simple cases such as $n=0,1$ or $2$. For instance for $n=1$, knowing that Majorana fermions are real and therefore $\bar{\psi} = \psi^\dagger \gamma^0 = \psi^T \gamma^0$, we can write the LHS as:  $$\psi_1^T \gamma^0 \gamma^\alpha \psi_2.$$  This is just a number, so it should be equal to its transpose. When we take the transpose, $\gamma^0$ takes a minus sign. If $\gamma^\alpha=\gamma^0$ then this one also takes a minus sign which cancels the first one and we get no overall sign. If $\gamma^\alpha=\gamma^1$ then the 2nd minus sign comes when we anticommute the two matrices. In every case I get:  $$ \bar{\psi}_1 \gamma^{\alpha} \psi_2 =  \psi_1^T \gamma^0 \gamma^\alpha \psi_2 = \psi_2^T \gamma^0 \gamma^\alpha \psi_1 = \bar{\psi}_2 \gamma^{\alpha} \psi_1,$$  even though the identity above says there should be a minus sign. My guess is that when I took the transpose of the LHS, I should have added a minus sign since I inverted two Grassmann-valued spinors in the process, otherwise I don't know what I did wrong.  On a related note, if the sign changes when we swap to spinors, does that imply that the trace of a fermion bilinear is no longer cyclic?  $$\text{Tr}\ \bar{\psi}\psi \neq \text{Tr}\ \psi \bar{\psi} ?$$     but the answer is unclear.  is actually pretty much the same question, but then why this "transpose antisymmetry" only rarely mentioned? Does it only hold for Majorana fermions?


I have some issues about choosing how to align a Date/time data type in a field. Which is the best way to align this type of date and why? Right or left? P.S We use WPF.  [------25.03.2015] or [25.03.2015------]  Thank you :)


Does Q play games with other species, or is it just humans (and possibly the Calamarain)? Why didn't Q torture the humans (as far as we know) as he did the Calamarain?


Cannot Change Permissions for Plist file in Mojave

I'm using Mojave and I'm trying to change the permissions for this file /System/Library/PrivateFrameworks/Slideshows.framework/Versions/A/Resources/Content/EffectDescriptions.plist I want to alter the duration that slides appear in my screensaver which I've figured out how to do but I cannot save my edits to the file.  I continually get the error Operation not permitted.  I have tried editing the file on the desktop that moving the file back but that does not work.  That operation is denied.  I cannot change permissions through getinfo and I cannot change permissions through the terminal command: sudo chown myname /System/Library/ And also sudo chown myname /System/Library/PrivateFrameworks/Slideshows.framework/Versions/A/Resources/Content/EffectDescriptions.plist This article seems to deal with the problem but I really cannot tell what the guy is saying:


Is it possible to customize data (or date-time) format in Windows (I am using Windows XP)?  The current format which is followed by the OS [to show date-modified, etc.] is MM/DD/YYYY or M/D/YYYY, whereas I have been comfortable with DD/MM/YYYY or D/M/YYYY format. I am finding it hard to refer Date-modified [which I use often] of files and folders.


Fault in proof of $\zeta(2) = \frac{\pi^2}{6}$

Consider the proof of:  $$\zeta(2) = \frac{\pi^{2}}{6}$$  So the proof assume that (because of Euler decomposition) $$\frac{\sin(x)}{x} = \prod_{n > 0}\left(1 - \frac{x^{2}}{(n\pi)^{2}}\right)$$  Why should we consider the $\frac{\sin(x)}{x}$, that $\sin(x)$ has the same decomposition?   Please tell me where's my fault.


What are the differences between special and general relativity?

What are the differences between  and ? I am looking for a naive, non-mathematical explanation.


How to properly spell "belonging to a virus"?

In a SU topic about computer viruses I wanted to write a sentence starting with something like The ability of a virus to.... So I started writing A viruse's ability to... and realized that viruse's doesn't seem quite right. Nor does viruss' or anything else I can come up with. What is the proper way to write this word in this context?


I tried to execute a .deb file and got the above error.  I just used sudo dpkg -i teamviewer_15.5.3_amd64.deb in my Downloads directory where the .deb file was located. I have dpkg version 1.19.7 (amd64) in my machine.  Here's what I'm getting:  (Reading database ... 230272 files and directories currently installed.) Preparing to unpack teamviewer_15.5.3_amd64.deb ... Unpacking teamviewer (15.5.3) over (15.5.3) ... dpkg: dependency problems prevent configuration of teamviewer:  teamviewer depends on libqt5qml5 (>= 5.5) | qt56-teamviewer; however:   Package libqt5qml5 is not installed.   Package qt56-teamviewer is not installed.  teamviewer depends on libqt5quick5 (>= 5.5) | qt56-teamviewer; however:   Package libqt5quick5 is not installed.   Package qt56-teamviewer is not installed.  teamviewer depends on libqt5webkit5 (>= 5.5) | qt56-teamviewer; however:   Package libqt5webkit5 is not installed.   Package qt56-teamviewer is not installed.  teamviewer depends on libqt5x11extras5 (>= 5.5) | qt56-teamviewer; however:   Package libqt5x11extras5 is not installed.   Package qt56-teamviewer is not installed.  teamviewer depends on qml-module-qtquick2 (>= 5.5) | qt56-teamviewer; however:   Package qml-module-qtquick2 is not installed.   Package qt56-teamviewer is not installed.  teamviewer depends on qml-module-qtquick-controls (>= 5.5) | qt56-teamviewer; however:   Package qml-module-qtquick-controls is not installed.   Package qt56-teamviewer is not installed.  teamviewer depends on qml-module-qtquick-dialogs (>= 5.5) | qt56-teamviewer; however:   Package qml-module-qtquick-dialogs is not installed.   Package qt56-teamviewer is not installed.  teamviewer depends on qml-module-qtquick-window2 (>= 5.5) | qt56-teamviewer; however:   Package qml-module-qtquick-window2 is not installed.   Package qt56-teamviewer is not installed.  teamviewer depends on qml-module-qtquick-layouts (>= 5.5) | qt56-teamviewer; however:   Package qml-module-qtquick-layouts is not installed.   Package qt56-teamviewer is not installed.  dpkg: error processing package teamviewer (--install):  dependency problems - leaving unconfigured Processing triggers for gnome-menus (3.36.0-1ubuntu1) ... Processing triggers for desktop-file-utils (0.24-1ubuntu2) ... Processing triggers for mime-support (3.64ubuntu1) ... Processing triggers for hicolor-icon-theme (0.17-2) ... Errors were encountered while processing:  teamviewer


i have the following piece of code but i could not detect why there is no output  when i debug it , the control flow is never goes inside for loop but i cannot figure out why   could anyone please help me ?  here is my code   public class DealWithStrings {     ArrayList<String> container = new ArrayList<>();      public void printDuplicate() {         String string = "aaabed";         String[] res = string.split("");          for (int i = 1; i < string.length(); i++) {             if (res[i] == res[i - 1]) {                 container.add(res[i]);             }         }          for (String s : container) {             System.out.println(s);         }     }      public static void main(String[] args) {         DealWithStrings d = new DealWithStrings();         d.printDuplicate();     } }


If I have multiple entry visa for schengen and i am Indian staying in UK can i travel to schengen countries more than once from UK till the VISA is valid?


Why is the result of this for and while loop different?

I have a for loop:  for host in $(cat ./hosts) do    echo -e "$host"    ssh -o "StrictHostKeyChecking no" $host "uptime" 2>/dev/null    echo -e "\n" done   and a while loop which is supposed to the the exact same job as the above for loop:  while read host do    echo -e "$host"    ssh -o "StrictHostKeyChecking no" $host "uptime" 2>/dev/null    echo -e "\n" done <./hosts   hosts is a file located at the same place as the scripts containing for and while loop and it contains some host name of remote servers. The for loop prints the expected result (for all the hosts listed in the hosts file) but in case of while loop it only prints the first host's uptime and quits!   hosts file contains one host name per line.  The question is why the behavior of these two loops are different?


Using javascript to change background image

The page in question:   I want to change this image in the #header from    to this new image    Is there a way to do it by pasting code in the console panel? (client side)  I tried:  var header = document.getElementById("header"); header.style.backgroundImage = 'url(http://i.imgur.com/htDLyzu.png)  no-repeat!important';


Regression without intercept: deriving $\hat{\beta}_1$ in least squares (no matrices)

In An Introduction to Statistical Learning (James et al.), in section 3.7 exercise 5, it states that the formula for $\hat{\beta}_1$ assuming linear regression without an intercept is  $$\hat{\beta}_1 = \dfrac{\displaystyle\sum\limits_{i=1}^{n}x_iy_i}{\displaystyle \sum\limits_{i=1}^{n}x_i^2}\text{,}$$ where $\hat{\beta}_0 = \bar{y}-\hat{\beta}_1\bar{x}$ and $\hat{\beta}_1 = \dfrac{\displaystyle S_{xy}}{S_{xx}}$ are the usual estimates under OLS for simple linear regression ($S_{xy} = \displaystyle\sum\limits_{i=1}^{n}(x_i - \bar{x})(y_i - \bar{y})$).  This is not the actual exercise; I am merely wondering how to derive the equation. Without using matrix algebra, how do I derive it?   My attempt: with $\hat{\beta}_0 = 0$, we have $\hat{\beta}_1 = \dfrac{\bar{y}}{\bar{x}} = \dfrac{S_{xy}}{S_{xx}}$.  After some algebra, it can be shown that $\displaystyle S_{xy} = \sum\limits_{i=1}^{n}x_i^2 - n\bar{x}\bar{y}$ and $\displaystyle S_{xx} = \sum\limits_{i=1}^{n}x_i^2 - n\bar{x}^2$. From here, I'm stuck.


How to share Eclipse workspace and project settings across a team?

We are a team of N developers, say. One of us starts up Eclipse for the first time, sets up some IDE preferences, creates a new project, adds source files (which are physically located elsewhere, just symbolic links added to Eclipse project), sets up build and run configurations and whatever else might be needed to flush the flow pipeline.  Now, what all files do I need to check-in to our repository, so that everyone gets those files automatically and all they need to do is launch Eclipse and they are good to go?  From my understanding, there are settings stored at "workspace" level, "project" level and then there are IDE preferences (which also need to be shared in our case, to maintain same IDE environment). But where are these files, and are they generic in a way that if I check them in, and other folks check them out, they are all set?  Hope the question makes sense :)


I was doing:  for (Object key : map.keySet())     if (something)         map.remove(key);   which threw a ConcurrentModificationException, so i changed it to:  for (Object key : new ArrayList<Object>(map.keySet()))     if (something)         map.remove(key);   this, and any other procedures that modify the map are in synchronized blocks.  is there a better solution?  if no one comes up with a better solution, first to say no gets the tick ;)


Let $n > 1$ be an integer. Then $2^n - 1\nmid 3^n - 1$. I don't know how to prove it. Can anybody help me, please?  In general, for a fixed positive integer $a > 1$, has $a^n - 1|(a +1)^n - 1$ any integer solutions?


Why is the use of ZFS without ECC RAM "not recommended"?

I've been reading up on FreeNAS and RAID Z, and one of the things  is that you shouldn't use ZFS (or more specifically, RAID Z) on a machine without ECC RAM. I'm wondering what the reasoning behind this is. Is this an issue with RAID Z specifically? Is there any particularly heightened risk from not using ECC RAM with ZFS vs other file systems? Or is this just a general concern about corrupt memory spreading to a filesystem which would otherwise have corrected the error thanks to its ?


Lottery winner has brain uploaded, then travels in a starship

I am looking for the title of a book / series i read many years ago, i have tried google but i just cant seem to get the search right so any help would be great.  The basis of the story is about a young guy who ends up winning the lotto which allows him to get the best health care and in the end transfer his mind to a computer and travel around on a star ship.  I cannot remember the characters name.  If i remember correctly it was a 2 or 3 book series.  If there are any other details that may help let me know what could be useful.  Again thank you.


Show that $(1-2^{1-z})\zeta(z)=\sum\limits_{s=1}^\infty \frac{(-1)^s}{s^z}=\frac{1}{\Gamma(z)}\int\limits_{0}^\infty \frac{t^{z-1}}{e^t+1}dt$ for Re$(z)>0$.  Not sure how to get started on this, we have covered some of the formulas for the $\zeta$ function but I don't really have any intuition regarding them.


Is it "she's a vegetarian" or "she's vegetarian"?

When should I not use indefinite articles? I get very confused.


I could just use:  obj_camera = bpy.data.objects["Camera"]   to get the camera, but it is possible to have a scene with multiple cameras.  So if that is the case, how can I choose the active one?


How can I view all of the flights between two cities across all dates?

I believe that the standard routes of carriers between two semi-major US cities always maintain the same route number (e.g. UA3271), and day of the week. I'm looking at planning travel for an interview, so dates are [currently] quite flexible (as in at least one month's range). Since that's the case, there are other constraints that go into my choice of flights. One would be the option to fly out of my home city, land in the interview location, conduct the interview, and fly out in the same day. I figure: if I can view the schedule for flights (i.e. routes) between the two cities, I can make an educated request for days of travel. Yes, I could likely work with the interview scheduler (and I will), but I'd like to be proactive in suggesting some dates to achieve my goal, as well as learn this skill for myself in the future. Thus:  Where can I view the daily routes and times for flights between two cities, on whatever rotating basis (e.g. day of the week) they may be on?


The spin of fundamental particles determines if they are bosons or fermions. The atoms also have bosonic or fermionic behavior, for example $\require{mhchem}\ce{^4He}$ has bosonic and $\ce{^3He}$ has fermionic statistics. Which quantity of atom determines its statistics?


How to extend height of an element to the bottom of its parent element

I want to extend the height of an element to the bottom of the height of its parent element. I couldn't find any way or solution to do it. Here is my code.  So, there is some content above the child element, and I want the child element to OCCUPY all the space that is below that. Basically: the rest of the parent element (to the bottom of its height).  I also tried making an awful visual display of the height of the child element should be extended -  (the area colored in red should be its new height).  Currently, it only has its own height with padding that I added in CSS and its element.   .parent {   background: #232323;   height: 500px; }  h1 {   color: white }  .child {   padding: 50px;   border: 3px solid red; }

*Some other content*

*The content of the child element*


Suppose that $T(0) = 1$ and define $T(n)$ as follows   $$ T(n) = 1 + \sum_{j=0}^{n-1} T(j) $$   Show that $T(n) = 2^n$.   If I substitute values, I can see that the sequence goes like $1, 2, 4, 8, \dotsc$, that is that they are powers of $2$.  But how do I mathematically prove it? Any hints should be good too.


Will my laptop HP 15bw088ax support Ubuntu? Does it contain the Wi-Fi driver already or do I have to install it separately?

My network adapter:  Bluetooth driver:  My laptop specifications:  HP 15 bw088ax AMD A9-9420 processor 2C+3G currently running on Windows  Do I need to be connected to internet to install Ubuntu 20.04 LTS? Please redirect me to the already answered questions if there are any.


I'd like to know which is the correct option:     He went to bed without my telling him to.   He went to bed without me telling him to.   I was pretty certain it is the first, but I am unclear on why.  Is telling a gerund or participle?


Prove that $ (A \cup B) \cap C \subseteq A \cup (B \cap C)$

I'm trying to practice proof writing, and found the following text question:  For all sets A,B,C:  $ (A \cup B) \cap C \subseteq A \cup (B \cap C)$  The first step I was thinking of showing is that:  $ (A \cup B) \cap C = (A \cap C) \cup (B\cap C)$  or the subset is the sliver only where A and B intersect C.  I'm kind of stuck on  where to go from here. I know the statement is true as the superset contains ALL of A, and the parts where C and B intersect, but I'm not really sure how to prove this. Any tips?


Is it possible to have LaTeX (or another program) to expand a the macros in a .tex file, and output the expanded LaTeX source?   If no such program exists: are LaTeX macros processed simply as string substitutions, before the document is interpreted? If so, it might be easy enough to write my own such converter.  Edit: The reason I ask is journals which don't accept LaTeX submissions with macros. It would be useful to be able to develop with my usual macros, and convert automatically to the 'macro-expanded' format for submission.


Can I still use the older Airport Utility 5.5.3 if I install the 6.0 version of Airport Utility?

I have a simple network setup, and have read some initial reviews that say the new Airport Utility 6 for Mac OS X lacks some of the advanced settings that the older utility provides. I depend on those settings for my network to operate properly.  Can I still keep the old utility around and use either tool or should I wait to upgrade until I'm sure all the bells and whistles I might need are added to the 6.0 version?    I am going to need to keep the older Airport Software around since some of my devices are too old for the new software, but I'm mostly interested in knowing that I won't be forced to abandon my current advanced settings if I try the new firmware or the new client software.


Install 18.04 server without network connection

The latest version of Ubuntu server (18.04) seems to demand network configuration and refuse to boot without it. I have no desire to connect the server in question to the internet for anything, and have installed previous versions of Ubuntu server without network no questions asked.  Is a network connection an absolute requirement for the latest version of Ubuntu server? Or is there something I'm missing?  The installation cannot proceed past the network configuration page unless an ethernet connection is active, by my current estimates. I have no ethernet network within range of the machine so can't test it on an internet-less network. I only have WiFi within immediate range (which does have internet access) but it won't recognise the device and it should be simpler to get the installation to happen without any updates than to go to the effort of finding the drivers to support the WiFi adapter.  Note that this is NOT a duplicate of  since the new installer seems to be the real problem here.


Should I cite all the open source python packages I used like numpy in my paper?

I used many open-source packages in my research, such as matplotlib, numpy, pandas, scipy, etc. And I found this on the website of SciPy: . Should I cite every one of them in my paper? (I'd like to cite them but there are so many of them which will make my paper even half or one page longer)


Rings of polynomials whose (partial) derivatives vanish are Noetherian?

I have the following two questions on rings of polynomials. They seemed similar enough that I thought I'd go ahead and group them here as opposed to making separate listings for them. The questions are:  ($1$) Determine whether or not the ring of polynomials in $z$ whose first $k$ derivatives vanish at the origin for some fixed positive integer $k$ is Noetherian. ($2$) Determine whether or not the ring of polynomials in $z$ and $w$ whose partial derivatives with respect to $w$ vanish for $z=0$ is Noetherian.  Note that $z$ and $w$ are complex variables, that is, the polynomials are over $\Bbb C$. My work: It seemed like I could view each of these as subrings of $\Bbb C[z]$ and $\Bbb C[z,w]$, and since both of these are Noetherian, I wanted to conclude that each of the above were Noetherian, but I realized it isn't necessarily the case that a subring of a Noetherian ring is Noetherian. Can anyone offer some help for me? Thanks!


Do I need a Visa or some kind of permission for a layover/stopover in the USA as a German citizen?

I booked a flight from Mexico to Germany with a 3 hour layover in the USA (Atlanta).  Do I need some kind of Visa or permission for this layover?  Unfortunately I can only find contradictory information about this. Some sources say I need a so called ESTA from , and others say I don't need anything. What do I really need?


Cross browser testing strategy on Mac OS?

I'm working on a Mac environment. Years ago I had four different "Parallels" installations to be able to test websites on four different IE versions. That worked for a while – but it is a bit crazy to have four different virtual PCs just for testing on four different browsers.  I am also aware of the application "Virtual PC 7" and "VirtualBox" and have tried to run Windows XP via "Boot Camp" –– but the overhead of these approaches is just a bit too much.  On the other hand I have tried some online services. Some seem to be promissing, but costy – and I seriously don't want to pay $20-$50 per month just for testing 1 or 2 websites per month.   There is of course also the free/trial versions – but… The free version of  won't have IE listed at all, 's free version won't show hi-res screenshots,  is PC only, and a.f.a.i.k. 's free 60 minutes are for one week only. The free tool  only brings up an error message.   Before I go any further, I would like to ask: does anybody have a recommendable light weight low cost cross browser testing strategy for Mac OS? Any tips / pointers appreciated.


I have tried following commands. sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 0C49F3730359A14518585931BC711F9BA15703C6 echo "deb http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-3.4.list sudo apt update sudo apt install mongodb-org  Using these i got the following error.     Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  mongodb-org : Depends: mongodb-org-shell but it is not going to be installed                Depends: mongodb-org-server but it is not going to be installed                Depends: mongodb-org-mongos but it is not going to be installed                Depends: mongodb-org-tools but it is not going to be installed E: Unable to correct problems, you have held broken packages.


Case I followed this  to create an effect that I want (being able to see a completely different world through an object (a shield in this case). I got this to work in blender 2.8+. The problem is that I have to render in cycles due to some nodes being used and these are only available in cycles. At the moment blender renders all 3 layers and smacks them together to generate the desired result which takes 3x as long. so my question is:  How can I preview this effect without having to render it? How can I tell blender to only render 1 layer to preview other effects?  Here are some screenshot of my project, hope it helps.  Shiled being used as mask  other dimension I want to capture by watching through the shield


Using grep after using find to get the files

So I'm relatively new to command line. I was able to use find to get an output of multiple files from multiple directories since there was no specific place these would be (I'm sure this can be shortened):  find ./ -name filename1.ext && find ./ -name filename2.ext && find ./ -name filename3.ext   Now that gave me the list of what I was wanting but now that I've found the files in question, I want to grep them for information.


Which spacing is correct? I've seen both being used. Plus, there isn't really anything saying which is correct.


I have upgraded my Ubuntu 14.04 to 16.04, but when I run sudo apt-get update  I get the following messages: W: Target Packages (main/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list.d/google-chrome-beta.list:3 and /etc/apt/sources.list.d/google-chrome.list:3 W: Target Packages (main/binary-all/Packages) is configured multiple times in /etc/apt/sources.list.d/google-chrome-beta.list:3 and /etc/apt/sources.list.d/google-chrome.list:3 W: Target Translations (main/i18n/Translation-en_US) is configured multiple times in /etc/apt/sources.list.d/google-chrome-beta.list:3 and /etc/apt/sources.list.d/google-chrome.list:3 W: Target Translations (main/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list.d/google-chrome-beta.list:3 and /etc/apt/sources.list.d/google-chrome.list:3 W: Target DEP-11 (main/dep11/Components-amd64.yml) is configured multiple times in /etc/apt/sources.list.d/google-chrome-beta.list:3 and /etc/apt/sources.list.d/google-chrome.list:3 W: Target DEP-11-icons (main/dep11/icons-64x64.tar) is configured multiple times in /etc/apt/sources.list.d/google-chrome-beta.list:3 and /etc/apt/sources.list.d/google-chrome.list:3 W: Target Packages (main/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list.d/google-chrome-beta.list:3 and /etc/apt/sources.list.d/google-chrome.list:3 W: Target Packages (main/binary-all/Packages) is configured multiple times in /etc/apt/sources.list.d/google-chrome-beta.list:3 and /etc/apt/sources.list.d/google-chrome.list:3 W: Target Translations (main/i18n/Translation-en_US) is configured multiple times in /etc/apt/sources.list.d/google-chrome-beta.list:3 and /etc/apt/sources.list.d/google-chrome.list:3 W: Target Translations (main/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list.d/google-chrome-beta.list:3 and /etc/apt/sources.list.d/google-chrome.list:3 W: Target DEP-11 (main/dep11/Components-amd64.yml) is configured multiple times in /etc/apt/sources.list.d/google-chrome-beta.list:3 and /etc/apt/sources.list.d/google-chrome.list:3 W: Target DEP-11-icons (main/dep11/icons-64x64.tar) is configured multiple times in /etc/apt/sources.list.d/google-chrome-beta.list:3 and /etc/apt/sources.list.d/google-chrome.list:3  help me out from this issue.


ElGamal Homomorphic Encryption Formula Question

With Public Key $(G, q, g, h)$ where $G$ is a group, $q$ prime, $g$ a generator of $G$, Am I right in thinking that:  $$\mathrm{Enc}(m;r) := (g^r, h^r \cdot g^m)$$


Hoping someone can help me here, We are a supplier of Kids Ride on cars and we are looking to provide personalised Numberplates for our ride on car range.  We had a supplier which made these and they were like a laminated sticker but could be fully customised. I guess we could make a template in excel or photoshop but need to know what type of printer and stickers we would need? They need to be professional looking and need to be suitable for outdoor use. Any suggestions will be greatly appreciated. Thanks.


I know there are a lot of similiar questions about this topic. But nevertheless I am not able to solve my problem.  I want to reshape a dataset of this structure:  Country Variable    2001    2002    2003 A   Demand  8   46  776 A   Supply  4576    576 576 A   Storage 5   765 765 B   Demand  7543    76  58 B   Supply  58  5   65 B   Storage 864 3   537 C   Demand  6   48  65 C   Supply  75  86  458 C   Storage 587 58  5   to this structure (long format):  Country Year  Demand  Supply  Storage ...   I tried this command:  a<-reshape(test1, direction="long", varying=list(names(test1)[3:ncol(test1)]),    v.names="Value", idvar="Time", timevar="Year", times=names(test1)[3:ncol(test1)])   but it is not (exactly) working:  > edit(a)  Country Variable Year Value Time  1.X2001 A Demand X2001 8 1  2.X2001 A Supply X2001 4576 2  3.X2001 A Storage X2001 5 3  4.X2001 B Demand X2001 7543 4  5.X2001 B Supply X2001 58 5  6.X2001 B Storage X2001 864 6  7.X2001 C Demand X2001 6 7  8.X2001 C Supply X2001 75 8  9.X2001 C Storage X2001 587 9  1.X2002 A Demand X2002 46 1  2.X2002 A Supply X2002 576 2  3.X2002 A Storage X2002 765 3  4.X2002 B Demand X2002 76 4  5.X2002 B Supply X2002 5 5  6.X2002 B Storage X2002 3 6  7.X2002 C Demand X2002 48 7  8.X2002 C Supply X2002 86 8  9.X2002 C Storage X2002 58 9  1.X2003 A Demand X2003 776 1  2.X2003 A Supply X2003 576 2  3.X2003 A Storage X2003 765 3  4.X2003 B Demand X2003 58 4  5.X2003 B Supply X2003 65 5  6.X2003 B Storage X2003 537 6  7.X2003 C Demand X2003 65 7  8.X2003 C Supply X2003 458 8  9.X2003 C Storage X2003 5 9    Can you help me? Where is my mistake?


How should you respond to "Give me a fish" / RTFM questions? I mean the case where people post questions simply to get someone else to write their code for them, on topics that would usually be the first result on Google if they had taken the effort to search once before posting.   Usually I just plug in a link that points them to the right place... and the Google search terms I used if I'm annoyed (aka I do their Google search for them). This is the "teach them to fish" approach. But given the big and growing SE user-base, these questions usually elicit someone to post an actual code sample — the "give them a fish" approach.   I'm wondering what the community thinks about this. I'm thinking we're making lazy people even lazier with the latter approach. The person just scrapes the code off the response and into his source and off he goes without being any smarter. The person is going to repeat the same behavior the next time he is stuck. Although I'm fine with people choosing to maintain their intellectual status-quo, is SE encouraging the wrong behavior?


How to generate good locators for elements in Web pages?

This site contains many questions that are about finding the right locator expression (XPath, CSS, etc) for an object in WebPage or about troubleshooting problems related in invalid or dynamic locators. For instance: .    How one can find a good locator expression? What tools can generate expressions matching a certain element automatically? How to troubleshoot such issues when element does not match expression?


I am trying to attain an ARIMA model for the following Time Series Data:    There is quite obviously a seasonal component - as the plot seems to oscillate between smaller and larger peaks, its seems to suggest that the pattern repeats every 48 timesteps.  I then took the seasonal difference and plotted the ACF & PACF:      From the ACF & PACF plots, I concluded that the model will most likely fit a $\text{ARIMA}(0,0,1)(0,1,1)_{48}$ model due the the shape of the PACF and the peaks at the ACF plots.  However, when trying to fit the data onto such model, the estimated coefficient for the regular fails the hypothesis test (roughly if $\mid\frac{\hat{\theta}}{\hat{\sigma}_\theta}\mid > 1.96$, then accept for some coefficient $\theta$).  I have tried other variations, but they consistently fail. I have come to the conclusion that I've made a grave error or I am missing a step. Note that when using Regular Differencing, the model does seem to fit better - but I don't know how to justify using Regular Differencing.  I have come to one of two conclusions: Either taking the seasonal difference of 48 is too high, or, the plot for PACF shows that the data may be non-stationary - therefore needing some Regular differencing.  Thank you


What's the name of the surface and Is it a $C^2$ smooth surface?

what's the name of the surface? Is it a $C^2$ smooth surface? Its implicit equation is: $(x−2)^2(x+2)^2+(y−2)^2(y+2)^2+(z−2)^2(z+2)^2+3(x^2y^2+x^2z^2+y^2z^2)+6xyz−10(x^2+y^2+z^2)+22=0$