Why revolutions (or turns) are dimensionless?

I think that the reason is because one revolution or one turn is equal to $2 \pi$ rad or to $360$ degrees.  We can relate rads and degrees to two units of length that cancel each other.  rad $= \frac{arc\: length}{radius\: of\: the \:arc\: length}$   degree $=$ arc length$ * \frac {1}{360}$ of the total circunference.  In both cases the meters from the numerator cancel with the meters from the denominator. This implies that rads and degrees are dimensionless, but not unitless.  Is there another explanation why a revolution is dimensionless?  Is there an analogous explanation, that meters with meters cancel each other, for revolutions?  Or you can only explain it equating revolutions with degrees or radians?  Morover, Tipler's Physics for scientists and engineers explains what a dimension is in this way.    I can measure the number of revolutions (for instance with a photoelectric sensor) of a turning plate. So I have a number with units(revolutions or rads). Don't we have a dimension in this case, the angle?


Find the values of $p$ such that $\left( \frac{7}{p} \right )= 1$ (Legendre Symbol)

Show that if $p$ is an odd prime coprime to $7$, then $\left( \frac{7}{p} \right) = 1$ if and only if $p \equiv \pm 1, \pm 3,$ or $\pm 9 \pmod{28}$. HINT: If $p$ is an odd prime, determine which values can $p$ take $\mod28$, and consider each of these values in turn. Note that if we know $p \mod 28$ then we know  $p \mod 4$, and hence we know whether $\frac{p-1}{2}$ is odd or even.   Here, $\left( \frac{a}{b} \right)$ is the Legendre symbol.   The bit I don't understand in the hint is, what do they mean by consider the values that $p$ can take $\mod 28$. Do they mean the values that would make $p$ a quadratic residue $\mod 28$, i.e all the $x$ values satisfying $x^2 \equiv \mod 28$, because then isn't this just $1,4,9,16,25$?  What do they mean the to "consider each of these values in turn"?


What is causing my "Unexpected EOF Error while looking for ..." error?

I am getting an issue while running a cron job for exporting all databases on my Godaddy Shared hosting Cpanel account. But I have trouble finding the syntax error in below command.  Same command is working on my AWS Ec2.  mysql -N -ubackup -pt -e 'show databases' | while read dbname; do mysqldump -ubackup -p123 --complete-insert -N "$dbname" > /home/test/sqlbackups/'$(date +"%Y-%m-%d")-$dbname'.sql;done   Error Received on Mail:  /bin/bash: -c: line 0: unexpected EOF while looking for matching `'' /bin/bash: -c: line 1: syntax error: unexpected end of file


Using left over pickle juice to make more pickles

Can the juice from store bought dill pickles be used to make more pickles.  Can fresh cucumbers put into this juice aquire the same flavor as buying more pickles. If so how long would the cucumbers have to be in the 'juice' for full flavor?


How do I write console output values (from eclipse) in excel sheet through selenium WebDriver?

I want to print my verification messages in Excel instead of Eclipse console. Can you provide your suggestion to do above scenario in Selenium?  Ex: Getting the Page title and printing in the console:  String title1=driver.getTitle(); System.out.println(title1);


Why is it legitimate to only observe motion, but call it time, such that concepts like “the relativity of simultaneity” are seen as possibly genuine?

My question is asking for evaluation of a new concept or paradigm within the framework of the current mainstream physics understanding of Relativity. Specifically, that concept or paradigm being that, “it seems we do not seem to actually  observe ourselves or anything else heading into a future, or leaving a temporal past behind us, or observe that a future is constantly arriving, or a past receding, or a thing called time passing, Therefore it may be possible that the universe is just as it actually appears to be, I.e. Just filled with matter(/energy), just, existing, changing, moving and interacting at various rates in all directions".  Evaluating this concept within Relativity; in Einstein's  section 1, it is stated (para 3) that...      If we wish to describe the motion of a material point, we give the values of its co-ordinates as functions of the time.   But the example given only says...     If, for instance, I say, “That train arrives here at 7 o'clock,” I mean something like this: “The pointing of the small hand of my watch to 7 and the arrival of the train are simultaneous events.”   So, in fact it seems the motion of a material point (the train), is only actually compared to the location and/or motion of another material point (a small rotating hand), but the motion of this second material point is just called “time”.  i.e. It seems logically no reason is given why we should assume that the train, and the pointer or “hand” are not just constantly existing, and moving or not, somewhere. That is, no reason is cited to assume the rotating hand is not just a rotating hand, or that a thing called time actually is passing, or that anything is other than existing and moving “simultaneously” ( to use a possibly redundant word).  However,  as Relativity (imo legitimately) does show that moving objects are changing within themselves more slowly, it seems to also infer from this that,     we cannot attach any absolute signification to the concept of simultaneity   Suggesting there might be genuine discrepancies about “simultaneity”, or even the order of events (for observers in different locations, moving at relative speed etc).  But, extra to just “calling” the rotation of a hand on a dial “time”, the passage of a thing called “time”, and the concept of  non-simultaneity being legitimate (i.e. the idea there are different times), does not seem to actually be demonstrated in the paper.  So, why should we accept the idea...     we cannot attach any absolute signification to the concept of simultaneity,   If it has not been shown that anything is other than "simultaneous" - (or rather "just happening"), rather than just considering that everything, may just always be somewhere, doing something, at relativistically  dilated rates, but still just somewhere, “now”?


I am trying to make the plot of a bell-shaped curve with two intervals shaded but I am only capable to fill only one area, so this is the chart I got. I thought that adding another \clip (axis cs:0,0) rectangle (axis cs:1.5, 0.24); with the right side coordinates would shade the opposite area in blue but not.  I am using the following code \usepackage{pgfplots} \pgfplotsset{compat=1.8} \begin{document}  \pgfmathdeclarefunction{gauss}{3}{% \pgfmathparse{1/(#3*sqrt(2*pi))*exp(-((#1-#2)^2)/(2*#3^2))}% }  \begin{tikzpicture} \begin{axis}[   no markers,    domain=0:6,    samples=100,   ymin=0,   axis lines*=left,    every axis y label/.style={at=(current axis.above origin),anchor=south},   every axis x label/.style={at=(current axis.right of origin),anchor=west},   height=5cm,    width=12cm,   xtick= {2, 1.5, 3},   xticklabels={$-z_{\alpha_{p}}$, $-z_{\alpha}$, 0},   ytick = \empty   enlargelimits=false,    clip=false,    axis on top,   grid = minor,   hide y axis   ]  \begin{scope}[yshift=-\pgflinewidth] \clip (axis cs:0,0) rectangle (axis cs:1.5, 0.24); \addplot [draw=none, fill=blue] {gauss(x, 3, 1)}; \end{scope}  \addplot [very thick,cyan!50!black] {gauss(x, 3, 1)}; \pgfmathsetmacro\valueB{gauss(1,1,7)} \pgfmathsetmacro\valueA{gauss(1,1,1.65)} \pgfmathsetmacro\valueC{gauss(1,1,1)}  %\draw [very thick, red]  (axis cs:1,0) -- (axis cs:1,\valueB); %\draw [very thick, red]  (axis cs:2,0) -- (axis cs:2,\valueA); %\draw [very thick, red]  (axis cs:3,0) -- (axis cs:3,\valueC);  %\node[below] at (axis cs:3,0)  {$0$};  %\node[below] at (axis cs:1.5,0) {$-z_{\alpha}$}; %\node[below] at (axis cs:2,0) {$-z_{\alpha_{p}}$}; \end{axis}  \end{tikzpicture}  \end{document}  Thanks for you help!


Can you generate a world with only one biome?

Is there a way to generate a world that's one biome, because I wanted to search for lots of jungle temples if the world is just one biome, but I don't if there's a possibility. I'm not asking how I can change what type of biomes I want, that would be more than one biome. I want to find a way to make a world one biome. Is there truly a way to create a world like this?


Finding elliptic curves achieving the upper and lower bounds of Hasse's Interval

I always thought that Hasse's bound is sharp (at least for elliptic curves). In other words I always thought that given a prime number $p$, I can find two elliptic curves $E_1,E_2$ over $\mathbb F_p$ such that  $\#E_1 = \lceil 1+p-2\sqrt p \rceil$ and $\#E_2 = \lfloor 1+p+2\sqrt p\rfloor$. But is this even true? If so, is there an easy way to construct these curves? I've seen the proof of how to obtain these bounds but I don't think it gives me any information on the sharpness of the bound.


I've just signed up to AWS and launched EC2, downloaded key (.pem) file then generated ppk file using puttykeygen. Using this ppk file I've tried to log in to the server via SSH using Putty but it's giving me Server refused our key error with pop up:  Disconnected: No support authentication methods available (server sent: publickey)   I've also used both ec2-user and root but both don't seem to work with same error.  I'm using Amazon Linux AMI so  page recommends using ec2-user which I am already using. I've also followed the instructions on that page step by step but getting the same error above.  I've also Googled around but couldn't come to the resolution. Is this a bug in Putty or am I missing something?


Please put answers underneath questions in Close review queue

Many times when going through the Close queue I see that people are using the too localized reason.  Sometimes the reason for this is in the comments (like the syntax error being pointed out), but a lot of times it's in the answer, so then I have to click on the question and look at the answers to see if it is really too localized.  Could we please get the answers shown underneath the question in the Close review queue?


What does 0[str] means in C where str is a string

While I was learning Strings in C I came across the following piece of code   #include <stdio.h>  int main() {     char str[15] = "Hello, World";      printf("str[0] = %c\n", str[0]);     printf("*(str + 0) = %c\n", *(str + 0));     printf("*(0 + str) = %c\n", *(0 + str));     printf("0[str] = %c\n", 0[str]); /* This line 0[str] */      return 0; }   Simple things what I can figured out from the program are  str[0] will produce H *(str + 0) will also produce H as it uses pointer arithmetic *(0 + str) is similar to *(str + 0) and will also produce H    What I can't figure out is what does 0[str] means and how does it evaluates to H. As what I have learnt is [ ] symbol represents an array and 0 is not an array.


how to descrease the height of select box .It is loading with large number of records like 200 or three hundered.I want to make it smaller


Word/phrase for a feature that could be both good and bad for something

Take this scenario:     a tool has a specific feature that could be regarded as an invaluable benefit for. However, this feature, if used in opposite direction may be counterproductive. In other words, the strength point may be the weakness point.   For example, feature X of a security mechanism could be leveraged to break that if used maliciously. So, what's the word/phrase to describe this feature? I think it should be something other than Achilles heel.


My problem is that I do not know how to disable the numbering for algorithms. I have created an algoritm and its number is "Algorithm 1", but I want to have "Algorithm".  \documentclass{article}  \usepackage[noend]{algorithmic}  % Hide endif .etc  \usepackage{algorithm}  \algsetup{indent=2em}  % Default 1 em  \renewcommand{\algorithmiccomment}[1]{\hspace{2em}// #1}  % Change to C-style comments, though still ugly  \begin{document} \begin{algorithm}     \caption{MyAlgorithm} \label{alg:MyAlgorithm}     \begin{algorithmic}[1]     % Default no line numbering        \end{algorithmic} \end{algorithm}  \end{document}


I recently came across this command in bash:  cat > filename << EOF   I do not understand the << EOF part. Googling the << operator, I only came across regular shift arithmetic left. Playing around with it gave me no insight either.  Any explanation would be appreciated!


I'm quite the beginner with blender (just finished the donut) and I wanted to make a 3D replica of a radio that I have, but I have no idea how to make the little holes properly that it has in it.I assume the best way to make it is with the boolean modifier but it takes my pc like 30 seconds to calculate. Is there a better way to do this?  These are my modifier settings:


Moving lines to separate files all at once

I have many files and I want to export certain lines to new files while maintaining the input files as they are. For example, I want all lines beginning with a to be sent to a new file, let's call that a.txt, and then I want all other lines to be sent to a separate file, bcd.txt.  a.......  b.......  c.......  a.......  d.......   Currently, I'm using grep '^a' infile.txt > a.txt to do the first part and then I duplicated the input file and used sed -i 's/^a.*$//g to just delete the a lines starting with a. Is there a way I can do both tasks, while maintaining the original input file and not duplicating it?


Do US Universities commonly offer admission without funding?

I am offered governmental scholarship (GSch) that I do not want to use for some reasons. I also don't want to lose the chance of PhD in a top university. I would use GSch, if I cannot get funded admission from a top university. Please read my  for more explanation of my situation.  My question is that do universities offer an admission without funding? So that, then I will have a chance to say 'I have another source of funding. Let me do PhD there'. For example, will I know I am in the waiting list? Do they put all the rejected students in the list?   Or should I mention about the GSch at the first place? or maybe I should mention it only in applications of some universities.  Would I loose a good acceptance chance of mentioning at the first place, if I wait for rejection/waiting list decision?


We have 2 nights in Bilbao, 1 night in Hondarribia and 1 night in Saint Jean de Luz.  We will be in this area a week before the Film Festival and I know everything will be very crowded. I thought of driving but thinking about struggling to find parking and huge parking fees has given me to consider bus.  What is the best way to do this trip round trip, leaving on the 14.09 and returning to Bilbao on 16.09? I need to be able to find the best bus connections and the times for these. Do you book round-trip tickets and get on and off on different days or point to point?  Thank you.


Why doesn't logging out of Stack Overflow log me out of Gmail?

Why does logging in to Stack Overflow keep me signed in to my Gmail email after logging out and regardless of the Stay signed in checkbox?  Steps to reproduce:   Browse to  and confirm you are logged out Browse to  and confirm you are logged out Click login Click Google Enter Email/Password and confirm Stay signed in is unchecked Click Sign in Click logout (up top) Click Logout (down below) Browse to  and confirm you are still logged in Click Sign out <- Shouldn't clicking Logout on Stack Overflow be doing the same thing as this? Browse to  and confirm you are logged out     Answers are making sense but my frustration is that clicking Logout (twice) on StackOverflow essentially does nothing. If I proceed to click login and Gmail I am immediately authenticated because I still have an active Gmail cookie. In order to effectively logout I need to click Logout twice on Stack Overflow and then manually browse to  and Sign out.


How come the damaged hydrogen fuel cells didn't cause an explosion in T1 final fight scene?

I was wondering if there is an explanation why in the final fight scene of T1, there was no explosion? Clearly the hydraulic press completely crushed the terminator unit and this should have compromised the hydrogen fuel cell.    If anything it would result in a explosion like this (picture from the T3 sequel just after terminator threw out the damaged hydrogen fuel cell) and blow up Sarah Conor along with the whole factory.


Protect .NET code from reverse engineering?

Obfuscation is one way, but it can't protect from breaking the piracy protection security of the application. How do I make sure that the application is not tampered with, and how do I make sure that the registration mechanism can't be reverse engineered?  Also it is possible to convert a C# application to native code, and  is too costly.  C# provides lot of features, and is the ideal language for my code, so writing the whole codebase again in C++ is out of the question.  Secure certificates can be easily removed from the signed assemblies in .NET.


How to split a 2 part mesh into 2 different meshes

I have a 3D model of a shotgun that's in 3 parts: The barrel, the chamber door thingy, and then the pump and the stock are in one part. I want to split the stock/pump part into their own individual parts. I can't use bisect because the parts are separate. What do I do? Here is a pic of my mesh for reference:


Show that SO(n) is a normal subgroup of O(n).  A normal subgroup is a subgroup which is invariant under conjugation by members of the group of which it is a part. SO(n) is the set of orthogonal matrices of determinant 1. O(n) is the set of real matrices whose inverses equal their transposes (orthogonal matrices). I'm simply bad at writing proofs. Please help?


How to stop Win10 from rebooting without consent?

I just lost 3 days worth of processing because win10 decided that the update was more important and rebooted the system without asking, notification or warning.  Is there a way to turn this ‘feature’ off for good?   Scheduling is not an option, since it will restart regardless.


If the diameter of graph is greater than 3 then the diameter of its complement graph is less than 3

Graph $G$ has the diameter greater than $3$. Prove that the diameter of   $G'$ (the complement graph) is less than $3$.   What I was thinking about:  $G$ has the diameter greater than $3$ $\implies$ $G$ has not less than $4$ vertices.  If the $u$ and $v$ are vertices in $G$ that represents the diameter, then in $G'$ there is the edge $uv$. So, I was thinking that only first neighbors can be the diameter of $G'$. We need to prove now that between every two neighbors in $G$ there is only one other vertex in $G'$ which connects these two vertices (so the diameter is less than $3$).


I am going to blink with LED from MCU I/O port. Where do I need to connect LED: VCC ot GND? I think it might be a difference whether the current goes into the inside MCU (when the port is low level and LED is connected to the VCC) or the current goes out from the MCU's port (when the port pin is high and the LED is pulled down to the GND). Is one of them better than another or they are equal and why?


Windows 10 HDD to SSD for primary partition

Just upgraded boot partition to a 480gb SSD and its so much quicker, but.. Now my primary partition  is divided as followed. [111.16GB System Reserved][224.53GB NTFS][111.333GB Recovery Partition] It pretty much split up all my storage into Recovery and Reserve leaving me with a very small portion of the disk. How can I shrink or remove this?


Which Lens is better to use for portrait photography?

Currently am using Canon EOS 600D with 18-55 mm lens. I am concentrating on portrait photography . i need some suggestions for the lens that i can use for it.


What is the meaning of the term "format", as used in  I received to  I posted on this forum:     LaTeX3' isn't released as a format: perhaps you mean expl3?    I received to the above mentioned question also mentions this term:     You can dump a format from the current expl3 but it will just do nothing because it doesn't provide basic things like an output routine. If you are already running some format (Plain TeX, LaTeX2e, ConTeXt, lollipop, etc) you can input the expl3 macro package and use everything it provides.            I think you are asking whether there exists a format which has expl3 preloaded, to which the answer is no.


Lightning - dynamically creating force:inputField

With the release of Spring '16 there appear to be significant improvements to the force:inputField components especially for the lookup fields.  We are trying to use them in our application, but are having issues generating them dynamically. In our use case the user may define a set of fields that they want displayed for their form. This means we need to generate a list of inputs based on a dynamic set of fields.  Here is a statically defined example of how we can show the Custom_Acccount_Lookup__c field.  <aura:attribute name="contact" type="Contact" default="{ 'sobjectType': 'Contact' }"/> <force:inputField value="{!v.contact.Custom_Account_Lookup__c}"/>   However how can we generate this same code if the field we want displayed was user defined? The code below obviously doesn't work, but is it possible to achieve this some other way? We have also tried to generate the component in the controller but run into similar issues when passing in the value.  <aura:attribute name="contact" type="Contact" default="{ 'sobjectType': 'Contact' }"/> <aura:attribute name="fieldToShow" type="String" default="Custom_Account_Lookup__c"/>  <force:inputField value="{!v.contact[v.fieldToShow]}"/>   We are starting to suspect that there is some pre-processing of the component code before it renders. Upon code inspection the component actually generated is a force:inputLookup which is not one that we can create but apparently Salesforce uses to display the lookup field.


I'm half way through a chance fighting program and I wanted to shorten my work by using functions. But I got the error,  UnboundLocalError: local variable 'Ehealth' referenced before assignment    This is my code so far...  import random import sys import time  print ("You encounter a wild boar.")  time.sleep(1)  Weapon = input("Do you use a 'Bow and Arrow' or a 'Sword'.")  Ehealth = (100) health = (100) Ealive = (1) alive = (1)  def attack():     damage = (random.randrange(5,21))     time.sleep(3)      print ("You attack the Boar for " + str(damage) + " attack points.")     time.sleep(3)      Ehealth = (Ehealth - damage)      print ("The Boars health is at " + str(Ehealth) + ".")     time.sleep(3)  if Weapon == ("Bow and Arrow"):     Emiss = (20)    #out of 40     miss = (15)     #out of 40      Espeed = (random.randrange(1,11))     speed = (random.randrange(1,11))      if Espeed > (speed):         print ("The Boar is faster than you so he attacks first.")         time.sleep(3)          print ("Your health is at " + str(health) + " and the Boars health is at " + str(Ehealth) + ".")         time.sleep(3)          while (alive == 1):      #1 = alive, 2 = dead             Emiss = (random.randrange(1,41))             if Emiss < (20):                  print ("The Boar missed.")                  attack()                  if Ehealth > (0):                     alive = (1)                      continue                  else:                     alive = (2)                     print ("You Won!")                      sys.exit()                Edamage = (random.randrange(5,16))              print ("The Boar attacks you with " + str(Edamage) + " attack points.")             time.sleep(4)              health = (health - Edamage)             time.sleep(4)              print ("Your health is at " + str(health) + ".")             time.sleep(4)              if alive <= (0):                 print ("You died...")                 sys.exit()              attack()              if Ehealth > (0):                 alive = (1)              else:                 alive = (2)                 print ("You Won!")                  sys.exit()   I got the error at the line on   Ehealth = (Ehealth - damage)   Any help would be appreciated.


Double posts: close the older or newer one?

I sometimes come across double posts (the exact same question, same user, posted within a short time). An example is this: , , posted with a minute or two between them. My reaction was to vote to close the newer of the two questions, while I can see that someone voted to close the older of them. What would be the preferred way here?


Father of 3 children got problems with the UK visa application

I'm a father of two daughters under 18 years old and a son over 18 years old. We have lived in Denmark for years, and my children are born here, but only my over 18 year old son has Danish nationality.   My daughters and I have got what the Danes call "opholdstilladelse"(-in english a residence permit) so we are still Sri Lankan nationalities.   We want to visit some family in the UK, but we are kind of stuck in the whole visa applying .    Do we each have to make our own visa application (My daughters and I)? If my son is a Danish citizen, is it true, that the rest of the family doesn't need to pay for our visas? (I've just heard some people talking about that)   I hope someone can help me fastest as possible, my children really need this vacation for once.


Do not understand what is meant by "in terms of n"

I took calculus 5 years ago so I am unaware of what is meant by in terms of the variables in this summation example. specifically these two questions. please help me understand what the steps are to solving these. I was unable to google my malfunction.  What is the value of the following summation in terms of $n$: $\sum\limits_{𝑖=𝑛+1}^{3𝑛} (2𝑖−3)$?  Determine the value of this summation, in terms of $a$, $b$, $c$ and $d$. Assume that $a < b$ and that all four are positive integers. $\sum\limits_{𝑖=𝑎}^{b} (𝑐𝑖+𝑑)$.


Upon creating some graphs with TikZ, I noticed that the border at one side was much larger than it needed to be. The cause seems to be the \pgfmathsetmacro command:  \documentclass{standalone} \usepackage{tikz} \begin{document}  %\pgfmathsetmacro{\a}{0} %\pgfmathsetmacro{\b}{0} %\pgfmathsetmacro{\c}{0} %\pgfmathsetmacro{\d}{0} %\pgfmathsetmacro{\e}{0}  \begin{tikzpicture} \draw (0, 0) rectangle (1, 1); \end{tikzpicture}  \end{document}   Without any defined macros, the output looks like this (Adobe reader background is gray):    With each macro, the size increases. With all five macros defined, it looks like this:    How can this behaviour be explained? Am I using the \pgfmathsetmacro in a wrong way? I did this a lot in the past and never had such a problem. The following did not help, the border didn't change at all:  \documentclass[border=0pt]{standalone}


How long will flour keep in the freezer in Food Saver Vacuum Sealed Bags?

I found some flour in my freezer that I stored 5 years ago in Food Saver vacuum sealed bags.  Do you think it's still safe to use?


How to remove too big spacing before par-command?

I am writing an article and have a following issue with the LaTeX. I placed "par"-command and the spacing before the paragraph increased badly. I tried without "par", just by pressing Enter two times and got the same result. Could anyone explain me why is that and how to overcome this? Thank you in advance.


How can I know how long home-cooked food will stay good in fridge?

As through the week we too busy to cook we have gotten the idea of cooking a big bunch of food in the weekend, storing it in the fridge and eat it later in the week.  I am a bit concerned how long things will stay good in the fridge. For example mashed potatoes (which is prepared with milk), minced meat steaks or a cream-based sauce.  Are there any general rules of thumb that can be used to estimate how long things will stay good? And are there any 'dangerous' foods, foods that can be spoiled but not show any mold or smell strange, but are not good to eat?


Comparing cell value date to app script date

I am trying to grab an entire row if the date value is the same as what's in my script. So far my date comparison never works and nothing is ever returned. In my sheet I have a simple date:  In App Script I am trying to grab any row that has the date of Oct 5th: function getSheetData() {   var selectDate = new Date('05/10/2020');      var activeSheet = SpreadsheetApp.getActiveSheet();   var dataRange = activeSheet.getDataRange().getValues();   for (var i = 0; i < dataRange.length; i++) {     if (dataRange[i][0] == selectDate) {       return dataRange[i];      }   } }  How do you compare the date object to return the row that has Oct 5th specified?


I want re-project my Esri Arcinfo ASCII (.asc) raster file to Albers Equal Area Projection Which is currently in WGS84 and output it as .asc file. But gdalwarp cannot output as .asc file but gdaltranslate can. Is there anyway that i can use gdalwarp output as gdaltranslate input.


This is one thing that keeps bugging me, and maybe there's a direct answer. Grammatically, which one is more correct of these two?  Does it make a difference?  I tried not to do that. I tried to not do that.


Do the double-size retina-screen community ads work on all sites?

and  both have some community ads that are twice the usual size — specifically 440 x 500 pixels. Apparently these work, and are for improved display on Retina screens.  Do all Stack Exchange sites support these double-size ads? In addition to Community Ads, will they work in   I suspect they might, but there's enough site-specific special case features across the network that I'm not sure. I'm looking for something conclusive, like a staff response or a link to something from staff.


I came to wonder, what is the difference between the following?  \dotsc \dotso   As well as between:  \dotsb \dotsi \dotsm


Badge suggestion: Zealot (got 3 questions with at least 10 downvotes each)

Or maybe some other variation of that, like "20 downvotes anywhere within 1 day". Probably it should be bronze regardless.  It seems like there's a  against this badge, but that'd be fine. It's just for fun anyway. :D  Well, maybe it will be an incentive for most not getting that. I don't know.  edit: What about this other perspective - out of over 40 badges, all for "good behavior" none is actually "awarded" for "bad behavior". So, having at least 1 could give us a better idea of how people are behaving in the "bad manner". As for how people would actually react to that, I say that guessing here is pure speculation.


Where are changelogs for updates to "apt"?

Today, I received updates including an update to the apt package.  Start-Date: 2016-04-07  06:33:13 Commandline: apt-get dist-upgrade Upgrade: apt:amd64 (1.0.1ubuntu2.11, 1.0.1ubuntu2.12), apt-transport-https:amd64 (1.0.1ubuntu2.11, 1.0.1ubuntu2.12), apt-utils:amd64 (1.0.1ubuntu2.11, 1.0.1ubuntu2.12), libapt-inst1.5:amd64 (1.0.1ubuntu2.11, 1.0.1ubuntu2.12), apt-doc:amd64 (1.0.1ubuntu2.11, 1.0.1ubuntu2.12), libapt-pkg4.12:amd64 (1.0.1ubuntu2.11, 1.0.1ubuntu2.12) End-Date: 2016-04-07  06:33:39   man apt tells me that ...     apt (Advanced Package Tool) is the command-line tool for handling         packages. It provides a commandline interface for the package management         of the system. See also apt-get(8) and apt-cache(8) for more low-level         command options.   However, I would like to know what changes have been made in this version (and subsequent versions) that may affect my usage of the package. Where can I find such information?  I have already read several older sources of information including .


A nilpotent matrix is similar to a strictly upper triangular matrix

Let $n>1$ and $A\in M_n(F).$ Suppose $A$ is nilpotent. Prove that $A$ is similar to a strictly upper triangular matrix by induction on $n$.  How should I do this? I don't know how to use the assumption to relate it to the definition of similarity of matrices that's why  I'm stuck.   Please help. Thanks.


TP-Link Archer T2U Plus not working on Ubuntu 19.10

I just got a TP-Link Archer T2U Plus. I couldn't get it working on Ubuntu 19.10. with Kernel 5.3.0-24-generic.  my lsusb:  Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 001 Device 004: ID 0bda:5621 Realtek Semiconductor Corp. HD WebCam Bus 001 Device 003: ID 8087:0aa7 Intel Corp. Bus 001 Device 002: ID 0581:0105 Racal Data Group Bus 001 Device 005: ID 2357:0120 TP-Link 802.11ac WLAN Adapter Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub   As you can see it is listed, however I cannot use it to connect to a network.  Is there any official or unofficial driver which I can use for Linux (not just Ubuntu but Raspbian as well)?  I would really appreciate your input.


How does the 'battles won' work after June 2017 gym update?

In the new gym system right before you start a battle against a defending Pokémon with with your own it shows the two Pokémon, their respective combat powers and battles won. How does the new battles won accumulate? Obviously every battle won increases the number, but do battles won when attacking and defending count? If a defending Pokémon beats multiple Pokémon in a row will it count as one or multiple battles and vice versa for attacking Pokémon? Do defeating raid Pokémon count? Also is the count still unique to a Pokémon when it is evolved?  The question is different from the former gym system () because it showed only the battles won by a defender when it defended a certain gym the time it was undefeated. Then a good gym could have Pokémon with about at best over 10 battles won. Now I've seen Pokémon with battles won count exceeding 900! Also when I attacked a gym every time my own Pokémon defeated the gym Pokémon the count went up.


Why is "" necessary for this for loop to run?

The code is below -   for (let n = 1; n <= 100; n++) {   let output = "";   if (n % 3 == 0) output += "Fizz";   if (n % 5 == 0) output += "Buzz";   console.log(output || n); }   If I do not have let output = "" the code will not run.  Why is that statement required?


How to get the location of a bezier curve's handle in Adobe Illustrator

How can I get the exact coordinates of the handle point?   For reference its the coordinates of the blue points at the end of the handles I am interested in.


I want sudo to behave like this, for all users:   If the user currently has a non-empty password, prompt for the password. If the user currently has an empty password, either prompt for the password and accept the empty string, or don't prompt at all and permit.   Is this possible? Right now, I have (1) but this is what happens for a user with an empty password:  $ sudo echo Sorry, try again. Sorry, try again. Sorry, try again. sudo: 3 incorrect password attempts   Alternatively, I can switch off password checking per-user, but that's not what I want, because the user might set a password later, and then sudo should prompt for it.


How to install system trusted CA certificate on Android without rooting

I need to install the firewall certificate on the devices of my company. Since I can't install a system trusted certificate without rooting the device I thought of creating an Android image that comes with the certificate and flash it into the devices, but...  Where or how should I put such cert on the image? Or if there is another solution that also doesn't envolves rooting I would be happy to hear!


If 4n+1 and 3n+1 are both perfect sqares, then 56|n. How can I prove this?

Prove that if $n$ is a natural number and $(3n+1)$ & $(4n+1)$ are both perfect squares, then $56$ will divide $n$.   Clearly we have to show that $7$ and $8$ both will divide $n$.  I considered first $3n+1=a^2$ and $4n+1=b^2$. $4n+1$ is a odd perfect square.  - so we have $4n+1\equiv 1\pmod{8}$; from this $2|n$ so $3n+1$ is a odd perfect square.  - so $3n+1\equiv 1\pmod{8}$ so $8|n$ but I can't show $7|n$. How do I show this?  Thanks for the help.


How does T'Challa have the spirit of the Black Panther during Civil War?

In Captain America: Civil War, T'Challa takes the mantle of the Black Panther after his father is killed. As the Black Panther, he appears to have enhanced abilities.  In , the Russos talk about T'Challa having superpowers and being enhanced during Civil War     JOE: It can absorb the energy, so it’s much harder to damage him as a character, and you can see that in the movie he can take a lot of punishment including bullets to the face. He is very well trained. He’s from one of the wealthiest countries on the planet, so there’s great infrastructure there; very technologically advanced country. So he’s been trained at the highest levels to fight, but he also has his own superpowers, which derive from the mythology of his nation. Those will be explored more in Black Panther, it’s clearly evident when he’s able to fight the Winter Soldier out of costume, and go toe-to-toe with him, that he is an enhanced individual.    In Black Panther, we see that in order to become the Black Panther,       one must imbibe juice from the heart-shaped flower and visit the spirit plane after being buried.   But before this,       T'Challa must have his Black Panther powers removed prior to the ritual combat challenge, which he does twice in the film.   This raises the question of how T'Challa could have possibly become the Black Panther abroad - or if he even really had.  How did Black Panther have his powers during Civil War?


Why does "Open With" display so many instances of an app?

When I select a file and right click on it to use the "Open With" option I see a list of the most likely applications for opening that file, but in my case, running 10.9.5, I see three and sometimes four instances of each recommended application for opening that particular file - see attached screenshot. Why is this? Is there a way to reduce that to one instance per app? If so, how?


I have an example of an array of objects a that I copy with slice() to b.  I alter one of the objects in a but it changes also b. Isn't slice supposed to copy the array, including its contents? I need a and b to have different pointers.  Javascript  var a = [{x1:1, x2:2}, {x1:3, x2:4}];  var b = a.slice();   a[1].x1 = 5;   console.log(b[1]);   this prints:  x1: 5  x2: 4


How did I just downvote and then upvote an answer?

In the question  I reacted, then re-considered.  I cocked up, downvoting an answer which did not deserve that, because I possess less than "necessary" reputation my downvote was not listed on public view but was registered on some database or other. I resolved to take it back by upvoting it.   The thing is, this did not negate my downvote - as far as I can tell - it positively contributed to an upvote - this is something that I did not intend to do.  No judgement intended on the question or the answer. And that's the whole big-thing point. Is this right?


"E: Sub-process /usr/bin/dpkg returned an error code (1) " What does this mean?

I've seen this message several times whenever someone has a problem installing, upgrading or removing some piece of software, but I wonder, what does it mean, and more importantly, is possible to solve it?  (Reading database ... 81657 files and directories currently installed.)  Removing mongodb-10gen ...  arg: remove  invoke-rc.d: unknown initscript, /etc/init.d/mongodb not found.  dpkg: error processing mongodb-10gen (--remove):   subprocess installed pre-removal script returned error exit status 100  invoke-rc.d: unknown initscript, /etc/init.d/mongodb not found.  dpkg: error while cleaning up:   subprocess installed post-installation script returned error exit status 100  Errors were encountered while processing:   mongodb-10gen  E: Sub-process /usr/bin/dpkg returned an error code (1)   (the above is just an example, not my actual problem)


I know shrink is the devil: It reverses page order and is responsible for skin cancer, data fragmentation, and global warming.  The list goes on... That being said, say I have a 100 GB database and I delete 50 GB of data -- not on one table, but a general pruning of old data on a database wide level, covering 90% of the tables -- does this constitute an appropriate use case for shrinking the database?  If not, what are the appropriate steps to take to clean house after removing such a high percentage of data from a database?  I can think of two: Rebuild Indexes and Update Stats. What else?


iOS: How do I configure my iAd account after I decided to change my app name and thus ultimately my bundle identifier?

Scenario = I created an app that I want to put into production. I also have created an App ID on my developer.apple.com account for that app and an iAd account that I believe was created using said App ID.  com.domainname.appname   Issue = I changed the name of my app and inso doing I got a new domain name for the new name.  Problem = Apple does not allow you to edit an existing App ID.   Question = How do I change my App ID?   com.newdomainname.newappname   Comment/Question = I know Apple says that it is impossible, therefore, can someone who has been through a name change like this before enlighten me with the steps necessary to accomplish an app name change and change the App ID as such to be concurrent with iAd and any other third party service I may be using with said App ID?  If I have to create a whole new App profile with Apple or whatever, that's fine. I just need to know the steps so I don't get anything wrong and fudge things up. If someone who has done this before can help me I'd appreciate it. Thanks.


I am using an xps 13 9365, which was data wiped from bios by a friend who then gave it to me thinking it was dead. I tried booting with a USB (current LTS distro (18.04 or similar)) boot disk and got into the language selection / setup menu. By using the F6 option I selected noapic. In bios sata is set to raid and legacy the secure boot option is off.   But when I try to install I get kicked into a tiny font window with the following message  (initramfs) mount: Mounting /cow on root failed: Invalid argument overlay mount failed  Any ideas?


Escaping _$ (underscore and dollar sign)

I have this Bash script  for i in 1 2 3 do     for j in 4 5 6     do         echo "hello_$i_$j"     done done   but it prints  hello_4 hello_5 hello_6    three times, whereas (you may guess) I want hello_1_4, hello_1_5, etc.  Escaping only the underscore or only the dollar sign does not work. Any ideas?  Thanks!


I've been looking into tools like Karabiner, which are cool, but I would like more control. In general, I'd like to remap specific keys to run AppleScript or some other code.  Ideally it wouldn't send the keystroke though to the active application.  Is there any way to do this?  At the moment I'd like to remap the numpad keys to focusing specific applications, and if possible, specific windows in those applications. A general way to run code would be best, but anything that can accomplish this would be very much appreciated.


Where is the usage of Ubuntu cloud guest image on OpenStack documented?

Whenever I set up a devstack or OpenStack deployment, I want to add the latest LTS Ubuntu server image. I succeeded several times in the past and I believe it can be achieved with something like:  wget http://uec-images.ubuntu.com/releases/12.04.2/release/ubuntu-12.04.2-server-cloudimg-amd64-disk1.img glance image-create --is-public true --disk-format qcow2 --container-format bare --name "precise" < ubuntu-12.04.2-server-cloudimg-amd64-disk1.img   I wonder, though, where can I find the officially supported documentation on doing this? How can I contribute to it? I sometimes experience problems and without official instructions I'm never sure if it's the above command or my deployment. I tried adding these instructions to the OpenStack official docs and/or the accompanying Disqus comments on two occasions, but these would get removed and I can't find a consistent, supported manual to do this, I would expect very basic, procedure.  Also, what about the elusive cloud-init options to guest images? Where can I find instructions on how to use those? From the terminal and from the web UI? I once had to go fishing for this information in the source code.  What I found so far is , but one that doesn't state what are the formats of the images - I always have to google for this information. There is  that lists many recipes on how to create your own images, but not how to use existing ones (or the premade ubuntu cloud images). Then there is the most easily found  that only links to some promotional pamphlets and the uninformative cloud images listing.  I know that this is a semi-bug report (which I would like to see fixed or help fix :) ), but I would also like to know the answers to the questions I posed.


Why Electric field inside the spherical shell is zero?

Why the field inside the conducting spherical shell is zero?  Professor Lewin said and I quote,"  there is NO charge inside the conductor  because any charge inside the conductor would make the electrons experience a force , the electrons will start to flow and they will kill the electric field."  But he says Electric field is zero inside the conductor and for that charge should be present to provide the electrons with force to cancel the field . Isn't it ?


What stops you from using fixed income in developing countries?

I was recently visiting a developing country and noticed that their interest rates are very high — ~15% with government bonds promising ~13% annually. I was just thinking, if the bid ask spread for that currency with the USD is B/A respectively, then what is stopping people from having B/A x (1+13%)-1 annual USD returns, which roughly turned out to be 8%?  8% for fixed income in USD is very high, but I don’t quite see the problem in my argument — assuming the currency value with respect to USD stays stable in that year.


In my campaign I'm running, all of my characters are good. But there's one character who's evil. And everything he does is making it harder for me, as a GM and for the players. He kills important people, he burns down buildings, etc. He's done this twice before, in one campaign he killed the other players. Pissing everyone off and cutting the campaign short. In another one he did nothing but setback the players on their journey. And he's doing it again. I want everyone in my games to have fun but nobody is when he's playing like this. I want my players to kill him, but they aren't too good at RPing so the Lawful Good Paladin looks past his murders and such. I don't want to have to kill him and remove him from the game but it seems like the only option. What can I do to try and stop this without going to extremes as to remove him from my game?


Is "looking at an RDP" the same as looking at pictures online?

I've always wondered if using a remote desktop is the same as looking at a series of pictures online. As far as I can tell, the client machine I use to log onto a remote desktop produces (draws) a series of images on the client screen in real-time in response to the changing screen content of some remote machine.   However, looking at a series of images online often results in plenty of bandwidth and data usage (>100MB per hour) whereas RDPs only seem to use about 20MB per hour even with a lot of window-switching within the RDP. How so?  How is the "visual content" of a remote desktop transmitted to a client? Is this the same as how content of images is transmitted?


Blender is creating weird artefacts when using a subdivision surface modifier

I was working on a helmet model in Blender. I applied a subdivision surface modifier and I get weird spaces. What can I do to get rid of those spaces without deleting the subdivision surface modifier?  I attached some photos for reference.


Theil–Sen estimator in R with more than one variable?

Can Theil-Sen be defined for multiple linear regression? If so, is there an implementation in R for it?  I simply want a formula a~b+c, but the package mblm fails with the (misleading) error message: stop("Only linear models are accepted"). Of course, this is a linear model: but they mean that Theil-Sen only works for two-dimensional linear models.


What exactly is Ubuntu Core, and how does it relate to Ubuntu itself (i.e. the main desktop and server distribution)?   I've read  to , which says it's just a minimal install of Ubuntu, but it says nothing about the "snappy" transactional updates that Mark Shuttleworth mentioned in .


Why are both LIGO detectors nearly co-aligned?

A lot of the papers I've been reading say that's the case, so we needed VIRGO to analyze the polarization of the GWs, but not a single one of them explains the reasoning behind this decision. Why weren't both LIGO detectors aligned differently in the first place?


test on fold change of the mean vs. mean of fold changes

Suppose we have 5 subjects. For each subject, biomarker is measured at t0, t1 and t2. Measured values are skewed. We want to compare the values at t1 and t2.  When we have skewed data, usually we do log-transformation. t test on log-transformed data is equivalent to comparing the fold change of the mean, which is also equivalent to comparing the geometric mean.    I can also calculate fold change for each subject at t1 and t2, both using t0 as baseline. If we do t test on the fold changes at t1 and t2, Are we comparing the mean of fold changes?   So the problem is fold change of the mean vs mean of fold changes.  If what we want to know is if there is any differences between t1 and t2, in terms of fold change, should we use fold change of the mean OR mean of the fold changes? Fold change and logFC is commonly used in differential gene analysis. I'm trying to get a better understanding of this issue.   See the example below. All test results are different....  # we have 5 subjects. Each subject is tested at t0, t1 and t2.  t0=c(0.2,0.3,0.5,0.2,0.1) t1 = t0+runif(5,min=0.5,max=2) t2 = t1+runif(5, min=0.5, max=1) t0_log2 = log2(t0) t1_log2 = log2(t1) t2_log2 = log2(t2) t0_fc = t0/t0 t1_fc = t1/t0 t2_fc = t2/t0  # test the diff of log-transformed result between t1 and t2 t.test(t1_log2, t2_log2, paired=T) # test the diff of fold change (both vs t0) between t1 and t2 t.test(t1_fc, t2_fc, paired=T)  # test the diff of log-transformed result between t0 and t1 t.test(t1_log2, t0_log2, paired=T) # test the diff of log-transformed result between t0 and t1 t.test(t1_fc, t0_fc, paired=T)   How do we properly interpret the results from t test above?  I really appreciate if anyone can clarify my confusion. Thank a lot.


Setting a dynamic sort name field in a linq query

I want to be able to get an OrderBy query working with a lambda expression so that I get a SQL query with the TOP(n) key word (big performance boost).  I am able to do this if I specifiy ...  PaginatedList = query.OrderBy(x => x.QuoteID).Skip(() => skipValue).Take(() => pageSize)   But because I want the orderBy field to be dynamic through a UI selection of a name I want to do something like this:  var propertyInfo = typeof(Data.Quote).GetProperty(sortName); Expression<Func<Data.Quote, object>> orderField = x => propertyInfo.GetValue(x, null); PaginatedList = query.OrderBy(orderField).Skip(() => skipValue).Take(() => pageSize)   This gives me the error:      "LINQ to Entities does not recognize the method 'System.Object   GetValue(System.Object)' method, and this method cannot be translated   into a store expression."   I tried this that's not of type Expression<Func<T, object>>  var propertyInfo = typeof(Data.Quote).GetProperty(sortName); Func<Data.Quote, object> orderField = x => propertyInfo.GetValue(x, null); PaginatedList = query.OrderBy(x => orderField).Skip(() => skipValue).Take(() => pageSize)   And I get this error:     "Unable to create a constant value of type [...]. Only primitive types   or enumeration types are supported in this context"   I'm sure there is a way to achieve this but at the moment not sure how.


confusion in a proof of local finiteness of partitions of unity in CW complexes in John Lee's Introduction to Smooth Manifolds

Suppose $X$ is a CW complex and $X_n$ is the $n$th skeleton. Suppose that for $k=0, \dots n$ we have defined partitions of unity $(\psi_\alpha^k)$ for $X_k$ subordinate to $(U_\alpha^k)$ satisfying the following property for each $\alpha \in A$ and each $k$: If $\psi_\alpha^{k-1} \equiv 0$ on an open subset $V \subset X_{k-1}$, then there is an open subset $V' \subset X_k$ containing $V$ on which $\psi_\alpha^k \equiv 0.$   This property is used in showing local finiteness of the partition of unity. If $x \in X_n,$ because $\psi_\alpha^n \equiv 0$ except when $\alpha$ is one of finitely many indices, and then the above property shows that $\psi_\alpha^{n+1} \equiv 0$ on $V'$ except when $\alpha$ is one of the same indices.   However, I cannot see how this is true. If the index set $A$ is infinite, then we cannot take intersections of the open sets. How can we ensure this?


How to create instance of a class with the parameters in the constructor using reflection?

for example:  public class Test {      public static void main(String[] args) throws Exception {         Car c= (Car) Class.forName("Car").newInstance();         System.out.println(c.getName());     } }  class Car {     String name = "Default Car";     String getName(){return this.name;} }   clear code.  But, if I add constructor with params, some like this:  public Car(String name) {this.name = name;}   I see: java.lang.InstantiationException  So, no I don't know, how pass constructor with params.  Please, help.


Grep display both matched and umatched lines

How can I use grep command to display both matched and unmatched lines? Matched line should be in red and other lines should be in normal color.  Is there a grep option available to do that?


Decrypt all RSA ciphertexts if you can break 1% of them

I was given a cryptography question during an interview the other day.   Imagine you are given an efficient algorithm which for a given RSA public key (n,e) is able to decrypt 1% of the messages encrypted with that key.   1% means that the algorithm will deterministically decrypt 1% of all possible ciphertexts on the first call, and will never decrypt the other 99% of all possible ciphertexts with any number of invocations.   Figure out an algorithm that uses this one and can decrypt any message. Any ideas?


I hope this is the right place to ask such question.  EDIT: And this question is not duplicate! I tried tracking down the host using services such as whois but they didn't provide an answer. So that route is not working  I have a client with a website but they don't remember their hosting provider. Upon searching based on the ip or the domain (using services such as whois) it still cannot be found.  I do have the credentials inlcuding the computer name, and upon searching based on the computer name I am directed to softLayer hosting provider. But they do not agree to provide any information. Could it be that the host actually uses softLayer service? (but again I don't know who the host is...)  The reason why I'm trying to find the hosting provider is that although I have the credentials, when trying to connect with WinSCP, I'm receving 'access denied'.  Is there something else I can do in order to find that hosting provider?  Thanks in advance


What is Deviance? (specifically in CART/rpart)

What is "Deviance," how is it calculated, and what are its uses in different fields in statistics?  In particular, I'm personally interested in its uses in CART (and its implementation in rpart in R).   I'm asking this since the  seems somewhat lacking and your insights will be most welcomed.


How do I remove a property from a JavaScript object?

Say I create an object as follows: let myObject = {   "ircEvent": "PRIVMSG",   "method": "newURI",   "regex": "^http://.*" };  How should I remove the property regex to end up with new myObject as follows? let myObject = {   "ircEvent": "PRIVMSG",   "method": "newURI" };


Execute command in remote active terminal

Suppose you have a terminal emulator (T1) open with a PID of 6350.  From another terminal, type this command (C1):  echo "ls\n" > /proc/6350/fd/0   This writes ls and the new line in T1 but does not execute it. Why?  I also tried using cat|bash with echo "ls\n" > /proc/catid/fd/0 but it is still not executed.  How can I echo the command into another terminal and have the command executed?  possible answer :  $ mkfifo toto; $ bash < toto; $ echo "ls" > toto;   In this case you cannot write anymore directly in the terminal (everything is displayed the same way the command (C1) displayed thing in this terminal.


If $f$ is continuous and $g$ is integrable on $[a,b]$, with $g(x) \ge 0$ for all $x \in [a,b]$ ...

Suppose $f : [a,b] \to \mathbb{R}$ is continuous and $g \in \mathcal{R}[a,b]$ with $g(x) \ge 0$ for all $x \in [a,b]$. Show that there exists a $c \in [a,b]$ such that $$\int_a^b f(x)g(x) \, dx = f(c) \int_a^b g(x) \, dx.$$   My attempt:  My class proved a theorem which states that $f$ attains its minimum and maximum ($m$ and $M$, respectively), since $f$ is continuous on a closed interval like $[a,b]$. So we would have $m \le f(x) \le M$. Multiplying both sides by $g$ and integrating, we get $$m \int_a^b g(x) \, dx \le \int_a^b f(x) g(x) \, dx \le M \int_a^b g(x) \, dx.$$  I am stuck after this. Where can I go from here?


How can a structure have infinite length and infinite surface area, but have finite volume?

Consider the curve $\frac{1}{x}$  where $x \geq 1$. Rotate this curve around the x-axis.   One Dimension - Clearly this structure is infinitely long.  Two Dimensions - Surface Area = $2\pi\int_∞^1\frac{1}{x}dx = 2\pi(\ln ∞ - \ln 1) = ∞$   Three Dimensions -  Volume = $\pi\int_∞^1{x}^{-2}dx = \pi(-\frac{1}{∞} + \frac{1}{1}) = \pi$   So this structure has infinite length and infinite surface area. However it has finite volume, which just does not make sense.  Even more interesting, the "walls" of this structure are infinitely thin. Since the volume is finite, we could fill this structure with a finite amount of paint. To fill the structure the paint would need to cover the complete surface area of the inside of this structure. Since the "walls" are infinitely thin, why would a finite amount of paint not be able to cover the outside of the "walls" too?  Please help me make sense of this whole thing.


What did James and Lily Potter do for a living? Did they have any job?


Can a file be maliciously changed in a way that maintains its original SHA-1 Hash?

According to  article, and many others, SHA-1 is not secure.  In my case, I am not concerned about passwords or digital certificates. I am concerned about file integrity.  Is it reasonably possible for a file (e.g. an ISO image or executable file) to be maliciously altered in a way that:   Maintains the original file's SHA-1 hash, and Maintains the file's overall content and operation (but of course now includes malicious content that was not originally there)   The way I see it, altering a file in a way that yields a SHA-1 collision would render the file totally useless. The ISO would be totally corrupt, or the executable file would be so utterly scrambled it wouldn't even be an executable file anymore.  But, the way I see it could well be wrong. So far I have found nothing on Google searches in regards to SHA-1's continued suitability for file verification. Any insights?


How can one simulate chalkboard lines in Tikz?    Perhaps something  could work, but a) would it then be necessary to specify lines as regions? and b) I cannot compile the code in the previous link, which makes pdflatex -shell-escape wondering:  [. . .] Package pgfplots notification 'compat/show suggested version=true': document ha s been generated with the most recent feature set (\pgfplotsset{compat=1.12}).  Runaway definition? -> ! TeX capacity exceeded, sorry [main memory size=5000000]. \pgfplotsapplistXXpushback@smallbufoverfl ...toka                                                   \the \t@pgfplots@tokb \the... l.16   \addplot3[surf,shader=interp] {rand};  !  ==> Fatal error occurred, no output PDF file produced! Transcript written on papyrus.log.   Edit: It seems that chalk-like filling can be produced using gaussian noise. I have no idea of how to do implement that with tikz/pgf though.


Setting NEI (Minecraft) to Cheat mode Doesn't work My Lock Mode is set to -1 and my Cheat mode is set to 2 but it still doesn't work I'm kinda confused because most of the forums i looked at told me to set these things to what they already were I also made sure i was in Global Settings not world which had the cheat mode locked (Playing Tekkit Legends if that has anything to do with it)


Inequality for positive definite matrices

Let $A$, $B$ be positive definite symmetric matrices. such that $A \leq B$, i.e., $(A - B)$ is a negative semi-definite matrix.  Is it true to conclude that $B^{-1} \leq A^{-1}$?  (I need to prove it in order to use in the proof of a theorem in stability of control systems)  For trivial examples $A=aI$ and $B=bI$, where $a \leq b$, the above statement is true.  In addition, I think it can simply be proven for the case that $A$, $B$ commute, i.e., $(A B = BA)$.  Thanks in advance.


Since daily rep caps out at 200, a large majority of upvotes on Jon's posts never get "counted" as rep.    For example, more than 70 upvotes on 11/17/17 did not count toward his rep total.   My question is: how many upvotes does  have?  Motive: I am interested in examining user output/quality using a less penalizing approach than rep counts (which is limited/throttled).    Specifically, I'm curious about who might have the most upvotes (vs rep), since those with daily high-rep don't get quantified equally to those that do not reach the daily max.   Update: This is not a dupe of  because my question is neither asked nor answered in that post.    I want to know the total number of upvotes a user (in this case Jon) has ever received across all posts on a given SE site (Stack Overflow).


How To Insert a Common Point Between 2 Pen Lines

I need to insert a common point in between 2 pen lines so I can draw a shape by overlapping lines and deleting lines after the point.  thanks in advance.


Prove a planar graph with all regions having even degree can be colored with 2 colors

My current idea is to use the dual graph, and prove that that is a bipartite graph, and so proving the statement. But I can't seem to figure out how even degree for all verticies means that it is bipartite.  Any help is appreciated. Thanks!


How do I rank equally on mobile & desktop?

I have a site that ranks #1 on Google for a specific keyword on mobile.  On desktop, it ranks #3.  What are the likely considerations I need to be aware of to try and bump up my desktop ranking?  Thanks for any insight.  Joe


Air travel layovers: How to prolong them to see the city?

Say I wanna go Malaga to Rio and the search engine offers me several options with layover at Paris CDG ranging from one to five hours.  Is there any way to tweak the results to have at least 14 hours of layover or even have the connecting flight depart the next day, so one can see Paris?  More specific: How can I combine flights to and from the hub myself, but have the advantages of the through-ticket (e.g. being safe, if one of the flights is cancelled or extremely delayed)?  (cities named are just token examples and don't need to be met specifically)


An analogue of Hensel's lifting for Fibonacci numbers

Let $F_0, F_1, F_2, \ldots$ be the Fibonacci numbers, defined by $F_0 = 0$, $F_1 = 1$ and $F_n = F_{n-1} + F_{n-2}$ for all $n\geq 2$.  In  question Oleg567 conjectured the following interesting fact about Fibonacci numbers: $$ k\mid F_n\quad\Longrightarrow\quad k^d\mid F_{k^{d-1}n} $$ where $k \in \mathbb{N}$ and $n \in \mathbb{N}$. This can be regarded as an analogue of Hensel's lifting lemma.  I would be glad to give a proof (following the share your knowledge, Q&A-style), based on a simple combinatorial identity, and see if others come out with more elegant ones.


What happens when we connect two generators in parallel with a single load?

I read that in large utility systems more and more generators are added to provide extra power. I'm lacking some basic knowledge here. So, what happens when we connect two generators in parallel? Is it like connecting 2 voltage sources in parallel with a resistor R? I'm trying to think it as a circuit but it doesn't help. Does the current in the load increase? And if so, how?


Export Excel data to exisitng sharepoint list using jquery

can we build a solution in jquery where we can export excel data to existing sharepoint list number of column in excel will be 56 or more with 5000 rows , i have to use on JSOM


Why do physicists dislike Naked singularities?

Why do physicists dislike ? Why do physicists consider the potential existence of Naked singularities as a serious problem?


If $p_1,...,p_n$ are all primes that exist, than $p_1\cdot p_2\cdot \cdot \cdot p_n + 1$ will always be prime. I am confused because I thought Euclid's proof of infinity of primes was based on proving existence of a prime that is other than assumed finitely many primes, i.e., $p_1, p_2, ..., p_n$. I always thought $p_1\cdot p_2\cdot \cdot \cdot p_n + 1$ was a prime because it is not divisible by any of the prime among $p_1,...,p_n$.    But this website says that $p_1\cdot p_2\cdot \cdot \cdot p_n + 1$ should not be considered as a prime?


I have a set of values $x$ and $y$ which are theoretically related exponentially:  $y = ax^b$  One way to obtain the coefficients is by applying natural logarithms in both sides and fitting a linear model:  > fit <- lm(log(y)~log(x)) > a <- exp(fit$coefficients[1]) > b <- fit$coefficients[2]   Another way to obtain this is using a nonlinear regression, given a theoretical set of start values:  > fit <- nls(y~a*x^b, start=c(a=50, b=1.3))   My tests show better and more theory-related results if I apply the second algorithm. However, I would like to know the statistical meaning and implications of each method.  Which of them is better?


Windows - display exact time instead of "1 hour ago"

This is really driving me nuts! Even Windows 10 went for this useless fashion in time reporting!!     How do I get Windows 10 to report exact time instead of this?


Show that if a function is nonnegative and continuous on [a,b] then f(x)=0 for all x in [a,b]

Show that if $f : [a, b] \to \mathbb{R}$ is non-negative and continuous on $[a, b]$ and  $$\int_{a}^{b} f(x)dx = 0$$ then  $f(x)=0$, for all $x ∈ [a, b]$.  I'm having difficulties in proving things to do with integrals, how do I start this?


What's the function of the three input resistors in the below circuit?

I want to know the function of the three 1Mohm resistor between the HVDC+ and HDVC-, they are R4 R14 and R17 in the below circuit, thanks for your attention and time!


Multicollinearity - doubt on regression coefficients

Why is it the case that when there is multicollinearity, the regression coefficients become indeterminate and their standard errors become infinite?


I am designing a small application in which I open a new form with some controls. I want to close this form if idle for some time. Let say the form is having many buttons, scroll bars, picture box....if none of them is clicked (within 10 seconds) the form should close.   I have used a timer of 10 seconds , i want to reset it if any of the control is pressed. I can do it individually but would become very cumbersome doing it for all the controls. Can i do it by some simpler way....I read on net:  foreach (Control cc in Controls)   but didn't knew how to use it. Please help.


How to prove $|\text{Aut(G)}|=2\implies |G|=3$

As suggested in the title I'm trying to prove $|G|=3$ given that $|\text{Aut}(G)|=2.$  First I thought that: for an automorphism, we have no choice for the identity element because the identity must go to the identity and for the other non-identity elements there are exactly $2$ permutations. So if $|G|=n$ then $(n-1)!=2\implies n=3$.   But I realized that the orders of elements are being preserved by automorphisms.  So any permutation is not allowed for considering the automorphisms.  Please help me to get the idea of the problem. Thank you.


We have various ways of invoking apex. Triggers, Inbound Webservices, @InvocableMethod,@RemoteAction and what not. Often we call some or other utility methods from these execution contexts. I have some generic utility method,that should behave differently from the context it is called?  I know about Trigger.isExecuting but it only tells if its running in trigger context or not.  I have a utility method that creates lead from Webservices, VF button click and via Lightning . Whenever we create a lead I want some special operations to be done via the source it was originated.(Its not just updating a simple field leadSource, I have some methods that creates some childs and update other records of other type) . I can achieve this by passing an extra parameter to utility method to tell about source, but i have then to edit hundred of other class that uses this utility method. If i could dynamically find out via which context this piece of code is running,then i would have to change only one class to satisfy my requirement.    Is there something in APEX that tells in what context the apex method was called?


I just recently encountered this problem in c++  std::cout << -5.0000004768371582 + 5 << "\n";   This will print -4.76837e-007 even though you would think it would print something like 0.000000476... I know floating points aren't always correct, but I've never seen this before. I've also seen this happen with other numbers.  Why is this. And how could I fix it?


How to print out words under words in python?

If you don't understand my title just ignore it and read this instead.... so this is my code...     alphabets=["a", "b","c", "d","e","f"]    nums=["one","two"]      for num in nums[:2]:         print(num.title())         print(alphabets[:3])    the output is like this......      one     ['a','b','c']     two     ['d','e','f']   I don't know what to do I already tried tons of different things. All I need is to get all the code in eight lines and I am expecting to get the output something like this...      one     ['a','b','c']     two     ['a','b','c']   the only problemis the second line outputs the same thing "a,b,and c" instead i want like "d,e,and f". Please Help! Thanks in advance!


Find radius of convergence of the complex power series $\sum_{n=0}^\infty (\frac{n!}{n^n})z^n$

I'm using the ratio test on the complex power series $\sum_{n=0}^\infty (\frac{n!}{n^n})z^n$. I'm able to get to $\frac{(n+1)!|z|^{n+1}}{(n+1)^{n+1}}(\frac{n^n}{n!|z|^n})=|z|\frac{n^n}{(n+1)^n}$. How should I interpret this result and determine the radius of convergence?


How do I redirect output of command into ls?

I have a problem with redirections :  $ which python3   gives me  /Library/Frameworks/Python.framework/Versions/3.7/bin/python3   and  $ ls -l /Library/Frameworks/Python.framework/Versions/3.7/bin/python3   gives me   lrwxr-xr-x  1 root  admin  9  5 fév 18:30 /Library/Frameworks/Python.framework/Versions/3.7/bin/python3 -> python3.7   but   which python3 | ls -l   don't gives me the same result.  Do you know why ? And what is the right command for redirection ?   I'm using OSX.  I have to say that the following question  may be the same as this one, but if I look the answers that were given, there I'm lost. To be useful, they require more advanced knowledge or study than those given here.


changing all the itemize into bullets in a beamer presentation

how can I set all the item into bullets (cobalt)?     \documentclass{beamer}  %\setbeamercolor{titlelike}{parent=structure,bg=cyan} %background color %\setbeamercolor{titlelike}{parent=structure,fg=blue} %colore titoli %\setbeamercolor{titlelike}{parent=structure,fg=yellow,bg=cyan} %colore e background in un comando   %%% duplicated <<<<<<<<<<<<<<<<<<<<<<<<< %%\usepackage{tikz} %%\usepgflibrary{arrows.meta} %%\usetikzlibrary{calc,quotes,angles}  %%\usepackage{pgfplots} %%\pgfplotsset{compat=1.16}  %%\usepgfplotslibrary{groupplots}  %%\usetikzlibrary{calc}   \usepackage{xcolor}  \definecolor{cobalt}{rgb}{0.0, 0.28, 0.67}  %\setbeamercolor{titlelike}{parent=structure,fg=cobalt,bg=violet!50}      \usepackage{tikz} \usepackage{subcaption} \usepgflibrary{arrows.meta} \usetikzlibrary{calc,quotes,angles}  \usepackage{pgfplots} \pgfplotsset{compat=1.16}  \usepgfplotslibrary{groupplots}   %\usetikzlibrary{calc} %rido <<<<<<<<<<<<<<  \setbeamercolor{itemize item}{fg=cobalt} % all frames will have cobalt bullets  \setbeamersize{text margin left=5mm,text margin right=5mm} %margini  %\usebackgroundtemplate{\includegraphics[width=\paperwidth]{logo.jpeg}} \title{\textbf{title } \\      \vspace{20pt}       \includegraphics[height=50pt]{logo.jpeg}}%<<<<<<<<<<<<<<<<<<<< changed \author{name}  \institute[VFU] % (optional) {% %  \inst{1}% <<<<<<<<<<<<<<<<   department\\   Uni   \and %  \inst{2}% <<<<<<<<<<<<<<<<<<<<   speker\\   speaker 2 }  \date[VLC 2013] % (optional) {date}  %\titlegraphic{\includegraphics[height=1.5cm]{example-grid-100x100pt}} %<<<<<<<<<<<<<<<<<<<<   \begin{document}  \maketitle  \setbeamercolor{background canvas}{bg=violet!20} %<<<<<<<<<<<<<<<<<<< added \setbeamercolor{titlelike}{parent=structure,fg=cobalt,bg=violet!50} %<<<<<<<<<<<<<<<<<<< added \begin{frame}  \frametitle{Title first slide} %<<<<<<<<<<<<<<<<<<< changed  %\begin{figure}[h]%<<<<<<<<<<<<<<<<<<< %\centering%<<<<<<<<<<<<<<<<<<< \begin{itemize} \item bla blla \item gla gla \end{itemize}  \end{frame}  \end{document}


How can we tell if the Earth is spinning without any external references?

The rotation of the Earth about its axis makes it bulge at the equator and contract at the poles due to the centrifugal forces. How do we know, without any external references, that the Earth is spinning if there is nothing to compare it to? For example, imagine it was spinning in empty space with no other objects. Does it still bulge at the equator?   Particularly, what can we say theoretically about it?


Is there a way to show that $\sqrt{p_{n}} < n$?  In , I show that $f_{2}(x)=\frac{x}{ln(x)} - \sqrt{x}$ is ascending, for $\forall x\geq e^{2}$. As a result, $\forall n \geq 3$ $$\frac{p_{n}}{ln(p_{n})} - \sqrt{p_{n}}\leq \frac{p_{n+1}}{ln(p_{n+1})} - \sqrt{p_{n+1}}$$ Also (and as a result), $\forall n \geq 3$ $$ \frac{p_{n}}{ln(p_{n})} - \sqrt{p_{n}} > 0$$ Or $$ \frac{\pi (p_{n})}{p_{n}/ln(p_{n})} < \frac{\pi (p_{n})}{\sqrt{p_{n}}}$$  According to  $$\displaystyle\smash{\lim_{n \to \infty }}\frac{\pi (p_{n})}{p_{n}/ln(p_{n})}=1$$ Or, $\forall \varepsilon >0$, $\exists N(\varepsilon )$: $\forall n>N(\varepsilon )$ $$1- \varepsilon < \frac{\pi (p_{n})}{p_{n}/ln(p_{n})} < 1+ \varepsilon$$ Or $$1- \varepsilon < \frac{\pi (p_{n})}{p_{n}/ln(p_{n})} < \frac{\pi (p_{n})}{\sqrt{p_{n}}}$$ As a result $\forall \varepsilon >0$, $\exists N(\varepsilon )$: $\forall n>N(\varepsilon )$ $$(1 - \varepsilon ) \cdot  \sqrt{p_{n}} < \pi (p_{n}) = n$$  But this is not enough.  Interestingly,  is true iff function $f_{4}(x)=\pi (x) - \sqrt{x}$ is strictly ascending ($x < y \Rightarrow f(x) < f(y)$) for prime arguments.  If $f_{4}(p_{n}) < f_{4}(p_{n+1})$ then $$\pi (p_{n}) - \sqrt{p_{n}} < \pi (p_{n+1}) - \sqrt{p_{n+1}}$$ Or $$\sqrt{p_{n+1}} - \sqrt{p_{n}} < \pi (p_{n+1}) - \pi (p_{n}) =1$$  And vice-versa, if $$\sqrt{p_{n+1}} - \sqrt{p_{n}} < 1$$ Then $$-\sqrt{p_{n}} < -\sqrt{p_{n+1}} + 1$$ Or $$\pi (p_{n})-\sqrt{p_{n}} < \pi (p_{n}) + 1 -\sqrt{p_{n+1}} = \pi (p_{n+1}) -\sqrt{p_{n+1}}$$  So, if Andrica's conjecture is true then $\forall n \geq 3$ $$\pi (p_{n})-\sqrt{p_{n}} > 0$$ Or $$\sqrt{p_{n}} < \pi (p_{n})= n$$


Expected number of turns for getting six 1's in six dice.

You have 6 unbiased dice.  What is the expected numbers of turns required to get 1 in all the faces such that whenever you get 1 in any of the dice, you do not roll it for next three turns.   For example, the die faces could be as follows:  Turn 1 $\rightarrow$ 1, 2, 3, 4, 5, 6 (since the first die came up with 1 on top, you do not roll the first die for next 3 turns)  Turn 2 $\rightarrow$ $\mathbf{1} $, 3, 3, 1, 4, 1  Turn 3 $\rightarrow$ $\mathbf{1}$, 5, 6, $\mathbf{1}$, 3, $\mathbf{1}$   Turn 4 $\rightarrow$ $\mathbf{1}$, 4, 4, $\mathbf{1}$, 2, $\mathbf{1}$   Turn 5 $\rightarrow$ 6, 1, 3, $\mathbf{1}$, 5, $\mathbf{1}$   Turn 6 $\rightarrow$ 2, $\mathbf{1}$, 1, 3, 2, 6  and so on. (Numbers in bold indicate that they were not rolled during that turn.)


force long text inside \item[{\texttt{}] to wrap

I have a LaTeX document that is automatically generated and then inserted as part of my own larger document with \input. This other document has a description environment for examples, one item for each. The problem is that some of them are very long and run out of the paper margins. Here's an example,  \begin{description}  \item[{\texttt{bp\_genbank\_ref\_extractor --transcripts=accession '"homo sapiens"[organism] AND H2B'}}] \mbox{}  Search Entrez gene with the query \texttt{'"homo sapiens"[organism] AND H2B'}, and save their transcripts sequences. Note that default value of \textbf{--limit} may only extract some of the hits.   \item[{\texttt{bp\_genbank\_ref\_extractor --transcripts=accession --proteins=accession --format=fasta '"homo sapiens"[organism] AND H2B' '"homo sapiens"[organism] AND MCPH1'}}] \mbox{}   Is there a way to force them to wrap around without changing the file? Something I can do before calling \input? The text there will run for several pages and is a section of the appendixes (I'm using the memoir class).  This document is generated automatically from the POD documentation of a perl script using pod2latex.


javascript - the scope of let isn't working as I expected

so I was practicing JavaScript on some website and stumbled upon this   let printNumTwo; for (let i = 0; i < 3; i++) {   if (i === 2) {     printNumTwo = function() {       return i;     };   } } console.log(printNumTwo());    why is it logging 2?  i is not defined outside of the for loop.


Looking for a sci-fi movie in which a human astronaut befriends an alien on a reddish planet

This probably wasn't a blockbuster back in its time as I remember the special effects didn't seem all that bombastic, but I do remember a few details.  A human astronaut lands (or crash-lands) on a prominently reddish planet. It might have been Mars, thought it might not have been. I think the atmosphere on said planet was humanly breathable (as in the astronaut does not wear his helmet).  This human astronaut needs to survive. He spots a humanoid alien, apparently also having crash-landed or otherwise in need of survival. He sees this alien consume some sort of greenish orb, apparently for nourishment. He sneaks up to the alien (or the alien craft) in an attempt to grab some of those greenish orbs. I don't remember whether he succeeds, but he does get beaten up by the alien.  The next bit of detail I remember was the human astronaut constructing some sort of shelter to protect both him and the alien from... meteor showers? The human astronaut piles up some rocks to build a hut while the alien, apparently having learned a few English words, says "shiiiiit" and "no solid". The human astronaut asks, incredulous, "No solid?" and punches the hut he just build. "See? Solid!" he proclaims, while the hut collapses a few seconds later. The alien laughs.  Later on the human astronaut is either caught by or accidentally fell into some sort of mouth-in-the-sand creature. He is saved by the alien in the process (or was it the alien who fell into the mouth-creature and was saved by the human astronaut). They witness the mouth-creature spitting out a turtle-like shell (from another local wildlife) of some sort. The human astronaut observes, and I paraphrase, "This stuff must be so tough that even [the mouth-creature] cannot digest it!" He then proceeds to build a meteor shelter from collected shells.  The last bit of detail I remember is when the alien becomes pregnant and is dying. The human astronaut, having thoroughly befriended the alien at this point, asks (and I paraphrase), "What do you mean you're pregnant? Aren't you a male?" to which the alien responds (and again I paraphrase), "For us it comes naturally, unlike for you humans whose pregnancy only comes after a brief period of pleasure". The alien then asks the human astronaut to bring the child to the alien's home planet and recite the names of the child's ancestors in front of... alien rulers, I guess. The last scene of the movie is of the human astronaut, having arrived at the alien's home planet, standing side-by-side (or perhaps hand-in-hand) with the alien child while chanting in an alien language (what I presume to be the names of the child's ancestors).


Finding formula for the $n^{th}$ partial sum

As a homework assignment, I'm supposed to find the formula for the nth partial sum of the series $$\sum_{n=1}^\infty \left(\frac{5}{4}\right)^{n-1}$$ In my efforts to solve this problem, I've computed the first four terms of the sequence of partial sums to try and find a pattern: Partial Sum $\quad\quad\quad$ Value $S_1$ = 1 $\quad\quad\quad\quad\quad\,\,\,\,\,$ 1 $S_2 = 1+\frac{5}{4}$ $\quad\quad\quad\,\,\,\, \frac{9}{4}$ $S_3 = \frac{9}{4}+\frac{25}{16}$ $\quad\quad\,\,\,\, \,\, \frac{61}{16}$ $S_4 = \frac{61}{16}+\frac{125}{64}$ $\quad\quad\ \frac{369}{64}$ I already know that this is a geometric series and that it diverges. However, I can't seem to figure out the formula $S_n$ for the $n^{th}$ partial sum that depends only on $n$, and not on the previous term (i.e. not the recursive formula). The denominator seems to be $4^{n-1}$ , but I can't find the pattern for the numerator. Any help is appreciated!


I am playing a cavalier with a lance.The lance description states "A lance deals double damage when used from the back of a charging mount. While mounted, you can wield a lance with one hand."  My GM says that to him the wording means that you only double the lances damage. Example: a 2d6 lance does 4d6. But my Strength bonus and power attack bonus would not be doubled.   So in total the attack would be 2d6(base)+2d6(doubling)+ 8(strength and power attack)for a total 4d6+8 damage roll.  But if I'm reading the rules about multiplying damage correct it states that.  "Sometimes you multiply damage by some factor, such as on a critical hit. Roll the damage (with all modifiers) multiple times and total the results."  This seems to mean that 2d6(base)+2d6(doubling)+8(str and power attack)(doubled) for a total of 4d6+16. Much like that of a x2 critical.  If someone could clarify which reasoning is correct, and why then I would be grateful.


Calculus of residue of function around poles of fractional order (complex analysis)

The complex function $f(z)=\frac{1}{\sqrt{z^2+r_0z}}$ with $r_0>0$ has two poles (at $z=0$ and $z=-r_0$). But they are not simple poles. They are poles of fractional order. Am I right? How I can calculate residue of the function at the poles? Please help me.   Thanks  Vahid


Sql developer how to copy to another tablespace

When copying database using SQL Developer it complaints that the source tablespace does not exist on destination database.  How can I copy schema and data from Database A tablespace t1 into Database B tablespace t2?  Note: I do not wish to use impdp.


How can I view the Android internal partition table?

I've rooted my device, put it in recovery mode, and have linked it to PC by .  How can I view the list of storage devices and partitions?  Note: fdisk doesn't work.


Lately I made some comments in a blog  which is like  "I think I should start to write stories after I completely ...... “ and someone pointed out that it should have been written like " I think I should start writing stories after I completely ... "  it actually makes sense, But I just wonder is "start to write"  grammatically wrong in the above context?


How to return only the second group from a regex

I have the following string ISA\*01*ABCD BA1\*Y\*1\*\*FR\*DTST103L000P72323232342\*\*NO\*NY\*\*DEVS\*\*ALB VESSEL EXAM1  all I want is to extract DTST103L000P72323232342 I am using the following regex. My question is how do I get second group (\w+)  only. (BA1\\\*\w\\\*\w{0,2}\\\*\w{0,2}\\\*\w{0,3}\\\*)(\w+) when I tried to backreference using the following (?<=BA1\\\*\w\\\*\w{0,2}\\\*\w{0,2}\*\w{0,3}\\\*)(\w+) I am getting per  the following error {0,2} A quantifier inside a lookbehind makes it non-fixed width  {0,2} A quantifier inside a lookbehind makes it non-fixed width  {0,3} A quantifier inside a lookbehind makes it non-fixed width  Thanks in advance.


Bijection between derangements and good permutations

A good permutation is a permutation of the numbers $1$ to $n$, such that $i$ is not followed by $i+1$ at any position in the permutation, for any $i \in \left\{1,2,\ldots,n-1\right\}$. Call the number of such permutations $S(n)$. Also, $D(n)$ is the number of  of $\left\{1,2,\ldots,n\right\}$. I am required to show that $S(n) = D(n) + D(n-1)$.  Note that an algebraic solution is possible, but I need a combinatorial argument i.e. by showing bijections between the two sets.


When I try to update or install new software it is not working. In addition, there is some white dashed red circle on the top right. I have asked similar question but none of the answers are working.  demisew@DemisewT:~$ sudo apt-get update [sudo] password for demisew:  N: Ignoring file 'google-chrome.list-30Aug2016' in directory '/etc/apt/sources.list.d/' as it has an invalid filename extension E: Malformed line 2 in source list /etc/apt/sources.list.d/andykimpe-idm-xenial.list (type) E: The list of sources could not be read. demisew@DemisewT:~$


How to switch between users on one terminal?

I'd like to log in as a different user without logging out of the current one (on the same terminal). How do I do that?


how to power save and lookup power usage in terminal

I have already installed  powertop , pm-utils , laptop-mode-tool , jupitor  , also power save with jupitor , cpu-frequency skilling powersave , pm-powersave true but power usage are 1 hour and 20 minutes on 50 percentage of battery , at least 130 minutes in window seven .   Ubuntu 12.04.3 kernel 3.8  ,lenovo z400 ,ivy i5-3230 M ,nvidia 740m with Intel 4000.


Prove there does not exist a holomorphic $g(z)$ defined on a neighborhood $U$ of $z=1$ equal to $f(z)=\sum_{n\ge0}z^{2^n}$

Let $D = \{z\in\mathbb C \vert\vert {z}\vert \lt 1\}$ be the open unit disc in the complex plane, and let $f(z)$ be the following power series of the complex variable $z$: $$f(z)=z+z^2+z^4+\cdots+z^{2^n}+\cdots.$$ By considering the limit $\lim_{x\to 1^{-}} f(x) $ as $0\lt x \lt 1 $ approaches $1$ from the left. How to show that there does not ecist a holomorphic function $g(z)$  defined on a neighborhood $U$ of $z=1$ such that $f(z)=g(z)$ for all $z\in U\cap D$ And how to deal with the limit $\lim_{x\to 1^{-}} f(x) $ as $0\lt x \lt 1 $


I was told the following basic facts:   Objects made of the same metal don’t fuse in the atmosphere because they form an oxide layer. They do fuse in space. Gold doesn’t oxidize.   Yet, gold nuggets held together also don’t fuse (I can pull them apart without resistance). How does each gold atom “know” which object it belongs to?


Value of recommendation letters from professors in a different field

I will be a second year math under-grad in September, and currently doing an internship at applied math research institute. However, my interest after my bachelors is to do PhD in pure math at a top math school. My question is:  How important would the recommendation letters from my current supervisors be while I apply to grad school? (Note: My supervisors are very active in their field of research, but are not quite famous.)


Select full file name when renaming on Windows

Does anyone know if it's possible to change a setting so that the full file name is selected when you rename a file in newer versions of Windows?  (i.e. to match the behavior in Windows XP).  Currently it doesn't select the extension, so I have to do it manually.


rename text before numerical value using a batch file

I have a list of files that need to be renamed, the original values are on the left the new values are on the right as follows:  B000R825I0_1.jpg    test_1.jpg B000R825I0_2.jpg    test_2.jpg   I am new to batch files but I have attempted the following:  ren B000R825I0*.jpg test*.jpg   The renamed files are now incorrectly showing as the values below:  testR825I0_1.jpg testR825I0_2.jpg   I'm not sure why this is happening, please can someone assist me?


Add a clear button when a saved draft is loaded

I can't believe this has not been asked, but I can't find it, so here it goes.  The save draft feature is cool, but I had a question that I figured out half way through.  It would be nice to have a clear button to clear out all the input.  It is not that it is very hard to go and manually clear out the title, question and tags, but the feature of the drafts seems incomplete without it.  If there is a clear button that I could not see please point it out to me.


I am a beginner in java and I want to use a centinel loop to repeat code as many times as the condition is not met. However I can't get it to work. This is my code so far:  import java.io.*;  public class Test {     public static void main(String args[]) throws IOException     {         InputStreamReader isr = new InputStreamReader(System.in);         BufferedReader br = new BufferedReader(isr);          String password = "Pass";         System.out.print("Enter the password: ");         String input = br.readLine();          while(input != password)         {             System.out.println("Wrong password.\n");             System.out.print("Enter the password: ");             input = br.readLine();         }     } }   However, every time I put the password it simply doesn't work. Could anybody help me please?


Nullpointer with JDBC DataSource getConnection()

I am receiving a nullpointer exception because of the following code returning null.  conn = ds.getConnection();  I've spent the whole evening trying to debug it, without any luck. And I'm aware of that there is a lot of posts about nullpointer exceptions with dataSource.getConnection(), but nothing has helped.   The website worked perfectly fine running on my Mac, but now I want to host it on my Raspberry Pi through Tomcat. I have installed Tomcat, and MySQL and set it all up. The website works, except for when it needs to use something from the database, when the nullpointer occurs.   I have confirmed that ds is not null from: ds = (DataSource) context.lookup("java:comp/env/jdbc/psite"); I've tried different varians of getConnection, such as DriverManager.getConnection(name,username,psw); On my Raspberry Pi in my Tomcat/lib I have my mysql-connector-...jar   My xml files looks like this:  Tomcat/conf/context.xml  <WatchedResource>WEB-INF/web.xml</WatchedResource> <Resource     name="jdbc/psite"     auth="Container"     type="javax.sql.DataSource"     username="sonie"     password="******"     driverClassName="com.mysql.jdbc.Driver"     url="jdbc:mysql://localhost:3306/psite     maxActive="8"     maxIdle="4" />   Tomcat/conf/server.xml  <Resource name="jdbc/psite"       global="jdbc/psite"       auth="Container"       type="javax.sql.DataSource"       driverClassName="com.mysql.jdbc.Driver"       url="jdbc:mysql://localhost:3306/psite"       username="sonie"       password="******"        maxActive="100"       maxIdle="20"       minIdle="5"       maxWait="10000"/>   MyProject/WEB-INF/web.xml  <resource-ref>     <res-ref-name>      jdbc/psite     </res-ref-name>     <res-type>      javax.sql.DataSource     </res-type>     <res-auth>      Container     </res-auth>   </resource-ref>   Any ideas what might be wrong? I'm pretty sure I've nailed it down to being some configuration problems on my Raspberry Pi, as it worked fine on my Mac previously.  EDIT:  Even though yes it is a Nullpointer, I haven't managed to debug it like a normal Nullpointer as it works fine on my Mac in eclipse, but not when it's deployed on the Raspberry Pi. So I can't get the printstack.  It's not duplicated because it's not possible to debug this like a normal NullPointer.


Sequence of rationals with an irrational limit have denominators going to infinity

Let $\alpha$ be an irrational real number and let $a_j$ be a sequence of rational numbers converging to $\alpha$. Suppose that each $a_j$ is a fraction expressed in lowest terms: $a_j = \alpha_j / \beta_j$. Prove that the $\beta_j$ tend to $\infty$  Attempt: AFSOC that $\beta_j$ does not tend to infinity, then it is bounded by some $M$. We can also find an interval $\alpha \in (k, k+1)$. Let $\epsilon > 0$, $\exists N_0$ such that for all $N > N_0$ we have $|a_N - \alpha|  < \epsilon$. So $|\frac{p_N}{q_N} - \alpha| < \epsilon$. We try to use the fact that $q$ is bounded but fail to derive a contradiction. I do not know how to use the fact that $\alpha$ is between two integers, although it might not be relevant at all.  Ideas?


If $\Big|z^3+\dfrac{1}{z^3}\Big| \leq 2$ then prove that $\Big|z+\dfrac{1}{z}\Big| \le 2$ for a complex number $z$.   My attempt:We have:  $|z^3+\frac{1}{z^3}|=|(z+\frac{1}{z})(z^2+\frac{1}{z^2}-1)|=|(z+\frac{1}{z})||(z^2+\frac{1}{z^2}-1)|$  So for proving that we need to prove $|(z^2+\frac{1}{z^2}-1)|>1$ Which is really easy when $z$ is a real number but not when $z$ is complex.


I live far away on the country side and the last 2 days i see a WiFi with a hidden SSID and i can't figure out were it comes from.  I don't have any neighbor living close enough either.  Any suggestions on how to find the physical unit?


There is a cpu soft lockup when I am entering the installation gui when I am installing ubuntu 16.04, how to report bug for this?


I am playing as a 2ft 6in halfling bard college of swords. I want to have a goliath barbarian in our party throw me at an enemy with my dual scimitars drawn. I believe this can be done. I asked my dm, who wasn't sure but was willing to let me do some research and math to find out whether or not it will work. So my question is: can a goliath barbarian throw a 45lbs halfling into the air to attack an enemy?


I am currently trying to reconcile “Name” fields from two separate data sources.  I have a number of names that are not an exact match but are close enough to be considered matched (examples below).   Do you have any ideas of how I can improve the number of automated matches?    I am already eliminating middle initials from the match criteria.    Current Match Formula:  =IFERROR(IF(LEFT(SYSTEM A,IF(ISERROR(SEARCH(" ",SYSTEM A)),LEN(SYSTEM A),SEARCH(" ",SYSTEM A)-1))=LEFT(SYSTEM B,IF(ISERROR(SEARCH(" ",SYSTEM B)),LEN(SYSTEM B),SEARCH(" ",SYSTEM B)-1)),"",IF(LEFT(SYSTEM A,FIND(",",SYSTEM A))=LEFT(SYSTEM B,FIND(",",SYSTEM B)),"Last Name Match","RESEARCH")),"RESEARCH")


When replacing a PS, how do I know I'm safe if device doesn't list current?

I recently acquired a Lantronix UDS1100 telnet-> serial converter. It came without a wall wart / power supply.  I have an extra power supply from an old modem that I think might work, but I want to be certain.  The Lantronix's stated specs are 9-30VDC, 9-24VAC, 1.5 watt max. It doesn't mention current.  My potential replacement lists output of +12V, 2.2A.  How does one determine if this is okay or not?


I have an old Facebook account that I created, uploaded a couple of photos and simply ignored (i.e. no friends added). Now, I can't remember the email address associated with the account and I don't remember the password either. How can I find out which email address I had associated with that account?  P.S. I have created a new Facebook account and my picture can be used to identify me (if I can get someone at Facebook to take a look). Other than that, I'm willing to have that old account deleted altogether if recovery isn't possible.  Is there a way to resolve this issue?


With the reference video below. How can i add shortcut key to screen & multiply. Any suggestion or help. Thanks


I have the following sentence: "The swimmer next to Cavic arrives just before he." My question is why can't we write "The swimmer next to Cavic arrives just before him"? Isn't "just before..." an prepositional phrase that modifies "arrives"? Thus, wouldn't what follows be the object of the preposition, and thus one would have to use the objective case "him"? I know that "he" is correct, but why is it correct, and why can we not use "him"?


Pressing enter on "find a stackexchange site" should go to first listed site

At the moment in the new StackExchange top-bar, when you type a search term into stackexchange site search and press Enter, the page refreshes or something similar. I think it would be better if you actually went to the first listed site in the search.   For example, if I typed "statistic", this brings up cross validated, and if I press Enter I would like to go to cross validated.    Similarly, and perhaps this should be another suggestion, up and down cursor keys should move the selection to the list of sites, enabling you to for example, press down key twice and then enter to go to the second listed site.  It might also be better to have some specific visual indication that you have you the selection corresponds to the first hit (i.e., like the Facebook search box).  As a side point I realised after a bit that you can tab and enter, which arguably works fine, but it was not the keyboard interaction that I was expecting. So I still think supporting both modes of keyboard interaction might be good.


Are the Q affected by widespread changes in the timeline?

I suspect the answer is "No", but felt I should ask anyway. Given that the everything we know about the Star Trek "universe" has changed with the Abrams reboot, I was wondering how this would affect the rest of the galaxy, especially the nearly omnipotent species like the Q or Organians. To keep the question specific, though, let's limit it to the Q Continuum.  Have we seen anything on-screen or in EU materials that would indicate the Q are subject (or immune, even) to widespread changes in the timeline?  I know that we've seen Q himself interact with alternate timelines on a couple of occasions, but those were localized events involving the Enterprise-D or Voyager crews. When it comes to large-scale alterations like the Mirror Universe, I don't think we've seen the Q involved...


Constructability of algebraic elements over $\mathbb{Q}$

I'm currently reading upon the classical straightedge and compass constructions and I came across the following theorem: lf a real number $c$ is constructible, then $c$ is algebraic of degree a power of $2$ over the field $\mathbb{Q}$. My question is, is the converse to the above theorem true? That is, if $c$ is algebraic of degree a power of $2$ over $\mathbb{Q}$, is $c$ constructible?