I'm currently a junior undergrad in a mathematics program, and emailed a prof at a different school if I would be able to apply as a candidate for a summer project he advertised on the school's website. I'm interested in attending this school for graduate work, and mentioned that to the prof.   In his response, he was very excited about my interest in his project (work in ocean sciences) and in the graduate program, and asked if I could send a transcript. I'm very happy about the response, because the prof was very enthusiastic, but due to (what I now know was and is) depression, my grades took a dip, which can be seen in my transcript. For reference, I've done poorly in a mathematics class and computer science class in my sophomore year (2 Cs, and a D in a genetics course, but that's unrelated to this project). Since then, I've gotten Bs in Calc III and Adv Calc (the only other courses relevant so far).   I know this is not a representation of of my ability, as I've done research projects utilizing the material from classes I've done poorly in, and have done well in the projects. At the same time, I don't want to make excuses for myself, and I don't know if it's fair to disclose that information to the prof to make him choose between a candidate like me, and someone else who is "normal".   How should I respond to this? Should I tell him I can't do his project because my grades aren't up to par, or should I try and explain myself?

I'm currently a 3rd year undergrad majoring in math/physics. I was admitted to my university through an honors program due to outstanding high school achievement (my university is a large public one, moderately well known in the US) with several scholarships.   But after my first semester, I fell back into a recurring bout of severe depression, and did not get help. My grades ended up tanking that next semester (C average). I thought I had overcome it by my second year, but soon developed psychosis and could no longer focus on studying; I neglected my health and hygiene, and I couldn't even get up some mornings to get to class. None of my professors are aware of my situation.   I finally sought help last spring and I've been doing better (keeping up with work, getting better grades, etc), but I feel like nothing will ever make up for those two years of mediocre grades. My overall GPA right now is sitting around a 2.5. I feel like while this is possible to explain away, I'm reluctant to divulge information about my severe mental illness to admissions because there is still a lot of stigma associated with it. I've seen mixed answers as to whether or not it's a good idea to do.  My question is, is there still a way for me to pursue applied mathematics in graduate school? Is graduate school aiming too high? And if so, do I talk about my limitations as far as my health is concerned?   I love math, and love learning. I've done a few practice Math Subject GRE exams, and they were fairly easy (as long as I study for the parts I'm not 100% on, of course). I've also done a few small math projects with grad students and I've worked in a lab since I was a freshman; I feel like I'm passionate enough about the subject to succeed but I'm afraid admission committees will not look past my GPA to see that and wouldn't risk having someone like me in their program.


Theorem: If $G$ is a finite group, then $c_a=o(G)/o(N(a))$; in other words, the number of elements conjugate to $a$ in $G$ is the index of the normalizer of $a$ in $G$.  Corollary: $o(G)=\sum \limits \dfrac{o(G)}{o(N(a))}$ where this sum runs over one element $a$ in each conjugate class.  Problem: Using Theorem as a tool, prove that if $o(G)=p^n$, $p$ a prime number, then $G$ has a subgroup of order $p^{\alpha}$ for all $0\leq \alpha \leq n$.  Can anyone help how to solve that problem? I was trying to use that center of $p$-group is nontrivial and induction of $n$ and tried to mix that with the class equation, but was not able to complete it.   Would be very thankful if somebody will demonstrate the solution of that problem.

Prove that if $|G| = p^n$ then $G$ has a subgroup of order $p^m$ for all $0\le m <n.$   Since $G$ is of prime-power order I know $|Z(G)| \ne e$ so there is an $a\in Z(G)$ with order $p$ such that $p \mid |Z(G)|$. Now, the subgroup generated by is normal since it's a subgroup of the center. How can I get this normal subgroup to be less than $n$?


Assuming you are level 1 and have access to any item that you can afford at character creation rolling the maximum amount of starting gold, and all spells that are available to you due to character creation, how high can your  AC become (permanently or temporary)?  Constraints:   Only , the Unearth Arcana is not legal for this character creation. All  are legal, all other races are illegal for character creation. Items are those that you can purchase. All spells, skills, feats and abilities available to a player character are eligible. A sole player character has to achieve this AC on their own, without any help from allies (pet companions, PCs, NPCs, etc.) Starting attributes can be rolled (that includes all 18s down the line) or achieved by point-buy. I have no preference for either.     Heavily related:   This linked question is about permanent AC. My current question, however, also includes options for increasing the AC with temporary means.

Assuming you are level 1 and have access to any item that you can afford at character creation rolling the maximum amount of starting gold, how high can your permanent  AC become (permanently, not for any lesser set duration)?  Constraints:   Only , Unearthed Arcana is not legal for this character creation. All  are legal, all other races are illegal for character creation. Items are those that you can purchase. All skills, feats and abilities available to a player character are eligible. A sole player character has to achieve this AC on their own, without any help from allies (pet companions, PCs, NPCs etc.) Starting attributes can be rolled (that includes all 18s down the line) or achieved by point-buy. I have no preference for either.     Heavily related:   This linked question also includes temporary AC. My current question, however, is strictly about permanent AC.


I have few questions regarding the behaviour of users on Stack Exchange which I want to know about from the users of Stack Exchange. Is there any proper platform to ask such questions where I can get sufficient response? Can meta sites serve this purpose?

(probably soon to be deleted) made me wonder what would be the right way to handle surveys like that:     I'm doing a worker interview for High School and I want to be a computer programmer.      What is your job title?   What is your work history?   ...   What are the duties of a beginner?   Where is work available?     To me it feels like spam but checking the  makes me doubt that it really qualifies. I find it somewhat difficult to state that questions like in above example advertise something:     A post should be marked as spam ONLY when it contains an ...   If there was a link to a survey off-site (like in most similar questions I've seen so far) I would easily flag it as spam. But this one didn't have link, it expected answers right there, on our site, making it hard to say what exactly is advertised. Or it would be correct to say something like asker advertises their survey?  Another option I considered was flagging for moderator attention. But I can't come up with compelling flag message that would justify mod involvement assuming that question can be closed with 3K users votes.  That leaves the only option to handle such questions - vote to close, correct? (At sites where I'm active such questions are blatant off-topic; maybe this is so network wide but I am not sure).


We have an issue, which I'm sure is commonplace, whereby after deploying our web application, some users experience problems resulting from not having the latest versions of CSS or Javascript files. As developers, we simply hit CTRL + F5 and the problems go away as our browsers download the latest version of the page and associated scripts and stylesheets. However, it's not really practical to expect our users to do this after every deployment.  I'm aware of the method of forcing browsers to download the latest versions of files by appending a query string to the references to those files, which sounds like it would work perfectly well, but I'm trying to work out how to implement this technique with the smallest overhead for our devs.  Ideally, I think what we need is some sort of automated process which can detect when changes to a .js or .css file are checked in to source control (we're using VSTS) and update any links to that file in the application. We're using  for dependency injection, so perhaps that would make things easier, but I still don't know how to implement this.  At present, the only solution I can think of is to instruct our devs, every time they modify a .js or .css file, to search the code for any references to that file and manually add a version number query string in each place. And then hope that they remember to do this.  Is there a better way?

I have noticed that some browsers (in particular, Firefox and ) are very zealous in using cached copies of .css and .js files, even between browser sessions. This leads to a problem when you update one of these files, but the user's browser keeps on using the cached copy. What is the most elegant way of forcing the user's browser to reload the file when it has changed? Ideally, the solution would not force the browser to reload the file on every visit to the page.  I have found  and  suggestion to be useful. It turns out there is a term for this: auto-versioning. I have posted a new answer below which is a combination of my original solution and John's suggestion. Another idea that was suggested by SCdF would be to append a bogus query string to the file. (Some Python code, to automatically use the timestamp as a bogus query string, was .) However, there is some discussion as to whether or not the browser would cache a file with a query string. (Remember, we want the browser to cache the file and use it on future visits. We only want it to fetch the file again when it has changed.)


What is the quickest way (in terms of necessary klicks or keystrokes from the empty desktop) of retrieving your own IP address in windows 10, specifically?   In Windows 7 and in case of wifi, you could get there rather quickly with wifi symbol task bar -> right click network -> status, but this possibility seems gone in Windows 10.   I seem forced to either use ipconfig (which is tedious if you have many interfaces e.g. from virtual machines) or open the network and sharing center which adds one window to the equation.  Is there a better, simpler way?

This may seem trivial but I'm looking for the quickest method to determine my PC's IP address within my network.   This changes regularly as I connect from one network to the next via DHCP The connection changes from wired to wireless Windows 7 PC (although ideally the perfect solution would work on all versions of Windows) Various adapters installed (e.g. VMWare, Tunnels, etc.)   I need to know this as I often run a local web server where I need to access files over the local network... and since it changes regularly I want the fastest method to retrieve the address.  My current flow is:   WindowsKey + R to open the Run dialog "cmd" + Enter to open a command prompt "ipconfig" + Enter to get the diagnostics info Scroll to or resize the window so that I can see the line in my Ethernet adapter Local Area Connection for my ipv4 Address Remember it to type elsewhere... or  Right click > select Mark > highlight the address > press Enter to copy it to the clipboard   This wasn't so bad with Windows XP when I had no additional adapters, tunnels, wireless connections etc. but the amount of data returned with this command makes it hard to pluck out.  Surely there must be a better, faster way! (bonus points if adding it to the clipboard is easily accomplished)


I have the following script. It prints all of first characters to console from passwd, but my expectation was to get only one character and for the program to then terminate.  #!/bin/sh   cat /etc/passwd | while read -r line do     echo ${line} |         grep -o . |         while read char         do             echo ${char}                exit 1                done done   Actual output:  r b d a (etc)   Expected output:  r

I have a script, that does not exit when I want it to.  An example script with the same error is:  #!/bin/bash  function bla() {     return 1 }  bla || ( echo '1' ; exit 1 )  echo '2'   I would assume to see the output:  :~$ ./test.sh 1 :~$   But I actually see:  :~$ ./test.sh 1 2 :~$   Does the () command chaining somehow create a scope? What is exit exiting out of, if not the script?


For instance, I know one should not turn on red lights, which is different from US/Mass. rules.   What are other things which can confuse a driver from US while driving in Italy? More generally, are there things a North American driver should know about driving in Europe?

There are the obvious ones. The US has the keep-your-lane system, where as in Europe you are expected to keep to the right (left for UK) as long as possible.  On my latest travel to the US, I was confronted with the possibility to go through a red light if you turn right, unless it is explicitly not allowed.  What should a european driver know when driving in the US? What are the do's and don'ts compared to driving in Europe.


Ok...this question hasn't been asked before, its very similar to some, but here's the difference:  I am making a soccer/football simulator game, that only has national teams (with no official logos) just the country names and flags. Now, my doubt is the following...can I use real player names (that play or played on that national team?)  From what I understand if I use a player name linked to a club like Barcelona FC (not a national team) I need the right from the club and the association that club is linked to, right? But If I am only linking the name just to a country...I might just need the permission of the actual player (that I am using his name) and not any other associations, correct?  Thanks a lot in advance! Cheers, Diego.

I'm writing a sports management simulation game. Like most sport management games, it makes heavy use of statistics. I would like to use real players, teams and league names.  i) Am I running the risk of getting into legal battles if I should use the real names? ii) Also what about team colours and emblems etc?    Update Much thanks for all the input!


if $a_0$, $a_1$, ..,$a_n$ are real numbers such that $a_0+\frac{a_1}{2}+\frac{a_2}{3}+\frac{a_n}{n+1}=0$ prove the polynomial $a_0+a_1x+...+a_nx^n=0$ has a solution between 0,1. This is a problem after Rolle theorem topic in real analysis.  let $f(x)=a_0+a_1x+...+a_nx^n$ I know polynomial above, is bounded and real valued and continuous on $[0,1]$. also the derivative of $f(x)$ exists for all point in $(0,1)$. so by Rolle theorem, if $f(0)=f(1)=0$ I can conclude there is a point $c\in(0,1)$ such that $f^{'}(c)=0$  My question is how can I then claim anything about the roots of f? ( I remember intermediate value theorem from calculus, but apparently this must not be the case here according to my text book )

Knowing that $$ \frac{a_0}{1} + \frac{a_1}{2} + \frac{a_2}{3} +\cdots + \frac{a_n}{n+1} =0$$ Prove that  $$ a_0 + a_1x + a_2x^2 + \cdots + a_nx^n = 0$$ has at least one real solution.  I suspect that it's proven with the intermediate value theorem. But can't find two numbers that satisfy it.


Is it grammatically correct to put both of related nouns in plural form? Like:   cards databases / databases of cards words variations / variations of words etc

How can I explain to a non-native speaker that while this is correct:     The felling of trees.    And this is also correct:     tree felling   This is not:     *trees felling   To a non-native it seems very reasonable that since many trees are being felled and given that the felling of trees uses the plural, the inverse form would also use the plural and become trees felling.  To a native speaker such as myself, the latter is very obviously wrong, but I couldn't figure out how to formalize this into a rule that a non-native can understand.


I would like to create filled chart similar to this image with marked gray vertical dotted lines.

I am looking shade the bounded area under the graph of f(x)=x^2 from 0 to 1. For my other plots I was fine using the shading with coordinates because they were all polygons. I've come across a bunch of threads with similar situations but didn't see anything quite similar enough for me to copy and manipulate the code. I The image below is exactly how I want it with the clear exception of the shading outside the box. Thanks  \usepackage{pgfplots} \pgfplotsset{width=7cm,compat=1.8}    \begin{figure}[!h]  \centering  \begin{tikzpicture}      \begin{axis}[enlargelimits=0.1]     \addplot[domain=-.15:1.05,blue] {x^2};         \addplot [thick,color=blue,mark=o,fill=blue,                      fill opacity=0.05]coordinates {             (1, 1)              (1, 0)             (0, 0)  };             \node [rotate=48] at (axis cs:  .7,  .59) {$y=x^2$};             \node [rotate=90] at (axis cs:  1.05,  .25) {$x=1$};     \end{axis} \end{tikzpicture}   \caption{$R=\left\{(x,y) \ |  \ 0 \leq y \leq x^2, x\leq 1 \right\}$}  \end{figure} \\     Edit:  The first and second answers below are perfect. What if I wanted the shaded area under the curve to stop at a certain y-value, instead of extending all the way down to the x-axis? Say, it goes down to y=.2?


After any update or upgrade operation I get the following:  Need to get 0 B/389 MB of archives. After this operation, 416 MB of additional disk space will be used. Do you want to continue? [Y/n] y Extracting templates from packages: 100% Preconfiguring packages ... Setting up systemd (237-3ubuntu7) ... Synchronizing state of ondemand.service with SysV service script with /lib/systemd/systemd-sysv-install. Executing: /lib/systemd/systemd-sysv-install enable ondemand [/usr/lib/tmpfiles.d/tmp.conf:15] Failed to replace specifiers: /tmp/systemd-private-%b-* [/usr/lib/tmpfiles.d/tmp.conf:16] Failed to replace specifiers: /tmp/systemd-private-%b-*/tmp [/usr/lib/tmpfiles.d/tmp.conf:17] Failed to replace specifiers: /var/tmp/systemd-private-%b-* [/usr/lib/tmpfiles.d/tmp.conf:18] Failed to replace specifiers: /var/tmp/systemd-private-%b-*/tmp dpkg: error processing package systemd (--configure):  installed systemd package post-installation script subprocess returned error exit status 1 Errors were encountered while processing:  systemd E: Sub-process /usr/bin/dpkg returned an error code (1)   This happens after trying to update to ubuntu 18 from 16 on WSL

I'm new to Unix but interested learn, so started trying to use bash/Ubuntu on Windows. Unfortunately, bash crashed and now bash/Ubuntu seems to be broken as most folders are now missing from the Ubuntu root folder, i.e.:  root@Desktop:~# ls root@Desktop:~# cd /root root@Desktop:~# ls root@Desktop:~# ls -a .  ..  .bashrc  .profile   I don't have a %localappdata%\lxss folder (I'm pretty certain this is where the Linux root was originally). I appear to have a %localappdata%\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc folder, which is apparently the new location for the Linux root, but it is not complete (i.e. doesn't contain a ...\LocalState\rootfs folder).  After searching for solutions on here and elsewhere, I've tried:   Completely uninstalling Ubuntu\bash from Windows with lxrun.exe /uninstall  full. As above, in conjunction with disabling and re-enabling the Windows Subsystem for Linux (beta) feature too. Running: apt-get remove upstart, apt-get remove udev, apt-get autoremove in bash.   Unfortunately none of the above have solved the problem. Can anybody suggest a way to perform a complete 'factory reset'?


Consider this shell redirect: telnet towel.blinkenlights.nl >> starWarz when it ends, the session will break, detach from host or something like that. I want to know how long the connection lasts. How might I determine this?

I'm trying to measure the execution time of a process that I call via the command line (i.e., I want to find out how long it takes to for the process to finish). Is there any command that I can add to the command calling the process that will achieve this?


In a problem based on selection of a team from the set of players ={R,S,T,U,V,W,X,Y,Z}, one the constraints is      Unless T and U are selected then V is selected.   I would like to know the propositional logic statement for this.  I understand "cond_A unless cond_B" logic but what does      Unless A then B mean?   Furthermore, in the specific scenario can T,U,V all be seleceted in the team?

The statement is from the book  by Rainer Kress:     A compact operator cannot have a bounded inverse unless its range has finite dimension.   Here are my questions:   How should I understand the word "unless" here? If one interprets the statement in the form of $A\rightarrow B$, what should be $A$ and $B$ respectively? Is there an operator such that its range has finite dimension, but it does not have a bounded inverse? There can be two cases for "not have a bounded inverse":  It does not have inverse.  It has an inverse but the inverse is unbounded.       For the first question, I think  we can translate a statement of the form "$P$ unless $Q$" as "if not $Q$, then $P$", or: $\neg Q → P$, according to this  for formal logic. But I'm not sure if the "unless" above is the same as the one here, which is the very reason why I ask the second question.


Hello Lightning Experts, My requirement is to bold the titles so I used slds-page-header__title slds-truncate in my lightning:accordionSection tag but the sub-headers is also getting bold. What do I need to do to display the bold headers and the normal sub-headers ? please take a look on my code and the Lightning UI. TIA `<lightning:accordionSection class="slds-page-header__title slds-truncate" name="{!$Label.c.MEDICATIONS}" label="{!$Label.c.MEDICATIONS}">                     <c:Assessment_Medications caseId="{! v.caseId}"                                                aura:id="medicationCmpId"                                               draftMedicationList ="{! v.medicationList}"                                               isAssessmentCompleted ="{! v.isStatusCompleted}"/>                 </lightning:accordionSection> `

Is it possible to change the lightning-accordion-section label font size, I tried by adding   class="slds-text-heading_medium" It print like below      Expecting to increase the Font Size and bold the text.  <lightning-accordion class="example-accordion"                          onsectiontoggle={handleToggleSection}                          active-section-name="B">         <lightning-accordion-section name="A"  class="slds-text-heading_medium" label="Accordion Title A">             <lightning-button-menu slot="actions"                                   alternative-text="Show menu"                                   icon-size="x-small"                                   menu-alignment="right">                 <lightning-menu-item value="New" label="Menu Item One"></lightning-menu-item>                 <lightning-menu-item value="Edit" label="Menu Item Two"></lightning-menu-item>             </lightning-button-menu>
This is the content area for section A.

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The section height expands to fit your content.
         </lightning-accordion-section>          <lightning-accordion-section name="B" label="Accordion Title B">
This is the content area for section B.

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.

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The section height expands to fit your content.
         </lightning-accordion-section>          <lightning-accordion-section name="C" label="Accordion Title C">
This is the content area for section C.

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The section height expands to fit your content.
         </lightning-accordion-section>     </lightning-accordion>


I heard that the light has zero mass. But I searched in internet, some people say light has mass and some people said doesn't. I am not sure what is the right answer.  And also I heard that the reason we can't travel in light speed is because we have mass but light doesn't. Please tell me the right answer.

Does light have mass? If yes, will it exert force? If no, then how are light particles are travelling at light speed? If light doesn't have mass how is it attracted by gravitational force (black holes)? And what actually is light?


Today I have turned on my pc and I found out that all my files in all my 5 Internal Harddrives and usbkey attached have been encrypted.  The extension is [supportcrypt2019@cock.li].Adame  Is there a way to get all my files back?

What should I do if my Windows computer seems to be infected with a virus or malware?  What are the symptoms of an infection? What should I do after noticing an infection? What can I do to get rid of it? how to prevent from infection by malware?   This question comes up frequently, and the suggested solutions are usually the same. This community wiki is an attempt to serve as the definitive, most comprehensive answer possible. Feel free to add your contributions via edits.


Background:  we had an old pc that was connected to some old label printers but that pc does not boot up anymore.  That pc was 32bit windows xp and the software for label printer only works on 32bit xp. So I install xp on a old windows 7 pc that had a serial port for the printers, and I got the old label software and printer drivers installed.    But I want to get the templates off the old hard drive  for the label printer software.  So I tried to connect the old HD to replacement pc as a slave ( on the same connection as the CD drive).  The pc/ Bios recognises the HD and when windows xp boots up it see the drive but i get an error when I try to open the drive "f:\ is not accessible, the request could not be performed because of an i/o device error  This is the old pc HD i'm trying to add.   This is the HD in replacement PC    This is the error msg   Update : The 250 drive is working fine, it's the 40gb drive I'm trying to access, but the they r 2 different types of HD (different connections, the bad drive has the same connections as the CD drive so I had to put it as a slave to that, as the other drive 250, had a different connection). The 250 is a sata HD (had to change the settings in the bios to get xp to install on it) could it be a issue because they r 2 different types of HD? On the old broken pc does not even boot to bios, think its unlikely both the motherboard and the HD broke at the same time

What steps can I take to try to recover lost or inaccessible data from any storage device?  Answers:   This applies to any computer storage device, e.g. internal/external hard drives, USB sticks, flash memory. The most important thing is to STOP using it, any type of I/O can ruin your chances of a recovery.     We have separate questions covering common problems with USB flash drives in greater detail:


I'm curious on how inheritance works in case of dictionary mutations, I always thought that with each new instance the inherited classes get recreated.  class A(object):     test = {"B": 0}      def change_test(self, index):         self.test["B"] += index      def __init__(self, **kwargs):         self.change_test(self.index)         super(A, self).__init__(**kwargs)   class B(A):     index = 1     def print_test(self):         print self.test   class C(A):     index = 2     def print_test(self):         print self.test  b = B() b.print_test()  c = C() c.print_test()   Why does this return {'B': 1} {'B': 3} and not {'B': 1} {'B': 2}?

Is it possible to have static class variables or methods in Python? What syntax is required to do this?


I'm trying to install python 3.6.1 on my Ubuntu 14.04 VM. I use the following commands:  sudo add-apt-repository ppa:jonathonf/python-3.6 sudo apt-get update sudo apt-get install python3.6   It installs successfully, however I believe I still have 2.7 installed, because when I run "sudo pip" it gives the following error:  Traceback (most recent call last):   File "/usr/bin/pip", line 9, in <module>     load_entry_point('pip==1.5.4', 'console_scripts', 'pip')()   File "/usr/local/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 542, in load_entry_point     return get_distribution(dist).load_entry_point(group, name)   File "/usr/local/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 2569, in load_entry_point     return ep.load()   File "/usr/local/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 2229, in load     return self.resolve()   File "/usr/local/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 2235, in resolve     module = __import__(self.module_name, fromlist=['__name__'], level=0)   File "/usr/lib/python2.7/dist-packages/pip/__init__.py", line 61, in <module>     from pip.vcs import git, mercurial, subversion, bazaar  # noqa EOFError: EOF read where object expected   How do I resolve this?

I am trying to install the Pillow module for python 3.3, but for that  I need to install pip. Every time that I install pip it installs for python 2.7, any help?


I'm a first time user of Ubuntu. Where can I get the Sound, Video, and Ethernet drivers for Ubuntu 12.04.2?

I've just installed Ubuntu and I need either video, wireless, or some sort of other manufacturer (non-opensource) driver. How can I run the tool that will fetch all of these for me? I'd like graphical instructions.  Related:


I have a few files that have fields of properties and personal information that I want to remove, the format is .odt. Basically, I want to strip out everything. What utilities are available for the job on Linux?

I am using LibreOffice on Linux. One way I know of viewing and removing metadata from a LibreOffice file is going to File -> Properties -> General, unchecking  “apply user data” and click reset. Then go to “Description” and “Custom” Properties and remove information from there, if exists.   Does it truly remove all the metadata or something is left and what is it and what other methods can I use to remove it?   Also, if I unzip a LibreOffice file, is contents.xml the only place where metadata may be found?  If I forgot to remove any metadata, is it possible that the username is transmitted?


I have a shortbread recipe that calls for butter, but doesn't say salted or not, just butter. Also it doesn't call for any salt. Which type of butter would be best?

When recipes call for “butter” but doesn’t specify “salted” or “unsalted”, which should I use? Does it matter?


How to compress a file into zip format without having zip package installed? Pretty much what I need to do. I tried tar -czf loremipsum.zip but the format isn't a correct zip format when I try to uncompress it on windows. I'm limited and won't be able to install the package. Is there any work around?

How can I create and extract zip archives from the command line?


I try to find how to schedule a run of "chkdsk.exe" on a ntfs/windows partition from linux. I already know that "gparted" sucess to do that after resizing a windows partition. But I need to schedule that manually (because gparted fail to resize a windows partition, due to some filesystem errors, and it will not schedule a "chkdsk.exe" on the partition). Did someone know how to do that ? I remember that someone tell me about a flag to set on the windows partition, but I don't remember the name of the flag, and I don't know if it's right.

Is there any way to mark a NTFS-fileystem dirty using ntfstools/ntfs-3g or any other tool, so it gets chkdsk'd when windows boots? I know I can do that from windows or the recovery console but I'm curious if this is possible.


I have designed two parts I wish to print in HO scale.  A drawing of a brick wall in 1:1 scale and exported to .stl comes into Anycubic Photon screen so small it is almost invisable.  Have not been able to change the size no matter what I do. Any help out there?

I've set my Units (in scene properties) to Metric, and the Scene Scale to 0.01 hoping to get the Blender dimensions it mm's. While the (normal) scale is 1 for x,y,z, the standard cube has the dimensions 2x2x2 cm. When I export this to an STL and open it in a slicing program (Netfabb, Slic3r or Cura) they all give the dimensions: 2x2x2 mm. While exporting, the scale is 1.  What am I doing wrong? I hope you can help me.  Thanks!


What is the reason 1/4 coefficient in the tensor multiplication of the electromagnetic field strength? $$\mathscr{L} = -\, \frac{1}{4} \, F_{\mu \nu} \, F^{\mu \nu}. \tag{1}$$

I have seen numerous 'derivations' of the Maxwell Lagrangian,  $$\mathcal{L} ~=~ -\frac{1}{4}F_{\mu \nu}F^{\mu \nu},$$  but every one has sneakily inserted a factor of $-1/4$ without explaining why. The Euler-Lagrange equations are the same no matter what constant we put in front of the contraction of the field strength tensors, so why the factor of $-1/4$?


I am trying to login the user through networking by using OkHttp library to send request and getting response. After running these when I open app and enter email and password as input and press the login button, my app crashes.  LoginFragment:   public void onClick(View view) {             String a=ed1.getText().toString();             String b=ed2.getText().toString();             Log.e("sas", "onClick: "+a );                 NetworkRequestAndResponse asyncTask = new NetworkRequestAndResponse(getActivity());                 asyncTask.execute(a,b);         }     });     return view;   AsyncTask:      public class NetworkRequestAndResponse extends AsyncTask<String,String,String> {     Context context;      public NetworkRequestAndResponse(Context context){         this.context = context.getApplicationContext();     }      @Override     protected String doInBackground(String... params) {         OkHttpClient okHttpClient = new OkHttpClient();         RequestBody requestBody= new FormBody.Builder().add("email",params[0])                         .add("password",params[1]).build();         Request request = new Request.Builder().url("http://192.168.1.8:8011/api/check")                         .post(requestBody).build();         Log.e("asd", "doInBackground: "+request );         Response response=null;         try {             response = okHttpClient.newCall(request).execute();           return response.body().string();         } catch (RuntimeException|IOException e){             Log.e("455", "doInBackground: ",e );         }         finally {             response.close();         }         return null;      }      @Override     protected void onPostExecute(String obj){          if (obj.equals("true")){             Intent intent = new Intent(context, WelcomeActivity.class);             context.startActivity(intent);         }else{             Toast.makeText(context,"Invalid Email or Password",Toast.LENGTH_SHORT).show();         }     } }   MainActivity:      protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.activity_main);     android.support.v4.app.FragmentManager fragmentManager = getSupportFragmentManager();     LoginFragment obj = new LoginFragment();     fragmentManager.beginTransaction().add(R.id.content,obj).commit();     MessagesFragment messagesFragment = new MessagesFragment(); } }   Error:

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


I've just learned how to insert pictures using the \includegraphics{} command. In the compiled PDF document, the file name is visible immediately below the image.   Is there a way to suppress the file name? (see the red arrows below)

Possible Duplicate:          When I add a piece of code of figure insertion to the context I'm faced with a problem: a number of irrelevant words appear.    Code:  \begin{figure}     \centering         \includegraphics[width=0.9\textwidth]{C:/Thesis/Latex/thesis_1(1)/Pictures/study area.jpg}         \rule{35em}{0.3pt}     \caption{The Grand St. Bernard wireless sensor network deployment (a) the coordinates of nodes according to the Swiss coordinate system (b) the distribution of the nodes in the study site \citep{r33}}     \label{fig:study area} \end{figure}   Problem:


Do I need "the" before the name of my university in the header?  Header:     Politechnika Wroclawska - name of university in my language      (the Wroclaw University of Technology) - translated name of university in the brackets   This header is contained in the official document.

Is the always used before the name of a school, college, or university?


I like to work in inches in Blender. When I export a mesh STL I have to scale the object by 3.28 to get the correct size STL object. Why 3.28?


Prove the  identity  $$\binom{0}{0}\binom{2n}{n}+\binom{2}{1}\binom{2n-2}{n-1}+\binom{4}{2}\binom{2n-4}{n-2}+\cdots+\binom{2n}{n}\binom{0}{0}=4^n.$$  This is reminiscent of the identity $\sum_{i=0}^n\binom{n}{i}^2=\binom{2n}{n}$, which has a nice combinatorial interpretation of choosing $n$ from $2n$ objects. But the identity in question is not easily related to a combinatorial interpretation. Also, for an induction proof, it is not clear how to relate the identity with $n$ to $n+1$.

Possible Duplicate:          This was part of a homework assignment that I had, and I couldn't figure it out. Now it is bugging me. Can anyone help me? Although a proof would be nice, I wouldn't mind a push in the right direction.   $\displaystyle\sum_{i=0}^n {2i \choose i}{2(n-i)\choose n-i} = 4^n$


Assume there exist $2$ natural numbers that are coprime ($m$ and $n$ such that $(m,n)=1$) such that for each $g$, $h \in G$ we have $g^m h^m = h^m g^m$ and $g^n h^n = h^n g^n$. Then $G$ is abelian group. (That means $ab=ba$.) Hint: $(m,n)=1$ then there exist $c,d\in\mathbb{Z}$ s.t. $cm+dn=1$. thus $$gh = g^{cm+dn}  h^{cm+dn} = g^{cm}  g^{dn}  h^{cm}  h^{dn} = (g^m)^c  (g^n)^d  (h^m)^c  (h^n)^d = (g^n)^d  (g^m)^c  (h^m)^c  (h^n)^d$$ Use property in hypothesis to reach $gh=hg$.  Please help me to continue.

Let $(G,.)$ be a group and $m,n \in\mathbb Z$ such that $\gcd(m,n)=1$. Assume that $$ \forall a,b \in G, \,a^mb^m=b^ma^m,$$ $$\forall a,b \in G, \, a^nb^n=b^na^n.$$  Then how prove $G$ is an abelian group?  Some context: Some of these commutation relations often imply that $G$ is abelian, for example , or . This looks like another example of this phenomenon, but the same techniques do not apply.


Find all integer solutions of $y^2=1+x+x^2+x^3+x^4$. I tried moving $x^4$ to the other side and factoring the LHS to get $(y+x^2)(y-x^2)=(x+1)(x^2+1)$, but I don't know what to do with that, or if it's even the right thing to do. Please help me out!

What are the integer numbers $x$ such as $x^4+x^3+x^2+x+1$ is the square of an integer?  $0$ and $-1$ are obvious answers, but how many are there?


We haven't gotten a lot of Finnish groups that we liked here at Bananas but I'm pretty happy with this four tracker from Helsinki, apparently recorded in the same place where the Ramones played in the 70's.   I know my question has already been answered. liked is past simple because it is a single action. But I don't agree with it or have not well understood  the answer.  'Bananas' is a music magazine. Every time they receive a record they make a review(like it or not) so this is not a single action and maybe in the future there will be some Finnish band they will like. It may change !!!

Please have a look at this sentence:     We haven't gotten a lot of Finnish groups that we liked here at Bananas but I'm pretty happy with this four tracker from Helsinki, apparently recorded in the same place where the Ramones played in the 70's.     The first verb is in present perfect (up to now) and the second is in simple past tense. I don't understand the simple past for the second verb.  Why "like" is not in its present perfect form as the first verb is?


According to , her last name is Mixer. As seen in this photo taken from  [see bottom left corner] Of course, I am inclined to believe the artist was just making a joke. Are there any other references to her last name?

In an  about The Force Awakens, the author suggests that:      Rey is Luke’s daughter.   I’ve missed any indicators of any such relationship while watching the movie.       For instance, I took neither Luke’s lightsaber calling out to Rey, nor her hug of consolation with General Organa as such. Is there any evidence that Luke is Rey’s father?    Is it known who Rey’s parents are?


I edit a small club journal which prints articles submitted by the members. Currently I'm using MS Word but want to change to ConTeXt. My desire is to have one file per article, with a master 'issue' file containing \input commands, one for each article.  I've created a custom command to standardise the appearance of the article title and author:  \JournalArticle{The Title of the Article}{Author Name}   and now I'd like to extend this to create a table of contents automatically. Currently I do the ToC by hand, producing a table similar to:  \starttable[|l|l|r] \HL \NC \bf Title \NC \bf Author \NC \bf Page \NC \FR \HL \NC The Title of the Article \NC John Doe      \NC 1 \NC\NR \NC Second Article           \NC Jack Daniels  \NC 2 \NC\NR \NC Third Article            \NC John Doe      \NC 2 \NC\LR \HL \stoptable   My problem is that I can't work out how to do this automatically.  I've looked at \defineregister et al but can't see how to store two values (title and name).  Alternatively I could use a buffer (since I don't need to sort the titles, just list them in the order they appear) but I can't see how to append to a buffer each time a new \JournalArticle is encountered.  Can someone point me to where this problem has been solved before, or suggest a solution please?

I'm getting stumped about how to generate the ToC for this book. I'm about to give up and just do it by hand. The author wants to include a lot of structural information that isn't present in the actual text, and none of the numbers "roll over" as they're want to do in ConTeXt.  This is the desired effect:    Narrator 1...      FIRST PART: PART SUBTITLE  1). First Poem // First Poem (Spanish title) . . . . . . . . . . . . . . . . .    1     Author of Poem (b. XXXX d. XXYY)  2). Second Poem // Poema Secunda . . . . . . . . . . . . . . . . . . . . . . .    3     Author of Poem    Narrator 2...  3). Third Poem // Third Poem . . . . . . . . . . . . . . . . . . . . . . . . .    5     Author      SECOND PART: Part 2  4). Fourth Poem // Fourth Poem . . . . . . . . . . . . . . . . . . . . . . . .    7     Author    Narrator 3...   The problems I have essentially boil down to these:   There is this weird "narrator" concept that doesn't seem to contain or be contained by the part/poem structure. A new part doesn't imply a new "narrator" and a new "narrator" doesn't imply a new part. I need to aggrandize each title with the title in translation and the author, and I want to typeset them nicely. I need poems to continue counting up across parts.   I see basically three approaches:   Make each poem a chapter and customize the appearance with \setuphead[chapter][....]. Then use \writebetweenlist[chapter] to add the Narrator and author information. Make a new list with \definelist[poem] and \definecombinedlist[content][part,poem]; continue using \writebetweenlist[poem] to insert the author and Narrator. This feels like the most conceptually valid option, but I think I'll still need a lot of customization. Forget all about ConTeXt and switch to plain TeX, use eplain's writetocentry system. Make it look right and forget maintainability.


here is my best attempt to explain my doubt: Look at the following case, when we have a fractions like 2/2 + 2/2 we don't solve them like 4/4 instead its 4/2 we don't increase the denominator.  If some alien saw this he would be why not add the denominator?, fortunately I know the reason, the denominator represents how many times an object has been divided in pure math the object are just numbers, since the amount of pieces something has been cut into does not add up by adding the pieces of some other object therefore the denominator does not add up.  As you can see from my above explanation the rules of not adding denominator makes sense but to someone who does no the explanation for not adding the denominators will just view them as mere rules.  That is the problem with my doubt, 2 x 2/2 to solve this we need to remove "2" from the numerator and the denominator but we don't divide both the "2's" only one, Now like for not adding the denominators there is some explanation, which I don't know.  My other question, we know that 4/2 is 2 and 2 x 2 = 4, so when we do 2 x 2 / 2 we don't divide both the numbers instead only one of them and arrive at the same answer, how?  These "reasons" I believe are never taught in school they are treated as rules, this is causing serious problems while solving questions because every concept in math depends on my understanding of these.

We know that 2 x 2 /2 can be solved by removing '2' from the denominator and numerator, we can't do the same if the operation was addition, These "rules" have been established based on the understanding of these operations and how these interact with each other.  Up until now, I've just been accepting it as a rule, but this causes a lot of discomforts while doing math.  I generally get good grades in math, but that's only by following these rules and patterns but there is no genuine understanding as to why we can remove "2" from the numerator and denominator in 2 x 2 /2 but we cannot in 2 + 2/2.  Secondly, 2 x 2 / 2 can be solved by removing "2" from the numerator and the denominator and it gives the same result as 4/2, how?. Is it an axiom?  I hope to gain an intuition for the above concepts, so I can be free from my long-held guilt.  Thanks.


I am trying to show that two groups are isomorphic only if a certain condition holds. I can show that a specific epimorphism between the two groups is one-to-one only if this condition holds, but it isn't obvious that for infinite groups that this should mean that there can't exist an isomorphism between the two groups.  If there is a non-one-to-one epimorphism from a group $G_1$ to a group $G_2$, does this mean that all epimorphisms from $G_1$ to $G_2$ are not one-to-one?

Let $G$ be any group such that  $$G\cong G/H$$ where $H$ is a normal subgroup of $G$.  If $G$ is finite, then $H$ is the trivial subgroup $\{e\}$. Does the result still hold when $G$ is infinite ? In what kind of group could I search for a counterexample ?


How can I change the size of text for figure captions?   Currently my code looks like,   \begin{figure}[H] \centering \includegraphics[scale=1]{Image.png} \caption{Caption} \end{figure}   This makes the Caption in the same size and font as the bulk text of my document. Ideally I would like it to be smaller.

My question is about changing the font size.  I have to insert two figures side by side. Coming to inserting the captions for the figures individually:  Figure 3: blah blah.....................Figure 4: blah blah...   I am able to change the font size of "blah blah". What I want to know is how to change the font size of "Figure 3" or "Figure 4", say the figure headers or something. I do not know what they are called to search on-line.


i get a virus, undetectable with virus scanners in offline OS state. The virus doesn't let to run antiviruses, debuggers, cmd, msconfig. Unfortunately, by backup is broken.  My idea is to force run in contaminated OS (Windows 7 x64) an antivirus or rootkit remover at system start or even before OS start to run the OS like in emulator, but i'm noob in the technologies like these.   I think this could produce better results than  of off-lined or online OS using different tools, because of another level of control - it's dynamic control of code execution, similar to debugging.  How and which tools|antiviruses can be run at boot of infected OS?  I did try to run with no success   aswmbr.exe   Autoruns.zip avast_free_antivirus_setup_online.exe  avg_antivirus_free_setup.exe avira_en_fass0_1341776598-1558627902__ws.exe ComboFix.exe GMER.exe  mb3-setup-37469.37469-3.7.1.2839-1.0.586-1.0.10430.exe mtze6570.exe  radix_installer.zip SmartFix.exe tdsskiller.exe msconfig cmd as admin far as admin.   Autoruns managed to run, but nothing set as being run at system startup, as everything was let out earlier.  Please note, the question is about how to run antivirus or tool over contaminated OS without antivirus installed in it.  There are , related to scanning or defending with antiviruses, but don't see solutions for unsuccessful offline scan with virus actively preventing antivirus start.  If you consider the question is been answered, please provide your exact link to the answer with explanation.

What should I do if my Windows computer seems to be infected with a virus or malware?  What are the symptoms of an infection? What should I do after noticing an infection? What can I do to get rid of it? how to prevent from infection by malware?   This question comes up frequently, and the suggested solutions are usually the same. This community wiki is an attempt to serve as the definitive, most comprehensive answer possible. Feel free to add your contributions via edits.


There are a lot of question regarding whether a function is or is not uniformly continuous or just continuous and there are a lot of $\epsilon_s$ and $\delta_s$ trying to show whether a function is uniform or not, on this compact or that convex space.  But the ultimate question is why do we care?  So okay, $f(x) = 2x$ is uniformly continuous on all $\mathbb{R}$, and $f(x) = x^2$ is not. Why do we care? Most of the useful functions out there are not uniformly continuous.  Are there some important implications (theorems/propositions/lemmas) of uniform continuity that a merely continuous function doesn't have?  Thanks!

I have solved many problems regarding uniform continuity, but still I can't understand the following:  Is there any practical application of this concept, or it is just a theoretical concept? Is there any wide application of this concept in any theorem or problem? In short, how did the concept of uniform continuity arise?


I often hear questions like will you? or shall you? used in an unusual way, and I would like to understand what that usage is for. Take this conversation for example:   How were you able to do it? You shall never know, shall you?   This shall you? isn't a normal questions, he's not really asking the other party to if he shall or *shall not. But what does it mean?  Thank you in advance for your help.

Now and then I come across an "affirmative imperative + will you?" construction where, I suspect, the speaker seems to be telling someone NOT to do something or censuring him/her for doing so, as opposed to making a request for a certain action, as in:     “Run away from me, will you?” His voice was hoarse and strangled in his throat. “I'll have your skin off your bones, I will!” He took a lurching step.   However, no English usage guides I turned to seemed to address this (supposed) usage.  Is my suspicion correct or am I on the wrong track here?


Today I had an issue today with PHP and MySQL (), which has already been solved but it awakened a new, more theorical, question.  The thing is that in MySQL database I had a field whose type was VARCHAR(64). When trying to insert a string from a php script, the full string was more than 64 bytes, making a var_dump proved it had 71. BUT, here is what I do not understand, running the exact same query, with the exact same string, but manually from phpmyadmin, it did fit in the 64-byte sql field.  So, here is the question. Is there any reason of why the same string in php takes more memory than inserting it directly to the database?  EDIT: Someone suggested a duplicate of a charset-related question. The charset in MySQL is utf8_general_ci. In PHP I have not defined the charset, but if I di print(mb_detect_encoding($string)); I get it is ASCII encoded. May this be the reason? How wrong can I be if I think ASCII takes less memory than utf8? (Anyways, in the script I have mysqli_set_charset($con,"utf8"); so it should be converted to utf8 before querying)

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


Yesterday I had to boot into Windows and when shutting down again Windows wanted to install updates (which is why I switched to Ubuntu in the first place).  Today I booted my PC and I get this screen:    Now I don't know what to do. Normally this is where the screen comes that lets me choose between Ubuntu 18.10 and the Windows Boot Manager.

I installed Windows 7, which ate Ubuntu's boot file. When starting up the computer, it now goes straight to Windows, without giving me the option of booting Ubuntu.   How can I get Ubuntu back?


I've read a few post on fetch vs pull. I get that to push to the remote you need to fetch. I also understand that if you need to checkout a branch that was added to the remote you need to fetch from the remote to update your local tracking branches. My question is why wouldn't I simply just to a pull? Why do most developers suggest doing a fetch instead? In what circumstance are you just doing a fetch? Draw a scenario for me.

What are the differences between git pull and git fetch?


I have been playing around with some JSON, trying to get and display the strings to show in a custom ListView with Textviews in my app. But I'm getting an NullPointerException when running. Can somebody tell me where I'm making a mistake and point me to a right direction maybe.    This is the JSON:  [{"id":"1","client_id":"1","client_name":"Company A"},{"id":"2","client_id":"2","client_name":"Company B"}]   this is the Model class:  public class Model {     private String client_name;     public String getClient_name() {         return client_name;     }     public void setClient_name(String client_name) {         this.client_name = client_name;     } }   Wrap class:  public class Wrap {    private ArrayList<Model> models;      public ArrayList<Model> getModels() {         return models;     }      public void setModels(ArrayList<Model> models) {         this.models = models;     } }   this is my Adapter:  public class Adapter extends ArrayAdapter<Model> {     public Adapter(Context context, int resource) {         super(context, resource);     }      @Override     public View getView(int position, View convertView, ViewGroup parent) {         ViewHolder viewHolder;          if (convertView == null) {             convertView = LayoutInflater.from(getContext()).inflate(R.layout.listview_item, null);             viewHolder = new ViewHolder(convertView);             convertView.setTag(viewHolder);         } else {             viewHolder = (ViewHolder) convertView.getTag();         }         final Model p = getItem(position);         viewHolder.textone.setText(p.getClient_name());          return convertView;     } }   The ViewHolder :  public class ViewHolder {     public TextView textone;     public ViewHolder(View convertView)     {        textone = (TextView)convertView.findViewById(R.id.txt_field);     } }   The url:  private static final String SO_URL = "http://www.example.com/webservice/?value"; private static final String PARAMS = "[{\"table\":\"locations\",\"operation\":\"select\"}]";   This is the AsyncTask's doInBackground method :  protected String doInBackground(Void... params) {             try {                 //Create an HTTP client                String  URL = URLEncoder.encode(PARAMS, "UTF-8");                 HttpClient client = new DefaultHttpClient();                 HttpPost httpPost = new HttpPost(SO_URL + URL);                  //Perform the request and check the status code                 HttpResponse response = client.execute(httpPost);                 StatusLine statusLine = response.getStatusLine();                 if(statusLine.getStatusCode() == 200) {                     HttpEntity entity = response.getEntity();                     InputStream content = entity.getContent();                      try {                         //Read the server response and attempt to parse it as JSON                         Reader reader = new InputStreamReader(content);                          Wrap wrap =  new Gson().fromJson(reader,Wrap.class);                         for (Model model : wrap.getModels()) {                             adapter.add(model);                         }                         adapter.notifyDataSetChanged();                         content.close();                     } catch (Exception ex) {                         Log.e(TAG, "Failed to parse JSON due to: " + ex);                         failedLoadingPosts();                     }                 } else {                     Log.e(TAG, "Server responded with status code: " + statusLine.getStatusCode());                     failedLoadingPosts();                 }             } catch(Exception ex) {                 Log.e(TAG, "Failed to send HTTP POST request due to: " + ex);                 failedLoadingPosts();             }             return null;   I'm getting this exception msg :  Failed to parse JSON due to: java.lang.NullPointerException: Attempt to invoke virtual method 'java.util.ArrayList com.bloomcore.dbnewapp.Wrap.getModels()' on a null object reference

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


I encountered a little problem. Say I have a mesh an the Vertices on top are not in the same Z-Position. I am looking for a method to have them all aligned in Z.  My approach is to select the 3 Vertices, grab the blue arrow to constrain the movement in the Z-Axis and want to snap to the vertex highlighted with the red circle.   My Snappingsettings    But for some reason they don´t have the same z-Position. They seem to keep their Offsets to each other?  I used this method in Maya.  Do you know a way how to get that working?  thanks in Advance Guido.

If you have a cluster of points selected like this:    how do you align the points so that they create a flat plane?


Is there any way that one could bind a parameter directly to the connection variable so it could be replaced in every prepared statement?  Could this work? :  $database = 'users'; $pdo_conn = connection variable; $pdo_conn->bindValue(':usersdb', $database, PDO::PARAM_STR);  // Query $pdo_query = $pdo_conn->prepare("SELECT * FROM :usersdb.users");   Thanks in advance!

Why can't I pass the table name to a prepared PDO statement?  $stmt = $dbh->prepare('SELECT * FROM :table WHERE 1'); if ($stmt->execute(array(':table' => 'users'))) {     var_dump($stmt->fetchAll()); }   Is there another safe way to insert a table name into a SQL query? With safe, I mean that I don't want to do  $sql = "SELECT * FROM $table WHERE 1"


So, I installed fedora on my system but the grub menu does not show up. I saw  but it was for Manjaro. How do I do it for fedora?

I installed Manjaro as my first distro and everything went pretty smoothly up until grub. When I select Windows 10 in the grub menu instead of Linux, windows takes a lot longer than usual to boot. Once booted, it seems fine - until the next boot where grub is completely skipped and windows is loaded into automatically.  The only way I have found to get grub back, is to enter my UEFI settings and rearrange the boot order so that Manjaro is on top. As soon as windows boots, this is rearranged so that Manjaro is down at the bottom of the list.  To sum up:   Grub works fine until windows is loaded, at which point it isn't used anymore To restore grub I must rearrange the UEFI boot order. This works until the next windows boot This problem doesn't occur with Linux, I can boot it many times over with no problems at all.   How can I prevent Windows 10 reordering the boot order in the UEFI so that grub is used all the time?


$0\lt a_1\lt 1$, $a_{n+1}=a_n+\dfrac{a_n^2}{n^2}$,  Find $\lim\limits_{n\to\infty} a_n$    Well,  $a_{n+1}\gt a_n$, But how to show that there is  an upper bound of $\{a_n\}$ ? What is the limit ? Thanks a lot

Let $\{a_{n}\}$ be defined with $a_{1}\in(0,1)$, and  $$a_{n+1}=a_{n}+\dfrac{a^2_{n}}{n^2}$$ for all $n\gt 0$.  Show that the sequence is  upper bounded.  My idea: since  $$a_{n+1}=a_{n}\left(1+\dfrac{a_{n}}{n^2}\right)$$ then $$\dfrac{1}{a_{n+1}}=\dfrac{1}{a_{n}}-\dfrac{1}{a_{n}+n^2}$$ then $$\dfrac{1}{a_{n}}-\dfrac{1}{a_{n+1}}=\dfrac{1}{a_{n}+n^2}$$ so $$\dfrac{1}{a_{1}}-\dfrac{1}{a_{n+1}}=\sum_{i=1}^{n}\dfrac{1}{a_{i}+i^2}$$ since $$a_{n+1}>a_{n}\Longrightarrow \dfrac{1}{a_{i}+i^2}<\dfrac{1}{a_{1}+i^2}$$ so $$\dfrac{1}{a_{n+1}}>\dfrac{1}{a_{1}}-\left(\dfrac{1}{1+a_{1}}+\dfrac{1}{2^2+a_{1}}+\cdots+\dfrac{1}{a_{1}+n^2}\right)$$ But the RHS might be $\lt0$ for a sufficiently large starting value; for instance, with $a_{1}=\dfrac{99}{100}$ then $$\dfrac{1}{a_{1}}-\left(\dfrac{1}{1+a_{1}}+\dfrac{1}{2^2+a_{1}}+\cdots+\dfrac{1}{a_{1}+n^2}\right)<0,n\to\infty$$  see:   so this method won't let me bound the series and I don't know what else to do.


I have always read strictfp restricts floating point calculations to IEEE-754 standard, but never read why their came the need for restricting the calculation's result according to this standard?

I've looked up what this does, but does anyone actually have an example of when you would use the strictfp keyword in Java? Has anyone actually found a use for this?  Would there be any side-effects of just putting it on all my floating point operations?


I wish to store either 0 or 1 in each bit of an allocated memory. For example I have char *block_of_memory = (char *)malloc(125000 * sizeof(char)) , here I have 125000 * 8 bits = 1000,000 bits of memory. How can I access each bit and give it a value as 0 or 1. Say , I want to make the 20th bit to 1 and 21st bit as 0.

How do you set, clear, and toggle a bit?


I was doing a group command (moving files) and something unfolded the asterisk (I think I clicked some key, and didn't notice) What happened was that:  mv *   turned into:  mv file1 file2 file3 dir1 dir2 dir3   This seems really usefull to me, since I could just remove the folders I didn't want to move, and move everything into one of the directories.  How do I unfold the asterisk again?   I have not been able to (through google or this site) to find out how to to this ;-) Thanks for the help

I remembered bash can do the following:  Suppose there are 3 files: a,b,c in the current directory, when I input:  $> somecommand *   and then press a key or key combinations or a key sequence, the wildcard * online expanded as:  $> somecommand a b c   but I cannot remember and cannot google out the key sequence! help!


Why is it that on all my calculators, when I subtract 12% from $56$, I get $49.28$, but when I add 12% to $50$, I get $56$?

Tried my best with the title. Ok, earlier while I was on break from work (I have low level math, and want to be more fond of mathematics)  I work retail, and 20% of taxes are taken out, and I am wanting to find out how much I made before 20% is taken out.  So I did some scribbling, and this is without googling so please be gentle. but lets say I make 2000 dollars per paycheck, so to see how much money I get after taxes I do 2000 * .8 which gives me 1600. I can also do 2000 * .2 which gives me 400 and then do 2000 - 400 (imo I don't like this way since I have a extra unnecessary step)  Anyways, I was pondering how to reverse that to have the answer be 2000, and what I did was 1600 * 1.20 (120%) which gave me 1920, and I thought that is odd so I did 1600 * 1.25 and answer was 2000 exact.  My question is why did I have to add extra 5% (25%) to get my answer? I am sure I did something wrong, and I fairly confident the formula I am using is a big no no.  edit; wow thank you all for your detailed answers. I am starting to like mathematics more and more.


When Energy is converted to matter, we know equal amounts of matter and antimatter are produced. What happens when matter and antimatter combine?

I used to read the term "pure energy" in the context of matter-antimatter annihilation.  Is the "pure energy" spoken of photons? Is it some form of heat?  Some kind of particles with mass?   Basically, what does "pure energy" in the context of matter-antimatter annihilation refer to?


The title says it all, what makes eye defects so common in the world? Whereas defects of any other body part is quite uncommon, I searched online and one of the articles said that 6 out of 10 people wear glasses, I think that is a big percentage of people with eye defects, BTW I'm myopic and I wear glasses too. Are all body parts defective to a certain degree, but It seems more pronounced in the case of eyes?  P.S  I know nothing about biology, I appreciate if someone could explain it with preferably less technical terms, this is my first question on BSE, let me know how I can make the post better.

Why do many humans have bad eyesight, such as near-sightedness, which hampers performance in a wide variety of tasks? Shouldn't there be evolutionary pressure towards better eyesight?


Suppose I'm given the mean and one quantile (e.g. the 95% quantile) of a random variable $x$, and I want to find the parameters $\alpha$ and $\beta$ of a Beta distribution that has the same mean and quantile. Is there an efficient way to do it in R?

Suppose I'm given the mean and one quantile (e.g. the 20% quantile) of a random variable $x$, and I want to find the parameters $\alpha$ and $\beta$ of a Beta distribution that has the same mean and quantile.  Is there an efficient way to do it?    Using just the mean, I know that since $\bar{x} = \frac{\alpha}{\alpha+\beta}$, we have $\beta = \frac{\alpha}{\bar{x}} - \alpha$.  So we only really have one parameter to estimate.  But I'm unsure how to use the quantile information to take the next step.  Maybe there's something I can do with the Incomplete Beta when I know the ratio $\frac{\beta}{\alpha} = \frac{1-\bar{x}}{\bar{x}}$?  I have access to R myself, so I could use a numerical optimizer for this, but ideally I need a method that can be carried out in Excel in someone else's environment.  Excel does have BETA.DIST() and BETA.INV() functions available.  A look-up table would be fine, but a closed-form formula would be better if it's possible.


I don't care for him so much. But she, I care a great deal for.      In this scenario, isn't it correct to say "She" rather than than "Her?"  (ex: Her, I care about vs. She, I care about.) My wife thinks it's "Her" instead of "She." Just trying to settle an argument. Is this sort of an improper way to shape the sentence? I feel like it's technically OK, but it's more acceptable to say "I don't care much for him, but I care a great deal for her.)

An online retail store is asking its customers to construct a sentence beginning with them in order to win a voucher. I just can't believe there's  any such sentence, at least I don't know of any!   I've had enough laughs with friends coming up with Americanisms that fit, so that's not what I'm looking for.  I'm just very curious, is such a sentence grammatically possible or is this store just being mischievous?


I have a very simple question: What is the terminal command for changing the volume? I ask because I want to set a keyboard shortcut via the keyboard settings and I need the terminal command for it.

I have an external sound card which mostly works fine, except that when its first plugged in, or when I turn on my laptop, the volume gets set to 100%. That is, the overall system volume, as shown in the sound indicator.  What I'm looking for is a terminal command that will set that volume to 50%, so that I can run it on login and not have to worry that the first audio I play is going to blare out at me if I forget to turn the volume down. What commands allow you to change that volume, i.e. the one in the sound indicator?  I've poked around in gsettings and dbus, but have been unable to find anything that would let me set the system volume like that. I do know about alsamixer, but that's not the solution I'm looking for, since that doesn't allow me to change the volume using the sound indicator or my laptop's multimedia keys.


I have a desktop running Windows XP, and I am seriously considering switching to Linux/Ubuntu once support from MS ends in a few weeks.  However, I have other computers in my house, all running relatively more modern variants of Windows, and thus part of a Windows network.  Can a Ubuntu machine function as part of a Windows network?  I know that I should be able to connect to my router via wire/wireless (although I'm a bit concerned at the number of questions I see regarding various people's connectivity issues in Ubuntu)...I'm just wondering if I'll still be able to do folder/file shares, etc.  Also, if anyone has any suggestions regarding any potential pitfalls I could avoid, that would be great.  Thanks!

I have a folder I want to share with a couple windows users on the network. I am using ubuntu 10.4 When I right click a folder I go to "Sharing Options" There are 3 check boxes. If I check the first 2 which are "share this folder" and "Allow others to create and delete files in this folder" I can now see this folder on the network from my pc. I cannot access it though, it asks for a username and password (I never set one up so I don't even know what credentials it wants.) I don't want to have to log in, I just want to be able to go right in. So If I check the third box, which is "guest access" I can now access the folder from my pc. But so can everyone else on the network. I just want myself and a couple other pc users on the network to be able to access it. I do not see anyplace where I can specify what users on the network have permission to access it? How do I do that?  update When I entered my user name and password for the linux machine, it gave me this error message:  \LINUX-SERVER\saga_repo is not accessible. You might not have permission to use this network resource. Contact the administrator of this server to find out if you have access permissions. Multiple connections to a server or shared resource by the same user, using more than one user name, are not allowed. Disconnect all previous connections to the server or shared resource and try again.  I noticed that when type in my username it defaults to @MY-DOMAIN so I also tried myuser@linux-server but still got the same message. Also the domain administrator (who knows nothing about linux) told me that the linux machine is not a part of the domain (even though I can see it when I go to My Network Places from my windows machine). I don't know if that means anything. I also tried created a new user on ubuntu to try to log in with and got the same message. I tried to log in with my user and the new user from a workers machine and I couldn't get in from there either but I just got an "access denied" dialog everytime on his machine. Is there possibly another step I am missing?


I tried to fix one problem and created another...  My update manager broke...     The package system is broken      Check if you are using third party repositories. If so disable them,   since they are a common source of problems. Furthermore run the   following command in a Terminal: apt-get install -f   I run apt-get install -f and I get:  missx@missx:~$ apt-get install -f E: Could not open lock file /var/lib/dpkg/lock - open (13: Permission denied) E: Unable to lock the administration directory (/var/lib/dpkg/), are you root?   I tried reinstalling software center i get this  missx@missx:~$ sudo apt-get --reinstall install software-center [sudo] password for missx:  Reading package lists... Done Building dependency tree        Reading state information... Done You might want to run 'apt-get -f install' to correct these: The following packages have unmet dependencies:  network-manager-dbg : Depends: network-manager (= 0.9.4.0-0ubuntu3) but 0.9.4.0-0ubuntu4.2 is to be installed or                                 libnm-util2 (= 0.9.4.0-0ubuntu3) but 0.9.4.0-0ubuntu4.2 is to be installed or                                 libnm-glib4 (= 0.9.4.0-0ubuntu3) but 0.9.4.0-0ubuntu4.2 is to be installed or                                 libnm-glib-vpn1 (= 0.9.4.0-0ubuntu3) but 0.9.4.0-0ubuntu4.2 is to be installed E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).   The network maneger is the piece of crap I installed yesterday to fix my wi-fi issue...  Don't have synaptic installed (that would be too easy, right..?)  sudo apt-get -f install   missx@missx:~$ sudo apt-get -f install  Reading package lists... Done Building dependency tree        Reading state information... Done Correcting dependencies... Done The following packages were automatically installed and are no longer required:   linux-headers-3.2.0-38 libsub-name-perl libparse-debianchangelog-perl   libnspr4-0d:i386 libsigc++-2.0-0c2a:i386 libcwidget3   libboost-iostreams1.46.1 libgconf2-4:i386 libapt-pkg4.12:i386   libio-string-perl linux-headers-3.2.0-38-generic libept1.4.12   libclass-accessor-perl libnss3-1d:i386 Use 'apt-get autoremove' to remove them. The following extra packages will be installed:   network-manager-dbg The following packages will be upgraded:   network-manager-dbg 1 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. 1 not fully installed or removed. Need to get 0 B/1,463 kB of archives. After this operation, 8,192 B of additional disk space will be used. Do you want to continue [Y/n]? y dpkg: dependency problems prevent configuration of network-manager-dbg:  network-manager-dbg depends on network-manager (= 0.9.4.0-0ubuntu3) | libnm-util2 (= 0.9.4.0-0ubuntu3) | libnm-glib4 (= 0.9.4.0-0ubuntu3) | libnm-glib-vpn1 (= 0.9.4.0-0ubuntu3); however:   Version of network-manager on system is 0.9.4.0-0ubuntu4.2.   Version of libnm-util2 on system is 0.9.4.0-0ubuntu4.2.   Version of libnm-glib4 on system is 0.9.4.0-0ubuntu4.2.   Version of libnm-glib-vpn1 on system is 0.9.4.0-0ubuntu4.2. dpkg: error processing network-manager-dbg (--configure):  dependency problems - leaving unconfigured No apport report written because the error message indicates its a followup error from a previous failure.                       Errors were encountered while processing:   network-manager-dbg     E: Sub-process /usr/bin/dpkg returned an error code (1)"

Occasionally, when I'm installing stuff, I get an error like the following:  Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  package1 : Depends: package2 (>= 1.8) but 1.7.5-1ubuntu1 is to be installed E: Unable to correct problems, you have held broken packages.   How can I resolve this?


Some time ago I installed windows and ubuntu on the same pc. There was a problem and in grub boot loader, windows didn't appear, and I needed to reinstall all.  Now I want to install windows and ubuntu on other pc, but i can't remember... do I need to install windows or ubuntu firstly?  Thank you!

I need my pre-installed version of Windows 7 (or any other version of Windows), how could I install Ubuntu without erasing it?


Why isn't a photon moving at c not justified in concluding that it is at rest and everything else is moving past it at c since relativity postulates that the laws of physics are invariant (i.e. identical) in all inertial systems (non-accelerating frames of reference)? Which part did I overlook?

Quite a few of the questions given on this site mention a photon in vacuum having a rest frame such as it having a zero mass in its rest frame. I find this contradictory since photons must travel at the speed of light in all frames according to special relativity.  Does a photon in vacuum have a rest frame?


I am an Indian citizen travelling to Singapore via Kuala Lumpur.  I have 2 flights (different air lines) from same terminal with layover of 5 hours in Kuala Lumpur. Not planning to go out of airport but as its different flights would need to collect luggage and go through immigration I guess.  New Delhi -> Kuala Lumpur (KLIA2) (Air Asia flight arrives 7.05 am)  Kuala Lumpur (KLIA2) -> Singapore (Jetstar flight departs 11.15 am)  Do I need any visa? Is it the transit visa which is required? How can I get the transit visa?

I am an Indian travelling from Cochin to Beijing via Kuala Lumpur, using Air Asia. My flight has a layover in Kuala Lumpur of about 10 hours. While booking, it was mentioned that I will need a transit visa in Malaysia and I need to check out and again check in.   Do I need a transit visa? If yes, how to get that from KLIA2 airport after checking out? I have a China visa with employment pass endorsed on my passport. Is that enough for travelling from Cochin to Kuala Lumpur? What are the formalities to get a transit visa? Is that straightforward?   Kindly guide me.


I am confused on how LSTM learn from word embedding. I know that LSTM accepts 3D input (sample, timesteps, features). So, when we use embedding layer (word2vec) and we have 300-d vector representation, how does LSTM learn. I do understand that for a sentence, the words are timesteps. However, when we deal with vectors should the timesteps be same as vectors?  If it is true, then how can LSTM learn the sequence of words in that case to predict anything about sentence.

I recently read a lot about neural networks using GRU or LSTM units. There are many easy to use frameworks like tensorflow that do not even require high knowledge about programming. Unfortunately, I never really found good information on how the training of those networks work. Simple backpropagation might probably not work for gated recurrent networks or is just too inefficient for networks with such a high number of variables to learn.  So my question is:  What are the state-of-the-art algorithms used for the initialization and training of neural networks with GRU or LSTM units? I am not looking for frameworks to use, but for initialization and update equations for the internal parameters.


I am playing a level 8 Incanter from Spheres of Power. As a full caster, this gives me a caster level of 8. I have a trait which increases my caster level for the destruction sphere by 1, and I have a stave of destruction (+1). This gives me a total CL of 10 in destruction. This has allowed me to qualify for the Wand Wielder feat, which requires a CL of 10 or higher.  Am I only allowed to use the feat when I'm wielding the staff (so I would be wielding both a stave and wand to benefit at the moment), or am I just allowed to have the stave on me?

Seeing  made me curious as it seems that a magic item is used to meet a feat's prerequisite.  Can items or spells be used to satisfy a feat's prerequisites? I know that if the character loses the item or the spell's duration runs out the character loses the ability to use the feat, but, until then, could the character take the feat?  For example, could a character with Strength 11 put on a  or have the spell  cast on him so that he could take the feat  that has as a prerequisite Strength 13?


I had the below scenario happen while playing MTG Arena. I have a 1/1 soldier token. I have given it protection from Red, by sacrificing an . My opponent has a  equipped with an . My soldier blocks the Rimrock Knight. Damage still gets through. I was under the impression that protection from red would force all damage to be absorbed by the soldier.  That was not the case.  I'm assuming this is a bug in my understanding of the rules, as opposed to a bug in Arena?

Say I have a 4/4 creature with trample. I attack, and my opponent blocks with a...   : Does my 4/4 trampler's extra 3 damage carry over even though the blocking creature wasn't dealt lethal damage? Does the situation change if my 4/4 trampler also has infect?  Can I even deal lethal damage to it? 0/1 Creature with protection from my creature's color: Can I deal damage to it at all?   When does the damage carry over to my opponent? I made all of these hypothetical creatures 0/1 for simplicity's sake. I know the creatures actually linked to are slightly different, but I believe this will simplify the answers.


I have made a collage with 5120 x 2880 px size using picasa.  Now I want to order a print of it.  What would be the best option to make a canvas print or a poster print?  I want the best size and picture quality.  And what can be the max size of my print in inches, considering the aspect ratio is intact... I dont want any cropping of my lovely collage. :)  Second question... the collage is composed of many pictures of people on it.  So what would be more suitable, a print on canvas or on poster?  I think a canvas is a cloth and poster is paper? Am I correct? and that canvas would give   a rough finish and poster a glossy one?

What size images do I need for common print sizes, such as wallet size, 8x10, and 16x20?  Is there a general formula?  How could that size change if, for example, a 16x20 was printed on canvas rather than photopaper?


After a recent Dota 2 patch it is no longer possible to search by player name. They have also removed the "skill level" function from their API, which means that you can't really see your skill level on websites like dotabuff.  Is it even possible to view your skill level? If so, how?

Supposedly DOTA 2 matchmaking is divided into brackets.  I want to know which difficulty bracket I'm in. How can I find this information?


I'm trying to create a chrome extension. I had a problem with the affectation of event for the new element that i append to the dom of site with  content. Js  If I add an event to an element' 'for example class'  exist already in the page, it works correctly. Just for my new appended element((in the code iadded a button ,the event is just an alert to test))  function tst() {   myclass = $("._3hg-._42ft");   myclass = myclass.not(".supp");   myclass.addClass("supp");   var patt = /https:\/\/(.)*\.facebook\.com\/(.)*\/(posts|photos|videos)\/(\w|\.|\d)*/g;   for (i = 0; i < myclass.length; i++) {     result = patt.exec(myclass[i]);     myclass.append('<button class="fact" id=' + result[0] + ' style="position: absolute;">fact</button>');   };    /* this is a simple event*/   /***********************/   $(".fact").on('click', function() {     alert("no event work ");   });

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


I want to display data on the profile page stored in firebase, but when I try to display text with only numbers, and run the application and then go to the profile page for the user, it gives an error like this:  E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.drheartbeatmonitor, PID: 3415 java.lang.RuntimeException: Unable to start activity  ComponentInfo{com.example.drheartbeatmonitor/com.example.drheartbeatmonitor.Profile}:  java.lang.NullPointerException: Attempt to invoke virtual method 'void  android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3449)     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3601)     at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)     at  android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)     at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066)     at android.os.Handler.dispatchMessage(Handler.java:106)     at android.os.Looper.loop(Looper.java:223)     at android.app.ActivityThread.main(ActivityThread.java:7656)     at java.lang.reflect.Method.invoke(Native Method)     at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)  Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void  android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference     at com.example.drheartbeatmonitor.Profile.onCreate(Profile.java:67)     at android.app.Activity.performCreate(Activity.java:8000)     at android.app.Activity.performCreate(Activity.java:7984)     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1309)     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3422)     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3601)      at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)      at  android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)      at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066)      at android.os.Handler.dispatchMessage(Handler.java:106)      at android.os.Looper.loop(Looper.java:223)      at android.app.ActivityThread.main(ActivityThread.java:7656)      at java.lang.reflect.Method.invoke(Native Method)      at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)    This is my code : 1.login page: String ID_Device = snapshot.child(Username).child("ID_Device").getValue().toString(); String HealthInsure = snapshot.child(Username).child("Health Insure").getValue().toString(); intent.putExtra("ID_Device", ID_Device); intent.putExtra("Health Insure", HealthInsure);  2. profile page String ID_Device = Patient.ID_Device; String HealthInsure = Patient.HealthInsure; health_insure.setText(HealthInsure); ID_Dev.setText(ID_Device);

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


What is the difference between  There got to be something wrong with him.   There's got to be something wrong with him.  I don't understand the function of 's.

There has got to be the establishment of a universal auxiliary language.   Does the verb got add more to the context or is it there just for emphasis? Is it even grammatical?  Using Google-Ngrams I found a few similar versions as follow: . For example;   For many from the North, however, it has seemed difficult and there has seemed to be a problem. There has come to be a convolution between this become enmeshed concept of marriage as it exists in the sacred and how it exists in the secular. Most of the time since I have been here, there has appeared to be considerable feeling in the minds of a few. There has had to be some negotiation, obviously, but I think we provided what our soldiers need and what our country needs.   In general, I wanna know if 'have/has'+past-participle+'to be' is grammatical.


I've traced an image (in this case, grand canyon) and it composed of several individual line segments. But now I want to give each of the closed shapes (again, not closed shapes, it just seem like it) a different fill color.  Is there any way I can close the shapes and convert them into polygons?   Earlier post did not answer my question ()

In the drawing you see five paths (orange pink green blue and red), which define the boundaries of 4 regions (a b c and d).  I now want to create those regions so they are fillable, and without crazy "op-art" effects due to differing directions. For instance, to create region b, I need to use the pink path (which is shared with c), the green path (shared with a) and part of the blue path (shared with d).  What is a process for doing this that is efficient?  My actual drawing has dozens of regions and I'd like a process that doesn't take a week.


I'd like to add a 2 minute delay to the boot time of my Ubuntu 20.04.2 Server. To do this on a Raspberry Pi I simply edited the  config.txt  in  /boot  to include boot_delay=120 . Which file should I edit on Ubuntu to achieve this?

I put ubuntu-spinner-logo PT on my old Ubuntu 19.04 PC, how can I increse duration of it, PT last untill boot ends,but spinning logo last for aprox. 15s and PC need about 40s to boot up. I found ubuntu-spinner-logo.script in:  usr/share/plymouth/themes/ubuntu-spinner-logo/   but I do not know how to modify it, or am I allowed to modify it due to licence of it. Thank you on your time.


I was wondering something about the $ of jQuery. I know that it refers to jQuery object, but I a found something a bit different today : $parent In the code I'm working on, that's a substitute to $(this).parent : eg : var $parent = $(this).parent();  So my question is, why $parent and not parent ? Is that the only selector ? How to use it this way ? And I'm not talking about the dotted functions like $.ajax or $.post.  Thaks for helping

I quite often see JavaScript with variables that start with a dollar sign. When/why would you choose to prefix a variable in this way?  (I'm not asking about $('p.foo') syntax that you see in jQuery and others, but normal variables like $name and $order)


I'm a bit confused here. When we take the derivative of  $$f(x)=\begin{cases}   x^2\sin{\biggl(\dfrac{1}{x}\biggr)}&x\neq0\\   0 &x=0\\ \end{cases} $$ It's derivative is not defined at $x=0$ as  $f(x)=2x\sin{\biggl(\dfrac{1}{x}\biggr)}-\cos{\biggl(\dfrac{1}{x}\biggr)}$.  However, approaching this problem through the limit form of the derivative gives the value of the derivative at $x=0$: $$f'(x)=\lim_{h\to 0}\dfrac{f(x+h)-f(x)}{h}$$ $$\implies f'(0)=\lim_{h\to0}\dfrac{h^2\sin{\biggl(\dfrac{1}{x}\biggr)}-0}{h}=0$$  What I'm curious about here is why differentiating $f(x)$ first and then entering $x=0$ is failing in contrast to finding the derivative through limits?

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


According to the Merriam Webster dictionary:     Moment - a very short period of time   Does the word "moment" in quantities like the moment of force or moment of inertia refer to this colloquial meaning of "moment" too? If so, where exactly is the "short period of time" involved in, say, moment of force? For me it has always been just the tendency of a force to rotate an object around an axis and I don't see any reference to time there.

What is the meaning of ? I'm little confused about the word as there are some terms like moment of momentum, moment of mass, moment of force, etc. I want to know what exactly is meant by the word "moment".


i getting this error when inserting a record with "<".  how to solve this error with inserting a string with "<" in it.  im using entity framework. this column has a datatype of nvarchar.  thanks in advance.

Every time a user posts something containing < or > in a page in my web application, I get this exception thrown.  I don't want to go into the discussion about the smartness of throwing an exception or crashing an entire web application because somebody entered a character in a text box, but I am looking for an elegant way to handle this.  Trapping the exception and showing     An error has occurred please go back and re-type your entire form again, but this time please do not use <   doesn't seem professional enough to me.  Disabling post validation (validateRequest="false") will definitely avoid this error, but it will leave the page vulnerable to a number of attacks.  Ideally: When a post back occurs containing HTML restricted characters, that posted value in the Form collection will be automatically HTML encoded. So the .Text property of my text-box will be something & lt; html & gt;  Is there a way I can do this from a handler?


In the village, the door on the far left is locked, despite me completely beating the game in terms of levels and inventory. How can I open that locked door? The last 2 things I need to do is open this door and beat the arcade games.

I've 'completed' the game, but didn't find the key for the first house. (I got the one for the arcade machine house). Where can I find it?


I don't do server stuffs on regular basis, I was just wondering how to check SSH login logs and found that it can be checked using sudo cat /var/log/auth.log and checked on my server and there were lots of Failed password for root from [IP] This is a newly installed remote server there's no way I could have logged so many times.  Then I read it carefully it says Failed password for root from [IP] I was like what? Its for root? I have created my separate user account and except the first time when I had to create a new user account I have never touch root user. It seems to me someone is trying his luck by bruteforcing for credentials. Still, I wanted to be sure so asking here.

I just checked my server's /var/log/auth.log and found that I'm getting over 500 failed password/break-in attempt notifications per day! My site is small, and its URL is obscure. Is this normal? Should I be taking any measures?


I had to report the mean running time of a java method. I do it the following way  //method start long startTime = System.nanoTime(); //method body here ... long estimationTime = System.nanoTime() - startTime;  //method end   I run the method many many times, log the results and then report the mean and variance of running time in microseconds.  Here is the problem I got the following values (very large spikes exist)   note that other values are not zeros (zoom in reveals it)   My Questions:   What the main cause of these outliers (spikes)? How to report the running time accurately in a case like this?   Take a look at the method  body (For the curious)  TraceRecord resultRecord = new TraceRecord();     resultRecord.setTimeStamp(timeStamp);     resultRecord.setUserID(userID);      if (sensorValue.getSensorType() == SensorType.WIFI) {         ArrayList<WifiBaseStation> wifiAPsInRange = new ArrayList<WifiBaseStation>();          for (int i = 0; i < sensorValue.getBaseStationsIdentifiers().length; i++) {              WifiBaseStation wifiAP = new WifiBaseStation(sensorValue.getRepresentativeName(i),                     sensorValue.getBaseStationsIdentifier(i));             wifiAP.getSignalStrengthsList().add(sensorValue.getSignalValue(i));             wifiAPsInRange.add(wifiAP);         }         if (wifiAPsInRange.size() > 0) {              double averageLong = 0;             double averageLat = 0;             int matchedCount = 0;              for (WifiBaseStation bs : wifiAPsInRange) {                 WifiBaseStation bsFromTable = WiFiUniqueWarDrivingTable.Get(bs.getMacAddress());                 if (bsFromTable != null) {                     GPSLocation locationFromTable = bsFromTable.getBaseStationLocationUsingAverage();                     if (locationFromTable != null) {                         averageLong += locationFromTable.getLongitude();                         averageLat += locationFromTable.getLatitude();                         matchedCount++;                     }else{                         averageLong++;                         averageLong--;                     }                 }else{                     averageLong++;                     averageLong--;                 }              }              if (averageLong != 0) {                 averageLong /= matchedCount;             }             if (averageLat != 0) {                 averageLat /= matchedCount;             }              if (averageLat != 0 && averageLong != 0) {                 resultRecord.setLocationPoint(new GPSLocation(averageLong, averageLat, 0));             } else {                 return null;             }         }      }

How do I get a method's execution time?   Is there a Timer utility class for things like timing how long a task takes, etc?     Most of the searches on Google return results for timers that schedule threads and tasks, which is not what I want.


Show that if n divides a single Fibonacci number, then it will divide infinitely many Fibonacci numbers.

While studying the Fibonacci sequence I encountered this problem in the handout, and I can not understand how to do it.     Show that if the Fibonacci sequence has a term divisible by a natural number $m$, then there are infinitely many such terms.


Given an integer n, I want to find S = gcd(1,n) + gcd(2,n) + gcd(3,n) + ....gcd(n,n). Now , there are I have firgured that the number should be something like  S =  φ(n) + x. Now I can't draw a relation upon x. May be I have to use the property gcd(a,n) = gcd(a+kn,n) or something like this.

I want to find this  $$ \sum_{k=1}^n \gcd(k,n)$$  but I don't know how to solve. Does anybody can help me to finding this problem.  Thanks.