shell find -delete "directory not empty"

I try to delete backup files on my Synology NAS older than 30 days. The files are in a directory which is created during download of the backup files from my webserver. After download, I want to check -mtime and then delete the older files.  Here comes the script:  #!/bin/sh  ## Datum auslesen datum=`date +%Y-%m-%d_%H-%M`  ## Mit wget die Datei AutoBackupDB-1.zip laden und in einem Ordner mit Datum uns Uhrzeit speichern  wget -m -P /volume1/Austauschordner/backup_xyz/$datum/ ftp://backup:backup@domain.tdl/AutoBackupDB-1.zip echo "Backup von xyz wurde erstellt! "  ## finde alle Ordner in einem angegebenen Verzeichnis mit dem Suchnamen die älter als die angegebenen Tage sind und lösche diese find /volume1/Austauschordner/ -type d -name 'backup_*' -ctime +30 -delete   If I run this script it tells me that the "directory isn't empty" and nothing will be deleted.  Is there an easy way or an option to delete everything in the directory?


Re-entering UK on a 6-months, multiple entry Standard Visitor (tourist) visa

I have a UK multiple entry tourist visa valid for six months. I have traveled once to London for a week. I want to visit Scotland and London again.  Can I use the same visa as it will expire in November?  Can I take the journey before that?  What do I need to do?


Steam through WINE; nothing happens after login

I have ubuntu 13.10 installed and I'm still very new to this. I'm still trying to grasp the system mechanics so I would like a step by step solution.  I've downloaded and installed wine 1.5 with winetricks. Using winetricks I installed Steam successfully. When I run Steam the login screen comes up fine. The problem appears after typing in my info and logging in. It just closes, with nothing appearing.  Anyone have any tips?


Consider a massless rope with pulling forces applied at each end.  How do we decide if tension is constant or not in a rope? Consider a few example scenarios:  For example, if there is a knot in the rope the tension is not constant throughout (why?. Similarly, if the rope is hung over a cylindrical pulley of a non-negligible radius, the tension is not constant (why?). If there isn't anything touching the rope, for example, 2 people tugging on the rope at each end, the tension is constant (why?).


Determine whether $\sum_{n=1}^{\infty}\frac{(-1)^n}{n \log^2(n+1)}$ converges absolutely or conditionally.

Problem  Let $S = \sum_{n=1}^{\infty}\frac{(-1)^n}{n\log^2(n+1)}$.   Determine the series converges absolutely or conditionally.   Attempt  $S=\sum_{n=1}^{\infty}( -1)^n a_n$   $a_n$ is monotonically decreasing and it approaches zero when $n$ approaches infinity. So series is convergent .   Doubt  How to check for absolute convergence?  Ratio test fails here. Root test is of no use.  I have attempted comparison tests using the fact that $n>\log(n)$, but no success there also.


While updating my Zorin 15.3 using sudo apt-get update and sudo apt-get upgrade i am getting this issue Processing triggers for initramfs-tools (0.130ubuntu3.11) ... update-initramfs: Generating /boot/initrd.img-5.4.0-45-generic W: Possible missing firmware /lib/firmware/rtl_nic/rtl8125a-3.fw for module r8169 W: Possible missing firmware /lib/firmware/rtl_nic/rtl8168fp-3.fw for module r8169 W: Possible missing firmware /lib/firmware/i915/tgl_dmc_ver2_04.bin for module i915 W: Possible missing firmware /lib/firmware/i915/skl_guc_33.0.0.bin for module i915 W: Possible missing firmware /lib/firmware/i915/bxt_guc_33.0.0.bin for module i915 W: Possible missing firmware /lib/firmware/i915/kbl_guc_33.0.0.bin for module i915 W: Possible missing firmware /lib/firmware/i915/glk_guc_33.0.0.bin for module i915 W: Possible missing firmware /lib/firmware/i915/kbl_guc_33.0.0.bin for module i915 W: Possible missing firmware /lib/firmware/i915/icl_guc_33.0.0.bin for module i915  can anyone help how to fix it?


Proof that the cardinality of the Cantor Set is c

I have proven that the Cantor set is uncountable using Cantors diagonalization argument in base $3$. Now I have to prove that it has cardinality $\mathfrak{c}$ due to the fact that it is uncountable  but I am struggling to even get started.   Any help would be appreciated.


I'm working with threads in Java 8 and I'm using the next code:  Runnable runnable = () -> {             LOGGER.info(....);            someCode           };                Thread thread = new Thread(runnable);           thread.start();  My doubt is how can I stop or interrupt the thread or it will be stopped with itself? Any ideas?


Using default Yaru theme, I want to change the font of top panel to match modified fonts in . Since Yaru theme has no shell theme as noticed:    I can't find the required CSS file in Yaru directory that include shell variables to modify. Any help is much appreciated.


Should we allow adding rep to bounties to extend their duration?

There are a few variables here that I was thinking about:   Spend rep to extend a bounty for a certain amount of time Allow the rep spent to extend duration to add into the original bounty Create minimums on the amount necessary to extend dependent on how long it has been up   These are just ideas and can be tweaked as necessary, but the idea in whole is to encourage people to spend more on rep and avoid "wasted" rep because there wasn't a good answer to a question while minimizing the amount of possible abuse. This was part of the idea to spend a small amount of rep to extend duration without adding to the rep so that you wouldn't have to spend the whole amount over again for a couple more days.  The typical use case that I am thinking of is when you create a bounty and it still gets no attention. I think it would be cool if you could then add onto it to turn it into a higher bounty instead of having those points completely gone.  Possible abuses:   Keeping bounty questions alive for inappropriately long times. There is already an answer but the author does not want to award the bounty.   For 1, you can resolve this by increasing the amount necessary to keep a question alive exponentially similar to what is already in place. You could also halve the amount of extended duration per extension. For 2, this is a problem with the existing system as well, but the author does not have a positive incentive not to award the points since he himself still cannot get them back.


Where are shell/terminal settings stored?

I updated my Ubuntu but it crashed during installation and I was not able to recover it (my hard drive crashed). I changed my hard drive and re-install ubuntu  I saved all my important docs (bookmark, documents etc...)   One thing I was unable to recover is the profile from my shell (I changed the color scheme, title, number of lines scrollback etc...)  Where can I save this so next time something happens I won't have to set my terminal settings all over again?


How to evaluate environment variables into a string in Python?

I have a string representing a path.  Because this application is used on Windows, OSX and Linux, we've defined environment variables to properly map volumes from the different file systems.  The result is:  "$C/test/testing"   What I want to do is evaluate the environment variables in the string so that they're replaced by their respective volume names.  Is there a specific command I'm missing, or do I have to take os.environ.keys() and manually replace the strings?


How do I get the Ender Dragon egg and what does it do?

So I finally killed the Ender Dragon! As I was climbing the portal back to the world, I noticed that on top of the column there was an egg. So I attacked, mined, clicked and nothing happened, it just teleported away. What does the egg do and how do I get it?


Rotating Cone - Finding Energy and Momentum

I think I've a conceptual lacuna that needs to be filled, when it comes to a rigid body possessing angular velocities along more than one axes.  Here's my doubt -   Consider the following solid cone (mass $m$), with semi-vertical angle $\alpha$ and radius $r$, rotating about the Z axis with some angular velocity $\omega$. The axis of the cone, is always at a height equal to its radius, from the XY plane.     1. How is the total kinetic energy of the cone calculated?  2. How is the angular momentum of the cone calculated? (about Z axis, for example)  My doubt is not limited to the above question, which has been taken only for the sake of an example - and I believe a solution to the above question will help me understand the concept better.   While calculating the kinetic energy of a rigid body rotating about more than one axis, what exactly is done and WHY?  The translational kinetic energy is $\dfrac{mv²}{2}$, where $v$ is the velocity of the center of mass; and the rotational kinetic energy is $\dfrac{I\omega²}{2}$, where I is the moment of inertia about the center of mass (really? not sure) and $\omega$ is the angular velocity about Z axis (or is it the resultant angular velocity of the body?). Also, is the moment of inertia supposed to be about an axis through the center of mass, or about Z axis?   It's a mess, in short. Please explain the solution of the problem, and also the concept in detail. Thanks a lot!    For greater clarity as to what area I face problems in, I add a second problem too, in which the body posseses angular velocities about three axes.     You may assume the necessary moments of inertia, and dimensions for the above object. Just want to know how it's done, the approach, more than the exact answer.


Give an example where $\int_{\bar A} f$ exists but $\int_A f$ does not for a continuos $f$ on a bounded open subset $A$ of $\mathbb{R}^n $

In the book of Analysis on Manifolds by Munkress, at page 121, it is asked that     Let $A$ be a bounded open set in $\mathbb{R}^n $; let $f: \mathbb{R}^n > \to \mathbb{R} $ be a bounded continuous function. Give an example   where $\int_{\bar A} f$ exists but $\int_A f$ does not.   I couldn't find any such example. I mean I do noticed that $A$ should not be rectifiable, and the only way I can think of that $f$ is not integrable on $A$ is that the set $E$ where the limit  $$\lim_{x \to x_0} f(x) = 0$$ fails for $x_0 \in \partial A$ has a non-zero measure, but then this set $E$ also contained in $\bar A$, so in such a case $\int_{\bar A} f$ also wouldn't exists.  In short, I'm looking for such an example.  Note: I have read  answer, but I have no idea what the answerer is talking about, so I wanted to ask a new question including my own thoughts.


I tried to install vlc using the software centre and something pop up saying that  This error could be caused by required additional software packages which are missing or not installable. Furthermore there could be a conflict between software packages which are not allowed to be installed at the same time.  And from the details:  The following packages have unmet dependencies:  vlc: Depends: vlc-nox (= 2.2.0~pre2+git20141011+r57575+24+12~ubuntu14.10.1) but 2.2.0~pre2+git20141011+r57575+24+12~ubuntu14.10.1 is to be installed      Depends: libavcodec-extra-56 (>= 6:11) but 6:11-1 is to be installed      Depends: libavutil54 (>= 6:11~beta1) but 6:11-1 is to be installed      Depends: libc6 (>= 2.16) but 2.19-10ubuntu2.1 is to be installed      Depends: libegl1-x11 but it is a virtual package      Depends: libfreetype6 (>= 2.2.1) but 2.5.2-2ubuntu1 is to be installed      Depends: libgcc1 (>= 1:4.1.1) but 1:4.9.1-16ubuntu6 is to be installed      Depends: libgles1 but it is a virtual package      Depends: libgles2 but it is a virtual package      Depends: libpulse0 (>= 1:1.0) but 1:4.0-0ubuntu22 is to be installed      Depends: libqtcore4 (>= 4:4.8.0) but 4:4.8.6+git49-gbc62005+dfsg-1ubuntu1 is to be installed      Depends: libqtgui4 (>= 4:4.8.0) but 4:4.8.6+git49-gbc62005+dfsg-1ubuntu1 is to be installed      Depends: libstdc++6 (>= 4.9) but 4.9.1-16ubuntu6 is to be installed      Depends: zlib1g (>= 1:1.2.3.3) but 1:1.2.8.dfsg-1ubuntu1 is to be installed   I tried using command and same thing happened.  Any suggestion?


How does physics explain the enormous disparity between the gravitational scale and the typical mass scale of the elementary particles? In other words, why is gravity so much weaker than the other forces, like electromagnetism?


Primitive roots and quadratic nonresidues modulo a prime of form $2^n+1$

Let $p$ be a prime number. We call a unit $a$ in $\Bbb Z/p\Bbb Z$ a primitive root, if $\text{ord}_p(a)=p-1$.  Any unit in $\Bbb Z/p\Bbb Z$ can be written as some power as some power of $a$. if $p$ is of the form $2^n +1$, prove that the primitive roots in $\Bbb Z/p\Bbb Z$ are precisely the quadratic non-residues modulo $p$, if $n > 1$ , prove $3$ is always a primitive root.    I tried but can't figure out.


tar + gz files from folder as is without to put inside all sub folder

we want to tar.gz all the following jars files  2.6.4.0-91/spark2/jars/super-csv-2.2.0.jar 2.6.4.0-91/spark2/jars/univocity-parsers-2.2.1.jar 2.6.4.0-91/spark2/jars/validation-api-1.1.0.Final.jar 2.6.4.0-91/spark2/jars/xbean-asm5-shaded-4.4.jar 2.6.4.0-91/spark2/jars/xercesImpl-2.9.1.jar 2.6.4.0-91/spark2/jars/xmlenc-0.52.jar 2.6.4.0-91/spark2/jars/xz-1.0.jar 2.6.4.0-91/spark2/jars/zookeeper-3.4.6.2.6.4.0-91.jar   so I do the following   cd /var/tmp tar -czvf archive.tar.gz /usr/hdp/2.6.4.0-91/spark2/jars   but when I do  tar xvf archive.tar.gz   we get the usr folder  usr    while the expected results should be only the jars as ( without the sub folders )       super-csv-2.2.0.jar     univocity-parsers-2.2.1.jar     validation-api-1.1.0.Final.jar     xbean-asm5-shaded-4.4.jar     xercesImpl-2.9.1.jar     jxmlenc-0.52.jar     xz-1.0.jar     zookeeper-3.4.6.2.6.4.0-91.jar   what is wrong with my syntax   cd /var/tmp  tar -czvf archive.tar.gz /usr/hdp/2.6.4.0-91/spark2/jars


Why don't these statements both return 'true'?

So I came across some strange behaviour in python :  >>> 2+1 is 3 True >>> 2000+1 is 2001 False   It doesn't use the correct logic when large integers are used, why is this?


If-statements not outputting variables when conditions are met

I'm having problems with the below code not outputting the JOptionPane.showMessageDialog variable outputs when the if statement conditions are met from JOptionPane.showInputDialog inputs. Would love some help as to why it's not meeting the conditions or outputting the variables, i've also tried println and it still does the same which is just running through each showInputDialog's one after another. Thanks in advance.  public static void main(String[] args) {     String findingCheese = "You arrive to a piece of day old cheese, the scent allures you to go closer";     String findingCrack = "You arrive to a small crack in the wall, it looks like you could fit if you go closer";     String walktoCrack = "You walk right up to the crack and realise you can fit in." + "\n";     walktoCrack = walktoCrack + "You have your front legs in just as you hear someone right behind you";     String eatCheese = "You walk up to the large piece of a cheese and can't resist the urge to eat it." + "\n";      eatCheese = eatCheese + "As you are eating you here someone right behind you";     String walkAway = "As you turn to run away, you realise the owner has been behind you this whole time, with one last wack your sight fades to black";     String cheeseFall = "As you run pass the cheese, the monster in the kitchen slips and falls on the cheese, allowing you to escape. You have beaten the kitchen. Congrats";     String youFit = "You charge into the crack realising you fit exactly, you esacpe as you hear the monster in the kitchen curse you. You have beaten the kitchen. Congrats";     String story = "";     story = story + "Welcome to the choose your own adventure horror story!" + "\n";     story = story + "You are a rat stuck in a kitchen, inside this kitchen is someone that doesn't want you there." + "\n";     story = story + "They want you dead! To escape, you must choose the correct directions and actions to take." + "\n";     story = story + "Good luck rodent.";     JOptionPane.showMessageDialog(null, story);     String direction = JOptionPane.showInputDialog("Enter which direction you want to go between left or right");     if ( direction == "Left" || direction == "left") {     JOptionPane.showMessageDialog(null, findingCheese);     }     if ( direction == "Right" || direction == "right") {     JOptionPane.showMessageDialog(null, findingCrack);     }     String closer = JOptionPane.showInputDialog("Do you want to go closer? yes or no");     if ( closer == "yes" || closer == "yes" && direction == "Left" || direction == "left") {     JOptionPane.showMessageDialog(null, eatCheese);     }     if ( closer == "yes" || closer == "yes" && direction == "Right" || direction == "right") {     JOptionPane.showMessageDialog(null, walktoCrack);     }     if ( closer == "no" || closer == "No") {         JOptionPane.showMessageDialog(null, walkAway);     }     String run = JOptionPane.showInputDialog("Do you want to run away right now? enter yes, if you want to continue forward enter no");     if ( run == "yes" || run == "Yes") {     JOptionPane.showMessageDialog(null, walkAway);     }     else if ( run == "no" || run == "No" && direction == "Left" || direction == "left") {     JOptionPane.showMessageDialog(null, cheeseFall);     }     else if (run == "no" || run == "No" && direction == "right" || direction == "Right") {     JOptionPane.showMessageDialog(null, youFit);     }         }


How can I play video or listen to music?

Recently I installed Ubuntu 14.04, now I am unable to play/listen to any music or video. I am a new user.


I have been told that $$[\hat x^2,\hat p^2]=2i\hbar (\hat x\hat p+\hat p\hat x)$$ illustrates operator ordering ambiguity.  What does that mean? I tried googling but to no avail.


Null Pointer Exception Java Shopping Cart "sort" Method

For a school assignment, we have to make a Shopping cart class, along with an Item class and a runner. I figured out how to print out a receipt for items the user enters, but one thing I can't figure out is how to write a sort method using insertion Sorting, which orders each item in the cart by its total cost (price * quantity)  Here is my error:  java.lang.NullPointerException     at ShoppingCart.sort(ShoppingCart.java:54)     at Shopping.main(Shopping.java:32)   I went back to the lines stated  ShoppingCart: (line 54)  public void sort() {     double temp;     int pos = 0;     for (int i = 1;i< cart.length;i++){       temp = cart[i].itemPrice(); //line 54       pos = i;       while (pos>0 && temp < cart[pos-1].itemPrice()) {         cart[pos] = cart[pos-1];         pos--;       }       cart[pos] = cart[i];     }   }   Shopping: (line 32)   cart.sort();   And here is my method to get the price in the Item Class  public double itemPrice(){      return total; }   I'm not sure how to fix the Null Pointer Exception error.


Would it be useful to remove hidden communities from the combined flair?

The new profile page has the wonderful new function to hide communities. But, as I can see, they are removed only from the new profiles — not from the site profiles still using the old profile page, and also not from the network-wide account page.  It seems to me as if the new profile page would be somehow an isolated part of the SE software. Is it an intentional feature?  From the viewpoint of the SE users taking part in multiple communities, the best solution would maybe be this:   if the site icons belonging to hidden communities didn't appear in the combined flair, but they would be still counted into the combined reputation.   From the other side, maybe you won't confuse things (especially with this mixed flair behavior), and try to isolate the new profile functionality, at least in its currently newborn state.


What cards transfer mana from colorless to any color?

So all I need to know is if there are any known MTG cards that say "pay one colorless mana: produce one mana of any color."


apt-get -y upgrade keep asking me to confirm keep /tmp/grub.xC3mMKP0zx file and i can't skip it

We have automated build bash script where at the beginning executed command  apt-get update; apt-get upgrade -q -y -u    --allow-downgrades --allow-remove-essential --allow-change-held-packages    --allow-change-held-packages --allow-unauthenticated;   but it keeps asking this question with popup in terminal     A new version (/tmp/grub.xC3mMKP0zx) of configuration file /etc/default/grub is available, but the version installed currently has been locally modified.     which is reason that automated script execution is hanging and i can't force skip it somehow with --allow* or -y options  our ubuntu is 16.04  how i kan avoid that popup appearce ?  Please help, Thanks  -- UPDATE --  I have tried many solutions  also this one:  which was mentioned as duplicate to this question   apt-get -o DPkg::Options::=--force-confdef upgrade -q -y -u --force-yes   it still the same promt popup asking for choose default option


Consider the recursive relation $ a_0=1, \ a_1=1 \ \ and \ \ a_{n+1}=a_n+a_{n-1} $.   Assuming that $ \ \ a=\lim |\frac{a_n}{a_{n+1}}| \ $ exists , find the limit $ \ a \ $.  Answer:  $ \ \ a=\lim |\frac{a_n}{a_{n+1}}|=\lim |\frac{a_n}{a_{n}+a_{n-1}}| $ , (since $a_{n+1}=a_n+a_{n-1}) ,   $  or, $ a=\lim |\frac{\frac{a_n}{a_{n-1}}}{\frac{a_n} {a_{n-1}}+1}| $   or, $ a=\frac{\lim|\frac{a_n}{a_{n-1}}|}{\lim|\frac{a_n}{a_{n-1}}+1|}=\frac{a}{\lim|\frac{a_n}{a_{n-1}}+1|}$ ,  (Since $ \lim |a_n /a_{n-1}|=\lim |a_{n+1}/a_n| $ ) .   Or, $ \lim|\frac{a_n}{a_{n-1}}+1|=1 $   But I can't proceed furher . Any help is really ppreciating .


Is it possible to use the find command to find all the "non-binary" files in a directory?  Here's the problem I'm trying to solve.  I've received an archive of files from a windows user.  This archive contains source code and image files.  Our build system doesn't play nice with files that have windows line endings.  I have a command line program (flip -u) that will flip line endings between *nix and windows.  So, I'd like to do something like this  find . -type f | xargs flip -u   However, if this command is run against an image file, or other binary media file, it will corrupt the file.  I realize I could build a list of file extensions and filter with that, but I'd rather have something that's not reliant on me keeping that list up to date.  So, is there a way to find all the non-binary files in a directory tree?  Or is there an alternate solution I should consider?


insuffient dont have enough space on my sd card

When I'm trying to download samthing it says "insuffient space on my device"my brean it does work when I hear that......it so confusing me..and I have engh space on my memory card


topology broken after extruding the mesh

Its a very simple question, I am not sure what will be the impact of this on rigging & animation of my Organic Model. I was trying to extruding the circle and when I switched from Edit mode to object mode, I found that the mesh is broken (refer ciruclar mesh)   Does it have impact on my rigging & animation & or any other stage (like UV mapping)


I am sort of new to Linux, and completely new to Ubuntu (20.10) as a whole.. I switched from Windows recently and have installed Wine to play Windows games, but it has completely messed up after installation. If I try to "sudo apt-get update" or "sudo apt update", it does nothing and gives an error which is: E: Malformed entry 1 in list file /etc/apt/sources.list.d/archive_uri-https_dl_winehq_org_wine-builds-ubuntu_focal-groovy.list (Component) E: The list of sources could not be read. E: Malformed entry 1 in list file /etc/apt/sources.list.d/archive_uri-https_dl_winehq_org_wine-builds-ubuntu_focal-groovy.list (Component) E: The list of sources could not be read.  I have tried completely reinstalling wine as a whole, and going into the file itself to try and fix it to the best I can but nothing is working. I couldn't even uninstall because it gives me the error. Coming here to ask is my last resort, and hopefully this can be fixed with the help of others.


Best Practice for captcha based protection against D.O.S to Nginx Proxy

The idea is explained   In simple words, Nginx Proxy plays the role of load balance and transmits the HTTP/HTTPS requests to servers.  If the number of request times within a certain period from an individual IP exceeds a threshold, it will trigger a captcha for the upcoming requests.  And the end-user must input the correct captcha code before he can continue to access the site.  Do you know any open source / free NGINX module for this usage? I searched on the Internet and here is one of them:  seems it needs modification.  Any suggestion / experience is welcome, thank you


Why was my link only answer flag for this question declined?

Why was my (Link only answer) flag for  question declined with the message:      flags should only be used to make moderators aware of content that   requires their intervention


What is the use of REAL random number generators in cryptography?

I understand the use of pseudo-random number generators. I am not getting mixed up between these and "real" random number generators.  However, I don't understand for what a real random number generator is used. If it is not deterministic, how can it be used in an algorithm?


Find my Mac: "Online, no location available"

I'm testing the "find my Mac" feature at icloud.com and one of my Macs can't be found. The site reports "Online, no location available".  I've looked around a bit including at Apple's , which includes troubleshooting for this situation. So I'll mention that:   Find My Mac is enabled on the Mac in System Preferences --> iCloud. The date and time zone on the Mac are correct. The Mac is connected to the internet via Wifi. Other Macs on the same Wifi network are found, so it doesn't appear to be a problem with Wifi location. Location Services is enabled in System Preferences --> Security & Privacy --> Privacy I am in the USA, where this feature should work (and as mentioned, does work for other Macs on the same network). I'm logged in to the same iCloud account on multiple Macs, but only the one Mac is not found.   Also, though not specifically mentioned in TS 4006 or on other sites that I've seen:   The Mac does not have a firewall enabled The "Play Sound" feature of Find my Mac works. If I click on this at icloud.com, a loud annoying noise plays on the affected Mac. The affected Mac is able to determine its own location well enough to set the time zone automatically and identify the city I'm in. Web sites that ask for my location on the Mac (e.g. Foursquare) get the correct location.   Rebooting the Mac does not have any effect on any of this.  The Mac is a 2012 MacBook Air, running Mac OS X 10.8.5, with all current updates applied.


How is a bitmap usually stored in a database?

This is the first time I'm storing data as a bitmap in a database, and was wondering how I should be storing it. For example, if I have four options:  colors = ['red', 'yellow', 'blue', 'green']   And the data is structured like this:  id      name        favorite_colors 1       'tom'       ['yellow', 'green']   I would like to store the favorite colors as a bitmap, for example, 0101 (red=0, yellow=1, blue=0, green=1).  What would be the correct way to store this?  For example, as a number?  id      name       favorite_colors 1       'tom'      5   -- field type = UNSIGNED INT   Or as raw binary?  id      name       favorite_colors 1       'tom'      b'0101'  -- what type would this be stored as?


I want to Calculate $\sum_{k=1}^n k2^{n-k}$. Here's my attempt:  $$\begin{align}  &\sum_{k=1}^n k2^{n-k} = \sum_{k=1}^n k2^{n+1}2^{-k-1} =2^{n+1}\sum_{k=1}^n k2^{-k-1} & &\text{(1)} \\ &k2^{-k-1} = -\frac{d}{dk}2^{-k} & &\text{(2)} \end{align}$$   Plugging $(2)$ to $(1)$,   $$\begin{aligned}  2^{n+1}\sum_{k=1}^n k2^{-k-1}  &= 2^{n+1}\sum_{k=1}^n-\frac{d}{dk}2^{-k} \\  &= -2^{n+1}\sum_{k=1}^n\frac{d}{dk}2^{-k} \\  &= -2^{n+1}\frac{d}{dk}\sum_{k=1}^n2^{-k} \\  &= -2^{n+1}\frac{d}{dk}(1-2^{-n}) \\ &= -2^{n+1}\cdot 0 \\ &= 0 \end{aligned}$$   Obviously, I don't know much about summation and derivative. Can you please let me know where I am doing wrong and give me a hint for this question? Thanks!


I have been asked this question in an interview. Please share your opinion.  The interviewer asked me "what's difference between system test and system integration test". I gave the below answer:  System Test – The process of testing an integrated system to verify that it meets specified requirements.  System Integration Test – Testing the integration of systems and packages; testing interfaces to external organizations (e.g. Electronic Data Interchange, Internet).  Then he asked me "what's the difference between automated system test and automated system integration test?"


When would it become necessary to use an OS for an ARM MCU

I take it an ARM MCU can be run without an OS - at which point might it become necessary to install one?  Can the mbed SDK run without the mbed-os or any other mbed for that matter?


Let $(X,d)$ a metric space. Show that $d'(x,y)=\dfrac{d(x,y)}{1+d(x,y)}$ define a metric on $X$.  Hello, I have this problem. The triangular inequality is my difficulty. Indeed, we have that show that $d'(x,z)\le d'(x,y)+d'(y,z),\forall x,y,z\in X.$ Good, I do this...  $d'(x,z)=\dfrac{d(x,z)}{1+d(x,z)}\le \dfrac{d(x,y)+d(y,z)}{1+d(x,z)}=\dfrac{d(x,y)}{1+d(x,z)}+\dfrac{d(y,z)}{1+d(x,z)}.$  I don't understand how does with $d(x,z)$? Or if exists any form for bounded this expression.


Maximal Ideals of Ring of real valued continuous functions defined over [0,1]

Suppose R be the ring of real valued continuous functions defined over [0,1].And if M is a maximal ideal of R.Then prove that M will be of following form. M={f in R| f(x)=0} for a fixed x in R  Obviously the ideal given by M(x)={f in R|f(x)=0} is an maximal ideal for a fixed choice of x in [0,1].  But starting from a random Maximal ideal how can I get to that form? Thanks in Advance


Auto-indentation of LaTeX Source code in TeXShop

Sometimes, I find it a bit hard to manually indent my code so that all the \begin{...}'s and \end{...}'s align vertically in my .tex source code.  In some code development environments, I know that there are options to auto-indent the beginnings and ends of loops, functions, and other code blocks. I'm wondering if there is a way to do this in TeXShop or any other freeware for latex code?


Scheduler can't find Environment.CurrentDirectory for a running console app

I have simple C# console app that gets data from config.ini located in same directory. Reference to config.ini implemented with Environment.CurrentDirectory:  IniFile myIni = new IniFile(Environment.CurrentDirectory + "\\config.ini");   Problem is when I'm running app with Scheduler, it can't find path to config.ini. How to set such path for running app with Scheduler?


Is there a way to make Eclipse wrap the line with the b's to a length of 120 per line? I wasn't able to configure the code formatter to wrap the line. This really drives me crazy...  public class Position {     public static void i() {         error("bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb");      }      private static void error(String string) {         // TODO Auto-generated method stub      } }


How to specify the parseObject to add in a List

I am trying to add some specific ParseObject in my List based on the username of the current user. But this code only ended up in NullPointerException on lines:  query.findInBackground(new FindCallback()  mStatus.add(status.get(i));  Somebody please help me solve this. Thank you.  @Nullable @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {     View view = null;     view = inflater.inflate(R.layout.update_status, container, false);      ParseUser currentUser = ParseUser.getCurrentUser();     final String strCurrentUsername = currentUser.getUsername();     if (currentUser != null) {          //try         final ParseQuery<ParseObject> query = new ParseQuery<ParseObject>("Status");         query.orderByDescending("createdAt");          query.findInBackground(new FindCallback<ParseObject>() {             @Override             public void done(final List<ParseObject> status, ParseException e) {                 if(e == null){                     //success                     for(int i = 0; i <status.size();i++){                         String usernow = status.get(i).getString("user");                         if(usernow.equals(strCurrentUsername)){                             Toast.makeText(getActivity(), "num"+i, Toast.LENGTH_SHORT).show();                             mStatus.add(status.get(i));                         }                         else i++;                     }                     //mStatus = status;                     StatusAdapter statusAdapter = new StatusAdapter( getListView().getContext(), mStatus);                     setListAdapter(statusAdapter);                  }else{                     //there was a problem                  }             }         });       } else {         Intent intent = new Intent(getActivity(), FirstActivity.class);         startActivity(intent);     }      return view; }


def method(n, i=1):     yield [n]     for i in range(i, n//5):         for j in method(n-i, i):             yield [i]+j   for this function, Can please anyone explain what is this doing? yield [n]


General solution to the PDE $xU_x+yU_y=0$

Solve the equation $xU_x+yU_y=0$.   From Partial Differential Equations: An Introduction, 2nd Ed. (Strauss, pg. 10). There are no boundary conditions.  Solution: The PDE can be written $(x,y)\cdot\nabla U(x,y)=0$, implying that the vector $(x,y)$ is tangent to the PDE's characteristic equation. Then I can write $dy/dx=y/x$, and to solve this ODE,  $$\frac{dy}{dx}=\frac yx \\ \ln y=\ln x+c_1 \\ y=cx \\ y/x=c$$  Hence, the PDE is dependent on $c$ and I can write $U(x,y)=f(y/x)$ for some function $f$, solving the problem.  Question: Is this solution correct? The hint for the question (supplied by the professor) said I should use a substitution of variables, but this seems reasonably valid.


MTG can you destroy a chosen sacrificed creature twice

Me and my friends were playing and I chose to destroy his creature but in response he used its ability to sacrifice it but in response I chose to use another instant of destroy target creature so my question is can I do that or no since the stack is involved and it’s not sacrificed to cast it since it’s already in play  So is it Scenario 1: I use “” to target his “” so he sacrifices it in response to deal 3 damage to my “” but in response to that I play another “Murder” that targets “Aerie Ouphes” again can I do that since by the stack my second “Murder” would go off first before his ability to sacrifice it  Also my friend thinks he can do Scenario 2: I use “Murder” to target his “Aerie Ouphes” so he sacrifices it in response to deal 3 damage to my “Vampire Nighthawk” but in response to that I play another “Murder” that targets “Aerie Ouphes” again but in response to my second “Murder” use “Aerie Ouphes” ability again choosing to sacrifice it and deal the damage to “Vampire Nighthawk” a second time but with the same card ability twice in a stack  I was thinking wouldn’t it go on the stack as  1: Murder targeting Aerie Ouphes 2: Aerie Ouphes ability to sacrifice it and deal damage to my Vampire Nighthawk 3: second Murder targeting Aerie Ouphes  Then the stack would go through with the last thing activated in the chain first


"It has not been unchanged." Is that a valid sentence?

Do I have to understand the sentence:     It has not been unchanged   .. as if the related subject actually changed, or whether there has been no change at all? In short, is this a double negative?


How to dynamically create a SQLite table having its columns named after a List elements?

For example: If I create a list people and that list contains Name, Age, Height as the elements, then a Table of Name People will be created, having the columns Name, Age, Height  I tried this code...  static final String DATABASE_NAME="MyDatabase";     static final int DATABASE_VERSION = 1;     static String TABLE_NAME=null;     static String CREATE_TABLE = null;     static List<String> COLUMNS = null;     static String DROP_TABLE = null;      private Context context;      public DBHandler(Context context,String Table_Name,List<String> columns,){         super(context,DATABASE_NAME,null,DATABASE_VERSION);         this.context = context;         this.TABLE_NAME=Table_Name;         this.COLUMNS = columns;         CREATE_TABLE ="CREATE TABLE "+TABLE_NAME+"("+COLUMNS.get(0)+" INTEGER PRIMARY KEY, "+COLUMNS.get(1)+" TEXT,"+COLUMNS.get(2)+" TEXT,"+COLUMNS.get(3)+" TEXT,"+COLUMNS.get(4)+" TEXT)";         DROP_TABLE = "DROP TABLE IF EXISTS "+TABLE_NAME;     }     public DBHandler(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {         super(context, DATABASE_NAME, factory, DATABASE_VERSION);         this.context=context;     }      @Override     public void onCreate(SQLiteDatabase sqLiteDatabase) {         sqLiteDatabase.execSQL(CREATE_TABLE);     }


Can I install Ubuntu on an empty hard drive? Or do I need Windows installed to install it?


When some people pronounce the word "getting", it sounds to me like they're saying something like "get'n". Is that some kind of dialect?


Setting a document in MS Word-12pt (12bp)

Warning  If you're looking for advice how to make your document look like it's been written in Word, this is most likely not the question you're looking for. This question is mostly of theoretical nature, as it results in tiny differences, which will most likely not be noticed by someone who doesn't allow the use of LaTeX.  Questions that might be more helpful for this matter are:           Question  I learned that MS Word uses a slightly different version of the unit "point" (pt) than TeX does:     The 12 point of Word will be PostScript point, which in TeX would be called 12bp. A TeX pt is slightly smaller: it's 1/72.27 inch, while a bp/PostScript point is 1/72 inch. See also    ( in )  I'm writing a paper that would usually be expected to be "typeset" in MS Word, thus I want to use the same font size as Word would.  How do I set a document e.g. in the "12pt" font size that MS Word would use?  In case it matters, I'm using the article document class, Latin Modern (lmodern) as a font with the T1 font encoding and compile with pdfLaTeX, but input on different set-ups is more than welcome.


Correct way of structuring CMake based project with Template class

I am having following compilation issue with my project with template class  Undefined symbols for architecture x86_64:   "Node<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >::Node(int, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >)", referenced from:       _main in main.cpp.o ld: symbol(s) not found for architecture x86_64 clang: error: linker command failed with exit code 1 (use -v to see invocation) make[2]: *** [apps/main] Error 1 make[1]: *** [apps/CMakeFiles/main.dir/all] Error 2 make: *** [all] Error 2   my files are structured as follows:  ├── include │   └── maple │       └── node.hpp ├── src │   ├── CMakeLists.txt │   └── node.cpp ├── apps │   ├── CMakeLists.txt │   └── main.cpp └── CMakeLists.txt   /CmakeLists.txt  add_subdirectory(src) add_subdirectory(apps)   /src/CMakeLists.txt  set(HEADER_LIST "${maple_SOURCE_DIR}/include/maple/node.hpp") add_library(node_lib STATIC node.cpp ${HEADER_LIST}) target_include_directories(node_lib PUBLIC ../include)   /app/CMakeLists.txt  add_executable(main main.cpp) target_link_libraries(main PRIVATE node_lib)   /include/maple/node.hpp  template <class T> class Node { private:     int key;     T value; public:     Node();     Node(int key, T value); };   /src/node.cpp  template<class T> Node<T>::Node() { }  template<class T> Node<T>::Node(int key, T value) {     key = key;     value = value; }  template Node<std::string>;   /app/main.cpp  int main()  {    Node<std::string> node(3, "abc");    return 0; }   Can anyone guide me on how to compile this project right?  I am already aware that the template class needs the implementation along with the definition  I am asking how to achieve compilation using Cmake when .h and .cpp for template class are in different directories, as in a typical C++ project.


How to get large amounts of xp safely and quickly in Minecraft?

Killing randomly spawned zombies at night is both dangerous and slow. Other methods - breeding animals, mining ores, smelting materials, fishing - builds up XP painfully slowly. Top level enchantment with the table requires 30 levels and uses up 3, that's 165 mobs to kill for first enchantment, and 34 mobs to recuperate from level 27 to 30. It's fairly hard to gather that much running at night and killing them as they attack you. For enchanting books, the top enchants may take up to 39 levels, and drain your levels to zero in the process. That's a whopping 350 mobs to kill, 1743 coal ore broken, or over half the levels obtained killing the ender dragon for the first time. Trying to gather enough XP for a good enchanted set of gear using these methods takes too long. Players in fully enchanted gear aren't uncommon, many of them even trade the good gear for prices that definitely don't look like worth weeks of grinding. How might they manage to obtain the XP necessary for dozens or hundreds of high level enchantments quickly and easily like that?


becoming a cryptographer after math studies

After studying philosophy and being a philosophy teacher, I took back studies 4 years ago and I did a bachelor in maths. I'm in maths grad school now (I'm 32), and I would like to work in cryptography. (I took as many algebra and arithmetic and logic courses as I could, and I'm studying Galois theory this semester.)  I have two questions:  First, how do people who have a background in pure mathematics convert into cryptographers ? For instance, I know very few programming languages (I only know some Python and Matlab, and know next to nothing in C and in object programming). Is it necessary to have knowledge and experience in a lot of languages, and in programming in general, to work in the field of cryptography?  My second question is : is my project realistic? Meaning, is there a chance some company will ever hire a guy who started studying maths with 28, and has no working experience in this field, or even computer science in general?  Thanks in advance for any answers, tips, suggestions, or even encouragements :)  Supplement question: is it necessary to have a PhD to work in cryptography, or is it possible with just a masters. If so, what are the differences between the jobs of someone who has a PhD and someone who hasn't?


Hidden Communities indicated despite the account being deleted

I have just noticed on my Chemistry (and other) profiles that it is stated that I have '1 hidden community' (as shown below):    This was true, until I had m membership at that site deleted a little while ago (2 days at the time of writing this question).  When I go to the list (by clicking 'edit list'), it is shown correctly that there are no hidden communities (as I had earlier had my membership there deleted):    Is this a bug?


If I delete Minecraft Pocket Edition, do I get my stuff when I download it again?

On my iPad I want to make a server.  It worked on a different WiFi.  When I got back to mine, it does not work.  So I think if I delete it, the server will be back.  Is that true?


I'm trying to prove the following Theorem from my Discrete mathematics lecture notes:   Let m $\ge 1$. If $a, b \in \mathbb{Z}_{m}^{*}$, then $ab \in \mathbb{Z}_{m}^{*} $.   Where,  $\mathbb{Z}_{m}^{*} = \{a \in \mathbb{Z}_m : gcd(a, m) = 1\}$   Since, $gcd(a, m) = 1$ and $gcd(b,m)=1$ my intuition tells me $gcd(ab, m) = 1$. However, I'm not sure how to prove $gcd(ab, m) =1$.   Can anyone give me a hint or post the proof of this?


Given a signal wire [7:0] dummy, how can I concatenate it n times?  That is, is there a notation for the following:  {dummy, ..., dummy} // n times   ?


Change Drupal interface language back to English

I made the mistake to translate the Drupal interface in my local language. But since the language is set into the database, I can't delete this language using the Drupal UI. And I'm not sure which file(s) to delete in the database.    Does anyone know a (faultlessly) way to translate the Drupal interface back to English?


Moving the 'center of the object' to the actual center...

I have sculpted a model in sculptris (maybe i have done something wrong, it's my first time) and exported it to an object then reduced polygones and stuff, and now i have some stuff to do in blender but i noticed that the center of my model isn't really the center. It has moved to his left and idk how to move it to the right position. I have never used Blender before so maybe it's a dumb question. Here's an image of what it looks like:     I'm not a Blender guru so please be as precise as you can if you know how to fix this.Thank you for your.


I'm using amsmath and its \tag command to tag equations. I remember having a situation where I liked having the tag on the left better than on the right. So I gave my class (which is report btw) the leqno options. Now, however, I find myself wanting to revert to reqno. However, I fear actually removing leqno will make the above mentioned situation look worse. I found that the solution in  does not work with equation: \documentclass{report} \usepackage[leqno]{amsmath}  \makeatletter \newcommand{\leqnomode}{\tagsleft@true} \newcommand{\reqnomode}{\tagsleft@false} \makeatother \begin{document}  \begin{align}   f(x) &= ax^2 + bx + c \\   g(x) &= dx^2 + ex + f \end{align}  \reqnomode  \begin{align}   f(x) &= ax^2 + bx + c \\   g(x) &= dx^2 + ex + f \tag{e} \end{align}  \begin{equation}   a^2+b^2=c^2.\tag{1} \end{equation}  \leqnomode  \begin{equation}   -\Delta\phi=4\pi k\rho.\tag{2} \end{equation}   \end{document}  Output:  The first equation should still be in \reqnomode (alias \tagsleft@false) from the second align, yet the tag is on the left. How do I solve the problem without using an align or such which are for multiline display and would therefore be out of place on a single one-line equation?


Show that given seven real numbers, it is always possible take two of them, such that $\left\vert\frac{a-b}{1+ab}\right\vert<\frac{1}{\sqrt{3}}$

Show that given seven real numbers, it is always possible take two of them, such that $$\left\vert\frac{a-b}{1+ab}\right\vert<\frac{1}{\sqrt{3}}$$   The "Pigeonhole principle" states that if $n$ items are put into $m$ containers, with $n > m$, then at least one container must contain more than one item, but how I an define my "container" such that meets the condition of the problem?


How to set the width of the last column with tabular package?

I want to generate a table with fixed column width. This works for all the columns except for the last column.   Working example (fixed column width for all column except the last one)  \documentclass{article} \usepackage{array} \usepackage{csvsimple} \usepackage{filecontents}  \begin{filecontents*}{grade.csv}     name,givennamex,matriculation,gender,grade     Maier,Hans,12348,m,1.0     Huber,Anna,23456,f,2.3     Weisbaeck,Werner,34567,m,5.0 \end{filecontents*}  \begin{document}     \begin{tabular}{>{\raggedright}m{2cm}|>{\raggedright}m{2cm}|c}%         \bfseries long title column 1 & \bfseries long title column 2 & \bfseries long title column 3% specify table head         \csvreader[head to column names]{grade.csv}{}% use head of csv as column names         {\\\hline\givennamex & \name & \matriculation}% specify your columns here     \end{tabular} \end{document}   Example with problem (fixed column width for all column including the last one)   \documentclass{article} \usepackage{array} \usepackage{csvsimple} \usepackage{filecontents}  \begin{filecontents*}{grade.csv}     name,givennamex,matriculation,gender,grade     Maier,Hans,12348,m,1.0     Huber,Anna,23456,f,2.3     Weisbaeck,Werner,34567,m,5.0 \end{filecontents*}  \begin{document}     \begin{tabular}{>{\raggedright}m{2cm}|>{\raggedright}m{2cm}|>{\raggedright}m{2cm}}%         \bfseries long title column 1 & \bfseries long title column 2 & \bfseries long title column 3% specify table head         \csvreader[head to column names]{grade.csv}{}% use head of csv as column names         {\\\hline\givennamex & \name & \matriculation}% specify your columns here     \end{tabular} \end{document}   What can I do to set the width of the last column?  EDIT  After the comments below I added the package ragged2e and changed the first line  \begin{tabular}{>{\raggedright}m{2cm}|>{\raggedright}m{2cm}|>{\raggedright}m{2cm}}%   to this one   \begin{tabular}{>{\raggedright}m{2cm}|>{\raggedright}m{2cm}|m{2cm}}%   Overall, the code is now the following:  \documentclass{article} \usepackage{array} \usepackage{csvsimple} \usepackage{filecontents} \usepackage{ragged2e}  \begin{filecontents*}{grade.csv}     name,givennamex,matriculation,gender,grade     Maier,Hans,12348,m,1.0     Huber,Anna,23456,f,2.3     Weisbaeck,Werner,34567,m,5.0 \end{filecontents*}  \begin{document}     \begin{tabular}{>{\raggedright}m{2cm}|>{\raggedright}m{2cm}|m{2cm}}%         \bfseries long title column 1 & \bfseries long title column 2 & \bfseries long title column 3% specify table head         \csvreader[head to column names]{grade.csv}{}% use head of csv as column names         {\\\hline\givennamex & \name & \matriculation}% specify your columns here     \end{tabular} \end{document}   There is still one Problem: I cannot set the last column as centered (I tried to write >{\raggedright}m{2cm} instead of m{2cm} but it doesn't work).


Why did everyone have to turn into Harry Potter?

In Deathly Hallows, why couldn’t Harry drink the polyjuice and turn into any Muggle?  Surely it would have been much easier than seven people turning into Harry Potter.


Suppose there exist subgroups $H,K\subseteq G$ such that $G = H \cup K$. Prove that $H = G$ or $K = G$.  I am not sure how to start?  Thanks in advance.


Centering a title under the x-axis of a pgfplot while ignoring the horizontal space occupied by the label for the plot

I have the plot of a rational function, and I have the label for it on the right side.  I code the option clip=false to allow the label to extend "outside the Cartesian plane."  I want the label for the plot to be centered with respect to the x-axis.  Right now, it is displayed with respect the the width occupied by the x-axis and the label for the plot.  \documentclass[10pt]{amsart}  \usepackage{tikz} \usetikzlibrary{calc,intersections,}  \usepackage{pgfplots} \pgfplotsset{compat=1.11}   \usepackage{mathtools,array}   \begin{document}  \begin{tikzpicture} \begin{axis}[width=3in, height=3in, axis equal image, clip=false,     axis lines=middle,     xmin=-5,xmax=5,     ymin=-5,ymax=5,     restrict y to domain=-5:5,     xtick={\empty},ytick={\empty},     xlabel=$x$,ylabel=$y$,     enlargelimits={abs=0.25cm},     axis line style={latex-latex},     xlabel style={at={(ticklabel* cs:1)},anchor=north west},     ylabel style={at={(ticklabel* cs:1)},anchor=south west} ]  \addplot[blue, domain=-5:5] {x^3/(x^2 + 1)} node[anchor=west, pos=1, font=\footnotesize] {$y=\dfrac{x^{3}}{x^{2}+1}$};  \end{axis}  %Title for the plot of the second rational function. \node[font=\bfseries, anchor=north, inner sep=0, align=center] at ($(current bounding box.south) +(0,-0.3)$) {\mbox{An illustration of the continuity of} \\ \mbox{a rational function defined on \boldmath$\mathbb{R}$\unboldmath}};  \end{tikzpicture}  \end{document}


Useful, systematic feedback to a user's review queue actions

Lacking confidence in my reviewing abilities, I usually avoid the review queue.  But, I've been asking a decent amount of questions lately and haven't found many questions I could answer (so as to maintain karmic neutrality or whatever).  So, I've been reviewing more lately.  Wanting to improve my reviewer chops, I've been looking around for ways of getting feedback, but not finding much.  Sure, sometimes the review system gives you a fake question, but those're pretty obviously good/bad.    Wanting to spur some good discussion, let's lay out some basics.    Hypotheticals Here are some hypothetical examples: (A) 85% of the questions I marked as "Looks OK" ended up being considered genuinely OK. (B) 40% of the questions I flagged for "Requires Editing" ended up being closed for needing more detail. (C) Typically when I flag a late answer to a  question, it's subsequently unanimously marked as OK.   Note that, in each of these cases, I'm learning something specific and actionable about my reviewing approach.  Also note that this information is nuanced:  it's easy to see whether or not my "Looks OK" reviews match the consensus with a check or X UI element (as ), and a percentage agreement with the consensus (as ) would provide a more quantitative metric.  But, neither would provide the more targeted feedback shown in hypotheticals (B) and (C).  Equally importantly, the , so we shouldn't give this impression.    Not Outsmarting Ourselves For several reasons (humans are imperfect, reviews are limited, etc.), we shouldn't push everyone to review exactly the same way.  So, an important question in any such improvement is how to allow for some wiggle room?  To me, this is the keystone to doing this right.  Indicating that the consensus answer is always right/wrong is a problematic precedent.  Perhaps the feedback system should compare how often my reviews deviated from the norm to how often others' reviews do so, i.e. normalizing the variance.  What about a system that provides notifications when we're making the same mistakes?  E.g. the next time I flag a late  answer, a pop-up tells me that reviewers don't usually agree with me when I do this.  In this way, a nudge is provided against my worst behaviors right as I'm making them.    As it stands, I've had a really hard time figuring out how to be a better reviewer, and it continues to be a deterrent to me reviewing items.  This feels bad for the community, and it feels fixable.  But, I'm far from a specialist in these matters, and don't have a good sense of what is doable.  So, how could automated reviewer feedback be better conveyed?  Do any of the ideas above hold water?    EDIT 1 The zeroth-order solution would be  or a slightly improved version in , though, as laid out in this question, I don't think it'd be hard to provide much more powerful feedback that also doesn't push people too hard toward reviewing the same way.    EDIT 2 Reorganized, updated throughout to juxtapose more strongly to the two related questions (for which this question is currently marked a duplicate), and to emphasize how this question differs.


Will an old (bad) post affect the reputation later?

Just consider the (general) scenario:   A new enthusiastic user joins  and asks a question. It isn't a very good one, so it naturally gets a lot of downvotes (around 3-4). Now, the reputation of the user stays at 1 and the user realizes his(/her) mistake. The user doesn't delete the post, and it stays there (it isn't deleted by anyone). Meanwhile, the user posts a good question/answer which brings in a lot of upvotes.   Now, my questions are:        Will the old undeleted post reduce the earned reputation of the user (or will it remain constant at the reputation earned by the new post)?   Will further downvotes to the old post affect the repuation?        PS: This is just an example of what I mean! :-(


Can the Artificer Artillerist's tiny-sized Eldritch Cannon that is not held in hand still ride or be carried elsewhere on the body?

As an Artillerist Artificer, if I create a tiny-sized Eldritch Cannon with legs, can I place this cannon somewhere on my person and let it use its legs to hold on to my character (on my head, shoulder (Predator!), wrist, belt, top of my backpack, etc.)?  I understand that with RAW, it cannot move on its own into an occupied space, so it would not be able to climb up onto me, but I think that I should still be able to pick it up and place it somewhere as an object interaction.  It could use its legs to hold on once in place.  If I can control it from up to 60 feet away, I would think that it shouldn't hinder the use of my hands for other actions once it is there.


Is it possible to publish a FLA from the command line?

In our project we have a large number (hundreds) of FLA files created by the artists in CS3, from which we compile SWFs to use in our Flex/AS3 application.  As part of a streamlined build/deploy system, it would be really handy to be able to automate publishing all these FLAs, and ideally deploying the SWFs too. I found some ways to do the batch publishing from CS3 using JSFL, but was surprised to discover CS3 doesn't apparently have any command-line functionality for this?  This is on a Linux system for what it's worth, I don't have experience with JSFL to know if you can run scripts from the command line somehow?  note: I should have said "Linux is preferred"... I don't use Linux but our server/build PC is Linux... I didn't realise CS3 was not compatible so I guess we can do this part on Windows.


What's the difference between  buf = (char*)std::malloc(aSize * sizeof(float));   and  buf = new char[aSize * sizeof(float)];   I have seen both used, and I usually use the first. However today I noticed that the second one has started sometimes throwing std::bad_alloc and crashing. Changing it to the first fixed the issue.  What exactly does each line do?


Show that  $ \quad \quad z^5-1=(z-1)(z^2+2z\cos{\dfrac{\pi}{5}}+1)(z^2-2z\cos{\dfrac{2\pi}{5}}+1)$   and deduce from this the closed formulas for $\cos{\dfrac{\pi}{5}}$ and $\cos{\dfrac{2\pi}{5}}$.    Here's what I did:  I assumed that it was correct, and using the fact that $z^5-1=(z-1)(z^4+z^3+z^2+z+1)$, I said that:  $ \quad z^4+z^3+z^2+z+1=(z^2+2z\cos{\dfrac{\pi}{5}}+1)(z^2-2z\cos{\dfrac{2\pi}{5}}+1)$  Letting $a=\cos{\dfrac{\pi}{5}}$ and $b=\cos{\dfrac{2\pi}{5}}$  $ \quad z^4+z^3+z^2+z+1=z^4+(2a-2b)z^3+(2-4ab)z^2+(2a-2b)z+1$   Equating the coefficients:  $\quad a-b= {1 \over 2} \quad$ and $ \quad ab={1 \over 4}$  Simultaneously solving, and knowing that $0<a<1$ and $0<b<1$:  $\cos{\dfrac{\pi}{5}}=\dfrac{1}{4} + \dfrac{\sqrt{5}}{4} \quad$ and $\quad \cos{\dfrac{2\pi}{5}}=-\dfrac{1}{4} + \dfrac{\sqrt{5}}{4}$  Then I said that, if I can prove the cosine formulas above in a different way, I have indirectly shown that the relationship shown in the question was true.  So, since $\cos{\pi}= \cos{(5 × (\frac{\pi}{5}))} =-1$ and with a little trig indentity,  $\quad 16{\cos^5{\pi \over 5}}-20{\cos^3{\pi \over 5}}+5{\cos{\pi \over 5}}+1=0$  With substitution $x=\cos{\pi \over 5}$:  $16x^5-20x^3+5x+1=0$, a polynomial that has roots at $x=-1$, $x= \frac{1}{4} - \frac{\sqrt{5}}{4}$, and $x=\frac{1}{4}+\frac{\sqrt{5}}{4}$.  The only possible solution is $\cos{\pi \over 5}=\frac{1}{4}+\frac{\sqrt{5}}{4}$, and the double angle formula shows that $ \cos{\frac{2\pi}{5}}=-\frac{1}{4} + \frac{\sqrt{5}}{4}$  My question, is there a simpler or more straightforward way of proving this?


For any integer $a,b$ let $N_{a,b}$ denote the number of positive integer $x<1000$ satisfying $x= a( mod\;27)$ and $x=b(mod\;37)$. Then

For any integer $a,b$ let $N_{a,b}$ denote the number of positive integer $x<1000$ satisfying $x= a \mod 27$ and $x=b \mod 37$. Then which of them is correct         there exist $a,b$ such that $N_{a,b} =0$    for all $a,b$, $N_{a,b}=1$   for all $a,b$, $N_{a,b}>1$   there exist $a,b$ such that $N_{a,b}$ and  there exist $a,b$ such that $N_{a,b}=2$.      Since we know that by Chinese Remainder Theorem if $m_1, m_2, .., m_k$ are pairwise relatively prime positive integers, and if $a_1, a_2, .., a_k$ are any integers, then the  simultaneous congruences $x ≡ a_1 (mod\;m_1), x ≡ a_2 (mod\;m_2), ..., x ≡ a_k (mod\;m_k)$ have a solution, and the solution is unique modulo $m$, where  $m = m_1m_2⋅⋅⋅m_k$. Then how we will approach by acoording to this theorem. So please someone help me and explain it.


Proving $A\setminus(B\setminus C)$ is not equal to $(A\setminus B)\setminus C$

I have several of these types of problems, and it would be great if I can get some help on one so I have a guide on how I can solve these.  The question is:      Prove $A \setminus (B\setminus C) \neq  (A\setminus B) \setminus C$   I know I must prove both sides are not equivalent to each other to complete this proof. Here's my shot: We start with left side.   if $x$ is in $A$, then $x$ is not in $B$, not not in $C$ so $x$ is in $A$ and $C$ if $x$ is in $A$, then it's not in $B$ $\rightarrow$ $(A\setminus B)$ but if $x$ is in $A\setminus B$, then it must not be in $C$ however, earlier we stated $x$ is in both $A$ and $C$ we see that the two sides are not equal   Is this the right idea?  Should I then reverse the proof to prove it the other way around, or is that unnecessary?  Should it be more formal?  Thanks!


How much memory is needed to run a Minecraft Server in 1.6.2?

What is a reasonable amount of RAM needed to run a Minecraft server?  I've already tried running a server with 256MB. However, within an hour, the server was crashing due to being out of memory.


Am I allowed to use company work in my portfolio?

This was one of my first clients. I want to use the work I've done to market myself as a designer & marketer but I'm afraid of legal backlash for using company information. Here's the catch, although I was working "for hire" - there is  No legally binding contract (I was sending contracts at the beginning & it became a he said she said with him promising me a bunch of things he didn't follow through with. There's maybe 3 files that he legally owns. All the rest he didn't want contracts for.) I filed taxes as a 1099 independent I provided all of my own equipment and tools (computer, apps, & drive) They didn't provide me with benefits (health) and only provided a workspace.  I ended up ceasing work with them because I was being exploited (less than 10k within a year) for all the work I was doing. With all that being said, I know I technically own copyrights since I had spoke briefly with a copyright attorney about it asking for some legal advice. I also looked into laws and work for hire regulations so I'd say I'm in the clear. But now I'm concerned about using the work for my portfolio and marketing myself as the sole designer that practically carried the company. What do I do? Should I remove the logo & company information? Does it matter?


How to keep chemical formulas on the same line using chemmacros?

I often refer to some chemicals often in my document (e.g. NH415NO3) and I keep getting line breaks in the middle of the chemical formula (e.g. if NH415NO3 comes at the end of a line, sometimes NH4 and 15NO3 are split onto different lines).  To get around this, and save typing, I created new commands for some chemicals:  \newcommand{\fan}{\mbox{\ch{^{15}NH4NO3}}} % \fan = 15NH4NO3 in mbox \newcommand{\afn}{\mbox{\ch{NH4^{15}NO3}}} % \afn = NH415NO3 in mbox \newcommand{\an}{\mbox{\ch{NH4NO3}}} % \an = NH4NO3 in mbox \newcommand{\fnto}{\mbox{\ch{^{15}N2O}}} % \fnto = 15N2O in mbox   However, when I use my new commands, there's no space after the chemical formula in the text. If I put an extra space in the command, like this:  \newcommand{\afn}{\mbox{\ch{NH4^{15}NO3}} } % \afn = NH415NO3 in mbox   then, I get an extra unwanted space if a full stop comes after the formula in the text.  How can I solve this problem?


Hierarchy missing, how do I bring it back?

I'm making a model in Blender and then I think I pressed something on my keyboard and then my hierarchy went missing! How can I bring it back again?  Thanks!


Blender 2.8 - How to bake an ambient occlusion map to a second UV texture on a multi material mesh?

I'm trying to bake an ambient occlusion map onto a second set of UVs onto an object with multiple materials on it (per face) for exporting to a game engine.  I have an object with multiple materials on it. I have materials assigned to each face:    This object also has two uv maps, one for the main textures, and one intended for the AO map lightmap pack unwrap.  I don't actually know if I need a separate material for the AO map, but this is the setup of the AO map material:    In the uv editor, I select the AO UV map, and the AO_Image image I've created, then I click bake:    But then I get multiple messages:  No active image found in material slot (0) for object "Level" No active image found in material "Material" (1) for object "Level" No active image found in material "Blue" (2) for object "Level" Circular dependency for image "brick-pattern-1.png" from object "Level" Circular dependency for image "grass-tiling.jpg" from object "Level" No active image found in material "Grass" (5) for object "Level" Circular dependency for image "AO__Map" from object "Level" Baking map saved to internal image, save it externally or pack it   And then any materials with image get the lightmap bake, which itself seems garbled for some reason:    Again, the intention is to bake a separate AO map onto a second uv map of a multi-texture object for exporting to a game engine. I'm not sure if this is the correct method. But I'm doing something wrong, because Blender falls over when trying to perform this task and I'm unclear why.


What is the equation of a general circle in 3-D space?

I know that $(x-x_0)^2+(y-y_0)^2-r^2=0$ is a general planar circle and $(x-x_0)^2+(y-y_0)^2+(z-z_0)^2-r^2=0$ is a general sphere.  I want to know the general expression of a circle in space.  Can anyone please give me some advice here?


sed - Use file1 to find replacements contained in file2 for lines from file3

I'm new here and haven't posted much, I'll try to make this as clear as I can.  I want to perform a find and replace that involves three files: find.csv identifies lines containing strings. I want to replace the entire line with a line from replace.csv. The third file is the mainfile.csv, which contains about 1000 lines.  This is what I have so far, but I'm getting an error message:  sed "s/$(cat find.csv)/$(cat replace.csv)/" mainfile.csv > out.csv sed: 1: "s/CHL_13_R4  DCK_09_R4  ...": unterminated substitute pattern   Here is what the contents of the files look like:  find.csv CHL_13_R4  DCK_09_R4  DCK_10_R4  DCK_11_R4  DCK_13_R4   replace.csv CHL_13_R12,CHL_13,R12,10/14/2014 DCK_09_R12,DCK_09,R12,10/14/2014 DCK_10_R32,DCK_10,R32,10/14/2014 DCK_11_R21,DCK_11,R21,10/14/2014   The mainfile contains entries as in replace.csv, but about 30 need to be updated. So, taking the first line as an example. The line in mainfile.csv that has 'CHL_13_R4' needs to be replaced with CHL_13_R12,CHL_13,R12,10/14/2014  Thanks for the help!


$\operatorname{Im} A = (\operatorname{ker} A^*)^\perp$

Let $A:\mathbb{R}^m \to \mathbb{R}^n$ be a linear transformation. We know that  there is a unique transformation $A^*:\mathbb{R}^n \to \mathbb{R}^m$ such that  $$\langle Ax,y\rangle = \langle x,A^*y \rangle, \forall x \in \mathbb{R}^m,y\in \mathbb{R}^n.$$ And we know also that the matrix of $A^*$ is $A^t$. Having this, prove that the equation $$Ax=b$$ has a solution if, and only if, $b$ is orthogonal to all of the vectors $y \in \operatorname{ker}A^*.$ Note that this is precisely $$\operatorname{Im} A = (\operatorname{ker} A^*)^\perp.$$ To show that $\operatorname{Im}A \subset (\operatorname{ker}A^*)^\perp$ is easy. If $b \in \operatorname{Im}A$ then $\exists x\in \mathbb{R}^m$ such that $Ax=b$. Then, if $y$ is any vector in $\operatorname{ker}A^*$, we have $$\langle b,y\rangle = \langle Ax,y\rangle$$ $$=\langle x,A^*y\rangle$$ $$=\langle x,0\rangle=0$$ and, therefore, $b \in (\operatorname{ker}A^*)^\perp$, i.e. $$\operatorname{Im}A \subset (\operatorname{ker}A^*)^\perp.$$ Now, how to show that, conversely, if $b \in (\operatorname{ker}A^*)^\perp$ then $b \in \operatorname{Im}A$?? Need some help... Sorry for duplicates... (I couldn't find this question over here...)


I referred to the urban dictionary and it says meta means something used to characterize something that is characteristically self-referential.  But I'm still confused. Cause I don't see any difference between English Language & Usage text and English Language & Usage meta


Find $\lim_\limits{n\to \infty}\underbrace{{\sin\sin\cdots\sin(x)}}_{n\text{ times}}$. Why am I wrong?

Find $\lim_\limits{n\to \infty}\underbrace{{\sin\sin\cdots\sin(x)}}_{n\text{ times}}$.  It is known that after the first sine, we get something in $[-1,1]$. If it is $0$ then it is constant and remains that way and so is the limit. Otherwise, $\sin x>0$ and therefore the sequence is monotonically non-increasing with an infimum $0$. Therefore converges to $0$. The is when $\sin x<0$, the sequence is monotonically non-decreasing and converges to the supremum, $0$.   I know there is the possibility of using the continuity of sine and and Heine definition of limits, but I want to understand why someone said it is incorrect.


How do enterprises test their web apps across all browsers, browser versions, and operating systems?

There are various websites which work perfectly on all the platforms and OS.  I want to know how they test their possibilities for every combination?


Deviation between European and American Stock exchanges

I live in Germany and I am trading stocks for around 6 months. My favorite stocks so far are mainly the big tech companies that we all know (Alphabet, Amazon) as well as the according indices (e.g. Nasdaq 100).  Due to the time lag between Europe and the US, I can trade for around 6.5 hours until the NYSE opens at 9.30 am. And when the NYSE opens, I often see a strong movement in stock prices. To me it seems that the price for a certain financial instrument being generated in Europe during the day, is not adopted by the US but more or less negated.  Do you know if this has more a technical reason or is it the sheer dominance of the US market?


Is it safe to manually delete the "field_deleted_*" tables and state API data?

I'm in an odd situation where the state data that tracks which fields are deleted has a field in it that does not have its associated field_deleted_data_* table. As result, when cron tries to purge the deleted field data, an exception is thrown because it runs a query on a non-existent table.  Is OK to just delete all the remaining field_deleted_data_* and field_deleted_revision_* tables and then delete the two state API rows from the key_value table, field.field.deleted and field.storage.deleted?


Top-aligned table cells with different font sizes and controlled spacing

I am trying to achieve a table where a few things have to work simultaneously. Several of these things have been discussed before, but I have been unable to make everything work at once (and some things at all).  I want to be able to use different font sizes in cells on the same row, and have them precisely aligned at the top. That has almost been achieved in the MWE below, but the letters of the smaller font are slightly below the letters of the larger font. (Previous discussion: , but the alignment is only close, not perfect.)  Edit: The top alignment should be for the maximum height of the font used, so that an 'a' ends up at the same height whether it is written by itself or followed by a tall letter, such as an 'l' (or, if the small 'b' next to the big 'B' in the example below is changed for a small 'a', the 'a' should not jump up to the ceiling.  I also want to be able to insert several rows of text with forced line breaks within a cell of the table, and those rows need to have the same spacing between them as normal text has. That has been achieved by nesting another table in a cell in the MWE below.  In addition, I want to be able to use \hfill to put something out in the right margin from within the nested table, which works in the MWE.  Further, the margins on the top, bottom and sides of the table should be zero, so that only the page margins determine the amount of white space around the table (as it is now, there is even a difference between the right and left margins -- although the margins were for some reason adjusted when I uploaded the pdf below, it is visible if you compile the code and look at the pdf directly).  Lastly, I would like to get rid of all automatic spacing between cells, and then define my own spacing. Preferably, I would like to be able to define the vertical spacing between cells in terms of line heights (for lines of the size that I specify for normal text, so 11pt in the example below), while the units of horizontal spacing would preferably be defined in terms of "the width of an 'm'", or something like that.  \documentclass[paper=a4,fontsize=11pt]{scrartcl} % KOMA-article class \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} \usepackage[english]{babel} % English language/hyphenation \usepackage{geometry} \usepackage{tabu} \usepackage{lipsum}  \pagestyle{empty} % No pagenumbers/headers/footers  \newcolumntype{V}{>{\vspace{0pt}}p}  \begin{document} \begin{tabular} [t]{@{}V{0.2\columnwidth}V{0.8\columnwidth}} % @{} is used to remove the margins from cells \Huge\textbf A & \begin{tabular}[t]{@{}p{0.8\columnwidth}} Lorem ipsum \hfill right-aligned\\ sem.\\ Lorem\\ ipsum \end{tabular} \\  \Huge\textbf B & b \\  \Huge\textbf C & \lipsum*[1] \\  \end{tabular} \end{document}     Edit 2013-03-25: I tried a different approach (with minipages) and asked a question: . As of writing this, I have one answer that is similar to the accepted answer below. It achieves correct spacing, but is limited to different sizes in the left column (if one wants to use \hfill in the right column), and the top alignment for the \Huge text is not perfect.  Edit 2013-03-25: I got an answer in the thread  where \strut was used to add space, and \vphantom{Qp} (adds the vertical space of what is written in the braces(Qp in this example)). That could most likely be used here to, to get the correct spacing between cells even if only short letters or letters that do not protrude downwards are used.


What's that sci-fi book where phones are dropped from orbit?  People are able to ask for things which are then manufactured and delivered to them.  I think the scheme is used to bring down an oppressive government.  I read this book a few years ago, and now I'm looking for more by this author.


How to show that the composite function of two injective functions is injective

I have 2 injective functions,$X:A \to B$ and $Y:B \to C$.      How do I show that $Y \circ X$ is injective.   In the form of a proof.


Can I apply and pay as a group for UK visit visas?

I cannot pay for courier charges for UK visit visa for my family. I'm using a UPS label. I tried to pay as a group but I cannot. Do I have to apply individually?


When I use gnome network manager it indicates that wireless is disabled by hardware switch while it is not. Even in windows I can not turn on my wireless!


What is the easiest way to filter a list in Java?

Currently when I want to filter a list I use to iterate over its elements and copy the elements that match my requirements to a new list but in this way I'm using O(2N) of spatial complexity. Is there a more efficient way to do it?


How to make a custom boot-up splash animation

I just found some cool boot-up video and audio file, and I want to make a custom boot-up animation in Ubuntu 11.04. Any suggestions?


I wish to create a taxonomy where the administrator users limit which terms can be tagged.    Suppose I have a vocabulary containing the following terms:   Football Golf Snooker   I want the tag autocomplete to show the tags that can be used. If I typed "Foo", the autocomplete should show "Football"; if I typed "Basketball," the autocomplete would not show anything, the node would submit, but no term is created.   Is this possible?


Second-order term of Baker-Campbell-Hausdorff formula

Let $G$ be a Lie group with Lie algebra $\mathfrak g$. I'm trying to prove the first two terms of the Baker-Campbell-Hausdorff formula for $\exp(tX)\exp(tY)$ satisfy $$ (\exp tX)(\exp tY) = \exp\big(t(X+Y) + \frac 1 2 t^2 [X,Y] + t^3 \hat Z(t)\big)  $$ for some smooth function $\hat Z: (-\epsilon, \epsilon) \to \mathfrak g$ and some $\epsilon > 0$, for every $X, Y \in \mathfrak g$.   What I've tried: Since $\exp : \mathfrak g \to G$ restricts to a diffeomorphism from a neighborhood of $0 \in \mathfrak{g}$ to a neighborhood of $e \in G$, the map $\phi : (-\epsilon, \epsilon) \to \mathfrak g$ defined by  $$ \phi(t) = \exp^{-1}(\exp tX \exp tY) $$ is smooth for some $\epsilon > 0$. So the problem amounts to proving $\phi''(0) = [X,Y]$ and applying Taylor's theorem. But I'm not sure how to do this without knowing the derivative of multiplication $G \times G \to G$ at general points $(g,h) \in G \times G$. I'm wondering if there's a more clever approach having something to do with the adjoint representations $\mathrm{Ad}: G \to \mathrm{GL}(\mathfrak g)$ and $\mathrm{Ad}_* = \mathrm{ad}: \mathfrak g \to \mathfrak{gl}(\mathfrak{g})$ since $\mathrm{ad}(X)Y = [X,Y]$. Any advice would be appreciated.


The time-axis and the space-axis overlap for a photon's world line. Does it mean that photon has no "past" or "future" but only "present" and no "there" but only "here"? I mean how does the photon observe the world?


How do you integrate $\int \frac{1}{a + \cos x} dx$?  Is it solvable by elementary methods?  I was trying to do it while incorrectly solving a homework problem but I couldn't find the answer.  Thanks!


Refreshing modified CSV layer without having to reopen file using PyQGIS?

With an CSV layer Qgis workspace [loaded as a delimited text layer], an external algorithm is ran; outputting (writing) new values to certain rows in the layers source CSV file.  The writing works properly (CSV can be opened in text editor immediately after ext. process to show the correct values in question), yet a problem arises in the Qgis updates.  The changed values; when viewed in the attribute table depict a 'NULL' value.  Although removing and reloading the layer properly updates the attribute table, I would like to avoid such; as important temp. display-label data / settings needs to be retained.[Possibly the only option?]  I have tested the following scripts without resolve:              csvDelimTextLayer.reload()             csvDelimTextLayer.updateFields()             iface.legendInterface().refreshLayerSymbology(csvDelimTextLayer)             iface.mapCanvas().refresh()     Spending some more time revealed the following work-flow:          -The algorithm which updates the CSV is activated          -The updates only show a 'NULL' value in the attribute table          -Immediately after confirming 'NULL's, save project and close QGIS          -Upon reopening the QGIS and the project, the proper data is displayed.  Additionally (and perhaps most importantly) now every time the algorithm is ran - the reflected changes (and values) are properly viewable in the attribute table without having to resave and restart QGis.      Does this indicate an error or missing step in my initial method of allocating data in PyQgis when writing and loading the CSV; which upon saving and restarting QGis is fulfilled?


If $\tau_1, \tau_2,\tau_3$ then which are correct?

Let, $\tau_1, \tau_2,\tau_3$ be three topologies on a set $X$ such that $\tau_1 \subset\tau_2\subset\tau_3$ and $(X,\tau_2)$ be compact $T_2$ space. Then,   (A) $\tau_1=\tau_2$ , if $(X,\tau_1)$ is $T_2$.  (B) $\tau_1=\tau_2$ , if $(X,\tau_1)$ is compact.  (C) $\tau_1=\tau_3$ , if $(X,\tau_3)$ is $T_2$.  (D) $\tau_2=\tau_3$ , if $(X,\tau_3)$ is compact.     I only know that closed subspace of a compact space is compact and $T_2$-ness is a heriditary property. But I have no idea how it depends on topologies , whether the topologies are finer or coarser.   Please help...........


Relationship between GIT, Bit bucket and source tree

I am new to GIT, currently in my project they are using bitbucket and SourceTree. I am only using bit bucket for cloning project and source tree for taking that project on my local drive.When does GIT come into the picture  My Confusion is:    What is the particular use of source tree, bit bucket and GIT?  How GIT is related to SurceTree and bit bucket? How GIT is related to Github?


Is it possible to change Android ID without root access nor factory reset?

I have an Android 10 phone (OnePlus 5) and I want to change the Android ID (I think this is what apps use to identify you sometimes). I read that either I can do a factory reset or root my phone, both of which probably involve wiping the data clean which I want to avoid, and rooting looks complicated. But I read that it's possible to change the Android ID by just using some command line tools, is it possible?


I want to change my splash screen image.but I cant found where is the bl_app_template_user location.I dont found the default splash screen image in that folder     this is my zip file    im using windows 7 professional 64 bit thanks alot


Inserting a PDF inputs it on the next page

I'm building an appendix, and there are a lot of PDF-documents. Each document should be its own appendix, that is each should be its own chapter.  The problem is that I want the PDF inserted right after the chapter-heading, but in practice its pushed to the next page.   \usepackage{pdfpages} % in config-file \begin{appendices}     \chapter{Appendix name }     \label{app:label}     \includepdf[pages={-}]{appendices/mypdf.pdf} \end{appendices}   That is: I get a page with a chapter-header, and no content, then a new page where the PDF is inserted. I haven't found any resources that explain this.  I looked in the answer given , but that does not work either. (\includepdf[scale=0.8,pages=1,pagecommand=\chapter{chapname}]{testpdf} ), gives the following result:    The other answer in the same question is to do the following (except it wants to do it section not chapter:  \includepdf[pages=1,pagecommand=\chapter{Chapter Heading}]{appendices/backend-README.pdf} \includepdf[pages=2-,pagecommand={}]{appendices/backend-README.pdf}   Which gives the same result as above.


Resource list errors cannot be fixed , makes me unable to install anything

I tried methods like deleting or updating the source list that I found on the web but these didn't fix it.


RegEx match between two words and get all occurrences

I am cleaning up XML files that contain HTML by using RegEx.  Some files contain multiple style-elements and I want to remove them all and content in between. For example:    &lt;STYLE&gt;    group 1 &lt;/STYLE&gt;    Random text here which shall not be removed. &lt;STYLE&gt;    group 2 &lt;/STYLE&gt;    Some more random text here which shall not be removed. &lt;STYLE&gt;    group 3 &lt;/STYLE&gt;   I am using the following RegEx with /s parameter   (&lt;STYLE&gt;).*(&lt;\/STYLE&gt;)   Problem is that this RegEx will match everything between <style> (#1) and last </style> (#3).   I would like to match only group, <style>, and </style> elements. How can this be accomplished?


If we have a number which represents the number of images, do you call that the images count or the image count?  If you take the example with the images you could say:     The '15' is the image count for this album   But you could also say:     What is the minimum images count to take part in the photography competition   Which one is correct? Do you use the pluralized noun or not?


how can i take out the version in my main.css file?

I have the same problem as you, i am seing my old css file, after editing it, because at the end of the css call appears something like this: "css/main.css?ver=4.2.2. If i take out the part that says "?ver=4.2.2" i could see my real main.css file. Please help, I need someone.


How to calculate this infinite sum: $\sum_\limits{n=1}^{\infty}\frac{1}{n^2}$

I don't understand how to get from the infinite sum $\sum_\limits{n=1}^{\infty}\frac{1}{n^2}$ to the solution $\frac{\pi ^2}{6} $.   Is it possible to calculate this by hand or do I just have to type it into a calculator and accept it as it is?


Is it true that: $$T\text{ isometric}\iff T^*\text{ left inverse}$$ Obviously: $$\text{"}\Rightarrow\text{": }\langle x,\tilde{x}\rangle=\langle Tx,T\tilde{x}\rangle=\langle x,T^*T\tilde{x}\rangle$$ $$\text{"}\Leftarrow\text{": }\langle Tx,T\tilde{x}\rangle=\langle x,T^*T\tilde{x}\rangle=\langle x,\tilde{x}\rangle$$ My problem is that I'm not sure about if the adjoint is left inverse then the operator necessarily is bounded so that domain issues might come into play...


Is the plural form of ID spelled ID's or ID?

How to write or tell that collection of Email ID's has been attached.


I am not a very techie girl. I used my brother's macbook air and saw some of his personal things which I should haven't. And I realised that he could see that in recents. How to delete them? After surfing a lot, I got to know about the recent files stored in plist in preferences, by the name com.apple.recentfiles.plist or LSSharedfiles.plist but I couldn't find a file/plist named above. Kindly help! As mentioned above it is macbook air and again I do not know much :(


How to resize (grow) APFS partition that is at the end of the drive?

[new info below post] -- I'm having trouble resizing an APFS partition on the 240Gb SSD in my Mac. I want to make all space available to the system partition "Macintosh SSD".  Output of diskutil list:  /dev/disk0 (internal, physical):    #:                       TYPE NAME                    SIZE       IDENTIFIER    0:      GUID_partition_scheme                        *240.1 GB   disk0    1:                        EFI EFI                     209.7 MB   disk0s1    2:                 Apple_Boot Boot OS X               134.2 MB   disk0s2    3:                 Apple_APFS Container disk1         81.9 GB    disk0s3  /dev/disk1 (synthesized):    #:                       TYPE NAME                    SIZE       IDENTIFIER    0:      APFS Container Scheme -                      +81.9 GB    disk1                                  Physical Store disk0s3    1:                APFS Volume Macintosh SSD           54.8 GB    disk1s1    2:                APFS Volume Preboot                 44.7 MB    disk1s2    3:                APFS Volume Recovery                509.5 MB   disk1s3    4:                APFS Volume VM                      20.5 KB    disk1s4    5:                APFS Volume Nieuw                   655.4 KB   disk1s5   I tried resizing the container, but this results in an error (see below). I believe due to the fact that the system partition is located at the end of the drive.  Mac-mini:~ admin$ diskutil apfs resizeContainer disk1 239g Started APFS operation Aligning grow delta to 157.073.416.192 bytes and targeting a new physical store size of 238.999.998.464 bytes Determined the maximum size for the targeted physical store of this APFS Container to be 81.926.582.272 bytes Error: -69519: The target disk is too small for this operation, or a gap is required in your partition map which is missing or too small, which is often caused by an attempt to grow a partition beyond the beginning of another partition or beyond the end of partition map usable space   Can anyone help me how to add the free space to the "Macintosh SSD" partition?  Thanks, Koen  Update 1: Thanks for the quick response! Though, I got replies that it may be a duplicate with . I think it is not, because:  - I have no disk0s3 "storage" volume that may be blocking the space; and - Running the command in step 3 in that post results in this error:  sh-3.2# diskutil apfs resizeContainer disk0s3 0 Started APFS operation Error: -69743: The new size must be different than the existing size   Thanks again for any help, it is much appreciated.  Update 2: Output of diskutil info disk0s3 | grep -e "Partition Offset" -e "Disk Size" as requested by David Anderson:     Partition Offset:          158130806784 Bytes (308849232 512-Byte-Device-Blocks)    Disk Size:                 81.9 GB (81926582272 Bytes) (exactly 160012856 512-Byte-Units)


How to derive the formula@NathanReed answer

Thanks! A very simple but great way to estimate mean curvatures@NathanReed answer. For my case, I also need an estimate of triangular mesh curvature, and I support this is what i was looking for. However, could you please show me (or any recommended literature) how is the following equation derived?  $$\frac{(n_1 - n_0).(p_1 - p_0)}{||p_1 - p_0||^2}$$


grep randomly appearing and disappearing in ps aux (ps aux | grep python)

This isn't an actual problem - but more of a curious question, when I run while true; do ps aux | grep abc; echo done; done I get the following:  user    29733  0.0  0.0  11748   924 pts/1    R+   20:25   0:00 grep --color=auto abc done user    29735  0.0  0.0  11748   920 pts/1    S+   20:25   0:00 grep --color=auto abc done user    29737  0.0  0.0  11748   924 pts/1    S+   20:25   0:00 grep --color=auto abc done done done done user    29745  0.0  0.0  11748   924 pts/1    R+   20:25   0:00 grep --color=auto abc done user    29747  0.0  0.0  11748   924 pts/1    R+   20:25   0:00 grep --color=auto abc done user    29749  0.0  0.0  11748   924 pts/1    R+   20:25   0:00 grep --color=auto abc done user    29751  0.0  0.0  11748   924 pts/1    R+   20:25   0:00 grep --color=auto abc done user    29753  0.0  0.0  11748   924 pts/1    S+   20:25   0:00 grep --color=auto abc done user    29755  0.0  0.0  11748   924 pts/1    S+   20:25   0:00 grep --color=auto abc done done user    29759  0.0  0.0  11748   924 pts/1    R+   20:25   0:00 grep --color=auto abc done user    29761  0.0  0.0  11748   920 pts/1    R+   20:25   0:00 grep --color=auto abc done   Sometimes grep doesn't actually see itself in ps aux. Is this just a timing issue between the two processes running? This also happens when I run the commands individually and not in a loop.   This is happening both on my computer and another machine over ssh, but it is happening more frequently on the remote computer (which the output is from).  Ubuntu 14.04


Why would you declare a specific class object as a more general object in Java?

In Java you can create a class, like Bicycle, and then a subclass of that class, RoadBike.  You could then instantiate a RoadBike object like this:  Bicycle bike = new RoadBike();   or like this:  Roadbike bike = new RoadBike();   or even like this:  Object bike = new RoadBike();   My question is, what is the purpose of declaring a specific object, like RoadBike, as a more general type, like Object or Bicycle? Why and when would you do this, and does it take more memory to declare it as a more general object?


I have tried repeatedly to change my Apple ID and password without success. I have followed all of the directions trying both my emails and asked for new passwords----no luck whatsoever.


Prove that if $a_n<b_n<c_n$ and $\sum a_n$ and $\sum c_n$ are convrgent then $\sum b_n $ converge

First of all argument bounded and monotone will not work because there is no restriction on sequences to be positive or negative, they can alternate irregularly.  I tried to make a use of comparison test but there was too many cases to consider and it was just too messy.  So I think the only way to approach the problem is directly from the definition. All I need to do is to prove that the sequence of partial sums $B_n=\sum^n_{i=0} b_i$ is convergent sequence.  So I tried to prove that $B_n$  is Cauchy because this seemed easier. $$a_n<b_n<c_n \\ \therefore \ a_n+a_{n+1}+...+a_{n+m}<b_n+b_{n+1}+...+b_{n+m}<c_n+c_{n+1}+...+c_{n+m}\\ \therefore  \ A_{n+m}-A_n<B_{n+m}-B_n<C_{n+m}-C_n$$ and by sandwich this goes to zero $B_{n+m}-B_n$ goes to zero as $n$ tend to infinity. The problem is that I need no this expressions but modulus of them and in this case it does not need to be true for example if  $A_{n+m}-A_n<0<B_{n+m}-B_n$. And here I am stuck


Does the Rogue have to declare that they're using Uncanny Dodge before or after damage is rolled?

I've played a Rogue character in a few campaigns. At level 5, Rogues gain the Uncanny Dodge feature, described as follows:     Starting at 5th level, when an attacker that you can see hits you with an attack, you can use your reaction to halve the attack’s damage against you.   In practice, this has never been an issue, as my DMs have always allowed me to choose whether to use Uncanny Dodge after damage has been rolled... But I recently came across someone asking whether it had to be done before or after damage was rolled, and I realized I wasn't sure.  So obviously, Uncanny Dodge can only be used after a successful attack roll by the enemy, but according to the rules, does Uncanny Dodge have to be decided upon before or after damage is rolled? (Both RAW and RAI answers are welcome as long as they are properly supported.)


Notation/name for the number of times a number can be exactly divided by $2$ (or a prime $p$)

I am using this simple snippet of code, variants of which I have seen in many places:  for(int k = 0 ; n % 2 == 0 ; k++)     n = n / 2;   This code repeatedly divides num by 2 until it is odd and on completion k contains the number of divisions performed.  I am wondering what the appropriate way to write this using mathematical notation is?  Does this correspond to some named concept?  Of course, $lg\ n$ gives the appropriate $k$ when $n$ is a power of 2, but not for anything else. For example, $k = 1$ when $n = 6$ and $k = 0$ when $n$ is odd.  So it looks it should be specified using a piece-wise function but there may be some mathematical concept or nomenclature here that I am not aware of...


I'm new in Python programming If there are websites where developers can share their add-ins and scripts that will be great. do you know any? unfortunately, arcgis.com only provide very few


I currently use a TCL A1 (A501DL) running Android Version 8.1.0. I went to check my Wi-Fi data usage. I scrolled down and seen all these apps! There are 9 of them. I've never seen them before and when I click them there is no app information. I checked all 44 apps I have, and it doesn't show any of these and it doesn't appear to be feeding off my battery data I already checked that. What's going on? Am I being hacked?? I don't use the cell data on this phone. I just use it for Wi-Fi. Somebody please help me! I'm kind of worried about my privacy now.


I keep bouncing into the following result. Let $X$ be a random variable with a cumulative distribution function $P(X<x)$. We draw $n$ independent values from this distribution, and the minimum of these $n$ values is $x_{min}$. Then for large $n$, it is true that:  $P(X< \langle x_{min}\rangle) = 1/n$  where $\langle x_{min}\rangle$ denotes the mean of $x_{min}$ over many trials. Can anyone please provide a proof and an intuitive understanding of the above relation?


How can I run python script in android studio with java

I have a script in python. Here is some of my code:  from splinter import Browser url = "http://arashiyan.ir/Narm/entekhab.html" browser=Browser('firefox') browser.visit(url) second_found = browser.find_by_name("LsnGrp[]")[3] second_found.fill("3")   I want to run this script in one part of my android application.I researched and find some frameworks like kivy but it will make complete app with python. does it possible with jython? Tnx


Expression for "intend to help but instead making things worse"

I want to say "someone (or something) intends to help, but instead it makes things worse". Is there any succinct expression or phrase for this?  Thanks.


minimum shutter speed for point and shoot camera

i m planing to buy a point and shoot digital camera, there are two options in nikon, i like both the cams but i am confused in one matter.   the details are as follows.  nikon cool pix l820 - max shutter speed 1/1500 and minimum shutter speed of 4 sec  nikon cool pix l820 - max shutter speed 1/4000 and minimum shutter speed of 1 sec  so if i purchase the first one(which is in my budget) what will be the effect of shutter speed on the photos.  please reply as soon as possible


Ubuntu 20.04 Partial Update: Clicked Yes: What are the repercussions?

I'm currently running 20.04, which I updated recently from 19.10. Last night I did an update through Software Updater and it offered to do a partial update, which I rashly (and regretfully) agreed to. Now I'm not sure what the repercussions are of if I need to recover from it. Here is what the dialog looks like:  I've run apt update/upgrade/clean/apt-get install -f/autoremove/--fix-missing-update/dpgk configure -a/etc. Each of these commands doesn't do anything special and doesn't indicate that anything was broken or even that it fixed anything. After searching the logs, I finally found /var/log/dpkg.log that indicated it removed and upgraded a tons of packages, many of which I don't really know or care about like fwupd-signed and initramfs-tools. Here is the start of the log output: 2020-06-15 22:05:27 startup packages remove 2020-06-15 22:05:27 status installed fwupd-signed:amd64 1.27+1.3.9-4 2020-06-15 22:05:27 remove fwupd-signed:amd64 1.27+1.3.9-4 <none> 2020-06-15 22:05:27 status half-configured fwupd-signed:amd64 1.27+1.3.9-4 2020-06-15 22:05:27 status half-installed fwupd-signed:amd64 1.27+1.3.9-4 2020-06-15 22:05:27 status config-files fwupd-signed:amd64 1.27+1.3.9-4 2020-06-15 22:05:27 status not-installed fwupd-signed:amd64 <none> 2020-06-15 22:05:27 startup archives unpack  And the end: 2020-06-15 22:06:52 status not-installed postfix:amd64 <none> 2020-06-15 22:06:52 startup packages configure 2020-06-15 22:06:52 trigproc ufw:all 0.36-6 <none> 2020-06-15 22:06:52 status half-configured ufw:all 0.36-6 2020-06-15 22:06:52 status installed ufw:all 0.36-6 2020-06-15 22:06:52 trigproc systemd:amd64 245.4-4ubuntu3.1 <none> 2020-06-15 22:06:52 status half-configured systemd:amd64 245.4-4ubuntu3.1 2020-06-15 22:06:52 status installed systemd:amd64 245.4-4ubuntu3.1 2020-06-15 22:06:52 trigproc rsyslog:amd64 8.2001.0-1ubuntu1 <none> 2020-06-15 22:06:52 status half-configured rsyslog:amd64 8.2001.0-1ubuntu1 2020-06-15 22:06:53 status installed rsyslog:amd64 8.2001.0-1ubuntu1 2020-06-15 22:08:09 startup packages configure 2020-06-15 22:08:13 startup packages configure  So what I don't understand is whether I actually have a problem with my system or if the partial update was benign. There seems to be no definitive way for me to check, at least none that I can DuckDuckGo for. What other sanity checks do you recommend I run?