Why does "is" operator behave differently then expected, in `id(i) is id(j)`?
Is there a difference between "==" and "is"?
Create subdomains on the fly with .htaccess (PHP) I am looking to create a system which on signup will create a subdomain on my website for the users account area.   e.g. johndoe.website.com  I think it would be something to do with the .htaccess file and possibly redirecting to another location on the website? I don't actually know. But any information to start me off would be greatly appreciated.  Creating a sign up area is not the problem - I have done this many a time. I am just unsure where to start with the subdomain. I'd like to remove my phone number from my iMessage account, but still have my phone enabled to receive messages sent to my email address (also used on iPad, Mac). Is there a way of doing this? How can Cooper communicate with his daughter before the time he went to space? I am going to shoot a wedding this weekend, and I want to do my best for my friend's big day.    What can I do to prepare for the day in order to minimize failures and mistakes? How do I avoid missing important shots? What backup plan should I have?   I have been shooting for 6 years or so, and I know wedding is one of the hardest thing to do. I have told my friend what I end up producing will be of no match with the work of dedicated wedding photographers, not even the ones that are about to fall out of business.  They are on a tight budget, they said some photos are still better than none, they really must minimize the cost as much as they can. I exaggerated again that my photos will be worse off than the cheapest wedding photographer you can find.  She has been a close friends for years, I want to do everything I can to help her.  Their wedding is at 12:30pm coming Sunday, I have visited the venue last Sunday at 12:30pm to check traffic condition and also the lighting.  The setup is mainly outdoor (no church), the indoor area will not have a good ceiling for bounce. Being at the middle of the day, this can mean some tricky fill flash. I have jot down a list of must-have shots. I am also asking for the seating plan and the event run-down.  Gear:   Canon EOS 60D , EF-S 15-85mm f/3.5-5.6 IS USM Canon EOS 450D (or I can borrow a 550D), EF 50mm f/1.4 Speedlite 580 EXII Speedlite 270 EXII Yongnuo 460 (a cheap but powerful manual flash as backup) Samsung EX-1 f/1.8 point and shoot (backup of a backup...?)   Other lenses that I have but I don't think will be useful:   50mm f/1.8 EF-S 50-250mm f/4.0-5.6 IS II EF-S 18-135mm f/3.5-5.6 IS (I have the better 15-85 on 60D, should I put this on the 450D as a backup allrounder?) EF-S 60mm f/2.8 Macro (should I replace 50mm f/1.4 with this for added macro? You can hardly use f/1.4 under direct sunlight if you want to have fill-flash)   I have two batteries for all cameras (60D 450D and EX1). I have like in total 64GB SD card (I am really inclined to get more, or bring a laptop for on-the-fly backup, or do both). I recently repaired my 580EXII, it has a brand new flash head so the recycle time is as good as it can be, I just need a tonne of batteries. No I don't have external power pack or battery grip for my cameras.  I have a great monopod, but a cheap tripod.  I am happy to bring everything, just putting them in the boot of my car. The carpark is on-site, walking from venue to my car is under 1 minute.  I will have my girlfriend carry the 450D and shoot details / non-portraits.  One concern that I have is fill flash, I really do not have a large surface to bounce off  from. I have shot events before but they are not as dynamic/critical as a wedding.  How do I prepare for differing weather conditions?  If its sunny, fill flash is probably going to be in every single shot. If its cloudy, I probably will turn off the flash. If it rains, my 60D should be fine I have used it in slight rain before, but I really don't know their plan and if they have extendable shelters etc.  What else should I prepare for? Having no experience I want to be as prepared as I can be. Maybe I have overlooked something, maybe there is something else I can do to ensure the shooting will go smoothly. Your help is greatly appreciated! Reviewer Stats showing wrong count I have totally reviewed 716 suggested edits, but it shows I've approved 486 suggestions and rejected 228.     I searched about it on meta. But, can't get solution. I thought that some of my reviewed posts might get deleted. So, I went to the review history and found      .   It should be a bug. Using past tense when referencing a still-true fact In the sentence: "I didn't know she had a son,"   Can I say "I didn't know she has a son" instead, because he is a teenager now?  Or are both correct? I am able to use the split command successfully to split large file into multiple smaller files. This is being achieved by following command  split -b 1G $temp_path $final_filepath   But only caveat is that these files many times contain last line which is split across 2 files. Is there any way to avoid that using split or any other command ? Divisor in $\mathbb{C}[X]$ $\implies$ divisor in $\mathbb{R}[X]$? let $P \in \mathbb{R}[X]$ be a real polynomial divisible by a polynomial $Q \in \mathbb{R}[X]$ in $\mathbb{C}[X]$. How can I easily show that $P$ is also divisible by $Q$ in $\mathbb{R}[X]$?  A simple argument without using higher algebraic theorems is desirable. If I could use instruments of higher algebra, the exercise I have to do in whole would be done in two lines. But I'm not allowed to use. I think there would be an easy argument which I can't see yet because of my mental fogginess that I have sometimes.  Thank you beforehand. Let $b_n$ decrease monotonically to zero, prove $\sum b_nz^n$ converges for $|z|\leq 1$ and $z\neq 1$ How do I perform a Perl substitution on a string while keeping the original? In Perl, what is a good way to perform a replacement on a string using a regular expression and store the value in a different variable, without changing the original?  I usually just copy the string to a new variable then bind it to the s/// regex that does the replacement on the new string, but I was wondering if there is a better way to do this?  $newstring = $oldstring; $newstring =~ s/foo/bar/g; How could I define function with function such as Coefficient? I've tried to install Ubuntu on a VMWare Virtual Machine, but it never gets past the  bootloader :  ISOLINUX 4.01 debian-20100714 ETCD Copyright (C) 1994-2010 H. Peter Anvin et al No DEFAULT or UI configuration directive found! boot: _   I've also tried to burn this .iso image to a CD and go from therem but I got the same problem.  Some more details :   VMWare Server 2.0.2 Build 203138 on Windows 2008 R2 ubuntu-10.10-desktop-i386.iso image used (downloaded yesterday evening) Problem:  Start page numbers from chapter one and also reflect this in the TOC.  Currently the code for TOC is:  \renewcommand{\contentsname}{Table of contents}  \setcounter{secnumdepth}{2} \setcounter{tocdepth}{2} \tableofcontents   I would appreciate if I can be pointed in the right direction. So far I have understood that you can use \chapter* in order not to include a chapter in the TOC.  Questions:  1) How would you force Latex to start numbering from chapter 1 and forward?  2) How can you start page numbering from the first chapter? Can I have a unique UV map for each frame? How do I calculate a time delta in my Google Spreadsheets? I've got a Google Spreadsheet that looks roughly like this:   Date        | Start time  | End time    | Minutes  ------------+-------------+-------------+-----------  1/11/2012   | 11:39       | 12:41       | ?!  ------------+-------------+-------------+-----------              |             |             |    Right now if I fill in the number of minutes between the two times of day by hand. Is there a straight-forward way to calculate a time delta and have the spreadsheet do it for me? To find minimum distance between two curves If $A$ and $B$ are square matrices such that $AB = I$, where $I$ is the identity matrix, show that $BA = I$.    I do not understand anything more than the following.   Elementary row operations. Linear dependence. Row reduced forms and their relations with the original matrix.   If the entries of the matrix are not from a mathematical structure which supports commutativity, what can we say about this problem?  P.S.: Please avoid using the transpose and/or inverse of a matrix. Why "grand theft auto", not "grand auto theft"? There is a video game series called "Grand Theft Auto".  According to its :     The name of the series references the term used in the US for motor   vehicle theft.      [...]      Motor vehicle theft or, grand theft auto, is the criminal act of   stealing or attempting to steal a car (or any other motor vehicle).   I always wondered why this term sounds so strange.   Shouldn't it be "grand auto theft" or maybe "grand theft of auto" instead? Are there any other terms with strange words order and/or missing prepositions like this? Do you really answer "How do you do?" with "How do you do?" EEVEE and Cycles render lighting differences I get different lightning render with the same scene camera setup.  Cycles render (both experimental and supported feature set) gets weaker lightning and needs more energy.  How can I get the same lightning and reflection setup with EEVEE and Cycles?