Superimposing architectural models onto street photographs
How to render a background image in 2.8?
How to find all files with the same extension within a directory I want to search for all .conf files in /etc/. I tried grep -r *.conf /etc, but the result isn't right. What am I doing wrong? Does Mathematica have a "MATLAB Builder" equivalent? MAC OS for Intel based PCs I have an Intel dual core PC with 4GB of RAM and Graphics card. For on of my student Assignment I need to install Latest possible MAC OS on my system as a secondary OS.  Like on boot it asks me that which OS i want to boot with Win 8.1 or Mac Os..  I searched on the internet and found two conflicting opinion some people said there are few MAC OS Version which can be directly installed on Intel PCs some says there aren't?   I am here to get rid of the confusion that is an official latest possible MAC OS version for Intel based PCs? If not what are my options if I want to run MAC OS on my PC.   Please not that Virtualization options won’t work for me, it has to be working as full OS not an os inside another. How to add user to a group from Mac OS X command line? trying to add a user to a group from the command line but can't figure out how?   Specifically this is on Mac OS X Server 10.5.8  like to add user to 'admin' and 'wheel' groups How to politely negotiate PhD funding offer? I have been fortunate enough to get accepted with 5 years guaranteed funding to my 2nd choice graduate school. While the guarantee is great, the funding is only for 9/months out of the year. Would it be rude to ask them to guarantee summer funding to me for the first year until I can write a grant to get on a RAship? I know I should be more appreciative, since not everyone gets funding, but just an increase of about ~3k a year would make living there so much better and I do not want to accept an offer at a lesser institution just because of money.  What would be the most polite way of doing this?  I want to make it clear that I am not trying to get more money for the sake of getting more money, moreover that I am just not comfortable with so little money and such a high living cost in that area.  Thank you for your time. How do you send a HEAD HTTP request in Python 2? What I'm trying to do here is get the headers of a given URL so I can determine the MIME type. I want to be able to see if http://somedomain/foo/ will return an HTML document or a JPEG image for example. Thus, I need to figure out how to send a HEAD request so that I can read the MIME type without having to download the content. Does anyone know of an easy way of doing this? C# LINQ find duplicates in List Interface vs Base class Is it fair to buy a return ticket I know I will never use just because it's cheaper? I am planning a trip to Asia and then back to Rio. The thing is that I am traveling on flexible dates, so I am thinking of buying a one way ticket to Hong Kong, and I was planning to do the same when I want to come back.  But what I noticed is that, for example, a one way ticket from Melbourne to Rio costs no less than $2700 dollars for the month of May.  When I do a search for a round-trip from Melbourne to Rio and back, I can find flights for $2200.  I know I will not be using that return to Melbourne, but I'd still prefer to save those $500.   Can there be any issue with buying a round-trip with a return that I will never use? Equivalent of "both" when referring to three or more items? What would be the correct word to use when referring to three or more items, in the same manner as the word both?  For example, using two words, with the word both:     "There are several recommendations I   have to further improve the sites —   both to improve their profit, and   decrease their cost."   Using three words, with a blank space in place of the correct word:     "There are several recommendations I   have to further improve the sites —   _ to improve their profit, decrease their cost and improve their   usability."   So, what would be the correct word to use in place of the __? How to create an OD road distance matrix in QGIS? I'm looking for the steps required to produce an origin-destination (OD) cost matrix.  What I'm looking for is a matrix of road distances. The distance matrix tool only produces euclidian distances. The QGIS Roadgraph plugin produces the shortest road distance from one origin to N destinations. What I need is a file containing distances from all origins to the N closest destinations. I have a lot of origins so repeating the analyses with Roadgraph is not an option. Thanks again.  I'm looking for a step-by-step description, starting from scratch (ie, with my 3 shapefiles: origins, destinations, road network). $F(x)$ versus $F[x]$ where $F$ is a field Variance of product of dependent variables Why doesn't my "Nikkor AF" lens autofocus on my Nikon D3300? How to access the correct `this` inside a callback? Travelling as an unmarried Western couple in Indonesia Formula for calculating $\sum_{n=0}^{m}nr^n$ I can't find .bash_profile in Ubuntu 14.04 in my /home/user directory. I used the ls -a command to see the .bash_profile, but there isn't such a file. Let $\mathcal{C}$ be a finite binary code such that for any two sequences $\{a_n\},\{b_n\}\in \mathcal{C}$ if $a_j\not=b_j$ for some $j$ then the concatenation binary sequence $a_1a_2\cdots a_n\not=b_1b_2\cdots b_n$, the Kraft-Mcmillan Inequality says that $$\sum_{i}\frac{N_i}{2^{i}}\le 1,$$where $N_i$ is the number of codes in $\mathcal{C}$ with length of $i$.  If we assume the code is prefix free, we will have an elegant probabilistic proof at  (consider the infinite binary sequence generated by i.i.d. binomial random variable with probability $1/2$, define $E_x$ be the event that the sequence has prefix $x\in \mathcal{C}$, then $\sum_i\frac{N_i}{2^i}\le \sum_i P[E_x]=  P[\cup_i E_x]=1$). But for the general case one will not necessarily have the events $E_i$s disjoint, I'm curious if similar argument exists for the general case. (The problem is an excercise in the probabilistic method of alon, I guess some probabilistic argument should exist)  (My attempt is that consider the product topology $T=\prod_i\mathcal C$ whose open sets generated by $E_x$s where $x$ is the concatenation codes of $\mathcal{C}$, we define a natural product measure $\mu$ over $T$ by $\mu(E_x)=2^{-|x|}$. Clearly $\mu(T)\le 1$ (as $T$ is a sub-topology of $\prod_i\{0,1\}$), I want to show $\mu(E_x\cap E_y)=0$ for $x\not=y\in \mathcal{C}$, if not we can find $E_z$ such that $E_z\subset E_x\cap E_y$ by compactness, if we can show $z$ can be write as concatenation code start with both $x,y$ we will done, but I get stuck at here.) Questions on perfect squares I recently attended a test which ask me two question based on perfect squares; here they are:  $1.$ How many even perfect squares between $1000$ and $5000$ are divisible by both $5$ and $9$?  $2.$ Can there be a perfect square whose digits consists of exactly $4$ ones, $4$ twos and $4$ zeroes in any order?  I haven't done anything much on perfect squares so I was reluctant to attempt them during exams, although as I had some spare time after finishing the other questions, I tried thinking about the first problem and I noticed that only $3600$ seems to satisfy the conditions, which is correct, but I don't know how to get this mathematically? And for the second problem, I don't have any clue till now.  Unfortunately they haven't given me any solutions for the questions, nor any ideas as to how to solve them (mathematically)?