Excel IF Statement identify when cell has contents
Display Blank when Referencing Blank Cell in Excel 2010
For example:   For an MVC architecture, should I prefer Ruby on Rails or PHP [closed] Gmail: What is a jQuery selector for incoming mail senders only? How to work with highly compressed and nested CSS in general? [closed]   Better to convert to   [closed] For an MVC architecture, should I prefer Ruby on Rails or PHP [closed] Gmail: What is a jQuery selector for incoming mail senders only? How to work with highly compressed and nested CSS in general?   I should first read the title and sometimes open the question to understand if the question is closed.  I think the [closed] mark  should be at the beginning of the title, not in the end, where I won't ever be if the title is long.  Also coloring will be a good improvement (via @Shadow Wizard). How many distinct ways to climb stairs in 1 or 2 steps at a time? (Fibonacci puzzle) There is a very interesting puzzle for Fibonacci sequence:     You are climbing a stair case. It takes n steps to reach to the top. Each time you can either climb $1$ or $2$ steps. In how many distinct ways can you climb to the top?   The answer is Fibonacci sequence: $F(n) = F(n - 1) + F(n - 2)$. The explanation is that you could reach the $n$th step either from the $(n - 1)$th step or $(n - 2)$th step.  What I fail to understand is why isn't the answer $F(n) = (F(n - 1) + 1) + (F(n - 2) + 2)$. Since, after reaching $(n - 1)$th step I have to take $1$ step to reach the $n$th step and after reaching $(n - 2)$th step I have to take another $2$ steps to reach the $n$th step.  I know I might be ignoring some very stupid detail but it's better to ask and be called a fool once than to remain a fool forever. Is there is any reason to make the permissions on an overridden C++ virtual function different from the base class?  Is there any danger in doing so?  For example:  class base {     public:         virtual int foo(double) = 0; }  class child : public base {     private:         virtual int foo(double); }   The  says that it is a bad idea, but doesn't say why.  I have seen this idiom in some code and I believe that the author was attempting to make the class final, based on an assumption that it is not possible to override a private member function.  However,  shows an example of overriding private functions.  Of course  recommends against doing so.  My concrete questions:   Is there any technical problem with using a different permission for virtual methods in derived classes vs base class? Is there any legitimate reason to do so? Tail sum for expectation In , the tail sum formula for expectation is introduced for a nonnegative (0,1,...) discrete random variable $X$:  $$E(X) = \sum_{i=0}^\infty P(X &gt; i).$$   I wonder if there is a similar formula for nonnegative continuous random variable $X$:  $$E(X) = \int_0^\infty P(X &gt; x) dx?$$  If no, are there some conditions for it to hold? And how can it be proved?  Here is my thought:  If the cdf $F$ of $X$ is bijective, then $X=F^{-1}(U)$ for some random variable $U$ uniformly distributed over $[0,1)$. So $$E(X) =     \int_0^1 F^{-1}(u) du.$$  To prove the tail sum formula, it suffices to prove $$\int_0^1     F^{-1}(u) du = \int_0^\infty P(X &gt; x) dx.$$ But I am stuck here.   What's more, is the condition that the cdf $F$ of $X$ is bijective really necessary for tail sum formula to hold? Can tail sum formula be generalized to a random variable that is not necessarily nonnegative?   Thanks! I saw a code change at work, where the mode values were changed from 777 to 0777 to make nfs setattr work. What is the difference in the 2 values? Let $X, Y$ be an exponentially distributed random variables with parameters $a, b$. Then $X$ has pdf:    $$f_X(x) =\begin{cases} a e^{-a x},&amp; x\geq 0\\ 0,&amp; \text{otherwise}.\end{cases}$$ Suppose $X$ and $Y$ independent. Show that $$\mathbb P(X&gt;Y) = \frac{b}{a+b}.$$   Now I thought the following: $$f(x,y) = f_X(x)\ f_Y(y) = abe^{-ax -by},\qquad\text{for } x,y &gt; 0.$$ And then $$\mathbb P(X&gt;Y) = \int_0^\infty \int_0^x a b e^{-ax -by}\,dydx$$ However, if I solve this (manually or using Wolframalpha), I can't seem to end up with $\frac{b}{a+b}$. Any ideas? My understanding is that GPUs are more efficient for running neural nets, but someone recently suggested to me that GPUs are only needed for the training phase. Once trained, it's actually more efficient to run them on CPUs.  Is this true? A closed form for a triple integral with sines and cosines Prove $(1-a)(1-b)(1-c)(1-d)&gt;1-a-b-c-d$ and $ a,b,c,d$ are real and between 0 and 1.    I can do this with $$(1-a)(1-b)&gt;1-a-b  \\ 1-a-b+ab&gt;1-a-b  \\ ab&gt;0  $$  But with $c$ and $d$, this becomes much more difficult. Can someone nudge me in the right direction? How do I deal with NAs in residuals in a regression in R? Why can't energy be created or destroyed? My physics instructor told the class, when lecturing about energy, that it can't be created or destroyed.  Why is that?  Is there a theory or scientific evidence that proves his statement true or false?  I apologize for the elementary question, but I sometimes tend to over-think things, and this is one of those times. :) Displaying dynamic table in Data Driven Pages environment? I am creating a map series that has many polygons per sheet. There is annotation for the polygons however some polygons are very small with no annotation for them (annotation would completely hide a polygon). Thus, I have an attribute table where labels are stored for those specific polygons.   How can I have that table displayed on the map, with only the attribute values per sheet, rather than all 2000+ values?   I am looking for a simple, dynamic solution. Must an uncountable subset of R have uncountably many accumulation points? Finding the limit of $(1-\cos(x))/x$ as $x\to 0$ with squeeze theorem How do I find:  $$ \lim_{x\to0}\frac{1-\cos(x)}{x} $$  Using the squeeze theorem.  Particularly, how would I arrive at its bounding functions?   If possible, please try not to use derivatives. Reputation and inbox notification shows up again after refresh This was asked before too. .  Currently I am facing the issue of appearance of reputation notification in above toolbar.  I can see the reputation notification, for every page refresh even after clicking and viewing the notification.  current browser: Chrome Version 36.0.1985.143 m What function satisfies $F'(x) = F(2x)$? What is the best filesystem to use cross-platform (Linux, Windows, OS X) which supports disk sizes of at least 2TB and file sizes >4GB?  I'm planning to use it on a USB drive on different computers.  Are there any filesystems that can be used on all the named OSes without installing additional drivers? Cross Browser Flash Detection in Javascript Does anyone have an example of script that can work reliably well across IE/Firefox to detect if the browser is capable of displaying embedded flash content. I say reliably because I know its not possible 100% of the time. Putting a table next to a figure Change email login to another id