Load DirectX model file with OpenSceneGraph
Loading a .X model in DirectX 9
When should we consider a dataset as imbalanced? I'm facing a situation where the numbers of positive and negative examples in a dataset are imbalanced.  My question is, are there any rules of thumb that tell us when we should subsample the large category in order to force some kind of balancing in the dataset.  Examples:   If the number of positive examples is 1,000 and the number of negative examples is 10,000, should I go for training my classifier on the full dataset or I should subsample the negative examples? The same question for 1,000 positive example and 100,000 negative. The same question for 10,000 positive and 1,000 negative. etc... If I run a randomForest model, I can then make predictions based on the model.  Is there a way to get a prediction interval of each of the predictions such that I know how "sure" the model is of its answer.  If this is possible is it simply based on the variability of the dependent variable for the whole model or will it have wider and narrower intervals depending on the particular decision tree that was followed for a particular prediction? switch a theme different per user role I plan to use the member plugin by Justin Tadlock  I wish to know if how could I, on the front side, auto switch to a theme according to a role status.. for example authors would have the site presented using theme 1 while editor would have the site presenter using theme 2  I would rather have 2 different theme rather than conditionals within one theme structure  Thank you in advance obtain a three-term asymptotic solution Each event has two possible outcomes: a and b.  Each event is independent.  Outcome a has $X\%$ chance of happening.  If we run $Y$ number of such events, what are the chances of getting $K$ outcomes a in a row, at least once?  To put it in practical terms imagine a series of coin tosses. Each coin toss has two possible outcomes: a = heads and b = tails. Outcome a = heads has a chance of $50\%$. If we run $Y = 100$ number of coin tosses, what are the chances of getting $K = 10$ outcomes a=heads in a row, at least once?   I'm using the practical example only so I can express the idea more clearly. I'm interested in finding out the general formulas and computations so that I can run the calculations for any $X$, $Y$, or $K$.  I would also be very interested in knowing how the probabilities would change if the events would not be independent. What if the more outcomes a we have in a row the bigger the chance of getting an outcome a in the next event? What if it's the other way around, and the more outcomes a in a row we have the lower the chance of getting another a? Elliptic Curves of different forms Looking at  to find a safe curve, I find that most curves described here are of a different form from that generally used.  In , for example, FpCurves take curves of the form $y^2 = x^3+ax+b$ (Weierstrass), whereas the (safe) curves found on the above linked have different forms, such as $y^2 = x^3+ax^2+x$ (Montgomery) - how do I translate between the two? How do I use the second form of curve with, for example, Bouncy Castle?  (Or do I simply have to accept that no safe curves of the Fp form exist?)    What else have I tried? Guide to Elliptic Curve Cryptography (Hankerson et.al.) covers curves of the forms $y^2 = x^3+ax+b$ for fields with characteristic > 3, and only offer alternatives (that are not interchangable with the safe curves, either) for lower characteristics, that are not very useable in my situation. Even then, some curves on the safe curves website are of forms that I cannot immediately find explained anywhere. There are several reasons to be looking for a ROM:   Upgrading or downgrading your stock ROM Looking for firmware from a different region/language Flashing a custom ROM for different features, removing bloat, etc.   But where can one find ROMs in the first place?  What sites are likely to have the ROM I need?  ; please add to the wiki answer instead of posting separate answers.  See also: How do I simulate in Photoshop what a piece will look like when printed on non-white paper? I'm designing a box in Photoshop that will be offset printed on unbleached paper. I haven't picked out a printer yet, so I don't know the exact kind of paper I'll be using and don't have access to it for proofs. For now I'm using a lightly-textured layer of tan color as a placeholder to mock it up.  What I'm trying to figure out is, how do I figure out how my design will look printed on natural paper rather than bleached white paper? I know that the brightness will be diminished and the hue will be altered, but I need to know how much so I can compensate for it as much as possible.  Is there a way to get at least a rough but reliably-simulated idea of how my prints will come out? Does it have to do with blend modes, or color separations? I'm at a bit of a loss here. What makes RSA secure by using prime numbers? I am just learning about the RSA algorithm. Looking at the first two steps:   Choose two distinct prime numbers $p$ and $q$. Compute $n = pq$.    I have some probably stupid questions:   Why do $p$ and $q$ have to be prime numbers? Why couldn't they be any integers or odd integers? Or does that break the whole algorithm? Because prime numbers are rare in comparison to regular integers, does restricting the algorithm to only prime numbers reduce security? It would seem easier to find the private key if an attacker knows it's only going to be some prime number? Given that the sequence $(v,Av,A^2v,...,A^nv)$ is linearly dependent (1), $A_{n \times n}$, over $\mathbb{F^n}$ prove that scalars $c_0,c_1,..,c_n$ exist (such that not all of them are zeroes) such that the matrix $M=c_0I+c_1A+..+c_nA^n$ is singular.    First I'm not sure how (*) can be used here exactly. We can say that the sequence $(c_0I,c_1A,..,c_nA^n)$ resembles the sequence (1) where $v=I$. But here we have scalar $c_i$ so it's not exactly the same sequence.   Maybe I could say that the sequence $(c_0I,c_1A,..,c_nA^n)$ is linearly dependent because it has $n+1$ elements while over $dim\mathbb{F^n}=n$ $\quad$(2).  Intuitively I understand that suppose we sum all the matrices $c_iA^i$ and then in the last sum operation we get to some $c_jA^j$ and if it's a linear combination of other matrices then we can have such a $c_j$ that: $$ c_oI+\sum_{i=1}^{n-1} c_iA^i+c_jA^j=0 $$ But I don't think this is enough to prove. Show that the set of all finite subsets of $\mathbb{N}$ is countable. Show that the set of all finite subsets of $\mathbb{N}$ is countable.   I'm not sure how to do this problem. I keep trying to think of an explicit formula for 1-1 correspondence like adding all the elements in each subset and sending that sum to itself in the natural numbers, but that wouldn't be 1-1 because, for example, the set {1,2,3} would send to 6 and so would the set {2,4}.  Multiplying all the elements in each subset and sending that product to itself in the natural numbers wouldn't work either since, for example, {2,3} would send to 5 and so would the set {1,5}. Any ideas? How to plot and solve the numerical solution of a integro-differential equation It's possible to do a array of Matrix in Matlab? Let $P$ be a probability measure on $(\Omega, \mathscr{F})$, If $a,b,\in\mathscr{F}$ and $A\subset B$, then $P(B)-P(A)=P(B\setminus A)\ge 0$.  So far I have:  $A\subset B \implies B\setminus A = B\cap A^c = \emptyset$ as $A$ and $B^c$ are disjoint. Since $A\cup (B\setminus A)=A\cup (B\cap A^c)=(A\cup B)\cap (A\cup A^c)=B\cap\Omega = B$  Then for $A,B\in \mathscr{F}\implies P(A\cup (B\setminus A))=P(A)+P(B\setminus A) = P(B)$ by countable additivity.  Rearranging, $P(B)-P(A)=P(B\setminus A) \ge 0$. How to mass delete your photos in your iPhone? I cannot do it in the phone itself, neither in iPhoto.  How can you delete all your photos in iPhone? What price should I charge for design services? I was hoping I would find some people in the industry that could help me decide what's the best price to charge to design (in this case) business cards.  What are standard prices for professional designers?  From a firm point of view? From a freelancer?  I don't want to overcharge clients but I don't want to ruin the industry by underselling my services. Running JAR file on Windows I have a JAR file named helloworld.jar. In order to run it, I'm executing the following command in a command-line window:  java -jar helloworld.jar   This works fine, but how do I execute it with double-click instead? Do I need to install any software? Linux Equivalent of Windows Ctrl to show Mouse Pointer In Windows, it is possible to set pressing Ctrl to display the current location of the mouse pointer, as per .  Is there a way of setting a key or key combination to perform the same action in Ubuntu? Note, this is the opposite of turning this function off, as detailed at . What is the difference between visibility:hidden and display:none? The CSS rules visibility:hidden and display:none both result in the element not being visible. Are these synonyms? What is a word for getting an award in a competition or being one of the top three?