# Eric Gregor

less info
reputation
617
bio website location age member for 2 years, 11 months seen 2 days ago profile views 234

# 308 Actions

 Mar29 comment Simple question about inequality involving eigenvalue of a matrix and a scaled version of that matrix It is fixed. Sorry for the typos. Mar29 revised Simple question about inequality involving eigenvalue of a matrix and a scaled version of that matrix fixed typos Mar29 revised Simple question about inequality involving eigenvalue of a matrix and a scaled version of that matrix edited body; edited tags; edited title Mar28 asked Simple question about inequality involving eigenvalue of a matrix and a scaled version of that matrix Feb7 revised mixture of multivariate Gaussians is elliptical? added 88 characters in body Feb7 comment mixture of multivariate Gaussians is elliptical? Can you be specific? Maybe write an answer? The link you showed seemed to suggest that linear combinations of elliptical functions were elliptical. If this is true than my second question remains. Feb7 comment mixture of multivariate Gaussians is elliptical? I think maybe your question was whether I was taking a convolution or a mixture. I am taking a mixture. Feb7 comment mixture of multivariate Gaussians is elliptical? The point is that you are drawing with probability $p$ from one distribution, and with probability $(1-p)$ from the other distribution. As I understand it this is called a mixture distribution. So my first question is whether this mixture of Gaussians is elliptical (it cannot be Gaussian). And if so how can we express it explicitly by the definition of an elliptical distribution. Feb7 revised mixture of multivariate Gaussians is elliptical? added 327 characters in body Feb7 comment mixture of multivariate Gaussians is elliptical? I don't understand the distinction, perhaps. We are drawing points/vectors from these distributions. I will shortly define elliptical distributions. Feb7 comment mixture of multivariate Gaussians is elliptical? These are probability distribution. In particular they are en.wikipedia.org/wiki/Multivariate_normal_distribution Feb7 revised mixture of multivariate Gaussians is elliptical? added 30 characters in body Feb7 asked mixture of multivariate Gaussians is elliptical? Oct8 accepted General question about matrix calculus with specific example (with attempted answer) Oct4 comment General question about matrix calculus with specific example (with attempted answer) I already solved this example in my question. It was the general case ($p\neq 2$ that bothered me). Oct4 comment General question about matrix calculus with specific example (with attempted answer) Yes, the last edit. Oct4 comment General question about matrix calculus with specific example (with attempted answer) Thanks, this looks right. But then what is the flaw in my last argument for what the derivative should be? Oct4 revised General question about matrix calculus with specific example (with attempted answer) added 257 characters in body; edited title Oct4 comment General question about matrix calculus with specific example (with attempted answer) Interesting. If you type that up as an answer, I can give you the bounty. No one else has taken a crack at it. Oct4 revised General question about matrix calculus with specific example (with attempted answer) added 198 characters in body