741 reputation
919
bio website
location
age
visits member for 4 years, 3 months
seen Nov 18 at 5:24

Sep
4
awarded  Popular Question
Aug
14
comment Reasoning that $ \sin2x=2 \sin x \cos x$
+1: This method also gives all of the double-angle (and triple-angle, etc.) formulas.
Aug
11
comment An interesting puzzle
I think a rough sketch might be that in order to create any significant probability mass in $\vert X-Y \vert$ between 1 and 2, you have to also create mass between 0 and 1. So, $P{|X−Y|≤1}$ is no less than half the LHS?
Aug
5
revised Reasoning that $ \sin2x=2 \sin x \cos x$
added 116 characters in body
Aug
5
answered Reasoning that $ \sin2x=2 \sin x \cos x$
May
7
awarded  Caucus
Apr
15
comment Log likelihood of a realization of a Poisson process?
Hi David, do you have a citation for the likelihood? I arrived at the same likelihood by reason directly from the entropy of a Poisson process given by McFadden.
Apr
14
awarded  Notable Question
Mar
21
accepted Graphically, what is positive semidefinite-ness?
Mar
21
comment Graphically, what is positive semidefinite-ness?
Thanks, I think I see it now. Essentially, Newton's method is looking for points with zero slope, and decides for each eigenvector whether to go towards a local maximum or minimum based on the sign of the eigenvalue. Is that right?
Mar
21
comment Graphically, what is positive semidefinite-ness?
Thanks for taking the time to answer. You're right that Newton's method will only give a local minimum (and will stop at a local maximum) since it's looking for a point where the gradient is zero. I am still having trouble visualizing the second part of your answer.
Mar
20
revised Graphically, what is positive semidefinite-ness?
added 282 characters in body
Mar
20
revised Graphically, what is positive semidefinite-ness?
obvious
Mar
20
revised Graphically, what is positive semidefinite-ness?
obvious
Mar
20
asked Graphically, what is positive semidefinite-ness?
Mar
13
awarded  Nice Question
Mar
12
accepted Notation for the set of all $x_i$
Mar
12
asked Notation for the set of all $x_i$
Feb
4
comment Probability problem of dice game
let us continue this discussion in chat
Feb
4
comment Probability problem of dice game
@joriki: Yes, it's solving a system of linear equations. You could have written it as a dynamic program that memoizes the transition probabilities and the probability of return for every state, which would be more efficient for a sparse transition matrix.