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visits member for 1 year, 8 months
seen Aug 18 at 8:38

Interested on statistics, mathematics and machine learning :)


Jul
31
comment Properties of the positive definite Hessian matrix of a convex function
+1 Okay, thank you very much =) So it's partly about selecting the matrix $A$ so that the calculations and expressions clean up to a nice form? =)
Jul
31
comment Properties of the positive definite Hessian matrix of a convex function
Hi @Avitus one more question if I may :) In your answer you wrote that $y_j=\pm \sqrt{k/\lambda_j}$, but in my book it is stated that the lengths of the semi axes are proportional to $1/\lambda_j$, that is the length is $y_j = c/\lambda_j$? Why the difference? =)
Jul
30
accepted Why does the focus point distances of an ellipse sum up to the length of the major axis diameter
Jul
29
comment Why does the focus point distances of an ellipse sum up to the length of the major axis diameter
aah...okay, so it's definition...not a fact?
Jul
29
comment Why does the focus point distances of an ellipse sum up to the length of the major axis diameter
This one :) nebula.deanza.edu/~bloom/math43/ellipse-derivation.pdf
Jul
29
asked Why does the focus point distances of an ellipse sum up to the length of the major axis diameter
Jul
29
comment Properties of the positive definite Hessian matrix of a convex function
+1 Thank you sir/madame =D I will try my very best :) I'm sir ;)
Jul
29
accepted Properties of the positive definite Hessian matrix of a convex function
Jul
29
comment Properties of the positive definite Hessian matrix of a convex function
+1 Excellent!, thank you for your time! Huge thank you =)
Jul
29
comment Properties of the positive definite Hessian matrix of a convex function
+1 Damn, you are an answer machine :D What would SE do without you ;D
Jul
29
comment Properties of the positive definite Hessian matrix of a convex function
+1 Thank you @Avitus for your help =) I think I'm ok with that :) I have a black box understanding of the idea, but if I would need to explain this to someone else, I perhaps couldn't do it. The connection between ellipsoid, Hessian, eigenvectors, positive definiteness etc. has been bugging me a long time and still I don't feel comfortable with the idea :P I haven't been able yet to find a tutorial, which would glue all the geometry, linear algebra, etc. together :/ If I could just get all the pieces fit together it would help me with a lot of situations :)
Jul
29
asked Properties of the positive definite Hessian matrix of a convex function
Jul
28
accepted Enlarging the space $PC(a,b)$ to include functions with one or more infinite singularities
Jul
28
comment Enlarging the space $PC(a,b)$ to include functions with one or more infinite singularities
+1 Thank you @Avitus you are great, as always ;D
Jul
28
comment Enlarging the space $PC(a,b)$ to include functions with one or more infinite singularities
Yes I'm interested in the "enlarged" space :) I was confused by the sentence: "It is easy enough to enlarge the space $PC(a,b)$ to include functions with one or more infinite regularities in the interval $(a,b)$". I guess this whole part in the book was confusing to me, I didn't quite get the idea of the "enlarged" space and was asking if someone could say the point in other words etc. =) Why does the author introduce the "enlarged" space? Why not just stick with $PC(a,b)$? =) Sometimes I miss the point totally :/
Jul
28
comment Enlarging the space $PC(a,b)$ to include functions with one or more infinite singularities
+1 Sorry @Avitus for my late reply. So umm, I didn't quite follow? You mean I should ask about the vector space containing piecewise cont. functions and functions with unbounded discontinuity points? =)
Jul
28
comment Enlarging the space $PC(a,b)$ to include functions with one or more infinite singularities
+1 Thank you for your help @Avitus =) You are correct, I'm dealing with piecewise cont. functions. Okay, I think I got it :) Appreciate it!
Jul
23
comment Why should I care about eigenvectors/eigenvalues
+1 Thnx guys for you help!. @Hakim About the link you provided, so...it's about making calculations simpler? =) is that it?
Jul
23
asked Why should I care about eigenvectors/eigenvalues
Jul
23
comment Do we need steepest descent methods, when minimizing quadratic functions?
+1 Thnz @littleO fixed it :)