vonjd

2,055 reputation

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bio	website	ephorie.de
	location	Germany
	age	43
visits	member for	2 years, 10 months
	seen	23 hours ago
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just an amateur fascinated by math

	2,055 reputation	bio	website	ephorie.de	visits	member for	2 years, 10 months
1224 badges		location	Germany		seen	23 hours ago

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104 Comments

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Apr 1	comment	Interpret the equation $17+28y+4x^2+4y^2=8x$ geometrically +1: Good derivation
Mar 12	comment	Birthday paradox: Comparing the original version with the same-birthday-as-you version Ok, I begin to see the idea. I think this comment is rather helpful, perhaps you want to include it into your original answer. Thank you again.
Mar 12	comment	Birthday paradox: Comparing the original version with the same-birthday-as-you version Thank you for your answer. I agree both are similar, yet in the case of the original paradox the falling factorial power in the numerator is growing considerable slower than $364$ to the $n$ in the other version. This is why you need $23$ in one case and $253$ in the other after all.
Mar 7	comment	How to prove that the limit is max(0,x)? How do we see that the result in the first case is not valid for x<0?
Mar 7	comment	Is there an analytic approximation to the minimum function? I think it is off by $\frac{log 2}{k}$ when equal.
Jan 21	comment	Software for simulating (partial) differential equations @macydanim - But I am still interested :-) Thank you
Jan 21	comment	Software for simulating (partial) differential equations @macydanim: Could you form that into an answer? Thank you!
Oct 22	comment	Mean, variance and regression relation to stocks This is a cross-post from Quant-Stackexchange (where it would belong anyway): quant.stackexchange.com/questions/4387/…. There it was down-voted and closed already.
Oct 22	comment	How to calculate this complex integral? Could you give a little more background on what you tried and where you get stuck? Thank you.
Oct 21	comment	How to round 0.4999… ? Is it 0 or 1? And rounding takes by definition the first digit which is 4 in this case. So this is exactly where the two definitions collide!
Oct 21	comment	How to round 0.4999… ? Is it 0 or 1? @AbhiBeckert: The case in point is that it is indeed equal to 0.5, as is 0.999... equal to 1: en.wikipedia.org/wiki/0.999...
Oct 21	comment	How to round 0.4999… ? Is it 0 or 1? @mindReader: Thank you. Indeed, please see my comment - the question would not make sense with Banker's rounding. I refer to the "Round half up"-Tie-breaking method.
Oct 21	comment	How to round 0.4999… ? Is it 0 or 1? @FakeName: Fair enough. What is obviously meant here is replacing a fractional decimal number by one with fewer digits with the "Round half up"-Tie-breaking method: en.wikipedia.org/wiki/Rounding
Jul 15	comment	Average run lengths for large numbers of trials: Intuition and proof @Downvoter: Why the downvote: Please comment how to enhance the question at least - thank you!
May 11	comment	Differential equations: Connection between repeated roots of characteristic equation and generalized eigenvectors Thank you, corrected the missing y.
Jan 25	comment	Integral paradox: Deterministic integral interpreted as limiting case of stochastic integral Thank you, the result squares very well with my simulations!
Jan 24	comment	Integral paradox: Deterministic integral interpreted as limiting case of stochastic integral @Michael: Could you please elaborate on that and put it into an answer. That would be great - thank you!
Oct 7	comment	Algorithm for optimizing width length of classes of an ordered list of data points under certain conditions @whuber: Do you think that the missing objective function is the problem? So let's take the "signal-to-noise ratio" as the function to optimize, i.e. the ratio of mean to standard deviation (en.wikipedia.org/wiki/Signal-to-noise_ratio).
Sep 26	comment	How to verify that the average is really a simple calculation? Thank you, joriki. The most enlightening part for me is: "[...] the question is then how to tell whether all the possible matches have the same probability of being drawn in the second draw "even though" two balls have already been removed. This is clearly the case, since the balls that were removed were themselves picked randomly with uniform distribution, so there's nothing there that could break the symmetry between the teams."
Sep 25	comment	How to verify that the average is really a simple calculation? So if you elaborate on this as an answer this would be great - Thank you again.