Recent content by areslagae

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    Modulo sum of random variables

    Hi all, I have a quick additional question. A colleague pointed out to me that the cited paper only proves the theorem from my first post in the case that Y is defined over [0,a]. However, the random variables (X + Y) mod a and (X + (Y mod a)) mod a have the same distribution...
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    Modulo sum of random variables

    Thanks for both your replies! At first, me (and my collegues) found this result somewhat counter-intuitive. It seems that you do not, but you most likely you have a deeper intuition. Meanwhile, I also found the following paper which is interesting in this context: The Distribution Functions...
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    Modulo sum of random variables

    If X is uniformly distributed over [0,a), and Y is independent, then X + Y (mod a) is uniformly distributed over [0,a), independent of the distribution of Y. Can anyone point me to a statistics text that shows this? Thanks,
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    Does E[X] = 0 Imply That E[Y/X] = 0?

    I actually mean division. So, if E[X] = 0, does E[Y/X] = 0 follow, for Y independent of X? Additionally, I have that X is symmetric. Intuitively, it seems that this does hold. E[Y/X] = E[Y] E[1/X] (X and Y are independent) So, it remains to be shown that, if E[X]=0, and X is symmetric, then...
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    Does E[X] = 0 Imply That E[Y/X] = 0?

    E[x] = 0 => e[y/x] = 0 ? (division, not cond prob) I have E[X] = 0. Does this imply that E[Y/X] = 0, for Y independent of X?
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    Can Mathematica Solve the Integral for Exponential Functions?

    Hello all, I am trying to solve an integral with Mathematica, but I do not succeed. I am wondering whether the integral cannot be solved, or whether Mathematica cannot solve the integral, or whether I am doing something wrong. Details: * Mathematica does not seem to be able to solve the...
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    Integrals with bessel functions

    The integral assume(a > 0); int(exp(a*cos(phi))*sin(phi)^2, phi = 0 .. Pi); equals to (Pi/a)*BesselI(1,a) I have solved the integral using Mathematica, which seems to solve all these integrals out of the box.
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    Integrals with bessel functions

    Thanks! Apparently, Mathematica is the only program that can solve several of the integrals I am dealing without of the box. Unfortunately, I do not have access to Mathematica. Would you please be so kind to try if Mathematica can solve int(exp(a*cos(phi))*(sin(phi))^2, phi = 0 .. Pi) with a...
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    4D angular coordinate system and corresponding hypervolume element

    Thanks. Is "4-D spherical coordinates" established terminology? Is this the "standard" transformation? I guess there are other ones?
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    4D angular coordinate system and corresponding hypervolume element

    I am looking for a 4D angular coordinate system (radius and three angles) and its corresponding "hypervolume element". 2D: polar coordinates - dA = r dr dtheta 3D: spherical coordinates - dV = r^2 sin(phi) dphi dtheta dr 4D: ?
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    Integrals with bessel functions

    I am trying to solve int(int(exp(a*cos(theta)*sin(phi))*sin(phi), phi = 0 .. Pi), theta = 0 .. 2*Pi) (1) with a a constant. Using the second last definite integral on http://en.wikipedia.org/wiki/List_of_integrals_of_exponential_functions the integral (1) reduces to...
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