Recent content by onanox

Yes, coming back to it I worded in a confusing way. Let me try to clear it up. The equation has the trivial solution u=0 . If you linearize the equation, you find that for r<0 this solution is linearly stable, its linearly unstable for r>0. The question concerns the form of this bifurcation...

I'm trying to solve question 4.12 from Cross and Greenside "pattern formation and dynamics in nonequilibrium systems". the question is about the equation \partial_t u = r u - (\partial_x ^2 +1)^2 u - g_2 u - u^3 Part A: with the ansatz u=\sum_{n=0}^\infty a_n cos(nx) show that the...

yea, you're right. Schwabl must be counting the dimension its embedded in or something.

I'm trying to follow Schwabl Thermodynamics, and I found the following equation for the surface area of a unit d-sphere: $$ \int d\Omega_d = \frac{2 \pi^{d/2}}{\Gamma(d/2)} $$ But this formula clearly fails for d=1: should be $$\pi$$ and d=2: should be $$ 4 \pi $$. What gives?

once again, I am NOT looking for an "inverse chi squared" distribution (which is really a reciprocal chi squared distribution) I am looking for an inverse function for the chi squared distribution.after reading that link, it becomes apparent that the chi squared CDF is equivalent to the...

thanks for this, I'll test it tomorrow but one of the conditions has me a bit confused: Q(xp)=1-P(xp)=p any idea what this means? especially noting that Q(x2p | v) = p

I meant, matlab's documentation does not give any real info except that they solve it numerically, yet when I try to use a similar method in AS3, the program errors on high values. I apologize for my ambiguity.

in MATLAB, they just numerically solve the integral, however, with large degrees of freedom (50,000 or so) the program will crash because the values are just too large. I guess this question is better suited for a programming board, and directed at larger number data types rather than better...

well isn't the characteristic function for the incomplete gamma function an integral? which is a sum? and just to clarify (and I might be wrong here) but I am not talking about the inverse chi-squared distribution, I am talking about the inverse function for the chi-squared function.

good point, I guess I was a bit vague. I am trying to calculate the incomplete-gamma function specifically for large arguments (around 50,000). I am using as3 to program it, and there isn't any flexibility on the language.

the problem is that each term in the series is too large to compute with standard data types, and that thread defines a product based on a sum and thus will not work.

a ground state oxygen atom has 2 pairs of electrons and 2 unpaired electrons, so it does matter. see hund's rule

is there a way to explicitly express the chi-squared inverse function? when programming it, I have had to resort to a guessing system where I find a chi value that is too low and too high, and evaluate the chi-squared CDF to reset the high and low points iteratively until it is within a...

if you actually have a proof like that, just post it wherever you want.

I am trying to write a computer program that involves finding 2 very large numbers (several thousand digits) and dividing them to get a reasonable sized number. the first number is a value of the gamma function, which can be defined as a product and thus easy to reduce with logs (find the sum...