Recent content by trmcclain

I'm hoping this will be the last time I call for help, but in any case, here it goes. I thought I had a handle on this before, but in all of my attempts, my code diverges within a few iterations. My problem is creating a spatial distribution of particles given a probability density. I've...

*facepalm* Got it.

Thank you for this. It happens that my n=1.8. Does this rule out Simpson's Rule?

Closed form in the sense of finite, yes. The equation is part of a probability density which I am using to scatter particles randomly using Newton-Raphson's Method. In order to do that, the function must be integrated from 0 to a finite upper limit.

Bump for more help. If I must perform a definite integral on erf(x)*f(x), and I don't want to do an infinite number of integration by parts (I really don't have the time), than what is the next step?

I realize this now, and I am glad that I asked first before just rolling with it.

Firstly - damnit. When you bring up trig it sort of slapped me in the face that of course I can't do that. Secondly - awesome resource. But my problem remains. If I try to perform a definite integral on the erf(x), not only does a gaussian appear, but also another erf(x) this time with an x...

My question is can i use that value for the erf(x) in order to take it out of the integral. If not, then I have to integrate it which will cause many headaches...

Homework Statement I'm working with a particularly malicious mass model function given as: λ^n*exp(-x^2)*(λ+x)^-n, λ=constant, n=constant (1.8 for those who care) The first round of integration by parts using u=(λ+x)^-n, du=-n(λ+x)^(-n-1)dx dv=exp(-x^2), v=sqrt(pi)/2*erf(x) Gives me...

I want to start out by saying that this is not a homework problem, this is something I'm trying to figure out for thesis work. If that should go in the homework problem section, I will gladly post there. A certain mass model I'm working with (Bissant & Gerhard) has a particularly gross form...

every orbit isn't necessarily circular, especially in globular clusters. Mostly they'll be precessing elliptical orbits, but I was told I can't assume elliptical-ness from the get go, I have to watch it evolve. So basically what I'm getting is that there is no trig or geometric relation that...

Important? I guess not really, they just showed what I tried. Maybe some more background as to the program I'm writing might help. It's for a project in graduate school, I'm trying to see what the effects of artificially inducing charge on a cloud of massive particles are, so kind of like...

But that only gives be B rotated to some angle \theta I fail to see how that will help me figure out the magnitude of A

Homework Statement I don't know if its possible to do this, but I ran into this problem when trying to right a program which creates orbits for individual points. Anyways... Given 2 position vectors (tails anchored to the origin), say A and B and the angle between them \theta, A is unknown...