Integration step too small for ODE equation
Tue, 03/22/2011 - 01:03 pm
I'm using IntegrateODE to fit a binding curve in a titration experiment. The general solution for the differential equation with respect to the amount titrated is shown in the image. However, the integrator shows the following error: "integration step size has gotten too small", even when I don't have any parameters set for the error tolerance. I've also tried using different methods (\M=(1..3)) with a similar outcome.
I've been able to work around it by solving the product of the polynomials on the numerator that follows Mt and then multiply everything by Sum(betai * xj)2, but at the moment I'm limited to polynomials of degree 2 and 3 (j=2,3)
1) Does anyone have an idea on how to get around the "step size" issue so that I can leave the polynomial in its native form ?
2) I've been reading on how to implement matrices to solve this problem, but this has been a dead end so far. Does anyone know of a simple problem that uses matrices to fit partition functions of this type?