Recent content by bers

Hi, can I say that a sphere is a plane, because in spherical coordinates, I can simply express it as <(r, \theta, \varphi)^T, (1, 0, 0)^T> = R? It does sound too easy to me. I'm asking because I'm thinking about whether it is valid to generalize results from the John-Radon transform (over...

Yes, I confirmed that this works using distorted data (y_i = f(x_i) + some error) with a non-zero residuum. I obtained the same estimates as with Matlab and a non-linear iterative procedure (and got wrong results with the total differential method, by the way). So that would mean I can obtain...

Hi, thanks for your answers. I do think, however, I did not point out two important things clearly enough: 1. I am aware of many iterative algorithms for this problem. However, I'm interested in a non-iterative solution. (Would you call this an ad-hoc solution?) Anyway, I want to have a...

Hi, I want to solve an overdetermined non-linear equation with the method of least squares. Assume it's f(x) = 1 + ax + a^2 + b, and I want to estimate a and b. This is non-linear, as I said, so the derivatives of the squared residuals involve a^3 terms and are difficult to solve. Now I thought...