User:JoblessLoser

if $$A x \approx b, Ax = a*x $$
 * $$x \approx \{A^T A + \alpha I\} A^T b$$
 * $$x \approx IFT \left[ \frac { (\tilde{a})^* .* \tilde{b} }{|\tilde{a}|^2 + \alpha} \right] $$

if $$A = [A_1 ; A_2 ; ...] \; (m \times n), \; b = [ b_1 ; b_2 ; ... ] \; (m \times 1), \; A_ix = a_i*x $$
 * $$x \approx IFT \left[ \frac { \sum_i \{ (\tilde{a_i})^* .* \tilde{b_i} \} }{ \sum_i |\tilde{a_i}|^2 + \alpha} \right] $$

(?)

Matrix multiplication

Levenberg-Marquardt algorithm

Tikhonov regularization