Example of the use of the Levenberg-Marquardt algorithm as implemented in Python by the leastsq function from scipy.optimize. Also included is expdatgen.py, which generates a data file, data.txt, containing tab-delimited x,y data generated by the function: F(x) = 0.625 + 1.33exp(-0.5x).
LMTest.py is then invoked to estimate the paramters a, b, c, for F(x) = a + bexp(cx). The estimated parameters are printed to std-out, and the data and modal are plotted with the plot annotated with the standard error.