Levenberg–Marquardt algorithm - Gaussian function with area

I present the Levenberg–Marquardt algorithm for fitting Gaussian function with the area.

The Gaussian function is very important in different disciplines of optics such as optical spectroscopy (Raman spectroscopy) or X-ray diffraction. Here, I publish Levenberg–Marquardt algorithm to fit Gaussian function with area. The fitting parameters are area, center, width and offset. The Levenberg–Marquardt algorithm was taken from document "METHODS FOR NON-LINEAR LEAST SQUARES PROBLEMS" of Technical University of Denmark. The document was written by authors: K. Madsen, H.B. Nielsen, O. Tingleff.