Implementation of a levenberg-marquardt algorithm to perform regression to I-V curves

Testing the physical properties of a solar cell will generate a data set following the format of an I-V curve. This data is useful in its raw form, but finding its equation can provide additional information, such as the short circuit current and open circuit voltage. The curve-fitting process can be done manually, but it lacks the precision and ease-of-use of a computer program. Some existing programs assume a vertical error estimator. These are ineffective for an I-V curve because they unduly weight the area around the short circuit current due to less variation. A better method is to use the perpendicular distance between the experimental data and a theoretical fit to optimize the fit to the data. This creates an accurate model of the characteristics of the solar cell over its entire I-V domain, instead of only at the few points sampled for the initial data set.