usage:
 [theta, obj_value, conv, iters] = nls_estimate(theta, data, model, modelargs, control, nslaves)

 inputs:
 theta: column vector of model parameters
 data: data matrix
 model: name of function that computes the vector of sums of squared errors
 modelargs: (cell) additional inputs needed by model. May be empty ("")
 control: (optional) BFGS or SA controls (see bfgsmin and samin). May be empty ("").
 nslaves: (optional) number of slaves if executed in parallel (requires MPITB)

 outputs:
 theta: NLS estimated value of parameters
 obj_value: the value of the sum of squared errors at NLS estimate
 conv: return code from bfgsmin (1 means success, see bfgsmin for details)
 iters: number of BFGS iteration used

 please see nls_example.m for examples of how to use this

Package: econometrics