NRBINVERSE: compute parametric point starting from physical point by
 inverting the NURBS map with a Newton scheme

 Calling Sequence:

   u = nrbinverse (nrb, x)
   u = nrbinverse (nrb, x, options)

    INPUT:

      nrb     - NURBS object
      x       - physical point
      options - options in the FIELD/VALUE format. Possible choices:
        'u0'      : starting point in the parametric domain for Newton 
                    (Default = .5 * ones (ndim, 1))
        'MaxIter' : maximum number of Newton iterations (Default = 10)
        'Display' : if true the some info are shown (Default = true)
        'TolX'    : tolerance for the step size in Newton iterations
                    (Default = 1e-8)
        'TolFun'  : tolerance for the residual in Newton iterations
                    (Default = 1e-8)

    OUTPUT:

      u            - the parametric points corresponding to x
      convergence  - false if the method reached the maximum number
                     of iteration without converging, true otherwise

 Copyright (C) 2016 Jacopo Corno

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

Package: nurbs