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evolve2D.m in LevelSetMethods.rar

			
function [phi] = evolve2D(phi, dx, dy, alpha, iterations, accuracy, is_signed_distance, normal_evolve, Vn, vector_evolve, u, v, kappa_evolve, b)
%
% function [phi] = evolve2D(phi, dx, dy, iterations, accuracy, ...
%   is_signed_distance, normal_evolve, Vn, vector_evolve, u, v, kappa_evolve, b)
%
% Calculates evolution for a 2D curve (3D level set function) phi.
% phi is the input level set function. 
%
% dx and dy are the resolution of the grid at x and y dimensions.
% alpha is a constant for calculating the euler step (dt). Should
% be between 0 and 1. 0.5 is quite safe whereas 0.9 can be risky.
% iterations specifies the number of iterations before the function returns.
% normal_evolve, vector_evolve, kappa_evolve should be either set to 0 and 1. This
% indicates if these forces are present or not. If any of these are set to 1,
% corresponding  variables (e.g. Vn, u, v, b) should not be an empty array []. if
% either normal_evolve or vector_evolve are set to 1, accuracy needs to be specified,
% otherwise accuracy can be set to an empty array. Allowed values for accuracy are
% 'ENO1', 'ENO2', 'ENO3', 'WENO'. These correspond to 1st, 2nd, 3rd and 5th order
% accurate schemes for calculating the derivative of phi. if both normal_evolve and
% vector_evolve are set to 1, then is_signed_distance needs to be specified. If phi is
% approximately a signed distance function, set this variable to 1. If
% is_signed_distance == 1, Godunov scheme will be used, otherwise Stencil Local
% Lax-Friedrichs (SLLF) scheme will be used (See Osher&Fedkiw section 6.4).
%
% Other variables (these are either a scalar or of the same size as phi):
% Vn: Force in the normal direction.
% u: x component of the vector field
% v: y component of the vector field
% b: this specifies the weighting for the curvature (always positive everywhere).
%
% Author: Baris Sumengen  sumengen@ece.ucsb.edu
% http://vision.ece.ucsb.edu/~sumengen/
%


tic

if alpha <= 0 | alpha >= 1 
    error('alpha needs to be between 0 an			

			...
			...
			... to be continued.

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