--- a
+++ b/combinedDeepLearningActiveContour/minFunc/ArmijoBacktrack.m
@@ -0,0 +1,108 @@
+function [t,x_new,f_new,g_new,funEvals,H] = ArmijoBacktrack(...
+    x,t,d,f,fr,g,gtd,c1,LS,tolX,debug,doPlot,saveHessianComp,funObj,varargin)
+%
+% Backtracking linesearch to satisfy Armijo condition
+%
+% Inputs:
+%   x: starting location
+%   t: initial step size
+%   d: descent direction
+%   f: function value at starting location
+%   fr: reference function value (usually funObj(x))
+%   gtd: directional derivative at starting location
+%   c1: sufficient decrease parameter
+%   debug: display debugging information
+%   LS: type of interpolation
+%   tolX: minimum allowable step length
+%   doPlot: do a graphical display of interpolation
+%   funObj: objective function
+%   varargin: parameters of objective function
+%
+% Outputs:
+%   t: step length
+%   f_new: function value at x+t*d
+%   g_new: gradient value at x+t*d
+%   funEvals: number function evaluations performed by line search
+%   H: Hessian at initial guess (only computed if requested
+
+% Evaluate the Objective and Gradient at the Initial Step
+if nargout == 6
+    [f_new,g_new,H] = feval(funObj, x + t*d, varargin{:}); 
+else
+    [f_new,g_new] = feval(funObj, x + t*d, varargin{:}); 
+end
+funEvals = 1;
+
+while f_new > fr + c1*t*gtd || ~isLegal(f_new)
+
+    temp = t;
+    if LS == 0 || ~isLegal(f_new)
+        % Backtrack w/ fixed backtracking rate
+        if debug
+            fprintf('Fixed BT\n');
+        end
+        t = 0.5*t;
+    elseif LS == 2 && isLegal(g_new)
+        % Backtracking w/ cubic interpolation w/ derivative
+        if debug
+            fprintf('Grad-Cubic BT\n');
+        end
+        t = polyinterp([0 f gtd; t f_new g_new'*d],doPlot);
+    elseif funEvals < 2 || ~isLegal(f_prev)
+        % Backtracking w/ quadratic interpolation (no derivative at new point)
+        if debug
+            fprintf('Quad BT\n');
+        end
+        t = polyinterp([0 f gtd; t f_new sqrt(-1)],doPlot);
+    else%if LS == 1
+        % Backtracking w/ cubic interpolation (no derivatives at new points)
+        if debug
+            fprintf('Cubic BT\n');
+        end
+        t = polyinterp([0 f gtd; t f_new sqrt(-1); t_prev f_prev sqrt(-1)],doPlot);
+    end
+
+    % Adjust if change in t is too small/large
+
+    if t < temp*1e-3
+        if debug
+            fprintf('Interpolated Value Too Small, Adjusting\n');
+        end
+        t = temp*1e-3;
+    elseif t > temp*0.6
+        if debug
+            fprintf('Interpolated Value Too Large, Adjusting\n');
+        end
+        t = temp*0.6;
+    end
+
+    f_prev = f_new;
+    t_prev = temp;
+    if ~saveHessianComp && nargout == 6
+        [f_new,g_new,H] = feval(funObj, x + t*d, varargin{:}); 
+    else
+        [f_new,g_new] = feval(funObj, x + t*d, varargin{:}); 
+    end
+    funEvals = funEvals+1;
+
+    % Check whether step size has become too small
+    if sum(abs(t*d)) <= tolX
+        if debug
+            fprintf('Backtracking Line Search Failed\n');
+        end
+        t = 0;
+        f_new = f;
+        g_new = g;
+        break;
+    end
+end
+
+% Evaluate Hessian at new point
+if nargout == 6 && funEvals > 1 && saveHessianComp
+    [f_new,g_new,H] = feval(funObj, x + t*d, varargin{:}); 
+    funEvals = funEvals+1;
+end
+
+x_new = x + t*d;
+
+end