function Xb=brackPlot(fun,xmin,xmax,nx)% BrackPlot find subintervals on x that contain sign changes of f(x)% Synopsis: Xb=brackPlot(fun,xmin,xmax,nx)% Xb=brackPlot(fun,xmin,xmax)% Input: fun=(string) name of mfile function that evaluates f(x)% xmin,xmax=endpoints of interval to subdivide into brackets% nx=(optional) number of samples along x axis used to test for% brackets.The interval xmin<=x<=xmax is divided into nx-1% subinterval. Default:nx=20% Output: Xb=two column matrix of bracket limits.% Xb(k,1) is the left (lower x value) bracket and % Xb(k,2) is the ringht bracket for the k^th potenntial root.% If no bracket are found,Xb=[].if nargin < 4 nx=20;end
% ----Plot f(x) on interval xmin <= x<= xmaxxp=linspace(xmin,xm
