05-21.txt

来自「MATLABR2007教程以及i习题和答案」· 文本 代码 · 共 14 行

% find the minimum of the function f(x)=x^3+a*x^2+b*x+c
function [x0,y] = funmin(a,b,c,x1,x2)
options = optimset('Display','off');
[x0,y] = fminbnd(@poly3,x1,x2,options);
    function y=poly3(x)        %the nested function
        y=x^3+a*x^2+b*x+c;
    end
% plot the function
fplot(@poly3,[x1,x2]);
hold on;
plot(x0,y,'.');
end

>> [x,y]=funmin(-1000,10,0,600,800)