arraymax.m

数字通信第四版原书的例程

function [sys, x0, str, ts] = arraymax(t,x,u,flag)
%ARRAYmax outputs the index of the maximum input.
%       This M-file is designed to be used in a SIMULINK S-function block.
%       This function will detecte the maximum number from the input and 
%       output the index number where the maximum number occured.

%       Wes Wang 4/13
%       Copyright (c) 1995-96 by The MathWorks, Inc.

if flag == 3
    sys = find(u==max(u));
    sys = sys(1) - 1;    
elseif flag == 0
    sys=zeros(7,1);
    %one sample rate
    sys(7) = 1;
    sys(4) = -1;
    sys(3) = 1;
    x0 = [];
    ts = [-1. 0];
else
    sys = [];
end;