getpoly.m

基于ＭＡＴＬＡＢ的辅助设计 简述了矩阵分析的重要性

function [array,ikey] = getpoly(string)

%GETPOLY is a MATLAB function which can be used to accept the
%     polynominal set in the 's' array which may contain
%     brackets.  IF IKEY=0, then aborted return is made and
%     there exists errors in the array representation.

%    Author: Ole Barup Sorensen, Rapid Data Ltd 

%    Copyright (c) 1989-94 by Rapid Data Ltd
%    Revision 10:32  07/02/94

mv = find(string ~= ' ');
string = string(mv);
ikey = 0;  nLen = length(string); array = 1;
ii = find(string=='('); ij = find(string==')');
if length(ii)~=length(ij),
   disp('( and ) mismatching'); 
else, ii = [ii length(string)+1]; 
   if (ii(1)~=1), 
      [array,ikey] = polyevl(string(1:ii(1)-1));
   end
   for i=1:length(ii)-1, 
      [array1,ikey] = polyevl(string(ii(i)+1:ij(i)-1));
      if i~=length(ii), 
         if (ii(i+1)-1~=ij(i)), 
            k0 = str2num(string(ij(i)+1:ii(i+1)-1));
            if length(k0)==0, 
               disp(['Error in sub-string ' ...
               string(ij(i)+1:ii(i+1)-1)]); return;
            end
         else
           k0 = 1;
         end
         for j=1:k0
            array = conv(array,array1);
         end
      end
   end
end